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Sample records for fast time response

  1. Study of the time response of a LuAG(Pr) crystal for fast timing applications

    Science.gov (United States)

    Fraile, L. M.; Mach, H.; Picado, E.; Vedia, V.; Udías, J. M.

    2013-06-01

    The recently developed praseodymium-doped lutetium aluminum garnet, LuAG(Pr), holds a strong potential for fast timing applications. In this study we report on the time response of LuAG(Pr) at 22Na and 60Co photon energies. The measurements were performed using a small crystal cube of 1 cm3 coupled to a Hamamatsu R5320 photomultiplier tube. The full width at half maximum (FWHM) time resolution is found to be 147±2 ps at 60Co energies, and 238±2 ps at 22Na.

  2. 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

  3. 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.; Barrillon, P.; Brandt, Søren; Budtz-Jørgensen, Carl; Castro-Tirado, A.J.; Chen, P.; Choi, J.N.; Choi, Y.J.; Connell, P.; Dagoret-Campagne, S.; Eyles, C.; Grossan, B.; Huang Huang, M.-H.A.; Jung, A.; Jeong, S.; Kim, J.E.; Kim, M.B.; Kim, S.-W.; Kim, Y.W.; Krasnov, A.S.; Lee, J.; Lim, H.; Linder, E.V.; Liu, T.-C.; Min, K.W.; Na, G.W.; Nam, J.W.; Panasyuk, M.I.; Park, H.W.; Ripa, J.; Reglero, V.; Rodrigo, J.M.; Smoot, G.F.; Svertilov, S.; Vedenkin, N.; Wang, M.-Z.; Yashin, I.

    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 optic...

  4. Wide dynamic range neutron flux monitor having fast time response for the Large Helical Device

    Energy Technology Data Exchange (ETDEWEB)

    Isobe, M., E-mail: isobe@nifs.ac.jp; Takeiri, Y. [National Institute for Fusion Science, Toki 509-5292 (Japan); Department of Fusion Science, The Graduate University for Advanced Studies, Toki 509-5292 (Japan); Ogawa, K.; Miyake, H.; Hayashi, H.; Kobuchi, T. [National Institute for Fusion Science, Toki 509-5292 (Japan); Nakano, Y.; Watanabe, K.; Uritani, A. [Department of Materials, Physics and Energy Engineering, Nagoya University, Nagoya 464-8603 (Japan); Misawa, T. [Kyoto University Research Reactor Institute, Kumatori 590-0494 (Japan); Nishitani, T. [Japan Atomic Energy Agency, Rokkasho 039-3212 (Japan); Tomitaka, M.; Kumagai, T.; Mashiyama, Y.; Ito, D.; Kono, S. [Toshiba Corporation, Fuchu 183-8511 (Japan); Yamauchi, M. [Toshiba Nuclear Engineering Services Corporation, Yokohama 235-8523 (Japan)

    2014-11-15

    A fast time response, wide dynamic range neutron flux monitor has been developed toward the LHD deuterium operation by using leading-edge signal processing technologies providing maximum counting rate up to ?5 × 10{sup 9} counts/s. Because a maximum total neutron emission rate over 1 × 10{sup 16} n/s is predicted in neutral beam-heated LHD plasmas, fast response and wide dynamic range capabilities of the system are essential. Preliminary tests have demonstrated successful performance as a wide dynamic range monitor along the design.

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

    Science.gov (United States)

    Park, I. H.; Ahmad, S.; Barrillon, P.; Brandt, S.; Budtz-Jørgensen, C.; Castro-Tirado, A. J.; Chen, P.; Choi, J. N.; Choi, Y. J.; Connell, P.; Dagoret-Campagne, S.; Eyles, C.; Grossan, B.; Huang, M.-H. A. Huang; Jung, A.; Jeong, S.; Kim, J. E.; Kim, M. B.; Kim, S.-W.; Kim, Y. W.; Krasnov, A. S.; Lee, J.; Lim, H.; Linder, E. V.; Liu, T.-C.; Min, K. W.; Na, G. W.; Nam, J. W.; Panasyuk, M. I.; Park, H. W.; Ripa, J.; Reglero, V.; Rodrigo, J. M.; Smoot, G. F.; Svertilov, S.; Vedenkin, N.; Wang, M.-Z.; Yashin, I.

    2013-07-01

    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.

  6. 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.

  7. Timing and position response of a block detector for fast neutron time-of-flight imaging

    Science.gov (United States)

    Laubach, M. A.; Hayward, J. P.; Zhang, X.; Cates, J. W.

    2014-11-01

    Our research effort seeks to improve the spatial and timing performance of a block detector made of a pixilated plastic scintillator (EJ-200), first demonstrated as part of Oak Ridge National Laboratory's Advanced Portable Neutron Imaging System. Improvement of the position and time response is necessary to achieve better resolution and contrast in the images of shielded special nuclear material. Time-of-flight is used to differentiate between gamma and different sources of neutrons (e.g., transmission and fission neutrons). Factors limiting the timing and position performance of the neutron detector have been revealed through simulations and measurements. Simulations have suggested that the degradation in the ability to resolve pixels in the neutron detector is due to those interactions occurring near the light guide. The energy deposition within the neutron detector is shown to affect position performance and imaging efficiency. This examination details how energy cuts improve the position performance and degrade the imaging efficiency. Measurements have shown the neutron detector to have a timing resolution of ?=238 ps. The majority of this timing uncertainty is from the depth-of-interaction (DOI) of the neutron which is confirmed by simulations and analytical calculations.

  8. Timing and position response of a block detector for fast neutron time-of-flight imaging

    International Nuclear Information System (INIS)

    Our research effort seeks to improve the spatial and timing performance of a block detector made of a pixilated plastic scintillator (EJ-200), first demonstrated as part of Oak Ridge National Laboratory's Advanced Portable Neutron Imaging System. Improvement of the position and time response is necessary to achieve better resolution and contrast in the images of shielded special nuclear material. Time-of-flight is used to differentiate between gamma and different sources of neutrons (e.g., transmission and fission neutrons). Factors limiting the timing and position performance of the neutron detector have been revealed through simulations and measurements. Simulations have suggested that the degradation in the ability to resolve pixels in the neutron detector is due to those interactions occurring near the light guide. The energy deposition within the neutron detector is shown to affect position performance and imaging efficiency. This examination details how energy cuts improve the position performance and degrade the imaging efficiency. Measurements have shown the neutron detector to have a timing resolution of ?=238 ps. The majority of this timing uncertainty is from the depth-of-interaction (DOI) of the neutron which is confirmed by simulations and analytical calculations

  9. Fast timing on XEUS

    Science.gov (United States)

    Strüder, Lothar; Barret, Didier; Fiorini, Carlo; Kendziorra, Eckhard; Lechner, Peter

    2004-02-01

    Fast X-ray timing observations are a method to probe strong gravity fields around compact massive objects. The European X-ray Evolving Universe Spectroscopy (XEUS) mission with its large collecting area telescope will be able to deliver the required extremely good photon statistics for these studies. The fast timing detector in the focal plane must be able to operate at up to 107 incoming photons from the brightest X-ray objects in the sky with an energy resolution of 200 eV FWHM at 5.9 keV at a dead time not exceeding 1% and a time resolution of 10 ?sec. Silicon Drift Detectors (SDDs) with their extremely small value of the readout capacitance have proved that they can handle high count rates with simultaneous good energy resolution. For the XEUS fast timing detector it is proposed to operate a multi-channel SDD at an out of focus position to distribute the flux of photons over a number of detector cells.

  10. Study of bi-alkali photocathode growth on glass by X-ray techniques for fast timing response photomultipliers

    Science.gov (United States)

    Xie, Junqi; Demarteau, Marcel; Wagner, Robert; Ruiz-Oses, Miguel; Liang, Xue; Ben-Zvi, Ilan; Attenkofer, Klaus; Schubert, Susanne; Smedley, John; Wong, Jared; Padmore, Howard; Woll, Arthur

    2014-03-01

    Bi-alkali antimonide photocathode is an essential component in fast timing response photomultipliers. Real-time in-situ grazing incidence x-ray diffraction and post-growth x-ray reflectivity measurement were performed to study the photocathode deposition process on glass substrate. Grazing incidence x-ray diffraction patterns show the formation of Sb crystalline, dissolution of crystalline phase Sb by the application of K vapor and reformation of refined crystal textures. XRR result exhibits that the film thickness increases ~ 4.5 times after K diffusion and almost have no change after Cs diffusion. Further investigation is expected to understand the photocathode growth process and provide guidelines for photocathode development.

  11. 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

  12. 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.

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

    Science.gov (United States)

    Régis, J.-M.; Rudigier, M.; Jolie, J.; Blazhev, A.; Fransen, C.; Pascovici, G.; Warr, N.

    2012-08-01

    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. Fast-Response Liquid Crystal Microlens

    Directory of Open Access Journals (Sweden)

    Su Xu

    2014-06-01

    Full Text Available 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 composites, consisting of LC and monomer, are an important extension of pure LC systems, which offer more flexibility and much richer functionality than LC alone. Due to the anchoring effect of a polymer network, microlenses, based on LC/polymer composites, have relatively fast response time in comparison with pure nematic LC microlenses. In addition, polymer-stabilized blue phase liquid crystal (PS-BPLC based on Kerr effect is emerging as a promising candidate for new photonics application. The major attractions of PS-BPLC are submillisecond response time and no need for surface alignment layer. In this paper, we review two types of fast-response microlenses based on LC/polymer composites: polymer dispersed/stabilized nematic LC and polymer-stabilized blue phase LC. Their basic operating principles are introduced and recent progress is reviewed by examples from recent literature. Finally, the major challenges and future perspectives are discussed.

  15. Fast, Responsive Decentralised Graph Colouring

    OpenAIRE

    Checco, Alessandro; Leith, Douglas J.

    2014-01-01

    We solve, in a fully decentralised way, the classic problem of colouring a graph. We propose a novel algorithm that is automatically responsive to topology changes, and we prove that it converges to a proper colouring in $O(N\\log{N})$ time with high probability for generic graphs (and in $O(\\log{N})$ time if $\\Delta=o(N)$) when the number of available colours is greater than $\\Delta$, the maximum degree of the graph. Moreover, this algorithm is significantly simpler and ea...

  16. 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

  17. 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.

  18. 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.

  19. Radiation induced synthesis of fast response stimuli responsive gels

    International Nuclear Information System (INIS)

    EB irradiation offers a unique method of synthesizing extremely fast-response temperature sensitive gels due to heterogeneous network structure produced during irradiation. These gels can be used as very efficient recyclable absorbents for many industrial applications

  20. Fast response bolometer for high temperature plasma

    International Nuclear Information System (INIS)

    A fast response bolometer is developed to measure the radiation loss from a high temperature plasma. Radiation from the plasma (mainly x-ray) is absorbed by a thin foil and heats it up. Change in far infrared (FIR) radiation, due to the change in temperature, emitted from the back surface of the foil is detected by an FIR detector which is contained in a shield box placed distant from a plasma generating machine to eliminate electrical noise. The FIR radiation is transmitted from the thin foil to the detector by a light pipe (metal pipe inner surface of which is polished). The foil (radiation absorber) consists of 5?m thick copper foil, both surfaces of which are coated with 1 ?m thick carbon to increase the sensitivity and to simplify the calibration procedure. Calibration is done by two methods: One is to obtain the relation between temperature of the foil and the output of the detector. The other is to measure the detector output when the foil is illuminated by a flashlight with known light energy. Latter calibration procedure is excellent in that it is reliable and can be carried out with the same arrangement as the radiation from the plasma is measured. The result of this calibration is 0.46mV/mJ. This figure can be increased by adoption of FIR light collecting system. Time response of the bolometer (conduction of heat from radiation absorbing surface to the back surface of the foil) is calculated to be 400 ns. The thickness of the foil is chosen in such a way that the radiation from the plasma with electron temperature of about 100 eV is almost completely absorbed. This bolometer is applicable to plasmas with higher temperature when the foil thickness is increased with the sacrifice of time response and sensitivity. (author)

  1. A new scintillation counter with very fast resolving time (1961)

    International Nuclear Information System (INIS)

    The rare gases used as scintillators are characterized by their short time of luminescence and by the linearity of their response as a function of the total energy imparted to the gas by the incident particle. It is possible with these scintillators, when associated with a fast response photomultiplier, to solve certain problems of nuclear physics demanding a linear detector with a very fast resolving time (a few nanoseconds). Two examples of the construction of this apparatus are described. The results obtained and future possibilities are briefly outlined. (author)

  2. Fast-response frequency-to-analog converter

    Science.gov (United States)

    Hagihara, F. S.

    1967-01-01

    Frequency-to-analog converter has a fast response time and a low ripple. The circuit uses a frequency-to-pulse converter which provides two pulse trains, both at the same frequency as that of the input signal, but with a 10 microsecond difference between the trains.

  3. 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

    International Nuclear Information System (INIS)

    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

  4. 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

    Energy Technology Data Exchange (ETDEWEB)

    Shimaoka, T., E-mail: t.shimaoka@eng.hokudai.ac.jp; Kaneko, J. H.; Tsubota, M. [Graduate School of Engineering, Hokkaido University, Sapporo 060-8628 (Japan); Arikawa, Y.; Nagai, T.; Kojima, S.; Abe, Y.; Sakata, S.; Fujioka, S.; Nakai, M.; Shiraga, H.; Azechi, H. [Osaka University, 2-6 Yamada-Oka, Suita, Osaka 565-0871 (Japan); Isobe, M. [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292 (Japan); Sato, Y. [The Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Chayahara, A.; Umezawa, H.; Shikata, S. [Diamond Research Laboratory, National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan)

    2015-05-15

    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{sup 7} cm/s and 1.0 ± 0.3 × 10{sup 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{sup 9} neutrons/shot.

  5. Ultra-fast timing with plastic scintillators

    International Nuclear Information System (INIS)

    Fast timing detectors for time-of-flight measurements are essential identification tools for isotopes studied at fragment separators at major heavy-ion research facilities. While today's standard technique of utilizing a plastic scintillator read out by few photomultiplier tubes proofs to be efficient, it does not provide the required time resolution for future key experiments at, for example, the Super-FRS at FAIR. A common present-day approach is to use diamond detectors instead. While they do provide a better time resolution compared to scintillators, they are more difficult to use and far more expensive. Results from tests using a new design approach with standard materials will be presented. This leads to a much improved performance, but remains both cost-efficient, compact, and reliable. The design goals and how to accomplish them will be exemplified by the LYCCA (Lund-York-Cologne CAlorimeter) detector aiming for fast-beam experiments at HISPEC within NUSTAR.

  6. Mutagenic response of peanut (arachis hypogaea L.) to fast neutrons

    International Nuclear Information System (INIS)

    Dominant seeds of peanut were treated with varying doses of fast neutrons employing efficient pre- and post-irradiation techniques for determination of various plant responses useful in a long range program of mutation breeding. Mean reductions in seedling height and frequency of M1 somatic mutations increased with increasing radiation dose. No reduction in M1 seedset was obtained even in the dose above the LD50 of 1600 rads. The frequency of M2 macromutations ranged from only 3.60 - 5.65 per 100 M2 plants. The genetic basis of each of these radiation responses is briefly discussed. The high sensitivity of M1 peanut seedlings and growing plants to fast neutrons is probably due to the highly differentiated seed embryo at the time of irradiation while the radioresistance exhibited by the matured plant appears to be related to the polyploid genome of the species. (Auth.)

  7. Fast rise time beam current monitor

    International Nuclear Information System (INIS)

    Two wall current monitors were developed. One was developed to learn properties of monitor. With a knowledge of those properties, another was carefully designed. This paper describes properties between design parameters and performances; for example, nominal resistance and effective resistance, resonant frequency of the monitor and rise time, Q-factor and overshoot, core's characteristics and bandwidth. Later wall current monitor has a fast rise time of ?250 ps, an output of ?1.4 V/A (effective resistance of 1.4?), a linearity within 2.2% in the current range of 0-10A, and broad bandwidth (20kHz-2GHz). (author)

  8. 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.

  9. 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)

  10. 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 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.)

  11. 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.

  12. 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...

  13. Fast response time alcohol gas sensor using nanocrystalline F-doped SnO2 films derived via sol–gel method

    Indian Academy of Sciences (India)

    Sarbani Basu; Yeong-Her Wang; C Ghanshyam; Pawan Kapur

    2013-08-01

    Pure and fluorine-modified tin oxide (SnO2) thin films (250–300 nm) were uniformly deposited on corning glass substrate using sol–gel technique to fabricate SnO2-based resistive sensors for ethanol detection. The characteristic properties of the multicoatings have been investigated, including their electrical conductivity and optical transparency in visible IR range. Pure SnO2 films exhibited a visible transmission of 90% compared with Fdoped films (80% for low doping and 60% for high doping). F-doped SnO2 films exhibited lower resistivity (0.12 × 10-4 cm) compared with the pure (14.16 × 10-4 cm) one. X-ray diffraction and scanning electron microscopy techniques were used to analyse the structure and surface morphology of the prepared films. Resistance change was studied at different temperatures (523–623 K) with metallic contacts of silver in air and in presence of different ethanol vapour concentrations. Comparative gas-sensing results revealed that the prepared F-doped SnO2 sensor exhibited the lowest response and recovery times of 10 and 13 s, respectively whereas that of pure SnO2 gas sensor, 32 and 65 s, respectively. The maximum sensitivities of both gas sensors were obtained at 623 K.

  14. 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

  15. Fast timing with XEUS: evaluation of different detector concepts

    Science.gov (United States)

    Kendziorra, Eckhard; Martin, Michael; Santangelo, Andrea; Wilms, Jörn; Barret, Didier; Skinner, Gerry; Strüder, Lothar; Lechner, Peter; Treis, Johannes

    2006-06-01

    With its large collecting area XEUS will be ideally suited to probe strong gravity fields around collapsed objects and to constrain the equation of state of dense matter in neutron stars. For these studies, detectors are needed which can measure 10 6 events/sec with high time resolution (10 ?sec) and good energy resolution (?E = 200 - 300 eV FWHM) combined with an energy and flux independent dead time. The current baseline for a dedicated fast timing detector on XEUS is an array of 19 silicon drift detectors (SDD) operated as single photon detectors. Optionally we have studied an array of 40 x 20 SDD/DEPFET macro pixel detectors read out at a constant frame rate of 10 5/sec. Alternatively to these two dedicated detectors, a high time resolution mode of the Wide Field Imager (1024 x 1024 DEPFET array with 78?m x 78?m pixels) is considered here. We have simulated the expected timing performance of these detector options based on results from laboratory measurements. We have performed Monte Carlo simulations using the latest available XEUS mirror response files for Crab like sources and intensities ranging from 102 up to 4x10 6 events/sec. Our results are discussed in the light of the scientific requirements for fast timing as expressed in the ESA Cosmic Vision 2015-2025 plan.

  16. Response time of internauts

    CERN Document Server

    Johansen, A

    2001-01-01

    A new experiment measuring the dynamical response of the Internet population to a ``point-like'' perturbation has been performed. The nature of the perturbation was that of an announcement, specifically a web-interview on stock market crashes, which contained the URL to the author's articles on the subject. It was established that the download rate obeys the relation ~ 1/t in qualitative agreement with previously reported results.

  17. Response of reverse convection to fast IMF transitions

    DEFF Research Database (Denmark)

    Taguchi, S.; Tawara, A.; Hairston, M. R.; Slavin, J. A.; Le, G.; Matzka, J.; Stolle, C.

    2015-01-01

    The nature of the transition that high-latitude reverse convection makes in response to fast interplanetary magnetic field (IMF) changes is investigated using observations from multiple spacecraft and a ground magnetometer array. We focused on two fast IMF-transition events on 22 April 2006. Immediately after the first event, three ST5 spacecraft identified a clear change in the distribution of the polar cap field-aligned current. Coordinate observations with the Greenland magnetometer chain sho...

  18. The Role of FAST in Pulsar Timing Arrays

    CERN Document Server

    Hobbs, G; Manchester, R N; Shannon, R M; Kerr, M; Lee, K J; Xu, R

    2014-01-01

    The Five-hundred-meter Aperture Spherical Telescope (FAST) will become one of the world-leading telescopes for pulsar timing array (PTA) research. The primary goals for PTAs are to detect (and subsequently study) ultra-low-frequency gravitational waves, to develop a pulsar-based time standard and to improve solar system planetary ephemerides. FAST will have the sensitivity to observe known pulsars with significantly improved signal-to-noise ratios and will discover a large number of currently unknown pulsars. We describe how FAST will contribute to PTA research and show that jitter- and timing-noise will be the limiting noise processes for FAST data sets. Jitter noise will limit the timing precision achievable over data spans of a few years while timing noise will limit the precision achievable over many years.

  19. Fast Timing for High-Rate Environments with Micromegas

    CERN Document Server

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

    2016-01-01

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

  20. 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.

  1. The Role of FAST in Pulsar Timing Arrays

    OpenAIRE

    Hobbs, G; Dai, S; R. N. Manchester; Shannon, R. M.; Kerr, M.; Lee, K. J.; Xu, R.

    2014-01-01

    The Five-hundred-meter Aperture Spherical Telescope (FAST) will become one of the world-leading telescopes for pulsar timing array (PTA) research. The primary goals for PTAs are to detect (and subsequently study) ultra-low-frequency gravitational waves, to develop a pulsar-based time standard and to improve solar system planetary ephemerides. FAST will have the sensitivity to observe known pulsars with significantly improved signal-to-noise ratios and will discover a large n...

  2. Plastic fiber scintillator response to fast neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Danly, C. R.; Sjue, S.; Wilde, C. H.; Merrill, F. E.; Haight, R. C. [Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States)

    2014-11-15

    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.

  3. 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

  4. Response features determining spike times.

    Science.gov (United States)

    Richmond, B J; Oram, M W; Wiener, M C

    1999-01-01

    Interpreting messages encoded in single neuronal responses requires knowing which features of the responses carry information. That the number of spikes is an important part of the code has long been obvious. In recent years, it has been shown that modulation of the firing rate with about 25 ms precision carries information that is not available from the total number of spikes across the whole response. It has been proposed that patterns of exactly timed (1 ms precision) spikes, such as repeating triplets or quadruplets, might carry information that is not available from knowing about spike count and rate modulation. A model using the spike count distribution, the low-pass filtered PSTH (bandwidth below 30 Hz), and, to a small degree, the interspike interval distribution predicts the numbers and types of exactly-timed triplets and quadruplets that are indistinguishable from those found in the data. From this it can be concluded that the coarse (correlation structure over time gives rise to the exactly timed patterns present in the recorded spike trains. Because the coarse temporal structure predicts the fine temporal structure, the information carried by the fine temporal structure must be completely redundant with that carried by the coarse structure. Thus, the existence of precisely timed spike patterns carrying stimulus-related information does not imply control of spike timing at precise time scales. PMID:10714266

  5. Quartz Cherenkov Counters for Fast Timing: QUARTIC

    OpenAIRE

    Albrow, M. G.; Kim, Heejong; Los, S.; Ramberg, E; Ronzhin, A.; Samoylenko, V.; Wenzel, H.; Zatserklyaniy, A.(University of Puerto Rico, Mayaguez, U.S.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 bea...

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

    Science.gov (United States)

    Fraile, L. M.; Mach, H.; Vedia, V.; Olaizola, B.; Paziy, V.; Picado, E.; Udías, J. M.

    2013-02-01

    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.

  7. 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.

  8. 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...

  9. 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...

  10. 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.

  11. Fast response and recovery of hydrogen sensing in Pd-Pt nanoparticle-graphene composite layers

    International Nuclear Information System (INIS)

    This study reports the fast response and recovery of hydrogen sensing in nanoparticle-graphene composite layers fabricated using chemical methods and comprising of isolated Pd alloy nanoparticles dispersed onto graphene layers. For 2% hydrogen at 40 0C and 1 atm pressure, a response time of < 2 s and a recovery time of 18 s are observed. The fast response and recovery observed during sensing are due to hydrogen-induced changes in the work function of the Pd alloy and modification in the distribution of defect states in the graphene band gap due to gas adsorption. The results of hydrogen sensing in the new class of Pd-Pt nanoparticle-graphene composite material are important for understanding the effect of gas adsorption on electronic conduction in graphene layers and for developing a new type of gas sensor based on changes in the electronic properties of the interface.

  12. Real?time, fast neutron detection for stimulated safeguards assay

    International Nuclear Information System (INIS)

    The advent of low?hazard organic liquid scintillation detectors and real?time pulse?shape discrimination (PSD) processing has suggested a variety of modalities by which fast neutrons, as opposed to neutrons moderated prior to detection, can be used directly to benefit safeguards needs. In this paper we describe a development of a fast?neutron based safeguards assay system designed for the assessment of 235U content in fresh fuel. The system benefits from real?time pulse?shape discrimination processing and auto?calibration of the detector system parameters to ensure a rapid and effective set?up protocol. These requirements are essential in optimising the speed and limit of detection of the fast neutron technique, whilst minimising the intervention needed to perform the assay.

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

    OpenAIRE

    Vartsky, D.; Mor, I; Goldberg, M. B.; Mardor, I.; Feldman, G; Bar, D.; Shor, A; Dangendorf, V.; Laczko, G.; Breskin, A.; 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.

  14. Acute metabolic response to fasted and postprandial exercise.

    Science.gov (United States)

    de Lima, Filipe Dinato; Correia, Ana Luiza Matias; Teixeira, Denilson da Silva; da Silva Neto, Domingos Vasco; Fernandes, Ítalo Sávio Gonçalves; Viana, Mário Boratto Xavier; Petitto, Mateus; da Silva Sampaio, Rodney Antônio; Chaves, Sandro Nobre; Alves, Simone Teixeira; Dantas, Renata Aparecida Elias; Mota, Márcio Rabelo

    2015-01-01

    The aim of this study was to analyze the acute metabolic response to exercise in fasting and postprandial. For this, ten individuals were submitted to an incremental treadmill test, with an initial speed of 5 and 1 km/h increments every minute, with no inclination, and a body composition assessment. After this 1st day, all volunteers were submitted to two experimental procedures (fasting and postprandial), with an aerobic exercise performed for 36 minutes at 65% of maximal oxygen consumption. At postprandial procedure, all subjects ingested a breakfast containing 59.3 g of carbohydrate (76.73%), 9.97 g of protein (12.90%), 8.01 g of lipids (10.37%), with a total energy intake of 349.17 kcal. An analysis of plasma concentration of triglycerides, lactate, and glucose was performed in two stages: before and after exercise. The Shapiro-Wilk test was used to verify the normality of the data. For analysis of glucose concentration, plasma lactate, and triglycerides, we used a repeated measures analysis of variance factorial 2×2, with Bonferroni multiple comparison test. The significance level of P<0.05 was adopted. The results indicated a maintenance level of glucose at fasting and a decrease in glucose concentration at postprandial exercise. Both conditions increase plasma lactate. Triglycerides also increased in the two experimental conditions; however, after exercise fasting, the increase was significantly higher than in the postprandial exercise. These data suggest that both exercises could increase plasma lactate and triglycerides. However, exercise performed in fasting condition decreases glucose concentration and increases triglycerides, even more than postprandial exercise. PMID:26316800

  15. Acute metabolic response to fasted and postprandial exercise

    Science.gov (United States)

    de Lima, Filipe Dinato; Correia, Ana Luiza Matias; Teixeira, Denilson da Silva; da Silva Neto, Domingos Vasco; Fernandes, Ítalo Sávio Gonçalves; Viana, Mário Boratto Xavier; Petitto, Mateus; da Silva Sampaio, Rodney Antônio; Chaves, Sandro Nobre; Alves, Simone Teixeira; Dantas, Renata Aparecida Elias; Mota, Márcio Rabelo

    2015-01-01

    The aim of this study was to analyze the acute metabolic response to exercise in fasting and postprandial. For this, ten individuals were submitted to an incremental treadmill test, with an initial speed of 5 and 1 km/h increments every minute, with no inclination, and a body composition assessment. After this 1st day, all volunteers were submitted to two experimental procedures (fasting and postprandial), with an aerobic exercise performed for 36 minutes at 65% of maximal oxygen consumption. At postprandial procedure, all subjects ingested a breakfast containing 59.3 g of carbohydrate (76.73%), 9.97 g of protein (12.90%), 8.01 g of lipids (10.37%), with a total energy intake of 349.17 kcal. An analysis of plasma concentration of triglycerides, lactate, and glucose was performed in two stages: before and after exercise. The Shapiro–Wilk test was used to verify the normality of the data. For analysis of glucose concentration, plasma lactate, and triglycerides, we used a repeated measures analysis of variance factorial 2×2, with Bonferroni multiple comparison test. The significance level of P<0.05 was adopted. The results indicated a maintenance level of glucose at fasting and a decrease in glucose concentration at postprandial exercise. Both conditions increase plasma lactate. Triglycerides also increased in the two experimental conditions; however, after exercise fasting, the increase was significantly higher than in the postprandial exercise. These data suggest that both exercises could increase plasma lactate and triglycerides. However, exercise performed in fasting condition decreases glucose concentration and increases triglycerides, even more than postprandial exercise. PMID:26316800

  16. A Capacitor-Free, Fast Transient Response Linear Voltage Regulator In a 180nm CMOS

    DEFF Research Database (Denmark)

    Deleuran, Alexander N.; Lindbjerg, Nicklas; Pedersen, Martin K.; Llimos Muntal, Pere; Jørgensen, Ivan Harald Holger

    2015-01-01

    A 1.8 V capacitor-free linear regulator with fast transient response based on a new topology with a fast and slow regulation loop is presented. The design has been laid out and simulated in a 0.18 µm CMOS process. The design has a low component count and is tailored for system-on-chip integration. A current step load from 0-50 mA with a rise time of 1 µs results in an undershoot in the output voltage of 140 mV for a period of 39 ns. The regulator sources up to 50 mA current load.

  17. Fast time-resolved aerosol collector: proof of concept

    Directory of Open Access Journals (Sweden)

    X.-Y. Yu

    2010-10-01

    Full Text Available Atmospheric particles can be collected in the field on substrates for subsequent laboratory analysis via chemically sensitive single particle methods such as scanning electron microscopy with energy dispersive x-ray analysis. With moving substrates time resolution of seconds to minutes can be achieved. In this paper, we demonstrate how to increase the time resolution when collecting particles on a substrate to a few milliseconds to provide real-time information. Our fast time-resolved aerosol collector ("Fast-TRAC" microscopically observes the particle collection on a substrate and records an on-line video. Particle arrivals are resolved to within a single frame (4–17 ms in this setup, and the spatial locations are matched to the subsequent single particle analysis. This approach also provides in-situ information on particle size and number concentration. Applications are expected in airborne studies of cloud microstructure, pollution plumes, and surface long-term monitoring.

  18. Fast time-resolved aerosol collector: proof of concept

    Directory of Open Access Journals (Sweden)

    X.-Y. Yu

    2010-06-01

    Full Text Available Atmospheric particles can be collected in the field on substrates for subsequent laboratory analysis via chemically sensitive single particle methods such as scanning electron microscopy with energy dispersive x-ray analysis. With moving substrates time resolution of seconds to minutes can be achieved. In this paper, we demonstrate how to increase the time resolution when collecting particles on a substrate to a few milliseconds to provide real-time information. Our fast time-resolved aerosol collector ("Fast-TRAC" microscopically observes the particle collection on a substrate and records an on-line video. Particle arrivals are resolved to within a single frame (4–17 ms in this setup, and the spatial locations are matched to the subsequent single particle analysis. This approach also provides in-situ information on particle size and number concentration. Applications are expected in airborne studies of cloud microstructure, pollution plumes, and surface long-term monitoring.

  19. Real time face recognition using adaboost improved fast PCA algorithm

    CERN Document Server

    Kumar, K Susheel; Tripathi, R C

    2011-01-01

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

  20. Fast response neutron scintillation detector for FIRE-X

    International Nuclear Information System (INIS)

    We have been developing fast responding neutron detectors with a view to revealing the effect of additional laser heating in FIREX-I (Fast Ignition Realization Experiment) by measuring the burn time with a time resolution under 100 ps at the relatively low neutron yield (about 106). The detector is constructed with a thin plastic-scintillaotor (BC-422), a micro-channel-plate photomultiplier tube (MCP-PMT) and a bundle optical fiber as a light-guide. The rise time of a neutron signal from the detector is measured to be 220 ps. The time-determination error for measuring burn time is estimated to be less than ± 46 ps from the data of characterization experiments measuring the transit time distribution of signals, and calculated values of Doppler broadening and the uncertainty of the scintillation time due to the thickness of the scintillator. In the future with more neutron yield, we will construct a scintillation-fiber-streak camera to detect burn history

  1. Modeling the response of fast reactor fuel to accident transients

    Energy Technology Data Exchange (ETDEWEB)

    Deitrich, L.W.; Gruber, E.E.; Hughes, T.H.; Hofmann, J.R.; Kramer, J.M.; Meek, C.C.; Ostensen, R.W.; Billone, M.C.; Shack, W.J.; Yang, C.I.

    1976-01-01

    Progress in modeling the response of fast reactor fuel to accident transients is reported in four areas: fission gas release from grains and intragranular fuel swelling, fission gas redistribution and internal pressurization in solid fuel, fuel cracking models, and fuel plasticity modeling. Applications of models in the first two areas to assessment of the comparative dispersal potential of fuel in a CRBR hypothetical unprotected loss-of-flow accident with that in recent experiments are presented. It is concluded that the reactor case presents a greater dispersal potential.

  2. 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..

  3. Fast exponential fitting algorithm for real-time instrumental use

    International Nuclear Information System (INIS)

    We report on a very fast fitting algorithm for single exponential functions which is based on the method of successive integration. The algorithm corrects the systematic error of trapezoidal integration. The new algorithm needs only 150 ?s for a dataset of 1536 points and is around 700 times faster than the nonlinear Levenberg-Marquardt fit provided by LABVIEW. This makes it suitable for real-time instrumental use. Beside the better time resolution, the acceleration allows more averaging, which leads to higher precision. In our experiment instrumental sensitivity was improved by a factor of 3.7

  4. Fast time variations of supernova neutrino fluxes and their detectability

    DEFF Research Database (Denmark)

    Lund, Tina; Marek, Andreas; Lunardini, Cecilia; Janka, Hans-Thomas; Raffelt, Georg

    2010-01-01

    In the delayed explosion scenario of core-collapse supernovae (SNe), the accretion phase shows pronounced convective overturns and a low-multipole hydrodynamic instability, the standing accretion shock instability (SASI). These effects imprint detectable fast time variations on the emerging neutrino flux. Among existing detectors, IceCube is best suited to this task, providing an event rate of ~1000 events per ms during the accretion phase for a fiducial SN distance of 10 kpc, comparable to what...

  5. Fast Intrinsic Mode Decomposition and Filtering of Time Series Data

    OpenAIRE

    Lu, Louis Yu

    2008-01-01

    The intrinsic mode function (IMF) provides adaptive function bases for nonlinear and non-stationary time series data. A fast convergent iterative method is introduced in this paper to find the IMF components of the data, the method is faster and more predictable than the Empirical Mode Decomposition method devised by the author of Hilbert Huang Transform. The approach is to iteratively adjust the control points on the data function corresponding to the extrema of the refinin...

  6. 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 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

  7. Acute metabolic response to fasted and postprandial exercise

    Directory of Open Access Journals (Sweden)

    Lima FD

    2015-08-01

    Full Text Available Filipe Dinato de Lima,1,2 Ana Luiza Matias Correia,1 Denilson da Silva Teixeira,2 Domingos Vasco da Silva Neto,2 Ítalo Sávio Gonçalves Fernandes,2 Mário Boratto Xavier Viana,2 Mateus Petitto,2 Rodney Antônio da Silva Sampaio,2 Sandro Nobre Chaves,2 Simone Teixeira Alves,2 Renata Aparecida Elias Dantas,2 Márcio Rabelo Mota2 1University of Brasília, Brasília, DF, Brazil; 2Universitary Center of Brasília (UniCEUB, Brasília, DF, BrazilAbstract: The aim of this study was to analyze the acute metabolic response to exercise in fasting and postprandial. For this, ten individuals were submitted to an incremental treadmill test, with an initial speed of 5 and 1 km/h increments every minute, with no inclination, and a body composition assessment. After this 1st day, all volunteers were submitted to two experimental procedures (fasting and postprandial, with an aerobic exercise performed for 36 minutes at 65% of maximal oxygen consumption. At postprandial procedure, all subjects ingested a breakfast containing 59.3 g of carbohydrate (76.73%, 9.97 g of protein (12.90%, 8.01 g of lipids (10.37%, with a total energy intake of 349.17 kcal. An analysis of plasma concentration of triglycerides, lactate, and glucose was performed in two stages: before and after exercise. The Shapiro–Wilk test was used to verify the normality of the data. For analysis of glucose concentration, plasma lactate, and triglycerides, we used a repeated measures analysis of variance factorial 2×2, with Bonferroni multiple comparison test. The significance level of P<0.05 was adopted. The results indicated a maintenance level of glucose at fasting and a decrease in glucose concentration at postprandial exercise. Both conditions increase plasma lactate. Triglycerides also increased in the two experimental conditions; however, after exercise fasting, the increase was significantly higher than in the postprandial exercise. These data suggest that both exercises could increase plasma lactate and triglycerides. However, exercise performed in fasting condition decreases glucose concentration and increases triglycerides, even more than postprandial exercise.Keywords: aerobic exercise, energy metabolism, blood glucose, lactic acid, triglycerides

  8. A CMOS integrated timing discriminator circuit for fast scintillation counters

    International Nuclear Information System (INIS)

    Based on a zero-crossing discriminator using a CR differentiation network for pulse shaping, a new CMOS integrated timing discriminator circuit is proposed for fast (tr ? 2 ns) scintillation counters at the cooler synchrotron COSY-Juelich. By eliminating the input signal's amplitude information by means of an analog continuous-time divider, a normalized pulse shape at the zero-crossing point is gained over a wide dynamic input amplitude range. In combination with an arming comparator and a monostable multivibrator this yields in a highly precise timing discriminator circuit, that is expected to be useful in different time measurement applications. First measurement results of a CMOS integrated logarithmic amplifier, which is part of the analog continuous-time divider, agree well with the corresponding simulations. Moreover, SPICE simulations of the integrated discriminator circuit promise a time walk well below 200 ps (FWHM) over a 40 dB input amplitude dynamic range

  9. 28 CFR 542.18 - Response time.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Response time. 542.18 Section 542.18... REMEDY Administrative Remedy Program § 542.18 Response time. If accepted, a Request or Appeal is... later than the third calendar day after filing. If the time period for response to a Request or...

