WorldWideScience

Sample records for high rate background

  1. Precise muon drift tube detectors for high background rate conditions

    Energy Technology Data Exchange (ETDEWEB)

    Engl, Albert

    2011-08-04

    The muon spectrometer of the ATLAS-experiment at the Large Hadron Collider consists of drift tube chambers, which provide the precise measurement of trajectories of traversing muons. In order to determine the momentum of the muons with high precision, the measurement of the position of the muon in a single tube has to be more accurate than {sigma}{<=}100 {mu}m. The large cross section of proton-proton-collisions and the high luminosity of the accelerator cause relevant background of neutrons and {gamma}s in the muon spectrometer. During the next decade a luminosity upgrade to 5.10{sup 34} cm{sup -2}s{sup -1} is planned, which will increase the background counting rates considerably. In this context this work deals with the further development of the existing drift chamber technology to provide the required accuracy of the position measurement under high background conditions. Two approaches of improving the drift tube chambers are described: - In regions of moderate background rates a faster and more linear drift gas can provide precise position measurement without changing the existing hardware. - At very high background rates drift tube chambers consisting of tubes with a diameter of 15 mm are a valuable candidate to substitute the CSC muon chambers. The single tube resolution of the gas mixture Ar:CO{sub 2}:N{sub 2} in the ratio of 96:3:1 Vol %, which is more linear and faster as the currently used drift gas Ar:CO{sub 2} in the ratio of 97:3 Vol %, was determined at the Cosmic Ray Measurement Facility at Garching and at high {gamma}-background counting rates at the Gamma Irradiation Facility at CERN. The alternative gas mixture shows similar resolution without background. At high background counting rates it shows better resolution as the standard gas. To analyse the data the various parts of the setup have to be aligned precisely to each other. The change to an alternative gas mixture allows the use of the existing hardware. The second approach are drift tubes

  2. Precise muon drift tube detectors for high background rate conditions

    CERN Document Server

    Engl, Albert; Dünnweber, Wolfgang

    The muon spectrometer of the ATLAS-experiment at the Large H adron Collider consists of drift tube chambers, which provide the precise m easurement of trajec- tories of traversing muons. In order to determine the moment um of the muons with high precision, the measurement of the position of the m uon in a single tube has to be more accurate than σ ≤ 100 m. The large cross section of proton-proton-collisions and th e high luminosity of the accelerator cause relevant background of neutrons and γ s in the muon spectrome- ter. During the next decade a luminosity upgrade [1] to 5 10 34 cm − 2 s − 1 is planned, which will increase the background counting rates consider ably. In this context this work deals with the further development of the existing drift chamber tech- nology to provide the required accuracy of the position meas urement under high background conditions. Two approaches of improving the dri ft tube chambers are described: • In regions of moderate background rates a faster and more lin ear ...

  3. High repetition rate laser-driven MeV ion acceleration at variable background pressures

    Science.gov (United States)

    Snyder, Joseph; Ngirmang, Gregory; Orban, Chris; Feister, Scott; Morrison, John; Frische, Kyle; Chowdhury, Enam; Roquemore, W. M.

    2017-10-01

    Ultra-intense laser-plasma interactions (LPI) can produce highly energetic photons, electrons, and ions with numerous potential real-world applications. Many of these applications will require repeatable, high repetition targets that are suitable for LPI experiments. Liquid targets can meet many of these needs, but they typically require higher chamber pressure than is used for many low repetition rate experiments. The effect of background pressure on the LPI has not been thoroughly studied. With this in mind, the Extreme Light group at the Air Force Research Lab has carried out MeV ion and electron acceleration experiments at kHz repetition rate with background pressures ranging from 30 mTorr to >1 Torr using a submicron ethylene glycol liquid sheet target. We present these results and provide two-dimensional particle-in-cell simulation results that offer insight on the thresholds for the efficient acceleration of electrons and ions. This research is supported by the Air Force Office of Scientific Research under LRIR Project 17RQCOR504 under the management of Dr. Riq Parra and Dr. Jean-Luc Cambier. Support was also provided by the DOD HPCMP Internship Program.

  4. Resolution and Efficiency of the ATLAS Muon Drift-Tube Chambers at High Background Rates

    CERN Document Server

    Deile, M.; Horvat, S.; Kortner, O.; Kroha, H.; Manz, A.; Mohrdieck-Mock, S.; Rauscher, F.; Richter, Robert; Staude, A.; Stiller, W.

    2016-01-01

    The resolution and efficiency of a precision drift-tube chamber for the ATLAS muon spectrometer with final read-out electronics was tested at the Gamma Irradiation Facility at CERN in a 100 GeV muon beam and at photon irradiation rates of up to 990 Hz/square cm which corresponds to twice the highest background rate expected in ATLAS. A silicon strip detector telescope was used as external reference in the beam. The pulse-height measurement of the read-out electronics was used to perform time-slewing corrections which lead to an improvement of the average drift-tube resolution from 104 microns to 82 microns without irradiation and from 128 microns to 108 microns at the maximum expected rate. The measured drift-tube efficiency agrees with the expectation from the dead time of the read-out electronics up to the maximum expected rate.

  5. Hawkes process model with a time-dependent background rate and its application to high-frequency financial data.

    Science.gov (United States)

    Omi, Takahiro; Hirata, Yoshito; Aihara, Kazuyuki

    2017-07-01

    A Hawkes process model with a time-varying background rate is developed for analyzing the high-frequency financial data. In our model, the logarithm of the background rate is modeled by a linear model with a relatively large number of variable-width basis functions, and the parameters are estimated by a Bayesian method. Our model can capture not only the slow time variation, such as in the intraday seasonality, but also the rapid one, which follows a macroeconomic news announcement. By analyzing the tick data of the Nikkei 225 mini, we find that (i) our model is better fitted to the data than the Hawkes models with a constant background rate or a slowly varying background rate, which have been commonly used in the field of quantitative finance; (ii) the improvement in the goodness-of-fit to the data by our model is significant especially for sessions where considerable fluctuation of the background rate is present; and (iii) our model is statistically consistent with the data. The branching ratio, which quantifies the level of the endogeneity of markets, estimated by our model is 0.41, suggesting the relative importance of exogenous factors in the market dynamics. We also demonstrate that it is critically important to appropriately model the time-dependent background rate for the branching ratio estimation.

  6. Survey of Gamma Dose and Radon Exhalation Rate from Soil Surface of High Background Natural Radiation Areas in Ramsar, Iran

    Directory of Open Access Journals (Sweden)

    Rouhollah Dehghani

    2013-09-01

    Full Text Available Background: Radon is a radioactive gas and the second leading cause of death due to lung cancer after smoking. Ramsar is known for having the highest levels of natural background radiation on earth. Materials and Methods: In this research study, 50 stations of high radioactivity areas of Ramsar were selected in warm season of the year. Then gamma dose and radon exhalation rate were measured.Results: Results showed that gamma dose and radon exhalation rate were in the range of 51-7100 nSv/hr and 9-15370 mBq/m2s, respectively.Conclusion: Compare to the worldwide average 16 mBq/m2s, estimated average annual effective of Radon exhalation rate in the study area is too high.

  7. Radon exhalation rate and natural radionuclide content in building materials of high background areas of Ramsar, Iran.

    Science.gov (United States)

    Bavarnegin, E; Fathabadi, N; Vahabi Moghaddam, M; Vasheghani Farahani, M; Moradi, M; Babakhni, A

    2013-03-01

    Radon exhalation rates from building materials used in high background radiation areas (HBRA) of Ramsar were measured using an active radon gas analyzer with an emanation container. Radon exhalation rates from these samples varied from below the lower detection limit up to 384 Bq.m(-2) h(-1). The (226)Ra, (232)Th and (40)K contents were also measured using a high resolution HPGe gamma- ray spectrometer system. The activity concentration of (226)Ra, (232)Th and (40)K content varied from below the minimum detection limit up to 86,400 Bq kg(-1), 187 Bq kg(-1) and 1350 Bq kg(-1), respectively. The linear correlation coefficient between radon exhalation rate and radium concentration was 0.90. The result of this survey shows that radon exhalation rate and radium content in some local stones used as basements are extremely high and these samples are main sources of indoor radon emanation as well as external gamma radiation from uranium series. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Resolution and Efficiency of Monitored Drift-Tube Chambers with Final Read-out Electronics at High Background Rates

    CERN Document Server

    Dubbert, J; Kortner, O; Kroha, H; Manz, A; Mohrdieck-Möck, S; Rauscher, F; Richter, R; Staude, A; Stiller, W

    2003-01-01

    The performance of a monitored drift-tube chamber for ATLAS with the final read-out electronics was tested at the Gamma Irradiation facility at CERN under varyin photon irradiation rates of up to 990~Hz\\,cm$^{-2}$ which corresponds to 10 times the highest background rate expected in ATLAS. The signal pulse-height measurement of the final read-out electronics was used to perform time-slewing corrections. The corrections improve the average single-tube resolution from 106~$\\mu$m to 89~$\\mu$m at the nominal discriminator threshold of 44~mV without irradiation, and from 114~$\\mu$m to 89~$\\mu$m at the maximum nominal irradiation rate in ATLAS of 100~Hz\\,cm$^{-2}$. The reduction of the threshold from 44~mV to 34~mV and the time-slewing corrections lead to an average single-tube resolution of 82~$\\mu$m without photon background and of 89~$\\mu$m at 100~Hz\\,cm$^{-2}$. The measured muon detection efficiency agrees with the expectation for the final read-out electronics.

  9. Background radiation dose-rates to non-human biota in a high mountain habitat in Norway

    DEFF Research Database (Denmark)

    Brown, J.E.; Gelsvik, R.; Kålås, J.A.

    2009-01-01

    concerning these radioisotopes for components of the ecosystem, field work was conducted in a semi-natural, mountainous location in central Norway. Preliminary (since no correction was made for ingrowth from 210Pb) whole-body activity concentrations of 210Po in 2 species of small mammal were commensurate...... with activity concentrations reported for reindeer muscle sampled at proximate locations, falling at a level of some 10s of Bq kg-1 by fresh weight. Statistical analyses of the data showed that bank vole and shrew 210Po data constitute different populations with different mean ranks. Unweighted dose......-rates attributable to the presence of internally distributed 210Po were calculated to be 0.07 μGy h-1 for Bank vole....

  10. Optimisation of the Read-out Electronics of Muon Drift-Tube Chambers for Very High Background Rates at HL-LHC and Future Colliders

    CERN Document Server

    Nowak, Sebastian; Gadow, Philipp; Ecker, Katharina; Fink, David; Fras, Markus; Kortner, Oliver; Kroha, Hubert; Müller, Felix; Richter, Robert; Schmid, Clemens; Schmidt-Sommerfeld, Korbinian; Zhao, Yazhou

    2016-01-01

    In the ATLAS Muon Spectrometer, Monitored Drift Tube (MDT) chambers and sMDT chambers with half of the tube diameter of the MDTs are used for precision muon track reconstruction. The sMDT chambers are designed for operation at high counting rates due to neutron and gamma background irradiation expected for the HL-LHC and future hadron colliders. The existing MDT read-out electronics uses bipolar signal shaping which causes an undershoot of opposite polarity and same charge after a signal pulse. At high counting rates and short electronics dead time used for the sMDTs, signal pulses pile up on the undershoot of preceding background pulses leading to a reduction of the signal amplitude and a jitter in the drift time measurement and, therefore, to a degradation of drift tube efficiency and spatial resolution. In order to further increase the rate capability of sMDT tubes, baseline restoration can be used in the read-out electronics to suppress the pile-up effects. A discrete bipolar shaping circuit with baseline...

  11. Spatial Seismicity Rates and Maximum Magnitudes for Background Earthquakes

    Science.gov (United States)

    Petersen, Mark D.; Mueller, Charles S.; Frankel, Arthur D.; Zeng, Yuehua

    2008-01-01

    The background seismicity model is included to account for M 5.0 - 6.5 earthquakes on faults and for random M 5.0 ? 7.0 earthquakes that do not occur on faults included in the model (as in earlier models of Frankel et al., 1996, 2002 and Petersen et al., 1996). We include four different classes of earthquake sources in the California background seismicity model: (1) gridded (smoothed) seismicity, (2) regional background zones, (3) special fault zone models, and (4) shear zones (also referred to as C zones). The gridded (smoothed) seismicity model, the regional background zone model, and the special fault zones use a declustered earthquake catalog for calculation of earthquake rates. Earthquake rates in shear zones are estimated from the geodetically determined rate of deformation across an area of high strain rate. We use a truncated exponential (Gutenberg-Richter, 1944) magnitude-frequency distribution to account for earthquakes in the background models.

  12. High Octane Fuel: Terminal Backgrounder

    Energy Technology Data Exchange (ETDEWEB)

    Moriarty, Kristi [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-02-11

    The Bioenergy Technologies Office of the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy sponsored a scoping study to assess the potential of ethanol-based high octane fuel (HOF) to reduce energy consumption and greenhouse gas emissions. When the HOF blend is made with 25%-40% ethanol by volume, this energy efficiency improvement is potentially sufficient to offset the reduced vehicle range often associated with the decreased volumetric energy density of ethanol. The purpose of this study is to assess the ability of the fuel supply chain to accommodate more ethanol at fuel terminals. Fuel terminals are midstream in the transportation fuel supply chain and serve to store and distribute fuels to end users. While there are no technical issues to storing more ethanol at fuel terminals, there are several factors that could impact the ability to deploy more ethanol. The most significant of these issues include the availability of land to add more infrastructure and accommodate more truck traffic for ethanol deliveries as well as a lengthy permitting process to erect more tanks.

  13. Accounting for orphaned aftershocks in the earthquake background rate

    Science.gov (United States)

    Van Der Elst, Nicholas

    2017-01-01

    Aftershocks often occur within cascades of triggered seismicity in which each generation of aftershocks triggers an additional generation, and so on. The rate of earthquakes in any particular generation follows Omori's law, going approximately as 1/t. This function decays rapidly, but is heavy-tailed, and aftershock sequences may persist for long times at a rate that is difficult to discriminate from background. It is likely that some apparently spontaneous earthquakes in the observational catalogue are orphaned aftershocks of long-past main shocks. To assess the relative proportion of orphaned aftershocks in the apparent background rate, I develop an extension of the ETAS model that explicitly includes the expected contribution of orphaned aftershocks to the apparent background rate. Applying this model to California, I find that the apparent background rate can be almost entirely attributed to orphaned aftershocks, depending on the assumed duration of an aftershock sequence. This implies an earthquake cascade with a branching ratio (the average number of directly triggered aftershocks per main shock) of nearly unity. In physical terms, this implies that very few earthquakes are completely isolated from the perturbing effects of other earthquakes within the fault system. Accounting for orphaned aftershocks in the ETAS model gives more accurate estimates of the true background rate, and more realistic expectations for long-term seismicity patterns.

  14. Accounting for orphaned aftershocks in the earthquake background rate

    Science.gov (United States)

    van der Elst, Nicholas J.

    2017-11-01

    Aftershocks often occur within cascades of triggered seismicity in which each generation of aftershocks triggers an additional generation, and so on. The rate of earthquakes in any particular generation follows Omori's law, going approximately as 1/t. This function decays rapidly, but is heavy-tailed, and aftershock sequences may persist for long times at a rate that is difficult to discriminate from background. It is likely that some apparently spontaneous earthquakes in the observational catalogue are orphaned aftershocks of long-past main shocks. To assess the relative proportion of orphaned aftershocks in the apparent background rate, I develop an extension of the ETAS model that explicitly includes the expected contribution of orphaned aftershocks to the apparent background rate. Applying this model to California, I find that the apparent background rate can be almost entirely attributed to orphaned aftershocks, depending on the assumed duration of an aftershock sequence. This implies an earthquake cascade with a branching ratio (the average number of directly triggered aftershocks per main shock) of nearly unity. In physical terms, this implies that very few earthquakes are completely isolated from the perturbing effects of other earthquakes within the fault system. Accounting for orphaned aftershocks in the ETAS model gives more accurate estimates of the true background rate, and more realistic expectations for long-term seismicity patterns.

  15. Background exposure rates of terrestrial wildlife in England and Wales

    Energy Technology Data Exchange (ETDEWEB)

    Beresford, N.A. [Centre for Ecology and Hydrology, CEH-Lancaster, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom)], E-mail: nab@ceh.ac.uk; Barnett, C.L. [Centre for Ecology and Hydrology, CEH-Lancaster, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom); Jones, D.G. [British Geological Society, Keyworth, Nottingham NG12 5GG (United Kingdom); Wood, M.D. [Institute for Sustainable Water Integrated Management and Ecosystem Research (SWIMMER), Nicholson Building, University of Liverpool, Liverpool, Merseyside L69 3GP (United Kingdom); Appleton, J.D.; Breward, N. [British Geological Society, Keyworth, Nottingham NG12 5GG (United Kingdom); Copplestone, D. [Environment Agency, Richard Fairclough House, Knutsford Road, Warrington, Cheshire WA4 1HG (United Kingdom)

    2008-09-15

    It has been suggested that, when assessing radiation impacts on non-human biota, estimated dose rates due to anthropogenically released radionuclides should be put in context by comparison to dose rates from natural background radiation. In order to make these comparisons, we need data on the activity concentrations of naturally occurring radionuclides in environmental media and organisms of interest. This paper presents the results of a study to determine the exposure of terrestrial organisms in England and Wales to naturally occurring radionuclides, specifically {sup 40}K, {sup 238}U series and {sup 232}Th series radionuclides. Whole-body activity concentrations for the reference animals and plants (RAPs) as proposed by the ICRP have been collated from literature review, data archives and a targeted sampling campaign. Data specifically for the proposed RAP are sparse. Soil activity concentrations have been derived from an extensive geochemical survey of the UK. Unweighted and weighted absorbed dose rates were estimated using the ERICA Tool. Mean total weighted whole-body absorbed dose rates estimated for the selected terrestrial organisms was in the range 6.9 x 10{sup -2} to 6.1 x 10{sup -1} {mu}Gy h{sup -1}.

  16. Rate Control Efficacy in Permanent Atrial Fibrillation : Successful and Failed Strict Rate Control Against a Background of Lenient Rate Control

    NARCIS (Netherlands)

    Groenveld, Hessel F.; Tijssen, Jan G. P.; Crijns, Harry J. G. M.; Van den Berg, Maarten P.; Hillege, Hans L.; Alings, Marco; Van Veldhuisen, Dirk J.; Van Gelder, Isabelle C.

    2013-01-01

    Objectives This study sought to investigate differences in outcome between patients treated with successful strict, failed strict, and lenient rate control. Background The RACE II (Rate Control Efficacy in Permanent Atrial Fibrillation) study showed no difference in outcome between lenient and

  17. establishment of background radiation dose rate in the vicinity

    African Journals Online (AJOL)

    nb

    .ac.tz). *Permanent address: Department of Physics, University of Dodoma. P. O. Box 339 Dodoma. ABSTRACT. The absorbed dose rate in air in the vicinity of the proposed Manyoni uranium mining project located in Singida region, Tanzania, ...

  18. Clinical Rating Project Interim Report Number 3: Background and Status.

    Science.gov (United States)

    Cason, Gerald J.

    A substantial and indispensable portion of the training of health professionals must be conducted in clinical settings and is performance oriented rather than cognitively oriented. Evaluation methods usually require reliance upon check lists and rating scales and capture a large volume of information in order to accurately reflect the complexity…

  19. Predicting the statistics of high-energy astrophysical backgrounds

    NARCIS (Netherlands)

    Feyereisen, M.R.

    2017-01-01

    This thesis presents improvements to a methodology for predicting the probability distribution of diffuse isotropic astrophysical backgrounds, applied to high-energy extragalactic gamma rays and neutrinos.

  20. Overcoming High Energy Backgrounds at Pulsed Spallation Sources

    CERN Document Server

    Cherkashyna, Nataliia; DiJulio, Douglas D.; Khaplanov, Anton; Pfeiffer, Dorothea; Scherzinger, Julius; Cooper-Jensen, Carsten P.; Fissum, Kevin G.; Ansell, Stuart; Iverson, Erik B.; Ehlers, Georg; Gallmeier, Franz X.; Panzner, Tobias; Rantsiou, Emmanouela; Kanaki, Kalliopi; Filges, Uwe; Kittelmann, Thomas; Extegarai, Maddi; Santoro, Valentina; Kirstein, Oliver; Bentley, Phillip M.

    2015-01-01

    Instrument backgrounds at neutron scattering facilities directly affect the quality and the efficiency of the scientific measurements that users perform. Part of the background at pulsed spallation neutron sources is caused by, and time-correlated with, the emission of high energy particles when the proton beam strikes the spallation target. This prompt pulse ultimately produces a signal, which can be highly problematic for a subset of instruments and measurements due to the time-correlated properties, and different to that from reactor sources. Measurements of this background have been made at both SNS (ORNL, Oak Ridge, TN, USA) and SINQ (PSI, Villigen, Switzerland). The background levels were generally found to be low compared to natural background. However, very low intensities of high-energy particles have been found to be detrimental to instrument performance in some conditions. Given that instrument performance is typically characterised by S/N, improvements in backgrounds can both improve instrument pe...

  1. On the bremsstrahlung background correction to the high-energy ...

    Indian Academy of Sciences (India)

    A methodology for bremsstrahlung (BS) background correction to extract a true Compton profile in high-energy Compton scattering experiments is presented. The BS background profiles for Hg, computed within the Born approximation, are estimated for different values of incident energy. It is seen for the first time that the BS ...

  2. On the bremsstrahlung background correction to the high-energy ...

    Indian Academy of Sciences (India)

    Abstract. A methodology for bremsstrahlung (BS) background correction to extract a true Compton profile in high-energy Compton scattering experiments is presented. The. BS background profiles for Hg, computed within the Born approximation, are estimated for different values of incident energy. It is seen for the first time ...

  3. Large fluctuations in the high-redshift metagalactic ionizing background

    Science.gov (United States)

    D'Aloisio, Anson; McQuinn, Matthew; Davies, Frederick B.; Furlanetto, Steven R.

    2018-01-01

    Recent observations have shown that the scatter in opacities amongst coeval segments of the Ly α forest increases rapidly at z > 5. In this paper, we assess whether the large scatter can be explained by fluctuations in the ionizing background in the post-reionization intergalactic medium. We find that matching the observed scatter at z ≈ 5.5 requires a short spatially averaged mean free path of 〈λmfp912〉 ≲ 15 h- 1 comoving Mpc, a factor of ≳3 shorter than direct measurements at z = 5.2. We argue that such rapid evolution in the mean free path is difficult to reconcile with our measurements of the global H I photoionization rate, which stay approximately constant over the interval z ≈ 4.8-5.5. However, we also show that measurements of the mean free path at z > 5 are likely biased towards higher values by the quasar proximity effect. This bias can reconcile the short values of 〈λmfp912〉 that are required to explain the large scatter in opacities. We discuss the implications of this scenario for cosmological reionization. Finally, we investigate whether other statistics applied to the z > 5 Ly α forest can shed light on the origin of the scatter. Compared to a model with a uniform ionizing background, models that successfully account for the scatter lead to enhanced power in the line-of-sight flux power spectrum on scales k ≲0.1 h Mpc-1. We find tentative evidence for this enhancement in observations of the high-redshift Ly α forest.

  4. Background parenchymal enhancement on baseline screening breast MRI: impact on biopsy rate and short-interval follow-up.

    LENUS (Irish Health Repository)

    Hambly, Niamh M

    2011-01-01

    Background parenchymal enhancement on breast MRI refers to normal enhancement of the patient\\'s fibroglandular tissue. The aim of this study was to determine the effect of background parenchymal enhancement on short-interval follow-up, biopsy, and cancer detection rate on baseline screening MRI in a high-risk group.

  5. Origin of the high energy cosmic neutrino background.

    Science.gov (United States)

    Dado, Shlomo; Dar, Arnon

    2014-11-07

    The diffuse background of very high energy extraterrestrial neutrinos recently discovered with IceCube is compatible with that expected from cosmic ray interactions in the Galactic interstellar medium plus that expected from hadronic interactions near the source and in the intergalactic medium of the cosmic rays which have been accelerated by the jets that produce gamma ray bursts.

  6. Seeking Solution: High-Performance Computing for Science. Background Paper.

    Science.gov (United States)

    Congress of the U.S., Washington, DC. Office of Technology Assessment.

    This is the second publication from the Office of Technology Assessment's assessment on information technology and research, which was requested by the House Committee on Science and Technology and the Senate Committee on Commerce, Science, and Transportation. The first background paper, "High Performance Computing & Networking for…

  7. High-Energy Neutron Backgrounds for Underground Dark Matter Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yu [Syracuse Univ., NY (United States)

    2016-01-01

    Direct dark matter detection experiments usually have excellent capability to distinguish nuclear recoils, expected interactions with Weakly Interacting Massive Particle (WIMP) dark matter, and electronic recoils, so that they can efficiently reject background events such as gamma-rays and charged particles. However, both WIMPs and neutrons can induce nuclear recoils. Neutrons are then the most crucial background for direct dark matter detection. It is important to understand and account for all sources of neutron backgrounds when claiming a discovery of dark matter detection or reporting limits on the WIMP-nucleon cross section. One type of neutron background that is not well understood is the cosmogenic neutrons from muons interacting with the underground cavern rock and materials surrounding a dark matter detector. The Neutron Multiplicity Meter (NMM) is a water Cherenkov detector capable of measuring the cosmogenic neutron flux at the Soudan Underground Laboratory, which has an overburden of 2090 meters water equivalent. The NMM consists of two 2.2-tonne gadolinium-doped water tanks situated atop a 20-tonne lead target. It detects a high-energy (>~ 50 MeV) neutron via moderation and capture of the multiple secondary neutrons released when the former interacts in the lead target. The multiplicity of secondary neutrons for the high-energy neutron provides a benchmark for comparison to the current Monte Carlo predictions. Combining with the Monte Carlo simulation, the muon-induced high-energy neutron flux above 50 MeV is measured to be (1.3 ± 0.2) ~ 10-9 cm-2s-1, in reasonable agreement with the model prediction. The measured multiplicity spectrum agrees well with that of Monte Carlo simulation for multiplicity below 10, but shows an excess of approximately a factor of three over Monte Carlo prediction for multiplicities ~ 10 - 20. In an effort to reduce neutron backgrounds for the dark matter experiment SuperCDMS SNO- LAB, an active neutron veto was developed

  8. Establishment of background radiation dose rate in the vicinity of the ...

    African Journals Online (AJOL)

    The absorbed dose rate in air in the vicinity of the proposed Manyoni uranium mining project located in Singida region, Tanzania, was determined so as to establish the baseline data for background radiation dose rate data prior to commencement of uranium mining activities. Twenty stations in seven villages were selected ...

  9. A high resolution, low background fast neutron spectrometer

    CERN Document Server

    Abdurashitov, J N; Kalikhov, A V; Matushko, V L; Shikhin, A A; Yants, V E; Zaborskaia, O S; Adams, J M; Nico, J S; Thompson, A K

    2002-01-01

    We discuss the possibility to create a spectrometer of full absorption based on liquid scintillator doped with enriched sup 6 Li. Of specific interest, the spectrometer will have energy resolution estimated to lie in the range 5-10% for 14 MeV neutrons. It will be sensitive to fluxes from 10 sup - sup 4 to 10 sup 6 cm sup - sup 2 s sup - sup 1 above a threshold of 1 MeV in a gamma-background of up to 10 sup 4 s sup - sup 1. The detector's efficiency will be determined by the volume of the scintillator only (approx 3 l) and is estimated to be 0.2-10%. The main reason for the poor resolution of an organic scintillator based spectrometer of full absorption is a non-linear light-yield of the scintillator for recoil protons. The neutron energy is occasionally distributed among recoil protons, and due to non-linear light-yield the total amount of light from all recoil protons ambiguously determines the initial neutron energy. The high-energy resolution will be achieved by compensation of the non-linear light-yield ...

  10. Radioactivity in the groundwater of a high background radiation area.

    Science.gov (United States)

    Shabana, E I; Kinsara, A A

    2014-11-01

    Natural radioactivity was measured in groundwater samples collected from 37 wells scattered in an inhabited area of high natural background radiation, in a purpose of radiation protection. The study area is adjacent to Aja heights of granitic composition in Hail province, Saudi Arabia. Initial screening for gross α and gross β activities showed levels exceeded the national regulation limits set out for gross α and gross β activities in drinking water. The gross α activity ranged from 0.17 to 5.41 Bq L(-)(1) with an average value of 2.15 Bq L(-)(1), whereas gross β activity ranged from 0.48 to 5.16 Bq L(-)(1), with an average value of 2.60 Bq L(-)(1). The detail analyses indicated that the groundwater of this province is contaminated with uranium and radium ((226)Ra and (228)Ra). The average activity concentrations of (238)U, (234)U, (226)Ra and (228)Ra were 0.40, 0.77, 0.29 and 0.46 Bq L(-)(1), respectively. The higher uranium content was found in the samples of granitic aquifers, whereas the higher radium content was found in the samples of sandstone aquifers. Based on the obtained results, mechanism of leaching of the predominant radionuclides has been discussed in detail. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Comparison of estimated and background subsidence rates in Texas-Louisiana geopressured geothermal areas

    Energy Technology Data Exchange (ETDEWEB)

    Lee, L.M.; Clayton, M.; Everingham, J.; Harding, R.C.; Massa, A.

    1982-06-01

    A comparison of background and potential geopressured geothermal development-related subsidence rates is given. Estimated potential geopressured-related rates at six prospects are presented. The effect of subsidence on the Texas-Louisiana Gulf Coast is examined including the various associated ground movements and the possible effects of these ground movements on surficial processes. The relationships between ecosystems and subsidence, including the capability of geologic and biologic systems to adapt to subsidence, are analyzed. The actual potential for environmental impact caused by potential geopressured-related subsidence at each of four prospects is addressed. (MHR)

  12. High-Rate Capable Floating Strip Micromegas

    Science.gov (United States)

    Bortfeldt, Jonathan; Bender, Michael; Biebel, Otmar; Danger, Helge; Flierl, Bernhard; Hertenberger, Ralf; Lösel, Philipp; Moll, Samuel; Parodi, Katia; Rinaldi, Ilaria; Ruschke, Alexander; Zibell, André

    2016-04-01

    We report on the optimization of discharge insensitive floating strip Micromegas (MICRO-MEsh GASeous) detectors, fit for use in high-energy muon spectrometers. The suitability of these detectors for particle tracking is shown in high-background environments and at very high particle fluxes up to 60 MHz/cm2. Measurement and simulation of the microscopic discharge behavior have demonstrated the excellent discharge tolerance. A floating strip Micromegas with an active area of 48 cm × 50 cm with 1920 copper anode strips exhibits in 120 GeV pion beams a spatial resolution of 50 μm at detection efficiencies above 95%. Pulse height, spatial resolution and detection efficiency are homogeneous over the detector. Reconstruction of particle track inclination in a single detector plane is discussed, optimum angular resolutions below 5° are observed. Systematic deviations of this μTPC-method are fully understood. The reconstruction capabilities for minimum ionizing muons are investigated in a 6.4 cm × 6.4 cm floating strip Micromegas under intense background irradiation of the whole active area with 20 MeV protons at a rate of 550 kHz. The spatial resolution for muons is not distorted by space charge effects. A 6.4 cm × 6.4 cm floating strip Micromegas doublet with low material budget is investigated in highly ionizing proton and carbon ion beams at particle rates between 2 MHz and 2 GHz. Stable operation up to the highest rates is observed, spatial resolution, detection efficiencies, the multi-hit and high-rate capability are discussed.

  13. High Resolution, High Frame Rate Video Technology

    Science.gov (United States)

    1990-01-01

    Papers and working group summaries presented at the High Resolution, High Frame Rate Video (HHV) Workshop are compiled. HHV system is intended for future use on the Space Shuttle and Space Station Freedom. The Workshop was held for the dual purpose of: (1) allowing potential scientific users to assess the utility of the proposed system for monitoring microgravity science experiments; and (2) letting technical experts from industry recommend improvements to the proposed near-term HHV system. The following topics are covered: (1) State of the art in the video system performance; (2) Development plan for the HHV system; (3) Advanced technology for image gathering, coding, and processing; (4) Data compression applied to HHV; (5) Data transmission networks; and (6) Results of the users' requirements survey conducted by NASA.

  14. Background mortality rates for recovering populations of Acropora cytherea in the Chagos Archipelago, central Indian Ocean.

    Science.gov (United States)

    Pratchett, M S; Pisapia, C; Sheppard, C R C

    2013-05-01

    This study quantified background rates of mortality for Acropora cytherea in the Chagos Archipelago. Despite low levels of anthropogenic disturbance, 27.5% (149/541) of A. cytherea colonies exhibited some level of partial mortality, and 9.0% (49/541) of colonies had recent injuries. A total of 15.3% of the overall surface area of physically intact A. cytherea colonies was dead. Observed mortality was partly attributable to overtopping and/or self-shading among colonies. There were also low-densities of Acanthaster planci apparent at some study sites. However, most of the recent mortality recorded was associated with isolated infestations of the coral crab, Cymo melanodactylus. A. cytherea is a relatively fast growing coral and these levels of mortality may be biologically unimportant. However, few studies have measured background rates of coral mortality, especially in the absence of direct human disturbances. These data are important for assessing the impacts of increasing disturbances, especially in projecting likely recovery. Copyright © 2013. Published by Elsevier Ltd.

  15. Nature of the Background Ultraviolet Radiation Field at High Redshifts

    Indian Academy of Sciences (India)

    tribpo

    thus necessary for the understanding of the early universe. AGNs are believed to be the major ... This ratio is insensitive to the particle density and the abundance of carbon, but is very sensitive to the ..... assuming the rest of the required flux to be of local, galactic origin, very high galactic flux is required. For most of the ...

  16. Family Background and Access to "High Status" Universities

    Science.gov (United States)

    Jerrim, John

    2013-01-01

    Economic inequality is high and rising in a number of developed countries, including in the United Kingdom and the United States. There are growing concerns that this may have negative implications for equality of opportunity, and the extent to which social disadvantage is transmitted across generations. It is widely believed that providing…

  17. High Performance Computing and Networking for Science--Background Paper.

    Science.gov (United States)

    Congress of the U.S., Washington, DC. Office of Technology Assessment.

    The Office of Technology Assessment is conducting an assessment of the effects of new information technologies--including high performance computing, data networking, and mass data archiving--on research and development. This paper offers a view of the issues and their implications for current discussions about Federal supercomputer initiatives…

  18. Assessment of ADHD Symptoms and the Issue of Cultural Variation: Are Conners 3 Rating Scales Applicable to Children and Parents With Migration Background?

    Science.gov (United States)

    Schmidt, Martin; Reh, Verena; Hirsch, Oliver; Rief, Winfried; Christiansen, Hanna

    2017-05-01

    The objective was to evaluate whether Conners 3 ( Conners 3rd edition) ratings of ADHD symptoms are robust to distortion by cultural variation when applied to children with migration background living in Germany. From 2010 to 2011, Conners 3 data (self-rating, parent rating, and teacher rating) of 243 children with Turkish migration background, aged 6 to 16 years, were collected in various German schools. Allocation of items to latent factors was tested with confirmatory analyses. Reliability and validity of resulting factors was calculated and influence of acculturation, gender, and age on rating-modalities was examined. Confirmatory factor analyses showed high model fits for all rating-modalities. Resulting scales had good reliability and validity. There was a small influence of acculturation on parent ratings of oppositional defiant disorder but not on ADHD core symptoms. Conners 3 ratings seem to be robust against influences of cultural variation. Their German translation can be utilized for children with Turkish migration background without limitation.

  19. Study of the CMS RPC detector performance in high radiation background conditions

    CERN Document Server

    Miguel Colin, Osvaldo

    2017-01-01

    The RPC system at the CMS Detector is operating successfully from beginning of the data taking. The high instantaneous luminosity causes an extremely high flux of ionizing particles. The long period of operation (Run1 and Run2) in a huge radiation background conditions, gives the opportunity to study the operation capability of the RPCs and also to predict a data-driven extrapolation about the expecting particle rates at HL LHC (High Luminosity) scenario. The obtained results in terms of measured rate, currents and integrated charged will be presented in the poster. When it is possible they will be compared to the relevant results obtained from the dedicated study where a set of test chambers have been irradiated at GIF++ laboratory setup.

  20. Autism's 'Worryingly' High Suicide Rates Spur Conference

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_165946.html Autism's 'Worryingly' High Suicide Rates Spur Conference Signs of ... News) -- High rates of suicide among people with autism are drawing specialists to a conference this week ...

  1. Background and anthropogenic radionuclide derived dose rates to freshwater ecosystem - Nuclear power plant cooling pond - Reference organisms

    Energy Technology Data Exchange (ETDEWEB)

    Nedveckaite, T., E-mail: tatjana@cablenet.lt [Institute of Physics of the Center of Physical Science and Technology, Savanoriu av, 231, LT-02300, Vilnius (Lithuania); Filistovic, V. [Institute of Physics of the Center of Physical Science and Technology, Savanoriu av, 231, LT-02300, Vilnius (Lithuania); Marciulioniene, D. [Institute of Botany, Zaliuju ezeru 49, LT-08406, Vilnius (Lithuania); Prokoptchuk, N.; Plukiene, R.; Gudelis, A.; Remeikis, V. [Institute of Physics of the Center of Physical Science and Technology, Savanoriu av, 231, LT-02300, Vilnius (Lithuania); Yankovich, T. [AREVA Resources Canada Inc., P.O. Box 9204, 817-45th Street West, Saskatoon, SK S7K 3X5 (Canada); Beresford, N.-A. [Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Av., Bailrigg, Lancaster, LA1 4AP (United Kingdom)

    2011-08-15

    The radiological assessment of non-human biota to demonstrate protection is now accepted by a number of international and national bodies. Therefore, it is necessary to develop a scientific basis to assess and evaluate exposure of biota to ionizing radiation. Radionuclides from the Ignalina Nuclear Power Plant (Lithuania) were discharged into Lake Druksiai cooling pond. Additional radionuclide migration and recharge to this lake from a hypothetical near-surface, low-level radioactive waste disposal, to be situated 1.5 km from the lake, had been simulated using RESRAD-OFFSITE code. This paper uses ERICA Integrated Approach with associated tools and databases to compare the radiological dose to freshwater reference organisms. Based on these data, it can be concluded that background dose rates to non-human biota in Lake Druksiai far exceed those attributable to anthropogenic radionuclides. With respect the fishery and corresponding annual committed effective human dose as a result of this fish consumption Lake Druksiai continues to be a high-productivity water body with intensive angling and possible commercial fishing. - Highlights: > Dose rates to the reference organisms are lower than expected from the background radioactivity. > Pelagic fish part of adult human annual committed effective dose would be as small as a few {mu}Sv y{sup -1}. > With respect the fishery Lake Druksiai continues to be a high-productivity water body.

  2. Human response to high-background radiation environments on Earth and in space

    Science.gov (United States)

    Durante, M.; Manti, L.

    2008-09-01

    The main long-term objective of the space exploration program is the colonization of the planets of the Solar System. The high cosmic radiation equivalent dose rate represents an inescapable problem for the safe establishment of permanent human settlements on these planets. The unshielded equivalent dose rate on Mars ranges between 100 and 200 mSv/year, depending on the Solar cycle and altitude, and can reach values as high as 360 mSv/year on the Moon. The average annual effective dose on Earth is about 3 mSv, nearly 85% of which comes from natural background radiation, reduced to less than 1 mSv if man-made sources and the internal exposure to Rn daughters are excluded. However, some areas on Earth display anomalously high levels of background radiation, as is the case with thorium-rich monazite bearing sand deposits where values 200 400 times higher than the world average can be found. About 2% of the world’s population live above 3 km and receive a disproportionate 10% of the annual effective collective dose due to cosmic radiation, with a net contribution to effective dose by the neutron component which is 3 4 fold that at sea level. Thus far, epidemiological studies have failed to show any adverse health effects in the populations living in these terrestrial high-background radiation areas (HBRA), which provide an unique opportunity to study the health implications of an environment that, as closely as possibly achievable on Earth, resembles the chronic exposure of future space colonists to higher-than-normal levels of ionizing radiation. Chromosomal aberrations in the peripheral blood lymphocytes from the HBRA residents have been measured in several studies because chromosomal damage represents an early biomarker of cancer risk. Similar cytogenetic studies have been recently performed in a cohort of astronauts involved in single or repeated space flights over many years. The cytogenetic findings in populations exposed to high dose-rate background radiation

  3. High bit rate BPSK receiver

    Science.gov (United States)

    Osorio-Marti, J. A.; Sieiro, J. J.; Lopez-Villegas, J. M.

    2005-06-01

    This work presents a simple differentially BPSK receiver front-end using a novel schema without the need of an explicit carrier recovery system. The main principle of operation is the conversion of the incoming BPSK signal into an ASK signal having the same modulation pattern. Two versions of the system have been designed. One is intended to work at the 433.92 MHz ISM band and the other at 2 GHz frequency band. Accordingly, two prototypes of the system core, the BPSK to ASK converter circuit, have been implemented and tested. First a hybrid version for the low frequency operation and, second a multi chip module (MCM) for the 2 GHz frequency band. The system performance has been evaluated using Agilent Technologies Advanced Design System (ADS) platform. The ability to jointly perform system, circuit and EM simulations and co-simulations is the main advantage of this design tool. Obtained results indicate that modulation rates up to 20 Mbits/s for the hybrid version and up to 80 Mbits/s for the MCM version can be reached.

  4. "Gaining Power through Education": Experiences of Honduran Students from High Poverty Backgrounds

    Science.gov (United States)

    Mather, Peter C.; Zempter, Christy; Ngumbi, Elizabeth; Nakama, Yuki; Manley, David; Cox, Haley

    2017-01-01

    This is a study of students from high-poverty backgrounds attending universities in Honduras. Based on a series of individual and focus group interviews, the researchers found students from high-poverty backgrounds face numerous practical challenges in persisting in higher education. Despite these challenges, participants succeeded due to a…

  5. High background radiation areas: the case of Villar de la Yegua village (Spain).

    Science.gov (United States)

    Sáinz, C; Quindós, L S; Fernández, P L; Gómez, J; Fuente, I; Quindós, L; Matarranz, J L

    2007-01-01

    The starting point of the Spanish experience in the study of High Background Radiation Areas is the development of a nationwide indoor radon survey carried out in 1988. This campaign, belonging to the first Spanish Radon Framework, consisted of approximately 2000 indoor radon measurements which represented a valuable basis to face rigorously the radon issue in Spain. Together but indepently from this survey, since 1991 the Spanish Nuclear Safety Council, the National Uranium Company and several Universities have developed the so-called MARNA project with the aim of estimating potential radon emission from external gamma dose rates, radium concentrations in soil and geological parameters. During the last decade, several regional surveys have also been conducted to determine exposure to natural sources of radiation in different highly populated background radiation areas. Among them, the surroundings of the village of Villar de la Yegua Town, located in the western province of Salamanca, is the most important area of Spain from a radiological point of view, with the highest indoor radon concentrations, of up to 15,000 Bq m(-3) being found there. Until now, the main result of the study in this area showed a geometric mean radon concentration of 818 Bq m(-3), which is 18 times higher than the national average. In this article, the results of the last survey, carried out in Villar de la Yegua during 2004 are summarised. A geometric mean radon concentration of 1356 Bq m(-3) was found. Dose estimation coming from radon inhalation is also shown.

  6. Very high background radiation areas of Ramsar, Iran: preliminary biological studies.

    Science.gov (United States)

    Ghiassi-nejad, M; Mortazavi, S M J; Cameron, J R; Niroomand-rad, A; Karam, P A

    2002-01-01

    People in some areas of Ramsar, a city in northern Iran, receive an annual radiation absorbed dose from background radiation that is up to 260 mSv y(-1), substantially higher than the 20 mSv y(-1) that is permitted for radiation workers. Inhabitants of Ramsar have lived for many generations in these high background areas. Cytogenetic studies show no significant differences between people in the high background compared to people in normal background areas. An in vitro challenge dose of 1.5 Gy of gamma rays was administered to the lymphocytes, which showed significantly reduced frequency for chromosome aberrations of people living in high background compared to those in normal background areas in and near Ramsar. Specifically, inhabitants of high background radiation areas had about 56% the average number of induced chromosomal abnormalities of normal background radiation area inhabitants following this exposure. This suggests that adaptive response might be induced by chronic exposure to natural background radiation as opposed to acute exposure to higher (tens of mGy) levels of radiation in the laboratory. There were no differences in laboratory tests of the immune systems, and no noted differences in hematological alterations between these two groups of people.

  7. Migration background and juvenile mental health: a descriptive retrospective analysis of diagnostic rates of psychiatric disorders in young people

    Directory of Open Access Journals (Sweden)

    Tilman Jakob Gaber

    2013-06-01

    Full Text Available Introduction: This article presents diagnostic rates for specific mental disorders in a German pediatric inpatient population over a period of 20 years with respect to migration background and socioeconomic status (SES. Methods: Diagnostic data were obtained over a period of 20 years from 8,904 patients who visited a child and adolescent psychiatry mental health service in Germany. Data from 5,985 diagnosed patients (ICD-9 and ICD-10 criteria were included with respect to gender, migration background, and SES. Results:Migration- and gender-specific effects were found for both periods of assessment. The group of boys with a migration background showed significantly higher rates of reactions to severe stress, adjustment disorders, and posttraumatic stress disorder compared to their male, non-migrant counterparts. Conversely, boys without a migration background showed a significantly higher percentage rate of hyperkinetic disorders than male migrants. Similar results were found for female migrants in the latter assessment period (ICD-10. In addition, female migrants showed lower rates of emotional disorders whose onset occurs in childhood compared to their non-migrant counterparts. Conclusions: Data from this investigation provide preliminary evidence that the prevalence of various psychiatric disorders in children and adolescents is influenced by migration background and SES.

  8. Background rates of acute mountain sickness-like symptoms at low altitude in adolescents using Lake Louise score.

    Science.gov (United States)

    Dallimore, Jon; Foley, Jo-ai; Valentine, Peter

    2012-03-01

    To record the incidence of symptoms consistent with a diagnosis of acute mountain sickness (AMS), using the Lake Louise questionnaire, in adolescents hiking at low altitude. The study was carried out on a cohort of 123 adolescents during a 3-day trip on Dartmoor, UK, at an altitude of less than 500 m. The incidence of symptoms experienced was measured using the Lake Louise questionnaire, which was completed twice daily by each participant. An episode consistent with AMS, but in the low altitude setting, was defined as a score of 3 or more on the Lake Louise questionnaire in the presence of a headache. There were 59 boys and 64 girls in the study with an average age of 16.7 years. The response rate was 100%. A total of 59 episodes of scores consistent with AMS was recorded during the 3-day period. Forty-two of these episodes were reported by girls (71%). AMS scores between 3 and 8 were recorded, and the daily incidence rates of scores consistent with AMS but at low altitude were between 7.3% and 11.3%. This study shows that adolescents at low altitude reported a background incidence of symptoms that at high altitude would lead to a diagnosis of AMS. Copyright © 2012 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

  9. High-Rate Receiver Design Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose an initial architectural and preliminary hardware design study for a high-rate receiver capable of decoding modulation suites specified by CCSDS 413.0-G-1...

  10. A Comparison between High-Energy Radiation Background Models and SPENVIS Trapped-Particle Radiation Models

    Science.gov (United States)

    Krizmanic, John F.

    2013-01-01

    We have been assessing the effects of background radiation in low-Earth orbit for the next generation of X-ray and Cosmic-ray experiments, in particular for International Space Station orbit. Outside the areas of high fluxes of trapped radiation, we have been using parameterizations developed by the Fermi team to quantify the high-energy induced background. For the low-energy background, we have been using the AE8 and AP8 SPENVIS models to determine the orbit fractions where the fluxes of trapped particles are too high to allow for useful operation of the experiment. One area we are investigating is how the fluxes of SPENVIS predictions at higher energies match the fluxes at the low-energy end of our parameterizations. I will summarize our methodology for background determination from the various sources of cosmogenic and terrestrial radiation and how these compare to SPENVIS predictions in overlapping energy ranges.

  11. Performance of the low pressure MWPCs for fission fragments under a high background

    Science.gov (United States)

    Song, Yu-Shou; Margaryan, A.; Hu, Bi-Tao; Tang, Li-Guang

    2011-08-01

    Two couples of low pressure multi-wire proportional chambers (MWPC) were located in the target chamber to detect fission fragments in a hypernuclei producing experiment at Thomas Jefferson National Laboratory (Jlab). In the experiment, a continuous wave (CW) electron beam was applied to form hypernuclei by electromagnetic interaction. In the target chamber, the high energy (1.853 GeV) and high intensity (500 nA) primary electron beam caused a high particle background, which influenced the detection of the fission fragments. This report described the design of the MWPCs and studied the fission-fragment detecting performance of them under such a high background. The efficiency of the MWPCs was given with the help of a high resolution kaon spectrometer. At the same time, the background particles were discussed with a Monte Carlo code based on GEANT4.

  12. Characterization of gaseous detectors at the CERN Gamma Irradiation Facility: GEM performance in presence of high background radiation

    CERN Document Server

    AUTHOR|(CDS)2097588

    Muon detection is an efficient tool to recognize interesting physics events over the high background rate expected at the Large Hadron Collider (LHC) at CERN. The muon systems of the LHC experiments are based on gaseous ionization detectors. In view of the High-Luminosity LHC (HL-LHC) upgrade program, the increasing of background radiation could affect the gaseous detector performance, especially decreasing the efficiency and shortening the lifetime through ageing processes. The effects of charge multiplication, materials and gas composition on the ageing of gaseous detectors have been studied for decades, but the future upgrade of LHC requires additional studies on this topic. At the CERN Gamma Irradiation Facility (GIF++), a radioactive source of cesium-137 with an activity of 14 TBq is used to reproduce reasonably well the expected background radiation at HL-LHC. A muon beam has been made available to study detector performance. The characterization of the beam trigger will be discussed in the present w...

  13. Thrombus Formation at High Shear Rates.

    Science.gov (United States)

    Casa, Lauren D C; Ku, David N

    2017-06-21

    The final common pathway in myocardial infarction and ischemic stroke is occlusion of blood flow from a thrombus forming under high shear rates in arteries. A high-shear thrombus forms rapidly and is distinct from the slow formation of coagulation that occurs in stagnant blood. Thrombosis at high shear rates depends primarily on the long protein von Willebrand factor (vWF) and platelets, with hemodynamics playing an important role in each stage of thrombus formation, including vWF binding, platelet adhesion, platelet activation, and rapid thrombus growth. The prediction of high-shear thrombosis is a major area of biofluid mechanics in which point-of-care testing and computational modeling are promising future directions for clinically relevant research. Further research in this area will enable identification of patients at high risk for arterial thrombosis, improve prevention and treatment based on shear-dependent biological mechanisms, and improve blood-contacting device design to reduce thrombosis risk.

  14. Breakdown Limit Studies in High Rate Gaseous Detectors

    CERN Document Server

    Ivaniouchenkov, Yu; Peskov, Vladimir; Ramsey, B D

    1998-01-01

    We report results from a systematic study of breakdown limits for novel high rate gaseous detectors: MICROMEGAS, CAT and GEM, together with more conventional devices such as thin-gap parallel-mesh chambers and high-rate wire chambers. It was found that for all these detectors, the maximum achievable gain, before breakdown appears, drops dramatically with incident flux, and is sometimes inversely proportional to it. Further, in the presence of alpha particles, typical of the backgrounds in high-energy experiments, additional gain drops of 1-2 orders of magnitude were observed for many detectors. It was found that breakdowns at high rates occur through what we have termed an "accumulative" mechanism, which does not seem to have been previously reported in the literature. Results of these studies may help in choosing the optimum detector for given experimental conditions.

  15. High-energy gamma-ray and neutrino backgrounds from star-forming galaxies

    NARCIS (Netherlands)

    Tamborra, I.

    2015-01-01

    Star-forming galaxies have been predicted to contribute considerably to the isotropic diffuse gamma-ray background. The hadronic interactions responsible for high-energy gamma rays also produce high-energy neutrinos. Assuming that at least 100 PeV cosmic rays can be produced and confined in

  16. High Strain Rate Characterisation of Composite Materials

    DEFF Research Database (Denmark)

    Eriksen, Rasmus Normann Wilken

    -reinforced polymers, were considered, and it was first shown that the loading history controls equilibrium process. Then the High-speed servo-hydraulic test machine was analysed in terms its ability to create a state of constant strain rate in the specimen. The invertible inertial forces in the load train prevented...... a linear elastic specimen to reach a state of constant strain rate before fracture. This was in contrast to ductile materials, which are widely tested with for the High-speed servohydraulic test machine. The development of the analysis and the interpretation of the results, were based on the experience...... from designing and constructing a high-speed servo-hydraulic test machine and by performing a comprehensive test series. The difficulties encountered in the test work could be addressed with the developed analysis. The conclusion was that the High-speed servo-hydraulic test machine is less suited...

  17. High resolution measurement of the glycolytic rate

    Directory of Open Access Journals (Sweden)

    Carla X Bittner

    2010-09-01

    Full Text Available The glycolytic rate is sensitive to physiological activity, hormones, stress, aging and malignant transformation. Standard techniques to measure the glycolytic rate are based on radioactive isotopes, are not able to resolve single cells and have poor temporal resolution, limitations that hamper the study of energy metabolism in the brain and other organs. A new method is described in this article, which makes use of a recently-developed FRET glucose nanosensor to measure the rate of glycolysis in single cells with high temporal resolution. Used in cultured astrocytes, the method showed for the first time that glycolysis can be activated within seconds by a combination of glutamate and K+, supporting a role for astrocytes in neurometabolic and neurovascular coupling in the brain. It was also possible to make a direct comparison of metabolism in neurons and astrocytes lying in close proximity, paving the way to a high-resolution characterization of brain energy metabolism. Single-cell glycolytic rates were also measured in fibroblasts, adipocytes, myoblasts and tumor cells, showing higher rates for undifferentiated cells and significant metabolic heterogeneity within cell types. This method should facilitate the investigation of tissue metabolism at the single-cell level and is readily adaptable for high-throughput analysis.

  18. The estimation of background production by cosmic rays in high-energy gamma ray telescopes

    Science.gov (United States)

    Edwards, H. L.; Nolan, P. L.; Lin, Y. C.; Koch, D. G.; Bertsch, D. L.; Fichtel, C. E.; Hartman, R. C.; Hunter, S. D.; Kniffen, D. A.; Hughes, E. B.

    1991-01-01

    A calculational method of estimating instrumental background in high-energy gamma-ray telescopes, using the hadronic Monte Carlo code FLUKA87, is presented. The method is applied to the SAS-2 and EGRET telescope designs and is also used to explore the level of background to be expected for alternative configurations of the proposed GRITS telescope, which adapts the external fuel tank of a Space Shuttle as a gamma-ray telescope with a very large collecting area. The background produced in proton-beam tests of EGRET is much less than the predicted level. This discrepancy appears to be due to the FLUKA87 inability to transport evaporation nucleons. It is predicted that the background in EGRET will be no more than 4-10 percent of the extragalactic diffuse gamma radiation.

  19. High Rate Performing Li-ion Battery

    Science.gov (United States)

    2015-02-09

    permeable to lithium ions and efficient in transferring the electrons into/from the LVP surface to the corresponding current collector. a) b) c) d) e...PO4)3/C for High Rate Lithium-ion Battery Applications”, Lee Hwang Sheng, Nail Suleimanov, Vishwanathan Ramar, Mangayarkarasi Murugan, Kuppan

  20. Concomitant chemoradiotherapy with high dose rate brachytherapy ...

    African Journals Online (AJOL)

    Purpose: This study aims to report the incidence of treatment-induced acute toxicities, local control and survival of patients with cervix cancer treated by external beam radiotherapy (EBR) and high-dose-rate (HDR) brachytherapy concomitant with weekly Cisplatin chemotherapy. Methods: Forty patients with FIGO Stages IB2 ...

  1. Impact of receiver and constellation on high rate GNSS phase rate measurements to monitor ionospheric irregularities

    Science.gov (United States)

    Ghoddousi-Fard, Reza

    2017-11-01

    High rate (1 Hz) GPS and GLONASS phase rate measurements from the global Real Time International GNSS Service (RT-IGS) network are used to monitor ionospheric irregularities. In this paper, impact of different receiver types and satellite constellations on GNSS-derived indices are studied. Constellation dependent background phase noise is quantified at RT-IGS stations for different receiver categories. Improved sampling of the ionosphere is achieved using multiple constellations. Correlation of hourly mean values of dual constellation GNSS indices with hourly magnetic ranges at a co-located auroral magnetic observatory slightly increased compared to when single constellation is used.

  2. High strain rate behaviour of polypropylene microfoams

    Directory of Open Access Journals (Sweden)

    Martínez A.B.

    2012-08-01

    Full Text Available Microcellular materials such as polypropylene foams are often used in protective applications and passive safety for packaging (electronic components, aeronautical structures, food, etc. or personal safety (helmets, knee-pads, etc.. In such applications the foams which are used are often designed to absorb the maximum energy and are generally subjected to severe loadings involving high strain rates. The manufacture process to obtain polymeric microcellular foams is based on the polymer saturation with a supercritical gas, at high temperature and pressure. This method presents several advantages over the conventional injection moulding techniques which make it industrially feasible. However, the effect of processing conditions such as blowing agent, concentration and microfoaming time and/or temperature on the microstructure of the resulting microcellular polymer (density, cell size and geometry is not yet set up. The compressive mechanical behaviour of several microcellular polypropylene foams has been investigated over a wide range of strain rates (0.001 to 3000 s−1 in order to show the effects of the processing parameters and strain rate on the mechanical properties. High strain rate tests were performed using a Split Hopkinson Pressure Bar apparatus (SHPB. Polypropylene and polyethylene-ethylene block copolymer foams of various densities were considered.

  3. High strain rate behaviour of polypropylene microfoams

    Science.gov (United States)

    Gómez-del Río, T.; Garrido, M. A.; Rodríguez, J.; Arencón, D.; Martínez, A. B.

    2012-08-01

    Microcellular materials such as polypropylene foams are often used in protective applications and passive safety for packaging (electronic components, aeronautical structures, food, etc.) or personal safety (helmets, knee-pads, etc.). In such applications the foams which are used are often designed to absorb the maximum energy and are generally subjected to severe loadings involving high strain rates. The manufacture process to obtain polymeric microcellular foams is based on the polymer saturation with a supercritical gas, at high temperature and pressure. This method presents several advantages over the conventional injection moulding techniques which make it industrially feasible. However, the effect of processing conditions such as blowing agent, concentration and microfoaming time and/or temperature on the microstructure of the resulting microcellular polymer (density, cell size and geometry) is not yet set up. The compressive mechanical behaviour of several microcellular polypropylene foams has been investigated over a wide range of strain rates (0.001 to 3000 s-1) in order to show the effects of the processing parameters and strain rate on the mechanical properties. High strain rate tests were performed using a Split Hopkinson Pressure Bar apparatus (SHPB). Polypropylene and polyethylene-ethylene block copolymer foams of various densities were considered.

  4. Detection of admittivity anomaly on high-contrast heterogeneous backgrounds using frequency difference EIT.

    Science.gov (United States)

    Jang, J; Seo, J K

    2015-06-01

    This paper describes a multiple background subtraction method in frequency difference electrical impedance tomography (fdEIT) to detect an admittivity anomaly from a high-contrast background conductivity distribution. The proposed method expands the use of the conventional weighted frequency difference EIT method, which has been used limitedly to detect admittivity anomalies in a roughly homogeneous background. The proposed method can be viewed as multiple weighted difference imaging in fdEIT. Although the spatial resolutions of the output images by fdEIT are very low due to the inherent ill-posedness, numerical simulations and phantom experiments of the proposed method demonstrate its feasibility to detect anomalies. It has potential application in stroke detection in a head model, which is highly heterogeneous due to the skull.

  5. High-resolution varve studies in Baldeggersee (Switzerland): Project overview and limnological background data

    NARCIS (Netherlands)

    Wehrli, B.; Lotter, A.F.; Schaller, T.; Sturm, M.

    1997-01-01

    This introduction to a series of high-resolution varve studies in Baldeggersee provides both an overview of the different subprojects as well as background information on relevant limnologial trends. The project was based on a new method of in-situ freezing of unconsolidated surficial

  6. Background Oriented Schlieren (BOS) measurement in supersonic flow with 4K high-speed camera

    Science.gov (United States)

    Ota, M.; Kurihara, K.; Arimoto, H.; Shida, K.; Inage, T.

    2017-02-01

    The Background Oriented Schlieren (BOS) technique is one of the novel measurement techniques and its application range is very wide. The principle of BOS is similar to that of the conventional schlieren technique, it exploits the bending of light ray caused by a refractive-index change corresponding to the density change in the medium. The BOS technique allows the quantitative measurement of density with very simple experimental setup and proper image analysis. Only a background and a digital camera are required for the experiment, so that even the real scale experiments can be realized. In recent years, the development of the high-speed camera is remarkable and so many high-speed phenomena can now be captured. To realize the precise measurement with BOS technique using high-speed camera, higher resolution (larger number of pixels) is desirable. In this paper, with a technical support from Nobby Tech Ltd., a 4K high-speed camera (4096 × 2160 pixels) is applied to the BOS measurement of the lateral jet/cross flow interaction filed in the supersonic wind tunnel test as a trial of the quantitative density measurement with higher resolution. The measurement system consists of a 4K high-speed camera and a pulsed laser for background illumination. A telecentric optical system is also employed to improve the spatial resolution of the measurement. The measurement results of BOS technique up to 1000 fps with higher resolution are discussed.

  7. COMPARISON OF NATURAL BACKGROUND DOSE RATES FOR RESIDENTS OF THE AMARGOSA VALLEY, NV, TO THOSE IN LEADVILLE, CO, AND THE STATES OF COLORADO AND NEVADA

    Energy Technology Data Exchange (ETDEWEB)

    D. Moeller and L. C. Sun

    2006-02-24

    In the latter half of 2005, the U.S. Environmental Protection Agency (USEPA) published a Proposed Rule (40 CFR Part 197) for establishing a dose rate standard for limiting radionuclide releases from the proposed Yucca Mountain high-level radioactive waste repository during the time period from 10{sup 4} to 10{sup 6} years after closure. The proposed standard was based on the difference in the estimated total dose rate from natural background in the Amargosa Valley and the ''average annual background radiation'' for the State of Colorado. As defined by the USEPA, ''natural background radiation consists of external exposures from cosmic and terrestrial sources, and internal exposures from indoor exposures to naturally-occurring radon''. On the basis of its assessments, the USEPA estimated that the difference in the dose rate in the two identified areas was 3.5 mSv y{sup -1}. The purpose of this review was to provide an independent evaluation and review of this estimate. One of the first observations was that, because site-specific dose rate measurements for the Amargosa Valley ''were not available'', the dose rates for various sources of natural background in that area, used by the USEPA in its assessment, were based on modifications of the average values for the State of Nevada. A second observation was that the conversion factor applied in estimating the dose rates due to exposures to indoor radon and its decay products was a factor of 2 higher than the currently accepted value. Further review revealed that site-specific data for many natural background sources in the Amargosa Valley were available. One particularly important observation was that about 91% of the residents of that area live in mobile homes which, due to their construction and design, have indoor radon concentrations comparable to, or less than, those outdoors. For that reason, alone, the USEPA estimate of the average dose rate for

  8. High strain rate deformation of layered nanocomposites

    Science.gov (United States)

    Lee, Jae-Hwang; Veysset, David; Singer, Jonathan P.; Retsch, Markus; Saini, Gagan; Pezeril, Thomas; Nelson, Keith A.; Thomas, Edwin L.

    2012-11-01

    Insight into the mechanical behaviour of nanomaterials under the extreme condition of very high deformation rates and to very large strains is needed to provide improved understanding for the development of new protective materials. Applications include protection against bullets for body armour, micrometeorites for satellites, and high-speed particle impact for jet engine turbine blades. Here we use a microscopic ballistic test to report the responses of periodic glassy-rubbery layered block-copolymer nanostructures to impact from hypervelocity micron-sized silica spheres. Entire deformation fields are experimentally visualized at an exceptionally high resolution (below 10 nm) and we discover how the microstructure dissipates the impact energy via layer kinking, layer compression, extreme chain conformational flattening, domain fragmentation and segmental mixing to form a liquid phase. Orientation-dependent experiments show that the dissipation can be enhanced by 30% by proper orientation of the layers.

  9. Magnetic Implosion for Novel Strength Measurements at High Strain Rates

    Energy Technology Data Exchange (ETDEWEB)

    Lee, H.; Preston, D.L.; Bartsch, R.R.; Bowers, R.L.; Holtkamp, D.; Wright, B.L.

