WorldWideScience

Sample records for fast time response

  1. Time response of fast-gated microchannel plates used as x-ray detectors

    International Nuclear Information System (INIS)

    We report measurements of the time response of fast-gated, micro- channel plate (MCP) detectors, using a <10 ps pulsewidth ultra-violet laser and an electronic sampling system to measure time resolutions to better than 25 ps. The results show that framing times of less than 100 ps are attainable with high gain. The data is compared to a Monte Carlo calculation, which shows good agreement. We also measured the relative sensitivity as a function of DC bias, and saturation effects for large signal inputs. In part B, we briefly describe an electrical ''time-of-flight'' technique, which we have used to measure the response time of a fast-gated microchannel plate (MCP). Thinner MCP's than previously used have been tested, and, as expected, show fast gating times and smaller electron multiplication. A preliminary design for an x-ray pinhole camera, using a thin MCP, is presented. 7 refs., 6 figs

  2. Ultra-Fast Flash Observatory: Fast Response Space Missions for Early Time Phase of Gamma Ray Bursts

    DEFF Research Database (Denmark)

    Park, I.H.; Ahmad, S.

    2013-01-01

    One of the unexplored domains in the study of gamma-ray bursts (GRBs) is the early time phase of the optical light curve. We have proposed Ultra-Fast Flash Observatory (UFFO) to address this question through extraordinary opportunities presented by a series of small space missions. The UFFO is equipped with a fast-response Slewing Mirror Telescope that uses a rapidly moving mirror or mirror array to redirect the optical beam rather than slewing the entire spacecraft or telescope to aim the optical instrument at the GRB position. The UFFO will probe the early optical rise of GRBs with sub-second response, for the first time, opening a completely new frontier in GRB and transient studies. Its fast response measurements of the optical emission of dozens of GRB each year will provide unique probes of the burst mechanism and test the prospect of GRB as a new standard candle, potentially opening up the z > 10 universe. We describe the current limit in early photon measurements, the aspects of early photon physics, our soon-to-be-launched UFFO-pathfinder mission, and our next planned mission, the UFFO-100.

  3. Real-time Holographic Display Based on a Super Fast Response Thin Film

    International Nuclear Information System (INIS)

    Real-time dynamic holographic display is obtained with super fast response in a thin film without any applied electric field. Holograms can be refreshed in the order of a millisecond and there is no cross talk between the recorded holograms because the hologram formed in the film is transient and can be completely self erased, and the hologram formation time and self-erasure time are both ?1 ms. Holographic video display is achieved, which shows the real-time holographic image display capability of the thin film, and its much higher resolution than those of commercially available spatial light modulators. Furthermore, multiplexed hologram display using two polarization directions of a recorded light and multiple color holographic display at different laser wavelengths are presented, which demonstrate the feasibility of a RGB color holographic three-dimensional display with the thin film. Because the sample is easy to be fabricated into a large size screen and needs no external applied electric field, we think that the film can be developed into a large-size, dynamic, and color holographic three-dimensional display in the future.

  4. Characterizing a fast-response, low-afterglow liquid scintillator for neutron time-of-flight diagnostics in fast ignition experiments.

    Science.gov (United States)

    Abe, Y; Hosoda, H; Arikawa, Y; Nagai, T; Kojima, S; Sakata, S; Inoue, H; Iwasa, Y; Iwano, K; Yamanoi, K; Fujioka, S; Nakai, M; Sarukura, N; Shiraga, H; Norimatsu, T; Azechi, H

    2014-11-01

    The characteristics of oxygen-enriched liquid scintillators with very low afterglow are investigated and optimized for application to a single-hit neutron spectrometer for fast ignition experiments. It is found that 1,2,4-trimethylbenzene has better characteristics as a liquid scintillator solvent than the conventional solvent, p-xylene. In addition, a benzophenon-doped BBQ liquid scintillator is shown to demonstrate very rapid time response, and therefore has potential for further use in neutron diagnostics with fast time resolution. PMID:25430305

  5. Characterizing a fast-response, low-afterglow liquid scintillator for neutron time-of-flight diagnostics in fast ignition experimentsa)

    Science.gov (United States)

    Abe, Y.; Hosoda, H.; Arikawa, Y.; Nagai, T.; Kojima, S.; Sakata, S.; Inoue, H.; Iwasa, Y.; Iwano, K.; Yamanoi, K.; Fujioka, S.; Nakai, M.; Sarukura, N.; Shiraga, H.; Norimatsu, T.; Azechi, H.

    2014-11-01

    The characteristics of oxygen-enriched liquid scintillators with very low afterglow are investigated and optimized for application to a single-hit neutron spectrometer for fast ignition experiments. It is found that 1,2,4-trimethylbenzene has better characteristics as a liquid scintillator solvent than the conventional solvent, p-xylene. In addition, a benzophenon-doped BBQ liquid scintillator is shown to demonstrate very rapid time response, and therefore has potential for further use in neutron diagnostics with fast time resolution.

  6. Time-resolved entropy measurements using a fast response entropy probe

    International Nuclear Information System (INIS)

    This paper describes a recently developed miniature fast response entropy probe and its application in the turbomachinery facilities at ETH Zurich. The development of the probe is motivated by the need to more clearly document the loss generation mechanisms in the harsh environment of turbomachines. The probe is comprised of a piezoresistive sensor and a pair of thin-film gauges that measure the unsteady pressure and temperature, respectively. The unsteady relative entropy can thus be determined. The design, manufacture and calibration of the probe are first presented in detail. Its application to detail the unsteady entropy field, and associated losses, in a centrifugal compressor, axial turbine and film cooling flows are then described

  7. High-temperature thin-film Pt-Ir thermocouple with fast time response

    Science.gov (United States)

    Tong, H. M.; Arjavalingam, G.; Haynes, R. D.; Hyer, G. N.; Ritsko, J. J.

    1987-05-01

    We have developed a thin-film Pt-Ir thermocouple which exhibits bulklike thermoelectric behavior up to 790 °C, the highest temperature observed with thin-film pure-element thermocouples. Using a Q-switched Nd:YAG laser and a signal averaging oscilloscope, its thermal response time was measured to be 60 ns. The ease of implementation in electronic devices coupled with the reproducibility over a wide temperature range make this thin-film thermocouple well suited for monitoring instantaneous temperatures during device processing.

  8. Enhanced surface anchoring energy for the photo-alignment layer with reactive mesogens for fast response time of liquid crystal displays

    International Nuclear Information System (INIS)

    We propose a method for enhancing the surface anchoring energy in photo-alignment (PA) through a two-step ultraviolet (UV) exposure process using reactive mesogens (RM) for fast response time characteristics of liquid crystal displays. We establish the azimuthal alignment direction through the first linearly polarized UV exposure process, as the conventional PA method does. We then achieve the stable alignment and strong surface anchoring energies of our method through the second unpolarized UV exposure process, which polymerizes the RM monomers within the vertical alignment layer. As a result, the fast response time characteristics are remarkably improved, and thermal stability is obtained. (paper)

  9. Quantum tunneling effects of 2-dimensional materials and their application for fast time response of deep UV detectors

    Science.gov (United States)

    Feng, Peter Xianping; Aldalbahi, Ali

    2015-03-01

    We report on our approach to low substrate temperature, digital control, fast (~ 1 minute) synthesis of 2D single crystalline BNNSs. We focus our experiments on studies of various effects (temperature, tunneling, breakdown, polarization, subtract, thickness) on electrical and electronic properties, as well as on sensitivity, response and recovery times, repeatability, lifetime of BNNSs-based deep UV detectors. Raman scattering spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), Transmission electron microscopy (TEM) and electrometer were used to characterize the BNNSs. SEM and TEM measurements clearly indicate that each sample/membrane consists of a large amount of ultra-thin, high-quality BNNSs with distribution over entire surfaces of substrates (3x3 cm2) . Electrical characterization reveals the effects of temperature on the electrical conductivity of transparent BNNSs highly depend on the directions of observations in the 2D case but vanished from the 3D bulk materials or thick films. This work is financially supported by Army research office/DoD grant (62826-RT-REP), as well as visiting professor program/KSU at KSA. Aldalbahi acknowledges the financial support by King Saud University

  10. Fast-time-response Zeeman polarimeter for the study of internal magnetic field structures in the JIPP T-IIU tokamak

    International Nuclear Information System (INIS)

    A Zeeman polarimeter with a fast time response much faster than the magnetic diffusion time of the plasma is developed to measure the poloidal magnetic field structure of a toroidal plasma. A specially developed Fabry-Perot interferometer has allowed us to measure the poloidal magnetic field with time resolution up to 1.5 ms. High signal-to-noise ratio is achieved by using a correlation technique based on the Fast Fourier Transform, and the minimum detectable poloidal field strength is found to be 0.003T. This polarimeter is successfully applied to fast current ramping experiments in the JIPP T-IIU, and both the clear production of skin current and the penetration of the current are observed. Also, the fact that the penetration of the skin current can be predicted by a model based on neoclassical resistivity is confirmed

  11. Fast-response pulsed manometer

    International Nuclear Information System (INIS)

    Fast-response pulsed manometer for measuring 10?s-500?s pulses of gas pressure is described. The PMI-10-2 ionization manometric transducer is used as pressure gauge. The range of measured pressures is 10-3-102 Pa

  12. Fast water oil spill response

    International Nuclear Information System (INIS)

    Of the many manuals currently available for oil spill response, few have any information on fast-water conditions even though just more than half of all oil spilled by volume in the United States between 1992 and 1997 happened in waterways with currents exceeding one knot. The Coast Guard recognized the absence of standard terminology that could be used for fast-water responses. For that reason, an initiative was undertaken to create a document that addresses only fast-water issues. Two major parts of the project were to provide information on deployment strategies and techniques to identify equipment that could improve recovery capabilities where existing systems do not work well. This paper described field demonstrations where boom deflectors and boom vanes were used. Efforts to increase the capability of booms and skimmers were also described. A field guide was developed for training and response purposes for spills in fast-water which makes it possible for on-scene commanders and area supervisors to define techniques and terminology for responders in the field. It is particularly useful for Coast Guard Marine Safety Units when working with Coast Guard operational units during an emergency response. 20 refs., 4 figs

  13. The time-walk of analog constant fraction discriminators using very fast scintillator detectors with linear and non-linear energy response

    International Nuclear Information System (INIS)

    The electronic ?–? fast timing technique allows for direct nuclear lifetime determination down to the few picoseconds region by measuring the time difference between two coincident ?-ray transitions. Using high resolution ultra-fast LaBr3(Ce) scintillator detectors in combination with the recently developed mirror symmetric centroid difference method, nuclear lifetimes are measured with a time resolving power of around 5 ps. The essence of the method is to calibrate the energy dependent position (centroid) of the prompt response function of the setup which is obtained for simultaneously occurring events. This time-walk of the prompt response function induced by the analog constant fraction discriminator has been determined by systematic measurements using different photomultiplier tubes and timing adjustments of the constant fraction discriminator. We propose a universal calibration function which describes the time-walk or the combined ?–? time-walk characteristics, respectively, for either a linear or a non-linear amplitude versus energy dependency of the scintillator detector output pulses.

  14. Reducing preoperative fasting time: A trend based on evidence

    OpenAIRE

    José Eduardo de Aguilar-Nascimento; Diana Borges Dock-Nascimento

    2010-01-01

    Preoperative fasting is mandatory before anesthesia to reduce the risk of aspiration. However, the prescribed 6-8 h of fasting is usually prolonged to 12-16 h for various reasons. Prolonged fasting triggers a metabolic response that precipitates gluconeogenesis and increases the organic response to trauma. Various randomized trials and meta-analyses have consistently shown that is safe to reduce the preoperative fasting time with a carbohydrate-rich drink up to 2 h before surgery. Benefits re...

  15. Response of fast plastic scintillator detector

    International Nuclear Information System (INIS)

    Plastic scintillator detector is widely used now a days for the time of flight measurement of high velocity charged and non charged particle in many experiment of nuclear and high energy physics. The important parameters of a plastic scintillator are its luminescence response to various types of radiation, its time response characteristics (i.e., rise time, decay time, transit time of the light), and the attenuation of the light traveling through it. We are planning to build an array of detectors for TOF measurements of high energy reaction fragments. For this purpose, various types of ultra fast plastic scintillator with different types of readout have been tested using different types of sources and cosmic muons at our SINP Laboratory. Details of the testing results on the response of these detectors to electron (137Cs), gamma (60Co) and heavy charge particle like alpha (from 241Am) will be presented in the symposium

  16. Fast response time of fringe-field switching liquid crystal mode devices with reactive mesogens in a planar alignment layer

    International Nuclear Information System (INIS)

    We report the response time of fringe-field switching (FFS) liquid crystal (LC) mode devices using an ultraviolet-curable reactive mesogen (RM) mixed in a planar alignment layer. The RM polymers within the alignment layer increase the surface azimuthal anchoring energy and the order parameter of the LC molecules. As a result, the falling time and the rising time in the FFS mode are improved by the enhanced azimuthal anchoring energy and the increased dielectric torque induced by higher order parameter of LCs. (paper)

  17. The high contrast ratio and fast response time of a liquid crystal display lit by a carbon nanotube field emission backlight unit

    International Nuclear Information System (INIS)

    We report on the fabrication of a carbon nanotube field emission backlight unit (CNT-BLU) and its application for liquid crystal displays (LCD). The CNT-BLU was operated with locally controllable luminance and impulse-type scanning. The local luminance control, which is based on a very small block size of 1 cm2, consisted of local dimming and local brightening. This resulted in the contrast ratio of the LCD-TV to be as high as 300 000:1. A fast response time of ?5.7 ms was also achieved from the LCD-TV lit by CNT-BLU, originating from the impulse-type scanning. In addition, the CNT-BLU showed long-term emission stability and high luminance uniformity

  18. Reducing preoperative fasting time: A trend based on evidence

    Directory of Open Access Journals (Sweden)

    José Eduardo de Aguilar-Nascimento

    2010-03-01

    Full Text Available Preoperative fasting is mandatory before anesthesia to reduce the risk of aspiration. However, the prescribed 6-8 h of fasting is usually prolonged to 12-16 h for various reasons. Prolonged fasting triggers a metabolic response that precipitates gluconeogenesis and increases the organic response to trauma. Various randomized trials and meta-analyses have consistently shown that is safe to reduce the preoperative fasting time with a carbohydrate-rich drink up to 2 h before surgery. Benefits related to this shorter preoperative fasting include the reduction of postoperative gastrointestinal discomfort and insulin resistance. New formulas containing amino acids such as glutamine and other peptides are being studied and are promising candidates to be used to reduce preoperative fasting time.

  19. LCD response time estimation

    OpenAIRE

    Adam, Pierre; Bertolino, Pascal; Chassery, Jean-Marc; Lebowsky, Fritz

    2006-01-01

    Techniques to reduce LCD motion blur are extensively used in industry and they depend on an inherent LCD parameter: response time. However, normative response time is not a sufficient reference to improve LCD performance. Rather, all the gray-to-gray response times quantities are required to obtain a good improvement quality. Consequently, we propose a novel LCD model to simulate as well as compute gray-to-gray transitions (response time and behavior) from a reduced measurement set.

  20. Preoperative fasting time in children.

    LENUS (Irish Health Repository)

    Adeel, S

    2012-02-01

    The aim of preoperative fasting is to prevent regurgitation and pulmonary aspiration while limiting potential problems of thirst, dehydration and hypoglycaemia. The American Society of Anaesthesiologists (ASA) has suggested guidelines for preoperative fasting for children undergoing elective surgery. We did a postal survey to determine the current practice regarding these guidelines amongst all specialist registrars in anaesthesia in Ireland. A questionnaire was sent to all specialist registrars in anaesthesia (90 in total), 60 (67%) were returned and analysed. The question asked was how long children should be kept fasting before elective surgery. The results of our survey suggest that most of the respondents are following the ASA guidelines for clear fluids and solids however there were differing opinion regarding the duration of fasting for formula milk and breast milk. In conclusion, we would recommend greater awareness and collaboration between anaesthetists, nurses and surgeons to ensure that fasting instructions are consistent with the ASA guidelines and that patient and their parents understand these directives as well.

  1. Fast response digital processing antenna

    Science.gov (United States)

    Hara, Yasuhiko; Fujii, Kouhei; Ishikawa, Hisashi; Kasamaki, Kenzo

    This paper describes a fast speed digital processing technique in order to deal with multiple jammers. The Gram-Schmidt method, using open loop decorrellation processors (DPs) that have a recursive digital low pass filter, is discussed by computer simulations. Then it is shown that a parallel processing technique has feasibility of equivalent convergence performance of DMI algorithm, without the calculation of an invert matrix. Next, description on designing and performance of the open-loop hard wired canceller which was built and tested is presented. The cancellation ratio of 40 dB and 25 dB was obtained for CW and noise, respectively. Finally, the result of the field test using the built canceller is presented and a good performance of jammer suppression could be recognized on PPI scope photograph.

  2. Implementing Fast Feedback Response in Agile Software Development

    OpenAIRE

    Rantamäki, Jaakko

    2014-01-01

    Receiving rapid feedback on software functionality in the agile software development methods is important. Traditionally, the test methods for measuring software functionality are based on simulated test tools and test environments. These methods can be time-consuming and do not always reveal problems that may arise when the software is integrated into the target hardware. In the scope of this research, a study is conducted whether a time efficient fast feedback response test process can...

  3. Magnetostrictive actuators with large displacement and fast response

    International Nuclear Information System (INIS)

    This paper presents the development of a giant magnetostrictive actuator (GMA) with large displacement and fast response. An elliptical flexure hinge lever amplification structure is designed and applied in the GMA. The finite element method is adopted for analyzing and optimizing flexure hinge geometry. Furthermore, the coil and magnetic circuit are studied to improve the driving system. Static and dynamic performances of the GMA are tested. As a result, displacement output amplification ratio can be 2.68 times in the static test. The dynamic performance testing indicates that the GMA with amplification structure can achieve a steady output on average of 140 µm between 0 and 130 Hz driving by 240 Oe, and the time response is 0.6 ms. These results show that large displacement and fast response are obtained simultaneously. (paper)

  4. Magnetostrictive actuators with large displacement and fast response

    Science.gov (United States)

    Zhang, Heng; Zhang, Tianli; Jiang, Chengbao

    2012-05-01

    This paper presents the development of a giant magnetostrictive actuator (GMA) with large displacement and fast response. An elliptical flexure hinge lever amplification structure is designed and applied in the GMA. The finite element method is adopted for analyzing and optimizing flexure hinge geometry. Furthermore, the coil and magnetic circuit are studied to improve the driving system. Static and dynamic performances of the GMA are tested. As a result, displacement output amplification ratio can be 2.68 times in the static test. The dynamic performance testing indicates that the GMA with amplification structure can achieve a steady output on average of 140 µm between 0 and 130 Hz driving by 240 Oe, and the time response is 0.6 ms. These results show that large displacement and fast response are obtained simultaneously.

  5. Response measurement of single-crystal chemical vapor deposition diamond radiation detector for intense X-rays aiming at neutron bang-time and neutron burn-history measurement on an inertial confinement fusion with fast ignition

    Science.gov (United States)

    Shimaoka, T.; Kaneko, J. H.; Arikawa, Y.; Isobe, M.; Sato, Y.; Tsubota, M.; Nagai, T.; Kojima, S.; Abe, Y.; Sakata, S.; Fujioka, S.; Nakai, M.; Shiraga, H.; Azechi, H.; Chayahara, A.; Umezawa, H.; Shikata, S.

    2015-05-01

    A neutron bang time and burn history monitor in inertial confinement fusion with fast ignition are necessary for plasma diagnostics. In the FIREX project, however, no detector attained those capabilities because high-intensity X-rays accompanied fast electrons used for plasma heating. To solve this problem, single-crystal CVD diamond was grown and fabricated into a radiation detector. The detector, which had excellent charge transportation property, was tested to obtain a response function for intense X-rays. The applicability for neutron bang time and burn history monitor was verified experimentally. Charge collection efficiency of 99.5% ± 0.8% and 97.1% ± 1.4% for holes and electrons were obtained using 5.486 MeV alpha particles. The drift velocity at electric field which saturates charge collection efficiency was 1.1 ± 0.4 × 107 cm/s and 1.0 ± 0.3 × 107 cm/s for holes and electrons. Fast response of several ns pulse width for intense X-ray was obtained at the GEKKO XII experiment, which is sufficiently fast for ToF measurements to obtain a neutron signal separately from X-rays. Based on these results, we confirmed that the single-crystal CVD diamond detector obtained neutron signal with good S/N under ion temperature 0.5-1 keV and neutron yield of more than 109 neutrons/shot.

  6. Response measurement of single-crystal chemical vapor deposition diamond radiation detector for intense X-rays aiming at neutron bang-time and neutron burn-history measurement on an inertial confinement fusion with fast ignition.

    Science.gov (United States)

    Shimaoka, T; Kaneko, J H; Arikawa, Y; Isobe, M; Sato, Y; Tsubota, M; Nagai, T; Kojima, S; Abe, Y; Sakata, S; Fujioka, S; Nakai, M; Shiraga, H; Azechi, H; Chayahara, A; Umezawa, H; Shikata, S

    2015-05-01

    A neutron bang time and burn history monitor in inertial confinement fusion with fast ignition are necessary for plasma diagnostics. In the FIREX project, however, no detector attained those capabilities because high-intensity X-rays accompanied fast electrons used for plasma heating. To solve this problem, single-crystal CVD diamond was grown and fabricated into a radiation detector. The detector, which had excellent charge transportation property, was tested to obtain a response function for intense X-rays. The applicability for neutron bang time and burn history monitor was verified experimentally. Charge collection efficiency of 99.5% ± 0.8% and 97.1% ± 1.4% for holes and electrons were obtained using 5.486 MeV alpha particles. The drift velocity at electric field which saturates charge collection efficiency was 1.1 ± 0.4 × 10(7) cm/s and 1.0 ± 0.3 × 10(7) cm/s for holes and electrons. Fast response of several ns pulse width for intense X-ray was obtained at the GEKKO XII experiment, which is sufficiently fast for ToF measurements to obtain a neutron signal separately from X-rays. Based on these results, we confirmed that the single-crystal CVD diamond detector obtained neutron signal with good S/N under ion temperature 0.5-1 keV and neutron yield of more than 10(9) neutrons/shot. PMID:26026521

  7. The response of mouse skin to fractionated doses of fast neutrons (66 Me Vp-Be) with variable interfraction and overall treatment times

    International Nuclear Information System (INIS)

    Beam availability for neutron therapy at the National Accelerator Centre at Faure, South Africa is such that treatment fractions are given at irregularly spaced intervals. Such treatment scheduling may not be optimal. Investigations were made using the acute skin reaction of the mouse foot to determine the effect of different numbers of regularly and irregularly spaced fractions of p(66)/Be neutrons. Assessment of results was both by average skin reaction and by ED50 values for the incidence of moist desquamation as established by probit analysis. Different numbers of fractions (between 6 and 11) and different times between fractions did not appear to affect the mouse foot response significantly when fractionation was completed within 11 days, i.e. before repopulation began to have an effect. When overall treatment times were longer than 11 days, the mouse foot responses to 6 and 9 fractions with variable interfraction times were similar, provided the overall treatment times were the same and the fractions were at least 24 h apart. The ?/? ratio was 87±27 (SE) Gy for the early response of the BALB/c mouse foot skin to p(66)/Be neutrons. The response of mouse skin to fractionated p(66)/Be neutrons was independent of fraction number or interfraction time, provided that the overall treatment time was the same. (orig.)

  8. Probing Human Response Times

    OpenAIRE

    Johansen, Anders

    2003-01-01

    In a recent preprint \\cite{eck}, the temporal dynamics of an e-mail network has been investigated by J.P. Eckmann, E. Moses and D. Sergi. Specifically, the time period between an e-mail message and its reply were recorded. It will be shown here that their data agrees quantitatively with the frame work proposed to explain a recent experiment on the response of ``internauts'' to a news publication \\cite{www2} despite differences in communication channels, topics, time-scale an...

  9. A constant fraction differential discriminator for use in a fast-fast timing system

    International Nuclear Information System (INIS)

    A constant fraction differential discriminator used in a fast-fast timing system is described. The discriminator performs both timing and energy range selection funcitons. The time walk is 120 ps for 1 ns risetime input signal from -50 mV to -5 V. The time resolution as a function of dynamic range in a fast-fast timing system is given. The FWHM is 201 ps when measured with 1.4:1 dynamic range

  10. Characteristics of fast response InSb submillimeter detector

    International Nuclear Information System (INIS)

    A highly sensitive, fast responding n-InSb detector for the millimeter and submillimeter region has been fabricated and optimized for use to measure the electron cyclotron emission from tokamak plasmas, in connection with bandpass filters or a rapid scanning Fourier transform spectrometer. The detector element is made of high purity n-type InSb and is in magnetic fields up to 12 kG. The spectral responsivity, response time and noise equivalent power (NEP) of the detector have been measured. The response time of 0.2 ?sec, and NEP of 1.0 x 10-10 W/?H sub(z) at 4.2 K and 8 kG and that of 2.3 x 10-11 W/?H sub(z) at 1.8 K and 10 kG are obtained. These values are useful for the measurements of electron cyclotron emission from tokamak plasmas. (author)

  11. A fast response temperature sensor based on fiber Bragg grating

    Science.gov (United States)

    Zhang, Dengpan; Wang, Jin; Wang, Yongjie; Dai, Xing

    2014-07-01

    Aimed at the requirement for a fast-response expendable ocean temperature sensor, this paper presents a new design scheme for an optic fiber sensor. Ocean temperature sensors require high sensitivity and high response speed, which must be up to milliseconds. The fiber Bragg grating (FBG) temperature sensor with high sensitivity has been declared in the last decade, but its response speed has been rarely reported. In this paper, a method is proposed which is to package an FBG with a metal tube. The response time of this sensor is 48.6?ms, which is an order of magnitude greater than that of an ordinary optical fiber temperature sensor. Temperature sensitivity is 27.6?pm/°C and the linearity is up to 0.9999. In addition, the sensor can be less than 15?mm. It offers a new way to detect ocean temperature.

  12. The relationship between shock response spectrum and fast Fourier transform

    International Nuclear Information System (INIS)

    In this paper the basic relationship between response spectrum and fast Fourier transform is laid down. Since a long time the response spectrum has been used by structural engineers in the seismic domain and nowadays it is going to be used to define transient motions. This way to define the excitation is more general and more real than the use of classical shape pulses for the reproduction of real environment. Nevertheless the response spectrum of a real excitation represents a loss of some information with respect to the Fourier transform. A useful discussion could arise from these observations. Appendix A gives the relationship between the mathematic Fourier transform and the digital Fourier transform given by computers, while Appendix B gives some examples of response spectra and Fourier transforms of simple functions. (author)

  13. A thermometer for fast response in cryogenic flow

    International Nuclear Information System (INIS)

    The measurement of transient temperatures in cryogenic fluid flow requires a highly sensitive, intrinsically fast sensor that is in good thermal contact with the fluid but in poor thermal contact with the solid walls confining the fluid. A resistance thermometer made from a 1 ?m thick silicon layer on a 125 ?m thick sapphire substrate has a calculated intrinsic response time of about 10 ns at 4 K, and its sensitivity is comparable to germanium or carbon thermometers in the range of 1-80 K. This paper describes a novel construction method to mount the small silicon-on-sapphire thermometer in an oscillating fluid flow. The large surface area of the thermometer provides good thermal contact with the fluid, while the suspension ensures poor thermal contact with the holder, maintains its fast response time, and withstands high velocities and frequencies of fluid oscillation. A self-heating response time of 300 ns was measured at 4 K in liquid and gaseous helium. Repeatability of the thermometer is + or - 10 mK at 4 K. Examples of the performance of this thermometer for helium gas oscillations in the frequency range of 1 Hz to 12 kHz are given

  14. Time non-variant and time variant fast random pulse generator

    International Nuclear Information System (INIS)

    The construction and specifications of a fast random pulse generator is described. It consists of a fast LED light source, a PMT, a fast discriminator, a fast amplifier, a fast counter and a negative feedback stable circuit. The counting rate of time non-variant random pulses is near 103 cps. Time variant random pulses can vary with the shape of time variant pulse

  15. Time of flight fast neutron radiography

    International Nuclear Information System (INIS)

    Neutron radiography with fast or thermal neutrons is a standard technique for non-destructive testing (NDT). Here we report results for fast neutron radiography both as an adjunct to pulsed fast neutron analysis (PFNA) and as a stand-alone method for NDT. PFNA is a new technique for utilizing a collimated pulsed neutron beam to interrogate items and determine their elemental composition. By determining the time of flight for gamma-rays produced by (n,n' gamma X) reactions, a three dimensional image can be produced. Neutron radiography data taken with the same beam provides an important constraint for image reconstruction, and in particular is important in inferring the amount of hydrogen within the interrogated item. As a stand-alone device, the radiography measurement can be used to image items as large as cargo containers as long as their density is not too high. The use of a pulsed beam gives the further advantage of a time of flight measurement on the transmitted neutrons. By gating the radiography signal on the time of flight appropriate to the energy of the primary neutrons, most build-up from scattered neutrons can be eliminated. The pulsed beam also greatly improves the signal to background and extends the range of the neutron radiography. Simulation results will be presented which display the advantage of this constraint in particular for statistically limited data. Experimental results will be presented which show some of the limitations likely in a PFNA sysme of the limitations likely in a PFNA system utilizing neutron radiography data. Experimental and simulation results will demonstrate possible uses for this type of radiographic data in identifying contraband substances such as drugs. (orig.)

  16. Wave-induced hydroelastic response of fast monohull displacement ships

    DEFF Research Database (Denmark)

    Jensen, JØrgen Juncher; Wang, Zhaohui

    1998-01-01

    High-speed ships are weight sensitive structures and high strength steel, aluminium or composites are preferred building materials. It is characteristic for these materials that they result in larger hull flexibility than more conventional materials. Therefore, for large fast ships the lowest natural frequencies of the global hull modes can be relatively low compared to the frequency of wave encounter.In the present paper the effect of hull flexibility on the wave-induced springing and whipping vibrations is investigated in stationary stochastic seaways. The calculations are performed using a quadratic strip theory formulated in the frequency domain and a fully non-linear time-domain strip theory. The hydroelastic response is thereby excited partly by resonance and partly by non-linear excitation. The calculations are carried out for a recent proposal for a fast monohull containership.

  17. Quartz Cherenkov Counters for Fast Timing: QUARTIC

    CERN Document Server

    Albrow, M G; Los, S; Ramberg, E; Ronzhin, A; Samoylenko, V; Wenzel, H; Zatserklyaniy, A

    2012-01-01

    We have developed particle detectors based on fused silica (quartz) Cherenkov radiators read out with micro-channel plate photomultipliers (MCP-PMTs) or silicon photomultipliers (SiPMs) for high precision timing (Sigma(t) about 10-15 ps). One application is to measure the times of small angle protons from exclusive reactions, e.g. p + p - p + H + p, at the Large Hadron Collider, LHC. They may also be used to measure directional particle fluxes close to external or stored beams. The detectors have small areas (square cm), but need to be active very close (a few mm) to the intense LHC beam, and so must be radiation hard and nearly edgeless. We present results of tests of detectors with quartz bars inclined at the Cherenkov angle, and with bars in the form of an "L" (with a 90 degree corner). We also describe a possible design for a fast timing hodoscope with elements of a few square mm.

  18. Fast-Response Liquid Crystal Microlens

    OpenAIRE

    Su Xu; Yan Li; Yifan Liu; Jie Sun; Hongwen Ren; Shin-Tson Wu

    2014-01-01

    Electrically tunable liquid crystal microlenses have attracted strong research attention due to their advantages of tunable focusing, voltage actuation, low power consumption, simple fabrication, compact structure, and good stability. They are expected to be essential optical devices with widespread applications. However, the slow response time of nematic liquid crystal (LC) microlenses has been a significant technical barrier to practical applications and commercialization. LC/polymer compos...

  19. Polycrystalline CVD diamond detector: Fast response and high sensitivity with large area

    International Nuclear Information System (INIS)

    Polycrystalline diamond was successfully used to fabricate a large area (diameter up to 46 mm) radiation detector. It was proven that the developed detector shows a fast pulsed response time and a high sensitivity, therefore its rise time is lower than 5 ns, which is two times faster than that of a Si-PIN detector of the same size. And because of the large sensitive area, this detector shows good dominance in fast pulsed and low density radiation detection

  20. Development of a small, nanosecond timing fast neutron spectrometer

    International Nuclear Information System (INIS)

    A neutron spectrometer has been developed for use inside a fast neutron assembly. The spectrometer is small and insensitive to gamma radiation. An optical system was developed which could collect about 80 per cent of the light from an NE213 liquid scintillator and transmit it along a 450 mm quartz light guide to a high performance photomultiplier. To enable the detector to be used as a nanosecond timing spectrometer, several calibration measurements were made of the detector efficiency and response to monoenergetic neutrons

  1. Fast Electromechanical Response in Liquid Crystal Elastomer Nanocomposites

    Science.gov (United States)

    Verduzco, Rafael; Agrawal, Aditya; Jacot, Jeff; Adetiba, Tomi

    2014-03-01

    Liquid crystal elastomers (LCEs) combine the elasticity of polymer networks with the fluidity and responsiveness of liquid crystals. LCEs can respond to a variety of external stimuli - heat, light, electric and magnetic fields - with large and reversible shape-changes. However, the response can be slow and/or require large external fields. Here, we present our recent work with LCE bilayers and LCE composite materials that demonstrates LCEs can respond quickly and with 3-D shape changes. Nematic LCE bilayers are prepared by depositing a PS film on top of a nematic LCE, and the bilayers exhibit reversible wrinkling, folding, and curling with temperature. The shape change of LCE bilayers is quantitatively predicted using finite-element modeling. Next, we show that a fast response to an electric field is achieved in nematic LCE composites. While typical nematic LCEs are relatively unresponsive to electric fields, LCE composites with 2 wt % carbon black can reversibly contract and expand in response to a 40 V electric field. The response time (0.1 - 10 Hz) and amplitude of shape change (1 - 20 %) depends on the external field and carbon black content. These composites may be useful for biomedical applications, such as substrates for dynamic cell culture and biocompatible scaffolds for heart tissue regeneration. Neonatal rat ventricular myocytes remain viable on LCE-carbon black bilayer substrates, and aligned myocyte cell sheets were successfully grown on LCE-composite bilayers.

  2. Fast Time-Domain Algorithms for UWB Bistatic SAR Processing

    OpenAIRE

    Vu, Viet; Sjo?gren, Thomas; Pettersson, Mats

    2013-01-01

    Two fast time-domain algorithms are introduced for ultrawideband-ultrawidebeam (UWB) bistatic synthetic aperture radar (SAR) processing; they are bistatic fast backprojection (BiFBP) and bistatic fast factorized backprojection (BiFFBP). Both algorithms process radar echoes on a subaperture and subimage basis in order to minimize processing time. They are shown to work with any configuration of bistatic SAR. They also own time-domain characteristics, which are essential...

  3. Security-constrained expansion planning of fast-response units for wind integration

    International Nuclear Information System (INIS)

    This paper proposes a stochastic expansion planning of fast-response thermal units for the large-scale integration of wind generation (WG). The paper assumes that the WG integration level is given and considers the short-term thermal constraints and the volatility of wind units in the planning of fast-response thermal units. The new fast-response units are proposed by market participants. The security-constrained expansion planning approach will be used by an ISO or a regulatory body to secure the optimal planning of the participants' proposed fast-response units with the WG integration. Random outages of generating units and transmission lines as well as hourly load and wind speed forecast errors are modeled in Monte Carlo scenarios. The Monte Carlo simplification methods are introduced to handle large-scale stochastic expansion planning as a tradeoff between the solution accuracy and the calculation time. The effectiveness of the proposed approach is demonstrated through numerical simulations. (author)

  4. Ultra-Fast Shapelets for Time Series Classification

    OpenAIRE

    Wistuba, Martin; Grabocka, Josif; Schmidt-Thieme, Lars

    2015-01-01

    Time series shapelets are discriminative subsequences and their similarity to a time series can be used for time series classification. Since the discovery of time series shapelets is costly in terms of time, the applicability on long or multivariate time series is difficult. In this work we propose Ultra-Fast Shapelets that uses a number of random shapelets. It is shown that Ultra-Fast Shapelets yield the same prediction quality as current state-of-the-art shapelet-based ti...

  5. High-power fast-response phase shifter

    International Nuclear Information System (INIS)

    A design of a high-power fast-response phase changer is considered. The phase changer developed for the system of increasing electron beam energy in a linear accelerator. The phase changer design is based on the use of the trackdecibel bridge. Diode switches are placed in two bridge shoulders at the equal distance from the slit. The phase changer is made of standard rectangular 72x34 mm waveguide. Phase changer tests in the pulse regime at a high power level (up to 10 kWt in the case of pulse duration of 2.5 ?s and beam off duty of 1000) have shown that the 20% increase of time phase changing takes place at this level

  6. Analysis of the seismic response of a fast reactor core

    International Nuclear Information System (INIS)

    This report deals with the methods to apply for a correct evaluation of the reactor core seismic response. Reference is made to up-to-date design data concerning the PEC core, taking into account the presence of the core-restraint plate located close to the PEC core elements top and applying the optimized iterative procedure between the vessel linear calculation and the non-linear ones limited to the core, which had been described in a previous report. It is demonstrated that the convergence of this procedure is very fast, similar to what obtained in the calculations of the cited report, carried out with preliminary data, and it is shown that the cited methods allow a reliable evaluation of the excitation time histories for the experimental tests in support of the seismic verification of the shutdown system and the core of a fast reactor, as well as relevant data for the experimental, structural and functional, verification of the core elements in the case of seismic loads

  7. Fluctuation-Response Relation and modeling in systems with fast and slow dynamics

    Directory of Open Access Journals (Sweden)

    G. Lacorata

    2007-10-01

    Full Text Available We show how a general formulation of the Fluctuation-Response Relation is able to describe in detail the connection between response properties to external perturbations and spontaneous fluctuations in systems with fast and slow variables. The method is tested by using the 360-variable Lorenz-96 model, where slow and fast variables are coupled to one another with reciprocal feedback, and a simplified low dimensional system. In the Fluctuation-Response context, the influence of the fast dynamics on the slow dynamics relies in a non trivial behavior of a suitable quadratic response function. This has important consequences for the modeling of the slow dynamics in terms of a Langevin equation: beyond a certain intrinsic time interval even the optimal model can give just statistical prediction.

  8. Plastic fiber scintillator response to fast neutrons

    International Nuclear Information System (INIS)

    The Neutron Imaging System at NIF uses an array of plastic scintillator fibers in conjunction with a time-gated imaging system to form an image of the neutron emission from the imploded capsule. By gating on neutrons that have scattered from the 14.1 MeV DT energy to lower energy ranges, an image of the dense, cold fuel around the hotspot is also obtained. An unmoderated spallation neutron beamline at the Weapons Neutron Research facility at Los Alamos was used in conjunction with a time-gated imaging system to measure the yield of a scintillating fiber array over several energy bands ranging from 1 to 15 MeV. The results and comparison to simulation are presented

  9. Plastic fiber scintillator response to fast neutrons.

    Science.gov (United States)

    Danly, C R; Sjue, S; Wilde, C H; Merrill, F E; Haight, R C

    2014-11-01

    The Neutron Imaging System at NIF uses an array of plastic scintillator fibers in conjunction with a time-gated imaging system to form an image of the neutron emission from the imploded capsule. By gating on neutrons that have scattered from the 14.1 MeV DT energy to lower energy ranges, an image of the dense, cold fuel around the hotspot is also obtained. An unmoderated spallation neutron beamline at the Weapons Neutron Research facility at Los Alamos was used in conjunction with a time-gated imaging system to measure the yield of a scintillating fiber array over several energy bands ranging from 1 to 15 MeV. The results and comparison to simulation are presented. PMID:25430353

  10. Actual preoperative fasting time in Brazilian hospitals: the BIGFAST multicenter study

    Directory of Open Access Journals (Sweden)

    Aguilar-Nascimento JE

    2014-02-01

    Full Text Available José E de Aguilar-Nascimento,1 Ana L de Almeida Dias,2 Diana B Dock-Nascimento,3 Maria Isabel TD Correia,4 Antonio CL Campos,5 Pedro Eder Portari-Filho,6 Sergio S Oliveira71Department of Surgery, Julio Muller University Hospital, Cuiaba, Brazil; 2Federal University of Mato Grosso, Cuiaba, Brazil; 3Department of Sciences and Food, Federal University of Mato Grosso, Cuiaba, Brazil; 4Department of Surgery, Federal University of Minas Gerais, Belo Horizonte, Brazil; 5Department of Surgery, Federal University of Parana, Curitiba, Brazil; 6Department of Surgery, Federal University of Rio de Janeiro State, Rio de Janeiro, Brazil; 7Service of Anesthesiology, Julio Muller University Hospital, Cuiaba, Brazil On behalf of the BIGFAST (Brazilian Group for the Study of Preoperative Fasting Time group Background: Prolonged fasting increases organic response to trauma. This multicenter study investigated the gap between the prescribed and the actual preoperative fasting times in Brazilian hospitals and factors associated with this gap. Methods: Patients (18–90-years-old who underwent elective operations between August 2011 and September 2012 were included in the study. The actual and prescribed times for fasting were collected and correlated with sex, age, surgical disease (malignancies or benign disease, operation type, American Society of Anesthesiologists score, type of hospital (public or private, and nutritional status. Results: A total of 3,715 patients (58.1% females with a median age of 49 (18–94 years from 16 Brazilian hospitals entered the study. The median (range preoperative fasting time was 12 (2–216 hours, and fasting time was longer (P<0.001 in hospitals using a traditional fasting protocol (13 [6–216] hours than in others that had adopted new guidelines (8 [2–48] hours. Almost 80% (n=2,962 of the patients were operated on after 8 or more hours of fasting and 46.2% (n=1,718 after more than 12 hours. Prolonged fasting was not associated with physical score, age, sex, type of surgery, or type of hospital. Patients operated on due to a benign disease had an extended duration of preoperative fasting. Conclusion: Actual preoperative fasting time is significantly longer than prescribed fasting time in Brazilian hospitals. Most of these hospitals still adopt traditional rather than modern fasting guidelines. All patients are at risk of long periods of fasting, especially those in hospitals that follow traditional practices. Keywords: preoperative fasting, preoperative care, multicenter study, intraoperative complications, guideline adherence, perioperative risk

  11. New charge sensitive preamplifier with a fast timing signal output

    International Nuclear Information System (INIS)

    A charge sensitive preamplifier with a fast timing output has been developed. Different from the Sherman's method which uses a low gain fast amplifier and a high gain slow amplifier in parallel as the second stage, the timing output of this preamplifier is extracted from the fast current signal in the collector current of the cascode type amplifier by using a current-voltage convertor. This preamplifier has a good resolution when used with a thin silicon detector which has a large capacitance. (auth.)

  12. Portion sizes and obesity: responses of fast-food companies.

    Science.gov (United States)

    Young, Lisa R; Nestle, Marion

    2007-07-01

    Because the sizes of food portions, especially of fast food, have increased in parallel with rising rates of overweight, health authorities have called on fast-food chains to decrease the sizes of menu items. From 2002 to 2006, we examined responses of fast-food chains to such calls by determining the current sizes of sodas, French fries, and hamburgers at three leading chains and comparing them to sizes observed in 1998 and 2002. Although McDonald's recently phased out its largest offerings, current items are similar to 1998 sizes and greatly exceed those offered when the company opened in 1955. Burger King and Wendy's have increased portion sizes, even while health authorities are calling for portion size reductions. Fast-food portions in the United States are larger than in Europe. These observations suggest that voluntary efforts by fast-food companies to reduce portion sizes are unlikely to be effective, and that policy approaches are needed to reduce energy intake from fast food. PMID:17585324

  13. A Fast Time-to-Pulse Height Converter

    International Nuclear Information System (INIS)

    A fast time-to-pulse height converter representing a development of Green and Bell's gated beam converter is described. The converter is compatible with 2 input pulses in the stop channel and exhibits excellent linearity and time resolution properties. High stability and large output pulses are obtained by using a large time constant in the converting network

  14. Fast-timing methods for semiconductor detectors

    International Nuclear Information System (INIS)

    The basic parameters are discussed which determine the accuracy of timing measurements and their effect in a practical application, specifically timing with thin-surface barrier detectors. The discussion focusses on properties of the detector, low-noise amplifiers, trigger circuits and time converters. New material presented in this paper includes bipolar transistor input stages with noise performance superior to currently available FETs, noiseless input terminations in sub-nanosecond preamplifiers and methods using transmission lines to couple the detector to remotely mounted preamplifiers. Trigger circuits are characterized in terms of effective rise time, equivalent input noise and residual jitter

  15. Fast timing methods for semiconductor detectors. Revision

    International Nuclear Information System (INIS)

    This tutorial paper discusses the basic parameters which determine the accuracy of timing measurements and their effect in a practical application, specifically timing with thin-surface barrier detectors. The discussion focusses on properties of the detector, low-noise amplifiers, trigger circuits and time converters. New material presented in this paper includes bipolar transistor input stages with noise performance superior to currently available FETs, noiseless input terminations in sub-nanosecond preamplifiers and methods using transmission lines to couple the detector to remotely mounted preamplifiers. Trigger circuits are characterized in terms of effective rise time, equivalent input noise and residual jitter

  16. Fast timing: Lifetime measurements with LaBr3 scintillators

    International Nuclear Information System (INIS)

    In order to perform half-life measurements at Alto, we developed a fast-timing setup using fast scintillators : LaBr3. The main components of our setup and their characteristics (timing properties) are presented. The resulting time resolution, obtained after optimization, and measured off-line with radioactive sources is discussed. This set-up was tested on-line by measuring using the slope method half-lives of 137-139Cs levels fed by the ?- decay of 137-139Xe. The neutron-rich Xe nuclei were produced by 238U photofission using, at low intensity, the electron beam and the line of the future facility ALTO. Our results show the ability of such a fast-timing system to measure half-lives lower than the total time resolution. Off-line and on-line results are discussed.

  17. Fast neutron response of coumarin in water and heavy water

    International Nuclear Information System (INIS)

    Response of coumarin in aqueous solution has been studied earlier for gamma rays and fast neutrons by fluorescence measurement. For further fast neutron studies, two systems viz coumarin in H20 and coumarin in D20, were irradiated with fast neutrons in SNIF facility in the swimming pool type APSARA reactor at Trombay. Neutron fluence was estimated by measuring induced activity in sulphur pellet and associated gamma radiation was estimated using CaS04:Dy TLD powder. The KERMA values were calculated for H20 and D20, assuming modified fission spectrum for fast neutron in SNIF position, and they were in the ratio of 2:1. Response of a chemical dosimetric system is expected to be proportional to the absorbed dose in the respective system for the same neutron fluence. This was experimentally found to be the case for coumarin in H20 or D20. These results are likely to be true in general for any aqueous chemical system. The limitations of using such a dual system for dosimetry in a mixed field is discussed. (author)

  18. Fast timing study of a CeBr3 crystal: Time resolution below 120 ps at 60Co energies

    International Nuclear Information System (INIS)

    We report on the time response of a novel inorganic scintillator, CeBr3. The measurements were performed using a cylindrical crystal of 1-in. in height and 1-in. in diameter at 22Na and 60Co photon energies. The time response was measured against a fast reference BaF2 detector. Hamamatsu R9779 and Photonis XP20D0 fast photomultipliers (PMTs) were used. The PMT bias voltages and Constant Fraction Discriminator settings were optimized with respect to the timing resolution. The Full Width at Half Maximum (FWHM) time resolution for an individual CeBr3 crystal coupled to Hamamatsu PMT is found here to be as low as 119 ps at 60Co energies, which is comparable to the resolution of 107 ps reported for LaBr3(Ce). For 511 keV photons the measured FWHM time resolution for CeBr3 coupled to the Hamamatsu PMT is 164 ps.

  19. Modeling and Analysis of the Role of Fast-Response Energy Storage in the Smart Grid

    CERN Document Server

    Su, Han-I

    2011-01-01

    The large short time-scale variability of renewable energy resources presents significant challenges to the reliable operation of power systems. This variability can be mitigated by deploying fast-ramping generators. However, these generators are costly to operate and produce environmentally harmful emissions. Fast-response energy storage devices, such as batteries and flywheels, provide an environmentally friendly alternative, but are expensive and have limited capacity. To study the environmental benefits of storage, we introduce a slotted-time dynamic residual dc power flow model with the prediction error of the difference between the generation (including renewables) and the load as input and the fast-ramping generation and the storage (charging/discharging) operation as the control variables used to ensure that the demand is satisfied (as much as possible) in each time slot. We assume the input prediction error sequence to be i.i.d. zero-mean random variables. The optimal power flow problem is then formu...

  20. Fast method to calculate tsunami arrival times

    Science.gov (United States)

    Lavrentyev, Mikhail; Romanenko, Alexey; Marchuk, Andery; Vassilyev, George

    2014-05-01

    Exact arrival time of tsunami wave at coast or/and sensor is among important parameters for tsunami risk mitigation. Among the existing methods we mention: simulation of synthetic tsunami wave propagation from the given source; permanent data check at sensor system. Both approaches require extended CPU time or data transfer. Here we suggest alternative method based only on kinematics computation. The method is based on kinematic calculation of tsunami wave front line. Precise algorithms to move the points at the front line and, in case of necessity, to add new points, have been proposed. To start with, this method was successfully tested in an area with constant depth. Then the model bathymetry with parabolic and sloping bottom relief, in which cases exact analytical solutions are available, were studied. New algorithm was proved to be precise. The method gives possibility to compute not only tsunami travel times but also the wave rays. Tsunami amplitude can be estimated by wave-ray's divergence and depth change along wave route. The wave amplitude was estimated and then compared to results of numerical tests, obtained within the shallow-water numerical modeling of tsunami propagation using the MOST software package. For the model (slope-like) bathymetry the results differs by only a few percent. The advantage of proposed method is rapidness and low computer resources requirement.

  1. The Commensal Real-time ASKAP Fast Transients (CRAFT) survey

    CERN Document Server

    Macquart, Jean-Pierre; Bower, G C; Bunton, J D; Chatterjee, S; Colegate, T; Cordes, J M; D'Addario, L; Deller, A; Dodson, R; Fender, R; Haines, K; Hall, P; Harris, C; Hotan, A; Johnston, S; Jones, D L; Keith, M; Koay, J Y; Lazio, T J W; Majid, W; Murphy, T; Navarro, R; Phillips, C; Quinn, P; Preston, R A; Stansby, B; Stairs, I; Stappers, B; Staveley-Smith, L; Tingay, S; Thompson, D; van Straten, W; Wagstaff, K; Warren, M; Wayth, R; Wen, L

    2010-01-01

    We are developing a purely commensal survey experiment for fast (<5s) transient radio sources. Short-timescale transients are associated with the most energetic and brightest single events in the Universe. Our objective is to cover the enormous volume of transients parameter space made available by ASKAP, with an unprecedented combination of sensitivity and field of view. Fast timescale transients open new vistas on the physics of high brightness temperature emission, extreme states of matter and the physics of strong gravitational fields. In addition, the detection of extragalactic objects affords us an entirely new and extremely sensitive probe on the huge reservoir of baryons present in the IGM. We outline here our approach to the considerable challenge involved in detecting fast transients, particularly the development of hardware fast enough to dedisperse and search the ASKAP data stream at or near real-time rates. Through CRAFT, ASKAP will provide the testbed of many of the key technologies and surve...

  2. Fast neutron time-of-flight spectrometer

    International Nuclear Information System (INIS)

    A modified time-of-flight spectrometer for investigations of (n, n') and (n, 2n) nuclear reactions is described. The spectrometer has neutron collimation based on detecting ? particles accompanying neutrons in the 3H(d, n)24He reaction. The sperometer flowsheet and its basic geometric parameters are presented. The spectrometer is made on the basis of 14.6 MeV DT neutron generator. 100 ?m thick scintillation film of activated polystyrene was used to detect alpha particles. Neutron density distribution over cone section optical bench by the ?n coincidences method application of 7x8 mm plastic scintillation as a neutron detector. Both scheme of n? separation according to a pulse shape and circular neutron detector shield consisting of 20 cm thick iron layer and a borated polyethylene layer were used to decrease background of random coincidences. A monitor of random coincidences based on detection of both neutrons and gamma radiation is included in the spectrometer for more exact determination of the background of random coincidences. Time resolution of the spectrometer is not worse than 0.85 ns. The spectrometer developed permits to set up scattered neutron spectrum with statistics of 104 pulses for iron scatterer for 108 n/s neutron flux over 4? and effect/background ratio=1:1

  3. Improved real-time holographic video display using super-fast-refresh liquid crystal films

    Science.gov (United States)

    Gao, Hongyue; Yu, Yingjie; Liu, Jicheng; Zeng, Chao; Liu, Pan; Yao, Qiuxiang; Zheng, Huadong; Zeng, Zhenxiang

    2015-03-01

    We have achieved real-time dynamic holographic display with holographic response time under an order of a microsecond using super-fast-response liquid crystal films. The hologram formation time and self-erasable time can both reach ~ 1 ms in this film. Holographic video display was realized using it without any cross talk between the holograms. However, the holographic display videos we obtained before need to be improved in image quality. This paper presents improvement of holographic video display of the films, and our achievement may be useful for its potential applications in a large-size, high-definition, and color holographic three-dimensional video display.

  4. Wave-induced Hydroelastic response of fast monohull ships

    DEFF Research Database (Denmark)

    Jensen, JØrgen Juncher

    1996-01-01

    High-speed ships are weight sensitive structures and high strength steel, aluminium or composites are preferred building materials. it is characteristic for these materials that they result in larger hull flexibility than more conventional materials. Therefore, for large fast ships the lowest natural frequencies of the global hull modes can be relatively low compared to the frequency of wave encounter. In the present paper the effect of hull flexibility on the wave-induced springing vibrations is investigated in stationary stochastic seaways. The calculations are performed within the framework of a quadratic strip theory formulated in the frequency domain. The springing response is thereby excited partly be resonance and partly by non-linear excitation. Special emphasis is given to the influence of springing on fatigue damage as the extreme responses even for very flexible ships are quite insensitive to the hull flexibility due to the high zero crossing periods associated with the extreme responses.

  5. Time Resolution of Fast Photomultipliers for Time of Flight PET

    International Nuclear Information System (INIS)

    Time resolution study of 1 inch Photonis XP1020 photomultiplier is reported. The number of photoelectrons, time jitter and time resolution with 4x4x20 mm3 LSO crystal were measured. All the mentioned PMT properties were measured at five positions on the photocathode.

  6. Time-resolved fast neutron imaging: simulation of detector performance

    CERN Document Server

    Vartsky, D; Goldberg, M B; Mardor, I; Feldman, G; Bar, D; Shor, A; Dangendorf, V; Laczko, G; Breskin, Amos; Chechik, R

    2004-01-01

    We have analyzed and compared the performance of two novel fast-neutron imaging methods with time-of-flight spectroscopy capability. Using MCNP and GEANT code simulations of neutron and charged-particle transport in the detectors, key parameters such as detection efficiency, the amount of energy deposited in the converter and the spatial resolution of both detector variants have been evaluated.

  7. Metabolomics of Ramadan fasting: an opportunity for the controlled study of physiological responses to food intake.

    Science.gov (United States)

    Mathew, Sweety; Krug, Susanne; Skurk, Thomas; Halama, Anna; Stank, Antonia; Artati, Anna; Prehn, Cornelia; Malek, Joel A; Kastenmüller, Gabi; Römisch-Margl, Werner; Adamski, Jerzy; Hauner, Hans; Suhre, Karsten

    2014-01-01

    High-throughput screening techniques that analyze the metabolic endpoints of biological processes can identify the contributions of genetic predisposition and environmental factors to the development of common diseases. Studies applying controlled physiological challenges can reveal dysregulation in metabolic responses that may be predictive for or associated with these diseases. However, large-scale epidemiological studies with well controlled physiological challenge conditions, such as extended fasting periods and defined food intake, pose logistic challenges. Culturally and religiously motivated behavioral patterns of life style changes provide a natural setting that can be used to enroll a large number of study volunteers. Here we report a proof of principle study conducted within a Muslim community, showing that a metabolomics study during the Holy Month of Ramadan can provide a unique opportunity to explore the pre-prandial and postprandial response of human metabolism to nutritional challenges. Up to five blood samples were obtained from eleven healthy male volunteers, taken directly before and two hours after consumption of a controlled meal in the evening on days 7 and 26 of Ramadan, and after an over-night fast several weeks after Ramadan. The observed increases in glucose, insulin and lactate levels at the postprandial time point confirm the expected physiological response to food intake. Targeted metabolomics further revealed significant and physiologically plausible responses to food intake by an increase in bile acid and amino acid levels and a decrease in long-chain acyl-carnitine and polyamine levels. A decrease in the concentrations of a number of phospholipids between samples taken on days 7 and 26 of Ramadan shows that the long-term response to extended fasting may differ from the response to short-term fasting. The present study design is scalable to larger populations and may be extended to the study of the metabolic response in defined patient groups such as individuals with type 2 diabetes. PMID:24906381

  8. UCP2 regulates the glucagon response to fasting and starvation.

    Science.gov (United States)

    Allister, Emma M; Robson-Doucette, Christine A; Prentice, Kacey J; Hardy, Alexandre B; Sultan, Sobia; Gaisano, Herbert Y; Kong, Dong; Gilon, Patrick; Herrera, Pedro L; Lowell, Bradford B; Wheeler, Michael B

    2013-05-01

    Glucagon is important for maintaining euglycemia during fasting/starvation, and abnormal glucagon secretion is associated with type 1 and type 2 diabetes; however, the mechanisms of hypoglycemia-induced glucagon secretion are poorly understood. We previously demonstrated that global deletion of mitochondrial uncoupling protein 2 (UCP2(-/-)) in mice impaired glucagon secretion from isolated islets. Therefore, UCP2 may contribute to the regulation of hypoglycemia-induced glucagon secretion, which is supported by our current finding that UCP2 expression is increased in nutrient-deprived murine and human islets. Further to this, we created ?-cell-specific UCP2 knockout (UCP2AKO) mice, which we used to demonstrate that blood glucose recovery in response to hypoglycemia is impaired owing to attenuated glucagon secretion. UCP2-deleted ?-cells have higher levels of intracellular reactive oxygen species (ROS) due to enhanced mitochondrial coupling, which translated into defective stimulus/secretion coupling. The effects of UCP2 deletion were mimicked by the UCP2 inhibitor genipin on both murine and human islets and also by application of exogenous ROS, confirming that changes in oxidative status and electrical activity directly reduce glucagon secretion. Therefore, ?-cell UCP2 deletion perturbs the fasting/hypoglycemic glucagon response and shows that UCP2 is necessary for normal ?-cell glucose sensing and the maintenance of euglycemia. PMID:23434936

  9. NASA AVOSS Fast-Time Wake Prediction Models: User's Guide

    Science.gov (United States)

    Ahmad, Nash'at N.; VanValkenburg, Randal L.; Pruis, Matthew

    2014-01-01

    The National Aeronautics and Space Administration (NASA) is developing and testing fast-time wake transport and decay models to safely enhance the capacity of the National Airspace System (NAS). The fast-time wake models are empirical algorithms used for real-time predictions of wake transport and decay based on aircraft parameters and ambient weather conditions. The aircraft dependent parameters include the initial vortex descent velocity and the vortex pair separation distance. The atmospheric initial conditions include vertical profiles of temperature or potential temperature, eddy dissipation rate, and crosswind. The current distribution includes the latest versions of the APA (3.4) and the TDP (2.1) models. This User's Guide provides detailed information on the model inputs, file formats, and the model output. An example of a model run and a brief description of the Memphis 1995 Wake Vortex Dataset is also provided.

  10. REAL TIME FACE RECOGNITION USING ADABOOST IMPROVED FAST PCA ALGORITHM

    Directory of Open Access Journals (Sweden)

    K. Susheel Kumar

    2011-08-01

    Full Text Available This paper presents an automated system for human face recognition in a real time background world fora large homemade dataset of persons face. The task is very difficult as the real time backgroundsubtraction in an image is still a challenge. Addition to this there is a huge variation in human face imagein terms of size, pose and expression. The system proposed collapses most of this variance. To detect realtime human face AdaBoost with Haar cascade is used and a simple fast PCA and LDA is used torecognize the faces detected. The matched face is then used to mark attendance in the laboratory, in ourcase. This biometric system is a real time attendance system based on the human face recognition with asimple and fast algorithms and gaining a high accuracy rate..

  11. Modelling of tokamak discharges with the fast central response to the boundary plasma perturbations

    International Nuclear Information System (INIS)

    One of the fundamental phenomena in tokamak plasmas is the fast propagation of electron temperature perturbation from the boundary to the plasma core (faster than the characteristic transport time). This phenomenon has been observed in different tokamak (and stellarator) experiments: fast plasma core response to the L-H mode transition, fast cold pulse propagation after laser impurity ablation or deuterium pellet injection and some others. Standard diffusive model of local turbulent transport fails to describe these phenomena. It was the reason for the conclusion on a non-local nature of transport in tokamaks. Results of detailed simulations of some discharges with the fast central responses to the boundary perturbations of different nature are presented in this work. Role of different transport mechanisms is investigated. modelling was performed by the ASTRA transport code. The model takes into consideration the behavior of the plasma neutral component and neutrals recycling at the wall. It is shown that the effect of fast central response in discharges under consideration can be explained without the assumption on the non-local character of transport processes in tokamaks. This effect may be attributed to the behavior of the neutral plasma component, which propagation time across the plasma column is sufficiently short (less than 100 ? s). A rapid change in the neutral flux into the plasma column may somewhat affect the plasma energy balance in the whole plasma croma energy balance in the whole plasma cross section almost simultaneously. For example, the rapid electron temperature increase in the plasma core after the fast L-H mode transition can be explained by the reduction of the cold electron source caused by the decrease of neutral flux in plasma. An opposite effect of fast drop of the core electron temperature after deuterium pellet injection may be explained by the rise of deuterium atom density in the plasma core with corresponding increase of ionization source of cold electrons. So, the neutral plasma component is responsible for the visible coupling plasma edge and the core in considered experiments in time interval just after events. (author)

  12. Fast photorefractive response of vanadium-doped lithium niobate in the visible region.

    Science.gov (United States)

    Dong, Yinfeng; Liu, Shiguo; Kong, Yongfa; Chen, Shaolin; Rupp, Romano; Xu, Jingjun

    2012-06-01

    A series of vanadium-doped lithium niobate crystals was grown and their photorefractive properties were investigated with a 532 nm laser. At a total light intensity of 471 mW/cm(2), a short response time of only 0.57 s was achieved for 0.1 mol.% vanadium in LiNbO(3). The photorefractive process is dominated by the diffusion field instead of the photovoltaic field. The dominant charge carriers are electrons. The possible mechanism for the fast photorefractive response is discussed. PMID:22660047

  13. Directional Detection of Fast Neutrons Using a Time Projection Chamber

    International Nuclear Information System (INIS)

    Spontaneous fission in Special Nuclear Material (SNM) such as plutonium and highly enriched uranium (HEU) results in the emission of neutrons with energies in the MeV range (hereafter 'fast neutrons'). These fast neutrons are largely unaffected by the few centimeters of intervening high-Z material that would suffice for attenuating most emitted gamma rays, while tens of centimeters of hydrogenous materials are required to achieve substantial attenuation of neutron fluxes from SNM. Neutron detectors are therefore an important complement to gamma-ray detectors in SNM search and monitoring applications. The rate at which SNM emits fast neutrons varies from about 2 per kilogram per second for typical HEU to some 60,000 per kilogram per second for metallic weapons grade plutonium. These rates can be compared with typical sea-level (cosmogenic) neutron backgrounds of roughly 5 per second per square meter per steradian in the relevant energy range (1). The fact that the backgrounds are largely isotropic makes directional neutron detection especially attractive for SNM detection. The ability to detect, localize, and ultimately identify fast neutron sources at standoff will ultimately be limited by this background rate. Fast neutrons are particularly well suited to standoff detection and localization of SNM or other fast neutrons sources. Fast neutrons have attenuation lengths of about 60 meters in air, and retain considerable information about their source direction even afteion about their source direction even after one or two scatters. Knowledge of the incoming direction of a fast neutron, from SNM or otherwise, has the potential to significantly improve signal to background in a variety of applications, since the background arriving from any one direction is a small fraction of the total background. Imaging or directional information therefore allows for source detection at a larger standoff distance or with shorter dwell times compared to nondirectional detectors, provided high detection efficiency can be maintained. Directional detection of neutrons has been previously considered for applications such as controlled fusion neutron imaging (2), nuclear fuel safety research (3), imaging of solar neutrons and SNM (4), and in nuclear science (5). The use of scintillating crystals and fibers has been proposed for directional neutron detection (6). Recently, a neutron scatter camera has been designed, constructed, and tested for imaging of fast neutrons, characteristic for SNM material fission (7). The neutron scatter camera relies on the measurement of the proton recoil angle and proton energy by time of flight between two segmented solid-state detectors. A single-measurement result from the neutron scatter camera is a ring containing the possible incident neutron direction. Here we describe the development and commissioning of a directional neutron detection system based on a time projection chamber (TPC) detector. The TPC, which has been widely used in particle and nuclear physics research for several decades, provides a convenient means of measuring the full 3D trajectory, specific ionization (i.e particle type) and energy of charged particles. For this application, we observe recoil protons produced by fast neutron scatters on protons in hydrogen or methane gas. Gas pressures of a few ATM provide reasonable neutron interaction/scattering rates

  14. Timing the moment of impact in fast human movements.

    Science.gov (United States)

    Brenner, Eli; van Dam, Maarten; Berkhout, Stef; Smeets, Jeroen B J

    2012-09-01

    The reported resolution of timing the moment of impact in fast human movements differs widely depending on the task. Surprisingly, better timing is reported for the demanding task of batting a ball than for the much simpler task of tapping in synchrony with two hands. We wondered whether this is because a sizeable part of timing variability arises from misjudging the distance in the direction of one's own movement, so that moving faster (as the bat does when moving toward a ball) improves timing. We found that moving faster does indeed improve timing in both the above-mentioned tasks. After removing the proposed contribution of misjudging the distance in the direction of one's own movement, we estimated that the remaining standard deviation in timing is just over 6ms for both tasks. PMID:22864313

  15. Response of fast-reactor core subassemblies to pressure transients

    International Nuclear Information System (INIS)

    An Arbitrary Lagrangian-Eulerian (ALE) finite element method for analyzing the transient, nonlinear fluid-structure interaction in fast-reactor core subassemblies is presented. The method combines the basic attributes of the finite element technique-namely, ease in modeling complex geometries and in mixing fluid elements with structural elements - and the flexibility in moving the fluid mesh offered by the ALE description. The result of this combination is a very versatile modeling technique which permits accommodation of large fluid and structure displacements and logically simple, but accurate fluid-structure coupling. Numerical results are presented to illustrate the effectiveness of the proposed method. These include the response of a single hexagonal duct to internal, static or dynamic, pressure loading for which numerical predictions are compared to experimental data, and applications to clustered hexcans. (orig.)