  10. Response of reverse convection to fast IMF transitions

    DEFF Research Database (Denmark)

    Taguchi, S.; Tawara, A.

    2015-01-01

    The nature of the transition that high-latitude reverse convection makes in response to fast interplanetary magnetic field (IMF) changes is investigated using observations from multiple spacecraft and a ground magnetometer array. We focused on two fast IMF-transition events on 22 April 2006. Immediately after the first event, three ST5 spacecraft identified a clear change in the distribution of the polar cap field-aligned current. Coordinate observations with the Greenland magnetometer chain showed that the near-noon Hall current distribution, which is closely related to the polar cap field-aligned current or reverse convection, was in a transition state for about 10 min. For the second event, the Greenland magnetic perturbations also showed that a transition state occurred in the near-noon sector for 10-15 min. Three DMSP spacecraft that traversed the polar cap provided evidence showing that variations of the ground magnetic perturbations were produced by the transition from clockwise plasma circulation to the anticlockwise circulation over the polar cap. A simple calculation based on the Biot-Savart law shows that the near-noon transition state is consistent with the approach of a new convection region to the near-noon sector at the speed of 0.5-1 km s-1, which is coupled with the moving away of the old convection region at a similar speed. For the higher-latitude sunward flow region, it is found that the convection takes a transition state almost simultaneously (within 1 min) with that in the near-noon sector, i.e., quasi-instantaneous response.

  11. Time dependent non-extinction probability for fast burst reactors

    Science.gov (United States)

    Gregson, Michael W.

    Sandia National Laboratories has successfully operated fast burst reactors over the past four decades. Fast burst reactors refer to a type of reactor that is able to achieve intense neutron pulses in very short periods of time using fissile material. Typically these systems are comprised of enriched metallic uranium fuel. During operation of a fast burst reactor, a phenomena known as a pre-initiation has been known to take place. A pre-initiation occurs when the neutron population exceeds some fiducial prior to achieving the final reactivity state in a pulse operation. Reactivity is determined from the physical configuration of the reactor and governs the average neutron population behavior. The purpose of this study is to examine the probability of initiation (or the pre-initiation probability) for a fast burst type of system, with emphasis on the Sandia Pulse Reactor-III (SPR-III) for physics parameters. The magnitude of the pre-initiation problem for SPR-III was examined to establish the magnitude of the phenomena. This work focuses on developing and numerically solving an equation that describes the nonextinction probability in a prompt critical assembly when the population is so low that it deviates from the average behavior. A zero dimensional (0-D) model is derived to describe the neutron non-extinction probability in a system where the reactivity is changing as a function of time. Analytical solutions to the model are provided where solutions could be found. Numerical solutions were obtained for a variety of cases applicable to fast burst reactor operation. Use of 0-D Monte Carlo techniques is also presented as a means to examine the low population stochastic behavior and for comparison to the deterministic solution. The 1-D time dependent equation for slab geometry was evaluated to highlight the importance of neutron leakage. The non-extinction probability equation was solved using a modified form of the standard fixed point iteration method. Other iteration techniques were also analyzed. Particular emphasis was extended to a linearized routine since the performance can be analyzed analytically and it allows for development of acceleration techniques. An accelerated routine was then developed and analyzed. The numerical performance between the iteration routines was thoroughly investigated. The impact of the acceleration routine on the iteration count and the associated decrease in runtime was evaluated.

  12. Response surface methodology to optimize novel fast disintegrating tablets using ? cyclodextrin as diluent.

    Science.gov (United States)

    Late, Sameer G; Banga, Ajay K

    2010-12-01

    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, X (1)), superdisintegrant (Croscarmellose sodium, X (2)), and direct compression aid (Spray dried lactose, X (3)). Tablets were prepared by direct compression method on B2 rotary tablet press using flat plain-face punches and characterized for weight variation, thickness, disintegration time (Y (1)), and hardness (Y (2)). Disintegration time was strongly affected by quadratic terms of ? cyclodextrin, croscarmellose sodium, and spray-dried lactose. The positive value of regression coefficient for ? cyclodextrin suggested that hardness increased with increased amount of ? cyclodextrin. In general, disintegration of tablets has been reported to slow down with increase in hardness. However in the present study, higher concentration of ? cyclodextrin was found to improve tablet hardness without increasing the disintegration time. Thus, ? cyclodextrin is proposed as a suitable diluent to achieve fast disintegrating tablets with sufficient hardness. Good correlation between the predicted values and experimental data of the optimized formulation validated prognostic ability of response surface methodology in optimizing fast disintegrating tablets using ? cyclodextrin as a diluent. PMID:21086083

  13. 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).

  14. 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)

  15. Resetting in time of recordings in ultra-fast cinematography

    International Nuclear Information System (INIS)

    In ultra-fast cinematography and photography the treatment and interpretation of the data contained in the recordings demand extremely precise readjustments in time. In the case of whole-image recordings by electro-optical cameras or flash sources the problem is resolved by the use of a chronometric unit taking into account the different events. For naving slit or spectrographic recordings the problem must be detail with differently and marking devices will be used to print resetting pulses on the recording themselves. Different marking devices are described

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

    Data.gov (United States)

    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...

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

    Data.gov (United States)

    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...

  18. 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.

  19. 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.

  20. Fast minute magnetic field coil for time-resolved nanospintronics

    CERN Document Server

    Pawliszak, ?ukasz; Zgirski, Maciej

    2014-01-01

    Nanospintronic and related research often requires the application of fast rising magnetic field pulses in the plane of the studied planar structure. We have designed and fabricated sub-milimeter-sized coils capable of delivering pulses of the magnetic field up to ~ 500 Oe in the plane of the sample with the rise time of order of 10 ns. The placement of the sample above the coil allows for an easy access to its surface with manipulators or light beams for, e.g., Kerr microscopy. We use the fabricated coil to drive magnetic domain walls in 1 ${\\mu}$ m wide permalloy wires and measure magnetic domain wall velocity as a function of the applied magnetic field.

  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. Conceptual Issues in Response-Time Modeling

    Science.gov (United States)

    van der Linden, Wim J.

    2009-01-01

    Two different traditions of response-time (RT) modeling are reviewed: the tradition of distinct models for RTs and responses, and the tradition of model integration in which RTs are incorporated in response models or the other way around. Several conceptual issues underlying both traditions are made explicit and analyzed for their consequences. We…

  3. EGR Control for Emisson Reduction Using Fast Response Sensors - Phase 1A

    Energy Technology Data Exchange (ETDEWEB)

    Gravel, Roland; Conley, Jason; Kittelson, David

    2008-09-30

    The overall objective of this project was to develop exhaust gas recirculation (EGR) control strategies using fast-response Particulate Matter (PM) sensors and NOx sensors to improve the quality of particulate and gaseous emissions from diesel engines. This project initially comprised three phases: (1) Phase IA - sensor requirements to meet PM sensor specifications, NOx sensor assessment, and initial model development for EGR control; (2) Phase IB - continue development on PM and NOx sensors, integrate the sensor signals into the control simulations, and finalize model development for control strategies; and (3) Phase II - validation testing of the control strategies. Only Phase 1A was funded by DOE and executed by Honeywell. The major objectives of Phase 1A of the project included: (1) Sensor validation and operation of fast-response PM and NOx sensors; (2) Control system modeling of low-pressure EGR controls, development of control strategies, and initial evaluation of these models and strategies for EGR control in diesel engines; (3) Sensor testing to understand applicability of fast-response PM sensors in determining loading rates of the particle trap; and (4) Model validation and sensor testing under steady-state and transient operational conditions of actual engines. In particular, specific objectives included demonstration of: (1) A PM sensor response time constant (T10 - T90) of better than 100 milliseconds (msec); (2) The ability to detect PM at concentrations from 0.2 to 2 Bosch smoke number (BSN) or equivalent; (3) PM sensor accuracy to within 20% BSN over the entire range of operation; and (4) PM sensor repeatability to within 10% over the PM entire sensor range equivalent to a BSN of 0.2 to 2.

  4. Using ferrite as a fast switch for improving rise time of IPNS extraction kicker

    International Nuclear Information System (INIS)

    The Kicker system is used to extract beam from the Rapid Cycling Synchrotron (RCS). The Kicker consists of four identical pulse circuits, each providing over 3.8 kA to each magnet winding. The magnet length is restricted to the space between vacuum bellows attached to the ring magnets. This leaves 0.89 m for the magnet. To keep the voltage low the magnet conductor is broke up into 4, 1/4-turn magnet windings. Each pulse circuit consists of a Pulse Forming Network (PFN) that is charged to 50 KV. The PFN is discharged through a thyratron into a 6.3-ohm transmission line to one of the magnet windings. Our system has always had marginal rise time of around 100 ns. Although the thyratron switching time is much faster than this, losses in the transmission lines cause the slower response. By using ferrite to make a fast switch between the transmission lines and the magnet, the rise time in the magnet can be reduced. To make a fast ferrite switch, the saturation point must carefully be chosen. Parameters related to choosing the proper ferrite to provide fast saturation, at the correct current will be discussed.

  5. 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

  6. FTSPlot: fast time series visualization for large datasets.

    Science.gov (United States)

    Riss, Michael

    2014-01-01

    The analysis of electrophysiological recordings often involves visual inspection of time series data to locate specific experiment epochs, mask artifacts, and verify the results of signal processing steps, such as filtering or spike detection. Long-term experiments with continuous data acquisition generate large amounts of data. Rapid browsing through these massive datasets poses a challenge to conventional data plotting software because the plotting time increases proportionately to the increase in the volume of data. This paper presents FTSPlot, which is a visualization concept for large-scale time series datasets using techniques from the field of high performance computer graphics, such as hierarchic level of detail and out-of-core data handling. In a preprocessing step, time series data, event, and interval annotations are converted into an optimized data format, which then permits fast, interactive visualization. The preprocessing step has a computational complexity of O(n x log(N)); the visualization itself can be done with a complexity of O(1) and is therefore independent of the amount of data. A demonstration prototype has been implemented and benchmarks show that the technology is capable of displaying large amounts of time series data, event, and interval annotations lag-free with x86_64 architecture currently up to 2(48) bytes are supported, and benchmarks have been conducted with 2(40) bytes/1 TiB or 1.3 x 10(11) double precision samples. The presented software is freely available and can be included as a Qt GUI component in future software projects, providing a standard visualization method for long-term electrophysiological experiments. PMID:24732865

  7. 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.

  8. 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.

  9. 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-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)

  10. 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

  11. A fast response variable optical attenuator based on blue phase liquid crystal.

    Science.gov (United States)

    Zhu, Ge; Wei, Bing-yan; Shi, Liang-yu; Lin, Xiao-wen; Hu, Wei; Huang, Zhang-di; Lu, Yan-qing

    2013-03-11

    Blue phase liquid crystals (BPLCs) are promising candidates for next generation display thanks to their fast response and quasi-isotropic optical properties. By taking these advantages, we propose to introduce the material into fiber-optic applications. As an example, a BPLC based variable optical attenuator (VOA) is demonstrated with a polarization independent design. The device shows normally-off feature when no field is applied. Response time down to submillisecond scale is achieved in switching between two arbitrary attenuation states. The attenuation range is also measured from 1480 to 1550 nm, which cover the whole telecomm S-band and part of the C-band. The overall performances reach the requirements for practical use; while still have room for further improvement. Through this example, the applicability of BPLC in fiber-optic devices is presented, which may impel the development of many other photonic applications from infrared to even microwave regions. PMID:23482104

  12. Dynamics of the flood response to slow-fast landscape-climate feedbacks

    Science.gov (United States)

    Perdigão, R. A. P.; Blöschl, G.

    2015-06-01

    The dynamical evolution of the flood response to landscape-climate feedbacks is evaluated in a joint nonlinear statistical-dynamical approach. For that purpose, a spatiotemporal sensitivity analysis is conducted on hydrological data from 1976-2008 over 804 catchments throughout Austria, and a general, data-independent nonlinear dynamical model is built linking floods with climate (via precipitation), landscape (via elevation) and their feedbacks. These involve nonlinear scale interactions, with landform evolution processes taking place at the millennial scale (slow dynamics), and climate adjusting in years to decades (fast dynamics). The results show that floods are more responsive to spatial (regional) than to temporal (decadal) variability. Catchments from dry lowlands and high wetlands exhibit similarity between the spatial and temporal sensitivities (spatiotemporal symmetry) and low landscape-climate codependence, suggesting they are not coevolving significantly. However, intermediate regions show differences between those sensitivities (symmetry breaks) and higher landscape-climate codependence, suggesting undergoing coevolution. The break of symmetry is an emergent behaviour from nonlinear feedbacks within the system. A new coevolution index is introduced relating spatiotemporal symmetry with relative characteristic celerities, which need to be taken into account in hydrological space-time trading. Coevolution is expressed here by the interplay between slow and fast dynamics, represented respectively by spatial and temporal characteristics. The dynamical model captures emerging features of the flood dynamics and nonlinear landscape-climate feedbacks, supporting the nonlinear statistical assessment of spatiotemporally asymmetric flood change. Moreover, it enables the dynamical estimation of flood changes in space and time from the given knowledge at different spatiotemporal conditions. This study ultimately brings to light emerging signatures of change in floods arising from nonlinear slow-fast feedbacks in the landscape-climate dynamics, and contributes towards a better understanding of spatiotemporal flood changes and underlying nonlinearly interacting drivers.

  13. A LaBr{sub 3}: Ce fast-timing array for DESPEC at FAIR

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, Oliver J., E-mail: O.J.Roberts@brighton.ac.uk [School of Computing, Engineering and Mathematics, University of Brighton, Brighton BN2 4GJ (United Kingdom); Bruce, Alison M. [School of Computing, Engineering and Mathematics, University of Brighton, Brighton BN2 4GJ (United Kingdom); Regan, Patrick H. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); National Physics Laboratory, Teddington, TW11 0LW (United Kingdom); Podolyák, Zsolt; Townsley, Christopher M. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Smith, John F.; Mulholland, Kieran F. [School of Engineering, The University of the West of Scotland, Paisley PA1 2BE (United Kingdom); Smith, Andrew [The University of Manchester, Oxford Road, Manchester, M13 9PL (United Kingdom)

    2014-06-01

    The design of a fast-timing ?-ray detection array aimed at measuring sub-nanosecond half-lives using LaBr{sub 3}: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.

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

    International Nuclear Information System (INIS)

    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. 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.

  16. Fast-response IR spatial light modulators with a polymer network liquid crystal

    Science.gov (United States)

    Peng, Fenglin; Chen, Haiwei; Tripathi, Suvagata; Twieg, Robert J.; Wu, Shin-Tson

    2015-03-01

    Liquid crystals (LC) have widespread applications for amplitude modulation (e.g. flat panel displays) and phase modulation (e.g. beam steering). For phase modulation, a 2? phase modulo is required. To extend the electro-optic application into infrared region (MWIR and LWIR), several key technical challenges have to be overcome: 1. low absorption loss, 2. high birefringence, 3. low operation voltage, and 4. fast response time. After three decades of extensive development, an increasing number of IR devices adopting LC technology have been demonstrated, such as liquid crystal waveguide, laser beam steering at 1.55?m and 10.6 ?m, spatial light modulator in the MWIR (3~5?m) band, dynamic scene projectors for infrared seekers in the LWIR (8~12?m) band. However, several fundamental molecular vibration bands and overtones exist in the MWIR and LWIR regions, which contribute to high absorption coefficient and hinder its widespread application. Therefore, the inherent absorption loss becomes a major concern for IR devices. To suppress IR absorption, several approaches have been investigated: 1) Employing thin cell gap by choosing a high birefringence liquid crystal mixture; 2) Shifting the absorption bands outside the spectral region of interest by deuteration, fluorination and chlorination; 3) Reducing the overlap vibration bands by using shorter alkyl chain compounds. In this paper, we report some chlorinated LC compounds and mixtures with a low absorption loss in the near infrared and MWIR regions. To achieve fast response time, we have demonstrated a polymer network liquid crystal with 2? phase change at MWIR and response time less than 5 ms.

  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 modified fast analog technique for determining luminescence decay times of scintillators

    International Nuclear Information System (INIS)

    The authors have modified their previous fast analog technique to determine the luminescence decay times of scintillators following an excitation with a Sr90 ?-source. In the original technique, the sample was excited with a nitrogen-pumped dye laser, and the fluorescence pulses (consisting of typically 50 to 1,000 photons) were detected by a multichannel plate photomultiplier tube (MCP-PMT). The output from the MCP-PMT was directed to a fast waveform digitizer triggered externally by the exciting laser. In the modified technique, the digitizer acquires the fluorescence decay in the internal trigger mode, as no corresponding external trigger pulse is available from the Sr90 source. For efficient light collection from scintillators, an ellipsoidal mirror assembly has been tested. The fluorescence decays are acquired as multi-photon pulses and are subsequently corrected for the temporal instrument response by using a deconvolution technique. The overall time resolution of the technique is about 100 ps. The fluorescence decay time obtained using this technique for a commercial scintillator (SCSN-81) agrees well with literature. The authors also discuss the results on new epoxy-polymer based scintillators prepared in their laboratory. The primary motivation for this work was development of new scintillators with shorter fluorescence decay times for high collision rate experiments

  19. Radiobiological response of fast neutrons on seedling growth of rice varieties with different amylose content

    International Nuclear Information System (INIS)

    Many studies are reported on radiation effects and on factors modifying the biological response of radiation in rice. However, little attention was directed towards studying effects of fast neutrons on seedling growth response of rice as a function of chemical constituents (e.g. amylose content). Experiments were conducted to investigate the dependency of amylose content in 4 rice cultivars on radiosensitivity to fast neutrons. From the results obtained a clear relationship between amylose content and sensitivity to fast neutrons could be shown. (author)

  20. 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...

  1. 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 L; 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, which...

  2. FAST

    DEFF Research Database (Denmark)

    Zuidmeer-Jongejan, Laurian; Fernandez-Rivas, Montserrat; Poulsen, Lars K.; Neubauer, Angela; Asturias, Juan; Blom, Lars; Boye, Joyce; Bindslev-Jensen, Carsten; Clausen, Michael Stellian; Ferrara, Rosa; Garosi, Paula; Huber, Hans; Jensen, Bettina M; Koppelman, Stef; Kowalski, Marek L; Lewandowska-Polak, Anna; Linhart, Birgit; Maillere, Bernard; Mari, Adriano; Martinez, Alberto; Mills, Clare En; Nicoletti, Claudio; Opstelten, Dirk-Jan; Papadopoulos, Nikos G; Portoles, Antonio; Rigby, Neil; Scala, Enrico; Schnoor, Heidi J; Sigursdottir, Sigurveig; Stavroulakis, Georg; Stolz, Frank; Swoboda, Ines; Valenta, Rudolf; van den Hout, Rob; Versteeg, Serge A; Witten, Marianne; van Ree, Ronald

    2012-01-01

    ABSTRACT: The FAST project (Food Allergy Specific Immunotherapy) aims at the development of safe and effective treatment of food allergies, targeting prevalent, persistent and severe allergy to fish and peach. Classical allergen-specific immunotherapy (SIT), using subcutaneous injections with aqueous food extracts may be effective but has proven to be accompanied by too many anaphylactic side-effects. FAST aims to develop a safe alternative by replacing food extracts with hypoallergenic recombin...

  3. A population study of fasting time and serum prostate-specific antigen (PSA level

    Directory of Open Access Journals (Sweden)

    Cheryl K Lau

    2014-10-01

    Full Text Available Prostate cancer is one of the most common cancers in men. Traditional screening and diagnostic methods include digital rectal examinations (DREs, biopsies and serum prostate-specific antigen (PSA tests, with the latter being the more popular. PSA is a biomarker for prostate cancer; however, it is highly sensitive to external factors as well as other prostate diseases. As such, the reliability of of the serum PSA level as a sole screening and diagnostic tool for prostate cancer is controversial. Recently, it has been shown that fasting extremes can affect concentrations of serum chemistry analytes, thus raising the question of whether or not fasting has an effect on the highly sensitive PSA biomarker. Patients testing for serum PSA levels are often concomitantly submitting to other tests that require fasting, subjecting certain patients to a fasting PSA level while others not. The objective of this study was to investigate whether this discrepancy in fasting state translates into an effect on serum PSA levels. Serum PSA levels and fasting time records for 157 276 men who underwent testing at Calgary Laboratory Services (CLS; Calgary, Alberta, Canada between 01 January 2010 and 31 March 2013 were accessed. Linear regression models of mean PSA levels and fasting times revealed a statistically important relationship at certain fasting times. Applying a dynamic mathematical model to explore the clinical effect of fasting suggests minimal impact on serum PSA result interpretation. Thus, patients can be tested for serum PSA levels regardless of their fasting state.

  4. Complex Behavior of Time Response of HgCdTe HOT Photodetectors

    Science.gov (United States)

    Pawluczyk, J.; Piotrowski, J.; Pusz, W.; Ko?niewski, A.; Orman, Z.; Gawron, W.; Piotrowski, A.

    2015-09-01

    We report on the time response of higher-operating-temperature (HOT, T ˜200 K to 300 K) fast long-cutoff-wavelength infrared (LWIR) HgCdTe photodetectors. For a long time, photoconductive and photoelectromagnetic devices operating near room temperature have been used as fast (sub-nanosecond) photodetectors. Unfortunately, such devices suffer from relatively low detectivity. Recent efforts have focused on heterojunction photodiodes that offer both fast response and high performance. This paper presents computer simulations and experimental studies that reveal mechanisms limiting the time response and design rules to achieve short response time of HOT LWIR photodiodes operating at both zero and reverse bias. Complex time response curves with fast and slow components have been observed. The latter has been found to be mainly determined by the ambipolar diffusion of photogenerated charge carriers and by the diffusion capacitance combined with the built-in or external series resistance. The limitations are especially pronounced in zero-biased photodiodes characterized by large diffusion capacitance, where series resistance of only 1 ? significantly reduces the response speed of devices with 100 ?m × 100 ?m photosensitive area.

  5. Development of a fast sampling system for estimation of impulse responses of mobile radio channels

    Science.gov (United States)

    Melancon, Pierre

    1994-07-01

    This paper describes the features of measurement equipment developed to measure impulse response estimates of mobile radio channels in less than a ms per measurement. The development of such equipment was required to measure mobile radio channels in realistic operating scenarios, in a normal sized vehicle moving at typical speeds in different environments. Up to speeds of 70 km/hr, the measurement period is short enough to assume the equipment is measuring the same channel during the whole sampling interval. AT the transmitter end of the measurement system, a wideband signal (10 MHz) is produced by modulating a carrier frequency with a 511 bit pseudo random sequence at 5 Mb/s and transmitted through the radio channel. The received signal is down-converted to 70 MHz and demodulated by a complex demodulator. The quadrature baseband signals at the demodulator outputs are then filtered and sampled at high speed by two fast digitizers. During this process, the data are stored in large memory banks to allow a fast sampling rate during a long period of time. Data are transferred to laser disks for further processing in the laboratory. Impulse response of radio channels are estimated by performing a software correlation between a measurement system back to back reference and real time measurements. A minivan was modified to hold the receiver, digitizers, memory banks and the computer. A shaft encoder was attached to its rear left wheel to trigger measurements while moving. Features of the system are discussed along with the effects of data block length, signal to noise ratio, sampling rate, memory size and phase stability on the design of the measurement equipment. Finally, some measurement results are presented and discussed.

  6. 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

  7. Fast Mapping Across Time: Memory Processes Support Children’s Retention of Learned Words

    OpenAIRE

    Vlach, Haley A.; Sandhofer, Catherine M.

    2012-01-01

    Children’s remarkable ability to map linguistic labels to referents in the world is commonly called fast mapping. The current study examined children’s (N?=?216) and adults’ (N?=?54) retention of fast-mapped words over time (immediately, after a 1-week delay, and after a 1-month delay). The fast mapping literature often characterizes children’s retention of words as consistently high across timescales. However, the current study demonstrates that learners forget word mappings at a rapid rate....

  8. Fast Mapping Across Time: Memory Processes Support Children's Retention of Learned Words

    OpenAIRE

    HaleyVlach

    2012-01-01

    Children's remarkable ability to map linguistic labels to objects in the world is referred to as fast mapping. The current study examined children's (N = 216) and adults’ (N = 54) retention of fast-mapped words over time (immediately, after a 1 week delay, and after a 1 month delay). The fast mapping literature often characterizes children's retention of words as consistently high across timescales. However, the current study demonstrates that learners forget word mappings at a rapid rate....

  9. Response of sapphire thermocurrent dosimeters to fast neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Pearson, D.W.; Moran, P.R.

    1975-01-01

    The response of sapphire (Al/sub 2/O/sub 3/) thermocurrent (TC) dosimeters to 14 MeV neutrons is about 10% of the response to cesium gamma rays on an equivalent tissue rad basis. The addition of proton radiator covers of methyl methacrylate increases this response to about 15%. The magnitude of the thermocurrent peak at 260/sup 0/ (peak 3) allows measurement of gamma ray exposures of 10 mR with a signal to noise ratio of about unity.

  10. A Ballistic Model of Choice Response Time

    Science.gov (United States)

    Brown, Scott; Heathcote, Andrew

    2005-01-01

    Almost all models of response time (RT) use a stochastic accumulation process. To account for the benchmark RT phenomena, researchers have found it necessary to include between-trial variability in the starting point and/or the rate of accumulation, both in linear (R. Ratcliff & J. N. Rouder, 1998) and nonlinear (M. Usher & J. L. McClelland, 2001)…

  11. High temperature fast response pressure probe for use in liquid metal droplet dispensers.

    Science.gov (United States)

    Rollinger, B; Mansour, M; Abhari, R S

    2012-06-01

    A miniature fast response high temperature pressure probe, with demonstrated use in liquid metals up to 255 °C (528 K), has been developed. Innovative packaging technologies have been applied to integrate a conventional piezoresistive silicon pressure sensor into the probe, without the need of an auxiliary water-cooling system. In situ static calibrations are used to verify the linearity of the pressure signal and the stability of the pressure sensitivity (0.5% standard deviation over 70 min at 255 °C). Dynamic calibration, completed in an air shock tube facility, yields the probe's natural frequency. This frequency, when corrected for probe operation in liquid tin, is found to be 100 kHz. The reliability and accuracy of the probe is assessed by mounting it in a tin droplet dispenser for use in an extreme ultraviolet light source. Droplet dispensers typically include an excitation mechanism, which can be based on the generation of acoustic pressure waves to impose a desired droplet frequency. The probe accuracy is verified by the comparison of pressure measurements with laser Doppler vibrometry measurements of the pressure generating structure. A reference pressure measurement, conducted at representative conditions, shows a complex frequency response, with peaks distributed over three orders of magnitude and maximum amplitude of 440 mbar. Time variance of the excitation mechanism due to thermal transients is studied by monitoring the pressure response during operation. Finally, the linearity of the excitation system, with respect to the excitation amplitude, is verified by response measurements. In conclusion, the developed probe is capable of characterizing the excitation mechanism of a liquid metal droplet dispenser. Additionally, real-time monitoring of the performance of the excitation system during long-term operation is possible. PMID:22755655

  12. 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)

  13. Development and validation of a two-dimensional fast-response flood estimation model

    Energy Technology Data Exchange (ETDEWEB)

    Judi, David R [Los Alamos National Laboratory; Mcpherson, Timothy N [Los Alamos National Laboratory; Burian, Steven J [UNIV OF UTAK

    2009-01-01

    A finite difference formulation of the shallow water equations using an upwind differencing method was developed maintaining computational efficiency and accuracy such that it can be used as a fast-response flood estimation tool. The model was validated using both laboratory controlled experiments and an actual dam breach. Through the laboratory experiments, the model was shown to give good estimations of depth and velocity when compared to the measured data, as well as when compared to a more complex two-dimensional model. Additionally, the model was compared to high water mark data obtained from the failure of the Taum Sauk dam. The simulated inundation extent agreed well with the observed extent, with the most notable differences resulting from the inability to model sediment transport. The results of these validation studies complex two-dimensional model. Additionally, the model was compared to high water mark data obtained from the failure of the Taum Sauk dam. The simulated inundation extent agreed well with the observed extent, with the most notable differences resulting from the inability to model sediment transport. The results of these validation studies show that a relatively numerical scheme used to solve the complete shallow water equations can be used to accurately estimate flood inundation. Future work will focus on further reducing the computation time needed to provide flood inundation estimates for fast-response analyses. This will be accomplished through the efficient use of multi-core, multi-processor computers coupled with an efficient domain-tracking algorithm, as well as an understanding of the impacts of grid resolution on model results.

  14. 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.))

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

    Science.gov (United States)

    Marx, O.; Brümmer, C.; Ammann, C.; Wolff, V.; Freibauer, A.

    2012-05-01

    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.

  16. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Régis, J.-M., E-mail: regis@ikp.uni-koeln.de [Institut für Kernphysik der Universität zu Köln, Zülpicher Str. 77, 50937 Köln (Germany); Mach, H. [Departamento de Física Atómica y Nuclear, Universidad Complutense, 28040 Madrid (Spain); Simpson, G.S. [Laboratoire de Physique Subatomique et de Cosmologie Grenoble, 53, rue des Martyrs, 38026 Grenoble Cedex (France); Jolie, J.; Pascovici, G.; Saed-Samii, N.; Warr, N. [Institut für Kernphysik der Universität zu Köln, Zülpicher Str. 77, 50937 Köln (Germany); Bruce, A. [School of Computing, Engineering and Mathematics, University of Brighton, Lewes Road, Brighton BN2 4GJ (United Kingdom); Degenkolb, J. [Institut für Kernphysik der Universität zu Köln, Zülpicher Str. 77, 50937 Köln (Germany); Fraile, L.M. [Departamento de Física Atómica y Nuclear, Universidad Complutense, 28040 Madrid (Spain); Fransen, C. [Institut für Kernphysik der Universität zu Köln, Zülpicher Str. 77, 50937 Köln (Germany); Ghita, D.G. [Horia Hulubei National Institute for Physics and Nuclear Engineering, 77125 Bucharest (Romania); and others

    2013-10-21

    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 LaBr{sub 3}(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 40keVfast-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.

  18. 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

  19. Exploration of ultra-fast electron dynamics using time-dependent R-matrix theory

    Science.gov (United States)

    van der Hart, Hugo; Rey, Hector; Hassouneh, Ola; Brown, Andrew

    2014-05-01

    When an atom is subjected to an intense laser field, the full atomic response can involve a collective response involving several electrons. This collective response will be affected by electron-electron repulsion, coupling the overall electron dynamics. In order to investigate this dynamics for a multi-electron system from first principles, we have developed time-dependent R-matrix theory. The theory applies the basic principles of R-matrix theory, in which all interactions between all electrons are taken into account close to the nucleus, but exchange interactions are neglected when one electron has become distanced from the parent atom. In this contribution, we will explain the basic principles of this theory and demonstrate its application to ultra-fast dynamics in C+, and harmonic generation in singly ionised noble-gas atoms. Both studies demonstrate that it is important to go beyond the single-active-electron approximation. This research has been supported by EPSRC UK, and by the EU Initial Training Network CORINF.

  20. Discriminated interresponse times: role of autoshaped responses.

    OpenAIRE

    Palmer, D C; Donahoe, J W; Crowley, M.A.

    1985-01-01

    When discriminated interresponse-time (IRT) procedures have been used to assess preference relations among temporally extended operants, deviations from matching have been obtained. Using a yoked-control procedure, the present study found that key pecking in a discriminated IRT procedure has two sources of strength--that arising from the response-reinforcer contingency that is explicitly arranged, and that arising from a stimulus-reinforcer contingency that is a by-product of the explicitly a...

  1. Fast Response Systems Using Feed Forward Loop for Fuzzy Tuned PID Controllers

    Directory of Open Access Journals (Sweden)

    M.Tharangini

    2014-08-01

    Full Text Available The temperature during heating processes more essential in oil quantity .Many of the research effort they developed new control technique to control and regulate the steam temperature in industries. This seems to be because PID controllers is simple structure, assure acceptable performances for a wide range of industrial plants and their usage (the tuning of their parameters is well known among industrial operators. PID with FLC with combination of this we neglected the steady sate errors. PID controllers are particularly suited for pure first- or second-order processes, while industrial plants often present characteristics such as high order, time delays, nonlinearities and so on challenges during design the PID is to tune the PID parameters gain that suite to the plant. To overcome this problem, feed forward tuning PID using the fuzzy logic controller with self-tuning method is utilized to regulate the steam temperature. It gives good process dynamic characteristic which are process rise time, process settling time, percent overshoot and less steady state error. The ability to track any parameters changes and has fast recovery the output response during disturbance period.

  2. Picosecond time measurement using ultra fast analog memories

    OpenAIRE

    Breton, D.(Laboratoire de l’Accélérateur Linéaire, IN2P3/CNRS et Université Paris-Sud 11, Centre Scientifique d’Orsay, F-91898, Orsay Cedex, France); Delagnes, E; Maalmi, J.

    2009-01-01

    The currently existing electronics dedicated to precise time measurement is mainly based on the use of constant fraction discriminators (CFD) associated with Time to Digital Converters (TDC). The constant fraction technique minimizes the time walk effect (dependency of timing on the pulse amplitude). Several attempts have been made to integrate CFD in multi-channel ASICs. But the time resolution measured on the most advanced one is of the order of 30 ps rms. Two main techniques are used for t...

  3. Response of gut microbiota to fasting and hibernation in Syrian hamsters.

    Science.gov (United States)

    Sonoyama, Kei; Fujiwara, Reiko; Takemura, Naoki; Ogasawara, Toru; Watanabe, Jun; Ito, Hiroyuki; Morita, Tatsuya

    2009-10-01

    Although hibernating mammals wake occasionally to eat during torpor, this period represents a state of fasting. Fasting is known to alter the gut microbiota in nonhibernating mammals; therefore, hibernation may also affect the gut microbiota. However, there are few reports of gut microbiota in hibernating mammals. The present study aimed to compare the gut microbiota in hibernating torpid Syrian hamsters with that in active counterparts by using culture-independent analyses. Hamsters were allocated to either torpid, fed active, or fasted active groups. Hibernation was successfully induced by maintaining darkness at 4 degrees C. Flow cytometry analysis of cecal bacteria showed that 96-h fasting reduced the total gut bacteria. This period of fasting also reduced the concentrations of short chain fatty acids in the cecal contents. In contrast, total bacterial numbers and concentrations of short chain fatty acids were unaffected by hibernation. Denaturing gradient gel electrophoresis of PCR-amplified 16S rRNA gene fragments indicated that fasting and hibernation modulated the cecal microbiota. Analysis of 16S rRNA clone library and species-specific real-time quantitative PCR showed that the class Clostridia predominated in both active and torpid hamsters and that populations of Akkermansia muciniphila, a mucin degrader, were increased by fasting but not by hibernation. From these results, we conclude that the gut microbiota responds differently to fasting and hibernation in Syrian hamsters. PMID:19700553

  4. Time-of-flight measurement of fast neutrons with Timepix detectors

    Science.gov (United States)

    Bergmann, B.; Nelson, R. O.; O'Donnell, J. M.; Pospisil, S.; Solc, J.; Takai, H.; Vykydal, Z.

    2014-05-01

    Timepix pixel detectors have been used to study the response of silicon hybrid pixel detectors to fast neutrons from a pulsed neutron beam at WNR FP30R, a 14 m long flight path, in the Los Alamos Neutron Science Center. Neutrons with kinetic energies up to 600 MeV were available. In order to enhance the conversion of neutrons to energetic charged particles, several converter foils and filters were attached to the 300 ?m thick silicon sensor, i.e. polyethylene, polyethylene with aluminum, 6LiF, 6LiF with aluminum, aluminum. The Time-of-Arrival mode of the Timepix detectors has permitted the application of the Time-of-Flight (TOF) technique for the assignment of the detected interactions in the form of clusters (groups of adjacent pixels) in the pixel matrix, to the kinetic energies of the incident neutrons. It was found that, for lower neutron energies ( ~ MeV range) the cluster rates below the polyethylene and the polyethylene and aluminum region, produced by recoil protons, are a good measure for the mean kinetic energies of neutrons. For energies above 50 MeV nuclear reactions in the silicon dominate the detector response. In this energy range the shape of the clusters indicates the neutron kinetic energy.

  5. Time-resolved fast-neutron imaging with a pulse-counting image intensifier

    OpenAIRE

    Dangendorf, Volker

    2007-01-01

    A new imaging method that combines high-efficiency fast-neutron detection with sub-ns time resolution is presented. This is achieved by exploiting the high neutron detection efficiency of a thick scintillator and the fast timing capability and flexibility of light-pulse detection with a dedicated image intensifier. The neutron converter is a plastic scintillator slab or, alternatively, a scintillating fibre screen. The scintillator is optically coupled to a pulse counting image intensifier wh...

