WorldWideScience

Sample records for high amplitude event

  1. Measuring the Energy Release of Low Amplitude Impact of High Explosive Events

    Science.gov (United States)

    Straight, J. W.; Idar, D. J.; Smith, L.; Osborn, M. A.; Viramontes, L. E.; Chavez, P. J.

    2004-07-01

    Predicting the degree of violence of high explosive (HE) reactions for a given event is desirable for risk assessments and a goal for computational models. Historically, different types of low amplitude impact tests on HE specimens have been performed to determine the critical impact-velocity threshold for high explosive violent reactions (HEVR). Additionally, the energy release relative to a steady-state detonation is also desirable for assessing the potential outcome of an accidental event. Traditionally, blast gauge measurements have been used to measure the overpressure of the HEVR event at a defined distance. This paper summarizes the use of this active technique coupled with a passive technique to derive average energy release curves for Modified Steven tests. A classic ballistic pendulum design was employed with the traditional blast gauge method. Calibration of the ballistic pendulum involved three elements. First, two mechanical measurements were related to the actual peak swing of the pendulum. Second, the general nature of the swing versus energy release curve was estimated. Two different approaches were used to estimate the momenta as a function of HE energy release using the Gurney relationships for an unsymmetrical sandwich. Finally, both techniques were simultaneously benchmarked with PBX 9501 calibration charges. Test results demonstrate the utility of using coupled diagnostic methods for low amplitude insult testing. Each set of data was fit to derive a working curve for the determination of the average energy release for HEVR event based on mass relative to a steady-state detonation. These tests results and working curve derivations are presented.

  2. High Amplitude Secondary Mass Drive

    Energy Technology Data Exchange (ETDEWEB)

    DYCK,CHRISTOPHER WILLIAM; ALLEN,JAMES J.; HUBER,ROBERT JOHN; SNIEGOWSKI,JEFFRY J.

    2000-07-06

    In this paper we describe a high amplitude electrostatic drive for surface micromachined mechanical oscillators that may be suitable for vibratory gyroscopes. It is an advanced design of a previously reported dual mass oscillator (Dyck, et. al., 1999). The structure is a 2 degree-of-freedom, parallel-plate driven motion amplifier, termed the secondary mass drive oscillator (SMD oscillator). During each cycle the device contacts the drive plates, generating large electrostatic forces. Peak-to-peak amplitudes of 54 {micro}m have been obtained by operating the structure in air with an applied voltage of 11 V. We describe the structure, present the analysis and design equations, and show recent results that have been obtained, including frequency response data, power dissipation, and out-of- plane motion.

  3. The Amplitude-Duration Relation of Observed El Nifio Events

    Institute of Scientific and Technical Information of China (English)

    Wu Yu-Jie; DUAN Wan-Suo

    2012-01-01

    The authors demonstrate that the E1 Nifio events in the pre- and post-1976 periods show two ampli- tude-duration relations. One is that the stronger E1 Nifio events have longer durations, which is robust for the moderate E1 Nifio events; the other is that the stronger E1 Nifio events have shorter durations but for strong E1 Nifio events. By estimating the sign and amplitude of the nonlinear dynamical heating (NDH) anomalies, the au- thors illustrate that the NDH anomalies are negligible for moderate E1 Nifio events but large for strong E1 Nifio events. In particular, the large NDH anomalies for strong E1 Nifio events are positive during the growth and mature phases, which favor warmer E1 Nifio events. During the decay phase, however, the negative NDH anomalies start to arise and become increasingly significant with the evolution of the E1 Nifio events, in which the negative NDH anomalies dampen the sea surface temperature anomalies (SSTA) and cause the E1 Nifio events to reach the SST normal state earlier. This pattern suggests that the nonlinearity tends to increase the intensities of strong E1 Nifio events and shorten their duration, which, together with the previous results showing a positive correlation between the strength of E1 Nifio events and the signifi- cance of the effect of nonlinear advection on the events (especially the suppression of nonlinearity on the SSTA during the decay phase), shows that the strong E1 Nifio events tend to have the amplitude-duration relation of the stronger E1 Nifio events with shorter durations. This result also lends support to the assertion that moderate E1 Nifio events possess the amplitude-duration relation of stronger E1 Nifio events with longer durations.

  4. Comparing Moment Release and Tremor Amplitudes in Cascadia ETS Events

    Science.gov (United States)

    Hall, K.; Schmidt, D. A.; Houston, H.

    2016-12-01

    A proposed relationship between the moment release of ETS and tremor duration. [Aguiar et al., 2009] compared moment from static inversions of slip with the overall duration of the entire ETS, finding a linear relationship between moment release and tremor duration. There is a logical relationship between the processes that generate slip and those that generate tremor. Spatially, we have seen that slip may occur up-dip of tremor [Houston, 2012] and [Hall and Houston, 2014] in Northern Cascadia. On the other hand, Bartlow et al. [2011] did not resolve a spatio-temporal difference between tremor and slow slip for the 2009 ETS in mid-Cascadia. This raises the possibility that there could be an as-yet-unrecognized regional difference. In order to explore spatio-temporal relationships between tremor and slow slip, I used the Extended Network Inversion Filter (ENIF) [Segall and Matthews, 1997] together with PNSN tremor locations. Preliminary results for the 2010 ETS event yield a M6.8 event that begins near Seattle on August 8th and propagates mainly to the north with some smaller slip to the south, following the propagation of the tremor, a pattern consistent with our static inversion results. The slip-pulse nature of the ETS process is clearly imaged, with some fault patches continuing to slip for several days after tremor has passed through, but not for the entire duration of the event. I then looked at tremor amplitudes [Ulberg and Creager, AGU Abs, 2013], which represent the amount of energy released in a five-minute tremor window. Because the tremor catalog has much finer temporal resolution than the GPS data, I sum the daily tremor amplitudes and compare to daily moment-rates from the time-dependent inversion, obtaining a correlation between moment-rate and tremor amplitude rate. This suggests that the energy released by tremor may be a direct proxy for energy released by slip.

  5. Hydrodynamic flow amplitude correlations in event-by-event fluctuating heavy-ion collisions

    CERN Document Server

    Qian, Jing

    2016-01-01

    The effects of event-by-event fluctuations in the initial geometry of the colliding nuclei are important in the analysis of final flow observables in relativistic heavy-ion collisions. We use hydrodynamic simulations to study the amplitude correlations between different orders of event-by-event fluctuating anisotropic flow harmonics. While the general trends seen in the experimental data are qualitatively reproduced by the model, deviations in detail, in particular for peripheral collisions, point to the need for more elaborate future calculations with a hybrid approach that describes the late hadronic stage of the evolution microscopically. It is demonstrated explicitly that the observed anti-correlation between $v_2$ and $v_3$ is the consequence of approximately linear hydrodynamic response to a similar anti-correlation of the corresponding initial eccentricities $\\epsilon_2$ and $\\epsilon_3$. For $n{\\,>\\,}3$, the hydrodynamic correlations between $v_{2,3}$ and $v_n$ deviate from the rescaled correlations a...

  6. Location of long-period events below Kilauea Volcano using seismic amplitudes and accurate relative relocation

    Science.gov (United States)

    Battaglia, J.; Got, J.-L.; Okubo, P.

    2003-01-01

    We present methods for improving the location of long-period (LP) events, deep and shallow, recorded below Kilauea Volcano by the permanent seismic network. LP events might be of particular interest to understanding eruptive processes as their source mechanism is assumed to directly involve fluid transport. However, it is usually difficult or impossible to locate their source using traditional arrival time methods because of emergent wave arrivals. At Kilauea, similar LP waveform signatures suggest the existence of LP multiplets. The waveform similarity suggests spatially close sources, while catalog solutions using arrival time estimates are widely scattered beneath Kilauea's summit caldera. In order to improve estimates of absolute LP location, we use the distribution of seismic amplitudes corrected for station site effects. The decay of the amplitude as a function of hypocentral distance is used for inferring LP location. In a second stage, we use the similarity of the events to calculate their relative positions. The analysis of the entire LP seismicity recorded between January 1997 and December 1999 suggests that a very large part of the LP event population, both deep and shallow, is generated by a small number of compact sources. Deep events are systematically composed of a weak high-frequency onset followed by a low-frequency wave train. Aligning the low-frequency wave trains does not lead to aligning the onsets indicating the two parts of the signal are dissociated. This observation favors an interpretation in terms of triggering and resonance of a magmatic conduit. Instead of defining fault planes, the precise relocation of similar LP events, based on the alignment of the high-energy low-frequency wave trains, defines limited size volumes. Copyright 2003 by the American Geophysical Union.

  7. Large-amplitude ULF waves at high latitudes

    Science.gov (United States)

    Guido, T.; Tulegenov, B.; Streltsov, A. V.

    2014-11-01

    We present results from the statistical study of ULF waves detected by the fluxgate magnetometer in Gakona, Alaska during several experimental campaigns conducted at the High Frequency Active Auroral Research Program (HAARP) facility in years 2011-2013. We analyzed frequencies of ULF waves recorded during 26 strongly disturbed geomagnetic events (substorms) and compared them with frequencies of ULF waves detected during magnetically quiet times. Our analysis demonstrates that the frequency of the waves carrying most of the power in almost all these events is less than 1 mHz. We also analyzed data from the ACE satellite, measuring parameters of the solar wind in the L1 Lagrangian point between Earth and Sun, and found that in several occasions there is a strong correlation between oscillations of the magnetic field in the solar wind and oscillations detected on the ground. We also found several cases when there is no correlation between signals detected on ACE and on the ground. This finding suggests that these frequencies correspond to the fundamental eigenfrequency of the coupled magnetosphere-ionosphere system, and the amplitude of these waves can reach significant magnitude when the system is driven by the external driver (for example, the solar wind) with this particular frequency. When the frequency of the driver does not match the frequency of the system, the waves still are observed, but their amplitudes are much smaller.

  8. GRMHD simulations of visibility amplitude variability for Event Horizon Telescope images of Sgr A*

    CERN Document Server

    Medeiros, Lia; Ozel, Feryal; Psaltis, Dimitrios; Kim, Junhan; Marrone, Daniel P; Sadowski, Aleksander

    2016-01-01

    Synthesis imaging of the black hole in the center of the Milky Way, Sgr A*, with the Event Horizon Telescope (EHT) rests on the assumption of a stationary image. We explore the limitations of this assumption using high-cadence GRMHD simulations of Sgr A*. We employ analytic models that capture the basic characteristics of the images to understand the origin of the variability in the simulated visibility amplitudes. We find that, in all simulations, the visibility amplitudes for baselines oriented perpendicular to the spin axis of the black hole typically decrease smoothly over baseline lengths that are comparable to those of the EHT. On the other hand, the visibility amplitudes for baselines oriented parallel to the spin axis show significant structure with one or more minima. This suggests that fitting EHT observations with geometric models will lead to reasonably accurate determination of the orientation of the black-hole on the plane of the sky. However, in the disk-dominated models, the locations and dept...

  9. Applicability of P/S amplitude ratios for the discrimination of low magnitude seismic events

    Institute of Scientific and Technical Information of China (English)

    PAN Chang-zhou; JIN Ping; WANG Hong-chun

    2007-01-01

    Applicability of regional P/S amplitude ratios for the discrimination of low-magnitude seismic events was tested and proved using earthquakes and explosions in Central Asia. Results obtained show that regional P/S amplitude ratios which may discriminate medium or large magnitude events well, are also applicable to low magnitude events. Their performances for low magnitude events are almost as good as that for medium or large events. Statistical comparisons based on 25 P/S discriminate from the four seismic stations WMQ, BLK, MUL and MAK showed that the average misclassification rate for low-magnitude seismic events averagely was only 2 percent higher than that for medium and large magnitude seismic events.

  10. Removal of residual nuclei following a cavitation event using low-amplitude ultrasound.

    Science.gov (United States)

    Duryea, Alexander P; Cain, Charles A; Tamaddoni, Hedieh A; Roberts, William W; Hall, Timothy L

    2014-10-01

    Microscopic residual bubble nuclei can persist on the order of 1 s following a cavitation event. These bubbles can limit the efficacy of ultrasound therapies such as shock wave lithotripsy and histotripsy, because they attenuate pulses that arrive subsequent to their formation and seed repetitive cavitation activity at a discrete set of sites (cavitation memory). Here, we explore a strategy for the removal of these residual bubbles following a cavitation event, using low-amplitude ultrasound pulses to stimulate bubble coalescence. All experiments were conducted in degassed water and monitored using high-speed photography. In each case, a 2-MHz histotripsy transducer was used to initiate cavitation activity (a cavitational bubble cloud), the collapse of which generated a population of residual bubble nuclei. This residual nuclei population was then sonicated using a 1 ms pulse from a separate 500-kHz transducer, which we term the bubble removal pulse. Bubble removal pulse amplitudes ranging from 0 to 1.7 MPa were tested, and the backlit area of shadow from bubbles remaining in the field following bubble removal was calculated to quantify efficacy. It was found that an ideal amplitude range exists (roughly 180 to 570 kPa) in which bubble removal pulses stimulate the aggregation and subsequent coalescence of residual bubble nuclei, effectively removing them from the field. Further optimization of bubble removal pulse sequences stands to provide an adjunct to cavitation-based ultrasound therapies such as shock wave lithotripsy and histotripsy, mitigating the effects of residual bubble nuclei that currently limit their efficacy.

  11. High Frequency Amplitude Detector for GMI Magnetic Sensors

    Directory of Open Access Journals (Sweden)

    Aktham Asfour

    2014-12-01

    Full Text Available A new concept of a high-frequency amplitude detector and demodulator for Giant-Magneto-Impedance (GMI sensors is presented. This concept combines a half wave rectifier, with outstanding capabilities and high speed, and a feedback approach that ensures the amplitude detection with easily adjustable gain. The developed detector is capable of measuring high-frequency and very low amplitude signals without the use of diode-based active rectifiers or analog multipliers. The performances of this detector are addressed throughout the paper. The full circuitry of the design is given, together with a comprehensive theoretical study of the concept and experimental validation. The detector has been used for the amplitude measurement of both single frequency and pulsed signals and for the demodulation of amplitude-modulated signals. It has also been successfully integrated in a GMI sensor prototype. Magnetic field and electrical current measurements in open- and closed-loop of this sensor have also been conducted.

  12. Subharmonic and fundamental high amplitude excitation of an axisymmetric jet

    Science.gov (United States)

    Raman, Ganesh; Rice, Edward J.

    1989-01-01

    The effect of simultaneous excitation at the fundamental and subharmonic frequencies on the behavior of a circular jet shear layer is studied. Attention is given to the effect of the initial phase difference, the Strouhal number pair, and amplitudes of the fundamental and subharmonic tones. High-amplitude excitation devices which can provide a wide range of forcing conditions when used in conjunction with equipment that produces complex waveforms are used.

  13. High Amplitude (delta)-Scutis in the Large Magellanic Cloud

    Energy Technology Data Exchange (ETDEWEB)

    Garg, A; Cook, K H; Nikolaev, S; Huber, M E; Rest, A; Becker, A C; Challis, P; Clocchiatti, A; Miknaitis, G; Minniti, D; Morelli, L; Olsen, K; Prieto, J L; Suntzeff, N B; Welch, D L; Wood-Vasey, W M

    2010-01-25

    The authors present 2323 High-Amplitude {delta}-Scutis (HADS) candidates discovered in the Large Magellanic Cloud (LMC) by the SuperMACHO survey (Rest et al. 2005). Frequency analyses of these candidates reveal that several are multimode pulsators, including 119 whose largest amplitude of pulsation is in the fundamental (F) mode and 19 whose largest amplitude of pulsation is in the first overtone (FO) mode. Using Fourier decomposition of the HADS light curves, they find that the period-luminosity (PL) relation defined by the FO pulsators does not show a clear separation from the PL-relation defined by the F pulsators. This differs from other instability strip pulsators such as type c RR Lyrae. They also present evidence for a larger amplitude, subluminous population of HADS similar to that observed in Fornax (Poretti et al. 2008).

  14. High Amplitude \\delta-Scutis in the Large Magellanic Cloud

    CERN Document Server

    Garg, A; Nikolaev, S; Huber, M E; Rest, A; Becker, A C; Challis, P; Clocchiatti, A; Miknaitis, G; Minniti, D; Morelli, L; Olsen, K; Prieto, J L; Suntzeff, N B; Welch, D L; Wood-Vasey, W M

    2010-01-01

    We present 2323 High-Amplitude \\delta-Scuti (HADS) candidates discovered in the Large Magellanic Cloud (LMC) by the SuperMACHO survey (Rest et al. 2005). Frequency analyses of these candidates reveal that several are multimode pulsators, including 119 whose largest amplitude of pulsation is in the fundamental (F) mode and 19 whose largest amplitude of pulsation is in the first overtone (FO) mode. Using Fourier decomposition of the HADS light curves, we find that the period-luminosity (PL) relation defined by the FO pulsators does not show a clear separation from the PL-relation defined by the F pulsators. This differs from other instability strip pulsators such as type c RR Lyrae. We also present evidence for a larger amplitude, subluminous population of HADS similar to that observed in Fornax (Poretti et al. 2008).

  15. Characterization of a subset of large amplitude noise events in VIRGO science run 1 (VSR1)

    Science.gov (United States)

    Del Prete, M.; Virgo Collaboration; LSC Collaboration

    2009-10-01

    We report about a characterization study of a subset of large amplitude noise events present in the main data channel of the VIRGO detector. The main motivation of this study is the identification of auxiliary channels which can be used to define veto procedures. We characterized large amplitude events both in the time and in the frequency domain. We found evidence of coincidences among these and disturbances detected by magnetometer's sensors or inside the main power supply. In some cases the disturbances were produced by events in the VIRGO environment such as lightnings, main power supply glitches and airplane traffic. We have found two auxiliary channels that can be used to veto events generated by main power supply glitches or lightnings. A procedure to clean the main channel based on them has been successfully tested. We have also identified two auxiliary channels which are useful for the identification of events generated by airplane traffic. These can be used to implement a vetoing procedure both in the time and in the frequency domain.

  16. Radial convection of finite ion temperature, high amplitude plasma blobs

    DEFF Research Database (Denmark)

    Wiesenberger, M.; Madsen, Jens; Kendl, Alexander

    2014-01-01

    We present results from simulations of seeded blob convection in the scrape-off-layer of magnetically confined fusion plasmas. We consistently incorporate high fluctuation amplitude levels and finite Larmor radius (FLR) effects using a fully nonlinear global gyrofluid model. This is in line...... with conditions found in tokamak scrape-off-layers (SOL) regions. Varying the ion temperature, the initial blob width, and the initial amplitude, we found an FLR dominated regime where the blob behavior is significantly different from what is predicted by cold-ion models. The transition to this regime is very...

  17. Simulation of transients of high amplitude in pipe systems

    NARCIS (Netherlands)

    Boersma, J.M.; Looijmans, K.N.H.

    1999-01-01

    Fast high-amplitude transients ask for a non-linear modelling approach in which large density variations and heat exchange can be considered. Operation of safety-valves, relief valves, the occurrence of valve failure and the start-up or shutdown of rotating equipment in industrial pipe systems can l

  18. Radial convection of finite ion temperature, high amplitude plasma blobs

    CERN Document Server

    Wiesenberger, M; Kendl, A

    2014-01-01

    We present results from simulations of seeded blob convection in the scrape-off-layer of magnetically confined fusion plasmas. We consistently incorporate high fluctuation amplitude levels and finite Larmor radius (FLR) effects using a fully nonlinear global gyrofluid model. This is in line with conditions found in tokamak scrape-off-layers (SOL) regions. Varying the ion temperature, the initial blob width and the initial amplitude, we found an FLR dominated regime where the blob behavior is significantly different from what is predicted by cold-ion models. The transition to this regime is very well described by the ratio of the ion gyroradius to the characteristic gradient scale length of the blob. We compare the global gyrofluid model with a partly linearized local model. For low ion temperatures we find that simulations of the global model show more coherent blobs with an increased cross-field transport compared to blobs simulated with the local model. The maximal blob amplitude is significantly higher in ...