  16. Seismic response analysis of the PEC fast reactor building

    International Nuclear Information System (INIS)

    In order to compute the motion induced by the design earthquakes at the vessel supporting structure, a seismic response analysis was performed for the PEC fast reactor, taking into account the effects of soil-structure interaction by use of experimentally determined soil parameters. The main aim of he analysis was to evaluate the safety margins present in the design calculations. A detailed 3D finite element model was set up for fixed base analysis; from the results of the 3D model a simplified equivalent model of the structure was then derived for soil-structure interaction analysis. The mathematical model was validated and calibrated by using the results of the experimental dynamic tests performed on the reactor building. The results have shown the adequacy of the computation methodologies, and in particular of those on the use of the equivalent model. (author)

  17. The photocurrent response of human cones is fast and monophasic

    Directory of Open Access Journals (Sweden)

    Lamb TD

    2006-04-01

    Full Text Available Abstract Background The precise form of the light response of human cone photoreceptors in vivo has not been established with certainty. To investigate the response shape we compare the predictions of a recent model of transduction in primate cone photoreceptors with measurements extracted from human cones using the paired-flash electroretinogram method. As a check, we also compare the predictions with previous single-cell measurements of ground squirrel cone responses. Results The predictions of the model provide a good description of the measurements, using values of parameters within the range previously determined for primate retina. The dim-flash response peaks in about 20 ms, and flash responses at all intensities are essentially monophasic. Three time constants in the model are extremely short: the two time constants for inactivation (of visual pigment and of transducin/phosphodiesterase are around 3 and 10 ms, and the time constant for calcium equilibration lies in the same range. Conclusion The close correspondence between experiment and theory, using parameters previously derived for recordings from macaque retina, supports the notion that the electroretinogram approach and the modelling approach both provide an accurate estimate of the cone photoresponse in the living human eye. For reasons that remain unclear, the responses of isolated photoreceptors from the macaque retina, recorded previously using the suction pipette method, are considerably slower than found here, and display biphasic kinetics.

  18. Fast fall-time ion beam in neutron generators

    International Nuclear Information System (INIS)

    Ion beam with a fast fall time is useful in building neutron generators for the application of detecting hidden, gamma-shielded SNM using differential die-away (DDA) technique. Typically a fall time of less than 1 (micro)s can't be achieved by just turning off the power to the ion source due to the slow decay of plasma density (partly determined by the fall time of the RF power in the circuit). In this paper, we discuss the method of using an array of mini-apertures (instead of one large aperture beam) such that gating the beamlets can be done with low voltage and a small gap. This geometry minimizes the problem of voltage breakdown as well as reducing the time of flight to produce fast gating. We have designed and fabricated an array of 16 apertures (4 x 4) for a beam extraction experiment. Using a gating voltage of 1400 V and a gap distance of 1 mm, the fall time of extracted ion beam pulses is less than 1 (micro)s at various beam energies ranging between 400 eV to 800 eV. Usually merging an array of beamlets suffers the loss of beam brightness, i.e., emittance growth, but that is not an important issue for neutron source applications

  19. A measurement of the response to fast neutrons of several materials dosemeters

    International Nuclear Information System (INIS)

    The response to fast neutrons was measured for three types of materials testing dosemeters: fast neutron dosimetry silicon diodes; beryllia, alumina and calcium fluoride TLDs; graphite walled ionisation chambers. The calibrations were made using a 3MW positive ion accelerator. The arrangement of the target, beam monitor and devices is described, and the measured fast neutron sensitivities are presented. (UK)

  20. Fast timing detectors for high field ?SR spectrometers

    International Nuclear Information System (INIS)

    Observation of the muon spin precession in high magnetic fields imposes strict requirements on the time resolution of scintillation counters used for detection of incoming muons and the decay positrons. The time resolution of PMT-based detectors is limited in high magnetic fields due to an additional broadening of the light pulses in the necessary light guides. The detector systems using photodetectors that are insensitive to magnetic field, such as multipixel Geiger-mode avalanche photodiodes (G-APDs), do not require light guides and thus can prove to be more advantageous for such application. In this work we build prototypes of fast-timing muon and positrons counters based on G-APDs. The detectors were tested in magnetic fields up to 4.8 T and showed a time resolution better than 50 ps (sigma).

  1. Fast timing detectors for high field muSR spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Stoykov, A., E-mail: alexey.stoykov@psi.c [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Joint Institute for Nuclear Research, 141980 Dubna, Moscow Region (Russian Federation); Scheuermann, R.; Sedlak, K. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)

    2009-04-15

    Observation of the muon spin precession in high magnetic fields imposes strict requirements on the time resolution of scintillation counters used for detection of incoming muons and the decay positrons. The time resolution of PMT-based detectors is limited in high magnetic fields due to an additional broadening of the light pulses in the necessary light guides. The detector systems using photodetectors that are insensitive to magnetic field, such as multipixel Geiger-mode avalanche photodiodes (G-APDs), do not require light guides and thus can prove to be more advantageous for such application. In this work we build prototypes of fast-timing muon and positrons counters based on G-APDs. The detectors were tested in magnetic fields up to 4.8 T and showed a time resolution better than 50 ps (sigma).

  2. Response of a fast reactor to a neutron source

    International Nuclear Information System (INIS)

    In the multigroup approximation, a fast homogeneous bare reactor has properties which for each spatial harmonic can be summed up by a matrix A. A classification of reactors is made as a function of this structure which varies with the considered medium. The eigenvalues of A are the decay constants obtained with a pulsed neutron source. In the spectrum of these eigenvalues, is often a marked line related to a fundamental. The line is not always single. The neutron spectrum may be calculated from the eigenvectors. A neutron source, according to its spectrum, excites more or less the various energy harmonics. The detector, for its part, does not have the same response to all harmonics. Phenomena are symmetrical. Equations of this problem are written in matrix form and applied to sources which can be pulsed, modulated or controlled by the reactor flux. FORTRAN IV codes computing the behaviour of the detector response are described in the Appendix. For the computation of eigenvalues and eigenvectors, some of these codes use sub-routines more accurate than the usual ones. (author)

  3. Measurement of the dynamic response of differential pressure transmitters using a response time tester

    International Nuclear Information System (INIS)

    AECL's response time tester (RTT) for pressure and differential-pressure (DP) transmitters provide a simple, fast and accurate means of measuring pressure transmitter step response time and response time characteristics as defined in ISA Standard ISA-S67.06. The step response method of measuring response time is used by all prominent sensor suppliers and provides a result that is readily understood. The measurement of response time characteristics, which includes the transfer function, provides a complete and sensitive characterization of the dynamic response of the sensor that can be used to predict the response to ramps or any other transient. The AECL Model 200 RTT uses standard instrument air as the source of test pressure, and is suitable for testing transmitters that operate at pressures less than 650 kPa. It can accurately measure step response times in the range of 20 to 2000 ms. It is thus capable of measuring the response times of most of the pressure instruments in the CANDU safety systems. The Model 200 RTT is completely contained in a cabinet that can be easily moved on built-in shock-absorbent wheels, to facilitate testing transmitter while on the bench or mounted on the instrument rack. The RTT comprises pressurized components in the front end, and computerized data acquisition components and analysis software in the back end. Tests are conducted by switching the pressure applied to the transmitter between two values using a long-life, fast acting 3-wayalues using a long-life, fast acting 3-way solenoid valve. The actual pressure applied to the transmitter is measured with a high-frequency reference transducer. Once the operator has connected the air supply and transmitter, and set the test pressures, the actual testing and analysis proceeds automatically. Four sets of tests are conducted. A number of comparisons, as required by ISA-S67.06, are made to verify that: the transmitter is linear with respect to direction and rate of change; and the results are consistent between two diverse test methods. The broadband noise tests are used to find the transfer function (all the significant time constants) of the transmitter. Given the transfer function, the expected response to a step input can be computed and compared to the measured step response, thus verifying both measurements. The results are summarized and printed on the built-in printer. Files are saved to disk for later review. (author)

  4. A Fast-Response Atmospheric Turbulence (FRAT) Probe with Gas-Sampling Ducts Project

    National Aeronautics and Space Administration — The objective of this proposal is to design, construct and test a high-frequency-response air-data probe, the Fast Response Atmospheric Turbulence probe (FRAT...

  5. A Fast-Response Atmospheric Turbulence (FRAT) Probe with Gas-Sampling Ducts Project

    National Aeronautics and Space Administration — Aeroprobe proposes to design, construct and test an air-data probe with substantially higher frequency response than currently available. This fast-response...

  6. Highly stable fast-neutron time-of-flight spectrometer

    International Nuclear Information System (INIS)

    A fast-neutron time-of-flight spectrometer with an electronic system for parameter stabilization in which reference signals pass through the same circuits as do the signals of the processes under study is described. This provides a twofold improvement in instrumental resolution in prolonged measurements, which amounts to 1.2 nsec. For a path length of 7 m, a neutron-beam energy width of 200 +/- 12 keV is measured for an average neutron energy of 14.6 MeV

  7. High stability fast neutron time-of-flight spectrometer

    International Nuclear Information System (INIS)

    A fast neutron time-of-flight spectrometer with electronic system of parameter stabilization, in which bench mark signals transmit in the same circuits that the signals of the processes investigated, is described. The time-of-flight spectrometer is developed on the basis of a low-voltage accelerator, tritium target of which serves as a neutron source. As a result a twofold improvement in the instrumental resolution in long-time measurements is achieved, being 1.2 ns. On the flight basis of 7 m the energy width of neutron beam equalling 200 ± 12 keV at the average neutron energy 14.6 MeV has been measured

  8. A Race Model for Responses and Response Times in Tests.

    Science.gov (United States)

    Ranger, Jochen; Kuhn, Jörg-Tobias; Gaviria, José-Luis

    2014-11-01

    Latent trait models for responses and response times in tests are often pure statistical models without a close connection to features of the assumed response process. In the present paper, a new model is presented that is more closely related to assumptions about the response process. The model is based on two increasing stochastic processes. Each stochastic process represents the accumulation of knowledge with respect to one of two response options, the correct and incorrect response. Both accumulators compete and the accumulator that first exceeds a critical level determines the response. General assumptions about the accumulators result in a race between two response times that follow a bivariate Birnbaum Saunders distribution. The model can be calibrated with marginal maximum likelihood estimation. Feasibility of the estimation approach is demonstrated in a simulation study. Additionally, a test of model fit is proposed. Finally, the model will be used for the analysis of an empirical data set. PMID:25381198

  9. Response times in email interchange

    CERN Document Server

    Johansen, A

    2003-01-01

    An alternative interpretation of e-mail interchange data presented by J.P. Eckmann, E. Moshes and D. Sergi in a recent preprint (cond-mat/0304433) is presented. The data agrees with the proposed frame work prosposed to explain two recent experiments on the response of ``internauts'' to a news publication.

  10. Digitally Controlled Point of Load Converter with Very Fast Transient Response

    DEFF Research Database (Denmark)

    Jakobsen, Lars TØnnes; Andersen, Michael Andreas E.

    2007-01-01

    This paper presents a new Digital Self-Oscillating Modulator (DiSOM) that allows the duty cycle to be changed instantly. The DiSOM modulator is shown to have variable switching that is a function of the duty cycle. Compared to a more traditional digital PWM modulator based on a counter and comparator the DiSOM modulator allows the sampling frequency of the output voltage control loop to be higher than the switching frequency of the power converter, typically a DC/DC converter. The features of the DiSOM modulator makes it possible to design a digitally controlled DC/DC converter with linear voltage mode control and very fast transient response. The DiSOM modulator is combined with a digital PID compensator algorithm is implemented in a hybrid CPLD/FPGA and is used to control a synchronous Buck converter, which is used in typical Point of Load applications. The computational time is only three clock cycles from the time the A/D converter result is read by the control algorithm to the time the duty cycle command is updated. A typical POL converter has been built and the experimental results show that the transient response of the converter is very fast. The output voltage overshoot is only 2.5% of the nominal output voltage when a load step of 50% - 100% of nominal output current is applied to the converter. The settling time is approximately 8 PWM cycles.

  11. A display module implemented by the fast high-temperatue response of carbon nanotube thin yarns.

    Science.gov (United States)

    Wei, Yang; Liu, Peng; Jiang, Kaili; Fan, Shoushan

    2012-05-01

    Suspending superaligned multiwalled carbon nanotube (MWCNT) films were processed into CNT thin yarns, about 1 ?m in diameter, by laser cutting and an ethanol atomization bath treatment. The fast high-temperature response under a vacuum was revealed by monitoring the incandescent light with a photo diode. The thin yarns can be electrically heated up to 2170 K in 0.79 mS, and the succeeding cool-down time is 0.36 mS. The fast response is attributed to the ultrasmall mass of the independent single yarn, large radiation coefficient, and improved thermal conductance through the two cool ends. The millisecond response time makes it possible to use the visible hot thin yarns as light-emitting elements of an incandescent display. A fully sealed display with 16 × 16 matrix was successfully fabricated using screen-printed thick electrodes and CNT thin yarns. It can display rolling characters with a low power consumption. More applications can be further developed based on the addressable CNT thermal arrays. PMID:22494045

  12. A novel fast timing micropattern gaseous detector: FTM

    CERN Document Server

    De Oliveira, Rui; Maggi, Marcello

    2015-01-01

    In recent years important progress in micropattern gaseous detectors has been achieved in the use of resistive material to build compact spark-protected devices. The novel idea presented here consists of the polarisation of WELL structures using only resistive electrodes. This allows a new device to be built with an architecture based on a stack of several coupled layers where drift and WELL multiplication stages alternate in the structure. The signals from each multiplication stage can be read out from any external readout boards through the capacitive couplings. Each layer provides a signal with a gain of 10^4 - 10^5. The main advantage of this new device is the dramatic improvement of the timing provided by the competition of the ionisation processes in the different drift regions, which can be exploited for fast timing at the high luminosity accelerators (e.g. HL-LHC upgrade) as well as applications outside particle physics.

  13. A novel fast timing micropattern gaseous detector: FTM

    CERN Document Server

    De Oliveira, Rui; Sharma, Archana

    2015-01-01

    In recent years important progress in micropattern gaseous detectors has been achieved in the use of resistive material to build compact spark-protected devices. The novel idea presented here consists of the polarisation of WELL structures using only resistive coating. This allows a new device to be built with an architecture based on a stack of several coupled layers where drift and WELL multiplication stages alternate in the structure. The signals from each multiplication stage can be read out from any external readout boards through the capacitive couplings. Each layer provides a signal with a gain of 10^4-10^5. The main advantage of this new device is the dramatic improvement of the timing provided by the competition of the ionisation processes in the different drift regions, which can be exploited for fast timing at the high luminosity accelerators (e.g. HL-LHC upgrade) as well as far applications like medical imaging.

  14. Fast atmospheric response to a sudden thinning of Arctic sea ice

    Science.gov (United States)

    Semmler, Tido; Jung, Thomas; Serrar, Soumia

    2015-05-01

    In order to understand the influence of a thinner Arctic sea ice on the wintertime atmosphere, idealized ensemble experiments with increased sea ice surface temperature have been carried out with the Integrated Forecast System of the European Centre for Medium-Range Weather Forecasts. The focus is on the fast atmospheric response to a sudden "thinning" of Arctic sea ice to disentangle the role of various different processes. We found that boundary layer turbulence is the most important process that distributes anomalous heat vertically. Anomalous longwave radiation plays an important role within the first few days before temperatures in the lower troposphere had time to adjust. The dynamic response tends to balance that due to boundary layer turbulence while cloud processes and convection play only a minor role. Overall the response of the atmospheric large-scale circulation is relatively small with up to 2 hPa in the mean sea level pressure during the first 15 days; the quasi-equilibrium response reached in the second and third month of the integration is about twice as large. During the first few days the response tends to be baroclinic in the whole Arctic. Already after a few days an anti-cyclonic equivalent-barotropic response develops over north-western Siberia and north-eastern Europe. The structure resembles very much that of the atmospheric equilibrium response indicating that fast tropospheric processes such as fewer quasi-barotropic cyclones entering this continental area are key opposed to slower processes such as those involving, for example, stratosphere-troposphere interaction.

  15. New optical hydrogen sensor with fast response time based on multilayer palladium-nickel-PTFE thin film for explosion-proof detection of high H II concentrations of 1-100%

    Science.gov (United States)

    Bramann, Gero; Zacharias, Bernd; Wienecke, Marion

    2007-07-01

    Hydrogen detection is of great interest in many fields such as hydrogen concentrations around the explosive limit of 4% or in areas where strong electrical fields are present. Optical sensors have the advantage that they are not affected by these conditions. A comparison of three thin film sensors made of Pd, Pd Ni and Pd Ni / PTFE to detect H II is made. The double-sided samples are purpose built by plasma sputtering, with a thickness of 4nm on each side. It is shown that the signal of a pure Pd deposit is strong but it cannot resist higher H II concentrations. The Pd Ni deposit has shown good results and is able to resolve even higher concentrations of 10% H II but cannot resist high concentrations of H II over many cycles. The new Pd Ni / PTFE deposit can be used many times for concentrations up to 100% without any damage and can detect concentrations of 1-100% of H II. Furthermore the response time for deposits of different thickness is tested.

  16. Interlock system with fast response against sudden foil rupture and vacuum failure in Linac structure

    International Nuclear Information System (INIS)

    A 10 MeV electron Linac is operational at Raja Ramanna Centre for Advanced Technology, Indore. To extract the intense electron beam from vacuum to atmosphere, it is scanned inside a vacuum chamber sealed with titanium foil at the exit. If scanning locks fails during high power operation at 200-300 Hz pulse repetition rate, the un-scanned beam will burn a hole in the window, leading to sudden failure of linac vacuum. Under such accidental situation, if subsequent RF pulse is delivered to the linac, the structure will get damaged. The interlocks used for vacuum failure detection are generally taken from the head of cold cathode gauge, which has large response time, hence not effective to protect linac under such accidental condition. We have carried out a series of experiments to simulate the process of accidental vacuum failure and investigated various methods for fast detection of vacuum failure and subsequent inhibition of RF pulses. The response time of the interlock from the vacuum gauge was measured to be 160 ms. Response of the analog output signal of gauge controller corresponding to change in vacuum is relatively fast but takes 20-30 ms to reflect measurable change in analog value. The ion current of the SIP is found very sensitive towards vacuum and responds very fast for any change in the vacuum level. An interlock circuit has been designed which senses the ion current signal of SIP and stops the master trigger system of the linac in less than 3 ms after rupture of the foil. Results of the experiments and design details of the interlock system are presented in this paper. (author)

  17. Synchronous timing of multi-energy fast beam extraction

    International Nuclear Information System (INIS)

    Synchronous triggering of fast beams is required because the field of Kicker Magnets must rise within the open space between one beam bunch and the next. Within the Brookhaven AGS, Fast Extracted Beam (FEB) triggering2 combines nominal timing, based on beam energy with bunch-to-bunch synchronization, based on the accelerating RF waveform. During beam acceleration, a single bunch is extracted at 22 GeV/c and within the same AGS cycle, the remaining eleven bunches are extracted at 28.4 GeV/c. When the single bunch is extracted, a hole, which is left in the remaining circulating beam, can appear in random locations within the second extraction during successive AGS cycles. To overcome this problem, a synchronous RF/12 counting scheme and logic circuitry are used to keep track of the bunch positions relative to each other, and to place the hole in any desired location within the second extraction. The RF/12 signal is used also to synchronize experimenters triggers

  18. Fast to forgive, slow to retaliate: intuitive responses in the ultimatum game depend on the degree of unfairness.

    Science.gov (United States)

    Ferguson, Eamonn; Maltby, John; Bibby, Peter A; Lawrence, Claire

    2014-01-01

    Evolutionary accounts have difficulty explaining why people cooperate with anonymous strangers they will never meet. Recently models, focusing on emotional processing, have been proposed as a potential explanation, with attention focusing on a dual systems approach based on system 1 (fast, intuitive, automatic, effortless, and emotional) and system 2 (slow, reflective, effortful, proactive and unemotional). Evidence shows that when cooperation is salient, people are fast (system 1) to cooperate, but with longer delays (system 2) they show greed. This is interpreted within the framework of the social heuristic hypothesis (SHH), whereby people overgeneralize potentially advantageous intuitively learnt and internalization social norms to 'atypical' situations. We extend this to explore intuitive reactions to unfairness by integrating the SHH with the 'fast to forgive, slow to anger' (FFSA) heuristic. This suggests that it is advantageous to be prosocial when facing uncertainty. We propose that whether or not someone intuitively shows prosociality (cooperation) or retaliation is moderated by the degree (certainty) of unfairness. People should intuitively cooperate when facing mild levels of unfairness (fast to forgive) but when given longer to decide about another's mild level of unfairness should retaliate (slow to anger). However, when facing severe levels of unfairness, the intuitive response is always retaliation. We test this using a series of one-shot ultimatum games and manipulate level of offer unfairness (50:50 60:40, 70:30, 80:20, 90:10) and enforced time delays prior to responding (1s, 2s, 8s, 15s). We also measure decision times to make responses after the time delays. The results show that when facing mildly unfair offers (60:40) people are fast (intuitive) to cooperate but with longer delays reject these mildly unfair offers: 'fast to forgive, and slow to retaliate'. However, for severely unfair offers (90:10) the intuitive and fast response is to always reject. PMID:24820479

  19. Mathematical modeling of the LCD response time

    OpenAIRE

    Adam, Pierre; Bertolino, Pascal; Lebowsky, Fritz

    2007-01-01

    Techniques to reduce LCD motion blur are extensively used in industry and they depend on an inherent LCD parameter: response time. However, normative response time is not a sufficient reference to improve LCD performance and all the gray-to-gray response-time quantities are required to obtain good improvement. However, measuring and gathering all the gray-to-gray transitions takes an excessive amount of time. Consequently, we propose a novel LCD model to simulate as well as compute gray-to-gr...

  20. The generalized centroid difference method for picosecond sensitive determination of lifetimes of nuclear excited states using large fast-timing arrays

    International Nuclear Information System (INIS)

    A novel method for direct electronic “fast-timing” lifetime measurements of nuclear excited states via ?–? coincidences using an array equipped with N?N equally shaped very fast high-resolution LaBr3(Ce) scintillator detectors is presented. Analogous to the mirror symmetric centroid difference method, the generalized centroid difference method provides two independent “start” and “stop” time spectra obtained by a superposition of the N(N?1)?–? time difference spectra of the N detector fast-timing system. The two fast-timing array time spectra correspond to a forward and reverse gating of a specific ?–? cascade. Provided that the energy response and the electronic time pick-off of the detectors are almost equal, a mean prompt response difference between start and stop events is calibrated and used as a single correction for lifetime determination. These combined fast-timing arrays mean ?–? time-walk characteristics can be determined for 40keV?152Eu ?-ray source. Due to reduction and cancellation of many possible systematic errors, the lifetime determination limit of the method over the total dynamic range is mainly determined by the statistics. The setup of an N=4 detector fast-timing array delivered an absolute time resolving power of 3 ps for 10 000 ?–? events per total fast timing array start and stop time spectrum. The new method is tested over the total dynamic range by the measurements of known picosecond lifetimes in standard ?-ray sources

  1. Fast, Linear Time Hierarchical Clustering using the Baire Metric

    CERN Document Server

    Contreras, Pedro

    2011-01-01

    The Baire metric induces an ultrametric on a dataset and is of linear computational complexity, contrasted with the standard quadratic time agglomerative hierarchical clustering algorithm. In this work we evaluate empirically this new approach to hierarchical clustering. We compare hierarchical clustering based on the Baire metric with (i) agglomerative hierarchical clustering, in terms of algorithm properties; (ii) generalized ultrametrics, in terms of definition; and (iii) fast clustering through k-means partititioning, in terms of quality of results. For the latter, we carry out an in depth astronomical study. We apply the Baire distance to spectrometric and photometric redshifts from the Sloan Digital Sky Survey using, in this work, about half a million astronomical objects. We want to know how well the (more costly to determine) spectrometric redshifts can predict the (more easily obtained) photometric redshifts, i.e. we seek to regress the spectrometric on the photometric redshifts, and we use clusterwi...

  2. Geosynchronous magnetic field responses to fast solar wind dynamic pressure enhancements: MHD field model

    Directory of Open Access Journals (Sweden)

    T. R. Sun

    2012-08-01

    Full Text Available We performed global MHD simulations of the geosynchronous magnetic field in response to fast solar wind dynamic pressure (Pd enhancements. Taking three Pd enhancement events in 2000 as examples, we found that the main features of the total field B and the dominant component Bz can be efficiently predicted by the MHD model. The predicted B and Bz varies with local time, with the highest level near noon and a slightly lower level around mid-night. However, it is more challenging to accurately predict the responses of the smaller component at the geosynchronous orbit (i.e., Bx and By. In contrast, the limitations of T01 model in predicting responses to fast Pd enhancements are presented.

  3. Response Time Optimization of a Reactor's Monitoring and Alarm System

    International Nuclear Information System (INIS)

    The reactor's monitoring system under development [1], measures neutron flux density using Boron lined ionization chambers. The current signal from the ionization chambers is amplified and digitized, and a digital processor calculates the momentary flux and its doubling time. An alarm signal is further generated whenever the flux is too high or grows too rapidly. The alarm signal is sent to the reactor's automatic emergency shut down circuit. Unfortunately, fluctuations and noise in the sampled signal have a significant influence on the calculated doubling time and may generate false alarms. Low-pass filtering of the signal will slow down the response time. An optimal filter should balance the conflicting requirements for fast response and for low rate false alarms

  4. Modeling and dynamic characteristics analysis on a three-stage fast-response and large-flow directional valve

    International Nuclear Information System (INIS)

    Highlights: • Presenting a valve with the fast response and high flow capacity simultaneously. • Dividing the response time into the starting delay ?t1 and opening time ?t2. • Proposing the change time ?tc and critical open value pc3cr of the control pressure. • The fast response relies on short change time ?tc and appropriate value of pc3cr. • Optimizing parameters associated with ?tc and pc3cr to improve valve response. - Abstract: The large transient power hydraulic systems, characterized by high pressure, large transient flow and high output power, have widespread industrial applications in converting powerful hydraulic energy to kinetic energy in a transient period. A conventional large flow rate directional valve is unable to be used in these applications due to the slow response. A directional control valve with fast response and high flow capacity simultaneously is presented for the large transient power hydraulic system in this paper. The valve utilizes a three-stage structure with two high-speed on/off solenoid valves as the pilot stage and two cartridge poppet valves as the secondary stage to overcome the fundamental trade off between valve response and flow capacity. A precise mathematical model of this valve considering both turbulent flow and laminar flow is developed. A test apparatus which has the ability to provide and measure transient large flow is built. The flow rate is estimated based on the pressure dynamics. The property parameters in the simulation model are optimized against measured data. According to the dynamic characteristics analysis, the valve response is split into the starting delay and opening time. The step response is rapid enough to provide a large transient flow, while the high flow capacity is not reduced due to the fast response. The main control pressure is characterized by its change time and critical open pressure and these two parameters determine the main-stage response. Some key structural factors concerning with these two parameters are discussed in detail and optimize to further reduce the response time

  5. A time-dependent study of fast neutrons in iron

    International Nuclear Information System (INIS)

    Using diffusion theory and the eigenfunction expansion method, a detailed time-dependent study of fast neutrons has been made for three iron assemblies: infinite, 1 m3, and 0.5 m3. Various results have been obtained by taking two different source energies, namely, 14.47 and 1.0076 MeV. All the calculations have been carried out using the 50-group cross-section set of Ahmed et al. For the 1.0076 MeV source, the time-dependent spectra exhibit two distinct peaks up to about 50 ns, energy variation of the mean slowing down time t /sup i/ /sub s/ shows ''anomalous'' behavior similar to that observed by Beynon et al., and the most probable time t /sup i/ /sub p/ has two different values for some energy groups below about 240 keV, in conformity with the results of White et al. The double values of t /sup i/ /sub p/ (except for the 40th and 41st groups) and the ''anomalous'' behavior observed in t /sup i/ /sub s/ cease when we take the source energy to be 14.47 MeV. Further, for all values of energy E /sup i/, the values of both t /sup i/ /sub s/ and t /sup i/ /sub p/ decrease as the size of the assembly is reduced. It has been shown that in the two larger assemblies, pseudoasymptotic conditions are established in certain time intervals. It was determined that some energy groups tend to cluster and decay with the same decay constant after a certain time

  6. Bubble masks for time-encoded imaging of fast neutrons.

    Energy Technology Data Exchange (ETDEWEB)

    Brubaker, Erik; Brennan, James S.; Marleau, Peter; Nowack, Aaron B.; Steele, John; Sweany, Melinda; Throckmorton, Daniel J.

    2013-09-01

    Time-encoded imaging is an approach to directional radiation detection that is being developed at SNL with a focus on fast neutron directional detection. In this technique, a time modulation of a detected neutron signal is induced-typically, a moving mask that attenuates neutrons with a time structure that depends on the source position. An important challenge in time-encoded imaging is to develop high-resolution two-dimensional imaging capabilities; building a mechanically moving high-resolution mask presents challenges both theoretical and technical. We have investigated an alternative to mechanical masks that replaces the solid mask with a liquid such as mineral oil. Instead of fixed blocks of solid material that move in pre-defined patterns, the oil is contained in tubing structures, and carefully introduced air gaps-bubbles-propagate through the tubing, generating moving patterns of oil mask elements and air apertures. Compared to current moving-mask techniques, the bubble mask is simple, since mechanical motion is replaced by gravity-driven bubble propagation; it is flexible, since arbitrary bubble patterns can be generated by a software-controlled valve actuator; and it is potentially high performance, since the tubing and bubble size can be tuned for high-resolution imaging requirements. We have built and tested various single-tube mask elements, and will present results on bubble introduction and propagation as a function of tubing size and cross-sectional shape; real-time bubble position tracking; neutron source imaging tests; and reconstruction techniques demonstrated on simple test data as well as a simulated full detector system.

  7. Fast and accurate calculations for cumulative first-passage time distributions in Wiener diffusion models

    DEFF Research Database (Denmark)

    Blurton, Steven Paul; Kesselmeier, M.

    2012-01-01

    We propose an improved method for calculating the cumulative first-passage time distribution in Wiener diffusion models with two absorbing barriers. This distribution function is frequently used to describe responses and error probabilities in choice reaction time tasks. The present work extends related work on the density of first-passage times [Navarro, D.J., Fuss, I.G. (2009). Fast and accurate calculations for first-passage times in Wiener diffusion models. Journal of Mathematical Psychology, 53, 222-230]. Two representations exist for the distribution, both including infinite series. We derive upper bounds for the approximation error resulting from finite truncation of the series, and we determine the number of iterations required to limit the error below a pre-specified tolerance. For a given set of parameters, the representation can then be chosen which requires the least computational effort.

  8. A Fasting-Responsive Signaling Pathway that Extends Life Span in C. elegans

    Directory of Open Access Journals (Sweden)

    Masaharu Uno

    2013-01-01

    Full Text Available Intermittent fasting is one of the most effective dietary restriction regimens that extend life span in C. elegans and mammals. Fasting-stimulus responses are key to the longevity response; however, the mechanisms that sense and transduce the fasting stimulus remain largely unknown. Through a comprehensive transcriptome analysis in C. elegans, we find that along with the FOXO transcription factor DAF-16, AP-1 (JUN-1/FOS-1 plays a central role in fasting-induced transcriptional changes. KGB-1, one of the C. elegans JNKs, acts as an activator of AP-1 and is activated in response to fasting. KGB-1 and AP-1 are involved in intermittent fasting-induced longevity. Fasting-induced upregulation of the components of the SCF E3 ubiquitin ligase complex via AP-1 and DAF-16 enhances protein ubiquitination and reduces protein carbonylation. Our results thus identify a fasting-responsive KGB-1/AP-1 signaling pathway, which, together with DAF-16, causes transcriptional changes that mediate longevity, partly through regulating proteostasis.

  9. Intrinsic Response Time of Graphene Photodetectors

    OpenAIRE

    Urich, Alexander; Unterrainer, Karl; Mueller, Thomas

    2011-01-01

    Graphene-based photodetectors are promising new devices for high-speed optoelectronic applications. However, despite recent efforts, it is not clear what determines the ultimate speed limit of these devices. Here, we present measurements of the intrinsic response time of metal-graphene-metal photodetectors with monolayer graphene using an optical correlation technique with ultrashort laser pulses. We obtain a response time of 2.1 ps that is mainly given by the short lifetime...

  10. Real-time lucky imaging in FastCam project

    Science.gov (United States)

    Rodríguez Ramos, L. F.; Piqueras Meseguer, J. J.; Martin Hernando, Y.; Oscoz, A.; Rebolo, R.

    2008-07-01

    Lucky imaging techniques implemented by the FastCam group (see http://www.iac.es/proyecto/fastcam/) at the Instituto de Astrofisica de Canarias have demonstrated its ability to obtain spectacular diffraction limited images in telescopes ranging from 1 to 4.2 m in visible wavelengths (mainly in the I band), at the expense of using only a small percentage of the available images. This work presents the development of a real-time processor, FPGA-based, capable of performing all the required processing involved in the lucky imaging technique: Bias and flat-field correction, quality evaluation of images, quality threshold for image selection, image recentering and accumulation, and finally sending through Gigabit Ethernet both raw and processed images to a PC computer. Furthermore, a real time display is generated directly from FPGA showing both types of images, plus a histogram of the computed quality values and the threshold used. All processes can co-exist physically located in separated places inside the FPGA, using its natural parallel approach, and can easily handle the 512x512 pixels at 30 fps found at the sensor camera output (an Andor Ixon+ DU-897ECSO EMCCD). Flexibility and parallel processing features of the reconfigurable logic have been used to implement a novel imaging strategy for segmented-mirror telescopes, allowing separate evaluation of every segment and posterior accumulation to achieve the resolution limit of a single segment with the integration capability of the full primary mirror.

  11. IQPNNI: moving fast through tree space and stopping in time.

    Science.gov (United States)

    Vinh, Le Sy; Von Haeseler, Arndt

    2004-08-01

    An efficient tree reconstruction method (IQPNNI) is introduced to reconstruct a phylogenetic tree based on DNA or amino acid sequence data. Our approach combines various fast algorithms to generate a list of potential candidate trees. The key ingredient is the definition of so-called important quartets (IQs), which allow the computation of an intermediate tree in O(n(2)) time for n sequences. The resulting tree is then further optimized by applying the nearest neighbor interchange (NNI) operation. Subsequently a random fraction of the sequences is deleted from the best tree found so far. The deleted sequences are then re-inserted in the smaller tree using the important quartet puzzling (IQP) algorithm. These steps are repeated several times and the best tree, with respect to the likelihood criterion, is considered as the inferred phylogenetic tree. Moreover, we suggest a rule which indicates when to stop the search. Simulations show that IQPNNI gives a slightly better accuracy than other programs tested. Moreover, we applied the approach to 218 small subunit rRNA sequences and 500 rbcL sequences. We found trees with higher likelihood compared to the results by others. A program to reconstruct DNA or amino acid based phylogenetic trees is available online (http://www.bi.uni-duesseldorf.de/software/iqpnni). PMID:15163768

  12. Fast versus slow response in climate change: implications for the global hydrological cycle

    Energy Technology Data Exchange (ETDEWEB)

    Bala, Govindasamy [Indian Institute of Science, Divecha Center for Climate Change and Center for Atmospheric and Oceanic Sciences, Bangalore (India); Caldeira, K. [Carnegie Institution, Department of Global Ecology, Stanford, CA (United States); Nemani, R. [NASA Ames Research Center, Santa Clara, CA (United States)

    2010-08-15

    Recent studies have shown that changes in global mean precipitation are larger for solar forcing than for CO{sub 2} forcing of similar magnitude. In this paper, we use an atmospheric general circulation model to show that the differences originate from differing fast responses of the climate system. We estimate the adjusted radiative forcing and fast response using Hansen's ''fixed-SST forcing'' method. Total climate system response is calculated using mixed layer simulations using the same model. Our analysis shows that the fast response is almost 40% of the total response for few key variables like precipitation and evaporation. We further demonstrate that the hydrologic sensitivity, defined as the change in global mean precipitation per unit warming, is the same for the two forcings when the fast responses are excluded from the definition of hydrologic sensitivity, suggesting that the slow response (feedback) of the hydrological cycle is independent of the forcing mechanism. Based on our results, we recommend that the fast and slow response be compared separately in multi-model intercomparisons to discover and understand robust responses in hydrologic cycle. The significance of this study to geoengineering is discussed. (orig.)

  13. Response times and response accuracy for odor localization and identification.

    Science.gov (United States)

    Kéïta, L; Frasnelli, J; La Buissonnière-Ariza, V; Lepore, F

    2013-05-15

    Although significant progress has been made over the last decades, the chemical senses remain less well explored than vision or audition. One method to assess participants' ability to identify or localize odors consists in the application of dichotomous stimuli (e.g., left- and right-sided stimulation). In this study we aimed to explore localization and identification mechanisms by investigating whether response times and response accuracy were correlated, with the aim of establishing the pertinence of response times as an additional measure for assessment of the olfactory function (1). We further examined an advantage of the right nostril which has been reported in several publications (2). We delivered two mixed olfactory/trigeminal odors (benzaldehyde and eucalyptol) to one nostril at a time in a pseudorandomized order to 23 normosmic participants; the other nostril received an odor-free air puff. In half of the trials we asked the participants to detect the stimulated nostril; in the other half, they indicated which odor they had received. We recorded response accuracy and response times. Participants reached higher accuracy in odor identification than in localization, driven by benzaldehyde. For the stimulus eucalyptol exclusively, we observed that participants were faster to respond after stimulation of the right nostril than to the left nostril, in the localization task. Finally, response times were correlated with response accuracy in the identification task, but not in localization. Our findings suggest that odor identification is easier than odor localization. In addition, we find further support for an advantage of the right nostril over the left nostril. Moreover, the measurement of reaction times may supplement other techniques of the assessment of odor identification. PMID:23454368

  14. A LaBr3: Ce fast-timing array for DESPEC at FAIR

    Science.gov (United States)

    Roberts, Oliver J.; Bruce, Alison M.; Regan, Patrick H.; Podolyák, Zsolt; Townsley, Christopher M.; Smith, John F.; Mulholland, Kieran F.; Smith, Andrew

    2014-06-01

    The design of a fast-timing ?-ray detection array aimed at measuring sub-nanosecond half-lives using LaBr3:Ce scintillation crystals is presented. This array will complement novel and existing charged particle and neutron detector arrays at the low-energy branch of a fragment separator (Super-FRS) to be built within the NuSTAR collaboration as part of the future Facility for Anti-proton and Ion Research (FAIR). The array will be used in conjunction with the Advanced Implantation Detector Array (AIDA), to measure implant-decay correlations. Monte-Carlo simulations have been performed to determine the design of the proposed fast-timing array around a localised implantation point. In particular, simulations were used to determine the full-energy peak efficiencies for single cylindrical, conical and 'hybrid' detector geometries, as well as complete array configurations of 'hybrid' and ?1.5 in.×2 in. cylindrical crystals. Timing precision calculations were then used to determine the timing response for each configuration based on its simulated efficiency. An informed decision based on the simulated efficiencies and timing precision calculations allowed the optimum configuration for the array to be determined.

  15. Seismic responses of a pool-type fast reactor with different core support designs

    International Nuclear Information System (INIS)

    In designing the core support system for a pool-type fast reactor, there are many issues which must be considered in order to achieve an optimum and balanced design. These issues include safety, reliability, as well as costs. Several design options are possible to support the reactor core. Different core support options yield different frequency ranges and responses. Seismic responses of a large pool-type fast reactor incorporated with different core support designs have been investigated. 4 refs., 3 figs

  16. Nanorod-Based Fast-Response Pressure-Sensitive Paints

    Science.gov (United States)

    Bencic, Timothy; VanderWal, Randall

    2007-01-01

    A proposed program of research and development would be devoted to exploitation of nanomaterials in pressuresensitive paints (PSPs), which are used on wind-tunnel models for mapping surface pressures associated with flow fields. Heretofore, some success has been achieved in measuring steady-state pressures by use of PSPs, but success in measuring temporally varying pressures has been elusive because of the inherent slowness of the optical responses of these materials. A PSP contains a dye that luminesces in a suitable wavelength range in response to photoexcitation in a shorter wavelength range. The luminescence is quenched by oxygen at a rate proportional to the partial pressure of oxygen and thus proportional to the pressure of air. As a result, the intensity of luminescence varies inversely with the pressure of air. The major problem in developing a PSP that could be easily applied to a wind-tunnel model and could be useful for measuring rapidly varying pressure is to provide very high gas diffusivity for rapid, easy transport of oxygen to and from active dye molecules. Most PSPs include polymer-base binders, which limit the penetration of oxygen to dye molecules, thereby reducing responses to pressure fluctuations. The proposed incorporation of nanomaterials (somewhat more specifically, nanorods) would result in paints having nanostructured surfaces that, relative to conventional PSP surfaces, would afford easier and more nearly complete access of oxygen molecules to dye molecules. One measure of greater access is effective surface area: For a typical PSP as proposed applied to a given solid surface, the nanometer-scale structural features would result in an exposed surface area more than 100 times that of a conventional PSP, and the mass of proposed PSP needed to cover the surface would be less than tenth of the mass of the conventional PSP. One aspect of the proposed development would be to synthesize nanorods of Si/SiO2, in both tangle-mat and regular- array forms, by use of chemical vapor deposition (CVD) and wet chemical processes, respectively. The rods would be coated with a PSP dye, and the resulting PSP signals would be compared with those obtained from PSP dye coats on conventional support materials. Another aspect of the proposed development would be to seek to exploit the quantum properties of nanorods of a suitable semiconductor (possibly GaN), which would be synthesized by CVD. These quantum properties of semiconductor nanorods include narrow-wavelength-band optical absorption and emission characteristics that vary with temperature. The temperature sensitivity might enable simultaneous measurement of fluctuating temperature and pressure and to provide a temperature correction for the PSP response.

  17. Fast binarized time-reversed adapted-perturbation (b-TRAP) optical focusing inside scattering media

    CERN Document Server

    Ma, Cheng; Liu, Yan; Wang, Lihong V

    2015-01-01

    Light scattering inhibits high-resolution optical imaging, manipulation and therapy deep inside biological tissue by preventing focusing. To form deep foci, wavefront-shaping and time-reversal techniques that break the optical diffusion limit have been developed. For in vivo applications, such focusing must provide high gain, high speed, and a large number of spatial modes. However, none of the previous techniques meet these requirements simultaneously. Here, we overcome this challenge by rapidly measuring the perturbed optical field within a single camera exposure followed by adaptively time-reversing the phase-binarized perturbation. Consequently, a phase-conjugated wavefront is synthesized within a millisecond, two orders of magnitude shorter than the digitally achieved record. We demonstrated real-time focusing in dynamic scattering media, and extended laser speckle contrast imaging to new depths. The unprecedented combination of fast response, high gain, and large mode count makes this work a major strid...

  18. A Fast Three-Dimensional Lighting Time Algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Yao, J

    2003-06-25

    A narrow band level-set method to calculate the physical lighting time in three dimensions has been implemented with arbitrary hexahedral element systems. This method does not involve finite difference calculation of spatial derivatives. Mesh regularity, and the local topologic equivalence to a regular mesh are not required. The lighting surface is represented by a collection of curved facets contained in partially burnt cells. Level-set functions are calculated by direct measurement of distance to the lighting surface, and are carried only for nodes of a set of elements in a narrow band that covers the lighting surface. In the case of a concave boundary, the nodal distances are calculated with geodesics. A polynomial fitting of nodal level-set values across elements provides third-order spatial accuracy where the surface is sufficiently smooth. The curvature of the lighting surface is explicitly calculated. The DSD levelset equation is integrated directly in the normal direction. The new algorithm is self-initialized and allows easy boundary treatment with body fitting meshes. It can also be used as a fast, accurate solver for general surface propagation problems.

  19. UCP2 regulates the glucagon response to fasting and starvation

    OpenAIRE

    Allister, Emma M.; Robson-doucette, Christine A.; Prentice, Kacey J.; Hardy, Alexandre B.; Sultan, Sobia; Gaisano, Herbert Y.; Kong, Dong; Gilon, Patrick; Herrera, Pedro Luis; Lowell, Bradford B.; Wheeler, Michael B.

    2013-01-01

    Glucagon is important for maintaining euglycemia during fasting/starvation, and abnormal glucagon secretion is associated with type 1 and type 2 diabetes; however, the mechanisms of hypoglycemia-induced glucagon secretion are poorly understood. We previously demonstrated that global deletion of mitochondrial uncoupling protein 2 (UCP2(-/-)) in mice impaired glucagon secretion from isolated islets. Therefore, UCP2 may contribute to the regulation of hypoglycemia-induced glucagon secretion, whi...

  20. Fast-response analog-to-digital processor for event selection by the difference in numbers of particles

    International Nuclear Information System (INIS)

    The method of construction and the basic circuit of the analog-to-digital processor which is intended for event selection by the difference in numbers of particles passed through two hodoscope planes is described. The planes have 64 and 128 outputs, respectively. The delay time for processor signals does not exceed 55 ns. For economy and fast response increase the method of the data compression is used and combination of analog and digital micro circuits is applied

  1. Impaired fasting glucose individuals: their response to oral glucose challenge

    International Nuclear Information System (INIS)

    To determine the frequency of Impaired Fasting Glucose (IFG) individuals in symptom free adults and their 2-h PG (two-hour plasma glucose) concentrations in standard Oral Glucose Tolerance Test (OGTT) with 75-g glucose. Fasting plasma glucose (FPG) of 859 symptom free adults was checked. Of them, 344(40%) were found to have IFG, who were subjected to standard OGTT with 75-g glucose and their 2-h PG results were recorded. Frequency distribution of FPG of 859 symptom free adults showed, 455(53%) were Normal Fasting Glucose (NFG 7.0 mmol/l). The difference in frequency of three groups of FPG was statistically significant (p<0.0001). Of 344 IFG individuals, who were subjected to standard OGTT, 182(53%) had Normal Glucose Tolerance (NGT), 127(37%) were Impaired Glucose Tolerance (IGT) and 35(10%) were diabetics. The difference in frequency of the three groups was statistically significant (p<0.0001). A significantly large number of asymptomatic adults are suffering from IFG in our set up. When IFG individuals are subjected to 75-g OGTT, their 2-h PG results showed about one third have IGT and also a significant number of IFG individuals are found to be patients of diabetes. (author)

  2. Shock-tube calibration of a fast-response pressure transducer

    Science.gov (United States)

    Chung, Kung-Ming; Lu, Frank K.

    1990-01-01

    The sensitivity of a miniature fast-response piezoresistive pressure transducer determined dynamically was found to be slightly higher than that determined statically. Thus, mean pressures in a turbulent or unsteady flowfield that are measured using statically-calibrated pressure transducers would be slightly above true values. Unsteady pressure measurements to obtain space-time correlations and spectra can, however, be properly performed if the slight error is acceptable. These measurements are, obviously, subjected to limitations imposed by the bandwidth and the spatial resolution of the transducer. The noise spectrum revealed that the noise is predominantly above the transducer's resonant frequency. Filtering to improve the signal-to-noise ratio is particularly necessary when using the transducers at their low range. Transducer drift increases the signal-to-noise ratio and can adversely affect mean measurements.

  3. Simulation of response functions of fast neutron sensors and development of thin neutron silicon sensor

    International Nuclear Information System (INIS)

    On radiation detection using silicon sensor, signals are produced from collected charges in a depletion layer; however, for high-energy particles, this depletion layer is extended due to funnelling phenomenon. The lengths of charge collection were experimentally obtained from proton peak energies in measured pulse-heights. The length is extended with increasing proton energy of up to 6 MeV, and then, is constant over 6 MeV. The response functions of fast neutron sensors were simulated for 5- and 15-MeV monoenergetic and 252Cf neutron sources using the Monte Carlo N-Particle eXtended code. The simulation results agree well with the experimental ones, including the effect of funnelling phenomenon. In addition, a thin silicon sensor was developed for a new real-time personal neutron dosemeter. Photon sensitivity is vanishingly smaller than neutron one by a factor of 5x10-4. The length of the depletion layer is extended due to the effect of funnelling phenomenon. With increasing proton energy, the length of charge collection is increased; and over 6 MeV of proton energy, the length stays constant. The response functions of fast neutron sensors were simulated for 5- and 15-MeV monoenergetic and 252Cf neutron sources. The simulated results agree well with the experimental ones, considering the effect of funnelling phenomenon. Using this simulation, the response functions of >20 MeV can be obtained. The simulation for high-energy neutrons helps one to develop new personal neutron dosemeters for radiation protection of aircrew. The thin silicon sensor operates as a totally depleted silicon detector, confirmed on a basis of the constant proton peak energy with bias voltage. The thin silicon sensor can be used for new personal neutron dosemeters with negligible photon sensitivity. It was vanishingly smaller than the neutron sensitivity by a factor of 5x10-4. (authors)

  4. Time Domain Response of the ARIANNA Detector

    CERN Document Server

    Barwick, S W; Besson, D Z; Hanson, J C; Klein, S R; Kleinfelder, S A; Piasecki, M; Ratzlaff, K; Reed, C; Roumi, M; Stezelberger, T; Tatar, J; Walker, J; Young, R; Zou, L

    2014-01-01

    The Antarctic Ross Ice Shelf Antenna Neutrino Array (ARIANNA) is a high-energy neutrino detector designed to record the Askaryan electric field signature of cosmogenic neutrino interactions in ice. To understand the inherent radio-frequency (RF) neutrino signature, the time-domain response of the ARIANNA RF receiver must be measured. ARIANNA uses Create CLP5130-2N log-periodic dipole arrays (LPDAs). The associated effective height operator converts incident electric fields to voltage waveforms at the LDPA terminals. The effective height versus time and incident angle was measured, along with the associated response of the ARIANNA RF amplifier. The results are verified by correlating to field measurements in air and ice, using oscilloscopes. Finally, theoretical models for the Askaryan electric field are combined with the detector response to predict the neutrino signature.

  5. Emergency response time optimisation using real-time traffic information

    Directory of Open Access Journals (Sweden)

    Miros?aw JASKU?OWSKI

    2007-01-01

    Full Text Available This paper describes possible approaches for optimal route selection foremergency vehicles. The presented navigation software’s architectures employ real-time traffic congestion information, matched to a tailored map. Four approaches have been described and reviewed against suitability in emergency response situations.

  6. Investigation of response time testing requirements

    International Nuclear Information System (INIS)

    The purpose of the Response Time Testing (RTT) Program was to determine if requirements for RTT could be eliminated for specific pressure and differential pressure transmitters and switches. This program was initiated when experience and historical data from a significant number of nuclear power plants indicated that, while RTT is both resource and exposure intensive, an insignificant number of pressure sensor failures have been detected through this type of testing. Assessment of plant response time data and performance of Failure Modes and Effects Analysis (FMEA) on sensor hardware were the mechanisms used by the program to determine the redundancy of RTT in conjunction with other required periodic testing (e.g., calibrations, channel checks, surveillance tests). In general, the FMEA results indicated RTT is redundant to other periodic tests. Results of the program identified only two response time failure modes and two manufacturing/handling defects that may not concurrently affect sensor output. The two failure modes affect a limited number of sensor models. Appropriate testing has been identified in cases where response time degradation may not be coincident with significant sensor output change. 14 refs., 19 figs., 39 tabs

  7. Excessive fasting times: still an underaddressed challenge for African pediatrics and anesthesia?

    Directory of Open Access Journals (Sweden)

    Pollach G

    2014-04-01

    Full Text Available Gregor Pollach,1,2 Rose Kapenda,2 Beauty Anusa,2 Ethel Waluza,2 Felix Namboya1,21Department of Anaesthesia and Intensive Care, College of Medicine, University of Malawi, 2Queen Elizabeth Central Hospital, Blantyre, Malawi, Central AfricaBackground: Children are starved before surgery following international preoperative guidelines. Extreme fasting is still reported, but data for Africa are scarce. Starving in hot climates leads to challenges arising from dehydration, hypotension, metabolic disturbances, and complications during induction of anesthesia. The purpose of this study was to evaluate the scope of the problem, identify possible reasons for this, and propose realistic solutions.Methods: We performed eleven prospective audits between 2008 and 2013 in Malawi to improve our preoperative fasting times. In total, 631 children (aged 3 days to 13 years were monitored. Training was provided, and the results were measured using a visual analog scale.Results: In 2008, the baseline audit showed a mean fasting time (MFT of 13.48 hours (31 patients. Training reduced the MFT to 8.77 hours (73 patients and 3.2 hours (35 patients in 2009. Without training, the MFT increased to 4.6 hours (35 patients in 2010 and to 10.2 hours (50 patients in 2011. A low level of training decreased the MFT to 8.13 hours (139 patients, in spring 2012. Educational activity brought the MFT down further to 7.86 hours (36 patients, in summer 2012. Lack of training in autumn 2012 increased MFT to 9.32 hours (151 patients, which then improved to 8.04 hours (27 patients as a result of renewed educational activity. In 2013, MFT increased to 9.8 hours (37 patients despite training. In June 2013, more education achieved a reduction in MFT to 6.52 hours (17 patients. The MFT across all audits (2008–2013 was 8.48 hours. Education reduces MFT, but only in the short term. Factors responsible for changes in MFT were identified.Conclusion: Excessive preoperative fasting is an underaddressed problem in Africa. Reduction is difficult, so it has to be accepted as an ongoing task.Keywords: child, infant, fluid, education, developing countries, Africa, fasting

  8. Fast Frequency and Time Domain Integral Equation Modelling for Marine CSEM Applications:

    OpenAIRE

    Moradi Tehrani, A.

    2012-01-01

    In this study we developed algorithms for fast frequency and time domain integral equation modelling for marine controlled-source electromagnetic (CSEM) applications. Solutions of integral equations for CSEM applications in a three-layered earth with an assumed reservoirs is examined using the conjugate gradient fast Fourier transformation (CG-FFT) method, which is used as a reference. For 3D configurations fast computational methods are relevant for both forward and inverse modelling stud...

  9. TDC-1/TDC-2. Full custom ASICs for fast time encoding

    International Nuclear Information System (INIS)

    Following the pre-diffused fast time encoder CRT-C, the Electronics Department has begun the design of a full custom fast encoder. We have realized an estimation circuit in 0.8 ? BiCMOS technology performing 3 multiphase VCO with 125 ps between phases. (author)

  10. TRANC – a novel fast-response converter to measure total reactive atmospheric nitrogen

    Directory of Open Access Journals (Sweden)

    V. Wolff

    2012-05-01

    Full Text Available The input and loss of plant available nitrogen (reactive nitrogen: Nr from/to the atmosphere can be an important factor for the productivity of ecosystems and thus for its carbon and greenhouse gas exchange. We present a novel converter for reactive nitrogen (TRANC: Total Reactive Atmospheric Nitrogen Converter, which offers the opportunity to quantify the sum of all airborne reactive nitrogen compounds (?Nr in high time resolution. The basic concept of the TRANC is the full conversion of all Nr to nitrogen monoxide (NO within two reaction steps. Initially, reduced Nr compounds are being oxidised, and oxidised Nr compounds are thermally converted to lower oxidation states. Particulate Nr is being sublimated and oxidised or reduced afterwards. In a second step, remaining higher nitrogen oxides or those generated in the first step are catalytically converted to NO with carbon monoxide used as reduction gas. The converter is combined with a fast response chemiluminescence detector (CLD for NO analysis and its performance was tested for the most relevant gaseous and particulate Nr species under both laboratory and field conditions. Recovery rates during laboratory tests for NH3 and NO2 were found to be 95 and 99%, respectively, and 97% when the two gases were combined. In-field longterm stability over an 11-month period was approved by a value of 91% for NO2. Effective conversion was also found for ammonium and nitrate containing particles. The recovery rate of total ambient Nr was tested against the sum of individual measurements of NH3, HNO3, HONO, NH4+, NO3?, and NOx using a combination of different well-established devices. The results show that the TRANC-CLD system precisely captures fluctuations in ?Nr concentrations and also matches the sum of all individual Nr compounds measured by the different single techniques. The TRANC features a specific design with very short distance between the sample air inlet and the place where the thermal and catalytic conversions to NO occur. This assures a short residence time of the sample air inside the instrument, and minimises wall sorption problems of water soluble compounds. The fast response time (e-folding times of 0.30 to 0.35 s were found during concentration step changes and high accuracy in capturing the dominant Nr species enables the converter to be used in an eddy covariance setup. Although a source attribution of specific Nr compounds is not possible, the TRANC is a new reliable tool for permanent measurements of the net ?Nr flux between ecosystem and atmosphere at a relatively low maintenance and reasonable cost level allowing for diurnal, seasonal and annual investigations.

  11. Formulation and optimization of fast dissolving intraoral drug delivery system for clobazam using response surface methodology.

    Science.gov (United States)

    Bala, Rajni; Khanna, Sushil; Pawar, Pravin K

    2013-07-01

    Clobazam is a newer 1,5-benzodiazepine used for the treatment of epilepsy. It is better tolerated and less sedating than other benzodiazepines. Absorption of the drug can be impacted by oral fast dissolving dosage form; this may have implications for epilepsy in pediatrics and those having difficulty in swallowing tablets/capsules resulting in improved patient compliance. The purpose of the present investigation was to formulate and optimize clobazam oro-dissolving tablets by direct compression method using response surface methodology (RSM). Oro-dispersible tablets of clobazam were prepared by direct compression method using crospovidone (2-6%) as a superdisintegrant, microcrystalline cellulose (MCC) (20-40%) was used as diluents along with directly compressible mannitol to enhance mouth feel. A 3(2) full factorial design was applied to investigate the combined effect of two formulation variables: amount of crospovidone and MCC over the independent variables disintegration time, wetting time and percent drug release. Disintegration time showed by all formulations was found to be in the range of 24.3-193 s based on evaluation parameters the formulation containing 6% of crospovidone and 30% of MCC showed promising performance against all other formulations. The results demonstrated that the RSM could efficiently be applied for the formulation of clobazam oro-dispersible tablets; therefore, constitute an advance in the management of epileptic attacks. PMID:24083203

  12. Effect of short-term fasting on lipolytic responsiveness in normal and obese human subjects

    International Nuclear Information System (INIS)

    In this study the rate of lipolysis (fatty acid and glycerol release into blood) has been quantified in both normal weight and obese volunteers after both 15 and 87 h of fasting. In each study, the basal rate and subsequent response to epinephrine infusion were determined. The rate of appearance (R/sub a/) of free fatty acids (FFA) and glycerol were quantified by infusion of [1-13C]palmitate and D-5-glycerol, respectively. Substrate flux rates per unit of body fat mass and lean body mass were calculated from total body water measurements using H218O dilution. In normal volunteers, the basal R/sub a/ FFA and R/sub a/ glycerol rose markedly with 87 h of fasting, whereas the increases were more modest in the obese subjects. However, the rate of mobilization of fat, in relation to the lean body mass, was higher in the obese subjects than in the normal subjects after 15 h of fasting, and the values were similar in both groups after 87 h of fasting. There was an increased lipolytic response to epinephrine after fasting in both groups. This increased sensitivity may have resulted from the enhancement of fatty acid-triglyceride substrate cycling that occurred after fasting

  13. Fast ?-ray coincidence timing using a BGO detector array in a nuclear reaction experiment

    International Nuclear Information System (INIS)

    The (7Li, 7Be) nuclear charge-exchange reaction has been investigated at E(7Li)=350 MeV. Coincidences were measured between the charged 7Be reaction products in the focal plane of a magnetic spectrometer and 430-keV Doppler-shifted ?-rays from the decay in flight of excited 7Be ejectiles. The latter were detected in a compact BGO detector array. Fast timing was used to optimize the separation between prompt and randoms events. The BGO output signals display the statistical distribution of the arrival times of individual photoelectrons from the photocathode in the photomultiplier tubes. A timing resolution of 6.5 ns relative to the accelerator RF was obtained. A simple model was successfully developed to simulate the BGO output signals with a statistical distribution of a predetermined number of photoelectrons modulated by the light output response of the scintillator and the single-photoelectron gain distribution and transit time through the photomultiplier tube. It is concluded that the timing resolution is primarily limited by the small number of photoelectrons. ((orig.))

  14. Parallel Configuration For Fast Superconducting Strip Line Detectors With Very Large Area In Time Of Flight Mass Spectrometry

    International Nuclear Information System (INIS)

    We realized a very fast and large Superconducting Strip Line Detector based on a parallel configuration of nanowires. The detector with size 200x200 ?m2 recorded a sub-nanosecond pulse width of 700 ps in FWHM (400 ps rise time and 530 ps relaxation time) for lysozyme monomers/multimers molecules accelerated at 175 keV in a Time of Flight Mass Spectrometer. This record is the best in the class of superconducting detectors and comparable with the fastest NbN superconducting single photon detector of 10x10 ?m2. We succeeded in acquiring mass spectra as the first step for a scale-up to ?mm pixel size for high throughput MS analysis, while keeping a fast response.