  6. Design, development and qualification of fast response temperature sensors for Sizewell B

    International Nuclear Information System (INIS)

    For Sizewell B Pressurized Water Reactor, one of the important variables to be measured is reactor coolant temperature. These measurements are achieved by the provision of temperature sensors mounted in the reactor coolant loops. These sensors provide safety-grade temperature measurement signals to both the Primary Protection System and the Secondary Protection System. The temperature measurements must be of adequate range and offer a sufficiently rapid response to provide accurate and timely signals to the Reactor Protection Systems for reactor trip and engineered safeguard features actuation functions. In recent years, for Westinghouse PWR applications the reactor coolant loop temperatures have been measured by suitable designs of fast response resistance temperature detectors mounted in specially profiled thermowells penetrating into the reactor coolant loop pipework. These temperature measurements must be achieved during normal, abnormal and Design Basis Event conditions. In order to demonstrate suitability for operation in Design basis event conditions for Sizewell B, the temperature sensors have to be qualified as Category 1E safety-related equipment for operation in a harsh environment. (Author)

  7. 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)

  8. 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

  9. A mixture hierarchical model for response times and response accuracy.

    Science.gov (United States)

    Wang, Chun; Xu, Gongjun

    2015-11-01

    In real testing, examinees may manifest different types of test-taking behaviours. In this paper we focus on two types that appear to be among the more frequently occurring behaviours - solution behaviour and rapid guessing behaviour. Rapid guessing usually happens in high-stakes tests when there is insufficient time, and in low-stakes tests when there is lack of effort. These two qualitatively different test-taking behaviours, if ignored, will lead to violation of the local independence assumption and, as a result, yield biased item/person parameter estimation. We propose a mixture hierarchical model to account for differences among item responses and response time patterns arising from these two behaviours. The model is also able to identify the specific behaviour an examinee engages in when answering an item. A Monte Carlo expectation maximization algorithm is proposed for model calibration. A simulation study shows that the new model yields more accurate item and person parameter estimates than a non-mixture model when the data indeed come from two types of behaviour. The model also fits real, high-stakes test data better than a non-mixture model, and therefore the new model can better identify the underlying test-taking behaviour an examinee engages in on a certain item. PMID:25873487

  10. Physiological responses of juvenile rainbow trout to fasting and swimming activity: Effects on body composition and condition indices

    Science.gov (United States)

    Simpkins, D.G.; Hubert, W.A.; Del Rio, C.M.; Rule, D.C.

    2003-01-01

    The physiological traits that allow fish to survive periods of limited food resources are poorly understood. We assessed changes in proximate body composition, relative organ mass, blood metabolites, and relative weight (Wr) of sedentary and actively swimming (15 cm/s) juvenile rainbow trout (154-182 mm total length) over 147 d of fasting. Fasting caused measurable responses that were augmented when fish were swimming. Lipids and plasma triacylglycerides declined over time. Proteins were catabolized simultaneously with lipid reserves, but ammonia concentrations in plasma did not increase. The liver somatic index (LSI) did not change substantially over 105 d, suggesting that gluconeogenesis maintained blood glucose concentrations and hepatic glycogen reserves for a substantial period of fasting. The gut somatic index (GSI) and Wr declined linearly during fasting, but the LSI did not decline until after 105 d of fasting. Consequently, the use of different body condition indices could lead to different conclusions about the condition of juvenile rainbow trout. Swimming activity caused fish to have lower lipid and protein reserves than those of sedentary fish. No mortalities were observed among sedentary fish, but mortalities occurred among actively swimming fish after 97 d of fasting when 3.2% or less lipid remained in their bodies. Body condition indices did not account for differences in proximate body composition between sedentary and actively swimming fish and were relatively poor predictors of lipid content and risk of mortality. The probability of mortality was most accurately predicted by percent lipid content. Therefore, we suggest that fisheries scientists consider using percent lipid content when evaluating the physiological status and risk of mortality due to starvation among juvenile rainbow trout.

  11. Predicting response times for the Spotify backend

    OpenAIRE

    Yanggratoke, Rerngvit; Kreitz, Gunnar; Goldmann, Mikael; Stadler, Rolf

    2012-01-01

    We model and evaluate the performance of a distributed key-value storage system that is part of the Spotify backend. Spotify is an on-demand music streaming service, offering low-latency access to a library of over 16 million tracks and serving over 10 million users currently. We first present a simplified model of the Spotify storage architecture, in order to make its analysis feasible. We then introduce an analytical model for the distribution of the response time, a key metric in the Spoti...

  12. A fast-response two-colour pyrometer

    Energy Technology Data Exchange (ETDEWEB)

    Cutler, D.P.

    1979-01-01

    An instrument is described which was developed in order to study the rate of rise and fall of temperature of a rapidly heated surface of unknown emissivity, e.g, the striking of coal cutting machine picks on the relatively hard quartzitic roof or floor of a coal seam. A day-to-day reproducibility of within 35/sup 0/C is achieved in measurements of temperatures in the range 500 to 1700/sup 0/C with heating times, from ambient, of about 0.5 ms. The instrument is self-contained and incorporates outlet sockets to either an oscilloscope or waveform analyser, and is housed within a modified camera body. The target is sighted using the focussing system of the camera.

  13. 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.

  14. Real time face recognition using adaboost improved fast PCA algorithm

    OpenAIRE

    Kumar, K. Susheel; Semwal, Vijay Bhaskar; Tripathi, R C

    2011-01-01

    This paper presents an automated system for human face recognition in a real time background world for a large homemade dataset of persons face. The task is very difficult as the real time background subtraction in an image is still a challenge. Addition to this there is a huge variation in human face image in terms of size, pose and expression. The system proposed collapses most of this variance. To detect real time human face AdaBoost with Haar cascade is used and a simple...

  15. Duration of fasting but not diurnal variation affects the response to glucagon in healthy cats.

    Science.gov (United States)

    Gilor, C; Glock, R; Gilor, S

    2015-10-01

    The role of glucagon disturbances in diabetes is increasingly recognized. Glucagon stimulation tests (GSTs) have been described in cats previously, but information is lacking on the response of cats to glucagon under specific conditions. The aim of this study was to assess a novel protocol for GST using human-recombinant glucagon and the effect of diurnal variation and duration of fasting using this protocol in healthy cats. All intravenous doses resulted in occasional vomiting and nausea, and eventually, a 20-?g/kg intramuscular dose was chosen. Five healthy cats were then used in a repeated-measures study. Cats were free-fed regularly at 7:30 AM and 5:30 PM for 30 min. In each cat, GST was performed at 7 PM after a 25-h fast (PM25), at 9 AM after a 25-h fast (AM25), and at 9 AM after a 15-h fast (AM15). Glucose and insulin concentrations were measured at -15, 0, 15, 25, 35, 45, and 60 min after stimulation. Baseline and peak concentrations were compared using the Friedman test. Baseline glucose and insulin did not differ significantly between treatment groups. Peak glucose concentrations occurred at 15 min and were significantly higher (P = 0.0085) at AM15 (mean ± standard deviation = 185.2 ± 43.0 mg/dL) vs AM25 (144.4 ± 10.5 mg/dL) and PM25 (128.0 ± 18.4 mg/dL). Similarly, peak insulin concentrations occurred at 15 min and were significantly higher (P = 0.04) at AM15 (1,911 ± 1,153 pg/mL) vs AM25 (739 ± 52 pg/mL) or PM25 (549 ± 366 pg/mL). In conclusion, prolonged fasting significantly blunted the glycemic response to glucagon compared with shorter fasting, but diurnal variation had no significant effect on glucose or insulin responses. PMID:26201763

  16. Brief Communication: Greenland's shrinking ice cover: ?fast times? but not that fast

    Directory of Open Access Journals (Sweden)

    P. Morin

    2011-11-01

    Full Text Available A map of Greenland in the 13th edition (2011 of the Times Comprehensive Atlas of the World made headlines because the publisher's media release mistakenly stated that the permanent ice cover had shrunk 15 % since the previous 10th edition (1999 revision. The claimed shrinkage was immediately challenged by glaciologists, then retracted by the publisher. Here we show: (1 accurate maps of ice extent based on 1978/1987 aerial surveys and recent MODIS imaging; and (2 shrinkage at 0.019 % a?1 in ? 50 000 km2 of ice in a part of east Greenland that is shown as ice-free in the Times Atlas.

  17. Time to let go of CARP? Not so fast

    OpenAIRE

    Monsod, Toby C.; Piza, Sharon A.

    2014-01-01

    The following note seeks to clarify the appreciation of data pertaining to agrarian reform as used in the discussion paper "CARP: time to let go" (henceforth Fabella (2014)). Fabella (2014) has three parts: the first part argues that "the cumulative weight of evidence suggests that the hypothesis that in economic terms CARP is a government failure has not been rejected." The second part offers possible reasons for that failure. The third part concludes, saying it is time to let go.

  18. Fast Accelerated Failure Time Modeling for Case-Cohort Data

    OpenAIRE

    Chiou, Steven; Kang, Sangwook; Yan, Jun

    2012-01-01

    Semiparametric accelerated failure time (AFT) models directly relate the predicted failure times to covariates and are a useful alternative to models that work on the hazard function or the survival function. For case-cohort data, much less development has been done with AFT models. In addition to the missing covariates outside of the sub-cohort in controls, challenges from AFT model inferences with full cohort are retained. The regression parameter estimator is hard to comp...

  19. Effect of time of day and fasting duration on measures of glycaemia

    DEFF Research Database (Denmark)

    Hulmán, A; Færch, K; Vistisen, D; Karsai, J; Nyári, T A; Tabák, A G; Brunner, E J; Kivimäki, M; Witte, Daniel

    2013-01-01

    AIMS/HYPOTHESIS: We aimed to study diurnal variation in glucose regulation by examining the effects of time of day and fasting duration on fasting plasma glucose (FPG), 2 h post-load plasma glucose (2hPG) and HbA(1c) levels. METHODS: We analysed data from 5,978 non-diabetic white men and women from the prospective Whitehall II Study. All studied participants fasted for at least 8 h before a clinical examination, which included an OGTT and anthropometric measurements. We fitted mixed-effects mode...

  20. Signal and Noise Analysis in TRION -Time-Resolved Integrative Optical Fast Neutron Detector

    OpenAIRE

    Vartsky, D.; Feldman, G; Mor, I; Goldberg, M. B.; Bar, D.; Dangendorf, V.

    2008-01-01

    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...

  1. Brief Communication: Greenland's shrinking ice cover: ?fast times? but not that fast

    OpenAIRE

    Morin, P.; G. J. Leonard; Jiskoot, H.; J. G. Cogley; Citterio, M.; Christoffersen, P.; Chen, C; J. E. Box; T. J. Benham; Bamber, J. L.; R. B. Alley; Ahlstrøm, A. P.; Kargel, J S; Scambos, T.; Sheldon, T.

    2011-01-01

    A map of Greenland in the 13th edition (2011) of the Times Comprehensive Atlas of the World made headlines because the publisher's media release mistakenly stated that the permanent ice cover had shrunk 15 % since the previous 10th edition (1999) revision. The claimed shrinkage was immediately challenged by glaciologists, then retracted by the publisher. Here we show: (1) accurate maps of ice extent based on 1978/1987 aerial surveys and recent MODIS imaging; and (2) shrinkage at 0.019 % ...

  2. 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.

  3. Fast-response underwater TSP investigation of subcritical instabilities of a cylinder in crossflow

    Science.gov (United States)

    Capone, Alessandro; Klein, Christian; Di Felice, Fabio; Beifuss, Uwe; Miozzi, Massimo

    2015-10-01

    We investigate the classic cylinder in crossflow case to test the effectiveness of a fast-response underwater temperature-sensitive paint coating (TSP) in providing highly resolved spatial and time observations of the action of a flow over a bluff body surface. The flow is investigated at Reynolds number crisis state. The obtained TSP image sequences convey an accurate description of the evolution of the main features in the fluid-cylinder interaction, like the separation line position, the pattern of the large coherent structures acting on the cylinder's surface and the small-scale intermittent streamwise arrays of vortices. Ad hoc data management and features extraction techniques are proposed which allow extraction of quantitative data, such as separation line position and vortex-shedding frequency, and results are compared to the literature. Use of TSP for water applications introduces an interesting point of view about the fluid-body interactions by focusing directly on the effect of the flow on the model surface.

  4. Decoupling and fast response current control for hydrid poloidal field coil system

    International Nuclear Information System (INIS)

    The report focuses on the hybrid poloidal field coil system. It is a multiple-input, multiple-output, multiple-variable system. A study is carried out with the aim of achieving fast response current control of a hybrid poloidal field coil system. Its characteristics are evaluated using a digital dynamics simulation model. Current control of a coil is discussed first, focusing on discrete-time approximation, decoupling control, deadbeat control, and configuration of a coil current controller. The simulation model is constructed based on the differential equatioin for an equivalent circuit. Simulation conditions are discussed and simulation results are presented. The investigation identifies a method and mechanism for current control of a hybrid poloidal field coil system with a multiple-input, multiple-output and multiple-variable feature. This coil current control method consists of decoupling control and deadbeat control to permit high-speed control of the coil current. The proposed decoupling control system can eliminate the effect of mutual inductance between poloidal field coils. It is demonstrated that no mutual interference appears between the currentrs in coils. (N.K.)

  5. Fast SIFT design for real-time visual feature extraction.

    Science.gov (United States)

    Chiu, Liang-Chi; Chang, Tian-Sheuan; Chen, Jiun-Yen; Chang, Nelson Yen-Chung

    2013-08-01

    Visual feature extraction with scale invariant feature transform (SIFT) is widely used for object recognition. However, its real-time implementation suffers from long latency, heavy computation, and high memory storage because of its frame level computation with iterated Gaussian blur operations. Thus, this paper proposes a layer parallel SIFT (LPSIFT) with integral image, and its parallel hardware design with an on-the-fly feature extraction flow for real-time application needs. Compared with the original SIFT algorithm, the proposed approach reduces the computational amount by 90% and memory usage by 95%. The final implementation uses 580-K gate count with 90-nm CMOS technology, and offers 6000 feature points/frame for VGA images at 30 frames/s and ? 2000 feature points/frame for 1920 × 1080 images at 30 frames/s at the clock rate of 100 MHz. PMID:23743775

  6. 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. The paper will present the results of the initial RTAI operating system tests, the design of the streaming architecture and the first experimental results.

  7. 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.

  8. Fast timing study of a CeBr{sub 3} crystal: Time resolution below 120 ps at {sup 60}Co energies

    Energy Technology Data Exchange (ETDEWEB)

    Fraile, L.M., E-mail: fraile@nuc2.fis.ucm.es [Grupo de Física Nuclear, Facultad de CC. Físicas, Universidad Complutense, CEI Moncloa, 28040 Madrid (Spain); Mach, H. [Grupo de Física Nuclear, Facultad de CC. Físicas, Universidad Complutense, CEI Moncloa, 28040 Madrid (Spain); Vedia, V.; Olaizola, B.; Paziy, V.; Picado, E.; Udías, J.M. [Grupo de Física Nuclear, Facultad de CC. Físicas, Universidad Complutense, CEI Moncloa, 28040 Madrid (Spain)

    2013-02-11

    We report on the time response of a novel inorganic scintillator, CeBr{sub 3}. The measurements were performed using a cylindrical crystal of 1-in. in height and 1-in. in diameter at {sup 22}Na and {sup 60}Co photon energies. The time response was measured against a fast reference BaF{sub 2} 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 CeBr{sub 3} crystal coupled to Hamamatsu PMT is found here to be as low as 119 ps at {sup 60}Co energies, which is comparable to the resolution of 107 ps reported for LaBr{sub 3}(Ce). For 511 keV photons the measured FWHM time resolution for CeBr{sub 3} coupled to the Hamamatsu PMT is 164 ps.

  9. 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

  10. Fast Time and Space Parallel Algorithms for Solution of Parabolic Partial Differential Equations

    Science.gov (United States)

    Fijany, Amir

    1993-01-01

    In this paper, fast time- and Space -Parallel agorithms for solution of linear parabolic PDEs are developed. It is shown that the seemingly strictly serial iterations of the time-stepping procedure for solution of the problem can be completed decoupled.

  11. UNCOUPLING PROTEIN-2 MODULATES THE LIPID METABOLIC RESPONSE TO FASTING IN MICE

    OpenAIRE

    Sheets, Anthony R.; Fülöp, Péter; Derdák, Zoltán; Kassai, Andrea; Sabo, Edmond; Mark, Nicholas M.; Paragh, György; Wands, Jack R.; Baffy, György

    2008-01-01

    Uncoupling protein-2 (UCP2) regulates insulin secretion by controlling ATP levels in ? cells. While UCP2 deficiency improves glycemic control in mice, increased expression of UCP2 interferes with glucose-stimulated insulin secretion. These observations link UCP2 to ? cell dysfunction in type 2 diabetes with a perplexing evolutionary role. We found higher residual serum insulin levels and blunted lipid metabolic responses in fasted ucp2?/? mice, supporting the concept that UCP2 evolved to supp...

  12. 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...

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

    OpenAIRE

    Leyffer, Sven; Safro, Ilya

    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 comb...

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

    OpenAIRE

    Late, Sameer G.; Ajay K. Banga

    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 an...

  15. 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 constraints 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 rise to a...

  16. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Takano, H; Yoshida, K; Tsuji, T; Koyama, T; Tsusaka, Y; Kagoshima, Y, E-mail: htakano@sci.u-hyogo.ac.j [Graduate School of Material Science, University of Hyogo, 3-2-1 Kouto, Kamigori, Ako, Hyogo 678-1297 (Japan)

    2009-09-01

    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.

  18. Corporate social responsibility approaches and implementation in selected fast food restaurants

    Directory of Open Access Journals (Sweden)

    Emma E. Montalbo

    2015-08-01

    Full Text Available This study sought to determine Corporate Social Responsibility approaches and implementation in Fast Food Restaurants in Batangas City, Philippines. The researchers employed a descriptive design and quantitative method in the analysis of data with the questionnaire as the main instrument. Five (5 restaurant- participants were purposively chosen from the total population of 15. Results showed that CSR related mission/vision is clearly not embedded in the institutional websites of fast food restaurants while personal relation/social proximity approach is highly evident. Also, factors in the implementation of corporate social responsibility in relation to philanthropic behavior, shows a significant behavioral change from the statistical result such as moderately evident. CSR approaches and implementation are highly evident that clearly proves the responsible behavior of local fast food restaurants. Institutional integration of CSR in the company’s mission/vision statements, structure, decisions, activities, communication, practices stated appears to be beneficial in light of new corporate-state-market-society relationship.

  19. 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.

  20. 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...

  1. 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.

  2. Response of urinary hydroxyproline to dietary protein and fasting in white-tailed deer

    Science.gov (United States)

    DelGiudice, G.D.; Seal, U.S.; Mech, L.D.

    1988-01-01

    The effects of dietary protein, fasting, and refeeding on urinary hydroxyproline of nine captive female white-tailed deer (Odocoileus virginianus) were examined from 23 February to 3 May 1984 in northern Minnesota. In the fasted group, mean hydroxyproline:creatinine (OHP:C) was greater (P less than 0.05) at week 4 compared to baseline at week 0. Between fasted deer and deer fed high protein-high energy (HPHE) and low protein-high energy (LPHE) diets, no difference in OHP:C ratios was detected during the initial 4 wk of the study. Urinary OHP:C ratios were significantly (P less than 0.05) greater in the fasted group during refeeding, concomitant with greater feed consumption and weight gain. There was also a significant (P less than 0.02) time effect in the fasted-refed group; OHP:C ratios increased during these two phases of the study. There was no difference between the HPHE and LPHE fed deer in renal OHP excretion. However, mean OHP:C ratios in yearlings (16.8 +/- 2.2) were greater (P less than 0.001) than in the adults (7.5 +/- 1.2) of those groups, indicating a higher collagen turnover rate. Urinary OHP:C shows potential as an indicator of growth and starvation, and the data presented may serve as reference values.

  3. Improving Adaptive Learning Technology through the Use of Response Times

    Science.gov (United States)

    Mettler, Everett; Massey, Christine M.; Kellman, Philip J.

    2011-01-01

    Adaptive learning techniques have typically scheduled practice using learners' accuracy and item presentation history. We describe an adaptive learning system (Adaptive Response Time Based Sequencing--ARTS) that uses both accuracy and response time (RT) as direct inputs into sequencing. Response times are used to assess learning strength and…

  4. 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…

  5. Fast computation of finite-time Lyapunov exponent fields for unsteady flows

    Science.gov (United States)

    Brunton, Steven L.; Rowley, Clarence W.

    2010-03-01

    This paper presents new efficient methods for computing finite-time Lyapunov exponent (FTLE) fields in unsteady flows. The methods approximate the particle flow map, eliminating redundant particle integrations in neighboring flow map calculations. Two classes of flow map approximations are investigated based on composition of intermediate flow maps; unidirectional approximation constructs a time-T map by composing a number of smaller time-h maps, while bidirectional approximation constructs a flow map by composing both positive- and negative-time maps. The unidirectional method is shown to be fast and accurate, although it is memory intensive. The bidirectional method is also fast and uses significantly less memory; however, it is prone to error which is large in regions where the opposite-time FTLE field is large, rendering it unusable. The algorithms are implemented and compared on three example fluid flows: a double gyre, a low Reynolds number pitching flat plate, and an unsteady ABC flow.

  6. 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

  7. Down-regulation of urinary AQP2 and unaffected response to hypertonic saline after 24 hours of fasting in humans

    DEFF Research Database (Denmark)

    Starklint, JØrn; Bech, Jesper NØrgaard

    2005-01-01

    In rats, 24 hours of fasting impairs urinary concentrating ability by down-regulation of aquaporin-2 (AQP2). We tested the hypothesis that 24 hours of fasting in humans reduces the capability to form AQP2 and impairs the antidiuretic response to hypertonic saline infusion.

  8. 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

  9. Demonstration of two-dimensional time-encoded imaging of fast neutrons

    Science.gov (United States)

    Brennan, J.; Brubaker, E.; Gerling, M.; Marleau, P.; McMillan, K.; Nowack, A.; Galloudec, N. Renard-Le; Sweany, M.

    2015-12-01

    We present a neutron detector system based on time-encoded imaging, and demonstrate its applicability toward the spatial mapping of special nuclear material. We demonstrate that two-dimensional fast-neutron imaging with 2° resolution at 2 m stand-off is feasible with only two instrumented detectors.

  10. Smart and hyper-fast responsive polyprodrug nanoplatform for targeted cancer therapy.

    Science.gov (United States)

    Xu, Xiao-Ding; Cheng, Yin-Jia; Wu, Jun; Cheng, Hong; Cheng, Si-Xue; Zhuo, Ren-Xi; Zhang, Xian-Zheng

    2016-01-01

    The rapid development and clinical trials of biodegradable nanoparticles (NPs) are heavily hindered by many factors, including poor drug loading, low drug concentration at disease sites, lack of active targeting function, etc. Herein, we developed a new smart and hype-responsive polyprodrug platform with five key elements (i.e. chemically incorporated drug molecules in backbone, stimuli-responsive bond, hyper-fast chain-breakage ability, hydrophilic segment and targeting ligand). Using 10-hydroxycamptothecin (HCPT) as model drug, we designed and prepared an exemplified redox-responsive amphiphilic polyprodrug via polycondensation and "click" chemistry. This polymer is composed of a hydrophobic HCPT-based polyprodrug, a hydrophilic poly(ethylene oxide) (PEG) chain and a tumor-targeting RGD tail. Employing nanoprecipitation technique, small-sized NPs (36 wt.%), 2) excellent tumor-targeting performance, 3) hyper-fast redox-responsive drug release (around 70% accumulative release within 2 h), 4) long blood circulation and 5) significant inhibition of tumor growth without side effects. PMID:26546916

  11. 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.

  12. Direct calculation of floor response spectra from the Fourier transform of ground movement - application to the SUPERPHENIX fast reactor project

    International Nuclear Information System (INIS)

    This paper describes a method for the direct calculation of floor response spectra from ground response spectra. The procedure utilized the Fourier transform of the ground movement. The mathematical derivations are given in detail, and the method is applied to the calculation of the floor response spectra for a structure which is a simplified model of the SUPERPHENIX fast breeder reactor power plant. (Auth.)

  13. Fast determination of earthquake magnitude and fault extent from real-time P-wave recordings

    Science.gov (United States)

    Colombelli, Simona; Zollo, Aldo

    2015-08-01

    This work is aimed at the automatic and fast characterization of the extended earthquake source, through the progressive measurement of the P-wave displacement amplitude along the recorded seismograms. We propose a straightforward methodology to quickly characterize the earthquake magnitude and the expected length of the rupture, and to provide an approximate estimate of the average stress drop to be used for Earthquake Early Warning and rapid response purposes. We test the methodology over a wide distance and magnitude range using a massive Japan earthquake, accelerogram data set. Our estimates of moment magnitude, source duration/length and stress drop are consistent with the ones obtained by using other techniques and analysing the whole seismic waveform. In particular, the retrieved source parameters follow a self-similar, constant stress-drop scaling (median value of stress drop = 0.71 MPa). For the M 9.0, 2011 Tohoku-Oki event, both magnitude and length are underestimated, due to limited, available P-wave time window (PTWs) and to the low-frequency cut-off of analysed data. We show that, in a simulated real-time mode, about 1-2 seconds would be required for the source parameter determination of M 4-5 events, 3-10 seconds for M 6-7 and 30-40 s for M 8-8.5. The proposed method can also provide a rapid evaluation of the average slip on the fault plane, which can be used as an additional discriminant for tsunami potential, associated to large magnitude earthquakes occurring offshore.

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

    Data.gov (United States)

    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...

  15. 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

  16. A real-time dynamic holographic material using a fast photochromic molecule

    OpenAIRE

    Ishii, Norihito; Kato, Tetsuya; Abe, Jiro

    2012-01-01

    We have developed a real-time, dynamic holographic material that exhibits rapid colouration upon irradiation with UV light and successive fast thermal bleaching within tens of milliseconds at room temperature. Photochromic polymer films were prepared by a simple solution-casting method from the benzene solution of the mixture of the photochromic molecule, poly(ethyl acrylate), and poly(phenoxyethyl acrylate). The real-time control of holographic images using the photochromic polymer film yiel...

  17. 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)

  18. A fast rise time high voltage pulse generator for bounded-wave EMP simulator

    International Nuclear Information System (INIS)

    A high voltage pulse generator with fast rise time is developed. The output wave of this generator is presented. The electromagnetic environment with 1.2 ns or 2.8 ns rise time and 50 ns pulse width can be produced when this generator is connected to bounded-wave EMP simulator which is used to investigate the EMP coupling effects of electrical equipment. (authors)

  19. Ionization chamber with fast timing properties and good energy resolution for fission fragment detection

    International Nuclear Information System (INIS)

    A twin ionization chamber for fission fragment detection is described. The chamber allows to extract both, fast timing- and energy proportional signals. A time resolution of 1.62 ns FWHM was obtained between two fission fragments detected in the two halves of the chamber. For 241Am ?-particles the chamber gave an energy resolution of 1.3 percent. As counting gas methane NTP was used

  20. The synthetic scattering function and application to the design of cold moderators for pulsed neutron sources: a fast response methane based array

    International Nuclear Information System (INIS)

    The Synthetic Scattering Function (SSF) allows a simple description of the incoherent interaction of slow neutrons with hydrogenous materials. The main advantages of this model reside in the analytical expressions that it produces for double-differential cross sections, energy-transfer kernels, and total cross sections, which in turn permit the fast evaluation of neutron scattering and transport properties. In this work we briefly discuss basic features of the SSF, review some previous applications to a number of moderating materials, and present new Monte Carlo results for a fast time-response moderator concept based on methane at low temperatures. (auth)

  1. Fast-Response Calmodulin-Based Fluorescent Indicators Reveal Rapid Intracellular Calcium Dynamics.

    Science.gov (United States)

    Helassa, Nordine; Zhang, Xiao-Hua; Conte, Ianina; Scaringi, John; Esposito, Elric; Bradley, Jonathan; Carter, Thomas; Ogden, David; Morad, Martin; Török, Katalin

    2015-01-01

    Faithful reporting of temporal patterns of intracellular Ca(2+) dynamics requires the working range of indicators to match the signals. Current genetically encoded calmodulin-based fluorescent indicators are likely to distort fast Ca(2+) signals by apparent saturation and integration due to their limiting fluorescence rise and decay kinetics. A series of probes was engineered with a range of Ca(2+) affinities and accelerated kinetics by weakening the Ca(2+)-calmodulin-peptide interactions. At 37?°C, the GCaMP3-derived probe termed GCaMP3fast is 40-fold faster than GCaMP3 with Ca(2+) decay and rise times, t1/2, of 3.3?ms and 0.9?ms, respectively, making it the fastest to-date. GCaMP3fast revealed discreet transients with significantly faster Ca(2+) dynamics in neonatal cardiac myocytes than GCaMP6f. With 5-fold increased two-photon fluorescence cross-section for Ca(2+) at 940?nm, GCaMP3fast is suitable for deep tissue studies. The green fluorescent protein serves as a reporter providing important novel insights into the kinetic mechanism of target recognition by calmodulin. Our strategy to match the probe to the signal by tuning the affinity and hence the Ca(2+) kinetics of the indicator is applicable to the emerging new generations of calmodulin-based probes. PMID:26527405

  2. Improving Item Response Theory Model Calibration by Considering Response Times in Psychological Tests

    Science.gov (United States)

    Ranger, Jochen; Kuhn, Jorg-Tobias

    2012-01-01

    Research findings indicate that response times in personality scales are related to the trait level according to the so-called speed-distance hypothesis. Against this background, Ferrando and Lorenzo-Seva proposed a latent trait model for the responses and response times in a test. The model consists of two components, a standard item response

  3. Efficient allocation of heterogeneous response times in information spreading process

    CERN Document Server

    Cui, Ai-Xiang; Tang, Ming; Fu, Yan; Liang, Xiaoming; Do, Younghae

    2014-01-01

    Recently, the impacts of spatiotemporal heterogeneities of human activities on spreading dynamics have attracted extensive attention. In this paper, to study heterogeneous response times on information spreading, we focus on the susceptible-infected spreading dynamics with adjustable power-law response time distribution based on uncorrelated scale-free networks. We find that the stronger the heterogeneity of response times is, the faster the information spreading is in the early and middle stages. Following a given heterogeneity, the procedure of reducing the correlation between the response times and degrees of individuals can also accelerate the spreading dynamics in the early and middle stages. However, the dynamics in the late stage is slightly more complicated, and there is an optimal value of the full prevalence time changing with the heterogeneity of response times and the response time-degree correlation, respectively. The optimal phenomena results from the efficient allocation of heterogeneous respon...

  4. 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

  5. Effect of training in the fasted state on metabolic responses during exercise with carbohydrate intake

    DEFF Research Database (Denmark)

    De Bock, K; Derave, W; Eijnde, B O; Hesselink, M K; Koninckx, E; Rose, Adam John; Schrauwen, P; Bonen, A; Richter, Erik A.; Hespel, P

    2008-01-01

    Skeletal muscle gene response to exercise depends on nutritional status during and after exercise, but it is unknown whether muscle adaptations to endurance training are affected by nutritional status during training sessions. Therefore, this study investigated the effect of an endurance training program (6 wk, 3 day/wk, 1-2 h, 75% of peak Vo(2)) in moderately active males. They trained in the fasted (F; n = 10) or carbohydrate-fed state (CHO; n = 10) while receiving a standardized diet [65 perc...

  6. Thermal remote sensing as a part of Exupéry volcano fast response system

    Science.gov (United States)

    Zakšek, Klemen; Hort, Matthias

    2010-05-01

    In order to understand the eruptive potential of a volcanic system one has to characterize the actual state of stress of a volcanic system that involves proper monitoring strategies. As several volcanoes in highly populated areas especially in south east Asia are still nearly unmonitored a mobile volcano monitoring system is currently being developed in Germany. One of the major novelties of this mobile volcano fast response system called Exupéry is the direct inclusion of satellite based observations. Remote sensing data are introduced together with ground based field measurements into the GIS database, where the statistical properties of all recorded data are estimated. Using physical modelling and statistical methods we hope to constrain the probability of future eruptions. The emphasis of this contribution is on using thermal remote sensing as tool for monitoring active volcanoes. One can detect thermal anomalies originating from a volcano by comparing signals in mid and thermal infrared spectra. A reliable and effective thermal anomalies detection algorithm was developed by Wright (2002) for MODIS sensor; it is based on the threshold of the so called normalized thermal index (NTI). This is the method we use in Exupéry, where we characterize each detected thermal anomaly by temperature, area, heat flux and effusion rate. The recent work has shown that radiant flux is the most robust parameter for this characterization. Its derivation depends on atmosphere, satellite viewing angle and sensor characteristics. Some of these influences are easy to correct using standard remote sensing pre-processing techniques, however, some noise still remains in data. In addition, satellites in polar orbits have long revisit times and thus they might fail to follow a fast evolving volcanic crisis due to long revisit times. Thus we are currently testing Kalman filter on simultaneous use of MODIS and AVHRR data to improve the thermal anomaly characterization. The advantage of this technique is that it increases the temporal resolution through using images from different satellites having different resolution and sensitivity. This algorithm has been tested for an eruption at Mt. Etna (2002) and successfully captures more details of the eruption evolution than would be seen by using only one satellite source. At the moment for Exupéry, merely MODIS (a sensor aboard NASA's Terra and Aqua satellite) data are used for the operational use. As MODIS is a meteorological sensor, it is suitable also for producing general overview images of the crisis area. Therefore, for each processed MODIS image we also produce RGB image where some basic meteorological features are classified: e.g. clouds, volcanic ash plumes, ocean, etc. In the case of detected hotspot an additional image is created; it contains the original measured radiances of the selected channels for the crisis area. All anomaly and processing parameters are additionally written into an XML file. The results are available in web GIS in the worst case two hours after NASA provides level 1b data online.

  7. 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.

  8. Study on influence of ratio between wideness and height of EMP simulator transmission line with fast rise-time to rise-time of EMP

    International Nuclear Information System (INIS)

    The relation of rise-time inner EMP simulator with fast rise-time and ratio between wideness and height of simulator transmission line is studied through calculation of inner field of EMP simulator with fast rise-time and monadic linear regression analysis using FEKO based on MoM. The results indicate that there is close positive correlation between rise-time of EMP simulator with fast rise-time and the ratio between wideness and height. In other words, the larger the ratio of transmission line between wideness and height becomes, the longer the rise-time becomes. (authors)

  9. A CFD-based wind solver for a fast response transport and dispersion model

    Energy Technology Data Exchange (ETDEWEB)

    Gowardhan, Akshay A [Los Alamos National Laboratory; Brown, Michael J [Los Alamos National Laboratory; Pardyjak, Eric R [UNIV OF UTAH; Senocak, Inanc [BOISE STATE UNIV

    2010-01-01

    In many cities, ambient air quality is deteriorating leading to concerns about the health of city inhabitants. In urban areas with narrow streets surrounded by clusters of tall buildings, called street canyons, air pollution from traffic emissions and other sources is difficult to disperse and may accumulate resulting in high pollutant concentrations. For various situations, including the evacuation of populated areas in the event of an accidental or deliberate release of chemical, biological and radiological agents, it is important that models should be developed that produce urban flow fields quickly. For these reasons it has become important to predict the flow field in urban street canyons. Various computational techniques have been used to calculate these flow fields, but these techniques are often computationally intensive. Most fast response models currently in use are at a disadvantage in these cases as they are unable to correlate highly heterogeneous urban structures with the diagnostic parameterizations on which they are based. In this paper, a fast and reasonably accurate computational fluid dynamics (CFD) technique that solves the Navier-Stokes equations for complex urban areas has been developed called QUIC-CFD (Q-CFD). This technique represents an intermediate balance between fast (on the order of minutes for a several block problem) and reasonably accurate solutions. The paper details the solution procedure and validates this model for various simple and complex urban geometries.

  10. Fast monitoring of epileptic seizures using recurrence time statistics of electroencephalography

    Directory of Open Access Journals (Sweden)

    Jianbo Gao

    2013-10-01

    Full Text Available Epilepsy is one of the most common disorders of the brain. Currently, determination of epileptic seizures often involves tedious, time-consuming visual inspection of electroencephalography (EEG data by medical experts. To better monitor seizures and make medications more effective, we propose a recurrence time based approach to characterize brain electrical activity. Recurrence times have a number of distinguished properties that make it very effective for forwarning epileptic seizures as well as studying propagation of seizures: 1 recurrence times amount to periods of periodic signals, 2 recurrence times are closely related to information dimension, Lyapunov exponent, and Kolmogorov entropy of chaotic signals, 3 recurrence times embody Shannon and Renyi entropies of random fields, and 4 recurrence times can readily detect bifurcation-like transitions in dynamical systems. In particular, property 4 dictates that unlike many other nonlinear methods, recurrence time method does not require the EEG data be chaotic and/or stationary. Moreover, the method only contains a few parameters that are largely signal-independent, and hence, is very easy to use. The method is also very fast—it is fast enough to on-line process multi-channel EEG data with a typical PC. Therefore, it has the potential to be an excellent candidate for real-time monitoring of epileptic seizures in a clinical setting.

  11. 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.