    1998-10-19

    Recently Lee and Preston have proposed to use magnetic implosions as a new method for measuring material strength in a regime of large strains and high strain rates inaccessible to previously established techniques. By its shockless nature, this method avoids the intrinsic difficulties associated with an earlier approach using high explosives. The authors illustrate how the stress-strain relation for an imploding liner can be obtained by measuring the velocity and temperature history of its inner surface. They discuss the physical requirements that lead us to a composite liner design applicable to different test materials, and also compare the code-simulated prediction with the measured data for the high strain-rate experiments conducted recently at LANL. Finally, they present a novel diagnostic scheme that will enable us to remove the background in the pyrometric measurement through data reduction.

  10. Evolution of high tooth replacement rates in sauropod dinosaurs.

    Directory of Open Access Journals (Sweden)

    Michael D D'Emic

    Full Text Available BACKGROUND: Tooth replacement rate can be calculated in extinct animals by counting incremental lines of deposition in tooth dentin. Calculating this rate in several taxa allows for the study of the evolution of tooth replacement rate. Sauropod dinosaurs, the largest terrestrial animals that ever evolved, exhibited a diversity of tooth sizes and shapes, but little is known about their tooth replacement rates. METHODOLOGY/PRINCIPAL FINDINGS: We present tooth replacement rate, formation time, crown volume, total dentition volume, and enamel thickness for two coexisting but distantly related and morphologically disparate sauropod dinosaurs Camarasaurus and Diplodocus. Individual tooth formation time was determined by counting daily incremental lines in dentin. Tooth replacement rate is calculated as the difference between the number of days recorded in successive replacement teeth. Each tooth family in Camarasaurus has a maximum of three replacement teeth, whereas each Diplodocus tooth family has up to five. Tooth formation times are about 1.7 times longer in Camarasaurus than in Diplodocus (315 vs. 185 days. Average tooth replacement rate in Camarasaurus is about one tooth every 62 days versus about one tooth every 35 days in Diplodocus. Despite slower tooth replacement rates in Camarasaurus, the volumetric rate of Camarasaurus tooth replacement is 10 times faster than in Diplodocus because of its substantially greater tooth volumes. A novel method to estimate replacement rate was developed and applied to several other sauropodomorphs that we were not able to thin section. CONCLUSIONS/SIGNIFICANCE: Differences in tooth replacement rate among sauropodomorphs likely reflect disparate feeding strategies and/or food choices, which would have facilitated the coexistence of these gigantic herbivores in one ecosystem. Early neosauropods are characterized by high tooth replacement rates (despite their large tooth size, and derived titanosaurs and

  11. High readmission rate after heart valve surgery

    DEFF Research Database (Denmark)

    Sibilitz, K L; Berg, S K; Thygesen, Lau Caspar

    2015-01-01

    age (hazard ratio (95% CI): 1.3 (1.0-1.6)), male sex (1.2 (1.0-1.5)), mitral valve surgery (1.3 (1.0-1.6)), and infective endocarditis after surgery (1.8 (1.1-3.0), p: 0.01) predicted readmission, whereas higher age (2.3 (1.0-5.4)), higher comorbidity score (3.2 (1.8-6.0)), and infective endocarditis......BACKGROUND: After heart valve surgery, knowledge on long-term self-reported health status and readmission is lacking. Thus, the optimal strategy for out-patient management after surgery remains unclear. METHODS: Using a nationwide survey with linkage to Danish registers with one year follow-up, we...... included all adults 6-12 months after heart valve surgery irrespective of valve procedure, during Jan-June 2011 (n = 867). Participants completed a questionnaire regarding health-status (n = 742), and answers were compared with age- and sex-matched healthy controls. Readmission rates and mortality were...

  12. Possible correlation between annual gravity change and shallow background seismicity rate at subduction zone by surface load

    Science.gov (United States)

    Mitsui, Yuta; Yamada, Kyohei

    2017-12-01

    The Gravity Recovery and Climate Experiment (GRACE) has monitored global gravity changes since 2002. Gravity changes are considered to represent hydrological water mass movements around the surface of the globe, although fault slip of a large earthquake also causes perturbation of gravity. Since surface water movements are expected to affect earthquake occurrences via elastic surface load or pore-fluid pressure increase, correlation between gravity changes and occurrences of small (not large) earthquakes may reflect the effects of surface water movements. In the present study, we focus on earthquakes smaller than magnitude 7.5 and examine the relation between annual gravity changes and earthquake occurrences at worldwide subduction zones. First, we extract amplitudes of annual gravity changes from GRACE data for land. Next, we estimate background seismicity rates in the epidemic-type aftershock sequence model from shallow seismicity data having magnitudes of over 4.5. Then, we perform correlation analysis of the amplitudes of the annual gravity changes and the shallow background seismicity rates, excluding source areas of large earthquakes, and find moderate positive correlation. It implies that annual water movements can activate shallow earthquakes, although the surface load elastostatic stress changes are on the order of or below 1 kPa, as small as a regional case in a previous study. We speculate that periodic stress perturbation is amplified through nonlinear responses of frictional faults.[Figure not available: see fulltext.

  13. Background rates of adverse pregnancy outcomes for assessing the safety of maternal vaccine trials in sub-Saharan Africa.

    Directory of Open Access Journals (Sweden)

    Lauren A V Orenstein

    Full Text Available Maternal immunization has gained traction as a strategy to diminish maternal and young infant mortality attributable to infectious diseases. Background rates of adverse pregnancy outcomes are crucial to interpret results of clinical trials in Sub-Saharan Africa.We developed a mathematical model that calculates a clinical trial's expected number of neonatal and maternal deaths at an interim safety assessment based on the person-time observed during different risk windows. This model was compared to crude multiplication of the maternal mortality ratio and neonatal mortality rate by the number of live births. Systematic reviews of severe acute maternal morbidity (SAMM, low birth weight (LBW, prematurity, and major congenital malformations (MCM in Sub-Saharan African countries were also performed.Accounting for the person-time observed during different risk periods yields lower, more conservative estimates of expected maternal and neonatal deaths, particularly at an interim safety evaluation soon after a large number of deliveries. Median incidence of SAMM in 16 reports was 40.7 (IQR: 10.6-73.3 per 1,000 total births, and the most common causes were hemorrhage (34%, dystocia (22%, and severe hypertensive disorders of pregnancy (22%. Proportions of liveborn infants who were LBW (median 13.3%, IQR: 9.9-16.4 or premature (median 15.4%, IQR: 10.6-19.1 were similar across geographic region, study design, and institutional setting. The median incidence of MCM per 1,000 live births was 14.4 (IQR: 5.5-17.6, with the musculoskeletal system comprising 30%.Some clinical trials assessing whether maternal immunization can improve pregnancy and young infant outcomes in the developing world have made ethics-based decisions not to use a pure placebo control. Consequently, reliable background rates of adverse pregnancy outcomes are necessary to distinguish between vaccine benefits and safety concerns. Local studies that quantify population-based background rates of

  14. Large Aperture "Photon Bucket" Optical Receiver Performance in High Background Environments

    Science.gov (United States)

    Vilnrotter, Victor A.; Hoppe, D.

    2011-01-01

    The potential development of large aperture groundbased "photon bucket" optical receivers for deep space communications, with acceptable performance even when pointing close to the sun, is receiving considerable attention. Sunlight scattered by the atmosphere becomes significant at micron wavelengths when pointing to a few degrees from the sun, even with the narrowest bandwidth optical filters. In addition, high quality optical apertures in the 10-30 meter range are costly and difficult to build with accurate surfaces to ensure narrow fields-of-view (FOV). One approach currently under consideration is to polish the aluminum reflector panels of large 34-meter microwave antennas to high reflectance, and accept the relatively large FOV generated by state-of-the-art polished aluminum panels with rms surface accuracies on the order of a few microns, corresponding to several-hundred micro-radian FOV, hence generating centimeter-diameter focused spots at the Cassegrain focus of 34-meter antennas. Assuming pulse-position modulation (PPM) and Poisson-distributed photon-counting detection, a "polished panel" photon-bucket receiver with large FOV will collect hundreds of background photons per PPM slot, along with comparable signal photons due to its large aperture. It is demonstrated that communications performance in terms of PPM symbol-error probability in high-background high-signal environments depends more strongly on signal than on background photons, implying that large increases in background energy can be compensated by a disproportionally small increase in signal energy. This surprising result suggests that large optical apertures with relatively poor surface quality may nevertheless provide acceptable performance for deep-space optical communications, potentially enabling the construction of cost-effective hybrid RF/optical receivers in the future.

  15. Background Modelling in Very-High-Energy gamma-ray Astronomy

    CERN Document Server

    Berge, D; Hinton, J

    2007-01-01

    Ground based Cherenkov telescope systems measure astrophysical gamma-ray emission against a background of cosmic-ray induced air showers. The subtraction of this background is a major challenge for the extraction of spectra and morphology of gamma-ray sources. The unprecedented sensitivity of the new generation of ground based very-high-energy gamma-ray experiments such as H.E.S.S. has lead to the discovery of many previously unknown extended sources. The analysis of such sources requires a range of different background modelling techniques. Here we describe some of the techniques that have been applied to data from the H.E.S.S. instrument and compare their performance. Each background model is introduced and discussed in terms of suitability for image generation or spectral analysis and possible caveats are mentioned. We show that there is not a single multi-purpose model, different models are appropriate for different tasks. To keep systematic uncertainties under control it is important to apply several mod...

  16. High dose rate brachytherapy for oral cancer

    Science.gov (United States)

    YamazakI, Hideya; Yoshida, Ken; Yoshioka, Yasuo; Shimizutani, Kimishige; Furukawa, Souhei; Koizumi, Masahiko; Ogawa, Kazuhiko

    2013-01-01

    Brachytherapy results in better dose distribution compared with other treatments because of steep dose reduction in the surrounding normal tissues. Excellent local control rates and acceptable side effects have been demonstrated with brachytherapy as a sole treatment modality, a postoperative method, and a method of reirradiation. Low-dose-rate (LDR) brachytherapy has been employed worldwide for its superior outcome. With the advent of technology, high-dose-rate (HDR) brachytherapy has enabled health care providers to avoid radiation exposure. This therapy has been used for treating many types of cancer such as gynecological cancer, breast cancer, and prostate cancer. However, LDR and pulsed-dose-rate interstitial brachytherapies have been mainstays for head and neck cancer. HDR brachytherapy has not become widely used in the radiotherapy community for treating head and neck cancer because of lack of experience and biological concerns. On the other hand, because HDR brachytherapy is less time-consuming, treatment can occasionally be administered on an outpatient basis. For the convenience and safety of patients and medical staff, HDR brachytherapy should be explored. To enhance the role of this therapy in treatment of head and neck lesions, we have reviewed its outcomes with oral cancer, including Phase I/II to Phase III studies, evaluating this technique in terms of safety and efficacy. In particular, our studies have shown that superficial tumors can be treated using a non-invasive mold technique on an outpatient basis without adverse reactions. The next generation of image-guided brachytherapy using HDR has been discussed. In conclusion, although concrete evidence is yet to be produced with a sophisticated study in a reproducible manner, HDR brachytherapy remains an important option for treatment of oral cancer. PMID:23179377

  17. Performance of Drift-Tube Detectors at High Counting Rates for High-Luminosity LHC Upgrades

    CERN Document Server

    Bittner, Bernhard; Kortner, Oliver; Kroha, Hubert; Manfredini, Alessandro; Nowak, Sebastian; Ott, Sebastian; Richter, Robert; Schwegler, Philipp; Zanzi, Daniele; Biebel, Otmar; Hertenberger, Ralf; Ruschke, Alexander; Zibell, Andre

    2016-01-01

    The performance of pressurized drift-tube detectors at very high background rates has been studied at the Gamma Irradiation Facility (GIF) at CERN and in an intense 20 MeV proton beam at the Munich Van-der-Graaf tandem accelerator for applications in large-area precision muon tracking at high-luminosity upgrades of the Large Hadron Collider (LHC). The ATLAS muon drifttube (MDT) chambers with 30 mm tube diameter have been designed to cope with and neutron background hit rates of up to 500 Hz/square cm. Background rates of up to 14 kHz/square cm are expected at LHC upgrades. The test results with standard MDT readout electronics show that the reduction of the drift-tube diameter to 15 mm, while leaving the operating parameters unchanged, vastly increases the rate capability well beyond the requirements. The development of new small-diameter muon drift-tube (sMDT) chambers for LHC upgrades is completed. Further improvements of tracking e?ciency and spatial resolution at high counting rates will be achieved with ...

  18. High Rate Proton Irradiation of 15mm Muon Drifttubes

    CERN Document Server

    INSPIRE-00295941

    2012-01-01

    Future LHC luminosity upgrades will significantly increase the amount of background hits from photons, neutrons and protons in the detectors of the ATLAS muon spectrometer. At the proposed LHC peak luminosity of 5*10^34 1/cm^2s, background hit rates of more than 10 kHz/cm^2 are expected in the innermost forward region, leading to a loss of performance of the current tracking chambers. Based on the ATLAS Monitored Drift Tube chambers, a new high rate capable drift tube detecor using tubes with a reduced diameter of 15mm was developed. To test the response to highly ionizing particles, a prototype chamber of 46 15mm drift tubes was irradiated with a 20 MeV proton beam at the tandem accelerator at the Maier-Leibnitz Laboratory, Munich. Three tubes in a planar layer were irradiated while all other tubes were used for reconstruction of cosmic muon tracks through irradiated and non-irradiated parts of the chamber. To determine the rate capability of the 15mm drift-tubes we investigated the effect of the proton hit ...

  19. High readmission rates and mental distress after infective endocarditis

    DEFF Research Database (Denmark)

    Rasmussen, Trine Bernholdt; Zwisler, Ann-Dorthe; Thygesen, Lau Caspar

    2017-01-01

    BACKGROUND: Infective endocarditis (IE) is a severe disease requiring lengthy hospitalisation. Little is known about patients' recovery after IE. The aims of this study in IE patients were; (i) to describe mortality, readmission, self-reported health and rehabilitation up to 1year post-discharge,......-off score of 8. Almost half (47%) had not been offered cardiac rehabilitation (CR). CONCLUSIONS: After IE, mortality and readmission rates were high and self-reported physical and mental health poor. These findings call for changes in in-hospital and post-discharge management....... in a questionnaire survey (responders n=122). Responses were compared with those of a background reference population and a heart valve surgery population. Mortality and readmission data from registers 12months post-discharge were investigated. RESULTS: Patients discharged after treatment for IE had a mortality...

  20. High-energy, high-rate materials processing

    Science.gov (United States)

    Marcus, H. L.; Bourell, D. L.; Eliezer, Z.; Persad, C.; Weldon, W.

    1987-12-01

    The increasingly available range of pulsed-power, high energy kinetic storage devices, such as low-inductance pulse-forming networks, compulsators, and homopolar generators, is presently considered as a basis for industrial high energy/high rate (HEHR) processing to accomplish shock hardening, drilling, rapid surface alloying and melting, welding and cutting, transformation hardening, and cladding and surface melting in metallic materials. Time-temperature-transformation concepts furnish the basis for a fundamental understanding of the potential advantages of this direct pulsed power processing. Attention is given to the HEHR processing of a refractory molybdenum alloy, a nickel-base metallic glass, tungsten, titanium aluminides, and metal-matrix composites.

  1. Molecular beam sampling system with very high beam-to-background ratio: The rotating skimmer concept

    Science.gov (United States)

    Benedikt, J.; Ellerweg, D.; von Keudell, A.

    2009-05-01

    A novel method of reducing the background pressure in a vacuum system used for sampling a molecular beam from a high pressure region is presented. A triple differential pumping stage is constructed with a chopper with rotating skimmer within the first pumping stage, which serves effectively as a valve separating periodically the vacuum system from the ambient environment. The mass spectrometry measurement of the species in the molecular beam show an excellent beam-to-background ratio of 14 and a detection limit below 1 ppm. The potential of this method for detection of low density reactive species in atmospheric pressure plasmas is demonstrated for the detection of oxygen atoms generated in an atmospheric pressure microplasma source.

  2. THE HIGH BACKGROUND RADIATION AREA IN RAMSAR IRAN: GEOLOGY, NORM, BIOLOGY, LNT, AND POSSIBLE REGULATORY FUN

    Energy Technology Data Exchange (ETDEWEB)

    Karam, P. A.

    2002-02-25

    The city of Ramsar Iran hosts some of the highest natural radiation levels on earth, and over 2000 people are exposed to radiation doses ranging from 1 to 26 rem per year. Curiously, inhabitants of this region seem to have no greater incidence of cancer than those in neighboring areas of normal background radiation levels, and preliminary studies suggest their blood cells experience fewer induced chromosomal abnormalities when exposed to 150 rem ''challenge'' doses of radiation than do the blood cells of their neighbors. This paper will briefly describe the unique geology that gives Ramsar its extraordinarily high background radiation levels. It will then summarize the studies performed to date and will conclude by suggesting ways to incorporate these findings (if they are borne out by further testing) into future radiation protection standards.

  3. Operation of high rate microstrip gas chambers

    CERN Document Server

    Barr, A J; Bouclier, Roger; Capéans-Garrido, M; Dominik, Wojciech; Manzin, G; Million, Gilbert; Hoch, M; Ropelewski, Leszek; Sauli, Fabio; Sharma, A

    1996-01-01

    We describe recent measurements carried out in well controlled and reproducible conditions to help understanding the factors affecting the short and long term behaviour of Microstrip Gas Chambers. Special care has been taken concerning the gas purity and choice of materials used in the system and for the detectors construction. Detectors built on glasses with surface resistivity in the range $10^{13}-10^{15} \\Omega/\\Box$ have shown satisfactory performance as they do not show charging-up process at high rate and stand the large doses required for the future high luminosity experiments (~10 mC·cm-1·yr-1). Concerning the lifetime measurements, it has been observed that chambers manufactured on high-resistivity glass are far more susceptible of suffering ageing than detectors made on low resistivity, electron-conducting supports, independently of the metal used for the artwork (chromium or gold) at least in clean gas conditions. The successfully operation in the laboratory of detectors manufactured on diamond-...

  4. The effects of residence duration in high background radiation areas on immune surveillance.

    Science.gov (United States)

    Borzoueisileh, Sajad; Monfared, Ali Shabestani; Abediankenari, Saeid; Mostafazadeh, Amrollah; Khosravifarsani, Meysam

    2013-01-01

    The effective dose received by humans from natural sources is about 2.4 mSv y(-1), but this is 10.2 mSv y(-1) for inhabitants of Ramsar, a city in northern Iran. Carcinogenesis is one of the most studied effects of radiation, especially in high doses. Nonetheless carcinogenesis of low doses is uncertain. A recent epidemiological study in high background radiation areas of Ramsar showed that the cancer incidence in this era is lower than neighbors. The reason of this different behavior is under study yet. NK cells, helper, and Cytotoxic T cells are most important components of the tumor immune surveillance. The counts and activities of these cells and also leukocytes, lymphocyte, neutrophil cells, and other important parameters were studied in the residents of Ramsar with different duration of exposure to chronic low dose radiation. Fifty residents of high background radiation areas, who were between 25 and 35 years and fully healthy, were selected randomly and their consent was obtained. Then, 2 cc fresh peripheral bloods were taken in sterile conditions. Complete blood cell counts were performed by an automatic hematology analyzer and CD4+, CD8+, NK, and CD107a+ cell counts were determined by monoclonal antibodies and flowcytometry. CD4+ and CD8+ percentages and the CD4/CD8 ratio were determined and the data were analyzed using SPSS 16. The percentages of CD4+ cells increase, but the counts of CD107a+ cells decline in higher exposure durations. The other parameters did not have significant regression with exposure duration. These confirm that living in high background radiation areas may induce changes in the immune system gradually and address more investigations.

  5. Effects of oxytocin on background anxiety in rats with high or low baseline startle.

    Science.gov (United States)

    Ayers, Luke; Agostini, Andrew; Schulkin, Jay; Rosen, Jeffrey B

    2016-06-01

    Oxytocin has antianxiety properties in humans and rodents. However, the antianxiety effects have been variable. To reduce variability and to strengthen the antianxiety effect of oxytocin in fear-potentiated startle, two experiments were performed. First, different amounts of light-shock pairings were given to determine the optimal levels of cue-specific fear conditioning and non-predictable startle (background anxiety). Second, the antianxiety effects of oxytocin were examined in rats with high and low pre-fear conditioning baseline startle to determine if oxytocin differentially affects high and low trait anxiety rats. Baseline pre-fear conditioning startle responses were first measured. Rats then received 1, 5, or 10 light-shock pairings. Fear-potentiated startle was then tested with two trial types: light-cued startle and non-cued startle trials. In the second experiment, rats fear conditioned with 10 light-shock pairings were administered either saline or oxytocin before a fear-potentiated startle test. Rats were categorized as low or high startlers by their pre-fear conditioning startle amplitude. Ten shock pairings produced the largest non-cued startle responses (background anxiety), without increasing cue-specific fear-potentiated startle compared to one and five light-shock pairings. Cue-specific fear-potentiated startle was unaffected by oxytocin. Oxytocin reduced background anxiety only in rats with low pre-fear startle responses. Oxytocin has population selective antianxiety effects on non-cued unpredictable threat, but only in rats with low pre-fear baseline startle responses. The low startle responses are reminiscent of humans with low startle responses and high trait anxiety.

  6. High-Dose-Rate Brachytherapy for the Treatment of Recalcitrant Keloids: A Unique, Effective Treatment Protocol

    NARCIS (Netherlands)

    van Leeuwen, M.C.E.; Stokmans, S.C.; Bulstra, A.E.J.; Meijer, O.W.M.; van Leeuwen, P.A.M.; Niessen, F.B.

    2014-01-01

    BACKGROUND:: Keloids cause aesthetic disfigurement and physical complaints, mainly pain and pruritus. Treatment of these scars is difficult, with high recurrence rates forming the main issue. Surgical excision with adjuvant radiotherapy is considered the most efficacious treatment. At their

  7. Upgrade Strategy for ALICE at High Rate

    CERN Document Server

    Musa, L

    2012-01-01

    The longterm goal of the ALICE experiment is to provide a precise characterization of the Quark-Gluon Plasma (QGP) state. Such a determination of its properties including initial temperature, degrees of freedom, speed of sound, and in general, transport coefficients would be a major achievement. This would go a long way towards a better understanding of QCD as a genuine multi-particle theory. To achieve this goal, high statistics measurements are required, which will give access also to the very rare physics channels needed to understand the dynamics of this condensed phase of QCD. The general upgrade strategy for the ALICE central barrel is conceived to deal with this challenge with expected Pb-Pb interaction rates of up to 50 kHz, that would provide an accumulated sample of the order of 10 nb^-1 in the period 2019-2023. In this document we sketch the modifications/replacements needed in all ALICE central barrel detectors and online systems (Trigger, DAQ and HLT) for high luminosity running. As the ALICE for...

  8. Socioeconomic background and high school completion: Mediation by health and moderation by national context.

    Science.gov (United States)

    Sznitman, Sharon R; Reisel, Liza; Khurana, Atika

    2017-04-01

    This study uses longitudinal data from the Norwegian Health Study linked with registry data (n = 13262) and the U.S. National Longitudinal Survey of Youth 1997 (n = 3604) to examine (1) whether adolescent health mediates the well-established relationship between socioeconomic background and successful high school completion, and (2) whether this mediated pathway of influence varies by national context. Adolescents from lower educated and lower income families reported poorer health, which negatively impacted their likelihood of graduating from high school. The partial mediational effect of adolescent health was stronger in the U.S. than in Norway. These results suggest that policies aimed at preventing high school dropout need to address adolescent health, in addition to the unequal opportunities derived from socioeconomic disadvantage. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. High Data Rate Architecture (HiDRA)

    Science.gov (United States)

    Hylton, Alan; Raible, Daniel

    2016-01-01

    high-rate laser terminals. These must interface with the existing, aging data infrastructure. The High Data Rate Architecture (HiDRA) project is designed to provide networked store, carry, and forward capability to optimize data flow through both the existing radio frequency (RF) and new laser communications terminal. The networking capability is realized through the Delay Tolerant Networking (DTN) protocol, and is used for scheduling data movement as well as optimizing the performance of existing RF channels. HiDRA is realized as a distributed FPGA memory and interface controller that is itself controlled by a local computer running DTN software. Thus HiDRA is applicable to other arenas seeking to employ next-generation communications technologies, e.g. deep space. In this paper, we describe HiDRA and its far-reaching research implications.

  10. Adaptive response of blood lymphocytes of inhabitants residing in high background radiation areas of ramsar- micronuclei, apoptosis and comet assays.

    Science.gov (United States)

    Mohammadi, Shahla; Taghavi-Dehaghani, Mahnaz; Gharaati, Mohammad R; Masoomi, Reza; Ghiassi-Nejad, Mehdi

    2006-11-01

    The hot springs in certain areas of Ramsar contain (226)Ra and (222)Rn. The effects of natural radiation on the inhabitants of these areas and the inhabitant's radiosensitivity or adaptive responses were studied. One group of volunteers from areas with high natural background radiation and another group from areas with normal background radiation were chosen as the case and control group respectively. The frequency of micronuclei, apoptosis, and DNA damage in peripheral blood mononuclear cells were measured following gamma irradiation (4 Gy). The incidence of micronuclei in the case group was significantly lower than that in the control group while their frequency of apoptosis was higher (P < 0.05). However, the rates of induced DNA damage and repair were significantly higher in the case group (P < 0.05). Smaller number of micronuclei and higher levels of apoptosis in the case group could be the result of higher resistance to radiation stress and a more rigorous checkpoint at cell division. However, regarding the alkaline labile sites, the individuals in the case group are more sensitive and susceptible to DNA damage. The results of micronuclei, apoptosis and repair studies suggest that an adaptive response might be induced in people residing in areas with high background radiation.

  11. Photocathodes for High Repetition Rate Light Sources

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Zvi, Ilan [Stony Brook Univ., NY (United States). Dept. of Physics and Astronomy. Center for Accelerator Science and Education

    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). Below details the Principal Investigators and contact information. Each PI submits separately for a budget through his corresponding institute. 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 (BNL – LBNL) b) Development and testing of a diamond amplifier for photocathodes (SBU -­ BNL) c) Tests of both cathodes in superconducting RF photoguns (SBU) and copper RF photoguns (LBNL) Our work made extensive use of synchrotron radiation materials science techniques, such as powder-­ and single-­crystal diffraction, x-­ray fluorescence, EXAFS and variable energy XPS. BNL and LBNL have many complementary facilities at the two light sources associated with these laboratories (NSLS and ALS, respectively); use of these will be a major thrust of our program and bring our understanding of these complex materials to a new level. In addition, CHESS at Cornell will be used to continue seamlessly throughout the NSLS dark period and

  12. Correlation Among Students’ Family Background, Academic Performance in Junior High School, and Senior High School Tracking in Taiwan

    Directory of Open Access Journals (Sweden)

    Ming-Fu Huang

    2014-12-01

    Full Text Available There were numerous previous studies on educational tracking. However, most of the data adopted in these studies were collected a decade ago, involving sample population 20-64 years of age. Among them, many elderly samples had undergone senior high school tracking in the early years. The present study used the data of students and parents from the 3rd wave (2005 of the Taiwan Education Panel Survey (TEPS. A path analysis was conducted to investigate the inequality of opportunities involved in the influence of student family background on educational tracking at the senior high school stage. The results show: although the overall percentage of junior high school graduates entering advanced levels was approximately 100% and almost all students of different family backgrounds entered advanced levels, the most crucial factor among those affecting educational tracking of senior high school stage was students’ academic performance during junior high school. Students with higher family socioeconomic status and fewer siblings showed better academic performance in junior high schools, and consequently had higher possibilities of entering public senior high schools leading to a more promising future. This indicates that though the inequality in the quantity of opportunities approached 0, the inequality in the quality of opportunities still remained, which fails to support the hypothesis of the maximally maintained inequality of educational opportunity (MMI; however, the result supports the hypothesis of the effectively maintained inequality of educational opportunity (EMI.

  13. Systematic Uncertainties in High-Rate Germanium Data

    Energy Technology Data Exchange (ETDEWEB)

    Gilbert, Andrew J.; Fast, James E.; Fulsom, Bryan G.; Pitts, William K.; VanDevender, Brent A.; Wood, Lynn S.

    2016-10-06

    For many nuclear material safeguards inspections, spectroscopic gamma detectors are required which can achieve high event rates (in excess of 10^6 s^-1) while maintaining very good energy resolution for discrimination of neighboring gamma signatures in complex backgrounds. Such spectra can be useful for non-destructive assay (NDA) of spent nuclear fuel with long cooling times, which contains many potentially useful low-rate gamma lines, e.g., Cs-134, in the presence of a few dominating gamma lines, such as Cs-137. Detectors in use typically sacrifice energy resolution for count rate, e.g., LaBr3, or visa versa, e.g., CdZnTe. In contrast, we anticipate that beginning with a detector with high energy resolution, e.g., high-purity germanium (HPGe), and adapting the data acquisition for high throughput will be able to achieve the goals of the ideal detector. In this work, we present quantification of Cs-134 and Cs-137 activities, useful for fuel burn-up quantification, in fuel that has been cooling for 22.3 years. A segmented, planar HPGe detector is used for this inspection, which has been adapted for a high-rate throughput in excess of 500k counts/s. Using a very-high-statistic spectrum of 2.4*10^11 counts, isotope activities can be determined with very low statistical uncertainty. However, it is determined that systematic uncertainties dominate in such a data set, e.g., the uncertainty in the pulse line shape. This spectrum offers a unique opportunity to quantify this uncertainty and subsequently determine required counting times for given precision on values of interest.

  14. Evaluation of High Level Environmental Background Radiation Areas and its Variation in Ramsar

    Directory of Open Access Journals (Sweden)

    Tayyeb Allahverdi Pourfallah

    2012-03-01

    Full Text Available Introduction The exposure of human beings to ionizing radiation from natural sources is a continuing and inescapable feature of life on earth. For most individuals, this exposure exceeds that from all man-made sources combined. Materials and Methods In this study, the annual effective dose in high level environmental background radiation areas (HLEBRAs of northern city of Ramsar in Iran was determined. For dosimetry, a gamma radiation dosimeter was used. Measurements were performed in more than 90 points in five districts with HLEBR around and near hot springs. Results In some areas, the annual effective dose from outdoor external gamma radiation in HLEBRAs (30 mSv/y exceeded the annual effective dose limit for radiation workers. Our results are evident that the population dose from normal background radiation in HLEBRAs is 200 times higher than corresponding values in Ramsar sea shore. To estimate the cosmic ray contribution, dose measurements were performed on the sea surface one km off the sea shore. Conclusion The observed differences over locations and measured doses between this study and the others revealed the dynamic nature of this phenomenon, and necessitate performing the periodic studies in these areas. Moreover, cytogenetic and immunologic researches for studying the long term effects of these high level environmental radiations on the residents of these HLEBRAs are necessary.

  15. Anderson localization in high temperature QCD: background configuration properties and Dirac eigenmodes

    Science.gov (United States)

    Cossu, Guido; Hashimoto, Shoji

    2016-06-01

    We investigate the properties of the background gauge field configurations that act as disorder for the Anderson localization mechanism in the Dirac spectrum of QCD at high temperatures. We compute the eigenmodes of the Möbius domain-wall fermion operator on configurations generated for the SU(3) gauge theory with two flavors of fermions, in the temperature range [0.9, 1.9]T c . We identify the source of localization of the eigenmodes with gauge configurations that are self-dual and support negative fluctuations of the Polyakov loop P L , in the high temperature sea of P L ˜ 1. The dependence of these observations on the boundary conditions of the valence operator is studied. We also investigate the spatial overlap of the left-handed and right-handed projected eigenmodes in correlation with the localization and the corresponding eigenvalue. We discuss an interpretation of the results in terms of monopole-instanton structures.

  16. A readout unit for high rate applications

    CERN Document Server

    Toledo, J; Domínguez, D; Guirao-Elias, A; Müller, H

    2002-01-01

    The LHCb readout unit (RU) is a custom entry stage to the readout network of a data-acquisition or trigger system. It performs subevent building from multiple link inputs toward a readout network via a PCI network interface or alternatively toward a high-speed link, via an S-link interface. Incoming event fragments are derandomized, buffered and assembled into single subevents. This process is based on a low- overhead framing convention and matching of equal event numbers. Programmable logic is used both in the input and output stages of the RU module, which may be configured either as a data-link multiplexer or as entry stage to a readout or trigger network. All FPGAs are interconnected via the PCI bus, which is hosted by a networked microprocessor card. Its main tasks are remote FPGA configuration and initialization of the PCI cards. The RU hardware architecture has been optimized for a throughput of up to 200 MB/s at a 1 MHz trigger rate, as required by the most demanding application, the LHCb level-1 trig...

  17. A high hypospadias rate in The Netherlands

    NARCIS (Netherlands)

    F.H. Pierik (Frank); A. Burdorf (Alex); R.J.M. Nijman (Rien); S.M.P.F. de Muinck Keizer-Schrama (Sabine); R.E. Juttmann (Rikard); R.F.A. Weber (Robert)

    2002-01-01

    textabstractBACKGROUND: Reports on increasing hypospadias trends are based on birth defect registries, which are prone to inaccuracy. We assessed the prevalence of hypospadias precisely, by prospective examination of all newborns in Rotterdam over a 2-year period. METHODS: A total

  18. High voltage high repetition rate pulse using Marx topology

    Science.gov (United States)

    Hakki, A.; Kashapov, N.

    2015-06-01

    The paper describes Marx topology using MOSFET transistors. Marx circuit with 10 stages has been done, to obtain pulses about 5.5KV amplitude, and the width of the pulses was about 30μsec with a high repetition rate (PPS > 100), Vdc = 535VDC is the input voltage for supplying the Marx circuit. Two Ferrite ring core transformers were used to control the MOSFET transistors of the Marx circuit (the first transformer to control the charging MOSFET transistors, the second transformer to control the discharging MOSFET transistors).

  19. High mitogenomic evolutionary rates and time dependency.

    NARCIS (Netherlands)

    Subramanian, S.; Denver, D.R.; Millar, C.D.; Heupink, T.; Aschrafi, A.; Emslie, S.D.; Baroni, C.; Lambert, D.M.

    2009-01-01

    Using entire modern and ancient mitochondrial genomes of Adelie penguins (Pygoscelis adeliae) that are up to 44000 years old, we show that the rates of evolution of the mitochondrial genome are two to six times greater than those estimated from phylogenetic comparisons. Although the rate of

  20. Characterization of a high-temperature superconducting bearing for use in a cosmic microwave background polarimeter

    Energy Technology Data Exchange (ETDEWEB)

    Hull, John R [Energy Technology Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Hanany, Shaul [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States); Matsumura, Tomotake [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States); Johnson, Bradley [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States); Jones, Terry [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)

    2005-02-01

    We have previously presented a design for a cosmic microwave background (CMB) polarimeter in which a cryogenically cooled half-wave plate rotates by means of a high-temperature superconducting (HTS) bearing. Here, a prototype bearing, consisting of a commercially available ring-shaped permanent magnet and an array of YBCO bulk HTS material, has been constructed. We measured its coefficient of friction and vibrational property as a function of several parameters, including temperature between 15 and 83 K, rotation frequency between 0.3 and 3.5 Hz, levitation distance between 6 and 10 mm and ambient pressure of {approx}10{sup -7} Torr. We concluded that the low rotational drag of the HTS bearing would allow rotations for long periods with minimal input power and negligible wear and tear, thus making this technology suitable for a future satellite mission.

  1. Perception of the Religion in High School Philosophy Curriculum and the IdeologicalBackground

    Directory of Open Access Journals (Sweden)

    Osman Zahid ÇİFÇİ

    2015-12-01

    Full Text Available A top title under which republic, education, philosophy and religion are used together must be interesting for people who are interested in the issue as key concepts in explaining the course of contemporary thought in Turkey. Yet, this study doesn‘t focus on debates among materialist or idealist movements appearing during Tanzimat Period, or on the issue of how religion or metaphysical problems are discussed in high-school coursebooks of philosophy. This study aims only at directing attentions over the curriculum in outline. Moreover, it, at least, brings forward the discussion of the large body of knowledge centralising the problem of religion in teaching philosophy. It also aims at detecting the ideological background responsible for the composition of the curriculum. Attracting attentions on the curriculum will of course provoke the minds towards interesting issues implied by concepts such as westernisation, republic, metaphysics, religion, and philosophy.

  2. High Data Rate Optical Wireless Communications Based on Ultraviolet Band

    KAUST Repository

    Sun, Xiaobin

    2017-10-01

    Optical wireless communication systems based on ultraviolet (UV)-band has a lot inherent advantages, such as low background solar radiation, low device dark noise. Besides, it also has small restrictive requirements for PAT (pointing, acquisition, and tracking) because of its high atmospheric scattering with molecules and aerosols. And these advantages are driving people to explore and utilize UV band for constructing and implementing a high-data-rate, less PAT communication links, such as diffuse-line-of-sight links (diffuse-LOS) and non-line-of-sight (NLOS). The responsivity of the photodetector at UV range is far lower than that of visible range, high power UV transmitters which can be easily modulated are under investigation. These factors make it is hard to realize a high-data-rate diffuse-LOS or NLOS UV communication links. To achieve a UV link mentioned above with current devices and modulation schemes, this thesis presents some efficient modulation schemes and available devices for the time being. Besides, a demonstration of ultraviolet-B (UVB) communication link is implemented utilizing quadrature amplitude modulation (QAM) orthogonal frequency-division multiplexing (OFDM). The demonstration is based on a 294-nm UVB-light-emitting-diode (UVB-LED) with a full-width at half-maximum (FWHM) of 9 nm, and according to the measured L-I-V curve, we set the bias voltage as 7V for maximum the ac amplitude and thus get a high signal-noise-ratio (SNR) channel, and the light output power is 190 μW with such bias voltage. Besides, there is a unique silica gel lens on top of the LED to concentrate the beam. A -3-dB bandwidth of 29 MHz was measured and a high-speed near-solar-blind communication link with a data rate of 71 Mbit/s was achieved using 8-QAM-OFDM at perfect alignment, and 23.6 Mbit/s using 2-QAM-OFDM when the angle subtended by the pointing direction of the UVB-LED and photodetector (PD) is 12 degrees, thus establishing a diffuse-line-of-sight (LOS) link

  3. High background radiation areas of Ramsar in Iran: evaluation of DNA damage by alkaline single cell gel electrophoresis (SCGE).

    Science.gov (United States)

    Masoomi, J R; Mohammadi, Sh; Amini, M; Ghiassi-Nejad, M

    2006-01-01

    The hot springs in special areas in Ramsar, a northern coastal town in Iran, contain (226)Ra and (222)Rn. The natural radiation effects, radiosensitivity or adaptive responses, on the inhabitants of high natural radiation in Ramsar were studied. The single cell gel electrophoresis was used to monitor DNA damages. Three groups of volunteers were selected, one from high natural background radiation areas as the case group and two from normal background radiation areas as controls (control 1 and control 2). The latter one had the similar living situation to case group while the other (control 2) had different living situation from the other groups. Peripheral blood mononuclear cells (PMNCs) were separated and irradiated by (60)Co source at five different gamma doses. It was found that the spontaneous level of DNA damage and the induced DNA damage in all challenging doses in case group was considerably higher than control groups (p < 0.05). On the other hand, the repair rate in those volunteers, who received less than 10.2 mSv/y was significantly more than the control groups. In the contrary, individuals who live in homes with more than 10.2 mSv/y had incomplete repair. Additionally the plasma and urinary levels of vitamin C were measured spectrophotometrically. Although the concentration of vitamin C of plasma was equal in case and control 1 groups, the urinary level of vitamin C was found to be lower in the case group.

  4. Fermi-LAT high-z active galactic nuclei and the extragalactic background light

    Science.gov (United States)

    Armstrong, Thomas; Brown, Anthony M.; Chadwick, Paula M.

    2017-10-01

    Observations of distant gamma-ray sources are hindered by the presence of the extragalactic background light (EBL). In order to understand the physical processes that result in the observed spectrum of sources, it is imperative that a good understanding of the EBL is included. In this work, an investigation into the imprint of the EBL on the observed spectra of high-redshift Fermi-LAT active galactic nuclei is presented. By fitting the spectrum below ˜10 GeV, an estimation of the unabsorbed intrinsic source spectrum is obtained; by applying this spectrum to data up to 300 GeV, it is then possible to derive a scaling factor for different EBL models. A second approach uses five sources (PKS 0426-380, 4C +55.17, Ton 116, PG 1246+586 and RBS 1432) that were found to exhibit very high energy (VHE) emission (Eγ > 100 GeV). Through Monte Carlo simulations, it is shown that the observation of VHE photons, despite the large distances of these objects, is consistent with current EBL models. Many of these sources would be observable with the upcoming ground-based observatory, the Cherenkov Telescope Array, leading to a better understanding of the EBL.

  5. Anderson localization in high temperature QCD: background configuration properties and Dirac eigenmodes

    Energy Technology Data Exchange (ETDEWEB)

    Cossu, Guido [Theory Center, IPNS, High Energy Accelerator Research Organization (KEK),1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Hashimoto, Shoji [Theory Center, IPNS, High Energy Accelerator Research Organization (KEK),1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); School of High Energy Accelerator Science,The Graduate University for Advanced Studies (Sokendai),1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan)

    2016-06-09

    We investigate the properties of the background gauge field configurations that act as disorder for the Anderson localization mechanism in the Dirac spectrum of QCD at high temperatures. We compute the eigenmodes of the Möbius domain-wall fermion operator on configurations generated for the SU(3) gauge theory with two flavors of fermions, in the temperature range [0.9,1.9]T{sub c}. We identify the source of localization of the eigenmodes with gauge configurations that are self-dual and support negative fluctuations of the Polyakov loop P{sub L}, in the high temperature sea of P{sub L}∼1. The dependence of these observations on the boundary conditions of the valence operator is studied. We also investigate the spatial overlap of the left-handed and right-handed projected eigenmodes in correlation with the localization and the corresponding eigenvalue. We discuss an interpretation of the results in terms of monopole-instanton structures.

  6. A Fluorogenic TMP-tag for High Signal-to-Background Intracellular Live Cell Imaging

    Science.gov (United States)

    Jing, Chaoran

    2013-01-01

    Developed to compliment the use of fluorescent proteins in live cell imaging, chemical tags enjoy the benefit of modular incorporation of organic fluorophores, opening the possibility of high photon output and special photophysical properties. However, the theoretical challenge in using chemical tags as opposed to fluorescent proteins for high-resolution imaging is background noise from unbound and/or non-specifically bound ligand-fluorophore. We envisioned we could overcome this limit by engineering fluorogenic trimethoprim-based chemical tags (TMP-tags) in which the fluorophore is quenched until binding with E. coli dihydrofolate reductase (eDHFR) tagged protein displaces the quencher. Thus, we began by building a non-fluorogenic, covalent TMP-tag based on a proximity-induced reaction known to achieve rapid and specific labeling both in vitro and inside of living cells. Here we take the final step and render the covalent TMP-tag fluorogenic. In brief, we designed a trimeric TMP-fluorophore-quencher molecule (TMP-Q-Atto520) with the quencher attached to a leaving group that, upon TMP binding to eDHFR, would be cleaved by a cysteine residue (Cys) installed just outside the binding pocket of eDHFR. We present the in vitro experiments showing that the eDHFR:L28C nucleophile cleaves the TMP-Q-Atto520 rapidly and efficiently, resulting in covalent labeling and remarkable fluorescence enhancement. Most significantly, while only our initial design, TMP-Q-Atto520 achieved the demanding goal of not only labeling highly abundant, localized intracellular proteins, but also less abundant, more dynamic cytoplasmic proteins. These results suggest that fluorogenic TMP-tag can significantly impact highresolution live cell imaging and further establish the potential of proximity-induced reactivity and organic chemistry more broadly as part of the growing toolbox for synthetic biology and cell engineering. PMID:23745575

  7. Gamma-ray Background Spectrum and Annihilation Rate in the Baryon-symmetric Big-bang Cosmology

    Science.gov (United States)

    Puget, J. L.

    1973-01-01

    An attempt was made to acquire experimental information on the problem of baryon symmetry on a large cosmological scale by observing the annihilation products. Data cover absorption cross sections and background radiation due to other sources for the two main products of annihilation, gamma rays and neutrinos. Test results show that the best direct experimental test for the presence of large scale antimatter lies in the gamma ray background spectrum between 1 and 70 MeV.

  8. The Impact of Background Radio and Television on High School Students' Homework Performance.

    Science.gov (United States)

    Pool, Marina M.; Koolstra, Cees M.; van der Voort, Tom H. A.

    2003-01-01

    Examines the impact of background media on Dutch students' performance and time spent on paper-and-pencil and memorization homework assignments. Notes that doing homework combined with watching a soap opera interfered with students' performance on both types of assignments. Indicates that music in the background left homework performance…

  9. Career Choices: Linguistic and Educational Socialization of Sudanese-Background High-School Students in Australia

    Science.gov (United States)

    Hatoss, Aniko; O'Neill, Shirley; Eacersall, Douglas

    2012-01-01

    This research investigated the linguistic and educational socialization of Sudanese refugee-background youth in Australia. The study focussed on exploring Sudanese-background secondary school students' career aspirations, motivations and obstacles. The research used a mixed-method approach including a survey conducted with students studying in six…

  10. High pulse number thermal shock tests on tungsten with steady state particle background

    Science.gov (United States)

    Wirtz, M.; Kreter, A.; Linke, J.; Loewenhoff, Th; Pintsuk, G.; Sergienko, G.; Steudel, I.; Unterberg, B.; Wessel, E.

    2017-12-01

    Thermal fatigue of metallic materials, which will be exposed to severe environmental conditions e.g. plasma facing materials in future fusion reactors, is an important issue in order to predict the life time of complete wall components. Therefore experiments in the linear plasma device PSI-2 were performed to investigate the synergistic effects of high pulse number thermal shock events (L = 0.38 GW m‑2, Δt = 0.5 ms) and stationary D/He (6%) plasma particle background on the thermal fatigue behavior of tungsten. Similar to experiments with pure thermal loads, the induced microstructural and surface modifications such as recrystallization and roughening as well as crack formation become more pronounced with increasing number of thermal shock events. However, the amount of damage significantly increases for synergistic loads showing severe surface roughening, plastic deformation and erosion resulting from the degradation of the mechanical properties caused by bombardment and diffusion of D/He to the surface and the bulk of the material. Additionally, D/He induced blistering and bubble formation were observed for all tested samples, which could change the thermal and mechanical properties of near surface regions.

  11. A Flat Universe from High-Resolution Maps of the Cosmic MicrowaveBackground Radiation

    Energy Technology Data Exchange (ETDEWEB)

    de Bernardis, P.; Ade, P.A.R.; Bock, J.J.; Bond, J.R.; Borrill,J.; Boscaleri, A.; Coble, K.; Crill, B.P.; De Gasperis, G.; Farese, P.C.; Ferreira, P.G.; Ganga, K.; Giacometti, M.; Hivon, E.; Hristov, V.V.; Iacoangeli, A.; Jaffe, A.H.; Lange, A.E.; Martinis, L.; Masi, S.; Mason,P.; Mauskopf, P.D.; Melchiorri, A.; Miglio, L.; Montroy, T.; Netterfield,C.B.; Pascale, E.; Piacentini, F.; Pogosyan, D.; Prunet, S.; Rao, S.; Romeo, G.; Ruhl, J.E.; Scaramuzzi, F.; Sforna, D.; Vittorio, N.

    2000-04-28

    The blackbody radiation left over from the Big Bang has been transformed by the expansion of the Universe into the nearly isotropic 2.73 K Cosmic Microwave Background. Tiny inhomogeneities in the early Universe left their imprint on the microwave background in the form of small anisotropies in its temperature. These anisotropies contain information about basic cosmological parameters, particularly the total energy density and curvature of the universe. Here we report the first images of resolved structure in the microwave background anisotropies over a significant part of the sky. Maps at four frequencies clearly distinguish the microwave background from foreground emission. We compute the angular power spectrum of the microwave background, and find a peak at Legendre multipole {ell}{sub peak} = (197 {+-} 6), with an amplitude DT{sub 200} = (69 {+-} 8){mu}K. This is consistent with that expected for cold dark matter models in a flat (euclidean) Universe, as favored by standard inflationary scenarios.

  12. Ultra high vacuum high precision low background setup with temperature control for thermal desorption mass spectroscopy (TDA-MS) of hydrogen in metals.

    Science.gov (United States)

    Merzlikin, Sergiy V; Borodin, S; Vogel, D; Rohwerder, M

    2015-05-01

    In this work, a newly developed UHV-based high precision low background setup for hydrogen thermal desorption analysis (TDA) of metallic samples is presented. Using an infrared heating with a low thermal capacity enables a precise control of the temperature and rapid cool down of the measurement chamber. This novel TDA-set up is superior in sensitivity to almost every standard hydrogen analyzer available commercially due to the special design of the measurement chamber, resulting in a very low hydrogen background. No effects of background drift characteristic as for carrier gas based TDA instruments were observed, ensuring linearity and reproducibility of the analysis. This setup will prove to be valuable for detailed investigations of hydrogen trapping sites in steels and other alloys. With a determined limit of detection of 5.9×10(-3)µg g(-1) hydrogen the developed instrument is able to determine extremely low hydrogen amounts even at very low hydrogen desorption rates. This work clearly demonstrates the great potential of ultra-high vacuum thermal desorption mass spectroscopy instrumentation. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Human exposure to high natural background radiation: what can it teach us about radiation risks?

    Energy Technology Data Exchange (ETDEWEB)

    Hendry, Jolyon H; Sohrabi, Mehdi; Burkart, Werner [Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Vienna (Austria); Simon, Steven L [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD (United States); Wojcik, Andrzej [Institute of Nuclear Chemistry and Technology, Warsaw (Poland); Cardis, Elisabeth [Centre for Research in Environmental Epidemiology (CREAL), Municipal Institute of Medical Research (IMIM-Hospital del Mar) and CIBER Epidemiologia y Salud Publica - CIBERESP, Barcelona (Spain); Laurier, Dominique; Tirmarche, Margot [Radiobiology and Epidemiology Department, Radiological and Human Health Division, Institute for Radiological Protection and Nuclear Safety, Fontenay-aux-Roses (France); Hayata, Isamu [National Institute of Radiological Sciences, Chiba (Japan)], E-mail: jhendry2002uk@yahoo.com

    2009-06-01

    Natural radiation is the major source of human exposure to ionising radiation, and its largest contributing component to effective dose arises from inhalation of {sup 222}Rn and its radioactive progeny. However, despite extensive knowledge of radiation risks gained through epidemiologic investigations and mechanistic considerations, the health effects of chronic low-level radiation exposure are still poorly understood. The present paper reviews the possible contribution of studies of populations living in high natural background radiation (HNBR) areas (Guarapari, Brazil; Kerala, India; Ramsar, Iran; Yangjiang, China), including radon-prone areas, to low dose risk estimation. Much of the direct information about risk related to HNBR comes from case-control studies of radon and lung cancer, which provide convincing evidence of an association between long-term protracted radiation exposures in the general population and disease incidence. The success of these studies is mainly due to the careful organ dose reconstruction (with relatively high doses to the lung), and to the fact that large-scale collaborative studies have been conducted to maximise the statistical power and to ensure the systematic collection of information on potential confounding factors. In contrast, studies in other (non-radon) HNBR areas have provided little information, relying mainly on ecological designs and very rough effective dose categorisations. Recent steps taken in China and India to establish cohorts for follow-up and to conduct nested case-control studies may provide useful information about risks in the future, provided that careful organ dose reconstruction is possible and information is collected on potential confounding factors.

  14. Human exposure to high natural background radiation: what can it teach us about radiation risks?

    Science.gov (United States)

    Hendry, Jolyon H; Simon, Steven L; Wojcik, Andrzej; Sohrabi, Mehdi; Burkart, Werner; Cardis, Elisabeth; Laurier, Dominique; Tirmarche, Margot; Hayata, Isamu

    2009-06-01

    Natural radiation is the major source of human exposure to ionising radiation, and its largest contributing component to effective dose arises from inhalation of (222)Rn and its radioactive progeny. However, despite extensive knowledge of radiation risks gained through epidemiologic investigations and mechanistic considerations, the health effects of chronic low-level radiation exposure are still poorly understood. The present paper reviews the possible contribution of studies of populations living in high natural background radiation (HNBR) areas (Guarapari, Brazil; Kerala, India; Ramsar, Iran; Yangjiang, China), including radon-prone areas, to low dose risk estimation. Much of the direct information about risk related to HNBR comes from case-control studies of radon and lung cancer, which provide convincing evidence of an association between long-term protracted radiation exposures in the general population and disease incidence. The success of these studies is mainly due to the careful organ dose reconstruction (with relatively high doses to the lung), and to the fact that large-scale collaborative studies have been conducted to maximise the statistical power and to ensure the systematic collection of information on potential confounding factors. In contrast, studies in other (non-radon) HNBR areas have provided little information, relying mainly on ecological designs and very rough effective dose categorisations. Recent steps taken in China and India to establish cohorts for follow-up and to conduct nested case-control studies may provide useful information about risks in the future, provided that careful organ dose reconstruction is possible and information is collected on potential confounding factors.

  15. Human exposure to high natural background radiation: what can it teach us about radiation risks?

    Science.gov (United States)

    Hendry, Jolyon H; Simon, Steven L; Wojcik, Andrzej; Sohrabi, Mehdi; Burkart, Werner; Cardis, Elisabeth; Laurier, Dominique; Tirmarche, Margot; Hayata, Isamu

    2014-01-01

    Natural radiation is the major source of human exposure to ionising radiation, and its largest contributing component to effective dose arises from inhalation of 222Rn and its radioactive progeny. However, despite extensive knowledge of radiation risks gained through epidemiologic investigations and mechanistic considerations, the health effects of chronic low-level radiation exposure are still poorly understood. The present paper reviews the possible contribution of studies of populations living in high natural background radiation (HNBR) areas (Guarapari, Brazil; Kerala, India; Ramsar, Iran; Yangjiang, China), including radon-prone areas, to low dose risk estimation. Much of the direct information about risk related to HNBR comes from case–control studies of radon and lung cancer, which provide convincing evidence of an association between long-term protracted radiation exposures in the general population and disease incidence. The success of these studies is mainly due to the careful organ dose reconstruction (with relatively high doses to the lung), and to the fact that large-scale collaborative studies have been conducted to maximise the statistical power and to ensure the systematic collection of information on potential confounding factors. In contrast, studies in other (non-radon) HNBR areas have provided little information, relying mainly on ecological designs and very rough effective dose categorisations. Recent steps taken in China and India to establish cohorts for follow-up and to conduct nested case–control studies may provide useful information about risks in the future, provided that careful organ dose reconstruction is possible and information is collected on potential confounding factors. PMID:19454802

  16. Radioprotective Effects of Sulfurcontaining Mineral Water of Ramsar Hot Spring with High Natural Background Radiation on Mouse Bone Marrow Cells

    Directory of Open Access Journals (Sweden)

    Heidari A. H.

    2017-12-01

    Full Text Available Background: We intend to study the inhibitory effect of sulfur compound in Ramsar hot spring mineral on tumor-genesis ability of high natural background radiation. Objective: The radioprotective effect of sulfur compounds was previously shown on radiation-induced chromosomal aberration, micronuclei in mouse bone marrow cells and human peripheral lymphocyte. Ramsar is known for having the highest level of natural background radiation on Earth. This study was performed to show the radioprotective effect of sulfur-containing Ramsar mineral water on mouse bone marrow cells. Method: Mice were fed three types of water (drinking water, Ramsar radioactive water containing sulfur and Ramsar radioactive water whose sulfur was removed. Ten days after feeding, mice were irradiated by gamma rays (0, 2 and 4 Gy. 48 and 72 hours after irradiating, mice were killed and femurs were removed. Frequency of micronuclei was determined in bone marrow erythrocytes. Results: A significant reduction was shown in the rate of micronuclei polychromatic erythrocyte in sulfur-containing hot spring water compared to sulfur-free water in hot spring mineral water. Gamma irradiation induced significant increases in micronuclei polychromatic erythrocyte (MNPCE and decreases in polychromatic erythrocyte/polychromatic erythrocyte + normochromatic erythrocyte ratio (PCEs/ PCEs+NCEs (P < 0.001 in sulfur-containing hot spring water compared to sulfur-free hot spring mineral water. Also, apparently there was a significant difference between drinking water and sulfur-containing hot spring water in micronuclei polychromatic erythrocyte and polychromatic erythrocyte/polychromatic erythrocyte+ normochromatic erythrocyte ratio. Conclusion: The results indicate that sulfur-containing mineral water could result in a significant reduction in radiation-induced micronuclei representing the radioprotective effect of sulfur compounds.

  17. High frame rate synthetic aperture duplex imaging

    DEFF Research Database (Denmark)

    Stuart, Matthias Bo; Tomov, Borislav Gueorguiev; Pihl, Michael Johannes

    2013-01-01

    Conventional color flow images are limited in velocity range and can either show the high velocities in systole or be optimized for the lower diastolic velocities. The full dynamics of the flow is, thus, hard to visualize. The dynamic range can be significantly increased by employing synthetic ap...

  18. Qualifying plasma diagnostics for a high power microwave background of ECRH heated discharges

    Energy Technology Data Exchange (ETDEWEB)

    Hirsch, M.; Baldzuhn, J.; Endler, M.; Laux, M.; Zhang, D.; Laqua, H.P.; Noke, F.; Purps, F.; Ewert, K. [Max-Planck Institut fur Plasmaphysik, EURATOM Association, D-17491 Greifswald (Germany); Oosterbeek, J.W. [Technische Universiteit Eindhoven, Den Doelch 2, 5612 AZ Eindhoven (Netherlands); Jimenez, R. [Associacion EURATOM/CIEMAT, av. Complutense 22, 28040, Madrid (Spain)

    2011-07-01

    Microwave background radiation resulting from multiple reflected unabsorbed ECRH / ECCD power may cause severe problems for microwave absorbing in-vessel components such as gaskets, bellows, windows, isolators and cable insulations in particular during long pulse operation. For qualifying in-vessel components of W7-X in the environment of an isotropic 140 GHz radiation the Microwave Stray Radiation Launch facility, MISTRAL is operated at IPP. Power flux densities of 10-40 kW/m{sup 2} are obtained with a pulsed power gyrotron launching the microwave via a corrugated transmission line and a vacuum window to the MISTRAL vessel. The focus of the program was on cable isolations as required e.g. for in-vessel magnetic diagnostics. Sufficient shielding is obtained in nearly closed metal pipes only. Cryo pumps require a temperature < 12 K where Hydrogen desorption starts. The cryo pumps are usually shielded from plasma radiation by so called chevron structures. It is investigated whether coating of these chevrons with a microwave absorbing layer yields a sufficient reduction of the stray radiation level to ensure cryo pump operation. Diagnostic windows have been tested also. Although the temperature rise even of uncooled ZnSe and quartz windows at 10 kW/m{sup 2} is uncritical with respect to damage the associated refractive index changes may be too high for some diagnostic purposes e.g. for interferometry. A possible shielding are meshes or {mu}W absorbing coatings. Integrated diagnostic mock-ups such as for the diamagnetic loop, the inner Rogowski coils, Mirnov coils and the bolometer head also have been tested

  19. Evaluation of aerosol sources at European high altitude background sites with trajectory statistical methods

    Science.gov (United States)

    Salvador, P.; Artíñano, B.; Pio, C. A.; Afonso, J.; Puxbaum, H.; Legrand, M.; Hammer, S.; Kaiser, A.

    2009-04-01

    During the last years, the analysis of a great number of back-trajectories from receptor sites has turned out to be a valuable tool to identify sources and sinks areas of atmospheric particulate matter (PM) or to reconstruct their average spatial distribution. A number of works have applied different trajectory statistical methods (TSM), which allow working simultaneously with back-trajectories computed from one or several receptor points and PM concentration values registered there. In spite of these methods have many limitations, they are simple and effective methods to detect the relevant source regions and the air flow regimes which are connected with regional and large-scale air pollution transport. In this study 5-day backward air trajectories arriving over 3 monitoring sites, were utilised and analysed simultaneously with the PM levels and chemical composition values registered there. These sites are located in the centre of Europe and can be classified into natural continental background (Schauinsland-SIL in Germany (1205 m asl), Puy de Dôme-PDD in France (1450 m asl) and Sonnblick-SBO in Austria (3106 m asl)). In the framework of the CARBOSOL European project, weekly aerosol samples were collected with High Volume Samplers (DIGITEL DH77) and PM10 (SIL and PDD) or PM2.5 (SBO) inlets, on quartz fibre filters. Filter samples were treated and analyzed for determining the levels of major organic fractions (OC, EC) and inorganic ions. Additionally, analyses for specific organic compounds were also carried out whenever was possible (Pio et al., 2007). For each day of the sampling period, four trajectories ending at 00:00, 06:00, 12:00 and 18:00 h UTC have been computed by the Norwegian Institute for Air Research NILU (SIL and PDD) and the Central Institute for Meteorology and Geophysics of Austria (SBO) using the FLEXTRA model (Stohl et al., 1995). In all, more than 8000 complete trajectories were available for analysis, each with 40 endpoints. Firstly air mass

  20. High data rate optical transceiver terminal

    Science.gov (United States)

    Clarke, E. S.

    1973-01-01

    The objectives of this study were: (1) to design a 400 Mbps optical transceiver terminal to operate from a high-altitude balloon-borne platform in order to permit the quantitative evaluation of a space-qualifiable optical communications system design, (2) to design an atmospheric propagation experiment to operate in conjunction with the terminal to measure the degrading effects of the atmosphere on the links, and (3) to design typical optical communications experiments for space-borne laboratories in the 1980-1990 time frame. As a result of the study, a transceiver package has been configured for demonstration flights during late 1974. The transceiver contains a 400 Mbps transmitter, a 400 Mbps receiver, and acquisition and tracking receivers. The transmitter is a Nd:YAG, 200 Mhz, mode-locked, CW, diode-pumped laser operating at 1.06 um requiring 50 mW for 6 db margin. It will be designed to implement Pulse Quaternary Modulation (PQM). The 400 Mbps receiver utilizes a Dynamic Crossed-Field Photomultiplier (DCFP) detector. The acquisition receiver is a Quadrant Photomultiplier Tube (QPMT) and receives a 400 Mbps signal chopped at 0.1 Mhz.

  1. The Very High Background Radiation Area in Ramsar, Iran: Public Health Risk or Signal for a Regulatory Paradigm Shift?

    Energy Technology Data Exchange (ETDEWEB)

    Karam, P. Andrew [Univ. of Rochester, Rochester, NY (United States); Mortazavi, S.M. Javad [Rafsanjan Univ. of Medical Sciences (Iran, Islamic Republic of). Medical Physics Dept.

    2001-07-01

    Ramsar, a city on the Caspian Sea in northern Iran hosts the highest measured natural background radiation levels in the world. These are due to the local geology and hydrogeology and, in some places, deliver radiation doses far in excess of those recommended for radiation workers. A population of about 2000 is exposed to average annual radiation levels of 10.2 mGy/yr and the highest recorded doses are about 260 mGy/yr. These high radiation levels are due to the deposition of {sup 226}Ra in local rocks and, because these rocks are used in the construction of many local houses, interior radiation levels are often similar to those found outside. The presence of areas such as Ramsar raises an interesting public health policy question: Is it necessary to relocate the inhabitants to areas of lower natural background radiation levels in the interests of public health? According to the linear, no-threshold (LNT) hypothesis, there is no doubt that relocating the population of Ramsar will result in a reduction in cancer incidence. Therefore, under any reasonable policy based on the LNT hypothesis, the public health is best served by relocating many of Ramsar's inhabitants to other areas along the Caspian Sea. At present, there is no reliable epidemiological data on cancer incidence among the inhabitants of Ramsar's high background radiation areas (HBRAs), but local physicians feel that local cancer incidence rates are lower than in neighboring cities. Furthermore, preliminary results indicate that there is a statistically significant radio adaptation in the inhabitants of Ramsar. Interestingly, it seems that the frequency of chromosome aberrations in the lymphocytes of the inhabitants of Ramsar is no higher than the control areas. This important finding suggests that the cancer rate in Ramsar should be no higher than in other comparable parts of Iran. In other HBRAs such as Yangjiang, China it has been reported that mortality from all cancers and those from

  2. The Effect of Minimum Wage Rates on High School Completion

    Science.gov (United States)

    Warren, John Robert; Hamrock, Caitlin

    2010-01-01

    Does increasing the minimum wage reduce the high school completion rate? Previous research has suffered from (1. narrow time horizons, (2. potentially inadequate measures of states' high school completion rates, and (3. potentially inadequate measures of minimum wage rates. Overcoming each of these limitations, we analyze the impact of changes in…

  3. High regression rate, high density hybrid fuels Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR program will investigate high energy density novel nanofuels combined with high density binders for use with an N2O oxidizer. Terves has developed...