  19. The Geodetic Matched Filter: Searching for Low Amplitude Slow Slip Events

    Science.gov (United States)

    Rousset, B.; Campillo, M.; Lasserre, C.; Frank, W.; Socquet, A.; Cotte, N.; Walpersdorf, A.; Kostoglodov, V.

    2016-12-01

    Since the discovery of Slow Slip Events (SSEs), many methods have successfully been applied to model obvious transient events in geodetic time series, such as the widely used network strain filter. Independent seismological observations of tremors or low frequency earthquakes (LFEs) are evidences of low amplitude slow deformation but do not always coincide with clear occurrences of transient signals in geodetic time series. One way to discriminate if the slow deformation information is present or not in geodetic data is to use the seismological catalog as a tracker. For example, Frank et. al 2015 used the LFEs bursts timings on the Mexican subduction zone to stack potential slow events included in GPS time series in order to increase the signal to noise ratio. It successfully produced a slow slip like signal corresponding to the average surface motion of all the stacked events. The aim of the present study is to find a way to extract the signal corresponding to slow slips, hidden in the noise of GPS time series, without using information from independent datasets. We take advantage of the Mexican continuous GPS network (40 stations) within Guerrero and Oaxaca regions. We first build templates of transient events by assembling a source function with green functions that link slip on the subduction interface to surface displacement. We then correlate the templates built on the whole interface with the GPS time-series cleaned of co-seismic, post-seismic signals and large SSEs. We apply a weighted stacking, that takes into account the location of GPS stations compared to the sliding patch, on all correlation functions across the GPS network. We perform an analysis on synthetic time series, where we add transients signals to noise enable to set a detection treshold. Applied on the same period of time as the one analyzed by Frank et al. 2015, this technique enables us to (i) detect in time the events corresponding to bursts of LFEs and (ii) locate and characterize the

  20. Frequencies and amplitudes of high-degree solar oscillations

    Science.gov (United States)

    Kaufman, James Morris

    Measurements of some of the properties of high-degree solar p- and f-mode oscillations are presented. Using high-resolution velocity images from Big Bear Solar Observatory, we have measured mode frequencies, which provide information about the composition and internal structure of the Sun, and mode velocity amplitudes (corrected for the effects of atmospheric seeing), which tell us about the oscillation excitation and damping mechanisms. We present a new and more accurate table of the Sun's acoustic vibration frequencies, nunl, as a function of radial order n and spherical harmonic degree l. These frequencies are averages over azimuthal order m and approximate the normal mode frequencies of a nonrotating spherically symmetric Sun near solar minimum. The frequencies presented here are for solar p- and f-modes with 180 less than or = l less than or = 1920, 0 less than or = n less than or = 8, and 1.7 mHz less than or = nunl less than or = 5.3 mHz. The uncertainties, sigmanl, in the frequencies areas are as low as 3.1 micro-Hz. The theoretically expected f-mode frequencies are given by omega squared = gkh approx. = gl/R, where g is the gravitational acceleration at the surface, kh is the horizontal component of the wave vector, and R is the radius of the Sun. We find that the observed frequencies are significantly less than expected for l greater than 1000, for which we have no explanation. Observations of high-degree oscillations, which have very small spatial features, suffer from the effects of atmospheric image blurring and image motion (or 'seeing'), thereby reducing the amplitudes of their spatial-frequency components. In an attempt to correct the velocity amplitudes for these effects, we simultaneously measured the atmospheric modulation transfer function (MTF) by looking at the effects of seeing on the solar limb. We are able to correct the velocity amplitudes using the MTF out to l approx. = 1200. We find that the frequency of the peak velocity power (as a

  1. Injection coupling with high amplitude transverse modes: Experimentation and simulation

    Science.gov (United States)

    Mery, Yoann; Ducruix, Sébastien; Scouflaire, Philippe; Candel, Sébastien

    2009-06-01

    High frequency combustion instabilities have technical importance in the design of liquid rocket engines. These phenomena involve a strong coupling between transverse acoustic modes and combustion. They are currently being investigated by combining experimentation and numerical simulations. On the experimental level, the coupling is examined in a model scale system featuring a multiple injector combustor (MIC) comprising five coaxial injectors fed with liquid oxygen and gaseous methane. This system is equipped with a novel VHAM actuator (Very High Amplitude Modulator) which comprises two nozzles and a rotating toothed wheel blocking the nozzles in an alternate fashion. This device was designed to obtain the highest possible levels of transverse oscillation in the MIC. After a brief review of the VHAM, this article reports cold flow experiments using this modulator. Velocity maps obtained under resonant conditions using the VHAM are examined at different instants during a cycle of oscillation. Experimental data are compared with numerical pressure and velocity fields obtained from an acoustic solver. The good agreement observed in the nozzle vicinity indicates that numerical simulations can be used to analyze the complex flow field generated by the VHAM. To cite this article: Y. Mery et al., C. R. Mecanique 337 (2009).

  2. High Amplitude (delta)-Scutis in the Large Magellanic Cloud

    National Research Council Canada - National Science Library

    Garg, A; Cook, K H; Nikolaev, S; Huber, M E; Rest, A; Becker, A C; Challis, P; Clocchiatti, A; Miknaitis, G; Minniti, D; Morelli, L; Olsen, K; Prieto, J L; Suntzeff, N B; Welch, D L; Wood-Vasey, W M

    2010-01-01

    ... (LMC) by the SuperMACHO survey (Rest et al. 2005). Frequency analyses of these candidates reveal that several are multimode pulsators, including 119 whose largest amplitude of pulsation is in the fundamental (F...

  3. The High Amplitude delta Scuti Star AD Canis Minoris

    Science.gov (United States)

    Axelsen, R. A.; Napier-Munn, T.

    2016-12-01

    The high amplitude delta Scuti star AD Canis Minoris was studied by photoelectric photometry (PEP) during one night in in February 2011 and by digital single lens reflex (DSLR) photometry during seven nights in January and February 2016. Nine light curve peaks were captured, eight of them by DSLR photometry. A review of the literature enabled us to tabulate 109 times of maximum since 1959, to which we added 9 times of maximum from our data, thus creating the largest dataset to date for this star. Assuming a linear ephemeris, the period of AD CMi was calculated to be 0.122974511 (+/- 0.000000004) d, almost identical to that quoted in earlier literature. We constructed an observed minus computed (O-C) diagram which exhibited a quasi-sinusoidal shape, and fitted a weighted model characterised by combined quadratic and trigonometric functions. The fit indicates that the shape of the O-C diagram is attributable to the effects of a slow increase in the pulsation period of AD CMi at a constant rate, and the light time effect of a binary pair, confirming the results from previous authors, and updating most of the coefficients of the equation for the fitted model. The values of all of the coefficients in the function are statistically significant. The rate of increase in the pulsation period of AD CMi was calculated from the entire dataset to be dP/dt = 6.17 (+/- 0.75) x 10-9 d yr-1 or dP/Pdt = 5.01 (+/- 0.61) x 10-8 yr-1.

  4. A study of daily variation in cosmic ray intensity during high/low amplitude days

    Indian Academy of Sciences (India)

    Rajesh K Mishra; Rekha Agarwal Mishra

    2007-03-01

    A detailed study has been conducted on the long-term changes in the diurnal, semi-diurnal and tri-diurnal anisotropies of cosmic rays in terms of the high/low amplitude anisotropic wave train events (HAE/LAE) during the period 1981-94 using the neutron monitor data from Deep River Neutron Monitoring Station. In all, 38 HAE and 28 LAE cases have been studied. An inter-comparison of the first three harmonics during these events has been made so as to understand the basic reason for the occurrence of these types of events. It has been observed that the phase of diurnal anisotropy shifts towards earlier hours for HAEs and it shifts towards earlier hour as compared to 18-h direction for LAEs. For semi-diurnal anisotropy, phase remains statistically the same for both HAE and LAE. In the case of tri-diurnal anisotropy, phase is evenly distributed for both types of events. The interplanetary magnetic field (IMF) and solar wind plasma (SWP) parameters during these events are also investigated. It has also been observed that HAE/LAEs are weakly dependent on high-speed solar wind velocity. The two types of solar wind streams (corotating streams and flare-generated streams) produce significant deviations in cosmic ray intensity during HAE/LAE.

  5. Role of the Ionosphere in the Generation of Large-Amplitude Ulf Waves at High Latitudes

    Science.gov (United States)

    Tulegenov, B.; Guido, T.; Streltsov, A. V.

    2014-12-01

    We present results from the statistical study of ULF waves detected by the fluxgate magnetometer in Gakona, Alaska during several experimental campaigns conducted at the High Frequency Active Auroral Research Program (HAARP) facility in years 2011-2013. We analyzed frequencies of ULF waves recorded during 26 strongly disturbed geomagnetic events (substorms) and compared them with frequencies of ULF waves detected during magnetically quite times. Our analysis demonstrates that the frequency of the waves carrying most of the power almost in all these events is less than 1 mHz. We also analyzed data from the ACE satellite, measuring parameters of the solar wind in the L1 Lagrangian point between Earth and Sun, and found that in several occasions there is a strong correlation between oscillations of the magnetic field in the solar wind and oscillations detected on the ground. We also found several cases when there is no correlation between signals detected on ACE and on the ground. This finding suggests that these frequencies correspond to the fundamental eigenfrequency of the coupled magnetosphere-ionosphere system. The low frequency of the oscillations is explained by the effect of the ionosphere, where the current is carried by ions through highly collisional media. The amplitude of these waves can reach significant magnitude when the system is driven by the external driver (for example, the solar wind) with this particular frequency. When the frequency of the driver does not match the frequency of the system, the waves still are observed, but their amplitudes are much smaller.

  6. Facilitation of epileptic activity during sleep is mediated by high amplitude slow waves.

    Science.gov (United States)

    Frauscher, Birgit; von Ellenrieder, Nicolás; Ferrari-Marinho, Taissa; Avoli, Massimo; Dubeau, François; Gotman, Jean

    2015-06-01

    Epileptic discharges in focal epilepsy are frequently activated during non-rapid eye movement sleep. Sleep slow waves are present during this stage and have been shown to include a deactivated ('down', hyperpolarized) and an activated state ('up', depolarized). The 'up' state enhances physiological rhythms, and we hypothesize that sleep slow waves and particularly the 'up' state are the specific components of non-rapid eye movement sleep that mediate the activation of epileptic activity. We investigated eight patients with pharmaco-resistant focal epilepsies who underwent combined scalp-intracerebral electroencephalography for diagnostic evaluation. We analysed 259 frontal electroencephalographic channels, and manually marked 442 epileptic spikes and 8487 high frequency oscillations during high amplitude widespread slow waves, and during matched control segments with low amplitude widespread slow waves, non-widespread slow waves or no slow waves selected during the same sleep stages (total duration of slow wave and control segments: 49 min each). During the slow waves, spikes and high frequency oscillations were more frequent than during control segments (79% of spikes during slow waves and 65% of high frequency oscillations, both P ∼ 0). The spike and high frequency oscillation density also increased for higher amplitude slow waves. We compared the density of spikes and high frequency oscillations between the 'up' and 'down' states. Spike and high frequency oscillation density was highest during the transition from the 'up' to the 'down' state. Interestingly, high frequency oscillations in channels with normal activity expressed a different peak at the transition from the 'down' to the 'up' state. These results show that the apparent activation of epileptic discharges by non-rapid eye movement sleep is not a state-dependent phenomenon but is predominantly associated with specific events, the high amplitude widespread slow waves that are frequent, but not

  7. Interpretation of seismic section by acoustic modeling. Study of large amplitude events; Hadoba modeling ni yoru jishin tansa danmen no kaishaku. Kyoshinhaba event ni taisuru kosatsu

    Energy Technology Data Exchange (ETDEWEB)

    Tamagawa, T.; Matsuoka, T.; Sato, T. [Japan Petroleum Exploration Corp., Tokyo (Japan); Minegishi, M.; Tsuru, T. [Japan National Oil Corp., Tokyo (Japan)

    1996-05-01

    A large amplitude event difficult to interpret was discovered in the overlap section in offset data beyond 10km targeting at deep structures, and the event was examined. A wave field modeling was carried out by use of a simplified synclinal structure model because it had been estimated that the large amplitude event had something to do with a synclinal structure. A pseudospectral program was used for modeling the wave field on the assumption that the synclinal structure model would be an acoustic body and that the surface would contain free boundaries and multiple reflection. It was found as the result that a discontinuous large amplitude event is mapped out in the synclinal part of the overlap section when a far trace is applied beyond the structure during a CMP overlap process. This can be attributed to the concentration of energy produced by multiple reflection in the synclinal part and by the reflection waves beyond the critical angle. Accordingly, it is possible that phenomena similar to those encountered in the modeling process are emerging during actual observation. 2 refs., 8 figs.

  8. Characteristics of Electron Distributions Observed During Large Amplitude Whistler Wave Events in the Magnetosphere

    Science.gov (United States)

    Wilson, Lynn B., III

    2010-01-01

    We present a statistical study of the characteristics of electron distributions associated with large amplitude whistler waves inside the terrestrial magnetosphere using waveform capture data as an addition of the study by Kellogg et al., [2010b]. We identified three types of electron distributions observed simultaneously with the whistler waves including beam-like, beam/flattop, and anisotropic distributions. The whistlers exhibited different characteristics dependent upon the observed electron distributions. The majority of the waveforms observed in our study have f/fce or = 8 nT pk-pk) whistler wave measured in the radiation belts. The majority of the largest amplitude whistlers occur during magnetically active periods (AE > 200 nT).

  9. Unusually low-amplitude anisotropic wave-train events of cosmic ray intensity during 1981-1994

    Indian Academy of Sciences (India)

    Rajesh K Mishra; Rekha Agarwal Mishra

    2005-02-01

    Investigation has been made for unusually low-amplitude anisotropic wave train events (LAE) for cosmic ray intensity data of Deep River neutron monitoring station during the period 1981-94. It has been observed that the phase of diurnal anisotropy remains in the same co-rotational direction for most of the LAEs while the phase shifts to early hours for some of the LAEs in diurnal anisotropy. During minimum solar activity, LAEs have been observed to be dominant. Solar wind plasma (SWP) parameters, interplanetary magnetic field and various features at solar disk have also been studied. The amplitude remains low continuously for most of the days while the phase shifts to earlier hours. Occurrence of LAE is independent of the nature of interplanetary magnetic field (IMF).

  10. Research on High Frequency Amplitude Attenuation of Electric Fast Transient Generator

    Directory of Open Access Journals (Sweden)

    Huafu Zhang

    2013-01-01

    Full Text Available In order to solve the amplitude attenuation of electric fast transient (EFT generator operating in high frequency, the charging and discharging process of energy storage capacitor in EFT generator are analyzed, the main circuit voltage variation mathematical model is established, the parameters of main loop circuit and the parameters of switch driving waveform which affect burst amplitude are discussed. Through the simulation, this paper puts forward effective methods to overcome burst amplitude attenuation in high frequency. The simulation results show that when the frequency is low, the duty ratio of drive signal have little effect on energy storage capacitor voltage amplitude attenuation. when the charging resistance is less than 500 Ω, the duty ratio of drive signal is less than 0.125, the repetition frequency of burst reaches 1.2 MHz, the amplitude attenuation of energy storage capacitor voltage is less than 9%, the amplitude of burst satisfies IEC61000-4-4 standards.

  11. DESIGN NOTE: A fast high-voltage pulse generator with variable amplitude and duration

    Science.gov (United States)

    Upadhyay, Jankee; Navathe, C. P.

    2006-07-01

    A high-voltage pulse generator based on a self-matched transmission line with variable pulse amplitude and duration is developed. Two avalanche transistor stacks are used as switches. The pulse width is varied by adjusting the delay in triggering two switches whereas amplitude is adjusted by adjusting load resistance. A pulse with amplitude of 800 V to 3.8 kV and width of 5 ns to 38 ns can be obtained using this circuit.

  12. High amplitude theta wave bursts: a novel electroencephalographic feature of rem sleep and cataplexy.

    Science.gov (United States)

    Lo Martire, Viviana Carmen; Bastianini, Stefano; Berteotti, Chiara; Silvani, Alessandro; Zoccoli, Giovanna

    2015-01-01

    High amplitude theta wave bursts (HATs) were originally described during REMS and cataplexy in ORX-deficient mice as a novel neurophysiological correlate of narcolepsy (Bastianini et al., 2012). This finding was replicated the following year by Vassalli et al. in both ORX-deficient narcoleptic mice and narcoleptic children during cataplexy episodes (Vassalli et al., 2013). The relationship between HATs and narcolepsy-cataplexy in mice and patients indicates that the lack of ORX peptides is responsible for this abnormal EEG activity, the physiological meaning of which is still unknown. This review aimed to explore different phasic EEG events previously described in the published literature in order to find analogies and differences with HATs observed in narcoleptic mice and patients. We found similarities in terms of morphology, frequency and duration between HATs and several physiological (mu and wicket rhythms, sleep spindles, saw-tooth waves) or pathological (SWDs, HVSs, bursts of polyphasic complexes EEG complexes reported in a mouse model of CJD, and BSEs) EEG events. However, each of these events also shows significant differences from HATs, and thus cannot be equaled to them. The available evidence thus suggests that HATs are a novel neurophysiological phenomenon. Further investigations on HATs are required in order to investigate their physiological meaning, to individuate their brain structure(s) of origin, and to clarify the neural circuits involved in their manifestation.

  13. External Drive to Inhibitory Cells Induces Alternating Episodes of High- and Low-Amplitude Oscillations

    NARCIS (Netherlands)

    Gonzalez, Oscar J. Avella; van Aerde, Karlijn I.; van Elburg, Ronald A. J.; Poil, Simon-Shlomo; Mansvelder, Huibert D.; Linkenkaer-Hansen, Klaus; van Pelt, Jaap; van Ooyen, Arjen

    2012-01-01

    Electrical oscillations in neuronal network activity are ubiquitous in the brain and have been associated with cognition and behavior. Intriguingly, the amplitude of ongoing oscillations, such as measured in EEG recordings, fluctuates irregularly, with episodes of high amplitude alternating with epi

  14. Brh V128 is a Double-Mode High-Amplitude delta Scuti Star

    Science.gov (United States)

    Bernhard, K.; Pejcha, O.; Proksch, W.; Quester, W.; van Cauteren, P.; Wils, P.

    2004-08-01

    CCD-V and unfiltered photometric data show that Brh V128 = GSC 1893-89 is a new high-amplitude double-mode Delta Scuti variable with a fundamental period of 0.1534 days and a period ratio of 0.767. The amplitude of the first overtone pulsation is slightly larger than that of the fundamental mode.

  15. Off-shell helicity amplitudes in high-energy factorization

    CERN Document Server

    van Hameren, Andreas; Kutak, Krzysztof

    2013-01-01

    In the Catani-Ciafaloni-Hautmann high-energy factorization approach a cross section is expressed as a convolution of unintegrated gluon densities and a gauge-invariant hard process, in which two incoming gluons are off-shell with momenta satisfying certain high-energy kinematics. We present two methods of evaluating the tree-level hard process with multiple final states. The first one assumes that only one of the gluons is off-shell and relies on the Slavnov-Taylor identities. Such asymmetric configuration of incoming gluons is phenomenologically important in small x probing by forward processes. The second method deals also with two off-shell gluons and is based on the analytic continuation of the off-shell gluons momenta to the complex space. The methods were implemented into Monte Carlo computer programs and used in phenomenological applications. The results of both methods are straightforwardly related to Lipatov's effective vertices in quasi-multi-regge kinematics.