  12. Effect of fasting on the transit time of 144Ce in the mouse gut

    International Nuclear Information System (INIS)

    Our work with G.I. absorption of actinide elements indicates greater absorption by fasted animals than by animals on regular diets (Weiss and Walburg, undated). Residence time of a metallic compound in the gut may be an important factor influencing G.I. absorption. Cerium-144 (III) chloride was administered by gavage to fasted mice and to mice on regular feed. The G.I. tract was excised, cut into sections, and the activity of each section determined as a function of time after dosing. Our results indicate rapid transit of 144CeCl3 along the empty mouse gut. One hour after dosing, about half the Ce is in the cecal contents; about 40% remains in stomach contents. Twelve hours after dosing, only about 2% remains in the cecum; by 16 hours, almost the entire dose has been cleared from the intestine. Transit times in mice with stomach and intestines containing food were 12 hours longer than in fasted mice. These results lead to the conclusion that factors other than G.I. residence time determine G.I. absorption of actinides in mice

  13. In-situ response time testing of force-balance pressure transmitters in nuclear power plants

    International Nuclear Information System (INIS)

    This paper reports on recommendations for response time testing of safety system pressure transmitters in nuclear power plants that are found in Regulatory Guide 1.118 and requirements are defined in plant technical specifications. The conventional testing method involves simultaneously applying a pressure ramp signal to the process transmitter and to a fast-response reference transmitter. The time delay between the response of the two transmitters, when they obtain a predetermined value, is called the process transmitter response time. This method is referred to as the ramp test. Although the ramp test is an accepted method, large variations in its results are sometimes encountered because of empirical difficulties associated with the test. This test requires access to each transmitter, and it must be performed inside the containment during shutdown. The in-situ test is accomplished by interrupting the power to the transmitter for a few seconds. It is referred to as the Power Interrupt (PI) test, and it can be conducted while the plant is operating. The test includes the entire electromechanical system and the response time is obtained by analyzing the transient response following the restoration of power to the transmitter. Response times obtained from the PI test and the ramp test are in good agreement and usually differ by less than 50 ms

  14. Using a fast-gated camera for measurements of transverse beam distributions and damping times

    Energy Technology Data Exchange (ETDEWEB)

    Minty, M.; Brown, R.; Decker, F.J.; Emma, P.; Krejcik, P.; Limberg, T.; McCormick, D.; Ross, M.; Siemann, R.; Spence, W.

    1992-11-01

    With a fast-gated camera, synchrotron light was used for studying the transverse beam distributions and damping times in the Stanford Linear Collider (SLC) damping rings. By digitizing the image in the camera signal, the turn-by-turn time evolution of the transverse beam distribution was monitored and analyzed. The projections of the digitized image were fit with Gaussian functions to determine the moments of the distribution. Practical applications include the determination of injection matching parameters and the transverse damping times. In this report we describe a synchrotron light monitor and present experimental data obtained in the SLC damping rings.

  15. Very fast doped LaBr.sub.3 scintillators and time-of-flight PET

    Science.gov (United States)

    Shah, Kanai S.

    2006-10-31

    The present invention concerns very fast scintillator materials capable of resolving the position of an annihilation event within a portion of a human body cross-section. In one embodiment, the scintillator material comprises LaBr.sub.3 doped with cerium. Particular attention is drawn to LaBr.sub.3 doped with a quantity of Ce that is chosen for improving the timing properties, in particular the rise time and resultant timing resolution of the scintillator, and locational capabilities of the scintillator.

  16. Dynamic Response of a fast near infra-red Mueller matrix ellipsometer

    CERN Document Server

    Aas, Lars Martin Sandvik; Kildemo, Morten; Lindgren, Mikael

    2010-01-01

    The dynamic response of a near infrared Ferroelectric Liquid Crystal based Mueller matrix ellipsometer (NIR FLC-MME) is presented. A time dependent simulation model, using the measured time response of the individual FLCs, is used to describe the measured temporal response. Furthermore, the impulse response of the detector and the pre-amplifier is characterized and included in the simulation model. The measured time-dependent intensity response of the MME is reproduced in simulations, and it is concluded that the switching time of the FLCs is the limiting factor for the Mueller matrix measurement time of the FLC-based MME. Based on measurements and simulations our FLC based NIR-MME system is estimated to operate at the maximum speed of approximately 16 ms per Mueller matrix measurement. The FLC-MME may be operated several times faster, since the switching time of the crystals depends on the individual crystal being switched, and to what state it is switched. As a demonstration, the measured temporal response ...

  17. 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)

  18. Response Time under Monetary Incentives. The Ultimatum Game

    OpenAIRE

    Brañas-Garza, Pablo; León-Mejía, Ana; Miller, Luis M.

    2007-01-01

    This paper studies the response times of experimental subjects playing the Ultimatum game in a laboratory setting using monetary incentives. We find that proposals are not significantly correlated with response time, whereas responders? behavior is positively and significantly correlated. Hence, consistent with Rubisntein (forthcoming) we find that response times may capture relevant cognitive processes. However, the use of monetary incentives causes a reversal of his findings. These results ...

  19. Response Times of Operators in a Control Room

    DEFF Research Database (Denmark)

    Platz, O.; Rasmussen, J.; Skanborg, Preben Zacho

    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.

  20. Fast neutron response of 6Li-depleted CLYC detectors up to 20 MeV

    International Nuclear Information System (INIS)

    The response of 6Li-depleted Cs2LiYCl6 (CLYC) to high-energy neutrons has been investigated using a pair of 1 in.×1 in. crystals. These are the first two detectors of their kind, which will comprise a 16-element array for studies in fast neutron spectroscopy. Their thermal neutron response has been compared with standard CLYC crystals with a 6Li enrichment of 95%, demonstrating excellent suppression of the overwhelming thermal neutron background. The response to mono-energetic neutrons over a range of 0.5 to 20 MeV was tested. From this, the response function, energy resolution, and pulse-shape discrimination up to 20 MeV were characterized. Detailed Monte Carlo investigations with MCNPX have been used to show that the dominant reaction mechanisms contributing to the observed response are 35Cl(n,p) and 35Cl(n,?). Preliminary investigations have also demonstrated the possibility for separating events from these two reactions

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

    International Nuclear Information System (INIS)

    Fast-timing measurements were performed in the region of the medium-mass 103,105,107Cd isotopes, produced in fusion evaporation reactions. Results on new and reevaluated half-lives are analyzed within a systematic study of transition rates. The 7/21+ states in 103,105,107Cd are interpreted as arising from a single-particle excitation. The 9/2+ states configuration assignment is based on the observed decay branches.

  2. 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 ne...

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

    DEFF Research Database (Denmark)

    Wilm, Jakob; Olesen, Oline Vinter; Jensen, Rasmus Ramsbøl; Højgaard, Liselotte; Larsen, Rasmus

    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...

  4. 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)

  5. 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)

  6. Orthographic influences on phoneme deletion response times.

    Science.gov (United States)

    Tyler, Michael D; Burnham, Denis K

    2006-11-01

    The aim of this paper is to provide further evidence that orthography plays a central role in phonemic awareness, by demonstrating an orthographic congruency effect in phoneme deletion. In four initial phoneme deletion experiments, adult participants produced the correct response more slowly with orthographically mismatched stimulus-response pairs (e.g., worth-earth) than with matched pairs (e.g., wage-age). This orthographic effect occurred with or without specific instructions to ignore spelling and when stimuli were presented with or without the to-be-deleted sound. In a final experiment, participants made more errors on complex than simple onset items, but there was no interaction with orthographic mismatch. The repeated observation of this robust orthographic effect suggests that participants are at least aware of orthography during phonemic awareness tasks, and it supports the view that phonemic awareness is directly subserved by orthography. PMID:16987786

  7. Changes in energy metabolism in response to 48 h of overfeeding and fasting in Caucasians and Pima Indians

    DEFF Research Database (Denmark)

    Weyer, C; Vozarova, B; Ravussin, E; Tataranni, P A; de Courten, Barbora

    2001-01-01

    Differences in the metabolic response to overfeeding and starvation may confer susceptibility or resistance to obesity in humans. To further examine this hypothesis, we assessed the changes in 24 h energy metabolism in response to short-term overfeeding and fasting in Caucasians (C) and Pima Indians (I), a population with a very high propensity for obesity.

  8. 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

  9. 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.

  10. 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 af...

  11. 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.

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

    Science.gov (United States)

    Junghansa, A. R.; Beyer, R.; Grosse, E.; Hannaske, R.; Kögler, T.; Massarczyk, R.; Schwengner, R.; Wagner, A.

    2015-05-01

    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.

  13. 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.

  14. 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…

  15. Dynamic response and time-frequency analysis for gear tooth crack detection

    Science.gov (United States)

    Mohammed, Omar D.; Rantatalo, Matti

    2016-01-01

    Vibration health monitoring is a non-destructive technique which can be applied to detect cracks propagating in gear teeth. This paper studies gear tooth crack detection by investigating the natural frequencies and by performing time-frequency analysis of a 6 DOF dynamic gear model. The gear mesh stiffness used in the model was calculated analytically for different cases of crack sizes. The frequency response functions (FRFs) of the model were derived for healthy and faulty cases and dynamic simulation was performed to obtain the time signal responses. A new approach involving a short-time Fourier transform (STFT) was applied where a fast Fourier transform (FFT) was calculated for successive blocks with different sizes corresponding to the time segments of the varying gear mesh stiffness. The relationship between the different crack sizes and the mesh-stiffness-dependent eigenfrequencies was studied in order to detect the tooth crack and to estimate its size.

  16. Test of relativistic time dilation with fast optical atomic clocks at different velocities

    Science.gov (United States)

    Reinhardt, Sascha; Saathoff, Guido; Buhr, Henrik; Carlson, Lars A.; Wolf, Andreas; Schwalm, Dirk; Karpuk, Sergei; Novotny, Christian; Huber, Gerhard; Zimmermann, Marcus; Holzwarth, Ronald; Udem, Thomas; Hänsch, Theodor W.; Gwinner, Gerald

    2007-12-01

    Time dilation is one of the most fascinating aspects of special relativity as it abolishes the notion of absolute time. It was first observed experimentally by Ives and Stilwell in 1938 using the Doppler effect. Here we report on a method, based on fast optical atomic clocks with large, but different Lorentz boosts, that tests relativistic time dilation with unprecedented precision. The approach combines ion storage and cooling with optical frequency counting using a frequency comb. 7Li+ ions are prepared at 6.4% and 3.0% of the speed of light in a storage ring, and their time is read with an accuracy of 2×10-10 using laser saturation spectroscopy. The comparison of the Doppler shifts yields a time dilation measurement represented by a Mansouri-Sexl parameter , consistent with special relativity. This constrains the existence of a preferred cosmological reference frame and CPT- and Lorentz-violating `new' physics beyond the standard model.

  17. Temporal response and real time measurements with 5GHz photocell-oscilloscope system at low light levels

    International Nuclear Information System (INIS)

    Experiments were carried out to investigate by means of picosecond mode-locked laser pulses the performance of fast vacuum photoelectric cells associated with a high sensitivity and high speed cathode-ray tube provided with a channel plate electron multiplier. With an amplitude sensitivity of 140mV/cm an overall time of response of less than 100 ps was measured

  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. Electron absorption of fast magnetosonic waves by transit time magnetic pumping in JET

    International Nuclear Information System (INIS)

    Direct electron damping of low frequency fast magnetosonic waves has been observed in the centre of high beta hydrogenic JET plasmas where transit time magnetic pumping is a significant component in the electron-wave interaction mechanism. The electron heating power profile was peaked on axis, extended across almost half the minor radius and accounted for 22±5% of the total radiofrequency power coupled to the plasma. After passing through the plasma core, the fast wave was absorbed by hydrogen ions at the second harmonic cyclotron resonance which was placed inboard of the magnetic axis and intersected the equatorial plane at one third of the minor radius. (author). Letter-to-the-editor. 25 refs, 8 figs

  20. 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°.

  1. Sputter ion pump based real time steam generator leak detection system for Fast Breeder Test Reactor

    International Nuclear Information System (INIS)

    The energy produced in Fast Breeder Test Reactor (FBTR) is transferred to feed water for generating superheated steam in once-through shell and tube type countercurrent steam generator (SG). Sodium and water/steam flow in shell and tube side respectively are separated by thin-walls of ferritic steel tubes. Material defects in these tubes can lead to leakage of water/steam into sodium, resulting in sodium water reactions leading to undesirable consequences. Detection of a leak at its inception, therefore, is important for the safe and reliable operation of the reactor. Monitoring hydrogen in sodium, produced during reaction of sodium with the leaked water or steam is a convenient way to accomplish this. This paper report the development of instrumentation using sputter ion pump and nickel diffuser for real time hydrogen detection in sodium for FBTR at Kalpakkam, which is the fore runner of Fast Reactor Technology in India. (author)

  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. Constraints of relic gravitational waves by Pulsar Timing Array: Forecasts for the FAST and SKA projects

    CERN Document Server

    Zhao, Wen; You, Xiao-Peng; Zhu, Zong-Hong

    2013-01-01

    Measurement of the pulsar timing residuals provides a direct way to detect relic gravitational waves at the frequency $f\\sim 1/{\\rm yr}$. In this paper, we investigate the constraints on the inflationary parameters, the tensor-to-scalar ratio $r$ and the tensor spectral index $n_t$, by the current and future Pulsar Timing Arrays (PTAs). We find that Five-hundred-meter Aperture Spherical radio Telescope (FAST) in China and the planned Square Kilometer Array (SKA) projects have the fairly strong abilities to test the phantom-like inflationary models. If $r=0.1$, FAST could give the constraint on the spectral index $n_t<0.38$, and SKA gives $n_t<0.30$. While an observation with the total time T=20yr, the pulsar noise level $\\sigma_w=30$ns and the monitored pulsar number $n=200$, could even constrain $n_t<0.05$. These are much tighter than those inferred from the current results of Parkers Pulsar Timing Array (PPTA) and European Pulsar Timing Array (EPTA). Especially, by studying the effects of various o...

  4. Fast Estimate of Rupture Process of Large Earthquakes via Real Time Hi-net Data

    Science.gov (United States)

    Wang, D.; Kawakatsu, H.; Mori, J. J.

    2014-12-01

    We developed a real time system based on Hi-net seismic array that can offer fast and reliable source information, for example, source extent and rupture velocity, for earthquakes that occur at distance of roughly 30°- 85°with respect to the array center. We perform continuous grid search on a Hi-net real time data stream to identify possible source locations (following Nishida, K., Kawakatsu, H., and S. Obara, 2008). Earthquakes that occurred off the bright area of the array (30°- 85°with respect to the array center) will be ignored. Once a large seismic event is identified successfully, back-projection will be implemented to trace the source propagation and energy radiation. Results from extended global GRiD-MT and real time W phase inversion will be combined for the better identification of large seismic events. The time required is mainly due to the travel time from the epicenter to the array stations, so we can get the results between 6 to 13 min depending on the epicenter distances. This system can offer fast and robust estimates of earthquake source information, which will be useful for disaster mitigation, such as tsunami evacuation, emergency rescue, and aftershock hazard evaluation.

  5. A fast-response production-inventory model for deteriorating seasonal products with learning in set-ups

    Directory of Open Access Journals (Sweden)

    Ibraheem Abdul

    2011-10-01

    Full Text Available The classical production-inventory model assumes that both demand and set-up costs are constant. However, in real manufacturing environment, managers usually embark on continuous improvement programmes that often lead to more effective use of tools and machineries and consequently reduction in set-up costs. In fact, constant emphasis on reduction of set-up costs is usually cited as one of the factors responsible for the efficiency of Japanese manufacturing methods. On the other hand, the demand for seasonal product is often characterized by a mixture of time-dependent patterns over the entire season. This paper investigates the effect of learning-based reduction in set-up costs on the optimal schedules and costs of a production-inventory system for deteriorating seasonal products. The demand pattern is a general three-phase ramp-type demand function that represents the various phases of demand commonly observed in many seasonal products in the market. A two-parameter Weibull-distribution function is used for the deterioration of items in order to make the model more generalized and realistic. The study further presents two different multi-period production strategies that can ensure a fast-response to customers’ demand and compare them with the usual single period strategy. The Numerical example and sensitivity analysis shows that learning-based reduction in set-up costs leads to higher production frequency and shorter production runs which are vital aspects of the just-in-time (JIT philosophy.

  6. Trap Engineering of CdTe Nanoparticle for High Gain, Fast Response, and Low Noise P3HT:CdTe Nanocomposite Photodetectors.

    Science.gov (United States)

    Wei, Haotong; Fang, Yanjun; Yuan, Yongbo; Shen, Liang; Huang, Jinsong

    2015-09-01

    Cd(2+) causes deep traps on the surface of CdTe quantum dots (QDs) often leading to a long response time for a photodetector. Poly(3-hexylthiophene) (P3HT) can be used to selectively passivate the Cd(2+) -related deep traps by forming a Cd-S bond, while maintaining the shallow traps. By tailoring the trap depth of the CdTe QDs, a high gain, fast response, and low noise P3HT:CdTe nanocomposite photodetector is achieved. PMID:26192923

  7. [Ecologic ethics: a response for our times].

    Science.gov (United States)

    Trejo, C

    1991-11-01

    To understand the ethics of our present time (macrocosmos), the patient-physician relationship (microcosmos complex) and its changes through history are analyzed. The patient-physician relationship is no longer between two individuals, it is plural and technified. An individualistic forms of ethic cannot answer the questions that arise from contemporary society. The power (political) of medical science has placed us at the threshold of a qualitative change, new that the human genome can be known and the very nature of the species can be modified. Man's destiny will depend on the way (ethic) he uses his knowledge. An ecological ethic could be the answer. PMID:9723085

  8. Measurement of heating laser injection time in a fast-ignition experiment

    International Nuclear Information System (INIS)

    The ability to measure the injection time of a heating laser synchronized to the imploded core plasma is very important in fast-ignition experiments. In this research, we demonstrate the successful measurement of the injection time using a new x-ray framing camera design. Thermal x-rays for imploded core measurement and hard x-rays for measurement of the heating laser injection time were discriminated using x-ray reflectors made of platinum. The measured hard x-ray signal was evaluated with numerical calculations and found to agree well with the calculated values. We have established a technique for estimating the heating laser injection time from the position of the peak intensity of the hard x-ray signal. (paper)

  9. Detecting changes in coupling with Granger causality method from time series with fast transient processes

    Science.gov (United States)

    Sysoev, Ilya V.; Sysoeva, Marina V.

    2015-08-01

    The ability of the Granger causality method to detect directed coupling between subsystems of a complex system in a moving time window is investigated on etalon oscillators. In particular, the time series consisting of alternate stationary regimes characterised by the different amplitude and shape of oscillations with fast transient processes between these regimes are considered, with similar transitions being possible due to changes either in the coupling or in the individual properties of subsystems. Two popular approaches to surrogate times series generation are used to check the significance of the method results. Two model structures: the standard linear and the special non-linear adapted to data are implemented. The Granger causality method using the model structure adapted to data is shown to be significantly advantageous in detecting coupling directionality and the instant time of the regime change than the standard linear method, while in some cases the sensitivity and the specificity of the adapted approach are insufficient.

  10. Development of a LaBr3(Ce) Fast-timing Array for FAIR

    International Nuclear Information System (INIS)

    A ?-ray spectrometer with fast-timing capabilities, constructed of LaBr3(Ce:5%) detectors, is under development for use at the future Facility for Anti-proton and Ion Research (FAIR). The physics aims of this device are to measure the half-lives of excited states in the region of ?50 ps to several ns, in exotic nuclei. Monte-Carlo simulations using the GEANT4 software package have determined the final design of this fast-timing array by calculating the full-energy peak efficiencies of several different detector geometries. The results of the simulated efficiencies for each configuration were used to calculate the timing precision. Consequently, an array of thirty six, section 3.8 x 5.1 cm cylindrical crystals was found to be the optimum configuration. The detectors were purchased and subsequently characterised, with each detector found to have intrinsic energy and timing resolutions of ? 2.8 % (FWHM) and ? 210 ps (FWHM) for the 1173 and 1332 keV decays from 60Co. (authors)

  11. Response of a fast neutron criticality monitor to prompt critical bursts

    International Nuclear Information System (INIS)

    A neutron-sensitive criticality monitor has been developed at the Lawrence Livermore Laboratory. The monitor's response characteristics to a nuclear criticality accident and to high ambient gamma and neutron radiation fields has been determined by exposure to actual prompt critical bursts using the Super Kukla fast burst reactor at the Nevada Test Site. The monitor head is composed of an (n,p) recoil plastic scintillator, photomultiplier tube, operational amplifier, power supply, calibration light and tantalum shield. The monitor detects most efficiently neutrons of about 10 MeV. Below 3 MeV, the detection efficiency decreases sharply. The detection efficiency for gamma radiation is low and can be further decreased by adding more tantalum around the detector. Results of the burst tests show that the smallest credible criticality accident will readily initiate an alarm. The monitor has been in use for about 2 years without false alarms. (author)

  12. Fast-response liquid commutating device with an inductive dynamic drive

    International Nuclear Information System (INIS)

    A description is given of a fast-response multiple-operation commutating device with an induction-dynamic drive designed for commutation of high currents in the high-voltage circuits of energy inductive storages. A high-speed flow of a liquid dielectrics, produced when the drive armature is being accelerated, is used for displacing a movable contact and influencing the electric arc. The device ensures commutation of 2 kA direct current in a circuit with a voltage of up to 100 kV during about 1 ms. Experimental studies of the device operation have shown that when breaking a circuit with a current of 100 A a voltage drop across the arc constitutes 1.6 kV, which is sufficient to fire a glow discharge in the gas-discharge current interrupter. With the current increase the voltage drop across the arc also increases

  13. A fast response hydrogen sensor with Pd metallic grating onto a fiber's end-face

    Science.gov (United States)

    Yan, Haitao; Zhao, Xiaoyan; Zhang, Chao; Li, Qiu-Ze; Cao, Jingxiao; Han, Dao-Fu; Hao, Hui; Wang, Ming

    2016-01-01

    We demonstrated an integrated hydrogen sensor with Pd metallic grating fabricated on a fiber end-face. The grating consists of three thin metal layers in stacks, Au, WO3 and Pd. The WO3 is used as a waveguide layer between the Pd and Au layer. The Pd layer is etched by using a focused ion beam (FIB) method, forming a Pd metallic grating with period of 450 nm. The sensor is experimentally exposed to hydrogen gas environment. Changing the concentration from 0% to 4% which is the low explosive limit (LEL), the resonant wavelength measured from the reflection experienced 28.10 nm spectral changes in the visible range. The results demonstrated that the sensor is sensitive for hydrogen detection and it has fast response and low temperature effect.

  14. Response of liquid metal fast breeder reactor containment to a hypothetical core meltdown accident

    International Nuclear Information System (INIS)

    This paper presents an analysis of the response of the containment building of a 2500-MWt liquid metal fast breeder reactor to a hypothetical reactor core meltdown. Although not mechanistically justifiable, this type of event is chosen for analysis as a basis for risk assessments. Containment space atmosphere compositions, temperatures, pressures, and structural temperatures are calculated, based on decay energy release and chemical reactions associated with the incident. The CACECO containment analysis code, which was used to make the calculations, is described in detail. Results of the study show that by utilizing the passive heat absorption capability of structures normally present in containment design, reactor plant containment integrity can be maintained for more than a day, even for extreme hypothetical events. (Auth.)

  15. Fast response neutron emission monitor for fusion reactor using stilbene scintillator and Flash-ADC.

    Science.gov (United States)

    Itoga, T; Ishikawa, M; Baba, M; Okuji, T; Oishi, T; Nakhostin, M; Nishitani, T

    2007-01-01

    The stilbene neutron detector which has been used for neutron emission profile monitoring in JT-60U has been improved, to respond to the requirement to observe the high-frequency phenomena in megahertz region such as toroidicity-induced Alfvén Eigen mode in burning plasma as well as the spatial profile and the energy spectrum. This high-frequency phenomenon is of great interest and one of the key issues in plasma physics in recent years. To achieve a fast response in the stilbene detector, a Flash-ADC is applied and the wave form of the anode signal stored directly, and neutron/gamma discrimination was carried out via software with a new scheme for data acquisition mode to extend the count rate limit to MHz region from 1.3 x 10(5) neutron/s in the past, and confirmed the adequacy of the method. PMID:17517674

  16. 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.

  17. Fast time resolution measurements of high concentrations of iodine above a Laminaria Digitata seaweed bed

    Science.gov (United States)

    Ball, Stephen; Adams, Thomas; Leblanc, Catherine; Potin, Philippe

    2013-04-01

    We report observations of extremely large concentrations of molecular iodine (I2) measured in situ above a seaweed bed composed of laminaria digitata (90%) and laminaria hyperborea (10%) growing in its natural habitat. Measurements were made off the coast of Roscoff in Brittany, France, during day-time low tides on several days in September and November 2012 with the greatest tidal amplitudes. Iodine was quantified using a portable, battery-powered broadband cavity enhanced absorption spectrometer (BBCEAS) deployed from the in-shore research vessel "Aurelia" operated by the Station Biologique de Roscoff. For the 5 second integration times used here, the BBCEAS instrument has a detection limit for iodine of 12 pptv (parts per trillion by volume). The boat was anchored above the seaweed bed before it was exposed to air by the ebbing tide; the boat was grounded on the seaweed bed around the tidal minimum, and then refloated as the incoming tide covered the seaweed. I2 concentrations were strongly anti-correlated with water depth. Initially little I2 was seen above background levels whilst the blades of the seaweed plants were floating on the water surface. However several hundred pptv of I2 was observed within a few minutes of the plants' stipes breaking the surface and first blades coming to rest on rocks out of the water. Iodine concentrations increased further as the tide ebbed, typically peaking around 1500 pptv around the tidal minimum (by which time the seaweed had been exposed for 45 minutes). I2 concentrations decreased rapidly back to background levels as the returning tide submerged the seaweeds. The concentration profiles showed a lot of high frequency structure, with I2 concentrations commonly varying by a factor 2 (or more) within 60 seconds. Additionally the profiles of I2 emitted from the seaweeds immediately below the instrument's inlet typically sat on a smoothly-varying background of approximately 100 pptv, which we attribute to I2 from other more-distant seaweeds whose emissions are better-mixed into the atmosphere. The peak I2 concentrations observed here are three to five times greater than the maximum amounts recorded above/closeby laminaria beds in previous studies: 350 pptv max in O Grove, Galicia, Spain (Mahajan et al., ACP, 11, 2545, 2011), and 302 and 547 pptv max at Mweenish Bay, near Mace Head, County Galway, Ireland (Huang et al., GRL, 37, L03803, 2010; ACPD, 12, 25915, 2012). In part, the larger peak concentrations seen here are a consequence of deploying a fast response instrument very close to the source, enabling the emission's high temporal variability to be captured with fewer averaging effects. Nevertheless, the I2 concentrations averaged over the 30 minute period around the tidal minimum were still typically 750 pptv, suggesting laminaria beds are even stronger emitters of I2 into coastal atmospheres than previously thought. Some implications for such high concentrations of iodine for the local atmospheric chemistry are considered. We acknowledge support from the European Community FP7 project "ASSEMBLE", grant 227799.

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

    International Nuclear Information System (INIS)

    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

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

    OpenAIRE

    Kisyov, S; Lalkovski, 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

    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/...

  1. 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

  2. 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.

  3. Table-top Femtosecond Ultra Fast Time Resolvable ARPES Facility at LANL

    Science.gov (United States)

    Li, Yinwan; Dakovski, Georgi; Durakiewicz, Tomasz; Rodriguez, George; Graham, Kevin

    2010-03-01

    A table-top ultra fast time resolved ARPES facility with time resolution of tens of femtoseconds is being constructed at Los Alamos National Laboratory. The system enables pump-probe scheme measurement with pump photon beam at low energy laser pulses and high energy probe photon beam obtained by higher harmonic generation (HHG). The pump-probe scheme enables the extension of the ARPES technique to measure the unoccupied states. The tunability of time-difference between probe pulse and pump pulse can be used in the dynamics study of the solids by measuring the decay of the excited states. In this presentation, I will introduce the principle of the technique and the current stage of the system at LANL.

  4. 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.

  5. 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

  6. 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

  7. Electro-mechanical response times and muscle strength after sleep deprivation.

    Science.gov (United States)

    Symons, J D; Bell, D G; Pope, J; VanHelder, T; Myles, W S

    1988-12-01

    This study examined the effect of 60 h of sleep deprivation (SD) on electromechanical response times (EMRT), maximal voluntary isometric contraction (MVC), rate of force development (RFD), and times required to reach various percentages of MVC, during a maximal voluntary isometric contraction of both the forearm flexors and leg extensors. Eleven male subjects were either sleep deprived for 60 h (E) or performed similar daily activities and slept 7 h per night (C). Performance variables were evaluated at the same time intervals during both conditions. No significant differences were observed between the E and C conditions for EMRT (pre-motor time, electro-mechanical delay, total reaction time) or muscular performance (MVC, RFD). The results suggest that subjects who have undergone 60 h of SD can react as fast, and with as much force, as those who have had 7 h of sleep per night. PMID:3219670

  8. 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

  9. 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.

  10. 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...

  11. Model for Predicting End User Web Page Response Time

    OpenAIRE

    Nagarajan, Sathya Narayanan; Ravikumar, Srijith

    2012-01-01

    Perceived responsiveness of a web page is one of the most important and least understood metrics of web page design, and is critical for attracting and maintaining a large audience. Web pages can be designed to meet performance SLAs early in the product lifecycle if there is a way to predict the apparent responsiveness of a particular page layout. Response time of a web page is largely influenced by page layout and various network characteristics. Since the network character...

  12. 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.

  13. 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.

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

    International Nuclear Information System (INIS)

    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

  15. Breaking cover: neural responses to slow and fast camouflage-breaking motion.

    Science.gov (United States)

    Yin, Jiapeng; Gong, Hongliang; An, Xu; Chen, Zheyuan; Lu, Yiliang; Andolina, Ian M; McLoughlin, Niall; Wang, Wei

    2015-08-22

    Primates need to detect and recognize camouflaged animals in natural environments. Camouflage-breaking movements are often the only visual cue available to accomplish this. Specifically, sudden movements are often detected before full recognition of the camouflaged animal is made, suggesting that initial processing of motion precedes the recognition of motion-defined contours or shapes. What are the neuronal mechanisms underlying this initial processing of camouflaged motion in the primate visual brain? We investigated this question using intrinsic-signal optical imaging of macaque V1, V2 and V4, along with computer simulations of the neural population responses. We found that camouflaged motion at low speed was processed as a direction signal by both direction- and orientation-selective neurons, whereas at high-speed camouflaged motion was encoded as a motion-streak signal primarily by orientation-selective neurons. No population responses were found to be invariant to the camouflage contours. These results suggest that the initial processing of camouflaged motion at low and high speeds is encoded as direction and motion-streak signals in primate early visual cortices. These processes are consistent with a spatio-temporal filter mechanism that provides for fast processing of motion signals, prior to full recognition of camouflage-breaking animals. PMID:26269500

  16. 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.

  17. 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.

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

    OpenAIRE

    Kuczaj, AK (Arkadiusz); 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...

  19. Femtosecond response time measurements of a Cs2Te photocathode

    OpenAIRE

    Aryshev, A.; Shevelev, M.; 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 photoc...

  20. Time-Space Decoupled Explicit Method for Fast Numerical Simulation of Tsunami Propagation

    Science.gov (United States)

    Guo, Anxin; Xiao, Shengchao; Li, Hui

    2015-02-01

    This study presents a novel explicit numerical scheme for simulating tsunami propagation using the exact solution of the wave equations. The objective of this study is to develop a fast and stable numerical scheme by decoupling the wave equation in both the time and space domains. First, the finite difference scheme of the shallow-water equations for tsunami simulation are briefly introduced. The time-space decoupled explicit method based on the exact solution of the wave equation is given for the simulation of tsunami propagation without including frequency dispersive effects. Then, to consider wave dispersion, the second-order accurate numerical scheme to solve the shallow-water equations, which mimics the physical frequency dispersion with numerical dispersion, is derived. Lastly, the computation efficiency and the accuracy of the two types of numerical schemes are investigated by the 2004 Indonesia tsunami and the solution of the Boussinesq equation for a tsunami with Gaussian hump over both uniform and varying water depths. The simulation results indicate that the proposed numerical scheme can achieve a fast and stable tsunami propagation simulation while maintaining computation accuracy.

  1. Time-resolved Fast Neutron Radiography of Air-water Two-phase Flows

    Science.gov (United States)

    Zboray, Robert; Dangendorf, Volker; Mor, Ilan; Tittelmeier, Kai; Bromberger, Benjamin; Prasser, Horst-Michael

    Neutron imaging, in general, is a useful technique for visualizing low-Z materials (such as water or plastics) obscured by high-Z materials. However, when significant amounts of both materials are present and full-bodied samples have to be examined, cold and thermal neutrons rapidly reach their applicability limit as the samples become opaque. In such cases one can benefit from the high penetrating power of fast neutrons. In this work we demonstrate the feasibility of time-resolved, fast neutron radiography of generic air-water two-phase flows in a 1.5 cm thick flow channel with Aluminum walls and rectangular cross section. The experiments have been carried out at the high-intensity, white-beam facility of the Physikalisch-Technische Bundesanstalt, Germany. Exposure times down to 3.33 ms have been achieved at reasonable image quality and acceptable motion artifacts. Different two-phase flow regimes such as bubbly slug and churn flows have been examined. Two-phase flow parameters like the volumetric gas fraction, bubble size and bubble velocities have been measured.

  2. Time and space resolved interferometry for laser-generated fast electron measurements

    International Nuclear Information System (INIS)

    A technique developed to measure in time and space the dynamics of the electron populations resulting from the irradiation of thin solids by ultraintense lasers is presented. It is a phase reflectometry technique that uses an optical probe beam reflecting off the target rear surface. The phase of the probe beam is sensitive to both laser-produced fast electrons of low-density streaming into vacuum and warm solid density electrons that are heated by the fast electrons. A time and space resolved interferometer allows to recover the phase of the probe beam sampling the target. The entire diagnostic is computationally modeled by calculating the probe beam phase when propagating through plasma density profiles originating from numerical calculations of plasma expansion. Matching the modeling to the experimental measurements allows retrieving the initial electron density and temperature of both populations locally at the target surface with very high temporal and spatial resolution (?4 ps,6 ?m). Limitations and approximations of the diagnostic are discussed and analyzed.

  3. Time and space resolved interferometry for laser-generated fast electron measurements

    Energy Technology Data Exchange (ETDEWEB)

    Antici, P. [Istituto Nazionale di Fisica Nucleare, Via E. Fermi, Frascati 40-00044 (Italy); ILE-Ecole Polytechnique-CNRS-ENSTA-Iogs-UP Sud, Batterie de l' Yvette, Palaiseau 91761 (France) and Dipartimento di Scienze di Base e Applicate per l' Ingegneria, Sapienza-Universita di Roma, Via A. Scarpa 14, Roma 00161 (Italy); LULI, Ecole Polytechnique, CNRS, CEA, UPMC, route de Saclay, Palaiseau 91128 (France); Chen, S. N. [Livermore National Laboratory, L-209, P.O. Box 808, Livermore, California 94550 (United States); Gremillet, L. [CEA, DAM, DIF, Arpajon, F-91297 (France); Grismayer, T.; Mora, P. [Centre de Physique Theorique, Ecole Polytechnique, CNRS, Palaiseau 91128 (France); Audebert, P.; Fuchs, J. [LULI, Ecole Polytechnique, CNRS, CEA, UPMC, route de Saclay, Palaiseau 91128 (France)

    2010-11-15

    A technique developed to measure in time and space the dynamics of the electron populations resulting from the irradiation of thin solids by ultraintense lasers is presented. It is a phase reflectometry technique that uses an optical probe beam reflecting off the target rear surface. The phase of the probe beam is sensitive to both laser-produced fast electrons of low-density streaming into vacuum and warm solid density electrons that are heated by the fast electrons. A time and space resolved interferometer allows to recover the phase of the probe beam sampling the target. The entire diagnostic is computationally modeled by calculating the probe beam phase when propagating through plasma density profiles originating from numerical calculations of plasma expansion. Matching the modeling to the experimental measurements allows retrieving the initial electron density and temperature of both populations locally at the target surface with very high temporal and spatial resolution ({approx}4 ps,6 {mu}m). Limitations and approximations of the diagnostic are discussed and analyzed.

  4. 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…

  5. Fracture response of several metals to fast heating of samples by intensive X-ray radiation

    Science.gov (United States)

    Golubev, Vladimir

    2015-06-01

    Results on studying the fracture response of metals samples in the form of thin disks to fast heating by the intensive pulse of X-ray radiation of a complete spectrum are presented in the paper. The samples of such metals as iron, copper, AMg6 aluminum, VT14 titanium, molybdenum, tungsten, cadmium, lead and zinc were tested. The samples were fixed in the special cartridges that were placed at such distances from the X-ray irradiator where the energy fluxes were 1.38, 0.90 and 0.29 kJ/cm2. The irradiating X-ray pulse was about 2 ns in duration. After testing, the depth of material ablation from a sample front surface and the degree and character of its spall damage were determined. The method of metallographic analysis was used for these purposes. The spectrum data were used for the calculations of samples heating. Numerical calculations of thermomechanical and shock wave loading conditions were made with the use of the equation of state taking into account the process of evaporation. The calculated value of maximum negative pressure in the sample at the coordinate corresponding to the depth of ablation and formation of spallation zones or spall cracks was conventionally accepted as the material resistance to spall fracture in such conditions. The comparison of obtained results with the data on the fracture of examined materials in the conditions of fast heating by the X-ray pulse with a hard spectrum and by the high-current electron beam of an electron pulse generator was conducted.

  6. Dose Ramadan Fasting Affects Inflammatory Responses: Evidences for Modulatory Roles of This Unique Nutritional Status via Chemokine Network

    OpenAIRE

    Akrami Mohajeri, Fateme; Ahmadi, Zahra; HASSANSHAHI, Gholamhossein; Akrami Mohajeri, Elham; Ravari, Ali; Ghalebi, Seyed Razi

    2013-01-01

    Objective(s): The impact of fasting in Ramadan as a unique type of nutritional regimen on biochemical and hematological parameters is still an issue of debate. Almost very little is known regarding the regulatory role(s) of this nutritional status on immune responses or inflammation.