  4. Can High-Performing Academies Overcome Family Background and Improve Social Mobility?

    Science.gov (United States)

    Barker, Bernard; Hoskins, Kate

    2017-01-01

    This article investigates whether schools that match Coalition Government criteria for excellence can enable hardworking students, regardless of background, to achieve good examination results and improved chances of social mobility. Students at two case-study academies were interviewed about family influences on their development and choice of…

  5. Role of Family Background, Student Behaviors, and School-Related Beliefs in Predicting High School Dropout

    Science.gov (United States)

    Parr, Alyssa K.; Bonitz, Verena S.

    2015-01-01

    The authors' purpose was to test a parsimonious model derived from social cognitive career theory (R. W. Lent, S. D. Brown, & G. Hackett, 1994) and expectancy value theory (J. S. Eccles & A. Wigfield, 2002) that integrates groups of variables (demographic background, student behaviors, and school-related beliefs) with the goal of…

  6. Factors affecting high resting pulse rate in military pilots

    Directory of Open Access Journals (Sweden)

    Minarma Siagian

    2014-02-01

    Full Text Available AbstrakLatar belakang: Pilot terpajan pada keadaan yang memerlukan kewaspadaan yang meningkatkan kegiatan sistem saraf simpatis. Hal ini dapat berdampak pada sistem kardiovaskular manusia, yang antara lain tercermin pada peningkatan frekuensi denyut jantung. Penelitian bertujuan untuk mengetahui pengaruh beberapa faktor yang meningkatkan frekuensi denyut jantung pada pilot. Metode:Penelitian nested case-control yang dilakukan pada pilot militer yang melakukan pemeriksaan fisik tahunan di Lembaga Kesehatan Penerbangan dan Ruang Angkasa (LAKESPRA Saryanto dari tahun 2003 sampai 2008. Data yang diperoleh dari rekam medik berupa umur, pangkat, jumlah jam terbang, rata-rata jam terbang per tahun, dan jenis pesawat. Hasil: Dari 539 pilot, terdapat 155 pilot dengan frekuensi nadi istirahat tinggi. Dibandingkan dengan pilot berumur 23-29 tahun, pilot berumur 30-39 tahun mempunyai risiko 66% lebih banyak untuk frekuensi nadi istirahat tinggi [rasio odds suaian (ORa = 1,66; 95% interval kepercayaan (CI = 1,17-2,35, P = 0,004], sedangkan yang berumur 40-49 tahun berisiko 2,4 kali (ORa = 2,40; P = 0,000]. Dibandingkan pilot pesawat transport, pilot pesawat tempur berisiko 59% lebih banyak dengan frekuensi nadi istirahat tinggi (ORa = 1,59; P = 0,002. Kesimpulan:Umur pilot yang semakin tua dan jenis pesawat tempur meningkatkan risiko frekuensi nadi istirahat pada pilot. (Health Science Indones 2013;2:51-4Kata kunci:umur, jenis pesawat terbang, frekuensi nadi istirahat, pilotAbstractBackground:Pilots are almost constantly exposed to emergency situations which increase sympathetic activity. This will affect the cardiovascular system, which among others will be reflected by increased resting pulse rate. The aim of this study was to investigate factors that increase resting pulse rate in pilots. Methods:A nested case-control study was conducted on Indonesian Air Force military pilots doing annual medical check-ups at the Saryanto Institute for Medical and Health

  7. High-Rate Strong-Signal Quantum Cryptography

    Science.gov (United States)

    Yuen, Horace P.

    1996-01-01

    Several quantum cryptosystems utilizing different kinds of nonclassical lights, which can accommodate high intensity fields and high data rate, are described. However, they are all sensitive to loss and both the high rate and the strong-signal character rapidly disappear. A squeezed light homodyne detection scheme is proposed which, with present-day technology, leads to more than two orders of magnitude data rate improvement over other current experimental systems for moderate loss.

  8. Backgrounds of Higher Suicide Rates among "Name University" Students: A Retrospective Study of the Past 25 Years.

    Science.gov (United States)

    Ishii, Kan'ichiro

    1985-01-01

    Investigated students who committed suicide at Kyoto University in Japan since 1956. Total trends of the suicide rate were reexamined in comparison with a control group, and the recent trends after the student strife (1970) were confirmed in comparison with the 15-year period before the strife. (Author/BL)

  9. Background for a new standard on pass-by measurement of combined roughness, track decay rate and vibroacoustic transfer functions

    NARCIS (Netherlands)

    Dittrich, M.G.; Létourneaux, F.; Dupuis, H.

    2013-01-01

    A measurement method for combined roughness, track decay rates and transfer functions derived from rail vibration during a train pass-by was initially developed in the late nineties [1]. This method has been then later implemented in software tools [2] and applied in several countries for various

  10. Background for a new standard on pass-by measurement of combined roughness, track decay rate and vibroacoustic transfer functions

    NARCIS (Netherlands)

    Dittrich, M.G.; Létourneaux, F.; Dupuis, H.

    2015-01-01

    A measurement method for combined roughness, track decay rates and transfer functions derived from rail vibration during a train pass-by was initially developed in the late nineties [1]. This method was later implemented in software tools [2] and applied in several countries for various purposes [3,

  11. Highly efficient resistive plate chambers for high rate environment

    CERN Document Server

    Cwiok, M; Górski, M; Królikowski, J

    1999-01-01

    The full scale prototype of an inverted double gap RPC module for ME-1/1 station of the CMS detector was tested in the gamma irradiation facility at the CERN SPS muon beam. The chamber made of medium resistivity bakelite and filled with "green gas" mixture of C /sub 2/H/sub 2/F/sub 4//iso-butane/SF/sub 6/ has wide efficiency plateau and good timing properties when operated in avalanche mode under continuous irradiation with strong /sup 137/Cs source for rates up to about 5 kHz/cm/sup 2//gap. (10 refs).

  12. Background-Oriented Schlieren for Large-Scale and High-Speed Aerodynamic Phenomena

    Science.gov (United States)

    Mizukaki, Toshiharu; Borg, Stephen; Danehy, Paul M.; Murman, Scott M.; Matsumura, Tomoharu; Wakabayashi, Kunihiko; Nakayama, Yoshio

    2015-01-01

    Visualization of the flow field around a generic re-entry capsule in subsonic flow and shock wave visualization with cylindrical explosives have been conducted to demonstrate sensitivity and applicability of background-oriented schlieren (BOS) for field experiments. The wind tunnel experiment suggests that BOS with a fine-pixel imaging device has a density change detection sensitivity on the order of 10(sup -5) in subsonic flow. In a laboratory setup, the structure of the shock waves generated by explosives have been successfully reconstructed by a computed tomography method combined with BOS.

  13. High rate flame synthesis of highly crystalline iron oxide nanorods

    Science.gov (United States)

    Merchan-Merchan, W.; Saveliev, A. V.; Taylor, A. M.

    2008-03-01

    Single-step flame synthesis of iron oxide nanorods is performed using iron probes inserted into an opposed-flow methane oxy-flame. The high temperature reacting environment of the flame tends to convert elemental iron into a high density layer of iron oxide nanorods. The diameters of the iron oxide nanorods vary from 10 to 100 nm with a typical length of a few microns. The structural characterization performed shows that nanorods possess a highly ordered crystalline structure with parameters corresponding to cubic magnetite (Fe3O4) with the [100] direction oriented along the nanorod axis. Structural variations of straight nanorods such as bends, and T-branched and Y-branched shapes are frequently observed within the nanomaterials formed, opening pathways for synthesis of multidimensional, interconnected networks.

  14. Social background effects and academic achievement during transition to high school

    OpenAIRE

    Aypay, Ahmet

    2002-01-01

    The study analyzes the factors that influence student transitions to high school, overall high school achievement, math, science, as well as verbal achievement. The sample included students in an Aegean city, Canakkale. The Sample (N=572) included 14 high schools, with the exception of two high schools in this town. The study found little or no effect of SES on academic achievement. Previous academic achievement was positively associated with academic achievement. School typ...

  15. Postoperative high-dose-rate brachytherapy in the prevention of keloids

    NARCIS (Netherlands)

    Veen, Ronald E.; Kal, Henk B.

    2007-01-01

    Background: The aim of this study is to show the efficiency of keloidectomy and postoperative interstitial high-dose-rate (HDR) brachytherapy in the prevention of keloids. Methods and Materials: Between 1998 and 2004, 35 patients with 54 keloids were treated postoperatively with HDR brachytherapy.

  16. Professionals Made in Germany: Employing a Turkish Migration Background in High-Status Positions

    Directory of Open Access Journals (Sweden)

    Ali Konyali

    2017-03-01

    Full Text Available This article emphasises the experiences of the prospective elite among the second generation in Germany by analysing empirical data collected through in-depth interviews across three occupational fields (law, education and corporate business. In spite of their disadvantaged background, some children of lower educated migrant parents from Turkey managed to occupy prestigious leadership positions. Many use their ethnic capital in creative and strategic ways to seek opportunities and obtain access to leading positions. They are now embracing new professional roles and have moved into new social circles due to their steep upward mobility. However, they still have to contend with the fact that their individual mobility stands in contrast to the low-status of the group to which they belong.

  17. The high-energy neutrino background - Limitations on models of deuterium production

    Science.gov (United States)

    Eichler, D.

    1979-01-01

    It is pointed out that Epstein's (1977) model for deuterium production via high-energy spallation reactions produces high-energy neutrinos in sufficient quantity to stand out above those that are produced by cosmic-ray interactions in earth's atmosphere. That the Reines experiment detected neutrinos of atmospheric origin without detecting any cosmic component restricts deuterium production by spallation reactions to very high redshifts (z at least about 300). Improved neutrino experiments may be able to push these limits back to recombination.

  18. Miniature High Stability High Temperature Space Rated Blackbody Radiance Source

    Science.gov (United States)

    Jones, J. A.; Beswick, A. G.

    1987-09-01

    This paper presents the design and test performance of a conical cavity type blackbody radiance source that will meet the requirements of the Halogen Occultation Experiment (HALOE) on the NASA Upper Atmospheric Research Satellite program (UARS). Since a radiance source meeting the requirements of this experiment was unavailable in the commercial market, a development effort was undertaken by the HALOE Project. The blackbody radiance source operates in vacuum at 1300 K + 0.5 K over any 15-minute interval, uses less than 7.5 watts of power, maintains a 49°C outer case temperature, and fits within the 2.5 x 2.5 x 3.0 inch envelope allocated inside the HALOE instrument. Also, the unit operates in air, during ground testing of the HALOE instrument, where it uses 17 watts of power with an outer case temperature of 66°C. The thrust of this design effort was to minimize the heat losses, in order to keep the power usage under 7.5 watts, and to minimize the amount of silica in the materials. Silica in the presence of the platinum heater winding used in this design would cause the platinum to erode, changing the operating temperature set-point. The design required the development of fabrication techniques which would provide very small, close tolerance parts from extremely difficult-to-machine materials. Also, a space rated ceramic core and unique, low thermal conductance, ceramic-to-metal joint was developed, tested and incorporated in this design. The completed flight qualification hardware has undergone performance, environmental and life testing. The design configuration and test results are discussed in detail in this paper.

  19. High Amplitude Background Slow Waves in Normal Children Aged 3 to 18 Months-Implications for the Consideration of Hypsarhythmia.

    Science.gov (United States)

    Mytinger, John R; Weber, Amanda; Vidaurre, Jorge

    2018-01-08

    To assess for the presence of high amplitude EEG background slow waves in normal young children. One hundred children with normal development ages 3 to 18 months had normal EEGs for spells and did not have seizures or epilepsy. Three electroencephalographers retrospectively reviewed 5 minutes of stable stage II sleep to measure background slow waves for peak-to-peak amplitudes. A standard 10-20 longitudinal bipolar montage was used. Interrater agreement was assessed by intraclass correlation coefficient. Interrater agreement between reviewers in the assessment of recurrent slow wave amplitudes was excellent (intraclass correlation coefficient = 0.97). Slow wave amplitudes were the highest in the posterior head regions for all patients. We found recurring slow waves of 500 µV in 17%, 49%, 30%, 3% and 1%, respectively. Although hypsarhythmia typically includes high amplitude background slow waves of >200 or >300 µV, we found that 83% and 34% of normal children had recurring posterior background slow waves of >200 or >300 µV, respectively. These data may be useful in the EEG background assessment of young children, for determining the presence or absence of hypsarhythmia, and determining treatment response in children with epileptic spasms.

  20. Change in Ethnic Identity across the High School Years among Adolescents with Latin American, Asian, and European Backgrounds

    Science.gov (United States)

    Kiang, Lisa; Witkow, Melissa R.; Baldelomar, Oscar A.; Fuligni, Andrew J.

    2010-01-01

    Changes in adolescents' ethnic identity (e.g., exploration, belonging) were examined over the 4 years of high school. Results from 541 adolescents (51% female) with Latin American, Asian, and European backgrounds suggest that, as a group, adolescents do not report developmental changes in their ethnic exploration and belonging over time. Yet,…

  1. Constraining Dark Matter and Ultra-High Energy Cosmic Ray Sources with Fermi-LAT Diffuse Gamma Ray Background

    Directory of Open Access Journals (Sweden)

    Kalashev Oleg

    2016-01-01

    Full Text Available We use the recent measurement of the isotropic γ–ray background (IGRB by Fermi LAT and analysis of the contribution of unresolved point γ–ray sources to IGRB to build constraints on the models of ultra-high cosmic rays (UHECR origin. We also calculate the minimal expected diffuse γ–ray flux produced by UHECR interactions with an interstellar photon background. Finally, for the subclass of dark matter (DM models with decaying weakly interacting massive particles (WIMP, we build constraints on the particle decay time using minimal expected contributions to the IGRB from unresolved point γ–ray sources and UHECR.

  2. Image Enhancement for High frame-rate Neutron Radiography

    OpenAIRE

    Saito, Y; Ito, D.

    2015-01-01

    High frame rate neutron radiography has been utilized to investigate two-phase flow in a metallic duct. However, images obtained by high frame-rate neutron radiography suffered from severe statistical noise due to its short exposure time. In this study, a spatio-temporal filter was applied to reduce the noise in the sequence images obtained by high frame-rate neutron radiography. Experiments were performed at the B4-port of the Research Reactor Institute, Kyoto University, which has a thermal...

  3. High Achievers from Low Socioeconomic Backgrounds: The Critical Role of Disciplinary Climate and Grit

    Science.gov (United States)

    Huang, Haigen; Zhu, Hao

    2017-01-01

    The purpose of this study was to examine whether school disciplinary climate and grit predicted low socioeconomic status (SES) students being high achievers in mathematics and science with a representative sample of 15-year-old students in the United States. Our analysis, using a two-level logistic hierarchical linear model (HLM), indicated both…

  4. Imagination and Aspiration: Flames of Possibility for Migrant Background High School Students and Their Parents

    Science.gov (United States)

    Naidoo, Loshini

    2015-01-01

    This paper aims to show how imagination is an important tool in the formation of aspiration and ethnic capital for young high school students and their parents in the city of Blacktown, New South Wales, Australia. Through semi-structured focus group interviews with parents, teachers and students, data from the demographic space of the school…

  5. Background data for modulus mapping high-performance polyethylene fiber morphologies

    Directory of Open Access Journals (Sweden)

    Kenneth E. Strawhecker

    2017-02-01

    Full Text Available The data included here provides a basis for understanding “Interior morphology of high-performance polyethylene fibers revealed by modulus mapping” (K.E. Strawhecker, E.J. Sandoz-Rosado, T.A. Stockdale, E.D. Laird, 2016 [1], in specific: the multi-frequency (AMFM atomic force microscopy technique and its application to ultra-high-molecular-weight Polyethylene (UHMWPE fibers. Furthermore, the data suggests why the Hertzian contact mechanics model can be used within the framework of AMFM theory, simple harmonic oscillator theory, and contact mechanics. The framework is first laid out followed by data showing cantilever dynamics, force-distance spectra in AC mode, and force-distance in contact mode using Polystyrene reference and UHMWPE. Finally topography and frequency shift (stiffness maps are presented to show the cases where elastic versus plastic deformation may have occurred.

  6. Natural radionuclide and radiological assessment of building materials in high background radiation areas of Ramsar, Iran.

    Science.gov (United States)

    Bavarnegin, Elham; Moghaddam, Masoud Vahabi; Fathabadi, Nasrin

    2013-04-01

    Building materials, collected from different sites in Ramsar, a northern coastal city in Iran, were analyzed for their natural radionuclide contents. The measurements were carried out using a high resolution high purity Germanium (HPGe) gamma-ray spectrometer system. The activity concentration of (226)Ra, (232)Th, and (40)K content varied from below the minimum detection limit up to 86,400 Bqkg(-1), 187 Bqkg(-1), and 1350 Bqkg(-1), respectively. The radiological hazards incurred from the use of these building materials were estimated through various radiation hazard indices. The result of this survey shows that values obtained for some samples are more than the internationally accepted maximum limits and as such, the use of them as a building material pose significant radiation hazard to individuals.

  7. Radiation Hardening Technique for the Background Calibration of High-Resolution Time-Interleaved ADCs

    Science.gov (United States)

    2017-03-01

    for off ADCs: but it lution, and e-event radiat 2-point sig ed to steer the stimation is in a single regist to enable e, and preven tion strikes...simulation of traditional calibration shortcomings – electrical and radiation -wise In order to study the operation of the calibration methods for high...with 500fs-step DLL using the traditional calibration method diverging after an SEU (red plot). Convergence after minimal disruption upon radiation is

  8. Transit dose calculation in high dose rate brachytherapy (HDR ...

    African Journals Online (AJOL)

    Transit doses around a high dose rate 192Ir brachytherapy source were calculated using Sievert Integral at positions where the moving source was located exactly between two adjacent dwell positions. The correspond-ing transit dose rates were obtained by using energy absorption coefficients. Discrete step sizes of 0.25 ...

  9. Rural and Urban High School Dropout Rates: Are They Different?

    Science.gov (United States)

    Jordan, Jeffrey L.; Kostandini, Genti; Mykerezi, Elton

    2012-01-01

    This study estimates the high school dropout rate in rural and urban areas, the determinants of dropping out, and whether the differences in graduation rates have changed over time. We use geocoded data from two nationally representative panel household surveys (NLSY 97 and NLSY 79) and a novel methodology that corrects for biases in graduation…

  10. Pedalling rate affects endurance performance during high-intensity cycling

    DEFF Research Database (Denmark)

    Nielsen, Jens Steen; Hansen, Ernst Albin; Sjøgaard, Gisela

    2004-01-01

    The purpose of this study into high-intensity cycling was to: (1) test the hypothesis that endurance time is longest at a freely chosen pedalling rate (FCPR), compared to pedalling rates 25% lower (FCPR-25) and higher (FCPR+25) than FCPR, and (2) investigate how physiological variables, such as m...

  11. High Count Rate Single Photon Counting Detector Array Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An optical communications receiver requires efficient and high-rate photon-counting capability so that the information from every photon, received at the aperture,...

  12. CASSINI HIGH RATE DETECTOR V17.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The High Rate Detector (HRD) from the University of Chicago is an independent part of the CDA instrument on the Cassini Orbiter that measures the dust flux and...

  13. CASSINI HIGH RATE DETECTOR V2.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The High Rate Detector (HRD) from the University of Chicago is an independent part of the CDA instrument on the Cassini Orbiter that measures the dust flux and...

  14. CASSINI HIGH RATE DETECTOR V12.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The High Rate Detector (HRD) from the University of Chicago is an independent part of the CDA instrument on the Cassini Orbiter that measures the dust flux and...

  15. CASSINI HIGH RATE DETECTOR V8.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The High Rate Detector (HRD) from the University of Chicago is an independent part of the CDA instrument on the Cassini Orbiter that measures the dust flux and...

  16. CASSINI HIGH RATE DETECTOR V10.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The High Rate Detector (HRD) from the University of Chicago is an independent part of the CDA instrument on the Cassini Orbiter that measures the dust flux and...

  17. CASSINI HIGH RATE DETECTOR V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The High Rate Detector (HRD) from the University of Chicago is an independent part of the CDA instrument on the Cassini Orbiter that measures the dust flux and...

  18. CASSINI HIGH RATE DETECTOR V13.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The High Rate Detector (HRD) from the University of Chicago is an independent part of the CDA instrument on the Cassini Orbiter that measures the dust flux and...

  19. CASSINI HIGH RATE DETECTOR V9.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The High Rate Detector (HRD) from the University of Chicago is an independent part of the CDA instrument on the Cassini Orbiter that measures the dust flux and...

  20. CASSINI HIGH RATE DETECTOR V3.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The High Rate Detector (HRD) from the University of Chicago is an independent part of the CDA instrument on the Cassini Orbiter that measures the dust flux and...

  1. CASSINI HIGH RATE DETECTOR V7.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The High Rate Detector (HRD) from the University of Chicago is an independent part of the CDA instrument on the Cassini Orbiter that measures the dust flux and...

  2. CASSINI HIGH RATE DETECTOR V4.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The High Rate Detector (HRD) from the University of Chicago is an independent part of the CDA instrument on the Cassini Orbiter that measures the dust flux and...

  3. CASSINI HIGH RATE DETECTOR V11.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The High Rate Detector (HRD) from the University of Chicago is an independent part of the CDA instrument on the Cassini Orbiter that measures the dust flux and...

  4. CASSINI HIGH RATE DETECTOR V14.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The High Rate Detector (HRD) from the University of Chicago is an independent part of the CDA instrument on the Cassini Orbiter that measures the dust flux and...

  5. CASSINI HIGH RATE DETECTOR V5.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The High Rate Detector (HRD) from the University of Chicago is an independent part of the CDA instrument on the Cassini Orbiter that measures the dust flux and...

  6. CASSINI HIGH RATE DETECTOR V6.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The High Rate Detector (HRD) from the University of Chicago is an independent part of the CDA instrument on the Cassini Orbiter that measures the dust flux and...

  7. High Burn Rate Hybrid Fuel for Improved Grain Design Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A novel type of fuel providing high burning rate for hybrid rocket applications is proposed. This fuel maintains a hydrodynamically rough surface to...

  8. The structure of teenage employment: Social background and the jobs held by high school seniors.

    Science.gov (United States)

    Hirschman, Charles; Voloshin, Irina

    2007-10-01

    Although it is widely assumed that work careers begin after the completion of schooling, most enrolled high school students are also workers. Teenage workers are heavily concentrated in the low wage service sector, but they are also found as supplemental part-time workers in many occupations, including clerical, retail sales, and blue collar employment. Gender, race/ethnicity, and socioeconomic origins are important determinants of the types of jobs that teenage students hold. Students from advantaged socioeconomic origins and students with above average grades are more likely to work in "good jobs," defined by lower hours of work per week and higher status.

  9. Quantum Communication with a High-Rate Entangled Photon Source

    Science.gov (United States)

    Wilson, Nathaniel C.; Chaffee, Dalton W.; Lekki, John D.; Wilson, Jeffrey D.

    2016-01-01

    A high generation rate photon-pair source using a dual element periodically-poled potassium titanyl phosphate (PP KTP) waveguide is described. The photon-pair source features a high pair generation rate, a compact power-efficient package, and continuous wave (CW) or pulsed operation. Characterization and test results are presented. Details and preliminary results of a laboratory free-space QKD experiment with the B92 protocol are also presented.

  10. High rate, fast timing Glass RPC for the high $\\eta$ CMS muon detectors

    CERN Document Server

    INSPIRE-00185093; Lagarde, François; Laktineh, Imad; Buridon, Victor; Chen, Xiushan; Combaret, Christophe; Eynard, Alexis; Germani, Lionel; Grenier, Gerald; Mathez, Hervé; Mirabito, Laurent; Petrukhin, Alexei; Steen, Arnaud; Tromeur, William; Wang, Yi; Gong, A.; Moreau, Nathalie; de la Taille, Christophe; Dulucq, Fréderic

    2017-02-11

    The HL-LHC phase is designed to increase by an order of magnitude the amount of data to be collected by the LHC experiments. To achieve this goal in a reasonable time scale the instantaneous luminosity would also increase by an order of magnitude up to $6 \\cdot 10^{34}$ cm$^{-2}$s$^{-1}$. The region of the forward muon spectrometer ($|\\eta| > 1.6$) is not equipped with RPC stations. The increase of the expected particles rate up to 2 kHz/cm$^2$ ( including a safety factor 3 ) motivates the installation of RPC chambers to guarantee redundancy with the CSC chambers already present. The actual RPC technology of CMS cannot sustain the expected background level. A new generation Glass-RPC (GRPC) using low resistivity glass (LR) is proposed to equip at least the two most far away of the four high eta muon stations of CMS. The design of small size prototypes and the studies of their performances under high rate particles flux is presented.

  11. High rate, fast timing Glass RPC for the high ${\\eta}$ CMS muon detectors

    CERN Document Server

    INSPIRE-00430500; Gouzevitch, M.; Laktineh, I.; Buridon, V.; Chen, X.; Combaret, C.; Eynard, A.; Germani, L.; Grenier, G.; Mathez, H.; Mirabito, L.; Petrukhin, A.; Steen, A.; Tromeur, W.; Wang, Y.; Gong, A.; Moreau, N.; de la Taille, C.; Dulucq, F.; Cimmino, A.; Crucy, S.; Fagot, A.; Gul, M.; Rios, A.A.O.; Tytgat, M.; Zaganidis, N.; Aly, S.; Assran, Y.; Radi, A.; Sayed, A.; Singh, G.; Abbrescia, M.; Iaselli, G.; Maggi, M.; Pugliese, G.; Verwilligen, P.; Van Doninck, W.F.; Colafranceschi, S.; Sharmag, A.; Benussi, L.; Bianco, S.; Piccolo, D.; Primavera, F.; Bhatnagar, V.; Kumari, R.; Mehta, A.; Singh, J.; Ahmad, A.; Ahmed, W.; Asghar, M.I.; Awan, I.M.; Hoorani, R.; Muhammad, S.; Shahzad, H.; Shah, M.A.; Cho, S.W.; Choi, S.Y.; Hong, B.; Kang, M.H.; Lee, K.S.; Lim, J.H.; Park, S.K.; Kim, M.S.; Carpinteyro Bernardino, S.; Pedraza, I.; Uribe Estradam, C.; Carrillo Moreno, S.; Vazquez Valencia, F.; Pant, L.M.; Buontempo, S.; Cavallo, N.; Esposito, M.; Fabozzi, F.; Lanza, G.; Orso, I.; Lista, L.; Meola, S.; Merola, M.; Paolucci, P.; Thyssen, F.; Braghieri, A.; Magnani, A.; Montagna, P.; Riccardi, C.; Salvini, P.; Vai, I.; Vitulo, P.; Ban, Y.; Qian, S.J.; Choi, M.; Choi, Y.; Goh, J.; Kim, D.; Aleksandrov, A.; Hadjiiska, R.; Iaydjiev, P.; Rodozov, M.; Stoykova, S.; Sultanov, G.; Vutova, M.; Dimitrov, A.; Litov, L.; Pavlov, B.; Petkov, P.; Bagaturia, I.; Lomidze, D.; Avila, C.; Cabrera, A.; Sanabria, J.C.; Crotty, I.; Vaitkus, J.

    2016-09-09

    The HL-LHC phase is designed to increase by an order of magnitude the amount of data to be collected by the LHC experiments. To achieve this goal in a reasonable time scale the instantaneous luminosity would also increase by an order of magnitude up to $6.10^{34} cm^{-2} s^{-1}$ . The region of the forward muon spectrometer ($|{\\eta}| > 1.6$) is not equipped with RPC stations. The increase of the expected particles rate up to $2 kHz/cm^{2}$ (including a safety factor 3) motivates the installation of RPC chambers to guarantee redundancy with the CSC chambers already present. The actual RPC technology of CMS cannot sustain the expected background level. The new technology that will be chosen should have a high rate capability and provides a good spatial and timing resolution. A new generation of Glass-RPC (GRPC) using low-resistivity (LR) glass is proposed to equip at least the two most far away of the four high ${\\eta}$ muon stations of CMS. First the design of small size prototypes and studies of their perfor...

  12. A rate-dependent Hosford-Coulomb model for predicting ductile fracture at high strain rates

    Directory of Open Access Journals (Sweden)

    Marcadet Stephane J.

    2015-01-01

    Full Text Available The Hosford-Coulomb model incorporates the important effect of the Lode angle parameter in addition to the stress triaxiality to predict the initiation of ductile fracture. A strain-rate dependent extension of the Hosford-Coulomb model is presented to describe the results from low, intermediate and high strain rate fracture experiments on advanced high strength steels (DP590 and TRIP780. The model predictions agree well with the experimental observation of an increase in ductility as function of strain rate for stress states ranging from uniaxial to equi-biaxial tension.

  13. Effect of high hydrostatic pressure processing on the background microbial loads and quality of cantaloupe puree.

    Science.gov (United States)

    Mukhopadhyay, Sudarsan; Sokorai, Kimberly; Ukuku, Dike; Fan, Xuetong; Juneja, Vijay

    2017-01-01

    The objective of this study was to investigate and evaluate the effects of high hydrostatic pressure (HHP) applied to cantaloupe puree (CP) on microbial loads and product quality during storage for 10days at 4°C. Freshly prepared, double sealed and double bagged CP (ca. 5g) was pressure treated at 300, 400 and 500MPa at 8°C and 15°C for 5min. Microflora populations, soluble solid content, pH, color, antioxidant activity, appearance and aroma were measured at 1, 6, and 10d of storage. Results showed that high pressure treatment of 300MPa (8°C and 15°C) resulted in reduction of total aerobic plate count from 3.3 to 1.8logCFU/g. The treatment reduced the populations of native aerobic plate count to non-detectable levels (detection limit 1logCFU/g) at 400MPa and 500MPa pressures at 15°C. Pressure treatment completely inactivated mold and yeast in puree below the limits of detection at day 1 and no regrowth was observed during 10days of storage at 4°C while mold and yeast in untreated puree survived during the storage. High pressure treatment did not show any adverse impact on physical properties as soluble solid content (SSC, 11.2°Brix) and acidity (pH, 6.9). The instrumental color parameters (L*, a*, b*) were affected due to HHP treatment creating a slightly lighter product, compared to control, as indicated by higher L.* and lower a* values. However the change was not detected by the sensory panel while evaluating appearance scores. Pressure treatment did not affect the antioxidant capacity of puree product compared to control. Visual appearance and sniffing aroma test by panel revealed no adverse changes in the sensory parameters as a result of HHP treatment. HHP method described in this study appears to be a promising way to inactivate spoilage microorganisms in the cantaloupe puree and maintain quality. This study provides a viable option for preservation and marketing this product. Published by Elsevier Ltd.

  14. High strain rate response of rabbit femur bones.

    Science.gov (United States)

    Shunmugasamy, Vasanth Chakravarthy; Gupta, Nikhil; Coelho, Paulo G

    2010-11-16

    Strain rate dependence of the mechanical response of hard tissues has led to a keen interest in their dynamic properties. The current study attempts to understand the high strain rate characteristics of rabbit femur bones. The testing was conducted using a split-Hopkinson pressure bar equipped with a high speed imaging system to capture the fracture patterns. The bones were also characterized under quasi-static compression to enable comparison with the high strain rate results. The quasi-static compressive moduli of the epiphyseal and diaphyseal regions were measured to be in the range of 2-3 and 5-7GPa, respectively. Under high strain rate loading conditions the modulus is observed to increase with strain rate and attains values as high as 15GPa for epiphyseal and 30GPa for diaphyseal regions of the femur. The strength at high strain rate was measured to be about twice the quasi-static strength value. A large number of small cracks initiated on the specimen surface close to the incident bar. Coalescence of crack branches leading to fewer large cracks resulted in specimen fragmentation. In comparison, the quasi-static failure was due to shear cracking. Copyright © 2010 Elsevier Ltd. All rights reserved.

  15. Performance of high flow rate samplers for respirable particle collection.

    Science.gov (United States)

    Lee, Taekhee; Kim, Seung Won; Chisholm, William P; Slaven, James; Harper, Martin

    2010-08-01

    The American Conference of Governmental Industrial hygienists (ACGIH) lowered the threshold limit value (TLV) for respirable crystalline silica (RCS) exposure from 0.05 to 0.025 mg m(-3) in 2006. For a working environment with an airborne dust concentration near this lowered TLV, the sample collected with current standard respirable aerosol samplers might not provide enough RCS for quantitative analysis. Adopting high flow rate sampling devices for respirable dust containing silica may provide a sufficient amount of RCS to be above the limit of quantification even for samples collected for less than full shift. The performances of three high flow rate respirable samplers (CIP10-R, GK2.69, and FSP10) have been evaluated in this study. Eleven different sizes of monodisperse aerosols of ammonium fluorescein were generated with a vibrating orifice aerosol generator in a calm air chamber in order to determine the sampling efficiency of each sampler. Aluminum oxide particles generated by a fluidized bed aerosol generator were used to test (i) the uniformity of a modified calm air chamber, (ii) the effect of loading on the sampling efficiency, and (iii) the performance of dust collection compared to lower flow rate cyclones in common use in the USA (10-mm nylon and Higgins-Dewell cyclones). The coefficient of variation for eight simultaneous samples in the modified calm air chamber ranged from 1.9 to 6.1% for triplicate measures of three different aerosols. The 50% cutoff size ((50)d(ae)) of the high flow rate samplers operated at the flow rates recommended by manufacturers were determined as 4.7, 4.1, and 4.8 microm for CIP10-R, GK2.69, and FSP10, respectively. The mass concentration ratio of the high flow rate samplers to the low flow rate cyclones decreased with decreasing mass median aerodynamic diameter (MMAD) and high flow rate samplers collected more dust than low flow rate samplers by a range of 2-11 times based on gravimetric analysis. Dust loading inside the

  16. Characteristics of highly rated leadership in nursing homes using item response theory.

    Science.gov (United States)

    Backman, Annica; Sjögren, Karin; Lindkvist, Marie; Lövheim, Hugo; Edvardsson, David

    2017-12-01

    To identify characteristics of highly rated leadership in nursing homes. An ageing population entails fundamental social, economic and organizational challenges for future aged care. Knowledge is limited of both specific leadership behaviours and organizational and managerial characteristics which have an impact on the leadership of contemporary nursing home care. Cross-sectional. From 290 municipalities, 60 were randomly selected and 35 agreed to participate, providing a sample of 3605 direct-care staff employed in 169 Swedish nursing homes. The staff assessed their managers' (n = 191) leadership behaviours using the Leadership Behaviour Questionnaire. Data were collected from November 2013 - September 2014, and the study was completed in November 2016. A two-parameter item response theory approach and regression analyses were used to identify specific characteristics of highly rated leadership. Five specific behaviours of highly rated nursing home leadership were identified; that the manager: experiments with new ideas; controls work closely; relies on subordinates; coaches and gives direct feedback; and handles conflicts constructively. The regression analyses revealed that managers with social work backgrounds and privately run homes were significantly associated with higher leadership ratings. This study highlights the five most important leadership behaviours that characterize those nursing home managers rated highest in terms of leadership. Managers in privately run nursing homes and managers with social work backgrounds were associated with higher leadership ratings. Further work is needed to explore these behaviours and factors predictive of higher leadership ratings. © 2017 John Wiley & Sons Ltd.

  17. Stretching of red blood cells at high strain rates

    Science.gov (United States)

    Mancuso, J. E.; Ristenpart, W. D.

    2017-10-01

    Most work on the mechanical behavior of red blood cells (RBCs) in flow has focused on simple shear flows. Relatively little work has examined RBC deformations in the physiologically important extensional flow that occurs at the entrance to a constriction. In particular, previous work suggests that RBCs rapidly stretch out and then retract upon entering the constriction, but to date no model predicts this behavior for the extremely high strain rates typically experienced there. In this Rapid Communication, we use high speed video to perform systematic measurements of the dynamic stretching behavior of RBCs as they enter a microfluidic constriction. We demonstrate that both the Kelvin-Voigt and Skalak viscoelastic models capture the observed stretching dynamics, up to strain rates as high as 2000 s-1. The results indicate that the effective elastic modulus of the RBC membrane at these strain rates is an order of magnitude larger than moduli measured by micropipette aspiration or other low strain rate techniques.

  18. Solidification at the High and Low Rate Extreme

    Energy Technology Data Exchange (ETDEWEB)

    Meco, Halim [Iowa State Univ., Ames, IA (United States)

    2004-12-19

    The microstructures formed upon solidification are strongly influenced by the imposed growth rates on an alloy system. Depending on the characteristics of the solidification process, a wide range of growth rates is accessible. The prevailing solidification mechanisms, and thus the final microstructure of the alloy, are governed by these imposed growth rates. At the high rate extreme, for instance, one can have access to novel microstructures that are unattainable at low growth rates. While the low growth rates can be utilized for the study of the intrinsic growth behavior of a certain phase growing from the melt. Although the length scales associated with certain processes, such as capillarity, and the diffusion of heat and solute, are different at low and high rate extremes, the phenomena that govern the selection of a certain microstructural length scale or a growth mode are the same. Consequently, one can analyze the solidification phenomena at both high and low rates by using the same governing principles. In this study, we examined the microstructural control at both low and high extremes. For the high rate extreme, the formation of crystalline products and factors that control the microstructure during rapid solidification by free-jet melt spinning are examined in Fe-Si-B system. Particular attention was given to the behavior of the melt pool at different quench-wheel speeds. Since the solidification process takes place within the melt-pool that forms on the rotating quench-wheel, we examined the influence of melt-pool dynamics on nucleation and growth of crystalline solidification products and glass formation. High-speed imaging of the melt-pool, analysis of ribbon microstructure, and measurement of ribbon geometry and surface character all indicate upper and lower limits for melt-spinning rates for which nucleation can be avoided, and fully amorphous ribbons can be achieved. Comparison of the relevant time scales reveals that surface-controlled melt

  19. Metallurgical applications of shock wave and high strain rate phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Murr, L.E.; Staudhammer, K.P.; Meyers, M.A.

    1986-01-01

    This book presents the papers given at a conference on the impact testing of metals. Topics considered at the conference included dynamic consolidation, the analysis of dislocation kinetics across shocks, high-strain-rate deformation, adiabatic shear band phenomena, dynamic fracture, explosive metal working, shock synthesis and the property modification of materials, and novel concepts and applications of high pressure.

  20. High flow rate microsieve for bio medical applications

    NARCIS (Netherlands)

    van Rijn, C.J.M.; Nijdam, W.; Elwenspoek, Michael Curt

    1995-01-01

    A new composite filtration membrane having a thin filtration or sieving layer has been developed. This filtration membrane with a high pore density and a narrow pore size distribution on a macro porous support shows good separation behaviour and a high flow rate. Because of the construction method,

  1. Authoritative School Climate and High School Dropout Rates

    Science.gov (United States)

    Jia, Yuane; Konold, Timothy R.; Cornell, Dewey

    2016-01-01

    This study tested the association between school-wide measures of an authoritative school climate and high school dropout rates in a statewide sample of 315 high schools. Regression models at the school level of analysis used teacher and student measures of disciplinary structure, student support, and academic expectations to predict overall high…

  2. Performance of the Ultra-High Rate Germanium (UHRGe) System

    Energy Technology Data Exchange (ETDEWEB)

    Fast, James E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Dion, Michael P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rodriguez, Douglas C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); VanDevender, Brent A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wood, Lynn S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wright, Michael E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2013-12-01

    This report describes the final performance achieved with the detector system developed for the Ultra High Rate Germanium (UHRGe) project. The system performance has been evaluated at low, moderate and high rates and includes the performance of real-time analysis algorithms running in the FPGA of the data acquisition system. This performance is compared to that of offline analyses of streaming waveform data collected with the same data acquisition system the performance of a commercial Multi-Channel Analyzer designed for high-resolution spectroscopy applications, the Canberra LYNX.

  3. Methodology for DSC calibration in high heating rates

    Directory of Open Access Journals (Sweden)

    Carlos Isidoro Braga

    2011-05-01

    Full Text Available Despite the large use of differential scanning calorimetry (DSC technique in advanced polymer materials characterization, the new methodology called DSC in high heating rates was developed. The heating rate during conventional DSC experiments varying from 10 to 20ºC.min-¹, sample mass from 10 to 15mg and standard aluminum sample pan weighting, approximately, 27mg. In order to contribute to a better comprehension of DSC behavior in different heating rates, this work correlates as high heating rate influences to the thermal events in DSC experiments. Samples of metallic standard (In, Pb, Sn and Zn with masses varying from 0.570mg to 20.9mg were analyzed in multiples sample heating rate from 4 to 324°C. min-¹. In order to make properly all those experiments, a precise and careful temperature and enthalpy calibrations were performed and deeply discussed. Thus, this work shows a DSC methodology able to generate good and reliable results on experiments under any researcher choice heating rates to characterize the advanced materials used, for example, for aerospace industry. Also it helps the DSC users to find in their available instruments, already installed, a better and more accurate DSC test results, improving in just one shot the analysis sensitivity and resolution. Polypropylene melting and enthalpy thermal events are also studied using both the conventional DSC method and high heating rate method.

  4. Evolution of high tooth replacement rates in sauropod dinosaurs.

    Science.gov (United States)

    D'Emic, Michael D; Whitlock, John A; Smith, Kathlyn M; Fisher, Daniel C; Wilson, Jeffrey A

    2013-01-01

    Tooth replacement rate can be calculated in extinct animals by counting incremental lines of deposition in tooth dentin. Calculating this rate in several taxa allows for the study of the evolution of tooth replacement rate. Sauropod dinosaurs, the largest terrestrial animals that ever evolved, exhibited a diversity of tooth sizes and shapes, but little is known about their tooth replacement rates. We present tooth replacement rate, formation time, crown volume, total dentition volume, and enamel thickness for two coexisting but distantly related and morphologically disparate sauropod dinosaurs Camarasaurus and Diplodocus. Individual tooth formation time was determined by counting daily incremental lines in dentin. Tooth replacement rate is calculated as the difference between the number of days recorded in successive replacement teeth. Each tooth family in Camarasaurus has a maximum of three replacement teeth, whereas each Diplodocus tooth family has up to five. Tooth formation times are about 1.7 times longer in Camarasaurus than in Diplodocus (315 vs. 185 days). Average tooth replacement rate in Camarasaurus is about one tooth every 62 days versus about one tooth every 35 days in Diplodocus. Despite slower tooth replacement rates in Camarasaurus, the volumetric rate of Camarasaurus tooth replacement is 10 times faster than in Diplodocus because of its substantially greater tooth volumes. A novel method to estimate replacement rate was developed and applied to several other sauropodomorphs that we were not able to thin section. Differences in tooth replacement rate among sauropodomorphs likely reflect disparate feeding strategies and/or food choices, which would have facilitated the coexistence of these gigantic herbivores in one ecosystem. Early neosauropods are characterized by high tooth replacement rates (despite their large tooth size), and derived titanosaurs and diplodocoids independently evolved the highest known tooth replacement rates among archosaurs.

  5. Integrating GPS with GLONASS for high-rate seismogeodesy

    Science.gov (United States)

    Geng, Jianghui; Jiang, Peng; Liu, Jingnan

    2017-04-01

    High-rate GPS is a precious seismogeodetic tool to capture coseismic displacements unambiguously and usually improved by sidereal filtering to mitigate multipath effects dominating the periods of tens of seconds to minutes. We further introduced GLONASS (Globalnaya navigatsionnaya sputnikovaya sistema) data into high-rate GPS to deliver over 2000 24 h displacements at 99 stations in Europe. We find that the major displacement errors induced by orbits and atmosphere on the low-frequency band that are not characterized by sidereal repeatabilities can be amplified markedly by up to 40% after GPS sidereal filtering. In contrast, integration with GLONASS can reduce the noise of high-rate GPS significantly and near uniformly over the entire frequency band, especially for the north components by up to 40%, suggesting that this integration is able to mitigate more errors than only multipath within high-rate GPS. Integrating GPS with GLONASS outperforms GPS sidereal filtering substantially in ameliorating displacement noise by up to 60% over a wide frequency band (e.g., 2 s-0.5 days) except a minor portion between 100 and 1000 s. High-rate multi-GNSS (Global Navigation Satellite System) can be enhanced further by sidereal filtering, which should however be carefully implemented to avoid adverse complications of the noise spectrum of displacements.

  6. [Eating Disorders in Female High School Students: Educational and Migration Background, School-Related Stress and Performance-Orientated Classes].

    Science.gov (United States)

    Grüttner, M

    2016-11-15

    Background: Many adolescents and young adults, especially young females, suffer from eating disorders or problematic nutrition behavior. Children and adolescents with migration background as well as from a lower social class are more likely to have eating disorders 1. Although schools are an important context in these age groups, there is a lack of scientific inquiry concerning the relationship between schooling and eating disorders. The present study investigates the relationship between performance-related stress at school and eating disorders while controlling for personnel and familial resources. Method: Interview data on the 7th grade high school students from the National Educational Panel Study (NEPS)* starting cohort 3 are used. The dependent variable is based on the SCOFF questionnaire. Logistic regressions are calculated using information from students and parents. Performance-related stress at school is operationalized by the negative deviation of realistic from idealistic educational aspirations (EA) and unfulfilled social expectations (SE), performance-oriented class climate is operationalized by students' perception of the performance-orientation of the teacher (PT) and the expectations of classmates (EC). Results: The results point towards an increased risk of suffering from an eating disorder due to performance-related school stress (EA: AME: 0.18; peating disorders. Conclusion: In order to prevent eating disorders in female high school students, attention should be paid to performance-orientation experienced at school and in the social background, and improved individual support for disadvantaged students should be made available. © Georg Thieme Verlag KG Stuttgart · New York.

  7. Digitized reality: Effects of high frame rate on visual perception

    OpenAIRE

    Loertscher, Miriam Laura; Iseli, Christian

    2016-01-01

    The digital revolution changed film production and its aesthetics in many ways. Although motion is a defining feature of moving images, it is also one of their most problematic aspects because of blurred images or other signal processing artifacts. An artistic research project was conducted to test the effects of high frame rates (HFR) on visual perception. Typical camera movements were recorded in different frame rates (24 / 48 / 96 fps) to generate test sequences for a cinema experiment. 69...

  8. A review of reaction rates in high temperature air

    Science.gov (United States)

    Park, Chul

    1989-01-01

    The existing experimental data on the rate coefficients for the chemical reactions in nonequilibrium high temperature air are reviewed and collated, and a selected set of such values is recommended for use in hypersonic flow calculations. For the reactions of neutral species, the recommended values are chosen from the experimental data that existed mostly prior to 1970, and are slightly different from those used previously. For the reactions involving ions, the recommended rate coefficients are newly chosen from the experimental data obtained more recently. The reacting environment is assumed to lack thermal equilibrium, and the rate coefficients are expressed as a function of the controlling temperature, incorporating the recent multitemperature reaction concept.

  9. THE AMERICAN HIGH SCHOOL GRADUATION RATE: TRENDS AND LEVELS*

    Science.gov (United States)

    Heckman, James J.; LaFontaine, Paul A.

    2009-01-01

    This paper applies a unified methodology to multiple data sets to estimate both the levels and trends in U.S. high school graduation rates. We establish that (a) the true rate is substantially lower than widely used measures; (b) it peaked in the early 1970s; (c) majority/minority differentials are substantial and have not converged for 35 years; (d) lower post-1970 rates are not solely due to increasing immigrant and minority populations; (e) our findings explain part of the slowdown in college attendance and rising college wage premiums; and (f) widening graduation differentials by gender help explain increasing male-female college attendance gaps. PMID:20625528

  10. High rate tests of the LHCb RICH Upgrade system

    CERN Multimedia

    Blago, Michele Piero

    2016-01-01

    One of the biggest challenges for the upgrade of the LHCb RICH detectors from 2020 is to readout the photon detectors at the full 40 MHz rate of the LHC proton-proton collisions. A test facility has been setup at CERN with the purpose to investigate the behaviour of the Multi Anode PMTs, which have been proposed for the upgrade, and their readout electronics at high trigger rates. The MaPMTs are illuminated with a monochromatic laser that can be triggered independently of the readout electronics. A first series of tests, including threshold scans, is performed at low trigger rates (20 kHz) for both the readout and the laser with the purpose to characterise the behaviour of the system under test. Then the trigger rate is increased in two separate steps. First the MaPMTs are exposed to high illumination by triggering the pulsed laser at a high (20 MHz) repetition rate while the DAQ is readout at the same low rate as before. In this way the performance of the MaPMTs and the attached electronics can be evaluated ...

  11. High strain rate superplasticity in metals and composites

    Energy Technology Data Exchange (ETDEWEB)

    Nieh, T.G.; Wadsworth, J. [Lawrence Livermore National Lab., CA (United States); Higashi, K. [Osaka Prefecture Univ., Sakai (Japan). Dept. of Mechanicl Systems Engineering

    1993-07-01

    Superplastic behavior at very high strain rates (at or above 1 s{sup {minus}1}) in metallic-based materials is an area of increasing interest. The phenomenon has been observed quite extensively in metal alloys, metal-matrix composites (MMC), and mechanically-alloyed (MA) materials. In the present paper, experimental results on high strain rate behavior in 2124 Al-based materials, including Zr-modified 2124, SiC-reinforced 2124, MA 2124, and MA 2124 MMC, are presented. Except for the required fine grain size, details of the structural requirements of this phenomenon are not yet understood. Despite this, a systematic approach to produce high strain rate superplasticity (HSRS) in metallic materials is given in this paper. Evidences indicate that the presence of a liquid phase, or a low melting point region, at boundary interfaces is responsible for HSRS.

  12. Complex pulsing schemes for high frame rate imaging

    DEFF Research Database (Denmark)

    Misaridis, Thanassis; Fink, Mathias; Jensen, Jørgen Arendt

    2002-01-01

    High frame rate ultrasound imaging can be achieved by simultaneous transmission of multiple focused beams along different directions. However, image quality degrades by the interference among beams. An alternative approach is to transmit spherical waves of a basic short pulse with frequency codin......B. With the proposed imaging strategy of pulse train excitation, a whole image can be formed with only two emissions, making it possible to obtain high quality images at a frame rate of 20 to 25 times higher than that of conventional phased array imaging......High frame rate ultrasound imaging can be achieved by simultaneous transmission of multiple focused beams along different directions. However, image quality degrades by the interference among beams. An alternative approach is to transmit spherical waves of a basic short pulse with frequency coding...

  13. Semi-solid electrodes having high rate capability

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, Yet-Ming; Duduta, Mihai; Holman, Richard; Limthongkul, Pimpa; Tan, Taison

    2017-11-28

    Embodiments described herein relate generally to electrochemical cells having high rate capability, and more particularly to devices, systems and methods of producing high capacity and high rate capability batteries having relatively thick semi-solid electrodes. In some embodiments, an electrochemical cell includes an anode, a semi-solid cathode that includes a suspension of an active material and a conductive material in a liquid electrolyte, and an ion permeable membrane disposed between the anode and the cathode. The semi-solid cathode has a thickness in the range of about 250 .mu.m-2,500 .mu.m, and the electrochemical cell has an area specific capacity of at least 5 mAh/cm.sup.2 at a C-rate of C/2.

  14. Weight gain in mice on a high caloric diet and chronically treated with omeprazole depends on sex and genetic background.

    Science.gov (United States)

    Saqui-Salces, Milena; Tsao, Amy C; Gillilland, Merritt G; Merchant, Juanita L

    2017-01-01

    The impact of omeprazole (OM), a widely used over-the-counter proton pump inhibitor, on weight gain has not been extensively explored. We examined what factors, e.g., diet composition, microbiota, genetic strain, and sex, might affect weight gain in mice fed a high caloric diet while on OM. Inbred C57BL/6J strain, a 50:50 hybrid (B6SJLF1/J) strain, and mice on a highly mixed genetic background were fed four diets: standard chow (STD, 6% fat), STD with 200 ppm OM (STD + O), a high-energy chow (HiE, 11% fat), and HiE chow with OM (HiE + O) for 17 wk. Metabolic analysis, body composition, and fecal microbiota composition were analyzed in C57BL/6J mice. Oral glucose tolerance tests were performed using mice on the mixed background. After 8 wk, female and male C57BL/6J mice on the HiE diets ate less, whereas males on the HiE diets compared with the STD diets gained weight. All diet treatments reduced energy expenditure in females but in males only those on the HiE + O diet. Gut microbiota composition differed in the C57BL/6J females but not the males. Hybrid B6SJLF1/J mice showed similar weight gain on all test diets. In contrast, mixed strain male mice fed a HiE + O diet gained ∼40% more weight than females on the same diet. In addition to increased weight gain, mixed genetic mice on the HiE + O diet cleared glucose normally but secreted more insulin. We concluded that sex and genetic background define weight gain and metabolic responses of mice on high caloric diets and OM. Copyright © 2017 the American Physiological Society.

  15. High removal rate laser-based coating removal system

    Science.gov (United States)

    Matthews, Dennis L.; Celliers, Peter M.; Hackel, Lloyd; Da Silva, Luiz B.; Dane, C. Brent; Mrowka, Stanley

    1999-11-16

    A compact laser system that removes surface coatings (such as paint, dirt, etc.) at a removal rate as high as 1000 ft.sup.2 /hr or more without damaging the surface. A high repetition rate laser with multiple amplification passes propagating through at least one optical amplifier is used, along with a delivery system consisting of a telescoping and articulating tube which also contains an evacuation system for simultaneously sweeping up the debris produced in the process. The amplified beam can be converted to an output beam by passively switching the polarization of at least one amplified beam. The system also has a personal safety system which protects against accidental exposures.

  16. Sensitivity to Envelope Interaural Time Differences at High Modulation Rates

    Science.gov (United States)

    Bleeck, Stefan; McAlpine, David

    2015-01-01

    Sensitivity to interaural time differences (ITDs) conveyed in the temporal fine structure of low-frequency tones and the modulated envelopes of high-frequency sounds are considered comparable, particularly for envelopes shaped to transmit similar fidelity of temporal information normally present for low-frequency sounds. Nevertheless, discrimination performance for envelope modulation rates above a few hundred Hertz is reported to be poor—to the point of discrimination thresholds being unattainable—compared with the much higher (>1,000 Hz) limit for low-frequency ITD sensitivity, suggesting the presence of a low-pass filter in the envelope domain. Further, performance for identical modulation rates appears to decline with increasing carrier frequency, supporting the view that the low-pass characteristics observed for envelope ITD processing is carrier-frequency dependent. Here, we assessed listeners’ sensitivity to ITDs conveyed in pure tones and in the modulated envelopes of high-frequency tones. ITD discrimination for the modulated high-frequency tones was measured as a function of both modulation rate and carrier frequency. Some well-trained listeners appear able to discriminate ITDs extremely well, even at modulation rates well beyond 500 Hz, for 4-kHz carriers. For one listener, thresholds were even obtained for a modulation rate of 800 Hz. The highest modulation rate for which thresholds could be obtained declined with increasing carrier frequency for all listeners. At 10 kHz, the highest modulation rate at which thresholds could be obtained was 600 Hz. The upper limit of sensitivity to ITDs conveyed in the envelope of high-frequency modulated sounds appears to be higher than previously considered. PMID:26721926

  17. Background dust emission following grassland fire: a snapshot across the particle-size spectrum highlights how high-resolution measurements enhance detection

    Energy Technology Data Exchange (ETDEWEB)

    Whicker, Jeffrey J [Los Alamos National Laboratory; Martin, Luis M [UNIV OF ARIZONA; Field, Jason P [UNIV OF ARIZONA; Villegas, Juan C [UNIV OF ARIZONA; Brehsears, David D [UNIV OF ARIZONA; Law, Darin J [UNIV OF ARIZONA; Urgeghe, Anna M [UNIV OF ARIZONA

    2009-01-01

    Dust emission rates vary temporally and with particle size. Many studies of dust emission focus on a particular temporal scale and the portion of the particle-size spectrum associated with a single instrument; fewer studies have assessed dust emission across the particle-size spectrum and associated temporal scales using multiple instruments. Particularly lacking are measurements following disturbances such as fire that are high-resolution and focused on finer particles - those with direct implications for human health and potential for long-distance biogeochemical transport - during less windy but more commonly occurring background conditions. We measured dust emissions in unburned and burned semiarid grassland using four different instruments spanning different combinations of temporal resolution and particle-size spectrum: Big Springs Number Eight (BSNE) and Sensit instruments for larger saltating particles, DustTrak instruments for smaller suspended particles, and Total Suspended Particulate (TSP) samplers for measuring the entire range of particle sizes. Unburned and burned sites differed in vegetation cover and aerodynamic roughness, yet surprisingly differences in dust emission rates were only detectable for saltation using BSNE and for smaller aerosols using DustTrak. Our results, surprising in the lack of consistently detected differences, indicate that high-resolution DustTrak measurements offered the greatest promise for detecting differences in background emission rates and that BSNE samplers, which integrate across height, were effective for longer intervals. More generally, our results suggest that interplay between particle size, temporal resolution, and integration across time and height can be complex and may need to be considered more explicitly for effective sampling for background dust emissions.

  18. Compressed sensing for high frame rate, high resolution and high contrast ultrasound imaging.

    Science.gov (United States)

    Jing Liu; Qiong He; Jianwen Luo

    2015-08-01

    Compressed sensing (CS) or compressive sampling allows much lower sampling frequency than the Nyquist sampling frequency. In this paper, we propose a novel technique, named compressed sensing based synthetic transmit aperture (CS-STA), to speed up the acquisition of ultrasound imaging. Ultrasound transducer transmits plane wave with random apodizations for several times and receives the corresponding echoes. The full dataset of STA is then recovered from the recorded echoes using a CS reconstruction algorithm. Finally, a standard STA beamforming is performed on the dataset to form a B-mode image. When the number of CS-STA firings is smaller than the number of STA firings, higher frame rate is achieved. In addition, CS-STA maintains the high resolution of STA because of the CS recovered full dataset of STA, and improves the contrast due to plane wave firings. Computer simulations and phantom experiments are carried out to investigate the feasibility and performance of the proposed CS-STA method. The CS-STA method is proven to be capable of obtaining simultaneously high frame rate, high solution and high contrast ultrasound imaging.

  19. GPU accelerated OCT processing at megahertz axial scan rate and high resolution video rate volumetric rendering

    Science.gov (United States)

    Jian, Yifan; Wong, Kevin; Sarunic, Marinko V.

    2013-03-01

    In this report, we describe how to highly optimize a CUDA based platform to perform real time optical coherence tomography data processing and 3D volumetric rendering using commercially-available cost-effective graphic processing units (GPUs). The maximum complete attainable axial scan processing rate (including memory transfer and rendering frame) was 2.2 megahertz for 16 bits pixel depth and 2048 pixels/A-scan, the maximum 3D volumetric rendering speed is 23 volumes/second (size:1024×256×200). To the best of our knowledge, this is the fastest processing rate reported to date with single-chip GPU and the first implementation of real time video rate volumetric OCT processing and rendering that is capable of matching the ultrahigh-speed OCT acquisition rates.

  20. Adolescent gynecomastia is associated with a high incidence of obesity, dysglycemia, and family background of diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Bindu Kulshreshtha

    2017-01-01

    Full Text Available Background: Gynecomastia during adolescence is common though etiology is not clear. We studied the clinical and hormonal profile of adolescent patients with gynecomastia. Methodology: Patients who had onset of breast development between age 10 and 20 years were included in this study. Their clinical profile, biochemical, and hormonal parameters were studied. Results: Of 94 patients with gynecomastia, 4 had hypogonadotropic hypogonadism, 4 had hypergonadotropic hypogonadism, and 1 had fibroadenosis, but in majority (90.4%, no apparent cause for breast enlargement was evident. In the idiopathic group, majority were obese (63%. Fourteen (16% patients had impaired fasting glucose or impaired glucose tolerance. Another twenty patients had subtle abnormalities (high 1 h glucose or glucose peak at 2 h. Twenty-nine percent of lean and 38% of obese patients had mild abnormalities in glucose profile. Sixty percent of patients had family background of diabetes. Obese patients had lower testosterone as compared to lean patients; however, estradiol, luteinizing hormone, and follicle-stimulating hormone levels were similar in the two groups. Conclusion: Gynecomastia during adolescence is associated with obesity, dysglycemia, and family background of diabetes mellitus.

  1. A New Approach for Estimating Background Rates of Erosion Using Concentration of Meteoric 10-Be Adhered to River Sediment: Application to the Rapidly Eroding Waipaoa Basin, New Zealand

    Science.gov (United States)

    Reusser, L. J.; Bierman, P. R.; Pavich, M.; Finkel, R.

    2007-12-01

    -day sediment yields are at least seven times higher than natural rates of sediment generation. This finding is in tight agreement with other estimates of pre-settlement sediment discharge from the Waipaoa Basin derived from middle shelf and nearby lake cores (Kettner et al., 2007; Page and Trustrum, 1997). Tributary basins (n=4) draining portions of the Waipaoa Basin dominated by landsliding in shallow soils yield an average background sediment generation rate of 106 ± 105 kg/(km2 * yr), assuming a deposition rate of 1.3 million atoms 10-Be/(cm2 * yr). Conversely, sediment shed from a basin dominated by severe gullying contains ~four times less 10-Be due to the contribution of deeply sourced material containing little or no meteoric 10-Be. Large basins to the north and south of the Waipaoa (n=3) yield similar background rates of sediment generation ranging from 0.25 to 1.6 million kg/(km2 * yr). Meteoric analysis of an additional 40 samples, as well as cross-calibration between in situ produced and meteoric 10-Be in 19 quartz-bearing samples will further test the robustness of this new approach for estimating natural rates of sediment generation and erosion.

  2. Low primary cesarean rate and high VBAC rate with good outcomes in an Amish birthing center.

    Science.gov (United States)

    Deline, James; Varnes-Epstein, Lisa; Dresang, Lee T; Gideonsen, Mark; Lynch, Laura; Frey, John J

    2012-01-01

    Recent national guidelines encourage a trial of labor after cesarean (TOLAC) as a means of increasing vaginal births after cesarean (VBACs) and decreasing the high US cesarean birth rate and its consequences (2010 National Institute of Health Consensus Statement and American College of Obstetricians and Gynecologists revised guideline). A birthing center serving Amish women in Southwestern Wisconsin offered an opportunity to look at the effects of local culture and practices that support vaginal birth and TOLAC. This study describes childbirth and perinatal outcomes during a 17-year period in LaFarge, Wisconsin. We undertook a retrospective analysis of the records of all women admitted to the birth center in labor. Main outcome measures include rates of cesarean deliveries, TOLAC and VBAC deliveries, and perinatal outcomes for 927 deliveries between 1993 and 2010. The cesarean rate was 4% (35 of 927), the TOLAC rate was 100%, and the VBAC rate was 95% (88 of 92). There were no cases of uterine rupture and no maternal deaths. The neonatal death rate of 5.4 of 1,000 was comparable to that of Wisconsin (4.6 of 1,000) and the United States (4.5 of 1,000). Both the culture of the population served and a number of factors relating to the management of labor at the birthing center have affected the rates of cesarean delivery and TOLAC. The results of the LaFarge Amish study support a low-technology approach to delivery where good outcomes are achieved with low cesarean and high VBAC rates.

  3. Electrophoretic Deposition of Gallium with High Deposition Rate

    Directory of Open Access Journals (Sweden)

    Hanfei Zhang

    2014-12-01

    Full Text Available In this work, electrophoretic deposition (EPD is reported to form gallium thin film with high deposition rate and low cost while avoiding the highly toxic chemicals typically used in electroplating. A maximum deposition rate of ~0.6 μm/min, almost one order of magnitude higher than the typical value reported for electroplating, is obtained when employing a set of proper deposition parameters. The thickness of the film is shown to increase with deposition time when sequential deposition is employed. The concentration of Mg(NO32, the charging salt, is also found to be a critical factor to control the deposition rate. Various gallium micropatterns are obtained by masking the substrate during the process, demonstrating process compatibility with microfabrication. The reported novel approach can potentially be employed in a broad range of applications with Ga as a raw material, including microelectronics, photovoltaic cells, and flexible liquid metal microelectrodes.

  4. High ratings of satisfaction with fertility treatment are common

    DEFF Research Database (Denmark)

    Schmidt, L; Holstein, B E; Boivin, J

    2003-01-01

    /delivery and the report of marital benefits resulting from the infertility experience. Lower social class was a significant predictor for satisfaction. CONCLUSIONS: Both men and women in fertility treatment had high ratings on medical and patient-centred care. It seemed that satisfaction with the psychosocial services...