  16. High extinction amplitude modulation in ultrashort pulse shaping

    CERN Document Server

    Lin, Yen-Wei

    2016-01-01

    We explored the issues related to the resolution and the modulation extinction when filtering the spectrum of a UV femtosecond laser with a standard ultrashort pulse shaper. We have learned that a higher pulse shaping resolution often requires a larger working beam size or a higher density grating for greater dispersion. However, these approaches also introduce more optical errors and degrade the extinction. In this work, we examined specifics of each component to determine the best configuration of our spectral filtering setup. As a proof-of-concept demonstration, we utilized elements available as standard products and achieved 100 GHz filtering resolution with high extinction at the UV-A wavelength, which is superb in this wavelength range. The high extinction spectral filtering is especially important while modifying a broadband laser for the optical control of molecule's internal state.

  17. Freeform high-speed large-amplitude deformable Piezo Mirrors

    CERN Document Server

    Wapler, Matthias C; Wallrabe, Ulrike

    2013-01-01

    We present a new type of tunable mirror with sharply-featured freeform displacement profiles, large displacements of several 100\\mu m and high operating frequencies close to the kHz range at 15mm diameter. The actuation principle is based on a recently explored "topological" displacement mode of piezo sheets. The prototypes presented here include a rotationally symmetric axicon, a hyperbolic sech-icon and a non-symmetric pyram-icon and are scalable to smaller dimensions. The fabrication process is economic and cleanroom-free, and the optical quality is sufficient to demonstrate the diffraction patterns of the optical elements.

  18. High-Energy String Scattering Amplitudes and Signless Stirling Number Identity

    Directory of Open Access Journals (Sweden)

    Jen-Chi Lee

    2012-07-01

    Full Text Available We give a complete proof of a set of identities (7 proposed recently from calculation of high-energy string scattering amplitudes. These identities allow one to extract ratios among high-energy string scattering amplitudes in the fixed angle regime from high-energy amplitudes in the Regge regime. The proof is based on a signless Stirling number identity in combinatorial theory. The results are valid for arbitrary real values L rather than only for L=0,1 proved previously. The identities for non-integer real value L were recently shown to be realized in high-energy compactified string scattering amplitudes [He S., Lee J.C., Yang Y., arXiv:1012.3158]. The parameter L is related to the mass level of an excited string state and can take non-integer values for Kaluza-Klein modes.

  19. Rapid high-amplitude circumferential slow wave propagation during normal gastric pacemaking and dysrhythmias.

    Science.gov (United States)

    O'Grady, G; Du, P; Paskaranandavadivel, N; Angeli, T R; Lammers, W J E P; Asirvatham, S J; Windsor, J A; Farrugia, G; Pullan, A J; Cheng, L K

    2012-07-01

    Gastric slow waves propagate aborally as rings of excitation. Circumferential propagation does not normally occur, except at the pacemaker region. We hypothesized that (i) the unexplained high-velocity, high-amplitude activity associated with the pacemaker region is a consequence of circumferential propagation; (ii) rapid, high-amplitude circumferential propagation emerges during gastric dysrhythmias; (iii) the driving network conductance might switch between interstitial cells of Cajal myenteric plexus (ICC-MP) and circular interstitial cells of Cajal intramuscular (ICC-IM) during circumferential propagation; and (iv) extracellular amplitudes and velocities are correlated. An experimental-theoretical study was performed. High-resolution gastric mapping was performed in pigs during normal activation, pacing, and dysrhythmia. Activation profiles, velocities, and amplitudes were quantified. ICC pathways were theoretically evaluated in a bidomain model. Extracellular potentials were modeled as a function of membrane potentials. High-velocity, high-amplitude activation was only recorded in the pacemaker region when circumferential conduction occurred. Circumferential propagation accompanied dysrhythmia in 8/8 experiments was faster than longitudinal propagation (8.9 vs 6.9 mm s(-1) ; P = 0.004) and of higher amplitude (739 vs 528 μV; P = 0.007). Simulations predicted that ICC-MP could be the driving network during longitudinal propagation, whereas during ectopic pacemaking, ICC-IM could outpace and activate ICC-MP in the circumferential axis. Experimental and modeling data demonstrated a linear relationship between velocities and amplitudes (P propagation. Rapid circumferential propagation also emerges during a range of gastric dysrhythmias, elevating extracellular amplitudes and organizing transverse wavefronts. One possible explanation for these findings is bidirectional coupling between ICC-MP and circular ICC-IM networks. © 2012 Blackwell Publishing Ltd.

  20. VizieR Online Data Catalog: VVV high amplitude NIR variable stars (Contreras Pena+, 2017)

    Science.gov (United States)

    Contreras Pena, C.; Lucas, P. W.; Minniti, D.; Kurtev, R.; Stimson, W.; Navarro Molina, C.; Borissova, J.; Kumar, M. S. N.; Thompson, M. A.; Gledhill, T.; Terzi, R.; Froebrich, D.; Caratti o Garatti, A.

    2017-08-01

    We present the single epoch ZYJHKs photometry obtained from VVV catalogues for 816 high-amplitude variables. We also present the amplitude of the Ks light curve of the objects derived from 2010-2015 photometry. For each object we also provide a provisional classification derived from the shape of the light curve. For objects found to be likely associated with SFRs we present an spectral index derived from the object's spectral energy distribution. (2 data files).

  1. Kepler observations of the high-amplitude δ Scuti star V2367 Cyg

    DEFF Research Database (Denmark)

    Balona, L. A.; Lenz, P.; Antoci, V.

    2012-01-01

    We analyse Kepler observations of the high-amplitude δ Scuti (HADS) star V2367 Cyg (KIC 9408694). The variations are dominated by a mode with frequency f1= 5.6611 d−1. Two other independent modes with f2= 7.1490 d−1 and f3= 7.7756 d−1 have amplitudes an order of magnitude smaller than f1. Nearly ...

  2. Development of high-voltage pulse generator with variable amplitude and duration

    Science.gov (United States)

    Upadhyay, J.; Sharma, M. L.; Ahuja, Aakash B.; Navathe, C. P.

    2014-06-01

    A high voltage pulse generator with variable amplitude (100-3000 V) and duration (100-2000 μs) has been designed and developed. The variable duration pulse has been generated by adopting a simple and novel technique of varying the turn off delay time of a high voltage Metal Oxide Semiconductor Field Effect Transistor (MOSFET) based switch by varying external gate resistance. The pulse amplitude is made variable by adjusting biasing supply of the high voltage switch. The high voltage switch has been developed using a MOSFET based stack of 3 kV rating with switching time of 7 ns.

  3. Short-lived high-amplitude cooling on Svalbard during the Dark Ages

    Science.gov (United States)

    van der Bilt, Willem; D`Andrea, William; Bakke, Jostein; Balascio, Nicholas; Werner, Johannes; Hoek, Wim

    2016-04-01

    As the paradigm of a stable Holocene climate has shifted, an increasing number of high-resolution proxy timeseries reveal dynamic conditions, characterized by high-amplitude climate shifts. Some of these events occurred during historical times and allow us to study the interaction between environmental and cultural change, providing valuable lessons for the near future. These include the Dark Ages Cold Period (DACP) between 300 and 800 AD, a period marked by political upheaval and climate instability that remains poorly investigated. Here, we present two temperature reconstructions from the High Arctic Svalbard Archipelago. To this end, we applied the established alkenone-based UK37 paleothermometer on sediments from two lakes on western Spitsbergen, Lake Hajeren and Lake Hakluyt. The Arctic is presently warming twice as fast as the global average and proxy data as well as model simulations suggest that this amplified response is characteristic for regional climate. The Arctic therefore provides a uniquely sensitive environment to study relatively modest climate shifts, like the DACP, that may not be adequately captured at lower-latitude sites. Owing to undisturbed sediments, a high sampling resolution and robust chronological control, the presented reconstructions resolve the attendant sub-centennial-scale climate shifts. Our findings suggest that the DACP marks a cold spell within the cool Neoglacial period, which started some 4 ka BP on Svalbard. Close investigation reveals a distinct temperature minimum around 500 AD that is reproduced in another alkenone-based temperature reconstruction from a nearby lake. At ± 1.75 °C, cooling underlines the sensitivity of Arctic climate as well as the magnitude of the DACP.

  4. Simple method for measuring vibration amplitude of high power airborne ultrasonic transducer: using thermo-couple.

    Science.gov (United States)

    Saffar, Saber; Abdullah, Amir

    2014-03-01

    Vibration amplitude of transducer's elements is the influential parameters in the performance of high power airborne ultrasonic transducers to control the optimum vibration without material yielding. The vibration amplitude of elements of provided high power airborne transducer was determined by measuring temperature of the provided high power airborne transducer transducer's elements. The results showed that simple thermocouples can be used both to measure the vibration amplitude of transducer's element and an indicator to power transmission to the air. To verify our approach, the power transmission to the air has been investigated by other common method experimentally. The experimental results displayed good agreement with presented approach. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Internal friction mechanism of Fe-19Mn alloy at low and high strain amplitude

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Shuke, E-mail: huangshuke@163.com [Institute of Machinery Manufacturing Technology, China Academy of Engineering Physics, Mianyang, Sichuan 621900 (China); Huang, Wenrong; Liu, Jianhui [Institute of Machinery Manufacturing Technology, China Academy of Engineering Physics, Mianyang, Sichuan 621900 (China); Teng, Jin; Li, Ning; Wen, Yuhua [School of Manufacturing Science and Engineering, Sichuan University, Chengdu, Sichuan 610065 (China)

    2013-01-10

    Fe-Mn damping alloy, which can decrease the vibrating and noise effectively, will be widely applied to household appliances, automobiles, industrial facilities, etc. In this paper, the internal friction mechanism of Fe-19Mn alloy at low strain amplitude (10{sup -5} range) and high strain amplitude (10{sup -4} range) was investigated. The internal friction was measured using multifunction internal friction equipment and reversal torsion pendulum. The microstructure was observed using scanning electron microscopy. The phase transformation temperatures were determined using differential scanning calorimetry. The results indicated that the internal friction of Fe-19Mn alloy after solution treating was related to strain amplitude. The internal friction mechanism was believed to the movements of four damping sources ({epsilon}-martensite variant boundaries, stacking fault boundaries in {epsilon}-martensite and {gamma}-austenite, {gamma}/{epsilon} interfaces), which could be explained using the interactive movements of Shockley partial dislocations and point defects. At low strain amplitude (10{sup -5} range), the bowing out movements of Shockley partial dislocations are the main moving mode of generating internal friction. At high strain amplitude (10{sup -4} range), however, the breaking away movements of Shockley partial dislocations are the high internal friction mechanism of Fe-19Mn alloy.

  6. The analysis of high amplitude of potential oscillations near the hollow cathode of ion thruster

    Science.gov (United States)

    Qin, Yu; Xie, Kan; Guo, Ning; Zhang, Zun; Zhang, Cen; Gu, Zengjie; Zhang, Yu; Jiang, Zhaorui; Ouyang, Jiting

    2017-05-01

    The influence of gas flow, current level, and different shapes of anode on the oscillation amplitude and the characteristics of the hollow cathode discharge were investigated. The average plasma potential, temporal measurements of plasma potential, ion density, the electron temperature, as well as waveforms of plasma potential for test conditions were measured. At the same time, the time-resolved images of the plasma plume were also recorded. The results show that the potential oscillations appear at high discharge current or low flow rate. The potential oscillation boundaries, the position of maximum amplitude of plasma potential, and the position where the highest ion density was observed, were found. Both of the positions are affected by different shapes of anode configurations. This high amplitude of potential oscillations is ionization-like instabilities. The xenon ions ionized in space was analyzed for the fast potential rise and spatial dissipation of the space xenon ions was the reason for the gradual potential delay.

  7. High performance single-error-correcting quantum codes for amplitude damping

    CERN Document Server

    Shor, Peter W; Smolin, John A; Zeng, Bei

    2009-01-01

    We construct families of high performance quantum amplitude damping codes. All of our codes are nonadditive and most modestly outperform the best possible additive codes in terms of encoded dimension. One family is built from nonlinear error-correcting codes for classical asymmetric channels, with which we systematically construct quantum amplitude damping codes with parameters better than any prior construction known for any block length n > 7 except n=2^r-1. We generalize this construction to employ classical codes over GF(3) with which we numerically obtain better performing codes up to length 14. Because the resulting codes are of the codeword stabilized (CWS) type, easy encoding and decoding circuits are available.

  8. Multiband carrierless amplitude/phase modulation for ultra-wideband high data rate wireless communications

    DEFF Research Database (Denmark)

    Puerta Ramírez, Rafael; Rommel, Simon; Altabas, Jose A.

    2016-01-01

    We report on the first experimental demonstration of carrierless amplitude/phase modulation in a flexible multiband approach for ultrawideband high-data-rate wireless communications. An effective bitrate of 2 GB/s is achieved while complying with the restrictions on the effective radiated power e...

  9. In search of objective manometric criteria for colonic high-amplitude propagated pressure waves

    NARCIS (Netherlands)

    De Schryver, AMP; Samsom, M; Smout, AJPM

    2002-01-01

    The aims of this study were to explore all characteristics of high-amplitude propagated contractions (HAPCs) that would allow them to be distinguished from nonHAPC colonic pressure waves, and to develop computer algorithms for automated HAPC detection. Colonic manometry recordings obtained from 24 h

  10. Numerical modeling of dune progression in a high amplitude meandering channel

    Science.gov (United States)

    Laboratory experiments carried out by Abad and Garcia (2009) in a high-amplitude Kinoshita meandering channel show bed morphodynamics to comprise steady (local scour and deposition) and unsteady (migrating bedforms) components. The experiments are replicated with a numerical model. The sediment tran...

  11. High initial amplitude and high Mach number effects on the evolution of the single-mode Richtmyer-Meshkov instability.

    Science.gov (United States)

    Rikanati, A; Oron, D; Sadot, O; Shvarts, D

    2003-02-01

    Effects of high-Mach numbers and high initial amplitudes on the evolution of the single-mode Richtmyer-Meshkov shock-wave induced hydrodynamic instability are studied using theoretical models, experiments, and numerical simulations. Two regimes in which there is a significant deviation from the linear dependence of the initial velocity on the initial perturbation amplitude are defined and characterized. In one, the observed reduction of the initial velocity is primarily due to large initial amplitudes. This effect is accurately modeled by a vorticity deposition model, quantifying both the effect of the initial perturbation amplitude and the exact shape of the interface. In the other, the reduction is dominated by the proximity of the shock wave to the interface. This effect is modeled by a modified incompressible model where the shock wave is mimicked by a moving bounding wall. These results are supplemented with high initial amplitude Mach 1.2 shock-tube experiments, enabling separation of the two effects. It is shown that in most of the previous experiments, the observed reduction is predominantly due to the effect of high initial amplitudes.

  12. Study of High and Low Amplitude Wave Trains of Cosmic Ray Diurnal Variation during Solar Cycle 23

    Indian Academy of Sciences (India)

    Ambika Singh; Anil Kumar Tiwari; S. P. Agrawal

    2010-06-01

    A detailed study has been conducted on the long-term changes in the diurnal variation of cosmic rays in terms of high and low amplitude wave trains event (HAEs/LAEs) during the period 1996–2008 (solar cycle 23), using the neutron monitor data from Kiel neutron monitoring station. As such, 17 HAE and 48 LAE cases have been detected and analyzed. These HAEs appear quite dominantly during the declining phase as well as near the maximum of the solar activity cycle 23. In contrast, the low amplitude events (LAEs) are inversely correlated with solar activity cycle. In fact, LAEs appear quite dominantly during the minimum phase of the solar activity. When we compare our results for diurnal phase with that observed on an annual average basis, we notice no significant diurnal phase shift for HAEs as well as for LAEs. Moreover, we find that the high-speed solar wind streams (HSSWS) do not play any significant role in causing these variations. These results are discussed on the basis of that observed in earlier cycles.

  13. Nonlinear reflection of high-amplitude laser pulses from relativistic electron mirrors

    Science.gov (United States)

    Kulagin, V. V.; Kornienko, V. N.; Cherepenin, V. A.

    2016-04-01

    A coherent X-ray pulse of attosecond duration can be formed in the reflection of a counterpropagating laser pulse from a relativistic electron mirror. The reflection of a high-amplitude laser pulse from the relativistic electron mirror located in the field of an accelerating laser pulse is investigated by means of two-dimensional (2D) numerical simulation. It is shown that provided the amplitude of the counterpropagating laser pulse is several times greater than the amplitude of the accelerating laser pulse, the reflection process is highly nonlinear, which causes a significant change in the X-ray pulse shape and its shortening up to generation of quasi-unipolar pulses and single-cycle pulses. A physical mechanism responsible for this nonlinearity of the reflection process is explained, and the parameters of the reflected X-ray pulses are determined. It is shown that the duration of these pulses may constitute 50 - 60 as, while their amplitude may be sub-relativistic.

  14. Non-Linear High Amplitude Oscillations in Wave-shaped Resonators

    Science.gov (United States)

    Antao, Dion; Farouk, Bakhtier

    2011-11-01

    A numerical and experimental study of non-linear, high amplitude standing waves in ``wave-shaped'' resonators is reported here. These waves are shock-less and can generate peak acoustic overpressures that can exceed the ambient pressure by three/four times its nominal value. A high fidelity compressible axisymmetric computational fluid dynamic model is used to simulate the phenomena in cylindrical and arbitrarily shaped axisymmetric resonators. Working fluids (Helium, Nitrogen and R-134a) at various operating pressures are studied. The experiments are performed in a constant cross-section cylindrical resonator in atmospheric pressure nitrogen and helium to provide model validation. The high amplitude non-linear oscillations demonstrated can be used as a prime mover in a variety of applications including thermoacoustic cryocooling. The work reported is supported by the US National Science Foundation under grant CBET-0853959.

  15. Novel method of high-accuracy wavefront-phase and amplitude correction for coronagraphy

    Science.gov (United States)

    Bowers, Charles W.; Woodgate, Bruce E.; Lyon, Richard G.

    2003-11-01

    Detection of extra-solar, and especially terrestrial-like planets, using coronagraphy requires an extremely high level of wavefront correction. For example, the study of Woodruff et al. (2002) has shown that phase uniformity of order 10-4λ(rms) must be achieved over the critical range of spatial frequencies to produce the ~1010 contrast needed for the Terrestrial Planet Finder (TPF) mission. Correction of wavefront phase errors to this level may be accomplished by using a very high precision deformable mirror (DM). However, not only phase but also amplitude uniformity of the same scale (~10-4) and over the same spatial frequency range must be simultaneously obtained to remove all residual speckle in the image plane. We present a design for producing simultaneous wavefront phase and amplitude uniformity to high levels from an input wavefront of lower quality. The design uses a dual Michelson interferometer arrangement incorporating two DM and a single, fixed mirror (all at pupils) and two beamsplitters: one with unequal (asymmetric) beam splitting and one with symmetric beam splitting. This design allows high precision correction of both phase and amplitude using DM with relatively coarse steps and permits a simple correction algorithm.

  16. High amplitude nonlinear acoustic wave driven flow fields in cylindrical and conical resonators.

    Science.gov (United States)

    Antao, Dion Savio; Farouk, Bakhtier

    2013-08-01

    A high fidelity computational fluid dynamic model is used to simulate the flow, pressure, and density fields generated in a cylindrical and a conical resonator by a vibrating end wall/piston producing high-amplitude standing waves. The waves in the conical resonator are found to be shock-less and can generate peak acoustic overpressures that exceed the initial undisturbed pressure by two to three times. A cylindrical (consonant) acoustic resonator has limitations to the output response observed at one end when the opposite end is acoustically excited. In the conical geometry (dissonant acoustic resonator) the linear acoustic input is converted to high energy un-shocked nonlinear acoustic output. The model is validated using past numerical results of standing waves in cylindrical resonators. The nonlinear nature of the harmonic response in the conical resonator system is further investigated for two different working fluids (carbon dioxide and argon) operating at various values of piston amplitude. The high amplitude nonlinear oscillations observed in the conical resonator can potentially enhance the performance of pulse tube thermoacoustic refrigerators and these conical resonators can be used as efficient mixers.