  7. Comparisons of Crosswind Velocity Profile Estimates Used in Fast-Time Wake Vortex Prediction Models

    Science.gov (United States)

    Pruis, Mathew J.; Delisi, Donald P.; Ahmad, Nashat N.

    2011-01-01

    Five methods for estimating crosswind profiles used in fast-time wake vortex prediction models are compared in this study. Previous investigations have shown that temporal and spatial variations in the crosswind vertical profile have a large impact on the transport and time evolution of the trailing vortex pair. The most important crosswind parameters are the magnitude of the crosswind and the gradient in the crosswind shear. It is known that pulsed and continuous wave lidar measurements can provide good estimates of the wind profile in the vicinity of airports. In this study comparisons are made between estimates of the crosswind profiles from a priori information on the trajectory of the vortex pair as well as crosswind profiles derived from different sensors and a regional numerical weather prediction model.

  8. 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.

  9. 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.

  10. Room temperature formaldehyde sensors with enhanced performance, fast response and recovery based on zinc oxide quantum dots/graphene nanocomposites

    Science.gov (United States)

    Huang, Qingwu; Zeng, Dawen; Li, Huayao; Xie, Changsheng

    2012-08-01

    Novel zinc oxide quantum dots (ZnO QDs) decorated graphene nanocomposites were fabricated by a facile solution-processed method. ZnO QDs with a size ca. 5 nm are nucleated and grown on the surface of the graphene template, and its distribution density can be easily controlled by the reaction time and precursor concentration. The ZnO QDs/graphene nanocomposite materials enhance formaldehyde sensing properties by 4 times compared to pure graphene at room temperature. Moreover, the sensors based on the nanocomposites have fast response (ca. 30 seconds) and recovery (ca. 40 seconds) behavior, excellent room temperature selectivity and stability. The gas sensing enhancement is attributed to the synergistic effect of graphene and ZnO QDs. The electron transfer between the ZnO QDs and the graphene is due to oxidation process of the analyzed gas on the ZnO QDs' surface. This proposed gas sensing mechanism is experimentally proved by DRIFT spectra results. The ZnO QDs/graphene nanocomposites sensors have potential applications for monitoring air pollution, especially for harmful and toxic VOCs (volatile organic compounds).

  11. 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)

  12. Fluctuation-Response Relations for Multi-Time Correlations

    CERN Document Server

    Eyink, G L

    1999-01-01

    We show that time-correlation functions of arbitrary order for any random variable in a statistical dynamical system can be calculated as higher-order response functions of the mean history of the variable. The response is to a ``control term'' added as a modification to the master equation for statistical distributions. The proof of the relations is based upon a variational characterization of the generating functional of the time-correlations. The same fluctuation-response relations are preserved within moment-closures for the statistical dynamical system, when these are constructed via the variational Rayleigh-Ritz procedure. For the 2-time correlations of the moment-variables themselves, the fluctuation-response relation is equivalent to an ``Onsager regression hypothesis'' for the small fluctuations. For correlations of higher-order, there is a new effect in addition to such linear propagation of fluctuations present instantaneously: the dynamical generation of correlations by nonlinear interaction of fl...

  13. Uniqueness of system response time for transient condensing flows

    Energy Technology Data Exchange (ETDEWEB)

    Wedekind, G.L.; Bhatt, B.L. (Oakland Univ., Rochester, MI (United States)); Beck, B.T. (Kansas State Univ., Manhattan (United States)); Roslund, G.L. (General Motors Corp., Detroit, MI (United States))

    1989-11-01

    The unique characteristics under consideration in this paper are encountered in condensing flows, and have to do with a system's response time for various degrees of outlet flow quality. Specifically, the system response time for condensing flows appears to increase monotonically with decreasing outlet flow quality, reaching a maximum for systems having an outlet flow quality of between 10 and 20%. The system response time then decreases for outlet flow qualities that are less than that value. These unique characteristics are predicted theoretically by system mean void fraction model. The purpose of this paper is to develop analytically the characteristics, explain the physics of the phenomena responsible, and discuss the experimental verification efforts that have thus far been carried out.

  14. Time-resolved fast-neutron pinhole camera for studying thermonuclear plasmas

    International Nuclear Information System (INIS)

    A fast-neutron pinhole camera with high detection efficiency and nanosecond time-resolution has been developed and applied to the investigation of the spatial and temporal distributions of DD- and DT-neutrons produced by thermonuclear plasmas. The pinhole consists of a specially designed 1.15 m long copper collimator with an effective aperture of 1 mm diameter. Several different types of spatial resolution detectors have been used at the image plane: (1) a multi-element, scintillation-photomultiplier system used for time-resolved measurements consisting of sixty-one individual detectors, (2) a scintillation-fiber-chamber coupled to a gated image-intensifier tube used for direct photographing of the neutron image, and (3) a propane bubble chamber used for time-integrated recording with a capability to distinguish DD- from DT-neutrons. Pulsed neutron sources with typical dimensions of 1 cm emitting of the order of 1012 neutrons over a time period of 10-100 nsec have been investigated. A spatial resolution of 1 mm and a time resolution of approximately 10 nsec was achieved in the investigations of dense plasma compression phenomena

  15. 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.

  16. 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.

  17. 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.

  18. Temporal Gillespie Algorithm: Fast Simulation of Contagion Processes on Time-Varying Networks.

    Science.gov (United States)

    Vestergaard, Christian L; Génois, Mathieu

    2015-10-01

    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 multiple 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, we provide pseudocode and its implementation in C++ for simulating the paradigmatic Susceptible-Infected-Susceptible and Susceptible-Infected-Recovered models and a Susceptible-Infected-Recovered model with non-constant recovery rates. For empirical networks, the temporal Gillespie algorithm is here typically from 10 to 100 times faster than rejection sampling. PMID:26517860

  19. Temporal Gillespie Algorithm: Fast Simulation of Contagion Processes on Time-Varying Networks

    Science.gov (United States)

    Vestergaard, Christian L.; Génois, Mathieu

    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 multiple 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, we provide pseudocode and its implementation in C++ for simulating the paradigmatic Susceptible-Infected-Susceptible and Susceptible-Infected-Recovered models and a Susceptible-Infected-Recovered model with non-constant recovery rates. For empirical networks, the temporal Gillespie algorithm is here typically from 10 to 100 times faster than rejection sampling. PMID:26517860

  20. Signal and Noise Analysis in TRION -Time-Resolved Integrative Optical Fast Neutron Detector

    CERN Document Server

    Vartsky, D; Mor, I; Goldberg, M B; Bar, D; Dangendorf, V

    2009-01-01

    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 colle...

  1. Calibration of the time response functions of a quenched plastic scintillator for neutron time of flight

    CERN Document Server

    Chen, J B; Peng, H S; Tang, C H; Zhang, B H; Ding, Y K; Chen, M; Chen, H S; Li, C G; Wen, T S; Yu, R Z

    2002-01-01

    The time response functions of an ultrafast quenched plastic scintillation detector used to measure neutron time of flight spectra were calibrated by utilizing cosmic rays and implosion neutrons from DT-filled capsules at the Shenguang II laser facility. These sources could be regarded as delta function pulses due to their much narrower time widths than those of the time response functions of the detection system. The results showed that the detector responses to DT neutrons and to cosmic rays were 1.18 and 0.96 ns FWHM, respectively.

  2. Effect of the fissile bead's and thermocouple wires' sizes on the response time of a fission couple

    Science.gov (United States)

    Liang, Wenfeng; Lu, Yi; Li, Meng; Fan, Xiaoqiang; Lu, Wei

    2014-05-01

    The fission couple is proposed as a fast response miniature neutron detector in the measurement of time dependent energy depositions within the fissile material based on theoretical analysis, but the response time of a fission couple is relatively slow in practice. The time lag originated from heat transfer process was demonstrated to be the dominating factor by theoretical simulations and experimental verification in this paper. The response of a fission couple as a function of the bead size and the thermocouple wires' sizes are simulated using ANSYS workbench. The decrease of wires' diameter results in the decrease of response time, and the increase of bead's diameter leads to a slight increase of response time. During a pulse heating transient in the fuel of Chinese Fast Burst Reactor II with a FWHM of 181?s, the time lag originated from heat transfer process is about tens of microseconds for the peaks of the change rate of temperature, and is of the order of milliseconds to achieve 85% of the temperature rise for a typical fission couple with a ? 1 mm fissile bead and two ? 0.05 mm thermocouple wires. The results obtained provide foundation for the optimization of fission couples.

  3. 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

  4. 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(np) to O(qp), and the number of floating-point operations are decreased from O(np(2)) to O(qp(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

  5. Time dependent density functional calculation of plasmon response in clusters

    Science.gov (United States)

    Wang, Feng; Zhang, Feng-Shou; Eric, Suraud

    2003-02-01

    We have introduced a theoretical scheme for the efficient description of the optical response of a cluster based on the time-dependent density functional theory. The practical implementation is done by means of the fully fledged time-dependent local density approximation scheme, which is solved directly in the time domain without any linearization. As an example we consider the simple Na2 cluster and compute its surface plasmon photoabsorption cross section, which is in good agreement with the experiments.

  6. 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.

  7. 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

  8. Intercomparison of fast response commercial gas analysers for nitrous oxide flux measurements under field conditions

    OpenAIRE

    Ü Rannik; S. Haapanala; Shurpali, N. J.; Mammarella, I; Lind, S.; N. Hyvönen; Peltola, O.; M. Zahniser; Martikainen, P. J.; Vesala, T.

    2014-01-01

    Four gas analysers capable of measuring nitrous oxide (N2O) concentration at a response time necessary for eddy covariance flux measurements were operated from spring till winter 2011 over a field cultivated with reed canary grass (RCG, Phalaris arundinaceae, 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-...

  9. 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.

  10. The first synchrotron infrared beamlines at the Advanced Light Source: Microspectroscopy and fast timing

    Energy Technology Data Exchange (ETDEWEB)

    Martin, M.C.; McKinney, W.R.

    1998-05-01

    A set of new infrared (IR) beamlines on the 1.4 bending magnet port at the Advanced Light Source, LBNL, are described. Using a synchrotron as an IR source provides considerable brightness advantages, which manifests itself most beneficially when performing spectroscopy on a microscopic length scale. Beamline (BL) 1.4.3 is a dedicated microspectroscopy beamline, where the much smaller focused spot size using the synchrotron source is utilized. This enables an entirely new set of experiments to be performed where spectroscopy on a truly microscopic scale is now possible. BL 1.4.2 consists of a vacuum FTIR bench with a wide spectral range and step-scan capabilities. The fast timing is demonstrated by observing the synchrotron electron storage pattern at the ALS.

  11. Simulation of Fast Neutron Radiography with a Time-of-Flight System

    Science.gov (United States)

    Chen, D.; Bao, J.; Zhang, Q.; Han, S.; Ren, J.; Nie, Y.; Ruan, X.; Hou, L.

    A novel fast neutron imaging method with Time-of-Flight was analyzed, which can provide a way to improve ratio of signal to noise for discrimination of scattered particles from the background, especially for bulky sample examination. For the same system spatial resolution, the length of each unit in scintillator detector array can be increased to improve detection efficiency, which is higher than for the traditional neutron image plate obviously. Key parameters such as detection efficiency and spatial resolution have been simulated by means of a Monte-Carlo method, and the ratio of signal to noise effect was estimated from MC and experimental results. Spatial resolution and contrast of compound sample have been calculated.

  12. 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.

  13. Fast-response optical and near-infrared GRB science with RATIR and RIMAS

    Science.gov (United States)

    Capone, John; RIMAS collaboration, RATIR project team

    2016-01-01

    As the Universe's most luminous transient events, long gamma-ray bursts (GRBs) are observed at cosmological distances. The afterglow emission generated by the burst's interaction with the surrounding medium presents the opportunity to study the local environment, as well as intervening systems. The transient nature of these events requires observations starting within minutes of the GRB to maximize the scientific opportunities.This dissertation work comprises efforts to advance the field with a new instrument, the Rapid Infrared Imager and Spectrograph (RIMAS). The optical design is complicated by the broad band coverage (0.97 to 2.39 microns) and the necessity of transmissive optics due to space and weight limitations on the telescope. Additionally, the entire optical system must be cooled to cryogenic temperatures to decrease the background from thermal emission. The completed instrument will be permanently installed on Lowell Observatory's new 4.3 meter Discovery Channel Telescope (DCT) located in Happy Jack, Arizona. The fast slew time of the telescope, combined with the instrument's ability to image in two bands simultaneously and switch to spectroscopic configurations in under a minute will allow observers to obtain photometric data within minutes and spectra within ~ ten minutes.In addition to instrumentation work on RIMAS's optics, early time photometric light curves have been studied primarily using data from the Reionization and Transients Infrared/Optical Project (RATIR). Early time photometric data in six optical and near-infrared (NIR) bands has allowed a study of color evolution in the early to late time SEDs. This study probes possible impacts of the GRB on the local medium as well as intrinsic changes in the afterglow emission.This work is made possible by the RATIR and RIMAS collaborations as well as financial support by the NSF.

  14. Assessing the Value of Regulation Resources Based on Their Time Response Characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Makarov, Yuri V.; Lu, Shuai; Ma, Jian; Nguyen, Tony B.

    2008-06-01

    Fast responsive regulation resources are potentially more valuable as a power system regulation resource (more efficient) because they allow applying controls at the exact moment and in the exact amount as needed. Faster control is desirable because it facilitates more reliable compliance with the NERC Control Performance Standards at relatively lesser regulation capacity procurements. The current California ISO practices and markets do not provide a differentiation among the regulation resources based on their speed of response (with the exception of some minimum ramping capabilities). Some demand response technologies, including some generation and energy storage resources, can provide quicker control actions. California ISO practices and markets could be updated to welcome more fast regulation resources into the California ISO service area. The project work reported in this work was pursuing the following objectives: • Develop methodology to assess the relative value of generation resources used for regulation and load following California ISO functions • This assessment should be done based on physical characteristics including the ability to quickly change their output following California ISO signals • Evaluate what power is worth on different time scales • Analyze the benefits of new regulation resources to provide effective compliance with the mandatory NERC Control Performance Standards • Evaluate impacts of the newly proposed BAAL and FRR standards on the potential value of fast regulation and distributed regulation resources • Develop a scope for the follow-up projects to pave a road for the new efficient types of balancing resources in California. The work included the following studies: • Analysis of California ISO regulating units characteristics • California ISO automatic generation system (AGC) analysis • California ISO regulation procurement and market analysis • Fast regulation efficiency analysis • Projection of the California ISO load following and regulation requirements into the future • Value of fast responsive resources depending on their ramping capability • Potential impacts of the balancing authority area control error limit (BAAL), which is a part of the newly proposed NERC standard “Balancing Resources and Demand” • Potential impacts of the Western Electricity Coordinating Council (WECC) frequency responsive reserve (FRR) standard • Recommendations for the next phase of the project. The following main conclusions and suggestions for the future have been made: • The analysis of regulation ramping requirements shows that the regulation system should be able to provide ramps of at least 40-60 MW per minute for a period up to 6 minutes. • Evaluate if changes are needed in the California ISO AGC system to effectively accommodate new types of fast regulation resources and minimize the California ISO regulation procurement. • California ISO may consider creating better market opportunities for and incentives for fast responsive resources. • An additional study of low probability high ramp events can be recommended to the California ISO. • The California ISO may be willing to consider establishing a more relaxed target CPS2 compliance level. • A BAAL-related study can be recommended for the California ISO as soon as more clarity is achieved concerning the actual enforcement of the BAAL standard and its numerical values for the California ISO. The study may involve an assessment of advantages of the distributed frequency-based control for the California ISO system. The market-related issues that arise in this connection can be also investigated. • A FRR-related study can be recommended for the California ISO as soon as more clarity is achieved concerning the actual enforcement of the FRR standard and its numerical values for the California ISO.

  15. Optimization of the Time Response of LaBr3(Ce) Detectors, and Its Dependence on Ce Concentration

    Science.gov (United States)

    Vedia, V.; Mach, H.; Fraile, L. M.; Lalkovski, S.; Udías, J. M.

    Fast inorganic scintillators that exhibit good spectroscopy performance, like LaBr3(Ce), are the crystals of choice for many applications; they play a crucial role in the Ultra Fast Timing technique by virtue of their good energy resolution and fast response [1]. This method, which is very sensitive to the LaBr3(Ce) time resolution, allows measurements of nuclear level lifetimes down to few ps range. There are indications that the nominal Ce concentration does strongly influence on the timing properties as well as it varies the photon yield and the energy resolution [2]. In this work we have searched for the best settings in order to optimize the time resolution of three cylindrical LaBr3(Ce) detectors equipped with crystals identical in volume and shape but with different Ce dopant concentration. The time resolution of every detector depends on the proper selection of the fast photomultiplier tube and the set up parameters that can be further optimized by fine-tuning of the Constant Fraction Discrimination (CFD) and the PMT bias voltage. Very good time resolution can be obtained with the ORTEC 935 CFD for very short time-delays. Timing properties of the three crystals were studied by delayed coincidence measurements against a reference BaF2 detector, whose time response is well known. The LaBr3(Ce) detector and the reference unit were placed in a close geometry with the radioactive source in between. We report timing results measured at the 60Co and 22Na energies.

  16. Comparison of LMFBR piping response obtained using response spectrum and time history methods

    International Nuclear Information System (INIS)

    The dynamic response to a seismic event is calculated for a piping system using a response spectrum analysis method and two time history analysis methods. The results from the analytical methods are compared to identify causes for the differences between the sets of analytical results. Comparative methods are also presented which help to gain confidence in the accuracy of the analytical methods in predicting piping system structure response during seismic events

  17. 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...

  18. A 3 A sink/source current fast transient response low-dropout G{sub m} driven linear regulator

    Energy Technology Data Exchange (ETDEWEB)

    Chu Xiuqin; Li Qingwei; Lai Xinquan; Yuan Bing [Institute of Electronic CAD, Xidian University, Xi' an 710071 (China); Li Yanming [School of Electronic and Control Engineering, Chang' an University, Xi' an 710064 (China); Zhao Yongrui, E-mail: liqw309@163.com, E-mail: xqchu@mail.xidian.edu.cn [Key Laboratory of High-Speed Circuit Design and EMC, Ministry of Education, Xidian University, Xi' an 710071 (China)

    2011-06-15

    A 3 A sink/source G{sub m}-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 G{sub m} (transconductance) driving technique, which provides high stability as well as a fast load transient response. The proposed LDO was fabricated by a 0.5 {mu}m standard CMOS process, and the die size is as small as 1.0 mm{sup 2}. The proposed LDO dissipates 220 {mu}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 {mu}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 {mu}s rising and falling time at three 10 {mu}F ceramic capacitors. (semiconductor integrated circuits)

  19. Time response of protection in event of vacuum failure based on Nude ionization gauge controller

    Science.gov (United States)

    Gao, Hui; Wang, Qiuping; Wang, Weibin; Wu, Qinglin; Chen, Wentong; Sheng, Liusi; Zhang, Yunwu

    2001-10-01

    This article describes the design and application of fast-response vacuum protection sensor module, based on the Nude ionization gauge and a homemade controller named GH07X. A simulative test indicated that the controller's response time was less than 200 ?s when 1 atm air rushed into the vacuum system through a pulsed valve with 0.8 mm orifice nozzle and the emitting current of the Nude gauge was 4 mA. The experiment result showed that the response time mainly depended on the gas density as well as the electron emitting current of the Nude gauge filament. Compared with the vacuum protection sensors based on sputter ion pump and cold-cathode gauge, GH07X is faster and reliable besides, GH07X can be used as an ultrahigh-vacuum slow valve interlock controller with response time of 100 ms, which is faster than other gauge controllers. The widely used field-bus interface CAN and common serial interface RS232/RS485 are embedded in GH07X controller system.

  20. 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)

  1. The Time Course Effect of Moderate Intensity Exercise on Response Execution and Response Inhibition

    Science.gov (United States)

    Joyce, Jennifer; Graydon, Jan; McMorris, Terry; Davranche, Karen

    2009-01-01

    This research aimed to investigate the time course effect of a moderate steady-state exercise session on response execution and response inhibition using a stop-task paradigm. Ten participants performed a stop-signal task whilst cycling at a carefully controlled workload intensity (40% of maximal aerobic power), immediately following exercise and…

  2. Statistical Tests of Conditional Independence between Responses and/or Response Times on Test Items

    Science.gov (United States)

    van der Linden, Wim J.; Glas, Cees A. W.

    2010-01-01

    Three plausible assumptions of conditional independence in a hierarchical model for responses and response times on test items are identified. For each of the assumptions, a Lagrange multiplier test of the null hypothesis of conditional independence against a parametric alternative is derived. The tests have closed-form statistics that are easy to…

  3. Adaptive Responses to Prochloraz Exposure That Alter Dose-Response and Time-Course Behaviors

    Science.gov (United States)

    Dose response and time-course (DRTC) are, along with exposure, the major determinants of health risk. Adaptive changes within exposed organisms in response to environmental stress are common, and alter DRTC behaviors to minimize the effects caused by stressors. In this project, ...

  4. Sensors Response Time validation using Dimensionality Reduction Techniques

    Directory of Open Access Journals (Sweden)

    S. Gayathri

    2013-04-01

    Full Text Available The temperature and Pressure sensors play a vital role in Nuclear Power Plants (NPP. The Rosemount temperature sensor helps to produce the exact temperature and pressure measurement of the nuclear power plant. The sensors that supply real data must respond quickly to the safety systems of NPP. In this paper, first the Dimensionality of the Original dataset is reduced by using Principal Component Analysis (PCA, Independent Component Analysis (ICA and Singular Value Decomposition (SVD. Finally the sensors Response Time is computed and compared with original response time.

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

    Energy Technology Data Exchange (ETDEWEB)

    Sulyaev, Yu.S., E-mail: sulyaev@inp.nsk.su [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, 630090 Novosibirsk (Russian Federation); Puryga, E.A.; Khilchenko, A.D. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Novosibirsk State Technical University, 630092 Novosibirsk (Russian Federation); Kvashnin, A.N. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Polosatkin, S.V. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, 630090 Novosibirsk (Russian Federation); Rovenskikh, A.F. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Burdakov, A.V.; Grishnyaev, E.V. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Novosibirsk State Technical University, 630092 Novosibirsk (Russian Federation)

    2013-08-21

    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 {sup 60}Co and {sup 252}Cf radiation sources, and deuterium neutron generator.

  6. Highly sensitive fast-response UV photodetectors based on epitaxial TiO{sub 2} films

    Energy Technology Data Exchange (ETDEWEB)

    Xing Jie; Wei Huiyun [School of Materials Sciences and Technology, China University of Geosciences, Beijing 100083 (China); Guo Erjia; Yang Fang, E-mail: jxing2011@gmail.com [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

    2011-09-21

    Epitaxial TiO{sub 2} thin films were fabricated on LaAlO{sub 3} single crystal substrates by RF magnetron sputtering. Ag electrodes were then evaporated on the TiO{sub 2} thin films to form metal-semiconductor-metal photoconductive detectors. The TiO{sub 2} photodetector exhibited a maximum photoresponse of 3.63 A W{sup -1} at 310 nm with a sharp cutoff wavelength at 380 nm. The ultraviolet (UV)-visible response rejection ratio (R310 nm/R390 nm) was about three orders of magnitude. The photocurrent response of the detectors scaled linearly with the applied bias and the incident light intensity. The dark current was only 0.14 nA at 10 V bias. A transient photovoltage with a rise time of {approx}8 ns and a full-width at half-maximum of {approx}90 ns was observed when the photodetector was under the irradiation of a 308 nm XeCl laser with 25 ns duration. The excellent performances of high responsivity and ultrahigh response speed suggest that the presented TiO{sub 2} detectors have promising potential in UV photodetection.

  7. Gender influence on response time to sensory stimuli.

    Science.gov (United States)

    Spierer, David K; Petersen, Rebecca A; Duffy, Kevin; Corcoran, Bradley M; Rawls-Martin, Tracye

    2010-04-01

    The purpose of this investigation was to examine the effect of auditory stimuli (AS) and visual stimuli (VS) on response time, speed, and distance in male and female college athletes. Thirty-five healthy National Collegiate Athletic Association Division I men's soccer and women's lacrosse athletes (mean age 20.7 +/- 2.3 years) participated in the study. This experiment was conducted in a laboratory environment, using a Cybex "Reactor" a 14-sensor force plate device used to detect response times, speed, and distance. Subjects stood on the "start" sensor and were instructed at the prompt (auditory: a prerecorded "go" command, visual: an illuminated circle on a television monitor) to run through the "end" sensor without braking. Three trials of each condition were performed by each subject. Movement time, speed, and distance were recorded for each trial. General linear model repeated measure analyses and post hoc 1-way analysis of variance were conducted on all dependent variables (p men compared with women under AS (p = 0.008) and VS (p men in the AS condition (p = 0.072), but transit time was faster in men in the VS condition (p men in response to AS (p < 0.05) and VS (p < 0.001). Male athletes respond faster as compared with female athletes, and cover greater distance when presented with VSs as compared to ASs. Data suggest that performance in male athletes related to response times, speed, and distance may be enhanced with the use of visual cueing or VSs. PMID:20300032

  8. 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 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

  9. 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 groups of buildings. The EPA PRIME model (Schulman et al., 2000) has been empirically derived to provide streamlines around a single isolated building

  10. SeaMon-HC Buoy. A specific real-time-lightweight-moored platform as a tool for fast hydrocarbon detection

    Science.gov (United States)

    Barrera, C.; Rueda, M. J.; Moran, R.; Llerandi, C.; Llinas, O.

    2009-04-01

    The present paper-work describes the design, last development stages and the derived results from a specific buoy platform for fast hydrocarbon detection in seawater. Under the name of SeaMon-HC, (Patent No. P200302219/8) the buoy represents a very chief tool for coastal monitoring, mainly surrounding areas with a high oil-spill risk level, like harbours, off-shore fish farming, beaches and so on. Nowadays, the Macaronesian area has nine units working in real-time, under the frame of the Red ACOMAR Network. The main innovative aspect from this buoy is the detection system. It's based in polymer technology, working as a resistance, who increase its value when the pollutant on water surface is detected. The response time from the sensor is a direct function of the hydrocarbon volatility level. For hydrocarbons with high volatility levels (like petrol), the sensor needs less time (around 3 minutes) than others with less volatility such as oils. SeaMon-HC is an autonomous, modular, reusable and a very low-cost development integrated by four subsystems (SS): SS-Flotation (different materials and shapes available); SS-Sensors (hydrocarbon detector and additional sensors -up to 15-, to solve specific sensor configuration requirements); SS-Power Supply (equipped in its basic configuration with a couple of solar modules and two 12V batteries) and the SS-Communication (based on a RF or GSM/GPRS modem technology, with a selectable communication frequency). All SeaMon-HC units, as well the rest of the ODAS buoys who joint together the Red ACOMAR Network, works in real-time, sending the collected information to the control centre that manages the communications, providing data, in a useful form (as a web site), to diverse socio-economic important sectors which make an exhaustive use of the littoral in the Macaronesian region. The access to the information by the users is done through a specific GIS software application.

  11. Timing criteria for supplemental BWR emergency response equipment

    International Nuclear Information System (INIS)

    The Great Tohuku Earthquake and subsequent Tsunami represented a double failure event which destroyed offsite power connections to Fukushima-Daiichi site and then destroyed on-site electrical systems needed to run decay heat removal systems. The accident could have been mitigated had there been supplemental portable battery chargers, supplemental pumps, and in-place piping connections to provide alternate decay heat removal. In response to this event in the USA, two national response centers, one in Memphis, Tennessee, and another in Phoenix, Arizona, will begin operation. They will be able to dispatch supplemental emergency response equipment to any nuclear plant in the U.S. within 24 hours. In order to define requirements for supplemental nuclear power plant emergency response equipment maintained onsite vs. in a regional support center it is necessary to confirm: (a) the earliest time such equipment might be needed depending on the specific scenario, (b) the nominal time to move the equipment from a storage location either on-site or within the region of a nuclear power plant, and (c) the time required to connect in the supplemental equipment to use it. This paper describes an evaluation process for a BWR-4 with a Mark I Containment starting with: (a) severe accident simulation to define best estimate times available for recovery based on the specific scenario, (b) identify the key supplemental response equipment needed at specific times to accomplish recovery of key safety functions, and (c) evaluate what types of equipment should be warehoused on-site vs. in regional response centers. (authors)

  12. Equilibrium and response properties of the integrate-and-fire neuron in discrete time

    Directory of Open Access Journals (Sweden)

    Moritz Helias

    2010-01-01

    Full Text Available The integrate-and-fire neuron with exponential postsynaptic potentials is a frequently employed model to study neural networks. Simulations in discrete time still have highest performance at moderate numerical errors, which makes them first choice for long-term simulations of plastic networks. Here we extend the population density approach to investigate how the equilibrium and response properties of the leaky integrate-and-fire neuron are affected by time discretization. We present a novel analytical treatment of the boundary condition at threshold, taking both discretization of time and finite synaptic weights into account. We uncover an increased membrane potential density just below threshold as the decisive property that explains the deviations found between simulations and the classical diffusion approximation. Temporal discretization and finite synaptic weights both contribute to this effect. Our treatment improves the standard formula to calculate the neuron’s equilibrium firing rate. Direct solution of the Markov process describing the evolution of the membrane potential density confirms our analysis and yields a method to calculate the firing rate exactly. Knowing the shape of the membrane potential distribution near threshold enables us to devise the transient response properties of the neuron model to synaptic input. We find a pronounced non-linear fast response component that has not been described by the prevailing continuous time theory for Gaussian white noise input.

  13. 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 transport signature in collision-dominated 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.

  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. 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.

  16. Improved fast-response heat transfer instrumentation for short-duration wind tunnels

    Science.gov (United States)

    Thorpe, Steven J.; Yoshino, Shin; Ainsworth, Roger W.; Harvey, Neil W.

    2004-09-01

    This paper describes the recent innovations associated with the fabrication and application of fast-response heat flux gauges in short-duration wind-tunnel facilities in Oxford. This work has been driven by the need to measure the heat transfer in an environment with large spatial and temporal variations in surface heat flux, caused by a flow-field that has significant high-frequency periodic fluctuations in both recovery temperature and heat transfer coefficient (namely, an axial flow turbine). A new approach to the fabrication of miniature surface heat flux thin-film gauges is described; this involves the use of a pulse laser to ablate (etch) the gauge and connecting track patterns directly onto electrically insulated and platinized components. This automated technique is shown to produce gauges of high geometrical tolerance at precisely known locations, and to create arrays of gauges on the experimental components rapidly. Typically, the platinum resistance elements are 1 mm by 0.08 mm in plan form and have closely repeatable characteristics (for example, resistance and temperature coefficient). A novel technique for measuring the adiabatic wall temperature and heat transfer coefficient in short-duration facilities is also presented; this includes the capability to measure the deterministic component of these unsteady parameters in periodic (pulsating) flows. The combination of the new high spatial density gauge arrays and the capability to measure unsteady adiabatic wall temperature allows unprecedented insight into the flow physics that influences the unsteady heat flux. In particular, it has been possible to establish whether heat transfer rate fluctuations in a turbine experiment are caused by changes in flow recovery temperature or by changes in heat transfer coefficient. Some example measurements taken in a high-speed turbine test facility are described. Finally, some of the recently manufactured heat transfer gauge systems are presented.

  17. Evaluation of Response Time in Ethernet-based Automation Systems

    OpenAIRE

    Marsal, Gaëlle; Denis, Bruno; Faure, Jean-Marc; Frey, Georg

    2006-01-01

    This paper presents a method to assess response time of automation system architectures including industrial switched Ethernet networks using client/server protocols. This method relies upon modeling of the behavior of the components of these architectures in the form of Hierarchical Timed Colored Petri Nets and upon simulation of these models. A case study exemplifies the method and shows how it can facilitate design of automation systems including this kind of industrial Ethernet networks.

  18. Specificity of Inferior Olive Response to Stimulus Timing

    OpenAIRE

    liu, T; Xu, D.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China); Ashe, J; Bushara, K.

    2008-01-01

    The inferior olive is the sole source of the climbing fiber system, one of the two major afferent systems of the cerebellum; however, its exact role remains unknown. A longstanding hypothesis is that the inferior olive with its unique intrinsic rhythmic firing properties mediates motor timing. However, direct evidence linking the inferior olive to timing behavior has been difficult to demonstrate in animal or human studies likely due to the inhibition of inferior olive responses by self-produ...

  19. 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 and the associated errors for the Planck HFI detectors. The effective beam is the angular 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 CMB 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 time response; and (c) the merging of several surveys to produce maps. The time response 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 determin...

  20. Proposal for a fast, zero suppressing circuit for the digitization of analog pulses over long memory times

    International Nuclear Information System (INIS)

    This report describes the design principles of a fast (100 MHz) time and pulse height digitizer that can record up to 15 analog pulses over 10-80 ?s memory times. Unlike other triggered circuits prepulse samples are recorded without the help of an analog delay line. The low power requirements of the circuit as well as its fast read-out characteristics make it very attractive for detectors with many digitizing channels. Conventional circuits are described as a reference for the evaluation of this new design. An ECL 10 K implementation of the circuit is presented in the third section. (orig.)

  1. In-situ response time testing of thermocouples

    Science.gov (United States)

    Hashemian, H. M.; Petersen, K. M.; Hashemian, M.; Beverly, D. D.; Miller, L. F.

    The Loop Current Step Response (LCSR) method has been developed for in situ response time testing of thermocouples and resistance thermometers. A means for measuring the sensor response for actual operating conditions and installation details is provided. This technology is ready to be assembled into an instrument for use in aerospace, nuclear, chemical and other industries where transient temperature measurements are important. The method provides time constant results within better than about 20 percent of value obtained from plunge tests. These results are based on tests performed in water at low flow rates (1M/sec) and in air flow rates ranging from a few meters per second to over a hundred kilometers per hour.

  2. 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)

  3. 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.

  4. Linear-response thermal time-dependent density functional theory

    CERN Document Server

    Pribram-Jones, Aurora; Burke, Kieron

    2015-01-01

    The van Leeuwen proof of linear-response time-dependent density functional theory (TDDFT) is generalized to thermal ensembles. This allows generalization to finite temperatures of the Gross-Kohn relation, the exchange-correlation kernel of TDDFT, and fluctuation dissipation theorem for DFT. This produces a natural method for generating new thermal exchange-correlation (XC) approximations.

  5. Surface Response-based Behavioral Modeling of Accurate Digitizers a Case Study on a Fast Digital Integrator at CERN

    CERN Document Server

    Arpaia, P; Spiezia, G; Tiso, S

    2007-01-01

    A statistical approach to behavioral modeling for assessing dynamic metrological performance during the concept design of accurate digitizers is proposed. A surface-response approach based on statistical experiment design is exploited for avoiding unrealistic hypothesis of linearity, optimizing simulation, exploring operating conditions systematically, as well as verifying identification and validation uncertainty. An actual case study on the dynamic metrological characterization of a Fast Digital Integrator for high-performance magnetic measurements at the European Organization for Nuclear Research (CERN) is presented.

  6. V2ic Control: A Novel Control Technique with Very Fast Response under Load and Voltage Steps

    OpenAIRE

    Viejo de Frutos, Miriam del; Alou Cervera, Pedro; Oliver Ramírez, Jesús Angel; García Suárez, Oscar; Cobos Márquez, José Antonio

    2011-01-01

    High switching frequencies (several MHz) allow the integration of low power DC/DC converters. Although, in theory, a high switching frequency would make possible to implement a conventional voltage mode control with very high bandwidth, in practice, parasitic effects and robustness make very complex to achieve bandwidths higher than 1MHz. This paper proposes a fast control technique to optimize the dynamic response of high switching frequency DC/DC converters. The proposed control is based on...

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

    OpenAIRE

    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 l...

  8. Influence of sensitive layer structure of surface-barrier Si-detector on response function of fast neutron spectrometer

    International Nuclear Information System (INIS)

    Paper presents the results of the efforts to calculate and to measure the response function of a fast neutron spectrometer as to recoil protons on the basis of a surface barrier Si-detector equipped with 0.2-2.4 mm thickness hydrogen containing converter for ?14 MeV neutron energy. One studied the key factors affecting the formation of the measured amplitude spectra and determined contribution of recoil proton scattering by nuclei in a converter and in a filter

  9. Timing and Fast Control and Readout Electronics Aspects of the LHCb Upgrade

    CERN Document Server

    Alessio, F; Jacobsson, R

    2008-01-01

    LHCb is considering an upgrade towards a full 40 MHz readout [1], possibly in several stages implying that a rudimentary rate control will still be needed. The rate control could be achieved by either maintaining the current L0 trigger infrastructure since it is already operating at 40MHz, or implementing simple local trigger decisions units in the new Readout Boards and control the rate via an 'intelligent' throttle mechanism. In this paper we make a first investigation of the possibilities for a new Timing and Fast Control (TFC) system based on completely new technologies, and the consequences for the readout electronics. We examine the current TFC, define the requirements for a new TFC, and propose a TFC architecture based on a single new Readout Supervisor 'Super-ODIN' instantiating several TFC masters to allow partitioning, and based on a shared high-speed optical link network for both the distribution of timing and synchronous control information, as well as trigger/throttle communication. The TFC inter...

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

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

    Directory of Open Access Journals (Sweden)

    Duc Thuan Vu

    2013-05-01

    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.

  16. Very high pressure liquid chromatography using fully porous particles: quantitative analysis of fast gradient separations without post-run times.