  15. Hydrothermal-grown ZnO as a fast response scintillator and EUV

    International Nuclear Information System (INIS)

    Next-generation extreme ultraviolet (EUV) applications will require the development of scintillator devices that are capable of fast imaging. As we have demonstrated recently, zinc oxide (ZnO) is a prominent candidate. In this talk, we will present our newest results on the scintillator properties of hydrothermal-grown ZnO crystal. The imaging capabilities of the ZnO scintillator is demonstrated by imaging the beam focal spot of an EUV laser emitting at 13.9 nm wavelength. The fluorescence image of the ZnO crystal was taken and compared with a high-resolution target as reference. The system's resolving power was determined to be ?5.5?m/pixel. These results present a feasible method to perform single-shot beam diagnostics for EUV sources using a ZnO scintillator. Additionally, the temporal response of the crystal has been further improved by modifying the crystal growth scheme. Its bandgap-related fluorescence lifetime was less than 100 ps for 290-nm pulsed excitation. Using the 51-nm excitation pulse of the of the X-Ray Free Electron Laser prototype at the Spring-8 research facility, a response time of ?70 picoseconds was confirmed. These results suggest that the hydrothermal-method grown ZnO is currently the fastest scintillator in the 50-60 nm wavelength. (author

  16. Collecting Psycholinguistic Response Time Data Using Amazon Mechanical Turk

    Science.gov (United States)

    Enochson, Kelly; Culbertson, Jennifer

    2015-01-01

    Researchers in linguistics and related fields have recently begun exploiting online crowd-sourcing tools, like Amazon Mechanical Turk (AMT), to gather behavioral data. While this method has been successfully validated for various offline measures—grammaticality judgment or other forced-choice tasks—its use for mainstream psycholinguistic research remains limited. This is because psycholinguistic effects are often dependent on relatively small differences in response times, and there remains some doubt as to whether precise timing measurements can be gathered over the web. Here we show that three classic psycholinguistic effects can in fact be replicated using AMT in combination with open-source software for gathering response times client-side. Specifically, we find reliable effects of subject definiteness, filler-gap dependency processing, and agreement attraction in self-paced reading tasks using approximately the same numbers of participants and/or trials as similar laboratory studies. Our results suggest that psycholinguists can and should be taking advantage of AMT and similar online crowd-sourcing marketplaces as a fast, low-resource alternative to traditional laboratory research. PMID:25822348

  17. Library of response functions with respect to energy for nuclear reactions in fast neutrons

    International Nuclear Information System (INIS)

    For some nuclear reactions caused by fast neutrons, values of the response function are given in points corresponding to discrete energies which are chosen in such a way that a linear interpolation is possible between these points in a E, Log (?(E)) graph. Coefficients are defined which allow, provided neutron spectra are known, the equivalent fission flow to be calculated. Finally, the recommended response functions averaged on the fission spectrum allow the reaction rates to be calculated from equivalent fission flows

  18. Waveform Timing Performance of a 5 GS/s Fast Pulse Sampling Module with DRS4

    CERN Document Server

    Wang, Jinhong; An, Qi

    2015-01-01

    We first clarify timing issues of non-uniform sampling intervals regarding a 5 GS/s fast pulse sampling module with DRS4. Calibration strategy is proposed, and as a result, the waveform timing performance is improved to be below 10 ps RMS. We then further evaluate waveform timing performance of the module by comparing with a 10 GS/s oscilloscope in a setup with plastic scintillators and fast PMTs. Different waveform timing algorithms are employed for analysis, and the module shows comparable timing performance with that of the oscilloscope.

  19. Fast-slow coincidence systems with very high time resolution

    International Nuclear Information System (INIS)

    The measuring of very short times has recently become increasingly important. In this paper the authors describe their studies on the various parts of a timing system in an attempt to improve its parameters. The detector system, i.e. the transit time differences of the photomultipliers, the construction of the divider network, the various types of timing discriminators, the time-to-pulse height converters and the gating system were investigated. Two types of constant fraction discriminators are introduced: one for general timing applications, the other placed inside the detector head for positron lifetime measurements. (author)

  20. The Fast Tracker Real Time Processor: high quality real-time tracking at ATLAS

    CERN Document Server

    Stabile, A; The ATLAS collaboration

    2011-01-01

    As the LHC luminosity is ramped up to the design level of 1x1034 cm?2 s?1 and beyond, the high rates, multiplicities, and energies of particles seen by the detectors will pose a unique challenge. Only a tiny fraction of the produced collisions can be stored on tape and immense real-time data reduction is needed. An effective trigger system must maintain high trigger efficiencies for the most important physics and at the same time suppress the enormous QCD backgrounds. This requires massive computing power to minimize the online execution time of complex algorithms. A multi-level trigger is an effective solution for an otherwise impossible problem. The Fast Tracker (FTK)[1], [2] is a proposed upgrade to the current ATLAS trigger system that will operate at full Level-1 output rates and provide high quality tracks reconstructed over the entire detector by the start of processing in Level-2. FTK is a dedicated Super Computer based on a mixture of advanced technologies. The architecture broadly employs powerf...

  1. Ultra fast proton response of myoglobin upon ligand dissociation

    International Nuclear Information System (INIS)

    In numerous biological processes, the ensuing protein structural changes accompanying a reaction at a specific site must spatially extend to mesoscopic dimensions to achieve a biological function. The molecular mechanism of cooperativity in oxygen binding of hemoglobin (Hb) is one of the classical problems in this aspect. The binding of small molecular ligands to the hemes in Hb is a highly localized perturbation. Nonetheless, this localized perturbation initiates a sequence of propagating structural events that culminates in a change of quaternary structure. The large-amplitude motions at the quaternary level, which form a communication link at the subunit interface, are driven by changes of the tertiary structure upon ligation. In this respect, myoglobin (Mb), which is structurally very similar to a subunit of Hb serves as a model system for the tertiary relaxation processes. Figure 1 demonstrates time-resolved UVRR difference spectra expanded the region of 650-1850 cm-1. The top and bottom traces correspond to the contracted probe-only spectrum and equilibrium deoxyMb minus MbCO difference spectrum, respectively. Tryptophan (Trp) and tyrosine (Tyr) bands appeared in the UVRR spectra are labeled by W and Y. In delay times between 5 and 300 ps, negative difference bands of W18, W16, and W3 modes showed little intensity change, on the other hand, negative difference band at 1620 cm-1 appreciably decreased in intensity. The intensity of W1 band wi in intensity. The intensity of W1 band with 226-nm excitation is less than one third of that of W3 band and the intensity of Trp bands other than W1 is invariant; hence, the intensity change of difference signal at 1620 cm-1 observed at 5 to 300 ps can be attributed to the intensity restoration of Y8a band. At 2.5 ns time delay, the transient difference spectrum does not coincide with the equilibrium difference spectrum. This means that the structural rearrangements toward the deoxy structure are not completed at 2.5 ns. Horse Mb has two Tyr residues: Tyr103 and Tyr146. X-ray crystallographic studies showed Tyr103 is exposed to the solvent in both deoxyMb and MbCO. Therefore, Tyr103 is not expected to show intensity changes upon CO dissociation. On the other hand, Tyr146 has a side chain which locates in the FG corner of Mb. It forms hydrogen bond to the backbone carbonyl of the proximal histidine (His93). Therefore, Tyr146 can be perturbed by the structural changes of the heme. We previously reported structural dynamics of Mb probed by visible resonance Raman spectroscopy. The data showed that the structural changes of the heme completes within 2 picoseconds and that there is structural relaxation around the heme with the time constant of 100 ps based on the frequency shift of iron-histidine stretching mode. The present data on the Tyr band are consistent with the previous data on heme and iron-histidine stretching band. Because Tyr146 forms hydrogen bond to the backbone carbonyl of the proximal histidine, spectral changes on both sites can be ascribed to the common protein motion in the heme vicinity of Mb. The Raman bands of Trp residues showed instantaneous intensity decrease and the intensity recovery in the nanosecond regime. In 100 ps region, there is no apparent intensity change for Trp bands in contrast to the change of Tyr Y8a band. Two Trp residues are involved in horse Mb: Trp7 and Trp14. Both residues are in the A helix and contact with the E helix. Although the A helix is far from the heme, intensity change of Trp bands occurs within 5 ps. It is hard to assume that the structural changes propagate from the heme group to the A helix in such a short time. More plausible idea is that upon CO dissociation the E helix moves and the movement perturbs the environments of Trp residues. Because the E helix locates just above the heme and can respond quickly to the dissociation. Time-resolved UVRR Measurements on Mb mutants, W7F and W14F, showed that Trp 14 contributes to the spectral changes in Figure 1 more than Trp7. Spectral changes in nanoseconds can be attributed to fo

  2. Fast response function for finite and bulk systems

    Science.gov (United States)

    Koval, Peter; Marchesin, Federico; Sanchez Portal, Daniel; Foerster, Dietrich

    2013-03-01

    Many-body perturbation theory of bulk systems is often realized within reciprocal space, using plane-wave (PW) basis sets. PW basis is advantageous because of its elementary basis functions and simple convergence control. However, the number of functions in PW basis grows with third power of unit cell size, irrespective of actual number of atoms present in the unit cell. Moreover, PW basis gives rise to full matrices in tensor algebra due to space-filling nature of PW. An alternative to PW would be usage of localized basis functions. In this contribution, we show how a basis of dominant products (DP) can be used to describe excitations in finite and bulk systems. We present calculations of absorption spectra and electron-energy loss spectra within time-dependent density functional theory, realized within DP basis. The usage of localized functions and iterative techniques allow to keep the complexity of the calculations rather low: the overall number of operations grows with third power of number of atoms in the unit cell.Moreover, we have recently shown that Hedin's GW calculations can also be performed using DP basis with an order-N3 scaling for finite systems. We are currently extending this GW methodology to bulk systems.

  3. Fast Response and High Sensitivity ZnO/glass Surface Acoustic Wave Humidity Sensors Using Graphene Oxide Sensing Layer

    OpenAIRE

    Xuan, Weipeng; He, Mei; Meng, Nan; He, Xingli; Wang, Wenbo; Chen, Jinkai; Shi, Tianjin; Hasan, Tawfique; Xu, Zhen; Xu, Yang; Luo, J. K.

    2014-01-01

    We report ZnO/glass surface acoustic wave (SAW) humidity sensors with high sensitivity and fast response using graphene oxide sensing layer. The frequency shift of the sensors is exponentially correlated to the humidity change, induced mainly by mass loading effect rather than the complex impedance change of the sensing layer. The SAW sensors show high sensitivity at a broad humidity range from 0.5%RH to 85%RH with < 1 sec rise time. The simple design and excellent stability of our GO-based S...

  4. Ultra-high throughput real-time instruments for capturing fast signals and rare events

    Science.gov (United States)

    Buckley, Brandon Walter

    Wide-band signals play important roles in the most exciting areas of science, engineering, and medicine. To keep up with the demands of exploding internet traffic, modern data centers and communication networks are employing increasingly faster data rates. Wide-band techniques such as pulsed radar jamming and spread spectrum frequency hopping are used on the battlefield to wrestle control of the electromagnetic spectrum. Neurons communicate with each other using transient action potentials that last for only milliseconds at a time. And in the search for rare cells, biologists flow large populations of cells single file down microfluidic channels, interrogating them one-by-one, tens of thousands of times per second. Studying and enabling such high-speed phenomena pose enormous technical challenges. For one, parasitic capacitance inherent in analog electrical components limits their response time. Additionally, converting these fast analog signals to the digital domain requires enormous sampling speeds, which can lead to significant jitter and distortion. State-of-the-art imaging technologies, essential for studying biological dynamics and cells in flow, are limited in speed and sensitivity by finite charge transfer and read rates, and by the small numbers of photo-electrons accumulated in short integration times. And finally, ultra-high throughput real-time digital processing is required at the backend to analyze the streaming data. In this thesis, I discuss my work in developing real-time instruments, employing ultrafast optical techniques, which overcome some of these obstacles. In particular, I use broadband dispersive optics to slow down fast signals to speeds accessible to high-bit depth digitizers and signal processors. I also apply telecommunication multiplexing techniques to boost the speeds of confocal fluorescence microscopy. The photonic time stretcher (TiSER) uses dispersive Fourier transformation to slow down analog signals before digitization and processing. The act of time-stretching effectively boosts the performance of the back-end electronics and digital signal processors. The slowed down signals reach the back-end electronics with reduced bandwidth, and are therefore less affected by high-frequency roll-off and distortion. Time-stretching also increases the effective sampling rate of analog-to-digital converters and reduces aperture jitter, thereby improving resolution. Finally, the instantaneous throughputs of digital signal processors are enhanced by the stretch factor to otherwise unattainable speeds. Leveraging these unique capabilities, TiSER becomes the ideal tool for capturing high-speed signals and characterizing rare phenomena. For this thesis, I have developed techniques to improve the spectral efficiency, bandwidth, and resolution of TiSER using polarization multiplexing, all-optical modulation, and coherent dispersive Fourier transformation. To reduce the latency and improve the data handling capacity, I have also designed and implemented a real-time digital signal processing electronic backend, achieving 1.5 tera-bit per second instantaneous processing throughput. Finally, I will present results from experiments highlighting TiSER's impact in real-world applications. Confocal fluorescence microscopy is the most widely used method for unveiling the molecular composition of biological specimens. However, the weak optical emission of fluorescent probes and the tradeoff between imaging speed and sensitivity is problematic for acquiring blur-free images of fast phenomena and cells flowing at high speed. Here I introduce a new fluorescence imaging modality, which leverages techniques from wireless communication to reach record pixel and frame rates. Termed Fluorescence Imaging using Radio-frequency tagged Emission (FIRE), this new imaging modality is capable of resolving never before seen dynamics in living cells - such as action potentials in neurons and metabolic waves in astrocytes - as well as performing high-content image assays of cells and particles in high-speed flow.

  5. Observation of very fast response signals from Pb absorber coupled transition edge sensor gamma-ray microcalorimeter

    International Nuclear Information System (INIS)

    We are developing a gamma-ray microcalorimeter for Positron Annihilation Spectroscopy. Our detector composed of a transition edge sensor (TES) thermometer and an epoxy coupled bulk Pb absorber has been reported an energy resolution of 4.7 keV FWHM at 662 keV with a tens of milliseconds long response time. To enhance the detector properties, we designed a new attachment method in the focus of improving the thermal coupling between the absorber and the TES. In the new design, we created epoxy-posts both on the TES film and on the absorber, and then they were connected together using an epoxy-dot put on the epoxy-post on the absorber. Measured current signal of this epoxy-post TES gamma-ray detector showed an ultra fast response with 80 ?s fall time.

  6. Combining Time Reversal and Fast Marching Method in Wireless Indoor Positioning

    Directory of Open Access Journals (Sweden)

    Guoping Chen

    2013-11-01

    Full Text Available Most of current wireless indoor positioning methods could not accurately obtain channel model, the mapping between spatial position and received signal features. The main factor for a precise channel model in an indoor environment is multipath effect. Time reversed (TR wireless indoor positioning method has been validated to effectively reduce signals fading or time delay affected by multipath effect. However, these advantages are depended on a prior known channel model, without this condition, the accuracy of TR method will be seriously deteriorated. To solve the shortcoming of a general TR method in an unknown channel model application, we present a combining Time Reversal and Fast Marching Method (TR-FMM positioning method. This method locates a target with two stages. In the stage one, the precise channel model of an indoor environment is estimated by FMM and simultaneous algebraic reconstruction technique (SART. In this stage, Time of Flight (TOF information generated by some fixed spatial position anchors are used to fulfill the indoor channel model estimation, then the needed channel impulse response (CIR for TR method will be obtained based on the estimated channel model. In the stage two, with the obtained CIR, any new joint mobile target will be accurately located by a general TR wireless indoor positioning method. Some numerical simulations have been presented to validate the proposed method. Simulative results depict the positioning deviation is less than 3cm for a newly joined mobile target with 1cm scale in a moderate complex indoor configure, and the accuracy of the positioning is improved 30 times comparing to a general TR method. The positioning time in the stage 2 is less than 3 minutes in a PC with 1.6 GHz dual CPUs and 2G Bytes memory. Obviously, the proposed method has great advantage in high accuracy and low complexity for wireless indoor positioning system.

  7. Response of six neutron survey meters in mixed fields of fast and thermal neutrons.

    Science.gov (United States)

    Kim, S I; Kim, B H; Chang, I; Lee, J I; Kim, J L; Pradhan, A S

    2013-10-01

    Calibration neutron fields have been developed at KAERI (Korea Atomic Energy Research Institute) to study the responses of commonly used neutron survey meters in the presence of fast neutrons of energy around 10 MeV. The neutron fields were produced by using neutrons from the (241)Am-Be sources held in a graphite pile and a DT neutron generator. The spectral details and the ambient dose equivalent rates of the calibration fields were established, and the responses of six neutron survey meters were evaluated. Four single-moderator-based survey meters exhibited an under-responses ranging from ?9 to 55 %. DINEUTRUN, commonly used in fields around nuclear reactors, exhibited an over-response by a factor of three in the thermal neutron field and an under-response of ?85 % in the mixed fields. REM-500 (tissue-equivalent proportional counter) exhibited a response close to 1.0 in the fast neutron fields and an under-response of ?50 % in the thermal neutron field. PMID:23620566

  8. Advanced vapor recognition materials for selective and fast responsive surface acoustic wave sensors: a review.

    Science.gov (United States)

    Afzal, Adeel; Iqbal, Naseer; Mujahid, Adnan; Schirhagl, Romana

    2013-07-17

    The necessity of selectively detecting various organic vapors is primitive not only with respect to regular environmental and industrial hazard monitoring, but also in detecting explosives to combat terrorism and for defense applications. Today, the huge arsenal of micro-sensors has revolutionized the traditional methods of analysis by, e.g. replacing expensive laboratory equipment, and has made the remote screening of atmospheric threats possible. Surface acoustic wave (SAW) sensors - based on piezoelectric crystal resonators - are extremely sensitive to even very small perturbations in the external atmosphere, because the energy associated with the acoustic waves is confined to the crystal surface. Combined with suitably designed molecular recognition materials SAW devices could develop into highly selective and fast responsive miniaturized sensors, which are capable of continuously monitoring a specific organic gas, preferably in the sub-ppm regime. For this purpose, different types of recognition layers ranging from nanostructured metal oxides and carbons to pristine or molecularly imprinted polymers and self-assembled monolayers have been applied in the past decade. We present a critical review of the recent developments in nano- and micro-engineered synthetic recognition materials predominantly used for SAW-based organic vapor sensors. Besides highlighting their potential to realize real-time vapor sensing, their limitations and future perspectives are also discussed. PMID:23830419

  9. Fast-response temperature-sensitive-paint measurements on a hypersonic transition cone

    Science.gov (United States)

    Ozawa, H.; Laurence, S. J.; Schramm, J. Martinez; Wagner, A.; Hannemann, K.

    2015-01-01

    Experiments are performed using a fast-response temperature-sensitive-paint (TSP) technique to measure the heat-flux distribution on a slender cone in a hypersonic shock tunnel under both laminar and transitional conditions. The millisecond-order test duration together with the self-luminosity of shock layers place stringent conditions on the choice of TSP luminophore and the TSP-layer thickness that can be employed. The luminosity and dimming from particulates in the free-stream cause additional problems in interpreting the obtained intensity profiles. Nevertheless, favorable agreement with thermocouple-based measurements show that it is possible to derive quantitatively accurate heat-flux distributions with the TSP technique for temperature rises of up to approximately 40 K above room temperature. The technique accuracy is adversely affected at higher temperatures, which is thought to result from non-constant thermal properties of the insulating base layer. At high unit Reynolds number conditions, time-resolved heat-flux distributions show large-scale unsteadiness in the boundary-layer transition location and reveal transient streamwise streaks developing in the transitional region.

  10. Y2K issues for real time computer systems for fast breeder test reactor

    International Nuclear Information System (INIS)

    Presentation shows the classification of real time systems related to operation, control and monitoring of the fast breeder test reactor. Software life cycle includes software requirement specification, software design description, coding, commissioning, operation and management. A software scheme in supervisory computer of fast breeder test rector is described with the twenty years of experience in design, development, installation, commissioning, operation and maintenance of computer based supervision control system for nuclear installation with a particular emphasis on solving the Y2K problem

  11. Thermal response of a field emitter subjected to ultra-fast laser illumination

    International Nuclear Information System (INIS)

    Using an ultra-fast laser assisted atom probe, the temporal evolution of the temperature of a tungsten field emitter subjected to illumination is studied. The combination of pump probe experiments and evaporation rate measurements is used to estimate the duration of field evaporation, the induced peak temperature and the cooling time. The main conclusion of the measurements is that, despite a significant heating of the tip by the laser pulse, the cooling time is anomalously fast, below 0.5 ns. Hence, thermal effects are considered to play a major role in ion emission in contrast to conclusions of our previous works. It is shown that the really fast anomalous cooling rate can only be related to a confined heating zone at the tip apex smaller than the wavelength of the laser.

  12. Organic scintillators response function modeling for Monte Carlo simulation of Time-of-Flight measurements

    International Nuclear Information System (INIS)

    In neutron Time-of-Flight (TOF) measurements performed with fast organic scintillation detectors, both pulse arrival time and amplitude are relevant. Monte Carlo simulation can be used to calculate the time–energy dependant neutron flux at the detector position. To convert the flux into a pulse height spectrum, one must calculate the detector response function for mono-energetic neutrons. MCNP can be used to design TOF systems, but standard MCNP versions cannot reliably calculate the energy deposited by fast neutrons in the detector since multiple scattering effects must be taken into account in an analog way, the individual recoil particles energy deposit being summed with the appropriate scintillation efficiency. In this paper, the energy response function of 2?×2? and 5?×5? liquid scintillation BC-501 A (Bicron) detectors to fast neutrons ranging from 20 keV to 5.0 MeV is computed with GEANT4 to be coupled with MCNPX through the “MCNP Output Data Analysis” software developed under ROOT (). - Highlights: ? GEANT4 has been used to model organic scintillators response to neutrons up to 5 MeV. ? The response of 2?×2? and 5?×5? BC501A detectors has been parameterized with simple functions. ? Parameterization will allow the modeling of neutron Time of Flight measurements with MCNP using tools based on CERN's ROOT.

  13. Some time dependent aspects of fast neutron induced atomic cascades

    International Nuclear Information System (INIS)

    Analytical results are obtained for the time-energy distribution of neutrons and the associated displaced atoms slowing down in an amorphous medium according to a general force law. Explicit results are given for the inverse power law, and applications to hard-sphere and Coulomb scattering are discussed. Complete results are obtained for the steady state energy distribution of particles arising from a primary knock-on, and from a neutron initiated cascade. The speed of the slowing down process is assessed by calculating the slowing down time of particles. Two different concepts of slowing down time are discussed, one based upon a density average and the other on a slowing down density average. It is shown that the latter definition is physically more realistic and mathematically simpler. (author)

  14. Count-to-count time interval distribution analysis in a fast reactor

    International Nuclear Information System (INIS)

    The most important kinetic parameters have been measured at the zero power fast reactor CORAL-I by means of the reactor noise analysis in the time domain, using measurements of the count-to-count time intervals. (Author) 69 refs

  15. An assessment of prompt neutron reproduction time in a reflector dominated fast critical system : ELECTRA

    OpenAIRE

    Suvdantsetseg, Erdenechimeg; Wallenius, Janne

    2014-01-01

    In this paper, an accurate method to evaluate the prompt neutron reproduction time for a reflector dominated fast critical reactor, ELECTRA, is discussed. To adequately handle the problem, explicit time dependent Monte Carlo calculations with MCNP, applying repeated time cut-off technique, is used and compared against the ? ? 1/v time dependent absorber method, applying artificial cross section data in the Monte Carlo code SERPENT. The results show that when a reflector plays a major role ...

  16. Fast-response instrument for automatic fission fragment track counting in glass detectors

    International Nuclear Information System (INIS)

    Developed is a fast-response instrument for automatic counting of tracks in semicylindrical glass detectors, used for measuring angular distributions of fission fragments. The instrument contains a photoelectric scanning projector, a focusing-deviating complex, a filtration block, a registrator and a zone-counting channel. The accuracy of counting the tracks is determined, being approximately 1.5%. It takes about 8 min to scrutinize the detector and set the data to digital print-out

  17. Response Surface Methodology to Optimize Novel Fast Disintegrating Tablets Using ? Cyclodextrin as Diluent

    OpenAIRE

    Late, Sameer G.; Banga, Ajay K.

    2010-01-01

    The objective of this work was to apply response surface approach to investigate main and interaction effects of formulation parameters in optimizing novel fast disintegrating tablet formulation using ? cyclodextrin as a diluent. The variables studied were diluent (? cyclodextrin, X1), superdisintegrant (Croscarmellose sodium, X2), and direct compression aid (Spray dried lactose, X3). Tablets were prepared by direct compression method on B2 rotary tablet press using flat plain-face punches ...

  18. Different Response of Body Weight Change According to Ketonuria after Fasting in the Healthy Obese

    OpenAIRE

    Kim, Hyeon-jeong; Joo, Nam-seok; Kim, Kwang-min; Lee, Duck-joo; Kim, Sang-man

    2012-01-01

    The relationship between obesity and ketonuria is not well-established. We conducted a retrospective observational study to evaluate whether their body weight reduction response differed by the presence of ketonuria after fasting in the healthy obese. We used the data of 42 subjects, who had medical records of initial urinalysis at routine health check-up and follow-up urinalysis in the out-patient clinic, one week later. All subjects in the initial urinalysis showed no ketonuria. However, ac...

  19. Response Time Patterns in a Stated Choice Experiment

    OpenAIRE

    Börjesson, Maria; Fosgerau, Mogens

    2015-01-01

    This paper studies how response times vary between unlabeled binary choice occasions in a stated choice (SC) experiment, with alternatives differing with respect to in-vehicle travel time and travel cost. The pattern of response times is interpreted as an indicator of the cognitive processes employed by the respondents when making their choices. We find clear signs of reference-dependence in response times in the form of a strong gain-loss asymmetry. Moreover, different patterns of response t...

  20. Real time control of a fast RF impedance matching system

    International Nuclear Information System (INIS)

    A real time control system has been developed to maintain an RF impedance match in the ion cyclotron range of frequencies (ICRF). This system is designed to adjust output parameters with a cycle period of approximately 100 ?seconds using commercially available VME based components and a UNIX workstation host. Advanced Ferrite Technologies (AFT) has developed the hybrid tuning system (HTS) which has the capability of tracking a mismatch on the time scale of milliseconds (2.5 MW, 60 MHz) by varying the magnetic field bias of ferrite loaded transmission lines. The control algorithm uses a combination of neural network and fuzzy logic techniques. Initial results of a test facility using a low power prototype are presented. 2 refs., 5 figs

  1. Fast and Flexible Multivariate Time Series Subsequence Search

    Science.gov (United States)

    Bhaduri, Kanishka; Oza, Nikunj C.; Zhu, Qiang; Srivastava, Ashok N.

    2010-01-01

    Multivariate Time-Series (MTS) are ubiquitous, and are generated in areas as disparate as sensor recordings in aerospace systems, music and video streams, medical monitoring, and financial systems. Domain experts are often interested in searching for interesting multivariate patterns from these MTS databases which often contain several gigabytes of data. Surprisingly, research on MTS search is very limited. Most of the existing work only supports queries with the same length of data, or queries on a fixed set of variables. In this paper, we propose an efficient and flexible subsequence search framework for massive MTS databases, that, for the first time, enables querying on any subset of variables with arbitrary time delays between them. We propose two algorithms to solve this problem (1) a List Based Search (LBS) algorithm which uses sorted lists for indexing, and (2) a R*-tree Based Search (RBS) which uses Minimum Bounding Rectangles (MBR) to organize the subsequences. Both algorithms guarantee that all matching patterns within the specified thresholds will be returned (no false dismissals). The very few false alarms can be removed by a post-processing step. Since our framework is also capable of Univariate Time-Series (UTS) subsequence search, we first demonstrate the efficiency of our algorithms on several UTS datasets previously used in the literature. We follow this up with experiments using two large MTS databases from the aviation domain, each containing several millions of observations. Both these tests show that our algorithms have very high prune rates (>99%) thus needing actual disk access for only less than 1% of the observations. To the best of our knowledge, MTS subsequence search has never been attempted on datasets of the size we have used in this paper.

  2. Continuous data recording on fast real-time systems

    International Nuclear Information System (INIS)

    The PCU-Project launched for the enhancement of the vertical stabilisation system at JET required the design of a new real-time control system with the challenging specifications of 2Gops and a cycle time of 50 ?s. The RTAI based architecture running on an x86 multi-core processor technology demonstrated to be the best platform for meeting the high requirements. Moreover, on this architecture thanks to the smart allocation of the interrupts it was possible to demonstrate simultaneous data streaming at 50 MBs on Ethernet while handling a real-time 100 kHz interrupt source with a maximum jitter of just 3 ?s. Because of the memory limitation imposed by 32 bit version Linux running in kernel mode, the RTAI-based new controller allows a maximum practical data storage of 800 MB per pulse. While this amount of data can be accepted for JET normal operation it posed some limitations in the debugging and commissioning of the system. In order to increase the capability of the data acquisition of the system we have designed a mechanism that allows continuous full bandwidth (56 MB/s) data streaming from the real-time task (running in kernel mode) to either a data collector (running in user mode) or an external data acquisition server. The exploited architecture involves a peer to peer mechanisms where the sender running in RTAI kernel mode broadcasts large chunks of data using UDP packets, implemented using the 'fcomm' RTAI extension , to a receiver that will store the data. Thea receiver that will store the data. The paper will present the results of the initial RTAI operating system tests, the design of the streaming architecture and the first experimental results.

  3. Fast, Linear Time Hierarchical Clustering using the Baire Metric

    OpenAIRE

    Contreras, Pedro; Murtagh, Fionn

    2011-01-01

    The Baire metric induces an ultrametric on a dataset and is of linear computational complexity, contrasted with the standard quadratic time agglomerative hierarchical clustering algorithm. In this work we evaluate empirically this new approach to hierarchical clustering. We compare hierarchical clustering based on the Baire metric with (i) agglomerative hierarchical clustering, in terms of algorithm properties; (ii) generalized ultrametrics, in terms of definition; and (iii)...

  4. Preparation and properties of fast temperature-responsive soy protein/PNIPAAm IPN hydrogels

    Directory of Open Access Journals (Sweden)

    Liu Yong

    2014-01-01

    Full Text Available The interpenetrating polymer network of fast temperature-responsive hydrogels based on soy protein and poly(N-isopropylacrylamide were successfully prepared using the sodium bicarbonate (NaHCO3 solutions as the reaction medium. The structure and properties of the hydrogels were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry and thermal gravimetric analysis. The swelling and deswelling kinetics were also investigated in detail. The results have shown that the proposed hydrogels had high porous structure, good miscibility and thermal stability, and fast temperature responsivity. The presence of NaHCO3 had little effect on the volume phase transition temperature (VPTT of the hydrogels, and the VPTTs were at about 32°C. Compared with the traditional hydrogels, the proposed hydrogels had much faster swelling and deswelling rate. The swelling mechanism of the hydrogels was the non-Fickian diffusion. This fast temperature-responsive hydrogels may have potential applications in the field of biomedical materials.

  5. Analyzing Response Times in Tests with Rank Correlation Approaches

    Science.gov (United States)

    Ranger, Jochen; Kuhn, Jorg-Tobias

    2013-01-01

    It is common practice to log-transform response times before analyzing them with standard factor analytical methods. However, sometimes the log-transformation is not capable of linearizing the relation between the response times and the latent traits. Therefore, a more general approach to response time analysis is proposed in the current…

  6. An assessment of prompt neutron reproduction time in a reflector dominated fast critical system: ELECTRA

    International Nuclear Information System (INIS)

    Highlights: • Prompt neutron reproduction time of ELECTRA is evaluated. • Static and dynamic reproduction times are distinguished for ELECTRA. • Avery-Cohn’s two-region prompt neutron theory is applied. - Abstract: In this paper, an accurate method to evaluate the prompt neutron reproduction time for a reflector dominated fast critical reactor, ELECTRA, is discussed. To adequately handle the problem, explicit time dependent Monte Carlo calculations with MCNP, applying repeated time cut-off technique, are used and compared against the ??1/v time dependent absorber method, applying artificial cross-section data in the Monte Carlo code SERPENT. The results show that when a reflector plays a major role in criticality for fast neutron reactor, the two methods predict different physical parameters (?=69±2 ns and ?=83±1 ns for time cut-off and the 1/v method respectively). The reason is explained by applying Avery-Cohn’s two-region prompt neutron model

  7. TRANC – a novel fast-response converter to measure total reactive atmospheric nitrogen

    Directory of Open Access Journals (Sweden)

    O. Marx

    2011-12-01

    Full Text Available The input and loss of plant available nitrogen (N from/to the atmosphere can be an important factor for the productivity of ecosystems and thus for its carbon and greenhouse gas exchange. We present a novel converter for the measurement of total reactive nitrogen (TRANC: Total Reactive Atmospheric Nitrogen Converter, which offers the opportunity to quantify the sum of all airborne reactive nitrogen (Nr compounds in high time resolution. The basic concept of the TRANC is the full conversion of total Nr to nitrogen monoxide (NO within two reaction steps. Initially, reduced N compounds are being oxidised, and oxidised N compounds are thermally converted to lower oxidation states. Particulate N is being sublimated and oxidised or reduced afterwards. In a second step, remaining higher N oxides or those originated in the first step are catalytically converted to NO with carbon monoxide used as reduction gas. The converter is combined with a fast response chemiluminescence detector (CLD for NO analysis and its performance was tested for the most relevant gaseous and particulate Nr species under both laboratory and field conditions. Recovery rates during laboratory tests for NH3 and NO2 were found to be 95 and 99%, respectively, and 97% when the two gases were combined. In-field longterm stability over an 11-month period was approved by a value of 91% for NO2. Effective conversion was also found for ammonium and nitrate containing particles. The recovery rate of total ambient Nr was tested against the sum of individual measurements of NH3, HNO3, HONO, NH4+, NO3?, and NOx using a combination of different well-established devices. The results show that the TRANC-CLD system precisely captures fluctuations in Nr concentrations and also matches the sum of all Nr compounds measured by the different single techniques. The TRANC features a specific design with very short distance between the sample air inlet and the place where the thermal and catalytic conversions to NO occur. This assures a short residence time of the sample air inside the instrument, and minimises wall sorption problems of water soluble compounds. The fast response time (half-value periods of 0.30 s were found during concentration step changes and high accuracy in capturing the dominant Nr species enables the converter to be used in an eddy covariance setup. Although a source attribution of specific Nr compounds is not possible, the TRANC is a new reliable tool for permanent measurements of the net Nr flux between ecosystem and atmosphere at a relatively low maintenance and reasonable cost level allowing for diurnal, seasonal and annual investigations.

  8. Effects of fractionated doses of fast neutrons or photons on the canine brain: evaluation by computerized tomography and evoked response recording

    International Nuclear Information System (INIS)

    The use of fast neutrons in the treatment of cancer necessitates a knowledge of the normal tissue responses. This study was designed to compare the late effects of fractionated doses of fast neutrons with fractionated doses of photons on canine brains by evoked response recording and viewing computerized tomograms (CT). A relative biological effectiveness (RBE) of 4 was obtained for normal brain tissue assessed by mortality and onset of neurologic symptoms. Every three months post-irradiation, visual and sensory evoked responses were recorded. Changes over time appeared to be minimal; however, computerized tomographs showed marked brain shrinkage. A method of quantitating cerebrospinal fluid and parenchymal volumes from scans is described and future use of these CT ratios to generate dose response curves and RBE values is postulated

  9. Continuously tunable and fast-response terahertz metamaterials using in-plane-switching dual-frequency liquid crystal cells.

    Science.gov (United States)

    Chen, Chia-Chun; Chiang, Wei-Fan; Tsai, Min-Cheng; Jiang, Shun-An; Chang, Tsung-Hao; Wang, Song-Hang; Huang, Chia-Yi

    2015-05-01

    A metamaterial that is embedded in an in-plane-switching dual-frequency liquid crystal cell is used to develop an electrically controllable terahertz (THz) metamaterial. The resonance peak of the metamaterial can be redshifted and blueshifted as the frequency of an external voltage is switched, and the response times for the redshift and blueshift are 1.044 and 1.376 ms, respectively. A simulation confirms the spectral redshift and blueshift. The variation in peak frequency as a function of applied frequency at the external voltage is presented. Experimental results show that the resonance peak of the metamaterial can be continuously tuned within a frequency range of 15 GHz as the applied frequency is switched between 19 and 22 kHz. Therefore, this metamaterial is a continuously tunable and fast-response THz filter and could be used for THz imaging and THz telecommunications. PMID:25927774

  10. Mesoscale Simulation Data for Initializing Fast-Time Wake Transport and Decay Models

    Science.gov (United States)

    Ahmad, Nashat N.; Proctor, Fred H.; Vanvalkenburg, Randal L.; Pruis, Mathew J.; LimonDuparcmeur, Fanny M.

    2012-01-01

    The fast-time wake transport and decay models require vertical profiles of crosswinds, potential temperature and the eddy dissipation rate as initial conditions. These inputs are normally obtained from various field sensors. In case of data-denied scenarios or operational use, these initial conditions can be provided by mesoscale model simulations. In this study, the vertical profiles of potential temperature from a mesoscale model were used as initial conditions for the fast-time wake models. The mesoscale model simulations were compared against available observations and the wake model predictions were compared with the Lidar measurements from three wake vortex field experiments.

  11. Fast X-ray micro-CT for real-time 4D observation

    International Nuclear Information System (INIS)

    Fast X-ray computed tomography (CT) system with sub-second order measurement for single CT acquisition has been developed. The system, consisting of a high-speed sample rotation stage and a high-speed X-ray camera, is constructed at synchrotron radiation beamline in order to utilize fully intense X-rays. A time-resolving CT movie (i.e. 4D CT) can be available by operating the fast CT system continuously. Real-time observation of water absorbing process of super-absorbent polymer (SAP) has been successfully performed with the 4D CT operation.

  12. Time and energy response of ZnO:Ga crystal to hard X-ray

    International Nuclear Information System (INIS)

    This paper introduces the time response of a new type ZnO. Ga crystal to a fast rep-rate pulse hard X-ray. The hard X-ray energy spectrum (from 10 keV to 100 keV) was measured by X-ray fluorescence analysis apparatus. The results show that the rise time is 316 ps, the FWHM is 440 ps, and the energy response to hard X-ray is flat when the X-ray energy greater than 40 keV. The ZnO:Ga crystal could be used as a component for hard X-ray detection. (authors)

  13. ALBA timing system - a known architecture with fast interlock system upgrade

    International Nuclear Information System (INIS)

    Like most of the newest synchrotron facilities the ALBA Timing System works on event based architecture. Its main particularity is that integrated with the Timing system a Fast Interlock System has been implemented which allows for an automated and synchronous reaction time from any-to-any point of the machine faster than 5 ?s. The list of benefits of combining both systems is large: very high flexibility, reuse of the timing actuators, direct synchronous output in different points of the machine reacting to an interlock, implementation of the Fast Interlock with very low cost increase as the timing optic fiber network is reused or the possibility of combined diagnostic tools implementation for triggers and interlocks. To enhance this last point a global time-stamp of 8 ns accuracy that could be used both for triggers and interlocks has been implemented. The system has been designed, installed and extensively used during the Storage Ring commissioning with very good results. (authors)

  14. Ultra Fast Timing Measurements at $^{78}$Ni and $^{132}$Sn

    CERN Multimedia

    2002-01-01

    We propose to measure level lifetimes in the exotic nuclei of $^{81}$Ga and $^{80}$Ga in the vicinity of $^{78}$Ni and of $^{135}$Sb and $^{134}$Sb above $^{132}$Sn by the time-delayed technique. These are relatively simple nuclear systems with a few particles and/or holes outside of the doubly-magic core thus can be treated rather precisely within the shell model. The anticipated new structure information on these nuclei, and in particular the lifetime results will put constrains on the model parameters and will serve to verify their predictions. The selected nuclei are some of the most exotic ones just above $^{78}$Ni or $^{132}$Sn, where the transition rates can be studied at present. Of the strongest interest is the nucleus of $^{81}$Ga, which has only 3 valence protons outside of $^{78}$Ni with the lowest proton orbits being $p_{3/2}$ and $f_{5/2}$. The Ml transition between these states, although allowed by the selection rules, should be $\\textit{l}$-forbidden thus very slow. This should give raise to a...

  15. Fast periodic presentation of natural images reveals a robust face-selective electrophysiological response in the human brain.

    Science.gov (United States)

    Rossion, Bruno; Torfs, Katrien; Jacques, Corentin; Liu-Shuang, Joan

    2015-01-01

    We designed a fast periodic visual stimulation approach to identify an objective signature of face categorization incorporating both visual discrimination (from nonface objects) and generalization (across widely variable face exemplars). Scalp electroencephalographic (EEG) data were recorded in 12 human observers viewing natural images of objects at a rapid frequency of 5.88 images/s for 60 s. Natural images of faces were interleaved every five stimuli, i.e., at 1.18 Hz (5.88/5). Face categorization was indexed by a high signal-to-noise ratio response, specifically at an oddball face stimulation frequency of 1.18 Hz and its harmonics. This face-selective periodic EEG response was highly significant for every participant, even for a single 60-s sequence, and was generally localized over the right occipitotemporal cortex. The periodicity constraint and the large selection of stimuli ensured that this selective response to natural face images was free of low-level visual confounds, as confirmed by the absence of any oddball response for phase-scrambled stimuli. Without any subtraction procedure, time-domain analysis revealed a sequence of differential face-selective EEG components between 120 and 400 ms after oddball face image onset, progressing from medial occipital (P1-faces) to occipitotemporal (N1-faces) and anterior temporal (P2-faces) regions. Overall, this fast periodic visual stimulation approach provides a direct signature of natural face categorization and opens an avenue for efficiently measuring categorization responses of complex visual stimuli in the human brain. PMID:25597037

  16. Fast tensor-product solvers: Part II: Spectral discretization in space and time.

    OpenAIRE

    Maday, Yvon; Rønquist, Einar M.

    2007-01-01

    We consider the numerical solution of an unsteady convection-diffusion equation using high order polynomial approximations both in space and time. General boundary conditions and initial conditions can be imposed. The method is fully implicit and enjoys exponential convergence in time and space for analytic solutions. This is con?rmed by numerical experiments (in one space dimension) using a spectral element approach in time and a pure spectral method in space. A fast tensor-product solver ha...

  17. Rapid analysis of fast GC effluents by time-of-flight MS

    Energy Technology Data Exchange (ETDEWEB)

    Borgerding, A.J.; Wilkerson, C.W. Jr. [Los Alamos National Lab., NM (United States)

    1995-12-31

    Recent studies in gas chromatography, utilizing short columns and incraesed flow rates, have reduced analysis times by a factor of 10 or more. Fast GC analysis of this type has great potential for improving environmental measurements. In addition to the improved sample throughput and resulting gains in productivity, rapid monitoring of various environmental systems is possible. There are, however, some difficulties interfacing FAst GC with mass spectrometry. Specifically, analyte peaks from Fast GC systems are usually less than a few hundred milliseconds, preventing the use of scanning instruments. In addition, the high volumetric flow rates from the GC can cause difficulties in maintaining a sufficient vacuum. In this paper, we study the potential of time-of-flight mass spectrometry along with the use of narrow bore GC columns to overcome these limitations. Early examples of the capabilities of this instrumentation for the analysis of volatile compounds in atmospheric samples are shown.

  18. Response Time Measurements of the NIF DANTE XRD-31 X-Ray Diodes (Pre-print)

    International Nuclear Information System (INIS)

    The XRD-31 is a fast, windowless X-ray vacuum photodiode developed by EG and G. It is currently the primary fast X-ray detector used to diagnose the X-rays on NIF and OMEGA on the multichannel DANTE spectrometer. The XRD-31 has a dynamic range of less than 1e-12 amps to more than 10 amps. A technique is described to measure the impulse response of the diodes to a 150 fs pulse of 200 nm laser light and a method to calculate the 'risetime' for a square pulse and compare it with the computed electron transit time from the photocathode to the anode. Measured response time for 5 XRD-31s assembled in early 2004 was 149.7 ps +-2.75 ps

  19. Response of some French beans (Phaseolus vulgaris L) varieties to fast neutron irradiation

    International Nuclear Information System (INIS)

    Response of some French beans (Phaseolus vulgaris L.) varieties to fast neutron irradiation. Seeds of French beans varieties, i.e. Local Bandung (white seed), Local Surakarta and Monel (black seed), and Hawaiian Wonder (brown seed) were irradiated with fast neutrons. Irradiation was carried out in the USIF of the TRIGA MARK II Reactor in the Research Centre for Nuclear Techniques Bandung, with doses of 7,5, 15,0, 22,5, 30,0, 37,5 and 45,0 Gy. Irradiated seeds were planted in plastic pots and grown in the green house. The responses of the seedlings to neutron irradiation were observed by measuring the length of hypocotyl, epicotyl and primary leaf size (length and width). The result of the study showed that epicotyl is the most sensitive to fast neutron irradiation followed by primary leaf size and hypocotyl. The D50 for the four varieties measured were significantly different. It was also shown that the black seed varieties were relatively more radioresistant than the other two. (author). 3 figs, 13 refs

  20. Fast adaptive responses in the oral jaw of Lake Victoria cichlids.

    Science.gov (United States)

    van Rijssel, Jacco C; Hoogwater, Ellen S; Kishe-Machumu, Mary A; van Reenen, Elize; Spits, Kevin V; van der Stelt, Ronald C; Wanink, Jan H; Witte, Frans

    2015-01-01

    Rapid morphological changes in response to fluctuating natural environments are a common phenomenon in species that undergo adaptive radiation. The dramatic ecological changes in Lake Victoria provide a unique opportunity to study environmental effects on cichlid morphology. This study shows how four haplochromine cichlids adapted their premaxilla to a changed diet over the past 30 years. Directly after the diet change toward larger and faster prey in the late 1980s, the premaxilla (upper jaw) changed in a way that is in agreement with a more food manipulating feeding style. During the 2000s, two zooplanktivorous species showed a reversal of morphological changes after returning to their original diet, whereas two other species showed no reversal of diet and morphology. These rapid changes indicate a potential for extremely fast adaptive responses to environmental fluctuations, which are likely inflicted by competition release and increase, and might have a bearing on the ability of haplochromines to cope with environmental changes. These responses could be due to rapid genetic change or phenotypic plasticity, for which there is ample evidence in cichlid fish structures associated with food capture and processing. These versatile adaptive responses are likely to have contributed to the fast adaptive radiation of haplochromines. PMID:25403383

  1. Influence of Ramadan Fasting on Anaerobic Performance and Recovery Following Short time High Intensity Exercise.

    Science.gov (United States)

    Karli, Umid; Guvenc, Alpay; Aslan, Alper; Hazir, Tahir; Acikada, Caner

    2007-01-01

    The aim of this study was to investigate the effects of Ramadan fasting on anaerobic power and capacity and the removal rate of lactate after short time high intensity exercise in power athletes. Ten male elite power athletes (2 wrestlers, 7 sprinters and 1 thrower, aged 20-24 yr, mean age 22.30 ± 1.25 yr) participated in this study. The subjects were tested three times [3 days before the beginning of Ramadan (Pre-RF), the last 3 days of Ramadan (End-RF) and the last 3 days of the 4(th) week after the end of Ramadan (After-RF)]. Anaerobic power and capacity were measured by using the Wingate Anaerobic Test (WAnT) at Pre-RF, End-RF and After- RF. Capillary blood samples for lactate analyses and heart rate recordings were taken at rest, immediately after WAnT and throughout the recovery period. Repeated measures of ANOVA indicated that there were no significant changes in body weight, body mass index, fat free mass, percentage of body fat, daily sleeping time and daily caloric intake associated with Ramadan fasting. No significant changes were found in total body water either, but urinary density measured at End-RF was significantly higher than After-RF. Similarity among peak HR and peak LA values at Pre-RF, End- RF and After-RF demonstrated that cardiovascular and metabolic stress caused by WAnT was not affected by Ramadan fasting. In addition, no influence of Ramadan fasting on anaerobic power and capacity and removal rate of LA from blood following high intensity exercise was observed. The results of this study revealed that if strength-power training is performed regularly and daily food intake, body fluid balance and daily sleeping time are maintained as before Ramadan, Ramadan fasting will not have adverse effects on body composition, anaerobic power and capacity, and LA metabolism during and after high intensity exercise in power athletes. Key pointsNo significant changes were assessed on body composition, daily sleeping time and caloric intake, and body fluid balance in regularly trained power athletes during Ramadan fasting.Ramadan fasting has no adverse effect on power outputs of short time high intensity exercise.No influence of Ramadan fasting on LA metabolism during high intensity exercise and passive recovery in regularly trained power athletes. PMID:24149483

  2. An Ultralow Power Fast-Response Nano-TCD CH4 sensor for UAV Airborne Measurements Project

    National Aeronautics and Space Administration — In this project, KWJ proposes to develop a low power, fast response, lightweight miniature CH4 measurement system based on KWJ nano-TCD sensor for airborne...

  3. A Comparison of Response Rate, Response Time, and Costs of Mail and Electronic Surveys.

    Science.gov (United States)

    Shannon, David M.; Bradshaw, Carol C.

    2002-01-01

    Compared response rates, response time, and costs of mail and electronic surveys using a sample of 377 college faculty members. Mail surveys yielded a higher response rate and a lower rate of undeliverable surveys, but response time was longer and costs were higher than for electronic surveys. (SLD)

  4. A UV LED-based fast-pulsed photoelectron source for time-of-flight studies.

    Czech Academy of Sciences Publication Activity Database

    Valerius, K.; Beck, M.; Arlinghaus, H.; Bonn, J.; Hannen, V.M.; Hein, H.; Ostrick, B.; Streubel, S.; Weinheimer, C.; Zbo?il, Miroslav

    2009-01-01

    Ro?. 11, - (2009), 063018/1-063018/16. ISSN 1367-2630 R&D Projects: GA MŠk LA318 Institutional research plan: CEZ:AV0Z10480505 Keywords : fast-pulsed * high-resolution * time-of-flight Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 3.312, year: 2009

  5. Fast MCMC sampling for Markov jump processes and continuous time Bayesian networks

    CERN Document Server

    Rao, Vinayak

    2012-01-01

    Markov jump processes and continuous time Bayesian networks are important classes of continuous time dynamical systems. In this paper, we tackle the problem of inferring unobserved paths in these models by introducing a fast auxiliary variable Gibbs sampler. Our approach is based on the idea of uniformization, and sets up a Markov chain over paths by sampling a finite set of virtual jump times and then running a standard hidden Markov model forward filtering-backward sampling algorithm over states at the set of extant and virtual jump times. We demonstrate significant computational benefits over a state-of-the-art Gibbs sampler on a number of continuous time Bayesian networks.

  6. Limits on Fast Radio Bursts at 145 MHz with ARTEMIS, a real-time software backend

    OpenAIRE

    Karastergiou, A.; Chennamangalam, J.; Armour, W; Williams, C.; Mort, B; Dulwich, F.; Salvini, S.; Magro, A.; Roberts, S.; Serylak, M; Doo, A.; Bilous, A. V.; Breton, R.P., R.; Falcke, H.; Griessmeier, J. -M.

    2015-01-01

    Fast Radio Bursts (FRBs), are millisecond radio signals that exhibit dispersion larger than what the Galactic electron density can account for. We have conducted a 1446 hour survey for Fast Radio Bursts (FRBs) at 145~MHz, covering a total of 4193 sq. deg on the sky. We used the UK station of the LOFAR radio telescope -- the Rawlings Array -- , accompanied for a majority of the time by the LOFAR station at Nan\\c{c}ay, observing the same fields at the same frequency. Our real-...

  7. Using Hydrologic Response Functions and Transit Time Distributions to Investigate Dynamic Catchment Behavior (Invited)

    Science.gov (United States)

    Heidbuechel, I.; Troch, P. A.

    2013-12-01

    There is a fundamental difference between the hydrologic response function and the transit time distribution - the former is a function of the catchment and reports how fast and how strongly the catchment responds to precipitation inputs while the latter describes individual precipitation events and characterizes the transport and storage of water particles throughout a catchment assigning a water age to each particle. Plotting both the hydrologic response function and the transit time distribution on one graph reveals the varying fractions of preevent water and allows for a qualitative assessment of dominant flow paths for individual precipitation events. Additionally, time series of varying hydrologic response functions and transit time distributions can be used to investigate the main controls of catchment response and transit times by relating them to topographical, soil and event parameters. Finally, it is also possible to integrate the changing hydrologic response functions and transit time distributions over time to construct master distributions. These are expressions of the catchment's general response and storage behavior and can thus be utilized to compare and hydrologically classify different catchments. Data from various catchments is used to illustrate these points.

  8. The Importance of Responsibility in Times of Crisis

    Directory of Open Access Journals (Sweden)

    Jacob Dahl Rendtorff

    2014-06-01

    Full Text Available In this paper I would like to show the importance of the concept of responsibility as the foundation of ethics in times of crisis in particular in the fields of politics and economics in the modern civilisation marked by globalization and technological progres. I consider the concept of responsibility as the key notion in order to understand the ethical duty in a modern technological civilisation. We can indeed observe a moralization of the concept of responsibility going beyond a strict legal definition in terms of imputability. The paper begins by discussing the humanistic foundations of such a concept of responsibility. It treats the historical origins of responsibility and it relates this concept to the concept of accountability. On the basis of this historical determination of the concept I would like to present the definition of the concept of responsibility as fundamental ethical principle that has increasing importance as the foundation of the principles of governance in modern welfare states. In this context the paper discusses the extension of the concept of responsibility towards institutional or corporate responsibility where responsibility does not only concerns the responsibility of individuals but also deals with the responsibility of institutional collectivities. In this way the paper is based on the following structure : 1 The ethical foundation of the concept of responsibility 2 Responsibility in technological civilisation 3 Political responsibility for good governance in the welfare state 4 Social responsibility of business corporations in times of globalization 5 Conclusion and discussion : changed conditions of responsibility in modern times.

  9. Fast and memory-efficient algorithms for computing quadratic time–frequency distributions

    OpenAIRE

    O' Toole, J.M.; Boashash, B

    2013-01-01

    Algorithms for computing time–frequency distributions (TFDs) limit computation time by reducing numerical operations. But these fast algorithms do not reduce the memory load. This article presents four TFD algorithms to minimise both the computation and memory loads. Each algorithm is optimised for a specific kernel category. Three algorithms reduce memory by computing an exact TFD without oversampling; the fourth algorithm, for the nonseparable kernel, reduces memory by computing a decimated...

  10. Development of a 'chronotron' for time of flight fast neutron spectrometer

    International Nuclear Information System (INIS)

    A chronotron using storage circuits of a 100 channels amplitude analyser has been developed in order to measure the time of flight of fast neutrons. A time dilatation is obtained by a distribution of 20 6BN6 tubes. The width at half maximum of prompt coincidences curve is 1,6.10-9 s for ?-? coincidences from An198 and 2.10-9 s for n-? coincidences from (d, t) reaction. (author)

  11. Ultra-fast transistor-based detectors for precise timing of near infrared and THz signals

    OpenAIRE

    Preu, S.; Mittendorff, M.; Winnerl, S.; Lu, H.; Gossard, A. C.; Weber, H. B.

    2013-01-01

    A whole class of two-color experiments involves intense, short Terahertz radiation pulses. A fast detector that is sensitive and able to resolve both near-infrared and Terahertz pulses at the same time is highly desirable. Here we present the first detector of this kind. The detector element is a GaAs-based field effect transistor operated at room temperature. THz detection is successfully demonstrated at frequencies up to 4.9 THz. The THz detection time constant is shorter ...

  12. Fast estimation methods for time series models in state-space form

    OpenAIRE

    Hiernaux, Alfredo G.; Casals Carro, José; Jerez Méndez, Miguel

    2005-01-01

    We propose two fast, stable and consistent methods to estimate time series models expressed in their equivalent state-space form. They are useful both, to obtain adequate initial conditions for a maximum-likelihood iteration, or to provide final estimates when maximum-likelihood is considered inadequate or costly. The state-space foundation of these procedures implies that they can estimate any linear fixed-coefficients model, such as ARIMA, VARMAX or structural time series models. The com...

  13. Response of multiferroic composites inferred from a fast-Fourier-transform-based numerical scheme

    International Nuclear Information System (INIS)

    The effective response and the local fields within periodic magneto-electric multiferroic composites are investigated by means of a numerical scheme based on fast Fourier transforms. This computational framework relies on the iterative resolution of coupled series expansions for the magnetic, electric and strain fields. By using an augmented Lagrangian formulation, a simple and robust procedure which makes use of the uncoupled Green operators for the elastic, electrostatics and magnetostatics problems is proposed. Its accuracy is assessed in the cases of laminated and fibrous two-phase composites for which analytical solutions exist

  14. Interlaboratory Validation for a Real-Time PCR Salmonella Detection Method Using the ABI 7500 FAST Real-Time PCR System.

    Science.gov (United States)

    Cheng, Chorng-Ming; Doran, Tara; Lin, Wen; Chen, Kai-Shun; Williams-Hill, Donna; Pamboukian, Ruiqing

    2015-06-01

    Sixteen FERN (Food Emergency Response Network) member laboratories collaborated in this study to verify extension of the real-time PCR Salmonella detection method originally designed for the single-tube Cepheid SmartCycler II and validated against the Salmonella method of the U. S. Food and Drug Administration Bacteriological Analytical Manual to the Applied Biosystems (ABI) 7500 FAST Real-Time PCR system multiwell plate platform. Four foods were selected for this study: chili powder, soft cheese, fish, and tomatoes; these foods represent products that are commonly analyzed for the presence of Salmonella for regulatory purposes. Each food consisted of six uninoculated control samples, six samples inoculated with low Salmonella levels (target 1 to 5 CFU/25 g), and six samples inoculated with high levels (target 10 to 50 CFU/25 g). All samples were tested for Salmonella using the 24-h quantitative PCR (qPCR) method for detecting Salmonella, which utilizes modified buffered peptone water as the sole enrichment medium and an internal control for the qPCR. Each of these 18 samples was individually analyzed for Salmonella by the collaborating laboratories using both the ABI 7500 FAST system (alternative method) and the SmartCycler II system (reference method). Statistical analysis of the data revealed no significant difference (P ? 0.05) between these two qPCR platforms except for the chili powder samples. The differences noted with chili powder (P = 0.0455) were attributed to the enhanced sensitivity of the ABI 7500 FAST system compared with the SmartCycler II system. The detection limit of both qPCR methods was 0.02 to 0.15 CFU/g. These results provide a solid basis for extending the 24-h qPCR Salmonella method to the ABI 7500 FAST system for high-throughput detection of Salmonella in foods. PMID:26038901

  15. Latent Response Times and Cognitive Processing on the FMCE

    Science.gov (United States)

    Bonham, Scott

    2008-10-01

    Latent response time analysis of students on an electronic version of the Force and Motion Conceptual Evaluation (FMCE) provides information on student reading patterns and the role of mental models in student reasoning. Regression analysis looked at the dependence of response times on characteristics of questions, such as amount of text and inclusion of graphs. Results indicate that students generally read through the question text and instructions when first presented, but do not systematically read through answer choices and graphs. Comparison of average response times between pre- and post-instructional assessment found a drop in response times when students used Newtonian ideas but no change for responses using the main alternative concept. The average response time for students who answered using a mix of Newtonian and alternative concepts was not different from those using primarily one or the other; questions rarely activated both concepts at the same time.

  16. Light touch modulates balance recovery following perturbation: from fast response to stance restabilization.

    Science.gov (United States)

    Martinelli, Alessandra Rezende; Coelho, Daniel Boari; Magalhães, Fernando Henrique; Kohn, André Fabio; Teixeira, Luis Augusto

    2015-05-01

    Light fingertip touch of a static bar generates extra somatosensory information used by the postural control system to reduce body sway. While the effect of light touch has been studied in quiet stance, less attention has been given to its potential benefit for reactive postural responses. In the present study, we tested the effect of light fingertip touch of a stable surface on recovery of postural stability from a mechanical perturbation. Participants stood upright on a force plate touching a static rigid bar while being pulled backward by a load. Unpredictable release of the load induced fast anterior body sway, requiring a reactive response to recover balance. Effect of light touch on postural responses was assessed as a function of vision and malleability of the support surface, analyzing different epochs ranging from the pre-perturbation period to recovery of a relatively stable quiet stance. Results showed that light touch induced lower magnitude of muscular activation in all epochs. Center of pressure (CoP) displacement/sway was affected by interaction of light touch with manipulation of the other sensory information. For the periods associated with quiet stance, light touch led to decreased CoP sway in the malleable surface in the pre-perturbation epoch, and in the condition combining no vision and malleable surface in the balance restabilization and follow-up quiet stance epochs. For the fast reactive response epoch, light touch induced smaller amplitude of CoP displacement across conditions, and lower CoP maximum velocity in the condition combining no vision and rigid surface. These results showed that light touch modulates postural responses in all epochs associated with an unanticipated mechanical perturbation, with a more noticeable effect in conditions manipulating sensory information relevant for balance control. PMID:25644655

  17. Elements for Response Time Statistics in ERP Transaction Systems

    OpenAIRE

    Mielke, Andreas

    2004-01-01

    We present some measurements and ideas for response time statistics in ERP systems. It is shown that the response time distribution of a given transaction in a given system is generically a log-normal distribution or, in some situations, a sum of two or more log-normal distributions. We present some arguments for this form of the distribution based on heuristic rules for response times, and we show data from performance measurements in actual systems to support the log-norma...

  18. Response Times of Operators in a Control Room

    DEFF Research Database (Denmark)

    Platz, O.; Rasmussen, J.

    1982-01-01

    A statistical analysis was made of operator response times recorded in the control room of a research reactor during the years 1972-1974. A homogeneity test revealed that the data consist of a mixture of populations. A small but statistically significant difference is found between day and night response times. Lognormal distributions are found to provide the best fit of the day and the night response times.

  19. Response times of operators in a control room

    International Nuclear Information System (INIS)

    A statistical analysis was made of operator response times recorded in the control room of a research reactor during the years 1972-1974. A homogeneity test revealed that the data consist of a mixture of populations. A small but statistically significant difference is found between day and night response times. Lognormal distributions are found to provide the best fit of the day and the night response times. (author)

  20. Elevated plasma leptin levels of fasted rainbow trout decrease rapidly in response to feed intake.

    Science.gov (United States)

    Johansson, Marcus; Björnsson, Björn Thrandur

    2015-04-01

    Leptin has an anorexigenic effect in fish, indicating a role in regulation of growth and energy homeostasis. The study aimed to further clarify the physiological role of leptin in rainbow trout, specifically its short-term response to feed intake after a period of fasting. Utilizing a salmonid leptin radioimmunoassay, the study demonstrates differences in plasma leptin levels in fishes with different nutritional status and at the onset of feeding. Some of the fasted fish were clearly in a state of anorexia, and did not initiate feeding during the 72h refeeding period. For those fish that did initiate feeding, both previously fed and fasted, plasma leptin levels rapidly decreased during the first 24h in correlation with increased amount of food reaching the gastrointestinal tract, while non-feeding individuals retained a high plasma leptin levels. The data indicate that the leptin-induced anorexic state is broken after onset of feeding and that the regulatory mechanisms leading to decreased plasma leptin levels are linked to nutrient levels. PMID:25745812

  1. Fast time-reversible algorithms for molecular dynamics of rigid-body systems.

    Science.gov (United States)

    Kajima, Yasuhiro; Hiyama, Miyabi; Ogata, Shuji; Kobayashi, Ryo; Tamura, Tomoyuki

    2012-06-21

    In this paper, we present time-reversible simulation algorithms for rigid bodies in the quaternion representation. By advancing a time-reversible algorithm [Y. Kajima, M. Hiyama, S. Ogata, and T. Tamura, J. Phys. Soc. Jpn. 80, 114002 (2011)] that requires iterations in calculating the angular velocity at each time step, we propose two kinds of iteration-free fast time-reversible algorithms. They are easily implemented in codes. The codes are compared with that of existing algorithms through demonstrative simulation of a nanometer-sized water droplet to find their stability of the total energy and computation speeds. PMID:22779579

  2. Development of a generalized model to analyze time and frequency responses for SAW sensors

    International Nuclear Information System (INIS)

    Most of the research on applications of wireless surface acoustic wave (SAW) sensors has focused on the fabrication process. No detailed theoretical models have been developed to illustrate the time and frequency domain characteristics of SAW devices. In this paper, the generalized model of the wireless SAW sensor is established by using the coupling-of-modes (COM) model together with the wave equations. The generalized model is developed to analyze four main applications, which include tag-ID design, the bio-reaction process, tension measurement and temperature sensing. Both the time response and frequency response are investigated to determine the appropriate signal processing for different applications. It is found that for the time response using the inverse fast Fourier transform (IFFT) is more suitable for tag-ID and the phase shift is better for bio-sensing, tension and temperature sensing. Furthermore, the developed model can be utilized to expedite the design process for wireless sensing devices

  3. Transcriptomic and metabolomic profiling of chicken adipose tissue in response to insulin neutralization and fasting

    Directory of Open Access Journals (Sweden)

    Ji Bo

    2012-08-01

    Full Text Available Abstract Background Domestic broiler chickens rapidly accumulate adipose tissue due to intensive genetic selection for rapid growth and are naturally hyperglycemic and insulin resistant, making them an attractive addition to the suite of rodent models used for studies of obesity and type 2 diabetes in humans. Furthermore, chicken adipose tissue is considered as poorly sensitive to insulin and lipolysis is under glucagon control. Excessive fat accumulation is also an economic and environmental concern for the broiler industry due to the loss of feed efficiency and excessive nitrogen wasting, as well as a negative trait for consumers who are increasingly conscious of dietary fat intake. Understanding the control of avian adipose tissue metabolism would both enhance the utility of chicken as a model organism for human obesity and insulin resistance and highlight new approaches to reduce fat deposition in commercial chickens. Results We combined transcriptomics and metabolomics to characterize the response of chicken adipose tissue to two energy manipulations, fasting and insulin deprivation in the fed state. Sixteen to 17 day-old commercial broiler chickens (ISA915 were fed ad libitum, fasted for five hours, or fed but deprived of insulin by injections of anti-insulin serum. Pair-wise contrasts of expression data identified a total of 2016 genes that were differentially expressed after correction for multiple testing, with the vast majority of differences due to fasting (1780 genes. Gene Ontology and KEGG pathway analyses indicated that a short term fast impacted expression of genes in a broad selection of pathways related to metabolism, signaling and adipogenesis. The effects of insulin neutralization largely overlapped with the response to fasting, but with more modest effects on adipose tissue metabolism. Tissue metabolomics indicated unique effects of insulin on amino acid metabolism. Conclusions Collectively, these data provide a foundation for further study into the molecular basis for adipose expansion in commercial poultry and identify potential pathways through which fat accretion may be attenuated in the future through genetic selection or management practices. They also highlight chicken as a useful model organism in which to study the dynamic relationship between food intake, metabolism, and adipose tissue biology.