  5. Advances in high rate anaerobic treatment: staging of reactor systems.

    NARCIS (Netherlands)

    Lier, van J.B.; Zee, van der F.P.; Tan, N.C.G.; Rebac, S.; Kleerebezem, R.

    2001-01-01

    Anaerobic wastewater treatment (AnWT) is considered as the most cost-effective solution for organically polluted industrial waste streams. Particularly the development of high-rate systems, in which hydraulic retention times are uncoupled from solids retention times, has led to a world-wide

  6. High rate of teenage pregnancy and sexually transmitted infections ...

    African Journals Online (AJOL)

    There is increased in teenage pregnancy despite the presence of dual protection practice and health care awareness programmes related to health and sexuality education in South Africa. The present study explores the underlying causes of high teenage pregnancy and sexually transmitted diseases rates, including HIV ...

  7. High Frame Rate Synthetic Aperture 3D Vector Flow Imaging

    DEFF Research Database (Denmark)

    Villagómez Hoyos, Carlos Armando; Holbek, Simon; Stuart, Matthias Bo

    2016-01-01

    , current volumetric ultrasonic flow methods are limited to one velocity component or restricted to a reduced field of view (FOV), e.g. fixed imaging planes, in exchange for higher temporal resolutions. To solve these problems, a previously proposed accurate 2-D high frame rate vector flow imaging (VFI...

  8. Minimum Variance Beamforming for High Frame-Rate Ultrasound Imaging

    DEFF Research Database (Denmark)

    Holfort, Iben Kraglund; Gran, Fredrik; Jensen, Jørgen Arendt

    2007-01-01

    emissions. An increase in resolution is seen when using only one single emission. Furthermore, it is seen that an increase of the number of emissions does not alter the FWHM. Thus, the MV beamformer introduces the possibility for high frame-rate imaging with increased resolution....

  9. Behaviour of uranium alloys at high loading rates

    Energy Technology Data Exchange (ETDEWEB)

    Rolc, S.; Pechacek, J.; Krejci, J. (Ceskoslovenska Akademie Ved, Brno (CS). Ustav Fyzikalni Metalurgie); Buchar, J.

    1991-10-01

    The mechanical behaviour of depleted uranium, uranium with molybdenum, niobium, titanium and rhenium was investigated under high strain rates. The Hopkinson split pressure bar was used. The spallation of these materials was also studied. The correlation of the spall strength, {sigma}{sub c}, with flow properties was found. 11 refs., 4 figs., 1 tab..

  10. High rates of catalytic hydrogen combustion with air over coated ...

    Indian Academy of Sciences (India)

    BHASKAR DEVU MUKRI

    2017-08-02

    Aug 2, 2017 ... High rates of catalytic hydrogen combustion with air over. Ti0.97Pd0.03O2−δ coated cordierite monolith. BHASKAR DEVU MUKRI. ∗ and M S HEGDE. Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012, India. E-mail: bhaskardm@gmail.com. MS received 9 May 2017; ...

  11. Temporal dynamics of high repetition rate pulsed single longitudinal ...

    Indian Academy of Sciences (India)

    Theoretical and experimental studies of temporal dynamics of grazing incidence grating (GIG) cavity, single-mode dye laser pumped by high repetition rate copper vapour laser (CVL) are presented. Spectral chirp of the dye laser as they evolve in the cavity due to transient phase dynamics of the amplifier gain medium is ...

  12. Adapting high-rate anaerobic treatment to Middle East conditions

    NARCIS (Netherlands)

    Mahmoud, N.A.; Zeeman, G.; Lier, van J.B.

    2008-01-01

    High-rate anaerobic technologies offer cost-effective solutions for sewage treatment in the Middle East and Palestine in particular. The sewage characteristics in Palestine are quite different from the values elsewhere and show solids contents of more than 1000 mg chemical oxygen demand (COD)ss/L

  13. Plant respirometer enables high resolution of oxygen consumption rates

    Science.gov (United States)

    Foster, D. L.

    1966-01-01

    Plant respirometer permits high resolution of relatively small changes in the rate of oxygen consumed by plant organisms undergoing oxidative metabolism in a nonphotosynthetic state. The two stage supply and monitoring system operates by a differential pressure transducer and provides a calibrated output by digital or analog signals.

  14. Methanol conversion in high-rate anaerobic reactors

    NARCIS (Netherlands)

    Weijma, J.; Stams, A.J.M.

    2001-01-01

    An overview on methanol conversion in high-rate anaerobic reactors is presented, with the focus on technological as well as microbiological aspects. The simple C1-compound methanol can be degraded anaerobically in a complex way, in which methanogens, sulfate reducing bacteria and homoacetogens

  15. Twinning in copper deformed at high strain rates

    Indian Academy of Sciences (India)

    †Department of Physics, Nelson Mandela Metropolitan University, Port Elizabeth, South Africa. MS received 25 February 2010; revised 13 August 2012. Abstract. Copper samples having varying microstructures were deformed at high strain rates using a split-. Hopkinson pressure bar. Transmission electron microscopy ...

  16. Background Opacities

    NARCIS (Netherlands)

    Kamp, I.; Monier, R.; Smalley, B.; Wahlgren, G.; Stee, Ph.

    2010-01-01

    In NLTE computations of trace elements in stellar atmospheres, background opacities are generally treated in LTE. It is thus important to assess the impact of different methods of including this background opacity on the statistical equilibrium of the trace element and its resulting NLTE abundance.

  17. Vaccination rates among the general adult population and high-risk groups in the United States.

    Directory of Open Access Journals (Sweden)

    Kathy Annunziata

    Full Text Available BACKGROUND: In order to adequately assess the effectiveness of vaccination in helping to control vaccine-preventable infectious disease, it is important to identify the adherence and uptake of risk-based recommendations. METHODS: The current project includes data from five consecutive datasets of the National Health and Wellness Survey (NHWS: 2007 through 2011. The NHWS is an annual, Internet-based health questionnaire, administered to a nationwide sample of adults (aged 18 or older which included items on vaccination history as well as high-risk group status. Vaccination rates and characteristics of vaccinees were reported descriptively. Logistic regressions were conducted to predict vaccination behavior from sociodemographics and risk-related variables. RESULTS: The influenza vaccination rate for all adults 18 years and older has increased significantly from 28.0% to 36.2% from 2007 to 2011 (ps<.05. Compared with those not at high risk (25.1%, all high-risk groups were vaccinated at a higher rate, from 36.8% (pregnant women to 69.7% (those with renal/kidney disease; however, considerable variability among high-risk groups was observed. Vaccination rates among high-risk groups for other vaccines varied considerably though all were below 50%, with the exception of immunocompromised respondents (57.5% for the hepatitis B vaccine and 52.5% for the pneumococcal vaccine and the elderly (50.4% for the pneumococcal. Multiple risk factors were associated with increased rate of vaccination for most vaccines. Significant racial/ethnic differences with influenza, hepatitis, and herpes zoster vaccination rates were also observed (ps<.05. CONCLUSIONS: Rates of influenza vaccination have increased over time. Rates varied by high-risk status, demographics, and vaccine. There was a pattern of modest vaccination rate increases for individuals with multiple risk factors. However, there were relatively low rates of vaccination for most risk-based recommendations

  18. High signal in bone marrow at diffusion-weighted imaging with body background suppression (DWIBS) in healthy children

    Energy Technology Data Exchange (ETDEWEB)

    Ording Mueller, Lil-Sofie; Avenarius, Derk [University Hospital North Norway, Department of Radiology, Tromsoe (Norway); Olsen, Oeystein E. [Great Ormond Street Hospital for Children, Department of Radiology, London (United Kingdom)

    2011-02-15

    In our experience, diffusion-weighted imaging with body background suppression (DWIBS) is hard to interpret in children who commonly have foci of restricted diffusion in their skeletons unrelated to pathology, sometimes in an asymmetrical pattern. This raises serious concern about the accuracy of DWIBS in cancer staging in children. To describe the signal distribution at DWIBS in the normal developing lumbar spine and pelvic skeleton. Forty-two healthy children underwent an MR DWIBS sequence of the abdomen and pelvis. An axial short-tau inversion-recovery (STIR) echo-planar imaging (EPI) pulse sequence was used. Two radiologists did a primary review of the images and based on these preliminary observations, separate scoring systems for the lumbar spine, pelvis and proximal femoral epiphyses/femoral heads were devised. Visual evaluation of the images was then performed by the two radiologists in consensus. The scoring was repeated separately 2 months later by a third radiologist. Restricted diffusion was defined as areas of high signal compared to the background. Coronal maximum intensity projection (MIP) reformats were used to assess the vertebral bodies. For the pelvis, the extension of high signal for each bone was given a score of 0 to 4. Cohen's Kappa interobserver agreement coefficients of signal distribution and asymmetry were calculated. All children had areas of high signal, both within the lumbar vertebral bodies and within the pelvic skeleton. Three patterns of signal distribution were seen in the lumbar spine, but no specific pattern was seen in the pelvis. There was a tendency toward a reduction of relative area of high signal within each bone with age, but also a widespread interindividual variation. Restricted diffusion is a normal finding in the pelvic skeleton and lumbar spine in children with an asymmetrical distribution seen in 48% of normal children in this study. DWIBS should be used with caution for cancer staging in children as this could

  19. The main natural lows of high-rate coal pyrolysis

    Directory of Open Access Journals (Sweden)

    Chemyavsky Nikola V.

    2003-01-01

    Full Text Available The importance of coal pyrolysis studies for the development of energy technologies is evident, since pvrolysis is the first stage of any process of coal thermal conversion. In combustion, pyrolysis determines conditions of coal ignition and the rate of char after-burning, in gasification, pyrolysis determines total yield of gasification products. It must be noted that in modern energy technologies pyrolysis occurs at high late of coal particle heating (=10 K/s for different fluidized bed, or FB-technologies or super-high-rate (>10**5 K/s for entrained-flow gasification, and in some of them at high pressure. In CETI during last 12 years the detailed study of pyrolysis in FB laboratory-scale PYROLYSIS-D plant and entramed-flow pilot-scale GSP-01 plant, was carried out. In this paper main results of mentioned investigations are given. Kinetic constants for bituminous coals and anthracite high heating rates in entrained flow for high temperatures (>1500 °C and >1900 °C, and in fluidized bed conditions in temperature range 972-1273 K. In order to describe data obtained in fluidized bed conditions, G--model based method of calculation of devolatization dynamics was suited to FB heating conditions. Calculated and experimental kinetic data are in good agreement. The result proves that at FB-pvrolysis conditions intrinsic mass-transfer limitations are negligible and devolatilization is really kinetic-controlled.

  20. Miniaturized Stretchable and High-Rate Linear Supercapacitors

    Science.gov (United States)

    Zhu, Wenjun; Zhang, Yang; Zhou, Xiaoshuang; Xu, Jiang; Liu, Zunfeng; Yuan, Ningyi; Ding, Jianning

    2017-07-01

    Linear stretchable supercapacitors have attracted much attention because they are well suited to applications in the rapidly expanding field of wearable electronics. However, poor conductivity of the electrode material, which limits the transfer of electrons in the axial direction of the linear supercapacitors, leads to a serious loss of capacity at high rates. To solve this problem, we use gold nanoparticles to decorate aligned multiwall carbon nanotube to fabricate stretchable linear electrodes. Furthermore, we have developed fine stretchable linear supercapacitors, which exhibited an extremely high elasticity up to 400% strain with a high capacitance of about 8.7 F g-1 at the discharge current of 1 A g-1.

  1. A High Rate Tension Device for Characterizing Brain Tissue

    CERN Document Server

    Rashid, Badar; Gilchrist, Michael; 10.1177/1754337112436900

    2013-01-01

    The mechanical characterization of brain tissue at high loading velocities is vital for understanding and modeling Traumatic Brain Injury (TBI). The most severe form of TBI is diffuse axonal injury (DAI) which involves damage to individual nerve cells (neurons). DAI in animals and humans occurs at strains > 10% and strain rates > 10/s. The mechanical properties of brain tissues at these strains and strain rates are of particular significance, as they can be used in finite element human head models to accurately predict brain injuries under different impact conditions. Existing conventional tensile testing machines can only achieve maximum loading velocities of 500 mm/min, whereas the Kolsky bar apparatus is more suitable for strain rates > 100/s. In this study, a custom-designed high rate tension device is developed and calibrated to estimate the mechanical properties of brain tissue in tension at strain rates < 90/s, while maintaining a uniform velocity. The range of strain can also be extended to 100% de...

  2. Background-Suppressed MR Venography of the Brain Using Magnitude Data: A High-Pass Filtering Approach

    Directory of Open Access Journals (Sweden)

    Zhaoyang Jin

    2014-01-01

    Full Text Available Conventional susceptibility-weighted imaging (SWI uses both phase and magnitude data for the enhancement of venous vasculature and, thus, is subject to signal loss in regions with severe field inhomogeneity and in the peripheral regions of the brain in the minimum-intensity projection. The purpose of this study is to enhance the visibility of the venous vasculature and reduce the artifacts in the venography by suppressing the background signal in postprocessing. A high-pass filter with an inverted Hamming window or an inverted Fermi window was applied to the Fourier domain of the magnitude images to enhance the visibility of the venous vasculature in the brain after data acquisition. The high-pass filtering approach has the advantages of enhancing the visibility of small veins, diminishing the off-resonance artifact, reducing signal loss in the peripheral regions of the brain in projection, and nearly completely suppressing the background signal. The proposed postprocessing technique is effective for the visualization of small venous vasculature using the magnitude data alone.

  3. High temporal resolution measurements of ozone precursors in a rural background station. A two-year study.

    Science.gov (United States)

    Navazo, M; Durana, N; Alonso, L; Gómez, M C; García, J A; Ilardia, J L; Gangoiti, G; Iza, J

    2008-01-01

    We present a very complete database of individual non-methane hydrocarbon (NMHC) measurements with high temporal resolution (hourly) in a rural background atmosphere. We show their use to characterize the biogenic NMHC as well as to identify the transport and impact of anthropogenic NMHC on rural areas. In January 2003 an automatic GC-FID analyzer of volatile organic compounds between 2 and 10 carbon atoms (C2-C10 VOCs) was placed in the centre of the Valderejo Natural Park in northern Iberia (42.87 degrees N, 3.22 degrees W), far away from important cities. The system operated continuously until December 2004. Data coverage was higher than 70% for a total of 59 VOC of both anthropogenic and biogenic origin, with detection limits in the range of pptv. Our results allow for the description of the behaviour of these compounds, in order to identify external impacts arriving to the sampling site which has been recognized to be highly representative of a rural background atmosphere. Biogenic VOC concentrations have been compared also with the calculated emissions, using Guenther's algorithm, and the discrepancies interpreted in terms of the different reactivity of such compounds.

  4. A model for low dose effects of low-LET radiation delivered at high dose rates

    Science.gov (United States)

    Schöllnberger, H.; Stewart, R.D.; Mitchel, R.E.J.

    2011-01-01

    In vitro studies show that protective tumour-reducing effects occur for low dose rates (mGy per minute). To account for these phenomena, we have previously developed stochastic and deterministic multi-stage cancer models that include radiation-induced adaptations in DNA repair processes and radical scavenging. Here, these models are extended to account for the induction of radioprotective mechanisms for low doses of low LET radiation delivered at high dose rates. Cellular adaptations in DNA repair are related to temporal changes in the amount of DNA damage in a cell. The combined effects of endogenous DNA damage, background radiation and artificial irradiation are considered. PMID:22318364

  5. High-frame-rate echocardiography with reduced sidelobe level.

    Science.gov (United States)

    Hasegawa, Hideyuki; Kanai, Hiroshi

    2012-11-01

    Echocardiography has become an indispensable modality for diagnosis of the heart. It enables observation of the shape of the heart and estimation of global heart function based on B-mode and M-mode imaging. Methods for echocardiographic estimation of myocardial strain and strain rate have also been developed to evaluate regional heart function. Furthermore, it has been recently shown that echocardiographic measurements of transmural transition of myocardial contraction/relaxation and propagation of vibration caused by closure of the heart valve would be useful for evaluation of myocardial function and viscoelasticity. However, such measurements require a frame rate (typically >200 Hz) much higher than that achieved by conventional ultrasonic diagnostic equipment. We have recently realized a high frame rate of about 300 Hz with a full field of view of 90° using diverging transmit beams and parallel receive beamforming. Although high-frame-rate imaging was made possible by this method, the side lobe level was slightly larger than that of the conventional method. To reduce the side lobe level, phase coherence imaging has recently been developed. Using this method, the spatial resolution is improved and the side lobe level is also reduced. However, speckle-like echoes, for example, echoes from the inside of the heart wall, are also suppressed. In the present study, a method for reducing the side lobe level while preserving speckle-like echoes was developed. The side lobe level was evaluated using a wire phantom. The side lobe level of the high-frame-rate imaging using unfocused diverging beams was improved by 13.3 dB by the proposed method. In in vivo measurements, a B-mode image of the heart of a 23-year-old healthy male could be obtained while preserving the speckle pattern in the heart wall at a frame rate of 316 Hz with a full field of view of 90°.

  6. Highly variable rates of genome rearrangements between hemiascomycetous yeast lineages.

    Directory of Open Access Journals (Sweden)

    2006-03-01

    Full Text Available Hemiascomycete yeasts cover an evolutionary span comparable to that of the entire phylum of chordates. Since this group currently contains the largest number of complete genome sequences it presents unique opportunities to understand the evolution of genome organization in eukaryotes. We inferred rates of genome instability on all branches of a phylogenetic tree for 11 species and calculated species-specific rates of genome rearrangements. We characterized all inversion events that occurred within synteny blocks between six representatives of the different lineages. We show that the rates of macro- and microrearrangements of gene order are correlated within individual lineages but are highly variable across different lineages. The most unstable genomes correspond to the pathogenic yeasts Candida albicans and Candida glabrata. Chromosomal maps have been intensively shuffled by numerous interchromosomal rearrangements, even between species that have retained a very high physical fraction of their genomes within small synteny blocks. Despite this intensive reshuffling of gene positions, essential genes, which cluster in low recombination regions in the genome of Saccharomyces cerevisiae, tend to remain syntenic during evolution. This work reveals that the high plasticity of eukaryotic genomes results from rearrangement rates that vary between lineages but also at different evolutionary times of a given lineage.

  7. Testing of fiber composites at high strain rates

    Science.gov (United States)

    Daniel, I. M.; Liber, T.

    1978-01-01

    An experimental investigation was conducted to determine strain rate effects in fiber composites. Unidirectional composite specimens of boron/epoxy, graphite/epoxy, S-glass/epoxy and Kevlar/epoxy were tested at tensile strain rates of up to 27 m/m/sec. Longitudinal, transverse and in-plane shear properties, including modulus, Poisson's ratio, strength and ultimate strain, were determined by testing 0-, 90and 10-degree unidirectional coupons. Strains were measured by means of strain gages bonded on the coupons and loads were measured by means of a strain gage load cell. All specimens were loaded in an electrohydraulic loading system. The 0-degree properties which are governed by the fibers do not vary much with strain rate except for the Kevlar/epoxy material which shows an increase in both modulus and strength. The strain rate effects on 90-degree properties were small with a general trend toward higher strength with increasing strain rate. The most noticeable effect was on in-plane shear properties with shear strength values at high strain rates approximately fifteen percent higher than static values.

  8. High triacylglycerol turnover rate in human skeletal muscle

    DEFF Research Database (Denmark)

    Sacchetti, Massimo; Saltin, Bengt; Olsen, David B

    2004-01-01

    could be due to the observed decline in plasma insulin concentration (-74%, P skeletal muscle in post-absorptive healthy individuals is esterified into IMTAG, due to its high turnover rate (29 h pool(-1)). An increase in FA level...... into IMTAG in vastus lateralis muscle was determined during two consecutive 4-h periods (2-6 h and 6-10 h). Fifty to sixty per cent of the FA taken up from the circulation were esterified into IMTAG, whereas 32 and 42% were oxidized between 2-6 and 6-10 h, respectively. IMTAG fractional synthesis rate was 3...

  9. High shear rate rheometry of low-viscosity liquids

    Science.gov (United States)

    Lodge, Arthur S.

    1987-11-01

    A new instrument called LODGE STRESSMETER was developed to measure the shear elasticity and viscosity of general and multigrade oils at high shear rates. This will make possible the measurements of normal stress difference N1 for values of shear rate up to 5 x 10 to the 5th power is temperature of 150 C. New surprising data show (as yet unexplained) the the N1 contribution to the minimum oil film thickness could be as much as 75 percent of the contribution from viscosity. This raises hope for the use of oils with lower viscosity, leading to improved fuel economy and an increase in the range of motorized vehicles.

  10. Dynamic High-Temperature Characterization of an Iridium Alloy in Compression at High Strain Rates

    Energy Technology Data Exchange (ETDEWEB)

    Song, Bo [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Experimental Environment Simulation Dept.; Nelson, Kevin [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Mechanics of Materials Dept.; Lipinski, Ronald J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Advanced Nuclear Fuel Cycle Technology Dept.; Bignell, John L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Structural and Thermal Analysis Dept.; Ulrich, G. B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Radioisotope Power Systems Program; George, E. P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Radioisotope Power Systems Program

    2014-06-01

    Iridium alloys have superior strength and ductility at elevated temperatures, making them useful as structural materials for certain high-temperature applications. However, experimental data on their high-temperature high-strain-rate performance are needed for understanding high-speed impacts in severe elevated-temperature environments. Kolsky bars (also called split Hopkinson bars) have been extensively employed for high-strain-rate characterization of materials at room temperature, but it has been challenging to adapt them for the measurement of dynamic properties at high temperatures. Current high-temperature Kolsky compression bar techniques are not capable of obtaining satisfactory high-temperature high-strain-rate stress-strain response of thin iridium specimens investigated in this study. We analyzed the difficulties encountered in high-temperature Kolsky compression bar testing of thin iridium alloy specimens. Appropriate modifications were made to the current high-temperature Kolsky compression bar technique to obtain reliable compressive stress-strain response of an iridium alloy at high strain rates (300 – 10000 s-1) and temperatures (750°C and 1030°C). Uncertainties in such high-temperature high-strain-rate experiments on thin iridium specimens were also analyzed. The compressive stress-strain response of the iridium alloy showed significant sensitivity to strain rate and temperature.

  11. Development of Fast High-Resolution Muon Drift-Tube Detectors for High Counting Rates

    CERN Document Server

    INSPIRE-00287945; Dubbert, J.; Horvat, S.; Kortner, O.; Kroha, H.; Legger, F.; Richter, R.; Adomeit, S.; Biebel, O.; Engl, A.; Hertenberger, R.; Rauscher, F.; Zibell, A.

    2011-01-01

    Pressurized drift-tube chambers are e?cient detectors for high-precision tracking over large areas. The Monitored Drift-Tube (MDT) chambers of the muon spectrometer of the ATLAS detector at the Large Hadron Collider (LHC) reach a spatial resolution of 35 micons and almost 100% tracking e?ciency with 6 layers of 30 mm diameter drift tubes operated with Ar:CO2 (93:7) gas mixture at 3 bar and a gas gain of 20000. The ATLAS MDT chambers are designed to cope with background counting rates due to neutrons and gamma-rays of up to about 300 kHz per tube which will be exceeded for LHC luminosities larger than the design value of 10-34 per square cm and second. Decreasing the drift-tube diameter to 15 mm while keeping the other parameters, including the gas gain, unchanged reduces the maximum drift time from about 700 ns to 200 ns and the drift-tube occupancy by a factor of 7. New drift-tube chambers for the endcap regions of the ATLAS muon spectrometer have been designed. A prototype chamber consisting of 12 times 8 l...

  12. Background Material

    DEFF Research Database (Denmark)

    Zandersen, Marianne; Hyytiäinen, Kari; Saraiva, Sofia

    This document serves as a background material to the BONUS Pilot Scenario Workshop, which aims to develop harmonised regional storylines of socio-ecological futures in the Baltic Sea region in a collaborative effort together with other BONUS projects and stakeholders.......This document serves as a background material to the BONUS Pilot Scenario Workshop, which aims to develop harmonised regional storylines of socio-ecological futures in the Baltic Sea region in a collaborative effort together with other BONUS projects and stakeholders....

  13. High Pressure Burn Rate Measurements on an Ammonium Perchlorate Propellant

    Energy Technology Data Exchange (ETDEWEB)

    Glascoe, E A; Tan, N

    2010-04-21

    High pressure deflagration rate measurements of a unique ammonium perchlorate (AP) based propellant are required to design the base burn motor for a Raytheon weapon system. The results of these deflagration rate measurements will be key in assessing safety and performance of the system. In particular, the system may experience transient pressures on the order of 100's of MPa (10's kPSI). Previous studies on similar AP based materials demonstrate that low pressure (e.g. P < 10 MPa or 1500 PSI) burn rates can be quite different than the elevated pressure deflagration rate measurements (see References and HPP results discussed herein), hence elevated pressure measurements are necessary in order understand the deflagration behavior under relevant conditions. Previous work on explosives have shown that at 100's of MPa some explosives will transition from a laminar burn mechanism to a convective burn mechanism in a process termed deconsolidative burning. The resulting burn rates that are orders-of-magnitude faster than the laminar burn rates. Materials that transition to the deconsolidative-convective burn mechanism at elevated pressures have been shown to be considerably more violent in confined heating experiments (i.e. cook-off scenarios). The mechanisms of propellant and explosive deflagration are extremely complex and include both chemical, and mechanical processes, hence predicting the behavior and rate of a novel material or formulation is difficult if not impossible. In this work, the AP/HTPB based material, TAL-1503 (B-2049), was burned in a constant volume apparatus in argon up to 300 MPa (ca. 44 kPSI). The burn rate and pressure were measured in-situ and used to calculate a pressure dependent burn rate. In general, the material appears to burn in a laminar fashion at these elevated pressures. The experiment was reproduced multiple times and the burn rate law using the best data is B = (0.6 {+-} 0.1) x P{sup (1.05{+-}0.02)} where B is the burn

  14. Background Checks for all Gun Buyers and Gun Violence Restraining Orders: State Efforts to Keep Guns from High-Risk Persons.

    Science.gov (United States)

    Vernick, Jon S; Alcorn, Ted; Horwitz, Joshua

    2017-03-01

    There were more than 36,000 firearm-related deaths in the U.S. in 2015. Under federal law, a background check is required only for gun purchases from licensed dealers. Research suggests that some persons prohibited from owning a gun turn to private sellers, including those identified online, to attempt to obtain a firearm. State-level approaches to make it more difficult for high-risk persons to purchase or possess firearms include universal background check (UBC) and gun violence restraining order (GVRO) laws. UBC laws, on the books in 18 states as of the end of 2016, can reduce both homicide and suicide rates. After Colorado adopted a UBC law in 2013, the number of background checks conducted by private sellers for sales occurring at places other than gun shows steadily increased. GVRO laws give law enforcement and families the authority to petition a court to temporarily remove firearms from an individual who presents a danger to himself or others during times of crisis, regardless of whether that person has been diagnosed with a mental illness. California enacted a GVRO law in 2014. Data are emerging to suggest the effectiveness of GVRO-type laws at averting suicides and providing an entryway to services.

  15. Perinatal outcomes in a South Asian setting with high rates of low birth weight

    Directory of Open Access Journals (Sweden)

    Joseph K S

    2009-02-01

    Full Text Available Abstract Background It is unclear whether the high rates of low birth weight in South Asia are due to poor fetal growth or short pregnancy duration. Also, it is not known whether the traditional focus on preventing low birth weight has been successful. We addressed these and related issues by studying births in Kaniyambadi, South India, with births from Nova Scotia, Canada serving as a reference. Methods Population-based data for 1986 to 2005 were obtained from the birth database of the Community Health and Development program in Kaniyambadi and from the Nova Scotia Atlee Perinatal Database. Menstrual dates were used to obtain comparable information on gestational age. Small-for-gestational age (SGA live births were identified using both a recent Canadian and an older Indian fetal growth standard. Results The low birth weight and preterm birth rates were 17.0% versus 5.5% and 12.3% versus 6.9% in Kaniyambadi and Nova Scotia, respectively. SGA rates were 46.9% in Kaniyambadi and 7.5% in Nova Scotia when the Canadian fetal growth standard was used to define SGA and 6.7% in Kaniyambadi and Conclusion High rates of fetal growth restriction and relatively high rates of preterm birth are responsible for the high rates of low birth weight in South Asia. Increased emphasis is required on health services that address the morbidity and mortality in all birth weight categories.

  16. High-rate measurement-device-independent quantum cryptography

    DEFF Research Database (Denmark)

    Pirandola, Stefano; Ottaviani, Carlo; Spedalieri, Gaetana

    2015-01-01

    Quantum cryptography achieves a formidable task - the remote distribution of secret keys by exploiting the fundamental laws of physics. Quantum cryptography is now headed towards solving the practical problem of constructing scalable and secure quantum networks. A significant step in this direction...... than those currently achieved. Our protocol could be employed to build high-rate quantum networks where devices securely connect to nearby access points or proxy servers....

  17. MIMO-OFDM for High Rate Underwater Acoustic Communications

    Science.gov (United States)

    2009-10-01

    Doppler estimation The channel Doppler effect can be viewed as caused by carrier frequency offsets (CFO) among the transmitters and the receivers [14...at es in H z 500m 1500m Fig. 4. Doppler estimates for one packet of 64 OFDM blocks at receiver 1; this Doppler shift is due to unintentional...IEEE JOURNAL OF OCEANIC ENGINEERING (TO APPEAR) 1 MIMO- OFDM for High Rate Underwater Acoustic Communications Baosheng Li, Student Member, IEEE, Jie

  18. Chromosome aberrations in peripheral blood lymphocytes of individuals living in high background radiation areas of Ramsar, Iran.

    Science.gov (United States)

    Zakeri, F; Rajabpour, M R; Haeri, S A; Kanda, R; Hayata, I; Nakamura, S; Sugahara, T; Ahmadpour, M J

    2011-11-01

    In order to investigate the biological effects of exposure to low-dose radiation and to assess the dose-effect relationship in residents of high background radiation areas (HBRAs) of Ramsar, cytogenetic investigation of unstable-type aberrations was performed in 15 healthy elderly women in a HBRA of Ramsar, Talesh mahalle, and in 10 elderly women living in a nearby control area with normal background radiation. In total, 77,714 cells were analyzed; 48,819 cells in HBRA residents and 28,895 cells in controls. On average, 3,108 cells per subject were analyzed (range 1,475-5,007 cells). Significant differences were found in the frequency of dicentric plus centric rings in 100 cells (0.207 ± 0.103 vs. 0.047 ± 0.027, p Ramsar, no positive correlation was found between the frequency of dicentric plus centric ring aberrations and the cumulative dose of the inhabitants estimated by direct individual dosimetry; however, obvious trends of increase with age appeared in the control group. Based on these results, individuals residing in HBRAs of Ramsar have an increased frequency of detectable abnormalities in unstable aberrations.

  19. High CD20+ background cells predict a favorable outcome in classical Hodgkin lymphoma and antagonize CD68+ macrophages.

    Science.gov (United States)

    Panico, Luigi; Tenneriello, Valentina; Ronconi, Fioravante; Lepore, Marianna; Cantore, Nicola; Dell'Angelo, Antonietta Carmela; Ferbo, Ludovica; Ferrara, Felicetto

    2015-06-01

    We studied by immunohistochemistry the background CD20 + cells in 131 cases of classical Hodgkin lymphoma (cHL). High CD20 + dispersed cells (CD20BG) showed a significant correlation with longer overall survival (OS) and a trend toward improved progression-free survival (PFS). At multivariate analysis high CD20BG was also an independent prognostic factor of improved PFS and OS. The prognostic role of CD20BG seems to be opposite with respect to tumor associated macrophages (TAMs) we studied previously in most cases of the series. We scored patients on the basis of the respective CD20BG and TAM count and found that the combination of low CD20BG and high TAMs was related to a significantly reduced PFS and OS at univariate and multivariate analysis. Microenvironment CD20 + cells seem to play a favorable prognostic role in cHL. Depletion of CD20 + cells together with an increase of TAMs identifies a group of patients with high-risk disease.

  20. Avalanche photo-detection for high data rate applications

    Science.gov (United States)

    Coldenstrodt-Ronge, H. B.; Silberhorn, C.

    2007-10-01

    Avalanche photo-detection is commonly used in applications which require single-photon sensitivity. We examine the limits of using avalanche photo-diodes (APD) for characterizing photon statistics at high data rates. To identify the regime of linear APD operation, we employ a ps-pulsed diode laser with variable repetition rates between 0.5 MHz and 80 MHz. We modify the mean optical power of the coherent pulses by applying different levels of well-calibrated attenuation. The linearity at high repetition rates is limited by the APD dead time and a nonlinear response arises at higher photon-numbers due to multiphoton events. Assuming Poissonian input-light statistics we ascertain the effective mean photon-number of the incident light with high accuracy. Time multiplexed detectors (TMD) allow us to accomplish photon-number resolution by 'photon chopping'. This detection setup extends the linear response function to higher photon-numbers and statistical methods may be used to compensate for nonlinearity. We investigate this effect, compare it to the single APD case and show the validity of the convolution treatment in the TMD data analysis.

  1. Semi-solid electrodes having high rate capability

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, Yet-Ming; Duduta, Mihai; Holman, Richard; Limthongkul, Pimpa; Tan, Taison

    2017-11-28

    Embodiments described herein relate generally to electrochemical cells having high rate capability, and more particularly to devices, systems and methods of producing high capacity and high rate capability batteries having relatively thick semi-solid electrodes. In some embodiments, an electrochemical cell includes an anode and a semi-solid cathode. The semi-solid cathode includes a suspension of an active material of about 35% to about 75% by volume of an active material and about 0.5% to about 8% by volume of a conductive material in a non-aqueous liquid electrolyte. An ion-permeable membrane is disposed between the anode and the semi-solid cathode. The semi-solid cathode has a thickness of about 250 .mu.m to about 2,000 .mu.m, and the electrochemical cell has an area specific capacity of at least about 7 mAh/cm.sup.2 at a C-rate of C/4. In some embodiments, the semi-solid cathode slurry has a mixing index of at least about 0.9.

  2. The flip-over effect in pulsed laser deposition: Is it relevant at high background gas pressures?

    Energy Technology Data Exchange (ETDEWEB)

    Ojeda-G-P, Alejandro [Paul Scherrer Institut, General Energy Research Department, 5232 Villigen-PSI (Switzerland); Schneider, Christof W., E-mail: christof.schneider@psi.ch [Paul Scherrer Institut, General Energy Research Department, 5232 Villigen-PSI (Switzerland); Döbeli, Max [Ion Beam Physics, ETH Zurich, CH-8093 Zurich (Switzerland); Lippert, Thomas; Wokaun, Alexander [Paul Scherrer Institut, General Energy Research Department, 5232 Villigen-PSI (Switzerland)

    2015-12-01

    Highlights: • The flip-over effect in PLD is observed up to high deposition pressures. • Consistent congruent transfer of the target composition is generally not correct. • The choice of deposition pressure can change the film composition strongly. • Large compositional changes appear at high off-axis angles and large spot sizes. - Abstract: In pulsed laser deposition the use of a rectangular or elliptical beam spot with a non 1:1 aspect ratio leads to the so called flip-over effect. Here, the longest dimension of the laser spot results in the shortest direction of plasma plume expansion. This effect has been mainly reported for vacuum depositions of single element targets and is particularly noticeable when the aspect ratio of the beam spot is large. We investigate the flip-over effect in vacuum and at three relevant background-gas pressures for pulsed laser deposition using a La{sub 0.4}Ca{sub 0.6}MnO{sub 3} target by measuring the thickness dependence of the deposited material as a function of angle. The film thicknesses and compositions are determined by Rutherford backscattering and argon is used to reduce the influence of additional chemical reactions in the plasma. The results show the prevalence of the flip-over effect for all pressures except for the highest, i.e. 1 × 10{sup −1} mbar, where the film thickness is constant for all angles. The composition profiles show noticeable compositional variations of up to 30% with respect to the target material depending on the background gas pressure, the angular location, and the laser spot dimensions.

  3. High Strain Rate and Shock-Induced Deformation in Metals

    Science.gov (United States)

    Ravelo, Ramon

    2012-02-01

    Large-scale non-equilibrium molecular Dynamics (MD) simulations are now commonly used to study material deformation at high strain rates (10^9-10^12 s-1). They can provide detailed information-- such as defect morphology, dislocation densities, and temperature and stress profiles, unavailable or hard to measure experimentally. Computational studies of shock-induced plasticity and melting in fcc and bcc single, mono-crystal metals, exhibit generic characteristics: high elastic limits, large directional anisotropies in the yield stress and pre-melting much below the equilibrium melt temperature for shock wave propagation along specific crystallographic directions. These generic features in the response of single crystals subjected to high strain rates of deformation can be explained from the changes in the energy landscape of the uniaxially compressed crystal lattice. For time scales relevant to dynamic shock loading, the directional-dependence of the yield strength in single crystals is shown to be due to the onset of instabilities in elastic-wave propagation velocities. The elastic-plastic transition threshold can accurately be predicted by a wave-propagation stability analysis. These strain-induced instabilities create incipient defect structures, which can be quite different from the ones, which characterize the long-time, asymptotic state of the compressed solid. With increase compression and strain rate, plastic deformation via extended defects gives way to amorphization associated with the loss in shear rigidity along specific deformation paths. The hot amorphous or (super-cooled liquid) metal re-crystallizes at rates, which depend on the temperature difference between the amorphous solid and the equilibrium melt line. This plastic-amorphous transition threshold can be computed from shear-waves stability analyses. Examples from selected fcc and bcc metals will be presented employing semi-empirical potentials of the embedded atom method (EAM) type as well as

  4. Scale dependence of rock friction at high work rate

    Science.gov (United States)

    Yamashita, Futoshi; Fukuyama, Eiichi; Mizoguchi, Kazuo; Takizawa, Shigeru; Xu, Shiqing; Kawakata, Hironori

    2015-12-01

    Determination of the frictional properties of rocks is crucial for an understanding of earthquake mechanics, because most earthquakes are caused by frictional sliding along faults. Prior studies using rotary shear apparatus revealed a marked decrease in frictional strength, which can cause a large stress drop and strong shaking, with increasing slip rate and increasing work rate. (The mechanical work rate per unit area equals the product of the shear stress and the slip rate.) However, those important findings were obtained in experiments using rock specimens with dimensions of only several centimetres, which are much smaller than the dimensions of a natural fault (of the order of 1,000 metres). Here we use a large-scale biaxial friction apparatus with metre-sized rock specimens to investigate scale-dependent rock friction. The experiments show that rock friction in metre-sized rock specimens starts to decrease at a work rate that is one order of magnitude smaller than that in centimetre-sized rock specimens. Mechanical, visual and material observations suggest that slip-evolved stress heterogeneity on the fault accounts for the difference. On the basis of these observations, we propose that stress-concentrated areas exist in which frictional slip produces more wear materials (gouge) than in areas outside, resulting in further stress concentrations at these areas. Shear stress on the fault is primarily sustained by stress-concentrated areas that undergo a high work rate, so those areas should weaken rapidly and cause the macroscopic frictional strength to decrease abruptly. To verify this idea, we conducted numerical simulations assuming that local friction follows the frictional properties observed on centimetre-sized rock specimens. The simulations reproduced the macroscopic frictional properties observed on the metre-sized rock specimens. Given that localized stress concentrations commonly occur naturally, our results suggest that a natural fault may lose its

  5. Study of radiation background at various high altitude locations in preparation for rare event search in cosmic rays

    Science.gov (United States)

    Bhattacharyya, R.; Dey, S.; Ghosh, Sanjay K.; Maulik, A.; Raha, Sibaji; Syam, D.

    2017-04-01

    Various phenomenological models presented over the years have hinted at the possible presence of strangelets, which are nuggets of Strange Quark Matter (SQM), in cosmic rays. One way to search for such rare events is through the deployment of large area Nuclear Track Detector (NTD) arrays at high mountain altitudes. Before the deployment of any such array can begin, a detailed study of the radiation background is essential. Also, a proper understanding of the response of detectors exposed to extreme weather conditions is necessary. With that aim, pilot studies were carried out at various high altitude locations in India such as Darjeeling (2200 m a.m.s.l), Ooty (2200 m a.m.s.l) and Hanle (4500 m a.m.s.l). Small arrays of CR-39 as well as high threshold Polyethylene Terephthalate (PET) detectors were given open air exposures for periods ranging from three months to two years. The findings of such studies are reported in this paper.

  6. Mortality and recurrence rates among systemically untreated high risk breast cancer patients included in the DBCG 77 trials

    DEFF Research Database (Denmark)

    Jensen, Maj Britt; Nielsen, Torsten O.; Knoop, Ann S.

    2018-01-01

    Background: Following loco-regional treatment for early breast cancer accurate prognostication is essential for communicating benefits of systemic treatment. The aim of this study was to determine time to recurrence and long-term mortality rates in high risk patients according to patient characte......Background: Following loco-regional treatment for early breast cancer accurate prognostication is essential for communicating benefits of systemic treatment. The aim of this study was to determine time to recurrence and long-term mortality rates in high risk patients according to patient...

  7. Optimization of the ATLAS (s)MDT readout electronics for high counting rates

    Energy Technology Data Exchange (ETDEWEB)

    Kortner, Oliver; Kroha, Hubert; Nowak, Sebastian; Schmidt-Sommerfeld, Korbinian [Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Foehringer Ring 6, 80805 Muenchen (Germany)

    2016-07-01

    In the ATLAS muon spectrometer, Monitored Drift Tube (MDT) chambers are used for precise muon track measurement. For the high background rates expected at HL-LHC, which are mainly due to neutrons and photons produced by interactions of the proton collision products in the detector and shielding, new small-diameter muon drift tube (sMDT)-chambers with half the drift tube diameter of the MDT-chambers and ten times higher rate capability have been developed. The standard MDT readout electronics uses bipolar shaping in front of a discriminator. This shaping leads to an undershoot of same charge but opposite polarity following each pulse. With count rates also the probability of having the subsequent pulse in this undershoot increases, which leads to losses in efficiency and spatial resolution. In order to decrease this effect, discrete prototype electronics including Baseline Restoration has been developed. Results of their tests and data taken with them during muon beamtime measurements at CERN's Gamma Irradiation Facility will be presented. which causes a deterioration of signal pulses by preceding background hits, leading to losses in muon efficiency and drift tube spatial resolution. In order to mitigate these so-called signal pile-up effects, new readout electronics with active baseline restoration (BLR) is under development. Discrete prototype electronics with BLR functionality has been tested in laboratory measurements and in the Gamma Irradiation Facility at CERN under high γ-irradiation rates. Results of the measurements are presented.

  8. Extremely High Mutation Rate of HIV-1 In Vivo.

    Directory of Open Access Journals (Sweden)

    José M Cuevas

    Full Text Available Rates of spontaneous mutation critically determine the genetic diversity and evolution of RNA viruses. Although these rates have been characterized in vitro and in cell culture models, they have seldom been determined in vivo for human viruses. Here, we use the intrapatient frequency of premature stop codons to quantify the HIV-1 genome-wide rate of spontaneous mutation in DNA sequences from peripheral blood mononuclear cells. This reveals an extremely high mutation rate of (4.1 ± 1.7 × 10-3 per base per cell, the highest reported for any biological entity. Sequencing of plasma-derived sequences yielded a mutation frequency 44 times lower, indicating that a large fraction of viral genomes are lethally mutated and fail to reach plasma. We show that the HIV-1 reverse transcriptase contributes only 2% of mutations, whereas 98% result from editing by host cytidine deaminases of the A3 family. Hypermutated viral sequences are less abundant in patients showing rapid disease progression compared to normal progressors, highlighting the antiviral role of A3 proteins. However, the amount of A3-mediated editing varies broadly, and we find that low-edited sequences are more abundant among rapid progressors, suggesting that suboptimal A3 activity might enhance HIV-1 genetic diversity and pathogenesis.

  9. High monetary reward rates and caloric rewards decrease temporal persistence.

    Science.gov (United States)

    Fung, Bowen J; Bode, Stefan; Murawski, Carsten

    2017-02-22

    Temporal persistence refers to an individual's capacity to wait for future rewards, while forgoing possible alternatives. This requires a trade-off between the potential value of delayed rewards and opportunity costs, and is relevant to many real-world decisions, such as dieting. Theoretical models have previously suggested that high monetary reward rates, or positive energy balance, may result in decreased temporal persistence. In our study, 50 fasted participants engaged in a temporal persistence task, incentivised with monetary rewards. In alternating blocks of this task, rewards were delivered at delays drawn randomly from distributions with either a lower or higher maximum reward rate. During some blocks participants received either a caloric drink or water. We used survival analysis to estimate participants' probability of quitting conditional on the delay distribution and the consumed liquid. Participants had a higher probability of quitting in blocks with the higher reward rate. Furthermore, participants who consumed the caloric drink had a higher probability of quitting than those who consumed water. Our results support the predictions from the theoretical models, and importantly, suggest that both higher monetary reward rates and physiologically relevant rewards can decrease temporal persistence, which is a crucial determinant for survival in many species. © 2017 The Authors.

  10. High rate of adaptive evolution in two widespread European pines.

    Science.gov (United States)

    Grivet, Delphine; Avia, Komlan; Vaattovaara, Aleksia; Eckert, Andrew J; Neale, David B; Savolainen, Outi; González-Martínez, Santiago C

    2017-11-07

    Comparing related organisms with differing ecological requirements and evolutionary histories can shed light on the mechanisms and drivers underlying genetic adaptation. Here, by examining a common set of hundreds of loci, we compare patterns of nucleotide diversity and molecular adaptation of two European conifers (Scots pine and maritime pine) living in contrasted environments and characterized by distinct population genetic structure (low and clinal in Scots pine, high and ecotypic in maritime pine) and demographic histories. We found higher nucleotide diversity in Scots pine than in maritime pine, whereas rates of new adaptive substitutions (ωa ), as estimated from the Distribution of Fitness Effects (DFE), were similar across species, and among the highest found in plants. Sample size and population genetic structure did not appear to have resulted in significant bias in estimates of ωa . Moreover, population contraction-expansion dynamics for each species did not differentially affect differentially the rate of adaptive substitution in these two pines. Several methodological and biological factors may underlie the unusually high rate of adaptive evolution of Scots pine and maritime pine. By providing two new case studies with contrasting evolutionary histories, we contribute to disentangling the multiple factors potentially affecting adaptive evolution in natural plant populations. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  11. Taylor dispersion analysis in coiled capillaries at high flow rates.

    Science.gov (United States)

    Lewandrowska, Anna; Majcher, Aldona; Ochab-Marcinek, Anna; Tabaka, Marcin; Hołyst, Robert

    2013-04-16

    Taylor Dispersion Analysis (TDA) has been performed for analytes moving at high flow rates in long, coiled capillaries. A thin injection zone of the analyte is stretched by the flow and final distribution of concentration of the analyte at the end of the capillary has the gaussian shape. The high flow rates in coiled capillary generate vortices. They convectively mix the analyte across the capillary. This mixing reduces the width of the gaussian distribution several times in comparison to the width obtained in a straight capillary in standard TDA. We have determined an empirical, scaling equation for the width as a function of the flow rate, molecular diffusion coefficient of the analyte, viscosity of the carrier phase, internal radius of the cylindrical capillary, and external radius of the coiled capillary. This equation can be used for different sizes of capillaries in a wide range of parameters without an additional calibration procedure. Our experimental results of flow in the coiled capillary could not be explained by current models based on approximate solutions of the Navier-Stokes equation. We applied the technique to determine the diffusion coefficients of the following analytes: salts, drugs, single amino acids, peptides (from dipeptides to hexapeptides), and proteins.

  12. Comparable cell survival between high dose rate flattening filter free and conventional dose rate irradiation.

    Science.gov (United States)

    Verbakel, Wilko F A R; van den Berg, Jaap; Slotman, Ben J; Sminia, Peter

    2013-04-01

    Investigation of clonogenic cell survival and cell proliferation following single dose and fractionated delivery of high dose rate flattening filter free (FFF) irradiation compared to conventional dose rates. The human astrocytoma D384, glioma T98 and lung carcinoma SW1573 cell lines were irradiated using either a single dose (0-12 Gy) or a fractionated protocol of 5 daily fractions of 2 Gy (D384) or 3 Gy (SW1573). Cells were irradiated inside a phantom using fixed gantry beams of a linear accelerator. A sliding window technique created homogeneous dose distributions over the surface of the cell cultures. Irradiations using standard beams (6 MV, 600 MU/min.) and high dose rate FFF beams (10 MV, 2400 MU/min.) were compared. Cell survival was determined by clonogenic assay. In the fractionated irradiation set-up, the number of clonogenic cells was estimated by including tumor cell proliferation during the overall treatment time in the analysis. All cell lines showed equal cell survival following irradiation using either the FFF beams or conventional flattened (FF) beams. This was observed after single dose exposure (0-12 Gy) as well as after fractionated irradiation (p = 0.08 for D384 and 0.20 for SW1373 cell lines). FFF irradiation with a dose rate of 2400 MU/min and four times higher dose per pulse compared to irradiation with FF beams did not change cell survival for three human cancer cell lines up to a fraction dose of 12 Gy compared to irradiation using FF beams.

  13. High-strain, high-strain-rate deformation of tantalum and tantalum-tungsten alloys

    OpenAIRE

    Vecchio, K.

    1994-01-01

    Under certain high strain rate conditions, plastic deformation can be assumed to be adiabatic, and a significant temperature increase can occur at large strains. In this study, tantalum and tantalum-tungsten alloys were subjected to high shear strains at high strain rate using a specially-designed stepped specimen in a Hopkinson bar. Upon completion of the deformation, the region is cooled to below one-half of the temperature achieved due to the adiabatic heating in less than one millisecond....

  14. High mortality rates after non-elective colon cancer resection

    DEFF Research Database (Denmark)

    Bakker, I S; Snijders, H S; Grossmann, Irene

    2016-01-01

    AIM: Colon cancer resection in a non-elective setting is associated with high rates of morbidity and mortality. The aim of this retrospective study is to identify risk factors for overall mortality after colon cancer resection with a special focus on non-elective resection. METHOD: Data were...... obtained from the Dutch Surgical Colorectal Audit. Patients undergoing colon cancer resection in the Netherlands between January 2009 and December 2013 were included. Patient, treatment and tumour factors were analyzed in relation to the urgency of surgery. The primary outcome was the thirty day...... postoperative mortality. RESULTS: The study included 30,907 patients. In 5934 (19.2%) of patients, a non-elective colon cancer resection was performed. There was a 4.4% overall mortality rate, with significantly more deaths after non-elective surgery (8.5% vs 3.4%, P

  15. GPU accelerated processing of astronomical high frame-rate videosequences

    Science.gov (United States)

    Vítek, Stanislav; Švihlík, Jan; Krasula, Lukáš; Fliegel, Karel; Páta, Petr

    2015-09-01

    Astronomical instruments located around the world are producing an incredibly large amount of possibly interesting scientific data. Astronomical research is expanding into large and highly sensitive telescopes. Total volume of data rates per night of operations also increases with the quality and resolution of state-of-the-art CCD/CMOS detectors. Since many of the ground-based astronomical experiments are placed in remote locations with limited access to the Internet, it is necessary to solve the problem of the data storage. It mostly means that current data acquistion, processing and analyses algorithm require review. Decision about importance of the data has to be taken in very short time. This work deals with GPU accelerated processing of high frame-rate astronomical video-sequences, mostly originating from experiment MAIA (Meteor Automatic Imager and Analyser), an instrument primarily focused to observing of faint meteoric events with a high time resolution. The instrument with price bellow 2000 euro consists of image intensifier and gigabite ethernet camera running at 61 fps. With resolution better than VGA the system produces up to 2TB of scientifically valuable video data per night. Main goal of the paper is not to optimize any GPU algorithm, but to propose and evaluate parallel GPU algorithms able to process huge amount of video-sequences in order to delete all uninteresting data.

  16. Handling high data rate detectors at Diamond Light Source

    Science.gov (United States)

    Pedersen, U. K.; Rees, N.; Basham, M.; Ferner, F. J. K.

    2013-03-01

    An increasing number of area detectors, in use at Diamond Light Source, produce high rates of data. In order to capture, store and process this data High Performance Computing (HPC) systems have been implemented. This paper will present the architecture and usage for handling high rate data: detector data capture, large volume storage and parallel processing. The EPICS area Detector frame work has been adopted to abstract the detectors for common tasks including live processing, file format and storage. The chosen data format is HDF5 which provides multidimensional data storage and NeXuS compatibility. The storage system and related computing infrastructure include: a centralised Lustre based parallel file system, a dedicated network and a HPC cluster. A well defined roadmap is in place for the evolution of this to meet demand as the requirements and technology advances. For processing the science data the HPC cluster allow efficient parallel computing, on a mixture of ×86 and GPU processing units. The nature of the Lustre storage system in combination with the parallel HDF5 library allow efficient disk I/O during computation jobs. Software developments, which include utilising optimised parallel file reading for a variety of post processing techniques, are being developed in collaboration as part of the Pan-Data EU Project (www.pan-data.eu). These are particularly applicable to tomographic reconstruction and processing of non crystalline diffraction data.

  17. Motivation of Dutch high school students from various backgrounds for applying to study medicine: a qualitative study

    Science.gov (United States)

    Wouters, Anouk; Croiset, Gerda; Isik, Ulviye; Kusurkar, Rashmi A

    2017-01-01

    Objective To explore high school students’ motivation for applying to study medicine and the factors that influence this. To find explanations for under-representation of minority students in medical education, descriptions of motivation of students with different background characteristics were compared. Design Qualitative phenomenological study using semistructured one-on-one interviews. Setting One predominantly white and one mixed high school in a large multicultural city in the Netherlands. The study was conducted in March–December 2015. Participants Twenty-four high school students, purposively sampled for demographic characteristics. Methods The analysis consisted of the coding of data using a template based on the motivation types (autonomous and controlled motivation) described by self-determination theory and open coding for factors that influence motivation. Results The main reasons for pursuing a medical career pertained to autonomous motivation (interest in science and helping people), but controlled motivation (eg, parental pressure, prestige) was also mentioned. Experiences with healthcare and patients positively influenced students’ autonomous motivation and served as a reality check for students’ expectations. Having to go through a selection process was an important demotivating factor, but did not prevent most students from applying. Having medical professionals in their network also sparked students’ interest, while facilitating easier access to healthcare experiences. Conclusions The findings showed a complex interplay between healthcare experiences, growing up in a medical family, selection processes and motivation. Healthcare experiences, often one of the selection criteria, help students to form autonomous motivation for studying medicine. However, such experiences as well as support in the selection process seem unequally accessible to students. As a result, under-represented students’ motivation decreases. Medical schools

  18. High Rate Laser Pitting Technique for Solar Cell Texturing

    Energy Technology Data Exchange (ETDEWEB)

    Hans J. Herfurth; Henrikki Pantsar

    2013-01-10

    High rate laser pitting technique for solar cell texturing Efficiency of crystalline silicon solar cells can be improved by creating a texture on the surface to increase optical absorption. Different techniques have been developed for texturing, with the current state-of-the-art (SOA) being wet chemical etching. The process has poor optical performance, produces surfaces that are difficult to passivate or contact and is relatively expensive due to the use of hazardous chemicals. This project shall develop an alternative process for texturing mc-Si using laser micromachining. It will have the following features compared to the current SOA texturing process: -Superior optical surfaces for reduced front-surface reflection and enhanced optical absorption in thin mc-Si substrates -Improved surface passivation -More easily integrated into advanced back-contact cell concepts -Reduced use of hazardous chemicals and waste treatment -Similar or lower cost The process is based on laser pitting. The objective is to develop and demonstrate a high rate laser pitting process which will exceed the rate of former laser texturing processes by a factor of ten. The laser and scanning technologies will be demonstrated on a laboratory scale, but will use inherently technologies that can easily be scaled to production rates. The drastic increase in process velocity is required for the process to be implemented as an in-line process in PV manufacturing. The project includes laser process development, development of advanced optical systems for beam manipulation and cell reflectivity and efficiency testing. An improvement of over 0.5% absolute in efficiency is anticipated after laser-based texturing. The surface textures will be characterized optically, and solar cells will be fabricated with the new laser texturing to ensure that the new process is compatible with high-efficiency cell processing. The result will be demonstration of a prototype process that is suitable for scale-up to a

  19. Design of high-bit-rate coherent communication links

    Science.gov (United States)

    Konyshev, V. A.; Leonov, A. V.; Nanii, O. E.; Novikov, A. G.; Treshchikov, V. N.; Ubaydullaev, R. R.

    2016-12-01

    We report an analysis of the problems encountered in the design of modern high-bit-rate coherent communication links. A phenomenological communication link model is described, which is suitable for solving applied tasks of the network design with nonlinear effects taken into account. We propose an engineering approach to the design that is based on the use of fundamental nonlinearity coefficients calculated in advance for the experimental configurations of communication links. An experimental method is presented for calculating the nonlinearity coefficient of communication links. It is shown that the proposed approach allows one to successfully meet the challenges in designing communication networks.

  20. On the response of rubbers at high strain rates.

    Energy Technology Data Exchange (ETDEWEB)

    Niemczura, Johnathan Greenberg (University of Texas-Austin)

    2010-02-01

    In this report, we examine the propagation of tensile waves of finite deformation in rubbers through experiments and analysis. Attention is focused on the propagation of one-dimensional dispersive and shock waves in strips of latex and nitrile rubber. Tensile wave propagation experiments were conducted at high strain-rates by holding one end fixed and displacing the other end at a constant velocity. A high-speed video camera was used to monitor the motion and to determine the evolution of strain and particle velocity in the rubber strips. Analysis of the response through the theory of finite waves and quantitative matching between the experimental observations and analytical predictions was used to determine an appropriate instantaneous elastic response for the rubbers. This analysis also yields the tensile shock adiabat for rubber. Dispersive waves as well as shock waves are also observed in free-retraction experiments; these are used to quantify hysteretic effects in rubber.

  1. New Approach to reduce High School Dropout Rates

    Directory of Open Access Journals (Sweden)

    Mauricio Cristhian Portillo-Torres

    2015-05-01

    Full Text Available From 2006 to 2014, the Ministry of Public Education of Costa Rica implemented four strategic actions to reduce high school dropout rates. The main purpose of these actions was to promote student participation and student identification with their school. Studies prepared by the Ministry of Education and the Comptroller of the Republic were revised to assess the impact of these actions. The result of these actions does not show an actual decrease in the number of students who leave high school. Therefore, a more holistic view is necessary to ensure the students’ stay. This review suggests using use the concept of student engagement and applying a three tier system-wide dropout preventive actions: universal, targeted and intensive.

  2. Automated Production of High Rep Rate Foam Targets

    Science.gov (United States)

    Hall, F.; Spindloe, C.; Haddock, D.; Tolley, M.; Nazarov, W.

    2016-04-01

    Manufacturing low density targets in the numbers needed for high rep rate experiments is highly challenging. This report summarises advances from manual production to semiautomated and the improvements that follow both in terms of production time and target uniformity. The production process is described and shown to be improved by the integration of an xyz robot with dispensing capabilities. Results are obtained from manual and semiautomated production runs and compared. The variance in the foam thickness is reduced significantly which should decrease experimental variation due to target parameters and could allow for whole batches to be characterised by the measurement of a few samples. The work applies to both foil backed and free standing foam targets.

  3. Resistance of the boreal forest to high burn rates.

    Science.gov (United States)

    Héon, Jessie; Arseneault, Dominique; Parisien, Marc-André

    2014-09-23

    Boreal ecosystems and their large carbon stocks are strongly shaped by extensive wildfires. Coupling climate projections with records of area burned during the last 3 decades across the North American boreal zone suggests that area burned will increase by 30-500% by the end of the 21st century, with a cascading effect on ecosystem dynamics and on the boreal carbon balance. Fire size and the frequency of large-fire years are both expected to increase. However, how fire size and time since previous fire will influence future burn rates is poorly understood, mostly because of incomplete records of past fire overlaps. Here, we reconstruct the length of overlapping fires along a 190-km-long transect during the last 200 y in one of the most fire-prone boreal regions of North America to document how fire size and time since previous fire will influence future fire recurrence. We provide direct field evidence that extreme burn rates can be sustained by a few occasional droughts triggering immense fires. However, we also show that the most fire-prone areas of the North American boreal forest are resistant to high burn rates because of overabundant young forest stands, thereby creating a fuel-mediated negative feedback on fire activity. These findings will help refine projections of fire effect on boreal ecosystems and their large carbon stocks.

  4. Spall fracture in aluminium alloy at high strain rates

    Science.gov (United States)

    Joshi, K. D.; Rav, Amit; Sur, Amit; Kaushik, T. C.; Gupta, Satish C.

    2016-05-01

    Spall fracture strength and dynamic yield strength has been measured in 8mm thick target plates of aluminium alloy Al2024-T4 at high strain rates generated in three plate impact experiments carried out at impact velocities of 180 m/s, 370 m/s and 560m/s, respectively, using single stage gas gun facility. In each experiment, the free surface velocity history of the Al2024-T4 sample plate measured employing velocity interferometer system for any reflector (VISAR) is used to determine the spall strength and dynamic yield strength of this material. The spall strength of 1.11 GPa, 1.16 GPa and 1.43 GPa, determined from measured free surface velocity history of sample material in three experiments performed at impact velocity of 180 m/s, 370 m/s and 560 m/s, respectively, are higher than the quasi static value of 0.469 GPa and display almost linearly increasing trend with increasing impact velocity or equivalently with increasing strain rates. The average strain rates just ahead of the spall fracture are determined to be 1.9×10 4/s, 2.0×104/s and 2.5×104/s, respectively. The dynamic yield strength determined in the three experiments range from 0.383 GPa to 0.407 GPa, which is higher than the quasi static value of 0.324GPa.

  5. Patrilineal background of esophageal cancer and gastric cardia cancer patients in a Chaoshan high-risk area in China.

    Directory of Open Access Journals (Sweden)

    Shuhui Liu

    Full Text Available The Taihang Mountain range of north-central China, the Southern region area of Fujian province, and the Chaoshan plain of Guangdong province are 3 major regions in China well known for their high incidence of esophageal cancer (EC. These areas also exhibit high incidences of gastric cardia cancer (GCC. The ancestors of the Chaoshanese, now the major inhabitants in the Chaoshan plain, were from north-central China. We hypothesized that EC and GCC patients in Chaoshan areas share a common ancestry with Taihang Mountain patients. We analyzed 16 East Asian-specific Y-chromosome biallelic markers (single nucleotide polymorphisms; Y-SNPs and 6 Y-chromosome short tandem repeat (Y-STR loci in 72 EC and 48 GCC patients from Chaoshan and 49 EC and 63 GCC patients from the Taihang Mountain range. We also compared data for 32 Chaoshan Hakka people and 24 members of the aboriginal She minority who live near the Chaoshan area. Analysis was by frequency distribution and principal component, correlation and hierarchical cluster analysis of Y-SNP. Chaoshan patients were closely related to Taihang Mountain patients, even though they are geographically distant. Y-STR analysis revealed that the 4 patient groups were more closely related with each other than with other groups. Network analysis of the haplogroup O3a3c1-M117 showed a high degree of patient-specific substructure. We suggest that EC and GCC patients from these 2 areas share a similar patrilineal genetic background, which may play an important role in the genetic factor of EC and GCC in these populations.

  6. STUDY OF HIGH RATE SEDIMENTATION TANK IN WATER TREATMENT PLANTS

    Directory of Open Access Journals (Sweden)

    M.R SHA MANSOURI

    2001-06-01

    Full Text Available Introduction: Sedimentation is considered as an important process in removing turbidity produced in water and wastewater plants. Gravity sedimentation is usually the first method considered in water treatment system. However, required overflow rates (OFRs to remove turbidity in the conventional clarifiers are too low. Therefore, the shallow depth sedimentation concept was studied remove turbidity in order to increase OFRs of gravity setting equipment. Methods: Using a pilot with parallel plates with effect area 1.5 m2 and 1.5 m depth. The independent parameters such as OFRs, sludge concentration and turbidity were evaluated for turbidity removal. The pilot is located in Isfahan Water Treatment Plant. Results: The efficacy of pilot for turbidity 10-50 NTU is equal to 50 percent (P<0.01. The maximum removal efficiency at sludge concentration 270 ml/lit was obtained (P<0.01. A nonlinear relationship exists between removal efficiency (TR%, sludge concentration (Sc over flowrates (OFR and influent turbidity (Tu in pilot. Discussion: By using high rate sedimentation tank in water treatment plant, detection time reduced from 3 hours to 20-30 minute, turbidity removal increased up to 30 percent in compare with conventional sedimentation. Also, it has economic benefits and high efficiency.