    Science.gov (United States)

    Stankovich, Joseph J; Gritti, Fabrice; Stevenson, Paul G; Beaver, Lois Ann; Guiochon, Georges

    2014-01-10

    Using a column packed with fully porous particles, four methods for controlling the flow rates at which gradient elution runs are conducted in very high pressure liquid chromatography (VHPLC) were tested to determine whether reproducible thermal conditions could be achieved, such that subsequent analyses would proceed at nearly the same initial temperature. In VHPLC high flow rates are achieved, producing fast analyses but requiring high inlet pressures. The combination of high flow rates and high inlet pressures generates local heat, leading to temperature changes in the column. Usually in this case a post-run time is input into the analytical method to allow the return of the column temperature to its initial state. An alternative strategy involves operating the column without a post-run equilibration period and maintaining constant temperature variations for subsequent analysis after conducting one or a few separations to bring the column to a reproducible starting temperature. A liquid chromatography instrument equipped with a pressure controller was used to perform constant pressure and constant flow rate VHPLC separations. Six replicate gradient separations of a nine component mixture consisting of acetophenone, propiophenone, butyrophenone, valerophenone, hexanophenone, heptanophenone, octanophenone, benzophenone, and acetanilide dissolved in water/acetonitrile (65:35, v/v) were performed under various experimental conditions: constant flow rate, two sets of constant pressure, and constant pressure operation with a programmed flow rate. The relative standard deviations of the response factors for all the analytes are lower than 5% across the methods. Programming the flow rate to maintain a fairly constant pressure instead of using instrument controlled constant pressure improves the reproducibility of the retention times by a factor of 5, when plotting the chromatograms in time. PMID:24296292

  17. Response of Gut Microbiota to Fasting and Hibernation in Syrian Hamsters? †

    OpenAIRE

    Sonoyama, Kei; Fujiwara, Reiko; Takemura, Naoki; Ogasawara, Toru; WATANABE, JUN; Ito, Hiroyuki; MORITA, Tatsuya

    2009-01-01

    Although hibernating mammals wake occasionally to eat during torpor, this period represents a state of fasting. Fasting is known to alter the gut microbiota in nonhibernating mammals; therefore, hibernation may also affect the gut microbiota. However, there are few reports of gut microbiota in hibernating mammals. The present study aimed to compare the gut microbiota in hibernating torpid Syrian hamsters with that in active counterparts by using culture-independent analyses. Hamsters were all...

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

    Science.gov (United States)

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

    2015-01-01

    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

  19. Limits on fast radio bursts at 145 MHz with ARTEMIS, a real-time software backend

    Science.gov (United States)

    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.; Falcke, H.; Grießmeier, J.-M.; Hessels, J. W. T.; Keane, E. F.; Kondratiev, V. I.; Kramer, M.; van Leeuwen, J.; Noutsos, A.; Os?owski, S.; Sobey, C.; Stappers, B. W.; Weltevrede, P.

    2015-09-01

    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 h survey for FRBs at 145 MHz, covering a total of 4193 deg2 on the sky. We used the UK station of the low frequency array (LOFAR) radio telescope - the Rawlings Array - accompanied for a majority of the time by the LOFAR station at Nançay, observing the same fields at the same frequency. Our real-time search backend, Advanced Radio Transient Event Monitor and Identification System - 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 d-1 for five ms-duration pulses above 62 Jy. The non-detection could be due to scatter-broadening, limitations on the volume and time searched, or the shape of FRB flux density spectra. Assuming the latter and that FRBs are standard candles, the non-detection is compatible with the published FRB sky rate, if their spectra follow a power law with frequency (? ??), with ? ? +0.1, demonstrating a marked difference from pulsar spectra. Our results suggest that surveys at higher frequencies, including the low frequency component of the Square Kilometre Array, will have better chances to detect, estimate rates and understand the origin and properties of FRBs.

  20. Real-time 3D medical structure segmentation using fast evolving active contours

    Science.gov (United States)

    Wang, Xiaotao; Wang, Qiang; Hao, Zhihui; Xu, Kuanhong; Guo, Ping; Ren, Haibing; Jang, Wooyoung; Kim, Jung-bae

    2014-03-01

    Segmentation of 3D medical structures in real-time is an important as well as intractable problem for clinical applications due to the high computation and memory cost. We propose a novel fast evolving active contour model in this paper to reduce the requirements of computation and memory. The basic idea is to evolve the brief represented dynamic contour interface as far as possible per iteration. Our method encodes zero level set via a single unordered list, and evolves the list recursively by adding activated adjacent neighbors to its end, resulting in active parts of the zero level set moves far enough per iteration along with list scanning. To guarantee the robustness of this process, a new approximation of curvature for integer valued level set is proposed as the internal force to penalize the list smoothness and restrain the list continual growth. Besides, list scanning times are also used as an upper hard constraint to control the list growing. Together with the internal force, efficient regional and constrained external forces, whose computations are only performed along the unordered list, are also provided to attract the list toward object boundaries. Specially, our model calculates regional force only in a narrowband outside the zero level set and can efficiently segment multiple regions simultaneously as well as handle the background with multiple components. Compared with state-of-the-art algorithms, our algorithm is one-order of magnitude faster with similar segmentation accuracy and can achieve real-time performance for the segmentation of 3D medical structures on a standard PC.

  1. 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.

  2. A fast least-squares arrival time estimator for scintillation pulses

    International Nuclear Information System (INIS)

    The true weighted least-squares (WLS) arrival time estimator for scintillation pulse detection was previously found to out-perform conventional arrival time estimators such as leading-edge and constant-fraction timers, but has limited applications because of its complexity. A new diagonalized version of the weighted least-squares (DWLS) estimator has been developed which, like the true WLS, incorporates the statistical properties of the scintillation detector. The new DWLS reduces estimator complexity at the expense of fundamental timing resolution. The advantage of the DWLS implementation is that only scalar multiplications and additions are needed instead of the matrix operations used in the true WLS. It also preserves the true WLS's ability to effectively separate piled-up pulses. The DWLS estimator has been applied to pulses which approximate the response of BGO and NaI(Tl) scintillation detectors. The timing resolution obtained with the DWLS estimator is then compared to conventional analog timers along with the Cramer-Rao lower bound on achievable timing error. The DWLS out-performs the conventional arrival time estimators but does not provide optimal performance compared to the lower bound; however, it is more robust than the true WLS estimator

  3. 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)

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

    Science.gov (United States)

    Ren, Shou-Tian; Wang, Qiang; Zhao, Feng; Qu, Shi-Liang

    2012-03-01

    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.

  5. 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 CTS data. (paper)

  6. 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

  7. Authentication of male beef by multiplex fast real-time PCR.

    Science.gov (United States)

    Herrero, Beatriz; Royo, Luis J; Lago, Fátima C; Vieites, Juan M; Espiñeira, Montserrat

    2013-01-01

    Meat is a significant source of high-quality nutrients, which are very important in the diet. Among meat products, one of the most prized is bovine meat, of which male beef has been designated to be of a higher quality. However, because of its similarity with female beef, deliberate or unintentional substitutions can occur. To avoid this, methodology based on the fast real-time polymerase chain reaction has been developed to authenticate the species and gender origin of beef. This technique consists of two polymerase chain reactions: one bovine-specific reaction and another Y-chromosome-specific multiplex reaction. This methodology has been validated for all kinds of beef products, including those subjected to intensive processing treatments, and it has subsequently been applied to 10 commercial samples labelled as ox to determine whether they are properly labelled. This assay has been shown to have high specificity, sensitivity and rapidity, with the potential to be a powerful tool in enforcing food labelling regulations. PMID:23167258

  8. 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

  9. Real Time Computer for Plugging Indicator Control of Prototype Fast Breeder Reactor

    International Nuclear Information System (INIS)

    Prototype Fast Breeder Reactor (PFBR) is in the advanced stage of construction at Kalpakkam, India. Liquid sodium is used as coolant to transfer the heat produced in the reactor core to steam water circuit. Impurities present in the sodium are removed using purification circuit. Plugging indicator is a device used to measure the purity of the sodium. Versa Module Europa bus based Real Time Computer (RTC) system is used for plugging indicator control. Hot standby architecture consisting of dual redundant RTC system with switch over logic system is the configuration adopted to achieve fault tolerance. Plugging indicator can be controlled in two modes namely continuous and discontinuous mode. Software based Proportional-Integral-Derivative (PID) algorithms are developed for plugging indicator control wherein the set point changes dynamically for every scan interval of the RTC system. Set points and PID constants are kept as configurable in runtime in order to control the process in very efficient manner, which calls for reliable communication between RTC system and control station, hence TCP/IP protocol is adopted. Performance of the RTC system for plugging indicator control was thoroughly studied in the laboratory by simulating the inputs and monitored the control outputs. The control outputs were also monitored for different PID constants. Continuous and discontinuous mode plots were generated. (authors)

  10. Fast-neutron Induced Reactions at the nELBE Time-of-flight Facility

    Science.gov (United States)

    Junghans, A. R.; Beyer, R.; Elekes, Z.; Grosse, E.; Hannaske, R.; Kögler, T.; Massarczyk, R.; Schwengner, R.; Wagner, A.

    2014-05-01

    The compact neutron-time-of-flight facility nELBE at the superconducting electron accelerator ELBE of Helmholtz-Zentrum Dresden-Rossendorf is being rebuilt and extended with a low-background experimental hall. The neutron radiator consists of a liquid lead circuit without additional neutron moderators. The useful neutron spectrum extends from some tens of keV to about 10 MeV. nELBE is intended to deliver cross section data of fast-neutron nuclear interactions e.g. for the transmutation of nuclear waste and improvement of neutron physical simulations of innovative nuclear systems. Before the extension of the facility, the photon production cross section of 56Fe was measured with an HPGe detector and the inelastic neutron scattering cross section to the first few excited states in 56Fe was determined. The neutron total cross sections of Au and Ta were determined in the energy from 200 keV to 7 MeV in a transmission experiment.

  11. Excited state lifetimes in 190Tc and 109Ru via the fast-timing method

    Science.gov (United States)

    Smith, M. K.; Bucher, B.; Aprahamian, A.; Mach, H.; Simpson, G.; Rissanen, J.; Aysto, J.; Eronen, T.; Ghita, D.; Karvonen, P.; Jokinen, A.; Moore, I. D.; Pentilla, H.; Reponen, M.; Weber, C.; Saastamoinen, A.; Kurcewicz, W.; Fraile, I. M.; Olaizola, B.; Ruchowska, E.

    2013-10-01

    The evolution of nuclear structure across isotopic and isobaric chains are of great interest to nuclear structure and for structure applications to nuclear astrophysics, specifically the r-process. The neutron-rich region around A = 110 is characterized by rapidly evolving structure, which is currently not completely understood. As such, we have investigated the A = 109 ?-decay chain at the Univ. of Jyvaskyla IGISOL facility. 109Mo was populated via proton-induced fission of 238U, which ?- decays to 109Tc and subsequently 109Ru. Lifetimes and gamma spectroscopy were measured with a multi-detector array consisting of of 2 HPGe, 2 LaBr and 1 plastic scintillator. ?- ?- ? triple coincidences were used to construct/check both level schemes, and measure lifetimes by the fast-timing method. New gamma ray transitions and picosecond range lifetimes will be presented for 109Tc and 109Ru. This work is supported by the NSF under grants PHY0822648 and PHY0758100; and by the Academy of Finland under the Centre of Excellence Programme 2006-2011.

  12. A Fast Topological Trigger for Real Time Analysis of Nanosecond Phenomena; Opening the Gamma Ray Window to Our Universe

    Energy Technology Data Exchange (ETDEWEB)

    Krennrich, Frank [Iowa State University

    2013-09-24

    This work was to enable the development of a proof-of-principle nanosecond trigger system that is designed to perform a real time analysis of fast Cherenkov light flashes from air showers. The basic building blocks of the trigger system have been designed and constructed, and a real world system is now operating in the VERITAS experiment.

  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. Ultimate response time of high electron mobility transistors

    Energy Technology Data Exchange (ETDEWEB)

    Rudin, Sergey; Rupper, Greg [U.S. Army Research Laboratory, Adelphi, Maryland 20783 (United States); Shur, Michael [Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

    2015-05-07

    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, U{sub 0}?=?U{sub g}???U{sub th}, where U{sub g} is the gate voltage and U{sub th} is the threshold voltage, such that ?U{sub 0}/L?time in the low mobility samples is on the order of L{sup 2}/(?U{sub 0}), in agreement with the analytical drift model. However, the decay is preceded by a delay time on the order of L/s, where s is the plasma wave velocity. This delay is the ballistic transport signature in collision-dominated 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.

  15. 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.

  16. Acetobacter aceti fast identification by Real Time PCR in spoiled wine samples

    Directory of Open Access Journals (Sweden)

    Attila Kántor

    2014-11-01

    Full Text Available Wine is a beverage that made from grape berries. However, without beneficial bacteria, we would not produce good wine. But very often wines contain acetic acid bacteria, which are undesirable in winemaking process. Acetic acid bacteria as known as a vinegar bacteria are Gram-negative, aerobic, rod-shaped and ubiquitous bacteria. This study was focused on species of acetic acid bacteria, specifically Acetobacter aceti that make spoilage in wine.The aim of our study was the identification of Acetobacter aceti in spoiled red wine samples, with plate dilution method on agar plates and using sensitive Real-time PCR (qPCR method. We cultivated Acetobacter aceti on GYC agar at 30°C, 48h. The one of main objective in the present work was the test fast, sensitive and reliable technique such as quantitative Real-time PCR and detecting the presence of Acetobacter aceti in wine samples with positive Acetobacteraceti control on amplification plot and melting curve. The next objective before  qPCR analysis was DNA extraction from wine samples incubated for one week at 28°C aerobically. We used five different red wine samples for this experiment: Alibernet 2013, Blaufränkisch 2013, Cabernet Sauvignon 2013, Dunaj 2012 and Saint-Laurent 2012. Next we extracted DNA from wine samples and from pure Acetobacter aceti CCM 3620T strain purchased from Czech collection of microorganisms in Brno. Susceptibility ofAcetobacter aceti was varied in different isolates from 102 to 107 CFU.mL-1. The number of Acetobacter cells on GYC medium ranged from 4.05 to 4.83log CFU.mL-1 in differentwine samples.The higher number of Acetobacter cells (4.83 log CFU.mL-1 was found in Cabernet Sauvignon 2013 wine.

  17. Response time testing of temperature sensors using loop current step response method

    Science.gov (United States)

    Hashemian, H. M.

    2013-09-01

    The difference between the response time of temperature sensors in the lab and in actual operation can be significant. The technique for testing the response time of temperature sensors in the lab is known as the plunge test. The technique for testing temperature sensor response time in-situ is referred to as the Loop Current Step Response (LCSR) test. This paper presents the theoretical foundation of LCSR (the test theory, the LCSR equation, and the test procedures). It then details the author's experimental research to validate its use in multiple applications (primarily in the nuclear power industry). The validity of the LCSR method depends on how well the design of the temperature sensor satisfies the assumptions of the LCSR test, the quality of the LCSR data in terms of signal-to-noise ratio, the application of proper sampling parameters for the data acquisition phase of LCSR, and the suitability of the algorithms and fitting processes used in the data analysis stage of LCSR. In multiple validation tests the author demonstrated that there is excellent (within ±10 percent) agreement between the median values of the response time produced by both the plunge and LCSR methods.

  18. 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.

  19. Time-resolved observation of fast domain-walls driven by vertical spin currents in short tracks

    International Nuclear Information System (INIS)

    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 107?A/cm2. 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. Time-delayed model of immune response in plants.

    Science.gov (United States)

    Neofytou, G; Kyrychko, Y N; Blyuss, K B

    2016-01-21

    In the studies of plant infections, the plant immune response is known to play an essential role. In this paper we derive and analyse a new mathematical model of plant immune response with particular account for post-transcriptional gene silencing (PTGS). Besides biologically accurate representation of the PTGS dynamics, the model explicitly includes two time delays to represent the maturation time of the growing plant tissue and the non-instantaneous nature of the PTGS. Through analytical and numerical analysis of stability of the steady states of the model we identify parameter regions associated with recovery and resistant phenotypes, as well as possible chronic infections. Dynamics of the system in these regimes is illustrated by numerical simulations of the model. PMID:26551159

  1. On the fast response of the Southern Ocean to changes in the zonal wind

    Directory of Open Access Journals (Sweden)

    D. J. Webb

    2007-09-01

    Full Text Available Model studies of the Southern Ocean, reported here, show that the Antarctic Circumpolar Current responds within two days to changes in the zonal wind stress at the latitudes of Drake Passage. Further investigation shows that the response is primarily barotropic and that, as one might expect, it is controlled by topography. Analysis of the results show that the changes in the barotropic flow are sufficient to transfer the changed surface wind stress to the underlying topography and that during this initial phase baroclinic processes are not involved.

    The model results also show that the Deacon Cell responds to changes in the wind stress on the same rapid time scale. It is shown that the changes in the Deacon Cell can also be explained by the change in the barotropic velocity field, an increase in the zonal wind stress producing an increased northward flow in shallow regions and southward flow where the ocean is deep. This new explanation is unexpected as previously the Deacon Cell has been thought of as a baroclinic feature of the ocean.

    The results imply that where baroclinic processes do appear to be involved in either the zonal momentum balance of the Southern Ocean or the formation of the Deacon Cell, they are part of the long term baroclinic response of the ocean's density field to the changes in the barotropic flow.

  2. Traffic model by braking capability and response time

    Science.gov (United States)

    Lee, Hyun Keun; Kim, Jeenu; Kim, Youngho; Lee, Choong-Ki

    2015-06-01

    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 a reasonable values of the parameters, and this is analytically supported. Our approach provides a new perspective in modeling traffic-flow safety and worrying situations like lane changing.

  3. Real-time information support for managing plant emergency responses

    International Nuclear Information System (INIS)

    The Three Mile Island Unit 2 accident highlighted the need to develop a systematic approach to managing plant emergency responses, to identify a better decision-making process, and to implement real-time information support for decision-making. The overall process management function is described and general information requirements for management of plant emergencies are identified. Basic information systems are being incorporated and future extensions and problem areas are discussed. (U.K.)

  4. Longitudinal time-dependent response of segmental tunnel linings

    OpenAIRE

    Arnau Delgado, Oriol; Molins i Borrell, Climent; Blom, C.B.M.; Walraven, Joost

    2012-01-01

    The longitudinal forces introduced by tunnel boring machines (TBMs) to the segmental tunnel linings influence their structural response. The analyses of the linings construction process and the ground-structure interaction mechanisms have shown the influence of the lining creep on the progressive loss of the initial longitudinal force. An analytical formulation to predict the remaining compression of the linings as a function of time is proposed, supported by means of a complete numerical mod...

  5. Response of several neutron measuring devices under the fractional change of thermal and fast neutrons

    International Nuclear Information System (INIS)

    Several neutron measuring devices were tested experimentally under the neutron fields characterized with two distinct kinds of thermal and fast neutron spectra. These neutron fields were constructed by the mixing of both thermal neutron calibration fields and fast neutron fields of AmBe source. Thermal neutron calibration fields were constructed using a graphite pile with the dimensions of 1.5 x 1.5 x 1.5 m3 and eight AmBe neutron sources. In order to make the fraction of fast neutron fluence vary in each neutron fields, a 111 GBq of AmBe neutron source was placed additionally in thermal neutron fields from 50 to 200 cm at the reference position. These neutron spectra were measured by using a KAERI Bonner Sphere system and dosimetric quantity delivered to neutron dosemeters such as survey meters and a Thermo Luminescence Dosimeter (TLD) was determined from these measurement results.

  6. Research on a Fast Delivery Production System: Just-in-time production system

    Directory of Open Access Journals (Sweden)

    Cai-feng LI

    2009-06-01

    Full Text Available In this paper, we analyzed calling the age to product or service for consumer demand living in the word. We come to a conclusion that speed or time is the key factors for enterpriser for competing intensely. So, the paper proposes JIT system achieve the tasks. Later, we address thoroughly the meaning of Just-in-time production system from speed and time angles and present two goals ultimate goal and the supporting goals implementation successfully. According to goal, this paper analyzed that implementing JIT should be achieved requires and carry out approaches. At last, this paper provided that JIT contribute benefits and causes to problem. Nonetheless, JIT is a robust production system for manufacturer and consumer. Moreover, I believe that it advent and it will be a main stream of a fluid production system for the future.
    Key words: just-in-time production system; fast delivery; continue quality improvement; manufacturing cells
    Résumé: Dans cette mémoire, nous analysons la vocation de l’âge à produire ou à servir pour la vie de la demande consommatrice dans le monde. Nous venons à une conclusion que la vitesse ou le temps est les facteurs clés en faveur de l’entrepreneur dans le but de rivaliser profondément. Donc, la mémoire propose le système JIT accomplit les tâches. Ensuite, nous adressons à fond le sens du système producteur JIT de la vitesse et les angles de temps et présentons deux buts, but ultime et l’implémentation des buts soutenant successivement. D’après le but, cette mémoire analyse que l’implémentation JIT doit être accomplie les demandes et exécuter les propositions. Enfin, cette mémoire fournit que le JIT contribue les avantages et les causes au problème. Malgré tout, JIT est un système robuste producteur pour les fabricants et les consommateurs. En plus, je crois qu’il se réalisera et sera un torrent d’un système producteur fluide pour l’avenir.
    Mots-Clés: Système producteur JIT ; livraison rapide ; amélioration qualitative continuelle; cellule fabricante

  7. High-fat diet feeding alters metabolic response to fasting/non fasting conditions. Effect on caveolin expression and insulin signalling

    Directory of Open Access Journals (Sweden)

    Martínez J Alfredo

    2011-04-01

    Full Text Available Abstract Background The effect of food intake on caveolin expression in relation to insulin signalling was studied in skeletal muscle and adipocytes from retroperitoneal (RP and subcutaneous (SC adipose tissue, comparing fasted (F to not fasted (NF rats that had been fed a control or high-fat (HF diet for 72 days. Methods Serum glucose was analysed enzymatically and insulin and leptin by ELISA. Caveolins and insulin signalling intermediaries (IR, IRS-1 and 2 and GLUT4 were determined by RT-PCR and western blotting. Caveolin and IR phosphorylation was measured by immunoprecipitation. Data were analysed with Mann-Whitney U test. Results High-fat fed animals showed metabolic alterations and developed obesity and insulin resistance. In skeletal muscle, food intake (NF induced activation of IR and increased expression of IRS-2 in control animals with normal metabolic response. HF animals became overweight, hyperglycaemic, hyperinsulinemic, hyperleptinemic and showed insulin resistance. In skeletal muscle of these animals, food intake (NF also induced IRS-2 expression together with IR, although this was not active. Caveolin 3 expression in this tissue was increased by food intake (NF in animals fed either diet. In RP adipocytes of control animals, food intake (NF decreased IR and IRS-2 expression but increased that of GLUT4. A similar but less intense response was found in SC adipocytes. Food intake (NF did not change caveolin expression in RP adipocytes with either diet, but in SC adipocytes of HF animals a reduction was observed. Food intake (NF decreased caveolin-1 phosphorylation in RP but increased it in SC adipocytes of control animals, whereas it increased caveolin-2 phosphorylation in both types of adipocytes independently of the diet. Conclusions Animals fed a control-diet show a normal response to food intake (NF, with activation of the insulin signalling pathway but without appreciable changes in caveolin expression, except a small increase of caveolin-3 in muscle. Animals fed a high-fat diet develop metabolic changes that result in insulin signalling impairment. In these animals, caveolin expression in muscle and adipocytes seems to be regulated independently of insulin signalling.

  8. Fast data readout and coding system for the processors in the real time regime

    International Nuclear Information System (INIS)

    A fast system designed to record and prepare data for event selection processor sistems is described. Representation of numbers and quantity of operated channels are realized in the binary code. The codes are transmitted along a fast highway to a special storage at a rate of 400 Mbit/s. Flowsheets are presented of the data read-out system, the coding module and of the module for converting data from the fast highway into parallel one. Main technical characteristics of the system are considered. It is underlined that the system can be used as a fast buffer to align the data flow prior to recording them into the memory unit. From the storage the data can be transmitted to the CAMAC highway

  9. 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.

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

    OpenAIRE

    Hideki Taniguchi, Toshio Sasaki, Hisae Fujita

    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.Methods: The patients, who were scheduled to undergo surgery for stomach cancer, were di...

  11. Fast time-correlated single-photon counting fluorescence lifetime acquisition using a 100 MHz semiconductor excitation source

    International Nuclear Information System (INIS)

    The fast and efficient collection of time-resolved fluorescence decay data is shown using a high repetition rate semiconductor laser excitation source optimally matched to low dead-time counting electronics. The 100 MHz repetition rate allows a measurement range of 10 ns without re-excitation of the sample. Rapid acquisition of time-resolved fluorescence data is essential for microscopy applications, such as fluorescence lifetime imaging. With this in mind we measured a representative dye (lifetime 376 ps) to determine the fastest collection time for a single exponential decay. Other dyes were also used with lifetimes ranging from ?90 ps to 4 ns. (technical design note)

  12. Real-time Pricing Demand Response in Operations

    Energy Technology Data Exchange (ETDEWEB)

    Widergren, Steven E.; Marinovici, Maria C.; Berliner, Teri; Graves, Alan

    2012-07-26

    Abstract—Dynamic pricing schemes have been implemented in commercial and industrial application settings, and recently they are getting attention for application to residential customers. Time-of-use and critical-peak-pricing rates are in place in various regions and are being piloted in many more. These programs are proving themselves useful for balancing energy during peak periods; however, real-time (5 minute) pricing signals combined with automation in end-use systems have the potential to deliver even more benefits to operators and consumers. Besides system peak shaving, a real-time pricing system can contribute demand response based on the locational marginal price of electricity, reduce load in response to a generator outage, and respond to local distribution system capacity limiting situations. The US Department of Energy (DOE) is teaming with a mid-west electricity service provider to run a distribution feeder-based retail electricity market that negotiates with residential automation equipment and clears every 5 minutes, thus providing a signal for lowering or raising electric consumption based on operational objectives of economic efficiency and reliability. This paper outlines the capability of the real-time pricing system and the operational scenarios being tested as the system is rolled-out starting in the first half of 2012.

  13. Method for Response Time Measurement of Electrosensitive Protective Devices.

    Science.gov (United States)

    Dzwiarek

    1996-01-01

    A great step towards the improvement of safety at work was made when electro-sensitive protective devices (ESPDs) were applied to the protection of press and robot-assisted manufacturing system operators. The way the device is mounted is crucial. The parameters of ESPD mounting that ensure safe distance with respect to the controlled dangerous zone are response time, sensitivity, and the dimensions of the detection zone. The proposed experimental procedure of response time measurement is realised in two steps, with a test piece penetrating the detection zone twice. In the first step, low speed penetration (at a speed v&infm;) enables the detection zone border to be localised. In the second step of measurement, the probe is injected at a high speed v&infd;. The actuator rod position is measured and when it is equal to the value L registered by the earlier measurements, counting time begins as well as the monitoring of the state of the equipment under test (EUT) output relays. After the state changes, time t&infp; is registered. The experimental procedure is realised on a special experimental stand. Because the stand has been constructed for certification purposes, the design satisfies the requirements imposed by Polski Komitet Normalizacyjny (PKN, 1995). The experimental results prove the measurement error to be smaller than +/- 0.6 ms. PMID:10602588

  14. Destruction of hazardous air pollutants using a fast rise time pulsed corona reactor

    Energy Technology Data Exchange (ETDEWEB)

    Korzekwa, R.A. [Los Alamos National Laboratory, Los Alamos, New Mexico87545-1663 (United States); Grothaus, M.G. [Southwest Research Institute, 6220 Culebra Road, P.O. Drawer 28510, San Antonio, Texas78228-0510 (United States); Hutcherson, R.K. [OSRAM Sylvania, Inc., 71 Cherry Hill Drive, Beverly, Massachusetts 01915 (United States); Roush, R.A. [Federal Bureau of Investigation, Engineering Research Facility, MS EST-5, Building 27958-A, Quantico, Virginia22135 (United States); Brown, R. [Naval Surface Warfare Center, Dahlgren, Virginia22448-5100 (United States)

    1998-04-01

    Increasingly stringent environmental regulation imposed on both the military and civilian sectors has created a growing demand for alternative abatement methods for a variety of hazardous compounds. One alternative, the nonthermal plasma, shows promise of providing an efficient means for the destruction of dilute concentrations of hazardous air pollutants. The Dahlgren Laboratory of the Naval Surface Warfare Center has extensively investigated one type of nonthermal plasma discharge, the pulsed corona reactor, for the destruction of volatile organic compounds and chemical warfare agents. In this reactor, a fast rise time ({approximately}10ns), short duration ({lt}100ns), high-voltage pulse is repetitively delivered to a wire-cylinder electrode geometry, thereby producing a multitude of streamer discharges along its length. The resulting nonthermal plasma contains highly reactive chemical radicals which can interact with and destroy the hazardous molecules entrained in the ambient atmosphere flowing through the reactor volume. Increased electrical efficiency was obtained using a combination of high efficiency constant-current capacitor-charging, high repetition-rate spark gap switching, and resonant energy transfer to the reactor. Promising results have been obtained for toluene, methylene chloride, and dichlorodifluoromethane in air at concentrations of a few hundred parts per million. The device has been operated at voltages up to 30 kV, pulse repetition rates up to 1.4 kHz, and flow rates up to 60 scr(l)/min. Detailed electrical measurements have been made to properly characterize the electrical properties of the pulsed corona reactor and to validate subsequent improvements in the reactor energy efficiency. {copyright} {ital 1998 American Institute of Physics.}

  15. Ultrastructural response of arcuate nucleus neurons to fasting in aged rats.

    Science.gov (United States)

    Kubasik-Juraniec, J; Zauszkiewicz-Pawlak, A; Kotlarz, G; Wo?niak, M; Knap, N

    2009-11-01

    The arcuate nucleus of the hypothalamus (ARH) is involved in the control of energy homeostasis. Leptin - an adipocyte derived hormone - is known to act on the hypothalamic nuclei and thus to control body weight by food intake reduction. Oxidative stress is believed to be implicated in leptin signalling. However, its relevance for leptin-induced signal transduction within ARH remains unclear. The goal of the study was to investigate the effect of fasting on morphological alterations of the neuronal endoplasmic reticulum/Golgi network as well as on the expression of leptin receptors in the arcuate nucleus of aged rats. Male Wistar rats, aged 24 months, were fasted for 96 hours. The control animals were fed ad libitum. Membranous whorls in the ARH neurons were visualized using the electron microscopy technique. Leptin receptors in the membranes of ARH neurons were determined immunohistochemically (IHC), and soluble leptin receptors in the plasma as well as plasma isoprostanes were quantified immunochemically (ELISA). An intense formation of membranous whorls was observed, directly associated with the cisternae of the rough endoplasmic reticulum, as well as lamellar bodies. Interestingly, the whorls were often localized near a well-developed Golgi complex. Moreover, some Golgi complexes displayed an early stage of whorl formation. Groups of residual lipofuscin granules were found in the immediate proximity of the whorls. An increased immunoreactivity with neuronal leptin receptors suggests that hypersensitive neurons may still effectively respond to the fasting serum levels of leptin, mediating ultrastructural transformation of ARH neurons during short-term fasting. Having observed a significant accumulation of lipofuscin granules and a marked increase of total 8-isoprostane serum level in the fasting rats, we hypothesize that signal transduction within the neurons of ARH is dependent on oxidative stress phenomena. PMID:19950070

  16. Simulating the Thermal Response of High Explosives on Time Scales of Days to Microseconds

    Energy Technology Data Exchange (ETDEWEB)

    Yoh, J J; McClelland, M A

    2003-07-16

    We present an overview of computational techniques for simulating the thermal cookoff of high explosives using a multi-physics hydrodynamics code, ALE3D. Recent improvements to the code have aided our computational capability in modeling the response of energetic materials systems exposed to extreme thermal environments, such as fires. We consider an idealized model process for a confined explosive involving the transition from slow heating to rapid deflagration in which the time scale changes from days to hundreds of microseconds. The heating stage involves thermal expansion and decomposition according to an Arrhenius kinetics model while a pressure-dependent burn model is employed during the explosive phase. We describe and demonstrate the numerical strategies employed to make the transition from slow to fast dynamics.

  17. Time-Dependent Increase in Network Response to Stimulation

    Science.gov (United States)

    Hamilton, Franz; Graham, Robert; Luu, Lydia; Peixoto, Nathalia

    2015-01-01

    In vitro neuronal cultures have become a popular method with which to probe network-level neuronal dynamics and phenomena in controlled laboratory settings. One of the key dynamics of interest in these in vitro studies has been the extent to which cultured networks display properties indicative of learning. Here we demonstrate the effects of a high frequency electrical stimulation signal in training cultured networks of cortical neurons. Networks receiving this training signal displayed a time-dependent increase in the response to a low frequency probing stimulation, particularly in the time window of 20–50 ms after stimulation. This increase was found to be statistically significant as compared to control networks that did not receive training. The timing of this increase suggests potentiation of synaptic mechanisms. To further investigate this possibility, we leveraged the powerful Cox statistical connectivity method as previously investigated by our group. This method was used to identify and track changes in network connectivity strength. PMID:26545098

  18. Sensitivity and response time improvements in millimeter-wave spectrometers

    International Nuclear Information System (INIS)

    A new version of a microwave spectrometer for the detection of gaseous pollutants and other atmospheric constituents is described. The spectrometer, which operates in the vicinity of 70 GHz, employs a Fabry-Perot resonator as a sample cell and uses superhetrodyne detection for high sensitivity. The spectrometer has been modified to incorporate a frequency doubler modulated at 30 MHz to permit operation with a single Gunn oscillator source. As a result, faster response time and somewhat greater sensitivity are obtained. The spectrometer is capable of detecting a minimum concentration of 1 ppM of SO2 diluted in air with a 1 second time constant. For OCS diluted in air, the minimum detectable concentration is 800 ppB and with a 10 second time constant 300 ppB

  19. 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.)

  20. 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.

  1. 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.

  2. Enhanced time response of 1-in. LaBr3(Ce) crystals by leading edge and constant fraction techniques

    OpenAIRE

    Vedia, V.; Mach, H.; Fraile, L.M.(Grupo de Física Nuclear, Universidad Complutense, CEI Moncloa, Madrid, E-28040, Spain); Udias, J. M.; Lalkovski, S.

    2015-01-01

    We have characterized in depth the time response of three detectors equipped with cylindrical LaBr$_{3}$ (Ce) crystals with dimensions of 1-in. in height and 1-in. in diameter, and having nominal Ce doping concentration of 5%, 8% and 10%. Measurements were performed at $^{60}$Co and $^{22}$Na {\\gamma}-ray energies against a fast BaF$_{2}$ reference detector. The time resolution was optimized by the choice of the photomultiplier bias voltage and the fine tuning of the paramet...

  3. Gamma-ray response of SOI bipolar junction transistors for fast, radiation tolerant front-end electronics

    OpenAIRE

    MANGHISONI, MASSIMO; Ratti, Lodovico; RE, VALERIO; SPEZIALI, VALERIA; AA. VV.

    2004-01-01

    This paper is devoted to studying the effects of g radiation on the electrical parameters of complementary bipolar junction transistors, part of an SOI (silicon on insulator) BiCMOS process, in view of the design of fast, rad-hard analog blocks. A survey of the total ionizing dose response has been carried out paying particular attention to its dependence on the layout and process choices. The final integrated doses are compatible with operation in the space environment and in high-energy ...

  4. Growth, carcass composition and meat quality response to dietary concentrations in fast-, medium- and slow-growing commercial broilers

    OpenAIRE

    Quentin, Maxime; Bouvarel, Isabelle; Berri, Cécile; Le Bihan-Duval, Elisabeth; Baéza, Elisabeth; Jégo, Yves; Picard, Michel

    2003-01-01

    Growth, carcass composition and certain meat quality traits were studied in fast (F), medium (M) and slow (S) growing broilers fed with 3 regimes appropriate for each chicken type and differing on average by 418 kJ$\\cdot$kg$^{-1}$ AMEn and 1% crude protein (P1 $>$ P2 $>$ P3). No significant interactions between chicken types and feed were measured before 3 weeks and after 6 weeks of age, indicating that the 3 genotypes had similar responses to the 3 diets during these periods. Before 3 weeks ...

  5. 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

  6. Time-dependent response of dissipative electron systems

    International Nuclear Information System (INIS)

    We present a systematic study of the influence of energy and phase relaxation on dynamic polarizability simulations in the linear response regime. The nonperturbative approach is based on explicit electron dynamics using short laser pulses of low intensities. To include environmental effects on the property calculation, we use the time-dependent configuration-interaction method in its reduced density matrix formulation. Both energy dissipation and nonlocal pure dephasing are included. The explicit treatment of time-resolved electron dynamics gives access to the phase shift between the electric field and the induced dipole moment, which can be used to define a useful uncertainty measure for the dynamic polarizability. The nonperturbative treatment is compared to perturbation theory expressions, as applied to a simple model system, the rigid H2 molecule. It is shown that both approaches are equivalent for low field intensities, but the time-dependent treatment provides complementary information on the phase of the induced dipole moment, which allows for the definition of an uncertainty associated with the computation of the dynamic polarizability in the linear response regime.

  7. Fast Response Scintillator Based Detector for MHD Induced Energetic Ion Losses in ASDEX Upgrade

    OpenAIRE

    García Muñoz, Manuel (fl. 1853)

    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...