  17. Dynamics of self-generated, large amplitude magnetic fields following high-intensity laser matter interaction

    CERN Document Server

    Sarri, G; Cecchetti, C A; Kar, S; Liseykina, T V; Yang, X H; Dieckmann, M E; Fuchs, J; Galimberti, M; Gizzi, L A; Jung, R; Kourakis, I; Osterholz, J; Pegoraro, F; Robinson, A P L; Romagnani, L; Willi, O; Borghesi, M

    2012-01-01

    The dynamics of magnetic fields with amplitude of several tens of Megagauss, generated at both sides of a solid target irradiated with a high intensity (? 1019W/cm2) picosecond laser pulse, has been spatially and temporally resolved using a proton imaging technique. The amplitude of the magnetic fields is sufficiently large to have a constraining effect on the radial expansion of the plasma sheath at the target surfaces. These results, supported by numerical simulations and simple analytical modeling, may have implications for ion acceleration driven by the plasma sheath at the rear side of the target as well as for the laboratory study of self-collimated high-energy plasma jets.

  18. Analysis of the Petersen Diagram of Double-Mode High-Amplitude {\\delta} Scuti Stars

    CERN Document Server

    Furgoni, Riccardo

    2016-01-01

    I created the Petersen diagram relative to all the Double Mode High Amplitude {\\delta} Scuti stars listed in the AAVSO's International Variable Star Index up to date December 29, 2015. For the first time I noticed that the ratio between the two periods P1/P0 seems in evident linear relation with the duration of the period P0, a finding never explicitly described in literature regarding this topic.

  19. Variable amplitude corrosion fatigue and fracture mechanics of weldable high strength jack-up steels

    OpenAIRE

    Etube, L. S.

    1998-01-01

    The tubular welded joints used in the construction of Offshore structures can experience millions of variable amplitude wave induced stress cycles during their operational life. Fatigue has been identified as the main cause of degradation of structural integrity in these structures. As a result, fatigue is an important consideration in their design. Jack-up legs are made from a range of high strength steels with yield strengths up to 70OMPa. These steels are thought to exhib...

  20. High-frequency lunar teleseismic events

    Science.gov (United States)

    Nakamura, Y.; Dorman, J.; Duennebier, F.; Ewing, M.; Lammlein, D.; Latham, G.

    1974-01-01

    A small number of seismic signals, including some of the strongest observed to date, have been identified as representing a fourth principal category of natural lunar seismic events with characteristics distinct from those produced by normal meteoroid impacts, deep moonquakes, and thermal moonquakes. These signals are much richer in high frequencies than other events observed at comparable distances, and display relatively impulsive P- and S-wave beginnings, indicating negligible seismic-wave scattering near the source. Source depths of these events may range between 0 and perhaps 300 km. These and other characteristics could represent either (1) meteoroids impacting upon outcrops of competent lunar crystal rock, (2) rare impacting objects that penetrate to competent rock below a scattering zone, or (3) shallow tectonic moonquakes.

  1. High-resolution, high-reflectivity operation of lamellar multilayer amplitude gratings: identification of the single-order regime

    NARCIS (Netherlands)

    Kozhevnikov, I. V.; van der Meer, R.; Bastiaens, H. M. J.; Boller, K. J.; F. Bijkerk,

    2010-01-01

    High resolution while maintaining high peak reflectivities can be achieved for Lamellar Multilayer Amplitude Gratings (LMAG) in the soft-x-ray (SXR) region. Using the coupled waves approach (CWA), it is derived that for small lamellar widths only the zeroth diffraction order needs to be considered f

  2. A high-stability non-contact dilatometer for low-amplitude temperature-modulated measurements

    Science.gov (United States)

    Luckabauer, Martin; Sprengel, Wolfgang; Würschum, Roland

    2016-07-01

    Temperature modulated thermophysical measurements can deliver valuable insights into the phase transformation behavior of many different materials. While especially for non-metallic systems at low temperatures numerous powerful methods exist, no high-temperature device suitable for modulated measurements of bulk metallic alloy samples is available for routine use. In this work a dilatometer for temperature modulated isothermal and non-isothermal measurements in the temperature range from room temperature to 1300 K is presented. The length measuring system is based on a two-beam Michelson laser interferometer with an incremental resolution of 20 pm. The non-contact measurement principle allows for resolving sinusoidal length change signals with amplitudes in the sub-500 nm range and physically decouples the length measuring system from the temperature modulation and heating control. To demonstrate the low-amplitude capabilities, results for the thermal expansion of nickel for two different modulation frequencies are presented. These results prove that the novel method can be used to routinely resolve length-change signals of metallic samples with temperature amplitudes well below 1 K. This high resolution in combination with the non-contact measurement principle significantly extends the application range of modulated dilatometry towards high-stability phase transformation measurements on complex alloys.

  3. WEATHER ON OTHER WORLDS. III. A SURVEY FOR T DWARFS WITH HIGH-AMPLITUDE OPTICAL VARIABILITY

    Energy Technology Data Exchange (ETDEWEB)

    Heinze, Aren N.; Metchev, Stanimir [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794-3800 (United States); Kellogg, Kendra, E-mail: aren.heinze@stonybrook.edu, E-mail: smetchev@uwo.ca [Department of Physics and Astronomy, The University of Western Ontario, 1151 Richmond St, London, ON N6A 3K7 (Canada)

    2015-03-10

    We have monitored 12 T dwarfs with the Kitt Peak 2.1 m telescope using an F814W filter (0.7-0.95 μm) to place in context the remarkable 10%-20% variability exhibited by the nearby T dwarf Luhman 16B in this wavelength regime. The motivation was the poorly known red optical behavior of T dwarfs, which have been monitored almost exclusively at infrared wavelengths, where variability amplitudes greater than 10% have been found to be very rare. We detect highly significant variability in two T dwarfs. The T2.5 dwarf 2MASS 13243559+6358284 shows consistent ∼17% variability on two consecutive nights. The T2 dwarf 2MASS J16291840+0335371 exhibits ∼10% variability that may evolve from night to night, similarly to Luhman 16B. Both objects were previously known to be variable in the infrared, but with considerably lower amplitudes. We also find evidence for variability in the T6 dwarf J162414.37+002915.6, but since it has lower significance, we conservatively refrain from claiming this object as a variable. We explore and rule out various telluric effects, demonstrating that the variations we detect are astrophysically real. We suggest that high-amplitude photometric variability for T dwarfs is likely more common in the red optical than at longer wavelengths. The two new members of the growing class of high-amplitude variable T dwarfs offer excellent prospects for further study of cloud structures and their evolution.

  4. [High-frequency ventilation. I. Distribution of alveolar pressure amplitudes during high frequency oscillation in the lung model].

    Science.gov (United States)

    Theissen, J; Lunkenheimer, P P; Niederer, P; Bush, E; Frieling, G; Lawin, P

    1987-09-01

    The pattern of intrapulmonary pressure distribution was studied during high-frequency ventilation in order to explain the inconsistent results reported in the literature. Methods. Pressure and flow velocity (hot-wire anemometry) were measured in different lung compartments: 1. In transalveolar chambers sealed to the perforated pleural surfaces of dried pig lungs; 2. In emphysema-simulating airbags sealed to the isolated bronchial trees of dried pig lungs; and 3. In transalveolar chambers sealed to the perforated pleural surfaces of freshly excised pig lungs. Results. 1. The pressure amplitudes change from one area to another and depending on the exciting frequency. 2. High-frequency oscillation is associated with an increase in pressure amplitude when the exciting frequency rises, whereas with conventional high-frequency jet ventilation the pressure amplitude is more likely to decrease with frequency. 3. During high-frequency jet ventilation the local pressure amplitude changes with the position of the tube in the trachea rather than with the exciting frequency. 4. When the volume of the measuring chamber is doubled the resulting pressure amplitude falls to half the control value. 5. The pressure amplitude and mean pressure measured in the transalveolar chamber vary more or less independently from the peak flow velocity. High-frequency ventilation is thus seen to be a frequency-dependant, inhomogeneous mode of ventilation that can essentially be homogenized by systematically changing the exciting frequency. The frequency-dependant response to different lung areas to excitation is likely to result from an intrabronchially-localized aerodynamic effect rather than the mechanical properties of the lung parenchyma.

  5. Speckle interferometric sensor to measure low-amplitude high frequency Ocular Microtremor (OMT)

    Science.gov (United States)

    Ryle, James P.; Al-Kalbani, Mohammed; Gopinathan, Unnikrishnan; Boyle, Gerard; Coakley, Davis; Sheridan, John T.

    2009-08-01

    Ocular microtremor (OMT) is a physiological high frequency (up to 150Hz) low amplitude (150-2500nm) involuntary tremor of the human eye. It is one of the three fixational ocular motions described by Adler and Fliegelman in 1934 as well as microsaccades and drift. Clinical OMT investigations to date have used eye-contacting piezoelectric probes or piezoelectric strain gauges. Before contact can be made, the eye must first be anaesthetised. In some cases, this induces eyelid spasms (blepharospasm) making it impossible to measure OMT. Using the contact probe method, the eye motion is mechanically damped. In addition to this, it is not possible to obtain exact information about the displacement. Results from clinical studies to date have given electrical signal amplitudes from the probe. Recent studies suggest a number of clinical applications for OMT, these include monitoring the depth of anaesthesia of a patient in surgery, prediction of outcome in coma, diagnosis of brainstem death. In addition to this, abnormal OMT frequency content is present in patients with neurological disorders such as Multiple sclerosis and Parkinson's disease. However for ongoing clinical investigations the contact probe method falls short of a non-contact accurate measurement solution. In this paper, we design a compact non contact phase modulating optical fiber speckle interferometer to measure eye motions. We present our calibration results using a calibrated piezoelectric vibration simulator. Digital signal processing is then performed to extract the low amplitude high frequency displacement information.

  6. Tip radius preservation for high resolution imaging in amplitude modulation atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Jorge R., E-mail: jorge.rr@cea.cu [Instituto de Ciencia de Materiales de Madrid, Sor Juana Inés de la Cruz 3, Canto Blanco, 28049 Madrid, España (Spain)

    2014-07-28

    The acquisition of high resolution images in atomic force microscopy (AFM) is correlated to the cantilever's tip shape, size, and imaging conditions. In this work, relative tip wear is quantified based on the evolution of a direct experimental observable in amplitude modulation atomic force microscopy, i.e., the critical amplitude. We further show that the scanning parameters required to guarantee a maximum compressive stress that is lower than the yield/fracture stress of the tip can be estimated via experimental observables. In both counts, the optimized parameters to acquire AFM images while preserving the tip are discussed. The results are validated experimentally by employing IgG antibodies as a model system.

  7. High CW power, phase and amplitude modulatorrealized with fast ferrite phase-shifters

    CERN Document Server

    Valuch, D

    2004-01-01

    Superconducting cavity resonators are suffering from detuning effects caused by high internal electromagnetic fields (Lorentz force detuning). For classical resonators working with continuous wave signals, this detuning is static and compensated by the slow mechanical tuning system. However, pulsing of superconducting cavities, an operational mode only recently considered, results in dynamic detuning effects. New ways to handle this effect have to be found and worked out. A way to supply several superconducting cavities in the particle accelerator by one large transmitter while keeping the possibility of controlling the field in each individual cavity is shown. By introducing a fast phase and amplitude modulator into each cavity feeder line, the individual deviations of each cavity with respect to the average can be compensated in order to equalize their behaviour for the main control loop, which will compensate the global detuning of all cavities. Several types of phase and amplitude modulators suitable for ...

  8. An ATLAS high mass dijet event

    CERN Multimedia

    ATLAS, Experiment

    2014-01-01

    A high mass dijet event: two high-pT jets with invariant mass 2.8 TeV. A track pT cut of 2.5 GeV has been applied for the display. 1st jet (ordered by pT): pT = 310 GeV, y = -2.0, φ = -0.2 2nd jet: pT = 280 GeV, y = 2.5, φ = 2.9 3rd jet: pT = 14 GeV, y = -0.9, φ = -1.0 Jet momenta are calibrated according to the "EM+JES" scheme. Event collected on 5 August 2010.

  9. Effects of thrust amplitude and duration of high velocity low amplitude spinal manipulation on lumbar muscle spindle responses to vertebral position and movement

    Science.gov (United States)

    Cao, Dong-Yuan; Reed, William R.; Long, Cynthia R.; Kawchuk, Gregory N.; Pickar, Joel G.

    2013-01-01

    OBJECTIVE Mechanical characteristics of high velocity low amplitude spinal manipulations (HVLA-SM) can be variable. Sustained changes in peripheral neuronal signaling due to altered load transmission to a sensory receptor’s local mechanical environment are often considered a mechanism contributing to the therapeutic effects of spinal manipulation. The purpose of this study was to determine whether an HVLA-SM’s thrust amplitude or duration altered neural responsiveness of lumbar muscle spindles to either vertebral movement or position. METHODS Anesthetized cats (n=112) received L6 HVLA-SMs delivered to the spinous process. Cats were divided into 6 cohorts depending upon the peak thrust force (25%, 55%, 85% body weight) or thrust displacement (1, 2, 3mm) they received. Cats in each cohort received 8 thrust durations (0–250ms). Afferent discharge from 112 spindles was recorded in response to ramp and hold vertebral movement before and after the manipulation. Changes in mean instantaneous frequency (MIF) during the baseline period preceding the ramps (ΔMIFresting), during ramp movements (ΔMIFmovement), and with the vertebra held in the new position (ΔMIFposition) were compared. RESULTS Thrust duration had a small but statistically significant effect on ΔMIFresting at all six thrust amplitudes compared to control (0ms thrust duration). The lowest amplitude thrust displacement (1mm) increased ΔMIFresting at all thrust durations. For all the other thrust displacements and forces, the direction of change in ΔMIFresting was not consistent and the pattern of change was not systematically related to thrust duration. Regardless of thrust force, displacement, or duration, ΔMIFmovement and ΔMIFposition were not significantly different from control. Conclusion Relatively low amplitude thrust displacements applied during an HVLA-SM produced sustained increases in the resting discharge of paraspinal muscle spindles regardless of the duration over which the thrust was

  10. Effects of thrust amplitude and duration of high-velocity, low-amplitude spinal manipulation on lumbar muscle spindle responses to vertebral position and movement.

    Science.gov (United States)

    Cao, Dong-Yuan; Reed, William R; Long, Cynthia R; Kawchuk, Gregory N; Pickar, Joel G

    2013-02-01

    Mechanical characteristics of high-velocity, low-amplitude spinal manipulations (HVLA-SMs) can vary. Sustained changes in peripheral neuronal signaling due to altered load transmission to a sensory receptor's local mechanical environment are often considered a mechanism contributing to the therapeutic effects of spinal manipulation. The purpose of this study was to determine whether variation in an HVLA-SM's thrust amplitude and duration alters the neural responsiveness of lumbar muscle spindles to either vertebral movement or position. Anesthetized cats (n = 112) received L6 HVLA-SMs delivered to the spinous process. Cats were divided into 6 cohorts depending upon the peak thrust force (25%, 55%, 85% body weight) or thrust displacement (1, 2, 3 mm) they received. Cats in each cohort received 8 thrust durations (0-250 milliseconds). Afferent discharge from 112 spindles was recorded in response to ramp and hold vertebral movement before and after the manipulation. Changes in mean instantaneous frequency (∆MIF) during the baseline period preceding the ramps (∆MIFresting), during ramp movement (∆MIFmovement), and with the vertebra held in the new position (∆MIFposition) were compared. Thrust duration had a small but statistically significant effect on ∆MIFresting at all 6 thrust amplitudes compared with control (0-millisecond thrust duration). The lowest amplitude thrust displacement (1 mm) increased ∆MIFresting at all thrust durations. For all the other thrust displacements and forces, the direction of change in ∆MIFresting was not consistent, and the pattern of change was not systematically related to thrust duration. Regardless of thrust force, displacement, or duration, ∆MIFmovement and ∆MIFposition were not significantly different from control. Relatively low-amplitude thrust displacements applied during an HVLA-SM produced sustained increases in the resting discharge of paraspinal muscle spindles regardless of the duration over which the thrust

  11. First Results with a Fast Phase and Amplitude Modulator for High Power RF Application

    CERN Document Server

    Frischholz, Hans; Valuch, D; Weil, C

    2004-01-01

    In a high energy and high power superconducting proton linac, it is more economical to drive several cavities with a single high power transmitter rather than to use one transmitter per cavity. However, this option has the disadvantage of not permitting individual control for each cavity, which potentially leads to instabilities. Provided that it can be built at a reasonable cost, a fast phase and amplitude modulator inserted into each cavity feeder line can provide the necessary control capability. A prototype of such a device has been built, based on two fast and compact high power RF phase-shifters, magnetically biased by external coils. The design is described, together with the results obtained at high and low power levels.

  12. Semi-blind Adaptive Beamforming for High-throughput Quadrature Amplitude Modulation Systems

    Institute of Scientific and Technical Information of China (English)

    Sheng Chen; Wang Yao; Lajos Hanzo

    2010-01-01

    A semi-blind adaptive beamforming scheme is proposed for wireless systems that employ high-throughput quadrature amplitude modulation signalling. A minimum number of training symbols, equal to the number of receiver antenna array's elements, are first utilised to provide a rough initial least squares estimate of the beamformer's weight vector. A concurrent constant modulus algorithm and soft decision-directed scheme is then applied to adapt the beamformer. This semi-blind adaptive beamforming scheme is capable of converging fast to the minimum mean-square-error beamforming solution, as demonstrated in our simulation study.

  13. Real-time, high frequency QRS electrocardiograph with reduced amplitude zone detection

    Science.gov (United States)

    Schlegel, Todd T. (Inventor); DePalma, Jude L. (Inventor); Moradi, Saeed (Inventor)

    2009-01-01

    Real time cardiac electrical data are received from a patient, manipulated to determine various useful aspects of the ECG signal, and displayed in real time in a useful form on a computer screen or monitor. The monitor displays the high frequency data from the QRS complex in units of microvolts, juxtaposed with a display of conventional ECG data in units of millivolts or microvolts. The high frequency data are analyzed for their root mean square (RMS) voltage values and the discrete RMS values and related parameters are displayed in real time. The high frequency data from the QRS complex are analyzed with imbedded algorithms to determine the presence or absence of reduced amplitude zones, referred to herein as ''RAZs''. RAZs are displayed as ''go, no-go'' signals on the computer monitor. The RMS and related values of the high frequency components are displayed as time varying signals, and the presence or absence of RAZs may be similarly displayed over time.

  14. Adhesive bond strength evaluation in composite materials by laser-generated high amplitude ultrasound

    Science.gov (United States)

    Perton, M.; Blouin, A.; Monchalin, J.-P.

    2011-01-01

    Adhesive bonding of composites laminates is highly efficient but is not used for joining primary aircraft structures, since there is presently no nondestructive inspection technique to ensure the quality of the bond. We are developing a technique based on the propagation of high amplitude ultrasonic waves to evaluate the adhesive bond strength. Large amplitude compression waves are generated by a short pulse powerful laser under water confinement and are converted after reflection by the assembly back surface into tensile waves. The resulting tensile stresses can cause a delamination inside the laminates or at the bond interfaces. The adhesion strength is evaluated by increasing the laser pulse energy until disbond. A good bond is unaffected by a certain level of stress whereas a weaker one is damaged. The method is shown completely non invasive throughout the whole composite assembly. The sample back surface velocity is measured by an optical interferometer and used to estimate stress history inside the sample. The depth and size of the disbonds are revealed by a post-test inspection by the well established laser-ultrasonic technique. Experimental results show that the proposed method is able to differentiate weak bond from strong bonds and to estimate quantitatively their bond strength.