  4. Pipelined multiprocessor computer architecture and fast parallel algorithms for real time robot control

    Energy Technology Data Exchange (ETDEWEB)

    Mun, W.

    1989-01-01

    As a result of the automation revolution, robots are assuming ever more complex and demanding tasks. Robot system control schemes for fast and precise robot motion require utilization of the entirety of the robot dynamic formulations and the ability to evaluate these formulations in real-time. The dynamic formulations, which take into account robot nonlinearities and dynamic coupling, are computationally intensive. They are difficult to implement in real-time at high sampling rates due to the time required to compute the dynamic formulations. Reducing the computation time for practical implementation can be achieved by developing a computing algorithm for the efficient evaluation of the dynamic formulations and by designing a dedicated computer architecture. The proposed solution is a pipelined multiprocessor computer architecture and fast parallel algorithms for real-time control. The multiprocessor system can be utilized to concurrently perform pipelined parallel computations, thereby substantially increasing controller processing speed and CPU utilization. Concurrent performance of pipelined parallel computations is based on consideration of the sequential dependencies of the dynamic formulations which are conductive to pipelining, and decomposition of the dynamic backward formulations for fast parallel computation. The performance of the proposed algorithms, called PAFP, is evaluated through analytic error analysis and experimental simulations, including motion simulations. It is compared to other approaches to the problem proposed by, respectively, Bejczy and Binder.

  5. The usefulness of time-dependent reactor accident consequence modelling for emergency response planning

    International Nuclear Information System (INIS)

    After major releases of radionuclides into the atmosphere fast reaction of authorities will be necessary to inform the public of potential consequences and to consider and optimize mitigating actions. These activities require availability of well designed computer models, adequate and fast measurements and prior training of responsible persons. The quantitative assessment models should be capable of taking into account of actual atmospheric dispersion conditions, actual deposition situation (dry, rain, snow, fog), seasonal status of the agriculture, food processing and distribution pathways, etc. In this paper the usefulness of such models will be discussed, their limitations, the relative importance of exposure pathways and a selection of important methods to decrease the activity in food products after an accident. Real-time reactor accident consequence models should be considered as a condition sine qua non for responsible use of nuclear power for electricity production

  6. Detection and imaging of moving targets in wide band SAS using fast time backprojection combined with space time processing

    OpenAIRE

    Pettersson, Mats; Zetterberg, Viktoria; Claesson, Ingvar

    2005-01-01

    This paper present a method to combine SAS (Synthetic Aperture Sonar) imaging of stationary targets with moving target detection and imaging. The proposed method uses a likelihood ratio for moving target detection in a wide band (WB) SAS system. For this paper, WB is defined as any systems having a large fractional bandwidth, i.e. an ultra wide frequency band combined with a wide antenna beam. The developed method combines time domain fast backprojection SAS processing...

  7. Interactions of fast and slow waves in problems with two time scales

    International Nuclear Information System (INIS)

    Consideration is given to certain symmetric hyperbolic systems of nonlinear partial differential equations whose solutions vary on two time scales, a slow scale t and a fast scale t/epsilon. It is shown that if the initial data are not prepared correctly for the suppression of the fast scale motion and contain errors of amplitude O(epsilon to the mu), so that only mu time derivatives of the solution are bounded at t 0, then fast waves of amplitude O(epsilon to the mu) will be present in the solution. The error introduced in the slow scale motion by nonlinear interactions of these waves, however, will only be of amplitude O(epsilon to the 2 mu) + O(epsilon to the mu + 1). Since this holds for any mu greater than 0, it extends the results given by Kreiss (1979, 1980). It is concluded that the effects of the fast waves can be controlled more easily than has been thought. There is thus partial justification for neglecting them in certain physical situations. 19 references

  8. The Effect of Holly Fasting Month of Ramadan on the Delayed Type Hypersensitivity Response to Purified Protein Derivative

    Directory of Open Access Journals (Sweden)

    M. Rahmani

    2003-04-01

    Full Text Available Studies during recent decade indicate that low calorie intake has potentiating effect on immune response . So the effect of fasting in holly month of Ramadan on cellular immune was studied. In this study , delayed type hypersensitivity (DTH to purified protein derivative (PPD test was selected to evaluate cellular immune response , because this test is not only very simple but also is valuable and reliable. This research studied DTH to PPD in two groups of students before and after the holly fasting month of Ramadan. The range of age in the both groups was 20-30 year. Mantoux method was the selected method to evaluate DTH response to PPD. DTH response to PPD in fasting group increased from 8.8 to 13 mm , which is statistically significant (P<0.05. It is noticeable that the differences between the rates of increasing DTH response to PPD in control group and fasting group was statistically significant (P<0.05. Based on the above finding it can be concluded that fasting has potentiating effect on cellular immune response.

  9. Dispersion of Response Times Reveals Cognitive Dynamics

    Science.gov (United States)

    Holden, John G.; Van Orden, Guy C.; Turvey, Michael T.

    2009-01-01

    Trial-to-trial variation in word-pronunciation times exhibits 1/f scaling. One explanation is that human performances are consequent on multiplicative interactions among interdependent processes-interaction dominant dynamics. This article describes simulated distributions of pronunciation times in a further test for multiplicative interactions and…

  10. A 3 A sink/source current fast transient response low-dropout Gm driven linear regulator

    International Nuclear Information System (INIS)

    A 3 A sink/source Gm-driven CMOS low-dropout regulator (LDO), specially designed for low input voltage and low cost, is presented by utilizing the structure of a current mirror Gm (transconductance) driving technique, which provides high stability as well as a fast load transient response. The proposed LDO was fabricated by a 0.5 ?m standard CMOS process, and the die size is as small as 1.0 mm2. The proposed LDO dissipates 220 ?A of quiescent current in no-load conditions and is able to deliver up to 3 A of load current. The measured results show that the output voltage can be resumed within 2 ?s with a less than 1 mV overshoot and undershoot in the output current step from -1.8 to 1.8 A with a 0.1 ?s rising and falling time at three 10 ?F ceramic capacitors. (semiconductor integrated circuits)

  11. Organic scintillators response function modeling for Monte Carlo simulation of Time-of-Flight measurements.

    Science.gov (United States)

    Carasco, C

    2012-07-01

    In neutron Time-of-Flight (TOF) measurements performed with fast organic scintillation detectors, both pulse arrival time and amplitude are relevant. Monte Carlo simulation can be used to calculate the time-energy dependant neutron flux at the detector position. To convert the flux into a pulse height spectrum, one must calculate the detector response function for mono-energetic neutrons. MCNP can be used to design TOF systems, but standard MCNP versions cannot reliably calculate the energy deposited by fast neutrons in the detector since multiple scattering effects must be taken into account in an analog way, the individual recoil particles energy deposit being summed with the appropriate scintillation efficiency. In this paper, the energy response function of 2?×2? and 5?×5? liquid scintillation BC-501 A (Bicron) detectors to fast neutrons ranging from 20 keV to 5.0 MeV is computed with GEANT4 to be coupled with MCNPX through the "MCNP Output Data Analysis" software developed under ROOT (Carasco, 2010). PMID:22100378

  12. A novel insitu estimation of time constant for core temperature sensors in Fast Breeder Reactor

    International Nuclear Information System (INIS)

    The temperature of sodium at the outlet nozzles of fuel sub-assemblies in a liquid metal cooled fast breeder reactor (LMFBR) is one of the most critical parameters to be monitored continuously for safe and reliable operation of the reactor. The installed time constant of the thermocouple is around 6 +/- 2 sec. This paper describes the method for determining the insitu time constant of the core monitoring thermocouples located inside thermowell using the bare central 2mm dia thermocouple of known time constant as reference. (author)

  13. Real-time fast ferrite ICRF tuning system on the Alcator C-Mod tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Y. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)], E-mail: ylin@psfc.mit.edu; Binus, A.; Wukitch, S.J. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2009-01-15

    A real-time ion cyclotron range of frequencies (ICRF) antenna matching system has been successfully implemented on Alcator C-Mod. This is a triple-stub tuning system working at 80 MHz, where one stub acts as a pre-matching stub and the other two stubs use fast ferrite tuners (FFTs) to accomplish fast tuning. It utilizes a digital controller for feedback control (200 {mu}s per iteration) using real-time antenna loading measurements as inputs and the coil currents to the FFT as outputs. The system has achieved and maintained matching for a large range of plasma parameters, including L-mode, H-mode, and plasmas with edge localized modes. It has succeeded in delivering up to 1.85 MW net rf power into H-mode plasmas at maximum voltage of 37 kV on the unmatched side of the matching system.

  14. Real-time fast ferrite ICRF tuning system on the Alcator C-Mod tokamak

    International Nuclear Information System (INIS)

    A real-time ion cyclotron range of frequencies (ICRF) antenna matching system has been successfully implemented on Alcator C-Mod. This is a triple-stub tuning system working at 80 MHz, where one stub acts as a pre-matching stub and the other two stubs use fast ferrite tuners (FFTs) to accomplish fast tuning. It utilizes a digital controller for feedback control (200 ?s per iteration) using real-time antenna loading measurements as inputs and the coil currents to the FFT as outputs. The system has achieved and maintained matching for a large range of plasma parameters, including L-mode, H-mode, and plasmas with edge localized modes. It has succeeded in delivering up to 1.85 MW net rf power into H-mode plasmas at maximum voltage of 37 kV on the unmatched side of the matching system

  15. Hierarchical Diffusion Models for Two-Choice Response Times

    Science.gov (United States)

    Vandekerckhove, Joachim; Tuerlinckx, Francis; Lee, Michael D.

    2011-01-01

    Two-choice response times are a common type of data, and much research has been devoted to the development of process models for such data. However, the practical application of these models is notoriously complicated, and flexible methods are largely nonexistent. We combine a popular model for choice response times--the Wiener diffusion…

  16. Linking Response-Time Parameters onto a Common Scale

    Science.gov (United States)

    van der Linden, Wim J.

    2010-01-01

    Although response times on test items are recorded on a natural scale, the scale for some of the parameters in the lognormal response-time model (van der Linden, 2006) is not fixed. As a result, when the model is used to periodically calibrate new items in a testing program, the parameter are not automatically mapped onto a common scale. Several…

  17. Fast-response magnet coil system for controlling plasma equilibrium in a tokamak with a strong magnetic field

    International Nuclear Information System (INIS)

    Two special fast-control coils are used to provide stability of a plasma filament in a horizontal plane of a tokamak with a strong magnetic field. According to the fast-response conditions satisfying the control system, power of the supply system for these coils is to constitute 35 MW (U=2.5 kV, I=14 kA). A basic circuit of the supply system with a capacitor is given, the circuit consists of a capacitor bank with a rectifier providing for a preliminary chage of a capacitor bank, thyristor switches, a shut-down system, circuit breakers, valve devices. A basic circuit of supply system for plasma equilibrium coil built on the base of fast-response and reliability priciples is presented. Fast voltage removal is provided by shorting out a c

  18. Response time patterns in a stated choice experiment

    DEFF Research Database (Denmark)

    Börjesson, Maria; Fosgerau, Mogens

    2015-01-01

    This paper studies how response times vary between unlabelled binary choice occasions in a stated choice (SC) experiment, with alternatives differing with respect to in-vehicle travel time and travel cost. The pattern of response times is interpreted as an indicator of the cognitive processes employed by the respondents when making their choices. We find clear signs of reference-dependence in response times in the form of a strong gain–loss asymmetry. Moreover, different patterns of response times for travel time and travel cost indicate that these attributes are processed in different ways by respondents. This may be of particular relevance for choice experiments in the transportation field, where the travel time attribute is central.

  19. Optimal core configurations related to the doubling time for modular fast reactors

    International Nuclear Information System (INIS)

    Based on the Prism modular reactor model (150 MW e), the paper proposes some geometrical configurations of a fast power reactor and assembly structure which are optimized for a minimum doubling time. The results show good breeding characteristics in the case of metallic fuel utilization (U-Pu-10%Zr). For the analyzed variants all the restriction related to the inherently safe reactor concept are satisfied. (Author)

  20. Development of a fast time-to-digital converter (TDC) using a programmable gate array

    International Nuclear Information System (INIS)

    A fast time-to-digital converter with a 5 ns step was designed and tested by utilizing a user-programmable gate array. The stabilities against temperature and supply voltage variation were measured. A module was built with this TDC, and was successfully used in the first-level trigger system of the ZEUS detector to reject proton-beam induced background events. (author)

  1. Time dependent solutions of the Fokker-Planck equation for fast fusion ions

    International Nuclear Information System (INIS)

    Approximate time dependent solutions for the Fokker-Planck equation for fast fusion ions from an isotropic, monoenergetic source are presented, for the problem of D - T - He3 reactions. The equations include the effect of diffusion, which is particularly noticeable in the distribution of particles of lower energy and in the formation of a tail of particles with energy higher than that of the source. (Author)

  2. SOA does not Reveal the Absolute Time Course of Cognitive Processing in Fast Priming Experiments

    OpenAIRE

    Tzur, Boaz; Frost, Ram

    2007-01-01

    Applying Bloch's law to visual word recognition research, both exposure duration of the prime and its luminance determine the prime's overall energy, and consequently determine the size of the priming effect. Nevertheless, experimenters using fast-priming paradigms traditionally focus only on the SOA between prime and target to reflect the absolute speed of cognitive processes under investigation. Some of the discrepancies in results regarding the time course of orthographic and phonological ...

  3. Cell fasting: Cellular response and application of serum starvation (ahead of publication

    Directory of Open Access Journals (Sweden)

    Masoomeh Aghababazadeh

    2014-12-01

    Full Text Available Humans suffer transient or persistent starvation due to a lack of food intake, either because of fasting, voluntary dieting, or due to the scarcity of available food. At the cellular level it is possible to possess pathological starvation during ischemia and solid tumors. Blood provides many nutrients to our cells, and researchers provide these nutrients to cells in culture in the form of enriched culture medium plus serum from animal sources. In response to starvation, animals use hormonal cues to mobilize stored resources to provide nutrients to individual cells. Besides whole-body responses to nutrient deprivation, individual cells sense and react to lack of nutrients. At the cellular level, starvation triggers different responses such as cell cycle arrest and apoptosis. Stop cycling for proliferating cells is the primary response to nutrient deprivation. Under certain conditions, the cell reacts to nutrient deprivation by engaging the mitochondrial pathway of apoptosis. Thus, serum starvation is regarded as a procedure to prepare cells for an experiment in serum-free conditions such as induction cell cycle synchronization. Several researchers have used serum starvation as a tool to study molecular mechanisms involved in different cellular process, metabolic researches and evaluation of a drug effect.

  4. Energy response of a fast-thermal neutron simultaneous counting detector

    International Nuclear Information System (INIS)

    A method of measuring the impurities of nuclear material samples using a pyrochemical multiple counter has been developed by Langner and others. The pyrochemical multiple counter consists of many thermal neutron detecting tubes arranged in four concentric rings within a polyethylene moderator, and a nuclear material sample is set in the center of the counter. Each ring of tubes has a different energy response owing to the difference of the effective moderator thickness, and each ring gives a different count with the same sample. The stopping power of the moderator varies with the incident neutron energy, and the differences in the counts from the various rings are related to the energy. The average energy of neutrons from a nuclear material sample varies with the impurities of the sample, therefore it is expected that the ratios of counts from the four rings will indicate the impurity concentration of the sample, and this was confirmed by experimentation. Langner and others used a multiple counter, but this method can be applied to two detectors which possess different energy responses and are in the same condition. In this paper, which investigates the applicability of this method to a fast-thermal neutron simultaneous counting detector which possesses two kinds of energy response in a single detector, we present the results of an experimental examination of the energy response of this detector to neutrons at energy of several MeV (J.P.N.)l MeV (J.P.N.)

  5. Modeling individual differences in response time and accuracy in numeracy.

    Science.gov (United States)

    Ratcliff, Roger; Thompson, Clarissa A; McKoon, Gail

    2015-04-01

    In the study of numeracy, some hypotheses have been based on response time (RT) as a dependent variable and some on accuracy, and considerable controversy has arisen about the presence or absence of correlations between RT and accuracy, between RT or accuracy and individual differences like IQ and math ability, and between various numeracy tasks. In this article, we show that an integration of the two dependent variables is required, which we accomplish with a theory-based model of decision making. We report data from four tasks: numerosity discrimination, number discrimination, memory for two-digit numbers, and memory for three-digit numbers. Accuracy correlated across tasks, as did RTs. However, the negative correlations that might be expected between RT and accuracy were not obtained; if a subject was accurate, it did not mean that they were fast (and vice versa). When the diffusion decision-making model was applied to the data (Ratcliff, 1978), we found significant correlations across the tasks between the quality of the numeracy information (drift rate) driving the decision process and between the speed/accuracy criterion settings, suggesting that similar numeracy skills and similar speed-accuracy settings are involved in the four tasks. In the model, accuracy is related to drift rate and RT is related to speed-accuracy criteria, but drift rate and criteria are not related to each other across subjects. This provides a theoretical basis for understanding why negative correlations were not obtained between accuracy and RT. We also manipulated criteria by instructing subjects to maximize either speed or accuracy, but still found correlations between the criteria settings between and within tasks, suggesting that the settings may represent an individual trait that can be modulated but not equated across subjects. Our results demonstrate that a decision-making model may provide a way to reconcile inconsistent and sometimes contradictory results in numeracy research. PMID:25637690

  6. Recognition of time-compressed speech does not predict recognition of natural fast-rate speech by older listeners.

    Science.gov (United States)

    Gordon-Salant, Sandra; Zion, Danielle J; Espy-Wilson, Carol

    2014-10-01

    This study investigated whether recognition of time-compressed speech predicts recognition of natural fast-rate speech, and whether this relationship is influenced by listener age. High and low context sentences were presented to younger and older normal-hearing adults at a normal speech rate, naturally fast speech rate, and fast rate implemented by time compressing the normal-rate sentences. Recognition of time-compressed sentences over-estimated recognition of natural fast sentences for both groups, especially for older listeners. The findings suggest that older listeners are at a much greater disadvantage when listening to natural fast speech than would be predicted by recognition performance for time-compressed speech. PMID:25324109

  7. Improving the Average Response Time in Collective I/O

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Chen; Sehrish, Saba; Liao, Wei-keng; Choudhary, Alok; Schuchardt, Karen L.

    2011-09-21

    In collective I/O, MPI processes exchange requests so that the rearranged requests can result in the shortest file system access time. Scheduling the exchange sequence determines the response time of participating processes. Existing implementations that simply follow the increasing order of file ofsets do not necessary produce the best performance. To minimize the average response time, we propose three scheduling algorithms that consider the number of processes per file stripe and the number of accesses per process. Our experimental results demonstrate improvements of up to 50% in the average response time using two synthetic benchmarks and a high-resolution climate application.

  8. Testing the fast-response neutron measuring channel on base of rhodium self-powered detector the AMB-200 reactor

    International Nuclear Information System (INIS)

    Tests of the fast-response neutron measuring channel based on the rhodium self-powered detector with electronic correction of detector response lag carried out in the AMB-200 reactor have shown that the channel response lag doesn't exceed 0.15s and it is applicable for monitoring transients in the reactor and that spatial effects in reactivity measurements are considerable and require account and suppression

  9. Influence of Time-Dependent Coupling Coefficients and Delay Times on the Kinetics of a Modular Fast Reactor Core

    International Nuclear Information System (INIS)

    Previous treatments of kinetics problems in modular and toroidal cores in fast breeder reactors have been based on Avery's coupled kinetics equations for partial integral fission sources. Most of these calculations do not take account of the time dependence of the reactivity coupling coefficients caused by possible flux tilting in an excursion. Furthermore, the effect of time delays for neutrons travelling between the modules, which is expected to be small, is not included in the model itself. The present investigation of the behaviour of two coupled modules is based on our recent derivation of coupled reactor kinetics equations from the Boltzmann equation. The distribution functions of delay times for neutrons are approximated by delta functions. It is shown that in three-group theory an analytical expression for the average delay time between two modules can still be derived. The calculation is based on the three-group leakage fluxes. Cross-sections are condensed from a 26-group set. Step changes in fission cross-sections are considered as perturbations. Coupling coefficients are calculated using the critical flux distribution and, to show the effect of time dependence, using the asymptotic flux distribution. Finally, a numerical method for solving coupled reactor kinetics equations is outlined. Comparing solutions of simple kinetics problems without feed-back but with time-dependent coupling coefficients and delay times to solutions without consideration of these tsolutions without consideration of these two effects, it is found that the influence of neutron delay times is indeed negligible for the usual transients considered in the safety analysis of fast breeder reactors. However, the inclusion of time-dependent coupling coefficients can markedly alter the module power during an excursion. (author)

  10. Computer Response Time Measurements of Mood, Fatigue and Symptom Scale Items: Implications for Scale Response Time Uses.

    Science.gov (United States)

    Ryman, David H.; And Others

    1988-01-01

    Describes study conducted with U.S. Marine Corps enlisted personnel to measure response time to computer-administered questionnaire items, and to evaluate how measurement of response time might be useful in various research areas. Topics addressed include mood states; the occurrence of straight lining; and experimental effects of sleep loss and…

  11. Responses of different ion species to fast plasma flows and local dipolarization in the plasma sheet

    Science.gov (United States)

    Ohtani, S.; Nosé, M.; Miyashita, Y.; Lui, A. T. Y.

    2015-01-01

    investigate the responses of different ion species (H+, He+, He++, and O+) to fast plasma flows and local dipolarization in the plasma sheet in terms of energy density. We use energetic (9-210 keV) ion composition measurements made by the Geotail satellite at r = 10~31 RE. The results are summarized as follows: (1) whereas the O+-to-H+ ratio decreases with earthward flow velocity, it increases with tailward flow velocity with steeper Vx dependence for perpendicular flows than for parallel flows; (2) for fast earthward flows, the energy density of each ion species increases without any clear preference for heavy ions; (3) for fast tailward flows, the ion energy density initially increases, then it decreases to below the preceding levels except for O+; (4) the O+-to-H+ ratio does not increase through local dipolarization irrespective of dipolarization amplitude, background Bz, X distance, and Vx; (5) in general, the H+ and He++ ions behave similarly. Result (1) can be attributed to radial transport in the presence of the earthward gradient of the background O+-to-H+ ratio. Results (2) and (4) suggest that ion energization at local dipolarization is not mass dependent in the energy range of our interest because the ions are not magnetized irrespective of species. Result (3) can be attributed to the thinning of the plasma sheet and the preferable field-aligned escape of the H+ ions on the tailward side of the reconnection site. Result (5) suggests that the solar wind is the primary source of the high-energy H+ ions.

  12. Time Series Technical Analysis via new Fast Estimation Methods: A Preliminary Study in Mathematical Finance

    CERN Document Server

    Fliess, Michel

    2008-01-01

    New fast estimation methods stemming from control theory lead to a fresh look at time series, which bears some resemblance to "technical analysis". The results are applied to a typical object of financial engineering, namely the forecast of foreign exchange rates, via a "model-free" setting, i.e., via repeated identifications of low order linear difference equations on sliding short time windows. Several convincing computer simulations, including the prediction of the position and of the volatility with respect to the forecasted trendline, are provided. $\\mathcal{Z}$-transform and differential algebra are the main mathematical tools.

  13. Influence of Ramadan Fasting on Anaerobic Performance and Recovery Following Short time High Intensity Exercise

    OpenAIRE

    Umid Karli; Alpay Guvenc; Alper Aslan; Tahir Hazir; Caner Acikada

    2007-01-01

    The aim of this study was to investigate the effects of Ramadan fasting on anaerobic power and capacity and the removal rate of lactate after short time high intensity exercise in power athletes. Ten male elite power athletes (2 wrestlers, 7 sprinters and 1 thrower, aged 20-24 yr, mean age 22.30 ± 1.25 yr) participated in this study. The subjects were tested three times [3 days before the beginning of Ramadan (Pre-RF), the last 3 days of Ramadan (End-RF) and the last 3 days of the 4th week a...

  14. Application of Time Projection Chambers with GEMs and Pixels to WIMP Searches and Fast Neutron Detection

    CERN Document Server

    Yamaoka, Jared; Garcia-Sciveres, Maurice; Jaegle, Igal; Kadyk, John; Nguyen, Young; Rosen, Marc; Ross, Steven; Thorpe, Thomas; Vahsen, Sven

    2012-01-01

    We present work on the detection of neutral particles via nuclear recoils in gas-filled Time Projection Chambers (TPCs). We employ Gas Electron Multipliers (GEMs) to amplify the signal and silicon pixel electronics to detect the avalanche charge. These technologies allow ionization in the target gas to be detected with low noise, improved position and time resolution, and high efficiency. We review experimental results obtained in previous years, and report on ongoing simulation studies and construction of the first prototype at the University of Hawaii. We also present prospects of using such detectors to perform direction-sensitive searches for WIMP dark matter and fast neutron from fissionable material.

  15. A Fast Pulsed Neutron Source for Time-of-Flight Detection of Nuclear Materials and Explosives

    International Nuclear Information System (INIS)

    AASC has built a fast pulsed neutron source based on the Dense Plasma Focus (DPF). The more current version stores only 100 J but fires at ?10-50 Hz and emits ?106n/pulse at a peak current of 100 kA. Both sources emit 2.45±0.1 MeV(DD) neutron pulses of ?25-40 ns width. Such fast, quasi-monoenergetic pulses allow time-of-flight detection of characteristic emissions from nuclear materials or high explosives. A test is described in which iron targets were placed at different distances from the point neutron source. Detectors such as Stilbene and LaBr3 were used to capture inelastically induced, 847 keV gammas from the iron target. Shielding of the source and detectors eliminated most (but not all) of the source neutrons from the detectors. Gated detection, pulse shape analysis and time-of-flight discrimination enable separation of gamma and neutron signatures and localization of the target. A Monte Carlo simulation allows evaluation of the potential of such a fast pulsed source for a field-portable detection system. The high rep-rate source occupies two 200 liter drums and uses a cooled DPF Head that is 3 in volume.

  16. Fast neutron measurements at the nELBE time-of-flight facility

    Directory of Open Access Journals (Sweden)

    Junghansa A. R.

    2015-01-01

    Full Text Available The compact neutron-time-of-flight facility nELBE at the superconducting electron accelerator ELBE of Helmholtz-Zentrum Dresden-Rossendorf has been rebuilt. A new enlarged experimental hall with a flight path of up to 10 m is available for neutron time-of-flight experiments in the fast energy range from about 50 keV to 10 MeV. nELBE is intended to deliver nuclear data of fast neutron nuclear interactions e.g. for the transmutation of nuclear waste and improvement of neutron physical simulations of innovative nuclear systems. The experimental programme consists of transmission measurements of neutron total cross sections, elastic and inelastic scattering cross section measurements, and neutron induced fission cross sections. The inelastic scattering to the first few excited states in 56Fe was investigated by measuring the gamma production cross section with an HPGe detector. The neutron induced fission of 242Pu was studied using fast ionisation chambers with large homogeneous actinide deposits.

  17. Fast-rise-time electromagnetic shock waves in nonlinear, ceramic dielectrics

    Science.gov (United States)

    Branch, G.; Smith, P. W.

    1996-08-01

    The generation of fast rise-time electromagnetic shock waves in nonlinear transmission lines containing ceramic ferroelectric dielectrics is investigated. The theory of shock wave evolution is explored and used to determine the desired characteristics of the nonlinear dielectric. The rise-time which would be expected in a barium - strontium titanate based ceramic dielectric is estimated from the material properties. This is compared with the actual rise-time obtained in a parallel plate transmission line made from blocks of the ceramic. Shock waves have been generated with amplitudes of 10 kV and 5 kA and a rise-time of 410 ps. The problems associated with measuring the rise-time of the shock waves are discussed.

  18. Improved time response for large area microchannel plate photomultiplier tubes in fusion diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Milnes, J. S., E-mail: james.milnes@photek.co.uk; Conneely, T. M.; Howorth, J. [Photek Ltd, 26 Castleham Road, St Leonards on Sea, East Sussex, TN38 9NS (United Kingdom); Horsfield, C. J. [AWE, Aldermaston, Reading, Berkshire, RG7 4PR (United Kingdom)

    2014-11-15

    Fusion diagnostics that utilise high speed scintillators often need to capture a large area of light with a high degree of time accuracy. Microchannel plate (MCP) photomultiplier tubes (PMTs) are recognised as the leading device for capturing fast optical signals. However, when manufactured in their traditional proximity focused construction, the time response performance is reduced as the active area increases. This is due to two main factors: the capacitance of a large anode and the difficulty of obtaining small pore MCPs with a large area. Collaboration between Photek and AWE has produced prototype devices that combine the excellent time response of small area MCP-PMTs with a large active area by replacing the traditional proximity-gap front section with an electro-optically focused photocathode to MCP. We present results from both single and double MCP devices with a 40 mm diameter active area and show simulations for the 100 mm device being built this year.

  19. Fast and Practical Head Tracking in Brain Imaging with Time-of-Flight Camera

    DEFF Research Database (Denmark)

    Wilm, Jakob; Olesen, Oline Vinter

    2013-01-01

    This paper investigates the potential use of Time-of-Flight cameras (TOF) for motion correction in medical brain scans. TOF cameras have previously been used for tracking purposes, but recent progress in TOF technology has made it relevant for high speed optical tracking in high resolution medical scanners. Particularly in MRI and PET, the newest generation of TOF cameras could become a method of tracking small and large scale patient movement in a fast and user friendly way required in clinical environments. We present a novel methodology for fast tracking from TOF point clouds without the need of expensive triangulation and surface reconstruction. Tracking experiments with a motion controlled head phantom were performed with a translational tracking error below 2mm and a rotational tracking error below 0.5°.

  20. Fast Response to Infection Spread and Cyber Attacks on Large-Scale Networks

    CERN Document Server

    Leyffer, Sven

    2012-01-01

    We present a strategy for designing fast methods of response to cyber attacks and infection spread on complex weighted networks. In these networks, nodes can be interpreted as primitive elements of the system, and weighted edges reflect the strength of interaction among these elements. The proposed strategy belongs to the family of multiscale methods whose goal is to approximate the system at multiple scales of coarseness and to obtain a solution of microscopic scale by combining the information from coarse scales. In recent years these methods have demonstrated their potential for solving optimization and analysis problems on large-scale networks. We consider an optimization problem that is based on the SIS epidemiological model. The objective is to detect the network nodes that have to be immunized in order to keep a low level of infection in the system.

  1. Response of the rat dunning R3327-AT1 prostate tumor to fractionated fast neutron treatment

    International Nuclear Information System (INIS)

    Clinically, certain categories of tumors respond well to fast neutrons. To understand the action of neutrons on tumor tissues, the authors are studying the Dunning rat prostate tumor system. The authors report the treatment response of the anaplastic AT-1 subline (volume doubling, 5.2 days) to 10 fraction of neutrons (0-1.6 Gy per fraction) versus Co-60 (2.4-4.8 Gy per fraction). As with one fraction, the tumors continued to increase in volume for 2 weeks after radiation, followed by a regrowth with no local control. Based on regrowth kinetics, a radiobiologic effectiveness (RBE) of about 3.3 was found, compared with an RBE of 3 for one fraction found in an earlier study

  2. INFLUENCE OF RAMADAN FASTING ON ANAEROBIC PERFORMANCE AND RECOVERY FOLLOWING SHORT TIME HIGH INTENSITY EXERCISE

    Directory of Open Access Journals (Sweden)

    Umid Karli

    2007-12-01

    Full Text Available The aim of this study was to investigate the effects of Ramadan fasting on anaerobic power and capacity and the removal rate of lactate after short time high intensity exercise in power athletes. Ten male elite power athletes (2 wrestlers, 7 sprinters and 1 thrower, aged 20-24 yr, mean age 22.30 ± 1.25 yr participated in this study. The subjects were tested three times [3 days before the beginning of Ramadan (Pre-RF, the last 3 days of Ramadan (End-RF and the last 3 days of the 4th week after the end of Ramadan (After-RF]. Anaerobic power and capacity were measured by using the Wingate Anaerobic Test (WAnT at Pre-RF, End-RF and After- RF. Capillary blood samples for lactate analyses and heart rate recordings were taken at rest, immediately after WAnT and throughout the recovery period. Repeated measures of ANOVA indicated that there were no significant changes in body weight, body mass index, fat free mass, percentage of body fat, daily sleeping time and daily caloric intake associated with Ramadan fasting. No significant changes were found in total body water either, but urinary density measured at End-RF was significantly higher than After-RF. Similarity among peak HR and peak LA values at Pre-RF, End- RF and After-RF demonstrated that cardiovascular and metabolic stress caused by WAnT was not affected by Ramadan fasting. In addition, no influence of Ramadan fasting on anaerobic power and capacity and removal rate of LA from blood following high intensity exercise was observed. The results of this study revealed that if strength-power training is performed regularly and daily food intake, body fluid balance and daily sleeping time are maintained as before Ramadan, Ramadan fasting will not have adverse effects on body composition, anaerobic power and capacity, and LA metabolism during and after high intensity exercise in power athletes

  3. Modeling of the Response Time of Thermal Flow Sensors

    Directory of Open Access Journals (Sweden)

    Walter Lang

    2011-10-01

    Full Text Available This paper introduces a simple theoretical model for the response time of thermal flow sensors. Response time is defined here as the time needed by the sensor output signal to reach 63.2% of amplitude due to a change of fluid flow. This model uses the finite-difference method to solve the heat transfer equations, taking into consideration the transient conduction and convection between the sensor membrane and the surrounding fluid. Program results agree with experimental measurements and explain the response time dependence on the velocity and the sensor geometry. Values of the response time vary from about 5 ms in the case of stagnant flow to 1.5 ms for a flow velocity of 44 m/s.

  4. Thermal emittance and response time of a cesium antimonide photocathode

    Science.gov (United States)

    Cultrera, Luca; Bazarov, Ivan; Bartnik, Adam; Dunham, Bruce; Karkare, Siddharth; Merluzzi, Richard; Nichols, Matthew

    2011-10-01

    Measurements of the intrinsic emittance and response time of a Cs3Sb photocathode are presented. The emittance is obtained with a solenoid scan technique using a high voltage dc photoemission gun. Photoemission response time is evaluated using a RF deflecting cavity synchronized to a picosecond laser pulse train. We find that Cs3Sb has both small mean transverse energy, 160 ± 10 meV at 532 nm laser wavelength, and a prompt response time (below the resolution of our measurement) making it a suitable material for high brightness electron photoinjectors.

  5. Response maxima in time-modulated turbulence: Direct Numerical Simulations

    CERN Document Server

    Kuczaj, A K; Lohse, D; Kuczaj, Arkadiusz K.; Geurts, Bernard J.; Lohse, Detlef

    2005-01-01

    The response of turbulent flow to time-modulated forcing is studied by direct numerical simulations of the Navier-Stokes equations. The large-scale forcing is modulated via periodic energy input variations at frequency $\\omega$. The response is maximal for frequencies in the range of the inverse of the large eddy turnover time, confirming the mean-field predictions of von der Heydt, Grossmann and Lohse (Phys. Rev. E 67, 046308 (2003)). In accordance with the theory the response maximum shows only a small dependence on the Reynolds number and is also quite insensitive to the particular flow-quantity that is monitored, e.g., kinetic energy, dissipation-rate, or Taylor-Reynolds number. At sufficiently high frequencies the amplitude of the kinetic energy response decreases as $1/\\omega$. For frequencies beyond the range of maximal response, a significant change in phase-shift relative to the time-modulated forcing is observed.

  6. Planck 2013 results. VII. HFI time response and beams

    CERN Document Server

    Ade, P A R; Armitage-Caplan, C; Arnaud, M; Ashdown, M; Atrio-Barandela, F; Aumont, J; Baccigalupi, C; Banday, A J; Barreiro, R B; Battaner, E; Benabed, K; Benoît, A; Benoit-Lévy, A; Bernard, J -P; Bersanelli, M; Bielewicz, P; Bobin, J; Bock, J J; Bond, J R; Borrill, J; Bouchet, F R; Bowyer, J W; Bridges, M; Bucher, M; Burigana, C; Cardoso, J -F; Catalano, A; Challinor, A; Chamballu, A; Chary, R -R; Chiang, L -Y; Chiang, H C; Christensen, P R; Church, S; Clements, D L; Colombi, S; Colombo, L P L; Couchot, F; Coulais, A; Crill, B P; Curto, A; Cuttaia, F; Danese, L; Davies, R D; de Bernardis, P; de Rosa, A; de Zotti, G; Delabrouille, J; Delouis, J -M; Désert, F -X; Diego, J M; Dole, H; Donzelli, S; Doré, O; Douspis, M; Dunkley, J; Dupac, X; Efstathiou, G; Enßlin, T A; Eriksen, H K; Finelli, F; Forni, O; Frailis, M; Fraisse, A A; Franceschi, E; Galeotta, S; Ganga, K; Giard, M; Giraud-Héraud, Y; González-Nuevo, J; Górski, K M; Gratton, S; Gregorio, A; Gruppuso, A; Gudmundsson, J E; Haissinski, J; Hansen, F K; Hanson, D; Harrison, D; Henrot-Versillé, S; Hernández-Monteagudo, C; Herranz, D; Hildebrandt, S R; Hivon, E; Hobson, M; Holmes, W A; Hornstrup, A; Hou, Z; Hovest, W; Huffenberger, K M; Jaffe, T R; Jaffe, A H; Jones, W C; Juvela, M; Keihänen, E; Keskitalo, R; Kisner, T S; Kneissl, R; Knoche, J; Knox, L; Kunz, M; Kurki-Suonio, H; Lagache, G; Lamarre, J -M; Lasenby, A; Laureijs, R J; Lawrence, C R; Leonardi, R; Leroy, C; Lesgourgues, J; Liguori, M; Lilje, P B; Linden-Vørnle, M; López-Caniego, M; Lubin, P M; Macías-Pérez, J F; MacTavish, C J; Maffei, B; Mandolesi, N; Maris, M; Marshall, D J; Martin, P G; Martínez-González, E; Masi, S; Matarrese, S; Matsumura, T; Matthai, F; Mazzotta, P; McGehee, P; Melchiorri, A; Mendes, L; Mennella, A; Migliaccio, M; Mitra, S; Miville-Deschênes, M -A; Moneti, A; Montier, L; Morgante, G; Mortlock, D; Munshi, D; Murphy, J A; Naselsky, P; Nati, F; Natoli, P; Netterfield, C B; Nørgaard-Nielsen, H U; Noviello, F; Novikov, D; Novikov, I; Osborne, S; Oxborrow, C A; Paci, F; Pagano, L; Pajot, F; Paoletti, D; Pasian, F; Patanchon, G; Perdereau, O; Perotto, L; Perrotta, F; Piacentini, F; Piat, M; Pierpaoli, E; Pietrobon, D; Plaszczynski, S; Pointecouteau, E; Polegre, A M; Polenta, G; Ponthieu, N; Popa, L; Poutanen, T; Pratt, G W; Prézeau, G; Prunet, S; Puget, J -L; Rachen, J P; Reinecke, M; Remazeilles, M; Renault, C; Ricciardi, S; Riller, T; Ristorcelli, I; Rocha, G; Rosset, C; Roudier, G; Rowan-Robinson, M; Rusholme, B; Sandri, M; Santos, D; Sauvé, A; Savini, G; Shellard, E P S; Spencer, L D; Starck, J -L; Stolyarov, V; Stompor, R; Sudiwala, R; Sureau, F; Sutton, D; Suur-Uski, A -S; Sygnet, J -F; Tauber, J A; Tavagnacco, D; Terenzi, L; Tomasi, M; Tristram, M; Tucci, M; Umana, G; Valenziano, L; Valiviita, J; Van Tent, B; Vielva, P; Villa, F; Vittorio, N; Wade, L A; Wandelt, B D; Yvon, D; Zacchei, A; Zonca, A

    2014-01-01

    This paper characterizes the effective beams, the effective beam window functions (EBWF) and the associated errors for the Planck High Frequency Instrument (HFI) detectors. The effective beam is the angular response including the effect of the optics, detectors, data processing and the scan strategy. The EBWF is the representation of this beam in the harmonic domain that is required to recover an unbiased measurement of the Cosmic Microwave Background (CMB) angular power spectrum. The HFI is a scanning instrument and its effective beams are the convolution of the optical response of the telescope and feeds, the processing of the time-ordered data and deconvolution of the bolometric and electronic time response, and the merging of several surveys to produce maps. The time response transfer functions are measured with observations of Jupiter and Saturn and by minimizing survey difference residuals. The scanning beam is the post-deconvolution angular response of the instrument, and is characterized with observat...

  7. New Photonis XP20D0 photomultiplier for fast timing in nuclear medicine

    International Nuclear Information System (INIS)

    Growing interest in the time-of-flight positron emission tomography (TOF PET) prompts the study of a new Photonis XP20D0 photomultiplier, equipped with a screening grid at the anode, in application to a fast timing with LSO and LaBr3 crystals. The high time resolution of 200±4 and 210±4 ps was obtained for 511 keV annihilation quanta using LaBr3 and LSO crystals in the coincidence experiment with a small BaF2 crystal, respectively. It reflects an importance of the grid and high quantum efficiency of the XP20D0. A high-time resolution observed in the present experiments makes good prospects for a development of TOF PET

  8. Multilevel Spatial Multiplexing -Space Time Trellis Coded Modulation System for Fast Fading MIMO Channel

    Directory of Open Access Journals (Sweden)

    K.Kavitha

    2014-03-01

    Full Text Available Multilevel Space Time Trellis Coded Modulation with antenna grouping, which has been proposed recently, has coding gain and diversity gain, which in turn provide high throughput with considerable low computational complexity. However its performance is limited by predefining the antenna groups per component codes. In this paper Multilevel Spatial Multiplexing-Space Time Trellis Coded Modulation (ML-SM-STTCM has been proposed, in which antenna group selection is made based on spatial modulation based on trellis coding proposed by Ertugrul Basar and team. This idea maximizes the spatial diversity. Since only selected antennas are used to transmit the signal, and also the antennas with less cross correlation are in the selected groups, we could able to achieve improved BER performance even in the fast fading channel. Since the antenna selection is based on the component code in the system, at the decoder without increase in the computational complexity, we could achieve better error performance. The performance of the proposed system is analysed with Viterbi decoding algorithm and sub optimal sequential decoding algorithm. In this system, the antenna groups are non-overlapping, hence, it needs Nt, the number transmitter antennas, more than what is required at time t. The computer simulation reveals that the proposed system gives better BER performance compared to Multilevel Space Time Trellis Coded Modulation (ML STTCM over fast fading channel with the same computational complexity both at the transmitter and receiver.

  9. The Importance of Responsibility in Times of Crisis

    OpenAIRE

    Jacob Dahl Rendtorff

    2014-01-01

    In this paper I would like to show the importance of the concept of responsibility as the foundation of ethics in times of crisis in particular in the fields of politics and economics in the modern civilisation marked by globalization and technological progres. I consider the concept of responsibility as the key notion in order to understand the ethical duty in a modern technological civilisation. We can indeed observe a moralization of the concept of responsibility going beyond a strict lega...

  10. ZnO(N)-Spiro-MeOTAD hybrid photodiode: an efficient self-powered fast-response UV (visible) photosensor

    Science.gov (United States)

    Game, Onkar; Singh, Upendra; Kumari, Tanya; Banpurkar, Arun; Ogale, Satishchandra

    2013-12-01

    Organic-inorganic hybrid photo-detectors with a self-sufficient mode of operation represent a research area of great current interest. In most efficient photodetectors and optoelectronic devices compound semiconductors containing toxic elements such as Cd, As, Te, S, Se etc. are used and these are also expensive. Hence there is also a rapidly growing interest in replacing these with environmentally friendly and earth-abundant materials. Herein, we report a facile solution-processed fabrication of a self-powered organic-inorganic hybrid photodetector using n-type oriented ZnO nanorods and p-type Spiro-MeOTAD semiconductor. ZnO is eco-friendly and earth-abundant, and Spiro-MeOTAD is non-hazardous. We show that the latter has far less toxicity than the toxic elements stated above. This visible blind UV photodetector shows high sensitivity (102) and a UV/visible rejection ratio of 300. It also exhibits fast response times of ?rise ~ 200 ?s and ?fall ~ 950 ?s. Importantly, with a small modification of nitrogen incorporation in ZnO one can also realize a highly-sensitive self-powered visible light photodetector with at least 1000% (or higher) improvements in quality factors (photocurrent/sensitivity/response time) as compared to previously reported organic-inorganic hybrid photo-detectors based on metal-chalcogenides (CdS-PANI or CuInSe2-P3HT). Interestingly, the broadband sensitivity of such N:ZnO-Spiro-MeOTAD photodiode enables sensing of low intensity (~28 ?W cm-2) ambient white light with a high photocurrent density of 120 nA cm-2 making it an efficient ambient white light detector.Organic-inorganic hybrid photo-detectors with a self-sufficient mode of operation represent a research area of great current interest. In most efficient photodetectors and optoelectronic devices compound semiconductors containing toxic elements such as Cd, As, Te, S, Se etc. are used and these are also expensive. Hence there is also a rapidly growing interest in replacing these with environmentally friendly and earth-abundant materials. Herein, we report a facile solution-processed fabrication of a self-powered organic-inorganic hybrid photodetector using n-type oriented ZnO nanorods and p-type Spiro-MeOTAD semiconductor. ZnO is eco-friendly and earth-abundant, and Spiro-MeOTAD is non-hazardous. We show that the latter has far less toxicity than the toxic elements stated above. This visible blind UV photodetector shows high sensitivity (102) and a UV/visible rejection ratio of 300. It also exhibits fast response times of ?rise ~ 200 ?s and ?fall ~ 950 ?s. Importantly, with a small modification of nitrogen incorporation in ZnO one can also realize a highly-sensitive self-powered visible light photodetector with at least 1000% (or higher) improvements in quality factors (photocurrent/sensitivity/response time) as compared to previously reported organic-inorganic hybrid photo-detectors based on metal-chalcogenides (CdS-PANI or CuInSe2-P3HT). Interestingly, the broadband sensitivity of such N:ZnO-Spiro-MeOTAD photodiode enables sensing of low intensity (~28 ?W cm-2) ambient white light with a high photocurrent density of 120 nA cm-2 making it an efficient ambient white light detector. Electronic supplementary information (ESI) available: SI-1: response time measurements of self powered hybrid ZnO-SPD under nanosecond pulsed UV laser, SI-2: Raman analysis of N:ZnO and ZnO SI-3: cytotoxicity study on Spiro-MeOTAD SI-4: electrochemical Mott-Schottky plots of ZnO and N:ZnO. See DOI: 10.1039/c3nr04727j

  11. A fast routine for fitting Cox models with time varying effects of the covariates.

    Science.gov (United States)

    Perperoglou, Aris; le Cessie, Saskia; van Houwelingen, Hans C

    2006-02-01

    The S-plus and R statistical packages have implemented a counting process setup to estimate Cox models with time varying effects of the covariates. The data set has to be re-arranged in a repeated measurement setting: the time is divided into small time intervals where a single event occurs and for each time interval, the covariate values and outcome in the interval for each subject still under observation are stacked to a large data set. This is the known (Tstart,Tstop] algorithm implemented in Therneau's Survival library (S-plus), which has been ported into an R package by Thomas Lumley. However, the expansion of a data set leads to a larger set, which can be hard to handle even with fast modern computers. We propose the use of a fast and efficient algorithm, written in R, which works on the original data without the use of an expansion. The computations are done on the original data set, with significant less memory resources used. This improves the computational time by orders of magnitude. The algorithm can also fit reduced rank Cox models with time varying effects. We illustrate the method on a large data set of 2433 breast cancer patients, a smaller study of 358 ovarian cancer patients, and compare the computational times on simulated data of up to 10,000 cases with SAS proc phreg and survival package in R. For larger data sets our algorithm was several times faster, and was able to handle larger data sets then SAS and R. PMID:16426701

  12. Light up ClO(-) in live cells using an aza-coumarin based fluorescent probe with fast response and high sensitivity.

    Science.gov (United States)

    Fan, Jiangli; Mu, Huiying; Zhu, Hao; Wang, Jingyun; Peng, Xiaojun

    2015-06-15

    Hypochlorous acid (HClO)/hypochlorite (ClO(-)), one of the reactive oxygen species (ROS), is a key microbicidal agent used for natural defense; however, HClO is also responsible for some human diseases. Although much effort has been made to develop HClO-selective fluorescent probes, many of them display a delayed response time and nanomole-sensitive probes are rare. In this study, we designed and synthesized an aza-coumarin based fluorescent probe for ClO(-) determination with fast response (completed within 2 min) and high sensitivity (detection limit is 25 nM). displayed a color change from pink to light yellow and a remarkable "turn-on" fluorescence response towards ClO(-). Confocal fluorescence microscopy experiments demonstrated that the probe could be applied for the live-cell imaging of exogenous and endogenous ClO(-). PMID:25997521

  13. Time domain modeling of tunable response of graphene

    DEFF Research Database (Denmark)

    Prokopeva, Ludmila; Emani, Naresh K.

    2013-01-01

    We present a causal numerical model for time domain simulations of the optical response of graphene. The dielectric function is approximated with a conductivity term, a Drude term and a number of the critical points terms.

  14. Elements for Response Time Statistics in ERP Transaction Systems

    CERN Document Server

    Mielke, A

    2004-01-01

    We present some measurements and ideas for response time statistics in ERP systems. It is shown that the response time distribution of a given transaction in a given system is generically a log-normal distribution or, in some situations, a sum of two or more log-normal distributions. We present some arguments for this form of the distribution based on heuristic rules for response times, and we show data from performance measurements in actual systems to support the log-normal form. Deviations of the log-normal form can often be traced back to performance problems in the system. Consequences for the interpretation of response time data and for service level agreements are discussed.

  15. High performance organic-inorganic perovskite-optocoupler based on low-voltage and fast response perovskite compound photodetector

    Science.gov (United States)

    Li, Dong; Dong, Guifang; Li, Wenzhe; Wang, Liduo

    2015-01-01

    Organic-inorganic hybrid photodetectors attract considerable attention because they can combine the advantages of both organic and inorganic systems. Here, a perovskite compound with a broad absorption spectrum and high power conversion efficiency is used as a photosensitive layer in an organic/inorganic hybrid heterojunction photodetector with a high and fast response. The high sensitivity exceeding 104 is obtained at bias of 0–4?V. Using a tandem organic light-emitting diode (OLED) as the light source, we fabricated an optocoupler device. The optocoupler achieved a maximum photoresponsivity of 1.0?A W?1 at 341.3??Wcm?2 at an input voltage of 6?V. The device also exhibits rapid response times of ?rise ~ 20??s and ?fall ~ 17??s; as well as a high current transfer ratio (CTR) of 28.2%. After applying an amplification circuit, the CTR of the optocoupler increases to 263.3%, which is comparable with that of commercial inorganic optocouplers. The developed hybrid optocoupler thus shows great promise for use in photonics. PMID:25600830

  16. High performance organic-inorganic perovskite-optocoupler based on low-voltage and fast response perovskite compound photodetector

    Science.gov (United States)

    Li, Dong; Dong, Guifang; Li, Wenzhe; Wang, Liduo

    2015-01-01

    Organic-inorganic hybrid photodetectors attract considerable attention because they can combine the advantages of both organic and inorganic systems. Here, a perovskite compound with a broad absorption spectrum and high power conversion efficiency is used as a photosensitive layer in an organic/inorganic hybrid heterojunction photodetector with a high and fast response. The high sensitivity exceeding 104 is obtained at bias of 0-4 V. Using a tandem organic light-emitting diode (OLED) as the light source, we fabricated an optocoupler device. The optocoupler achieved a maximum photoresponsivity of 1.0 A W-1 at 341.3 ?Wcm-2 at an input voltage of 6 V. The device also exhibits rapid response times of ?rise ~ 20 ?s and ?fall ~ 17 ?s as well as a high current transfer ratio (CTR) of 28.2%. After applying an amplification circuit, the CTR of the optocoupler increases to 263.3%, which is comparable with that of commercial inorganic optocouplers. The developed hybrid optocoupler thus shows great promise for use in photonics.

  17. Drude response of slow and fast electrons in the heavy-fermion compound UNi2Al3

    International Nuclear Information System (INIS)

    The unusual metallic behavior of heavy-fermion compounds at low temperatures is caused by mobile charge carriers with a large effective mass. This mass enhancement (compared to normal electrons) goes hand in hand with a reduction of the transport scattering time, which can directly be studied with optical spectroscopy: the characteristic Drude roll-off moves to very low frequencies. Here we combine microwave and THz spectroscopy to study thin films of the heavy-fermion compound UNi2Al3 in a broad frequency range. At frequencies of a few GHz, a full Drude response indicates the dynamics of the heavy electrons in UNi2Al3. Surprisingly, at considerably higher frequencies (around 300 GHz) we observe a similar structure that is very reminiscent of Drude behavior. We interpret these two features as the Drude response of - at low frequencies - correlated, slow electrons and - at higher frequencies - uncorrelated, fast electrons. The temperature dependence and anisotropy of these two Drude roll-offs correspond to each other. These results also shed new light on previous studies of the related compound UPd2Al3.

  18. Development of fast response bi-luminophore pressure-sensitive paint by means of an inkjet printing technique

    Science.gov (United States)

    Egami, Y.; Ueyama, J.; Furukawa, S.; Kameya, T.; Matsuda, Y.; Yamaguchi, H.; Niimi, T.

    2015-06-01

    A novel fast response bi-luminophore pressure-sensitive paint (PSP) by inkjet printing of sensor-dot arrays on an anodized aluminum (AA) substrate has been developed for unsteady flow measurements. A bi-luminophore AA-PSP, which is a combination of PSP and temperature-sensitive paint (TSP), is essential for precise pressure measurements, because the PSP result needs the temperature correction. However, a conventional bi-luminophore AA-PSP prepared by a dipping method does not work well due to the interference between the PSP and TSP luminophores. To overcome this problem, we have developed isolated dot arrays of PSP and TSP formed on an anodized aluminum substrate by an inkjet printing method. In this study, platinum tetrakis (pentafluorophenyl) porphyrin (PtTFPP) and ZnS-AgInS2 (ZAIS) were employed as pressure- and temperature-sensitive dyes, respectively. A suitable solvent was chosen for each dye to form the dots with uniform, high luminescence intensity, and high sensitivity. The developed bi-luminophore AA-PSP could simultaneously measure pressure and temperature and could reduce the temperature effect of the PSP from ?0.97%/K (without temperature correction) to ?0.01%/K (with temperature correction). It showed a pressure response time of 17.8? ± ?0.8??s at 90% pressure rise to a step change of pressure, which is in the same range as a conventional AA-PSP.

  19. Signal and noise analysis in TRION-Time-Resolved Integrative Optical Fast Neutron detector

    Energy Technology Data Exchange (ETDEWEB)

    Vartsky, D; Feldman, G; Mor, I; Goldberg, M B; Bar, D [Soreq NRC, 81800 Yavne (Israel); Dangendorf, V [Physikalisch-Technische Bundesanstalt (PTB), 38116 Braunschweig (Germany)], E-mail: david@soreq.gov.il

    2009-02-15

    TRION is a sub-mm spatial resolution fast neutron imaging detector, which employs an integrative optical time-of-flight technique. The detector was developed for fast neutron resonance radiography, a method capable of detecting a broad range of conventional and improvised explosives. In this study we have analyzed in detail, using Monte-Carlo calculations and experimentally determined parameters, all the processes that influence the signal and noise in the TRION detector. In contrast to event-counting detectors where the signal-to-noise ratio is dependent only on the number of detected events (quantum noise), in an energy-integrating detector additional factors, such as the fluctuations in imparted energy, number of photoelectrons, system gain and other factors will contribute to the noise. The excess noise factor (over the quantum noise) due to these processes was 4.3, 2.7, 2.1, 1.9 and 1.9 for incident neutron energies of 2, 4, 7.5, 10 and 14 MeV, respectively. It is shown that, even under ideal light collection conditions, a fast neutron detection system operating in an integrative mode cannot be quantum-noise-limited due to the relatively large variance in the imparted proton energy and the resulting scintillation light distributions.

  20. Speed-Accuracy Response Models: Scoring Rules Based on Response Time and Accuracy

    Science.gov (United States)

    Maris, Gunter; van der Maas, Han

    2012-01-01

    Starting from an explicit scoring rule for time limit tasks incorporating both response time and accuracy, and a definite trade-off between speed and accuracy, a response model is derived. Since the scoring rule is interpreted as a sufficient statistic, the model belongs to the exponential family. The various marginal and conditional distributions…

  1. On-line automatic sensor response time analysis system

    International Nuclear Information System (INIS)

    An on-line automatic sensor response time analysis system in Taipower's Maanshan PWR nuclear power plant is presented. The algorithm applied in the system is the noise analysis technique which is an indirect method of determining sensor response time. This technique includes the power spectral density analysis and the autoregressive analysis methods. The system can also be used for long-term surveillance of sensor performance trends and cross-comparison of redundant sensors for predictive maintenance purposes. (author)

  2. Neural Basis of Adaptive Response Time Adjustment during Saccade Countermanding

    OpenAIRE

    POUGET, Pierre; Logan, Gordon D; Palmeri, Thomas J.; Boucher, Leanne; Paré, Martin; Schall, Jeffrey D.

    2011-01-01

    Humans and macaque monkeys adjust their response time adaptively in stop signal (countermanding) tasks, responding slower after stop-signal trials than after control trials with no stop signal. We investigated the neural mechanism underlying this adaptive response time adjustment in macaque monkeys performing a saccade countermanding task. Earlier research showed that movements are initiated when the random accumulation of presaccadic movement-related activity reaches a fixed threshold. We fo...

  3. Response maxima in time-modulated turbulence: Direct numerical simulations

    OpenAIRE

    Kuczaj, Ak; Geurts, Bj; Lohse, D.

    2006-01-01

    The response of turbulent flow to time-modulated forcing is studied by direct numerical simulations of the Navier-Stokes equations. The large-scale forcing is modulated via periodic energy input variations at frequency $\\omega$. The response is maximal for frequencies in the range of the inverse of the large eddy turnover time, confirming the mean-field predictions of von der Heydt, Grossmann and Lohse (Phys. Rev. E 67, 046308 (2003)). In accordance with the theory the respo...

  4. Effects of Ramadan on physical capacities of North African boys fasting for the first time

    Science.gov (United States)

    Fenneni, Mohamed A.; Latiri, Imed; Aloui, Asma; Rouatbi, Sonia; Saafi, Mohamed A.; Bougmiza, Iheb; Chamari, Karim; Saad, Helmi Ben

    2014-01-01

    Introduction Most of the literature related to the effects of Ramadan fasting on physical performance has focused on adults, and only three studies have examined its impact on children’s physical performance. Aims To examine the effects of Ramadan fasting on first-time fasting boys’ performance in short-term explosive exercises [vertical and horizontal jump tests (VJT and HJT), 20-m and 30-m sprints and medicine-ball throw (MBT)], as well as in sub-maximal endurance [6-min walking distance (6MWD) measured during the 6-min walk test (6MWT)]. Methods Eighteen Tunisian boys [mean±standard deviation (SD) of age and body mass (BM): 11.9±0.8 y and 55.4±18.2 kg, respectively] were included. The experimental design comprised four testing phases: 2-weeks before Ramadan (BR), the end of the second week (R2) and the fourth week (R4) of Ramadan, and 10–12 days after the end of Ramadan (AR). At each phase, boys performed two test sessions in the afternoon (15:00–17:00 h) interrupted by 48 h of recovery (first test session: BM, VJT, HJT, and 20-m and 30-m sprint tests; second session: MBT and 6MWT). The study was conducted during the summer of 2012 from July 5 to August 29. Results 6MWDs (m) were significantly shorter during R2 (652±101) and R4 (595±123) compared to BR (697±86) and came back to baseline values AR. BM (kg) mean±SD did not significantly change during R2 (52±15) and during R4 (53±15) compared to BR (55±17), and short-term explosive performances were unchanged throughout the study. Conclusion In non-athletic children, first-ever Ramadan fasting impairs sub-maximal aerobic capacity but has no effect on BM or short-term explosive performance. PMID:25261691

  5. Pulse generator using transistors and silicon controlled rectifiers produces high current pulses with fast rise and fall times

    Science.gov (United States)

    Woolfson, M. G.

    1966-01-01

    Electrical pulse generator uses power transistors and silicon controlled rectifiers for producing a high current pulse having fast rise and fall times. At quiescent conditions, the standby power consumption of the circuit is equal to zero.

  6. Response time as an index for selective auditory cognitive deficits.

    Science.gov (United States)

    Nilipour, Reza; Clarke, Stephanie; Noudoost, Behrad; Saber, Golbarg Tarighat; Najlerahim, Abdolrahman

    2004-01-01

    The full or partial recovery of cognitive functions following brain lesions is believed to rely on the recruitment of alternative neural networks. This has been shown anatomically for selective auditory cognitive functions (Adriani et al. 2003b). We investigate here behavioral correlates that may accompany the use of alternative processing networks and in particular the resulting increase in response times. The performance of 5 patients with right or left unilateral hemispheric infarction and 6 normal control subjects in sound identification, asemantic sound recognition, sound localization, and sound motion perception was evaluated by the number of correct replies and response times for correct and wrong replies. Performance and response times were compared across patients and normal control subjects. Two patients with left lesions were deficient in sound identification and sound motion perception and normal in sound localization and asemantic sound recognition; one patient with right lesion was deficient in sound localization and sound motion perception and normal in sound identification and asemantic sound recognition; deficient performance was associated with increased response times. The remaining 2 patients (1 with left, 1 with right lesion) had normal performance in all 4 tasks but had significantly longer response times in some (but not all) tasks. Patients with normal or deficient performance tended more often than normal subjects to give faster correct than wrong replies. We propose that increased response time is an indication of processing within an alternative network. PMID:15366249

  7. Improvement of Response of CR-39 Nuclear Track Detectors in Fast Neutron Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Brede, H.J. [Braunschweig (Germany); Gisbertz, A.; Koehler, I.; Pitt, E.; Scharmann, A. [Giessen (Germany)

    1999-07-01

    CR-39 in combination with (n,p) radiators is used in routine fast neutron dosimetry. This material is highly sensitive to charged particles. Its application is restricted due to a high lower limit of detection caused by the large scattering from the background even from badge to badge of a single manufacturer. For its improvement it is necessary to investigate the etch process in detail. CR-39 was chemically and electrochemically etched in NaOH. The response to protons as the track generating particles in neutron dosimetry was measured as a function of the angle of particle incidence in the energy range up to 7.5 MeV. Appropriate proton beams were produced by Rutherford backscattering of accelerator particles. By means of a special evaluation technique the influence of stray particles was reduced. The curve of the critical angle of incidence for proton detection as a function of energy was determined experimentally. It can now serve as a basis for neutron response modelling. (author)

  8. Fast Time-Varying Volume Rendering Using Time-Space Partition (TSP) Tree

    Science.gov (United States)

    Shen, Han-Wei; Chiang, Ling-Jen; Ma, Kwan-Liu

    1999-01-01

    We present a new, algorithm for rapid rendering of time-varying volumes. A new hierarchical data structure that is capable of capturing both the temporal and the spatial coherence is proposed. Conventional hierarchical data structures such as octrees are effective in characterizing the homogeneity of the field values existing in the spatial domain. However, when treating time merely as another dimension for a time-varying field, difficulties frequently arise due to the discrepancy between the field's spatial and temporal resolutions. In addition, treating spatial and temporal dimensions equally often prevents the possibility of detecting the coherence that is unique in the temporal domain. Using the proposed data structure, our algorithm can meet the following goals. First, both spatial and temporal coherence are identified and exploited for accelerating the rendering process. Second, our algorithm allows the user to supply the desired error tolerances at run time for the purpose of image-quality/rendering-speed trade-off. Third, the amount of data that are required to be loaded into main memory is reduced, and thus the I/O overhead is minimized. This low I/O overhead makes our algorithm suitable for out-of-core applications.