  8. Fuel pins and core response under liquid-metal fast breeder reactor transient overpower accident conditions

    International Nuclear Information System (INIS)

    Since the earlier liquid-metal fast breeder reactor transient overpower assessments were done (1975), new experimental data and modeling improvements have occurred that indicate later failures and more molten fuel squirted into the channel with a higher propensity for plugging. An initial sweepout still occurs, and an analysis shows that even if coherent instead of the expected stochastic failures occur, the blockages are partial, the reactor is strongly shut down, and a coolable geometry exists. Hence, the overall consequences would be benign

  9. Fast-response high-resolution temperature sonde aimed at contamination-free profile observations

    Directory of Open Access Journals (Sweden)

    K. Shimizu

    2010-12-01

    Full Text Available An innovative temperature sonde, equipped with an ultra thin tungsten wire (10 ?m in diameter, has been developed to meet the scientific requirements suitable for climate change research. The response time, shorter than 40 ms achieved at the altitude of 30 km, enables the temperature observations with the radiation correction of less than 0.5 K in the whole observation range. Test flights during the development stage reveal significant artificial perturbations in the observed temperature profiles. They are identified as the thermal contamination arising primarily from radiosonde package box with some additional effect from the launching balloon. The modification of the sensor mount successfully removed the contribution from the former effect. On the other hand, some filtering procedure need to be applied to remove the latter, although the use of a long suspension line will be effective. There remain unavoidable small fluctuations (less than 0.4 K that are brought about by the solid angle modulation of the illumination against the sensor body in the daytime. While conventional radiation correction may unintentionally have taken a part of such contaminations into account, they may not be properly corrected in existing radiosonde data, as the origin of errors has not been identified. Our tungsten sonde that scarcely relies on the ambiguous correction procedures will be ideal for serving as a kind of an international reference.

  10. Fast-response high-resolution temperature sonde aimed at contamination-free profile observations

    Directory of Open Access Journals (Sweden)

    K. Shimizu

    2010-08-01

    Full Text Available An innovative temperature sonde, equipped with an ultra thin tungsten wire, has been developed to meet the scientific requirements suitable for climate change research. The response time, shorter than 40 ms achieved at the altitude of 30 km, enables the temperature observations with the radiation correction of less than 0.4 K in the whole observation range. Test flights during the development stage reveal significant artificial perturbations in the observed temperature profiles. They are identified as the thermal contamination arising primarily from radiosonde package box with some additional effect from the launching balloon. The modification of the sensor mount successfully removed the contribution from the former effect. On the other hand, some filtering procedure need to be applied to remove the latter, although the use of a long suspension line will be effective to reduce the noise. There remain unavoidable small fluctuations (less than 0.4 K that are brought about by the solid angle modulation of the illumination against the sensor body in the daytime. While conventional radiation correction may unintentionally have taken a part of such contaminations into account, they may not be properly corrected in existing radiosonde data, as the origin of errors has not been identified. Our tungsten sonde that scarcely relies on the ambiguous correction procedures is ideal for serving as an international reference.

  11. 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.

  12. The response of quiescent cell populations in murine solid tumors to irradiation with fast neutrons

    International Nuclear Information System (INIS)

    5-bromo-2'-deoxyuridine (BUdR) was injected into SCC VII tumor-bearing mice intraperitoneally to label all proliferating tumor cells. The mice were irradiated with fast neutrons or X-rays. Immediately, or 24 h after irradiation, the tumors were excised, minced and trypsinized. The tumor cell suspensions were incubated with cytochalasin-B (a cytokinesis blocker). The micronucleus frequency was determined using immunofluorescence staining to BUdR. The cells that were not labeled with BUdR could be regarded as the quiescent cells. The micronucleus frequency in total tumor cells was determined from the irradiated tumors that were not pretreated with BUdR. The difference in radiosensitivity between total and quiescent cells was markedly reduced with fast neutrons, especially at higher doses of radiation. Potentially lethal damage repair by total and quiescent cells was inhibited more strongly with neutrons than with X-rays. When using fast neutrons, the radiosensitivity of solid tumors depends on their heterogeneity less critically than for X-rays. (orig.)

  13. Very fast mass balance and other fuel cycle responses calculations for studying back end of fuel cycle scenarii

    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 a 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. (author)

  14. A novel 4D fast track finding system using precise space and time information of the hit

    CERN Document Server

    Neri, Nicola

    2015-01-01

    We propose a novel fast track finding system capable of reconstructing four dimensional particle trajectories in real time using precise space and time information of the hits. Recent developments in silicon pixel detectors achieved 150 ps time resolution and intense R&D is in progress to improve the timing performance, aiming at 10 ps. The use of the precise space and time information allows the suppression of background hits not compatible with the time of passage of the particle and the determination of its time evolution. The fast track finding device that we are proposing is based on a massively parallel algorithm implemented in commercial field-programmable gate array using a pipelined architecture. We describe the algorithm and its implementation for a tracking system prototype based on 8 planes of silicon sensors used as a case study. According to simulations the suppression of noise hits is effective in reducing fake track combinations and improving real-time track reconstruction in presence of b...

  15. 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.

  16. Fast but not intuitive, slow but not reflective: Decision conflict drives reaction times in social dilemmas.

    Science.gov (United States)

    Evans, Anthony M; Dillon, Kyle D; Rand, David G

    2015-10-01

    When people have the chance to help others at a cost to themselves, are cooperative decisions driven by intuition or reflection? To answer this question, recent studies have tested the relationship between reaction times (RTs) and cooperation, reporting both positive and negative correlations. To reconcile this apparent contradiction, we argue that decision conflict (rather than the use of intuition vs. reflection) drives response times, leading to an inverted-U shaped relationship between RT and cooperation. Studies 1 through 3 show that intermediate decisions take longer than both extremely selfish and extremely cooperative decisions. Studies 4 and 5 find that the conflict between self-interested and cooperative motives explains individual differences in RTs. Manipulating conflictedness causes longer RTs and more intermediate decisions, and RTs mediate the relationship between conflict and intermediate decisions. Finally, Studies 6 and 7 demonstrate that conflict is distinct from reflection by manipulating the use of intuition (vs. reflection). Experimentally promoting reliance on intuition increases cooperation, but has no effects on decision extremity or feelings of conflictedness. In sum, we provide evidence that RTs should not be interpreted as a direct proxy for the use of intuitive or reflective processes, and dissociate the effects of conflict and reflection in social decision making. (PsycINFO Database Record PMID:26413891

  17. 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

  18. Time domain responses of hydraulic bushing with two flow passages

    Science.gov (United States)

    Chai, Tan; Dreyer, Jason T.; Singh, Rajendra

    2014-02-01

    Hydraulic bushings are commonly employed in vehicle suspension and body sub-frame systems to control motion, vibration, and structure-borne noise. Since literature on this topic is sparse, a controlled bushing prototype which accommodates a combination of long and short flow passages and flow restriction elements is first designed, constructed and instrumented. Step-up and step-down responses of several typical fluid-filled bushing configurations are measured along with steady harmonic time histories of transmitted force and internal pressures. To analyze the experimental results and gain physical insights into the hydraulic bushing system, lumped system models of bushings with different design features are developed, and analytical expressions of transmitted force and internal pressure responses are derived by using the convolution method. Parametric studies are also conducted to examine the effect of hydraulic element parameters. System parameters are successfully estimated for both harmonic and step responses using theory and measurements, and the dynamic force measurements are analyzed using analytical predictions. Finally, some nonlinearities of the system are also observed, and the fluid resistance of flow passage is found to be the most nonlinear element.

  19. A novel Fast Gas Chromatography based technique for higher time resolution measurements of speciated monoterpenes in air

    OpenAIRE

    Jones, C E; Kato, S.; Y. Nakashima; Y. Kajii

    2013-01-01

    Biogenic emissions supply the largest fraction of non-methane volatile organic compounds (VOC) from the biosphere to the atmospheric boundary layer, and typically comprise a complex mixture of reactive terpenes. Due to this chemical complexity, achieving comprehensive measurements of biogenic VOC (BVOC) in air within a satisfactory time resolution is analytically challenging. To address this, we have developed a novel, fully automated Fast Gas Chromatography...

  20. 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.

  1. Soft real-time EPICS extensions for fast control: A case study applied to a TCV equilibrium algorithm

    International Nuclear Information System (INIS)

    Highlights: • Implementation of a soft real-time control system based on EPICS technology. • High data throughput system control implementation. • GPU technology applied to fast control. • EPICS fast control based solution. • Fast control and data acquisition in Linux. - Abstract: For new control systems development, ITER distributes CODAC Core System that is a software package based on Linux RedHat, and includes EPICS (Experimental Physics and Industrial Control System) as software control system solution. EPICS technology is being widely used for implementing control systems in research experiments and it is a very well tested technology, but presents important lacks to meet fast control requirements. To manage and process massive amounts of acquired data, EPICS requires additional functions such as: data block oriented transmissions, links with speed-optimized data buffers and synchronization mechanisms not based on system interruptions. This EPICS limitation turned out clearly during the development of the Fast Plant System Controller Prototype for ITER based on PXIe platform. In this work, we present a solution that, on the one hand, is completely compatible and based on EPCIS technology, and on the other hand, extends EPICS technology for implementing high performance fast control systems with soft-real time characteristics. This development includes components such as: data acquisition, processing, monitoring, data archiving, and data streaming (via network and shared memory). Additionally, it is important to remark that this system is compatible with multiple Graphics Processing Units (GPUs) and is able to integrate MatLab code through MatLab engine connections. It preserves EPICS modularity, enabling system modification or extension with a simple change of configuration, and finally it enables parallelization based on data distribution to different processing components. With the objective of illustrating the presented solution in an actual tokamak application, we have implemented fundamental tokamak equilibrium quantities such as plasma position, Shafranov shift or internal inductance. The algorithms have been parallelized and implemented for its execution on CPU, GPUs and Matlab, and have been tested using actual magnetic data from the TCV tokamak fast control system

  2. Time-dose response of human tumors and normal tissues during and after fractionated radiation treatment

    International Nuclear Information System (INIS)

    The background and some results of initial applications of a new model of time-dose response of tumors as well as fast-renewing normal tissues to fractionated radiation therapy are presented. Both the linear-quadratic and the single-hit/single-target, single-hit/multi-target model may be used for the single-dose survival of both the viable stem cells and the clonogenic tumor cells. Normal tissue tolerance is expressed as a minimum acceptable level of normal tissue functionality, due to insufficient production of replacement cells, which in turn is caused by radiation-induced depletion of the viable stem cell population. A logistic function describes the homeostatically controlled inter-fraction and post-treatment normal tissue stem cell repopulation. The onset of stem cell repopulation may be delayed, and the doubling rate of clonogenic tumor cells may increase, upon the onset of treatment. Criteria for the selection of acceptable parameter values for normal tissue as well as tumors are described. An interactive Fortran77 program has been developed to assist in the search for acceptable parameter values, the simulation of the time-dose response of normal tissues and tumors to conventional clinical fractionation schemes and the exploration of alternative schedules, including hyperfractionation. Some provisional results are presented. 29 refs.; 11 figs.; 2 tabs

  3. 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

  4. Fast neutron detection with germanium detectors: computation of response functions for the 692 keV inelastic scattering peak

    International Nuclear Information System (INIS)

    The dependence of the shape of the right-sided broadening of the inelastic scattering peak at 692 keV in the pulse-height distribution measured with a Ge detector in fast neutron fields on the energy of the incident neutrons has been analyzed. A model incorporating the process contributing to the energy deposition that engender the peak, including the partitioning of the energy deposition by the Ge recoils, was developed. With a Monte Carlo code based on this model, the detector response associated with this peak was computed and compared with results of measurements with quasi-monoenergetic neutrons for energies between 0.88 and 2.1 MeV. A set of 80 response functions for neutron energies in the range from the reaction threshold at 0.7 to 6 MeV was computed, which will serve as a starting point for methods, which aim at obtaining information on the spectral distribution of fast neutron fields for this energy range from measurements with a Ge detector. (orig.)

  5. 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...

  6. 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.

  7. Fast pulsed UV light source and calibration of non-linear photomultiplier response

    International Nuclear Information System (INIS)

    A novel ultraviolet pulsed-light source with a digitally controlled amplitude has been developed and used to determine the response of the BURLE 8850 photomultiplier tube for light intensities close to that corresponding to single photoelectrons to those well beyond the linear response region

  8. Matching plant and animal processes to alter nutrient supply in strip-grazed cattle: timing of herbage and fasting allocation.

    Science.gov (United States)

    Gregorini, P; Gunter, S A; Beck, P A

    2008-04-01

    This work aimed to assess the impact of timing of herbage allocation and fasting on patterns of ingestive behavior, herbage intake, ruminal fermentation, nutrient flow to the duodenum, and site and extent of digestion. Treatments were daily herbage allocation in the afternoon (1500 h, AHA), morning (0800 h, MHA), AHA after 20 h of fasting (AHAF), and MHA after 20 h of fasting (MHAF). Four ruminally and duodenally fistulated heifers (279 +/- 99 kg of BW) individually strip-grazed wheat pastures in a Latin-square design. Eating, rumination, and idling behavior were recorded every 2 min, and bite and eating step rates were measured hourly while the heifers were grazing (11 h MHA and AHA; 4 h MHAF and AHAF). Ruminal DM pools were measured 4 times daily (0800, 1200, 1500, and 1900 h) to estimate daily herbage DMI and its pattern. Ruminal fluid was sampled at these same times and also at 2300 h. Duodenal digesta was sampled over 2 d to determine the site of herbage digestibility. Treatments did not affect daily herbage DMI (16.5 g/ kg of BW, SE = 0.0025; P > 0.05). However, they altered the eating pattern; the evening grazing bout of AHA and AHAF was greater (P 0.05) among MHA, MHAF, and AHAF; however, it averaged 970, 40, 300, and 540 g/d, respectively, greater (P 0.05) for MHA, AHA, and AHAF, but was lower for MHAF (P 0.05) within fasted and nonfasted treatments; however, it was greater (P 0.05) among MHA, MHAF, and AHAF, but was greater (P patterns, and its impact on nutrient supply. At the same amount of resource allocation, nutrient supply to grazing cattle can be modified through strategic grazing management. PMID:18192561

  9. Optimal scan timing of hepatic arterial-phase imaging of hypervascular hepatocellular carcinoma determined by multiphasic fast CT imaging technique

    Energy Technology Data Exchange (ETDEWEB)

    Kagawa, Yuki; Okada, Masahiro; Yagyu, Yukinobu; Kumano, Seishi; Murakami, Takamichi [Dept. of Radiology, Kinki Univ. Faculty of Medicine, Osaka (Japan)], e-mail: murakami@med.kindai.ac.jp; Kanematsu, Masayuki [Dept. of Radiology, Gifu Univ., School of Medicine, Gifu (Japan); Kudo, Masayuki [CT Research JP, GE Healthcare JP Corporation, Tokyo (Japan)

    2013-10-15

    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 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.

  10. 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 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

  11. 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.

  12. 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

  13. 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,...

  14. Bulk acid-fast staining of sputum smears: time to end a taboo

    OpenAIRE

    Kam, K. M.; Yip, C. W.; Tang, H. S.; Van Deun, A.

    2009-01-01

    SETTING: A high-throughput laboratory routinely performing fluorescence microscopy for acid-fast bacilli (AFB) smear with automated bulk staining. OBJECTIVES: To determine the risk of false-positive AFB sputum smears from bulk staining showing as smear-positive, culture-negative specimens, or a decrease in smear- and culture-positives. DESIGN: Direct AFB smear and Löwenstein-Jensen culture were performed for a total of 39 350 routine sputum specimens. Of these, 6633 were randomly selected for...

  15. Detectors for Time-of-Flight Fast-Neutron Radiography: 1. Neutron Counting Gas Detector

    CERN Document Server

    Dangendorf, V; Chechik, R; Goldberg, M; Laczko, G; Mor, I; Reginatto, M; Vartsky, D

    2004-01-01

    One of our two methods for fast-neutron imaging with spectrometric capability is presented here. It is a neutron-counting technique based on a hydrogenous neutron converter coupled to Gaseous Electron Multipliers (GEM). The principles of the detection techniques and the optimization of the converter, electron amplification and the readout are described. Evaluation of the properties are derived from a experiment in a pulsed neutron beam of spectral distribution between 2 and 10 MeV

  16. Detectors for Time-of-Flight Fast-Neutron Radiography: 1. Neutron Counting Gas Detector

    OpenAIRE

    Dangendorf, V.; Breskin, A.; Chechik, R.; Goldberg, M.; Laczko, G.; Mor, I; Reginatto, M.; Vartsky, D.

    2004-01-01

    One of our two methods for fast-neutron imaging with spectrometric capability is presented here. It is a neutron-counting technique based on a hydrogenous neutron converter coupled to Gaseous Electron Multipliers (GEM). The principles of the detection techniques and the optimization of the converter, electron amplification and the readout are described. Evaluation of the properties are derived from a experiment in a pulsed neutron beam of spectral distribution between 2 and ...

  17. Intercomparison of fast response commercial gas analysers for nitrous oxide flux measurements under field conditions

    Directory of Open Access Journals (Sweden)

    Ü. Rannik

    2014-08-01

    Full Text Available Four gas analysers capable of measuring nitrous oxide (N2O concentration at a response time necessary for eddy covariance flux measurements were operated from spring till winter 2011 over a field cultivated with reed canary grass (RCG, Phalaris arundinaceae, 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 emission, lasting for about two weeks after fertilization in late May, was characterised by an up to two orders of magnitude higher emission, whereas during the rest of the campaign the N2O fluxes were small, from 0.1 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 cumulatively highest N2O estimates (with 29% higher value 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 reason for these episodic higher and lower estimates by the two instruments is not currently known, suggesting further need for detailed evaluation of instrument performance under field conditions with emphasis on stability, calibration and, in particular, simultaneous accurate determination of water vapour concentration due to its large impact on small N2O fluxes through spectroscopic and dilution corrections. The instrument CW-TILDAS-CS was characterised by the lowest noise level (std 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. Both instruments based on Continuous-Wave Quantum Cascade Lasers, CW-TILDAS-CS and N2O/CO-23d, were able to determine the same sample of low N2O fluxes with high mutual coefficient of determination at 30 min averaging level and with minor systematic difference over the observation period of several months.

  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. PMID:25905626

  19. 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.

  20. 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.)

  1. 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.

  2. 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 

  3. Revealing real-time emotional responses: a personalized assessment based on heartbeat dynamics.

    Science.gov (United States)

    Valenza, Gaetano; Citi, Luca; Lanatá, Antonio; Scilingo, Enzo Pasquale; Barbieri, Riccardo

    2014-01-01

    Emotion recognition through computational modeling and analysis of physiological signals has been widely investigated in the last decade. Most of the proposed emotion recognition systems require relatively long-time series of multivariate records and do not provide accurate real-time characterizations using short-time series. To overcome these limitations, we propose a novel personalized probabilistic framework able to characterize the emotional state of a subject through the analysis of heartbeat dynamics exclusively. The study includes thirty subjects presented with a set of standardized images gathered from the international affective picture system, alternating levels of arousal and valence. Due to the intrinsic nonlinearity and nonstationarity of the RR interval series, a specific point-process model was devised for instantaneous identification considering autoregressive nonlinearities up to the third-order according to the Wiener-Volterra representation, thus tracking very fast stimulus-response changes. Features from the instantaneous spectrum and bispectrum, as well as the dominant Lyapunov exponent, were extracted and considered as input features to a support vector machine for classification. Results, estimating emotions each 10 seconds, achieve an overall accuracy in recognizing four emotional states based on the circumplex model of affect of 79.29%, with 79.15% on the valence axis, and 83.55% on the arousal axis. PMID:24845973

  4. Fast time-domain modeling of fluid-coupled cMUT cells: from the single cell to the 1-D linear array element.

    Science.gov (United States)

    Sénégond, Nicolas; Boulmé, Audren; Plag, Camille; Teston, Franck; Certon, Dominique

    2013-07-01

    We report a fast time-domain model of fluid-coupled cMUTs developed to predict the transient response-i.e., the impulse pressure response--of an element of a linear 1-D array. Mechanical equations of the cMUT diaphragm are solved with 2-D finite-difference schemes. The time-domain solving method is a fourth--order Runge-Kutta algorithm. The model takes into account the electrostatic nonlinearity and the contact with the bottom electrode when the membrane is collapsed. Mutual acoustic coupling between cells is introduced through the numerical implementation of analytical solutions of the impulse diffraction theory established in the case of acoustic sources with rectangular geometry. Processing times are very short: they vary from a few minutes for a single cell to a maximum of 30 min for one element of an array. After a description of the model, the impact of the nonlinearity and the pull-in/pull-out phenomena on the dynamic behavior of the cMUT diaphragm is discussed. Experimental results of mechanical displacements obtained by interferometric measurements and the acoustic pressure field are compared with simulations. Different excitation signals-high-frequency bandwidth pulses and toneburst excitations of varying central frequency-were chosen to compare theory with experimental results. PMID:25004518

  5. A Fast Merge Sort

    OpenAIRE

    Abhyankar, D

    2014-01-01

    Merge sort is one of the most efficient ways to solve sorting problem. Our research suggests that it is still responsive to clever optimizations. A considerably fast variation of Merge sort has been proposed in this paper. Proposed algorithm uses some novel optimizations to improve the speed of the proposed algorithm. Proposed algorithm not only applies some novel optimizations but also retains most of the old optimizations which were effective in reducing space and time. In a...

  6. 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

    2015-01-01

    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, MR3.0 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, MR4.5 was consistently superior in the dasatinib group at all time points from 6 months onwards, reaching 61% vs. 21% (P < 0.05) at 36 months. Sixty-four vs. 71% of the patients in the 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

  7. Time-varying boundaries for diffusion models of decision making and response time.

    Science.gov (United States)

    Zhang, Shunan; Lee, Michael D; Vandekerckhove, Joachim; Maris, Gunter; Wagenmakers, Eric-Jan

    2014-01-01

    Diffusion models are widely-used and successful accounts of the time course of two-choice decision making. Most diffusion models assume constant boundaries, which are the threshold levels of evidence that must be sampled from a stimulus to reach a decision. We summarize theoretical results from statistics that relate distributions of decisions and response times to diffusion models with time-varying boundaries. We then develop a computational method for finding time-varying boundaries from empirical data, and apply our new method to two problems. The first problem involves finding the time-varying boundaries that make diffusion models equivalent to the alternative sequential sampling class of accumulator models. The second problem involves finding the time-varying boundaries, at the individual level, that best fit empirical data for perceptual stimuli that provide equal evidence for both decision alternatives. We discuss the theoretical and modeling implications of using time-varying boundaries in diffusion models, as well as the limitations and potential of our approach to their inference. PMID:25538642

  8. Effect of treatment time on low temperature plasma nitriding of stainless steel by saddle field neutral fast atom beam source

    International Nuclear Information System (INIS)

    Recent research carried out in laboratories showed that Saddle field neutral fast atom beam source is a promising method for nitriding of stainless steel. In the present work, the effect of treatment time on the microstructural and mechanical properties of plasma-nitrided stainless steel sample was investigated by this new method. Plasma nitriding was carried out at 420 deg. C and at a pressure of 0.1 Pa for a time range of 1 to 12 h. SEM-EDX, microhardness tests, optical microscopy and X-ray diffraction (XRD) were used to evaluate the mechanical and structural properties of the nitrided layer. It was found that nitriding time has a pronounced effect on the structural and mechanical properties of low-temperature plasma-nitrided samples and produced a precipitation-free thin hard nitrided layer within a short processing time

  9. HTS coil with enhanced thermal stability in over-current operation for fast response magnet power application

    Science.gov (United States)

    Kim, Hyungjun; Kim, Jinsub; Lee, Jeyull; Kuk Ko, Tae

    2015-10-01

    This paper examines the effect of improved winding geometry on high-temperature superconducting (HTS) coils for use in superconducting power applications. One of the most important functions in such a superconducting magnetic energy storage system is to charge-discharge the superconducting coils as fast as possible to secure sufficient power demand. The HTS coils are vulnerable to the thermal instability caused by cyclic and/or unexpected charge-discharge variation. Therefore, it is necessary to enhance the safety of the HTS coils under fast response operation at the request of varying loads. In this study, improved thermal stability in over-current operation is demonstrated by implementing the proposed insulation scheme. The performance of the HTS coil with the proposed winding geometry was experimentally evaluated in comparison with a conventional insulation (CI) coil. Cryo-stability characteristics of the proposed coil are verified with a circuit analysis under a charge-discharge operation scenario. The results of this study show the usefulness of the proposed winding coil as a replacement for CI coils, which have drawbacks related to thermal recovery rate in over-current operation.

  10. Monoterpene separation by coupling proton transfer reaction time-of-flight mass spectrometry with fastGC.

    Science.gov (United States)

    Materi?, Dušan; Lanza, Matteo; Sulzer, Philipp; Herbig, Jens; Bruhn, Dan; Turner, Claire; Mason, Nigel; Gauci, Vincent

    2015-10-01

    Proton transfer reaction mass spectrometry (PTR-MS) is a well-established technique for real-time analysis of volatile organic compounds (VOCs). Although it is extremely sensitive (with sensitivities of up to 4500 cps/ppbv, limits of detection still somewhat limited, as isomers cannot be separated. Recently, selectivity-enhancing measures, such as manipulation of drift tube parameters (reduced electric field strength) and using primary ions other than H3O(+), such as NO(+) and O2 (+), have been introduced. However, monoterpenes, which belong to the most important plant VOCs, still cannot be distinguished so more traditional technologies, such as gas chromatography mass spectrometry (GC-MS), have to be utilised. GC-MS is very time consuming (up to 1 h) and cannot be used for real-time analysis. Here, we introduce a sensitive, near-to-real-time method for plant monoterpene research-PTR-MS coupled with fastGC. We successfully separated and identified six of the most abundant monoterpenes in plant studies (?- and ?-pinenes, limonene, 3-carene, camphene and myrcene) in less than 80 s, using both standards and conifer branch enclosures (Norway spruce, Scots pine and black pine). Five monoterpenes usually present in Norway spruce samples with a high abundance were separated even when the compound concentrations were diluted to 20 ppbv. Thus, fastGC-PTR-ToF-MS was shown to be an adequate one-instrument solution for plant monoterpene research. PMID:26253230

  11. Preliminary time response data from ITT MCP PMT

    International Nuclear Information System (INIS)

    Preliminary data obtained with an ITT image intensifier tube operated as a photomultiplier are presented. Some applications such as weapons diagnostics, laser plasma diagnostics, and diagnostic developments such as fast radiation-to-light converters, and fiber optic pulse dispersion are described

  12. 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

  13. 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.

  14. A defined network of fast-spiking interneurons in orbitofrontal cortex: responses to behavioral contingencies and ketamine administration

    Directory of Open Access Journals (Sweden)

    Dara L Sosulski

    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.

  15. Note: Fabrication of a fast-response and user-friendly environmental chamber for atomic force microscopes

    Science.gov (United States)

    Ji, Yanfeng; Hui, Fei; Shi, Yuanyuan; Han, Tingting; Song, Xiaoxue; Pan, Chengbin; Lanza, Mario

    2015-10-01

    The atomic force microscope is one of the most widespread tools in science, but many suppliers do not provide a competitive solution to make experiments in controlled atmospheres. Here, we provide a solution to this problem by fabricating a fast-response and user-friendly environmental chamber. We corroborate the correct functioning of the chamber by studying the formation of local anodic oxidation on a silicon sample (biased under opposite polarities), an effect that can be suppressed by measuring in a dry nitrogen atmosphere. The usefulness of this chamber goes beyond the example here presented, and it could be used in many other fields of science, including physics, mechanics, microelectronics, nanotechnology, medicine, and biology.

  16. Computation Offloading for Frame-Based Real-Time Tasks under Given Server Response Time Guarantees

    Directory of Open Access Journals (Sweden)

    Anas S. M. Toma

    2014-11-01

    Full Text Available Computation offloading has been adopted to improve the performance of embedded systems by offloading the computation of some tasks, especially computation-intensive tasks, to servers or clouds. This paper explores computation offloading for real-time tasks in embedded systems, provided given response time guarantees from the servers, to decide which tasks should be offloaded to get the results in time. We consider frame-based real-time tasks with the same period and relative deadline. When the execution order of the tasks is given, the problem can be solved in linear time. However, when the execution order is not specified, we prove that the problem is NP-complete. We develop a pseudo-polynomial-time algorithm for deriving feasible schedules, if they exist.  An approximation scheme is also developed to trade the error made from the algorithm and the complexity. Our algorithms are extended to minimize the period/relative deadline of the tasks for performance maximization. The algorithms are evaluated with a case study for a surveillance system and synthesized benchmarks.

  17. Fast time resolved measurements of the EEDF (Electron Energy Distribution Function) in a helicon wave plasma

    International Nuclear Information System (INIS)

    One of the biggest problems encountered when using electric probe diagnostics in RF plasmas is the high frequency fluctuation of the plasma potential. This fluctuation makes the probe sheath voltage drop an unknown quantity and in general makes the analysis of the probe characteristic impossible. In addition, the entire integrated volume of the fluctuating sheath will add displacement current to the probe signal, causing further distortion. In the past, the authors have used high impedance mini-inductors built into the probe tip to reduce the RF sheath voltage drop. This scheme is easy to implement but has two major drawbacks: (1) the effectiveness of this filtering method requires a low ratio of sheath to circuit impedance, which limits the range of plasma parameters over which the probe is reliable, and (2) this method cannot measure fast variations of the EEDF, which have been inferred from fast fluctuations of the plasma optical emission. For these reasons, they have used a gridded energy analyzer with a 250-MHz digitizing oscilloscope to measure the instantaneous electron current over an entire RF period. Each signal can be recorded, and by varying the DC grid bias the current-voltage characteristic can be constructed at any phase of the RF cycle. Special considerations in the analyzer design, measured EEDFs under various discharge conditions, and comparison with results from RF-compensated Langmuir probes will be discusseded

  18. 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.

  19. 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

  20. The variability of the incremental postprandial portal vein flow response is partly caused by a relationship between fasting flow rate and phase activity of the migrating motor complex

    DEFF Research Database (Denmark)

    Rasmussen, L; Mortensen, M B

    1999-01-01

    OBJECTIVE: Results from studies on portal flow rate (PFR) have demonstrated a considerable intra- as well as interindividual variability of the incremental integrated response (IIR). We hypothesized that part of the variation of the IIR might be related to variability of the fasting PFR caused by a relationship between PFR and characteristics of the migrating motor complex (MMC). DESIGN: We examined 12 healthy men and PFR was recorded by using the percutaneous colour Doppler technique. Gastric emptying (GE) was determined by scintigraphy and the meal consisted of an omelette of 100 g (1400 kJ; 60% fat, 20% protein, 20% carbohydrates) tagged with 99mTc sulphur colloids followed by 150 ml water mixed with 111In DTPA. The design included recording of PFR in phase II as well as in phase III of the MMC. Meal ingestion took place in the following duodenal phase I. Postprandial recordings of GE and PFR were performed at 10 min intervals for the following 2 h. RESULTS: Median (95% confidence limits) amount of solid emptied at 120 min was 68% (59-81%). PFR in phase III was significantly higher than in phase II (1.56 l/min (1.35-1.93 l/min) vs 0.96 l/min (0.84-1.12 l/min), P< 0.001). PFR increased after the meal and a peak flow of 2.19 l/min (1.58-2.46 I/min) was recorded 10 min after ingestion (P< 0.01 vs phase III). Based on these characteristics a difference in IIR is to be expected, and the calculations revealed that IIR is considerably higher in the phase II series than in the phase III series (50 l/min x 120 min (8-90 l/min) vs -26 l/min x 120 min (-55 to 1 l/min), P< 0.001). In both series a weak but significant inverse relationship was demonstrated between amounts emptied during a 20-min period and the corresponding IIR (n = 72; r = -0.27, P< 0.05 (III); r = -0.29; P< 0.05 (II)). CONCLUSION: We conclude that fasting PFR is related to phase activity of the MMC and characteristics of the postprandial IIR depend upon MMC activity at the time of recording of the fasting value. Future studies on PFR need to be performedwith phase related recording of fasting flow and meal ingestion in relation to preselected characteristics of the MMC.

  1. An Analysis of Variance Approach for the Estimation of Response Time Distributions in Tests

    Science.gov (United States)

    Attali, Yigal

    2010-01-01

    Generalizability theory and analysis of variance methods are employed, together with the concept of objective time pressure, to estimate response time distributions and the degree of time pressure in timed tests. By estimating response time variance components due to person, item, and their interaction, and fixed effects due to item types and…

  2. High-speed real-time magnetic resonance imaging of fast tongue movements in elite horn players

    OpenAIRE

    Iltis, Peter W.; Frahm, Jens; Voit, Dirk; Joseph, Arun A.; Schoonderwaldt, Erwin; Altenmüller, Eckart

    2015-01-01

    This paper describes the use of high-speed real-time (RT) magnetic resonance imaging (MRI) in quantifying very rapid motor function within the oropharyngeal cavity of six elite horn players. Based on simultaneous sound recordings, the efficacy of RT-MRI films at 30 and 100 frames per second (fps) was assessed for tongue movements associated with double tonguing performance. Serial images with a nominal temporal resolution of 10.0 and 33.3 ms were obtained by highly undersampled radial fast lo...

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

    Directory of Open Access Journals (Sweden)

    Hideki Taniguchi, Toshio Sasaki, Hisae Fujita

    2012-01-01

    Full Text Available 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.Methods: The patients, who were scheduled to undergo surgery for stomach cancer, were divided into two groups of 15 patients each. Before surgery, patients in the control group were managed with conventional preoperative fasting time, while patients in the “enhanced recovery after surgery (ERAS” group were managed with “shortened preoperative fasting time” and “reduced laxative medication.” TBW was measured on the day before surgery and the day of surgery before entering the operating room. Defecation times and anesthesia-related vomiting and aspiration were monitored.Results: TBW values on the day of surgery showed changes in both groups as compared with those on the day before surgery, but the rate of change was smaller in the ERAS group than in the control group (2.4±6.8% [12 patients] vs. ?10.6±4.6% [14 patients], p<0.001. Defecation times were less in the ERAS group. Vomiting and aspiration were not observed in either group.Conclusion: The results suggest that preoperative management with “shorted preoperative fasting time” and “reduced administration of laxatives” is effective in the maintenance of TBW in elective surgical patients.

  4. Angular response characteristic of pyramid shape fast neutron dosimeter using CR-39 films

    International Nuclear Information System (INIS)

    CR-39 is a highly sensitive etched track detector for neutron monitoring and dosimetry applications but its dose equivalent response is strongly direction dependent with respect to the incident neutrons. This is considered to be a major drawback for their use. In the present study, an attempt has been made to develop a pyramid shaped dosimeter, which consists of polyethylene material of thickness 1 mm with the provision to hold three CR-39 films at an angle of 35 deg. to each other. The response of CR-39 in this configuration under optimum electrochemical etching at elevated temperature have been found nearly angular independent and therefore the dosimeter can be used for neutron monitoring, i.e. personnel as well as area monitoring

  5. Cardio-respiratory responses to moderately heavy aerobic exercise during the Ramadan fasts.

    OpenAIRE

    J. M. Ramadan; M. Barac-Nieto

    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...

  6. Fast construction of the Kohn--Sham response function for molecules

    OpenAIRE

    Koval, Peter; Foerster, Dietrich; Coulaud, Olivier

    2009-01-01

    The use of the LCAO (Linear Combination of Atomic Orbitals) method for excited states involves products of orbitals that are known to be linearly dependent. We identify a basis in the space of orbital products that is local for orbitals of finite support and with a residual error that vanishes exponentially with its dimension. As an application of our previously reported technique we compute the Kohn--Sham density response function $\\chi_{0}$ for a molecule consisting of $N$...

  7. Cross-Polarized Reflected Light Measurement of Fast Optical Responses Associated with Neural Activation

    OpenAIRE

    Yao, Xin-Cheng; Foust, Amanda; Rector, David M; Barrowes, Benjamin; GEORGE, JOHN S.

    2005-01-01

    We developed an optical probe for cross-polarized reflected light measurements and investigated optical signals associated with electrophysiological activation in isolated lobster nerves. The cross-polarized baseline light intensity (structural signal) and the amplitude of the transient response to stimulation (functional signal) measured in reflected mode were dependent on the orientation of the nerve axis relative to the polarization plane of incident light. The maximum structural signal an...

  8. Gamma-ray fast-timing coincidence measurements from the 18O+18O fusion-evaporation reaction using a mixed LaBr3-HPGe array.

    Science.gov (United States)

    Alharbi, T; Mason, P J R; Regan, P H; Podolyák, Zs; M?rginean, N; Nakhostin, M; Bowry, M; Bucurescu, D; C?ta-Danil, G; C?ta-Danil, I; Deleanu, D; Filipescu, D; Glodariu, T; Ghi??, D; M?rginean, R; Mihai, C; Negret, A; Pascu, S; Sava, T; Stroe, L; Suliman, G; Zamfir, N V; Bruce, A M; Rodriguez Triguero, C; Bender, P C; Garg, U; Erduran, M N; Kusoglu, A; Bostan, M; Detistov, P; Alkhomashi, N; Sinha, A K; Chakrabarti, R; Ghugre, S S

    2012-07-01

    We report on a gamma-ray coincidence analysis using a mixed array of hyperpure germanium and cerium-doped lanthanum tri-bromide (LaBr3:Ce) scintillation detectors to study nuclear electromagnetic transition rates in the pico-to-nanosecond time regime in 33,34P and 33S following fusion-evaporation reactions between an 18O beam and an isotopically enriched 18O implanted tantalum target. Energies from decay gamma-rays associated with the reaction residues were measured in event-by-event coincidence mode, with the measured time difference information between the pairs of gamma-rays in each event also recorded using the ultra-fast coincidence timing technique. The experiment used the good full-energy peak resolution of the LaBr3:Ce detectors coupled with their excellent timing responses in order to determine the excited state lifetime associated with the lowest lying, cross-shell, I?=4- "intruder" state previously reported in the N=19 isotone 34P. The extracted lifetime is consistent with a mainly single-particle M2 multipolarity associated with a f7/2?d5/2 single particle transition. PMID:22154387

  9. Real-time Responsiveness for Ethics Oversight During Disaster Research.

    Science.gov (United States)

    Eckenwiler, Lisa; Pringle, John; Boulanger, Renaud; Hunt, Matthew

    2015-11-01

    Disaster research has grown in scope and frequency. Research in the wake of disasters and during humanitarian crises - particularly in resource-poor settings - is likely to raise profound and unique ethical challenges for local communities, crisis responders, researchers, and research ethics committees (RECs). Given the ethical challenges, many have questioned how best to provide research ethics review and oversight. We contribute to the conversation concerning how best to ensure appropriate ethical oversight in disaster research and argue that ethical disaster research requires of researchers and RECs a particular sort of ongoing, critical engagement which may not be warranted in less exceptional research. We present two cases that typify the concerns disaster researchers and RECs may confront, and elaborate upon what this ongoing engagement might look like - how it might be conceptualized and utilized - using the concept of real-time responsiveness (RTR). The central aim of RTR, understood here as both an ethical ideal and practice, is to lessen the potential for research conducted in the wake of disasters to create, perpetuate, or exacerbate vulnerabilities and contribute to injustices suffered by disaster-affected populations. Well cultivated and deployed, we believe that RTR may enhance the moral capacities of researchers and REC members, and RECs as institutions where moral agency is nurtured and sustained. PMID:26481207

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

    OpenAIRE

    DucThuan Vu; Hwang Pyung

    2013-01-01

    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...