  7. Dose determination in high dose-rate brachytherapy.

    Science.gov (United States)

    Houdek, P V; Schwade, J G; Wu, X; Pisciotta, V; Fiedler, J A; Serago, C F; Markoe, A M; Abitbol, A A; Lewin, A A; Braunschweiger, P G

    1992-01-01

    Although high dose-rate brachytherapy with a single, rapidly moving radiation source is becoming a common treatment modality, a suitable formalism for determination of the dose delivered by a moving radiation source has not yet been developed. At present, brachytherapy software simulates high dose-rate treatments using only a series of stationary sources, and consequently fails to account for the dose component delivered while the source is in motion. We now describe a practical model for determination of the true, total dose administered. The algorithm calculates both the dose delivered while the source is in motion within and outside of the implanted volume (dynamic component), and the dose delivered while the source is stationary at a series of fixed dwell points. It is shown that the dynamic dose element cannot be ignored because it always increases the dose at the prescription points and, in addition, distorts the dose distribution within and outside of the irradiated volume. Failure to account for the dynamic dose component results in dosimetric errors that range from significant (> 10%) to negligible (source activity, and source speed as defined by the implant geometry.

  8. High-rep-rate Thomson scattering for LHD

    Science.gov (United States)

    den Hartog, D. J.; Borchardt, M. T.; Holly, D. J.; Schmitz, O.; Yasuhara, R.; Yamada, I.; Funaba, H.; Osakabe, M.; Morisaki, T.

    2017-10-01

    A high-rep-rate pulse-burst laser system is being built for the LHD Thomson scattering (TS) diagnostic. This laser will have two operating scenarios, a fast-burst sequence of 15 kHz rep rate for at least 15 ms, and a slow-burst sequence of 1 kHz for at least 50 ms. There will be substantial flexibility in burst sequences for tailoring to experimental requirements. This new laser system will operate alongside the existing lasers in the LHD TS diagnostic, and will use the same beamline. This increase in temporal resolution capability complements the high spatial resolution (144 points) of the LHD TS diagnostic, providing unique measurement capability unmatched on any other fusion experiment. The new pulse-burst laser is a straightforward application of technology developed at UW-Madison, consisting of a Nd:YAG laser head with modular flashlamp drive units and a customized control system. Variable pulse-width drive of the flashlamps is accomplished by IGBT (insulated gate bipolar transistor) switching of electrolytic capacitor banks. Direct control of the laser Pockels cell drive enables optimal pulse energy extraction, producing >1.5 J q-switched pulses with 20 ns FWHM. Burst operation of this laser system will be used to capture fast time evolution of the electron temperature and density profiles during events such as ELMs, RMP perturbations, and various MHD modes. This work is supported by the U. S. Department of Energy and the National Institute for Fusion Science (Japan).

  9. High-temperature rate constant measurements for OH+xylenes

    KAUST Repository

    Elwardani, Ahmed Elsaid

    2015-06-01

    The overall rate constants for the reactions of hydroxyl (OH) radicals with o-xylene (k 1), m-xylene (k 2), and p-xylene (k 3) were measured behind reflected shock waves over 890-1406K at pressures of 1.3-1.8atm using OH laser absorption near 306.7nm. Measurements were performed under pseudo-first-order conditions. The measured rate constants, inferred using a mechanism-fitting approach, can be expressed in Arrhenius form as:k1=2.93×1013exp(-1350.3/T)cm3mol-1s-1(890-1406K)k2=3.49×1013exp(-1449.3/T)cm3mol-1s-1(906-1391K)k3=3.5×1013exp(-1407.5/T)cm3mol-1s-1(908-1383K)This paper presents, to our knowledge, first high-temperature measurements of the rate constants of the reactions of xylene isomers with OH radicals. Low-temperature rate-constant measurements by Nicovich et al. (1981) were combined with the measurements in this study to obtain the following Arrhenius expressions, which are applicable over a wider temperature range:k1=2.64×1013exp(-1181.5/T)cm3mol-1s-1(508-1406K)k2=3.05×109exp(-400/T)cm3mol-1s-1(508-1391K)k3=3.0×109exp(-440/T)cm3mol-1s-1(526-1383K) © 2015 The Combustion Institute.

  10. High energy high rate pulsed power processing of materials by powder consolidation and by railgun deposition

    Science.gov (United States)

    Persad, C.; Marcus, H. L.; Weldon, W. F.

    1987-03-01

    This exploratory research program was initiated to investigate the potential of using pulse power sources for powder consolidation, deposition and other High Energy High Rate Processing. The characteristics of the High Energy High Rate (1MJ/s) powder consolidation using megampere current pulses from a Homopolar Generator, have been defined. Molybdenum Alloy TZM, A Nickel based metallic glass, Copper graphite composites, and P/M Aluminum Alloy X7091 have been investigated. The powder consolidation process produced high densification rates. Density values of 80% to 99% could be obtained with sub second high temperature exposure. Specific energy input and applied pressure were controlling process parameters. Time Temperature Transformation (TTT) concepts underpin a fundamental understanding of pulsed power processing. Deposition experiments were conducted using an exploding foil device (EFD) providing an armature feed to railgun mounted in a vacuum chamber. The material to be deposited - in plasma, gas, liquid or solid state - was accelerated electromagnetically in the railgun and deposited on a substrate.

  11. A high repetition rate XUV seeding source for FLASH2

    Energy Technology Data Exchange (ETDEWEB)

    Willner, Arik

    2012-05-15

    Improved performance of free-electron laser (FEL) light sources in terms of timing stability, pulse shape and spectral properties of the amplified FEL pulses is of interest in material science, the fields of ultrafast dynamics, biology, chemistry and even special branches in industry. A promising scheme for such an improvement is direct seeding with high harmonic generation (HHG) in a noble gas target. A free-electron laser seeded by an external extreme ultraviolet (XUV) source is planned for FLASH2 at DESY in Hamburg. The requirements for the XUV/soft X-ray source can be summarized as follows: A repetition rate of at least 100 kHz in a 10 Hz burst is needed at variable wavelengths from 10 to 40 nm and pulse energies of several nJ within a single laser harmonic. This application requires a laser amplifier system with exceptional parameters, mJ-level pulse energy, 10-15 fs pulse duration at 100 kHz (1 MHz) burst repetition rate. A new optical parametric chirped-pulse amplification (OPCPA) system is under development in order to meet these requirements, and very promising results have been achieved in the last three years. In parallel to this development, a new HHG concept is necessary to sustain high average power of the driving laser system and to generate harmonics with high conversion efficiencies. Currently, the highest conversion efficiency with HHG has been demonstrated using gas-filled capillary targets. For our application, only a free-jet target can be used for HHG, in order to overcome damage threshold limitations of HHG target optics at a high repetition rate. A novel dual-gas multijet gas target has been developed and first experiments show remarkable control of the degree of phase matching forming the basis for improved control of the harmonic photon flux and the XUV pulse characteristics. The basic idea behind the dual-gas concept is the insertion of matching zones in between multiple HHG sources. These matching sections are filled with hydrogen which

  12. Cosmological Evolution of the Central Engine in High-Luminosity, High-Accretion Rate AGN

    Directory of Open Access Journals (Sweden)

    Matteo Guainazzi

    2014-12-01

    Full Text Available In this paper I discuss the status of observational studies aiming at probing the cosmological evolution of the central engine in high-luminosity, high-accretion rate Active Galactic Nuclei (AGN. X-ray spectroscopic surveys, supported by extensive multi-wavelength coverage, indicate a remarkable invariance of the accretion disk plus corona system, and of their coupling up to redshifts z≈6. Furthermore, hard X-ray (E >10 keV surveys show that nearby Seyfert Galaxies share the same central engine notwithstanding their optical classication. These results suggest that the high-luminosity, high accretion rate quasar phase of AGN evolution is homogeneous over cosmological times.

  13. Complication Rates of Ostomy Surgery Are High and Vary Significantly Between Hospitals

    Science.gov (United States)

    Sheetz, Kyle H.; Waits, Seth A.; Krell, Robert W.; Morris, Arden M.; Englesbe, Michael J.; Mullard, Andrew; Campbell, Darrell A.; Hendren, Samantha

    2014-01-01

    Structured Abstract Background Ostomy surgery is common and has traditionally been associated with high rates of morbidity and mortality, suggesting an important target for quality improvement. Objective To evaluate the variation in outcomes after ostomy creation surgery within Michigan in order to identify targets for quality improvement. Design Retrospective cohort study. Setting The 34-hospital Michigan Surgical Quality Collaborative (MSQC). Patients Patients undergoing ostomy creation surgery between 2006-2011. Main outcome measures We evaluated hospitals' morbidity and mortality rates after risk-adjustment (age, comorbidities, emergency v. elective, procedure type). Results 4,250 patients underwent ostomy creation surgery; 3,866 (91.0%) procedures were open and 384 (9.0%) were laparoscopic. Unadjusted morbidity and mortality rates were 43.9% and 10.7%, respectively. Unadjusted morbidity rates for specific procedures ranged from 32.7% for ostomy-creation-only procedures to 47.8% for Hartmann's procedures. Risk-adjusted morbidity rates varied significantly between hospitals, ranging from 31.2% (95%CI 18.4-43.9) to 60.8% (95%CI 48.9-72.6). There were five statistically-significant high-outlier hospitals and three statistically-significant low-outlier hospitals for risk-adjusted morbidity. The pattern of complication types was similar between high- and low-outlier hospitals. Case volume, operative duration, and use of laparoscopic surgery did not explain the variation in morbidity rates across hospitals. Conclusions Morbidity and mortality rates for modern ostomy surgery are high. While this type of surgery has received little attention in healthcare policy, these data reveal that it is both common and uncommonly morbid. Variation in hospital performance provides an opportunity to identify quality improvement practices that could be disseminated among hospitals. PMID:24819104

  14. 18F-GP1, a Novel PET Tracer Designed for High-Sensitivity, Low-Background Detection of Thrombi.

    Science.gov (United States)

    Lohrke, Jessica; Siebeneicher, Holger; Berger, Markus; Reinhardt, Michael; Berndt, Mathias; Mueller, Andre; Zerna, Marion; Koglin, Norman; Oden, Felix; Bauser, Marcus; Friebe, Matthias; Dinkelborg, Ludger M; Huetter, Joachim; Stephens, Andrew W

    2017-07-01

    Thromboembolic diseases such as myocardial infarction, stroke, transient ischemic attacks, and pulmonary embolism are major causes of morbidity and mortality worldwide. Glycoprotein IIb/IIIa (GPIIb/IIIa) is the key receptor involved in platelet aggregation and is a validated target for therapeutic approaches and diagnostic imaging. The aim of this study was to develop and characterize a specific small-molecule tracer for PET imaging that binds with high affinity to GPIIb/IIIa receptors and has suitable pharmacokinetic properties to overcome limitations of previous approaches. Methods: Binding of 18F-GP1 to GPIIb/IIIa receptors was investigated in competition binding assays and autoradiography using a fresh cardiac thrombus from an explanted human heart. The clot-to-blood ratio for 18F-GP1 was investigated by an in vitro blood flow model. Biodistribution and thrombus detection was investigated in cynomolgus monkeys after insertion of a roughened catheter into either the vena cava or the aorta. Results:18F-GP1 is an 18F-labeled small molecule for PET imaging of thrombi. The half maximal inhibitory concentration of 18F-GP1 to GPIIb/IIIa was 20 nM. 18F-GP1 bound to thrombi with a mean clot-to-blood ratio of 95. Binding was specific and can be displaced by excess nonradioactive derivative. Binding was not affected by anticoagulants such as aspirin or heparin. 18F-GP1 showed rapid blood clearance and a low background after intravenous injection in cynomolgus monkeys. Small arterial, venous thrombi, thrombotic depositions on damaged endothelial surface, and small cerebral emboli were detected in vivo by PET imaging. Conclusions:18F-GP1 binds specifically with high affinity to the GPIIb/IIIa receptor involved in platelet aggregation. Because of its favorable preclinical characteristics, 18F-GP1 is currently being investigated in a human clinical study. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

  15. A digital approach for real time high-rate high-resolution radiation measurements

    Energy Technology Data Exchange (ETDEWEB)

    Gerardi, G.; Abbene, L., E-mail: leonardo.abbene@unipa.it

    2014-12-21

    Modern spectrometers are currently developed by using digital pulse processing (DPP) systems, showing several advantages over traditional analog electronics. The aim of this work is to present digital strategies, in a time domain, for the development of real time high-rate high-resolution spectrometers. We propose a digital method, based on the single delay line (SDL) shaping technique, able to perform multi-parameter analysis with high performance even at high photon counting rates. A robust pulse shape and height analysis (PSHA), applied on single isolated time windows of the detector output waveforms, is presented. The potentialities of the proposed strategy are highlighted through both theoretical and experimental approaches. To strengthen our approach, the implementation of the method on a real-time system together with some experimental results are presented. X-ray spectra measurements with a semiconductor detector are performed both at low and high photon counting rates (up to 1.1 Mcps)

  16. Motivation of Dutch high school students from various backgrounds for applying to study medicine: a qualitative study.

    Science.gov (United States)

    Wouters, Anouk; Croiset, Gerda; Isik, Ulviye; Kusurkar, Rashmi A

    2017-06-02

    To explore high school students' motivation for applying to study medicine and the factors that influence this. To find explanations for under-representation of minority students in medical education, descriptions of motivation of students with different background characteristics were compared. Qualitative phenomenological study using semistructured one-on-one interviews. One predominantly white and one mixed high school in a large multicultural city in the Netherlands. The study was conducted in March-December 2015. Twenty-four high school students, purposively sampled for demographic characteristics. The analysis consisted of the coding of data using a template based on the motivation types (autonomous and controlled motivation) described by self-determination theory and open coding for factors that influence motivation. The main reasons for pursuing a medical career pertained to autonomous motivation (interest in science and helping people), but controlled motivation (eg, parental pressure, prestige) was also mentioned. Experiences with healthcare and patients positively influenced students' autonomous motivation and served as a reality check for students' expectations. Having to go through a selection process was an important demotivating factor, but did not prevent most students from applying. Having medical professionals in their network also sparked students' interest, while facilitating easier access to healthcare experiences. The findings showed a complex interplay between healthcare experiences, growing up in a medical family, selection processes and motivation. Healthcare experiences, often one of the selection criteria, help students to form autonomous motivation for studying medicine. However, such experiences as well as support in the selection process seem unequally accessible to students. As a result, under-represented students' motivation decreases. Medical schools should be aware of this and could create opportunities to acquire healthcare

  17. High count rate gamma camera with independent modules

    Science.gov (United States)

    Massari, R.; Ucci, A.; Campisi, C.; Scopinaro, F.; Soluri, A.

    2015-11-01

    Advances in nuclear medical imaging are based on the improvements of the detector's performance. Generally the research is focussed on the spatial resolution improvement. However, another important parameter is the acquisition time that can significantly affect performance in some clinical investigation (e.g. first-pass cardiac studies). At present, there are several clinical imaging systems which are able to solve these diagnostic requirements, such as the D-SPECT Cardiac Imaging System (Spectrum Dynamics) or the Nucline Cardiodesk Medical Imaging System (Mediso). Actually, these solutions are organ-specific dedicated systems, while it would be preferable having general purpose planar detectors with high counting rate. Our group has recently introduced the use of scintillation matrices whose size is equal to the overall area of a position sensitive photomultiplier tube (PSPMT) in order to design a modular gamma camera. This study allowed optimising the overall pixel identification by improving and controlling the light collection efficiency of each PSPMT. Although we achieved a solution for the problems about the dead area at the junction of the PSPMTs when they are set side by side. In this paper, we propose a modular gamma camera design as the basis to build large area detectors. The modular detector design allows us to achieve better counting performance. In this approach, each module that is made of one or more PSPMTs, can actually acquire data independently and simultaneously, increasing the overall detection efficiency. To verify the improvement in count rate capability we have built two detectors with a field of view of 5 × 5cm2, by using four R8900-C12 PSPMTs (Hamamatsu Photonics K.K.). Each PSPMT was coupled to a dedicated discrete scintillation structure designed to obtain a good homogeneity, high imaging performance and high efficiency. One of the detectors was designed as a standard gamma camera, while the other was composed by four independent

  18. Advances in high-rate uncooled detector fabrication at Raytheon

    Science.gov (United States)

    Black, S. H.; Kraft, R.; Medrano, A.; Kocian, T.; Bradstreet, D.; Williams, R.; Yang, T.

    2010-04-01

    Over the past two years Raytheon has made a major investment aimed at establishing a high volume uncooled manufacturing capability. This effort has addressed three elements of the uncooled value stream, namely bolometer fabrication, packaging and calibration/test. To facilitate a low cost / high volume source of bolometers Raytheon has formed a partnership with a high volume 200mm commercial silicon wafer fabrication. Over a 12 month period Raytheon has installed 200mm VOx deposition equipment, matched the metrology used on the Raytheon 150mm line, transferred the process flow used to fabricate Raytheon's double layer bolometer process and qualified the product. In this paper we will review the process transfer methodology and bolometer performance. To reduce bolometer packaging cost and increase production rates, Raytheon has implemented an automated packaging line. This line utilizes automated adhesive dispense, component pick and place, wire bonding and solder seal. In this paper we will review the process flow, qualification process and line capacity Calibration and test has traditionally been performed using a number of temperature chambers, with increased throughput being obtained by adding more chambers. This comes at the expense of increased test labor required to feed the chambers and an increased energy and floor space foot print. To avoid these collateral costs, Raytheon has implemented an automated robotic calibration cell capable of performing in excess of 5,000 calibrations a month. In this paper we will provide an overview of the calibration cell along with takt time and throughput data.

  19. High rate copper and energy recovery in microbial fuel cells

    Science.gov (United States)

    Rodenas Motos, Pau; ter Heijne, Annemiek; van der Weijden, Renata; Saakes, Michel; Buisman, Cees J. N.; Sleutels, Tom H. J. A.

    2015-01-01

    Bioelectrochemical systems (BESs) are a novel, promising technology for the recovery of metals. The prerequisite for upscaling from laboratory to industrial size is that high current and high power densities can be produced. In this study we report the recovery of copper from a copper sulfate stream (2 g L-1 Cu2+) using a laboratory scale BES at high rate. To achieve this, we used a novel cell configuration to reduce the internal voltage losses of the system. At the anode, electroactive microorganisms produce electrons at the surface of an electrode, which generates a stable cell voltage of 485 mV when combined with a cathode where copper is reduced. In this system, a maximum current density of 23 A m-2 in combination with a power density of 5.5 W m-2 was produced. XRD analysis confirmed 99% purity in copper of copper deposited onto cathode surface. Analysis of voltage losses showed that at the highest current, most voltage losses occurred at the cathode, and membrane, while anode losses had the lowest contribution to the total voltage loss. These results encourage further development of BESs for bioelectrochemical metal recovery. PMID:26150802

  20. Children with Down's syndrome display high rates of hyperuricaemia.

    Science.gov (United States)

    Kashima, Ayako; Higashiyama, Yukie; Kubota, Masaru; Kawaguchi, Chiharu; Takahashi, Yukihiro; Nishikubo, Toshiya

    2014-08-01

    Several studies show that hyperuricaemia, abnormally high levels of uric acid in the blood, frequently occurs in adult Down's syndrome patients, but paediatric research is scarce. We aimed to clarify its prevalence in paediatric Down's syndrome patients and its association with lifestyle-related laboratory variables and nutritional intake, to consider possible effects in later life. We compared 52 Down's syndrome patients, from one to 15 years of age, with age-matched controls. Hyperuricaemia was defined using reference values established for children, as uric acid z-scores of more than 2.0. Nutritional intake was estimated using 3-day dietary records. Hyperuricaemia occurred in 17 Down's patients (32.7%) and was significantly higher in Down's patients than the controls. The prevalence was also significantly higher in males. There were no significant differences between hyperuricaemia-positive and hyperuricaemia-negative patients in terms of age, body mass index standard deviation scores, fasting blood glucose, insulin, homeostasis model assessment-insulin resistance and triglyceride, and purine body intake was similar. There were differences in high-density lipoprotein cholesterol. We found high rates of hyperuricaemia from early childhood in Down's syndrome patients. This suggests careful management of Down's syndrome patients, as hyperuricaemia is an independent risk factor for lifestyle-related diseases in adulthood. ©2014 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  1. Habituation to low or high protein intake does not modulate basal or postprandial muscle protein synthesis rates: a randomized trial

    NARCIS (Netherlands)

    Gorissen, S.H.; Horstman, Astrid; Franssen, Rinske; Kouw, I.W.; Wall, B.T.; Burd, N.A.; Groot, de C.P.G.M.; Loon, van L.J.C.

    2017-01-01

    Background: Muscle mass maintenance is largely regulated by basal muscle protein synthesis rates and the ability to increase muscle protein synthesis after protein ingestion. To our knowledge, no previous studies have evaluated the impact of habituation to either low protein intake (LOW PRO) or high

  2. Dynamic mathematical model of high rate algal ponds (HRAP).

    Science.gov (United States)

    Jupsin, H; Praet, E; Vasel, J L

    2003-01-01

    This article presents a mathematical model to describe High-Rate Algal Ponds (HRAPs). The hydrodynamic behavior of the reactor is described as completely mixed tanks in series with recirculation. The hydrodynamic pattern is combined with a subset of River Water Quality Model 1 (RWQM1), including the main processes in liquid phase. Our aim is to develop models for WSPs and aerated lagoons, too, but we focused on HRAPs first for several reasons: Sediments are usually less abundant in HRAP and can be neglected, Stratification is not observed and state variables are constant in a reactor cross section, Due to the system's geometry, the reactor is quite similar to a plugflow type reactor with recirculation, with a simple advection term. The model is based on mass balances and includes the following processes: *Phytoplankton growth with NO3-, NO2- and death, *Aerobic growth of heterotrophs with NO3-, NH4+ and respiration, *Anoxic growth of heterotrophs with NO3-, NO2- and anoxic respiration, *Growth of nitrifiers (two stages) and respiration. The differences with regard to RWQM1 are that we included a limiting term associated with inorganic carbon on the growth rate of algae and nitrifiers, gas transfers are taken into account by the familiar Adeney equation, and a subroutine calculates light intensity at the water surface. This article presents our first simulations.

  3. An MWPC readout chip for high rate environment

    CERN Document Server

    Kano, H; Ikeno, M; Sasaki, O; Sato, K; Matsuura, S

    2000-01-01

    An ASIC has been fabricated in order to readout data from an MWPC that is installed in high rate environment. 16 channels and an ancillary control circuit are packed in a chip, and a channel consists of LVDS Receiver and 100-stage shift register array for delay. A hit data from the chamber is once input in the shift register array, and is just output from it when the trigger signal is set. If a channel contains a signal during a gate followed by the trigger, the channel is regarded to contain a hit. The primary purpose to construct the chip is for test beam and cosmic ray test of ATLAS thin gap chambers (TGC), which are used for the muon trigger signal generation. The architecture of the ASIC is so simple and uidependent from the specific readout scheme of ATLAS TGC. It will be found that the ASIC is adopted easily for any readout scheme of MWPC like detector. 3 Refs.

  4. Wastewater treatment high rate algal ponds for biofuel production.

    Science.gov (United States)

    Park, J B K; Craggs, R J; Shilton, A N

    2011-01-01

    While research and development of algal biofuels are currently receiving much interest and funding, they are still not commercially viable at today's fossil fuel prices. However, a niche opportunity may exist where algae are grown as a by-product of high rate algal ponds (HRAPs) operated for wastewater treatment. In addition to significantly better economics, algal biofuel production from wastewater treatment HRAPs has a much smaller environmental footprint compared to commercial algal production HRAPs which consume freshwater and fertilisers. In this paper the critical parameters that limit algal cultivation, production and harvest are reviewed and practical options that may enhance the net harvestable algal production from wastewater treatment HRAPs including CO(2) addition, species control, control of grazers and parasites and bioflocculation are discussed. Copyright © 2010 Elsevier Ltd. All rights reserved.

  5. Performance of high-rate gravel-packed oil wells

    Energy Technology Data Exchange (ETDEWEB)

    Unneland, Trond

    2001-05-01

    Improved methods for the prediction, evaluation, and monitoring of performance in high-rate cased-hole gravel-packed oil wells are presented in this thesis. The ability to predict well performance prior to the gravel-pack operations, evaluate the results after the operation, and monitor well performance over time has been improved. This lifetime approach to performance analysis of gravel-packed oil wells contributes to increase oil production and field profitability. First, analytical models available for prediction of performance in gravel-packed oil wells are reviewed, with particular emphasis on high-velocity flow effects. From the analysis of field data from three North Sea oil fields, improved and calibrated cased-hole gravel-pack performance prediction models are presented. The recommended model is based on serial flow through formation sand and gravel in the perforation tunnels. In addition, new correlations for high-velocity flow in high-rate gravel-packed oil wells are introduced. Combined, this improves the performance prediction for gravel-packed oil wells, and specific areas can be targeted for optimized well design. Next, limitations in the current methods and alternative methods for evaluation and comparison of well performance are presented. The most widely used parameter, the skin factor, remains a convenient and important parameter. However, using the skin concept in direct comparisons between wells with different reservoir properties may result in misleading or even invalid conclusions. A discussion of the parameters affecting the skin value, with a clarification of limitations, is included. A methodology for evaluation and comparison of gravel-packed well performance is presented, and this includes the use of results from production logs and the use of effective perforation tunnel permeability as a parameter. This contributes to optimized operational procedures from well to well and from field to field. Finally, the data sources available for

  6. The strain-rate sensitivity of high-strength high-toughness steels.

    Energy Technology Data Exchange (ETDEWEB)

    Dilmore, M.F. (AFRL/MNMW, Eglin AFB, FL); Crenshaw, Thomas B.; Boyce, Brad Lee

    2006-01-01

    The present study examines the strain-rate sensitivity of four high strength, high-toughness alloys at strain rates ranging from 0.0002 s-1 to 200 s-1: Aermet 100, a modified 4340, modified HP9-4-20, and a recently developed Eglin AFB steel alloy, ES-1c. A refined dynamic servohydraulic method was used to perform tensile tests over this entire range. Each of these alloys exhibit only modest strain-rate sensitivity. Specifically, the strain-rate sensitivity exponent m, is found to be in the range of 0.004-0.007 depending on the alloy. This corresponds to a {approx}10% increase in the yield strength over the 7-orders of magnitude change in strain-rate. Interestingly, while three of the alloys showed a concominant {approx}3-10% drop in their ductility with increasing strain-rate, the ES1-c alloy actually exhibited a 25% increase in ductility with increasing strain-rate. Fractography suggests the possibility that at higher strain-rates ES-1c evolves towards a more ductile dimple fracture mode associated with microvoid coalescence.

  7. High-rate anaerobic treatment of palm oil mill effluent

    Directory of Open Access Journals (Sweden)

    Masao Ukita

    2001-11-01

    Full Text Available Palm oil mil effluent (POME contains high amount of organic matter, oil & grease, total solids and suspended solids. Anaerobic treatment of POME was conducted at room temperature (30±2ºC and high temperature (50±0.5ºC. The effects of hydraulic retention time (HRT, organic loading rate (OLR, COD:N ratio and temperature on the anaerobic digestion of POME were investigated. The optimum conditions were found to be 10 days HRT, OLR of 9.50 kg COD m-3d-1, COD:N ratio of 65 and the optimum temperature at 50ºC. The highest COD reduction of 81.1% was achieved. Biogas production in general was greater than 0.30 m3/kg COD/d. Comparison on anaerobic treatment using POME and POME treated by thermotolerant polymer-producing fungi Rhizopus sp. ST4 revealed that the biopretreated POME gave higher COD removal (72.6% but lower biogas production (0.97 m3/m3/d or 0.27 m3/kg COD/d than the POME without pretreatment (56.1% and 1.16 m3/m3/d or 0.37 m3/kg COD/d, respectively.

  8. Fast Timing for High-Rate Environments with Micromegas

    CERN Document Server

    Papaevangelou, Thomas; Ferrer-Ribas, Esther; Giomataris, Ioannis; Godinot, Cyprien; Gonzalez Diaz, Diego; Gustavsson, Thomas; Kebbiri, Mariam; Oliveri, Eraldo; Resnati, Filippo; Ropelewski, Leszek; Tsiledakis, Georgios; Veenhof, Rob; White, Sebastian

    2016-01-01

    The current state of the art in fast timing resolution for existing experiments is of the order of 100 ps on the time of arrival of both charged particles and electromagnetic showers. Current R&D on charged particle timing is approaching the level of 10 ps but is not primarily directed at sustained performance at high rates and under high radiation (as would be needed for HL-LHC pileup mitigation). We demonstrate a Micromegas based solution to reach this level of performance. The Micromegas acts as a photomultiplier coupled to a Cerenkov-radiator front window, which produces sufficient UV photons to convert the ~100 ps single-photoelectron jitter into a timing response of the order of 10-20 ps per incident charged particle. A prototype has been built in order to demonstrate this performance. The first laboratory tests with a pico-second laser have shown a time resolution of the order of 27 ps for ~50 primary photoelectrons, using a bulk Micromegas readout.

  9. Fast Timing for High-Rate Environments with Micromegas

    Directory of Open Access Journals (Sweden)

    Papaevangelou Thomas

    2018-01-01

    Full Text Available The current state of the art in fast timing resolution for existing experiments is of the order of 100 ps on the time of arrival of both charged particles and electromagnetic showers. Current R&D on charged particle timing is approaching the level of 10 ps but is not primarily directed at sustained performance at high rates and under high radiation (as would be needed for HL-LHC pileup mitigation. We demonstrate aMicromegas based solution to reach this level of performance. The Micromegas acts as a photomultiplier coupled to a Cerenkovradiator front window, which produces sufficient UV photons to convert the ∼100 ps single-photoelectron jitter into a timing response of the order of 10-20 ps per incident charged particle. A prototype has been built in order to demonstrate this performance. The first laboratory tests with a pico-second laser have shown a time resolution of the order of 27 ps for ∼50 primary photoelectrons, using a bulk Micromegas readout.

  10. High-Redshift Type Ia Supernova Rates in Galaxy Cluster and Field Environments

    Science.gov (United States)

    Barbary, Kyle Harris

    This thesis presents Type Ia supernova (SN Ia) rates from the Hubble Space Telescope (HST) Cluster Supernova Survey, a program designed to efficiently detect and observe high-redshift supernovae by targeting massive galaxy clusters at redshifts 0.9 z z > 0.9 SNe. The SN Ia rate is found to be 0.50+0.23-0.19 (stat) +0.10-0.09 (sys) h 702 SNuB (SNuB = 10-12 SNe Lsun,B-1 yr-1), or in units of stellar mass, 0.36+0.16-0.13 (stat) +0.07-0.06 (sys) h 702 SNuM (SNuM = 10-12 SNe M sun-1 yr-1). This represents a factor of approximately 5 +/- 2 increase over measurements of the cluster rate at z influence of younger stellar populations the rate is also calculated specifically in cluster red-sequence galaxies and in morphologically early-type galaxies, with results similar to the full cluster rate. Finally, the upper limit of one host-less cluster SN Ia detected in the survey implies that the fraction of stars in the intra-cluster medium is less than 0.47 (95% confidence), consistent with measurements at lower redshifts. The volumetric SN Ia rate can also be used to constrain the SN Ia delay time distribution. However, there have been discrepancies in recent analyses of both the high-redshift rate and its implications for the delay time distribution. Here, the volumetric SN Ia rate out to z ˜ 1.6 is measured, based on ˜12 SNe Ia in the foregrounds and backgrounds of the clusters targeted in the survey. The rate is measured in four broad redshift bins. The results are consistent with previous measurements at z > 1 and strengthen the case for a SN Ia rate that is greater than approximately 0.6 x 10-4 h70 3 yr-1 Mpc-3 at z ˜ 1 and flattening out at higher redshift. Assumptions about host-galaxy dust extinction used in different high-redshift rate measurements are examined. Different assumptions may account for some of the difference in published results for the z ˜ 1 rate.

  11. Construction and Test of Muon Drift Tube Chambers for High Counting Rates

    CERN Document Server

    Schwegler, Philipp; Dubbert, Jörg

    2010-01-01

    Since the start of operation of the Large Hadron Collider (LHC) at CERN on 20 November 2009, the instantaneous luminosity is steadily increasing. The muon spectrometer of the ATLAS detector at the LHC is instrumented with trigger and precision tracking chambers in a toroidal magnetic field. Monitored Drift-Tube (MDT) chambers are employed as precision tracking chambers, complemented by Cathode Strip Chambers (CSC) in the very forward region where the background counting rate due to neutrons and γ's produced in shielding material and detector components is too high for the MDT chambers. After several upgrades of the CERN accelerator system over the coming decade, the instantaneous luminosity is expected to be raised to about five times the LHC design luminosity. This necessitates replacement of the muon chambers in the regions with the highest background radiation rates in the so-called Small Wheels, which constitute the innermost layers of the muon spectrometer end-caps, by new detectors with higher rate cap...

  12. NATURAL RADIOACTIVITY LEVEL AND ELEMENTAL COMPOSITION OF SOIL SAMPLES FROM A HIGH BACKGROUND RADIATION AREA ON EASTERN COAST OF INDIA (ODISHA).

    Science.gov (United States)

    Sahoo, S K; Kierepko, R; Sorimachi, A; Omori, Y; Ishikawa, T; Tokonami, S; Prasad, G; Gusain, G S; Ramola, R C

    2016-10-01

    A comprehensive study was carried out to determine the radioactivity concentration of soil samples from different sites of a high background radiation area in the eastern coast of India, Odisha state. The dose rate measured in situ varied from 0.25 to 1.2 µSv h-1 The gamma spectrometry measurements indicated Th series elements as the main contributors to the enhanced level of radiation and allowed the authors to find the mean level of the activity concentration (±SD) for 226Ra, 228Th and 40K as 130±97, 1110±890 and 360±140 Bq kg-1, respectively. Human exposure from radionuclides occurring outdoor was estimated based on the effective dose rate, which ranged from 0.14±0.02 to 2.15±0.26 mSv and was higher than the UNSCEAR annual worldwide average value 0.07 mSv. Additionally, X-ray fluorescence analysis provided information about the content of major elements in samples and indicated the significant amount of Ti (7.4±4.9 %) in soils. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. High strain rate modeling of ceramics and ceramic composites

    Science.gov (United States)

    Espinosa, H. D.

    1994-07-01

    The high strain rate response of an AlN/AlN/Al composite manufactured by Lanxide Armor Products, Inc., has been studied through normal and pressure-shear plate impact experiments. Differences in the measured shear resistance, as a function of the impact configuration, motivated the examination of the material response by means of a microcracking multiple-plane model and a continuum elasto-viscoplastic constitutive model. Numerical simulations of the normal impact experiments do not support microcracking as the dominant inelastic mechanism. By contrast, an elasto-viscoplastic description of the material behavior predicts the main features of the normal stress history and the thickness dependence of the Hugoniot elastic limit. Nonetheless, the elasto-viscoplastic model cannot reproduce both the normal and pressure-shear experiments with a single set of model parameters. The inadequacy of the continuum elasto-viscoplastic model seems to result from the isotropic assumption embodied in its formulation. The shear resistance measured in the pressure-shear experiments is adequately predicted by a microcracking multiple-plane model. The agreement seems to hinge in the continuous shearing of the material on a micro-localized fashion, i.e. only one orientation becomes dominant and controls the inelastic shear deformation rate. This event does not occur in the normal impact configuration, in which the amount of inelasticity is primarily controlled by the elastic compressibility of the material. These findings explain the higher sensitivity to damage and microplasticity observed in the pressure-shear configuration, as well as the softer material response recorded in this configuration.

  14. Growth rate of sheep fed high fat ration

    Directory of Open Access Journals (Sweden)

    Darwinsyah Lubis

    1998-10-01

    Full Text Available Incorporating high amount of fats into the ration for ruminants will affect the rumen microbes adversely and will reducefiber digestion potential. To correct such negative effects, the free fatty acids used for feed should be bond with Ca++, so it canpassing through the rumen savely (rumen by-pass fat. To test the Ca-fat utilization biologically, 20 growing male Garut shee pwere used and fed with 4 type of isocaloric-isoprotein concentrate feed which were allotted based on a randomized block desig nwith 5 replications. The concentrate (C-A was a positive control diet, while C-B was substituted with 10% free fatty acids (negative control, C-C was substituted with 10% Ca-fat, and C-D with 15% Ca-fat. The concentrate feed was fed at 500 g/d, while forage (King grass was 4 kg/d. Results of the experiment showed that the negative effect of free fatty acids can be corrected if it was given in the form of Ca-fat. Growth rate curve indicating a good growing pattern, with average daily gain was 100.18, 87.68, 112.86, and 115.00 g/d (P0.05. Carcass production was relatively good, where for C-A, C-B, C-C, and C-D were 14.84, 14.68, 16.34, and 15.72 kg (P<0.05 respectively, with final live weights of 34.00, 31.74, 34.58, and 34.30 kg (P<0.05. It can be concluded that Ca-fat (rumen by-pass fat can be used as an energy source component for growing sheep diet, and give the best result at 10% substitution rate in concentrate feed.

  15. An infrared high rate video imager for various space applications

    Science.gov (United States)

    Svedhem, Hâkan; Koschny, Detlef

    2010-05-01

    Modern spacecraft with high data transmission capabilities have opened up the possibility to fly video rate imagers in space. Several fields concerned with observations of transient phenomena can benefit significantly from imaging at video frame rate. Some applications are observations and characterization of bolides/meteors, sprites, lightning, volcanic eruptions, and impacts on airless bodies. Applications can be found both on low and high Earth orbiting spacecraft as well as on planetary and lunar orbiters. The optimum wavelength range varies depending on the application but we will focus here on the near infrared, partly since it allows exploration of a new field and partly because it, in many cases, allows operation both during day and night. Such an instrument has to our knowledge never flown in space so far. The only sensors of a similar kind fly on US defense satellites for monitoring launches of ballistic missiles. The data from these sensors, however, is largely inaccessible to scientists. We have developed a bread-board version of such an instrument, the SPOSH-IR. The instrument is based on an earlier technology development - SPOSH - a Smart Panoramic Optical Sensor Head, for operation in the visible range, but with the sensor replace by a cooled IR detector and new optics. The instrument is using a Sofradir 320x256 pixel HgCdTe detector array with 30µm pixel size, mounted directly on top of a four stage thermoelectric Peltier cooler. The detector-cooler combination is integrated into an evacuated closed package with a glass window on its front side. The detector has a sensitive range between 0.8 and 2.5 µm. The optical part is a seven lens design with a focal length of 6 mm and a FOV 90deg by 72 deg optimized for use at SWIR. The detector operates at 200K while the optics operates at ambient temperature. The optics and electronics for the bread-board has been designed and built by Jena-Optronik, Jena, Germany. This talk will present the design and the

  16. A prototype High Purity Germanium detector for high resolution gamma-ray spectroscopy at high count rates

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, R.J., E-mail: rjcooper@lbl.gov [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Amman, M.; Luke, P.N. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Vetter, K. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Department of Nuclear Engineering, University of California, Berkeley, CA 94720 (United States)

    2015-09-21

    Where energy resolution is paramount, High Purity Germanium (HPGe) detectors continue to provide the optimum solution for gamma-ray detection and spectroscopy. Conventional large-volume HPGe detectors are typically limited to count rates on the order of ten thousand counts per second, however, limiting their effectiveness for high count rate applications. To address this limitation, we have developed a novel prototype HPGe detector designed to be capable of achieving fine energy resolution and high event throughput at count rates in excess of one million counts per second. We report here on the concept, design, and initial performance of the first prototype device.

  17. No variation and low synonymous substitution rates in coral mtDNA despite high nuclear variation

    Directory of Open Access Journals (Sweden)

    Hellberg Michael E

    2006-03-01

    Full Text Available Abstract Background The mitochondrial DNA (mtDNA of most animals evolves more rapidly than nuclear DNA, and often shows higher levels of intraspecific polymorphism and population subdivision. The mtDNA of anthozoans (corals, sea fans, and their kin, by contrast, appears to evolve slowly. Slow mtDNA evolution has been reported for several anthozoans, however this slow pace has been difficult to put in phylogenetic context without parallel surveys of nuclear variation or calibrated rates of synonymous substitution that could permit quantitative rate comparisons across taxa. Here, I survey variation in the coding region of a mitochondrial gene from a coral species (Balanophyllia elegans known to possess high levels of nuclear gene variation, and estimate synonymous rates of mtDNA substitution by comparison to another coral (Tubastrea coccinea. Results The mtDNA surveyed (630 bp of cytochrome oxidase subunit I was invariant among individuals sampled from 18 populations spanning 3000 km of the range of B. elegans, despite high levels of variation and population subdivision for allozymes over these same populations. The synonymous substitution rate between B. elegans and T. coccinea (0.05%/site/106 years is similar to that in most plants, but 50–100 times lower than rates typical for most animals. In addition, while substitutions to mtDNA in most animals exhibit a strong bias toward transitions, mtDNA from these corals does not. Conclusion Slow rates of mitochondrial nucleotide substitution result in low levels of intraspecific mtDNA variation in corals, even when nuclear loci vary. Slow mtDNA evolution appears to be the basal condition among eukaryotes. mtDNA substitution rates switch from slow to fast abruptly and unidirectionally. This switch may stem from the loss of just one or a few mitochondrion-specific DNA repair or replication genes.

  18. Algal biofuels from wastewater treatment high rate algal ponds.

    Science.gov (United States)

    Craggs, R J; Heubeck, S; Lundquist, T J; Benemann, J R

    2011-01-01

    This paper examines the potential of algae biofuel production in conjunction with wastewater treatment. Current technology for algal wastewater treatment uses facultative ponds, however, these ponds have low productivity (∼10 tonnes/ha.y), are not amenable to cultivating single algal species, require chemical flocculation or other expensive processes for algal harvest, and do not provide consistent nutrient removal. Shallow, paddlewheel-mixed high rate algal ponds (HRAPs) have much higher productivities (∼30 tonnes/ha.y) and promote bioflocculation settling which may provide low-cost algal harvest. Moreover, HRAP algae are carbon-limited and daytime addition of CO(2) has, under suitable climatic conditions, the potential to double production (to ∼60 tonnes/ha.y), improve bioflocculation algal harvest, and enhance wastewater nutrient removal. Algae biofuels (e.g. biogas, ethanol, biodiesel and crude bio-oil), could be produced from the algae harvested from wastewater HRAPs, The wastewater treatment function would cover the capital and operation costs of algal production, with biofuel and recovered nutrient fertilizer being by-products. Greenhouse gas abatement results from both the production of the biofuels and the savings in energy consumption compared to electromechanical treatment processes. However, to achieve these benefits, further research is required, particularly the large-scale demonstration of wastewater treatment HRAP algal production and harvest.

  19. Accuracy of High-Rate GPS for Seismology

    Science.gov (United States)

    Elosegui, P.; Davis, J. L.; Oberlander, D.; Baena, R.; Ekstrom, G.

    2006-01-01

    We built a device for translating a GPS antenna on a positioning table to simulate the ground motions caused by an earthquake. The earthquake simulator is accurate to better than 0.1 mm in position, and provides the "ground truth" displacements for assessing the technique of high-rate GPS. We found that the root-mean-square error of the 1-Hz GPS position estimates over the 15-min duration of the simulated seismic event was 2.5 mm, with approximately 96% of the observations in error by less than 5 mm, and is independent of GPS antenna motion. The error spectrum of the GPS estimates is approximately flicker noise, with a 50% decorrelation time for the position error of approx.1.6 s. We that, for the particular event simulated, the spectrum of dependent error in the GPS measurements. surface deformations exceeds the GPS error spectrum within a finite band. More studies are required to determine whether a generally optimal bandwidth exists for a target group of seismic events.

  20. Adiabatic flow curves of metallic materials at high strain rates

    Energy Technology Data Exchange (ETDEWEB)

    El-Magd, E. [Technische Hochschule Aachen (Germany); Scholles, H. [Rheinmetall Industrie GmbH, Unterluess (Germany); Weisshaupt, H. [Rheinmetall Industrie GmbH, Unterluess (Germany)

    1996-08-01

    Dynamic compression tests are carried out on Armco iron, Cr-V-steel, Ni-Cr-Mo-V-steel, an austenitic Ni-Cr-Mo-steel, tantalum, nickel and Ni{sub 3}Al and magnesium. The flow curves are analysed to determine the influence of the deformation energy which is transformed into heat on the flow behaviour and mechanical stability. Not only the material properties but also the conditions of friction between the specimen and the compresion tool are found to have a greate influence on the flow stress reduction and stability. High frictional forces promote mechanical instability of materials with low strain hardening and low strain rate sensitivity. (orig.) [Deutsch] Schlagdruckversuche werden an Armcoeisen, CrV-Stahl, NiCr-MoV-Stahl, austenitischen NiCrMo-Stahl, Tantal, Nickel, Ni{sub 3}Al und Magnesium durchgefuehrt. Die ermittelten Fliesskurven werden analysiert, um den Einfluss der in Waerme umgewandelte Verformungsarbeit auf das Fliessverhalten und die mechanische Stabilitaet zu erfassen. Nicht nur die Werkstoffeigenschaften sondern auch die Reibungsbedingungen erweisen sich als massgebliche Einflussgroessen fuer Fliessspannungsabnahme und die Stabilitaet. Hohe Reibungskraefte foerdern die Verformungslokalisierung und die mechanische Instabilitaet von Werkstoffen mit niedriger Verfestigung und niedriger Geschwindigkeitsempfindlichkeit. (orig.)

  1. Pregnancy after kidney transplantation: high rates of maternal complications

    Directory of Open Access Journals (Sweden)

    Cristina Candido

    Full Text Available Abstract Introduction: Women regain fertility a few time after renal transplantation. However, viability of pregnancy and maternal complications are still unclear. Objective: To describe the outcomes of pregnancies in kidney transplanted patients, focusing on maternal complications. Methods: Retrospective study of pregnancies in kidney transplanted patients between 2004 and 2014, followed up 12 months after delivery. Each pregnancy was considered an event. Results: There were 53 pregnancies in 36 patients. Mean age was 28 ± 5years. Pregnancy occurred 4.4 ± 3.0 years post-transplant. Immunosuppression before conception was tacrolimus, azathioprine, and prednisone in 74% of the cases. There were 15% miscarriages in the 1st trimester and 8% in 2nd trimester. In 41% of the cases, it was necessary to induce labor. From all births, 22% were premature and 17% very premature. There were 5% stillbirths and 5% of neonatal deaths. De novo proteinuria occurred in 60%, urinary tract infection in 23%, preeclampsia in 11%, acute rejection in 6%, and graft loss in 2% of the cases. It was observed a significant increase in creatinine at preconception comparing to 3rd trimester and follow-up (1.17 vs. 1.46 vs. 1.59 mg/dL, p < 0.001. Conclusion: Although the sample is limited, the number of miscarriages was higher than in the general population, with high rates of maternal complications. Sustained increase of creatinine suggests increased risk of graft loss in long-term.

  2. Bats and birds: Exceptional longevity despite high metabolic rates.

    Science.gov (United States)

    Munshi-South, Jason; Wilkinson, Gerald S

    2010-01-01

    Bats and birds live substantially longer on average than non-flying mammals of similar body size. The combination of small body size, high metabolic rates, and long lifespan in bats and birds would not seem to support oxidative theories of ageing that view senescence as the gradual accumulation of damage from metabolic byproducts. However, large-scale comparative analyses and laboratory studies on a few emerging model species have identified multiple mechanisms for resisting oxidative damage to mitochondrial DNA and cellular structures in both bats and birds. Here we review these recent findings, and suggest areas in which additional progress on ageing mechanisms can be made using bats and birds as novel systems. New techniques for determining the age of free-living, wild individuals, and robustly supported molecular phylogenies, are under development and will improve the efforts of comparative biologists to identify ecological and evolutionary factors promoting long lifespan. In the laboratory, greater development of emerging laboratory models and comparative functional genomic approaches will be needed to identify the molecular pathways of longevity extension in birds and bats. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

  3. MATHEMATICAL MODELING OF HEATING RATE PRODUCT AT HIGH HEAT TREATMENT

    Directory of Open Access Journals (Sweden)

    M. M. Akhmedova

    2014-01-01

    Full Text Available Methods of computing and mathematical modeling are all widely used in the study of various heat exchange processes that provide the ability to study the dynamics of the processes, as well as to conduct a reasonable search for the optimal technological parameters of heat treatment.This work is devoted to the identification of correlations among the factors that have the greatest effect on the rate of heating of the product at hightemperature heat sterilization in a stream of hot air, which are chosen as the temperature difference (between the most and least warming up points and speed cans during heat sterilization.As a result of the experimental data warming of the central and peripheral layers compote of apples in a 3 liter pot at high-temperature heat treatment in a stream of hot air obtained by the regression equation in the form of a seconddegree polynomial, taking into account the effects of pair interaction of these parameters. 

  4. Strain rate viscoelastic analysis of soft and highly hydrated biomaterials.

    Science.gov (United States)

    Tirella, A; Mattei, G; Ahluwalia, A

    2014-10-01

    Measuring the viscoelastic behavior of highly hydrated biological materials is challenging because of their intrinsic softness and labile nature. In these materials, it is difficult to avoid prestress and therefore to establish precise initial stress and strain conditions for lumped parameter estimation using creep or stress-relaxation (SR) tests. We describe a method ( ɛ˙M or epsilon dot method) for deriving the viscoelastic parameters of soft hydrated biomaterials which avoids prestress and can be used to rapidly test degradable samples. Standard mechanical tests are first performed compressing samples using different strain rates. The dataset obtained is then analyzed to mathematically derive the material's viscoelastic parameters. In this work a stable elastomer, polydimethylsiloxane, and a labile hydrogel, gelatin, were first tested using the ɛ˙M, in parallel SR was used to compare lumped parameter estimation. After demonstrating that the elastic parameters are equivalent and that the estimation of short-time constants is more precise using the proposed method, the viscoelastic behavior of porcine liver was investigated using this approach. The results show that the constitutive parameters of hepatic tissue can be quickly quantified without the application of any prestress and before the onset of time-dependent degradation phenomena. © 2013 Wiley Periodicals, Inc.

  5. High prevalence rate of left superior vena cava determined by ...

    African Journals Online (AJOL)

    Background: Persistent left superior vena cava (LSVC) is one of the common anomalies of the systemic veins. Its prevalence is 0.10.3% in the general population and is more common with congenital heart disease (CHD). The importance of detecting persistent LSVC prior to cardiac surgery is paramount for systemic veins ...

  6. High prevalence rate of left superior vena cava determined by ...

    African Journals Online (AJOL)

    2013-10-08

    Oct 8, 2013 ... Background: Persistent left superior vena cava (LSVC) is one of the common anomalies of the systemic veins. Its prevalence is 0.1Á0.3% in the general population and is more common with congenital heart disease. (CHD). The importance of detecting persistent LSVC prior to cardiac surgery is paramount ...

  7. Characterizing the Completeness of Spitzer IRAC Imaging and the GLIMPSE Point Source Catalog in High-background Regions

    Science.gov (United States)

    Kobulnicky, Henry A.; Alexander, M.; Brian, B.; Meade, M.; Whitney, B.; Churchwell, E.

    2012-01-01

    The Spitzer Space Telescope Galactic Legacy MidPlane Survey Extraordinaire (GLIMPSE) programs (GLIMPSE I, II, 3D, 360) have surveyed hundreds of square degrees of the Galactic Plane in four (two for GLIMPSE 360) mid-infrared bandpasses with the Infrared Array Camera (IRAC). The resulting GLIMPSE Point Source Catalog contains over 100 million objects and has become a widely used resource. Other large and Legacy Spitzer programs have used IRAC to survey additional regions totaling over 100 square degrees. The utility of the data and of the point source catalogs from ANY IRAC observations is limited, however, by the fact that the completeness of the photometric catalogs vary inversely with background surface brightness. This is especially significant in the 5.8 and 8.0 micron (IRAC1 and IRAC2) bands where diffuse interstellar PAH features are strong. In this contribution we use fake star tests to characterize the completeness and reliability of single-frame, single-band data from the commonly used short-exposure IRAC observing modes as a function of background surface brightness and stellar magnitude. We also explore empirically the completeness of the GLIMPSE Point Source Catalog as a function of background brightness and magnitude. We provide plots and analytical prescriptions to allow an end user to asses the completeness over specified magnitude and background brightness ranges.

  8. Teaching Evolution in New Jersey Public High Schools: Examining the Influence of Personal Belief and Religious Background on Teaching Practices

    Science.gov (United States)

    Smith, Carlen

    2010-01-01

    The purpose of this study was to determine relationships between New Jersey biology teachers' personal characteristics and religious backgrounds and the time spent and approach to teaching evolution. The research instrument chosen was a cross-sectional survey. Survey questions were presented in various forms: fill in, single response, Likert…

  9. High-order harmonic generation using a high-repetition-rate turnkey laser

    CERN Document Server

    Lorek, Eleonora; Heyl, Christoph Michael; Carlström, Stefanos; Paleček, David; Zigmantas, Donatas; Mauritsson, Johan

    2014-01-01

    We generate high-order harmonics at high pulse repetition rates using a turnkey laser. High-order harmonics at 400 kHz are observed when argon is used as target gas. In neon we achieve generation of photons with energies exceeding 90 eV ($\\sim$13 nm) at 20 kHz. We measure a photon flux of 4.4$\\cdot10^{10}$ photons per second per harmonic in argon at 100 kHz. Many experiments employing high-order harmonics would benefit from higher repetition rates, and the user-friendly operation opens up for applications of coherent extreme ultra-violet pulses in new research areas.

  10. Investigation of the Effects of Facility Background Pressure on the Performance and Voltage-Current Characteristics of the High Voltage Hall Accelerator

    Science.gov (United States)

    Kamhawi, Hani; Huang, Wensheng; Haag, Thomas; Spektor, Rostislav

    2014-01-01

    The National Aeronautics and Space Administration (NASA) Science Mission Directorate In-Space Propulsion Technology office is sponsoring NASA Glenn Research Center to develop a 4 kW-class Hall thruster propulsion system for implementation in NASA science missions. A study was conducted to assess the impact of varying the facility background pressure on the High Voltage Hall Accelerator (HiVHAc) thruster performance and voltage-current characteristics. This present study evaluated the HiVHAc thruster performance in the lowest attainable background pressure condition at NASA GRC Vacuum Facility 5 to best simulate space-like conditions. Additional tests were performed at selected thruster operating conditions to investigate and elucidate the underlying physics that change during thruster operation at elevated facility background pressure. Tests were performed at background pressure conditions that are three and ten times higher than the lowest realized background pressure. Results indicated that the thruster discharge specific impulse and efficiency increased with elevated facility background pressure. The voltage-current profiles indicated a narrower stable operating region with increased background pressure. Experimental observations of the thruster operation indicated that increasing the facility background pressure shifted the ionization and acceleration zones upstream towards the thruster's anode. Future tests of the HiVHAc thruster are planned at background pressure conditions that are expected to be two to three times lower than what was achieved during this test campaign. These tests will not only assess the impact of reduced facility background pressure on thruster performance, voltage-current characteristics, and plume properties; but will also attempt to quantify the magnitude of the ionization and acceleration zones upstream shifting as a function of increased background pressure.

  11. High Growth Rate Metal-Organic Molecular Beam Epitaxy for the Fabrication of GaAs Space Solar Cells

    Science.gov (United States)

    Freundlich, A.; Newman, F.; Monier, C.; Street, S.; Dargan, P.; Levy, M.

    2005-01-01

    In this work it is shown that high quality GaAs photovoltaic devices can be produced by Molecular Beam Epitaxy (MBE) with growth rates comparable to metal-organic chemical vapor deposition (MOCVD) through the subsitution of group III solid sources by metal-organic compounds. The influence the III/V flux-ratio and growth temperatures in maintaining a two dimensional layer by layer growth mode and achieving high growth rates with low residual background impurities is investigated. Finally subsequent to the study of the optimization of n- and p doping of such high growth rate epilayers, results from a preliminary attempt in the fabrication of GaAs photovoltaic devices such as tunnel diodes and solar cells using the proposed high growth rate approach are reported.

  12. High adsorption rate is detrimental to bacteriophage fitness in a biofilm-like environment

    Directory of Open Access Journals (Sweden)

    Shao Yongping

    2009-10-01

    Full Text Available Abstract Background Bacterial biofilm is ubiquitous in nature. However, it is not clear how this crowded habitat would impact the evolution of bacteriophage (phage life history traits. In this study, we constructed isogenic λ phage strains that only differed in their adsorption rates, because of the presence/absence of extra side tail fibers or improved tail fiber J, and maker states. The high cell density and viscosity of the biofilm environment was approximated by the standard double-layer agar plate. The phage infection cycle in the biofilm environment was decomposed into three stages: settlement on to the biofilm surface, production of phage progeny inside the biofilm, and emigration of phage progeny out of the current focus of infection. Results We found that in all cases high adsorption rate is beneficial for phage settlement, but detrimental to phage production (in terms of plaque size and productivity and emigration out of the current plaque. Overall, the advantage of high adsorption accrued during settlement is more than offset by the disadvantages experienced during the production and emigration stages. The advantage of low adsorption rate was further demonstrated by the rapid emergence of low-adsorption mutant from a high-adsorption phage strain with the side tail fibers. DNA sequencing showed that 19 out of the 21 independent mutant clones have mutations in the stf gene, with the majority of them being single-nucleotide insertion/deletion mutations occurring in regions with homonucleotide runs. Conclusion We conclude that high mutation rate of the stf gene would ensure the existence of side tail fiber polymorphism, thus contributing to rapid adaptation of the phage population between diametrically different habitats of benthic biofilm and planktonic liquid culture. Such adaptability would also help to explain the maintenance of the stf gene in phage λ's genome.

  13. High dwelling vacancy rate and high prices of housing in Malta : A mediterranean phenomenon

    NARCIS (Netherlands)

    Vakili-Zad, C.; Hoekstra, J.S.C.M.

    2011-01-01

    Current data from South European countries, especially Malta, indicates the existence of some contradictory forces in the housing market that defy the law of supply and demand and require explanation. In a ‘normal’ housing market, it can be expected that a high dwelling vacancy rate would help keep

  14. Evolution of plastic anisotropy for high-strain-rate computations

    Energy Technology Data Exchange (ETDEWEB)

    Schiferl, S.K.; Maudlin, P.J.

    1994-12-01

    A model for anisotropic material strength, and for changes in the anisotropy due to plastic strain, is described. This model has been developed for use in high-rate, explicit, Lagrangian multidimensional continuum-mechanics codes. The model handles anisotropies in single-phase materials, in particular the anisotropies due to crystallographic texture--preferred orientations of the single-crystal grains. Textural anisotropies, and the changes in these anisotropies, depend overwhelmingly no the crystal structure of the material and on the deformation history. The changes, particularly for a complex deformations, are not amenable to simple analytical forms. To handle this problem, the material model described here includes a texture code, or micromechanical calculation, coupled to a continuum code. The texture code updates grain orientations as a function of tensor plastic strain, and calculates the yield strength in different directions. A yield function is fitted to these yield points. For each computational cell in the continuum simulation, the texture code tracks a particular set of grain orientations. The orientations will change due to the tensor strain history, and the yield function will change accordingly. Hence, the continuum code supplies a tensor strain to the texture code, and the texture code supplies an updated yield function to the continuum code. Since significant texture changes require relatively large strains--typically, a few percent or more--the texture code is not called very often, and the increase in computer time is not excessive. The model was implemented, using a finite-element continuum code and a texture code specialized for hexagonal-close-packed crystal structures. The results for several uniaxial stress problems and an explosive-forming problem are shown.

  15. Interstitial high-dose-rate brachytherapy in eyelid cancer.

    Science.gov (United States)

    Mareco, Virgínia; Bujor, Laurentiu; Abrunhosa-Branquinho, André N; Ferreira, Miguel Reis; Ribeiro, Tiago; Vasconcelos, Ana Luisa; Ferreira, Cidalina Reis; Jorge, Marília

    2015-01-01

    To report the experience and the outcomes of interstitial high-dose-rate (HDR) brachytherapy (BT) of eyelid skin cancer at the Department of Radiotherapy of Hospital de Santa Maria in Lisbon. Seventeen patients (pts; mean age, 73.75 years) who underwent eyelid interstitial HDR BT with an (192)Ir source between January 2011 and February 2013 were analyzed. Lesions were basal (94%) and squamous (6%) cell carcinomas, on lower (88%) or upper (6%) eyelids, and on inner canthus (6%). T-stage was Tis (6%), T1 (46%), T2 (36%), and T3a (12%). The purpose of BT was radical (12%), adjuvant to surgery (71%), or salvage after surgery (18%). The BT implant and treatment planning were based on the Stepping Source Dosimetry System. The median total dose was 42.75 Gy (range, 32-50 Gy), with a median of 10 fractions (range, 9-11 fractions), twice daily, 6 h apart. The median V100 was 2.38 cm(3) (range, 0.83-5.59 cm(3)), and the median V150 was 1.05 cm(3) (range, 0.24-3.12 cm(3)). At a median followup of 40 months (range, 7-43 months), the local control was 94.1%. There was one local recurrence and one non-related death. The BT was well tolerated. Madarosis was the most common late effect (65% of pts) and was related with higher values of V100 (p = 0.027). Cosmetic outcomes were good and excellent in 70% of pts. Interstitial HDR BT is a feasible and safe technique for eyelid skin cancers, with good local control. Recurrent lesions and higher volumes receiving the prescribed dose were associated with worse outcomes. Copyright © 2015 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  16. Mode locking of fiber lasers at high repetition rates

    Science.gov (United States)

    Usechak, Nicholas G.

    Mode-locked fiber lasers have become indispensable tools in many fields as their use is no longer relegated to the optics community. In the future, their size will decrease and their applications will become far more prevalent than they are today. At present, the field is undergoing a cardinal shift as these devices have become commercially available in the last decade. This has put an emphasis on long-term performance and reliability as these devices are beginning to be integrated into complex systems in areas as diverse as medical optics, micro-machining, forensics, and tracking as well as their obvious use as laboratory tools or sources in telecommunications. This is also resulting in a transition from research to engineering. Since the field of mode-locked lasers has been extensively studied for over forty years, one may expect that little has been overlooked. However, since the mode-locking phenomena is governed by nonlinear partial differential equations, a rich degree of effects exist and the field has not yet been exhausted. During the past two decades, the main emphasis has been on short-pulse generation; however, the main thrust of research is likely to change to producing high-power devices, which will result in limiting effects and thermal issues that are currently ignored for low-power sources. Finally, detailed studies have generally been performed numerically as analytic solutions only exist in limiting cases. In this thesis, mode-locked fiber lasers are studied experimentally, numerically, and theoretically. The experimental work focuses on high-repetition rate, mode-locked cavities, which are then modeled numerically. A semi-analytic tool, which goes beyond the prior theories and includes all of the effects experienced by steady-state, mode-locked pulses as they propagate in a laser cavity, is also derived. The only caveats to this approach are an assumption of the pulse shape and the requirement that it not change during propagation through the

  17. Effect of high heating rate on thermal decomposition behaviour of ...

    Indian Academy of Sciences (India)

    but rely on the concentration of hydrogen. The model ... first-order rate law. Lehmhus and Rausch (2004) have annealed TiH2 pow- der in air and argon. In argon, the powder does not develop a surface layer and as a result, a small amount of hydro- gen is lost ... rate effect on the thermal decomposition behaviour of TiH2.

  18. Do high fetal catecholamine levels affect heart rate variability and ...

    African Journals Online (AJOL)

    Objectives. To deternrine the relationship between Umbilical arterial catecholamine levels and fetal heart rate variability and meconium passage. Study design. A prospective descriptive study was perfonned. Umbilical artery catecholamine levels were measured in 55 newborns and correlated with fetal heart rate before ...

  19. Increasing seatbelt usage rate among high school students.

    Science.gov (United States)

    2010-01-01

    While seatbelt use has increased considerably during the last two decades, non-use and inconsistent use is still a significant problem, especially among youths. In addition, population-wide seatbelt rates may appear acceptable, but the rate is low in...