  9. Fast Tracker: a hardware real time track finder for the ATLAS trigger system

    International Nuclear Information System (INIS)

    The Fast Tracker (FTK) is an integral part of the trigger upgrade program of the ATLAS detector at the Large Hadron Collider (LHC). As the LHC luminosity approaches its design level of 1034 cm?2s?1, the combinatorial problem posed by charged particle tracking becomes increasingly difficult due to the swelling of multiple interactions per bunch crossing. The FTK is a highly-parallel hardware system intended to provide high-quality tracks with transverse momentum above 1 GeV in real time for online trigger system. The FTK system's design, based on a mixture of advanced technologies, and the expected physics performance will be presented

  10. Real-time generation of atmospheric turbulence phase screen with non-uniform fast Fourier transform

    Science.gov (United States)

    Jia, Peng; Cai, Dongmei; Wang, Dong; Basden, Alastair

    2015-06-01

    High-fidelity Monte Carlo simulation of atmospheric turbulence phase screens is important for performance testing of astronomical adaptive optics systems. With a sparse spectrum model and an optimal sampling method, it is possible to generate an atmospheric turbulence phase screen with high fidelity. However, the phase screen generation speed is limited by the algorithm structure of this technique. A non-uniform fast Fourier transform technique is proposed in this paper to accelerate phase screen generation speed. This method is able to generate huge atmospheric turbulence phase screens with high fidelity and an acceptable time-cost enabling practical adaptive optics simulations of forthcoming Extremely Large Telescopes.

  11. Fast Seismic Modeling and Reverse Time Migration on a GPU Cluster

    OpenAIRE

    Abdelkhalek, Rached; Calendra, Henri; Coulaud, Olivier; Latu, Guillaume; Roman, Jean

    2009-01-01

    We have designed a fast parallel simulator that solves the acoustic wave equation on a GPU cluster. Solving the acoustic wave equation in an oil exploration industrial context aims at speeding up seismic modeling and Reverse Time Migration. We consider a finite difference approach on a regular mesh, in both 2D and 3D cases. The acoustic wave equation is solved in either a constant density or a variable density domain. All the computations are done in single precision, since double precision i...

  12. Fast imaging of marine controlled-source EM data using time domain electromagnetic migration

    Science.gov (United States)

    Endo, M.; Furukawa, T.; Zhdanov, M. S.

    2008-12-01

    The application of electromagnetic (EM) methods in petroleum and mining exploration requires development of appropriate imaging techniques, which provide the means for fast but accurate evaluation of the observed data. Time domain electromagnetic (TDEM) methods are widely used in geophysical exploration. However, practical interpretation of TDEM data is mainly based on a simple one-dimensional (1D) inversion of the data at any given observation point. Due to increased interest in the time-domain technique in offshore petroleum exploration with a controlled-source of the EM field, the development of multidimensional interpretation of TDEM data is required. In this paper, a fast approach to TDEM data interpretation using the method of TDEM migration is introduced. The computation of the migration field is based on downward extrapolation of the observed field in reverse time. An effective method of EM migration based on the operator of an integral transformation in the spatial-temporal domain is examined. A migration geoelectrical image is constructed using the convolution of the background and migration fields. Also, the technique is extended for interpretation of TDEM data observed both in land surveys with layered background media and in marine hydrocarbon exploration by introducing an adjoint land geoelectrical model for a given model and a corresponding adjoint field. The accuracy of this imaging technique is demonstrated successfully using synthetic TDEM data simulating mining exploration and hydrocarbon exploration in land and marine survey environments, respectively. The results ensure that this imaging technique works reasonably well.

  13. Using Graphs for Fast Error Term Approximation of Time-varying Datasets

    Energy Technology Data Exchange (ETDEWEB)

    Nuber, C; LaMar, E C; Pascucci, V; Hamann, B; Joy, K I

    2003-02-27

    We present a method for the efficient computation and storage of approximations of error tables used for error estimation of a region between different time steps in time-varying datasets. The error between two time steps is defined as the distance between the data of these time steps. Error tables are used to look up the error between different time steps of a time-varying dataset, especially when run time error computation is expensive. However, even the generation of error tables itself can be expensive. For n time steps, the exact error look-up table (which stores the error values for all pairs of time steps in a matrix) has a memory complexity and pre-processing time complexity of O(n2), and O(1) for error retrieval. Our approximate error look-up table approach uses trees, where the leaf nodes represent original time steps, and interior nodes contain an average (or best-representative) of the children nodes. The error computed on an edge of a tree describes the distance between the two nodes on that edge. Evaluating the error between two different time steps requires traversing a path between the two leaf nodes, and accumulating the errors on the traversed edges. For n time steps, this scheme has a memory complexity and pre-processing time complexity of O(nlog(n)), a significant improvement over the exact scheme; the error retrieval complexity is O(log(n)). As we do not need to calculate all possible n2 error terms, our approach is a fast way to generate the approximation.

  14. Femtosecond response time measurements of a Cs2Te photocathode

    CERN Document Server

    Aryshev, A; Honda, Y; Terunuma, N; Urakawa, J

    2015-01-01

    We present the response time measurements of a Cs2Te photocathode illuminated with two 100 fs duration, variable time separation laser pulses at 266 nm wavelength. The response time was confirmed in dispersive region downstream of a 12-cell standing wave S-band acceleration structure using a well-known RF zero-crossing technique. At the same time it was also measured by changing mechanical path-length difference between two micro-bunches. Both methods agree that Cs2Te photocathode time response is of the order of 250 fs and thereby it is possible to generate and control a THz sequence of relativistic electron bunches by a conventional S-band RF gun. This result further opens a possibility to construct wide-range tunable THz FEL.

  15. Fast and Accurate Computation of Time-Domain Acoustic Scattering Problems with Exact Nonreflecting Boundary Conditions

    CERN Document Server

    Wang, Li-Lian; Zhao, Xiaodan

    2011-01-01

    This paper is concerned with fast and accurate computation of exterior wave equations truncated via exact circular or spherical nonreflecting boundary conditions (NRBCs, which are known to be nonlocal in both time and space). We first derive analytic expressions for the underlying convolution kernels, which allow for a rapid and accurate evaluation of the convolution with $O(N_t)$ operations over $N_t$ successive time steps. To handle the onlocality in space, we introduce the notion of boundary perturbation, which enables us to handle general bounded scatters by solving a sequence of wave equations in a regular domain. We propose an efficient spectral-Galerkin solver with Newmark's time integration for the truncated wave equation in the regular domain. We also provide ample numerical results to show high-order accuracy of NRBCs and efficiency of the proposed scheme.

  16. Ultra-fast transistor-based detectors for precise timing of near infrared and THz signals

    CERN Document Server

    Preu, S; Winnerl, S; Lu, H; Gossard, A C; Weber, H B

    2013-01-01

    A whole class of two-color experiments involves intense, short Terahertz radiation pulses. A fast detector that is sensitive and able to resolve both near-infrared and Terahertz pulses at the same time is highly desirable. Here we present the first detector of this kind. The detector element is a GaAs-based field effect transistor operated at room temperature. THz detection is successfully demonstrated at frequencies up to 4.9 THz. The THz detection time constant is shorter than 30 ps, the optical time constant is 150 ps. This detector is ideally suited for precise, simultaneous resolution of optical and THz pulses and for pulse characterization of high-power THz pulses up to tens of kW peak power levels. The dynamic range of the detector was as large as 65 $\\pm$ 3 dB/$\\sqrt{Hz}$, enabling applications in a large variety of experiments and setups, also including table-top systems.

  17. Time response of temperature sensors using neural networks

    International Nuclear Information System (INIS)

    Primary coolant RTDs (Resistance Temperature Detector) typically feed the plant's control and safety systems and must, therefore, be very accurate and have good dynamic performance. The response time of RTDs has been characterized by a single parameter called the time constant defined as the time it takes for the sensor output to achieve 63.2 percent of its final value after a step change in temperature. This step change is typically achieved by suddenly immersing the sensor in a rotating tank of water, called Plunge Test. In nuclear reactors, however, plunge testing is inconvenient because nuclear reactor service conditions are difficult to reproduce in the laboratory. An in-situ test method called LCSR - Loop Current Step Response test was developed to measure remotely the response time of RTDs. In the LCSR method, the response time of the sensor is identified by means of the LCSR transformation that involves the dynamic response modal time constants determination using a nodal heat-transfer model. For this reason, this calculation is not simple and requires specialized personnel. This work combines the two methodologies, Plunge test and LCSR test, using neural networks. With the use of neural networks it will not be necessary to use the LCSR transformation to determine sensor's time constant and this leads to more robust results. (author)

  18. The ITER Fast Plant System Controller ATCA prototype Real-Time Software Architecture

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, B.B., E-mail: bernardo@ipfn.ist.utl.pt [Associacao EURATOM/IST Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, P-1049-001 Lisboa (Portugal); Santos, B.; Carvalho, P.F.; Neto, A. [Associacao EURATOM/IST Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, P-1049-001 Lisboa (Portugal); Boncagni, L. [Associazione Euratom-ENEA sulla Fusione, Frascati Research Centre, Division of Fusion Physics, Frascati, Rome (Italy); Batista, A.J.N.; Correia, M.; Sousa, J.; Gonçalves, B. [Associacao EURATOM/IST Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, P-1049-001 Lisboa (Portugal)

    2013-10-15

    Highlights: ? High performance ATCA systems for fast control and data acquisition. ? IEEE1588 timing system and synchronization. ? Plasma control algorithms. ? Real-time control software frameworks. ? Targeted for nuclear fusion experiments with long duration discharges. -- Abstract: IPFN is developing a prototype Fast Plant System Controller (FPSC) based in ATCA embedded technologies dedicated to ITER CODAC data acquisition and control tasks in the sub-millisecond range. The main goal is to demonstrate the usability of the ATCA standard and its enhanced specifications for the high speed, very high density parallel data acquisition needs of the most demanding ITER tokamak plasma Instrumentation and Control (I and C) systems. This effort included the in-house development of a new family of high performance ATCA I/O and timing boards. The standard ITER software system CODAC Core System (CCS) v3.1, with the control based in the EPICS system does not cover yet the real-time requirements fulfilled by this hardware, so a new set of software components was developed for this specific platform, attempting to integrate and leverage the new features in CSS, for example the Multithreaded Application Real Time executor (MARTe) software framework, the new Data Archiving Network (DAN) solution, an ATCA IEEE-1588-2008 timing interface, and the Intelligent Platform Management Interface (IPMI) for system monitoring and remote management. This paper presents the overall software architecture for the ATCA FPSC, as well a discussion on the ITER constrains and design choices and finally a detailed description of the software components already developed.

  19. The ITER Fast Plant System Controller ATCA prototype Real-Time Software Architecture

    International Nuclear Information System (INIS)

    Highlights: ? High performance ATCA systems for fast control and data acquisition. ? IEEE1588 timing system and synchronization. ? Plasma control algorithms. ? Real-time control software frameworks. ? Targeted for nuclear fusion experiments with long duration discharges. -- Abstract: IPFN is developing a prototype Fast Plant System Controller (FPSC) based in ATCA embedded technologies dedicated to ITER CODAC data acquisition and control tasks in the sub-millisecond range. The main goal is to demonstrate the usability of the ATCA standard and its enhanced specifications for the high speed, very high density parallel data acquisition needs of the most demanding ITER tokamak plasma Instrumentation and Control (I and C) systems. This effort included the in-house development of a new family of high performance ATCA I/O and timing boards. The standard ITER software system CODAC Core System (CCS) v3.1, with the control based in the EPICS system does not cover yet the real-time requirements fulfilled by this hardware, so a new set of software components was developed for this specific platform, attempting to integrate and leverage the new features in CSS, for example the Multithreaded Application Real Time executor (MARTe) software framework, the new Data Archiving Network (DAN) solution, an ATCA IEEE-1588-2008 timing interface, and the Intelligent Platform Management Interface (IPMI) for system monitoring and remote management. This paper presents the overall software architecture for the ATCA FPSC, as well a discussion on the ITER constrains and design choices and finally a detailed description of the software components already developed

  20. Time response of temperature sensors using neural networks

    International Nuclear Information System (INIS)

    In a PWR nuclear power plant, the primary coolant temperature and feedwater temperature are measured using RTDs (Resistance Temperature Detectors). These RTDs typically feed the plant's control and safety systems and must, therefore, be very accurate and have good dynamic performance. The response time of RTDs is characterized by a single parameter called the Plunge Time Constant defined as the time it takes the sensor output to achieve 63.2 percent of its final value after a step change in temperature. Nuclear reactor service conditions are difficult to reproduce in the laboratory, and an in-situ test method called LCSR (Loop Current Step Response) test was developed to measure remotely the response time of RTDs. >From this test, the time constant of the sensor is identified by means of the LCSR transformation that involves the dynamic response modal time constants determination using a nodal heat-transfer model. This calculation is not simple and requires specialized personnel. For this reason an Artificial Neural Network has been developed to predict the time constant of RTD from LCSR test transient. It eliminates the transformations involved in the LCSR application. A series of LCSR tests on RTDs generates the response transients of the sensors, the input data of the networks. Plunge tests are used to determine the time constants of the RTDs, the desired output of the ANN, trained using these sets of input/output data. This methodology was firstly applied to theoretical data simulating 10 RTDs with different time constant values, resulting in an average error of about 0.74 %. Experimental data from three different RTDs was used to predict time constant resulting in a maximum error of 3,34 %. The time constants values predicted from ANN were compared with those obtained from traditional way resulting in an average error of about 18 % and that shows the network is able to predict accurately the sensor time constant. (author)

  1. Temperature Responses to Spectral Solar Variability on Decadal Time Scales

    Science.gov (United States)

    Cahalan, Robert F.; Wen, Guoyong; Harder, Jerald W.; Pilewskie, Peter

    2010-01-01

    Two scenarios of spectral solar forcing, namely Spectral Irradiance Monitor (SIM)-based out-of-phase variations and conventional in-phase variations, are input to a time-dependent radiative-convective model (RCM), and to the GISS modelE. Both scenarios and models give maximum temperature responses in the upper stratosphere, decreasing to the surface. Upper stratospheric peak-to-peak responses to out-of-phase forcing are approx.0.6 K and approx.0.9 K in RCM and modelE, approx.5 times larger than responses to in-phase forcing. Stratospheric responses are in-phase with TSI and UV variations, and resemble HALOE observed 11-year temperature variations. For in-phase forcing, ocean mixed layer response lags surface air response by approx.2 years, and is approx.0.06 K compared to approx.0.14 K for atmosphere. For out-of-phase forcing, lags are similar, but surface responses are significantly smaller. For both scenarios, modelE surface responses are less than 0.1 K in the tropics, and display similar patterns over oceanic regions, but complex responses over land.

  2. Fast response air-to-fuel ratio measurements using a novel device based on a wide band lambda sensor

    International Nuclear Information System (INIS)

    A crucial parameter influencing the formation of pollutant gases in internal combustion engines is the air-to-fuel ratio (AFR). During transients on gasoline and diesel engines, significant AFR excursions from target values can occur, but cycle-by-cycle AFR resolution, which is helpful in understanding the origin of deviations, is difficult to achieve with existing hardware. This is because current electrochemical devices such as universal exhaust gas oxygen (UEGO) sensors have a time constant of 50–100 ms, depending on the engine running conditions. This paper describes the development of a fast reacting device based on a wide band lambda sensor which has a maximum time constant of ?20 ms and enables cyclic AFR measurements for engine speeds of up to ?4000 rpm. The design incorporates a controlled sensor environment which results in insensitivity to sample temperature and pressure. In order to guide the development process, a computational model was developed to predict the effect of pressure and temperature on the diffusion mechanism. Investigations regarding the sensor output and response were carried out, and sensitivities to temperature and pressure are examined. Finally, engine measurements are presented

  3. Fast responsive and highly efficient optical upconverter based on phosphorescent OLED.

    Science.gov (United States)

    Chu, Xinbo; Guan, Min; Niu, Litao; Zeng, Yiping; Li, Yiyang; Zhang, Yang; Zhu, Zhanping; Wang, Baoqiang

    2014-11-12

    In this work, an organic-inorganic hybrid optical upconverter that can convert irradiated 980 nm IR light to 510 nm green phosphorescence sensitively was fabricated and studied. fac-Tris(2-phenylpyridine) iridium (Ir(ppy)3) doped 4,4'-bis(N-carbazolyl)-1,1'-biphenyl (CBP) was used as emitting layer in the phosphorescent organic light-emitting diode (OLED) unit. The upconverter using a phosphorescent OLED as display unit can achieve a higher upconversion efficiency and a low power consumption when compared with the one using fluorescent. An upconversion efficiency of 4.8% can be achieved for phosphorescent device at 15 V, much higher than that of fluorescent one (2.0%). The upconverter's transient optical and electric response to IR pulse were also investigated for the first time. The response time was found to be influenced by IR intensity and applied voltage. It has a response time as short as 60 ?s. The rapid response property of the upconverter makes it feasible to be applied to high-speed IR imaging systems. PMID:25310022

  4. Design and evaluation of a device for fast multispectral time-resolved fluorescence spectroscopy and imaging

    Energy Technology Data Exchange (ETDEWEB)

    Yankelevich, Diego R. [Department of Electrical and Computer Engineering, University of California, 3101 Kemper Hall, Davis, California 95616 (United States); Department of Biomedical Engineering, University of California, 451 Health Sciences Drive, Davis, California 95616 (United States); Ma, Dinglong; Liu, Jing; Sun, Yang; Sun, Yinghua; Bec, Julien; Marcu, Laura, E-mail: lmarcu@ucdavis.edu [Department of Biomedical Engineering, University of California, 451 Health Sciences Drive, Davis, California 95616 (United States); Elson, Daniel S. [Hamlyn Centre for Robotic Surgery, Department of Surgery and Cancer, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom)

    2014-03-15

    The application of time-resolved fluorescence spectroscopy (TRFS) to in vivo tissue diagnosis requires a method for fast acquisition of fluorescence decay profiles in multiple spectral bands. This study focusses on development of a clinically compatible fiber-optic based multispectral TRFS (ms-TRFS) system together with validation of its accuracy and precision for fluorescence lifetime measurements. It also presents the expansion of this technique into an imaging spectroscopy method. A tandem array of dichroic beamsplitters and filters was used to record TRFS decay profiles at four distinct spectral bands where biological tissue typically presents fluorescence emission maxima, namely, 390, 452, 542, and 629 nm. Each emission channel was temporally separated by using transmission delays through 200 ?m diameter multimode optical fibers of 1, 10, 19, and 28 m lengths. A Laguerre-expansion deconvolution algorithm was used to compensate for modal dispersion inherent to large diameter optical fibers and the finite bandwidth of detectors and digitizers. The system was found to be highly efficient and fast requiring a few nano-Joule of laser pulse energy and <1 ms per point measurement, respectively, for the detection of tissue autofluorescent components. Organic and biological chromophores with lifetimes that spanned a 0.8–7 ns range were used for system validation, and the measured lifetimes from the organic fluorophores deviated by less than 10% from values reported in the literature. Multi-spectral lifetime images of organic dye solutions contained in glass capillary tubes were recorded by raster scanning the single fiber probe in a 2D plane to validate the system as an imaging tool. The lifetime measurement variability was measured indicating that the system provides reproducible results with a standard deviation smaller than 50 ps. The ms-TRFS is a compact apparatus that makes possible the fast, accurate, and precise multispectral time-resolved fluorescence lifetime measurements of low quantum efficiency sub-nanosecond fluorophores.

  5. Physiotherapy Exercise After Fast-Track Total Hip and Knee Arthroplasty: Time for Reconsideration?

    DEFF Research Database (Denmark)

    Bandholm, Thomas; Kehlet, Henrik

    2012-01-01

    Bandholm T, Kehlet H. Physiotherapy exercise after fast-track total hip and knee arthroplasty: time for reconsideration? Major surgery, including total hip arthroplasty (THA) and total knee arthroplasty (TKA), is followed by a convalescence period, during which the loss of muscle strength and function is considerable, especially early after surgery. In recent years, a combination of unimodal evidence-based perioperative care components has been demonstrated to enhance recovery, with decreased need for hospitalization, convalescence, and risk of medical complications after major surgery-the fast-track methodology or enhanced recovery programs. It is the nature of this methodology to systematically and scientifically optimize all perioperative care components, with the overall goal of enhancing recovery. This is also the case for the care component "physiotherapy exercise" after THA and TKA. The 2 latest meta-analyses on the effectiveness of physiotherapy exercise after THA and TKA generally conclude that physiotherapy exercise after THA and TKA either does not work or is not very effective. The reason for this may be that the "pill" of physiotherapy exercise typically offered after THA and TKA does not contain the right active ingredients (too little intensity) or is offered at the wrong time (too late after surgery). We propose changing the focus to earlier initiated and more intensive physiotherapy exercise after THA and TKA (fast-track physiotherapy exercise), to reduce the early loss of muscle strength and function after surgery. Ideally, the physiotherapy exercise interventions after THA and TKA should be simple, using few and well-chosen exercises that are described in detail, adhering to basic exercise physiology principles, if possible.

  6. Human cortical responses to slow and fast binaural beats reveal multiple mechanisms of binaural hearing.

    Science.gov (United States)

    Ross, Bernhard; Miyazaki, Takahiro; Thompson, Jessica; Jamali, Shahab; Fujioka, Takako

    2014-10-15

    When two tones with slightly different frequencies are presented to both ears, they interact in the central auditory system and induce the sensation of a beating sound. At low difference frequencies, we perceive a single sound, which is moving across the head between the left and right ears. The percept changes to loudness fluctuation, roughness, and pitch with increasing beat rate. To examine the neural representations underlying these different perceptions, we recorded neuromagnetic cortical responses while participants listened to binaural beats at a continuously varying rate between 3 Hz and 60 Hz. Binaural beat responses were analyzed as neuromagnetic oscillations following the trajectory of the stimulus rate. Responses were largest in the 40-Hz gamma range and at low frequencies. Binaural beat responses at 3 Hz showed opposite polarity in the left and right auditory cortices. We suggest that this difference in polarity reflects the opponent neural population code for representing sound location. Binaural beats at any rate induced gamma oscillations. However, the responses were largest at 40-Hz stimulation. We propose that the neuromagnetic gamma oscillations reflect postsynaptic modulation that allows for precise timing of cortical neural firing. Systematic phase differences between bilateral responses suggest that separate sound representations of a sound object exist in the left and right auditory cortices. We conclude that binaural processing at the cortical level occurs with the same temporal acuity as monaural processing whereas the identification of sound location requires further interpretation and is limited by the rate of object representations. PMID:25008412

  7. Synthesis of fast response crosslinked PVA-g-NIPAAm nanohydrogels by very low radiation dose in dilute aqueous solution

    Science.gov (United States)

    Fathi, Marziyeh; Reza Farajollahi, Ali; Akbar Entezami, Ali

    2013-05-01

    Nanohydrogels of poly(vinyl alcohol)-g-N-isopropylacrylamide (PVA-g-NIPAAm) are synthesized by PVA and NIPAAm dilute aqueous solution using much less radiation dose of 1-20 Gy via intramolecular crosslinking at ambient temperature. The radiation synthesis of nanohydrogels is performed in the presence of tetrakis (hydroxymethyl) phosphonium chloride (THPC) due to its rapid oxygen scavenging abilities and hydrogen peroxide (H2O2) as a source of hydroxyl radicals. The effect of radiation dose, feed composition ratio of PVA and H2O2 is investigated on swelling properties such as temperature and pH dependence of equilibrium swelling ratio as well as deswelling kinetics. Experimental data exhibit high equilibrium swelling ratio and fast response time for the synthesized nanohydrogels. The average molecular weight between crosslinks (Mc) and crosslinking density (?x) of the obtained nanohydrogels are calculated from swelling data as a function of radiation dose, H2O2 and PVA amount. Fourier transform infrared spectroscopy (FT-IR), elemental analysis of nitrogen content and thermogravimetric analysis (TGA) are used to confirm the grafting reaction. Lower critical solution temperature (LCST) is measured around 33 °C by differential scanning calorimetry (DSC) for PVA-g-NIPAAm nanohydrogels. Dynamic light scattering (DLS) data demonstrate that the increase of radiation dose leads to the decreasing in dimension of nanohydrogels. Also, rheological studies are confirmed an improvement in the mechanical properties of the nanohydrogels with increasing the radiation dose. A cytotoxicity study exhibits a good biocompatibility for the obtained nanohydrogels. The prepared nanohydrogels show fast swelling/deswelling behavior, high swelling ratio, dual sensitivity and good cytocompatibility, which may find potential applications as biomaterial.

  8. Analysis of Shiraz Solar Thermal Power Plant Response Time

    Directory of Open Access Journals (Sweden)

    K. Azizian

    2013-01-01

    Full Text Available Shiraz pilot solar thermal power plant is the first Iranian solar power plant constructed near the city of Shiraz, Iran. The main purpose of constructing this pilot plant was to acquire the technology of developing parabolic trough solar thermal power plants for future energy production from solar energy. This plant consists of 48 parabolic trough collectors; each one has 25m long and 3.4 m wide. The plant consists of two cycles, oil heat absorbing cycle and steam production cycle. The plant performance and transition period to reach steady state condition or damping some disturbances as well as oil cycle heating and steam generation rate depends on several factors such as oil cycle response time. Response time is a parameter that can be used for efficient control of solar power plant. To study response time, field experimental measurements have been made during the years 2009 to 2010 based on the standard procedure and plant simulation. The experiments include: plant start up, evaluation of oil temperature increase in the field of collectors, solar radiation measurements, temperature and pressure changes in the heat exchangers, weather temperature changes and wind speed and the effect of above changes on the system response time are determined. Two modeling methods (based on the recommended standards of finding response time are employed. Results show that response time of the oil cycle varies from 150 seconds to 400 seconds by measurements, while by modeling simulation it is about 400-500 seconds. Response time is strongly depends on the environmental conditions such as oil temperture, wind and ambient temperature and specially the oil mass flow rate.

  9. Limits on Fast Radio Bursts at 145 MHz with ARTEMIS, a real-time software backend

    CERN Document Server

    Karastergiou, A; Armour, W; Williams, C; Mort, B; Dulwich, F; Salvini, S; Magro, A; Roberts, S; Serylak, M; Doo, A; Bilous, A V; Breton, R P; Falcke, H; Griessmeier, J -M; Hessels, J W T; Keane, E F; Kondratiev, V I; Kramer, M; van Leeuwen, J; Noutsos, A; Oslowski, S; Sobey, C; Stappers, B W; Weltevrede, P

    2015-01-01

    Fast Radio Bursts (FRBs), are millisecond radio signals that exhibit dispersion larger than what the Galactic electron density can account for. We have conducted a 1446 hour survey for Fast Radio Bursts (FRBs) at 145~MHz, covering a total of 4193 sq. deg on the sky. We used the UK station of the LOFAR radio telescope -- the Rawlings Array -- , accompanied for a majority of the time by the LOFAR station at Nan\\c{c}ay, observing the same fields at the same frequency. Our real-time search backend, ARTEMIS, utilizes graphics processing units to search for pulses with dispersion measures up to 320 cm$^{-3}$ pc. Previous derived FRB rates from surveys around 1.4~GHz, and favoured FRB interpretations, motivated this survey, despite all previous detections occurring at higher dispersion measures. We detected no new FRBs above a signal-to-noise threshold of 10, leading to the most stringent upper limit yet on the FRB event rate at these frequencies: 29 sky$^{-1}$ day$^{-1}$ for 5~ms-duration pulses above 62~Jy. The no...

  10. Distributed architecture and fast parallel algorithms in real-time robot control

    Energy Technology Data Exchange (ETDEWEB)

    Binder, E.E.

    1985-01-01

    Control algorithms for accurate and fast moving robots require the use of the complete dynamic model of the robot. The complete dynamic model takes into account the nonlinearity and coupling terms of the whole structure. The time of computing the dynamic equations determines whether they are usable in practical applications. Reducing the computation time can be achieved by simplifying the dynamic model, simplifying the calculations, and improving the computer's computation speed. The proposed solution is a distributed computer architecture, and new fast parallel algorithms which allow efficient utilization of the computers. This architecture has several advantages: modularity, reliability, spatial distribution, and speed. Because of the serial nature of the dynamic calculations, it is difficult to achieve efficient utilizations of the multiple computers. With the new algorithms, motion, and force values, which must be passed between the computers, are replaced by predicted values. The predicted information is acquired from values calculated in previous sample intervals. This allows efficient use of the computers and increases the computation speed of the control algorithms.

  11. Planck 2013 results. VII. HFI time response and beams

    DEFF Research Database (Denmark)

    Planck Collaboration,, no-firstname; Ade, P. A. R.

    2013-01-01

    This paper characterizes the effective beams, the effective beam window functions (EBWF) and the associated errors for the Planck High Frequency Instrument (HFI) detectors. The effective beam is the angular response including the effect of the optics, detectors, data processing and the scan strategy. The EBWF is the representation of this beam in the harmonic domain that is required to recover an unbiased measurement of the Cosmic Microwave Background (CMB) angular power spectrum. The HFI is a scanning instrument and its effective beams are the convolution of the optical response of the telescope and feeds, the processing of the time-ordered data and deconvolution of the bolometric and electronic time response, and the merging of several surveys to produce maps. The time response transfer functions are measured with observations of Jupiter and Saturn and by minimizing survey difference residuals. The scanning beam is the post-deconvolution angular response of the instrument, and is characterized with observations of Mars. The main beam solid angles are determined to better than 0.5% at each HFI frequency band. Observations of Jupiter and Saturn limit near sidelobes to ~0.1% of the total solid angle. Time response residuals remain as long tails in the scanning beams, but contribute

  12. Metabolic response to 36 hours of fasting in young men born small vs appropriate for gestational age

    DEFF Research Database (Denmark)

    JØrgensen, Sine W; BrØns, Charlotte

    2015-01-01

    AIMS/HYPOTHESIS: Being born small for gestational age (SGA) is associated with an increased risk of type 2 diabetes in an affluent society, but could confer an improved chance of survival during sparse living conditions. We studied whether insulin action and other metabolic responses to prolonged fasting differed between 21 young adults born SGA and 18 matched controls born appropriate for gestational age (AGA). METHODS: A frequently sampled IVGTT and indirect calorimetry measurements were performed after a 36 h fast. Endogenous glucose production, insulin sensitivity (SI), first-phase insulin secretion and glucose effectiveness were estimated by stable isotope tracer techniques and minimal modelling. Muscle and fat biopsies were obtained after 35 h of fasting. RESULTS: During fasting, SGA individuals experienced a more pronounced decrease in serum insulin and lower plasma triacylglycerol levels compared with AGA individuals. In addition, energy expenditure decreased in SGA but increased in AGA individuals.After fasting, SGA individuals displayed lower fat oxidation than AGA individuals. SG was reduced in SGA compared with AGA individuals, whereas hepatic or whole body insulin action (SI) did not differ between groups. SGA individuals had increased muscle PPARGC1A DNA methylation. We found no differences in adipose tissue PPARGC1A DNA methylation, muscle and adipose tissue PPARGC1A mRNA expression, or muscle glycogen levels between the groups. CONCLUSION: Compared with AGA individuals, SGA individuals displayed a more energy-conserving and energy-conserving cardiometabolic response to 36 h fasting. The role of increased muscle PPARGC1A DNA methylation in mediating this response requires further study.

  13. Metabolic response to 36 hours of fasting in young men born small vs appropriate for gestational age

    DEFF Research Database (Denmark)

    JØrgensen, Sine W; BrØns, Charlotte

    2015-01-01

    AIMS/HYPOTHESIS: Being born small for gestational age (SGA) is associated with an increased risk of type 2 diabetes in an affluent society, but could confer an improved chance of survival during sparse living conditions. We studied whether insulin action and other metabolic responses to prolonged fasting differed between 21 young adults born SGA and 18 matched controls born appropriate for gestational age (AGA). METHODS: A frequently sampled IVGTT and indirect calorimetry measurements were performed after a 36 h fast. Endogenous glucose production, insulin sensitivity (SI), first-phase insulin secretion and glucose effectiveness were estimated by stable isotope tracer techniques and minimal modelling. Muscle and fat biopsies were obtained after 35 h of fasting. RESULTS: During fasting, SGA individuals experienced a more pronounced decrease in serum insulin and lower plasma triacylglycerol levels compared with AGA individuals. In addition, energy expenditure decreased in SGA but increased in AGA individuals.After fasting, SGA individuals displayed lower fat oxidation than AGA individuals. SG was reduced in SGA compared with AGA individuals, whereas hepatic or whole body insulin action (SI) did not differ between groups. SGA individuals had increased muscle PPARGC1A DNA methylation. We found no differences in adipose tissue PPARGC1A DNA methylation, muscle and adipose tissue PPARGC1A mRNA expression, or muscle glycogen levels between the groups. CONCLUSION: Compared with AGA individuals, SGA individuals displayed a more energy-conserving and energy-conserving cardiometabolic response to 36 h fasting. The role of increased muscle PPARGC1A DNA methylation in mediating this response requires further study.

  14. ZnO(N)-Spiro-MeOTAD hybrid photodiode: an efficient self-powered fast-response UV (visible) photosensor.

    Science.gov (United States)

    Game, Onkar; Singh, Upendra; Kumari, Tanya; Banpurkar, Arun; Ogale, Satishchandra

    2014-01-01

    Organic-inorganic hybrid photo-detectors with a self-sufficient mode of operation represent a research area of great current interest. In most efficient photodetectors and optoelectronic devices compound semiconductors containing toxic elements such as Cd, As, Te, S, Se etc. are used and these are also expensive. Hence there is also a rapidly growing interest in replacing these with environmentally friendly and earth-abundant materials. Herein, we report a facile solution-processed fabrication of a self-powered organic-inorganic hybrid photodetector using n-type oriented ZnO nanorods and p-type Spiro-MeOTAD semiconductor. ZnO is eco-friendly and earth-abundant, and Spiro-MeOTAD is non-hazardous. We show that the latter has far less toxicity than the toxic elements stated above. This visible blind UV photodetector shows high sensitivity (10(2)) and a UV/visible rejection ratio of 300. It also exhibits fast response times of ?(rise) ~ 200 ?s and ?(fall) ~ 950 ?s. Importantly, with a small modification of nitrogen incorporation in ZnO one can also realize a highly-sensitive self-powered visible light photodetector with at least 1000% (or higher) improvements in quality factors (photocurrent/sensitivity/response time) as compared to previously reported organic-inorganic hybrid photo-detectors based on metal-chalcogenides (CdS-PANI or CuInSe2-P3HT). Interestingly, the broadband sensitivity of such N:ZnO-Spiro-MeOTAD photodiode enables sensing of low intensity (~28 ?W cm(-2)) ambient white light with a high photocurrent density of 120 nA cm(-2) making it an efficient ambient white light detector. PMID:24232600

  15. Finite Time Extinction for Stochastic Sign Fast Diffusion and Self-Organized Criticality

    Science.gov (United States)

    Gess, Benjamin

    2015-04-01

    We prove finite time extinction for stochastic sign fast diffusion equations driven by linear multiplicative space-time noise, corresponding to the Bak-Tang-Wiesenfeld model for self-organized criticality. This solves a problem posed and left open in several works: (Barbu, Methods Appl Sci 36:1726-1733, 2013; Röckner and Wang, J Lond Math Soc (2) 87:545-560, 2013; Barbu et al. J Math Anal Appl 389:147-164, 2012; Barbu and Röckner, Comm Math Phys 311:539-555, 2012; Barbu et al., Comm Math Phys 285:901-923, 2009, C R Math Acad Sci Paris 347(1-2):81-84, 2009). The highly singular-degenerate nature of the drift in interplay with the stochastic perturbation causes the need for new methods in the analysis of mass diffusion, and several new estimates and techniques are introduced.

  16. Synthesis of fast response crosslinked PVA-g-NIPAAm nanohydrogels by very low radiation dose in dilute aqueous solution

    International Nuclear Information System (INIS)

    Nanohydrogels of poly(vinyl alcohol)-g-N-isopropylacrylamide (PVA-g-NIPAAm) are synthesized by PVA and NIPAAm dilute aqueous solution using much less radiation dose of 1–20 Gy via intramolecular crosslinking at ambient temperature. The radiation synthesis of nanohydrogels is performed in the presence of tetrakis (hydroxymethyl) phosphonium chloride (THPC) due to its rapid oxygen scavenging abilities and hydrogen peroxide (H2O2) as a source of hydroxyl radicals. The effect of radiation dose, feed composition ratio of PVA and H2O2 is investigated on swelling properties such as temperature and pH dependence of equilibrium swelling ratio as well as deswelling kinetics. Experimental data exhibit high equilibrium swelling ratio and fast response time for the synthesized nanohydrogels. The average molecular weight between crosslinks (Mc) and crosslinking density (?x) of the obtained nanohydrogels are calculated from swelling data as a function of radiation dose, H2O2 and PVA amount. Fourier transform infrared spectroscopy (FT-IR), elemental analysis of nitrogen content and thermogravimetric analysis (TGA) are used to confirm the grafting reaction. Lower critical solution temperature (LCST) is measured around 33 °C by differential scanning calorimetry (DSC) for PVA-g-NIPAAm nanohydrogels. Dynamic light scattering (DLS) data demonstrate that the increase of radiation dose leads to the decreasing in dimension of nanohydrogels. Also, rheological studies are confirmed an improvement in the mechanical properties of the nanohydrogels with increasing the radiation dose. A cytotoxicity study exhibits a good biocompatibility for the obtained nanohydrogels. The prepared nanohydrogels show fast swelling/deswelling behavior, high swelling ratio, dual sensitivity and good cytocompatibility, which may find potential applications as biomaterial. - Highlights: ? A new radiation polymerization method is offered in dilute aqueous solution.? This method provides PVA-g-NIPAAm nanohydrogels by radiation dose of 1–20 Gy. ? Using THPC and H2O2 leads to the polymerization with much less radiation dose. ? The obtained nanohydrogels exhibit fast swelling/deswelling rate. ? Nanohydrogels indicate good rheological properties and biocompatibility

  17. Conceptual question response times in Peer Instruction classrooms

    Science.gov (United States)

    Miller, Kelly; Lasry, Nathaniel; Lukoff, Brian; Schell, Julie; Mazur, Eric

    2014-12-01

    Classroom response systems are widely used in interactive teaching environments as a way to engage students by asking them questions. Previous research on the time taken by students to respond to conceptual questions has yielded insights on how students think and change conceptions. We measure the amount of time students take to respond to in-class, conceptual questions [ConcepTests (CTs)] in two introductory physics courses taught using Peer Instruction and use item response theory to determine the difficulty of the CTs. We examine response time differences between correct and incorrect answers both before and after the peer discussion for CTs of varying difficulty. We also determine the relationship between response time and student performance on a standardized test of incoming physics knowledge, precourse self-efficacy, and gender. Our data reveal three results of interest. First, response time for correct answers is significantly faster than for incorrect answers, both before and after peer discussion, especially for easy CTs. Second, students with greater incoming physics knowledge and higher self-efficacy respond faster in both rounds. Third, there is no gender difference in response rate after controlling for incoming physics knowledge scores, although males register significantly more attempts before committing to a final answer than do female students. These results provide insight into effective CT pacing during Peer Instruction. In particular, in order to maintain a pace that keeps everyone engaged, students should not be given too much time to respond. When around 80% of the answers are in, the ratio of correct to incorrect responses rapidly approaches levels indicating random guessing and instructors should close the poll.

  18. An improved space-time kinetics method for fast and thermal reactor analysis

    International Nuclear Information System (INIS)

    An improved space-time kinetics method that can be applied to the analysis of either fast or thermal reactor transients is presented. The method (called quasi-static synthesis - QSS) blends the concepts of formal reduction (i.e., the quasi-static method) and time synthesis into a single unified approach to handle the space-time equations. In particular, the method links the lumped parameter formalism of the quasi-static approach (used to compute the relative amplitude or power in the reactor) with a time synthesis techniques employed in the determination of spatial/spectral shape-functions needed in defining the lumped parameters. A unique feature of the synthesis procedure is that the trial-shapes used in synthesizing shape-functions are computed as the transient progresses, thus obviating the need for precomputed trial-shapes. Preliminary results obtained with the method indicate reduced computer time, while maintaining computational accuracy, when compared to several other kinetics presently in use. In addition to the development of the QSS method, this dissertation also introduces a simple and efficient approach for solving the point kinetics equations. Starting with an integral form of these equations, the only assumption made is that the time-dependent amplitude-function varies linearly between kinetics time steps (being exact at the time steps). The resulting semi-implicit integration algorithms for the amplitude-function and precursor concentrations appear to on and precursor concentrations appear to allow for large kinetics time steps than do most conventional methods. Furthermore, because these algorithms are of such a simple nature, the computing cost per kinetics time step is also greatly reduced

  19. Modeling the viscoplastic micromechanical response of two-phase materials using fast Fourier transforms

    Energy Technology Data Exchange (ETDEWEB)

    Lebensohn, Ricardo A [Los Alamos National Laboratory; Lee, Sukbin [CMU; Rollett, Anthony D [CMU

    2009-01-01

    A viscoplastic approach using the Fast Fourier Transform (FFT) method for obtaining local mechanical response is utilized to study microstructure-property relationships in composite materials. Specifically, three-dimensional, two-phase digital materials containing isotropically coarsened particles surrounded by a matrix phase, generated through a Kinetic Monte Carlo Potts model for Ostwald ripening, are used as instantiations in order to calculate the stress and strain rate fields under uniaxial tension. The effects of the morphology of the matrix phase, the volume fraction and the contiguity of particles, and the polycrystallinity of matrix phase, on the stress and strain rate fields under uniaxial tension are examined. It is found that the first moments of the stress and strain rate fields have a different dependence on the particle volume fraction and the particle contiguity from their second moments. The average stresses and average strain rates of both phases and of the overall composite have rather simple relationships with the particle volume fraction whereas their standard deviations vary strongly, especially when the particle volume fraction is high, and the contiguity of particles has a noticeable effect on the mechanical response. It is also found that the shape of stress distribution in the BCC hard particle phase evolves as the volume fraction of particles in the composite varies, such that it agrees with the stress field in the BCC polycrystal as the volume of particles approaches unity. Finally, it is observed that the stress and strain rate fields in the microstructures with a polycrystalline matrix are less sensitive to changes in volume fraction and contiguity of particles.

  20. A fast dynamic response dc-dc converter for high voltage applications

    International Nuclear Information System (INIS)

    This paper present a fast dynamic response de-de converter for high voltage application such as medical use X-ray generator. In the proposed de-de converter a zero-current switching series resonant inverter is used to drive input terminals of voltage multiplier circuit. The zero-current switching series resonant inverter operates at fixed frequency and duly ratio. A control circuit is used at the lower arm of the inverter, to control the effective input voltage across the inverter. At the turn on the inverter is supplied with maximum effective input voltage, which results in quick rise-up of the output voltage. As the output voltage approaches to 80% of it target voltage, the effective input voltage is reduced to a value which corresponds to the target output voltage, as a result the rise rate of the output voltage becomes slow and overshoot is avoided. The effectiveness of the proposed control scheme has been confirmed experimentally with a laboratory scale- down prototype. (author)

  1. Fast-response fiber-optic anemometer with temperature self-compensation.

    Science.gov (United States)

    Liu, Guigen; Hou, Weilin; Qiao, Wei; Han, Ming

    2015-05-18

    We report a novel fiber-optic anemometer with self-temperature compensation capability based on a Fabry-Pérot interferometer (FPI) formed by a thin silicon film attached to the end face of a single-mode fiber. Guided in the fiber are a visible laser beam from a 635 nm diode laser used to heat the FPI and a white-light in the infrared wavelength range as the signal light to interrogate the optical length of the FPI. Cooling effects on the heated sensor head by wind is converted to a wavelength blueshift of the reflection spectral fringes of the FPI. Self-temperature-compensated measurement of wind speed is achieved by recording the difference in fringe wavelengths when the heating laser is turned on and then off. Large thermal-optic coefficient and thermal expansion coefficient of silicon render a high sensitivity that can also be easily tuned by altering the heating laser power. Furthermore, the large thermal diffusivity and the small mass of the thin silicon film endow a fast sensor response. PMID:26074604

  2. Assessment of negative phototaxis in long-term fasted Glyptocidaris crenularis: a new insight into measuring stress responses of sea urchins in aquaculture

    Science.gov (United States)

    Tian, Xiaofei; Wei, Jing; Zhao, Chong; Feng, Wenping; Sun, Ping; Chang, Yaqing

    2015-01-01

    A cost-effective method was designed to measure the behavioral response of negative phototaxis to high-intensity illumination in the sea urchin Glyptocidaris crenularis. Ninety sea urchins were randomly and equally divided into two aquaculture environment groups: a fasted group, which was starved during the experiment, and a fed group. After 10 months, the total mortality of each group was recorded. Then, 15 sea urchins were randomly selected from each group and behavioral responses to high-intensity illumination were investigated for each sea urchin. After the behavioral experiment, body measurements of the trial sea urchins were taken. The results reveal that food deprivation significantly affected test diameter ( Pfood deprivation also affected negative phototaxis behaviors of time to rapid spine movement ( P0.05). The mortality rates of fasted and fed urchins were 6.7% and 0%, respectively. The present study provides evidence that food deprivation has a significant effect on phenotypic traits and behavioral responses to high-intensity illumination in the sea urchin G. crenularis. With this method, environmental stressors can be easily detected by measuring proper optional indicators. This study provides a new insight into measuring stress responses of sea urchins in aquaculture. However, further studies should be carried out to understand more environmental factors and to compare this potential behavioral method with immune, physiological, and epidemiological approaches.

  3. Preoperative Management of Surgical Patients by “Shortened Fasting Time”: A Study on the Amount of Total Body Water by Multi-Frequency Impedance Method

    OpenAIRE

    Taniguchi, Hideki; Sasaki, Toshio; Fujita, Hisae

    2012-01-01

    Aim: Preoperative fasting is an established procedure to be practiced for patients before surgery, but optimal preoperative fasting time still remains controversial. The aim of this study was to investigate the effect of “shortened preoperative fasting time” on the change in the amount of total body water (TBW) in elective surgical patients. TBW was measured by multi-frequency impedance method.

  4. The noise-time of response compromise in d.c. period meters. A new type of circuit (1961)

    International Nuclear Information System (INIS)

    The report compares the characteristics of three period meter circuits: - a linear circuit - a circuit which is non-linear according to the nuclear reactor period - a circuit which is non-linear according to the period and the power of the reactor. This last type of reactor has a fast time of response if the power is high or if the period is short, and it has a slow time of response when the power is low and the period long; this system makes it possible to maintain the noise at an acceptable level under all normal working conditions of the reactor. (author)

  5. A fast density-based clustering algorithm for real-time Internet of Things stream.

    Science.gov (United States)

    Amini, Amineh; Saboohi, Hadi; Wah, Teh Ying; Herawan, Tutut

    2014-01-01

    Data streams are continuously generated over time from Internet of Things (IoT) devices. The faster all of this data is analyzed, its hidden trends and patterns discovered, and new strategies created, the faster action can be taken, creating greater value for organizations. Density-based method is a prominent class in clustering data streams. It has the ability to detect arbitrary shape clusters, to handle outlier, and it does not need the number of clusters in advance. Therefore, density-based clustering algorithm is a proper choice for clustering IoT streams. Recently, several density-based algorithms have been proposed for clustering data streams. However, density-based clustering in limited time is still a challenging issue. In this paper, we propose a density-based clustering algorithm for IoT streams. The method has fast processing time to be applicable in real-time application of IoT devices. Experimental results show that the proposed approach obtains high quality results with low computation time on real and synthetic datasets. PMID:25110753

  6. Reaction-time response of a large commercial aircraft

    International Nuclear Information System (INIS)

    The reaction-time response of a large commercial aircraft is defined. The aircraft is examined as a thin-walled tubular missile. The impact is assumed soft, and the target's effect on the reaction-time response is neglected. The reaction-time response is defined assuming a normal impact on a rigid wall. The reaction-time response is defined with the analytical Riera method and with the numerical explicit finite element method. The Riera force history is solved with the finite difference method. For the finite element method, two codes are used: Abaqus/Explicit and LS-DYNA. Focus is on the sensitivity study of the used methods. The outer shell of the aircraft is modeled, and an approximation for the mass-distribution is made. Sensitivity to modeling assumptions is studied in order to get information on the adequacy of modeling. The results indicate relatively small sensitivity to modeling assumptions. The wings should be modeled more accurately in order to obtain the dominant frequency response in global structural analysis. (author)

  7. Synchronous timing of multi-energy fast beam extraction during a single AGS cycle

    International Nuclear Information System (INIS)

    Synchronous triggering of fast beams is required because the field of Kicker Magnets must rise within the open space between one beam bunch and the next. Within the Brookhaven AGS, Fast Extracted Beam (FEB) triggering combines nominal timing, based on beam energy with bunch-to-bunch synchronization, based on the accelerating rf waveform. During beam acceleration, a single bunch is extracted at 22 GeV/c and within the same AGS cycle, the remaining eleven bunches are extracted at 28.4 GeV/c. When the single bunch is extracted, a ''hole'', which is left in the remaining circulating beam, can appear in random locations within the second extraction during successive AGS cycles. To overcome this problem, a synchronous rf/12 counting scheme and logic circuitry are used to keep track of the bunch positions relative to each other, and to place the ''hole'' in any desired location within the second extraction. The rf/12 signal is used also to synchronize experimenters triggers

  8. The first synchrotron infrared beamlines at the Advanced Light Source: Spectromicroscopy and fast timing

    International Nuclear Information System (INIS)

    Two recently commissioned infrared beamlines on the 1.4 bending magnet port at the Advanced Light Source, LBNL, are described. Using a synchrotron as an IR source provides three primary advantages: increased brightness, very fast light pulses, and enhanced far-IR flux. The considerable brightness advantage manifests itself most beneficially when performing spectroscopy on a microscopic length scale. Beamline (BL) 1.4.3 is a dedicated FTIR spectromicroscopy beamline, where a diffraction-limited spot size using the synchrotron source is utilized. BL 1.4.2 consists of a vacuum FTIR bench with a wide spectral range and step-scan capability. This BL makes use of the pulsed nature of the synchrotron light as well as the far-IR flux. Fast timing is demonstrated by observing the pulses from the electron bunch storage pattern at the ALS. Results from several experiments from both IR beamlines will be presented as an overview of the IR research currently being done at the ALS

  9. The First Synchrotron Infrared Beamlines at the ALS Spectromicroscopy and Fast Timing

    CERN Document Server

    Martin, M C; Martin, Michael C.; Kinney, Wayne R. Mc

    1999-01-01

    Two recently commissioned infrared beamlines on the 1.4 bending magnet port at the Advanced Light Source, LBNL, are described. Using a synchrotron as an IR source provides three primary advantages: increased brightness, very fast light pulses, and enhanced far-IR flux. The considerable brightness advantage manifests itself most beneficially when performing spectroscopy on a microscopic length scale. Beamline (BL) 1.4.3 is a dedicated FTIR spectromicroscopy beamline, where a diffraction-limited spot size using the synchrotron source is utilized. BL 1.4.2 consists of a vacuum FTIR bench with a wide spectral range and step-scan capability. This BL makes use of the pulsed nature of the synchrotron light as well as the far-IR flux. Fast timing is demonstrated by observing the pulses from the electron bunch storage pattern at the ALS. Results from several experiments from both IR beamlines will be presented as an overview of the IR research currently being done at the ALS.

  10. Time-resolved study of early radiation response

    Energy Technology Data Exchange (ETDEWEB)

    Ponette, V.; Giocanti, N.; Favaudon, V. [Unite 350 INSERM, Institut Curie, Centre Universitaire, 91 - Orsay (France)

    1997-03-01

    The early steps of radiation response in the three rodent or human cultured cell lines were investigated using a linear electron accelerator operated in a slit-dose mode. The results show that pulse exposure to relatively weak doses of low-LET radiation brings about altered susceptibility to radiation evolving synchronously over extended periods of time. This process was named W-effect from the shape of its time-dependent profile, as revealed upon exposure to the probing dose of radiation. The method may allow dissecting the early steps of the bulk cell response to radiation. (N.C.)

  11. Time-resolved study of early radiation response

    International Nuclear Information System (INIS)

    The early steps of radiation response in the three rodent or human cultured cell lines were investigated using a linear electron accelerator operated in a slit-dose mode. The results show that pulse exposure to relatively weak doses of low-LET radiation brings about altered susceptibility to radiation evolving synchronously over extended periods of time. This process was named W-effect from the shape of its time-dependent profile, as revealed upon exposure to the probing dose of radiation. The method may allow dissecting the early steps of the bulk cell response to radiation. (N.C.)

  12. Fast responsive fluorescence turn-on sensor for Cu2+ and its application in live cell imaging

    International Nuclear Information System (INIS)

    A new effective fluorescent sensor based on rhodamine was synthesized, which was induced by Cu2+ in aqueous media to produce turn-on fluorescence. The new sensor 1 exhibited good selectivity for Cu2+ over other heavy and transition metal (HTM) ions in H2O/CH3CN(7:3, v/v). Upon addition of Cu2+, a remarkable color change from colorless to pink was easily observed by the naked eye, and the dramatic fluorescence turn-on was corroborated. Furthermore, kinetic assay indicates that sensor 1 could be used for real-time tracking of Cu2+ in cells and organisms. In addition, the turn-on fluorescent change upon the addition of Cu2+ was also applied in bioimaging. - Highlights: ? A new effective fluorescent sensor based on rhodamine was developed to detect Cu2+. ? The sensor exhibited fast response, good selectivity at physiological pH condition. ? The sensor was an effective intracellular Cu2+ ion imaging agent.

  13. Study of toroidal current penetration during current ramp in JIPP T-IIU with fast response Zeeman polarimeter

    International Nuclear Information System (INIS)

    The toroidal current penetration is studied in current ramp experiments of the JIPP T-IIU tokamak. The poloidal magnetic field profile in the peripheral region of a plasma (0.5 ? ? ? 1.0) has been measured directly with a newly developed fast response Zeeman polarimeter. The experimental results indicate that an obvious skin effect of toroidal current density is clearly observed during both the current ramp-up and ramp-down experiments. The experimentally obtained toroidal current density profiles are well described by the profiles calculated on the assumption of the neoclassical electrical conductivity. Quasi-linear ?'-analysis of tearing modes for the measured current density profile is consistent with time behaviour of coherent MHD modes such as m=4/n=1 or m=3/n=1 (m: poloidal mode number, n: toroidal mode number) often observed during the current ramp-up phase. The effect of these MHD modes on current penetration during the current ramp-up discharges is studied. (author)

  14. Fast maximum likelihood estimation using continuous-time neural point process models.

    Science.gov (United States)

    Lepage, Kyle Q; MacDonald, Christopher J

    2015-06-01

    A recent report estimates that the number of simultaneously recorded neurons is growing exponentially. A commonly employed statistical paradigm using discrete-time point process models of neural activity involves the computation of a maximum-likelihood estimate. The time to computate this estimate, per neuron, is proportional to the number of bins in a finely spaced discretization of time. By using continuous-time models of neural activity and the optimally efficient Gaussian quadrature, memory requirements and computation times are dramatically decreased in the commonly encountered situation where the number of parameters p is much less than the number of time-bins n. In this regime, with q equal to the quadrature order, memory requirements are decreased from O(n p) to O(q p), and the number of floating-point operations are decreased from O(n p (2)) to O(q p (2)). Accuracy of the proposed estimates is assessed based upon physiological consideration, error bounds, and mathematical results describing the relation between numerical integration error and numerical error affecting both parameter estimates and the observed Fisher information. A check is provided which is used to adapt the order of numerical integration. The procedure is verified in simulation and for hippocampal recordings. It is found that in 95 % of hippocampal recordings a q of 60 yields numerical error negligible with respect to parameter estimate standard error. Statistical inference using the proposed methodology is a fast and convenient alternative to statistical inference performed using a discrete-time point process model of neural activity. It enables the employment of the statistical methodology available with discrete-time inference, but is faster, uses less memory, and avoids any error due to discretization. PMID:25788412

  15. Surface layer characteristics derived from fast-response micrometeorological observations over a mountain peak in the central Himalayas

    Science.gov (United States)

    Solanki, Raman; Dhaka, Surendra; Rajeev, Kunjukrishnapillai; Singh, Narendra; Nadimpally, Kirankumar

    Diurnal evolution of atmospheric boundary layer over hilly terrains is highly complex and least understood. Fast-response micrometeorological observations carried out at Manora Peak, Nainital (29.2°N, 79.3°E, 1960 m ASL), a hill station located in the Central Himalayas during March-2013 to February-2014 has been used to investigate diurnal variations in the surface layer characteristics, energy budget and atmospheric circulation over complex terrains. This study mainly employs tower-based sonic anemometer observations (25 Hz) carried out at two levels (12 m and 27 m above the ground level) which are used to derive the variations of zonal, meridional and vertical winds, virtual temperature, momentum flux, turbulent kinetic energy, and Monin-Obukhov stability parameter during fair-weather conditions. In general, this station is manifested by warm and dry conditions as well as relatively high wind speed during pre-monsoon season (March-May); while highly moist conditions prevail during the summer monsoon season (June-September). The sensible heat flux (SHF) undergoes a prominent diurnal variation during winter and pre-monsoon seasons with peak values (200 to 400 Wm-2) occurring between 11-15 Local Time (LT) and weakly negative values (typically -20 Wm-2) during night, the latter indicating a downward transfer of heat from atmosphere to surface. The noon-time peak values systematically increases from winter to pre-monsoon season. Remarkably, the large noon-time values of SHF observed during the pre-monsoon season over this station (peak SHF of more than 400 Wm-2 during May) arise from the forced lifting of air masses, caused by the prevailing horizontal winds that blow perpendicular to the mountain. The intricate details of the surface layer parameters and fluxes over this site will assist in investigating how such a complex topography influences the flux generation process.

  16. [Fast and accurate extraction of ring-down time in cavity ring-down spectroscopy].

    Science.gov (United States)

    Wang, Dan; Hu, Ren-Zhi; Xie, Pin-Hua; Qin, Min; Ling, Liu-Yi; Duan, Jun

    2014-10-01

    Research is conducted to accurate and efficient algorithms for extracting ring-down time (r) in cavity ring-down spectroscopy (CRDS) which is used to measure NO3 radical in the atmosphere. Fast and accurate extraction of ring-down time guarantees more precise and higher speed of measurement. In this research, five kinds of commonly used algorithms are selected to extract ring-down time which respectively are fast Fourier transform (FFT) algorithm, discrete Fourier transform (DFT) algorithm, linear regression of the sum (LRS) algorithm, Levenberg-Marquardt (LM) algorithm and least squares (LS) algorithm. Simulated ring-down signals with various amplitude levels of white noises are fitted by using five kinds of the above-mentioned algorithms, and comparison and analysis is conducted to the fitting results of five kinds of algorithms from four respects: the vulnerability to noises, the accuracy and precision of the fitting, the speed of the fitting and preferable fitting ring-down signal waveform length The research results show that Levenberg-Marquardt algorithm and linear regression of the sum algorithm are able to provide more precise results and prove to have higher noises immunity, and by comparison, the fitting speed of Leven- berg-Marquardt algorithm turns out to be slower. In addition, by analysis of simulated ring-down signals, five to ten times of ring-down time is selected to be the best fitting waveform length because in this case, standard deviation of fitting results of five kinds of algorithms proves to be the minimum. External modulation diode laser and cavity which consists of two high reflectivity mirrors are used to construct a cavity ring-down spectroscopy detection system. According to our experimental conditions, in which the noise level is 0.2%, linear regression of the sum algorithm and Levenberg-Marquardt algorithm are selected to process experimental data. The experimental results show that the accuracy and precision of linear regression of the sum algorithm is considerably close to those of Levenberg-Marquardt algorithm, and on the other hand, the fitting speed of linear regression of the sum algorithm is faster than that of Levenberg-Marquardt algorithm about five times. The experimental results are consistent with the simulation analysis, and it indicates that linear regression of the sum algorithm is the desirable fitting method, as far as our experimental conditions are concerned. PMID:25739236

  17. Catching the fast action. Time resolution in high-energy X-ray studies

    International Nuclear Information System (INIS)

    Many important biological, chemical, and physical processes involve intermediate or excited states that last for very short times - in the range of milliseconds to nanoseconds, or thousandths to billionths of a second. These short-lived states are interesting not only in themselves, but as they contribute to the overall dynamic process. Knowing about them often leads to new insights and a better understanding of the final or ground state. In studies of the temporal evolution of fast processes, investigators have had to rely mainly on techniques other than x-ray diffraction and spectroscopy because of the inherent weakness of conventional x-ray sources. Within the last decade, however, a new source of intense radiation has become available: high-energy storage rings. The Cornell High Energy Synchrotron Source (CHESS), operated in conjunction with the Cornell Electron Storage Ring (CESR), is providing time-resolved studies. Almost all the intrinsic properties of synchrotron radiation can be exploited in some way for studying transient phenomena. The most straightforward application is the use of the high flux available from storage rings to decrease data-collection time. In other techniques, both the high flux and the continuous spectrum of radiation are utilized. And in some experiments the pulsed nature of the emitted radiation provides ways of looking at processes with very short time scales

  18. Ultimate response time of high electron mobility transistors

    Science.gov (United States)

    Rudin, Sergey; Rupper, Greg; Shur, Michael

    2015-05-01

    We present theoretical studies of the response time of the two-dimensional gated electron gas to femtosecond pulses. Our hydrodynamic simulations show that the device response to a short pulse or a step-function signal is either smooth or oscillating time-decay at low and high mobility, ?, values, respectively. At small gate voltage swings, U0 = Ug - Uth, where Ug is the gate voltage and Uth is the threshold voltage, such that ?U0/L devices, which becomes important during very short time periods. In the high mobility devices, the period of the decaying oscillations is on the order of the plasma wave velocity transit time. Our analysis shows that short channel field effect transistors operating in the plasmonic regime can meet the requirements for applications as terahertz detectors, mixers, delay lines, and phase shifters in ultra high-speed wireless communication circuits.

  19. EVALUATION OF A FAST-RESPONSE URBAN WIND MODEL - COMPARISON TO SINGLE-BUILDING WIND TUNNEL DATA

    International Nuclear Information System (INIS)

    Prediction of the 3-dimensional flow field around buildings and other obstacles is important for a number of applications, including urban air quality studies, the tracking of plumes from accidental releases of toxic air contaminants, indoor/outdoor air pollution problems, and thermal comfort assessments. Various types of computational fluid dynamics (CFD) models have been used for determining the flow fields around buildings (e.g., Reisner et al., 1998; Eichhorn et al., 1988). Comparisons to measurements show that these models work reasonably well for the most part (e.g., Ehrhard et al., 2 ; Johnson and Hunter, 1998; Murakami, 1997). However, CFD models are computationally intensive and for some applications turn-around time is of the essence. For example, planning and assessment studies in which hundreds of cases must be analyzed or emergency response scenarios in which plume transport must be computed quickly. Several fast-response dispersion models of varying levels of fidelity have been developed to explicitly account for the effects of a single building or groups of buildings (e.g., UDM - Hall et al. (2000), NRC-Ramsdell and Fosmire (1995), CBP-3 - Yamartino and Wiegand (1986), APRAC - Daerdt et al. (1973)). Although a few of these models include the Hotchkiss and Harlow (1973) analytical solution for potential flow in a notch to describe the velocity field within an urban canyon, in general, these models do not explicitly compute the velocity field around grouply compute the velocity field around groups of buildings. The EPA PRIME model (Schulman et al., 2000) has been empirically derived to provide streamlines around a single isolated building

  20. Program for the analysis of time series. [by means of fast Fourier transform algorithm

    Science.gov (United States)

    Brown, T. J.; Brown, C. G.; Hardin, J. C.