  15. Resonance of a Metal Drop under the Effect of Amplitude-Modulated High Frequency Magnetic Field

    Science.gov (United States)

    Guo, Jiahong; Lei, Zuosheng; Zhu, Hongda; Zhang, Lijie; Magnetic Hydrodynamics(Siamm) Team; Magnetic Mechanics; Engineering(Smse) Team

    2016-11-01

    The resonance of a sessile and a levitated drop under the effect of high frequency amplitude-modulated magnetic field (AMMF) is investigated experimentally and numerically. It is a new method to excite resonance of a metal drop, which is different from the case in the presence of a low-frequency magnetic field. The transient contour of the drop is obtained in the experiment and the simulation. The numerical results agree with the experimental results fairly well. At a given frequency and magnetic flux density of the high frequency AMMF, the edge deformations of the drop with an azimuthal wave numbers were excited. A stability diagram of the shape oscillation of the drop and its resonance frequency spectrum are obtained by analysis of the experimental and the numerical data. The results show that the resonance of the drop has a typical character of parametric resonance. The National Natural Science Foundation of China (No. 51274237 and 11372174).

  16. Thermal effects on seeded finite ion temperature, high amplitude plasma blobs

    CERN Document Server

    Held, M; Madsen, J; Kendl, A

    2016-01-01

    Thermal effects on the perpendicular convection of seeded pressure blobs in the scrape-off layer of magnetised fusion plasmas are investigated. Our numerical study is based on a four field full-F gyrofluid model, which entails the consistent description of high fluctuation amplitudes and dynamic finite Larmor radius effects. We find that a temperature perturbation increases the maximal blob velocity and that a finite Larmor radius contributes to highly compact blob structures with finite poloidal motion. An extensive parameter study reveals that a smooth transition to this compact blob regime occurs when the finite Larmor radius effect strength, defined by the ratio of the ion diamagnetic to the perpendicular vorticity, exceeds unity. The maximal blob velocities excellently agree with the inertial velocity scaling law over more than an order of magnitude. We show that the finite Larmor radius effect strength affects the radial transport and verify the here presented empirical scaling law for the maximal radia...

  17. An output amplitude configurable wideband automatic gain control with high gain step accuracy

    Institute of Scientific and Technical Information of China (English)

    何晓丰; 莫太山; 马成炎; 叶甜春

    2012-01-01

    An output amplitude configurable wideband automatic gain control (AGC) with high gain step accuracy for the GNSS receiver is presented.The amplitude of an AGC is configurable in order to cooperate with baseband chips to achieve interference suppression and be compatible with different full range ADCs.And what's more,the gain-boosting technology is introduced and the circuit is improved to increase the step accuracy.A zero,which is composed by the source feedback resistance and the source capacity,is introduced to compensate for the pole.The AGC is fabricated in a 0.18 μm CMOS process.The AGC shows a 62 dB gain control range by 1 dB each step with a gain error of less than 0.2 dB.The AGC provides 3 dB bandwidth larger than 80 MHz and the overall power consumption is less than 1.8 mA,and the die area is 800 × 300μm2.

  18. Relativistic electron scattering by magnetosonic waves: Effects of discrete wave emission and high wave amplitudes

    Energy Technology Data Exchange (ETDEWEB)

    Artemyev, A. V., E-mail: ante0226@gmail.com [Space Research Institute, RAS, Moscow (Russian Federation); Mourenas, D.; Krasnoselskikh, V. V. [LPC2E/CNRS - University of Orleans, Orleans (France); Agapitov, O. V. [Space Sciences Laboratory, University of California, Berkeley, California 94720 (United States)

    2015-06-15

    In this paper, we study relativistic electron scattering by fast magnetosonic waves. We compare results of test particle simulations and the quasi-linear theory for different spectra of waves to investigate how a fine structure of the wave emission can influence electron resonant scattering. We show that for a realistically wide distribution of wave normal angles θ (i.e., when the dispersion δθ≥0.5{sup °}), relativistic electron scattering is similar for a wide wave spectrum and for a spectrum consisting in well-separated ion cyclotron harmonics. Comparisons of test particle simulations with quasi-linear theory show that for δθ>0.5{sup °}, the quasi-linear approximation describes resonant scattering correctly for a large enough plasma frequency. For a very narrow θ distribution (when δθ∼0.05{sup °}), however, the effect of a fine structure in the wave spectrum becomes important. In this case, quasi-linear theory clearly fails in describing accurately electron scattering by fast magnetosonic waves. We also study the effect of high wave amplitudes on relativistic electron scattering. For typical conditions in the earth's radiation belts, the quasi-linear approximation cannot accurately describe electron scattering for waves with averaged amplitudes >300 pT. We discuss various applications of the obtained results for modeling electron dynamics in the radiation belts and in the Earth's magnetotail.

  19. Squeeze Film Dampers Executing Small Amplitude Circular-Centered Orbits in High-Speed Turbomachinery

    Directory of Open Access Journals (Sweden)

    Sina Hamzehlouia

    2016-01-01

    Full Text Available This work represents a pressure distribution model for finite length squeeze film dampers (SFDs executing small amplitude circular-centered orbits (CCOs with application in high-speed turbomachinery design. The proposed pressure distribution model only accounts for unsteady (temporal inertia terms, since based on order of magnitude analysis, for small amplitude motions of the journal center, the effect of convective inertia is negligible relative to unsteady (temporal inertia. In this work, the continuity equation and the momentum transport equations for incompressible lubricants are reduced by assuming that the shapes of the fluid velocity profiles are not strongly influenced by the inertia forces, obtaining an extended form of Reynolds equation for the hydrodynamic pressure distribution that accounts for fluid inertia effects. Furthermore, a numerical procedure is represented to discretize the model equations by applying finite difference approximation (FDA and to numerically determine the pressure distribution and fluid film reaction forces in SFDs with significant accuracy. Finally, the proposed model is incorporated into a simulation model and the results are compared against existing SFD models. Based on the simulation results, the pressure distribution and fluid film reaction forces are significantly influenced by fluid inertia effects even at small and moderate Reynolds numbers.

  20. ATLAS event containing two high energy photons

    CERN Multimedia

    ATLAS

    2011-01-01

    An event where two energetic photons ("gammas") are produced in a proton-proton collision in ATLAS. Many events of this type are produced by well-understood Standard Model processes ("backgrounds") which do not involve Higgs particles. A small excess of events of this type with similar masses could indicate evidence for Higgs particle production, but any specific event is most likely to be from the background.

  1. Variable amplitude corrosion fatigue and fracture mechanics of weldable high strength jack-up steels

    Science.gov (United States)

    Etube, Linus Sone

    The tubular welded joints used in the construction of Offshore structures can experience millions of variable amplitude wave induced stress cycles during their operational life. Fatigue has been identified as the main cause of degradation of structural integrity in these structures. As a result, fatigue is an important consideration in their design. Jack-up legs are made from a range of high strength steels with yield strengths up to TOOMPa. These steels are thought to exhibit fatigue resistance properties which are different when compared with conventional fixed platform steels such as BS 4360 50D and BS 7191 355D. The difference in their behaviour was heightened by the discovery, in the late 80s and early 90s, of extensive cracking around the spud can regions of several Jack-ups operating in the North Sea. It was thought that these steels may be more susceptible to hydrogen cracking and embrittlement. There was the additional requirement to study their behaviour under realistic loading conditions typical of the North Sea environment. This thesis contains results of an investigation undertaken to assess the performance of a typical high strength weldable Jack-up steel under realistic loading and environmental conditions. Details of the methodology employed to develop a typical Jack-up Offshore Standard load History (JOSH) are presented. The factors which influence fatigue resistance of structural steels used in the construction of Jack-up structures are highlighted. The methods used to model the relevant factors for inclusion in JOSH are presented with particular emphasis on loading and structural response interaction. Results and details of experimental variable amplitude corrosion fatigue (VACF) tests conducted using JOSH are reported and discussed with respect to crack growth mechanisms in high strength weldable Jack-up steels. Different fracture mechanics models for VACF crack growth prediction are compared and an improved generalised methodology for fast

  2. Giant-amplitude, high-work density microactuators with phase transition activated nanolayer bimorphs.

    Science.gov (United States)

    Liu, Kai; Cheng, Chun; Cheng, Zhenting; Wang, Kevin; Ramesh, Ramamoorthy; Wu, Junqiao

    2012-12-12

    Various mechanisms are currently exploited to transduce a wide range of stimulating sources into mechanical motion. At the microscale, simultaneously high amplitude, high work output, and high speed in actuation are hindered by limitations of these actuation mechanisms. Here we demonstrate a set of microactuators fabricated by a simple microfabrication process, showing simultaneously high performance by these metrics, operated on the structural phase transition in vanadium dioxide responding to diverse stimuli of heat, electric current, and light. In both ambient and aqueous conditions, the actuators bend with exceedingly high displacement-to-length ratios up to 1 in the sub-100 μm length scale, work densities over 0.63 J/cm(3), and at frequencies up to 6 kHz. The functionalities of actuation can be further enriched with integrated designs of planar as well as three-dimensional geometries. Combining the superior performance, high durability, diversity in responsive stimuli, versatile working environments, and microscale manufacturability, these actuators offer potential applications in microelectromechanical systems, microfluidics, robotics, drug delivery, and artificial muscles.

  3. High efficiency processing for reduced amplitude zones detection in the HRECG signal

    Science.gov (United States)

    Dugarte, N.; Álvarez, A.; Balacco, J.; Mercado, G.; Gonzalez, A.; Dugarte, E.; Olivares, A.

    2016-04-01

    Summary - This article presents part of a more detailed research proposed in the medium to long term, with the intention of establishing a new philosophy of electrocardiogram surface analysis. This research aims to find indicators of cardiovascular disease in its early stage that may go unnoticed with conventional electrocardiography. This paper reports the development of a software processing which collect some existing techniques and incorporates novel methods for detection of reduced amplitude zones (RAZ) in high resolution electrocardiographic signal (HRECG).The algorithm consists of three stages, an efficient processing for QRS detection, averaging filter using correlation techniques and a step for RAZ detecting. Preliminary results show the efficiency of system and point to incorporation of techniques new using signal analysis with involving 12 leads.

  4. High Capacity Phase/Amplitude Modulated Optical Communication Systems and Nonlinear Inter-Channel Impairments

    Science.gov (United States)

    Tavassoli, Vahid

    This thesis studies and mathematically models nonlinear interactions among channels of modern high bit rate (amplitude/) phase modulated optical systems. First, phase modulated analogue systems are studied and a differential receiving method is suggested with experimental validation. The main focus of the rest of the thesis is on digital advanced modulation format systems. Cross-talk due to fiber Kerr nonlinearity in two-format hybrid systems as well as 16-QAM systems is mathematically modelled and verified by simulation for different system parameters. A comparative study of differential receivers and coherent receivers is also given for hybrid systems. The model is based on mathematically proven assumptions and provides an intuitive analytical understanding of nonlinear cross-talk in such systems.

  5. Pulsation analysis of the high amplitude δ Scuti star CW Serpentis

    Science.gov (United States)

    Niu, Jia-Shu; Fu, Jian-Ning; Zong, Wei-Kai

    2013-10-01

    Time-series photometric observations were made for the high amplitude δ Scuti star CW Ser between 2011 and 2012 at the Xinglong Station of National Astronomical Observatories, Chinese Academy of Sciences. After performing the frequency analysis of the light curves, we confirmed the fundamental frequency of f = 5.28677 c d-1, together with seven harmonics of the fundamental frequency, which are newly detected. No additional frequencies were detected. The O — C diagram, produced with the 21 newly determined times of maximum light combined with those provided in the literature, helps to obtain a new ephemeris formula of the times of maximum light with the pulsation period of 0.189150355 ± 0.000000003 d.

  6. Noninvasive respiratory support of juvenile rabbits by high-amplitude bubble continuous positive airway pressure.

    Science.gov (United States)

    Diblasi, Robert M; Zignego, Jay C; Tang, Dennis M; Hildebrandt, Jack; Smith, Charles V; Hansen, Thomas N; Richardson, C Peter

    2010-06-01

    Bubble continuous positive airway pressure (B-CPAP) applies small-amplitude, high-frequency oscillations in airway pressure (DeltaPaw) that may improve gas exchange in infants with respiratory disease. We developed a device, high-amplitude B-CPAP (HAB-CPAP), which provides greater DeltaPaw than B-CPAP provides. We studied the effects of different operational parameters on DeltaPaw and volumes of gas delivered to a mechanical infant lung model. In vivo studies tested the hypothesis that HAB-CPAP provides noninvasive respiratory support greater than that provided by B-CPAP. Lavaged juvenile rabbits were stabilized on ventilator nasal CPAP. The animals were then supported at the same mean airway pressure, bias flow, and fraction of inspired oxygen (FiO2) required for stabilization, whereas the bubbler angle was varied in a randomized crossover design at exit angles, relative to vertical, of 0 (HAB-CPAP0; equivalent to conventional B-CPAP), 90 (HAB-CPAP90), and 135 degrees (HAB-CPAP135). Arterial blood gases and pressure-rate product (PRP) were measured after 15 min at each bubbler angle. Pao2 levels were higher (p<0.007) with HAB-CPAP135 than with conventional B-CPAP. PaCO2 levels did not differ (p=0.073) among the three bubbler configurations. PRP with HAB-CPAP135 were half of the PRP with HAB-CPAP0 or HAB-CPAP90 (p=0.001). These results indicate that HAB-CPAP135 provides greater respiratory support than conventional B-CPAP does.

  7. A compact, low jitter, nanosecond rise time, high voltage pulse generator with variable amplitude

    Science.gov (United States)

    Mao, Jiubing; Wang, Xin; Tang, Dan; Lv, Huayi; Li, Chengxin; Shao, Yanhua; Qin, Lan

    2012-07-01

    In this paper, a compact, low jitter, nanosecond rise time, command triggered, high peak power, gas-switch pulse generator system is developed for high energy physics experiment. The main components of the system are a high voltage capacitor, the spark gap switch and R = 50 Ω load resistance built into a structure to obtain a fast high power pulse. The pulse drive unit, comprised of a vacuum planar triode and a stack of avalanche transistors, is command triggered by a single or multiple TTL (transistor-transistor logic) level pulses generated by a trigger pulse control unit implemented using the 555 timer circuit. The control unit also accepts user input TTL trigger signal. The vacuum planar triode in the pulse driving unit that close the first stage switches is applied to drive the spark gap reducing jitter. By adjusting the charge voltage of a high voltage capacitor charging power supply, the pulse amplitude varies from 5 kV to 10 kV, with a rise time of gas-switch and available capacitor recovery time.

  8. Detecting phase-amplitude coupling with high frequency resolution using adaptive decompositions.

    Science.gov (United States)

    Pittman-Polletta, Benjamin; Hsieh, Wan-Hsin; Kaur, Satvinder; Lo, Men-Tzung; Hu, Kun

    2014-04-15

    Phase-amplitude coupling (PAC)--the dependence of the amplitude of one rhythm on the phase of another, lower-frequency rhythm - has recently been used to illuminate cross-frequency coordination in neurophysiological activity. An essential step in measuring PAC is decomposing data to obtain rhythmic components of interest. Current methods of PAC assessment employ narrowband Fourier-based filters, which assume that biological rhythms are stationary, harmonic oscillations. However, biological signals frequently contain irregular and nonstationary features, which may contaminate rhythms of interest and complicate comodulogram interpretation, especially when frequency resolution is limited by short data segments. To better account for nonstationarities while maintaining sharp frequency resolution in PAC measurement, even for short data segments, we introduce a new method of PAC assessment which utilizes adaptive and more generally broadband decomposition techniques - such as the empirical mode decomposition (EMD). To obtain high frequency resolution PAC measurements, our method distributes the PAC associated with pairs of broadband oscillations over frequency space according to the time-local frequencies of these oscillations. We compare our novel adaptive approach to a narrowband comodulogram approach on a variety of simulated signals of short duration, studying systematically how different types of nonstationarities affect these methods, as well as on EEG data. Our results show: (1) narrowband filtering can lead to poor PAC frequency resolution, and inaccuracy and false negatives in PAC assessment; (2) our adaptive approach attains better PAC frequency resolution and is more resistant to nonstationarities and artifacts than traditional comodulograms. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Efficient Ultra-High Speed Communication with Simultaneous Phase and Amplitude Regenerative Sampling (SPARS)

    Science.gov (United States)

    Carlowitz, Christian; Girg, Thomas; Ghaleb, Hatem; Du, Xuan-Quang

    2017-08-01

    For ultra-high speed communication systems at high center frequencies above 100 GHz, we propose a disruptive change in system architecture to address major issues regarding amplifier chains with a large number of amplifier stages. They cause a high noise figure and high power consumption when operating close to the frequency limits of the underlying semiconductor technologies. Instead of scaling a classic homodyne transceiver system, we employ repeated amplification in single-stage amplifiers through positive feedback as well as synthesizer-free self-mixing demodulation at the receiver to simplify the system architecture notably. Since the amplitude and phase information for the emerging oscillation is defined by the input signal and the oscillator is only turned on for a very short time, it can be left unstabilized and thus come without a PLL. As soon as gain is no longer the most prominent issue, relaxed requirements for all the other major components allow reconsidering their implementation concepts to achieve further improvements compared to classic systems. This paper provides the first comprehensive overview of all major design aspects that need to be addressed upon realizing a SPARS-based transceiver. At system level, we show how to achieve high data rates and a noise performance comparable to classic systems, backed by scaled demonstrator experiments. Regarding the transmitter, design considerations for efficient quadrature modulation are discussed. For the frontend components that replace PA and LNA amplifier chains, implementation techniques for regenerative sampling circuits based on super-regenerative oscillators are presented. Finally, an analog-to-digital converter with outstanding performance and complete interfaces both to the analog baseband as well as to the digital side completes the set of building blocks for efficient ultra-high speed communication.

  10. A high-density ERP study reveals latency, amplitude, and topographical differences in multiple sclerosis patients versus controls.

    LENUS (Irish Health Repository)

    Whelan, R

    2012-02-01

    OBJECTIVE: To quantify latency, amplitude and topographical differences in event-related potential (ERP) components between multiple sclerosis (MS) patients and controls and to compare ERP findings with results from the paced auditory serial addition test (PASAT). METHODS: Fifty-four subjects (17 relapsing remitting (RRMS) patients, 16 secondary progressive (SPMS) patients, and 21 controls) completed visual and auditory oddball tasks while data were recorded from 134 EEG channels. Latency and amplitude differences, calculated using composite mean amplitude measures, were tested using an ANOVA. Topographical differences were tested using statistical parametric mapping (SPM). RESULTS: In the visual modality, P2, P3 amplitudes and N2 latency were significantly different across groups. In the auditory modality, P2, N2, and P3 latencies and N1 amplitude were significantly different across groups. There were no significant differences between RRMS and SPMS patients on any ERP component. There were topographical differences between MS patients and controls for both early and late components for the visual modality, but only in the early components for the auditory modality. PASAT score correlated significantly with auditory P3 latency for MS patients. CONCLUSIONS: There were significant ERP differences between MS patients and controls. SIGNIFICANCE: The present study indicated that both early sensory and later cognitive ERP components are impaired in MS patients relative to controls.

  11. Spline-based high-accuracy piecewise-polynomial phase-to-sinusoid amplitude converters.

    Science.gov (United States)

    Petrinović, Davor; Brezović, Marko

    2011-04-01

    We propose a method for direct digital frequency synthesis (DDS) using a cubic spline piecewise-polynomial model for a phase-to-sinusoid amplitude converter (PSAC). This method offers maximum smoothness of the output signal. Closed-form expressions for the cubic polynomial coefficients are derived in the spectral domain and the performance analysis of the model is given in the time and frequency domains. We derive the closed-form performance bounds of such DDS using conventional metrics: rms and maximum absolute errors (MAE) and maximum spurious free dynamic range (SFDR) measured in the discrete time domain. The main advantages of the proposed PSAC are its simplicity, analytical tractability, and inherent numerical stability for high table resolutions. Detailed guidelines for a fixed-point implementation are given, based on the algebraic analysis of all quantization effects. The results are verified on 81 PSAC configurations with the output resolutions from 5 to 41 bits by using a bit-exact simulation. The VHDL implementation of a high-accuracy DDS based on the proposed PSAC with 28-bit input phase word and 32-bit output value achieves SFDR of its digital output signal between 180 and 207 dB, with a signal-to-noise ratio of 192 dB. Its implementation requires only one 18 kB block RAM and three 18-bit embedded multipliers in a typical field-programmable gate array (FPGA) device.