  20. Spectroscopic measurement of high-frequency electric fields in the interaction of explosive debris plasma with magnetized background plasma

    Energy Technology Data Exchange (ETDEWEB)

    Bondarenko, A. S., E-mail: AntonBondarenko@ymail.com; Schaeffer, D. B.; Everson, E. T.; Clark, S. E.; Constantin, C. G.; Niemann, C. [Department of Physics and Astronomy, University of California-Los Angeles, Los Angeles, California 90095 (United States)

    2014-12-15

    The collision-less transfer of momentum and energy from explosive debris plasma to magnetized background plasma is a salient feature of various astrophysical and space environments. While much theoretical and computational work has investigated collision-less coupling mechanisms and relevant parameters, an experimental validation of the results demands the measurement of the complex, collective electric fields associated with debris-background plasma interaction. Emission spectroscopy offers a non-interfering diagnostic of electric fields via the Stark effect. A unique experiment at the University of California, Los Angeles, that combines the Large Plasma Device (LAPD) and the Phoenix laser facility has investigated the marginally super-Alfvénic, quasi-perpendicular expansion of a laser-produced carbon (C) debris plasma through a preformed, magnetized helium (He) background plasma via emission spectroscopy. Spectral profiles of the He II 468.6 nm line measured at the maximum extent of the diamagnetic cavity are observed to intensify, broaden, and develop equally spaced modulations in response to the explosive C debris, indicative of an energetic electron population and strong oscillatory electric fields. The profiles are analyzed via time-dependent Stark effect models corresponding to single-mode and multi-mode monochromatic (single frequency) electric fields, yielding temporally resolved magnitudes and frequencies. The proximity of the measured frequencies to the expected electron plasma frequency suggests the development of the electron beam-plasma instability, and a simple saturation model demonstrates that the measured magnitudes are feasible provided that a sufficiently fast electron population is generated during C debris–He background interaction. Potential sources of the fast electrons, which likely correspond to collision-less coupling mechanisms, are briefly considered.

  1. Characterization of an ultraviolet imaging detector with high event rate ROIC (HEROIC) readout

    Science.gov (United States)

    Nell, Nicholas; France, Kevin; Harwit, Alex; Bradley, Scott; Franka, Steve; Freymiller, Ed; Ebbets, Dennis

    2016-07-01

    We present characterization results from a photon counting imaging detector consisting of one microchannel plate (MCP) and an array of two readout integrated circuits (ROIC) that record photon position. The ROICs used in the position readout are the high event rate ROIC (HEROIC) devices designed to handle event rates up to 1 MHz per pixel, recently developed by the Ball Aerospace and Technologies Corporation in collaboration with the University of Colorado. An opaque cesium iodide (CsI) photocathode sensitive in the far-ultraviolet (FUV; 122-200 nm), is deposited on the upper surface of the MCP. The detector is characterized in a chamber developed by CU Boulder that is capable of illumination with vacuum-ultraviolet (VUV) monochromatic light and measurement of absolute ux with a calibrated photodiode. Testing includes investigation of the effects of adjustment of internal settings of the HEROIC devices including charge threshold, gain, and amplifier bias. The detector response to high count rates is tested. We report initial results including background, uniformity, and quantum detection efficiency (QDE) as a function of wavelength.

  2. High birth rates despite easy access to contraception and abortion

    DEFF Research Database (Denmark)

    Hognert, Helena; Skjeldestad, Finn E; Gemzell-Danielsson, Kristina

    2017-01-01

    INTRODUCTION: The aim of this study was to describe and compare contraceptive use, fertility, birth, and abortion rates in the Nordic countries. MATERIAL AND METHODS: National data on births, abortions, fertility rate (1975-2013), redeemed prescriptions of hormonal contraceptives and sales figures...... contraception followed by the levonorgestrel-releasing intrauterine system were the most common methods. During 1975-2013 abortion rates decreased in Denmark (from 27/1000 women to 15/1000 women aged 15-44/1000 women) and Finland (from 20 to 10/1000 women), remained stable in Norway (≈16) and Sweden (≈20......) and increased in Iceland (from 6 to 15/1000 women). Birth rates remained stable around 60/1000 women aged 15-44 in all countries except for Iceland where the birth rate decreased from 95 to 65/1000 women. Abortion rates were highest in the age group 20-24 years. In the same age group, Sweden had a lower...

  3. Study of the performance of ATLAS muon drift-tube chambers in magntic fields and at high irradiation rates

    Energy Technology Data Exchange (ETDEWEB)

    Valderanis, Chrysostomos

    2012-07-26

    The performance of ATLAS muon drift-tube (MDT) chambers has been studied in detail using high-energy muon beams. The measurements of the drift tube properties in magnetic fields showed that inelastic collisions of the drifting electrons with the CO{sub 2} molecules in the Ar:CO{sub 2} (93:7) gas mixture of the MDT chambers have to be taken into account in the simulation of the drift properties. Such inelastic collisions are now correctly treated by the Garfield simulation programme from version 9 providing an accurate description of the behaviour of the ATLAS muon drift tubes, in particular in the magnetic field. Measurements at the Gamma Irradiation Facility at CERN were performed to study the performance of the MDT chambers in the presence of high {gamma} ray background fluences. The chambers have a spatial resolution better than 40 {mu}m at the nominal background rates expected at the Large Hadron Collider design luminosity of 10{sup 34} cm{sup -2}s{sup -1} and a resolution better than 50 {mu}m for up to five times higher background rates. Efficient muon detection up to background counting rates of 500 kHz per tube corresponding to 35% occupancy was demonstrated.

  4. Space-time encoding for high frame rate ultrasound imaging

    DEFF Research Database (Denmark)

    Misaridis, Thanssis; Jensen, Jørgen Arendt

    2002-01-01

    Frame rate in ultrasound imaging can be dramatically increased by using sparse synthetic transmit aperture (STA) beamforming techniques. The two main drawbacks of the method are the low signal-to-noise ratio (SNR) and the motion artifacts, that degrade the image quality. In this paper we propose......, due to the orthogonality of the temporal encoded wavefronts. Thus, with this method, the frame rate is doubled compared to previous systems. Another advantage is the utilization of temporal codes which are more robust to attenuation. With the proposed technique it is possible to obtain images...

  5. A multiwire proportional counter for very high counting rates

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, A.F.; Guedes, G.P. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Tamura, E. [Laboratorio Nacional de Luz Sincrotron (LNLS), Campinas, SP (Brazil); Pepe, I.M.; Oliveira, N.B. [Bahia Univ., Salvador, BA (Brazil). Inst. de Fisica

    1997-12-01

    Preliminary measurements in a proportional counter with two independently counting wires showed that counting rates up to 10{sup 6} counts/s per wire can be reached without critical loss in the true versus measured linearity relation. Results obtained with a detector containing 30 active wires (2 mm pitch) are presented. To each wire is associated a fast pre-amplifier and a discriminator channel. Global counting rates in excess to 10{sup 7} events/s are reported. Data acquisition systems are described for 1D (real time) and 2D (off-line) position sensitive detection systems. (author) 13 refs., 6 figs.

  6. Ultrafast high strain rate acoustic wave measurements at high static pressure in a diamond anvil cell

    Science.gov (United States)

    Armstrong, Michael R.; Crowhurst, Jonathan C.; Reed, Evan J.; Zaug, Joseph M.

    2009-02-01

    We describe experiments demonstrating the generation of ultrafast, high strain rate acoustic waves in a precompressed transparent medium at static pressure up to 24 GPa. We also observe shock waves in precompressed aluminum with transient pressures above 40 GPa under precompression. Using ultrafast interferometry, we determine parameters such as the shock pressure and acoustic wave velocity using multiple and single shot methods. These methods form the basis for material experiments under extreme conditions which are challenging to access using other techniques.

  7. Strain Rate Effect on Tensile Behavior for a High Specific Strength Steel: From Quasi-Static to Intermediate Strain Rates

    OpenAIRE

    Wei Wang; Yan Ma; Muxin Yang; Ping Jiang; Fuping Yuan; Xiaolei Wu

    2017-01-01

    The strain rate effect on the tensile behaviors of a high specific strength steel (HSSS) with dual-phase microstructure has been investigated. The yield strength, the ultimate strength and the tensile toughness were all observed to increase with increasing strain rates at the range of 0.0006 to 56/s, rendering this HSSS as an excellent candidate for an energy absorber in the automobile industry, since vehicle crushing often happens at intermediate strain rates. Back stress hardening has been ...

  8. Analysis of Factors Causing Poor Passing Rates and High Dropout Rates among Primary School Girls in Malawi

    Science.gov (United States)

    Mzuza, Maureen Kapute; Yudong, Yang; Kapute, Fanuel

    2014-01-01

    Factors that cause poor examination passing rates and high dropout rates among primary school girls in Malawi were analysed. First hand data was collected by conducting a survey in all the three regions of Malawi. The respondents to the questionnaire were girls (402) who are repeating the last class in primary schools (Standard 8), primary school…

  9. High bit rate optical transmission using midspan spectral inversion ...

    African Journals Online (AJOL)

    conjugaison de phase optique; inversion spectrale. Abstract. The problem of the phase noise generated by nonlinear effects and chromatic dispersion can limit the transmission distance and the bit rate for phase-shift-keying modulation formats. In this paper, the compensation of the nonlinear and linear effects by a midspan ...

  10. Anomalous electric field changes and high flash rate beneath a ...

    Indian Academy of Sciences (India)

    In spite of many experimental and theoretical studies the relationships between storm dynamics, severe weather,and lightning activity have been least understood.Measurements of electric field made under a severe thunderstorm at a northeastern Indian station,Guwahati,India are reported. Lightning flash rate increases ...

  11. A multi-region assessment of population rates of cardiac catheterization and yield of high-risk coronary artery disease

    Directory of Open Access Journals (Sweden)

    Clement Fiona M

    2011-11-01

    Full Text Available Abstract Background There is variation in cardiac catheterization utilization across jurisdictions. Previous work from Alberta, Canada, showed no evidence of a plateau in the yield of high-risk disease at cardiac catheterization rates as high as 600 per 100,000 population suggesting that the optimal rate is higher. This work aims 1 To determine if a previously demonstrated linear relationship between the yield of high-risk coronary disease and cardiac catheterization rates persists with contemporary data and 2 to explore whether the linear relationship exists in other jurisdictions. Methods Detailed clinical information on all patients undergoing cardiac catheterization in 3 Canadian provinces was available through the Alberta Provincial Project for Outcomes Assessment in Coronary Heart (APPROACH disease and partner initiatives in British Columbia and Nova Scotia. Population rates of catheterization and high-risk coronary disease detection for each health region in these three provinces, and age-adjusted rates produced using direct standardization. A mixed effects regression analysis was performed to assess the relationship between catheterization rate and high-risk coronary disease detection. Results In the contemporary Alberta data, we found a linear relationship between the population catheterization rate and the high-risk yield. Although the yield was slightly less in time period 2 (2002-2006 than in time period 1(1995-2001, there was no statistical evidence of a plateau. The linear relationship between catheterization rate and high-risk yield was similarly demonstrated in British Columbia and Nova Scotia and appears to extend, without a plateau in yield, to rates over 800 procedures per 100,000 population. Conclusions Our study demonstrates a consistent finding, over time and across jurisdictions, of linearly increasing detection of high-risk CAD as population rates of cardiac catheterization increase. This internationally-relevant finding

  12. High estradiol levels improve false memory rates and meta-memory in highly schizotypal women.

    Science.gov (United States)

    Hodgetts, Sophie; Hausmann, Markus; Weis, Susanne

    2015-10-30

    Overconfidence in false memories is often found in patients with schizophrenia and healthy participants with high levels of schizotypy, indicating an impairment of meta-cognition within the memory domain. In general, cognitive control is suggested to be modulated by natural fluctuations in oestrogen. However, whether oestrogen exerts beneficial effects on meta-memory has not yet been investigated. The present study sought to provide evidence that high levels of schizotypy are associated with increased false memory rates and overconfidence in false memories, and that these processes may be modulated by natural differences in estradiol levels. Using the Deese-Roediger-McDermott paradigm, it was found that highly schizotypal participants with high estradiol produced significantly fewer false memories than those with low estradiol. No such difference was found within the low schizotypy participants. Highly schizotypal participants with high estradiol were also less confident in their false memories than those with low estradiol; low schizotypy participants with high estradiol were more confident. However, these differences only approached significance. These findings suggest that the beneficial effect of estradiol on memory and meta-memory observed in healthy participants is specific to highly schizotypal individuals and might be related to individual differences in baseline dopaminergic activity. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  13. High Strain Rate Testing of Welded DOP-26 Iridium

    Energy Technology Data Exchange (ETDEWEB)

    Schneibel, J. H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Miller, R. G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Carmichael, C. A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Fox, E. E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ulrich, G. B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); George, E. P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-08-01

    The iridium alloy DOP-26 is used to produce Clad Vent Set cups that protect the radioactive fuel in radioisotope thermoelectric generators (RTGs) which provide electric power for spacecraft and rovers. In a previous study, the tensile properties of DOP-26 were measured over a wide range of strain rates and temperatures and reported in ORNL/TM-2007/81. While that study established the properties of the base material, the fabrication of the heat sources requires welding, and the mechanical properties of welded DOP-26 have not been extensively characterized in the past. Therefore, this study was undertaken to determine the mechanical properties of DOP-26 specimens containing a transverse weld in the center of their gage sections. Tensile tests were performed at room temperature, 750, 900, and 1090°C and engineering strain rates of 1×10-3 and 10 s-1. Room temperature testing was performed in air, while testing at elevated temperatures was performed in a vacuum better than 1×10-4 Torr. The welded specimens had a significantly higher yield stress, by up to a factor of ~2, than the non-welded base material. The yield stress did not depend on the strain rate except at 1090°C, where it was slightly higher for the faster strain rate. The ultimate tensile stress, on the other hand, was significantly higher for the faster strain rate at temperatures of 750°C and above. At 750°C and above, the specimens deformed at 1×10-3 s-1 showed pronounced necking resulting sometimes in perfect chisel-edge fracture. The specimens deformed at 10 s-1 exhibited this fracture behavior only at the highest test temperature, 1090°C. Fracture occurred usually in the fusion zone of the weld and was, in most cases, primarily intergranular.

  14. High growth rate homoepitaxial diamond film deposition at high temperatures by microwave plasma-assisted chemical vapor deposition

    Science.gov (United States)

    Vohra, Yogesh K. (Inventor); McCauley, Thomas S. (Inventor)

    1997-01-01

    The deposition of high quality diamond films at high linear growth rates and substrate temperatures for microwave-plasma chemical vapor deposition is disclosed. The linear growth rate achieved for this process is generally greater than 50 .mu.m/hr for high quality films, as compared to rates of less than 5 .mu.m/hr generally reported for MPCVD processes.

  15. Fast optical signal processing in high bit rate OTDM systems

    DEFF Research Database (Denmark)

    Poulsen, Henrik Nørskov; Jepsen, Kim Stokholm; Clausen, Anders

    1998-01-01

    As all-optical signal processing is maturing, optical time division multiplexing (OTDM) has also gained interest for simple networking in high capacity backbone networks. As an example of a network scenario we show an OTDM bus interconnecting another OTDM bus, a single high capacity user...

  16. Compact Beamformer Design with High Frame Rate for Ultrasound Imaging

    Directory of Open Access Journals (Sweden)

    Jun Luo

    2014-04-01

    Full Text Available In medical field, two-dimension ultrasound images are widely used in clinical diagnosis. Beamformer is critical in determining the complexity and performance of an ultrasound imaging system. Different from traditional means implemented with separated chips, a compact beamformer with 64 effective channels in a single moderate Field Programmable Gate Array has been presented in this paper. The compactness is acquired by employing receive synthetic aperture, harmonic imaging, time sharing and linear interpolation. Besides that, multi-beams method is used to improve the frame rate of the ultrasound imaging system. Online dynamic configuration is employed to expand system’s flexibility to two kinds of transducers with multi-scanning modes. The design is verified on a prototype scanner board. Simulation results have shown that on-chip memories can be saved and the frame rate can be improved on the case of 64 effective channels which will meet the requirement of real-time application.

  17. Why Do Most Countries Set High Tax Rates on Capital?

    OpenAIRE

    Marceau, Nicolas; Mongrain, Steeve; Wilson, John D.

    2007-01-01

    We consider tax competition in a world with tax bases exhibiting different degrees of mobility, modeled as mobile and immobile capital. An agreement among countries not to give preferential treatment to mobile capital results in an equilibrium where mobile capital is nevertheless taxed relatively lightly. In particular, one or two of the smallest countries, measured by their stocks of immobile capital, choose relatively low tax rates, thereby attracting mobile capital away from the other coun...

  18. Data compression techniques applied to high resolution high frame rate video technology

    Science.gov (United States)

    Hartz, William G.; Alexovich, Robert E.; Neustadter, Marc S.

    1989-01-01

    An investigation is presented of video data compression applied to microgravity space experiments using High Resolution High Frame Rate Video Technology (HHVT). An extensive survey of methods of video data compression, described in the open literature, was conducted. The survey examines compression methods employing digital computing. The results of the survey are presented. They include a description of each method and assessment of image degradation and video data parameters. An assessment is made of present and near term future technology for implementation of video data compression in high speed imaging system. Results of the assessment are discussed and summarized. The results of a study of a baseline HHVT video system, and approaches for implementation of video data compression, are presented. Case studies of three microgravity experiments are presented and specific compression techniques and implementations are recommended.

  19. High Resolution, Range/Range-Rate Imager Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Visidyne proposes to develop a design for a small, lightweight, high resolution, in x, y, and z Doppler imager to assist in the guidance, navigation and control...

  20. High counting rate, two-dimensional position sensitive timing RPC

    CERN Document Server

    Petrovici, M.; Simion, V; Bartos, D; Caragheorgheopol, G; Deppner, I; Adamczewski-Musch, J; Linev, S; Williams, MCS; Loizeau, P; Herrmann, N; Doroud, K; Radulescu, L; Constantin, F

    2012-01-01

    Resistive Plate Chambers (RPCs) are widely employed as muon trigger systems at the Large Hadron Collider (LHC) experiments. Their large detector volume and the use of a relatively expensive gas mixture make a closed-loop gas circulation unavoidable. The return gas of RPCs operated in conditions similar to the experimental background foreseen at LHC contains large amount of impurities potentially dangerous for long-term operation. Several gas-cleaning agents, characterized during the past years, are currently in use. New test allowed understanding of the properties and performance of a large number of purifiers. On that basis, an optimal combination of different filters consisting of Molecular Sieve (MS) 5Å and 4Å, and a Cu catalyst R11 has been chosen and validated irradiating a set of RPCs at the CERN Gamma Irradiation Facility (GIF) for several years. A very important feature of this new configuration is the increase of the cycle duration for each purifier, which results in better system stabilit...

  1. Yeast sex: surprisingly high rates of outcrossing between asci.

    Directory of Open Access Journals (Sweden)

    Helen A Murphy

    Full Text Available BACKGROUND: Saccharomyces yeasts are an important model system in many areas of biological research. Very little is known about their ecology and evolution in the wild, but interest in this natural history is growing. Extensive work with lab strains in the last century uncovered the Saccharomyces life cycle. When nutrient limited, a diploid yeast cell will form four haploid spores encased in a protective outer layer called the ascus. Confinement within the ascus is thought to enforce mating between products of the same meiotic division, minimizing outcrossing in this stage of the life cycle. METHODOLOGY/PRINCIPAL FINDINGS: Using a set of S. cerevisiae and S. paradoxus strains isolated from woodlands in North America, we set up trials in which pairs of asci were placed in contact with one another and allowed to germinate. We observed outcrossing in approximately 40% of the trials, and multiple outcrossing events in trials with three asci in contact with each other. When entire populations of densely crowded asci germinated, approximately 10-25% of the resulting colonies were outcrossed. There were differences between the species with S. cerevisiae having an increased tendency to outcross in mass mating conditions. CONCLUSIONS/SIGNIFICANCE: Our results highlight the potential for random mating between spores in natural strains, even in the presence of asci. If this type of mating does occur in nature and it is between close relatives, then a great deal of mating behavior may be undetectable from genome sequences.

  2. High energy high repetition-rate thin-disk amplifier for OPCPA pumping

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, Michael

    2013-08-15

    The development of a pump laser system for a high power and high repetition rate optical parametric chirped-pulse amplification (OPCPA) is presented in this thesis. The OPCPA system requires pump pulse energies in the range of tens of millijoules at high repetition rates with sub-picosecond pulse durations. This can be achieved to some extend with Innoslab amplifier technology. However, scaling to higher pulse energies at high repetition rates may be problematic. With the thin-disk amplifier presented in this thesis, output energies of 140 mJ at 100 kHz repetition rate could be achieved in burst-mode operation, which is a world record for this type of laser amplifier. Due to its material and spectral properties, ytterbium doped YAG (Yb:YAG) is used as a gain medium for the high power amplifier stages. The low quantum defect and the comparatively large emission bandwidth makes this material the choice for high power operation and sub-picosecond compressed pulse durations. The output beam profile as well as the shape of the output bursts is ideal to pump an OPCPA system. An OPCPA output energy in the millijoule range with repetition rates of 100 kHz to 1 MHz is needed to generate seed pulses for the FEL and for the application as pump-probe laser at the FEL facility. Since the development of this laser system needs to meet requirements set by the Free-Electron Laser in Hamburg (FLASH), the amplifier is conceived for burst-mode operation. The main requirement is a high intra-burst pulse repetition rate of more than 100 kHz and a uniform pulse train (burst) with equal properties for every pulse. The burst-mode is an operation mode where the laser never reaches a lasing equilibrium, which means that the behavior of the amplifier is similar to a switch-on of the laser system for every burst. This makes the development of the amplifier system difficult. Therefore, an analytical model has been developed to study the amplification process during the burst. This includes the

  3. Ultrafast high strain rate acoustic wave measurements at high static pressure in a diamond anvil cell

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, M; Crowhurst, J; Reed, E; Zaug, J

    2008-02-04

    We have used sub-picosecond laser pulses to launch ultra-high strain rate ({approx} 10{sup 9} s{sup -1}) nonlinear acoustic waves into a 4:1 methanol-ethanol pressure medium which has been precompressed in a standard diamond anvil cell. Using ultrafast interferometry, we have characterized acoustic wave propagation into the pressure medium at static compression up to 24 GPa. We find that the velocity is dependent on the incident laser fluence, demonstrating a nonlinear acoustic response which may result in shock wave behavior. We compare our results with low strain, low strain-rate acoustic data. This technique provides controlled access to regions of thermodynamic phase space that are otherwise difficult to obtain.

  4. High strain rate behavior of alloy 800H at high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Shafiei, E., E-mail: shafiei.ehsan.mse@gmail.com

    2016-05-15

    In this paper, a new model using linear estimation of strain hardening rate vs. stress, has been developed to predict dynamic behavior of alloy 800H at high temperatures. In order to prove the accuracy and competency of the presented model, Johnson–Cook model pertaining modeling of flow stress curves was used. Evaluation of mean error of flow stress at deformation temperatures from 850 °C to 1050 °C and at strain rates of 5 S{sup −1} to 20 S{sup −1} indicates that the predicted results are in a good agreement with experimentally measured ones. This analysis has been done for the stress–strain curves under hot working condition for alloy 800H. However, this model is not dependent on the type of material and can be extended for any similar conditions.

  5. An Investigation of the High Rate Volumetric Properties of Snow.

    Science.gov (United States)

    1981-11-01

    v: IV$ LIEA < VISCOELAS TIC LIEA MA TERIA L TIME t () CREEP TEST EI>L LINEA R V/SC QELASTIcI MA 7CR/A L U (b) DEFORMATION - RATE TEST i iqur,. 1...GRAIN and NECK GEOMETRY 7 2 I~~~~~~r b.IELZE RI GOER I ~ ~ ~ 1 z~g~ P9 . A~peetto fgan~dbodgoer o ekgot tuc ~ ~ ~ ~ReIO ofIo efrain ITT I 34 during the...Spontaneous Fracture Invitation in Mountain Snowpacks. J. of Glaciology, Vol. 19, No. 81. Salm, B. (1974) A Constitutive Equation for Creeping Snow

  6. A Lithium-Air Battery Stably Working at High Temperature with High Rate Performance.

    Science.gov (United States)

    Pan, Jian; Li, Houpu; Sun, Hao; Zhang, Ye; Wang, Lie; Liao, Meng; Sun, Xuemei; Peng, Huisheng

    2018-02-01

    Driven by the increasing requirements for energy supply in both modern life and the automobile industry, the lithium-air battery serves as a promising candidate due to its high energy density. However, organic solvents in electrolytes are likely to rapidly vaporize and form flammable gases under increasing temperatures. In this case, serious safety problems may occur and cause great harm to people. Therefore, a kind of lithium-air that can work stably under high temperature is desirable. Herein, through the use of an ionic liquid and aligned carbon nanotubes, and a fiber shaped design, a new type of lithium-air battery that can effectively work at high temperatures up to 140 °C is developed. Ionic liquids can offer wide electrochemical windows and low vapor pressures, as well as provide high thermal stability for lithium-air batteries. The aligned carbon nanotubes have good electric and heat conductivity. Meanwhile, the fiber format can offer both flexibility and weavability, and realize rapid heat conduction and uniform heat distribution of the battery. In addition, the high temperature has also largely improved the specific powers by increasing the ionic conductivity and catalytic activity of the cathode. Consequently, the lithium-air battery can work stably at 140 °C with a high specific current of 10 A g -1 for 380 cycles, indicating high stability and good rate performance at high temperatures. This work may provide an effective paradigm for the development of high-performance energy storage devices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. The Oxford unicompartmental knee fails at a high rate in a high-volume knee practice.

    Science.gov (United States)

    Schroer, William C; Barnes, C Lowry; Diesfeld, Paul; LeMarr, Angela; Ingrassia, Rachel; Morton, Diane J; Reedy, Mary

    2013-11-01

    The Oxford knee is a unicompartmental implant featuring a mobile-bearing polyethylene component with excellent long-term survivorship results reported by the implant developers and early adopters. By contrast, other studies have reported higher revision rates in large academic practices and in national registries. Registry data have shown increased failure with this implant especially by lower-volume surgeons and institutions. In the setting of a high-volume knee arthroplasty practice, we sought to determine (1) the failure rate of the Oxford unicompartmental knee implant using a failure definition for aseptic loosening that combined clinical features, plain radiographs, and scintigraphy, and (2) whether increased experience with this implant would decrease failure rate, if there is a learning curve effect. Eighty-three Oxford knee prostheses were implanted between September 2005 and July 2008 by the principal investigator. Radiographic and clinical data were available for review for all cases. A failed knee was defined as having recurrent pain after an earlier period of recovery from surgery, progressive radiolucent lines compared with initial postoperative radiographs, and a bone scan showing an isolated area of uptake limited to the area of the replaced compartment. Eleven knees in this series failed (13%); Kaplan-Meier survivorship was 86.5% (95% CI, 78.0%-95.0%) at 5 years. Failure occurrences were distributed evenly over the course of the study period. No learning curve effect was identified. Based on these findings, including a high failure rate of the Oxford knee implant and the absence of any discernible learning curve effect, the principal investigator no longer uses this implant.

  8. Measuring target detection performance in paradigms with high event rates.

    Science.gov (United States)

    Bendixen, Alexandra; Andersen, Søren K

    2013-05-01

    Combining behavioral and neurophysiological measurements inevitably implies mutual constraints, such as when the neurophysiological measurement requires fast-paced stimulus presentation and hence the attribution of a behavioral response to a particular preceding stimulus becomes ambiguous. We develop and test a method for validly assessing behavioral detection performance in spite of this ambiguity. We examine four approaches taken in the literature to treat such situations. We analytically derive a new variant of computing the classical parameters of signal detection theory, hit and false alarm rates, adapted to fast-paced paradigms. Each of the previous approaches shows specific shortcomings (susceptibility towards response window choice, biased estimates of behavioral detection performance). Superior performance of our new approach is demonstrated for both simulated and empirical behavioral data. Further evidence is provided by reliable correspondence between behavioral performance and the N2b component as an electrophysiological indicator of target detection. The appropriateness of our approach is substantiated by both theoretical and empirical arguments. We demonstrate an easy-to-implement solution for measuring target detection performance independent of the rate of event presentation. Thus overcoming the measurement bias of previous approaches, our method will help to clarify the behavioral relevance of different measures of cortical activation. Copyright © 2012 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  9. Do Ubiquitous Laptop Initiatives Decrease the High School Dropout Rate?

    Science.gov (United States)

    Basham, Misty Dawn

    2012-01-01

    In 2007, Mooresville Graded School District developed a strategic plan to infuse twenty-first-century learning skills into the schools by providing staff and students in grades four through twelve with a laptop computer. In late fall of 2007, Mooresville High School deployed laptops to all certified staff and to the entire student body in the…

  10. Decreased reproductive rates in sheep fed a high selenium diet

    Science.gov (United States)

    High Se-containing forages grow on seleniferous soils in many parts of the United States and throughout the world. Selenium is an essential trace element that is required for many physiological processes but can also be either acutely or chronically toxic to livestock. Anecdotal reports of decrease...

  11. SAFT Li-ion Technology for High Rate Applications

    National Research Council Canada - National Science Library

    Nechev, Kamen; Deveney, Bridget; Guseynov, Teymur; Erbacher, John; Vukson, Stephen

    2006-01-01

    SAFT will present an update of its state-of-the art Very High Power (VHP) Lithium-ion (Li-ion) technology. The VHP cells are currently being qualified for use in military aircraft applications as well as in future military hybrid vehicles...

  12. High Rate of Mobilization for blaCTX-Ms

    Science.gov (United States)

    Reik, Rebecca A.; Jacobs, Stephen D.; Medina, Mónica; Meyer, Matthew P.; McGowan, John E.; Tenover, Fred C.

    2008-01-01

    We constructed a phylogenetic analysis of class A β-lactamases and found that the blaCTX-Ms have been mobilized to plasmids ≈10 times more frequently than other class A β-lactamases. We also found that the blaCTX-Ms are descended from a common ancestor that was incorporated in ancient times into the chromosome of the ancestor of Kluyvera species through horizontal transfer. Considerable sequence divergence has occurred among the descendents of that ancestral gene sequence since that gene was inserted. That divergence has mainly occurred in the presence of purifying selection, which indicates a slow rate of evolution for blaCTX-Ms in the pre–antimicrobial drug era. PMID:18325257

  13. Fiber Optic Rate Sensors For High-G Environment Applications

    Science.gov (United States)

    Moore, Emery L.; Hertzberg, Alex

    1990-02-01

    Advances in modern warfare require the development of artillery munitions that travel beyond the visual horizon. It is not unusual, particularly in undulating terrain, for the direct line of sight from the forward edge of the battle area (FEBA) to the attacking forces to be limited to 2,000 meters. In addition to terrain, influences of clouds, fog, rain and smoke combine to limit the direct line of sight. Mobile targets also decrease probability of kill. What is called for and what has been developed are "smart munitions" that allow the artilleryman to "fire and forget." The technique which accommodates this fire and forget philosophy utilizes a projectile having a radiation detector (or seeker) to sense the target and inertial rate sensors supported by a computer or processor. However, even though we have smart shells today room for improvement exists in weight, power, shelf life, environmental ruggedness and cost.

  14. American High School Students from Different Ethnic Backgrounds: The Role of Parents and the Classroom in Achievement Motivation

    Science.gov (United States)

    Kim, Jung-In

    2015-01-01

    The purpose of this study was to investigate the relationships between ethnically diverse US high school students' (N = 331) perceptions of their parents' or classroom's motivating factors and their achievement motivation in their math class, connecting achievement goal orientation and self-determination theories. Two hypothesized path models were…

  15. Case Studies of Success: Supporting Academic Success for Students with High Potential from Ethnic Minority and Economically Disadvantaged Backgrounds

    Science.gov (United States)

    Tomlinson, Carol Ann; Jarvis, Jane M.

    2014-01-01

    The underrepresentation of ethnic minority and economically disadvantaged students in gifted education must be understood in terms of broader school contexts and practices. This qualitative study investigated how teachers and schools contributed to the academic success of minority students of high potential from economically disadvantaged…

  16. Delayed high school start times later than 8:30am and impact on graduation rates and attendance rates.

    Science.gov (United States)

    McKeever, Pamela Malaspina; Clark, Linda

    2017-04-01

    The first purpose of this study was to investigate changes in high school graduation rates with a delayed school start time of later than 8:30am. The second aim of the study was to analyze the association between a delayed high school start time later than 8:30am and attendance rates. In the current study, a pre-post design using a repeated-measures analysis of variance was used to examine changes in attendance and graduation rates 2 years after a delayed start was implemented. Public high schools from 8 school districts (n=29 high schools) located throughout 7 different states. Schools were identified using previous research from the Children's National Medical Center's Division of Sleep Medicine Research Team. A total membership of more than 30,000 high school students enrolled in the 29 schools identified by the Children's National Medical Center's Research Team. A pre-post design was used for a within-subject design, controlling for any school-to-school difference in the calculation of the response variable. This is the recommended technique for a study that may include data with potential measurement error. Findings from this study linked a start time of later than 8:30am to improved attendance rates and graduation rates. Attendance rates and graduation rates significantly improved in schools with delayed start times of 8:30am or later. School officials need to take special notice that this investigation also raises questions about whether later start times are a mechanism for closing the achievement gap due to improved graduation rates. Copyright © 2017 National Sleep Foundation. Published by Elsevier Inc. All rights reserved.

  17. Space-time encoding for high frame rate ultrasound imaging.

    Science.gov (United States)

    Misaridis, Thanassis X; Jensen, Jørgen A

    2002-05-01

    Frame rate in ultrasound imaging can be dramatically increased by using sparse synthetic transmit aperture (STA) beamforming techniques. The two main drawbacks of the method are the low signal-to-noise ratio (SNR) and the motion artifacts, that degrade the image quality. In this paper we propose a spatio-temporal encoding for STA imaging based on simultaneous transmission of two quasi-orthogonal tapered linear FM signals. The excitation signals are an up- and a down-chirp with frequency division and a cross-talk of -55 dB. The received signals are first cross-correlated with the appropriate code, then spatially decoded and finally beamformed for each code, yielding two images per emission. The spatial encoding is a Hadamard encoding previously suggested by Chiao et al. [in: Proceedings of the IEEE Ultrasonics Symposium, 1997, p. 1679]. The Hadamard matrix has half the size of the transmit element groups, due to the orthogonality of the temporal encoded wavefronts. Thus, with this method, the frame rate is doubled compared to previous systems. Another advantage is the utilization of temporal codes which are more robust to attenuation. With the proposed technique it is possible to obtain images dynamically focused in both transmit and receive with only two firings. This reduces the problem of motion artifacts. The method has been tested with extensive simulations using Field II. Resolution and SNR are compared with uncoded STA imaging and conventional phased-array imaging. The range resolution remains the same for coded STA imaging with four emissions and is slightly degraded for STA imaging with two emissions due to the -55 dB cross-talk between the signals. The additional proposed temporal encoding adds more than 15 dB on the SNR gain, yielding a SNR at the same order as in phased-array imaging.

  18. STIR: Tailored Interfaces for High Strength Composites Across Strain Rates

    Science.gov (United States)

    2013-09-02

    the aramid class of fibers (Kevlar®, Twaron®) because the highly crystalline structure offers one of the highest specific toughness ratios and specific...1. Structure of an aramid (Kevlar®) fiber , showing stable aromatic carbon rings attached to backbone chains and hydrogen bonding among the chains...surface groups of the aramid fiber have been attempted with limited success. Most of these chemical enhancements focused on the attachment of

  19. High Attenuation Rate for Shallow, Small Earthquakes in Japan

    Science.gov (United States)

    Si, Hongjun; Koketsu, Kazuki; Miyake, Hiroe

    2017-09-01

    We compared the attenuation characteristics of peak ground accelerations (PGAs) and velocities (PGVs) of strong motion from shallow, small earthquakes that occurred in Japan with those predicted by the equations of Si and Midorikawa (J Struct Constr Eng 523:63-70, 1999). The observed PGAs and PGVs at stations far from the seismic source decayed more rapidly than the predicted ones. The same tendencies have been reported for deep, moderate, and large earthquakes, but not for shallow, moderate, and large earthquakes. This indicates that the peak values of ground motion from shallow, small earthquakes attenuate more steeply than those from shallow, moderate or large earthquakes. To investigate the reason for this difference, we numerically simulated strong ground motion for point sources of M w 4 and 6 earthquakes using a 2D finite difference method. The analyses of the synthetic waveforms suggested that the above differences are caused by surface waves, which are predominant at stations far from the seismic source for shallow, moderate earthquakes but not for shallow, small earthquakes. Thus, although loss due to reflection at the boundaries of the discontinuous Earth structure occurs in all shallow earthquakes, the apparent attenuation rate for a moderate or large earthquake is essentially the same as that of body waves propagating in a homogeneous medium due to the dominance of surface waves.

  20. Study of possible Supersymmetric processes and Mini Black Hole production and comparison to background events with high transverse energy in the ATLAS experiment

    Science.gov (United States)

    Melamed-Katz, Arie

    2009-11-01

    The ATLAS detector, which was installed at one of the interaction points of the Large Hadron Collider (LHC), has the capability to discover 'new physics' beyond the Standard Model (SM) already during its first year of operation. In this work an assessment of ATLAS capabilities regarding the detection of some 'new physics' signals is performed. In the course of this research all relevant SM background sources were produced. These sources were studied with several simulation tools and the results are compared. In the scope of these background studies, a verification procedure that relies on expected SM production rates was developed. This procedure is able to distinguish between new physics and a faked one originating in malfunctioning detector. Supersymmetry (SUSY) is one of the best candidates for the theory 'beyond the Standard Model'. It predicts the existence of new symmetry between bosons and fermions, and assumes a new fermion partner for each SM boson and a new boson partner for each SM fermion. A major part of the present research is the study of different SUSY scenarios and their SM background. The study is done both at the phenomenological level and at the experimental level, where ATLAS capabilities to detect the signals are assessed. A special emphasis was made on R-Parity Violating (RPV) processes, which might not manifest themselves immediately like the R-Parity Conserving (RPC) case, which is much easier to detect. Two main categories of RPV signals were studied: supersymmetric particles production through RPC process and their subsequent decay through RPV coupling, and resonating supersymmetric particle creation. Two specific resonating scenarios are studied here for the first time. Analysis methods for the various RPV signals were developed and ATLAS sensitivity was estimated. In addition, a special scenario in the RPV framework that behaves like RPC ("fake RPC") was studied. One will have to take this scenario into consideration if SUSY RPC signal

  1. An increase in rates of obstetric haemorrhage in a setting of high HIV seroprevalence

    Directory of Open Access Journals (Sweden)

    E Shabalala

    2017-07-01

    Full Text Available Background. Obstetric haemorrhage (OH is the leading cause of maternal mortality worldwide, although, indirectly, HIV is also a leading cause of maternal mortality in some settings with a high HIV seroprevalence. Objective. To determine the possible association between increasing rates of OH and HIV or its treatment. Methods. We conducted a retrospective chart review of women with OH at King Edward VIII Hospital, Durban, South Africa, over a 3-year period (2009 - 2011, during which the drug regimen for the prevention of mother-to-child transmission was evolving from single-dose nevirapine to antenatal zidovudine combined with intrapartum nevirapine (also referred to as dual therapy, and finally to a combination or highly active antiretroviral therapy (cART or HAART. Cases of OH (including abruptio placentae, placenta praevia, unspecified antepartum haemorrhage (APH, and postpartum haemorrhage (PPH were identified from maternity delivery records, and the relevant data extracted. Results. We analysed the records of 448 women diagnosed with OH. Even though the incidence of OH was low, the study found an increasing number of cases during the 3-year period. PPH – not APH – was associated with HIV seropositivity (odds ratio 1.84, 95% confi­dence interval 1.14 - 2.95. cART was not associated with an increased risk of haemorrhage. Conclusion. HIV was associated with a high risk of PPH, and its possible association with HIV treatment needs further research.

  2. Effect of Δ9-stearoyl-ACP-desaturase-C mutants in a high oleic background on soybean seed oil composition.

    Science.gov (United States)

    Ruddle, Paul; Whetten, Rebecca; Cardinal, Andrea; Upchurch, Robert G; Miranda, Lilian

    2014-02-01

    Two new sources of elevated seed stearic acid were identified and the feasibility of an elevated stearic acid, high oleic acid germplasm was studied. Soybean [Glycine max (L.) Merr.] oil typically contains 2-4% stearic acid. Oil with at least 20% stearic acid is desirable because of its improved baking properties and health profile. This study identifies two new sources of high stearic acid and evaluates the interaction of high stearic and oleic acid alleles. TCHM08-1087 and TCHM08-755, high stearic acid 'Holladay' mutants, were crossed to FAM94-41-3, a line containing a point mutation in a seed-specific isoform of a Δ9-stearoyl-acyl carrier protein-desaturase (SACPD-C). F2-derived lines were evaluated for fatty acid content in four field environments. Sequencing of SACPDs in TCHM08-1087 and TCHM08-755 revealed distinct deletions of at least one megabase encompassing SACPD-C in both lines. After genotyping, the additive effect for stearic acid was estimated at +1.8% for the SACPD-C point mutation and +4.1% for the SACPD-C deletions. Average stearic acid in lines homozygous for the deletions was 12.2%. A FAM94-41-3-derived line and TCHM08-1087-11, a selection from TCHM08-1087, were crossed to S09-2902-145, a line containing missense mutations in two fatty acid desaturases (FAD2-1A and FAD2-1B). F1 plants were grown in a greenhouse and individual F2 seed were genotyped and phenotyped. No interaction was observed between either FAD2-1A or FAD2-1B and any of the SACPD-C mutant alleles. Seed homozygous mutant for SACPD-C/FAD2-1A/FAD2-1B contained 12.7% stearic acid and 65.5% oleic acid while seed homozygous for the SACPD-C deletion and mutant for FAD2-1A and FAD2-1B averaged 10.4% stearic acid and 75.9% oleic acid.

  3. A High Rated Solar Water Distillation Unit for Solar Homes

    Directory of Open Access Journals (Sweden)

    Abhishek Saxena

    2016-01-01

    Full Text Available India is presently focusing on complete utilization of solar energy and saving fossil fuels, which are limited. Various solar energy systems like solar cookers, solar water heaters, solar lanterns, solar PV lights, and solar lamps are continuously availing by the people of India at a low cost and on good subsidies. Apart from this, India is a solar energy promising country with a good number of solar homes (carrying solar energy systems in its various locations. The present paper focuses on a unique combination of solar dish cooker (SDC and solar water heater (SWH to produce distilled water with a high distillate and a high daily productivity. The procedure has been discussed on the basis of experimental testing to produce distilled water by combining an evacuated type SWH and a SDC. Experimentation has been carried out in MIT, Moradabad (longitude, 28.83°N, and latitude, 78.78°E by developing the same experimental setup on behalf of solar homes. The daily productivity of distilled water was found around 3.66 litres per day in full sunshine hours for an approximated pH value of 7.7 and a ppm value of 21. The payback period (PBP has been estimated around 1.16 years of the present system.

  4. High macrosomia rate in healthy fetuses after enlarged nuchal translucency.

    Science.gov (United States)

    Timmerman, E; Pajkrt, E; Snijders, R J M; Bilardo, C M

    2014-02-01

    The aim of this study was to investigate the association of the first trimester screening variables nuchal translucency (NT), pregnancy associated plasma protein (PAPP-A), and free beta-human chorionic gonadotrophin (βhCG) and birth weight, with a focus on the prediction of macrosomia. The database of our Fetal Medicine Unit was searched for all singleton pregnancies, who underwent first trimester Down syndrome screening. Live born infants born at term without chromosomal or structural defects from non-diabetic mothers constituted the study population. Birth weight percentiles were corrected for gestational age at delivery, parity, and gender. Macrosomia was defined as birth weight ≥95th centile. We included 6503 fetuses. Multivariate analysis demonstrated that birth weight centile was positively correlated with NT multiples of the median (MoM), PAPP-A MoM, and maternal body mass index, and it was negatively correlated with smoking. An NT ≥95th centile was present in 315 fetuses (4.8%). Although median birth weight centile was not significantly different between cases with NT ≥95th centile and those 95th centile was more common (11% vs 7%) in the presence of NT ≥95th centile. Pregnancy associated plasma protein was elevated (≥95th centile) in 303 cases (7.9%). Median birth weight was higher (P56 vs P51, P = 0.03) in case of elevated PAPP-A compared with PAPP-A macrosomia rate in case of PAPP-A ≥95th centile (7.4% vs 6.3%, P = 0.07). Area under the receiver operating characteristics (ROC) curve for the prediction of macrosomia (birth weight ≥95th centile) by NT MoM, PAPP-A MoM, maternal body mass index, and maternal smoking was 0.64 (P macrosomia. © 2013 John Wiley & Sons, Ltd.

  5. High-rate behaviour of iron ore pellet

    Science.gov (United States)

    Gustafsson, Gustaf; Häggblad, Hans-Åke; Jonsén, Pär; Nishida, Masahiro

    2015-09-01

    Iron ore pellets are sintered, centimetre-sized spheres of ore with high iron content. Together with carbonized coal, iron ore pellets are used in the production of steel. In the transportation from the pelletizing plants to the customers, the iron ore pellets are exposed to different loading situations, resulting in degradation of strength and in some cases fragmentation. For future reliable numerical simulations of the handling and transportation of iron ore pellets, knowledge about their mechanical properties is needed. This paper describes the experimental work to investigate the dynamic mechanical properties of blast furnace iron ore pellets. To study the dynamic fracture of iron ore pellets a number of split Hopkinson pressure bar tests are carried out and analysed.

  6. High Dynamic Optimized Carrier Loop Improvement for Tracking Doppler Rates

    Directory of Open Access Journals (Sweden)

    Amirhossein Fereidountabar

    2015-01-01

    Full Text Available Mathematical analysis and optimization of a carrier tracking loop are presented. Due to fast changing of the carrier frequency in some satellite systems, such as Low Earth Orbit (LEO or Global Positioning System (GPS, or some planes like Unmanned Aerial Vehicles (UAVs, high dynamic tracking loops play a very important role. In this paper an optimized tracking loop consisting of a third-order Phase Locked Loop (PLL assisted by a second-order Frequency Locked Loop (FLL for UAVs is proposed and discussed. Based on this structure an optimal loop has been designed. The main advantages of this approach are the reduction of the computation complexity and smaller phase error. The paper shows the simulation results, comparing them with a previous work.

  7. Learning rate and temperament in a high predation risk environment

    Science.gov (United States)

    DePasquale, C.; Wagner, Tyler; Archard, G.A.; Ferguson, B.; Braithwaite, V.A.

    2014-01-01

    Living in challenging environments can influence the behavior of animals in a number of ways. For instance, populations of prey fish that experience frequent, nonlethal interactions with predators have a high proportion of individuals that express greater reaction to risk and increased activity and exploration—collectively known as temperament traits. Temperament traits are often correlated, such that individuals that are risk-prone also tend to be active and explore more. Spatial learning, which requires the integration of many sensory cues, has also been shown to vary in fish exposed to different levels of predation threat. Fish from areas of low predation risk learn to solve spatial tasks faster than fish from high predation areas. However, it is not yet known whether simpler forms of learning, such as learning associations between two events, are similarly influenced. Simple forms of associative learning are likely to be affected by temperament because a willingness to approach and explore novel situations could provide animals with a learning advantage. However, it is possible that routine-forming and inflexible traits associated with risk-prone and increased exploratory behavior may act in the opposite way and make risk-prone individuals poorer at learning associations. To investigate this, we measured temperament in Panamanian bishop fish (Brachyrhaphis episcopi) sampled from a site known to contain many predators. The B. episcopi were then tested with an associative learning task. Within this population, fish that explored more were faster at learning a cue that predicted access to food, indicating a link between temperament and basic learning abilities.

  8. Learning rate and temperament in a high predation risk environment.

    Science.gov (United States)

    DePasquale, C; Wagner, T; Archard, G A; Ferguson, B; Braithwaite, V A

    2014-11-01

    Living in challenging environments can influence the behavior of animals in a number of ways. For instance, populations of prey fish that experience frequent, nonlethal interactions with predators have a high proportion of individuals that express greater reaction to risk and increased activity and exploration-collectively known as temperament traits. Temperament traits are often correlated, such that individuals that are risk-prone also tend to be active and explore more. Spatial learning, which requires the integration of many sensory cues, has also been shown to vary in fish exposed to different levels of predation threat. Fish from areas of low predation risk learn to solve spatial tasks faster than fish from high predation areas. However, it is not yet known whether simpler forms of learning, such as learning associations between two events, are similarly influenced. Simple forms of associative learning are likely to be affected by temperament because a willingness to approach and explore novel situations could provide animals with a learning advantage. However, it is possible that routine-forming and inflexible traits associated with risk-prone and increased exploratory behavior may act in the opposite way and make risk-prone individuals poorer at learning associations. To investigate this, we measured temperament in Panamanian bishop fish (Brachyrhaphis episcopi) sampled from a site known to contain many predators. The B. episcopi were then tested with an associative learning task. Within this population, fish that explored more were faster at learning a cue that predicted access to food, indicating a link between temperament and basic learning abilities.

  9. High-dose-rate interstitial brachytherapy for the treatment of penile carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Petera, J.; Odrazka, K.; Zouhar, M.; Bedrosova, J.; Dolezel, M. [Dept. of Oncology and Radiotherapy, Charles Univ. Medical School and Teaching Hospital, Hradec Kralove (Czech Republic)

    2004-02-01

    Background: interstitial low-dose-rate (LDR) brachytherapy allows conservative treatment of T1-T2 penile carcinoma. High-dose-rate (HDR) is often considered to be dangerous for interstitial implants because of a higher risk of complications, but numerous reports suggest that results may be comparable to LDR. Nevertheless, there are no data in the literature available regarding HDR interstitial brachytherapy for carcinoma of the penis. Case report: a 64-year-old man with T1 NO MO epidermoid carcinoma of the glans is reported. Interstitial HDR brachytherapy was performed using the stainless hollow needle technique and a breast template for fixation and good geometry. The dose delivered was 18 x 3 Gy twice daily. Results: after 232 days from brachytherapy, the patient was without any evidence of the tumor, experienced no serious radiation-induced complications, and had a fully functional organ. Conclusion: HDR interstitial brachytherapy is feasible in selected case of penis carcinoma, when careful planning and small single fractions are used. (orig.)

  10. Participant retention practices in longitudinal clinical research studies with high retention rates

    Directory of Open Access Journals (Sweden)

    Martha Abshire

    2017-02-01

    Full Text Available Abstract Background There is a need for improving cohort retention in longitudinal studies. Our objective was to identify cohort retention strategies and implementation approaches used in studies with high retention rates. Methods Longitudinal studies with ≥200 participants, ≥80% retention rates over ≥1 year of follow-up were queried from an Institutional Review Board database at a large research-intensive U.S. university; additional studies were identified through networking. Nineteen (86% of 22 eligible studies agreed to participate. Through in-depth semi-structured interviews, participants provided retention strategies based on themes identified from previous literature reviews. Synthesis of data was completed by a multidisciplinary team. Results The most commonly used retention strategies were: study reminders, study visit characteristics, emphasizing study benefits, and contact/scheduling strategies. The research teams were well-functioning, organized, and persistent. Additionally, teams tailored their strategies to their participants, often adapting and innovating their approaches. Conclusions These studies included specialized and persistent teams and utilized tailored strategies specific to their cohort and individual participants. Studies’ written protocols and published manuscripts often did not reflect the varied strategies employed and adapted through the duration of study. Appropriate retention strategy use requires cultural sensitivity and more research is needed to identify how strategy use varies globally.

  11. Electromagnetic analysis of a superconducting transformer for high current characterization of cable in conduit conductors in background magnetic field

    Science.gov (United States)

    Wu, Xiangyang; Tan, Yunfei; Fang, Zhen; Jiang, Donghui; Chen, Zhiyou; Chen, Wenge; Kuang, Guangli

    2017-10-01

    A large cable-in-conduit-conductor (CICC) test facility has been designed and fabricated at the High Magnetic Field Laboratory of the Chinese Academy of Sciences (CHMFL) in order to meet the test requirement of the conductors which are applied to the future fusion reactor. The critical component of the test facility is an 80 kA superconducting transformer which consists of a multi-turn primary coil and a minor-turn secondary coil. As the current source of the conductor samples, the electromagnetic performance of the superconducting transformer determines the stability and safety of the test facility. In this paper, the key factors and parameters, which have much impact on the performance of the transformer, are analyzed in detail. The conceptual design and optimizing principles of the transformer are discussed. An Electromagnetic-Circuit coupled model built in ANSYS Multiphysics is successfully used to investigate the electromagnetic characterization of the transformer under the dynamic operation condition.

  12. Bringing High Rate, Low Latency Data From Unimak Island, Alaska

    Science.gov (United States)

    Feaux, K.; Jackson, M.; Mencin, D.; Gallaher, W.; Smith, S.; Bohnenstiehl, K.; Borsa, A.; Enders, M.; Coyle, B.; Paskievitch, J.; Read, C.

    2009-05-01

    The Plate Boundary Observatory (PBO), part of the NSF-funded EarthScope project, completed the installation of a fourteen GPS stations, eight tiltmeters, one webcam, and one digital broadband seismometer on Unimak Island, Alaska in August, 2008. PBO collaborated with the USGS, who provided engineering support for this project. Combined with the USGS operated seismic network, the Unimak Island network is a state of the art scientific network. The primary data communications goal of the project was to design and implement a robust data communications network capable of downloading 15-sec daily GPS files and to test the streaming of 1- Hz GPS data at a select set of GPS stations on Unimak Island. As part of the permitting agreement with the landowner, PBO co-located the GPS stations with existing USGS seismic stations. The high-speed radio link deployed allowed the USGS to test the feasibility of broadband seismometer installations on Unimak Island. This collaboration with the USGS was another successful joint operation between PBO and the USGS. The technical and logistical challenges involved in the project as well as some preliminary results of the data communications system will be presented. These challenges include complicated logistics, bad weather, complex network geometries with multiple radio repeaters, long distance RF transmission over water, hardware bandwidth limitations, power limitations, space limitations, as well as working in bear country on an incredibly remote and active volcano.

  13. High-pitch dual-source CT coronary angiography: systolic data acquisition at high heart rates

    Energy Technology Data Exchange (ETDEWEB)

    Goetti, Robert; Feuchtner, Gudrun; Desbiolles, Lotus; Fischer, Michael Alexander; Karlo, Christoph; Baumueller, Stephan [University Hospital Zurich, Institute of Diagnostic Radiology, Zurich (Switzerland); Stolzmann, Paul; Scheffel, Hans; Alkadhi, Hatem [University Hospital Zurich, Institute of Diagnostic Radiology, Zurich (Switzerland); Massachusetts General Hospital and Harvard Medical School, Cardiac MR PET CT Program, Boston, MA (United States); Leschka, Sebastian [University Hospital Zurich, Institute of Diagnostic Radiology, Zurich (Switzerland); Kantonsspital St. Gallen, Institute of Radiology, St. Gallen (Switzerland)

    2010-11-15

    To assess the effect of systolic data acquisition for electrocardiography (ECG)-triggered high-pitch computed tomography (CT) on motion artefacts of coronary arteries in patients with high heart rates (HRs). Eighty consecutive patients (15 women, age 67 {+-} 14 years) with HR {>=}70 bpm underwent CT angiography of the thoracic aorta (CTA) on 128-slice dual-source CT in ECG-triggered high-pitch acquisition mode (pitch = 3.2) set at 60% (group A, n = 40) or 30% (group B, n = 40) of the RR interval. Two blinded readers graded coronary artery image quality on a three-point scale. Radiation doses were calculated. Inter-observer agreement in grading image quality of the 1,154 coronary segments was good ({kappa} = 0.62). HRs were similar in groups A and B (85 {+-} 13 bpm vs 85 {+-} 14 bpm, p not significant). Significantly fewer coronary segments with non-diagnostic image quality occurred (i.e. score 3) in group B than in group A [2.8% (16/579) vs 8.3% (48/575), p < 0.001]. Seventeen patients (42.5%) of group A and 12 patients (30.0%) of group B had at least one non-diagnostic segment. Effective radiation doses were 2.3 {+-} 0.3 mSv for chest CTA. A systolic acquisition window for high-pitch dual-source CTA in patients with high HRs ({>=}70 bpm) significantly improves coronary artery image quality at a low radiation dose. (orig.)

  14. Carbon-Based Oxamate Cobalt(III Complexes as Bioenzyme Mimics for Contaminant Elimination in High Backgrounds of Complicated Constituents

    Directory of Open Access Journals (Sweden)

    Nan Li

    2017-10-01

    Full Text Available Complex wastewater with massive components is now a serious environmental issue facing humanity. Selective removal of low-concentration contaminants in mixed constituents holds great promise for increasing water supplies. Bioenzymes like horseradish peroxidase exhibit oxidizing power and selectivity. Here, we manufactured its mimic through immobilizing non-heme oxamate anionic cobalt(III complex ([CoIII(opba]−, opba = o-phenylenebis(oxamate onto pyridine (Py modified multiwalled carbon nanotubes ([CoIII(opba]−-Py-MWCNTs, MWCNTs = multiwalled carbon nanotubes, where MWCNTs captured substrates and Py functioned as the fifth ligand. We chose typical azo dye (C.I. Acid Red 1 and antibiotic (ciprofloxacin as model substrates. Without •OH, this catalyst could detoxify target micropollutants efficiently at pH from 8 to 11. It also remained efficient in repetitive tests, and the final products were non-poisonous OH-containing acids. Combined with radical scavenger tests and electron paramagnetic resonance result, we speculated that high-valent cobalt-oxo active species and oxygen atom transfer reaction dominated in the reaction pathway. According to density functional theory calculations, the electron spin density distribution order showed that electron-withdrawing ligand was beneficial for inward pulling the excess electron and lowering the corresponding energy levels, achieving an electrophilic-attack enhancement of the catalyst. With target removal property and recyclability, this catalyst is prospective in water detoxication.

  15. Influence of cannabis use trajectories, grade repetition and family background on the school-dropout rate at the age of 17 years in France.

    Science.gov (United States)

    Legleye, Stéphane; Obradovic, Ivana; Janssen, Eric; Spilka, Stanislas; Le Nézet, Olivier; Beck, François

    2010-04-01

    Research has shown that cannabis use contributes to school dropout, but few studies have distinguished the age at onset of use from the age at progression to daily use neither their interaction with grade repetition. This study is based on a French representative cross-sectional survey (N = 29,393 teenagers aged 17 years) and uses retrospective data. The influence of drug-use patterns family socio-economic status, early grade repetition, single-parent families and daily tobacco smoking (ORa > or = 2.6). The link with the move to daily cannabis use was more evident when it occurred or =15 years (ORa = 1.45 for both sexes). The onset of cannabis use was not significant when occurring <14 years of age, but was linked to school attainment when occurring at age 15-16 years (ORa = 0.80 for boys and 0.64 for girls). Results are similar for alcohol use. Repeating a grade before beginning to use cannabis increased the dropout rates compared with the opposite sequence. Girls were more affected by early grade repetition and by early and daily cannabis use. Cannabis use is rarely a trigger for grade repetition but can have either damaging or positive effects on school attainment depending of the level of use. Positive social competence reflected by peer initiation should be investigated to understand this paradoxical effect.

  16. Exploring the MIS M2 glaciation occurring during a warm and high atmospheric CO2 Pliocene background climate

    Science.gov (United States)

    Tan, Ning; Ramstein, Gilles; Dumas, Christophe; Contoux, Camille; Ladant, Jean-Baptiste; Sepulchre, Pierre; Zhang, Zhongshi; De Schepper, Stijn

    2017-08-01

    Prior to the Northern Hemisphere glaciation around ∼2.7 Ma, a large global glaciation corresponding to a 20 to 60 m sea-level drop occurred during Marine Isotope Stage (MIS) M2 (3.312-3.264 Ma), interrupted the period of global warmth and high CO2 concentration (350-450 ppmv) of the mid Piacenzian. Unlike the late Quaternary glaciations, the M2 glaciation only lasted 50 kyrs and occurred under uncertain CO2 concentration (220-390 ppmv). The mechanisms causing the onset and termination of the M2 glaciation remain enigmatic, but a recent geological hypothesis suggests that the re-opening and closing of the shallow Central American Seaway (CAS) might have played a key role. In this article, thanks to a series of climate simulations carried out using a fully coupled Atmosphere Ocean General Circulation Model (GCM) and a dynamic ice sheet model, we show that re-opening of the shallow CAS helps precondition the low-latitude oceanic circulation and affects the related northward energy transport, but cannot alone explain the onset of the M2 glaciation. The presence of a shallow open CAS, together with favourable orbital parameters, 220 ppmv of CO2 concentration, and the related vegetation and ice sheet feedback, led to a global ice sheet build-up producing a global sea-level drop in the lowest range of proxy-derived estimates. More importantly, our results show that the simulated closure of the CAS has a negligible impact on the NH ice sheet melt and cannot explain the MIS M2 termination.

  17. Differences in the Influence of Family Background and Social Activities on Smoking of Minority and White High School Seniors, 1976–2004

    OpenAIRE

    Pampel, Fred C.

    2008-01-01

    This population-based study of high school seniors examines differences in the influence of several important determinants of smoking among white, African-American, Hispanic, and other teens. With national survey data for each year from 1976 to 2004, logistic regression is used to test for differences across race and ethnic groups (averaged over all years) in the effects on daily smoking of background factors such as living arrangements and parents’ education and social activities such as aca...

  18. Ilmenite Nanotubes for High Stability and High Rate Sodium-Ion Battery Anodes.

    Science.gov (United States)

    Yu, Litao; Liu, Jun; Xu, Xijun; Zhang, Liguo; Hu, Renzong; Liu, Jiangwen; Ouyang, Liuzhang; Yang, Lichun; Zhu, Min

    2017-05-23

    To solve the problem of large volume change and low electronic conductivity of earth-abundant ilmenite used in rechargeable Na-ion batteries (SIBs), an anode of tiny ilmenite FeTiO3 nanoparticle embedded carbon nanotubes (FTO⊂CNTs) has been successfully proposed. By introducing a TiO2 shell on metal-organic framework (Fe-MOF) nanorods by sol-gel deposition and subsequent solid-state annealing treatment of these core-shell Fe-MOF@TiO2, such well-defined FTO⊂CNTs are obtained. The achieved FTO⊂CNT electrode has several distinct advantages including a hollow interior in the hybrid nanostructure, fully encapsulated ultrasmall electroactive units, flexible conductive carbon matrix, and stable solid electrolyte interface (SEI) of FTO in cycles. FTO⊂CNT electrodes present an excellent cycle stability (358.8 mA h g-1 after 200 cycles at 100 mA g-1) and remarkable rate capability (201.8 mA h g-1 at 5000 mA g-1) with a high Coulombic efficiency of approximately 99%. In addition, combined with the typical Na3V2(PO4)3 cathode to constitute full SIBs, the assembled FTO⊂CNT//Na3V2(PO4)3 batteries are also demonstrated with superior rate capability and a long cycle life.

  19. Consistent high clinical pregnancy rates and low ovarian hyperstimulation syndrome rates in high-risk patients after GnRH agonist triggering and modified luteal support

    DEFF Research Database (Denmark)

    Iliodromiti, Stamatina; Blockeel, Christophe; Tremellen, Kelton P

    2013-01-01

    Are clinical pregnancy rates satisfactory and the incidence of OHSS low after GnRH agonist trigger and modified intensive luteal support in patients with a high risk of ovarian hyperstimulation syndrome (OHSS)?......Are clinical pregnancy rates satisfactory and the incidence of OHSS low after GnRH agonist trigger and modified intensive luteal support in patients with a high risk of ovarian hyperstimulation syndrome (OHSS)?...

  20. Estimation of background incidence rates of Guillain-Barré syndrome in Germany - a retrospective cohort study with electronic healthcare data.

    Science.gov (United States)

    Hense, Sabrina; Schink, Tania; Kreisel, Stefan H; Marcelon, Lydie; Simondon, François; Tahden, Maike; Garbe, Edeltraut

    2014-01-01

    The Guillain-Barré syndrome (GBS) occurs after infections and as an adverse reaction to vaccines. No detailed information on incidence rates (IRs) in Germany is available. This retrospective cohort study estimated age- and sex-specific IRs of GBS in Germany in the years 2007-2009 based on electronic healthcare data from the German Pharmacoepidemiological Research Database (GePaRD). Two case definitions were applied. GBS cases had a main discharge diagnosis of GBS. GBS_PROCEDURE cases in addition had codes for relevant diagnostic procedures. Crude and standardized IRs (SIRs) with 95% confidence intervals were stratified by year, age group, sex, region and season. IR ratios (IRRs) for each stratification factor were calculated by multivariable Poisson regression. Among 13,297,678 persons, 889 (693) incident GBS (GBS_PROCEDURE) cases were identified. Overall SIRs per 100,000 person years were 2.4 (2.2-2.5) for GBS and 1.8 (1.7-2.0) for GBS_PROCEDURE. (S)IRs increased with age, peaking in the age group 70-79 years (IR GBS: 5.5 (4.7-6.5)) and were higher in males than in females (e.g., IR GBS: IRR = 1.5 (1.3-1.7)) and in February-April, as compared to the rest of the year. No regional pattern was observed. (S)IRs of GBS in Germany differed by age, sex and season and were comparable to those found in other studies. RESULTS might be used as a comparator in vaccine safety monitoring. © 2014 S. Karger AG, Basel.