    1974-01-01

    A digital computer program for the Fourier analysis of discrete time data is described. The program was designed to handle multiple channels of digitized data on general purpose computer systems. It is written, primarily, in a version of FORTRAN 2 currently in use on CDC 6000 series computers. Some small portions are written in CDC COMPASS, an assembler level code. However, functional descriptions of these portions are provided so that the program may be adapted for use on any facility possessing a FORTRAN compiler and random-access capability. Properly formatted digital data are windowed and analyzed by means of a fast Fourier transform algorithm to generate the following functions: (1) auto and/or cross power spectra, (2) autocorrelations and/or cross correlations, (3) Fourier coefficients, (4) coherence functions, (5) transfer functions, and (6) histograms.

  1. In-beam fast-timing measurements in 103,105,107Cd

    CERN Document Server

    Kisyov, S; Marginean, N; Bucurescu, D; Atanasova, L; Balabanski, D L; Cata-Danil, Gh; Cata-Danil, I; Daugas, J -M; Deleanu, D; Detistov, P; Filipescu, D; Georgiev, G; Ghita, D; Glodariu, T; Jolie, J; Judson, D S; Lozeva, R; Marginean, R; Mihai, C; Negret, A; Pascu, S; Radulov, D; Regis, J -M; Rudigier, M; Sava, T; Stroe, L; Suliman, G; Zamfir, N V; Zell, K O; Zhekova, M

    2011-01-01

    Fast-timing measurements were performed recently in the region of the medium-mass 103,105,107Cd isotopes, produced in fusion evaporation reactions. Emitted gamma-rays were detected by eight HPGe and five LaBr3:Ce detectors working in coincidence. Results on new and re-evaluated half-lives are discussed within a systematic of transition rates. The $7/2_1^+$ states in 103,105,107Cd are interpreted as arising from a single-particle excitation. The half-life analysis of the $11/2_1^-$ states in 103,105,107Cd shows no change in the single-particle transition strength as a function of the neutron number.

  2. Artificial diamonds as radiation-hard detectors for ultra-fast fission-fragment timing

    International Nuclear Information System (INIS)

    In the framework of the construction of the double time-of-flight spectrometer VERDI, where we aim at measuring pre- and post-neutron masses directly and simultaneously, ultra-fast time pick-up detectors based on artificial diamond material were investigated for the first time with fission fragments from 252Cf (0.5MeV/u9 fission-fragments/cm2 together with more than 3.5×109 neutrons/cm2 and 3×1010?-particles/cm2. This fluence is characteristic for fission experiments. The pre-requisite for the observed signal stability is the application of priming of the diamond material with a strong ?-source for about 48 h. The intrinsic timing resolution of a 100?m thick polycrystalline CVD diamond detector with a size of 1×1 cm2 was determined to ?int=(283±41)ps by comparison with Monte-Carlo simulations. Using broadband pre-amplifiers, 4-fold segmented detectors of same total size and with a thickness of 180?m show an intrinsic timing resolution of ?int=(106±21)ps. This is highly competitive with the best micro-channel plate detectors. Due to the limited and batch-dependent charge collection efficiency of poly-crystalline diamond material, the detection efficiency for fission fragments may be smaller than 100%. -- Highlights: ? First use of chemical vapor deposited diamond for heavy ions with kinetic energies below 2 MeV per nucleon. ? Fission-fragment time-of-flight measurements with a timing resolution better than 150 ps. ? Radiation-hard fission event trigger to be used in an intense neutron field

  3. Artificial diamonds as radiation-hard detectors for ultra-fast fission-fragment timing

    Energy Technology Data Exchange (ETDEWEB)

    Oberstedt, S., E-mail: stephan.oberstedt@ec.europa.eu [European Commission, DG Joint Research Centre (IRMM), B-2440 Geel (Belgium); Borcea, R.; Bry?, T.; Gamboni, Th.; Geerts, W.; Hambsch, F.-J. [European Commission, DG Joint Research Centre (IRMM), B-2440 Geel (Belgium); Oberstedt, A. [Fundamental Fysik, Chalmers Tekniska Högskola, S-41296 Göteborg (Sweden); Akademin för Naturvetenskap och Technik, Örebro Universitet, S-70182 Örebro (Sweden); Vidali, M. [European Commission, DG Joint Research Centre (IRMM), B-2440 Geel (Belgium)

    2013-06-21

    In the framework of the construction of the double time-of-flight spectrometer VERDI, where we aim at measuring pre- and post-neutron masses directly and simultaneously, ultra-fast time pick-up detectors based on artificial diamond material were investigated for the first time with fission fragments from {sup 252}Cf (0.5MeV/utiming resolution of a 100?m thick polycrystalline CVD diamond detector with a size of 1×1 cm{sup 2} was determined to ?{sub int}=(283±41)ps by comparison with Monte-Carlo simulations. Using broadband pre-amplifiers, 4-fold segmented detectors of same total size and with a thickness of 180?m show an intrinsic timing resolution of ?{sub int}=(106±21)ps. This is highly competitive with the best micro-channel plate detectors. Due to the limited and batch-dependent charge collection efficiency of poly-crystalline diamond material, the detection efficiency for fission fragments may be smaller than 100%. -- Highlights: ? First use of chemical vapor deposited diamond for heavy ions with kinetic energies below 2 MeV per nucleon. ? Fission-fragment time-of-flight measurements with a timing resolution better than 150 ps. ? Radiation-hard fission event trigger to be used in an intense neutron field.

  4. Time dependent start-up thermal analysis of a Super Fast Reactor

    International Nuclear Information System (INIS)

    Highlights: • Time dependent startup thermal analysis of a Super Fast Reactor is performed. • A recirculation system is used for pressurization and for generating supercritical steam. • MCST satisfies the criterion both during subcritical pressure and during power-raising. • MCST is not sensitive to the change of inlet temperature, gap volume and flow rate because of high flow to power ratio. • CHF is not limiting the MCST during subcritical pressure due to large margin of heat flux. -- Abstract: The startup system of a supercritical pressure light water cooled fast reactor (Super FR) is studied by time dependent thermal-hydraulic analysis. The plant analysis code is developed based on an innovative upward flow pattern in all the assemblies of the Super FR. A recirculation system consisting of a steam drum, a circulation pump, and a heat exchanger is used for the startup. Detailed procedures are performed and the maximum cladding surface temperature (MCST) at rated power, 640 °C, is used as the criterion. Firstly a small constant nuclear power is used for rising the core feed water temperature to be 280 °C through the recirculation system. Secondly, pressurization is done in the recirculation system from atmospheric to operating pressure, 25 MPa, by raising the power. Thirdly, line-switching from recirculation mode to once-through direct-cycle is performed while turbines are started by supercritical steam at supercritical pressure. Finally the power is raised to be 100% of power followed by raising the flow rate. During pressurization the heat flux margin is large due to low power used for pressurization and the MCST is much lower than the criterion. The MCST is not sensitive to the inlet temperature, the flow rate, and the gap volume of the core because of high flow to power ratio. Smaller dimension of steam drum can be used for pressurization stably. The MCST satisfies the criterion both during subcritical pressure and during power-raising

  5. ULTRAFAST DEPHASING TIME MEASUREMENT IN CRESYL FAST VIOLET DOPED CELLULOSE BY PHOTON ECHOES WITH TEMPORALLY INCOHERENT LIGHT

    OpenAIRE

    Nakatsuka, H.; Fujiwara, M.; Kuroda, R

    1985-01-01

    Photon echoes with broad spectrum nanosecond laser pulses have been used to measure a femtosecond dephasing time (homogeneous transverse relaxation time) T2 of the S0?1 transition of Cresyl Fast Violet molecules in a cellulose film. The measured T2 was much shorter at a shorter wavelength 5940A than that at a longer wavelength 6250A near the band edge.

  6. CHARACTERISTICS OF A FAST RISE TIME POWER SUPPLY FOR A PULSED PLASMA REACTOR FOR CHEMICAL VAPOR DESTRUCTION

    Science.gov (United States)

    Rotating spark gap devices for switching high-voltage direct current (dc) into a corona plasma reactor can achieve pulse rise times in the range of tens of nanoseconds. The fast rise times lead to vigorous plasma generation without sparking at instantaneous applied voltages highe...

  7. Time-domain response of the ARIANNA detector

    Science.gov (United States)

    Barwick, S. W.; Berg, E. C.; Besson, D. Z.; Duffin, T.; Hanson, J. C.; Klein, S. R.; Kleinfelder, S. A.; Piasecki, M.; Ratzlaff, K.; Reed, C.; Roumi, M.; Stezelberger, T.; Tatar, J.; Walker, J.; Young, R.; Zou, L.

    2015-03-01

    The Antarctic Ross Ice Shelf Antenna Neutrino Array (ARIANNA) is a high-energy neutrino detector designed to record the Askaryan electric field signature of cosmogenic neutrino interactions in ice. To understand the inherent radio-frequency (RF) neutrino signature, the time-domain response of the ARIANNA RF receiver must be measured. ARIANNA uses Create CLP5130-2N log-periodic dipole arrays (LPDAs). The associated effective height operator converts incident electric fields to voltage waveforms at the LDPA terminals. The effective height versus time and incident angle was measured, along with the associated response of the ARIANNA RF amplifier. The results are verified by correlating to field measurements in air and ice, using oscilloscopes. Finally, theoretical models for the Askaryan electric field are combined with the detector response to predict the neutrino signature.

  8. In situ response time measurements of RTD temperature sensors

    International Nuclear Information System (INIS)

    The loop-current-step-response test provides a mean for determining the time constant of resistence thermometers. The test consist in heating the sensor a few degrees above ambient temperature by causing a step pertubation in the electric current that flows through the sensor leads. The developed mathematical transformation permits to use data collected during the internal heating transient to predict the sensor response to perturbations in fluid temperature. Experimental data obtained show that the time constant determined by method is within 15 percent of true value. The loop-current-step-response test is a remote in situ test, which can be performed with the sensor installed in the process. Consequently it takes account the local heat transfer conditions, and appropriated for nuclear power plants, where sensors are installed in points of difficult access. (author)

  9. Improvement in MFTF data base system response times

    International Nuclear Information System (INIS)

    The Supervisory Control and Diagnostic System for the Mirror Fusion Test Facility (MFTF) has been designed as an event driven system. To this end we have designed a data base notification facility in which a task can request that it be loaded and started whenever an element in the data base is changed beyond some user defined range. Our initial implementation of the notify facility exhibited marginal response times whenever a data base table with a large number of outstanding notifies was written into. In this paper we discuss the sources of the slow response and describe in detail a new structure for the list of notifies which minimizes search time resulting in significantly faster response

  10. Giving is a question of time: Response times and contributions to a real world public good

    OpenAIRE

    Lohse, Johannes; Goeschl, Timo; Diederich , Johannes

    2014-01-01

    Recent experimental research has examined whether contributions to public goods can be traced back to intuitive or deliberative decision-making, using response times in public good games in order to identify the specific decision process at work. In light of conflicting results, this paper reports on an analysis of response time data from an online experiment in which over 3400 subjects from the general population decided whether to contribute to a real world public good. The between-subjects...

  11. Response Of TLD-600 to Continue And Discrete Fast Neutron Doses Irradiation

    International Nuclear Information System (INIS)

    Irradiation to three groups of TLD-600 with fast neutron dose from AmBe source have been carried out. Each group consist of 20 TLD cards. First and second group were irradiated continually by doses vary from 50, 100, 250, 500 and 750 mrem. For each dose value of each group was irradiated four TLD card. The third group was irradiated by total dose same to the first group, but the dose was delivered discreetly 13 times during three months. TL intensity of first group (A) were read directly after irradiation, and TL intensity of second group (B) and third group (C) were read after irradiation of third group finished. Irradiation of first and second group were same to the condition of irradiation during TLD calibration in Laboratory. The different between those two group are there is not fading of TL. intensity on first group and fading during three months on second group. Irradiation of third group was assumed same to the condition of irradiation when TLD was used for personal dose monitoring. From the calculation of comparison value of TL intensity for several condition of irradiation it was obtained the quotient value of B/A, C/A and C/B were: 0.93, 0.92 and 0.99 respectively. Such data shows the necessity of fading correction of eight percent during neutron dose evaluation using TLD-600

  12. Fast response double series resonant high-voltage DC-DC converter

    Science.gov (United States)

    Lee, S. S.; Iqbal, S.; Kamarol, M.

    2012-10-01

    In this paper, a novel double series resonant high-voltage dc-dc converter with dual-mode pulse frequency modulation (PFM) control scheme is proposed. The proposed topology consists of two series resonant tanks and hence two resonant currents flow in each switching period. Moreover, it consists of two high-voltage transformer with the leakage inductances are absorbed as resonant inductor in the series resonant tanks. The secondary output of both transformers are rectified and mixed before supplying to load. In the resonant mode operation, the series resonant tanks are energized alternately by controlling two Insulated Gate Bipolar Transistor (IGBT) switches with pulse frequency modulation (PFM). This topology operates in discontinuous conduction mode (DCM) with all IGBT switches operating in zero current switching (ZCS) condition and hence no switching loss occurs. To achieve fast rise in output voltage, a dual-mode PFM control during start-up of the converter is proposed. In this operation, the inverter is started at a high switching frequency and as the output voltage reaches 90% of the target value, the switching frequency is reduced to a value which corresponds to the target output voltage. This can effectively reduce the rise time of the output voltage and prevent overshoot. Experimental results collected from a 100-W laboratory prototype are presented to verify the effectiveness of the proposed system.

  13. FACTORS RESPONSIBLE FOR TURNOVER IN A FAST FOOD COMPANY OF SANTA MARIA – RS

    Directory of Open Access Journals (Sweden)

    Marian dos Santos Rosa

    2012-05-01

    Full Text Available In the current scene of the organizations, each time more, the collaborator comes conquering excellent space, where the good course of the functional activities depends on the motivation of each one of these members. Inside of this context, the present objective study to analyze the organizational climate, focusing in the motivation and the rotation of the collaborators of a great company of Fast Food of the city of Saint Maria- RS, known world-wide in this sort. Study of cases was carried through, using the Survey method, being the characterized research as exploratory, quantitative and descriptive, where 57 collaborators had answered to a questionnaire of 65 questions having aimed at to answer the problematic one of the study. The gotten results disclose that the collaborators correctly are trained and as consequence the quality is seen as a positive factor, however one has left of these collaborators if it showed not motivated, influenced for the half organizational not to be very healthful, had to the environment of extreme pressure that is part of the routine of this organization, beyond a sufficiently young team of collaborators, main factors of an index of turnover considerable, identified in this company.

  14. Fast response double series resonant high-voltage DC-DC converter

    International Nuclear Information System (INIS)

    In this paper, a novel double series resonant high-voltage dc-dc converter with dual-mode pulse frequency modulation (PFM) control scheme is proposed. The proposed topology consists of two series resonant tanks and hence two resonant currents flow in each switching period. Moreover, it consists of two high-voltage transformer with the leakage inductances are absorbed as resonant inductor in the series resonant tanks. The secondary output of both transformers are rectified and mixed before supplying to load. In the resonant mode operation, the series resonant tanks are energized alternately by controlling two Insulated Gate Bipolar Transistor (IGBT) switches with pulse frequency modulation (PFM). This topology operates in discontinuous conduction mode (DCM) with all IGBT switches operating in zero current switching (ZCS) condition and hence no switching loss occurs. To achieve fast rise in output voltage, a dual-mode PFM control during start-up of the converter is proposed. In this operation, the inverter is started at a high switching frequency and as the output voltage reaches 90% of the target value, the switching frequency is reduced to a value which corresponds to the target output voltage. This can effectively reduce the rise time of the output voltage and prevent overshoot. Experimental results collected from a 100-W laboratory prototype are presented to verify the effectiveness of the proposed system.

  15. Time resolved mass flow measurements for a fast gas delivery system

    International Nuclear Information System (INIS)

    A technique is demonstrated whereby the delivered mass and flow rate vs. time of a short rise time gas delivery system may be accurately determined. The gas mass M which flows past a point in a gas delivery system by an arbitrary time t may be accurately measured if that point is sealed off within a time interval short compared to the mass flow time scale. If the ejected mass is allowed to equilibrate in a known volume after being cut off from its source, a conventional static pressure measurement before and after injection, and application of the ideal gas law suffices. Assuming reproducibility, a time history M(t) may be generated, allowing the flow rate vs. time dM(t)/dt to be determined. Mass flow measurements are presented for a fast delivery system in which the flow of argon through a 3.2 mm I.D., 0.76 mm thick copper tube is cut off by imploding (? pinching) the tube using a single turn tungsten magnetic field coil. Pinch discharge parameters are 44 ?f, 20 kV, 47 nH, 3.5 m?, 584 kA, and 8.63 ps current period. Optical measurements of the tube's internal area vs. time indicate that the tube is sealed 2 ps from the time the tube is still 90% open (7 ?s from the start of pinch current). The pinch delay is varied from 500--1,500 ps from the valve trigger (0--1,000 ps from the start of gas flow). The mass injected into the test volume is ? 100 ?g during this interval. The leak rate of the sealed tube results in a mass increase of only ? 0.1 ?g by the time se of only ? 0.1 ?g by the time the pressure gauge stabilizes (6 s). Results are correlated with piezoelectric probe measurements of the gas flow and 2-D axisymmetric numerical simulations of the ? pinch process. Simulations of a ? pinch suitable for characterizing an annular supersonic nozzle typical of those used in gas puff z pinches are discussed

  16. Using random response input in Ibrahim Time Domain

    DEFF Research Database (Denmark)

    Olsen, Peter; Brincker, R.

    2013-01-01

    In this paper the time domain technique Ibrahim Time Domain (ITD) is used to analyze random time data. ITD is known to be a technique for identification of output only systems. The traditional formulation of ITD is claimed to be limited, when identifying closely spaced modes, because of the technique being Single Input Multiple Output (SIMO). It has earlier been showed that when modifying ITD with Toeplitz matrix averaging. Identification of time data with closely spaced modes is improved. In the traditional formulation of ITD the time data has to be free decays or impulse response functions. In this article it is showed that when using the modified ITD random time data can be analyzed. The application of the technique is displayed by a case study, with simulations and experimental data.

  17. Fast-Response, Sensitivitive and Low-Powered Chemosensors by Fusing Nanostructured Porous Thin Film and IDEs-Microheater Chip

    OpenAIRE

    Zhengfei Dai; Lei Xu; Guotao Duan; Tie Li; Hongwen Zhang; Yue Li; Yi Wang; Yuelin Wang; Weiping Cai

    2013-01-01

    The chemiresistive thin film gas sensors with fast response, high sensitivity, low power consumption and mass-produced potency, have been expected for practical application. It requires both sensitive materials, especially exquisite nanomaterials, and efficient substrate chip for heating and electrical addressing. However, it is challenging to achieve repeatable microstructures across the films and low power consumption of substrate chip. Here we presented a new sensor structure via the fusio...

  18. Development of a fast response detector using Yb:Lu2O3 scintillator for lifetime measurement positron emission tomography

    International Nuclear Information System (INIS)

    We propose a three-dimensional imaging measurement method of the defect distribution inside industrial materials by measuring the lifetime of positrons in addition to the imaging technique of positron emission tomography. A compact and fast response detector which uses an Yb3+-doped Lu2O3 scintillator and a photomultiplier tube was developed and tested. We have successfully measured the positron lifetimes of a bulk material using the Yb:Lu2O3 scintillator. (author)

  19. A real-time fast radio burst: polarization detection and multiwavelength follow-up

    CERN Document Server

    Petroff, E; Barr, E D; Barsdell, B R; Bhat, N D R; Bian, F; Burke-Spolaor, S; Caleb, M; Champion, D; Chandra, P; Da Costa, G; Delvaux, C; Flynn, C; Gehrels, N; Greiner, J; Jameson, A; Johnston, S; Kasliwal, M M; Keane, E F; Keller, S; Kocz, J; Kramer, M; Leloudas, G; Malesani, D; Mulchaey, J S; Ng, C; Ofek, E O; Perley, D A; Possenti, A; Schmidt, B P; Shen, Yue; Stappers, B; Tisserand, P; van Straten, W; Wolf, C

    2014-01-01

    Fast radio bursts (FRBs) are one of the most tantalizing mysteries of the radio sky; their progenitors and origins remain unknown and until now no rapid multiwavelength follow-up of an FRB has been possible. New instrumentation has decreased the time between observation and discovery from years to seconds, and enables polarimetry to be performed on FRBs for the first time. We have discovered an FRB (FRB 140514) in real-time on 14 May, 2014 at 17:14:11.06 UTC at the Parkes radio telescope and triggered follow-up at other wavelengths within hours of the event. FRB 140514 was found with a dispersion measure (DM) of 562.7(6) cm$^{-3}$ pc, giving an upper limit on source redshift of $z \\lesssim 0.5$. FRB 140514 was found to be 21$\\pm$7% (3-$\\sigma$) circularly polarized on the leading edge with a 1-$\\sigma$ upper limit on linear polarization $<10%$. We conclude that this polarization is intrinsic to the FRB. If there was any intrinsic linear polarization, as might be expected from coherent emission, then it may...

  20. Multi-purpose fast neutron spectrum analyzer with real-time signal processing

    International Nuclear Information System (INIS)

    Diagnostics of hot ion component of plasma on the products of fusion reactions is widely used on thermonuclear facilities. In case of employment of neutron spectrometers, based on organics scintillators, there is advanced technique developed to eliminate neutron pulses from gamma background—digital pulse shape discrimination. For every DPSD application it is necessary to use the fast (2–5 ns) and precise (12 bit) transient ADC unit with large amount of onboard memory for storing every digitized scintillation pulses during shot time. At present time the duration of hot thermonuclear plasma burning in large tokamaks approximate to 1 min, and this requires very high onboard memory capacity (?100 GB). This paper describes a neutron spectrum analyzer with real-time DPSD algorithm, implemented to ADC unit. This approach saves about two orders of onboard memory capacity, gives the possibility of instant use of outcome to feedback systems. This analyzer was tested and calibrated with help of 60Co and 252Cf radiation sources, and deuterium neutron generator

  1. Fast magnetic response in gigahertz-band for columnar-structured Fe nanoparticle assembly

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, T., E-mail: tomoyuki@ecei.tohoku.ac.jp; Tate, R. [Department of Electronic Engineering, Graduate School of Engineering, Tohoku University, 6-6-05 Aza-Aoba, Aramaki, Aoba-ku, Sendai 980-8579 (Japan); Kura, H. [New Industry Creation Hatchery Center (NICHe), Tohoku University, 6-6-10 Aza-Aoba, Aramaki, Aoba-ku, Sendai 980-8579 (Japan); Oikawa, T.; Hata, K. [Samsung R and D Institute Japan Co., Ltd., 2-7 Sugasawa-cho, Tsurumi-ku, Yokohama 230-0027 (Japan)

    2014-05-07

    High density Fe-based ferromagnetic nanoparticle (NP) assembly is expected to have unique magnetic properties, such as superferromagnetism and super-spin-glass, different from magnetically isolated NP systems due to strong dipole interactions among the NPs. A high dipole interaction field, H{sub dip}, of ?3.5 kOe can result in a high effective internal field to the magnetic moment of the NP, expecting for ultra-fast magnetic response, that is, a high magnetic resonance frequency, f{sub r}, of ?10 GHz. However, for a simply molded Fe NP assembly, a low f{sub r} was observed due to inhomogeneous distribution of the internal field, implying the necessity of a unidirectional state of H{sub dip} for higher f{sub r}. In this study, we fabricated a columnar Fe NP assembly for realizing the unidirectional state of H{sub dip} by applying our uniquely developed external field-induced agglomeration method for monodispersed Fe NPs (13 nm in average size) as a function of the field (0–30 kOe) and volume fraction of the Fe NPs (0.5%–51%) in a polymer matrix with dimensions of 4 mm × 4 mm × 0.7 mm{sup t}. A columnar-structured Fe NP assembly was successfully achieved along an in-plane direction (defined as the x-axis) under optimized conditions. From static magnetization curves, induced uniaxial magnetic anisotropy was observed according to the shape of the columnar structure of the Fe NP assembly, where easy and hard axes of magnetization were realized along the parallel (x-axis) and normal directions (in-plane y-axis and z-axis in the thickness direction) to the external field during the process, respectively. Interestingly, this fabricated columnar-structured Fe NP assembly exhibited very high f{sub r} in the range from 3 to 11 GHz judging from the complex susceptibility spectra obtained. The f{sub r} values were well-scaled by a modified Snoek's-limit-law using demagnetization factors quantitatively estimated from the static magnetization curves. Thus, shape-induced anisotropy originating from the unidirectional state of H{sub dip} in the columnar structure of the Fe NP assembly plays an important role for high frequency magnetic response in the GHz-band.

  2. Fast magnetic response in gigahertz-band for columnar-structured Fe nanoparticle assembly

    International Nuclear Information System (INIS)

    High density Fe-based ferromagnetic nanoparticle (NP) assembly is expected to have unique magnetic properties, such as superferromagnetism and super-spin-glass, different from magnetically isolated NP systems due to strong dipole interactions among the NPs. A high dipole interaction field, Hdip, of ?3.5 kOe can result in a high effective internal field to the magnetic moment of the NP, expecting for ultra-fast magnetic response, that is, a high magnetic resonance frequency, fr, of ?10 GHz. However, for a simply molded Fe NP assembly, a low fr was observed due to inhomogeneous distribution of the internal field, implying the necessity of a unidirectional state of Hdip for higher fr. In this study, we fabricated a columnar Fe NP assembly for realizing the unidirectional state of Hdip by applying our uniquely developed external field-induced agglomeration method for monodispersed Fe NPs (13 nm in average size) as a function of the field (0–30 kOe) and volume fraction of the Fe NPs (0.5%–51%) in a polymer matrix with dimensions of 4 mm × 4 mm × 0.7 mmt. A columnar-structured Fe NP assembly was successfully achieved along an in-plane direction (defined as the x-axis) under optimized conditions. From static magnetization curves, induced uniaxial magnetic anisotropy was observed according to the shape of the columnar structure of the Fe NP assembly, where easy and hard axes of magnetization were realized along the parallel (x-axis) and normal directions (in-plane y-axis and z-axis in the thickness direction) to the external field during the process, respectively. Interestingly, this fabricated columnar-structured Fe NP assembly exhibited very high fr in the range from 3 to 11 GHz judging from the complex susceptibility spectra obtained. The fr values were well-scaled by a modified Snoek's-limit-law using demagnetization factors quantitatively estimated from the static magnetization curves. Thus, shape-induced anisotropy originating from the unidirectional state of Hdip in the columnar structure of the Fe NP assembly plays an important role for high frequency magnetic response in the GHz-band

  3. Improvement of Varioptic's liquid lens based on electrowetting: how to obtain a short response time and its application in the design of a high resolution iris biometric system

    Science.gov (United States)

    Burger, Benjamin; Meimon, Serge C.; Petit, Cyril; Nguyen, Minh Chau

    2015-02-01

    This communication presents the results obtained for decreasing the response time of electrowetting-based real time focus correctors (liquid lenses). In order to provide a compact iris biometric system demonstrator, we have achieved a response time at 90% of 7.5 ms for a change in focalization from 0 diopter to 10 diopter with a liquid lens having an aperture of 1.9 mm. We have used a hydrodynamic fluid reorganization model to predict the features of these fast liquid lenses and evaluated the sensivity of the response time to the different conception parameters.

  4. Timing and causality in the generation of learned eyelid responses

    Directory of Open Access Journals (Sweden)

    RaudelSánchez-Campusano

    2011-08-01

    Full Text Available The cerebellum-red nucleus-facial motoneuron (Mn pathway has been reported as being involved in the proper timing of classically conditioned eyelid responses. This special type of associative learning serves as a model of event timing for studying the role of the cerebellum in dynamic motor control. Here, we have re-analyzed the firing activities of cerebellar posterior interpositus (IP neurons and orbicularis oculi (OO Mns in alert behaving cats during classical eyeblink conditioning, using a delay paradigm. The aim was to revisit the hypothesis that the IP neurons can be considered a neuronal phase-modulating device supporting OO Mns firing with an emergent timing mechanism and an explicit correlation code during learned eyelid movements. Optimized experimental and computational tools allowed us to determine the different causal relationships (temporal order and correlation code during and between trials. These intra- and inter-trial timing strategies expanding from sub-second range (millisecond timing to longer-lasting ranges (interval timing expanded the functional domain of cerebellar timing beyond motor control. Interestingly, the results supported the above-mentioned hypothesis. The causal inferences were influenced by the precise motor and premotor spike-timing in the cause-effect interval, and, in addition, the timing of the learned responses depended on cerebellar-Mn network causality. Furthermore, the timing of CRs depended upon the probability of simulated causal conditions in the cause-effect interval and not the mere duration of the inter-stimulus interval. In this work, the close relation between timing and causality was verified. It could thus be concluded that the firing activities of IP neurons may be related more to the proper performance of ongoing CRs (i.e., the proper timing as a consequence of the pertinent causality than to their generation and/or initiation.

  5. Development of a very fast spectral response measurement system for analysis of hydrogenated amorphous silicon solar cells and modules

    International Nuclear Information System (INIS)

    Highlights: ? Spectral response equipment for measuring a-Si:H solar cells in a few seconds. ? Equipment based on 16 LEDs with simultaneous illumination of the solar cell. ? The current generated by each LED is analyzed by a Fast Fourier Transform. ? Cheap equipment without lock-in technology for the current measurement. ? Measurement error vs. conventional measurement less than 1% in Jsc. - Abstract: An important requirement for a very fast spectral response measurement system is the simultaneous illumination of the solar cell at multiple well defined wavelengths. Nowadays this can be done by means of light emitting diodes (LEDs) available for a multitude of wavelengths. For the purpose to measure the spectral response (SR) of amorphous silicon solar cells a detailed characterization of LEDs emitting in the wavelength range from 300 nm to 800 nm was performed. In the here developed equipment the LED illumination is modulated in the frequency range from 100 Hz to 200 Hz and the current generated by each LED is analyzed by a Fast Fourier Transform (FFT) to determine the current component corresponding to each wavelength. The equipment provides a signal to noise ratio of 2–4 orders of magnitude for individual wavelengths resulting in a precise measurement of the SR over the whole wavelength range. The difference of the short circuit current determined from the SR is less than 1% in comparison to a conventional system with monochromator.with monochromator.

  6. A Novel of Hybrid Magnet Engine Valve Actuator Using Shorted Turn for Fast Initial Response

    Directory of Open Access Journals (Sweden)

    DucThuan Vu

    2013-01-01

    Full Text Available A variable valve timing (VVT can improve fuel efficiency, reduce CO2 emission and increase torque output. To achieve VVT in internal combustion engine, new devices such as mechanical, hydraulic, motor-driven and electromagnetic actuator have been developed in past years to replace the conventional camshaft valve train system used currently. Among these, the electromagnetic actuator using solenoids is the most advance system to provide the most flexibility to valve timing, but it has critical drawback of high power consumption. This paper presents a novel design of Hybrid Magnet Engine Valve Actuator (HMEVA using shorted turn. A shorted turn is placed into existing design in order to reduce the inductance of coil and improve the initial response. Dynamic finite element analysis using commercial electromagnetic solver “MAXWEL” is performed to simulate the improvement of dynamic characteristic of model.

  7. Predicting aquifer response time for application in catchment modeling.

    Science.gov (United States)

    Walker, Glen R; Gilfedder, Mat; Dawes, Warrick R; Rassam, David W

    2015-05-01

    It is well established that changes in catchment land use can lead to significant impacts on water resources. Where land-use changes increase evapotranspiration there is a resultant decrease in groundwater recharge, which in turn decreases groundwater discharge to streams. The response time of changes in groundwater discharge to a change in recharge is a key aspect of predicting impacts of land-use change on catchment water yield. Predicting these impacts across the large catchments relevant to water resource planning can require the estimation of groundwater response times from hundreds of aquifers. At this scale, detailed site-specific measured data are often absent, and available spatial data are limited. While numerical models can be applied, there is little advantage if there are no detailed data to parameterize them. Simple analytical methods are useful in this situation, as they allow the variability in groundwater response to be incorporated into catchment hydrological models, with minimal modeling overhead. This paper describes an analytical model which has been developed to capture some of the features of real, sloping aquifer systems. The derived groundwater response timescale can be used to parameterize a groundwater discharge function, allowing groundwater response to be predicted in relation to different broad catchment characteristics at a level of complexity which matches the available data. The results from the analytical model are compared to published field data and numerical model results, and provide an approach with broad application to inform water resource planning in other large, data-scarce catchments. PMID:24842053

  8. A Fast-Time Study of Aircraft Reordering in Arrival Sequencing and Scheduling

    Science.gov (United States)

    Carr, Greg; Neuman, Frank; Tobias, Leonard (Technical Monitor)

    1998-01-01

    In order to ensure that the safe capacity of the terminal area is not exceeded, Air Traffic Management ATM often places restrictions on arriving flights transitioning from en route airspace to terminal airspace. This restriction of arrival traffic is commonly referred to as arrival flow management, and includes techniques such as metering, vectoring, fix-load balancing, and the imposition of miles-in-trail separations. These restrictions are enacted without regard for the relative priority which airlines may be placing on individual flights based on factors such as crew criticality, passenger connectivity, critical turn times, gate availability, on-time performance, fuel status, or runway preference. The development of new arrival flow management techniques which take into consideration priorities expressed by air carriers will likely reduce the economic impact of ATM restrictions on the airlines and lead to increased airline economic efficiency by allowing airlines to have greater control over their individual arrival banks of aircraft. NASA and the Federal Aviation Administration (FAA) have designed and developed a suite of software decision support tools (DSTs) collectively known as the Center TRACON Automation System (CTAS). One of these tools, the Traffic Management Advisor (TMA) is currently being used at the Fort Worth Air Route Traffic Control Center to perform arrival flow management of traffic into the Dallas/Fort Worth airport (DFW). The TMA is a time-based strategic planning tool that assists Traffic Management Coordinators (TMCs) and En Route Air Traffic Controllers in efficiently balancing arrival demand with airport capacity. The primary algorithm in the TMA is a real-time scheduler which generates efficient landing sequences and landing times for arrivals within about 200 no a. from touchdown. This scheduler will sequence aircraft so that they arrive in a first- come - first-served (FCFS) order. While FCFS sequencing establishes a fair order based on estimated times of arrival, it does not take into account individual airline priorities among incoming flights. NASA is exploring the possibility of allowing airlines to express relative arrival priorities to air traffic management through the development of new CTAS scheduling algorithms which take into consideration airline arrival preferences. The accommodation of airline priorities in arrival sequencing and scheduling would under most circumstances result in a deviation from a "natural" or FCFS arrival order. As a First step toward developing airline influenced sequencing algorithms, an investigation was conducted to determine the feasibility of reordering arrival traffic from a strict FCFS sequence. A fast-time simulation has been developed which allows statistical evaluation of sequencing and scheduling algorithms for arrival traffic at the Dallas/Fort Worth Airport. In contrast to real-time simulation or field tests, which would require on the order of ninety minutes to examine a single traffic rush period, the fast-time simulation allows examination of multiple rush periods in a matter of seconds.

  9. Time evolution of fast ion distributions in MHD-active tokamak plasmas based on HAGIS/Fokker-Planck code coupling

    International Nuclear Information System (INIS)

    A coupling of two numerical codes has been developed and implemented, which enables the simulation of long-time behaviour of fast ion distributions in MHD-active tokamak plasmas. In the coupled system the codes FIDIT (Fast Ion Distributions In Tokamaks) and HAGIS (Hamiltonian Guiding Centre System) are used iteratively. FIDIT is a Fokker-Planck code capable of calculating the evolution of a population of energetic ions accounting for Coulomb collisions and ripple induced transport effects. The code HAGIS simulates the time evolution of an ensemble of waves driven by fast ions and the redistribution of the fast ion population caused by these waves. Since the characteristic times of collisional and wave-induced changes of the fast ion distribution are well separated, the iterative approach is justified. The switch between the codes is based on a criterion determining the (in-)stability of toroidicity induced Alfénic eigenmodes (TAEs). FIDIT/HAGIS has been successfully applied for modelling experiments conducted at the Joint European Torus (JET) and for predictive simulations of fusion alpha particles in the International Thermonuclear Experimental Reactor (ITER). In the ITER simulations a synergetic transport effect has been identified, which emerges from the co-action of collisional convective/diffusive transport and wave-induced transport. (author)

  10. Slow-rise and fast-drop current feature of ultraviolet response spectra for ZnO-nanowire film modulated by water molecules

    International Nuclear Information System (INIS)

    This study describes the fabrication of ZnO-nanowire films by electro-chemical anodization of Zn foil. The ZnO films are characterized by field emission scanning electron microscopy, X-ray diffraction patterns, and transmission electron microscopy, respectively. The ultraviolet (UV) photo-response properties of the surface-contacted ZnO film are studied through the current evolution processes under different relative humidities. Unlike the usually observed current spectra of the ZnO films, the drop time is shorter than the rise time. The photo-conductivity gain G and the response time ? are both increased with the increase of the applied bias. The photo-conductivity gain G is lowered with the increase of the environmental humidity, while the response time ? is increased. These results can be explained by considering three different surface processes: 1) the electron-hole (e—p) pair generation by the UV light illumination, 2) the following surface O?2 species desorption, and 3) the photo-catalytic hydrolysis of water molecules adsorbed on the ZnO surface. The slow-rise and fast-drop current feature is suggested to originate from the sponge-like structure of the ZnO nanowires. (interdisciplinary physics and related areas of science and technology)

  11. Fault tolerant distributed real time computer systems for I and C of prototype fast breeder reactor

    International Nuclear Information System (INIS)

    Highlights: • Architecture of distributed real time computer system (DRTCS) used in I and C of PFBR is explained. • Fault tolerant (hot standby) architecture, fault detection and switch over are detailed. • Scaled down model was used to study functional and performance requirements of DRTCS. • Quality of service parameters for scaled down model was critically studied. - Abstract: Prototype fast breeder reactor (PFBR) is in the advanced stage of construction at Kalpakkam, India. Three-tier architecture is adopted for instrumentation and control (I and C) of PFBR wherein bottom tier consists of real time computer (RTC) systems, middle tier consists of process computers and top tier constitutes of display stations. These RTC systems are geographically distributed and networked together with process computers and display stations. Hot standby architecture comprising of dual redundant RTC systems with switch over logic system is deployed in order to achieve fault tolerance. Fault tolerant dual redundant network connectivity is provided in each RTC system and TCP/IP protocol is selected for network communication. In order to assess the performance of distributed RTC systems, scaled down model was developed with 9 representative systems and nearly 15% of I and C signals of PFBR were connected and monitored. Functional and performance testing were carried out for each RTC system and the fault tolerant characteristics were studied by creating various faults into the system and observed the performance. Various quality of service parameters like connection establishment delay, priority parameter, transit delay, throughput, residual error ratio, etc., are critically studied for the network

  12. Fault tolerant distributed real time computer systems for I and C of prototype fast breeder reactor

    Energy Technology Data Exchange (ETDEWEB)

    Manimaran, M., E-mail: maran@igcar.gov.in; Shanmugam, A.; Parimalam, P.; Murali, N.; Satya Murty, S.A.V.

    2014-03-15

    Highlights: • Architecture of distributed real time computer system (DRTCS) used in I and C of PFBR is explained. • Fault tolerant (hot standby) architecture, fault detection and switch over are detailed. • Scaled down model was used to study functional and performance requirements of DRTCS. • Quality of service parameters for scaled down model was critically studied. - Abstract: Prototype fast breeder reactor (PFBR) is in the advanced stage of construction at Kalpakkam, India. Three-tier architecture is adopted for instrumentation and control (I and C) of PFBR wherein bottom tier consists of real time computer (RTC) systems, middle tier consists of process computers and top tier constitutes of display stations. These RTC systems are geographically distributed and networked together with process computers and display stations. Hot standby architecture comprising of dual redundant RTC systems with switch over logic system is deployed in order to achieve fault tolerance. Fault tolerant dual redundant network connectivity is provided in each RTC system and TCP/IP protocol is selected for network communication. In order to assess the performance of distributed RTC systems, scaled down model was developed with 9 representative systems and nearly 15% of I and C signals of PFBR were connected and monitored. Functional and performance testing were carried out for each RTC system and the fault tolerant characteristics were studied by creating various faults into the system and observed the performance. Various quality of service parameters like connection establishment delay, priority parameter, transit delay, throughput, residual error ratio, etc., are critically studied for the network.

  13. High time resolution electron measurement by Fast Electron energy Spectrum Analyzer (FESA)

    International Nuclear Information System (INIS)

    We have newly developed an electron energy analyzer FESA (Fast Electron energy Spectrum Analyzer) for a future magnetospheric satellite mission SCOPE. The SCOPE mission is designed in order that observational studies from the cross-scale coupling viewpoint are enabled. One of the key observations necessary for the SCOPE mission is high-time resolution electron measurement. Eight FESAs on a spinning spacecraft are capable of measuring three dimensional electron distribution function with time resolution of 8 msec. FESA consists of two electrostatic analyzers that are composed of three nested hemispherical deflectors. Single FESA functions as four top-hat type electrostatic analyzers that can measure electrons with four different energies simultaneously. By measuring the characteristics of the test model FESA, we proved the validity of the design concept of FESA. Based on the measured characteristics, we designed FESA optimized for the SCOPE mission. This optimized analyzer has good enough performance to measure three dimensional electron distribution functions around the magnetic reconnection region in the Earth's magnetotail.

  14. Fast magnetosonic wave excitation by an array of wires with time-modulated currents

    Directory of Open Access Journals (Sweden)

    G. Sanchez-Arriaga

    2010-02-01

    Full Text Available The excitation of Fast Magnetosonic (FMS waves by a cylindrical array of parallel tethers carrying time-modulated current is discussed. The tethers would fly vertical in the equatorial plane, which is perpendicular to the geomagnetic field when its tilt is ignored, and would be stabilized by the gravity gradient. The tether array would radiate a single FMS wave. In the time-dependent background made of geomagnetic field plus radiated wave, plasma FMS perturbations are excited in the array vicinity through a parametric instability. The growth rate is estimated by truncating the evolution equation for FMS perturbations to the two azimuthal modes of lowest order. Design parameters such as tether length and number, required power and mass are discussed for Low Earth Orbit conditions. The array-attached wave structure would have the radiated wave controlled by the intensity and modulation frequency of the currents, making an active experiment on non-linear low frequency waves possible in real space plasma conditions.

  15. Computationally Efficient Partial Crosstalk Cancellation in Fast Time-Varying DSL Crosstalk Environments

    Directory of Open Access Journals (Sweden)

    Lee M. Garth

    2007-01-01

    Full Text Available Line selection (LS, tone selection (TS, and joint tone-line selection (JTLS partial crosstalk cancellers have been proposed to reduce the online computational complexity of far-end crosstalk (FEXT cancellers in digital subscriber lines (DSL. However, when the crosstalk profile changes rapidly over time, there is an additional requirement that the partial crosstalk cancellers, particularly the LS and JTLS schemes, should also provide a low preprocessing complexity. This is in contrast to the case for perfect crosstalk cancellers. In this paper, we propose two novel channel matrix inversion methods, the approximate inverse (AI and reduced inverse (RI schemes, which reduce the recurrent complexity of the LS and JTLS schemes. Moreover, we propose two new classes of JTLS algorithms, the subsort and Lagrange JTLS algorithms, with significantly lower computational complexity than the recently proposed optimal greedy JTLS scheme. The computational complexity analysis of our algorithms shows that they provide much lower recurrent complexities than the greedy JTLS algorithm, allowing them to work efficiently in very fast time-varying crosstalk environments. Moreover, the analytical and simulation results demonstrate that our techniques are close to the optimal solution from the crosstalk cancellation point of view. The results also reveal that partial crosstalk cancellation is more beneficial in upstream DSL, particularly for short loops.

  16. Time-delayed upper atmospheric responses to solar EUV irradiation

    Science.gov (United States)

    Zhang, Shunrong; Erickson, Philip; Goncharenko, Larisa

    2015-04-01

    It is well recognized that solar EUV irradiations at various wavelengths are the dominant driver of the quiet-time upper atmospheric variations, including thermospheric temperature and densities, as well as ionospheric density and temperatures. However, responses of the upper atmosphere have been found not as straightforward as expected, but rather complicated with time-delays for approximately 2 days relative to solar flux proxy F10.7. Using measurements of TIMED/SEE solar UV flux at various wavelengths and incoherent scatter radar-based ionospheric and thermospheric parameters, this paper addresses characteristic upper atmospheric variability on the time scales from hours to days, and the associated solar UV variations. It is found that exospheric temperature Tex is most sensitive to solar EUV flux with an approximately 2-day delay at wavelengths of 27--34 nm (including 30.4 nm). In fact, a 20--60-hour time delay occurs in Tex response to EUV flux at the 27-34 nm band, with shorter delays in the morning and longer delays in the afternoon and at night. Ionospheric electron delays are altitude dependent: in the E-region, there is no time delay, and in the F2 region, there exist delays for 2-3 days in both electron density and ion temperature. These delays are perhaps representatives of the upper atmospheric memory and will be discussed in the paper.

  17. High-Voltage Power Supply With Fast Rise and Fall Times

    Science.gov (United States)

    Bearden, Douglas B.; Acker, Richard M.; Kapuslka, Robert E.

    2007-01-01

    A special-purpose high-voltage power supply can be electronically switched on and off with fast rise and fall times, respectively. The output potential is programmable from 20 to 1,250 V. An output current of 50 A can be sustained at 1,250 V. The power supply was designed specifically for electronically shuttering a microchannel plate in an x-ray detector that must operate with exposure times as short as 1 ms. The basic design of the power supply is also adaptable to other applications in which there are requirements for rapid slewing of high voltages. The power-supply circuitry (see figure) includes a preregulator, which is used to program the output at 1/30 of the desired output potential. After the desired voltage has been set, the outputs of a pulse width modulator (PWM) are enabled and used to amplify the preregulator output potential by 30. The amplification is achieved by use of two voltage doublers with a transformer that has two primary and two secondary windings. A resistor is used to limit the current by controlling the drive voltage of two field-effect transistors (FETs) during turn-on of the PWM. A pulse transformer is used to turn on four FETs to short-circuit four output capacitors when the outputs of the PWM have been disabled. The most notable aspects of the performance of the power supply are a rise time of only 80 s and a fall time of only 60 s at a load current of 50 A or less. Another notable aspect is that the application of a 0-to-5-V square wave to a shutdown pin of the PWM causes the production of a 0-to-1,250-V square wave at the output terminals.

  18. Consumer responses to time varying prices for electricity

    International Nuclear Information System (INIS)

    We report new experimental evidence of the household response to weekday differentials in peak and off-peak electricity prices. The data come from Auckland, New Zealand, where peak residential electricity consumption occurs in winter for heating. Peak/off-peak price differentials ranged over four randomly selected groups from 1.0 to 3.5. On average, there was no response except in winter. In winter, participant households reduced electricity consumption by at least 10%, took advantage of lower off-peak prices but did not respond to the peak price differentials. Response varied with house and household size, time spent away from home, and whether water was heated with electricity. - Highlights: ? Seasonal effects in winter. ? High conservation effect from information. ? Higher peak prices no effect on peak use. ? Low off-peak prices encourage less conservation off-peak.

  19. Response calculation of containment structures of a simplified fast reactor model in real scale during an HCDA by Astarte-4B code

    International Nuclear Information System (INIS)

    This report presents the results, obtained by ASTARTE-4B code, of the reference calculation for a Benchmark concerning the internal structure and containment response following an HCDA for a simplified model of type fast reactor. This Benchmark was proposed by the working group CONT of CCE for the fast reactors

  20. Diurnal Alterations of Refraction, Anterior Segment Biometrics, and Intraocular Pressure in Long-Time Dehydration due to Religious Fasting.

    Science.gov (United States)

    Baser, Gonen; Cengiz, Hakan; Uyar, Murat; Seker Un, Emine

    2014-11-19

    Abstract Purpose: To investigate the effects of dehydration due to fasting on diurnal changes of intraocular pressure, anterior segment biometrics, and refraction. Subjects and methods: The intraocular pressures, anterior segment biometrics (axial length: AL; Central corneal thickness: CCT; Lens thickness: LT; Anterior chamber depth: ACD), and refractive measurements of 30 eyes of 15 fasting healthy male volunteers were recorded at 8:00 in the morning and 17:00 in the evening in the Ramadan of 2013 and two months later. The results were compared and the statistical analyses were performed using the Rstudio software version 0.98.501. The variables were investigated using visual (histograms, probability plots) and analytical methods (Kolmogorov-Smirnov/Shapiro-Wilk test) to determine whether or not they were normally distributed. Results: The refractive values remained stable in the fasting as well as in the control period (p?=?0.384). The axial length measured slightly shorter in the fasting period (p?=?0.001). The corneal thickness presented a diurnal variation, in which the cornea measured thinner in the evening. The difference between the fasting and control period was not statistically significant (p?=?0.359). The major differences were observed in the anterior chamber depth and IOP. The ACD was shallower in the evening during the fasting period, where it was deeper in the control period. The diurnal IOP difference was greater in the fasting period than the control period. Both were statistically significant (p?=?0.001). The LT remained unchanged in both periods. Conclusions: The major difference was shown in the anterior chamber shallowing in the evening hours and IOP. Our study contributes the hypothesis that the posterior segment of the eye is more responsible for the axial length alterations and normovolemia has a more dominant influence on diurnal IOP changes. PMID:25409203

  1. Spectrum response and analysis of 77 GHz band collective Thomson scattering diagnostic for bulk and fast ions in LHD plasmas

    International Nuclear Information System (INIS)

    A collective Thomson scattering (CTS) diagnostic was developed and used to measure the bulk and fast ions originating from 180 keV neutral beams in the Large Helical Device (LHD). Electromagnetic waves from a gyrotron at 77 GHz with 1 MW power output function as both the probe and electron cyclotron heating beam. To clarify the diagnostic applicability of the gyrotron in the 77 GHz frequency band, we investigated the dependence of the probe and receiver beam trajectories in plasmas with high electron densities of (4–5) × 1019 m?3 and low electron densities of (1–2) × 1019 m?3. At high density, a stray radiation component was observed in the CTS spectrum whereas it was negligibly small at low density. The CTS spectrum was measured and analysed after the in situ beam alignment using a beam scan. Qualitatively, the CTS spectrogram shows consistent response to ion temperatures of 1–2 keV for electron densities of (1–2) × 1019 m?3 and electron temperatures of 2–4 keV. The measured CTS spectrum shows an asymmetric shape at the foot of the bulk-ion region during the injection of 180 keV fast ions. This shape is explained by the fast-ion distribution in the velocity space (v?, v?) based on Monte Carlo simulation results. The analysis method of the CTS spectra is used to evaluate the ion temperature and fast-ion velocity distribution from the measured

  2. Planck 2013 results. VII. HFI time response and beams

    Science.gov (United States)

    Planck Collaboration; Ade, P. A. R.; Aghanim, N.; Armitage-Caplan, C.; Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bobin, J.; Bock, J. J.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Bowyer, J. W.; Bridges, M.; Bucher, M.; Burigana, C.; Cardoso, J.-F.; Catalano, A.; Challinor, A.; Chamballu, A.; Chary, R.-R.; Chiang, H. C.; Chiang, L.-Y.; Christensen, P. R.; Church, S.; Clements, D. L.; Colombi, S.; Colombo, L. P. L.; Couchot, F.; Coulais, A.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Delouis, J.-M.; Désert, F.-X.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Dunkley, J.; Dupac, X.; Efstathiou, G.; Enßlin, T. A.; Eriksen, H. K.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Galeotta, S.; Ganga, K.; Giard, M.; Giraud-Héraud, Y.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J. E.; Haissinski, J.; Hansen, F. K.; Hanson, D.; Harrison, D.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hornstrup, A.; Hou, Z.; Hovest, W.; Huffenberger, K. M.; Jaffe, A. H.; Jaffe, T. R.; Jones, W. C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knoche, J.; Knox, L.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lamarre, J.-M.; Lasenby, A.; Laureijs, R. J.; Lawrence, C. R.; Leonardi, R.; Leroy, C.; Lesgourgues, J.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; MacTavish, C. J.; Maffei, B.; Mandolesi, N.; Maris, M.; Marshall, D. J.; Martin, P. G.; Martínez-González, E.; Masi, S.; Massardi, M.; Matarrese, S.; Matsumura, T.; Matthai, F.; Mazzotta, P.; McGehee, P.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C. B.; Nørgaard-Nielsen, H. U.; Noviello, F.; Novikov, D.; Novikov, I.; Osborne, S.; Oxborrow, C. A.; Paci, F.; Pagano, L.; Pajot, F.; Paoletti, D.; Pasian, F.; Patanchon, G.; Perdereau, O.; Perotto, L.; Perrotta, F.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polegre, A. M.; Polenta, G.; Ponthieu, N.; Popa, L.; Poutanen, T.; Pratt, G. W.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Reinecke, M.; Remazeilles, M.; Renault, C.; Ricciardi, S.; Riller, T.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Roudier, G.; Rowan-Robinson, M.; Rusholme, B.; Sandri, M.; Santos, D.; Sauvé, A.; Savini, G.; Scott, D.; Shellard, E. P. S.; Spencer, L. D.; Starck, J.-L.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sureau, F.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Tavagnacco, D.; Terenzi, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Umana, G.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Vittorio, N.; Wade, L. A.; Wandelt, B. D.; Yvon, D.; Zacchei, A.; Zonca, A.

    2014-11-01

    This paper characterizes the effective beams, the effective beam window functions and the associated errors for the Planck High Frequency Instrument (HFI) detectors. The effective beam is theangular response including the effect of the optics, detectors, data processing and the scan strategy. The window function is the representation of this beam in the harmonic domain which is required to recover an unbiased measurement of the cosmic microwave background angular power spectrum. The HFI is a scanning instrument and its effective beams are the convolution of: a) the optical response of the telescope and feeds; b) the processing of the time-ordered data and deconvolution of the bolometric and electronic transfer function; and c) the merging of several surveys to produce maps. The time response transfer functions are measured using observations of Jupiter and Saturn and by minimizing survey difference residuals. The scanning beam is the post-deconvolution angular response of the instrument, and is characterized with observations of Mars. The main beam solid angles are determined to better than 0.5% at each HFI frequency band. Observations of Jupiter and Saturn limit near sidelobes (within 5°) to about 0.1% of the total solid angle. Time response residuals remain as long tails in the scanning beams, but contribute less than 0.1% of the total solid angle. The bias and uncertainty in the beam products are estimated using ensembles of simulated planet observations that include the impact of instrumental noise and known systematic effects. The correlation structure of these ensembles is well-described by five error eigenmodes that are sub-dominant to sample variance and instrumental noise in the harmonic domain. A suite of consistency tests provide confidence that the error model represents a sufficient description of the data. The total error in the effective beam window functions is below 1% at 100 GHz up to multipole ? ~ 1500, and below 0.5% at 143 and 217 GHz up to ? ~ 2000.

  3. Real-Time Quantitative PCR and Fast QPCR Have Similar Sensitivity and Accuracy with HIV cDNA Late Reverse Transcripts and 2-LTR Circles

    OpenAIRE

    Yoder, Kristine E.; Fishel, Richard

    2008-01-01

    Real time fluorescent quantitative PCR (universal QPCR) methods are used routinely in both academic and clinical research to measure HIV cDNA. Fast QPCR allows for faster ramping times between cycles and smaller reaction volumes, but may lose sensitivity and accuracy. We demonstrate that primer sets for HIV late reverse transcripts and 2-LTR circles have similar sensitivity and accuracy with either universal or fast QPCR methods. However, both cost and time are reduced with fast QPCR.

  4. Object Oriented Query Response Time for UML Models

    Directory of Open Access Journals (Sweden)

    Santosh Kumar

    2012-07-01

    Full Text Available Nowadays, the size of database of any business organization is increasing and many of the companies are shifted the old structured database into the object oriented database. Due to increase of size of database complexity of database is increasing therefore, it is necessary to optimize the object oriented query response time from the complex object oriented database. In the present paper, a real case study of Life Insurance Corporation of India is taken and sample object oriented database is designed by the use of SQL Server 2008. A UML model is designed for computing the object oriented query response time. Table and graph are also represented for the computed records in five runs.

  5. Faraday cup with nanosecond response and adjustable impedance for fast electron beam characterization

    International Nuclear Information System (INIS)

    A movable Faraday cup design with simple structure and adjustable impedance is described in this work. This Faraday cup has external adjustable shunt resistance for self-biased measurement setup and 50 ? characteristic impedance to match with 50 ? standard BNC coaxial cable and vacuum feedthroughs for nanosecond-level pulse signal measurements. Adjustable shunt resistance allows self-biased measurements to be quickly acquired to determine the electron energy distribution function. The performance of the Faraday cup is validated by tests of response time and amplitude of output signal. When compared with a reference source, the percent difference of the Faraday cup signal fall time is less than 10% for fall times greater than 10 ns. The percent difference of the Faraday cup signal pulse width is below 6.7% for pulse widths greater than 10 ns. A pseudospark-generated electron beam is used to compare the amplitude of the Faraday cup signal with a calibrated F-70 commercial current transformer. The error of the Faraday cup output amplitude is below 10% for the 4-14 kV tested pseudospark voltages. The main benefit of this Faraday cup is demonstrated by adjusting the external shunt resistance and performing the self-biased method for obtaining the electron energy distribution function. Results from a 4 kV pseudospark discharge indicate a ''double-humped'' energy distribution.

  6. Faraday cup with nanosecond response and adjustable impedance for fast electron beam characterization.

    Science.gov (United States)

    Hu, Jing; Rovey, Joshua L

    2011-07-01

    A movable Faraday cup design with simple structure and adjustable impedance is described in this work. This Faraday cup has external adjustable shunt resistance for self-biased measurement setup and 50 ? characteristic impedance to match with 50 ? standard BNC coaxial cable and vacuum feedthroughs for nanosecond-level pulse signal measurements. Adjustable shunt resistance allows self-biased measurements to be quickly acquired to determine the electron energy distribution function. The performance of the Faraday cup is validated by tests of response time and amplitude of output signal. When compared with a reference source, the percent difference of the Faraday cup signal fall time is less than 10% for fall times greater than 10 ns. The percent difference of the Faraday cup signal pulse width is below 6.7% for pulse widths greater than 10 ns. A pseudospark-generated electron beam is used to compare the amplitude of the Faraday cup signal with a calibrated F-70 commercial current transformer. The error of the Faraday cup output amplitude is below 10% for the 4-14 kV tested pseudospark voltages. The main benefit of this Faraday cup is demonstrated by adjusting the external shunt resistance and performing the self-biased method for obtaining the electron energy distribution function. Results from a 4 kV pseudospark discharge indicate a "double-humped" energy distribution. PMID:21806182

  7. Faraday cup with nanosecond response and adjustable impedance for fast electron beam characterization

    Science.gov (United States)

    Hu, Jing; Rovey, Joshua L.

    2011-07-01

    A movable Faraday cup design with simple structure and adjustable impedance is described in this work. This Faraday cup has external adjustable shunt resistance for self-biased measurement setup and 50 ? characteristic impedance to match with 50 ? standard BNC coaxial cable and vacuum feedthroughs for nanosecond-level pulse signal measurements. Adjustable shunt resistance allows self-biased measurements to be quickly acquired to determine the electron energy distribution function. The performance of the Faraday cup is validated by tests of response time and amplitude of output signal. When compared with a reference source, the percent difference of the Faraday cup signal fall time is less than 10% for fall times greater than 10 ns. The percent difference of the Faraday cup signal pulse width is below 6.7% for pulse widths greater than 10 ns. A pseudospark-generated electron beam is used to compare the amplitude of the Faraday cup signal with a calibrated F-70 commercial current transformer. The error of the Faraday cup output amplitude is below 10% for the 4-14 kV tested pseudospark voltages. The main benefit of this Faraday cup is demonstrated by adjusting the external shunt resistance and performing the self-biased method for obtaining the electron energy distribution function. Results from a 4 kV pseudospark discharge indicate a "double-humped" energy distribution.

  8. Time-Dependent Adaptation in the Hemodynamic Response to Hypoxia

    Science.gov (United States)

    Marcus, Noah J.; Olson, E. Burt; Bird, Cynthia E.; Philippi, Nathan R.; Morgan, Barbara J.

    2009-01-01

    In rats, acute exposure to hypoxia causes a decrease in mean arterial pressure (MAP) caused by a predominance of hypoxic vasodilation over chemoreflex-induced vasoconstriction. We previously demonstrated that exposure to chronic intermittent hypoxia (CIH) impairs hypoxic vasodilation in isolated resistance arteries; therefore, we hypothesized that the acute systemic hemodynamic responses to hypoxia would be altered by exposure to CIH. To test this hypothesis, rats were exposed to CIH for 14 days. Heart rate (HR) and MAP were monitored by telemetry. On the first day of CIH exposure, acute episodes of hypoxia caused a decrease in MAP (-9±5 mmHg) and an increase in HR (+45±4 beats/minute). On the 14th day of CIH exposure the depressor response was attenuated (-4±1 mmHg; 44% of the day 1 response) and the tachycardia enhanced (+68±2 beats/minute; 151% of the day 1 response). The observed time-dependent modulation of the acute hemodynamic responses to hypoxia may reflect important changes in neurocirculatory regulation that contribute to CIH-induced hypertension. PMID:19013546

  9. Aperiodic traffic in response time analyses with adjustable safety level

    OpenAIRE

    Khan, Dawood; Navet, Nicolas; Bavoux, Bernard; Migge, Jörn

    2009-01-01

    In distributed real-time systems it is crucial to ensure the temporal validity of the data exchanged among the nodes. Classically, the frame Worst Case Response Time (WCRT) analyses, and the software tools which implement them, do not take into account the aperiodic traffic. One of the main reasons for this is that the aperiodic traffic is generally very difficult to characterize (i.e., the arrival patterns of the aperiodic frames). The consequence of this is that one tends to underestimate t...

  10. A Scheme to Reduce Response Time in Cloud Computing Environment

    Directory of Open Access Journals (Sweden)

    Ashraf Zia

    2013-07-01

    Full Text Available The area of cloud computing has become popular from the last decade due to its enormous benefits such as lower cost, faster development and access to highly available resources. Apart from these core benefits some challenges are also associated with it such as QoS, security, trust and better resource management. These challenges are caused by the infrastructure services provided by various cloud vendors on need basis. Empirical studies on cloud computing report that existing quality of services solutions are not enough as well as there are still many gaps which need to be filled. Also, there is a dire need to develop appropriate frameworks to improve response time of the clouds. In this paper, we have made an attempt to fill this gap by proposing a framework that focuses on improving the response time factor of the QoS in the cloud environment such as reliability and scalability. We believe that if the response time are communicating effectively and have awareness of the nearest and best possible resource available then the remaining issues pertaining to QoS can be reduced to a greater extent.

  11. High frequency dielectrophoretic response of microalgae over time.

    Science.gov (United States)

    Hadady, Hanieh; Wong, Johnson J; Hiibel, Sage R; Redelman, Doug; Geiger, Emil J

    2014-12-01

    The high frequency dielectrophoresis (>20 MHz) response of microalgae cells with different lipid content was monitored over time. Chlamydomonas reinhardtii was cultured in regular medium and under nitrogen-depleted conditions in order to produce populations of cells with low and high lipid content, respectively. The electrical conductivity of the culture media was also monitored over the same time. The upper crossover frequency decreased for high-lipid cells over time. The single-shell model predicts that the upper crossover frequency is dictated primarily by the dielectric properties of the cytoplasm. The high frequency DEP response of the high-lipid cells' cytoplasm was changed by lipid accumulation. DEP response of the low-lipid cells also varied with the conductivity of the culture media due to nutrient consumption. Relative lipid content was estimated with BODIPY 505/515 dye by calculating the area-weighted intensity average of fluorescent images. Finally, microalgae cells were successfully separated based on lipid content at 41 MHz and DEP media conductivity 106 ± 1 ?S/cm. PMID:25229637

  12. Modeling responses and response times in personality tests with rating scales

    Directory of Open Access Journals (Sweden)

    Jochen Ranger

    2013-12-01

    Full Text Available In this article several latent trait models for the joint distribution of the responses and response times in rating scales are compared. Among these models are two generalizations of established models for binary items, namely a generalization of the approach of Ferrando and Lorenzo-Seva (2007a and a generalization of the approach of Ranger and Ortner (2011. Two new models and a variant of the hierarchical model of van der Linden (2007 are also considered. All these models combine the graded response model with a response time model based on the log-normal distribu-tion. The models differ in the assumed relationship between the expected log response time and the underlying latent traits. Although the proposed models have different interpretations and implications they can all be calibrated within the same general framework using marginal maximum likelihood estimation and an application of the ECM-algorithm. The models are used for the analysis of an empirical data set. According to the AIC index, the generalization of the model of Ranger and Ortner (2011 can represent the data best.