  12. Study of readout architectures for triggerless high event rate detectors at CLIC

    CERN Document Server

    Kulis, S

    2011-01-01

    In this work possible readout architectures for future detectors at CLIC are discussed. These detectors will need a triggerless readout electronics with amplitude and time reconstruction and they may operate with very high event rates (≥ 1 hits / channel / bunch train of 156 ns). The main subject of this study, both theoretical and experimental, is a readout based on the deconvolution principle. The basic principle, the performance, the advantages and limitations of this technique are discussed. In the case of extremely high event rates (> 4 hits / channel / bunch train) a readout based on a gated integrator and correlated double sampling is proposed.

  13. High-amplitude electrical stimulation can reduce elicited neuronal activity in visual prosthesis

    Science.gov (United States)

    Barriga-Rivera, Alejandro; Guo, Tianruo; Yang, Chih-Yu; Abed, Amr Al; Dokos, Socrates; Lovell, Nigel H.; Morley, John W.; Suaning, Gregg J.

    2017-01-01

    Retinal electrostimulation is promising a successful therapy to restore functional vision. However, a narrow stimulating current range exists between retinal neuron excitation and inhibition which may lead to misperformance of visual prostheses. As the conveyance of representation of complex visual scenes may require neighbouring electrodes to be activated simultaneously, electric field summation may contribute to reach this inhibitory threshold. This study used three approaches to assess the implications of relatively high stimulating conditions in visual prostheses: (1) in vivo, using a suprachoroidal prosthesis implanted in a feline model, (2) in vitro through electrostimulation of murine retinal preparations, and (3) in silico by computing the response of a population of retinal ganglion cells. Inhibitory stimulating conditions led to diminished cortical activity in the cat. Stimulus-response relationships showed non-monotonic profiles to increasing stimulating current. This was observed in vitro and in silico as the combined response of groups of neurons (close to the stimulating electrode) being inhibited at certain stimulating amplitudes, whilst other groups (far from the stimulating electrode) being recruited. These findings may explain the halo-like phosphene shapes reported in clinical trials and suggest that simultaneous stimulation in retinal prostheses is limited by the inhibitory threshold of the retinal ganglion cells. PMID:28209965

  14. Skeletal bone morphology is resistant to the high amplitude seasonal leptin cycle in the Siberian hamster.

    Science.gov (United States)

    Rousseau, K; Atcha, Z; Denton, J; Cagampang, F R A; Ennos, A R; Freemont, A J; Loudon, A S I

    2005-09-01

    Recent studies have suggested that the adipocyte-derived hormone, leptin, plays a role in the regulation of metabolism. Here, we tested this hypothesis in the seasonally breeding Siberian hamster, as this species exhibits profound seasonal changes in adiposity and circulating leptin concentrations driven by the annual photoperiodic cycle. Male hamsters were kept in either long (LD) or short (SD) photoperiods. Following exposure to short photoperiods for 8 weeks animals exhibited a significant weight-loss and a 16-fold reduction of serum leptin concentrations. At Week 9, animals in both photoperiods were infused with leptin or PBS via osmotic mini-pump for 14 days. Chronic leptin infusion mimicked LD-like concentrations in SD-housed animals and caused a further decline in body weight and adipose tissue. In LD-housed animals, leptin infusion resulted in a significant elevation of serum concentrations above natural LD-like levels, but had no discernable effect on body weight or overall adiposity. Both bending and compression characteristics and histomorphometric measurements of trabecular bone mass were unaltered by leptin treatment or photoperiod. Our data therefore show that despite a high natural amplitude cycle of leptin, this hormone has no apparent role in the regulation of bone metabolism, and therefore do not support recent propositions that this hormone is an important component in the metabolism of bone tissue.

  15. High amplitude phase resetting in rev-erbalpha/per1 double mutant mice.

    Directory of Open Access Journals (Sweden)

    Corinne Jud

    Full Text Available Over time, organisms developed various strategies to adapt to their environment. Circadian clocks are thought to have evolved to adjust to the predictable rhythms of the light-dark cycle caused by the rotation of the Earth around its own axis. The rhythms these clocks generate persist even in the absence of environmental cues with a period of about 24 hours. To tick in time, they continuously synchronize themselves to the prevailing photoperiod by appropriate phase shifts. In this study, we disrupted two molecular components of the mammalian circadian oscillator, Rev-Erbalpha and Period1 (Per1. We found that mice lacking these genes displayed robust circadian rhythms with significantly shorter periods under constant darkness conditions. Strikingly, they showed high amplitude resetting in response to a brief light pulse at the end of their subjective night phase, which is rare in mammals. Surprisingly, Cry1, a clock component not inducible by light in mammals, became slightly inducible in these mice. Taken together, Rev-Erbalpha and Per1 may be part of a mechanism preventing drastic phase shifts in mammals.

  16. Computing transition rates for the 1-D stochastic Ginzburg--Landau--Allen--Cahn equation for finite-amplitude noise with a rare event algorithm

    CERN Document Server

    Rolland, J; Simonnet, E

    2015-01-01

    In this paper we compute and analyse the transition rates and duration of reactive trajectories of the stochastic 1-D Allen-Cahn equations for both the Freidlin-Wentzell regime (weak noise or temperature limit) and finite-amplitude white noise, as well as for small and large domain. We demonstrate that extremely rare reactive trajectories corresponding to direct transitions between two metastable states are efficiently computed using an algorithm called adaptive multilevel splitting. This algorithm is dedicated to the computation of rare events and is able to provide ensembles of reactive trajectories in a very efficient way. In the small noise limit, our numerical results are in agreement with large-deviation predictions such as instanton-like solutions, mean first passages and escape probabilities. We show that the duration of reactive trajectories follows a Gumbel distribution like for one degree of freedom systems. Moreover, the mean duration growths logarithmically with the inverse temperature. The prefa...

  17. The Spectral Amplitude of Stellar Convection and Its Scaling in the High-Rayleigh-number Regime

    Science.gov (United States)

    Featherstone, Nicholas A.; Hindman, Bradley W.

    2016-02-01

    Convection plays a central role in the dynamics of any stellar interior, and yet its operation remains largely hidden from direct observation. As a result, much of our understanding concerning stellar convection necessarily derives from theoretical and computational models. The Sun is, however, exceptional in that regard. The wealth of observational data afforded by its proximity provides a unique test bed for comparing convection models against observations. When such comparisons are carried out, surprising inconsistencies between those models and observations become apparent. Both photospheric and helioseismic measurements suggest that convection simulations may overestimate convective flow speeds on large spatial scales. Moreover, many solar convection simulations have difficulty reproducing the observed solar differential rotation owing to this apparent overestimation. We present a series of three-dimensional stellar convection simulations designed to examine how the amplitude and spectral distribution of convective flows are established within a star’s interior. While these simulations are nonmagnetic and nonrotating in nature, they demonstrate two robust phenomena. When run with sufficiently high Rayleigh number, the integrated kinetic energy of the convection becomes effectively independent of thermal diffusion, but the spectral distribution of that kinetic energy remains sensitive to both of these quantities. A simulation that has converged to a diffusion-independent value of kinetic energy will divide that energy between spatial scales such that low-wavenumber power is overestimated and high-wavenumber power is underestimated relative to a comparable system possessing higher Rayleigh number. We discuss the implications of these results in light of the current inconsistencies between models and observations.

  18. Quantifying the high-velocity, low-amplitude spinal manipulative thrust: a systematic review.

    Science.gov (United States)

    Downie, Aron S; Vemulpad, Subramanyam; Bull, Peter W

    2010-09-01

    The purpose of this study was to systematically review studies that quantify the high-velocity, low-amplitude (HVLA) spinal thrust, to qualitatively compare the apparatus used and the force-time profiles generated, and to critically appraise studies involving the quantification of thrust as an augmented feedback tool in psychomotor learning. A search of the literature was conducted to identify the sources that reported quantification of the HVLA spinal thrust. MEDLINE-OVID (1966-present), MANTIS-OVID (1950-present), and CINAHL-EBSCO host (1981-present) were searched. Eligibility criteria included that thrust subjects were human, animal, or manikin and that the thrust type was a hand-delivered HVLA spinal thrust. Data recorded were single force, force-time, or displacement-time histories. Publications were in English language and after 1980. The relatively small number of studies, combined with the diversity of method and data interpretation, did not enable meta-analysis. Twenty-seven studies met eligibility criteria: 17 studies measured thrust as a primary outcome (13 human, 2 cadaver, and 2 porcine). Ten studies demonstrated changes in psychomotor learning related to quantified thrust data on human, manikin, or other device. Quantifiable parameters of the HVLA spinal thrust exist and have been described. There remain a number of variables in recording that prevent a standardized kinematic description of HVLA spinal manipulative therapy. Despite differences in data between studies, a relationship between preload, peak force, and thrust duration was evident. Psychomotor learning outcomes were enhanced by the application of thrust data as an augmented feedback tool. Copyright © 2010 National University of Health Sciences. Published by Mosby, Inc. All rights reserved.

  19. Amplitude-integrated electroencephalographic activity is suppressed in preterm infants with high scores on illness severity

    NARCIS (Netherlands)

    ter Horst, Hendrik J.; Jongbloed-Pereboom, Marjolein; van Eykern, Leo A.; Bos, Arend F.

    2011-01-01

    Background: The neonatal acute physiology score. SNAP-II, reflects the severity of illness in newborns. In term newborns, amplitude integrated EEG (aEEG), is depressed following asphyxia. In preterm infants aEEG is discontinuous, and therefore more difficult to assess compared to term infants. Aims:

  20. A novel smart rotor support with shape memory alloy metal rubber for high temperatures and variable amplitude vibrations

    Science.gov (United States)

    Ma, Yanhong; Zhang, Qicheng; Zhang, Dayi; Scarpa, Fabrizio; Liu, Baolong; Hong, Jie

    2014-12-01

    The work describes the design, manufacturing and testing of a smart rotor support with shape memory alloy metal rubber (SMA-MR) elements, able to provide variable stiffness and damping characteristics with temperature, motion amplitude and excitation frequency. Differences in damping behavior and nonlinear stiffness between SMA-MR and more traditional metal rubber supports are discussed. The mechanical performance shown by the prototype demonstrates the feasibility of using the SMA-MR concept for active vibration control in rotordynamics, in particular at high temperatures and large amplitude vibrations.

  1. The influence of temperature dynamics and dynamic finite ion Larmor radius effects on seeded high amplitude plasma blobs

    DEFF Research Database (Denmark)

    Held, Magnus; Wiesenberger, M.; Madsen, Jens

    2016-01-01

    Thermal effects on the perpendicular convection of seeded pressure blobs in the scrape-off layer of magnetised fusion plasmas are investigated. Our numerical study is based on a four field full-F gyrofluid model, which entails the consistent description of high fluctuation amplitudes and dynamic...

  2. A single high dose of escitalopram increases mismatch negativity without affecting processing negativity or P300 amplitude in healthy volunteers

    DEFF Research Database (Denmark)

    Wienberg, M; Glenthøj, Birte Yding; Jensen, K S

    2009-01-01

    processing. The present study was designed to replicate and further extent the results of our initial study on the effects of a low dose of escitalopram (10 mg) on MMN, PN and P300 amplitude. In a randomised, double-blind, cross-over experiment, 20 healthy male volunteers received either a single, orally...... administered dose of 15 mg escitalopram (a highly selective serotonin reuptake inhibitor (SSRI)) or placebo, after which their PN, MMN and P300 amplitude were assessed. Similar to our initial study with 10 mg escitalopram, 15 mg escitalopram significantly increased MMN, while it did not affect P300 amplitude....... In contrast to our initial study, however, the currently higher dose of escitalopram did not increase PN. Results support the view that a broad range of increased serotonergic activity enhances MMN, while the relationship between serotonin and PN seems more complex. The current study does not support...

  3. An unusual very low-mass high-amplitude pre-main sequence periodic variable

    CERN Document Server

    Rodriguez-Ledesma, Maria V; Ibrahimov, Mansur; Messina, Sergio; Parihar, Padmakar; Hessman, Frederic; de Oliveira, Catarina Alves; Herbst, William

    2012-01-01

    We have investigated the nature of the variability of CHS7797, an unusual periodic variable in the Orion Nebula Cluster. An extensive I-band photometric data set of CHS7797 was compiled between 2004-2010 using various telescopes. Further optical data have been collected in R and z' bands. In addition, simultaneous observations of the ONC region including CHS7797 were performed in the I, J, Ks and IRAC [3.6] and [4.5] bands over a time interval of about 40d. CHS7797 shows an unusual large-amplitude variation of about 1.7 mag in the R, I, and z' bands with a period 17.786. The amplitude of the brightness modulation decreases only slightly at longer wavelengths. The star is faint during 2/3 of the period and the shape of the phased light-curves for seven different observing seasons shows minor changes and small-amplitude variations. Interestingly, there are no significant colour-flux correlations for wavelengths smaller than 2microns, while the object becomes redder when fainter at longer wavelengths. CHS7797 ha...

  4. Strong S-wave attenuation and actively degassing magma beneath Taal volcano, Philippines, inferred from source location analysis using high-frequency seismic amplitudes

    Science.gov (United States)

    Kumagai, H.; Lacson, R. _Jr., Jr.; Maeda, Y.; Figueroa, M. S., II; Yamashina, T.

    2014-12-01

    Taal volcano, Philippines, is one of the world's most dangerous volcanoes given its history of explosive eruptions and its close proximity to populated areas. A key feature of these eruptions is that the eruption vents were not limited to Main Crater but occurred on the flanks of Volcano Island. This complex eruption history and the fact that thousands of people inhabit the island, which has been declared a permanent danger zone, together imply an enormous potential for disasters. The Philippine Institute of Volcanology and Seismology (PHIVOLCS) constantly monitors Taal, and international collaborations have conducted seismic, geodetic, electromagnetic, and geochemical studies to investigate the volcano's magma system. Realtime broadband seismic, GPS, and magnetic networks were deployed in 2010 to improve monitoring capabilities and to better understand the volcano. The seismic network has recorded volcano-tectonic (VT) events beneath Volcano Island. We located these VT events based on high-frequency seismic amplitudes, and found that some events showed considerable discrepancies between the amplitude source locations and hypocenters determined by using onset arrival times. Our analysis of the source location discrepancies points to the existence of a region of strong S-wave attenuation near the ground surface beneath the east flank of Volcano Island. This region is beneath the active fumarolic area and above sources of pressure contributing inflation and deflation, and it coincides with a region of high electrical conductivity. The high-attenuation region matches that inferred from an active-seismic survey conducted at Taal in 1993. Our results, synthesized with previous results, suggest that this region represents actively degassing magma near the surface, and imply a high risk of future eruptions on the east flank of Volcano Island.

  5. Large-amplitude jumps and non-Gaussian dynamics in highly concentrated hard sphere fluids.

    Science.gov (United States)

    Saltzman, Erica J; Schweizer, Kenneth S

    2008-05-01

    Our microscopic stochastic nonlinear Langevin equation theory of activated dynamics has been employed to study the real-space van Hove function of dense hard sphere fluids and suspensions. At very short times, the van Hove function is a narrow Gaussian. At sufficiently high volume fractions, such that the entropic barrier to relaxation is greater than the thermal energy, its functional form evolves with time to include a rapidly decaying component at small displacements and a long-range exponential tail. The "jump" or decay length scale associated with the tail increases with time (or particle root-mean-square displacement) at fixed volume fraction, and with volume fraction at the mean alpha relaxation time. The jump length at the alpha relaxation time is predicted to be proportional to a measure of the decoupling of self-diffusion and structural relaxation. At long times corresponding to mean displacements of order a particle diameter, the volume fraction dependence of the decay length disappears. A good superposition of the exponential tail feature based on the jump length as a scaling variable is predicted at high volume fractions. Overall, the theoretical results are in good accord with recent simulations and experiments. The basic aspects of the theory are also compared with a classic jump model and a dynamically facilitated continuous time random-walk model. Decoupling of the time scales of different parts of the relaxation process predicted by the theory is qualitatively similar to facilitated dynamics models based on the concept of persistence and exchange times if the elementary event is assumed to be associated with transport on a length scale significantly smaller than the particle size.

  6. High Performance of Space Vector Modulation Direct Torque Control SVM-DTC Based on Amplitude Voltage and Stator Flux Angle

    Directory of Open Access Journals (Sweden)

    Hassan Farhan Rashag

    2013-04-01

    Full Text Available Various aspects related to controlling induction motor are investigated. Direct torque control is an original high performance control strategy in the field of AC drive. In this proposed method, the control system is based on Space Vector Modulation (SVM, amplitude of voltage in direct- quadrature reference frame (d-q reference and angle of stator flux. Amplitude of stator voltage is controlled by PI torque and PI flux controller. The stator flux angle is adjusted by rotor angular frequency and slip angular frequency. Then, the reference torque and the estimated torque is applied to the input of PI torque controller and the control quadrature axis voltage is determined. The control d-axis voltage is determined from the flux calculator. These q and d axis voltage are converted into amplitude voltage. By applying polar to Cartesian on amplitude voltage and stator flux angle, direct voltage and quadratures voltage are generated. The reference stator voltages in d-q are calculated based on forcing the stator voltage error to zero at next sampling period. By applying inverse park transformation on d-q voltages, the stator voltages in &alpha and &beta frame are generated and apply to SVM. From the output of SVM, the motor control signal is generated and the speed of the induction motor regulated toward the rated speed. The simulation Results have demonstrated exceptional performance in steady and transient states and shows that decrease of torque and flux ripples is achieved in a complete speed range.

  7. Evaluation of a Hopkinson bar fly-away technique for high amplitude shock accelerometer calibration

    Energy Technology Data Exchange (ETDEWEB)

    Togami, T.C.; Bateman, V.I.; Brown, F.A.

    1997-11-01

    A split Hopkinson bar technique has been developed to evaluate the performance of accelerometers that measure large amplitude pulses. An evaluation of this technique has been conducted in the Mechanical Shock Laboratory at Sandia National Laboratories (SNL) to determine its use in the practical calibration of accelerometers. This evaluation consisted of three tasks. First, the quartz crystal was evaluated in a split Hopkinson bar configuration to evaluate the quartz gage`s sensitivity and frequency response at force levels of 18,000, 35,000 and 53,000 N at ambient temperature, {minus}48 C and +74 C. Secondly, the fly away technique was evaluated at shock amplitudes of 50,000, 100,000, 150,000 and 200,000 G (1 G = 9.81 m/s{sup 2}) at ambient temperature, {minus}48 C and +74 C. Lastly, the technique was performed using a NIST calibrated reference accelerometer. Comparisons of accelerations calculated from the quartz gage data and the measured acceleration data have shown very good agreement. Based on this evaluation, the authors expect this split Hopkinson fly away technique to be certified by the SNL Primary Standards Laboratory.