  1. The Effect of Lace-up Ankle Braces on Injury Rates in High School Football Players

    Science.gov (United States)

    McGuine, Timothy A.; Hetzel, Scott; Wilson, John; Brooks, Alison

    2013-01-01

    Background Although a nkle injuries occur frequently in high school football players no prospective studies have been performed to determine if wearing lace-up ankle braces will reduce the incidence and severity of ankle and other lower extremity injuries in these athletes. Purpose Determine if lace-up ankle braces reduce the incidence and severity of lower extremity injuries sustained by high school football players. Design Cluster randomized controlled trial. Methods 2081 players from 50 high schools were randomly-assigned to braced or control group. Braced group subjects wore lace-up ankle braces during the 2010 football season. Athletic trainers recorded brace compliance, athletic exposures and injuries. Cox Proportional Hazards models were utilized to compare injury rates between groups. Injury severity (days lost) was tested with Wilcoxon Rank Sum. Results The rate of acute ankle injury (per 1,000 exposures) was 0.48 in the braced group compared to 1.12 in the control group (Cox Hazard Ratio (HR)=0.39, 95% Confidence Interval [CI] 0.24, 0.65, pinjuries was the same (5 days) in both groups (p=0.985). The rate of acute knee injury was 0.70 in the braced group compared to 0.69 in the control group, (HR=0.92 [0.57, 1.47], p=0.721). There was no difference (p=0.242) in the severity of knee injuries between the groups (controls 11.5 days, braced =17 days. The rate of other lower extremity injuries was 0.95 in the braced group and 1.32 in the control group, (HR=0.72 [0.48, 1.09], p=0.117) while the severity was similar in both groups (6 days versus 7 days, p=0.295). Conclusions Players who used lace-up ankle braces had a lower incidence of acute ankle injuries but no difference in the incidence of acute knee or other lower extremity injuries. Braces did not reduce the severity of ankle, knee or other lower extremity injuries. PMID:21926383

  2. Strain Rate Effect on Tensile Behavior for a High Specific Strength Steel: From Quasi-Static to Intermediate Strain Rates

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2017-12-01

    Full Text Available The strain rate effect on the tensile behaviors of a high specific strength steel (HSSS with dual-phase microstructure has been investigated. The yield strength, the ultimate strength and the tensile toughness were all observed to increase with increasing strain rates at the range of 0.0006 to 56/s, rendering this HSSS as an excellent candidate for an energy absorber in the automobile industry, since vehicle crushing often happens at intermediate strain rates. Back stress hardening has been found to play an important role for this HSSS due to load transfer and strain partitioning between two phases, and a higher strain rate could cause even higher strain partitioning in the softer austenite grains, delaying the deformation instability. Deformation twins are observed in the austenite grains at all strain rates to facilitate the uniform tensile deformation. The B2 phase (FeAl intermetallic compound is less deformable at higher strain rates, resulting in easier brittle fracture in B2 particles, smaller dimple size and a higher density of phase interfaces in final fracture surfaces. Thus, more energy need be consumed during the final fracture for the experiments conducted at higher strain rates, resulting in better tensile toughness.

  3. Construct and Predictive Validity of Social Acceptability: Scores From High School Teacher Ratings on the School Intervention Rating Form

    Science.gov (United States)

    Harrison, Judith R.; State, Talida M.; Evans, Steven W.; Schamberg, Terah

    2016-01-01

    The purpose of this study was to evaluate the construct and predictive validity of scores on a measure of social acceptability of class-wide and individual student intervention, the School Intervention Rating Form (SIRF), with high school teachers. Utilizing scores from 158 teachers, exploratory factor analysis revealed a three-factor (i.e.,…

  4. Pixel-Level and Robust Vibration Source Sensing in High-Frame-Rate Video Analysis

    Directory of Open Access Journals (Sweden)

    Mingjun Jiang

    2016-11-01

    Full Text Available We investigate the effect of appearance variations on the detectability of vibration feature extraction with pixel-level digital filters for high-frame-rate videos. In particular, we consider robust vibrating object tracking, which is clearly different from conventional appearance-based object tracking with spatial pattern recognition in a high-quality image region of a certain size. For 512 × 512 videos of a rotating fan located at different positions and orientations and captured at 2000 frames per second with different lens settings, we verify how many pixels are extracted as vibrating regions with pixel-level digital filters. The effectiveness of dynamics-based vibration features is demonstrated by examining the robustness against changes in aperture size and the focal condition of the camera lens, the apparent size and orientation of the object being tracked, and its rotational frequency, as well as complexities and movements of background scenes. Tracking experiments for a flying multicopter with rotating propellers are also described to verify the robustness of localization under complex imaging conditions in outside scenarios.

  5. Is there an association between the high-risk medication star ratings and member experience CMS star ratings measures?

    Science.gov (United States)

    Erickson, Sara C; Leslie, R Scott; Patel, Bimal V

    2014-11-01

    Methods to achieve high star ratings for the High-Risk Medication (HRM) measure are thought to result in unintended consequences and to compromise several member experience measures that ultimately put at risk the plan sponsor's Medicare Part D Centers for Medicare Medicaid (CMS) star rating.  To determine if HRM scores are associated with relevant member experience measure scores.  This is a cross-sectional analysis utilizing CMS 2013 and 2014 plan star ratings reports (2011 and 2012 benefit year data) for Medicare Advantage prescription drug (MA-PD) plans and prescription drug plans (PDPs). Medicare contracts with complete data for all measures of interest in 2013 and 2014 star ratings reports were included (N = 443). Bivariate linear regressions were performed for each of 2 independent variables: (1) 2014 HRM score and (2) 2013 to 2014 change in HRM score. Dependent variables were the 2014 scores for "Getting Needed Prescription Drugs," "Complaints about Drug Plan," "Rating of Drug Plan," and "Members Choosing to Leave the Plan." The bivariate linear regressions demonstrated weak positive associations between the 2014 HRM score and each of the 2014 member experience measures that explained 0.5% to 4% (R2) of variance of these measures. The bivariate regressions for the 2013 to 2014 change in the HRM score and 2014 member experience measures of interest demonstrated associations accounting for 1% to 8% of variance (R2). The greatest associations were observed between each independent variable and the 2014 "Getting Needed Prescription Drugs" score with correlation coefficients of 0.21 and 0.29.  HRM star ratings and change in HRM star ratings are weakly correlated with member experience measures in concurrent measurement periods. Plan sponsors may be more aggressive in HRM utilization management, since it is unlikely to negatively impact CMS summary star ratings

  6. Medically inoperable endometrial cancer in patients with a high body mass index (BMI): Patterns of failure after 3-D image-based high dose rate (HDR) brachytherapy

    DEFF Research Database (Denmark)

    Acharya, Sahaja; Esthappan, Jacqueline; Badiyan, Shahed

    2016-01-01

    BACKGROUND AND PURPOSE: High BMI is a reason for medical inoperability in patients with endometrial cancer in the United States. Definitive radiation is an alternative therapy for these patients; however, data on patterns of failure after definitive radiotherapy are lacking. We describe...... the patterns of failure after definitive treatment with 3-D image-based high dose rate (HDR) brachytherapy for medically inoperable endometrial cancer. MATERIALS AND METHODS: Forty-three consecutive patients with endometrial cancer FIGO stages I-III were treated definitively with HDR brachytherapy...

  7. Using NIF to Test Theories of High-Pressure, High-Rate Plastic Flow in Metals

    Science.gov (United States)

    Rudd, Robert E.; Arsenlis, A.; Cavallo, R. M.; Huntington, C. M.; McNaney, J. M.; Park, H. S.; Powell, P.; Prisbrey, S. T.; Remington, B. A.; Swift, D.; Wehrenberg, C. E.; Yang, L.

    2017-10-01

    Precisely controlled plasmas are playing key roles both as pump and probe in experiments to understand the strength of solid metals at high energy density (HED) conditions. In concert with theoretical advances, these experiments have enabled a predictive capability to model material strength at Mbar pressures and high strain rates. Here we describe multiscale strength models developed for tantalum starting with atomic bonding and extending up through the mobility of individual dislocations, the evolution of dislocation networks and so on until the ultimate material response at the scale of an experiment. Experiments at the National Ignition Facility (NIF) probe strength in metals ramp compressed to 1-8 Mbar. The model is able to predict 1 Mbar experiments without adjustable parameters. The combination of experiment and theory has shown that solid metals can behave significantly differently at HED conditions. We also describe recent studies of lead compressed to 3-5 Mbar. Work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA273.

  8. A novel VLSI processor for high-rate, high resolution spectroscopy

    CERN Document Server

    Pullia, Antonio; Gatti, E; Longoni, A; Buttler, W

    2000-01-01

    A novel time-variant VLSI shaper amplifier, suitable for multi-anode Silicon Drift Detectors or other multi-element solid-state X-ray detection systems, is proposed. The new read-out scheme has been conceived for demanding applications with synchrotron light sources, such as X-ray holography or EXAFS, where both high count-rates and high-energy resolutions are required. The circuit is of the linear time-variant class, accepts randomly distributed events and features: a finite-width (1-10 mu s) quasi-optimal weight function, an ultra-low-level energy discrimination (approx 150 eV), and a full compatibility for monolithic integration in CMOS technology. Its impulse response has a staircase-like shape, but the weight function (which is in general different from the impulse response in time-variant systems) is quasi trapezoidal. The operation principles of the new scheme as well as the first experimental results obtained with a prototype of the circuit are presented and discussed in the work.

  9. High-power, high repetition rate, tunable, ultrafast vortex beam in the near-infrared

    Science.gov (United States)

    Aadhi, A.; Samanta, G. K.

    2018-01-01

    We report on experimental demonstration of high power, ultrafast, high repetition rate (RR) vortex beam source tunable in the near-IR wavelength range. Based on single-pass optical parametric generation of Yb-fiber laser of vortex order l p = 1 in a 50 mm long MgO doped periodically poled LiNbO3 crystal, the source produces signal beam in vortex profile of order l s = 1 across 1433–1553 nm. Additionally, the source produces broadband idler radiation tunable across 3379–4132 nm in the Gaussian beam profile. We observed that the vortex profile of the pump beam is always transferred to the signal beam due to the highest overlapping integral among the interacting beams and the idler maintains a Gaussian spatial profile owing to the conservation of orbital angular momentum in optical parametric processes. For a pump power of 4.72 W, the signal and idler beams have a maximum power of 1.7 W at 1509 nm and 0.48 W at 3625 nm respectively. The signal vortex beam has output pulses of width ∼637 fs at a RR of 78 MHz. The signal (idler) has a spectral width of 4.3 nm (129.5 nm) and a passive peak-to-peak power fluctuation better than 3% (1.1%) over 30 min, respectively.

  10. Memory performance on the Auditory Inference Span Test is independent of background noise type for young adults with normal hearing at high speech intelligibility.

    Science.gov (United States)

    Rönnberg, Niklas; Rudner, Mary; Lunner, Thomas; Stenfelt, Stefan

    2014-01-01

    Listening in noise is often perceived to be effortful. This is partly because cognitive resources are engaged in separating the target signal from background noise, leaving fewer resources for storage and processing of the content of the message in working memory. The Auditory Inference Span Test (AIST) is designed to assess listening effort by measuring the ability to maintain and process heard information. The aim of this study was to use AIST to investigate the effect of background noise types and signal-to-noise ratio (SNR) on listening effort, as a function of working memory capacity (WMC) and updating ability (UA). The AIST was administered in three types of background noise: steady-state speech-shaped noise, amplitude modulated speech-shaped noise, and unintelligible speech. Three SNRs targeting 90% speech intelligibility or better were used in each of the three noise types, giving nine different conditions. The reading span test assessed WMC, while UA was assessed with the letter memory test. Twenty young adults with normal hearing participated in the study. Results showed that AIST performance was not influenced by noise type at the same intelligibility level, but became worse with worse SNR when background noise was speech-like. Performance on AIST also decreased with increasing memory load level. Correlations between AIST performance and the cognitive measurements suggested that WMC is of more importance for listening when SNRs are worse, while UA is of more importance for listening in easier SNRs. The results indicated that in young adults with normal hearing, the effort involved in listening in noise at high intelligibility levels is independent of the noise type. However, when noise is speech-like and intelligibility decreases, listening effort increases, probably due to extra demands on cognitive resources added by the informational masking created by the speech fragments and vocal sounds in the background noise.

  11. Ka-Band TWT High-Efficiency Power Combiner for High-Rate Data Transmission

    Science.gov (United States)

    Wintucky, Edwin G.; Simons, Rainee; Vaden, Karl R.; Lesny, Gary G.; Glass, Jeffrey L.

    2007-01-01

    A four-port magic-T hybrid waveguide junction serves as the central component of a high-efficiency two-way power combiner circuit for transmitting a high-rate phase-modulated digital signal at a carrier frequency in the Ka-band (between 27 and 40 GHz). This power combiner was developed to satisfy a specific requirement to efficiently combine the coherent outputs of two traveling-wavetube (TWT) amplifiers that are typically characterized by power levels on the order of 100 W or more. In this application, the use of a waveguide-based power combiner (instead of a coaxial-cable- or microstrip-based power combiner, for example) is dictated by requirements for low loss, high power-handling capability, and broadband response. Combiner efficiencies were typically 90 percent or more over both the linear and saturated output power regions of operation of the TWTs . Figure 1 depicts the basic configuration of the magic-T hybrid junction. The coherent outputs of the two TWTs enter through ports 1 and 4. As a result of the orientations of the electromagnetic fields, which also provides a needed high port-to-port isolation, of these two input signals and the interior design of the magic-T junction, the input powers are divided so as to add in phase at one output port (port 2), and to be opposite in phase and hence cancel each other at the opposite coplanar output port (port 3). The net result is that the output power at port 2 is essentially double that of the output of one TWT, minus the power lost in the magic-T hybrid junction. Optimum performance as a high-efficiency power combiner thus requires a balance of both power and phase at the input ports of the magic-T. Replicas of this two-way combiner can be arranged in a binary configuration to obtain a 2n-way (where n is an integer) combiner. For example, Figure 2 illustrates the use of three two-way combiners to combine the outputs of four TWTs.

  12. Methane conversion efficiency as a simple control parameter for an anaerobic digester at high loading rates.

    Science.gov (United States)

    Charles, W; Carnaje, N P; Cord-Ruwisch, R

    2011-01-01

    The anaerobic digestion process is globally applied to the treatment of highly concentrated wastes such as industrial and rural effluents, and sewage sludge. However, it is known to be relatively unstable. When loaded with high concentrations of organic material, unwanted volatile fatty acids (VFA) are often produced rather than methane (CH4) gas which can lead to digester acidification and failure. This study investigated digester behaviour under high loading rates, testing the usefulness of stoichiometric methane conversion efficiency as a digester control parameter at high loading rates. Our results show that, in general, the CH4 production rate was proportional to the feed rate (loading rate). However, at very high loading rates, the CH4 production rate was not proportional to the increase in the feeding rate. Consequently, VFA accumulated and the H2 partial pressure increased. The proportionality of the loading rate and gas production rate is stoichiometrically expressed as the conversion efficiency. We found that conversion efficiency was a useful indicator as an early warning of digester imbalance. The digester remained stable at conversion efficiencies above 75%. Dropping below 70% signified the onset of digester failure. As loading rate and methane production data are readily available on-line in most anaerobic digestion plants, the conversion efficiency can be monitored on-line and used as an efficient control technique to maintain safe operation of anaerobic digesters at high loading rates.

  13. Safety and efficacy of low fluence, high repetition rate versus high fluence, low repetition rate 810-nm diode laser for axillary hair removal in Chinese women.

    Science.gov (United States)

    Li, Wenhai; Liu, Chengyi; Chen, Zhou; Cai, Lin; Zhou, Cheng; Xu, Qianxi; Li, Houmin; Zhang, Jianzhong

    2016-11-01

    High-fluence diode lasers with contact cooling have emerged as the gold standard to remove unwanted hair. Lowering the energy should result in less pain and could theoretically affect the efficacy of the therapy. To compare the safety and efficacy of a low fluence high repetition rate 810-nm diode laser to those of a high fluence, low repetition rate diode laser for permanent axillary hair removal in Chinese women. Ninety-two Chinese women received four axillae laser hair removal treatments at 4-week intervals using the low fluence, high repetition rate 810-nm diode laser in super hair removal (SHR) mode on one side and the high fluence, low repetition rate diode laser in hair removal (HR) mode on the other side. Hair counts were done at each follow-up visit and 6-month follow-up after the final laser treatment using a "Hi Quality Hair Analysis Program System"; the immediate pain score after each treatment session was recorded by a visual analog scale. The overall median reduction of hair was 90.2% with the 810-nm diode laser in SHR mode and 87% with the same laser in HR mode at 6-month follow-up. The median pain scores in SHR mode and in HR mode were 2.75 and 6.75, respectively. Low fluence, high repetition rate diode laser can efficiently remove unwanted hair but also significantly improve tolerability and reduce adverse events during the course of treatment.

  14. High-Strain, High-Strain-Rate Deformation Behavior of Tantalum and Tantalum-Tungsten Based Alloys

    OpenAIRE

    Marquis, F; Chen, Y.; Chen, Y.

    1997-01-01

    The microstructural evolution in high-strain, high-strain-rate deformation of annealed tantalum and tantalum-tungsten alloys with 1 and 2.5 wt.% and the occurrence of shear localization has been investigated. The microstructure generated at high strain rates progresses from highly dislocated grains, to lath cells, to subgrains, and finally to small grains as the shear strain increases. The temperature rise predictions from the constitutive equations which describe the materials behavior indic...

  15. Assessment of indoor radiation dose received by the residents of natural high background radiation areas of coastal villages of Kanyakumari district, Tamil Nadu, India

    Energy Technology Data Exchange (ETDEWEB)

    Deva Jayanthi, D., E-mail: d.devajayanthi@gmail.co [Department of Physics, Women' s Christian College, Nagercoil 629001 (India); Maniyan, C.G. [Environmental Assessment Division, BARC, Mumbai 400085 (India); Perumal, S. [Department of Physics and Research Centre, S.T.Hindu College, Nagercoil 629002 (India)

    2011-07-15

    Radiation exposure and effective dose received through two routes of exposure, viz. external and internal, via inhalation, by residents of 10 villages belonging to Natural High Background Radiation Areas (NHBRA) of coastal regions of Kanyakumari District and Tamil Nadu in India were studied. While the indoor gamma radiation levels were monitored using Thermo Luminescent Dosimeters (TLDs), the indoor radon and thoron gas concentrations were measured using twin chamber dosimeters employing Solid State Nuclear Track Detectors (SSNTDs, LR-115-II). The average total annual effective dose was estimated and found to be varying from 2.59 to 8.76 mSv. -- Highlights: {yields} The effective dose received by the villages of Natural High Background Area (NHBRA) such as Enayam, Midalam and Mel Midalam is high when compared with other study areas. {yields} The high dose indicates higher concentration of radioactive nuclides like Thorium and Uranium in the soil. {yields} As radiation is harmful to human life, the external and internal doses can be reduced by removing the monazite content present in the soil by mineral separation. {yields} Contribution from vegetables, fruits, fish and other non vegetarian items are also being examined. {yields} These results along with other socio-economic factors can throw considerable light on the epidemiological impacts due to low levels of chronic exposure.

  16. JEM-X background models

    DEFF Research Database (Denmark)

    Huovelin, J.; Maisala, S.; Schultz, J.

    2003-01-01

    Background and determination of its components for the JEM-X X-ray telescope on INTEGRAL are discussed. A part of the first background observations by JEM-X are analysed and results are compared to predictions. The observations are based on extensive imaging of background near the Crab Nebula...... on revolution 41 of INTEGRAL. Total observing time used for the analysis was 216 502 s, with the average of 25 cps of background for each of the two JEM-X telescopes. JEM-X1 showed slightly higher average background intensity than JEM-X2. The detectors were stable during the long exposures, and weak orbital...... phase dependence in the background outside radiation belts was observed. The analysis yielded an average of 5 cps for the diffuse background, and 20 cps for the instrument background. The instrument background was found highly dependent on position, both for spectral shape and intensity. Diff use...

  17. Design of high gradient, high repetition rate damped C -band rf structures

    Science.gov (United States)

    Alesini, David; Bellaveglia, Marco; Bini, Simone; Gallo, Alessandro; Lollo, Valerio; Pellegrino, Luigi; Piersanti, Luca; Cardelli, Fabio; Migliorati, Mauro; Mostacci, Andrea; Palumbo, Luigi; Tocci, Simone; Ficcadenti, Luca; Pettinacci, Valerio

    2017-03-01

    The gamma beam system of the European Extreme Light Infrastructure-Nuclear Physics project foresees the use of a multibunch train colliding with a high intensity recirculated laser pulse. The linac energy booster is composed of 12 traveling wave C -band structures, 1.8 m long with a field phase advance per cell of 2 π /3 and a repetition rate of 100 Hz. Because of the multibunch operation, the structures have been designed with a dipole higher order mode (HOM) damping system to avoid beam breakup (BBU). They are quasiconstant gradient structures with symmetric input couplers and a very effective damping of the HOMs in each cell based on silicon carbide (SiC) rf absorbers coupled to each cell through waveguides. An optimization of the electromagnetic and mechanical design has been done to simplify the fabrication and to reduce the cost of the structures. In the paper, after a review of the beam dynamics issues related to the BBU effects, we discuss the electromagnetic and thermomechanic design criteria of the structures. We also illustrate the criteria to compensate the beam loading and the rf measurements that show the effectiveness of the HOM damping.

  18. Design of high gradient, high repetition rate damped C-band rf structures

    Directory of Open Access Journals (Sweden)

    David Alesini

    2017-03-01

    Full Text Available The gamma beam system of the European Extreme Light Infrastructure–Nuclear Physics project foresees the use of a multibunch train colliding with a high intensity recirculated laser pulse. The linac energy booster is composed of 12 traveling wave C-band structures, 1.8 m long with a field phase advance per cell of 2π/3 and a repetition rate of 100 Hz. Because of the multibunch operation, the structures have been designed with a dipole higher order mode (HOM damping system to avoid beam breakup (BBU. They are quasiconstant gradient structures with symmetric input couplers and a very effective damping of the HOMs in each cell based on silicon carbide (SiC rf absorbers coupled to each cell through waveguides. An optimization of the electromagnetic and mechanical design has been done to simplify the fabrication and to reduce the cost of the structures. In the paper, after a review of the beam dynamics issues related to the BBU effects, we discuss the electromagnetic and thermomechanic design criteria of the structures. We also illustrate the criteria to compensate the beam loading and the rf measurements that show the effectiveness of the HOM damping.

  19. High Serum FSH is Associated with Brown Oocyte Formation and a Lower Pregnacy Rate in Human IVF Parctice

    Directory of Open Access Journals (Sweden)

    Hongyi Xu

    2016-07-01

    Full Text Available Background/Aims: To investigate whether brown zona pellucida (ZP of oocytes affects the outcome of fertilization, embryo quality and pregnancy rate in in vitro fertilization-embryo transfer (IVF-ET. Methods: Based on the ZP color of their oocytes, a total number of 703 patients dated from 2012 to 2014 were divided into a normal egg group (group A and a brown oocyte group (group B, with 629 and 74 cases, respectively. Clinical characteristics, gonadotropin (Gn days, Gn dosage, serum hormone levels on the day of human chorionic gonadotropin (HCG injection, ZP thickness (ZPT of the eggs, fertilization rate, rescue intracytoplasmic sperm injection (rICSI rate, good-quality embryo rate and pregnancy rate were compared between the two groups. Results: No significant differences were found in the duration and the causes of infertility, and their basal level of endocrine hormone before IVF-ET between normal egg group and brown egg group. The level of serum hormone including estradiol, progesterone and luteinizing hormone on the day of HCG injection were again similar. Moreover, there were no differences in number of mature oocytes, oocyte fertilization rates and rICSI rates after IVF between the two groups. However, we observed that the ZPT of brown oocytes (group B was higher than that of normal oocytes (group A. Moreover, the Gn dosage and FSH levels on the day of HCG injection were significantly higher in group B than in group A and the good-quality embryo rate and pregnancy rate in group B were lower than those in group A. Conclusion: Compared with normal eggs, oocytes with a brown ZP were found to have a higher ZPT, lower embryo quality and lower pregnancy rate, which might be due to a high Gn dosage injection and high serum FSH levels during IVT-ET cycles.

  20. Principal Transformational Leadership Behaviors, Teachers' Sense of Efficacy, and Student Graduation Rates in High Needs High Schools

    Science.gov (United States)

    Lilla, Darlene

    2013-01-01

    This study was an examination of teachers' perceptions of principal leadership behavior, Teaching Efficacy, and Personal Teaching Efficacy in high needs high schools with high and low graduation rates. The participants, one hundred twelve teachers from six high schools on Long Island, New York, responded to a 44-item survey instrument. The six…

  1. Graphics processing unit accelerated optical coherence tomography processing at megahertz axial scan rate and high resolution video rate volumetric rendering.

    Science.gov (United States)

    Jian, Yifan; Wong, Kevin; Sarunic, Marinko V

    2013-02-01

    In this report, we describe how to highly optimize a computer unified device architecture based platform to perform real-time processing of optical coherence tomography interferometric data and three-dimensional (3-D) volumetric rendering using a commercially available, cost-effective, graphics processing unit (GPU). The maximum complete attainable axial scan processing rate, including memory transfer and displaying B-scan frame, was 2.24 MHz for 16 bits pixel depth and 2048 fast Fourier transform size; the maximum 3-D volumetric rendering rate, including B-scan, en face view display, and 3-D rendering, was ~23 volumes/second (volume size: 1024×256×200). To the best of our knowledge, this is the fastest processing rate reported to date with a single-chip GPU and the first implementation of real-time video-rate volumetric optical coherence tomography (OCT) processing and rendering that is capable of matching the acquisition rates of ultrahigh-speed OCT.

  2. Graphics processing unit accelerated optical coherence tomography processing at megahertz axial scan rate and high resolution video rate volumetric rendering

    Science.gov (United States)

    Jian, Yifan; Wong, Kevin; Sarunic, Marinko V.

    2013-02-01

    In this report, we describe how to highly optimize a computer unified device architecture based platform to perform real-time processing of optical coherence tomography interferometric data and three-dimensional (3-D) volumetric rendering using a commercially available, cost-effective, graphics processing unit (GPU). The maximum complete attainable axial scan processing rate, including memory transfer and displaying B-scan frame, was 2.24 MHz for 16 bits pixel depth and 2048 fast Fourier transform size; the maximum 3-D volumetric rendering rate, including B-scan, en face view display, and 3-D rendering, was ˜23 volumes/second (volume size: 1024×256×200). To the best of our knowledge, this is the fastest processing rate reported to date with a single-chip GPU and the first implementation of real-time video-rate volumetric optical coherence tomography (OCT) processing and rendering that is capable of matching the acquisition rates of ultrahigh-speed OCT.

  3. Meditation-induced changes in high-frequency heart rate variability predict smoking outcomes

    Directory of Open Access Journals (Sweden)

    Daniel J. Libby

    2012-03-01

    Full Text Available Background: High-frequency heart rate variability (HF-HRV is a measure of parasympathetic nervous system output that has been associated with enhanced self-regulation. Low resting levels of HF-HRV are associated with nicotine dependence and blunted stress-related changes in HF-HRV are associated with decreased ability to resist smoking. Meditation has been shown to increase HF-HRV. However, it is unknown whether tonic levels of HF-HRV or acute changes in HF-HRV during meditation predict treatment responses in addictive behaviors such as smoking cessation. Purpose: To investigate the relationship between HF-HRV and subsequent smoking outcomes. Methods: HF-HRV during resting baseline and during mindfulness meditation was measured within two weeks of completing a 4-week smoking cessation intervention in a sample of 31 community participants. Self-report measures of smoking were obtained at a follow up 17-weeks after the initiation of treatment. Results: Regression analyses indicated that individuals exhibiting acute increases in HF-HRV from resting baseline to meditation smoked fewer cigarettes at follow-up than those who exhibited acute decreases in HF-HRV (b=-4.94, p=.009. Conclusion: Acute changes in HF-HRV in response to meditation may be a useful tool to predict smoking cessation treatment response.

  4. High strain rate sensitivity of hardness in quinary Ti-Zr-Hf-Cu-Ni high entropy metallic glass thin films

    Science.gov (United States)

    Zhao, Shaofan; Wang, Haibin; Xiao, Lin; Guo, Nan; Zhao, Delin; Yao, Kefu; Chen, Na

    2017-10-01

    Quinary Ti-Zr-Hf-Cu-Ni high-entropy metallic glass thin films were produced by magnetron sputter deposition. Nanoindentation tests indicate that the deposited film exhibits a relatively large hardness of 10.4±0.6 GPa and a high elastic modulus of 131±11 GPa under the strain rate of 0.5 s-1. Specifically, the strain rate sensitivity of hardness measured for the thin film is 0.05, the highest value reported for metallic glasses so far. Such high strain rate sensitivity of hardness is likely due to the high-entropy effect which stabilizes the amorphous structure with enhanced homogeneity.

  5. High-pressure xenon time projection Titanium chamber: a methodology for detecting background radiation in neutrinoless double-beta decay experiments

    Science.gov (United States)

    Bachri, A.; Elmhamdi, A.; Hawron, M.; Grant, P.; Zazoum, B.; Martin, C.

    2017-10-01

    The xenon time projection chamber (TPC) promises a novel detection method for neutrinoless double-beta decay (0ν β β ) experiments. The TPC is capable of discovering the rare 0ν β β ionization signal of a distinct topological signature, with a decay energy Qββ = 2.458 MeV . However, more frequent internal (within TPC) and external events are also capable of depositing energy in the range of the Qβ β -value inside the chamber, thus mimicking 0ν β β or interfering with its direct observation. In the following paper, we illustrate a methodology for background radiation evaluation, assuming a basic cylindrical design for a toy titanium TPC that is capable of containing 100 kg of xenon gas at 20 atm pressure; we estimate the background budget and analyze the most prominent problematic events via theoretical calculation. Gamma rays emitted from nuclei of 214Bi and 208Tl present in the outer-shell titanium housing of the TPC are an example of such events for which we calculate probabilities of occurrences. We also study the effect of alpha-neutron (α-n)-induced neutrons and calculate their rate. Alpha particles which are created by the decay of naturally occurring uranium and thorium present in most materials, can react with the nucleus of low Z elements, prompting the release of neutrons and leading to thermal neutron capture. Our calculations suggest that the typical polytetrafluoroethylene (PTFE) inner coating of the chamber would constitute the primary material for neutron production, specifically; we find that the fluorine component of Teflon is much more likely to undergo an (α-n) reaction. From known contamination, we calculate an alpha production rate to be 5.5 × 107 alpha/year for the highest-purity titanium vessel with a Teflon lining. Lastly, using measurements of neutron flux from alpha bombardment, we estimate the expected neutron flux from the materials of the proposed toy TPC and identify all gamma rays (prompt or delayed, of energies

  6. Evaluation of DNA damage in the root cells of Allium cepa seeds growing in soil of high background radiation areas of Ramsar-Iran.

    Science.gov (United States)

    Saghirzadeh, M; Gharaati, M R; Mohammadi, Sh; Ghiassi-Nejad, M

    2008-10-01

    Plants are unique in their ability to serve as in situ monitors for environmental genotoxins. We have used the alkaline comet assay for detecting induced DNA damage in Allium cepa to estimate the impact of high levels of natural radiation in the soils of inhabited zones of Ramsar. The average specific activity of natural radionuclides measured in the soil samples for 226Ra was 12,766 Bq kg(-1) whereas in the control soils was in the range of 34-60 Bq kg(-1). A positive strong significant correlation of the DNA damage in nuclei of the root cells of A. cepa seeds germinated in the soil of high background radiation areas with 226Ra specific activity of the soil samples was observed. The results showed high genotoxicity of radioactively contaminated soils. Also the linear increase in the DNA damage indicates that activation of repair enzymes is not triggered by exposure to radiation in HBRA.

  7. Evaluation of DNA damage in the root cells of Allium cepa seeds growing in soil of high background radiation areas of Ramsar - Iran

    Energy Technology Data Exchange (ETDEWEB)

    Saghirzadeh, M. [Department of Basic Science, Gonabad University of Medical Sciences, Gonabad (Iran, Islamic Republic of); Gharaati, M.R. [Faculty of Science, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Mohammadi, Sh. [Nuclear Science and Technology Research Institute (NSTRI), Radiation Applications Research School, Tehran 11365-3486 (Iran, Islamic Republic of)], E-mail: smohammadi@aeoi.org.ir; Ghiassi-Nejad, M. [Faculty of Science, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)

    2008-10-15

    Plants are unique in their ability to serve as in situ monitors for environmental genotoxins. We have used the alkaline comet assay for detecting induced DNA damage in Allium cepa to estimate the impact of high levels of natural radiation in the soils of inhabited zones of Ramsar. The average specific activity of natural radionuclides measured in the soil samples for {sup 226}Ra was 12,766 Bq kg{sup -1} whereas in the control soils was in the range of 34-60 Bq kg{sup -1}. A positive strong significant correlation of the DNA damage in nuclei of the root cells of A. cepa seeds germinated in the soil of high background radiation areas with {sup 226}Ra specific activity of the soil samples was observed. The results showed high genotoxicity of radioactively contaminated soils. Also the linear increase in the DNA damage indicates that activation of repair enzymes is not triggered by exposure to radiation in HBRA.

  8. Sex differences in aggression among children of low and high gender inequality backgrounds: a comparison of gender role and sexual selection theories.

    Science.gov (United States)

    Nivette, Amy E; Eisner, Manuel; Malti, Tina; Ribeaud, Denis

    2014-01-01

    It is well understood in aggression research that males tend to exhibit higher levels of physical aggression than females. Yet there are still a number of gaps in our understanding of variation in sex differences in children's aggression, particularly in contexts outside North America. A key assumption of social role theory is that sex differences vary according to gender polarization, whereas sexual selection theory accords variation to the ecological environment that consequently affects male competition [Archer, J. (2009). Behavioral and Brain Sciences, 32, 249-311; Kenrick, D., & Griskevicious, V. (2009). More holes in social roles [Comment]. Behavioral and Brain Sciences, 32, 283-285]. In the present paper, we explore these contradicting theoretical frameworks by examining data from a longitudinal study of a culturally diverse sample of 863 children at ages 7-13 in Zurich, Switzerland. Making use of the large proportion of children from highly diverse immigrant background we compare the size of the sex difference in aggression between children whose parents were born in countries with low and with high levels of gender inequality. The results show that sex differences in aggression are generally larger among children with parents from high gender inequality backgrounds. However, this effect is small in comparison to the direct effect of a child's biological sex. We discuss implications for future research on sex differences in children's aggression. © 2014 Wiley Periodicals, Inc.

  9. Low-Dose-Rate Definitive Brachytherapy for High-Grade Vaginal Intraepithelial Neoplasia

    Science.gov (United States)

    Monnier, Laurie; Dumas, Isabelle; Morice, Philippe; Pautier, Patricia; Duvillard, Pierre; Azoury, Fares; Mazeron, Renaud; Haie-Meder, Christine

    2011-01-01

    Background. Treatment of high-grade vaginal intraepithelial neoplasia (VAIN) is controversial and could include surgical excision, topical medication, brachytherapy, or other treatments. We report the results of low-dose-rate (LDR) vaginal brachytherapy for grade 3 VAIN (VAIN-3) over a 25-year period at Gustave Roussy Institute. Patients and Methods. We retrospectively reviewed the files of all patients treated at Gustave Roussy Institute for VAIN-3 since 1985. The treatment consisted of LDR brachytherapy using a personalized vaginal mold and delivered 60 Gy to 5 mm below the vaginal mucosa. All patients had at least an annual gynecological examination, including a vaginal smear. Results. Twenty-eight patients were eligible. The median follow-up was 41 months. Seven patients had a follow-up brachytherapy was 63 years (range, 38–80 years). Twenty-six patients had a history of VAIN recurring after cervical intraepithelial neoplasia and 24 had a previous hysterectomy. The median brachytherapy duration was 4.5 days. Median doses to the International Commission of Radiation Units and Measurements rectum and bladder points were 68 Gy and 45 Gy, respectively. The median prescription volume (60 Gy) was 74 cm3. Only one “in field” recurrence occurred, corresponding to a 5- and 10-year local control rate of 93% (95% confidence interval, 70%–99%). The treatment was well tolerated, with no grade 3 or 4 late toxicity and only one grade 2 digestive toxicity. No second cancers were reported. Conclusion. LDR brachytherapy is an effective and safe treatment for vaginal intraepithelial neoplasia. PMID:21262875

  10. GERD assessment including pH metry predicts a high response rate to PPI standard therapy

    Directory of Open Access Journals (Sweden)

    Kandulski Arne

    2013-01-01

    Full Text Available Abstract Background Inadequate response to proton pump inhibitor (PPI therapy in patients with gastroesophageal reflux disease (GERD is reported in up to 40%. Patients with non erosive reflux disease (NERD have lower response rates compared to patients with erosive reflux disease (ERD; pH metry contributes to GERD diagnosis and is critical for proper diagnosis of NERD. Aim of the study was to assess the need for doubling esomeprazole standard dose (40 mg for 4 weeks in PPI naive patients with typical reflux symptoms and diagnosis of GERD based on endoscopy and 48 hours, wireless pH metry. Methods All patients underwent upper GI endoscopy. Symptoms were recorded with a structured questionnaire (RDQ and acid exposure was determined by 48 hours, wireless pH monitoring (BRAVO. In case of abnormal acid exposure, patients received a short term treatment with esomeprazole 40 mg q.d. for 4 weeks. If symptoms persisted, patients underwent a second pH metry on PPI and the dose was increased to 40 mg b.i.d. Results 31 consecutive patients with typical reflux symptoms underwent 48 hours pH monitoring. 22 patients (71% had abnormal acid exposure, 9 patients had normal pH metry (29%. Of the 9 patients with normal pH metry, 2 were found with erosive esophagitis and 7 without endoscopic abnormalities. 24 patients with documented GERD received esomeprazole treatment. 21 patients achieved complete symptom resolution with 40 mg q.d. after 4 weeks (88%. Only 2 patients required doubling the dose of esomeprazole for complete symptom resolution, 1 patient remained with symptoms. Conclusions Patients with typical reflux symptoms and abnormal acid exposure have a high response rate to standard dose esomeprazole regardless of whether they have ERD or NERD.

  11. Programmable High-Rate Multi-Mission Receiver for Space Communications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Current and upcoming NASA space links require both highly reliable low-rate communications links supporting critical TT&C, ranging and voice services and highly...

  12. 31 CFR 356.21 - How are awards at the high yield or discount rate calculated?

    Science.gov (United States)

    2010-07-01

    ... discount rate calculated? 356.21 Section 356.21 Money and Finance: Treasury Regulations Relating to Money... high yield or discount rate calculated? (a) Awards to submitters. We generally prorate bids at the highest accepted yield or discount rate under § 356.20(a)(2) of this part. For example, if 80.15% is the...

  13. Heart Rates of High School Physical Education Students during Team Sports, Individual Sports, and Fitness Activities

    Science.gov (United States)

    Laurson, Kelly R.; Brown, Dale D.; Cullen, Robert W.; Dennis, Karen K.

    2008-01-01

    This study examined how activity type influenced heart rates and time spent in target heart rate zones of high school students participating in physical education classes. Significantly higher average heart rates existed for fitness (142 plus or minus 24 beats per minute [bpm]) compared to team (118 plus or minus 24 bpm) or individual (114 plus or…

  14. Sri Lanka; Background Papers

    OpenAIRE

    International Monetary Fund

    1995-01-01

    This Background Paper on Sri Lanka provides information on the economic developments during 1992–95. Developments in the domestic and external sectors are discussed. The deficiencies of the official consumer price index that resulted in a substantial understatement of inflation performance in 1994 and alternative estimates of underlying inflation are described. The structural rigidities in the labor market that perpetuate high unemployment and limit job growth are also described. The paper al...

  15. submitter Study of possible Supersymmetric processes and Mini Black Hole production and comparison to background events with high transverse energy in the ATLAS experiment

    CERN Document Server

    Melamed-Katz, Arie

    2009-01-01

    The ATLAS detector, which was installed at one of the interaction points of the Large Hadron Collider (LHC), has the capability to discover 'new physics' beyond the Standard Model (SM) already during its first year of operation. In this work an assessment of ATLAS capabilities regarding the detection of some 'new physics' signals is performed. In the course of this research all relevant SM background sources were produced. These sources were studied with several simulation tools and the results are compared. In the scope of these background studies, a verification procedure that relies on expected SM production rates was developed. This procedure is able to distinguish between new physics and a faked one originating in malfunctioning detector. Supersymmetry (SUSY) is one of the best candidates for the theory 'beyond the Standard Model'. It predicts the existence of new symmetry between bosons and fermions, and assumes a new fermion partner for each SM boson and a new boson partner for each SM fermion. A maj...

  16. The assessment of cytotoxic T cell and natural killer cells activity in residents of high and ordinary background radiation areas of Ramsar-Iran

    Directory of Open Access Journals (Sweden)

    Sajad Borzoueisileh

    2013-01-01

    Full Text Available The effective radiation dose of human from natural sources is about 2.4 mSv/y and the dose limit for radiation workers is 20 mSv/y. Ramsar, a city in Iran, has been the subject of concern in the last forty years for a high level of radiation measured in some spots as high as 260 mSv/y. Carcinogenesis is one of the most studied effects of radiation especially in high doses. Recent studies showed that the high level of natural radiation received by inhabitants of this area, paradoxically don′t have significant health effect. Natural killer (NK cells and cytotoxic T cells are the most important cells in tumor immune surveillance and CD107a is a widely expressed intracellular protein located in the lysosomal/endosomal membrane. CD107a transiently located on the cell membrane can be used as a marker of CD8 + T cell degranulation following stimulation. It is also expressed, to a lower extent, on activated NK cells. In this study, 60 healthy people were selected randomly and their consent obtained and confounding factors such as sex, age, life-styles was matched then the count of activated NK and CD8 + cells was compared in high and normal background radiation areas inhabitants of Ramsar. After filling the questionnaire and measurement of background radiation, blood samples of 30 healthy people from each region were analyzed immediately by means of flowcytometry. The leukocytes and their subsets were not significantly different between two groups and the count of active cells was higher in control group. The result shows that the changes in immune system occur due to radiation and maybe it is as a result of higher radiosensitivity of activated cells.

  17. The assessment of cytotoxic T cell and natural killer cells activity in residents of high and ordinary background radiation areas of Ramsar-Iran.

    Science.gov (United States)

    Borzoueisileh, Sajad; Monfared, Ali Shabestani; Abediankenari, Saeid; Mostafazadeh, Amrollah

    2013-01-01

    The effective radiation dose of human from natural sources is about 2.4 mSv/y and the dose limit for radiation workers is 20 mSv/y. Ramsar, a city in Iran, has been the subject of concern in the last forty years for a high level of radiation measured in some spots as high as 260 mSv/y. Carcinogenesis is one of the most studied effects of radiation especially in high doses. Recent studies showed that the high level of natural radiation received by inhabitants of this area, paradoxically don't have significant health effect. Natural killer (NK) cells and cytotoxic T cells are the most important cells in tumor immune surveillance and CD107a is a widely expressed intracellular protein located in the lysosomal/endosomal membrane. CD107a transiently located on the cell membrane can be used as a marker of CD8 + T cell degranulation following stimulation. It is also expressed, to a lower extent, on activated NK cells. In this study, 60 healthy people were selected randomly and their consent obtained and confounding factors such as sex, age, life-styles was matched then the count of activated NK and CD8 + cells was compared in high and normal background radiation areas inhabitants of Ramsar. After filling the questionnaire and measurement of background radiation, blood samples of 30 healthy people from each region were analyzed immediately by means of flowcytometry. The leukocytes and their subsets were not significantly different between two groups and the count of active cells was higher in control group. The result shows that the changes in immune system occur due to radiation and maybe it is as a result of higher radiosensitivity of activated cells.

  18. Internal resistance of plastic bonded (pressed type) high rate Ni electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Kulcsar, S.; Horvath P.; Csath, G.; Smaroglay, M.

    1982-07-01

    Internal resistance is one of the most important characteristics of Ni-Cd cells. It has a great effect on the discharge voltage, capacity, and high rate behaviour. In this paper we report the results of an investigation in connection with the internal resistance of the plastic bonded Ni electrode and its variation as a function of pressure and high rate cycling.

  19. High School Dropout, Graduation, and Completion Rates: Better Data, Better Measures, Better Decisions

    Science.gov (United States)

    Hauser, Robert M., Ed.; Koenig, Judith Anderson, Ed.

    2011-01-01

    High school graduation and dropout rates have long been used as indicators of educational system productivity and effectiveness and of social and economic well being. While determining these rates may seem like a straightforward task, their calculation is in fact quite complicated. How does one count a student who leaves a regular high school but…

  20. Measuring ADHD and ODD Symptoms and Impairment Using High School Teachers' Ratings

    Science.gov (United States)

    Evans, Steven W.; Brady, Christine E.; Harrison, Judith R.; Bunford, Nora; Kern, Lee; State, Talida; Andrews, Christiana

    2013-01-01

    We analyzed the results of high school teachers' ratings of symptoms of attention deficit hyperactivity disorder (ADHD) and oppositional defiant disorder, as well as school-related impairment of 875 adolescents. One hundred forty-three teachers at 19 high schools across 4 states each rated 6 students from their first-period classes according to…

  1. Analog Readout and Analysis Software for the Ultra-High Rate Germanium (UHRGe) Project

    Energy Technology Data Exchange (ETDEWEB)

    Fast, James E.; Aguayo Navarrete, Estanislao; Evans, Allan T.; VanDevender, Brent A.; Rodriguez, Douglas C.; Wood, Lynn S.

    2011-09-01

    High-resolution high-purity germanium (HPGe) spectrometers are needed for Safeguards applications such as spent fuel assay and uranium hexafluoride cylinder verification. In addition, these spectrometers would be applicable to other high-rate applications such as non-destructive assay of nuclear materials using nuclear resonance fluorescence. Count-rate limitations of today's HPGe technologies, however, lead to concessions in their use and reduction in their efficacy. Large-volume, very high-rate HPGe spectrometers are needed to enable a new generation of nondestructive assay systems. The Ultra-High Rate Germanium (UHRGe) project is developing HPGe spectrometer systems capable of operating at unprecedented rates, 10 to 100 times those available today. This report documents current status of developments in the analog electronics and analysis software.

  2. Sensitivity to Antibiotics of Bacteria Exposed to Gamma Radiation Emitted from Hot Soils of the High Background Radiation Areas of Ramsar, Northern Iran.

    Science.gov (United States)

    Mortazavi, Seyed Mohammad Javad; Zarei, Samira; Taheri, Mohammad; Tajbakhsh, Saeed; Mortazavi, Seyed Alireza; Ranjbar, Sahar; Momeni, Fatemeh; Masoomi, Samaneh; Ansari, Leila; Movahedi, Mohammad Mehdi; Taeb, Shahram; Zarei, Sina; Haghani, Masood

    2017-04-01

    Over the past several years our laboratories have investigated different aspects of the challenging issue of the alterations in bacterial susceptibility to antibiotics induced by physical stresses. To explore the bacterial susceptibility to antibiotics in samples of Salmonella enterica subsp. enterica serovar Typhimurium (S. typhimurium), Staphylococcus aureus, and Klebsiella pneumoniae after exposure to gamma radiation emitted from the soil samples taken from the high background radiation areas of Ramsar, northern Iran. Standard Kirby-Bauer test, which evaluates the size of the zone of inhibition as an indicator of the susceptibility of different bacteria to antibiotics, was used in this study. The maximum alteration of the diameter of inhibition zone was found for K. pneumoniae when tested for ciprofloxacin. In this case, the mean diameter of no growth zone in non-irradiated control samples of K. pneumoniae was 20.3 (SD 0.6) mm; it was 14.7 (SD 0.6) mm in irradiated samples. On the other hand, the minimum changes in the diameter of inhibition zone were found for S. typhimurium and S. aureus when these bacteria were tested for nitrofurantoin and cephalexin, respectively. Gamma rays were capable of making significant alterations in bacterial susceptibility to antibiotics. It can be hypothesized that high levels of natural background radiation can induce adaptive phenomena that help microorganisms better cope with lethal effects of antibiotics.

  3. High resolution, high frame rate video technology development plan and the near-term system conceptual design

    Science.gov (United States)

    Ziemke, Robert A.

    1990-01-01

    The objective of the High Resolution, High Frame Rate Video Technology (HHVT) development effort is to provide technology advancements to remove constraints on the amount of high speed, detailed optical data recorded and transmitted for microgravity science and application experiments. These advancements will enable the development of video systems capable of high resolution, high frame rate video data recording, processing, and transmission. Techniques such as multichannel image scan, video parameter tradeoff, and the use of dual recording media were identified as methods of making the most efficient use of the near-term technology.

  4. High frame rate retrospectively triggered Cine MRI for assessment of murine diastolic function.

    Science.gov (United States)

    Coolen, Bram F; Abdurrachim, Desiree; Motaal, Abdallah G; Nicolay, Klaas; Prompers, Jeanine J; Strijkers, Gustav J

    2013-03-01

    To assess left ventricular (LV) diastolic function in mice with Cine MRI, a high frame rate (>60 frames per cardiac cycle) is required. For conventional electrocardiography-triggered Cine MRI, the frame rate is inversely proportional to the pulse repetition time (TR). However, TR cannot be lowered at will to increase the frame rate because of gradient hardware, spatial resolution, and signal-to-noise limitations. To overcome these limitations associated with electrocardiography-triggered Cine MRI, in this paper, we introduce a retrospectively triggered Cine MRI protocol capable of producing high-resolution high frame rate Cine MRI of the mouse heart for addressing left ventricular diastolic function. Simulations were performed to investigate the influence of MRI sequence parameters and the k-space filling trajectory in relation to the desired number of frames per cardiac cycle. An optimized protocol was applied in vivo and compared with electrocardiography-triggered Cine for which a high-frame rate could only be achieved by several interleaved acquisitions. Retrospective high frame rate Cine MRI proved superior to the interleaved electrocardiography-triggered protocols. High spatial-resolution Cine movies with frames rates up to 80 frames per cardiac cycle were obtained in 25 min. Analysis of left ventricular filling rate curves allowed accurate determination of early and late filling rates and revealed subtle impairments in left ventricular diastolic function of diabetic mice in comparison with nondiabetic mice. Copyright © 2012 Wiley Periodicals, Inc.

  5. Survival rate in nasopharyngeal carcinoma improved by high caseload volume: a nationwide population-based study in Taiwan

    Directory of Open Access Journals (Sweden)

    Chou Pesus

    2011-08-01

    Full Text Available Abstract Background Positive correlation between caseload and outcome has previously been validated for several procedures and cancer treatments. However, there is no information linking caseload and outcome of nasopharyngeal carcinoma (NPC treatment. We used nationwide population-based data to examine the association between physician case volume and survival rates of patients with NPC. Methods Between 1998 and 2000, a total of 1225 patients were identified from the Taiwan National Health Insurance Research Database. Survival analysis, the Cox proportional hazards model, and propensity score were used to assess the relationship between 10-year survival rates and physician caseloads. Results As the caseload of individual physicians increased, unadjusted 10-year survival rates increased (p p = 0.001 after adjusting for comorbidities, hospital, and treatment modality. When analyzed by propensity score, the adjusted 10-year survival rate differed significantly between patients treated by high-volume physicians and patients treated by low/medium-volume physicians (75% vs. 61%; p Conclusions Our data confirm a positive volume-outcome relationship for NPC. After adjusting for differences in the case mix, our analysis found treatment of NPC by high-volume physicians improved 10-year survival rate.

  6. Differences in the influence of family background and social activities on smoking of minority and white high school seniors, 1976-2004.

    Science.gov (United States)

    Pampel, Fred C

    2008-12-01

    This population-based study of high school seniors examines differences in the influence of several important determinants of smoking among white, African-American, Hispanic, and other teens. With national survey data for each year from 1976 to 2004, logistic regression is used to test for differences across race and ethnic groups (averaged over all years) in the effects on daily smoking of background factors such as living arrangements and parents' education and social activities such as academic performance and religiosity. The results show similarity in effects across racial categories, but some determinants have weaker or reversed effects for African-American and Hispanic youth than for white youth. For example, high parents' education increases smoking among Hispanic youth, has little influence among African Americans, and decreases smoking among whites. These results suggest that smoking patterns of minority teens differ in some ways from those of white teens.

  7. High Spectral Resolution Observation of the Soft Diffuse X-ray Background in the Direction of the Galactic Anti-Center

    Science.gov (United States)

    Wulf, Dallas; Eckart, Mega E.; Galeazzi, Massimiliano; Jaeckel, Felix; Kelley, Richard L.; Kilbourne, Caroline A.; McCammon, Dan; Morgan, Kelsey M.; Porter, Frederick S.; Szymkowiak, Andrew E.

    2018-01-01

    High spectral resolution observations in the soft x-rays are necessary for understanding and modelling the hot component of the interstellar medium and its contribution to the Soft X-ray Background (SXRB). This extended source emission cannot be resolved with most wavelength dispersive spectrometers, making energy dispersive microcalorimeters the ideal choice for these observations. We present here the analysis of the most recent sounding rocket flight of the University of Wisconsin-Madison/Goddard Space Flight Center X-ray Quantum Calorimeter (XQC), a large area silicon thermistor microcalorimeter. This 111 second observation integrates a nearly 1 steradian field of view in the direction of the galactic anti-center (l, b = 165°, -5°) and features ~5 eV spectral resolution below 1 keV. Direct comparison will also be made to the previous, high-latitude observations.

  8. Blood lactate, heart rate and rating of perceived exertion responses of elite surf lifesavers to high-performance competition.

    Science.gov (United States)

    Sinclair, Wade H; Kerr, Rebecca M; Spinks, Warwick L; Leicht, Anthony S

    2009-01-01

    A paucity of empirical research exists into surf lifesaving competition from which coaches and athletes may formulate training and recovery strategies. Seventeen (male=9; female=8) high-performance surf lifesavers (21.2+/-3.9 years) contested multiple rounds of team and individual events at a 2-day surf lifesaving competition. Individual events consisted of the multi-discipline ironman (IRON), paddle board (BOARD) and surf swim (SWIM). Blood lactate (BLa), rating of perceived exertion (RPE) and heart rate (HR) were determined following heats, semi-finals and final. IRON HR and RPE following semi-finals (153.0+/-21.6beatsmin(-1) and 14.4+/-1.5) and final (171.0+/-9.1beatsmin(-1) and 19.1+/-0.2) were greater than heats (141.8+/-17.2beatsmin(-1) and 12.0+/-1.9; psurf lifesavers employ race strategies with all-out maximal exercise limited to semi-finals and finals.

  9. The use of Spark Plasma Sintering method for high-rate diffusion welding of high-strength UFG titanium alloys

    Science.gov (United States)

    Nokhrin, A. V.; Chuvil'deev, V. N.; Boldin, M. S.; Piskunov, A. V.; Kozlova, N. A.; Chegurov, M. K.; Popov, A. A.; Lantcev, E. A.; Kopylov, V. I.; Tabachkova, N. Yu

    2017-07-01

    The article provides an example of applying the technology of spark plasma sintering (SPS) to ensure high-rate diffusion welding of high-strength ultra-fine-grained UFG titanium alloys. Weld seams produced from Ti-5Al-2V UFG titanium alloy and obtained through SPS are characterized by high density, hardness and corrosion resistance.

  10. Development and characterisation of new high-rate muon drift tube detectors

    Energy Technology Data Exchange (ETDEWEB)

    Bittner, Bernhard

    2012-07-25

    With the increase of the LHC luminosity above the design value and the higher background counting rates, detectors in the ATLAS muon spectrometer have to be replaced because the limits of the radiation tolerance will be exceeded. Therefore drift tube chambers with 15 mm tube diameter were developed. The required construction accuracy was verified and the limits of the resolution and efficiency were determined in a muon beam and under gamma irradiation and compared to model expectations.

  11. Comparison of the subjective sense of high or low metabolism and objectively measured resting metabolic rate.

    Science.gov (United States)

    Wallhuss, Andreas; Isik, Markus; Nystrom, Fredrik H

    2010-09-01

    To measure caloric intake, physical activity level and resting metabolic rate in participants having the subjective opinion of either having a high or low metabolic rate. Recruitment by local advertising of healthy subjects feeling that they have high or low metabolism, i.e. either a tendency to easily stay lean ('high') or to very easily gain weight ('low') also when taking food intake in comparison with physical activity into account. Walking distance was estimated by pedometry, assessment of caloric intake was determined by food registration. Measurement of resting metabolic rate was performed in the fasting state. We recruited 44 participants with a sense of 'high' metabolism and 12 subjects in the contrasting group. Subjects with 'high' metabolism were leaner ('high': 20.4 +/- 2.1 kg/m(2), 'low': 27.8 +/- 7.5 kg/m(2), p difference in the measured resting metabolic rate between the two groups ('high': 7230 +/- 1233 kJ/24 h, 'low': 7430 +/- 1422 kJ/24 h, p = 0.6), nor was there any difference in physical activity measured by pedometry. Resting metabolic rate was negatively correlated with age and positively correlated with BMI in multivariate analyses of the total cohort. The sense of having a low or high metabolic rate is not related to actual resting metabolic rate.

  12. Computational modeling of dynamic mechanical properties of pure polycrystalline magnesium under high loading strain rates

    Directory of Open Access Journals (Sweden)

    Li Qizhen

    2015-01-01

    Full Text Available Computational simulations were performed to investigate the dynamic mechanical behavior of pure polycrystalline magnesium under different high loading strain rates with the values of 800, 1000, 2000, and 3600 s−1. The Johnson-Cook model was utilized in the simulations based on finite element modeling. The results showed that the simulations provided well-matched predictions of the material behavior such as the strain rate-time history, the stress-strain curve, and the temperature increase. Under high loading strain rates, the tested material experienced linear strain hardening at the early stage of plastic deformation, increased strain hardening at the intermediate plastic deformation region, and decreased strain hardening at the region before fracture. The strain hardening rates for the studied high loading strain rate cases do not vary much with the change of strain rates.

  13. High Detection Rates of Enteropathogens in Asymptomatic Children Attending Day Care

    NARCIS (Netherlands)

    Enserink, Remko; Scholts, Rianne; Bruijning-Verhagen, Patricia; Duizer, Erwin; Vennema, Harry; de Boer, Richard; Kortbeek, Titia; Roelfsema, Jeroen; Smit, Henriette; Kooistra-Smid, Mirjam; van Pelt, Wilfrid

    2014-01-01

    Background: Gastroenteritis morbidity is high among children under the age of four, especially amongst those who attend day care. Objective: To determine the prevalence of a range of enteropathogens in the intestinal flora of children attending day care and to relate their occurrence with

  14. Cytotoxic therapy for membranous nephropathy and renal insufficiency: improved renal survival but high relapse rate.

    NARCIS (Netherlands)

    Buf-Vereijken, P.W.G. du; Branten, A.J.W.; Wetzels, J.F.M.

    2004-01-01

    BACKGROUND: Patients with idiopathic membranous nephropathy (iMN) and renal insufficiency have a high risk for progression to end-stage renal disease (ESRD). In the short term, treatment with oral cyclophosphamide and steroids attenuates the deterioration of renal function in these patients;

  15. Modeling strong‐motion recordings of the 2010 Mw 8.8 Maule, Chile, earthquake with high stress‐drop subevents and background slip

    Science.gov (United States)

    Frankel, Arthur

    2017-01-01

    Strong‐motion recordings of the Mw 8.8 Maule earthquake were modeled using a compound rupture model consisting of (1) a background slip distribution with large correlation lengths, relatively low slip velocity, and long peak rise time of slip of about 10 s and (2) high stress‐drop subevents (asperities) on the deeper portion of the rupture with moment magnitudes 7.9–8.2, high slip velocity, and rise times of slip of about 2 s. In this model, the high‐frequency energy is not produced in the same location as the peak coseismic slip, but is generated in the deeper part of the rupture zone. Using synthetic seismograms generated for a plane‐layered velocity model, I find that the high stress‐drop subevents explain the observed Fourier spectral amplitude from about 0.1 to 1.0 Hz. Broadband synthetics (0–10 Hz) were calculated by combining deterministic synthetics derived from the background slip and asperities (≤1  Hz) with stochastic synthetics generated only at the asperities (≥1  Hz). The broadband synthetics produced response spectral accelerations with low bias compared to the data, for periods of 0.1–10 s. A subevent stress drop of 200–350 bars for the high‐frequency stochastic synthetics was found to bracket the observed spectral accelerations at frequencies greater than 1 Hz. For most of the stations, the synthetics had durations of the Arias intensity similar to the observed records.

  16. Alterations in lipids & lipid peroxidation in rats fed with flavonoid rich fraction of banana (Musa paradisiaca) from high background radiation area.

    Science.gov (United States)

    Krishnan, Kripa; Vijayalakshmi, N R

    2005-12-01

    A group of villages in Kollam district of Kerala, southern part of India are exposed to a higher dose of natural radiation than global average. Yet no adverse health effects have been found in humans, animals and plants in these areas. The present study was carried out to understand whether radiation affects the quantity and quality of flavonoids in plants grown in this area of high radiation, and to assess the effect of feeding flavonoid rich fraction (FRF) of the two varieties of banana to rats on their biochemical parameters like lipids, lipid peroxides and antioxidant enzyme levels. A total of 42 albino rats were equally divided into 7 groups. Rats fed laboratory diet alone were grouped under group I (normal control). Groups II and V received flavonoid rich fraction (FRF) from the fruits of two varieties of Musa paradisiaca, Palayamkodan and Rasakadali respectively from normal background radiation area (Veli) and treated as controls. Rats of groups III and IV received FRF of Palayamkodan from high background radiation areas (HBRAs) - Neendakara and Karunagappally respectively while groups VI and VII received FRF of Rasakadali from HBRAs. At the end of the experimental period of 45 days, lipids, lipid peroxides and antioxidant enzymes from liver, heart and kidney were analyzed. FRF of Palayamkodan and Rasakadali varieties showed significant hypolipidaemic and antioxidant activities. But these activities were found to be lowered in plants grown in HBRAs, particularly in Karunagappally area. Of the two, Palayamkodan variety was more effective in reducing lipids and lipid peroxides. MDA and hydroperoxides were significantly diminished in rats given FRF of banana from Veli (control area) only. FRF from plants grown in HBRAs exerted inhibition in the activities of antioxidant enzymes in the liver of rats and this inhibitory effect was maximum in rats fed FRF from Karunagappally. Banana grown in HBRAs is of lower quality with less efficient antioxidant system

  17. High rates of denitrification and nitrate removal in cold seep sediments.

    Science.gov (United States)

    Bowles, Marshall; Joye, Samantha

    2011-03-01

    We measured denitrification and nitrate removal rates in cold seep sediments from the Gulf of Mexico. Heterotrophic potential denitrification rates were assayed in time-series incubations. Surficial sediments inhabited by Beggiatoa exhibited higher heterotrophic potential denitrification rates (32 μM N reduced day(-1)) than did deeper sediments (11 μM N reduced day(-1)). Nitrate removal rates were high in both sediment horizons. These nitrate removal rates translate into rapid turnover times (cycling at cold seeps and the requirement for novel mechanisms to provide nitrate to the sediment microbial community.

  18. High sensitivity isotope analysis with a /sup 252/Cf--/sup 235/U fueled subcritical multiplier and low background photon detector systems

    Energy Technology Data Exchange (ETDEWEB)

    Wogman, N.A.; Rieck, H.G. Jr.; Laul, J.C.; MacMurdo, K.W.

    1976-09-01

    A /sup 252/Cf activation analysis facility has been developed for routine multielement analysis of a wide variety of solid and liquid samples. The facility contains six sources of /sup 252/Cf totaling slightly over 100 mg. These sources are placed in a 93 percent /sup 235/U-enriched uranium core which is subcritical with a K effective of 0.985 (multiplication factor of 66). The system produces a thermal flux on the order of 10/sup +1/ neutrons per square centimeter per second. A pneumatic rabbit system permits automatic irradiation, decay, and counting regimes to be performed unattended on the samples. The activated isotopes are analyzed through their photon emissions with state-of-the-art intrinsic Ge detectors, Ge(Li) detectors, and NaI(Tl) multidimensional gamma ray spectrometers. High efficiency (25 percent), low background, anticoincidence shielded Ge(Li) gamma ray detector systems have been constructed to provide the lowest possible background, yet maintain a peak to Compton ratio of greater than 1000 to 1. The multidimensional gamma ray spectrometer systems are composed of 23 cm diameter x 20 cm thick NaI(Tl) crystals surrounded by NaI(Tl) anticoincidence shields. The detection limits for over 65 elements have been determined for this system. Over 40 elements are detectable at the 1 part per million level at a precision of +-10 percent.