  13. Determinants of Children's Use of and Time Spent in Fast-Food and Full-Service Restaurants

    Science.gov (United States)

    McIntosh, Alex; Kubena, Karen S.; Tolle, Glen; Dean, Wesley; Kim, Mi-Jeong; Jan, Jie-Sheng; Anding, Jenna

    2011-01-01

    Objective: Identify parental and children's determinants of children's use of and time spent in fast-food (FF) and full-service (FS) restaurants. Design: Analysis of cross-sectional data. Setting: Parents were interviewed by phone; children were interviewed in their homes. Participants: Parents and children ages 9-11 or 13-15 from 312 families…

  14. A Dosemeter Based on Nuclear Track Etched Detectors for Thermal, Fast and High Energy Neutrons with Flat Response

    Energy Technology Data Exchange (ETDEWEB)

    Bouassoule, T.; Fernandez, F.; Marin, M.; Tomas, M. [Ballaterra (Spain)

    1999-07-01

    The response of a neutron dosemeter based on plastic track detectors has been studied. The dosemeter (converter + detector) configurations used consist of a CR-39 detector 500 {mu}m thick and a Makrofol converter 300 {mu}m thick for fast neutrons (configuration 1) and 3 mm of air used as converter for thermal neutrons (configuration 2). The possibility of using Makrofol as a high energy neutron dosemeter has also been studied. In order to validate the results obtained from Monte Carlo simulations using the MCNP4A code, a set of irradiations by monoenergetic neutron beams has been performed at the Physikalisch-Technische Bundesanstalt (PTB), Gesellschaft fur Strahlen-Und Umweltforschung (GSF) and Paul Scherrer Institut (PSI) neutron irradiation facilities. Irradiations with realistic fields were performed at the Cadarache Nuclear Centre. An excellent agreement has been found between the simulated and the experimental values, not only for fast neutrons but also for thermal neutrons. (author)

  15. Fast time domain reflectometry (TDR) measurement approach for investigating the liquefaction of soils

    International Nuclear Information System (INIS)

    Time domain reflectometry (TDR) was used for the spatial observation of transient density changes in a laboratory shake-box apparatus. Shake-box experiments are conducted to investigate the liquefaction of soils due to seismic excitation. As a sensor, a flat ribbon cable was placed within a water saturated sand column two metres in height. In the experiment, the soil column was excited at its base with a sinusoidal signal with low frequencies and moderate amplitudes. During the tests, TDR measurements were conducted with a repetition rate of 30 s?1. Temporal density changes during the liquefaction and reconsolidation process of the quartz sand along the sensor could be shown through signal analysis. The mean porosities calculated from the relative dielectric permittivity using a soil-specific calibration function could be determined with an RMSD-value of 0.02 compared to the porosities determined from the height of the sample. With the metrological set-up for the TDR measurements being used, fast temporal changes in the density profile could be qualitatively visualized indicating the movement of the reconsolidation front during the liquefaction

  16. Overview of the SPS/LEP fast broadcast message timing system

    International Nuclear Information System (INIS)

    A fast broadcast message system, also referred to as the general machine timing system, has recently been installed at CERN's Super Proton Synchrotron (SPS). It is used to control the SPS in its roles as a multi-cycling, multi-user service accelerator. The messages are centrally generated by an IBM compatible PC/AT card and broadcast to all users of the system. At the receiving end the frames are decoded and presented to the user in the form of either an interrupt to his intelligent equipment, a hardware pulse or a short message. They are used to synchronise the SPS when used as a 450 GeV fixed target machine, a 315 GeV p-pbar collider, a 100/450 GeV pulsing-coasting machine and also as an injector for the Large Electron Positron (LEP) machine. In the future it will also be used for LEP control. Implementation details and constraints are described, as are experience to date and foreseen expansions

  17. Beyond Mean Response Latency: Response Time Distributional Analyses of Semantic Priming

    Science.gov (United States)

    Balota, David A.; Yap, Melvin J.; Cortese, Michael J.; Watson, Jason M.

    2008-01-01

    Chronometric studies of language and memory processing typically emphasize changes in mean response time (RT) performance across conditions. However, changes in mean performance (or the lack thereof) may reflect distinct patterns at the level of underlying RT distributions. In seven experiments, RT distributional analyses were used to better…

  18. Characterisation of nanoparticle emissions and exposure at traffic intersections through fast-response mobile and sequential measurements

    Science.gov (United States)

    Goel, Anju; Kumar, Prashant

    2015-04-01

    Quantification of disproportionate contribution made by signalised traffic intersections (TIs) to overall daily commuting exposure is important but barely known. We carried out mobile measurements in a car for size-resolved particle number concentrations (PNCs) in the 5-560 nm range under five different ventilation settings on a 6 km long busy round route with 10 TIs. These ventilation settings were windows fully open and both outdoor air intake from fan and heating off (Set1), windows closed, fan 25% on and heating 50% on (Set2), windows closed, fan 100% on and heating off (Set3), windows closed, fan off and heating 100% on (Set4), and windows closed, fan and heating off (Set5). Measurements were taken sequentially inside and outside the car cabin at 10 Hz sampling rate using a solenoid switching system in conjunction with a fast response differential mobility spectrometer (DMS50). The objectives were to: (i) identify traffic conditions under which TIs becomes hot-spots of PNCs, (ii) assess the effect of ventilation settings in free-flow and delay conditions (waiting time at a TI when traffic signal is red) on in-cabin PNCs with respect to on-road PNCs at TIs, (iii) deriving the relationship between the PNCs and change in driving speed during delay time at the TIs, and (iv) quantify the contribution of exposure at TIs with respect to overall commuting exposure. Congested TIs were found to become hot-spots when vehicle accelerate from idling conditions. In-cabin peak PNCs followed similar temporal trend as for on-road peak PNCs. Reduction in in-cabin PNC with respect to outside PNC was highest (70%) during free-flow traffic conditions when both fan drawing outdoor air into the cabin and heating was switched off. Such a reduction in in-cabin PNCs at TIs was highest (88%) with respect to outside PNC during delay conditions when fan was drawing outside air at 25% on and heating was 50% on settings. PNCs and change in driving speed showed an exponential-fit relationship during the delay events at TIs. Short-term exposure for ?2% of total commuting time in car corresponded to ?25% of total respiratory doses. This study highlights a need for more studies covering diverse traffic and geographical conditions in urban environments so that the disparate contribution of exposure at TIs can be quantified.

  19. Time-resolved observation of fast domain-walls driven by vertical spin currents in short tracks

    Energy Technology Data Exchange (ETDEWEB)

    Sampaio, Joao; Lequeux, Steven; Chanthbouala, Andre; Cros, Vincent; Grollier, Julie [Unité Mixte de Physique CNRS/Thales and Université Paris-Sud 11, 1 Ave. A. Fresnel, 91767 Palaiseau (France); Metaxas, Peter J. [Unité Mixte de Physique CNRS/Thales and Université Paris-Sud 11, 1 Ave. A. Fresnel, 91767 Palaiseau (France); School of Physics, M013, University of Western Australia, 35 Stirling Highway, Crawley WA 6009 (Australia); Matsumoto, Rie; Yakushiji, Kay; Kubota, Hitoshi; Fukushima, Akio; Yuasa, Shinji [National Institute of Advanced Industrial Science and Technology (AIST) 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Nishimura, Kazumasa; Nagamine, Yoshinori; Maehara, Hiroki; Tsunekawa, Koji [Process Development Center, Canon ANELVA Corporation, Kurigi 2-5-1, Asao, Kawasaki, Kanagawa 215-8550 (Japan)

    2013-12-09

    We present time-resolved measurements of the displacement of magnetic domain-walls (DWs) driven by vertical spin-polarized currents in track-shaped magnetic tunnel junctions. In these structures, we observe very high DW velocities (600?m/s) at current densities below 10{sup 7}?A/cm{sup 2}. We show that the efficient spin-transfer torque combined with a short propagation distance allows avoiding the Walker breakdown process and achieving deterministic, reversible, and fast (?1?ns) DW-mediated switching of magnetic tunnel junction elements, which is of great interest for the implementation of fast DW-based spintronic devices.

  20. Lithium niobate stress gauge current diagnostic for noninductive measurement of fast-rise-time multimegampere currents

    International Nuclear Information System (INIS)

    Accurate modeling of load behavior in Z-pinch plasma radiation sources driven by high-current generators requires the measurement of fast-rise-time multimegampere currents close to the load. Conventional current diagnostics mounted in inductive cavities (such as B loops and Rogowski coils) fail at small radius because of electrical breakdown produced by high dI/dt. In this paper, we describe the use of large-signal, nanosecond-time-resolution lithium niobate piezoelectric stress gauges to directly measure the magnetic pressure B2/2?0=?0I2/8?2r2 generated at radius r by a current I flowing in a radial transmission line. Current measurements have been performed at radius r=2.54x10-2 m on Sandia National Laboratories' Proto-II (10 TW) and SATURN (30 TW) gas puff Z-pinch experiments with maximum currents of 10.1 MA and dI/dt to 2.1x1014 A/s. Comparisons with Faraday rotation and B current diagnostic measurements at large radius are presented. Bremsstrahlung noise problems unique to the SATURN gas puff source are discussed. For a Y-cut lithium niobate stress gauge on a pure tungsten electrode, current densities up to I/2?r=78 MA/m can be measured before the electrode yield strength and the piezoelectric operating stress limit are exceeded. Above the Hugoniot elastic limit of the electrode material, the dynamic range and accuracy of the diagnostic are greatly reduced, but it appears c are greatly reduced, but it appears that the technique can be extended to higher current densities using an X-cut quartz piezoelectric element and a tungsten-sapphire electrode impedance stack

  1. Time response measurements of pressure sensors using pink noise technique

    International Nuclear Information System (INIS)

    This work presents an experimental setup for Pink Noise method application on pressure transmitters' response times. The Pink Noise method consists on injecting artificial pressure noise into the pressure transmitter. The artificial pressure noise is generated using a current-to-pressure (I-to-P) converter, which is driven by a random noise signal generator. The output pressure transmitter noise is then analyzed using conventional Noise Analysis Technique. Noise signals may be interpreted using spectral techniques or empirical time series models. The frequency domain method consists of evaluating the Power Spectral Density (PSD) function. The information needed for time constant estimation can be obtained by fitting an all-pole transfer function to this power spectral density. (author)

  2. Linear response characteristics of time-dependent time fractional Fokker–Planck equation systems

    International Nuclear Information System (INIS)

    The time fractional Fokker–Planck equation approach is an important tool for modeling subdiffusion. When the external field is time modulated, two types of time-dependent time fractional Fokker–Planck equations have been proposed, both reduced to the same time-dependent time fractional Fokker–Planck equation when the external field is time uncorrelated. The first type is strictly deduced as the continuous limit of the continuous time random walk with time modulated Boltzmann jumping weight, while the second type is derived by ideally assuming that the jump probabilities can be evaluated at the start of the waiting time prior to jumping. For the first time we obtain the linear response characteristic for the first type of the time fractional Fokker–Planck equation systems, and for a comparison we revisit the corresponding result for the second type of the time fractional Fokker–Planck equation systems, and the similarity and difference between them is discussed with an application example. The investigation not only helps in understanding the competition between subdiffusion and time-dependent modulation, but also has significance in accessing the spectral properties of spontaneous fluctuation and the linear dynamic susceptibility of external perturbation in subdiffusive processes. (paper)

  3. Time orientation, planning horizons and responsibility into the future

    International Nuclear Information System (INIS)

    Subjects of four categories (social science students, engineering students, retired people and nuclear waste experts) were asked about past events, planning, risks and future time with emphasis on energy related issues and in particular questions concerning spent nuclear waste. Among, the results reported it was found that events in the past were located more or less correctly and that events further back systematically too close to the present. Today's responsibility into the future was judged to cover 3 to 6 generations ahead and an adequate planning horizon for a local community to be on the average 11 to 14 years. Adequate planning horizons for the handling of spent nuclear fuel were judged to be from 100 to 500 years. The responsibility for effects of today's decisions was judged to be from about 100 to 300 years into the future for environmental pollution and from about 50 to 600 years for nuclear waste. However, non-negliqable proportions of the subjects choose a more moral standpoint and gave answers indicating that responsibility had to be unlimited. Some sex differences were found and an interaction with age offered as a hypothesis to be investigated in the future. Interrelations between clusters of questions revealed some links from past time and planning to judgements of environmental and nuclear power related risks. (orig.)

  4. Caire - A real-time feedback system for emergency response

    International Nuclear Information System (INIS)

    In cases of nuclear emergencies it is the primary task of emergency response forces and decision making authorities to act properly. Whatever the specific reason for the contingency may be, a quick and most accurate estimate of the radiation exposure in consequence of the emergency must be made. This is a necessary prerequisite for decisions on protective measures and off-site emergency management. With respect to this fact ant the recent experience of the Chernobyl accident, remote monitoring systems have increased their importance as an inherent part of environmental surveillance installations in the FRG and in other countries. The existing systems in Germany are designed to cover both, routine operation and emergency situations. They provide site specific meteorological data, gross effluent dose rates, and dose rate measurements at on-site and approximately 30 off-site locations in the vicinity of a plant. Based on such telemetric surveillance networks an advanced automatic on-line system named CAIRE (Computer Aided Response to Emergencies) has been developed as a real time emergency response tool for nuclear facilities. this tool is designed to provide decision makers with most relevant radiation exposure data of the population at risk. The development phase of CAIRE has already been finished. CAIRE is now in an operational status and available for applications in emergency planning and response

  5. Fast, visual specialization for reading in English revealed by the topography of the N170 ERP response

    Directory of Open Access Journals (Sweden)

    McCandliss Bruce D

    2005-08-01

    Full Text Available Abstract Background N170 effects associated with visual words may be related to perceptual expertise effects that have been demonstrated for faces and other extensively studied classes of visual stimuli. Although face and other object expertise effects are typically bilateral or right-lateralized, the spatial topography of reading-related N170 effects are often left-lateralized, providing potential insights into the unique aspects of reading-related perceptual expertise. Methods Extending previous research in German 1, we use a high-density channel array to characterize the N170 topography for reading-related perceptual expertise in English, a language with inconsistent spelling-to-sound mapping. N170 effects related to overall reading-related expertise are defined by contrasting responses to visual words versus novel symbol strings. By contrasting each of these conditions to pseudowords, we examined how this reading-related N170 effect generalizes to well-ordered novel letter strings. Results A sample-by-sample permutation test computed on word versus symbol ERP topographies revealed differences during two time windows corresponding to the N170 and P300 components. Topographic centroid analysis of the word and symbol N170 demonstrated significant differences in both left-right as well as inferior-superior dimensions. Words elicited larger N170 negativities than symbols at inferior occipito-temporal channels, with the maximal effect over left inferior regions often unsampled in conventional electrode montages. Further contrasts produced inferior-superior topographic effects for the pseudoword-symbol comparison and left-lateralized topographic effects for the word-pseudoword comparison. Conclusion Fast specialized perception related to reading experience produces an N170 modulation detectable across different EEG systems and different languages. Characterization of such effects may be improved by sampling with greater spatial frequency recordings that sample inferior regions. Unlike in German, reading-related expertise effects in English produced only partial generalization in N170 responses to novel pseudowords. The topographic inferior-superior N170 differences may reflect general perceptual expertise for orthographic strings, as it was found for words and pseudowords across both languages. The topographic left-right N170 difference between words and pseudowords was only found in English, and may suggest that ambiguity in pronunciating novel pseudowords due to inconsistency in spelling-to-sound mapping influences early stages of letter string processing.

  6. Time-dependent calculations of transfer ionization by fast proton-helium collision in one-dimensional kinematics

    OpenAIRE

    Serov, Vladislav V.; Kheifets, A. S.

    2014-01-01

    We analyze a transfer ionization (TI) reaction in the fast proton-helium collision $\\rm H^+ + He \\to H^0 + He^{2+} + e^-$ by solving a time-dependent Schr\\"odinger equation (TDSE) under the classical projectile motion approximation in one-dimensional kinematics. In addition, we construct various time independent analogues of our model using lowest order perturbation theory in the form of the Born series. By comparing various aspects of the TDSE and the Born series calculatio...

  7. Fast analytical methods for the correction of signal random time-shifts and application to segmented HPGe detectors

    CERN Document Server

    Désesquelles, P; Korichi, A; Blanc, F Le; Olariu, A; Petrache, C M; 10.1016/j.nimb.2008.11.042

    2009-01-01

    Detection systems rely more and more on on-line or off-line comparison of detected signals with basis signals in order to determine the characteristics of the impinging particles. Unfortunately, these comparisons are very sensitive to the random time shifts that may alter the signal delivered by the detectors. We present two fast algebraic methods to determine the value of the time shift and to enhance the reliability of the comparison to the basis signals.

  8. Randomised trial investigating the relationship of response rate for blood sample donation to site of biospecimen collection, fasting status and reminder letter: The 45 and Up Study

    Directory of Open Access Journals (Sweden)

    Banks Emily

    2012-09-01

    Full Text Available Abstract Background Various options exist for collecting biospecimens and biomarkers from cohort study participants, and these have important logistic, resource and scientific implications. Evidence on how different collection methods affect participation and data quality is lacking. This parallel-design randomised trial, the Link-Up Study, involved blood sample donation and other data collection among participants in an existing cohort study, The 45 and Up Study. It aimed to investigate the relation of fasting status, reminder letters and data collection site to response rates, data quality and biospecimen yield. Methods Individuals aged 45 and over participating in The 45 and Up Study and living ?20 km from central Wagga Wagga, NSW (regional area or ?10 km from central Parramatta, NSW (urban area (n?=?2340 were randomised, stratified by area of residence, to be invited to give a blood sample and additional data by attending either a clinic established specifically for the trial, with an appointment time (“dedicated clinic”, n?=?1336 or an existing local commercial pathology centre (n?=?1004. Within dedicated clinic groups, participants were randomised into fasting (n?=?668 or non-fasting (n?=?668 and, at the Parramatta pathology centre site, reminder letter after two weeks (n?=?336 or no reminder (n?=?334. Results Overall, 33% (762/2340 of invitees took part in the Link-Up Study; 41% (410/1002 among regional and 26% (352/1338 among urban-area residents (p? Conclusions Among cohort study participants, response rates for an additional study involving biospecimen collection, but not data quality or average biospecimen yield, were considerably higher at dedicated clinics than at existing commercial pathology sites.

  9. Fast-starting after a breath: air-breathing motions are kinematically similar to escape responses in the catfish Hoplosternum littorale

    DEFF Research Database (Denmark)

    Domenici, Paolo; Norin, Tommy

    2015-01-01

    Fast-starts are brief accelerations commonly observed in fish within the context of predator–prey interactions. In typical C-start escape responses, fish react to a threatening stimulus by bending their body into a C-shape during the first muscle contraction (i.e. stage 1) which provides a sudden acceleration away from the stimulus. Recently, similar C-starts have been recorded in fish aiming at a prey. Little is known about C-starts outside the context of predator–prey interactions, though recent work has shown that escape response can also be induced by high temperature. Here, we test the hypothesis that air-breathing fish may use C-starts in the context of gulping air at the surface. Hoplosternum littorale is an air-breathing freshwater catfish found in South America. Field video observations reveal that their air-breathing behaviour consists of air-gulping at the surface, followed by a fast turn which re-directs the fish towards the bottom. Using high-speed video in the laboratory, we compared the kinematics of the turn immediately following air-gulping performed by H. littorale in normoxia with those of mechanically-triggered C-start escape responses and with routine (i.e. spontaneous) turns. Our results show that air-breathing events overlap considerably with escape responses with a large stage 1 angle in terms of turning rates, distance covered and the relationship between these rates. Therefore, these two behaviours can be considered kinematically comparable, suggesting that air-breathing in this species is followed by escape-like C-start motions, presumably to minimise time at the surface and exposure to avian predators. These findings show that C-starts can occur in a variety of contexts in which fish may need to get away from areas of potential danger.

  10. Predicting Student Responsiveness to Fast ForWord Using DIBELS Subtests

    Science.gov (United States)

    Cavallo, Fernando

    2012-01-01

    The current study was completed through a retrospective analysis of school records of elementary school students in the Northeast Region of the Philadelphia School District (PSD) who have participated in the Fast ForWord (FFW) Language program. The data requested from student records included: demographic information (e.g., gender, grade, age,…

  11. Influence of the Helicopter Time Domain Electromagnetic System Off-Time Response by the Transmitter Assembly

    Science.gov (United States)

    Vetrov, A.; Mejzr, I.

    2010-12-01

    While developing a new Helicopter Time Domain Electromagnetic system (P-THEM), Pico Envirotec Inc (PEI) has studied the effect of the transmitter assembly on the acquired data. The P-THEM system consists of a loop-transmitter assembly, powered by a motor generator, 3-axis coil receiver attached at the midpoint of a tow cable and an additional Z-axis (dB/dt) receiver installed on the rear section of the transmitter loop. The system is towed by a helicopter on a 230 foot long tow cable. The transmitter loop is designed to produce a peak magnetic moment of approximately 250,000 NIA with a base frequency of 30 Hz (adjustable to 25Hz) and a quarter length duty cycle (4 ms on-time). The secondary field acquired with a dB/dt receiver coil consists of a ground response and a system response: SF=Rg+Rsys, where SF - the secondary field, Rg - ground response, Rsys - system response. The system itself, especially the transmitter assembly, being a conductor in an induced magnetic field, creates a magnetic anomaly. The influence of the transmitter assembly anomaly on the received signal depends on the position of the receiver coil against the transmitter, the intensity of on-time pulse and transmitter electro-magnetic properties. At the same time, the ground response acquired with a receiver coil depends on the length and the moment of transmitter pulse, as well as the position and distance of the receiver coil from the ground. This can be for vertical field (Z) receiver coil described as RXz(t)=e(t)pz(t)Rgz(t)+d(t)k(t)j(t)TXz(t), where RXz(t) - receiver response, e(t) - elevation of the receiver over the ground, pz(t) - horizontal projection of the receiver coil, Rgz(t) - vertical component of ground response, d(t) - distance (elevation) between the receiver coil and the transmitter loop, k(t) - the position of the receiver in the transmitter field, j(t) - the transmitter assembly electromagnetic properties, TXz(t) -transmitter field (Primary field on-time, and transmitter assembly response off-time). Changes in the electromagnetic properties of the transmitter loop and mechanical vibrations of the transmitter and receiver are much lower frequency in comparison with the base frequency and can be omitted from consideration of a one cycle length period. The transmitter assembly response has to be subtracted from acquired off-time decay for a correct interpretation of ground response. The transmitter influence is very low when the receiving coil is placed far away. However, the transmitter influence is very important when the receiver is close to the transmitter assembly due to the transmitter anomaly decay which then becomes greater than the ground response. The transmitter assembly off-time response can be registered when the system is flown at a sufficiently high altitude and it is not affected by ground conductors. A number of experiments were conducted to determine the transmitter influence content in the acquired data. The secondary dB/dt receiver installed at different elevations over the transmitter loop in test flights It showed the influence change of the transmitter assembly on the acquired secondary field (OFF-time) dependent upon the distance between the transmitter assembly and the receiver loop.

  12. Development of a very fast spectral response measurement system for analysis of hydrogenated amorphous silicon solar cells and modules

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, J.A., E-mail: jose.rodriguez@tsolar.eu [Dept. Technology, Development and Innovation, T-Solar Global S.A., Parque Tecnologico de Galicia, Avda. de Vigo 5, E-32900 San Cibrao das Vinas (Ourense) (Spain); Fortes, M. [Departamento de Electronica e Computacion, Universidade de Santiago de Compostela, 15782 Santiago de Compostela (Spain); Alberte, C.; Vetter, M.; Andreu, J. [Dept. Technology, Development and Innovation, T-Solar Global S.A., Parque Tecnologico de Galicia, Avda. de Vigo 5, E-32900 San Cibrao das Vinas (Ourense) (Spain)

    2013-01-01

    Highlights: Black-Right-Pointing-Pointer Spectral response equipment for measuring a-Si:H solar cells in a few seconds. Black-Right-Pointing-Pointer Equipment based on 16 LEDs with simultaneous illumination of the solar cell. Black-Right-Pointing-Pointer The current generated by each LED is analyzed by a Fast Fourier Transform. Black-Right-Pointing-Pointer Cheap equipment without lock-in technology for the current measurement. Black-Right-Pointing-Pointer Measurement error vs. conventional measurement less than 1% in J{sub sc}. - Abstract: An important requirement for a very fast spectral response measurement system is the simultaneous illumination of the solar cell at multiple well defined wavelengths. Nowadays this can be done by means of light emitting diodes (LEDs) available for a multitude of wavelengths. For the purpose to measure the spectral response (SR) of amorphous silicon solar cells a detailed characterization of LEDs emitting in the wavelength range from 300 nm to 800 nm was performed. In the here developed equipment the LED illumination is modulated in the frequency range from 100 Hz to 200 Hz and the current generated by each LED is analyzed by a Fast Fourier Transform (FFT) to determine the current component corresponding to each wavelength. The equipment provides a signal to noise ratio of 2-4 orders of magnitude for individual wavelengths resulting in a precise measurement of the SR over the whole wavelength range. The difference of the short circuit current determined from the SR is less than 1% in comparison to a conventional system with monochromator.

  13. Phase Error Calculation for Fast Time-Domain Bistatic SAR Algorithms

    OpenAIRE

    Vu, Viet; Sjo?gren, Thomas; Pettersson, Mats

    2013-01-01

    In synthetic aperture radar (SAR) processing, there is a trade-off between accuracy and speed. The approximations in an algorithm help to increase the algorithm’s speed but cause deterministic phase errors which directly affect the SAR image quality. This paper discusses the phase error calculations for bistatic fast backprojection (BiFBP) and bistatic fast factorized backprojection (BiFFBP) which are essential for setting their parameters. The phase error calculatio...

  14. Fast Response and High Sensitivity ZnO/glass Surface Acoustic Wave Humidity Sensors Using Graphene Oxide Sensing Layer

    Science.gov (United States)

    Xuan, Weipeng; He, Mei; Meng, Nan; He, Xingli; Wang, Wenbo; Chen, Jinkai; Shi, Tianjin; Hasan, Tawfique; Xu, Zhen; Xu, Yang; Luo, J. K.

    2014-11-01

    We report ZnO/glass surface acoustic wave (SAW) humidity sensors with high sensitivity and fast response using graphene oxide sensing layer. The frequency shift of the sensors is exponentially correlated to the humidity change, induced mainly by mass loading effect rather than the complex impedance change of the sensing layer. The SAW sensors show high sensitivity at a broad humidity range from 0.5%RH to 85%RH with SAW humidity sensors, complemented with full humidity range measurement, highlights their potential in a wide range of applications.

  15. Traffic model by braking capability and response time

    CERN Document Server

    Lee, Hyun Keun; Kim, Youngho; Lee, Choong-Ki

    2015-01-01

    We propose a microscopic traffic model where the update velocity is determined by the deceleration capacity and response time. It is found that there is a class of collisions that cannot be distinguished by simply comparing the stop positions. The model generates the safe, comfortable, and efficient traffic flow in numerical simulations with the reasonable values of the parameters, and this is analytically supported. Our approach provides a new perspective in modeling the traffic-flow safety and the perturbing situations like lane change.

  16. Very fast mass balance and other fuel cycle response calculations for studying back end of fuel cycle scenari

    International Nuclear Information System (INIS)

    In order to optimize nuclear fuel utilization, as far as irradiation and storage are concerned, the Research and Development Division of Electricite de France (EDF) developed as fast and accurate software that simulates a fuel assembly life from the inside-reactor stay to the final repository: STRAPONTIN. The discrepancies between reference calculations and STRAPONTIN are generally smaller than 5 %. Moreover, the low calculation time enables to couple STRAPONTIN to any large code in order to widen its scope without impairing its CPU time. (authors)

  17. Greater impairment of postprandial triacylglycerol than glucose response in metabolic syndrome subjects with fasting hyperglycaemia

    OpenAIRE

    Jackson, Kim; Walden, Charlotte; Murray, Peter; Smith, Adrian; Minihane, Anne Marie; Lovegrove, Julie; Williams, Christine

    2013-01-01

    Abstract Objective: Studies have started to question whether a specific component or combinations of metabolic syndrome (MetS) components may be more important in relation to cardiovascular disease risk. Our aim was to examine the impact of the presence of raised fasting glucose as a MetS component on postprandial lipaemia. Methods: Men classified with the MetS underwent a sequential test meal investigation, in which blood samples were taken at regular intervals after a test breakfa...

  18. Formulation and optimization of fast dissolving intraoral drug delivery system for clobazam using response surface methodology

    OpenAIRE

    Bala, Rajni; Khanna, Sushil; Pawar, Pravin K.

    2013-01-01

    Clobazam is a newer 1,5-benzodiazepine used for the treatment of epilepsy. It is better tolerated and less sedating than other benzodiazepines. Absorption of the drug can be impacted by oral fast dissolving dosage form; this may have implications for epilepsy in pediatrics and those having difficulty in swallowing tablets/capsules resulting in improved patient compliance. The purpose of the present investigation was to formulate and optimize clobazam oro-dissolving tablets by direct compressi...

  19. Fast Response Scintillator Based Detector for MHD Induced Energetic Ion Losses in ASDEX Upgrade

    OpenAIRE

    García Muñoz, Manuel

    2006-01-01

    In fusion plasma devices, fast particles i.e. suprathermal ions generated by heating systems and fusion born a particles must be well confined, until they have transferred their energy to the plasma bulk. Signicant loss of these ions may reduce drastically the heating eficiency and, in addition, may cause damage to plasma facing components in the vacuum vessel, if it is suficiently intense and localized. A detailed knowledge of the underlying physics in particular in the presence of magnetohy...

  20. Fasting leptin and appetite responses induced by a 4-day 65%-energy-restricted diet

    OpenAIRE

    Mars, M.; de Graaf, C.; C. P. G. M. de Groot; van Rossum, C. T M; Kok, F J

    2006-01-01

    OBJECTIVE: Animal studies show that the leptin decline after acute severe caloric restriction is a peripheral signal to increase food intake. However, most human studies have failed to observe such a relationship. We studied the acute effects of severe caloric restriction on the association between serum leptin concentrations and subjective appetite. SUBJECTS: A total of 44 healthy adult men (aged: 43 +/- 5 years; BMI: 27.3 +/- 3.2 kg/m(2)). MEASUREMENTS: Fasting serum leptin concentrations a...

  1. Unsaturated-zone fast-path flow calculations for Yucca Mountain groundwater travel time analyses (GWTT-94)

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, B.W.; Altman, S.J. [Sandia National Labs., Albuquerque, NM (United States); Robey, T.H. [Spectra Research Institute, Albuquerque, NM (United States)] [and others

    1995-08-01

    Evaluation of groundwater travel time (GWTT) is required as part of the investigation of the suitability of Yucca Mountain as a potential high-level nuclear-waste repository site. The Nuclear Regulatory Commission`s GWTT regulation is considered to be a measure of the intrinsic ability of the site to contain radionuclide releases from the repository. The work reported here is the first step in a program to provide an estimate of GWTT at the Yucca Mountain site in support of the DOE`s Technical Site Suitability and as a component of a license application. Preliminary estimation of the GWTT distribution in the unsaturated zone was accomplished using a numerical model of the physical processes of groundwater flow in the fractured, porous medium of the bedrock. Based on prior investigations of groundwater flow at the site, fractures are thought to provide the fastest paths for groundwater flow; conditions that lead to flow in fractures were investigated and simulated. Uncertainty in the geologic interpretation of Yucca Mountain was incorporated through the use of geostatistical simulations, while variability of hydrogeologic parameters within each unit was accounted for by the random sampling of parameter probability density functions. The composite-porosity formulation of groundwater flow was employed to simulate flow in both the matrix and fracture domains. In this conceptualization, the occurrence of locally saturated conditions within the unsaturated zone is responsible for the initiation of fast-path flow through fractures. The results of the GWTT-94 study show that heterogeneity in the hydraulic properties of the model domain is an important factor in simulating local regions of high groundwater saturation. Capillary-pressure conditions at the surface boundary influence the extent of the local saturation simulated.

  2. Unsaturated-zone fast-path flow calculations for Yucca Mountain groundwater travel time analyses (GWTT-94)

    International Nuclear Information System (INIS)

    Evaluation of groundwater travel time (GWTT) is required as part of the investigation of the suitability of Yucca Mountain as a potential high-level nuclear-waste repository site. The Nuclear Regulatory Commission's GWTT regulation is considered to be a measure of the intrinsic ability of the site to contain radionuclide releases from the repository. The work reported here is the first step in a program to provide an estimate of GWTT at the Yucca Mountain site in support of the DOE's Technical Site Suitability and as a component of a license application. Preliminary estimation of the GWTT distribution in the unsaturated zone was accomplished using a numerical model of the physical processes of groundwater flow in the fractured, porous medium of the bedrock. Based on prior investigations of groundwater flow at the site, fractures are thought to provide the fastest paths for groundwater flow; conditions that lead to flow in fractures were investigated and simulated. Uncertainty in the geologic interpretation of Yucca Mountain was incorporated through the use of geostatistical simulations, while variability of hydrogeologic parameters within each unit was accounted for by the random sampling of parameter probability density functions. The composite-porosity formulation of groundwater flow was employed to simulate flow in both the matrix and fracture domains. In this conceptualization, the occurrence of locally saturated conditions within the unsaturated zone is responsible for the initiation of fast-path flow through fractures. The results of the GWTT-94 study show that heterogeneity in the hydraulic properties of the model domain is an important factor in simulating local regions of high groundwater saturation. Capillary-pressure conditions at the surface boundary influence the extent of the local saturation simulated

  3. Faraday rotation in a multimode optical fiber in a fast rise-time, high magnetic field

    International Nuclear Information System (INIS)

    A magneto-optic Faraday rotation diagnostic was implemented on a Z-pinch driven flux-compression generator to measure line-averaged, megagauss, axial-magnetic fields up to 1.6 MG with rise times of 30 kG/ns. The axial-magnetic field rotated the plane of polarization of a 2-W argon laser beam in a 0.725-mm-diam, fused silica quartz fiber mounted coaxial with the Z pinch. The rapid rise time and the high radiation environment presented by the Z-pinch plasma caused a high-pressure impulse <100 kbar, to be coupled into the quartz-fiber probe disrupting the polarization-preserving properties of the fiber. The time scale for disruption was characteristic of a shock propagating radially through the fiber to its core. This paper will describe the response of the Faraday diagnostic under these conditions and present a simple model that describes the effects of fiber depolarization that is consistent with previous observations of stress-induced depolarization in optical fibers

  4. Fast-response liquid crystal display by the VA-IPS display mode with nematic liquid crystal and polymer networks

    Science.gov (United States)

    Chen, Tien-Jung; Lin, Guan-Jhong; Chen, Bo-Yu; Wu, Jin-Jei; Yang, Ying-Jay

    2012-10-01

    To improve electrooptical characteristics of the vertical aligned (VA) liquid crystal displays (LCDs), the monomer material and in-plane switching (IPS) field produced by interdigital electrodes are employed in LC cells. The fast switching response and well optical transmittance of the VA-IPS display mode are successfully achieved by mixing the nematic LC with polymer networks, attributed to the surface anchoring, and the molecular orientation of the LC cell will be further governed, especially under the greater applied voltage. Furthermore, the high concentration doping of the monomer can effectively improve the response behavior, but it also results in the transmittance sacrificed due to the light scattering, and the threshold voltage (Vth) increased.

  5. Intercomparison of six fast-response sensors for the eddy-covariance flux measurement of nitrous oxide over agricultural grassland

    Science.gov (United States)

    Nemitz, Eiko; Famulari, Daniela; Ibrom, Andreas; Vermeulen, Alex; Hensen, Arjan; van den Bulk, Pim; Loubet, Benjamin; Laville, Patricia; Mammarella, Ivan; Haapanala, Sami; Lohila, Annalea; Laurila, Tuomas; Eva, Rabot; Laborde, Marie; Cowan, Nicholas; Anderson, Margaret; Helfter, Carole

    2015-04-01

    Nitrous oxide (N2O) is the third most important greenhouse gas and its terrestrial budget remains poorly constraint, with bottom up and top down estimates of country emissions often disagreeing by more than a factor of two. Whilst the measurements of the biosphere / atmosphere exchange of CO2 with micrometeorological methods is commonplace, emissions of CH4 and N2O are more commonly measured with enclosure techniques due to limitations in fast-response sensors with good signal-to-noise characteristics. Recent years have seen the development of a range of instruments based on optical spectroscopy. This started in the early 1990s with instruments based on lead salt lasers, which had temperamental long-term characteristics. More recent developments in quantum cascade lasers has lead to increasingly stable instruments, initially based on pulsed, later on continuous wave lasers. Within the context of the European FP7 Infrastructure Project InGOS ('Integrated non-CO2 Greenhouse gas Observing System'), we conducted an intercomparison of six fast response sensors for N2O: three more or less identical instruments based on off-axis Integrated Cavity Optical Spectrocopy (ICOS) (Los Gatos Research Inc.) and three instruments based on quantum cascade laser absorption spectrometry (Aerodyne Research Inc.): one older generation pulsed instrument (p-QCL) and two of the latest generation of compact continuous wave instruments (cw-QCL), operating at two different wavelengths. One of the ICOS instruments was operated with an inlet drier. In addition, the campaign was joined by a relaxed eddy-accumulation system linked to a FTIR spectrometer (Ecotech), a gradient system based on a home-built slower QCL (INRA Orleans) and a fast chamber system. Here we present the results of the study and a detailed examination of the various corrections and errors of the different instruments. Overall, with the exception of the older generation QCL, the average fluxes based on the different fast-response instruments agreed within +/- 7.4%, although fluxes were moderate. The cw-QCL systems showed somewhat better signal-to-noise characteristics and a lower flux detection limit than the ICOS analysers. Intriguingly, there seemed to be some minor differences between the ICOS instruments which showed cross sensitivities to CO to varying degree. Overall the study demonstrates, that, while not cheap, both the ICOS-based instruments and the cw-QCLs are suitable for the measurement of even moderate N2O fluxes.

  6. Differential adaptive responses to 1- or 2-day fasting in various mouse tissues revealed by quantitative PCR analysis

    Science.gov (United States)

    Yamamoto, Junya; Kamata, Shotaro; Miura, Asumi; Nagata, Tomoko; Kainuma, Ryo; Ishii, Isao

    2015-01-01

    Dietary or caloric restriction confers various clinical benefits. Short-term fasting of mice is a common experimental procedure that may involve systemic metabolic remodeling, which may significantly affect experimental outputs. This study evaluated adaptive cellular responses after 1- or 2-day fasting in 13 mouse tissues by quantitative PCR using 15 marker primer sets for the activation of ubiquitin–proteasome (Atrogin-1 and MuRF1), autophagy–lysosome (LC3b, p62 and Lamp2), amino acid response (Asns, Trib3, Herpud1, xCT, and Chop), Nrf2-mediated antioxidant (HO-1 and Gsta1), and amino acid transport (Slc38a2, Slc7a5, and Slc7a1) systems. Differential activation profiles obtained in seven highly (thymus, liver, spleen, and small intestine) or mildly (stomach, kidney, and colon) atrophied tissues as well as in six non-atrophied tissues (brain, eye, lung, heart, skeletal muscle, and testis) suggested tissue-specific active metabolic remodeling. PMID:25973363

  7. Time-resolved two-color monochromatic x-ray imagers for fast-ignitor plasmas

    Science.gov (United States)

    Tanabe, Minoru; Fujiwara, Takashi; Fujioka, Shinsuke; Nishimura, Hiroaki; Shiraga, Hiroyuki; Azechi, Hiroshi; Mima, Kunioki

    2008-11-01

    Ultrafast two-dimensional (2D) x-ray imaging is required to investigate the dynamics of fast-heated core plasma in fast ignition research. A novel x-ray imager, consisting of two toroidally bent Bragg crystals and an ultrafast two-dimensional x-ray imaging camera, has been demonstrated in order to measure an electron temperature profile of fast-ignitor plasma. Sequential, two-color, and 2D monochromatic x-ray images of laser-imploded core plasma were obtained with a temporal resolution of 20 ps, a spatial resolution of 31 ?m, and a spectral resolution of over 200, simultaneously. Details of the experimental results and analysis will be discussed

  8. Fast Mode Decision on H.264/AVC Baseline Profile for real-time performance

    OpenAIRE

    Nieto Doncel, Marcos; Salgado Álvarez de Sotomayor, Luis; Cabrera Quesada, Julian; García Santos, Narciso

    2008-01-01

    In this paper a new fast mode decision (FMD) algorithm is proposed for the recent H.264/AVC video coding standard, aiming to reduce its computational load without loosing coding efficiency. This algorithm identifies redundancy and selects the minimum sub-set of modes for each macroblock (MB) required to provide high rate-distortion (RD) efficiency. It is based on a fast analysis of the histogram of the difference image between frames which classifies the areas of each frame as active or non-a...

  9. A GPU-based real time high performance computing service in a fast plant system controller prototype for ITER

    Energy Technology Data Exchange (ETDEWEB)

    Nieto, J., E-mail: jnieto@sec.upm.es [Grupo de Investigacion en Instrumentacion y Acustica Aplicada. Universidad Politecnica de Madrid, Crta. Valencia Km-7, Madrid 28031 Spain (Spain); Arcas, G. de; Ruiz, M. [Grupo de Investigacion en Instrumentacion y Acustica Aplicada. Universidad Politecnica de Madrid, Crta. Valencia Km-7, Madrid 28031 Spain (Spain); Vega, J. [Asociacion EURATOM/CIEMAT para Fusion, Madrid (Spain); Lopez, J.M.; Barrera, E. [Grupo de Investigacion en Instrumentacion y Acustica Aplicada. Universidad Politecnica de Madrid, Crta. Valencia Km-7, Madrid 28031 Spain (Spain); Castro, R. [Asociacion EURATOM/CIEMAT para Fusion, Madrid (Spain); Sanz, D. [Grupo de Investigacion en Instrumentacion y Acustica Aplicada. Universidad Politecnica de Madrid, Crta. Valencia Km-7, Madrid 28031 Spain (Spain); Utzel, N.; Makijarvi, P.; Zabeo, L. [ITER Organization, CS 90 046, 13067 St. Paul lez Durance Cedex (France)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Implementation of fast plant system controller (FPSC) for ITER CODAC. Black-Right-Pointing-Pointer GPU-based real time high performance computing service. Black-Right-Pointing-Pointer Performance evaluation with respect to other solutions based in multi-core processors. - Abstract: EURATOM/CIEMAT and the Technical University of Madrid UPM are involved in the development of a FPSC (fast plant system control) prototype for ITER based on PXIe form factor. The FPSC architecture includes a GPU-based real time high performance computing service which has been integrated under EPICS (experimental physics and industrial control system). In this work we present the design of this service and its performance evaluation with respect to other solutions based in multi-core processors. Plasma pre-processing algorithms, illustrative of the type of tasks that could be required for both control and diagnostics, are used during the performance evaluation.

  10. A GPU-based real time high performance computing service in a fast plant system controller prototype for ITER

    International Nuclear Information System (INIS)

    Highlights: ? Implementation of fast plant system controller (FPSC) for ITER CODAC. ? GPU-based real time high performance computing service. ? Performance evaluation with respect to other solutions based in multi-core processors. - Abstract: EURATOM/CIEMAT and the Technical University of Madrid UPM are involved in the development of a FPSC (fast plant system control) prototype for ITER based on PXIe form factor. The FPSC architecture includes a GPU-based real time high performance computing service which has been integrated under EPICS (experimental physics and industrial control system). In this work we present the design of this service and its performance evaluation with respect to other solutions based in multi-core processors. Plasma pre-processing algorithms, illustrative of the type of tasks that could be required for both control and diagnostics, are used during the performance evaluation.

  11. The genetic architecture of fasting plasma triglyceride response to fenofibrate treatment

    Science.gov (United States)

    Metabolic response to the triglyceride (TG)-lowering drug, fenofibrate, is shaped by interactions between genetic and environmental factors, yet knowledge regarding the genetic determinants of this response is primarily limited to single gene effects. Since very low density lipoprotein (VLDL) is the...

  12. Fast monitoring of motor exhaust components by resonant multi-photon ionisation and time-of-flight mass spectrometry

    Science.gov (United States)

    Franzen, Jochen; Frey, Rüdiger; Nagel, Holger

    1995-03-01

    A new analytical procedure is provided by the combination of two types of spectroscopy. Resonant ionization of selected compounds by multiphoton ionization is based on results of absorption spectroscopy for the compound molecules of interest and time-of-flight mass spectrometry serves for the unambigious detection of these compounds. An interesting application of this method is the fast exhaust gas analysis. In the development of future combustion engines, the management of dynamic motor processes becomes predominant because by more than 90 % of all the dangerous exhaust pollutions are produced in instationary motor phases such as fast speed or load changes. The investigation of dynamic processes however, requires fast analytical procedures with millisecond time resolution together with the capability to measure individual components in a very complex gas mixture The objectives for a development project of such an instrument were set by the Research Association for Combustion Engines (Forschungsvereinigung Verbrennungskraftmaschinen, FVV, Germany): Up to ten substances should be monitored synchroneously with a time resolution of about 10 milliseconds, with concentration limits of 1 part per million and with a precision better than 10 % relative standard deviation. Such a laser mass spectrometer for fast multi-component automotive exhaust analyses has been developed in a joint research project by Bruker-Franzen Analytik GmbH, Dornier GmbH and the Technical University of Munich. The system has been applied at a motor test facility to investigate the emissions of the aromatic hydrocarbons benzene, toluene and xylene, of nitric oxide and acetaldehyde in stationary and dynamic engine operation. These measurements demonstrate that strong emission of these pollutants takes place at instationary engine operation and in particular that these compounds are emitted at different times, giving new information about the processes in the combustion chamber and in the exhaust pipe.

  13. Fast three-dimensional terahertz computed tomography using real-time line projection of intense terahertz pulse

    OpenAIRE

    Jewariya, Mukesh; Abraham, Emmanuel; Kitaguchi, Takayuki; Ohgi, Yoshiyuki; Minami, Masa-aki; Araki, Tsutomu; Yasui, Takeshi

    2013-01-01

    We demonstrated fast three-dimensional transmission terahertz computed tomography by using real-time line projection of intense terahertz beam generated by optical rectification in lithium niobate crystal. After emphasizing the advantage of intense terahertz pulse generation for two-dimensional spatio-temporal terahertz imaging, peak-to-peak amplitudes of pulsed terahertz electric field have been used to obtain a series of projection images at different rotation angles. Then a standard recons...

  14. Ghrelin, motilin, insulin concentration in healthy infants in the first months of life: relation to fasting time and anthropometry

    OpenAIRE

    Liguori, Stefania Alfonsina; Miniero, Roberto; Silvestro, Leandra; Oggero, Roberto; FISSORE, MARIA FRANCESCA

    2006-01-01

    AIMS: This study aimed to investigate: (i) the relation between fasting time and serum ghrelin, motilin and insulin concentrations and (ii) the correlations between these hormones and anthropometrical parameters of infants in the first 18 months of life. PATIENT AND METHODS: A cross-sectional study on 62 term infants was performed. Blood samples for hormonal assay were obtained at least 1 h after feeding. Weight, length and head circumference were recorded. Plasma ghrelin, motilin and insulin...

  15. LHCb: Beam and Background Monitoring and the Upgrade of the Timing and Fast Control System of the LHCb experiment at CERN

    CERN Multimedia

    Alessio, F

    2009-01-01

    The LHCb experiment at CERN is preparing for first real data taking, foreseen by the end of the year 2009 with the start-up of the LHC. A large amount of work of commissioning, tests and improvements of the full detector has been done in order to optimize its performance. During my first year as a Doctoral Student at CERN, I have been working on the timing and readout control of the LHCb experiment in the frame of the LHCb Online group. The group is responsible for the full data acquisition of the LHCb experiment, from the Front-End Electronics (FEE) to the storage of the data for offline analysis, as well as the Timing and Fast Control (TFC) system. The latter controls and distributes centrally timing and trigger information, as well as synchronous and asynchronous commands to the readout system. It is also responsible for receiving and adjusting the bunch and orbit clocks of the LHC machine and distributing it to the electronics of the whole experiment. It is of vital importance to assure that the timing o...

  16. Fast and sensitive detection of mycotoxins in wheat using microfluidics based Real-time Electrochemical Profiling.

    Science.gov (United States)

    Olcer, Zehra; Esen, Elif; Muhammad, Turghun; Ersoy, Aylin; Budak, Sinan; Uludag, Y?ld?z

    2014-12-15

    The objective of the study has been the development of a new sensing platform, called Real-time Electrochemical Profiling (REP) that relies on real-time electrochemical immunoassay detection. The proposed REP platform consists of new electrode arrays that are easy to fabricate, has a small imprint allowing microfluidic system integration, enables multiplexed amperometric measurements and performs well in terms of electrochemical immunoassay detection as shown through the deoxynivalenol detection assays. The deoxynivalenol detection has been conducted according to an optimised REP assay protocol using deoxynivalenol standards at varying concentrations and a standard curve was obtained (y=-20.33ln(x)+124.06; R(2)=0.97) with a limit of detection of 6.25 ng/ml. As both ELISA and REP detection methods use horse radish peroxidase as the label and 3.3',5.5'-Tetramethylbenzidine as the substrate, the performance of the REP platform as an ELISA reader has also been investigated and a perfect correlation between the deoxynivalenol concentration and the current response was obtained (y=-14.56ln(x)+101.02; R(2)=0.99). The calibration curves of both assays have been compared to conventional ELISA tests for confirmation. After assay optimisation using toxin spiked buffer, the deoxynivalenol detection assay has also been performed to detect toxins in wheat grain. PMID:24998314

  17. A fast algorithm to compute precise type-2 centroids for real-time control applications.

    Science.gov (United States)

    Chakraborty, Sumantra; Konar, Amit; Ralescu, Anca; Pal, Nikhil R

    2015-02-01

    An interval type-2 fuzzy set (IT2 FS) is characterized by its upper and lower membership functions containing all possible embedded fuzzy sets, which together is referred to as the footprint of uncertainty (FOU). The FOU results in a span of uncertainty measured in the defuzzified space and is determined by the positional difference of the centroids of all the embedded fuzzy sets taken together. This paper provides a closed-form formula to evaluate the span of uncertainty of an IT2 FS. The closed-form formula offers a precise measurement of the degree of uncertainty in an IT2 FS with a runtime complexity less than that of the classical iterative Karnik-Mendel algorithm and other formulations employing the iterative Newton-Raphson algorithm. This paper also demonstrates a real-time control application using the proposed closed-form formula of centroids with reduced root mean square error and computational overhead than those of the existing methods. Computer simulations for this real-time control application indicate that parallel realization of the IT2 defuzzification outperforms its competitors with respect to maximum overshoot even at high sampling rates. Furthermore, in the presence of measurement noise in system (plant) states, the proposed IT2 FS based scheme outperforms its type-1 counterpart with respect to peak overshoot and root mean square error in plant response. PMID:24691554

  18. Combating Shill Bidding in Real Time: Prevention, Detection and Response

    Directory of Open Access Journals (Sweden)

    Kazi Mamun

    2015-04-01

    Full Text Available Human cheating has been a barrier to establishing trust among e-commerce users, throughout the last two decades. In particular, in online auctions, since all the transactions occur among anonymous users, trust is difficult to establish and maintain. Shill bidding happens when bidders bid exclusively to inflate (in forward auctions or deflate (in reverse auctions prices in online auctions. At present, shill bidding is the most severe and persistent form of cheating in online auctions, but still there are only a few or no established techniques for shill defense at run-time. In this paper, I evaluate the strengths and weaknesses of existing approaches to combating shill bidding. I also propose the ShillFree1 auction system to secure and protect auction systems from shill bidders for both forward and reverse auctions. More precisely, by using a variety of bidding behavior and user history, proposed auction system prevents, monitors and detects shill activities in real time. Moreover, to detect shilling thoroughly I propose IP tracking techniques. The system also takes necessary actions against shill activities at run-time. The experimental results demonstrate that, by prevention, detection and response mechanisms, the proposed auction system keeps the auction users secured from shill bidding and therefore establishes trust among online auction users.

  19. Whole genome sequence analysis of the arctic-lineage strain responsible for distemper in Italian wolves and dogs through a fast and robust next generation sequencing protocol.

    Science.gov (United States)

    Marcacci, Maurilia; Ancora, Massimo; Mangone, Iolanda; Teodori, Liana; Di Sabatino, Daria; De Massis, Fabrizio; Camma', Cesare; Savini, Giovanni; Lorusso, Alessio

    2014-06-01

    Dynamic surveillance and characterization of canine distemper virus (CDV) circulating strains are essential against possible vaccine breakthroughs events. This study describes the setup of a fast and robust next-generation sequencing (NGS) Ion PGM™ protocol that was used to obtain the complete genome sequence of a CDV isolate (CDV2784/2013). CDV2784/2013 is the prototype of CDV strains responsible for severe clinical distemper in dogs and wolves in Italy during 2013. CDV2784/2013 was isolated on cell culture and total RNA was used for NGS sample preparation. A total of 112.3 Mb of reads were assembled de novo using MIRA version 4.0rc4, which yielded a total number of 403 contigs with 12.1% coverage. The whole genome (15,690 bp) was recovered successfully and compared to those of existing CDV whole genomes. CDV2784/2013 was shown to have 92% nt identity with the Onderstepoort vaccine strain. This study describes for the first time a fast and robust Ion PGM™ platform-based whole genome amplification protocol for non-segmented negative stranded RNA viruses starting from total cell-purified RNA. Additionally, this is the first study reporting the whole genome analysis of an Arctic lineage strain that is known to circulate widely in Europe, Asia and USA. PMID:24642239

  20. Regulation of mouse hepatic genes in response to diet induced obesity, insulin resistance and fasting induced weight reduction

    Directory of Open Access Journals (Sweden)

    Mantzoros Christos

    2005-06-01

    Full Text Available Abstract Background Obesity is associated with insulin resistance that can often be improved by caloric restriction and weight reduction. Although many physiological changes accompanying insulin resistance and its treatment have been characterized, the genetic mechanisms linking obesity to insulin resistance are largely unknown. We used DNA microarrys and RT-PCR to investigate significant changes in hepatic gene transcription in insulin resistant, diet-induced obese (DIO-C57/BL/6J mice and DIO-C57/BL/6J mice fasted for 48 hours, whose weights returned to baseline levels during these conditions. Results Transcriptional profiling of hepatic mRNA revealed over 1900 genes that were significantly perturbed between control, DIO, and fasting/weight reduced DIO mice. From this set, our bioinformatics analysis identified 41 genes that rigorously discriminate these groups of mice. These genes are associated with molecular pathways involved in signal transduction, and protein metabolism and secretion. Of particular interest are genes that participate in pathways responsible for modulating insulin sensitivity. DIO altered expression of genes in directions that would be anticipated to antagonize insulin sensitivity, while fasting/ weight reduction partially or completely normalized their levels. Among these discriminatory genes, Sh3kbp1 and RGS3, may have special significance. Sh3kbp1, an endogenous inhibitor of PI-3-kinase, was upregulated by high-fat feeding, but normalized to control levels by fasting/weight reduction. Because insulin signaling occurs partially through PI-3-kinase, increased expression of Sh3kbp1 by DIO mice may contribute to hepatic insulin resistance via inhibition of PI-3-kinase. RGS3, a suppressor of G-protein coupled receptor generation of cAMP, was repressed by high-fat feeding, but partially normalized by fasting/weight reduction. Decreased expression of RGS3 may augment levels of cAMP and thereby contribute to increased, cAMP-induced, hepatic glucose output via phosphoenolpyruvate carboxykinase (PCK1, whose mRNA levels were also elevated. Conclusion These findings demonstrate that hepatocytes respond to DIO and weight reduction by controlling gene transcription in a variety of important molecular pathways. Future studies that characterize the physiological significance of the identified genes in modulating energy homeostasis could provide a better understanding of the mechanisms linking DIO with insulin resistance.

  1. Hardware realization of a fast neural network algorithm for real-time tracking in HEP experiments

    International Nuclear Information System (INIS)

    A fast pattern recognition system for HEP experiments, based on artificial neural network algorithms (ANN), has been realized with standard electronics. The multiplicity and location of tracks in an event are determined in less than 75 ns. Hardware modules of this first level trigger were extensively tested for performance and reliability with data from the CPLEAR experiment. (orig.)

  2. Optimal scan timing of hepatic arterial-phase imaging of hypervascular hepatocellular carcinoma determined by multiphasic fast CT imaging technique

    International Nuclear Information System (INIS)

    Background: A new multiphasic fast imaging technique, known as volume helical shuttle technique, is a breakthrough for liver imaging that offers new clinical opportunities in dynamic blood flow studies. This technique enables virtually real-time hemodynamics assessment by shuttling the patient cradle back and forth during serial scanning. Purpose: To determine optimal scan timing of hepatic arterial-phase imaging for detecting hypervascular hepatocellular carcinoma (HCC) with maximum tumor-to-liver contrast by volume helical shuttle technique. Material and Methods: One hundred and one hypervascular HCCs in 50 patients were prospectively studied by 64-channel multidetector-row computed tomography (MDCT) with multiphasic fast imaging technique. Contrast medium containing 600 mg iodine per kg body weight was intravenously injected for 30 s. Six seconds after the contrast arrival in the abdominal aorta detected with bolus tracking, serial 12-phase imaging of the whole liver was performed during 24-s breath-holding with multiphasic fast imaging technique during arterial phase. By placing regions of interest in the abdominal aorta, portal vein, liver parenchyma, and hypervascular HCCs on the multiphase images, time-density curves of anatomical regions and HCCs were composed. Timing of maximum tumor-to-liver contrast after the contrast arrival in the abdominal aorta was determined. Results: For the detection of hypervascular HCC at arterial phase, mean time and value of maxirterial phase, mean time and value of maximum tumor-to-liver contrast after the contrast arrival were 21 s and 38.0 HU, respectively. Conclusion: Optimal delay time for the hepatic arterial-phase imaging maximizing the contrast enhancement of hypervascular HCCs was 21 s after arrival of contrast medium in the abdominal aorta

  3. A GEANT4 study on the time resolution of a fast plastic scintillator read out by a G-APD

    International Nuclear Information System (INIS)

    The time resolution of a fast scintillation counter, consisting of a plastic scintillator read out by a Geiger-mode Avalanche Photodiode, is studied over a wide range of the number of detected photons (primary photoelectrons) using the GEANT4 simulation toolkit. Different timing definitions such as first photon detection, leading edge and constant fraction discrimination are considered. In the latter case the predictions are compared with the existing experimental data. We also show that due to the finite scintillation rise time, finite scintillator dimensions and also due to the finite single photon time resolution in G-APD cells, the time resolution for the first detected photon in real detectors substantially deviates from the ??1/Nphe dependence, theoretically predicted for a scintillator with zero rise time.

  4. A GEANT4 study on the time resolution of a fast plastic scintillator read out by a G-APD

    Energy Technology Data Exchange (ETDEWEB)

    Sedlak, K., E-mail: kamil.sedlak@psi.ch [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Stoykov, A.; Scheuermann, R. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)

    2012-12-22

    The time resolution of a fast scintillation counter, consisting of a plastic scintillator read out by a Geiger-mode Avalanche Photodiode, is studied over a wide range of the number of detected photons (primary photoelectrons) using the GEANT4 simulation toolkit. Different timing definitions such as first photon detection, leading edge and constant fraction discrimination are considered. In the latter case the predictions are compared with the existing experimental data. We also show that due to the finite scintillation rise time, finite scintillator dimensions and also due to the finite single photon time resolution in G-APD cells, the time resolution for the first detected photon in real detectors substantially deviates from the {sigma}{approx}1/N{sub phe} dependence, theoretically predicted for a scintillator with zero rise time.

  5. Design and development of a fast-response ionization gauge controller

    International Nuclear Information System (INIS)

    Fast pressure measurements in the divertor and pump limiter chambers used in magnetic confinement fusion experiments require a system that can respond to a broad range of pressures while maintaining good noise immunity. Available designs of gauge controllers were unable to provide a acceptable noise immunity. A fast ionization gauge controller that can respond to pressure changes in the range from 1 x 10-1 to 2 x 10-5 Torr in less than 10 ms using a Schultz-Phelps gauge assembly has been developed. The Schultz-Phelps gauge provides full coverage of the desired pressure range and is less susceptible to magnetic field interference than other available types of ionization gauges. The gauge controller as designed provides simultaneous readout of three decades of pressure. Major design concerns have been to minimize noise induced by the gauge tube filament drive and noise pickup by the ionization current electrometer. By using DC filament drive, a major shortcoming of available gauge controllers, i.e., 60-Hz pickup caused by filament modulation of the electron current, has been overcome. Second, by locating the electrometer amplifier as close to the Schultz-Phelps gauge as possible, cable-induced noise pickup has been reduced to an acceptable level. Problems encountered in the design and test of the gauge controller and future improvements are discussed. 3 refs., 4 figs

  6. Design and performance of a fast thermal response miniature Chromium Potassium Alum (CPA) salt pill for use in a millikelvin cryocooler

    Science.gov (United States)

    Bartlett, J.; Hardy, G.; Hepburn, I. D.

    2015-01-01

    The design and performance of a fast thermal response miniature (24 mm outer diameter by 30 mm long) Chromium Potassium Alum (CPA) salt pill is described. The need for a fast thermal response has been driven by the development of a continuously operating millikelvin cryocooler (mKCC) which uses 2 T superconducting magnets that can be ramped to full field in 30 s. The consequence of magnetising and demagnetising the CPA pill in such a short time is that thermal boundary resistance and eddy current heating have a significant impact on the performance of the pill, which was investigated in detail using modelling. The complete design of a prototype CPA pill is described in this paper, including the methods used to minimise thermal boundary resistance and eddy current heating as well as the manufacturing and assembly processes. The performance of the prototype CPA pill operated from a 3.6 K bath is presented, demonstrating that a complete CPA cycle (magnetising, cooling to bath and demagnetising) can be accomplished in under 2.5 min, with magnetisation and demagnetisation taking just 30 s each. The cold finger base temperature of the prototype varies with demagnetisation speed as a consequence of eddy current heating; for a 30 s demagnetisation, a base temperature of 161 mK is obtained, whilst for a 5 min demagnetisation, a base temperature of 149 mK was measured (both from a 3.6 K and 2 T starting position). The measured hold times of the CPA pill at 200 mK, 300 mK, and 1 K are given, proving that the hold time far exceeds the recycle time and demonstrating the potential for continuous operation when two ADRs are used in a tandem configuration. The ease and speed at which the CPA pill temperature can be changed and controlled when stepping between operating temperatures in the range of 200 mK to 4 K using a servo control program is also shown, once again highlighting the excellent thermal response of the pill. All of the test results are in good agreement with the modelling used to design the CPA pill, giving good confidence in our ability to understand and estimate the effects of eddy current heating and thermal boundary resistance. To conclude, the design for the CPA pill to be used in the mKCC (which is heavily based on the design of the prototype) is presented.

  7. Response of Bose gases in time-dependent optical superlattices

    CERN Document Server

    Hild, M; Roth, R

    2006-01-01

    The dynamic response of ultracold Bose gases in one-dimensional optical lattices and superlattices is investigated based on an exact numerical time evolution in the framework of the Bose-Hubbard model. The system is excited by a temporal amplitude modulation of the lattice potential, as it was already realized in experiment. For regular lattice potentials, the dynamic signatures of the superfluid to Mott-insulator transition are studied and the position and the fine-structure of the resonances is explained by a linear response analysis. This serves as a preparation for the investigation of dynamical signatures of quantum phase transitions in two-colour superlattice potentials. Using direct simulations as well as a perturbative analysis it is shown that the excitation spectrum changes significantly when going from the homogeneous Mott-insulator the quasi Bose-glass phase. A characteristic and experimentally accessible signature for the quasi Bose-glass is the appearance of low-lying resonances and a suppressio...

  8. The time factor in the radiation response of the kidney

    International Nuclear Information System (INIS)

    In this article a survey is given of the time factor in the radiation response of the kidney. The radiation tolerance of the kidney is influenced by complex radiobiological and physiological factors and functional assays of damage cannot necessarily be equated with reproductive cell survival. No one animal model or assay system can provide a complete understanding of the problems involved. A complete understanding can only come from the study of a variety of assay techniques in several animal models with a frank interchange of views of the different findings likely to be obtained. The relationship between iso-effect dose and fraction number produced remarkably good agreement when the different model systems and assay techniques were compared. (Auth.)