  8. Implications of high amplitude atmospheric CO2 fluctuations on past millennium climate change

    Science.gov (United States)

    van Hoof, Thomas; Kouwenberg, Lenny; Wagner-Cremer, Friederike; Visscher, Henk

    2010-05-01

    Stomatal frequency analysis of leaves of land plants preserved in peat and lake deposits can provide a proxy record of pre-industrial atmospheric CO2 concentration complementary to measurements in Antarctic ice cores. Stomatal frequency based CO2 trends from the USA and NW European support the presence of significant CO2 variability during the first half of the last millennium (Kouwenberg et al., 2005; Wagner et al., 2004; van Hoof et al., 2008). The timing of the most significant perturbation in the stomata records (1200 AD) is in agreement with an observed CO2 fluctuation in the D47 Antarctic ice-core record (Barnola et al., 1995; van Hoof et al., 2005). The amplitude of the stomatal frequency based CO2 changes (> 34ppmv) exceeds the maximum amplitude of CO2 variability in the D47 ice core (Proceedings of the National Academy of Sciences of the USA, v. 105, no. 41, pp. 15815-15818 Wagner F., L.L.R. Kouwenberg, T.B. van Hoof and H. Visscher 2004. Reproducibility of Holocene atmospheric CO2 records based on stomatal frequency. Quartenary Science Reviews. V. 23, pp. 1947-1954

  9. High-Energy Solar Particle Events in Cycle 24

    Science.gov (United States)

    Gopalswamy, N.; Makela, P.; Yashiro, S.; Xie, H.; Akiyama, S.; Thakur, N.

    2015-01-01

    The Sun is already in the declining phase of cycle 24, but the paucity of high-energy solar energetic particle (SEP) events continues with only two ground level enhancement (GLE) events as of March 31, 2015. In an attempt to understand this, we considered all the large SEP events of cycle 24 that occurred until the end of 2014. We compared the properties of the associated CMEs with those in cycle 23. We found that the CME speeds in the sky plane were similar, but almost all those cycle-24 CMEs were halos. A significant fraction of (16%) of the frontside SEP events were associated with eruptive prominence events. CMEs associated with filament eruption events accelerate slowly and attain peak speeds beyond the typical GLE release heights. When we considered only western hemispheric events that had good connectivity to the CME nose, there were only 8 events that could be considered as GLE candidates. One turned out to be the first GLE event of cycle 24 (2012 May 17). In two events, the CMEs were very fast (>2000 km/s) but they were launched into a tenuous medium (high Alfven speed). In the remaining five events, the speeds were well below the typical GLE CME speed (2000 km/s). Furthermore, the CMEs attained their peak speeds beyond the typical heights where GLE particles are released. We conclude that several factors contribute to the low rate of high-energy SEP events in cycle 24: (i) reduced efficiency of shock acceleration (weak heliospheric magnetic field), (ii) poor latitudinal and longitudinal connectivity), and (iii) variation in local ambient conditions (e.g., high Alfven speed).

  10. Short duration high amplitude flares detected on the M dwarf star KIC 5474065

    CERN Document Server

    Ramsay, Gavin; Hakala, Pasi; Garcia-Alvarez, David; Brooks, Adam; Barclay, Thomas; Still, Martin

    2013-01-01

    Using data obtained during the RATS-Kepler project we identified one short duration flare in a 1 hour sequence of ground based photometry of the dwarf star KIC 5474065. Observations made using GTC show it is a star with a M4 V spectral type. Kepler observations made using 1 min sampling show that KIC 5474065 exhibits large amplitude (deltaF/F>0.4) optical flares which have a duration as short as 10 mins. We compare the energy distribution of flares from KIC 5474065 with that of KIC 9726699, which has also been observed using 1 min sampling, and ground based observations of other M dwarf stars in the literature. We discuss the possible implications of these short duration, relatively low energy flares would have on the atmosphere of exo-planets orbiting in the habitable zone of these flare stars.

  11. Multiband Carrierless Amplitude Phase Modulation for High Capacity Optical Data Links

    DEFF Research Database (Denmark)

    Iglesias Olmedo, Miguel; Zuo, Tianjian; Jensen, Jesper Bevensee

    2014-01-01

    packaging. Therefore, increasing effort is now put into the possibility of exploiting higher order modulation formats with increased spectral efficiency and reduced optical transceiver complexity. As these type of links are based on intensity modulation and direct detection, modulation formats relying...... on optical coherent detection can not be straight forwardly employed. As an alternative and more viable solution, this paper proposes the use of carrierless amplitude phase (CAP) in a novel multiband approach (MultiCAP) that achieves record spectral efficiency, increases tolerance towards dispersion......Short range optical data links are experiencing bandwidth limitations making it very challenging to cope with the growing data transmission capacity demands. Parallel optics appears as a valid short-term solution. It is, however, not a viable solution in the long-term because of its complex optical...

  12. Using domain walls to perform non-local measurements with high spin signal amplitudes

    Science.gov (United States)

    Savero Torres, W.; Pham, V.-T.; Zahnd, G.; Laczkowski, P.; Nguyen, V.-D.; Beigné, C.; Notin, L.; Jamet, M.; Marty, A.; Vila, L.; Attané, J.-P.

    2016-07-01

    Standard non-local measurements require lateral spin-valves with two different ferromagnetic electrodes, to create and to detect the spin accumulation. Here we show that non-local measurements can also be performed in a cross-shaped nanostructure, made of a single ferromagnetic wire connected to an orthogonal non-magnetic wire. A magnetic domain wall located underneath the ferromagnetic/non-magnetic interface is used to control the magnetizations of the injection and detection zones. As these zones can be very close, our results display spin signals possessing amplitudes larger than those obtained in conventional non-local measurements. We also show that this method can be used as a domain wall detection technique.

  13. The Spectral Amplitude of Stellar Convection and its Scaling in the High-Rayleigh-Number Regime

    CERN Document Server

    Featherstone, Nicholas A

    2015-01-01

    Convection plays a central role in the dynamics of any stellar interior, and yet its operation remains largely-hidden from direct observation. As a result, much of our understanding concerning stellar convection necessarily derives from theoretical and computational models. The Sun is, however, exceptional in that regard. The wealth of observational data afforded by its proximity provides a unique testbed for comparing convection models against observations. When such comparisons are carried out, surprising inconsistencies between those models and observations become apparent. Both photospheric and helioseismic measurements suggest that convection simulations may overestimate convective flow speeds on large spatial scales. Moreover, many solar convection simulations have difficulty reproducing the observed solar differential rotation due to this apparent overestimation. We present a series of 3-dimensional (3-D) stellar convection simulations designed to examine how the amplitude and spectral distribution of ...

  14. High-energy solar particle events in cycle 24

    CERN Document Server

    Gopalswamy, Nat; Yashiro, Seiji; Xie, Hong; Akiyama, Sachiko; Thakur, Neeharika

    2015-01-01

    The Sun is already in the declining phase of cycle 24, but the paucity of high-energy solar energetic particle (SEP) events continues with only two ground level enhancement (GLE) events as of March 31, 2015. In an attempt to understand this, we considered all the large SEP events of cycle 24 that occurred until the end of 2014. We compared the properties of the associated CMEs with those in cycle 23. We found that the CME speeds in the sky plane were similar, but almost all those cycle-24 CMEs were halos. A significant fraction of (16%) of the frontside SEP events were associated with eruptive prominence events. CMEs associated with filament eruption events accelerate slowly and attain peak speeds beyond the typical GLE release heights. When we considered only western hemispheric events that had good connectivity to the CME nose, there were only 8 events that could be considered as GLE candidates. One turned out to be the first GLE event of cycle 24 (2012 May 17). In two events, the CMEs were very fast (>2000...

  15. The effects of photobiomodulation and low-amplitude high-frequency vibration on bone healing process: a comparative study.

    Science.gov (United States)

    Rajaei Jafarabadi, M; Rouhi, G; Kaka, G; Sadraie, S H; Arum, J

    2016-12-01

    This study aimed at investigating the effects of photobiomodulation (PBM) and low-amplitude high-frequency (LAHF) whole body mechanical vibration on bone fracture healing process when metallic plates are implanted in rats' femurs. Forty male rats weighing between 250 and 350 g, 12 weeks old, were employed in this study. A transverse critical size defect (CSD) was made in their right femurs that were fixed by stainless steel plates. After the surgery, the rats were divided equally into four groups: low-level laser therapy group (GaAlAs laser, 830 nm, 40 mW, 4 J/cm(2), 0.35 cm beam diameter, LLLT), whole body vibration group (60 Hz, 0.1 mm amplitude, 1.5 g, WBV), a combination of laser and vibration group (LV), and the control group (C). Each group was divided into two subgroups based on sacrifice dates. The rats were sacrificed at intervals of 3 and 6 weeks after the surgery to extract their right femurs for radiography and biomechanical and histological analyses, and the results were analyzed using standard statistical methods. Radiographic analyses showed greater callus formation in the LLLT and WBV groups than in control group at both 3 (P low-amplitude high-frequency WBV both had a positive impact on bone healing process, for critical size defects in the presence of a stainless steel implant. But their combination, i.e., low-level laser therapy and low-amplitude high-frequency whole body vibration (LV), interestingly did not accelerate the fractured bone healing process.

  16. Association among parental substance use disorder, p300 amplitude, and neurobehavioral disinhibition in preteen boys at high risk for substance use disorder.

    Science.gov (United States)

    Habeych, Miguel E; Sclabassi, Robert J; Charles, Prophete J; Kirisci, Levent; Tarter, Ralph E

    2005-06-01

    The P300 amplitude of the event-related potential as a mediator of the association between parental substance use disorder (SUD) and child's neurobehavioral disinhibition was assessed. The P300 amplitude was recorded using an oddball task in sons of fathers having either lifetime SUD (n = 105) or no psychiatric disorder (n = 160). Neurobehavioral disinhibition was assessed using measures of affect regulation, behavior control, and executive cognitive function. Parental SUD and child's P300 amplitude accounted for, respectively, 16.6% and 16.8% of neurobehavioral disinhibition variance. Controlling for parental and child psychopathology, an association between parental SUD and child's P300 amplitude was not observed. It was concluded that the P300 amplitude does not mediate the association between parental SUD and child's neurobehavioral disinhibition.

  17. The MACHO Project Sample of Galactic Bulge High-Amplitude Scuti Stars: Pulsation Behavior and Stellar Properties

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, D.P.; Cook, K.H.; Freeman, K.C.; Geha, M.; Griest, K.; Lehner, M.J.; Marshall, S.L.; McNamara, B.J.; Minniti, D.; Nelson, C.; Peterson, B.A.; Popowski, P.; Pratt, M.R.; Quinn, P.J.; Rodgers, A.W.; Sutherland, W.; Templeton, M.R.; Vandehei, T.; Welch, D.L.

    1999-11-16

    We have detected 90 objects with periods and lightcurve structure similar to those of field {delta} Scuti stars, using the Massive Compact Halo Object (MACHO) Project database of Galactic bulge photometry. If we assume similar extinction values for all candidates and absolute magnitudes similar to those of other field high-amplitude {delta} Scuti stars (HADS), the majority of these objects lie in or near the Galactic bulge. At least two of these objects are likely foreground {delta} Scuti stars, one of which may be an evolved nonradial pulsator, similar to other evolved, disk-population {delta} Scuti stars. We have analyzed the light curves of these objects and find that they are similar to the light curves of field {delta} Scuti stars and the {delta} Scuti stars found by the Optical Gravitational Lens Experiment (OGLE). However, the amplitude distribution of these sources lies between those of low- and high-amplitude {delta} Scuti stars, which suggests that they may be an intermediate population. We have found nine double-mode HADS with frequency ratios ranging from 0.75 to 0.79, four probable double- and multiple-mode objects, and another four objects with marginal detections of secondary modes. The low frequencies (5-14 cycles d{sup -1}) and the observed period ratios of {approx}0.77 suggest that the majority of these objects are evolved stars pulsating in fundamental or first overtone radial modes.

  18. Stability analysis of amplitude death in delay-coupled high-dimensional map networks and their design procedure

    Science.gov (United States)

    Watanabe, Tomohiko; Sugitani, Yoshiki; Konishi, Keiji; Hara, Naoyuki

    2017-01-01

    The present paper studies amplitude death in high-dimensional maps coupled by time-delay connections. A linear stability analysis provides several sufficient conditions for an amplitude death state to be unstable, i.e., an odd number property and its extended properties. Furthermore, necessary conditions for stability are provided. These conditions, which reduce trial-and-error tasks for design, and the convex direction, which is a popular concept in the field of robust control, allow us to propose a design procedure for system parameters, such as coupling strength, connection delay, and input-output matrices, for a given network topology. These analytical results are confirmed numerically using delayed logistic maps, generalized Henon maps, and piecewise linear maps.

  19. Computing Transition Rates for the 1-D Stochastic Ginzburg-Landau-Allen-Cahn Equation for Finite-Amplitude Noise with a Rare Event Algorithm

    Science.gov (United States)

    Rolland, Joran; Bouchet, Freddy; Simonnet, Eric

    2016-01-01

    In this article we compute and analyse the transition rates and duration of reactive trajectories of the stochastic 1-D Allen-Cahn equations for both the Freidlin-Wentzell regime (weak noise or temperature limit) and finite-amplitude white noise, as well as for small and large domain. We demonstrate that extremely rare reactive trajectories corresponding to direct transitions between two metastable states are efficiently computed using an algorithm called adaptive multilevel splitting. This algorithm is dedicated to the computation of rare events and is able to provide ensembles of reactive trajectories in a very efficient way. In the small noise limit, our numerical results are in agreement with large-deviation predictions such as instanton-like solutions, mean first passages and escape probabilities. We show that the duration of reactive trajectories follows a Gumbel distribution like for one degree of freedom systems. Moreover, the mean duration growths logarithmically with the inverse temperature. The prefactor given by the potential curvature grows exponentially with size. The main novelty of our work is that we also perform an analysis of reactive trajectories for large noises and large domains. In this case, we show that the position of the reactive front is essentially a random walk. This time, the mean duration grows linearly with the inverse temperature and quadratically with the size. Using a phenomenological description of the system, we are able to calculate the transition rate, although the dynamics is described by neither Freidlin-Wentzell or Eyring-Kramers type of results. Numerical results confirm our analysis.

  20. Acoustic minor losses in high amplitude resonators with single-sided junctions

    Science.gov (United States)

    Doller, Andrew J.

    Steady flow engineering handbooks like Idelchik20 do not exist for investigators interested in acoustic (oscillating) fluid flows in complex resonators. Measurements of acoustic minor loss coefficients are presented in this dissertation for a limited number of resonator configurations having single-sided junctions. While these results may be useful, the greater purpose of this work is to provide a set of controlled measurements that can be used to benchmark computational models of acoustic flows used for more complicated resonator structures. The experiments are designed around a driver operating at 150 Hz enabling acoustic pressures in excess of 10k Pa in liquid cooled, temperature controlled resonators with 90°, 45° and 25° junctions. These junctions join a common 109 cm long 4.7 cm diameter section to a section of 8.4 mm diameter tube making two sets of resonators: one set with a small diameter length approximately a quarter-wavelength (45 cm), the other approximately a half-wavelength (112 cm). The long resonators have a velocity node at the junction; the short resonators have a velocity anti-node generating the greatest minor losses. Input power is measured by an accelerometer and a pressure transducer at the driver. A pressure sensor at the rigid termination measures radiation pressure from the driver and static junction pressure, as well as the acoustic pressure used to calculate linear thermal and viscous resonator wall losses. At the largest amplitudes, the 90° junction was found to dissipate as much as 0.3 Watt, 1/3 the power of linear losses alone. For each junction, the power dissipation depends on acoustic pressure differently: pressure cubed for the 90°, pressure to the 3.76 for the 45° and pressure to the 4.48 for the 25°. Common among all resonators, blowing acoustic half-cycle minor losses (KB) are excited at lower amplitudes than the suction half-cycle (KS) minor losses. Data collected for the 90° junction shows KB reaches an asymptotic

  1. High sensitivity phonon-mediated kinetic inductance detector with combined amplitude and phase read-out

    Science.gov (United States)

    Cardani, L.; Casali, N.; Colantoni, I.; Cruciani, A.; Bellini, F.; Castellano, M. G.; Cosmelli, C.; D'Addabbo, A.; Di Domizio, S.; Martinez, M.; Tomei, C.; Vignati, M.

    2017-01-01

    Developing wide-area cryogenic light detectors with baseline resolution better than 20 eV is one of the priorities of next generation bolometric experiments searching for rare interactions, as the simultaneous read-out of the light and heat signals enables background suppression through particle identification. Among the proposed technological approaches for the phonon sensor, the naturally multiplexed Kinetic Inductance Detectors (KIDs) stand out for their excellent intrinsic energy resolution and reproducibility. The potential of this technique was proved by the CALDER project that reached a baseline resolution of 154 ± 7 eV RMS by sampling a 2 × 2 cm2 Silicon substrate with 4 Aluminum KIDs. In this paper, we present a prototype of Aluminum KID with improved geometry and quality factor. The design improvement, as well as the combined analysis of amplitude and phase signals, allowed to reach a baseline resolution of 82 ± 4 eV by sampling the same substrate with a single Aluminum KID.

  2. Resolving longitudinal amplitude and phase information of two continuous data streams for high-speed and real-time processing

    Directory of Open Access Journals (Sweden)

    A. Guntoro

    2009-05-01

    Full Text Available Although there is an increase of performance in DSPs, due to its nature of execution a DSP could not perform high-speed data processing on a continuous data stream. In this paper we discuss the hardware implementation of the amplitude and phase detector and the validation block on a FPGA. Contrary to the software implementation which can only process data stream as high as 1.5 MHz, the hardware approach is 225 times faster and introduces much less latency.

  3. Surrogate data modeling the relationship between high frequency amplitudes and Higuchi fractal dimension of EEG signals in anesthetized rats.

    Science.gov (United States)

    Spasic, Sladjana; Kalauzi, Aleksandar; Kesic, Srdjan; Obradovic, Milica; Saponjic, Jasna

    2011-11-21

    We used spectral analysis and Higuchi fractal dimension (FD) to correlate the EEG spectral characteristics of the sensorimotor cortex, hippocampus, and pons with their corresponding EEG signal complexities in anesthetized rats. We have explored the quantitative relationship between the mean FDs and EEG wide range high frequency (8-50 Hz) activity during ketamine/xylazine versus nembutal anesthesia at surgical plane. Using FD we detected distinct inter-structure complexity pattern and uncovered for the first time that the polygraphically and behaviorally defined anesthetized state at surgical plane as equal during experiment in two anesthetic regimens, is not the same with respect to the degree of neuronal activity (degree of generalized neuronal inhibition achieved) at different brain levels. Using the correlation of certain brain structure EEG spectral characteristics with their corresponding FDs, and the surrogate data modeling, we determined what particular frequency band contributes to EEG complexities in ketamine/xylazine versus nembutal anesthesia. In this study we have shown that the quantitative relationship between higher frequency EEG amplitude and EEG complexity is the best-modeled by surrogate data as a 3rd order polynomial. On the base of our EEG amplitude/EEG complexity relationship model, and the evidenced spectral differences in ketamine versus nembutal anesthesia we have proved that higher amplitudes of sigma, beta, and gamma frequency in ketamine anesthesia yields to higher FDs.

  4. Consequence Prioritization Process for Potential High Consequence Events (HCE)

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, Sarah G. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-10-31

    This document describes the process for Consequence Prioritization, the first phase of the Consequence-Driven Cyber-Informed Engineering (CCE) framework. The primary goal of Consequence Prioritization is to identify potential disruptive events that would significantly inhibit an organization’s ability to provide the critical services and functions deemed fundamental to their business mission. These disruptive events, defined as High Consequence Events (HCE), include both events that have occurred or could be realized through an attack of critical infrastructure owner assets. While other efforts have been initiated to identify and mitigate disruptive events at the national security level, such as Presidential Policy Directive 41 (PPD-41), this process is intended to be used by individual organizations to evaluate events that fall below the threshold for a national security. Described another way, Consequence Prioritization considers threats greater than those addressable by standard cyber-hygiene and includes the consideration of events that go beyond a traditional continuity of operations (COOP) perspective. Finally, Consequence Prioritization is most successful when organizations adopt a multi-disciplinary approach, engaging both cyber security and engineering expertise, as in-depth engineering perspectives are required to recognize and characterize and mitigate HCEs. Figure 1 provides a high-level overview of the prioritization process.