  19. High-Rate Fast-Time GRPC for the high eta CMS muon detectors

    CERN Document Server

    Mirabito, Laurent

    2016-01-01

    CMS detector. In their single-gap version we will show that they can stand rates of few ${\\rm kHz/cm}^2$. We also demonstrate that using multi-gap glass RPC, a time resolution of about 60 ps is achieved.

  20. High rates of unsuccessful transfer to adult care among young adults with juvenile idiopathic arthritis

    Directory of Open Access Journals (Sweden)

    Duffy Ciarán M

    2010-01-01

    Full Text Available Abstract Background This study aimed to describe the proportion of patients with juvenile idiopathic arthritis (JIA who had experienced an unsuccessful transfer from a pediatric rheumatology team to an adult rheumatologist and to compare the characteristics of those who achieved successful transfer to those who did not. Methods We conducted a systematic chart review of all patients with JIA who attended their final Montreal Children's Hospital JIA clinic appointment between 1992 and 2005. We tracked these patients for the two years after transfer to an adult rheumatologist. We then compared characteristics of patients with successful and unsuccessful transfers of care. Variables pertaining to disease characteristics, disease severity and psychosocial factors were examined. Univariate analyses were performed to determine if any single factor was associated with the outcome of unsuccessful transfer of care. Results 52% of patients fulfilled our criteria for unsuccessful transfer. Of the variables tested, an active joint count (AJC of zero at last visit was associated with the outcome of unsuccessful transfer (OR = 2.67 (CI 1.16-6.16; p = 0.0199. Conclusions Despite the presence of a coordinated process of transfer from pediatric to adult health care for the majority of the patients in this study, there was a high rate of unsuccessful transfer and/or sustained follow up which is disheartening. We found that patients with less active disease at the time of transfer, as indicated by a lower AJC, were more likely to be lost to follow up. Recent literature suggests that even in the least severe categories of JIA, 50% of patients persist with active disease into adulthood. Thus educating all JIA patients about the possibility of disease flare in adulthood may improve their adherence to recommendations for sustained follow-up in the adult milieu. This may lead to improvement of longitudinal outcomes for all JIA patients.

  1. National High School Athlete Concussion Rates From 2005-2006 to 2011-2012.

    Science.gov (United States)

    Rosenthal, Joseph A; Foraker, Randi E; Collins, Christy L; Comstock, R Dawn

    2014-07-01

    High school athletes are at risk for concussions. Although a previously published study showed an increase in concussion rates for a single school district, it remains unknown if the rate of concussions among high school athletes is increasing nationally. To investigate national high school athlete concussion rates over time. Descriptive epidemiologic study. The rate of concussions per 1000 athlete-exposures was calculated for academic years 2005-2006 through 2011-2012 using the High School Reporting Information Online sports injury surveillance system. During the 7-year period of this study, High School Reporting Information Online captured 4024 concussions with overall concussion diagnosis rates increasing significantly from 0.23 to 0.51 (P = .004). Concussion diagnosis rates increased for each of the 9 sports studied, with 5 sports having statistically significant increases over this 7-year period. The study analysis indicates that national concussion diagnosis rates for high school sports have increased significantly over time. © 2014 The Author(s).

  2. High speed and adaptable error correction for megabit/s rate quantum key distribution.

    Science.gov (United States)

    Dixon, A R; Sato, H

    2014-12-02

    Quantum Key Distribution is moving from its theoretical foundation of unconditional security to rapidly approaching real world installations. A significant part of this move is the orders of magnitude increases in the rate at which secure key bits are distributed. However, these advances have mostly been confined to the physical hardware stage of QKD, with software post-processing often being unable to support the high raw bit rates. In a complete implementation this leads to a bottleneck limiting the final secure key rate of the system unnecessarily. Here we report details of equally high rate error correction which is further adaptable to maximise the secure key rate under a range of different operating conditions. The error correction is implemented both in CPU and GPU using a bi-directional LDPC approach and can provide 90-94% of the ideal secure key rate over all fibre distances from 0-80 km.

  3. High hydrogen production rate of microbial electrolysis cell (MEC) with reduced electrode spacing.

    Science.gov (United States)

    Cheng, Shaoan; Logan, Bruce E

    2011-02-01

    Practical applications of microbial electrolysis cells (MECs) require high hydrogen production rates and a compact reactor. These goals can be achieved by reducing electrode spacing but high surface area anodes are needed. The brush anode MEC with electrode spacing of 2 cm had a higher hydrogen production rate and energy efficiency than an MEC with a flat cathode and a 1-cm electrode spacing. The maximum hydrogen production rate with a 2 cm electrode spacing was 17.8 m(3)/m(3)d at an applied voltage of E(ap)=1 V. Reducing electrode spacing increased hydrogen production rates at the lower applied voltages, but not at the higher (>0.6 V) applied voltages. These results demonstrate that reducing electrode spacing can increase hydrogen production rate, but that the closest electrode spacing do not necessarily produce the highest possible hydrogen production rates. Copyright © 2010 Elsevier Ltd. All rights reserved.

  4. Generation of µW level plateau harmonics at high repetition rate.

    Science.gov (United States)

    Hädrich, S; Krebs, M; Rothhardt, J; Carstens, H; Demmler, S; Limpert, J; Tünnermann, A

    2011-09-26

    The process of high harmonic generation allows for coherent transfer of infrared laser light to the extreme ultraviolet spectral range opening a variety of applications. The low conversion efficiency of this process calls for optimization or higher repetition rate intense ultrashort pulse lasers. Here we present state-of-the-art fiber laser systems for the generation of high harmonics up to 1 MHz repetition rate. We perform measurements of the average power with a calibrated spectrometer and achieved µW harmonics between 45 nm and 61 nm (H23-H17) at a repetition rate of 50 kHz. Additionally, we show the potential for few-cycle pulses at high average power and repetition rate that may enable water-window harmonics at unprecedented repetition rate. © 2011 Optical Society of America

  5. Mechanical Properties of Transgenic Silkworm Silk Under High Strain Rate Tensile Loading

    Science.gov (United States)

    Chu, J.-M.; Claus, B.; Chen, W.

    2017-12-01

    Studies have shown that transgenic silkworm silk may be capable of having similar properties of spider silk while being mass-producible. In this research, the tensile stress-strain response of transgenic silkworm silk fiber is systematically characterized using a quasi-static load frame and a tension Kolsky bar over a range of strain-rates between 10^{-3} and 700/s. The results show that transgenic silkworm silk tends to have higher overall ultimate stress and failure strain at high strain rate (700/s) compared to quasi-static strain rates, indicating rate sensitivity of the material. The failure strain at the high strain rate is higher than that of spider silk. However, the stress levels are significantly below that of spider silk, and far below that of high-performance fiber. Failure surfaces are examined via scanning electron microscopy and reveal that the failure modes are similar to those of spider silk.

  6. Time-Efficient High-Rate Data Flooding in One-Dimensional Acoustic Underwater Sensor Networks

    Directory of Open Access Journals (Sweden)

    Jae Kyun Kwon

    2015-10-01

    Full Text Available Because underwater communication environments have poor characteristics, such as severe attenuation, large propagation delays and narrow bandwidths, data is normally transmitted at low rates through acoustic waves. On the other hand, as high traffic has recently been required in diverse areas, high rate transmission has become necessary. In this paper, transmission/reception timing schemes that maximize the time axis use efficiency to improve the resource efficiency for high rate transmission are proposed. The excellence of the proposed scheme is identified by examining the power distributions by node, rate bounds, power levels depending on the rates and number of nodes, and network split gains through mathematical analysis and numerical results. In addition, the simulation results show that the proposed scheme outperforms the existing packet train method.

  7. Mechanical Properties of Transgenic Silkworm Silk Under High Strain Rate Tensile Loading

    Science.gov (United States)

    Chu, J.-M.; Claus, B.; Chen, W.

    2017-09-01

    Studies have shown that transgenic silkworm silk may be capable of having similar properties of spider silk while being mass-producible. In this research, the tensile stress-strain response of transgenic silkworm silk fiber is systematically characterized using a quasi-static load frame and a tension Kolsky bar over a range of strain-rates between 10^{-3} and 700/s. The results show that transgenic silkworm silk tends to have higher overall ultimate stress and failure strain at high strain rate (700/s) compared to quasi-static strain rates, indicating rate sensitivity of the material. The failure strain at the high strain rate is higher than that of spider silk. However, the stress levels are significantly below that of spider silk, and far below that of high-performance fiber. Failure surfaces are examined via scanning electron microscopy and reveal that the failure modes are similar to those of spider silk.

  8. High rates of catalytic hydrogen combustion with air over Ti ₀. ₉₇Pd ...

    Indian Academy of Sciences (India)

    High rates of catalytic hydrogen combustion with air over Ti ₀. ... For 50 mL of H ₂, it showed rates of the reaction around 36.45 μmol/g/s at room temperature and 230 μmol/g/s at 60◦C. It was found that the rate of reaction due ... Finally, we propose a mechanism of hydrogen and oxygen recombination reaction over Ti ₀.

  9. High strain-rate compressive behavior and constitutive modeling of selected polymers

    OpenAIRE

    Yokoyama T; Nakai K

    2012-01-01

    The present paper deals with constitutive modeling of the compressive stress-strain behavior of selected polymers at strain rates from 10−3 to 103/s using a modified Ramberg-Osgood equation. High strain-rate compressive stress-strain curves for four different commercially available extruded polymers are determined on the standard split Hopkinson pressure bar. The low and intermediate strain-rates compressive stress-strain relations are measured in an Instron testing machine. The five paramete...

  10. Effects of high, low, and thinning rates of alternative reinforcement on response elimination and resurgence.

    Science.gov (United States)

    Sweeney, Mary M; Shahan, Timothy A

    2013-07-01

    A common treatment for operant problem behavior is alternative reinforcement. When alternative reinforcement is removed or reduced, however, resurgence of the target behavior can occur. Shahan and Sweeney (2011) developed a quantitative model of resurgence based on behavioral momentum theory that suggests higher rates of alternative reinforcement result in faster response elimination and greater resurgence when removed, whereas lower rates of alternative reinforcement result in slower response elimination but are followed by less resurgence. Thus, the present study was designed to examine whether faster target response elimination and less resurgence could be achieved by beginning with a high rate of alternative reinforcement and gradually thinning it such that a low rate is ultimately removed during a simulated treatment lapse. Results showed that high rates of alternative reinforcement were more effective than low or thinning rates at target response suppression but resulted in resurgence when discontinued. Low and thinning rates, on the other hand, were less effective at response suppression but target responding did not increase when alternative reinforcement was discontinued. The quantitative model cannot currently account for the finding that lower-rate alternative reinforcement may not effectively disrupt behavior relative to an extinction only control. Relative advantages of high, low, thinning, or no alternative reinforcement are discussed with respect to suppression of target response rate during treatment, resurgence when alternative reinforcement is removed, and alternative response persistence, while taking into account differences between this animal model and modern applied behavior analytic treatments. © Society for the Experimental Analysis of Behavior.

  11. High mortgage rates in the Low Countries: what happened in the Spring of 2009?

    NARCIS (Netherlands)

    Dijkstra, M.A.; Randag, F.; Schinkel, M.P.

    2014-01-01

    Since the Spring of 2009, Dutch mortgage rates have been structurally high, both in comparison to the rest of Europe and to funding costs. This paper reviews the debate on possible causes, which are of two kinds: (i) the higher mortgage rates reflect higher funding costs; and (ii) softer competition

  12. High frame rate retrospectively triggered Cine MRI for assessment of murine diastolic function

    NARCIS (Netherlands)

    Coolen, Bram F.; Abdurrachim, Desiree; Motaal, Abdallah G.; Nicolay, Klaas; Prompers, Jeanine J.; Strijkers, Gustav J.

    2013-01-01

    To assess left ventricular (LV) diastolic function in mice with Cine MRI, a high frame rate (>60 frames per cardiac cycle) is required. For conventional electrocardiography-triggered Cine MRI, the frame rate is inversely proportional to the pulse repetition time (TR). However, TR cannot be lowered

  13. HIGH STRAIN RATE BEHAVIOUR OF AN AZ31 + 0.5 Ca MAGNESIUM ALLOY

    Directory of Open Access Journals (Sweden)

    Josef Pešička

    2012-01-01

    Full Text Available The paper reports behaviour of magnesium alloy AZ31 (nominal composition 3 % Al - 1 % Zn – balance Mg with an addition of 0.5 wt. % Ca at high strain rates. Samples were prepared by the squeeze cast technology. Dynamic compression Hopkinson tests were performed at room temperature with impact velocities ranging from 11.2 to 21.9 m.s-1. A rapid increase of the flow stress and the strain rate sensitivity was observed at high strain rates. Transmission electron microscopy showed extremely high dislocation density and mechanical twins of two types. Adiabatic shear banding is discussed as the reason for the observed behaviour at high strain rates.

  14. High Rate Plastic Deformation and Failure of Tungsten-Sintered Metals

    National Research Council Canada - National Science Library

    Bjerke, Todd

    2004-01-01

    The competition between plastic deformation and brittle fracture during high rate loading of a tungsten-sintered metal is examined through impact experiments, post-experiment microscopy, and numerical simulation...

  15. High Energy Single Frequency Fiber Laser at Low Repetition Rate Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR phase II project proposes a single frequency high energy fiber laser system operating at low repetition rate of 10 Hz to 1 kHz for coherent Lidar systems...

  16. Feeding an infant with high arched palate by high flow rate bottle nipple.

    Science.gov (United States)

    Eren, Abdulkadir; Bilgin, Huseyin; Kara, Semra

    2015-01-01

    For infants with high arched palate, feeding is one of the most immediate challenges faced by parents and caretakers. General suggestions for feeding in infants with cleft palate may be adapted to infants with high arched palate. These include oral feeding facilitation techniques and special feeding tools. Here we present a newborn with a high arched palate and serious feeding problems who was fed easily by a large size and a large hole nipple, ordinarily used for infants older than 6 months, instead of specialized feeding equipment.

  17. Worksite interventions for preventing physical deterioration among employees in job-groups with high physical work demands: Background, design and conceptual model of FINALE

    Directory of Open Access Journals (Sweden)

    Mortensen Ole S

    2010-03-01

    Full Text Available Abstract Background A mismatch between individual physical capacities and physical work demands enhance the risk for musculoskeletal disorders, poor work ability and sickness absence, termed physical deterioration. However, effective intervention strategies for preventing physical deterioration in job groups with high physical demands remains to be established. This paper describes the background, design and conceptual model of the FINALE programme, a framework for health promoting interventions at 4 Danish job groups (i.e. cleaners, health-care workers, construction workers and industrial workers characterized by high physical work demands, musculoskeletal disorders, poor work ability and sickness absence. Methods/Design A novel approach of the FINALE programme is that the interventions, i.e. 3 randomized controlled trials (RCT and 1 exploratory case-control study are tailored to the physical work demands, physical capacities and health profile of workers in each job-group. The RCT among cleaners, characterized by repetitive work tasks and musculoskeletal disorders, aims at making the cleaners less susceptible to musculoskeletal disorders by physical coordination training or cognitive behavioral theory based training (CBTr. Because health-care workers are reported to have high prevalence of overweight and heavy lifts, the aim of the RCT is long-term weight-loss by combined physical exercise training, CBTr and diet. Construction work, characterized by heavy lifting, pushing and pulling, the RCT aims at improving physical capacity and promoting musculoskeletal and cardiovascular health. At the industrial work-place characterized by repetitive work tasks, the intervention aims at reducing physical exertion and musculoskeletal disorders by combined physical exercise training, CBTr and participatory ergonomics. The overall aim of the FINALE programme is to improve the safety margin between individual resources (i.e. physical capacities, and

  18. Laryngeal High-Speed Videoendoscopy: Sensitivity of Objective Parameters towards Recording Frame Rate

    Directory of Open Access Journals (Sweden)

    Anne Schützenberger

    2016-01-01

    Full Text Available The current use of laryngeal high-speed videoendoscopy in clinic settings involves subjective visual assessment of vocal fold vibratory characteristics. However, objective quantification of vocal fold vibrations for evidence-based diagnosis and therapy is desired, and objective parameters assessing laryngeal dynamics have therefore been suggested. This study investigated the sensitivity of the objective parameters and their dependence on recording frame rate. A total of 300 endoscopic high-speed videos with recording frame rates between 1000 and 15 000 fps were analyzed for a vocally healthy female subject during sustained phonation. Twenty parameters, representing laryngeal dynamics, were computed. Four different parameter characteristics were found: parameters showing no change with increasing frame rate; parameters changing up to a certain frame rate, but then remaining constant; parameters remaining constant within a particular range of recording frame rates; and parameters changing with nearly every frame rate. The results suggest that (1 parameter values are influenced by recording frame rates and different parameters have varying sensitivities to recording frame rate; (2 normative values should be determined based on recording frame rates; and (3 the typically used recording frame rate of 4000 fps seems to be too low to distinguish accurately certain characteristics of the human phonation process in detail.

  19. Adhesives: Test Method, Group Assignment, and Categorization Guide for High-Loading-Rate Applications

    Science.gov (United States)

    2014-06-01

    Apparent Shear Strength of Single- Lap -Joint Adhesively Bonded Metal Specimens by Tension Loading [Metal- to-Metal]).5 Samples are to be stored in a...the Army, Washington, DC, 2 October 2007. 5. ASTM Standard D1002-10 "Standard Test Method for Apparent Shear Strength of Single- Lap -Joint Adhesively ... adhesives for high-loading-rate applications relevant to U.S. Army needs. 15. SUBJECT TERMS adhesive , testing, single lap joint, high loading rate

  20. Parasympathetic neural activity accounts for the lowering of exercise heart rate at high altitude

    DEFF Research Database (Denmark)

    Boushel, Robert Christopher; Calbet, J A; Rådegran, G

    2001-01-01

    In chronic hypoxia, both heart rate (HR) and cardiac output (Q) are reduced during exercise. The role of parasympathetic neural activity in lowering HR is unresolved, and its influence on Q and oxygen transport at high altitude has never been studied.......In chronic hypoxia, both heart rate (HR) and cardiac output (Q) are reduced during exercise. The role of parasympathetic neural activity in lowering HR is unresolved, and its influence on Q and oxygen transport at high altitude has never been studied....

  1. High-sensitive spectrometer of fast neutrons and the results of fast neutron background flux measurements at the Gallium-Germanium Solar Neutrino Experiment

    CERN Document Server

    Abdurashitov, J N; Kalikhov, A V; Matushko, V L; Shikhin, A A; Yants, V E; Zaborskaia, O S

    2002-01-01

    The principle of operation, design, registration system and main characteristics of a fast neutron spectrometer are described. The spectrometer is intended for direct measurements of ultra low fluxes of fast neutrons. It is sensitive to neutron fluxes of 10 sup - sup 7 cm sup - sup 2 s sup - sup 1 and lower. The detection efficiency of fast neutrons with simultaneous energy measurement was determined from Monte-Carlo simulation to be equal to 0.11+-0.01. The background counting rate in the detector corresponds to a neutron flux of (6.5+-2.1)x10 sup - sup 7 cm sup - sup 2 s sup - sup 1 in the range 1.0-11.0 MeV. The natural neutron flux from the surrounding mine rock at the depth of 4600 m of water equivalent was measured to be (7.3+-2.4)x10 sup - sup 7 cm sup - sup 2 s sup - sup 1 in the range 1.0-11.0 MeV. The flux of fast neutrons in the SAGE main room was measured to be <2.3x10 sup - sup 7 cm sup - sup 2 s sup - sup 1 in 1.0-11.0 MeV energy range.

  2. Effect of algal recycling rate on the performance of Pediastrum boryanum dominated wastewater treatment high rate algal pond.

    Science.gov (United States)

    Park, J B K; Craggs, R J

    2014-01-01

    Recycling a portion of gravity harvested algae promoted the dominance of a rapidly settling colonial alga, Pediastrum boryanum (P. boryanum) and improved both biomass productivity and settleability in High Rate Algal Pond (HRAP) treating domestic wastewater. The effect of algal recycling rate on HRAP performance was investigated using 12 replicate mesocosms (18 L) that were operated semi-continuously under ambient conditions. Three experiments were conducted during different seasons with each experiment lasting up to 36 days. Recycling 10%, 25%, and 50% of the 'mass' of daily algal production all increased total biomass concentration in the mesocosms. However, recycling >10% reduced the organic content (volatile suspended solids (VSS)) of the mesocosm biomass from 83% to 68% and did not further increase biomass productivity (based on VSS). This indicates that if a HRAP is operated with a low algal concentration and does not utilise all the available sunlight, algal recycling increases the algal concentration up to an optimum level, resulting in higher algal biomass productivity. Recycling 10% of the daily algal production not only increased biomass productivity by ∼40%, but increased biomass settleability by ∼25%, which was probably a consequence of the ∼30% increase in P. boryanum dominance in the mesocosms compared with controls without recycling.

  3. Investigation of a reacting jet injected into vitiated crossflow using CARS, high repetition rate OH-PLIF, and high repetition rate PIV

    Science.gov (United States)

    Roa, Mario

    The proposed PhD thesis research program will be carried out in a staged combustion test rig developed with funding from Siemens Power Generation Inc. and the United States Department of Energy. This research program will study the reacting flow field created by an injector that is axially distributed along the combustor with use the laser diagnostics methods: Coherent Anti-Stokes Raman Spectroscopy (CARS), high repetition rate OH Planar Laser Induced Florescence (OHPLIF), and high repetition rate Particle Image Velocimetry (PIV), to determine why certain conditions result in low NOx emissions. This data will be used to validated the development of more precise computer models. These laser diagnostic techniques will be applied to the reacting jet produced using an extended, premixed 10 mm injector using both natural gas (NG) and hydrogen (H2) as fuels. The objective of this thesis research is to use advance laser diagnostics to gain insight into the reacting flow field resulting form transverse injection into a vitiated cross flow. The advance laser diagnostics will also provide insight into pollution formation mechanisms and will be used for validating CFD models of the transverse jet injection. The following measurements will be performed: (1) dual pump nitrogen/hydrogen (H2/ N2) CARS at the midplane of the extended 10 mm nozzle, (2) high repetition rate OH-PLIF and emission sampling for the same extended nozzle using NG and H2 as secondary fuel, (3) and combing both high repetition OH-PLIF and high repetition rate PIV for extended 10 mm nozzle for both NG and H2 secondary fuel. The PIV measurements will be combined with OH-PLIF in a simultaneous manner, with the OH fluorescence centered between the two PIV laser pulses. The dual pump H2/N2 CARS system will be used to measure both temperature of the reacting jet and the species concentration ratio of H2/ N2. The high repetition rate OH-PLIF, conducted with a 5 kHz, dual cavity Nd:YAG laser that optically pumps a

  4. Indirect high-bandwidth stabilization of carrier-envelope phase of a high-energy, low-repetition-rate laser.

    Science.gov (United States)

    Fu, Yuxi; Takahashi, Eiji J; Midorikawa, Katsumi

    2016-06-13

    We demonstrate a method of stabilizing the carrier-envelope phase (CEP) of low-repetition-rate, high-energy femtosecond laser systems such as TW-PW class lasers. A relatively weak high-repetition-rate (~1 kHz) reference pulse copropagates with a low-repetition-rate (10 Hz) high-energy pulse, which are s- and p-polarized, respectively. Using a Brewster angle window, the reference pulse is separated after the power amplifier and used for feedback to stabilize its CEP. The single-shot CEP of the high-energy pulse is indirectly stabilized to 550 mrad RMS, which is the highest CEP stability ever reported for a low-repetition-rate (10-Hz) high-energy laser system. In this novel method, the feedback frequency of the reference pulse from the front-end preamplifier can be almost preserved. Thus, higher CEP stability can be realized than for lower frequencies. Of course, a reference pulse with an even higher repetition rate (e.g., 10 kHz) can be easily employed to sample and feed back CEP jitter over a broader frequency bandwidth.

  5. Test Method for High β Particle Emission Rate of 63Ni Source Plate

    Directory of Open Access Journals (Sweden)

    ZHANG Li-feng

    2015-01-01

    Full Text Available For the problem of measurement difficulties of β particle emission rate of Ni-63 source plate used for Ni-63 betavoltaic battery, a relative test method of scintillation current method was erected according to the measurement principle of scintillation detector.β particle emission rate of homemade Ni-63 source plate was tested by the method, and the test results were analysed and evaluated, it was initially thought that scintillation current method was a feasible way of testing β particle emission rate of Ni-63 source plate with high β particle emission rate.

  6. Instantaneous rate of loading during manual high-velocity, low-amplitude spinal manipulations.

    Science.gov (United States)

    Gudavalli, Maruti Ram

    2014-06-01

    The objective of this study was to determine the instantaneous rate of loading during manual high-velocity, low-amplitude spinal manipulations (HVLA SMs) in the lumbar and thoracic regions and compare to the average rates of loading. Force-time profiles were recorded using a hand force transducer placed between the hand of a doctor of chiropractic and the subject's back during 14 HVLA SM thrusts on asymptomatic volunteers while 3 doctors of chiropractic delivered the spinal manipulations. Doctors also delivered 36 posterior to anterior thoracic manipulations on a mannequin. Data were collected at a sampling rate of 1000 Hz using Motion Monitor software. Force-time profile data were differentiated to obtain instantaneous rates of loading. The data were reduced using a custom-written MathCad program and analyzed descriptively. The instantaneous rates of loading were 1.7 to 1.8 times higher than average rates of loading, and instantaneous rates of unloading were 2.1 to 2.6 times the average rates of unloading during HVLA SMs. Maximum instantaneous rates of loading occurred 102 to 111 milliseconds prior to peak load. Maximum instantaneous rates of unloading occurred 121 to 154 milliseconds after the peak load. These data may be useful for further understanding of HVLA SMs. The instantaneous rates of loading and where they occurred may be useful data for understanding and describing HVLA SMs. Copyright © 2014 National University of Health Sciences. Published by Mosby, Inc. All rights reserved.

  7. Experimental Investigation on Minimum Frame Rate Requirements of High-Speed Videoendoscopy for Clinical Voice Assessment.

    Science.gov (United States)

    Deliyski, Dimitar D; Powell, Maria Eg; Zacharias, Stephanie Rc; Gerlach, Terri Treman; de Alarcon, Alessandro

    2015-03-01

    This study investigated the impact of high-speed videoendoscopy (HSV) frame rates on the assessment of nine clinically-relevant vocal-fold vibratory features. Fourteen adult patients with voice disorder and 14 adult normal controls were recorded using monochromatic rigid HSV at a rate of 16000 frames per second (fps) and spatial resolution of 639×639 pixels. The 16000-fps data were downsampled to 16 other rate denominations. Using paired comparisons design, nine common clinical vibratory features were visually compared between the downsampled and the original images. Three raters reported the thresholds at which: (1) a detectable difference between the two videos was first noticed, and (2) differences between the two videos would result in a change of clinical rating. Results indicated that glottal edge, mucosal wave magnitude and extent, aperiodicity, contact and loss of contact of the vocal folds were the vibratory features most sensitive to frame rate. Of these vibratory features, the glottal edge was selected for further analysis, due to its higher rating reliability, universal prevalence and consistent definition. Rates of 8000 fps were found to be free from visually-perceivable feature degradation, and for rates of 5333 fps, degradation was minimal. For rates of 4000 fps and higher, clinical assessments of glottal edge were not affected. Rates of 2000 fps changed the clinical ratings in over 16% of the samples, which could lead to inaccurate functional assessment.

  8. Micro-Structural Response of DP 600 to High Strain Rate Deformation

    Science.gov (United States)

    Hamburg, Brian; Schneider, Judy; Jones, Stanley E.

    2008-01-01

    The object of this study was to investigate the micro-structural response of DP 600 subjected to high strain rate, ballistic impact tests. The ballistic tests were conducted using normal impact of a hardened steel penetrator into a 2 mm thick sheet of DP 600. The average strain rates produced from this test method are on the order of 10(exp 5)/s. Electron microscopy was used to investigate the microstructure before and after high strain rate deformation. A variation in material response was observed between tests conducted at 0.8 x 105 and 25 x 10(exp 5)/s.

  9. Experimental verification of corrosive vapor deposition rate theory in high velocity burner rigs

    Science.gov (United States)

    Gokoglu, S. A.; Santoro, G. J.

    1986-01-01

    The ability to predict deposition rates is required to facilitate modelling of high temperature corrosion by fused salt condensates in turbine engines. A corrosive salt vapor deposition theory based on multicomponent chemically frozen boundary layers (CFBL) has been successfully verified by high velocity burner rig experiments. The experiments involved internally air-impingement cooled, both rotating full and stationary segmented cylindrical collectors located in the crossflow of sodium-seeded combustion gases. Excellent agreement is found between the CFBL theory an the experimental measurements for both the absolute amounts of Na2SO4 deposition rates and the behavior of deposition rate with respect to collector temperature, mass flowrate (velocity) and Na concentration.

  10. Development of wide-range constitutive equations for calculations of high-rate deformation of metals

    Directory of Open Access Journals (Sweden)

    Preston D.

    2011-01-01

    Full Text Available For development of models of strength and compressibility of metals in wide range of pressures (up to several megabar and strain rates ~ 1÷108 s−1, the method of dynamic tests is used. Since direct measurement of strength is impossible under complicated intensive high-rate loading, a formal model is created at first, and then it is updated basing on comparison with many experiments, which are sensitive to shear strength. Elastic-plastic, viscous-elastic-plastic and relaxation integral models became nowadays most commonly used. The basic unsolved problems in simulation of high-rate deformation of metals are mentioned in the paper.

  11. Problems and solutions in high-rate multichannel hybrid photodiode design The CMS experience

    CERN Document Server

    Cushman, P B

    2002-01-01

    The unique conditions of the CMS experiment (4 T magnetic field, restricted access, high neutron radiation, and 25-ns bunch-crossings) necessitated the development of a new type of high-rate multichannel hybrid photodiode for the tile/fiber hadronic calorimeter. New complexities arose in the push toward high-rate operation, necessitating design changes in the diode structure and surface treatment. The product is now capable of high-rate operation with low crosstalk and leakage current. Lifetime studies of high-voltage behavior, total charge, and irradiation have shown that the tubes will survive the ten years of CMS running with only a few percent change in gain and manageable leakage current rise. (13 refs).

  12. Biosorption of cadmium by Brevundimonas sp. ZF12 strain, a novel biosorbent isolated from hot-spring waters in high background radiation areas

    Energy Technology Data Exchange (ETDEWEB)

    Masoudzadeh, Nasrin [Department of Molecular Genetics, National Institute of Genetic Engineering and Biotechnology (NIGEB), P.O. Box 14155-6343, Tehran (Iran, Islamic Republic of); Department of Biology, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Zakeri, Fardideh [Department of Molecular Genetics, National Institute of Genetic Engineering and Biotechnology (NIGEB), P.O. Box 14155-6343, Tehran (Iran, Islamic Republic of); National Radiation Protection Department - Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of); Lotfabad, Tayebe bagheri [Department of Molecular Genetics, National Institute of Genetic Engineering and Biotechnology (NIGEB), P.O. Box 14155-6343, Tehran (Iran, Islamic Republic of); Sharafi, Hakimeh [Department of Molecular Genetics, National Institute of Genetic Engineering and Biotechnology (NIGEB), P.O. Box 14155-6343, Tehran (Iran, Islamic Republic of); Department of Biology, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Masoomi, Fatemeh; Zahiri, Hoseein Shahbani; Ahmadian, Gholamreza [Department of Molecular Genetics, National Institute of Genetic Engineering and Biotechnology (NIGEB), P.O. Box 14155-6343, Tehran (Iran, Islamic Republic of); Noghabi, Kambiz Akbari, E-mail: Akbari@nigeb.ac.ir [Department of Molecular Genetics, National Institute of Genetic Engineering and Biotechnology (NIGEB), P.O. Box 14155-6343, Tehran (Iran, Islamic Republic of)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer Isolation and characterization of a novel cadmium-biosorbent (Brevundimonas sp. ZF12) from high background radiation areas. Black-Right-Pointing-Pointer Brevundimonas sp. ZF12 caused 50% removal of cadmium at the concentration level of 250 ppm. Black-Right-Pointing-Pointer Solution pH values used for the reusability study have powerful desorptive features to recover Cd ions sorbed onto the biomass. Black-Right-Pointing-Pointer This is the first study carried out so far for the cadmium removal from aqueous solutions by a novel biosorbent Brevundimonas sp. ZF12. Black-Right-Pointing-Pointer In our opinion, the isolate can be an attractive alternative to remove the cadmium-containing wastewaters. - Abstract: The aim of this study is to screen cadmium biosorbing bacterial strains isolated from soils and hot-springs containing high concentrations of radium ({sup 226}Ra) in Ramsar using a batch system. Brevundimonas sp. ZF12 strain isolated from the water with high {sup 226}Ra content caused 50% removal of cadmium at a concentration level of 250 ppm. The biosorption equilibrium data are fitted well by the Langmuir adsorption isotherm and kinetic studies indicated that the biosorption follows pseudo second-order model. The effect of different physico-chemical parameters like biomass concentration, pH, cadmium concentration, temperature and contact time on cadmium sorption was also investigated using FTIR, SEM and XRD analytical techniques. A high desorption efficiency (above 90%) was obtained using a pH range of 2.0-4.0. Reusability of the biomass was examined under consecutive biosorption-desorption cycles repeated thrice. In conclusion, Brevundimonas sp. ZF12 is proposed as an excellent cadmium biosorbent that may have important applications in Cd removal from wastewaters.

  13. Development of a silicone ablator for high-heat-flux and high-shear-rate condition

    Science.gov (United States)

    Campbell, R. A.; Ramseyer, J. A.; Huntress, A.

    1972-01-01

    A silicone material was developed which gives suitable ablative protection in the high heat flux, high shear environments encountered in severe reentry applications, such as nose cones for ballistic vehicles and protection of leading edges or other critical areas of a vehicle. In addition, the ease of handling, low application cost, and room temperature cure make such a silicon material suitable nozzles for the large rockets necessary for vehicle launching. The development of this product is traced from the selection of suitable polymers through the choice of fillers and the finalization of filler loadings.

  14. Stabilizing HIV prevalence masks high HIV incidence rates amongst rural and urban women in KwaZulu-Natal, South Africa

    OpenAIRE

    Karim, Quarraisha Abdool; Kharsany, Ayesha BM; Frohlich, Janet A; Werner, Lise; Mashego, May; Mlotshwa, Mukelisiwe; Madlala, Bernadette T; Ntombela, Fanelesibonge; Abdool Karim, Salim S

    2010-01-01

    Background In mature generalized human immunodeficiency virus (HIV) epidemics, as survival from accessing antiretroviral treatment (ART) increases, HIV prevalence data may be suboptimal and difficult to interpret without HIV incidence rates.

  15. Lower implantation rates in high responders: evidence for an altered endocrine milieu during the preimplantation period.

    Science.gov (United States)

    Pellicer, A; Valbuena, D; Cano, F; Remohí, J; Simón, C

    1996-06-01

    To determine serum E2 and P levels around the time of implantation in normal and high IVF responders. In Vitro Fertilization program at the Instituto Valenciano de Infertilidad. Twenty-nine women undergoing IVF, who accepted to be studied daily, were classified according to the number of oocytes retrieved in normal (n = 16) and high responders (n = 13). Prospective study in which blood was drawn daily from the day of hCG administration (day 0) up to 7 days later (day 6). In vitro fertilization parameters (number of ampules, FSH-hMG, number of oocytes, fertilization rates, number of transferred embryos, implantation rates, and pregnancy rates); serum E2 and P levels during the 7 days of the study. Implantation rate was significantly higher in normal (18.5%) as compared with high (0%) responders. Estradiol and P levels were elevated significantly in high responders. The E2:P ratio was significantly different between normal and high responders during the preimplantation period. Pregnancy and implantation rates decreased as serum E2 levels increased on days 4 to 6 of the study. A different endocrine milieu between normal and high responders is detected by daily steroid measurements up to the preimplantation period, suggesting that this difference could be responsible for an impaired implantation in high responder patients undergoing IVF. An increase in serum E2 levels seems to be the cause of this difference.

  16. Cosmic Microwave Background as a Thermal Gas of SU(2 Photons: Implications for the High-z Cosmological Model and the Value of H0

    Directory of Open Access Journals (Sweden)

    Steffen Hahn

    2017-01-01

    Full Text Available Presently, we are facing a 3σ tension in the most basic cosmological parameter, the Hubble constant H0. This tension arises when fitting the Lambda-cold-dark-matter model (ΛCDM to the high-precision temperature-temperature (TT power spectrum of the Cosmic Microwave Background (CMB and to local cosmological observations. We propose a resolution of this problem by postulating that the thermal photon gas of the CMB obeys an SU(2 rather than U(1 gauge principle, suggesting a high-z cosmological model which is void of dark-matter. Observationally, we rely on precise low-frequency intensity measurements in the CMB spectrum and on a recent model independent (low-z extraction of the relation between the comoving sound horizon rs at the end of the baryon drag epoch and H0 (rsH0=const. We point out that the commonly employed condition for baryon-velocity freeze-out is imprecise, judged by a careful inspection of the formal solution to the associated Euler equation. As a consequence, the above-mentioned 3σ tension actually transforms into a 5σ discrepancy. To make contact with successful low-z  ΛCDM cosmology we propose an interpolation based on percolated/depercolated vortices of a Planck-scale axion condensate. For a first consistency test of such an all-z model we compute the angular scale of the sound horizon at photon decoupling.

  17. Brittle materials at high-loading rates: an open area of research

    Science.gov (United States)

    Forquin, Pascal

    2017-01-01

    Brittle materials are extensively used in many civil and military applications involving high-strain-rate loadings such as: blasting or percussive drilling of rocks, ballistic impact against ceramic armour or transparent windshields, plastic explosives used to damage or destroy concrete structures, soft or hard impacts against concrete structures and so on. With all of these applications, brittle materials are subjected to intense loadings characterized by medium to extremely high strain rates (few tens to several tens of thousands per second) leading to extreme and/or specific damage modes such as multiple fragmentation, dynamic cracking, pore collapse, shearing, mode II fracturing and/or microplasticity mechanisms in the material. Additionally, brittle materials exhibit complex features such as a strong strain-rate sensitivity and confining pressure sensitivity that justify expending greater research efforts to understand these complex features. Currently, the most popular dynamic testing techniques used for this are based on the use of split Hopkinson pressure bar methodologies and/or plate-impact testing methods. However, these methods do have some critical limitations and drawbacks when used to investigate the behaviour of brittle materials at high loading rates. The present theme issue of Philosophical Transactions A provides an overview of the latest experimental methods and numerical tools that are currently being developed to investigate the behaviour of brittle materials at high loading rates. This article is part of the themed issue 'Experimental testing and modelling of brittle materials at high strain rates'.

  18. Local Access to Family Planning Services and Female High School Dropout Rates.

    Science.gov (United States)

    Hicks-Courant, Katherine; Schwartz, Aaron L

    2016-04-01

    To assess whether geographic access to family planning services is associated with a reduced female high school dropout rate. We conducted a retrospective cross-sectional study. We merged the location of Planned Parenthood and Title X clinics with microdata from the 2012-2013 American Community Surveys. The association between female high school dropout rates and local clinic access was assessed using nearest-neighbor matching estimation. Models included various covariates to account for sociodemographic differences across communities and male high school dropout rates to account for unmeasured community characteristics affecting educational outcomes. Our sample included 284,910 16- to 22-year-old females. The presence of a Planned Parenthood clinic was associated with a decrease (4.08% compared with 4.83%; relative risk ratio 0.84, Pschool dropout rates. This association was consistent across several model specifications. The presence of a Title X clinic was associated with a decrease (4.79% compared with 5.07%; relative risk ratio 0.94, P=.03) in female high school dropout rates, an association that did not remain significant across model specifications. Local access to Planned Parenthood is associated with lower high school dropout rates in young women.

  19. High Sensitivity Carbon Nanotubes Flow-Rate Sensors and Their Performance Improvement by Coating

    Directory of Open Access Journals (Sweden)

    Xing Yang

    2010-05-01

    Full Text Available A new type of hot-wire flow-rate sensor (HWFS with a sensing element made of a macro-sized carbon nanotube (CNT strand is presented in this study. An effective way to improve repeatability of the CNT flow-rate sensor by coating a layer of Al2O3 on the CNT surface is proposed. Experimental results show that due to the large surface-to-volume ratio and thin coated Al2O3 layer, the CNT flow-rate sensor has higher sensitivity and faster response than a conventional platinum (Pt HWFS. It is also demonstrated that the covered CNT flow-rate sensor has better repeatability than its bare counterpart due to insulation from the surrounding environment. The proposed CNT flow-rate sensor shows application potential for high-sensitivity measurement of flow rate.

  20. High Sensitivity Carbon Nanotubes Flow-Rate Sensors and Their Performance Improvement by Coating

    Science.gov (United States)

    Yang, Xing; Zhou, Zhaoying; Wang, Dingqu; Liu, Xiaoli

    2010-01-01

    A new type of hot-wire flow-rate sensor (HWFS) with a sensing element made of a macro-sized carbon nanotube (CNT) strand is presented in this study. An effective way to improve repeatability of the CNT flow-rate sensor by coating a layer of Al2O3 on the CNT surface is proposed. Experimental results show that due to the large surface-to-volume ratio and thin coated Al2O3 layer, the CNT flow-rate sensor has higher sensitivity and faster response than a conventional platinum (Pt) HWFS. It is also demonstrated that the covered CNT flow-rate sensor has better repeatability than its bare counterpart due to insulation from the surrounding environment. The proposed CNT flow-rate sensor shows application potential for high-sensitivity measurement of flow rate. PMID:22399913

  1. High repetition rate multi-channel source of high-power rf-modulated pulses

    Science.gov (United States)

    Ulmaskulov, M. R.; Pedos, M. S.; Rukin, S. N.; Sharypov, K. A.; Shpak, V. G.; Shunailov, S. A.; Yalandin, M. I.; Romanchenko, I. V.; Rostov, V. V.

    2015-07-01

    This paper presents the results of testing a high voltage pulse generator based on parallel gyromagnetic nonlinear transmission lines filled with saturable ferrite. The generator is capable of producing almost identical stable rf-modulated nanosecond high voltage pulses in each of the two, or four, parallel output channels. The output voltage amplitude in each channel can reach -285 or -180 kV, respectively, with a rf modulation depth of up to 60%. Drive pulses were produced as the packets of duration 1-5 s at a pulse repetition frequency of 800 Hz using a driver equipped with all-solid-state switches. Splitting the driver pulse provided electric field strengths in the channels which were below the breakdown field strength of the transmission lines. As a result, the use of nonlinear transmission lines of reduced diameter made it possible to increase the center frequency of the excited rf oscillations to ˜2 GHz.

  2. High repetition rate multi-channel source of high-power rf-modulated pulses.

    Science.gov (United States)

    Ulmaskulov, M R; Pedos, M S; Rukin, S N; Sharypov, K A; Shpak, V G; Shunailov, S A; Yalandin, M I; Romanchenko, I V; Rostov, V V

    2015-07-01

    This paper presents the results of testing a high voltage pulse generator based on parallel gyromagnetic nonlinear transmission lines filled with saturable ferrite. The generator is capable of producing almost identical stable rf-modulated nanosecond high voltage pulses in each of the two, or four, parallel output channels. The output voltage amplitude in each channel can reach -285 or -180 kV, respectively, with a rf modulation depth of up to 60%. Drive pulses were produced as the packets of duration 1-5 s at a pulse repetition frequency of 800 Hz using a driver equipped with all-solid-state switches. Splitting the driver pulse provided electric field strengths in the channels which were below the breakdown field strength of the transmission lines. As a result, the use of nonlinear transmission lines of reduced diameter made it possible to increase the center frequency of the excited rf oscillations to ∼2 GHz.

  3. High-energy, high-rate consolidation of tungsten and tungsten-based composite powders

    Energy Technology Data Exchange (ETDEWEB)

    Raghunathan, S.K.; Persad, C.; Bourell, D.L.; Marcus, H.L. (Center for Materials Science and Engineering, Univ. of Texas, Austin (USA))

    1991-01-20

    Tungsten and tungsten-based heavy alloys are well known for their superior mechanical properties at elevated temperatures. However, unalloyed tungsten is difficult to consolidate owing to its very high melting temperature (3683 K). The additions of small amounts of low-melting elements such as iron, nickel, cobalt and copper, facilitate the powder processing of dense heavy alloys at moderate temperatures. Energetic high-current pulses have been used recently for powder consolidation. In this paper, the use of a homopolar generator as a power source to consolidate selected tungsten and tungsten-based alloys is examined. Various materials were consolidated including unalloyed tungsten, W-Nb, W-Ni, and tungsten heavy alloy with boron carbide. The effect of process parameters such as pressure and specific energy input on the consolidation of different alloy systems is described in terms of microstructure and property relationships. (orig.).

  4. A video event trigger for high frame rate, high resolution video technology

    Science.gov (United States)

    Williams, Glenn L.

    1991-01-01

    When video replaces film the digitized video data accumulates very rapidly, leading to a difficult and costly data storage problem. One solution exists for cases when the video images represent continuously repetitive 'static scenes' containing negligible activity, occasionally interrupted by short events of interest. Minutes or hours of redundant video frames can be ignored, and not stored, until activity begins. A new, highly parallel digital state machine generates a digital trigger signal at the onset of a video event. High capacity random access memory storage coupled with newly available fuzzy logic devices permits the monitoring of a video image stream for long term or short term changes caused by spatial translation, dilation, appearance, disappearance, or color change in a video object. Pretrigger and post-trigger storage techniques are then adaptable for archiving the digital stream from only the significant video images.

  5. Citation Rate of Highly-Cited Papers in 100 Kinesiology-Related Journals

    Science.gov (United States)

    Knudson, Duane

    2015-01-01

    This study extended previous research on several citation-based bibliometric variables for highly cited articles in a large (N = 100) number of journals related to Kinesiology. Total citations and citation rate of the 30 most highly cited articles in each journal were identified by searchers of "Google Scholar (GS)". Other major…

  6. Learning curve of MRI-based planning for high-dose-rate brachytherapy for prostate cancer

    DEFF Research Database (Denmark)

    Buus, Simon; Rylander, Susanne; Hokland, Steffen

    2016-01-01

    Purpose To evaluate introduction of MRI-based high-dose-rate brachytherapy (HDRBT), including procedure times, dose-volume parameters, and perioperative morbidity. Methods and Materials Study included 42 high-risk prostate cancer patients enrolled in a clinical protocol, offering external beam...

  7. Federal High School Graduation Rate Policies and the Impact on New Mexico

    Science.gov (United States)

    Alliance for Excellent Education, 2009

    2009-01-01

    In today's economy, employers increasingly demand that workers have a high school diploma, yet America's graduation rates are unacceptably low, particularly among poor and minority students. Nationally, only about 70 percent of students graduate from high school on time with a regular diploma; for African American and Hispanic students, this…

  8. DNA-fueled molecular machine enables enzyme-free target recycling amplification for electronic detection of microRNA from cancer cells with highly minimized background noise.

    Science.gov (United States)

    Shi, Kai; Dou, Baoting; Yang, Cuiyun; Chai, Yaqin; Yuan, Ruo; Xiang, Yun

    2015-08-18

    The variations in microRNA (miRNA) expression levels can be useful biomarkers for the diagnosis of different cancers. In this work, on the basis of a new miRNA-triggered molecular machine for enzyme-free target recycling signal amplification, the development of a simple electronic sensor for highly sensitive detection of miRNA-21 from human breast cancer cells is described. The three-stand DNA duplex probes are self-assembled on the gold electrode surface to fabricate the sensor. The miRNA-21 target binds to the terminal toehold region of the probes, displaces one of the short strands through toehold-mediated strand displacement reactions, and exposes the secondary toehold region for subsequent hybridization with the methylene blue (MB)-modified DNA fuel strand, which further displaces both the miRNA-21 target and the other short strand to activate the operation of the molecular machine. As a result, the miRNA-21 target is cyclically reused, and many MB-DNA fuel strands are attached to the sensor surface, leading to a significantly amplified current response for sensitive detection of miRNA-21 down to 1.4 fM. The developed sensor also shows high sequence discrimination capability and can be used to monitor miRNA-21 expression levels in cancer cells. Moreover, this sensor avoids the involvement of any enzymes for target recycling amplification and features with highly minimized background noise for miRNA detection, which makes this method hold great potential for convenient monitoring of different miRNA biomarkers for early diagnosis of various cancers.

  9. Mass Spectrometric Determination of Uranium and Thorium in High Radiopurity Polymers Using Ultra Low Background Electroformed Copper Crucibles for Dry Ashing

    Energy Technology Data Exchange (ETDEWEB)

    Arnquist, Isaac J.; Hoppe, Eric J.; Bliss, Mary; Grate, Jay W.

    2017-02-21

    A rapid new method for determining the U and Th mass concentrations in high radiopurity plastics is described, consisting of 1) dry ashing the plastic sample and tracers in low mass crucibles made of ultra low background electroformed copper (ULB EF-Cu) foil cut and folded into boats, 2) dissolving both the ash and the boat in acid, 3) performing a column separation to remove copper, and 4) determining the elements of interest by isotope dilution mass spectrometry. This method was demonstrated on both unfluorinated and fluorinated plastics, demonstrating high tracer recoveries and detection limits to pg/g (i.e., parts per trillion) levels or below, corresponding to μBq/kg of material. Samples of biomedical polyester (Max-Prene® 955) and a fluoropolymer (polyvinylidene fluoride, PVDF) were analyzed in powder raw material forms as well as solids in the form of pellets or injection molded parts. The polyester powder contained 6 pg/g and 2 pg/g for Th and U respectively. These levels correspond to 25 and 25 μBq/kg radioactivity, respectively. Determinations on samples of PVDF powder were typically below 1 pg/g for Th and 2 pg/g for U, corresponding to 4 and 25 μBq/kg radioactivity, respectively. The use of low mass ULB EF-Cu boats for dry ashing successfully overcame the problem of crucible-generated contaminants in the analysis; absolute detection limits, calculated as 3 × standard deviation of the process blanks, were typically 20-100 fg within a sample set. Complete dissolution of the ash and low mass boat provided high tracer recoveries, and provides a convincing method to recover both the tracer and sample isotopes when full equilibration of tracer isotopes with sample isotopes is not possible prior to beginning chemical sample processing on solids.

  10. Carbon Surface Layers on a High-Rate LiFePO4

    Energy Technology Data Exchange (ETDEWEB)

    Gabrisch, Heike; Wilcox, James D.; Doeff, Marca M.

    2005-09-06

    Transmission electron microscopy (TEM) was used to image particles of a high-rate LiFePO4 sample containing a small amount of in situ carbon. The particle morphology is highly irregular, with a wide size distribution. Nevertheless, coatings, varying from about 5-10 nm in thickness, could readily be detected on surfaces of particles as well as on edges of agglomerates. Elemental mapping using Energy Filtered TEM (EFTEM) indicates that these very thin surface layers are composed of carbon. These observations have important implications for the design of high-rate LiFePO4 materials in which, ideally, a minimal amount of carbon coating is used.

  11. Quartz measurement in coal dust with high-flow rate samplers: laboratory study.

    Science.gov (United States)

    Lee, Taekhee; Lee, Eun Gyung; Kim, Seung Won; Chisholm, William P; Kashon, Michael; Harper, Martin

    2012-05-01

    A laboratory study was performed to measure quartz in coal dust using high-flow rate samplers (CIP10-R, GK2.69 cyclone, and FSP10 cyclone) and low-flow rate samplers [10-mm nylon and Higgins-Dewell type (BGI4L) cyclones] and to determine whether an increased mass collection from high-flow rate samplers would affect the subsequent quartz measurement by Fourier transform infrared (FTIR) and X-ray diffraction (XRD) analytical procedures. Two different sizes of coal dusts, mass median aerodynamic diameter 4.48 μm (Coal Dust A) and 2.33 μm (Coal Dust B), were aerosolized in a calm air chamber. The mass of coal dust collected by the samplers was measured gravimetrically, while the mass of quartz collected by the samplers was determined by FTIR (NIOSH Manual of Analytical Method 7603) and XRD (NIOSH Manual of Analytical Method 7500) after one of two different indirect preparations. Comparisons between high-flow rate samplers and low-flow rate samplers were made by calculating mass concentration ratios of coal dusts, net mass ratios of coal dusts, and quartz net mass. Mass concentrations of coal dust from the FSP10 cyclone were significantly higher than those from other samplers and mass concentrations of coal dust from 10-mm nylon cyclone were significantly lower than those from other samplers, while the CIP10-R, GK2.69, and BGI4L samplers did not show significant difference in the comparison of mass concentration of coal dusts. The BGI4L cyclone showed larger mass concentration of ∼9% compared to the 10-mm nylon cyclone. All cyclones provided dust mass concentrations that can be used in complying with the International Standard Organization standard for the determination of respirable dust concentration. The amount of coal dust collected from the high-flow rate samplers was found to be higher with a factor of 2-8 compared to the low-flow rate samplers but not in direct proportion of increased flow rates. The high-flow rate samplers collected more quartz compared to

  12. High strain rate characterization of low-density low-strength materials

    Science.gov (United States)

    Sawas, O.; Brar, N. S.; Brockman, R. A.

    1998-07-01

    The Conventional Split Hopkinson Bar (CSHB) is a reliable experimental technique for measuring high strain rate properties of high-strength materials. Attempts to use the CSHB for similar measurements in more compliant materials, such as plastics and foams, are limited by the maximum achievable strain and high noise-to-signal ratios. This work introduces an all-polymeric split Hopkinson bar (APSHB) experiment, which overcomes these limitations. The proposed method uses polymeric pressure bars to achieve a closer impedance match between the pressure bars and the specimen materials, thus providing both low noise-to-signal ratio data and a longer input pulse for higher maximum strain. Data reduction procedures for APSHB that account for the viscoelastic behavior of the pressure bars are presented. Comparing the high strain rate response of 1100 Al obtained from CSHB and APSHB validates these procedures. Stress-strain data at strain rates of 500-2000/s for polycarbonate, polyurethane foam, and styrofoam are presented.

  13. Periodic venting of MABR lumen allows high removal rates and high gas-transfer efficiencies.

    Science.gov (United States)

    Perez-Calleja, P; Aybar, M; Picioreanu, C; Esteban-Garcia, A L; Martin, K J; Nerenberg, R

    2017-09-15

    The membrane-aerated biofilm reactor (MABR) is a novel treatment technology that employs gas-supplying membranes to deliver oxygen directly to a biofilm growing on the membrane surface. When operated with closed-end membranes, the MABR provides 100-percent oxygen transfer efficiencies (OTE), resulting in significant energy savings. However, closed-end MABRs are more sensitive to back-diffusion of inert gases, such as nitrogen. Back-diffusion reduces the average oxygen transfer rates (OTR), consequently decreasing the average contaminant removal fluxes (J). We hypothesized that venting the membrane lumen periodically would increase the OTR and J. Using an experimental flow cell and mathematical modeling, we showed that back-diffusion gas profiles developed over relatively long timescales. Thus, very short ventings could re-establish uniform gas profiles for relatively long time periods. Using modeling, we systematically explored the effect of the venting interval (time between ventings). At moderate venting intervals, opening the membrane for 20 s every 30 min, the venting significantly increased the average OTR and J without substantially impacting the OTEs. When the interval was short enough, in this case shorter than 20 min, the OTR was actually higher than for continuous open-end operation. Our results show that periodic venting is a promising strategy to combine the advantages of open-end and closed end operation, maximizing both the OTR and OTE. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. The Advanced Bionics High Resolution Mode: stimulation rates up to 5000 pps.

    Science.gov (United States)

    Buechner, Andreas; Frohne-Büchner, Carolin; Gaertner, Lutz; Stoever, Timo; Battmer, Rolf D; Lenarz, Thomas

    2010-01-01

    The technology of stimulation rates between 1500 and 5000 pulses per second per channel (pps/ch) brings a benefit for all users. However, the fastest possible rate does not necessarily lead to best hearing performance in each individual subject. Individual optimization of stimulation rate is recommended. The aim of this study was to investigate the effect of high stimulation rates on speech perception ability. Thirteen subjects with at least 3 months of experience with conventional Clarion speech coding strategies were recruited into cross-over studies. The first study investigated stimulation rates of 1500, 2000 and 3000 pps/ch, the second study investigated rates of 2500 and 5000 pps/ch. Speech perception data were collected for testing in quiet and in competing noise. On average, speech perception performance increased significantly when changing from conventional speech coding strategies to High Resolution Mode. Subjects who preferred continous interleaved sampling (CIS) in standard mode appeared to obtain better results with rates of 2500 or 3000 pps/ch than with 5000 pps/ch. The stimulation rate that led to best performance provided the highest stimulation current efficiency in the majority of subjects.

  15. Rankings of High School Sports Injury Rates Differ Based on Time Loss Assessments.

    Science.gov (United States)

    Kerr, Zachary Y; Roos, Karen G; Djoko, Aristarque; Dompier, Thomas P; Marshall, Stephen W

    2017-11-01

    To examine how injury definition inclusiveness affects the rank order of injury rates in 27 high school (HS) sports. The National Athletic Treatment, Injury and Outcomes Network (NATION) used certified athletic trainers (ATs) to collect injury and athlete-exposure (AE) data in practices and competitions for 27 HS sports during the 2011/2012 to 2013/2014 academic years. Time loss (TL) injuries resulted in ≥24 hours of participation restriction. Nontime loss (NTL) injuries resulted in sports. High school student-athletes. Sports injury data from the National Athletic Treatment, Injury and Outcomes Network. Time loss and TL + NTL injury rates were calculated. Sport-specific rates were placed in rank order, stratified by gender. Most of the 47 014 injuries reported were NTL (82.8%). Among boys' sports, TL injury rates were greatest in football (3.27/1000AE) and wrestling (2.43/1000AE); TL + NTL injury rates were greatest also in football (15.29/1000AE) and wrestling (11.62/1000AE). Among girls' sports, TL injury rates were greatest in soccer (1.97/1000AE) and basketball (1.76/1000AE); TL + NTL injury rates were greatest in field hockey and lacrosse (both 11.32/1000AE). The rank order of injury rates and the resulting injury prevention priorities may depend on injury definition inclusiveness, particularly in female HS sports.

  16. Creep Strain and Strain Rate Response of 2219 Al Alloy at High Stress Levels

    Science.gov (United States)

    Taminger, Karen M. B.; Wagner, John A.; Lisagor, W. Barry

    1998-01-01

    As a result of high localized plastic deformation experienced during proof testing in an International Space Station connecting module, a study was undertaken to determine the deformation response of a 2219-T851 roll forging. After prestraining 2219-T851 Al specimens to simulate strains observed during the proof testing, creep tests were conducted in the temperature range from ambient temperature to 107 C (225 F) at stress levels approaching the ultimate tensile strength of 2219-T851 Al. Strain-time histories and strain rate responses were examined. The strain rate response was extremely high initially, but decayed rapidly, spanning as much as five orders of magnitude during primary creep. Select specimens were subjected to incremental step loading and exhibited initial creep rates of similar magnitude for each load step. Although the creep rates decreased quickly at all loads, the creep rates dropped faster and reached lower strain rate levels for lower applied loads. The initial creep rate and creep rate decay associated with primary creep were similar for specimens with and without prestrain; however, prestraining (strain hardening) the specimens, as in the aforementioned proof test, resulted in significantly longer creep life.

  17. Heart rate reveals torpor at high body temperatures in lowland tropical free-tailed bats.

    Science.gov (United States)

    O'Mara, M Teague; Rikker, Sebastian; Wikelski, Martin; Ter Maat, Andries; Pollock, Henry S; Dechmann, Dina K N

    2017-12-01

    Reduction in metabolic rate and body temperature is a common strategy for small endotherms to save energy. The daily reduction in metabolic rate and heterothermy, or torpor, is particularly pronounced in regions with a large variation in daily ambient temperature. This applies most strongly in temperate bat species (order Chiroptera), but it is less clear how tropical bats save energy if ambient temperatures remain high. However, many subtropical and tropical species use some daily heterothermy on cool days. We recorded the heart rate and the body temperature of free-ranging Pallas' mastiff bats ( Molossus molossus ) in Gamboa, Panamá, and showed that these individuals have low field metabolic rates across a wide range of body temperatures that conform to high ambient temperature. Importantly, low metabolic rates in controlled respirometry trials were best predicted by heart rate, and not body temperature . Molossus molossus enter torpor-like states characterized by low metabolic rate and heart rates at body temperatures of 32°C, and thermoconform across a range of temperatures. Flexible metabolic strategies may be far more common in tropical endotherms than currently known.

  18. Super high-rate fabrication of high-purity carbon nanotube aerogels from floating catalyst method for oil spill cleaning

    Science.gov (United States)

    Khoshnevis, Hamed; Mint, Sandar Myo; Yedinak, Emily; Tran, Thang Q.; Zadhoush, Ali; Youssefi, Mostafa; Pasquali, Matteo; Duong, Hai M.

    2018-02-01

    In this study, we apply an advanced floating catalyst method to fabricate carbon nanotube (CNT) aerogels at super high deposition rate for oil spill cleaning. The aerogels consist of 3D porous network of stacking double-walled CNT bundles with low catalyst impurity (9%) and high thermal stability (650 °C). With high porosity, surface areas, and water contact angles, the CNT aerogels exhibit a high oil adsorption of up to 107 g/g and good reusability of up to four adsorption-burning cycles. This work suggests that the lightweight, porous, and super hydrophobic CNT aerogels can be promising sorbent materials for environmental applications.

  19. GNSS seismometer: Seismic phase recognition of real-time high-rate GNSS deformation waves

    Science.gov (United States)

    Nie, Zhaosheng; Zhang, Rui; Liu, Gang; Jia, Zhige; Wang, Dijin; Zhou, Yu; Lin, Mu

    2016-12-01

    High-rate global navigation satellite systems (GNSS) can potentially be used as seismometers to capture short-period instantaneous dynamic deformation waves from earthquakes. However, the performance and seismic phase recognition of the GNSS seismometer in the real-time mode, which plays an important role in GNSS seismology, are still uncertain. By comparing the results of accuracy and precision of the real-time solution using a shake table test, we found real-time solutions to be consistent with post-processing solutions and independent of sampling rate. In addition, we analyzed the time series of real-time solutions for shake table tests and recent large earthquakes. The results demonstrated that high-rate GNSS have the ability to retrieve most types of seismic waves, including P-, S-, Love, and Rayleigh waves. The main factor limiting its performance in recording seismic phases is the widely used 1-Hz sampling rate. The noise floor also makes recognition of some weak seismic phases difficult. We concluded that the propagation velocities and path of seismic waves, macro characteristics of the high-rate GNSS array, spatial traces of seismic phases, and incorporation of seismographs are all useful in helping to retrieve seismic phases from the high-rate GNSS time series.

  20. Effects of Adiabatic Heating on the High Strain Rate Deformation of Polymer Matrix Composites

    Science.gov (United States)

    Sorini, Chris; Chattopadhyay, Aditi; Goldberg, Robert K.

    2017-01-01

    Polymer matrix composites (PMCs) are increasingly being used in aerospace structures that are expected to experience complex dynamic loading conditions throughout their lifetime. As such, a detailed understanding of the high strain rate behavior of the constituents, particularly the strain rate, temperature, and pressure dependent polymer matrix, is paramount. In this paper, preliminary efforts in modeling experimentally observed temperature rises due to plastic deformation in PMCs subjected to dynamic loading are presented. To this end, an existing isothermal viscoplastic polymer constitutive formulation is extended to model adiabatic conditions by incorporating temperature dependent elastic properties and modifying the components of the inelastic strain rate tensor to explicitly depend on temperature. It is demonstrated that the modified polymer constitutive model is capable of capturing strain rate and temperature dependent yield as well as thermal softening associated with the conversion of plastic work to heat at high rates of strain. The modified constitutive model is then embedded within a strength of materials based micromechanics framework to investigate the manifestation of matrix thermal softening, due to the conversion of plastic work to heat, on the high strain rate response of a T700Epon 862 (T700E862) unidirectional composite. Adiabatic model predictions for high strain rate composite longitudinal tensile, transverse tensile, and in-plane shear loading are presented. Results show a substantial deviation from isothermal conditions; significant thermal softening is observed for matrix dominated deformation modes (transverse tension and in-plane shear), highlighting the importance of accounting for the conversion of plastic work to heat in the polymer matrix in the high strain rate analysis of PMC structures.