  11. Changes across time in the temporal responses of auditory nerve fibers stimulated by electric pulse trains.

    Science.gov (United States)

    Miller, Charles A; Hu, Ning; Zhang, Fawen; Robinson, Barbara K; Abbas, Paul J

    2008-03-01

    Most auditory prostheses use modulated electric pulse trains to excite the auditory nerve. There are, however, scant data regarding the effects of pulse trains on auditory nerve fiber (ANF) responses across the duration of such stimuli. We examined how temporal ANF properties changed with level and pulse rate across 300-ms pulse trains. Four measures were examined: (1) first-spike latency, (2) interspike interval (ISI), (3) vector strength (VS), and (4) Fano factor (FF, an index of the temporal variability of responsiveness). Data were obtained using 250-, 1,000-, and 5,000-pulse/s stimuli. First-spike latency decreased with increasing spike rate, with relatively small decrements observed for 5,000-pulse/s trains, presumably reflecting integration. ISIs to low-rate (250 pulse/s) trains were strongly locked to the stimuli, whereas ISIs evoked with 5,000-pulse/s trains were dominated by refractory and adaptation effects. Across time, VS decreased for low-rate trains but not for 5,000-pulse/s stimuli. At relatively high spike rates (>200 spike/s), VS values for 5,000-pulse/s trains were lower than those obtained with 250-pulse/s stimuli (even after accounting for the smaller periods of the 5,000-pulse/s stimuli), indicating a desynchronizing effect of high-rate stimuli. FF measures also indicated a desynchronizing effect of high-rate trains. Across a wide range of response rates, FF underwent relatively fast increases (i.e., within 100 ms) for 5,000-pulse/s stimuli. With a few exceptions, ISI, VS, and FF measures approached asymptotic values within the 300-ms duration of the low- and high-rate trains. These findings may have implications for designs of cochlear implant stimulus protocols, understanding electrically evoked compound action potentials, and interpretation of neural measures obtained at central nuclei, which depend on understanding the output of the auditory nerve. PMID:18204987

  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. Finite-time rotation number: A fast indicator for chaotic dynamical structures

    Energy Technology Data Exchange (ETDEWEB)

    Szezech, J.D., E-mail: jds98@fisica.ufpr.br [Instituto de Física, Universidade de São Paulo, 5315-970, São Paulo, São Paulo (Brazil); Departamento de Matemática e Estatística, Universidade Estadual de Ponta Grossa, 84033-240, Ponta Grossa, Paraná (Brazil); Schelin, A.B., E-mail: schelin@if.usp.br [Instituto de Física, Universidade de São Paulo, 5315-970, São Paulo, São Paulo (Brazil); Departamento de Física, Universidade Tecnológica Federal do Paraná, 80230-901, Curitiba, Paraná (Brazil); Caldas, I.L., E-mail: ibere@if.usp.br [Instituto de Física, Universidade de São Paulo, 5315-970, São Paulo, São Paulo (Brazil); Lopes, S.R., E-mail: lopes@fisica.ufpr.br [Departamento de Física, Universidade Federal do Paraná, 81531-990, Curitiba, Paraná (Brazil); Morrison, P.J., E-mail: morrison@physics.utexas.edu [Department of Physics, The University of Texas at Austin, Austin, TX 78712 (United States); Viana, R.L., E-mail: rlv640@gmail.com [Departamento de Física, Universidade Federal do Paraná, 81531-990, Curitiba, Paraná (Brazil)

    2013-02-04

    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.

  14. Fast responses of metabolites in Vicia faba L. to moderate NaCl stress.

    Science.gov (United States)

    Geilfus, Christoph-Martin; Niehaus, Karsten; Gödde, Victoria; Hasler, Mario; Zörb, Christian; Gorzolka, Karin; Jezek, Mareike; Senbayram, Mehmet; Ludwig-Müller, Jutta; Mühling, Karl H

    2015-07-01

    Salt stress impairs global agricultural crop production by reducing vegetative growth and yield. Despite this importance, a number of gaps exist in our knowledge about very early metabolic responses that ensue minutes after plants experience salt stress. Surprisingly, this early phase remains almost as a black box. Therefore, systematic studies focussing on very early plant physiological responses to salt stress (in this case NaCl) may enhance our understanding on strategies to develop crop plants with a better performance under saline conditions. In the present study, hydroponically grown Vicia faba L. plants were exposed to 90 min of NaCl stress, whereby every 15 min samples were taken for analyzing short-term physiologic responses. Gas chromatography-mass spectrometry-based metabolite profiles were analysed by calculating a principal component analysis followed by multiple contrast tests. Follow-up experiments were run to analyze downstream effects of the metabolic changes on the physiological level. The novelty of this study is the demonstration of complex stress-induced metabolic changes at the very beginning of a moderate salt stress in V. faba, information that are very scant for this early stage. This study reports for the first that the proline analogue trans-4-hydroxy-L-proline, known to inhibit cell elongation, was increasingly synthesized after NaCl-stress initiation. Leaf metabolites associated with the generation or scavenging of reactive oxygen species (ROS) were affected in leaves that showed a synchronized increase in ROS formation. A reduced glutamine synthetase activity indicated that disturbances in the nitrogen assimilation occur earlier than it was previously thought under salt stress. PMID:25900421

  15. A Study of Improving Response Time Verification Method for Pressure Transmitters

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jungyang; Ha, Jaehong; Jung, Insoo; Jo, Junghee; Kim, Hangbae [Korea Power Engineering Company, Inc., Daejeon (Korea, Republic of)

    2007-10-15

    Technical Specifications (TS) of OPR1000 type nuclear power plants in Korea require pressure sensor response time testing (RTT) to ensure sensor performance per assumption in plant safety analyses. However, the need for pressure sensor response time testing is not clear because the nominal sensor response times are in the order of milliseconds while overall loop response time limits being from several seconds to tens of seconds. Additionally, response time testing does not appear to identify response time degradation or failures. Consequently, the need for this testing has been questioned, and a study to determine if response time testing is necessary to justify the assumptions in plant safety analyses in the United States has been conducted and NRC has approved to remove the test requirements for them. A similar study was conducted for OPR1000 type nuclear power plants and the results are presented here.

  16. A Study of Improving Response Time Verification Method for Pressure Transmitters

    International Nuclear Information System (INIS)

    Technical Specifications (TS) of OPR1000 type nuclear power plants in Korea require pressure sensor response time testing (RTT) to ensure sensor performance per assumption in plant safety analyses. However, the need for pressure sensor response time testing is not clear because the nominal sensor response times are in the order of milliseconds while overall loop response time limits being from several seconds to tens of seconds. Additionally, response time testing does not appear to identify response time degradation or failures. Consequently, the need for this testing has been questioned, and a study to determine if response time testing is necessary to justify the assumptions in plant safety analyses in the United States has been conducted and NRC has approved to remove the test requirements for them. A similar study was conducted for OPR1000 type nuclear power plants and the results are presented here

  17. Improvements in fast-response flood modeling: desktop parallel computing and domain tracking

    Energy Technology Data Exchange (ETDEWEB)

    Judi, David R [Los Alamos National Laboratory; Mcpherson, Timothy N [Los Alamos National Laboratory; Burian, Steven J [UNIV. OF UTAH

    2009-01-01

    It is becoming increasingly important to have the ability to accurately forecast flooding, as flooding accounts for the most losses due to natural disasters in the world and the United States. Flood inundation modeling has been dominated by one-dimensional approaches. These models are computationally efficient and are considered by many engineers to produce reasonably accurate water surface profiles. However, because the profiles estimated in these models must be superimposed on digital elevation data to create a two-dimensional map, the result may be sensitive to the ability of the elevation data to capture relevant features (e.g. dikes/levees, roads, walls, etc...). Moreover, one-dimensional models do not explicitly represent the complex flow processes present in floodplains and urban environments and because two-dimensional models based on the shallow water equations have significantly greater ability to determine flow velocity and direction, the National Research Council (NRC) has recommended that two-dimensional models be used over one-dimensional models for flood inundation studies. This paper has shown that two-dimensional flood modeling computational time can be greatly reduced through the use of Java multithreading on multi-core computers which effectively provides a means for parallel computing on a desktop computer. In addition, this paper has shown that when desktop parallel computing is coupled with a domain tracking algorithm, significant computation time can be eliminated when computations are completed only on inundated cells. The drastic reduction in computational time shown here enhances the ability of two-dimensional flood inundation models to be used as a near-real time flood forecasting tool, engineering, design tool, or planning tool. Perhaps even of greater significance, the reduction in computation time makes the incorporation of risk and uncertainty/ensemble forecasting more feasible for flood inundation modeling (NRC 2000; Sayers et al. 2000).

  18. Fast Monte Carlo Estimation of Timing Yield: Importance Sampling with Stochastic Logical Effort (ISLE)

    CERN Document Server

    Bayrakci, Alp Arslan; Tasiran, Serdar

    2008-01-01

    In the nano era in integrated circuit fabrication technologies, the performance variability due to statistical process and circuit parameter variations is becoming more and more significant. Considerable effort has been expended in the EDA community during the past several years in trying to cope with the so-called statistical timing problem. Most of this effort has been aimed at generalizing the static timing analyzers to the statistical case. In this paper, we take a pragmatic approach in pursuit of making the Monte Carlo method for timing yield estimation practically feasible. The Monte Carlo method is widely used as a golden reference in assessing the accuracy of other timing yield estimation techniques. However, it is generally believed that it can not be used in practice for estimating timing yield as it requires too many costly full circuit simulations for acceptable accuracy. In this paper, we present a novel approach to constructing an improvedMonte Carlo estimator for timing yield which provides the...

  19. Research on a Fast Delivery Production System: Just-in-time production system

    OpenAIRE

    Cai-feng LI

    2009-01-01

    In this paper, we analyzed calling the age to product or service for consumer demand living in the word. We come to a conclusion that speed or time is the key factors for enterpriser for competing intensely. So, the paper proposes JIT system achieve the tasks. Later, we address thoroughly the meaning of Just-in-time production system from speed and time angles and present two goals ultimate goal and the supporting goals implementation successfully. According to goal, this paper analyzed that ...

  20. 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...

  1. Fault Diagnosis of Ball Bearing using Time Domain Analysis and Fast Fourier Transformation

    OpenAIRE

    Pravesh Durkhure*1; , Akhilesh Lodwal*2

    2014-01-01

    In this study Fault diagnosis of Ball bearings is done by statistical analysis under various time domain parameters. The objective of this study is to investigate the correlation between time domain and frequency domain analysis of vibration signature to judge and find the fault in bearing. This is achieved by vibration analysis and investigating different time domain parameter like Kurtosis, Skewness, Crest factor, RMS Value. For this purpose the bearing is coupled to the mot...

  2. Nanodomain coupling explains Ca2+ independence of transmitter release time course at a fast central synapse

    OpenAIRE

    Arai, Itaru; Jonas, Peter

    2014-01-01

    A puzzling property of synaptic transmission, originally established at the neuromuscular junction, is that the time course of transmitter release is independent of the extracellular Ca2+ concentration ([Ca2+]o), whereas the rate of release is highly [Ca2+]o-dependent. Here, we examine the time course of release at inhibitory basket cell-Purkinje cell synapses and show that it is independent of [Ca2+]o. Modeling of Ca2+-dependent transmitter release suggests that the invariant time course of ...

  3. Effect of flow rate, excitation level and solids content on the time response in an electro-rheological valve

    Science.gov (United States)

    Peel, D. J.; Bullough, W. A.

    1993-01-01

    Diverse regimes of the fast time response of an electro-rheological fluid are identified in a presentation of experimental results which show the effects of the application of step and dc based sine wave excitations to a series of set flows in one valve. The form of pressure response is complex and depends to some extent on the rate of flow and applied electric field magnitude. Some frequency domain behavior is related to the step wave performance. Apart from their value as a foundation study for a new area of rheology, the results are important to the rapidly developing subject of flexibly operated smart machines and an aid in target setting to developers of the hydraulic semi-conductors on which some of them are based.

  4. Time Evolution of Climate Response to Supervolcano Eruption

    Science.gov (United States)

    Stenchikov, G. L.

    2011-12-01

    A supervolcano could inject into the stratosphere enormous amount of SO2, in comparison with the recent historic eruptions, and therefore it is expected to produce strong reduction of the surface air temperature globally. However the climate response to stratospheric super-injections of sulfur-containing gases might not scale linearly with respect to the effects of moderate eruptions of the historic period. Here we find that, counter-intuitively, very large volcanic eruptions might cause climate warming, at least for a prolonged initial period after an eruption. Supervolcano eruptions like the Toba eruption 75,000 years ago have injected into the atmosphere hundreds of times more SO2 than the largest volcanic eruptions of the 20th century. The huge mass of sulfur from a Toba-size eruption could potentially produce a sulfate aerosol layer with optical depth of more than 40. However, the gas-to-particle conversion process might be effectively slowed down because SO2 and an initially formed relatively thin aerosol layer will absorb and reflect UV radiation, reducing actinic fluxes and OH production to almost zero within and below the SO2 layer. Therefore SO2 would not be quickly converted to sulfate aerosols, but would stay in the stratosphere for years. Because SO2, like ozone, is a strong greenhouse gas it would cause significant IR warming for an extended period until it will be converted to sulfate aerosols or removed. We have simulated Toba eruption using the NASA GISS ModelE, and find that coupled climate model results and available proxy data support this hypothesis.

  5. 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.

  6. Antiferroelectric Thin-Film Capacitors with High Energy-Storage Densities, Low Energy Losses, and Fast Discharge Times.

    Science.gov (United States)

    Ahn, Chang Won; Amarsanaa, Gantsooj; Won, Sung Sik; Chae, Song A; Lee, Dae Su; Kim, Ill Won

    2015-12-01

    We demonstrate a capacitor with high energy densities, low energy losses, fast discharge times, and high temperature stabilities, based on Pb0.97Y0.02[(Zr0.6Sn0.4)0.925Ti0.075]O3 (PYZST) antiferroelectric thin-films. PYZST thin-films exhibited a high recoverable energy density of Ureco = 21.0 J/cm(3) with a high energy-storage efficiency of ? = 91.9% under an electric field of 1300 kV/cm, providing faster microsecond discharge times than those of commercial polypropylene capacitors. Moreover, PYZST thin-films exhibited high temperature stabilities with regard to their energy-storage properties over temperatures ranging from room temperature to 100 °C and also exhibited strong charge-discharge fatigue endurance up to 1 × 10(7) cycles. PMID:26606502

  7. 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°.

  8. 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

  9. 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

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

    OpenAIRE

    V. Wolff; Freibauer, A.; Ammann, C.; C. Brümmer; Marx, O.

    2012-01-01

    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...

  12. 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.

  13. Modeling an Application's Theoretical Minimum and Average Transactional Response Times

    Energy Technology Data Exchange (ETDEWEB)

    Paiz, Mary Rose [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    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.

  14. [Alteration of neural oscillations in hippocampal CA3 area in the fast avoidance response rat before and after electric shock avoidance training].

    Science.gov (United States)

    Wang, Wei-Wei; Wang, Dan-Dan; Wang, Dan; Guan, Yan; Tang, Ying-Ying; Ye, Zheng; Li, Jing; Li, Min; Zhu, Zai-Man; Pan, Qun-Wan

    2015-10-25

    The purpose of the present study is to explore the relationship of spatial learning ability and specific electrical activities of neural oscillations in the rat. The fast and general avoidance response groups were selected on the basis of the animals' responses to the electric shock in Y type maze, and their local field potentials (LFPs) of hippocampal CA3 area were recorded by wireless telemetry before and after shock avoidance training, respectively. The components of neural oscillations related to spatial identifying and learning ability were analyzed. The results showed that, compared with the general avoidance response group, the fast avoidance response group did not show any differences of LFPs in hippocampal CA3 area before electric shock avoidance trial, but showed significantly increased percentages of 0-10 Hz and 30-40 Hz rhythm in right hippocampal CA3 area after the shock avoidance training (P general avoidance response rats were significantly reduced after training (P < 0.01). These results suggest that the increased percentages of ?2 and ?1 rhythm and high-level (unchanged) percentage of ? rhythm in the right hippocampus CA3 area might be related to strong spatial cognition ability of fast avoidance response rats. PMID:26490066

  15. Investigation of the CLEAN deconvolution method for use with Late Time Response analysis of multiple objects

    Science.gov (United States)

    Hutchinson, Simon; Taylor, Christopher T.; Fernando, Michael; Andrews, David; Bowring, Nicholas

    2014-10-01

    This paper investigates the application of the CLEAN non-linear deconvolution method to Late Time Response (LTR) analysis for detecting multiple objects in Concealed Threat Detection (CTD). When an Ultra-Wide Band (UWB) frequency radar signal is used to illuminate a conductive target, surface currents are induced upon the object which in turn give rise to LTR signals. These signals are re-radiated from the target and the results from a number of targets are presented. The experiment was performed using double ridged horn antenna in a pseudo-monostatic arrangement. A Vector network analyser (VNA) has been used to provide the UWB Frequency Modulated Continuous Wave (FMCW) radar signal. The distance between the transmitting antenna and the target objects has been kept at 1 metre for all the experiments performed and the power level at the VNA was set to 0dBm. The targets in the experimental setup are suspended in air in a laboratory environment. Matlab has been used in post processing to perform linear and non-linear deconvolution of the signal. The Wiener filter, Fast Fourier Transform (FFT) and Continuous Wavelet Transform (CWT) are used to process the return signals and extract the LTR features from the noise clutter. A Generalized Pencil-of-Function (GPOF) method was then used to extract the complex poles of the signal. Artificial Neural Networks (ANN) and Linear Discriminant Analysis (LDA) have been used to classify the data.

  16. Fast neutron response of TLD-300 in tissue-equivalent phantoms

    International Nuclear Information System (INIS)

    Simultaneous measurements of the neutron and photon dose using thermoluminescence detectors of the type TLD-300 by means of the two main glow peaks reveal an inconsistency in the determination of the response coefficients in the radiation field of a 14.1 MeV therapy unit. Evaluations of the neutron sensitivity relative to that for photons results in a systematic variation with the depth in the phantom. This variation can be reproduced in a first approximation by a modified method of linear regression, if in addition to the primary 14.1 MeV neutron component a second one from scattered neutrons of approximately half of this energy is assumed. The observed inconsistency can be attributed to the variation of the neutron spectrum with the position in the phantom and is essentially suppressed by using 1.5 mm thick Teflon instead of A-150 as encapsulating material for TLD-300. In consequence, the photon sensitivities hi for both glow peaks turn out to be 1.0 and the two neutron sensitivities ki in A-150 material are independent of the position in the phantom. (Author)

  17. A new global robust stability criteria for uncertain neural networks with fast time-varying delays

    International Nuclear Information System (INIS)

    This paper deals with the problem of robust stability for uncertain neural networks with time-varying delays. The system possesses time-varying and norm-bounded uncertainties. The time-varying delay function in this paper is not required to be either continuously differentiable, or its derivative less than one. Based on Lyapunov-Krasovskii functional approach, new delay-dependent and delay-derivative-dependent stability criteria are presented, which are given in terms of linear matrix inequalities (LMIs). Numerical examples are given to illustrate the effectiveness and less conservativeness of the developed techniques

  18. 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.

  19. A fast transient response low dropout regulator with current control methodology

    Energy Technology Data Exchange (ETDEWEB)

    Ma Zhuo; Guo Yang; Duan Zhikui; Xie Lunguo; Chen Jihua; Yu Jinshan, E-mail: guoyang@nudt.edu.cn [School of Computer, National University of Defense Technology, Changsha 410073 (China)

    2011-08-15

    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 {mu}F decoupling capacitor, the experimental results based on a 0.13 {mu}m CMOS process show that the output voltage is 1.0 V; when the workload changes from 100 {mu}A to 100 mA transiently, the stable dropout is 4.25 mV, the settling time is 8.2 {mu}s and the undershoot is 5.11 mV; when the workload changes from 100 mA to 100 {mu}A transiently, the stable dropout is 4.25 mV, the settling time is 23.3 {mu}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.

  20. An optrode particle geometry to decrease response time.

    Science.gov (United States)

    Walters, Jamie D; Hall, Elizabeth A H

    2011-11-21

    A hollow 3 ?m sensing microcapsule containing chromoionophores within a 100 nm organosilica shell is reported. This shows a response to an ion step two orders of magnitude faster than 'filled' sensing particles of similar diameter. Incorporation of chromoionophores ETH 5294 and ETH 7061 in the capsule shell is shown with a t(90) response 15 min for filled particles of similar diameters. This ultrafast geometry is also extended to dual ionophore dye incorporation and preliminary exploration of a FRET-based ratiometric method is examined to extend the pH response range, using a single excitation wavelength. PMID:21968523

  1. Carbohydrate-rich breakfast attenuates glycaemic, insulinaemic and ghrelin response to ad libitum lunch relative to morning fasting in lean adults.

    Science.gov (United States)

    Chowdhury, Enhad A; Richardson, Judith D; Tsintzas, Kostas; Thompson, Dylan; Betts, James A

    2015-07-14

    Breakfast omission is associated with obesity and CVD/diabetes, but the acute effects of extended morning fasting upon subsequent energy intake and metabolic/hormonal responses have received less attention. In a randomised cross-over design, thirty-five lean men (n 14) and women (n 21) extended their overnight fast or ingested a typical carbohydrate-rich breakfast in quantities relative to RMR (i.e. 1963 (sd 238) kJ), before an ad libitum lunch 3 h later. Blood samples were obtained hourly throughout the day until 3 h post-lunch, with subjective appetite measures assessed. Lunch intake was greater following extended fasting (640 (sd 1042) kJ, Pbreakfast, with total intake lower than the breakfast trial (3887 (sd 1326) v. 5213 (sd 1590) kJ, Pbreakfast (both Pbreakfast trial, remaining greater than the morning fasting trial throughout the afternoon (all PBreakfast increased some anorectic hormones during the afternoon but paradoxically abolished ghrelin suppression by the second meal. Extending morning fasting until lunch altered subsequent metabolic and hormonal responses but without greater appetite during the afternoon. The present study clarifies the impact of acute breakfast omission and adds novel insights into second-meal metabolism. PMID:26004166

  2. Time-of-flight techniques applied to neutron spectra measurements in fast subcritical assemblies

    International Nuclear Information System (INIS)

    Time-of-flight measurements on Uranium-Graphite assemblies were performed using the BCMN linear accelerator. Methods to provide scalar spectra averaged over a core cell from these experimental results are described

  3. Nanodomain coupling explains Ca²? independence of transmitter release time course at a fast central synapse.

    Science.gov (United States)

    Arai, Itaru; Jonas, Peter

    2014-01-01

    A puzzling property of synaptic transmission, originally established at the neuromuscular junction, is that the time course of transmitter release is independent of the extracellular Ca(2+) concentration ([Ca(2+)]o), whereas the rate of release is highly [Ca(2+)]o-dependent. Here, we examine the time course of release at inhibitory basket cell-Purkinje cell synapses and show that it is independent of [Ca(2+)]o. Modeling of Ca(2+)-dependent transmitter release suggests that the invariant time course of release critically depends on tight coupling between Ca(2+) channels and release sensors. Experiments with exogenous Ca(2+) chelators reveal that channel-sensor coupling at basket cell-Purkinje cell synapses is very tight, with a mean distance of 10-20 nm. Thus, tight channel-sensor coupling provides a mechanistic explanation for the apparent [Ca(2+)]o independence of the time course of release. PMID:25487988

  4. Delaunay Triangulation of Imprecise Points, Preprocess and Actually Get a Fast Query Time

    OpenAIRE

    Devillers, Olivier

    2010-01-01

    We propose a new algorithm to preprocess a set of n disjoint unit disks in O(n log n) expected time, allowing to compute the Delaunay triangulation of a set of n points, one from each disk, in O(n) expected time. Our algorithm has the same asymptotic complexity as previous ones for this problem, but our algorithm is much simpler and it runs faster in practice than a direct computation of the Delaunay triangulation.

  5. Software Refactoring: Solving the Time-Dependent Schrodinger Equation via Fast Fourier Transforms and Parallel Programming

    OpenAIRE

    Jordi Marti; Amani Tahat; Ali Khwaldeh

    2012-01-01

    In this study a multiprocessor C++ message passing interface implementation of a new bit-reversal algorithm to numerically solve the time dependent Schrodinger equation using a spectral method based on Fourier transform was presented. The major issues of parallel computer performance were discussed in terms of efficiency; speed up, cost and fraction of the execution time that could be parallelized. The scalable performance to a very high number of processors was addressed as well as com...

  6. Time evolution of the distribution function of fast neutral beam injected into a plasma

    International Nuclear Information System (INIS)

    We have studied in this paper the time evolution of a neutral beam injected into a plasma. The relaxation time of neutral beam having initially a ?-function shaped distribution function, can be estimated by calculating the eigenvalues of Fokker-Plank Operator (FPO). The coefficients of the FPO for our problem are determined from Rosenbluth potentials. Stationary and nonstationary solutions are found and discussed for the distribution function of neutral test particles. (author). 5 refs

  7. Graphics processing unit accelerated non-uniform fast Fourier transform for ultrahigh-speed, real-time Fourier-domain OCT

    OpenAIRE

    Zhang, Kang; Kang, Jin U

    2010-01-01

    We implemented fast Gaussian gridding (FGG)-based non-uniform fast Fourier transform (NUFFT) on the graphics processing unit (GPU) architecture for ultrahigh-speed, real-time Fourier-domain optical coherence tomography (FD-OCT). The Vandermonde matrix-based non-uniform discrete Fourier transform (NUDFT) as well as the linear/cubic interpolation with fast Fourier transform (InFFT) methods are also implemented on GPU to compare their performance in terms of image quality and processing speed. 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. R&D for a Dedicated Fast Timing Layer in the CMS Endcap Upgrade

    CERN Document Server

    White, Sebastian N

    2014-01-01

    The PhaseII Upgrades of CMS are being planned for the High Luminosity LHC (HL-LHC) era when the mean number of interactions per beam crossing ("in-time pileup") is expected to reach ~140-200. The potential backgrounds arising from mis-associated jets and photon showers, for example, during event reconstruction could be reduced if physics objects are tagged with an "event time". This tag is fully complementary to the "event vertex" which is already commonly used to reduce mis-reconstruction. Since the tracking vertex resolution is typically ~10^{-3} (50 micron/4.8cm) of the rms vertex distribution, whereas only ~10^{-1} (i.e. 20 vs.170 picoseconds (psec)) is demonstrated for timing, it is often assumed that only photon (i.e. EM calorimeter or shower-max) timing is of interest. We show that the optimal solution will likely be a single timing layer which measures both charged particle and photon time (a pre-shower layer).

  11. CauseMap: fast inference of causality from complex time series

    Directory of Open Access Journals (Sweden)

    M. Cyrus Maher

    2015-03-01

    Full Text Available Background. Establishing health-related causal relationships is a central pursuit in biomedical research. Yet, the interdependent non-linearity of biological systems renders causal dynamics laborious and at times impractical to disentangle. This pursuit is further impeded by the dearth of time series that are sufficiently long to observe and understand recurrent patterns of flux. However, as data generation costs plummet and technologies like wearable devices democratize data collection, we anticipate a coming surge in the availability of biomedically-relevant time series data. Given the life-saving potential of these burgeoning resources, it is critical to invest in the development of open source software tools that are capable of drawing meaningful insight from vast amounts of time series data. Results. Here we present CauseMap, the first open source implementation of convergent cross mapping (CCM, a method for establishing causality from long time series data (?25 observations. Compared to existing time series methods, CCM has the advantage of being model-free and robust to unmeasured confounding that could otherwise induce spurious associations. CCM builds on Takens’ Theorem, a well-established result from dynamical systems theory that requires only mild assumptions. This theorem allows us to reconstruct high dimensional system dynamics using a time series of only a single variable. These reconstructions can be thought of as shadows of the true causal system. If reconstructed shadows can predict points from opposing time series, we can infer that the corresponding variables are providing views of the same causal system, and so are causally related. Unlike traditional metrics, this test can establish the directionality of causation, even in the presence of feedback loops. Furthermore, since CCM can extract causal relationships from times series of, e.g., a single individual, it may be a valuable tool to personalized medicine. We implement CCM in Julia, a high-performance programming language designed for facile technical computing. Our software package, CauseMap, is platform-independent and freely available as an official Julia package. Conclusions. CauseMap is an efficient implementation of a state-of-the-art algorithm for detecting causality from time series data. We believe this tool will be a valuable resource for biomedical research and personalized medicine.

  12. Fast detection of Noroviruses using a real-time PCR assay and automated sample preparation

    Directory of Open Access Journals (Sweden)

    Schmid Michael

    2004-06-01

    Full Text Available Abstract Background Noroviruses (NoV have become one of the most commonly reported causative agents of large outbreaks of non-bacterial acute gastroenteritis worldwide as well as sporadic gastroenteritis in the community. Currently, reverse transcriptase polymerase chain reaction (RT-PCR assays have been implemented in NoV diagnosis, but improvements that simplify and standardize sample preparation, amplification, and detection will be further needed. The combination of automated sample preparation and real-time PCR offers such refinements. Methods We have designed a new real-time RT-PCR assay on the LightCycler (LC with SYBR Green detection and melting curve analysis (Tm to detect NoV RNA in patient stool samples. The performance of the real-time PCR assay was compared with that obtained in parallel with a commercially available enzyme immunoassay (ELISA for antigen detection by testing a panel of 52 stool samples. Additionally, in a collaborative study with the Baden-Wuerttemberg State Health office, Stuttgart (Germany the real-time PCR results were blindly assessed using a previously well-established nested PCR (nPCR as the reference method, since PCR-based techniques are now considered as the "gold standard" for NoV detection in stool specimens. Results Analysis of 52 clinical stool samples by real-time PCR yielded results that were consistent with reference nPCR results, while marked differences between the two PCR-based methods and antigen ELISA were observed. Our results indicate that PCR-based procedures are more sensitive and specific than antigen ELISA for detecting NoV in stool specimens. Conclusions The combination of automated sample preparation and real-time PCR provided reliable diagnostic results in less time than conventional RT-PCR assays. These benefits make it a valuable tool for routine laboratory practice especially in terms of rapid and appropriate outbreak-control measures in health-care facilities and other settings.

  13. Fast and Low-Complexity Simulations of the Inquiry Time in Bluetooth

    DEFF Research Database (Denmark)

    Figueiras, Joao; Schwefel, Hans-Peter

    2006-01-01

    The timing behavior of the Inquiry Procedure in Bluetooth is relevant for several important functionalities, in particular topology formation and localization. The detailed Inquiry procedure is rather complex and simulation models may become inefficient if they implement the full detailed specification. This paper presents an abstracted model to approximate the distribution of Bluetooth inquiry time for scenarios in which multiple Bluetooth nodes perform the inquiry procedure. The abstracted model leads to a simple algorithm which can be used in simulation models to generate samples from that distribution. The evaluation of the algorithm shows that it is faster as compared to a full implementation of the inquiry procedure, while it accurately approximates the inquiry time.

  14. Development and Simulation Assessment of Semiconductor Production System Enhancements for Fast Cycle Times

    OpenAIRE

    Stubbe, Kilian

    2010-01-01

    Long cycle times in semiconductor manufacturing represent an increasing challenge for the industry and lead to a growing need of break-through approaches to reduce it. Small lot sizes and the conversion of batch processes to mini-batch or single-wafer processes are widely regarded as a promising means for a step-wise cycle time reduction. Our analysis with discrete-event simulation and queueing theory shows that small lot size and the replacement of batch tools with mini-batch or single wafer...

  15. R&D for a Dedicated Fast Timing Layer in the CMS Endcap Upgrade

    OpenAIRE

    White, Sebastian N.

    2014-01-01

    The PhaseII Upgrades of CMS are being planned for the High Luminosity LHC (HL-LHC) era when the mean number of interactions per beam crossing ("in-time pileup") is expected to reach ~140-200. The potential backgrounds arising from mis-associated jets and photon showers, for example, during event reconstruction could be reduced if physics objects are tagged with an "event time". This tag is fully complementary to the "event vertex" which is already commonly used to reduce mis...

  16. Practical and fast quantum random number generation based on photon arrival time relative to external reference

    International Nuclear Information System (INIS)

    We present a practical high-speed quantum random number generator, where the timing of single-photon detection relative to an external time reference is measured as the raw data. The bias of the raw data can be substantially reduced compared with the previous realizations. The raw random bit rate of our generator can reach 109 Mbps. We develop a model for the generator and evaluate the min-entropy of the raw data. Toeplitz matrix hashing is applied for randomness extraction, after which the final random bits are able to pass the standard randomness tests

  17. Enhanced performance of fast-response 3-hole wedge probes for transonic flows in axial turbomachinery

    Energy Technology Data Exchange (ETDEWEB)

    Delhaye, D.; Paniagua, G. [von Karman Institute for Fluid Dynamics, Turbomachinery and Propulsion Department, Rhode-Saint-Genese (Belgium); Fernandez Oro, J.M. [Universidad de Oviedo, Area de Mecanica de Fluidos, Gijon (Spain); Denos, R. [European Commission, Directorate General for Research, Brussels (Belgium)

    2011-01-15

    The paper presents the development and application of a three-sensor wedge probe to measure unsteady aerodynamics in a transonic turbine. CFD has been used to perform a detailed uncertainty analysis related to probe-induced perturbations, in particular the separation zones appearing on the wedge apex. The effects of the Reynolds and Mach numbers are studied using both experimental data together with CFD simulations. The angular range of the probe and linearity of the calibration maps are enhanced with a novel zonal calibration technique, used for the first time in compressible flows. The data reduction methodology is explained and demonstrated with measurements performed in a single-stage high-pressure turbine mounted in the compression tube facility of the von Karman Institute. The turbine was operated at subsonic and transonic pressure ratios (2.4 and 5.1) for a Reynolds number of 10{sup 6}, representative of modern engine conditions. Complete maps of the unsteady flow angle and rotor outlet Mach number are documented. These data allow the study of secondary flows and rotor trailing edge shocks. (orig.)

  18. 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...

  19. Molecular-flow time properties of RIB type vapor-transport systems using a fast-valve

    International Nuclear Information System (INIS)

    The advent of the fast-valve device, described previously, permits measurement of molecular-flow times of chemically active or inactive gaseous species through radioactive ion beam (RIB) target–ion–source systems, independent of size, geometry and materials of construction. Thus, decay losses of short-half-life RIBs can be determined for a given target/vapor-transport system in advance of on-line operation, thereby ascertaining the feasibility of the system design for successful processing of a given isotope. In this article, molecular-flow-time theory and experimentally measured molecular-flow time data are given for serial- and parallel-coupled Ta metal RIB vapor-transport systems similar to those used at ISOL based RIB facilities. In addition, the effect of source type on the molecular-flow time properties of a given system is addressed, and a chemical passivation method for negating surface adsorption enthalpies for chemically active gaseous species on Ta surfaces is demonstrated

  20. Molecular-flow time properties of RIB type vapor-transport systems using a fast-valve

    Energy Technology Data Exchange (ETDEWEB)

    Alton, G.D., E-mail: altondgd@aim.com [Oak Ridge National Laboratory, Oak Ridge, TN 37831-6372 (United States); Bilheux, J.-C. [Oak Ridge National Laboratory, Oak Ridge, TN 37831-6372 (United States); Zhang, Y. [Oak Ridge National Laboratory, Oak Ridge, TN 37831-6372 (United States); Michigan State University, East Lansing, MI 48824 (United States); Liu, Y. [Oak Ridge National Laboratory, Oak Ridge, TN 37831-6372 (United States)

    2014-06-01

    The advent of the fast-valve device, described previously, permits measurement of molecular-flow times of chemically active or inactive gaseous species through radioactive ion beam (RIB) target–ion–source systems, independent of size, geometry and materials of construction. Thus, decay losses of short-half-life RIBs can be determined for a given target/vapor-transport system in advance of on-line operation, thereby ascertaining the feasibility of the system design for successful processing of a given isotope. In this article, molecular-flow-time theory and experimentally measured molecular-flow time data are given for serial- and parallel-coupled Ta metal RIB vapor-transport systems similar to those used at ISOL based RIB facilities. In addition, the effect of source type on the molecular-flow time properties of a given system is addressed, and a chemical passivation method for negating surface adsorption enthalpies for chemically active gaseous species on Ta surfaces is demonstrated.