  9. Interplanetary response to solar long time-scale phenomena

    International Nuclear Information System (INIS)

    The authors briefly review the experimental knowledge gained in the recent years on the interplanetary response to solar long-time scale phenomena such as the coronal magnetic structure and its evolution. Observational evidence that solar wind flow in the outer corona comes from the unipolar diverging magnetic regions of the photosphere is discussed along with relations to coronal holes. High-speed solar wind streams observed within the boundary of interplanetary magnetic sectors are associated with these structures. Their boundaries appear as very narrow velocity shears. The value of the maximum velocity increase is related to the amount of divergence of the field lines at the base of the corona which is less in large unipolar regions and causes the expansion to be faster according to theoretical models. Radial variations and solar cycle modulations of these structures are also presented. (Auth.)

  10. Field response and switching times in biaxial nematics.

    Science.gov (United States)

    Berardi, Roberto; Muccioli, Luca; Zannoni, Claudio

    2008-01-14

    We study by means of virtual molecular dynamics computer experiments the response of a bulk biaxial nematic to an applied external field and, in particular, the relative speed of reorientation of the principal director axis and of the secondary one, typical of these new materials, upon a pi2 field switch. We perform the simulations setting up and integrating the equations of motion for biaxial Gay-Berne particles using quaternions and a suitable time reversible symplectic integrator. We find that switching of the secondary axis is up to an order of magnitude faster than that of the principal axis, and that under fields above a certain strength a reorganization of local domains, temporarily disrupting the nematic and biaxial ordering, rather than a collective concerted reorientation occurs. PMID:18205473

  11. A Nonintrusive Approach to Estimate Web Server Response Time

    Directory of Open Access Journals (Sweden)

    Mehul Nalin Vora

    2013-02-01

    Full Text Available With proliferation of internet and webapplications usage, server performance is a critical research area in last decade. This paper presents a nonintrusive approach to estimate server response time for user-initiated web-page requests from web-server access-log data using a variant of fuzzy c-means algorithm. The approach presented here is particularly suitable for a system of web-application(s accessed concurrently by multiple users and running in a constrained production environment where minimal amount of monitoring or logging data is available. In such scenarios, proposed approach will be useful conducting advance system level testing as well as in verifying compliance to service level agreements (SLAs. Algorithm presented here has been tested using open source web application JPetStoreApp and java based load testing framework Grinder.

  12. LYSO scintillator studies for a fast low-energy calorimeter

    Science.gov (United States)

    Djilkibaev, R.; Karavichev, O.; Postoev, V.

    2015-03-01

    Detector cells consisting of fast LYSO crystals viewed by avalanche photo-diodes were designed, built and bench-tested. Using two avalanche photo-diodes per crystal and using fast pulse shaping provided the light yield, low noise, and fast response needed for use in 50 MeV calorimetry for high beam rates. The achieved stochastic term coefficient is 0.17% and the time response was characterized by a single decay term of 50 ns.

  13. Dasatinib induces fast and deep responses in newly diagnosed chronic myeloid leukaemia patients in chronic phase: clinical results from a randomised phase-2 study (NordCML006).

    Science.gov (United States)

    Hjorth-Hansen, Henrik; Stenke, Leif; Söderlund, Stina; Dreimane, Arta; Ehrencrona, Hans; Gedde-Dahl, Tobias; Gjertsen, Bjørn Tore; Höglund, Martin; Koskenvesa, Perttu; Lotfi, Kourosh; Majeed, Waleed; Markevärn, Berit; Ohm, Lotta; Olsson-Strömberg, Ulla; Remes, Kari; Suominen, Merja; Simonsson, Bengt; Porkka, Kimmo; Mustjoki, Satu; Richter, Johan

    2015-03-01

    We randomised 46 newly diagnosed patients with chronic myeloid leukaemia (median age 56) to receive dasatinib 100 mg QD or imatinib 400 mg QD and report outcome as an intention-to-treat analysis with 36 months follow-up. Early cytogenetic and molecular responses were superior in the dasatinib group, with a tendency that imatinib patients caught up with time. For instance, MR(3.0) was reached at 3 months in 36% vs. 8% (P = 0.02), at 12 months in 81% vs. 46% (P = 0.02) and at 18 months in 73% vs. 65% (n.s.) of the patients in the two groups. In contrast, MR(4.5) was consistently superior in the dasatinib group at all time points from 6 months onwards, reaching 61% vs. 21% (P dasatinib and imatinib arms, respectively, remained on assigned drug. Dasatinib dose was frequently reduced, but with maintained excellent effect. One imatinib patient progressed to blastic phase, but no CML-related deaths occurred. In conclusion, our data compare favourably with those of the dasatinib registration study, DASISION. The fast and deep molecular responses induced by dasatinib compared with imatinib may be exploited to increase the proportion of patients who can achieve a treatment-free remission after treatment discontinuation. PMID:25082346

  14. A time-resolved spectroscopic diagnostic based on fast scintillator and optical fiber array for z-pinch plasmas.

    Science.gov (United States)

    Ye, Fan; Qin, Yi; Jiang, Shuqing; Xue, Feibiao; Li, Zhenghong; Yang, Jianlun; Xu, Rongkun; Anan'ev, S S; Dan'ko, S A; Kalinin, Yu G

    2009-10-01

    We report a specially designed type of temporal resolved x-ray spectroscopic diagnostic using a spherically bent quartz crystal for z-pinch plasmas. Registration of time-resolved spectra was accomplished by coupling fast plastic scintillator, an optical fiber array, an optical streak camera, and a charge coupled device as the recording medium of this diagnostic. The diagnostic has been tested in imploding wire array experiments on S-300 pulsed power facility. Time-resolved K-shell lines were successfully obtained for aluminum wire array implosion plasmas. PMID:19895094

  15. Development of time-of-flight neutron detector with fast-decay and low-afterglow scintillator for fast ignition experiment

    Directory of Open Access Journals (Sweden)

    Nagai T.

    2013-11-01

    Full Text Available A fast-decay and low-afterglow liquid scintillator was developed for the fast ignition experiment at the Institute of Laser Engineering (ILE. The liquid scintillator was coupled to a gated photomultiplier (PMT, and the gating performance under high-intensity ?-rays was experimentally checked. In 2010, a detector with a high detection efficiency of 10?4 was developed and installed in this experiment. The neutron yield in the fast heating experiment was successfully measured using this detector.

  16. Real-time interactive three-dimensional display of signal and contrast in fast MR imaging

    International Nuclear Information System (INIS)

    The authors present personal computer software that generates a high-resolution three-dimensional color display of the MR image's contrast and/or signal intensity versus user-chosen tissue and pulse sequence parameters for conventional sequences and various types of fast sequences using low flip angles and gradient-recalled echoes. These predictions have been correlated with images obtained at 0.5 and 1.5 T and have been applied to study the effects of magnetic susceptibility and contrast agent concentration in fast MR imaging. The speed and ease of operation allow interactive use, which facilitates insight into the influence of parameters on contrast and is useful for both teaching purposes and clinical and experimental investigation

  17. Temporal Gillespie algorithm: Fast simulation of contagion processes on time-varying networks

    CERN Document Server

    Vestergaard, Christian L

    2015-01-01

    Stochastic simulations are one of the cornerstones of the analysis of dynamical processes on complex networks, and are often the only accessible way to explore their behavior. The development of fast algorithms is paramount to allow large-scale simulations. The Gillespie algorithm can be used for fast simulation of stochastic processes, and variants of it have been applied to simulate dynamical processes on static networks. However, its adaptation to temporal networks remains non-trivial. We here present a temporal Gillespie algorithm that solves this problem. Our method is applicable to general Poisson (constant-rate) processes on temporal networks, stochastically exact, and up to orders of magnitude faster than traditional simulation schemes based on rejection sampling. We also show how it can be extended to simulate non-Markovian processes. The algorithm is easily applicable in practice, and as an illustration we detail how to simulate both Poissonian and non-Markovian models of epidemic spreading. Namely,...

  18. Analog electro-optical readout of SiPMs achieves fast timing required for time-of-flight PET/MR

    Science.gov (United States)

    Bieniosek, M. F.; Levin, C. S.

    2015-05-01

    The design of combined positron emission tomography/magnetic resonance (PET/MR) systems presents a number of challenges to engineers, as it forces the PET system to acquire data in a space constrained environment that is sensitive to electro-magnetic interference and contains high static, radio frequency and gradient fields. In this work we validate fast timing performance of a PET scintillation detector using a potentially very compact, very low power, and MR compatible readout method in which analog silicon photomultipliers (SiPM) signals are transmitted optically away from the MR bore with little or even no additional readout electronics. This analog ‘electro-optial’ method could reduce the entire PET readout in the MR bore to two compact, low power components (SiPMs and lasers). Our experiments show fast timing performance from analog electro-optical readout with and without pre-amplification. With 3 mm × 3 mm × 20 mm lutetium–yttrium oxyorthosilicate (LYSO) crystals and Excelitas SiPMs the best two-sided fwhm coincident timing resolution achieved was 220 +/? 3 ps in electrical mode, 230 +/? 2 ps in electro-optical with preamp mode, and 253 +/? 2 ps in electro-optical without preamp mode. Timing measurements were also performed with Hamamatsu SiPMs and 3 mm × 3 mm × 5 mm crystals. In the future the timing degradation seen can be further reduced with lower laser noise or improvements SiPM rise time or gain.

  19. Higher order time asymptotics of fast diffusion in euclidean space: a dynamical systems approach

    OpenAIRE

    Denzler, Jochen; Koch, Herbert; McCann, Robert

    2012-01-01

    This paper quantifies the speed of convergence and higher- order asymptotics of fast diffusion dynamics on R^n to the Barenblatt (self similar) solution. Degeneracies in the parabolicity of this equation are cured by re-expressing the dynamics on a manifold with a cylindrical end, called the cigar. The nonlinear evolution becomes differentiable in Hoelder spaces on the cigar. The linearization of the dynamics is given by the Laplace-Beltrami operator plus a transport term (w...

  20. The First Synchrotron Infrared Beamlines at the ALS: Spectromicroscopy and Fast Timing

    OpenAIRE

    Martin, Michael C.; Mckinney, Wayne R.

    1999-01-01

    Two recently commissioned infrared beamlines on the 1.4 bending magnet port at the Advanced Light Source, LBNL, are described. Using a synchrotron as an IR source provides three primary advantages: increased brightness, very fast light pulses, and enhanced far-IR flux. The considerable brightness advantage manifests itself most beneficially when performing spectroscopy on a microscopic length scale. Beamline (BL) 1.4.3 is a dedicated FTIR spectromicroscopy beamline, where a ...

  1. A fast, flexible and low cost real time data acquisition system for nuclear physics experiments

    International Nuclear Information System (INIS)

    A system has been developed to permit fast, efficient data collection from a relatively complex nuclear experiment. Incorporated into this system is the communication framework for on-line analysis of the incoming data. The system makes extensive use of readily available low cost Intel based microprocessors. Results from recent measurements of the 16O(?,n) cross section made using tagged photons, performed at previously unachievable collection rates are presented. 6 refs., 6 figs

  2. The effects of time pressure on chess skill: an investigation into fast and slow processes underlying expert performance.

    Science.gov (United States)

    van Harreveld, Frenk; Wagenmakers, Eric-Jan; van der Maas, Han L J

    2007-09-01

    The ability to play chess is generally assumed to depend on two types of processes: slow processes such as search, and fast processes such as pattern recognition. It has been argued that an increase in time pressure during a game selectively hinders the ability to engage in slow processes. Here we study the effect of time pressure on expert chess performance in order to test the hypothesis that compared to weak players, strong players depend relatively heavily on fast processes. In the first study we examine the performance of players of various strengths at an online chess server, for games played under different time controls. In a second study we examine the effect of time controls on performance in world championship matches. Both studies consistently show that skill differences between players become less predictive of the game outcome as the time controls are tightened. This result indicates that slow processes are at least as important for strong players as they are for weak players. Our findings pose a challenge for current theorizing in the field of expertise and chess. PMID:17186308

  3. A "package solution" fast track program can reduce the diagnostic waiting time in head and neck cancer

    DEFF Research Database (Denmark)

    SØrensen, Jesper Roed; Johansen, JØrgen

    2014-01-01

    In 2007, a fast track program for patients with suspicion of head and neck cancer (HNC) was introduced in Denmark to reduce unnecessary waiting time. The program was based on so called "package solutions" including pre-booked slots for outpatient evaluation, imaging, and diagnostic surgical procedures. The purpose of this study is to present a model for fast track handling of patients suspicious of cancer in the head and neck region and to evaluate the effect of implementation on the diagnostic work up time. Patients with suspicion of HNC referred to the same university department of ENT Head and Neck Surgery during three comparable time intervals 2006-2007, 2007-2008, and 2011-2012 (groups 1-3) were investigated. We recorded the time from patient referral, to first consultation and final diagnosis. The first interval was before initiation of the "package solution", the second just after the introduction, and the third interval represents the current situation. The median time from referral to first consultation was reduced from eight calendar days in group 1 to only one day in groups 2 and 3 (p 

  4. Trigger-responsive, fast-degradable poly(?-amino ester)s for enhanced DNA unpackaging and reduced toxicity.

    Science.gov (United States)

    Deng, Xiaojian; Zheng, Nan; Song, Ziyuan; Yin, Lichen; Cheng, Jianjun

    2014-06-01

    Poly(?-amino ester)s (PBAEs) represent an important class of cationic gene delivery materials which, however, suffer from uncontrolled DNA release due in part to the slow degradation of their polyester backbone. Additionally, PBAEs with high molecular weight (MW) also show considerable toxicities. In this study, we designed and developed PBAEs with trigger-responsive domains built-in polymer backbones that can be rapidly cleaved upon external UV light triggering to promote intracellular DNA release as well as reduce material toxicity. Photo-responsive PBAEs were prepared via polyaddition of (2-nitro-1,3-phenylene)bis(methylene) diacrylate and a bifunctional amine. The nitrobenzene moiety was placed in each repeating unit of the PBAE to allow fast response to external UV irradiation, and thus the ester linkers were cleaved and the polymers were degraded within several minutes upon UV irradiation. Cationic PBAEs with high MWs were able to mediate effective intracellular gene delivery, while upon UV irradiation post-transfection, enhanced DNA unpackaging and reduced material toxicity were observed, which collectively contributed to greatly improved transfection efficiencies in various mammalian cell types tested. This strategy allows precise manipulation of material toxicity and gene release profiles of PBAEs, and thus provides an effective design approach to address critical issues in non-viral gene delivery. PMID:24674461

  5. Frequency analysis of the visual steady-state response measured with the fast optical signal in younger and older adults

    Science.gov (United States)

    Tse, Chun-Yu; Gordon, Brian A.; Fabiani, Monica; Gratton, Gabriele

    2010-01-01

    Relatively high frequency activity (>4 Hz) carries important information about the state of the brain or its response to high frequency events. The electroencephalogram (EEG) is commonly used to study these changes because it possesses high temporal resolution and a good signal-to-noise ratio. However, it provides limited spatial information. Non-invasive fast optical signals (FOS) have been proposed as a neuroimaging tool combining spatial and temporal resolution. Yet, this technique has not been applied to study high frequency brain oscillations because of its relatively low signal-to-noise ratio. Here we investigate the sensitivity of FOS to relatively high-frequency brain oscillations. We measured the steady-state optical response elicited in medial and lateral occipital cortex by checkerboard reversals occurring at 4, 6, and 8 Hz in younger and older adults. Stimulus-dependent oscillations were observed at the predicted stimulation frequency. In addition, in the younger adults the FOS steady-state response was smaller in lateral than medial areas, whereas in the older adults it was reversed in these two cortical regions. This may reflect diminished top-down inhibitory control in the older adults. The results indicate that FOS can be used to study the modulation of relatively high-frequency brain oscillations in adjacent cortical regions. PMID:20566389

  6. A Bivariate Lognormal Response-Time Model for the Detection of Collusion between Test Takers

    Science.gov (United States)

    van der Linden, Wim J.

    2009-01-01

    A bivariate lognormal model for the distribution of the response times on a test by a pair of test takers is presented. As the model has parameters for the item effects on the response times, its correlation parameter automatically corrects for the spuriousness in the observed correlation between the response times of different test takers because…

  7. A defined network of fast-spiking interneurons in orbitofrontal cortex: responses to behavioral contingencies and ketamine administration

    Directory of Open Access Journals (Sweden)

    DaraLSosulski

    2009-11-01

    Full Text Available Orbitofrontal cortex (OFC is a region of prefrontal cortex implicated in the motivational control of behavior and in related abnormalities seen in psychosis and depression. It has been hypothesized that a critical mechanism in these disorders is the dysfunction of GABAergic interneurons that normally regulate prefrontal information processing. Here, we studied a subclass of interneurons isolated in rat OFC using extracellular waveform and spike train analysis. During performance of a goal-directed behavioral task, the firing of this class of putative fast-spiking (FS interneurons showed robust temporal correlations indicative of a functionally coherent network. FS cell activity also co-varied with behavioral response latency, a key indicator of motivational state. Systemic administration of ketamine, a drug that can mimic psychosis, preferentially inhibited this cell class. Together, these results support the idea that OFC-FS interneurons form a critical link in the regulation of motivation by prefrontal circuits during normal and abnormal brain and behavioral states.

  8. Intercomparison of fast response commercial gas analysers for nitrous oxide flux measurements under field conditions

    Science.gov (United States)

    Rannik, Ü.; Haapanala, S.; Shurpali, N. J.; Mammarella, I.; Lind, S.; Hyvönen, N.; Peltola, O.; Zahniser, M.; Martikainen, P. J.; Vesala, T.

    2015-01-01

    Four gas analysers capable of measuring nitrous oxide (N2O) concentration at a response time necessary for eddy covariance flux measurements were operated from spring until winter 2011 over a field cultivated with reed canary grass (RCG, Phalaris arundinacea, L.), a perennial bioenergy crop in eastern Finland. The instruments were TGA100A (Campbell Scientific Inc.), CW-TILDAS-CS (Aerodyne Research Inc.), N2O / CO-23d (Los Gatos Research Inc.) and QC-TILDAS-76-CS (Aerodyne Research Inc.). The period with high emissions, lasting for about 2 weeks after fertilization in late May, was characterized by an up to 2 orders of magnitude higher emission, whereas during the rest of the campaign the N2O fluxes were small, from 0.01 to 1 nmol m-2 s-1. Two instruments, CW-TILDAS-CS and N2O / CO-23d, determined the N2O exchange with minor systematic difference throughout the campaign, when operated simultaneously. TGA100A produced the cumulatively highest N2O estimates (with 29% higher values during the period when all instruments were operational). QC-TILDAS-76-CS obtained 36% lower fluxes than CW-TILDAS-CS during the first period, including the emission episode, whereas the correspondence with other instruments during the rest of the campaign was good. The reasons for systematic differences were not identified, suggesting further need for detailed evaluation of instrument performance under field conditions with emphasis on stability, calibration and any other factors that can systematically affect the accuracy of flux measurements. The instrument CW-TILDAS-CS was characterized by the lowest noise level (with a standard deviation of around 0.12 ppb at 10 Hz sampling rate) as compared to N2O / CO-23d and QC-TILDAS-76-CS (around 0.50 ppb) and TGA100A (around 2 ppb). We identified that for all instruments except CW-TILDAS-CS the random error due to instrumental noise was an important source of uncertainty at the 30 min averaging level and the total stochastic error was frequently of the same magnitude as the fluxes when N2O exchange was small at the measurement site. Both instruments based on continuous-wave quantum cascade laser, CW-TILDAS-CS and N2O / CO-23d, were able to determine the same sample of low N2O fluxes with a high mutual coefficient of determination at the 30 min averaging level and with minor systematic difference over the observation period of several months. This enables us to conclude that the new-generation instrumentation is capable of measuring small N2O exchange with high precision and accuracy at sites with low fluxes.

  9. Reclaiming Spare Capacity and Improving Aperiodic Response Times in Real-Time Environments

    Directory of Open Access Journals (Sweden)

    Liu Xue

    2011-01-01

    Full Text Available Abstract Scheduling recurring task sets that allow some instances of the tasks to be skipped produces holes in the schedule which are nonuniformly distributed. Similarly, when the recurring tasks are not strictly periodic but are sporadic, there is extra processor bandwidth arising because of irregular job arrivals. The additional computation capacity that results from skips or sporadic tasks can be reclaimed to service aperiodic task requests efficiently and quickly. We present techniques for improving the response times of aperiodic tasks by identifying nonuniformly distributed spare capacity—because of skips or sporadic tasks—in the schedule and adding such extra capacity to the capacity queue of a BASH server. These gaps can account for a significant portion of aperiodic capacity, and their reclamation results in considerable improvement to aperiodic response times. We present two schemes: NCLB-CBS, which performs well in periodic real-time environments with firm tasks, and NCLB-CUS, which can be deployed when the basic task set to schedule is sporadic. Evaluation via simulations and implementation suggests that performance improvements for aperiodic tasks can be obtained with limited additional overhead.

  10. A fast time-to-digital converter for position-sensitive radiation detectors with delay line readouts

    International Nuclear Information System (INIS)

    A fast time-to-digital converter (TDC) has been developed for use with position-sensitive radiation detectors having delay line readouts. The device is recommended for detector applications where high position resolution and low distortion are required at high rates. The device has 2 ns time resolution, less than 0.1% differential nonlinearity, and a recovery time of 70 ns. When used with a detector system having a delay line of temporal length ?, the following performance has been achieved: (1) a position digitization of 1 position resolution element per ns of delay line; (2) an average dead time of (3/4 ? + 70) ns; (3) a maximum incident radiation rate of ?4/?; and (4) a maximum conversion rate of ? 1/(3?). Discriminator circuits reduce pile-up distortion to negligible levels for rates as high as those listed above. Finally, two converters may be connected together for synchronous operation as required by 2-dimensional (?-?) detectors. (orig.)

  11. Time-resolved optical imaging through turbid media using a fast data acquisition system based on a gated CCD camera

    Energy Technology Data Exchange (ETDEWEB)

    D' Andrea, Cosimo; Comelli, Daniela; Pifferi, Antonio; Torricelli, Alessandro; Valentini, Gianluca; Cubeddu, Rinaldo [INFM-Dipartimento di Fisica and IFN-CNR, Politecnico di Milano Piazza Leonardo da Vinci 32, I-20133 Milan (Italy)

    2003-07-21

    In this paper, we propose a novel approach for the acquisition of time-resolved data for optical tomography. A fast gated CCD has been used as a parallel detector to acquire in one shot the light intensity exiting a phantom within a very short time slice. By using a pulsed illumination and repeating the acquisition at different delays, the time behaviour of the diffused transmittance can be recorded very quickly. Scattering inclusions embedded in a 5 cm thick phantom have been revealed by fitting a set of 120 images, delayed 50 ps from one another, with a mathematical model based on the random walk theory. Moreover, absorption inclusions have been detected in time-gated images taken at suitable delays.

  12. Time-resolved optical imaging through turbid media using a fast data acquisition system based on a gated CCD camera

    International Nuclear Information System (INIS)

    In this paper, we propose a novel approach for the acquisition of time-resolved data for optical tomography. A fast gated CCD has been used as a parallel detector to acquire in one shot the light intensity exiting a phantom within a very short time slice. By using a pulsed illumination and repeating the acquisition at different delays, the time behaviour of the diffused transmittance can be recorded very quickly. Scattering inclusions embedded in a 5 cm thick phantom have been revealed by fitting a set of 120 images, delayed 50 ps from one another, with a mathematical model based on the random walk theory. Moreover, absorption inclusions have been detected in time-gated images taken at suitable delays

  13. Brainstem auditory evoked responses in man. 1: Effect of stimulus rise-fall time and duration

    Science.gov (United States)

    Hecox, K.; Squires, N.; Galambos, R.

    1975-01-01

    Short latency (under 10 msec) responses elicited by bursts of white noise were recorded from the scalps of human subjects. Response alterations produced by changes in the noise burst duration (on-time), inter-burst interval (off-time), and onset and offset shapes were analyzed. The latency of the most prominent response component, wave V, was markedly delayed with increases in stimulus rise time but was unaffected by changes in fall time. Increases in stimulus duration, and therefore in loudness, resulted in a systematic increase in latency. This was probably due to response recovery processes, since the effect was eliminated with increases in stimulus off-time. The amplitude of wave V was insensitive to changes in signal rise and fall times, while increasing signal on-time produced smaller amplitude responses only for sufficiently short off-times. It was concluded that wave V of the human auditory brainstem evoked response is solely an onset response.

  14. Particle size distributions from laboratory-scale biomass fires using fast response instruments

    Directory of Open Access Journals (Sweden)

    S. Hosseini

    2010-04-01

    Full Text Available Particle size distribution from biomass combustion is an important parameter as it affects air quality, climate modelling and health effects. To date particle size distributions reported from prior studies vary not only due to difference in fuels but also difference in experimental conditions. This study aims to report characteristics of particle size distribution in a well controlled repeatable lab scale biomass fires for southwestern US fuels. The combustion facility at the USDA Forest Service's Fire Science Laboratory (FSL, Missoula, MT provided repeatable combustion and dilution environment ideal for particle size distribution study. For a variety of fuels tested the major mode of particle size distribution was in the range of 29 to 52 nm, which was attributable to dilution of the fresh smoke. Comparing volume size distribution from Fast Mobility Particle Sizer (FMPS and Aerodynamic Particle Sizer (APS measurements, ~30% of particle volume was attributable to the particles ranging from 0.5 to 10 ?m for PM10. Geometric mean diameter rapidly increased during flaming and gradually decreased during mixed and smoldering phase combustion. Most of fuels gave unimodal distribution during flaming phase and strong biomodal distribution during smoldering phase. The mode of combustion (flaming, mixed and smoldering could be better distinguished using slopes in Modified Combustion Efficiency (MCE vs. geometric mean diameter from each mode of combustion than only using MCE values.

  15. Containment response to postulated core meltdown accidents in the Fast Flux Test Facility

    International Nuclear Information System (INIS)

    An assessment of the containment margin available in the Fast Flux Test Facility to mitigate the consequences of a postulated failure on in-vessel post-accident heat removal following a hypothetical core-disruptive accident (HCDA) has been completed. Two general meltdown configurations (termed in-vessel and ex-vessel) have been considered, and it is concluded that: (1) For the in-vessel meltdown scenario, the quantity of sodium assumed ejected from the vessel into the cavity during the HCDA is crucial to the subsequent reactor containment building (RCB) pressurization. If the reactor cavity liner is also assumed to fail, then the containment integrity could be challenged within 10 hours. (2) For the ex-vessel meltdown scenario, the collapse of the reactor cavity floor, which allows sodium to contact the unlined subcavity, is crucial to the subsequent RCB pressurization. Predictions of cavity floor penetration vary between 2 to 60 hours depending on the initial assumptions made; however, after floor collapse occurs overpressurization of the RCB occurs rapidly within several hours

  16. Fast time resolution charge-exchange measurements during the fishbone instability in the poloidal divertor experiment

    International Nuclear Information System (INIS)

    Measurements of fast ion losses due to the fishbone instability during high ?/sub T/q neutral beam heated discharges in the Poloidal Divertor Experiment have been made using two new vertical-viewing charge-exchange analyzers. The measurements show that the instability has an n=1 toroidal mode number, and that it ejects beam ions in a toroidally rotating beacon directed outward along a major radius. Observations of ejected ions with energies up to twice the beam injection energy at R approx. = R0 + a indicate the presence of a non-?-conserving acceleration mechanism

  17. An expert system for real-time diagnostics of a fast reactor fuel reprocessing plant

    International Nuclear Information System (INIS)

    To provide on-line operator support for surveillance and diagnostics of a remotely operated fast reactor fuel reprocessing plant, where process parameters are evaluated from indirect instrumental measurements, a modular prototype expert system OASIS (Operator Assistant) is being developed at our laboratory. Design of this expert system is based on several new concepts. Unlike other available expert systems, it is not based on commercial shells. Instead it has a custom designed knowledge engineering architecture which is user-friendly to a high degree. (author). 7 refs., 2 figs

  18. Cardio-respiratory responses to moderately heavy aerobic exercise during the Ramadan fasts.

    OpenAIRE

    Ramadan, J. M.; Barac-nieto, M.

    2000-01-01

    OBJECTIVES The aim of this study was to quantify the magnitude of the cardiovascular and respiratory changes that occur during the month of Ramadan in response to moderately heavy aerobic physical exertion. METHODS Eighteen sedentary Kuwaiti adult males were tested under thermo-neutral conditions during a spring-like month of Ramadan and one month thereafter. RESULTS There were no significant changes in maximal exercise capacity, treadmill walking efficiency, percentage VO2 max...

  19. Metabolomics of Ramadan fasting: an opportunity for the controlled study of physiological responses to food intake

    OpenAIRE

    Mathew, Sweety; Krug, Susanne; Skurk, Thomas; Halama, Anna; Stank, Antonia; Artati, Anna; Prehn, Cornelia; Malek, Joel A.; Kastenmüller, Gabi; Römisch-Margl, Werner; Adamski, Jerzy; Hauner, Hans; Suhre, Karsten

    2014-01-01

    High-throughput screening techniques that analyze the metabolic endpoints of biological processes can identify the contributions of genetic predisposition and environmental factors to the development of common diseases. Studies applying controlled physiological challenges can reveal dysregulation in metabolic responses that may be predictive for or associated with these diseases. However, large-scale epidemiological studies with well controlled physiological challenge conditions, such as exte...

  20. Fast Transcriptional Responses to Domestication in the Brook Charr Salvelinus fontinalis

    OpenAIRE

    Sauvage, Christopher; Dero?me, Nicolas; Normandeau, Eric; St -cyr, Je?ro?me; Audet, Ce?line; Bernatchez, Louis

    2010-01-01

    Domestication has been practiced for centuries yet directed toward relatively few terrestrial crops and animals. While phenotypic and quantitative genetic changes associated with domestication have been amply documented, little is known about the molecular changes underlying the phenotypic evolution during the process. Here, we have investigated the brook charr (Salvelinus fontinalis) responses to artificial selection by means of transcriptional analysis of ?32,000 cDNA features performed i...

  1. Photoconductivity and Response Times of Single-Walled Carbon Nanotube Bundles on Quartz

    Science.gov (United States)

    Castellini, O. M.; Marcus, Matthew S.; Simmons, J. M.; Eriksson, M. A.

    2004-03-01

    We report that photocurrent measured from single walled nanotube bundles have response times 7.5 ms when irradiated with visible light. The response times are surprisingly long considering the large carrier velocities in the nanotube. We propose that inter-tube coupling plays a role in the long response times, and estimate an inter-tube resistance of 568MW. We studied the effect of adsorbed oxygen forming trap states by varying oxygen partial pressure and find a negligible change in response times. Measurements of response times from visible light are possible because the substrate is quartz, which prevents coupling of the nanotube circuit to light absorbed by the substrate.

  2. Integrated response and transit time distributions of watersheds by combining hydrograph separation and long-term transit time modeling

    OpenAIRE

    M. C. Roa-García; Weiler, M.

    2010-01-01

    We present a new modeling approach analyzing and predicting the Transit Time Distribution (TTD) and the Response Time Distribution (RTD) from hourly to annual time scales as two distinct hydrological processes. The model integrates Isotope Hydrograph Separation (IHS) and the Instantaneous Unit Hydrograph (IUH) approach as a tool to provide a more realistic description of transit and response time of water in catchments. Individual event simulations and parameterizations were combined with lon...

  3. Growth and characterization of rutile TiO2 nanorods on various substrates with fabricated fast-response metal-semiconductor-metal UV detector based on Si substrate

    Science.gov (United States)

    Selman, Abbas M.; Hassan, Z.

    2015-07-01

    Rutile-phase titanium dioxide nanorods (NRs) were synthesized successfully on p-type silicon (Si) (1 1 1), c-plane sapphire (Al2O3), glass coated with fluorine-doped tin oxide (FTO), glass, and quartz substrates via chemical bath deposition method. All substrates were seeded with a TiO2 seed layer synthesized with a radio frequency reactive magnetron sputtering system prior to NRs growth. The effect of substrate type on structural, morphological, and optical properties of rutile TiO2 NRs was studied. X-ray diffraction, Raman spectroscopy, and field-emission scanning electron microscopy analyses showed the tetragonal rutile structure of the synthesized TiO2 NRs. Optical properties were examined with photoluminescence (PL) spectroscopy of the grown rutile NRs on all substrates, with the spectra exhibiting one strong ultraviolet emission peak intensity compared with broad visible peak. The optimal sample of rutile NRs was grown on Si substrate. Thus, a fast-response metal-semiconductor-metal ultraviolet (UV) detector was fabricated. Upon exposure to 365 nm light (2.3 mW/cm2) at 5 V bias, the device displays 2.62 × 10-5 A photocurrent, and the response and recovery times are calculated as 18.5 and 19.1 ms, respectively. These results demonstrate that the fabricated high-quality photodiode is a promising candidate as a low-cost UV photodetector for commercially integrated photoelectronic applications.

  4. On assessing operator response time in human reliability analysis (HRA) using a possibilistic fuzzy regression model

    International Nuclear Information System (INIS)

    Operator response times for off-normal events in nuclear power plants have been used to assess human failure probabilities. Usually, log-normal distribution is applied to the relation of response times and failure probabilities. In the literature there have been several studies on estimating the response times. Since the response times are affected by the performance shaping factors, a regression model can be applied to estimate the response times. The conventional regression model regards the deviations between the observed and estimated values as measurement errors. However, the deviations of the dependent variable, the response times can be dependent upon the fuzziness of the parameters for the independent variables, the performance shaping factors. In this research, possibilistic linear regression models have been used to asses fuzzy parameters and furthermore response times associated with the performance shaping factors

  5. Low distortion, continuously tunable, positive and negative time delays by slow and fast light using stimulated Brillouin scattering

    Energy Technology Data Exchange (ETDEWEB)

    Shi Zhimin, E-mail: zshi@optics.rochester.ed [Institute of Optics, University of Rochester, Rochester, NY 14627 (United States); Schweinsberg, Aaron; Vornehm, Joseph E. [Institute of Optics, University of Rochester, Rochester, NY 14627 (United States); Martinez Gamez, M. Alejandrina [Centro de Investigaciones en Optica, Loma del Bosque 115, Col. Lomas del Campestre, Leon 37150, Gto. (Mexico); Boyd, Robert W., E-mail: boyd@optics.rochester.ed [Institute of Optics, University of Rochester, Rochester, NY 14627 (United States)

    2010-08-30

    We demonstrate a single optical timing module that can provide both tunable delay and advancement with low distortion using a reconfigurable gain medium based on stimulated Brillouin scattering. Dual-stage intensity modulation method is used to achieve optimized gain profiles for both slow- and fast-light operation. Using 6.5 ns Gaussian pulses, we demonstrate a continuous temporal adjustment from a fractional advancement of 0.31 to a fractional delay of 0.82, giving more than a full pulse width of total tunability.

  6. Fast-Response, Sensitivitive and Low-Powered Chemosensors by Fusing Nanostructured Porous Thin Film and IDEs-Microheater Chip

    Science.gov (United States)

    Dai, Zhengfei; Xu, Lei; Duan, Guotao; Li, Tie; Zhang, Hongwen; Li, Yue; Wang, Yi; Wang, Yuelin; Cai, Weiping

    2013-04-01

    The chemiresistive thin film gas sensors with fast response, high sensitivity, low power consumption and mass-produced potency, have been expected for practical application. It requires both sensitive materials, especially exquisite nanomaterials, and efficient substrate chip for heating and electrical addressing. However, it is challenging to achieve repeatable microstructures across the films and low power consumption of substrate chip. Here we presented a new sensor structure via the fusion of metal-oxide nanoporous films and micro-electro-mechanical systems (MEMS)-based sensing chip. An interdigital-electrodes (IDEs) and microheater integrated MEMS structure is designed and employed as substrate chip to in-situ fabricate colloidal monolayer template-induced metal-oxide (egg. SnO2) nanoporous sensing films. This fused sensor demonstrates mW-level low power, ultrafast response (~1 s), and parts-per-billion lever detection for ethanol gas. Due to the controllable template strategy and mass-production potential, such micro/nano fused high-performance gas sensors will be next-generation key miniaturized/integrated devices for advanced practical applications.

  7. Response of RadFET Dosimeters to High Fluences of Fast Neutrons

    CERN Document Server

    Ravotti, F; Moll, Michael; Ilgner, C; Camanzi, B; Holmes-Siedle, A G; 10.1109/TNS.2005.852709

    2005-01-01

    We present irradiation experiments carried out on RadFETs in the 20.4 MeV high intensity T2 neutron beam at the CRC-UCL in Belgium. The aim of the test was to characterize the neutron response of RadFETs in view of their use as an integrated part of a radiationmonitoring sensor for the CERN Large Hadron Collider (LHC) experiments. Two types of RadFETs were investigated up to a total neutron fluence of 3x10^14 cm-2 corresponding to a deposited dose of 744 Gy in Silicon. The responses of bare devices to neutrons are compared to the commonly used reference measurements with gamma rays. It is found that the gamma ray calibration cannot directly be adopted to convert the RadFET signals into neutron dose. In a second experiment, the influence of a plastic packaging, simulated by Polyethylene slabs of different thicknesses, was tested in the neutron beam and compared to GEANT4 Monte Carlo simulations. An increase of the RadFET neutron sensitivity by a factor of up to 7 due to the packaging is found. The influence of...

  8. Modeling an Application's Theoretical Minimum and Average Transactional Response Times.

    Energy Technology Data Exchange (ETDEWEB)

    Paiz, Mary Rose

    2015-04-01

    The theoretical minimum transactional response time of an application serves as a ba- sis for the expected response time. The lower threshold for the minimum response time represents the minimum amount of time that the application should take to complete a transaction. Knowing the lower threshold is beneficial in detecting anomalies that are re- sults of unsuccessful transactions. On the converse, when an application's response time falls above an upper threshold, there is likely an anomaly in the application that is causing unusual performance issues in the transaction. This report explains how the non-stationary Generalized Extreme Value distribution is used to estimate the lower threshold of an ap- plication's daily minimum transactional response time. It also explains how the seasonal Autoregressive Integrated Moving Average time series model is used to estimate the upper threshold for an application's average transactional response time.

  9. A flowing liquid test system for assessing the linearity and time-response of rapid fibre optic oxygen partial pressure sensors.

    OpenAIRE

    Chen, R; Hahn, CE; Farmery, AD

    2012-01-01

    The development of a methodology for testing the time response, linearity and performance characteristics of ultra fast fibre optic oxygen sensors in the liquid phase is presented. Two standard medical paediatric oxygenators are arranged to provide two independent extracorporeal circuits. Flow from either circuit can be diverted over the sensor under test by means of a system of rapid cross-over solenoid valves exposing the sensor to an abrupt change in oxygen partial pressure, P O2. The syst...

  10. Response of the R3327-AT1 Dunning prostate tumor to fast neutrons and cobalt-60

    International Nuclear Information System (INIS)

    Reasons why neutron therapy may be successful include tumor's rate of proliferation, state of oxygenation at time of onset of radiation and the efficacy of reoxygenation during therapy, inherent radioresistance and repair capacity. In an effort to better understand the action of neutrons on tumor tissues we started studies with the Dunning rat prostate tumor system. This tumor system has sublines available with differing histologies, doubling times, hormone dependency and metastatic potential. The present report pertains to anaplastic carcinoma R3327-AT1 subline. The tumors transplanted into the distal thigh received single doses of 8 through 15 Gy of 14.5 MeV neutrons and 18 through 30 Gy Co-60 after they had reached a volume of about 450 mm3. The tumors exhibited a dose dependent retardation in further growth. An RBE of 3 was estimated by comparing the time required for a tumor to reach a normalized value of five times the initial treatment volume. We plan to extend our studies to include a slower growing well differentiated subline. (orig.)

  11. TREAT fast-neutron hodoscope: improvements in time and mass resolution of fuel motion

    International Nuclear Information System (INIS)

    The fast-neutron hodoscope at the Transient Reactor Test Facility detects fuel motion in thick opaque capsules during in-core destructive transient tests. Counts from several hundred detectors, each with rates up to a megahertz, are collected at intervals as short as a millisecond for up to tens of seconds. The large amount of data must be decoded, normalized, represented in suitable forms, and analyzed. A computer-controlled magnet disk data acquisition system has been installed which provides shorter data collection intervals, simplifies decoding, and permits immediate data analysis. Data normalizations and representations have been developed which significantly increase the dynamic range, yield sensitive quantitative indications of fuel mass motion, and render the data intuitively comprehensible. The improved hodoscope system performance level is demonstrated by results from a recent transient test, Pinex-2, which show the quantitative evolution of fuel mass motion from 1515 MW peak reactor power through a 1 MW post-scram radiation level

  12. Finite-time rotation number: A fast indicator for chaotic dynamical structures

    International Nuclear Information System (INIS)

    Lagrangian coherent structures are effective barriers, sticky regions, that separate chaotic phase space regions of different dynamical behavior. The usual way to detect such structures is by calculating finite-time Lyapunov exponents. We show that similar results can be obtained for time-periodic systems by calculating finite-time rotation numbers, which are faster to compute. We illustrate our claim by considering examples of continuous- and discrete-time dynamical systems of physical interest.

  13. Microwave phase shifter with controllable power response based on slow-and fast-light effects in semiconductor optical amplifiers

    DEFF Research Database (Denmark)

    Xue, Weiqi; Sales, Salvador

    2009-01-01

    We suggest and experimentally demonstrate a method for increasing the tunable rf phase shift of semiconductor waveguides while at the same time enabling control of the rf power. This method is based on the use of slow- and fast-light effects in a cascade of semiconductor optical amplifiers combined with the use of spectral filtering to enhance the role of refractive index dynamics. A continuously tunable phase shift of 240° at a microwave frequency of 19 GHz is demonstrated in a cascade of two semiconductor optical amplifiers, while maintaining an rf power change of less than 1.6 dB. The technique is scalable to more amplifiers and should allow realization of an rf phase shift of 360°.

  14. Probing Planetary Bodies for Subsurface Volatiles: GEANT4 Models of Gamma Ray, Fast, Epithermal, and Thermal Neutron Response to Active Neutron Illumination

    Science.gov (United States)

    Chin, G.; Sagdeev, R.; Su, J. J.; Murray, J.

    2014-12-01

    Using an active source of neutrons as an in situ probe of a planetary body has proven to be a powerful tool to extract information about the presence, abundance, and location of subsurface volatiles without the need for drilling. The Dynamic Albedo of Neutrons (DAN) instrument on Curiosity is an example of such an instrument and is designed to detect the location and abundance of hydrogen within the top 50 cm of the Martian surface. DAN works by sending a pulse of neutrons towards the ground beneath the rover and detecting the reflected neutrons. The intensity and time of arrival of the reflection depends on the proportion of water, while the time the pulse takes to reach the detector is a function of the depth at which the water is located. Similar instruments can also be effective probes at the polar-regions of the Moon or on asteroids as a way of detecting sequestered volatiles. We present the results of GEANT4 particle simulation models of gamma ray, fast, epithermal, and thermal neutron responses to active neutron illumination. The results are parameterized by hydrogen abundance, stratification and depth of volatile layers, versus the distribution of neutron and gamma ray energy reflections. Models will be presented to approximate Martian, lunar, and asteroid environments and would be useful tools to assess utility for future NASA exploration missions to these types of planetary bodies.

  15. Large scale simulation of macromolecules in solution: Combining the periodic fast multipole method with multiple time step integrators

    Science.gov (United States)

    Figueirido, Francisco; Levy, Ronald M.; Zhou, Ruhong; Berne, B. J.

    1997-06-01

    Large scale simulations of macromolecules in solution that do not suffer from artifacts arising from force truncations are becoming feasible. New force evaluation algorithms such as the fast multipole method (FMM) and multiple time scale integration methods such as the reversible reference system propagator algorithm (r-RESPA) have been combined and used to perform fast and stable simulations of large macromolecular systems. A consistent treatment of the long-range forces in simulations with periodic boundary conditions requires the use of a periodic form of the Coulomb potential. In this article, the FMM is extended to periodic systems, and combined with RESPA, yielding a new algorithm that is successfully applied to the simulation of large biomolecules in solution. If the interactions at different stages are separated smoothly, good energy conservation is obtained even for time steps as large as 12 fs on a system of over 40 000 atoms, and a CPU speedup of more than a factor of 20 is achieved compared to the standard Verlet integrator with Ewald sum for the Coulombic interaction. As compared with the recently developed particle-mesh Ewald (PME) method, the periodic r-RESPA/FMM has a break-even point at about 20 000 atoms; for larger systems, r-RESPA/FMM is expected to be more efficient.

  16. A new type of fast-neutron detector

    International Nuclear Information System (INIS)

    A new type of fast-neutron detector has been reported. The detector with quick time response, bit linear current and excellent anti-radiation interference performance works under the condition of non-vacuum and no power supply

  17. 75 FR 37712 - Temporary Suspension of Certain Oil Spill Response Time Requirements To Support Deepwater Horizon...

    Science.gov (United States)

    2010-06-30

    ...Time Requirements To Support Deepwater Horizon Oil Spill of National Significance...relocated in support of the Deepwater Horizon SONS response. By providing...to aid in the response to the Deepwater Horizon SONS. The rule also...

  18. Time-dependent calculations of transfer ionization by fast proton-helium collision in one-dimensional kinematics

    CERN Document Server

    Serov, Vladislav V

    2014-01-01

    We analyze a transfer ionization (TI) reaction in the fast proton-helium collision $\\rm H^+ + He \\to H^0 + He^{2+} + e^-$ by solving a time-dependent Schr\\"odinger equation (TDSE) under the classical projectile motion approximation in one-dimensional kinematics. In addition, we construct various time independent analogues of our model using lowest order perturbation theory in the form of the Born series. By comparing various aspects of the TDSE and the Born series calculations, we conclude that the recent discrepancies of experimental and theoretical data may be attributed to deficiency of the Born models used by other authors. We demonstrate that the correct Born series for TI should include the momentum space overlap between the double ionization amplitude and the wave function of the transferred electron.

  19. Time-dependent calculations of transfer ionization by fast proton-helium collision in one-dimensional kinematics

    Science.gov (United States)

    Serov, Vladislav V.; Kheifets, A. S.

    2014-12-01

    We analyze a transfer ionization (TI) reaction in the fast proton-helium collision H++He ?H0+He2 ++ e- by solving a time-dependent Schrödinger equation (TDSE) under the classical projectile motion approximation in one-dimensional kinematics. In addition, we construct various time-independent analogs of our model using lowest-order perturbation theory in the form of the Born series. By comparing various aspects of the TDSE and the Born series calculations, we conclude that the recent discrepancies of experimental and theoretical data may be attributed to deficiency of the Born models used by other authors. We demonstrate that the correct Born series for TI should include the momentum-space overlap between the double-ionization amplitude and the wave function of the transferred electron.

  20. Real-time processing of fast-scan cyclic voltammetry (FSCV) data using a field-programmable gate array (FPGA).

    Science.gov (United States)

    Bozorgzadeh, Bardia; Covey, Daniel P; Heidenreich, Byron A; Garris, Paul A; Mohseni, Pedram

    2014-01-01

    This paper reports the hardware implementation of a digital signal processing (DSP) unit for real-time processing of data obtained by fast-scan cyclic voltammetry (FSCV) at a carbon-fiber microelectrode (CFM), an electrochemical transduction technique for high-resolution monitoring of brain neurochemistry. Implemented on a field-programmable gate array (FPGA), the DSP unit comprises a decimation filter and an embedded processor to process the oversampled FSCV data and obtain in real time a temporal profile of concentration variation along with a chemical signature to identify the target neurotransmitter. Interfaced with an integrated, FSCV-sensing front-end, the DSP unit can successfully process FSCV data obtained by bolus injection of dopamine in a flow cell as well as electrically evoked, transient dopamine release in the dorsal striatum of an anesthetized rat. PMID:25570384

  1. Calculation of the optical response of atomic clusters using time-dependent density functional theory and local orbitals

    Science.gov (United States)

    Tsolakidis, Argyrios; Sánchez-Portal, Daniel; Martin, Richard M.

    2002-12-01

    We report on a general method for the calculation of the frequency-dependent optical response of clusters based upon time-dependent density functional theory (TDDFT). The implementation is done using explicit propagation in the time domain and a self-consistent program that uses a linear combination of atomic orbitals (LCAO). Our actual calculations employ the SIESTA program, which is designed to be fast and accurate for large clusters. We use the adiabatic local density approximation to account for exchange and correlation effects. Results are presented for the imaginary part of the linear polarizability, Im ?(?), and the dipole strength function, S(?), of C60 and Na8, and compared to previous calculations and to experiment. We also develop a method for the calculation of the integrated frequency-dependent second-order nonlinear polarizability for the case of a step function electric field, ?˜step(?), and present results for C60.

  2. Time response of Cd0.9Zn0.1Te crystals under transient and pulsed irradiation

    Directory of Open Access Journals (Sweden)

    X. C. Zhao

    2012-03-01

    Full Text Available A CdZnTe detector based on high-quality Cd0.9Zn0.1Te crystals was developed and tested as a monitor in high-intensity radiation fields. The current–voltage measurements were performed using thermally evaporated Au contacts deposited on the crystals, which revealed resistivity of 1010 ?·cm. Typical leakage current for the planar devices was ?3 nA for a field strength of 1000 V·cm–1. The test results show that the CdZnTe detector has a fast time response, with a rise time of approximately 2 ns, when exposed to transient and pulsed irradiation of X-rays or electron beams. The decay of current curves is observed and discussed according to charge carrier trapping effects and space-charge accumulation mechanisms. It is suggested that the current decreases quickly with strengthening of the electric field, possibly because of charge de-trapping.

  3. Fast Data in the Era of Big Data: Twitter's Real-Time Related Query Suggestion Architecture

    OpenAIRE

    Mishne, Gilad; Dalton, Jeff; Li, Zhenghua; Sharma, Aneesh; Lin, Jimmy

    2012-01-01

    We present the architecture behind Twitter's real-time related query suggestion and spelling correction service. Although these tasks have received much attention in the web search literature, the Twitter context introduces a real-time "twist": after significant breaking news events, we aim to provide relevant results within minutes. This paper provides a case study illustrating the challenges of real-time data processing in the era of "big data". We tell the story of how ou...

  4. A fast transient response low dropout regulator with current control methodology

    International Nuclear Information System (INIS)

    A transient performance optimized CCL-LDO regulator is proposed. In the CCL-LDO, the control method of the charge pump phase-locked loop is adopted. A current control loop has the feedback signal and reference current to be compared, and then a loop filter generates the gate voltage of the power MOSFET by integrating the error current. The CCL-LDO has the optimized damping coefficient and natural resonant frequency, while its output voltage can be sub-1-V and is not restricted by the reference voltage. With a 1 ?F decoupling capacitor, the experimental results based on a 0.13 ?m CMOS process show that the output voltage is 1.0 V; when the workload changes from 100 ?A to 100 mA transiently, the stable dropout is 4.25 mV, the settling time is 8.2 ?s and the undershoot is 5.11 mV; when the workload changes from 100 mA to 100 ?A transiently, the stable dropout is 4.25 mV, the settling time is 23.3 ?s and the overshoot is 6.21 mV. The PSRR value is more than -95 dB. Most of the attributes of the CCL-LDO are improved rapidly with a FOM value of 0.0097.

  5. A fast low-power time-to-voltage converter for high luminosity collider detectors

    International Nuclear Information System (INIS)

    A new CMOS integrated circuit has been designed to measure the time interval between two digital voltage pulses. The measurement is stored as an analog voltage on a capacitor for later digitization. The targeted range of measurable times is 5-25 nanoseconds, with a resolution of 0.5 nanoseconds. An additional feature of the circuit is a storge depth of 8 samples, i.e. 8 consecutive time measurements may be recorded individually. Hence, the chip is a combination of a time-to-voltage converter (TVC) and an analog memory

  6. A Double-Threshold Technique for Fast Time-Correspondence Imaging

    CERN Document Server

    Li, Ming-Fei; Liu, Xue-Feng; Yao, Xu-Ri; Luo, Kai-Hong; Fan, Heng; Wu, Ling-An

    2013-01-01

    We present a robust imaging method based on time-correspondence imaging and normalized ghost imaging (GI) that sets two thresholds to select the reference frame exposures for image reconstruction. This double-threshold time-correspondence imaging protocol always gives better quality and signal-to-noise ratio than previous GI schemes, and is insensitive to surrounding noise. Moreover, only simple add and minus operations are required while less data storage space and computing time are consumed, thus faster imaging speeds are attainable. The protocol offers a general approach applicable to all GI techniques, and marks a further step forward towards real-time practical applications of correlation imaging.

  7. Time Course of Classically Conditioned Purkinje Cell Response is Determined by Initial Part of Conditioned Stimulus

    OpenAIRE

    Jirenhed, Dan-anders; Hesslow, Germund

    2011-01-01

    Classical conditioning of a motor response such as eyeblink is associated with the development of a pause in cerebellar Purkinje cell firing that is probably an important driver of the overt response. This conditioned Purkinje cell response is adaptively timed and has a specific temporal profile that probably explains the time course of the overt behavior. It is generally assumed that the temporal properties of the conditioned Purkinje cell response are determined by the temporal pattern of t...

  8. Motion-deblurred, fast-response pressure-sensitive paint on a rotor in forward flight

    International Nuclear Information System (INIS)

    A pressure-sensitive paint (PSP) system capable of measuring the global, unsteady pressure distribution on a rotating surface without resorting to phase averaging is applied to a two-bladed model propeller in edgewise freestream flow. A gated lifetime-based technique captures the paint luminescence after a single pulse of high-energy laser excitation, yielding a signal-to-noise ratio sufficient to avoid image averaging. The selection of a porous polymer/ceramic matrix base with platinum tetra(pentafluorophenyl) porphyrin (PtTFPP) as the luminophore afforded high frequency response and pressure sensitivity, but the long lifetime of PtTFPP caused blurring in the long-exposure image of the rotating blade. An approach to deblurring based on the lifetime of the paint and surface motion is described and validated by results obtained from a disc of 17.8 cm diameter spinning at 70 Hz. An infrared camera recorded wind-on and -off temperature maps to provide a temperature correction for the PSP. The single-shot PSP technique with motion deblurring and temperature correction is then applied to a vertically mounted model propeller with a 25.4 cm diameter and 10.2 cm pitch. Surface pressure maps for the advancing and retreating blades are presented for a spin rate of 70 Hz and advance ratio of 0.3. The higher suction peak and other features on the advancing blade due to its larger effective velocity are detected by the paint system, while the retreating blade shows a qualitatively different distribution. (paper)

  9. Motion-deblurred, fast-response pressure-sensitive paint on a rotor in forward flight

    Science.gov (United States)

    Juliano, Thomas J.; Disotell, Kevin J.; Gregory, James W.; Crafton, Jim; Fonov, Sergey

    2012-04-01

    A pressure-sensitive paint (PSP) system capable of measuring the global, unsteady pressure distribution on a rotating surface without resorting to phase averaging is applied to a two-bladed model propeller in edgewise freestream flow. A gated lifetime-based technique captures the paint luminescence after a single pulse of high-energy laser excitation, yielding a signal-to-noise ratio sufficient to avoid image averaging. The selection of a porous polymer/ceramic matrix base with platinum tetra(pentafluorophenyl) porphyrin (PtTFPP) as the luminophore afforded high frequency response and pressure sensitivity, but the long lifetime of PtTFPP caused blurring in the long-exposure image of the rotating blade. An approach to deblurring based on the lifetime of the paint and surface motion is described and validated by results obtained from a disc of 17.8 cm diameter spinning at 70 Hz. An infrared camera recorded wind-on and -off temperature maps to provide a temperature correction for the PSP. The single-shot PSP technique with motion deblurring and temperature correction is then applied to a vertically mounted model propeller with a 25.4 cm diameter and 10.2 cm pitch. Surface pressure maps for the advancing and retreating blades are presented for a spin rate of 70 Hz and advance ratio of 0.3. The higher suction peak and other features on the advancing blade due to its larger effective velocity are detected by the paint system, while the retreating blade shows a qualitatively different distribution.

  10. Fast Tracker : A Hardware Real Time Track Finder for the ATLAS Trigger System

    CERN Document Server

    Kimura, N; The ATLAS collaboration

    2013-01-01

    The Large Hadron Collider (LHC) after the 2013-­?2014 shutdown period is expected to improve the yet impressive performance obtained up to this year: collisions’ energy will increase to 14 TeV and instantaneous luminosity will reach and then overcome 10^34 cm?2s?1, with a bunch crossing period of 25 ns. The LHC experiments will need to adapt to the more crowded events, maintaining the physics output and the quality of the final results. The pileup higher than the LHC run 1, with peaks expected to reach 50 or more, will make more difficult to have efficient online selection of rare events based mostly on calorimeters and muon detectors as it is done now. A more extensive use of the information collected by the tracking detector will allow building more robust selections, limiting the degradation effects due to the high pileup. We report on the development of the Fast Tracker (FTK) processor for the ATLAS experiment, devoted to reconstruct tracks with transverse momentum above 1 GeV in the whole detect...

  11. Higher order time asymptotics of fast diffusion in euclidean space: a dynamical systems approach

    CERN Document Server

    Denzler, Jochen; McCann, Robert

    2012-01-01

    This paper quantifies the speed of convergence and higher- order asymptotics of fast diffusion dynamics on R^n to the Barenblatt (self similar) solution. Degeneracies in the parabolicity of this equation are cured by re-expressing the dynamics on a manifold with a cylindrical end, called the cigar. The nonlinear evolution becomes differentiable in Hoelder spaces on the cigar. The linearization of the dynamics is given by the Laplace-Beltrami operator plus a transport term (which can be suppressed by introducing appropriate weights into the function space norm), plus a finite-depth potential well with a universal profile. In the limiting case of the (linear) heat equation, the depth diverges, the number of eigenstates increases without bound, and the continuous spectrum recedes to infinity. We provide a detailed study of the linear and nonlinear problems in Hoelder spaces on the cigar, including a sharp boundedness estimate for the semi-group, and use this as a tool to obtain sharp convergence results toward t...

  12. Development of fast wave systems tolerant of time-varying loading

    International Nuclear Information System (INIS)

    A new approach to fast wave antenna array design based on the traveling wave antenna has been successfully demonstrated on the JFT-2M tokamak. A traveling wave antenna is powered though a single feed and the power flow from element to element is only via mutual reactive coupling. A combine is a particular type of traveling wave antenna, in which only the fed element and the element at the downstream end of the array are connected to vacuum feed troughs, while the intermediate elements are terminated with reactances inside the vacuum chamber. A twelve element combine for operation at 200 MHz was designed and fabricated at General Atomics, and installed and operated on the JFT-2M tokamak. The full output power of a single transmitter, 0.2 MW, was coupled to tokamak discharges with very little conditioning required. The input impedance of the combine was well matched to the transmission line impedance for all loading conditions, including vacuum (no plasma), Taylor discharge cleaning plasmas, and ohmic, L- and H-mode tokamak discharges with neutral beam heating without any adjustment of tuning elements

  13. Improved target detection and bearing estimation utilizing fast orthogonal search for real-time spectral analysis

    International Nuclear Information System (INIS)

    The problem of target detection and tracking in the ocean environment has attracted considerable attention due to its importance in military and civilian applications. Sonobuoys are one of the capable passive sonar systems used in underwater target detection. Target detection and bearing estimation are mainly obtained through spectral analysis of received signals. The frequency resolution introduced by current techniques is limited which affects the accuracy of target detection and bearing estimation at a relatively low signal-to-noise ratio (SNR). This research investigates the development of a bearing estimation method using fast orthogonal search (FOS) for enhanced spectral estimation. FOS is employed in this research in order to improve both target detection and bearing estimation in the case of low SNR inputs. The proposed methods were tested using simulated data developed for two different scenarios under different underwater environmental conditions. The results show that the proposed method is capable of enhancing the accuracy for target detection as well as bearing estimation especially in cases of a very low SNR

  14. Fast CCD camera for x-ray photon correlation spectroscopy and time-resolved x-ray scattering and imaging

    International Nuclear Information System (INIS)

    A new, fast x-ray detector system is presented for high-throughput, high-sensitivity, time-resolved, x-ray scattering and imaging experiments, most especially x-ray photon correlation spectroscopy (XPCS). After a review of the architectures of different CCD chips and a critical examination of their suitability for use in a fast x-ray detector, the new detector hardware is described. In brief, its principal component is an inexpensive, commercial camera - the SMD1M60 - originally designed for optical applications, and modified for use as a direct-illumination x-ray detector. The remainder of the system consists of two Coreco Imaging PC-DIG frame grabber boards, located inside a Dell Power-edge 6400 server. Each frame grabber sits on its own PCI bus and handles data from 2 of the CCD's 4 taps. The SMD1M60 is based on a fast, frame-transfer, 4-tap CCD chip, read out at12-bit resolution at frame rates of up to 62 Hz for full frame readout and up to 500 Hz for one-sixteenth frame readout. Experiments to characterize the camera's suitability for XPCS and small-angle x-ray scattering (SAXS) are presented. These experiments show that single photon events are readily identified, and localized to within a pixel index or so. This is a sufficiently fine spatial resolution to maintain the speckle contrast at an acceptable value for XPCS measurements. The detective quantum efficiency of the SMD1M60 is 49% for directly-detected 6.3 keV x rays. The effects of data acquisition strategs. The effects of data acquisition strategies that permit near-real-time data compression are also determined and discussed. Overall, the SMD1M60 detector system represents a major improvement in the technology for time-resolved x-ray experiments, that require an area detector with time-resolutions in few-milliseconds-to-few-seconds range, and it should have wide applications, extending beyond XPCS

  15. Performance of SiPMT array readout for fast time-of-flight detectors

    International Nuclear Information System (INIS)

    Scintillator based time-of-flight detectors may use conventional photomultipliers for the readout. Problems arise in presence of stray magnetic fields. SiPMT arrays are insensitive to magnetic fields and are a suitable option to replace photomultipliers. Timing performances for several SiPMT arrays have been studied and results are presented

  16. Fast reactor parameter optimization taking into account changes in fuel charge type during reactor operation time

    International Nuclear Information System (INIS)

    The formulation and solution of optimization problem for parameters determining the layout of the central part of sodium cooled power reactor taking into account possible changes in fuel charge type during reactor operation time are performed. The losses under change of fuel composition type for two reactor modifications providing for minimum doubling time for oxide and carbide fuels respectively, are estimated

  17. Sonoluminescence as Instrument for the Measurement of Time Parameters of Fast Photomultipliers

    CERN Document Server

    Vorobev, P V; Frolov, A R; Shaftan, T V

    1998-01-01

    The apparatus description for control of the time parameters of photomultipliers with high time resolution is described. For generation of ultrashort light flashes have been used sonoluminescence effect -- emission of the light flashes which is appearing at the stressed interior of collapsing air microbubble by sound wave in water.

  18. Response time of an ER-fluid under shear and flow modes

    International Nuclear Information System (INIS)

    The response times of an ER-fluid in shear and flow modes under the effect of AC- and DC-fields were investigated experimentally. In shear mode, the response time was obtained under the effect of different shear rates and electrical field strengths by comparing the shear stress measured statically with that measured dynamically. The response times in shear mode decreased with increasing the field strength and decreasing the shear rate. In flow mode, the response times of the ER-fluid under various electric field strengths and flow rates were determined from the pressure measurements in channel flow. The response times in flow modewere exponentially decreasedwith the increase of the volumetric flow rate and the electric field strength. In both modes, increasing the frequency of the AC-field led to increase of the response time of the ER-fluid.

  19. Response Time as Self-Schema Indicator : Implications for Personality Assessment

    OpenAIRE

    Hedlund, Lars-erik

    2010-01-01

    The focal objective of this thesis was to examine the potential advantage of introducing the self-schema concept, indexed by response time, into personality assessment. The basic rationale for the use of response time is that a self-schema facilitates response time for self-referent information as it permits people to make assessments easier and automatic. A self-schema is a cognitive structure containing the generic knowledge that people have about themselves, influencing all aspects of the ...

  20. Comparative study of on-line response time measurement methods for platinum resistance thermometer

    International Nuclear Information System (INIS)

    This study deals with the in site determination of the response time of platinum resistance sensor. In the first part of this work, two methods furnishing the reference response time of the sensors are studied. In the second part of the work, two methods obtaining the response time without dismounting of the sensor, are studied. A comparative study of the performances of these methods is included for fluid velocities varying from 0 to 10 m/sec, in both laboratory and plant conditions