  5. Achieving High Resolution Timer Events in Virtualized Environment.

    Science.gov (United States)

    Adamczyk, Blazej; Chydzinski, Andrzej

    2015-01-01

    Virtual Machine Monitors (VMM) have become popular in different application areas. Some applications may require to generate the timer events with high resolution and precision. This however may be challenging due to the complexity of VMMs. In this paper we focus on the timer functionality provided by five different VMMs-Xen, KVM, Qemu, VirtualBox and VMWare. Firstly, we evaluate resolutions and precisions of their timer events. Apparently, provided resolutions and precisions are far too low for some applications (e.g. networking applications with the quality of service). Then, using Xen virtualization we demonstrate the improved timer design that greatly enhances both the resolution and precision of achieved timer events.

  6. The High Latitude D Region During Electron Precipitation Events

    Science.gov (United States)

    Hargreaves, J. K.; Collis, P. N.; Korth, A.

    1984-01-01

    The fluxes of energetic electrons entering the high-latitude atmosphere during auroral radio absorption events and their effect on the electron density in the auroral D region are discussed. An attempt was made to calculate the radio absorption during precipitation events from the fluxes of energetic electrons measured at geosynchronous orbit, and then to consider the use of absorption measurements to indicate the magnetospheric particle fluxes, the production rates, and electron densities in the D region.

  7. High latitude D region during electron precipitation events

    Energy Technology Data Exchange (ETDEWEB)

    Hargreaves, J.K.; Collis, P.N.; Korth, A.

    1984-05-01

    The fluxes of energetic electrons entering the high-latitude atmosphere during auroral radio absorption events and their effect on the electron density in the auroral D region are discussed. An attempt was made to calculate the radio absorption during precipitation events from the fluxes of energetic electrons measured at geosynchronous orbit, and then to consider the use of absorption measurements to indicate the magnetospheric particle fluxes, the production rates, and electron densities in the D region.

  8. High-Resolution Structural Monitoring of Ionospheric Absorption Events

    Science.gov (United States)

    2013-07-01

    figure 1, taken from observations by the 30 MHz riometer operating at the High Frequency Active Auroral Research Program ( HAARP ) facility in Alaska...1200 UTC and persisting for the next two days. Figure 3 shows two records from the HAARP 30 MHz riometer, pasted together to cover 20 November 2003...absorption event seen by HAARP 30 MHz riometer. Figure 2: Electron depletion event 8 observed by HEO-3 satellite on 20 November 2003. Figure 3

  9. High Energy Asymptotics of the Scattering Amplitude for the Schrödinger Equation

    Indian Academy of Sciences (India)

    D Yafaev

    2002-02-01

    We find an explicit function approximating at high energies the kernel of the scattering matrix with arbitrary accuracy. Moreover, the same function gives all diagonal singularities of the kernel of the scattering matrix in the angular variables.

  10. High amplitude vortex-induced pulsations in a gas transport system

    NARCIS (Netherlands)

    Kriesels, P.C.; Peters, M.C.A.M.; Hirschberg, A.; Wijnands, A.P.J.; Iafrati, A.; Riccardi, G.; Piva, R.; Bruggeman, J.C.

    1995-01-01

    High Reynolds number, low Mach number gas flows in pipe systems with closed side branches exhibit spectacular low frequency self-sustained pulsations driven by periodic vortex shedding at specific values of the Strouhal number. A detailed study is presented of the behaviour of the flow in a system w

  11. Amplitude limits and nonlinear damping of shear-Alfvén waves in high-beta low-collisionality plasmas

    Science.gov (United States)

    Squire, J.; Schekochihin, A. A.; Quataert, E.

    2017-05-01

    This work, which extends Squire et al (Astrophys. J. Lett. 2016 830 L25), explores the effect of self-generated pressure anisotropy on linearly polarized shear-Alfvén fluctuations in low-collisionality plasmas. Such anisotropies lead to stringent limits on the amplitude of magnetic perturbations in high-β plasmas, above which a fluctuation can destabilize itself through the parallel firehose instability. This causes the wave frequency to approach zero, ‘interrupting’ the wave and stopping its oscillation. These effects are explored in detail in the collisionless and weakly collisional ‘Braginskii’ regime, for both standing and traveling waves. The focus is on simplified models in one dimension, on scales much larger than the ion gyroradius. The effect has interesting implications for the physics of magnetized turbulence in the high-β conditions that are prevalent in many astrophysical plasmas.

  12. Low amplitude insult project: PBX 9501 high explosive violent reaction experiments

    Energy Technology Data Exchange (ETDEWEB)

    Idar, D.J.; Lucht, R.A.; Straight, J.W.; Scammon, R.J.; Browning, R.V.; Middleditch, J.; Dienes, J.K.; Skidmore, C.B.; Buntain, G.A.

    1998-12-31

    The Modified Steven test geometry has been used with several different target designs to investigate the mechanical loading behavior of PBX 9501 to a low velocity impact. A 2 kg. mild steel spigot projectile is launched via a new powder driven gun design, from {approximately} 20 to 105 m/s, at lightly confined, steel targets. Brief descriptions of the gun design and operation are given. The threshold velocity to reaction for various target designs, different PBX 9501 lots, and different high explosive (HE) thicknesses are reported and compared. Various diagnostics have been employed to evaluate the pressure profile and timing, and target strain behavior relative to projectile impact. The violence of reaction, as measured by both passive and active techniques, is reported relative to a steady state detonation in PBX 9501. Experimental results suggest slightly different ignition mechanisms dominate based on (HE) thickness, resulting in delayed reactions from {approximately} 0.2- to 2.8-ms after impact. Post-test analyses of the PBX 9501 are briefly summarized.

  13. Low amplitude insult project: PBX 9501 high explosive violent reaction experiments

    Energy Technology Data Exchange (ETDEWEB)

    Idar, D.J.; Lucht, R.A.; Straight, J.W.; Scammon, R.J.; Browning, R.V.; Middleditch, J.; Dienes, J.K.; Skidmore, C.B.; Buntain, G.A.

    1998-12-31

    The Modified Steven test geometry has been used with several different target designs to investigate the mechanical loading behavior of PBX 9501 to a low velocity impact. A 2 kg. mild steel spigot projectile is launched via a new powder driven gun design, from {approximately} 20 to 105 m/s, at lightly confined, steel targets. Brief descriptions of the gun design and operation are given. The threshold velocity to reaction for various target designs, different PBX 9501 lots, and different high explosive (HE) thicknesses are reported and compared. Various diagnostics have been employed to evaluate the pressure profile and timing, and target strain behavior relative to projectile impact. The violence of reaction, as measured by both passive and active techniques, is reported relative to a steady state detonation in PBX 9501. Experimental results suggest slightly different ignition mechanisms dominate based on (HE) thickness, resulting in delayed reactions from {approximately} 0.2- to 2.8-ms after impact. Post-test analyses of the PBX 9501 are briefly summarized.

  14. An ATLAS event with a high mass dijet system

    CERN Multimedia

    ATLAS, Experiment

    2014-01-01

    Event with a high mass dijet system: the invariant mass of the two highest-pT jets is 2.55 TeV. The highest pT jet has a pT of 420 GeV, and an eta of -1.51, the second leading jet has pT of 320 GeV and an eta of 2.32. Jet momenta are calibrated according to the "EM+JES" scheme. No other jets are found with pT above 20 GeV. Event collected on 4 July 2010.

  15. A highly asymmetric dijet event of the ATLAS experiment

    CERN Multimedia

    ATLAS, Experiment

    2014-01-01

    A highly asymmetric dijet event, with one jet with ET > 100 GeV and no evident recoiling jet, and with high energy calorimeter cell deposits distributed over a wide azimuthal region. Only tracks with pT > 2.6 GeV are shown, and only calorimeter energy deposits with cell energy ET > 700 MeV in the electromagnetic calorimeter, and E > 1 GeV in the hadronic calorimeter.

  16. Morphology of High-Multiplicity Events in Heavy Ion Collisions

    CERN Document Server

    Naselsky, P; Christensen, P R; Damgaard, P H; Frejsel, A; Gaardhøje, J J; Hansen, A; Hansen, M; Kim, J; Verkhodanov, O; Wiedemann, U A

    2012-01-01

    We discuss opportunities that may arise from subjecting high-multiplicity events in relativistic heavy ion collisions to an analysis similar to the one used in cosmology for the study of fluctuations of the Cosmic Microwave Background (CMB). To this end, we discuss examples of how pertinent features of heavy ion collisions including global characteristics, signatures of collective flow and event-wise fluctuations are visually represented in a Mollweide projection commonly used in CMB analysis, and how they are statistically analyzed in an expansion over spherical harmonic functions. If applied to the characterization of purely azimuthal dependent phenomena such as collective flow, the expansion coefficients of spherical harmonics are seen to contain redundancies compared to the set of harmonic flow coefficients commonly used in heavy ion collisions. Our exploratory study indicates, however, that these redundancies may offer novel opportunities for a detailed characterization of those event-wise fluctuations t...

  17. Achieving High Resolution Timer Events in Virtualized Environment.

    Directory of Open Access Journals (Sweden)

    Blazej Adamczyk

    Full Text Available Virtual Machine Monitors (VMM have become popular in different application areas. Some applications may require to generate the timer events with high resolution and precision. This however may be challenging due to the complexity of VMMs. In this paper we focus on the timer functionality provided by five different VMMs-Xen, KVM, Qemu, VirtualBox and VMWare. Firstly, we evaluate resolutions and precisions of their timer events. Apparently, provided resolutions and precisions are far too low for some applications (e.g. networking applications with the quality of service. Then, using Xen virtualization we demonstrate the improved timer design that greatly enhances both the resolution and precision of achieved timer events.

  18. High-amplitude THz and GHz strain waves, generated by ultrafast screening of piezoelectric fields in InGaN/GaN multiple quantum wells

    DEFF Research Database (Denmark)

    Porte, Henrik; van Capel, P.J.S.; Turchinovich, Dmitry

    2010-01-01

    Screening of large built-in piezoelectric fields in InGaN/GaN quantum wells leads to high-amplitude acoustic emission. We will compare acoustic emission by quantum wells with different thicknesses with photoluminescence; indicating screening.......Screening of large built-in piezoelectric fields in InGaN/GaN quantum wells leads to high-amplitude acoustic emission. We will compare acoustic emission by quantum wells with different thicknesses with photoluminescence; indicating screening....

  19. Amplitude differences in high-frequency fMRI signals between eyes open and eyes closed resting states.

    Science.gov (United States)

    Yuan, Bin-Ke; Wang, Jue; Zang, Yu-Feng; Liu, Dong-Qiang

    2014-01-01

    Recent studies employing rapid sampling techniques have demonstrated that the resting state fMRI (rs-fMRI) signal exhibits synchronized activities at frequencies much higher than the conventional frequency range (high-frequency fluctuations between different resting states. Here, we acquired rs-fMRI data at a high sampling rate (TR = 400 ms) from subjects with both eyes open (EO) and eyes closed (EC), and compared the amplitude of fluctuation (AF) between EO and EC for both the low- and high-frequency components. In addition to robust AF differences in the conventional low frequency band (high-frequency (primarily in 0.1-0.35 Hz) differences. The high-frequency results without covariates regression exhibited noisy patterns. For the data with nuisance covariates regression, we found a significant and reproducible reduction in high-frequency AF between EO and EC in the bilateral PSMC and the supplementary motor area (SMA), and an increase in high-frequency AF in the left middle occipital gyrus (MOG). Furthermore, we investigated the effect of sampling rate by down-sampling the data to effective TR = 2 s. Briefly, by using the rapid sampling rate, we were able to detect more regions with significant differences while identifying fewer artifactual differences in the high-frequency bands as compared to the down-sampled dataset. We concluded that (1) high-frequency fluctuations of rs-fMRI signals can be modulated by different resting states and thus may be of physiological importance; and (2) the regression of covariates and the use of fast sampling rates are superior for revealing high-frequency differences in rs-fMRI signals.

  20. Surface Wave Amplitude Anomalies in the Western United States

    Science.gov (United States)

    Eddy, C.; Ekstrom, G.

    2011-12-01

    We determine maps of local surface wave amplitude factors across the Western United States for Rayleigh and Love waves at discrete periods between 25 and 125s. Measurements of raw amplitude anomalies are made from data recorded at 1161 USArray stations for minor arc arrivals of earthquakes with Mw>5.5 occurring between 2006 and 2010. We take the difference between high-quality amplitude anomaly measurements for events recorded on station pairs less than 2 degrees apart. The mean of these differences for each station pair is taken as the datum. Surface wave amplitudes are controlled by four separate mechanisms: focusing due to elastic structure, attenuation due to anelastic structure, source effects, and receiver effects. By taking the mean of the differences of amplitude anomalies for neighboring stations, we reduce the effects of focusing, attenuation, and the seismic source, thus isolating amplitude anomalies due to near-receiver amplitude effects. We determine local amplitude factors for each USArray station by standard linear inversion of the differential data set. The individual station amplitude factors explain the majority of the variance of the data. For example, derived station amplitude factors for 50s Rayleigh waves explain 92% of the variance of the data. We explore correlations between derived station amplitude factors and local amplitude factors predicted by crust and upper mantle models. Maps of local amplitude factors show spatial correlation with topography and geologic structures in the Western United States, particularly for maps derived from Rayleigh wave amplitude anomalies. A NW-SE trending high in amplitude factors in Eastern California is evident in the 50s map, corresponding to the location of the Sierra Nevada Mountains. High amplitude factors are observed in Colorado and New Mexico in the 50s-125s maps in the location of the highest peaks of the Rocky Mountains. High amplitude factors are also seen in Southern Idaho and Eastern Wyoming in

  1. High resolution simulations of extreme weather event in south Sardinia

    Science.gov (United States)

    Dessy, C.

    2010-05-01

    In the last decade, like most region of Mediterranean Europe, Sardinia has experienced severe precipitation events generating flash floods resulting in loss of lives and large economic damage. A numerical meteorological operational set-up is applied in the local weather service with the aim to improve the operational short range weather forecast of the Service with particular attention to intense, mostly rare and potentially severe, events. On the early hours of 22 October 2008 an intense and almost stationary mesoscale convective system interested particularly the south of Sardinia, heavy precipitation caused a flash flood with fatalities and numerous property damages. The event was particularly intense: about 400 mm of rain in 12 hours (a peak of 150 mm in an hour) were misured by the regional network of weather stations and these values appear extremely meaningfulls since those are about seven times the climatological monthly rainfall for that area and nearly the climatological annual rainfall. With the aim to improve significantly quantitative precipitation forecasting, it was evaluated a different set-up of a high resolution convection resolving model (MM5) initialised with different initial and boundary conditions (ECMWF and NCAR). In this paper it is discussed the meteorological system related to the mentioned event by using different numerical weather models (GCM and LAM) combined with conventional data, radar Doppler and Meteosat images. Preliminary results say that a different set-up of a non hydrostatic model can forecast severe convection events in advance of about one day and produce more realistic rainfall than that current operational and also improve the weather forecasts to respect the ECMWF-GCM. So it could drive an operational alert system in order to limit the risks associated with heavy precipitation events.

  2. Boundary Layer Ventilation Processes During a High Pressure Event

    Science.gov (United States)

    Gray, S. L.; Dacre, H. F.; Belcher, S. E.

    2006-12-01

    It is often assumed that ventilation of the atmospheric boundary layer is weak during high pressure events. But is this always true? Here we investigate the processes responsible for ventilation of the atmospheric boundary layer during a high pressure event that occured on the 9 May 2005 using the UK Met Office Unifed Model. Pollution sources are represented by the constant emission of a passive tracer everywhere over land. The ventilation processes observed include a sea breeze circulation, turbulent mixing across the top of the boundary layer followed by large-scale ascent, and shallow convection. Vertical distributions of tracer are validated with AMPEP (Aircraft Measurement of chemical Processing Export fluxes of Pollutants over the UK) CO aircraft measurements and are shown to agree impressively well. Budget calculations of tracers are performed in order to determine the relative importance of these ventilation processes. The sea breeze circulation was found to ventilate 26% of the boundary layer tracer by sunset of which 2% was above 2km. A combination of the sea breeze circulation and turbulent mixing ventilated 46% of the boundary layer tracer, of which 10% was above 2km. Finally, the sea breeze circulation, turbulent mixing and shallow convection processes together ventilated 52% of the tracer into the free troposphere, of which 26% was above 2km. Hence this study shows that signicant ventilation of the boundary layer can occur during high pressure events; turbulent mixing and convection processes can double the amount of pollution ventilated from the boundary layer.

  3. Nano-structural characteristics of carbon nanotube-polymer composite films for high-amplitude optoacoustic generation

    Science.gov (United States)

    Baac, Hyoung Won; Ok, Jong G.; Lee, Taehwa; Jay Guo, L.

    2015-08-01

    We demonstrate nano-structural characteristics of carbon nanotube (CNT)-polydimethylsiloxane (PDMS) composite films that can be used as highly efficient and robust ultrasound transmitters for diagnostic and therapeutic applications. An inherent architecture of the nano-composite provides unique thermal, optical, and mechanical properties that are accommodated not just for efficient energy conversion but also for extraordinary robustness against pulsed laser ablation. First, we explain a thermoacoustic transfer mechanism within the nano-composite. CNT morphologies are examined to determine a suitable arrangement for heat transfer to the surrounding PDMS. Next, we introduce an approach to enhance optical extinction of the composite films, which uses shadowed deposition of a thin Au layer through an as-grown CNT network. Finally, the transmitter robustness is quantified in terms of laser-induced damage threshold. This reveals that the CNT-PDMS films can withstand an order-of-magnitude higher optical fluence (and extinction) than a Cr film used as a reference. Such robustness is crucial to increase the maximum-available optical energy for optoacoustic excitation and pressure generation. All of these structure-originated characteristics manifest the CNT-PDMS composite films as excellent optoacoustic transmitters for high-amplitude and high-frequency ultrasound generation.

  4. Multi-fluid approach to high-frequency waves in plasmas: I. Small-amplitude regime in fully ionized medium

    CERN Document Server

    Martínez-Gómez, David; Terradas, Jaume

    2016-01-01

    Ideal MHD provides an accurate description of low-frequency Alfv\\'en waves in fully ionized plasmas. However, higher frequency waves in many plasmas of the solar atmosphere cannot be correctly described by ideal MHD and a more accurate model is required. Here, we study the properties of small-amplitude incompressible perturbations in both the low and the high frequency ranges in plasmas composed of several ionized species. We use a multi-fluid approach and take into account the effects of collisions between ions and the inclusion of Hall's term in the induction equation. Through the analysis of the corresponding dispersion relations and numerical simulations we check that at high frequencies ions of different species are not as strongly coupled as in the low frequency limit. Hence, they cannot be treated as a single fluid. In addition, elastic collisions between the distinct ionized species are not negligible for high frequency waves since an appreciable damping is obtained. Furthermore, Coulomb collisions be...

  5. Nano-structural characteristics of carbon nanotube-polymer composite films for high-amplitude optoacoustic generation.

    Science.gov (United States)

    Baac, Hyoung Won; Ok, Jong G; Lee, Taehwa; Guo, L Jay

    2015-09-14

    We demonstrate nano-structural characteristics of carbon nanotube (CNT)-polydimethylsiloxane (PDMS) composite films that can be used as highly efficient and robust ultrasound transmitters for diagnostic and therapeutic applications. An inherent architecture of the nano-composite provides unique thermal, optical, and mechanical properties that are accommodated not just for efficient energy conversion but also for extraordinary robustness against pulsed laser ablation. First, we explain a thermoacoustic transfer mechanism within the nano-composite. CNT morphologies are examined to determine a suitable arrangement for heat transfer to the surrounding PDMS. Next, we introduce an approach to enhance optical extinction of the composite films, which uses shadowed deposition of a thin Au layer through an as-grown CNT network. Finally, the transmitter robustness is quantified in terms of laser-induced damage threshold. This reveals that the CNT-PDMS films can withstand an order-of-magnitude higher optical fluence (and extinction) than a Cr film used as a reference. Such robustness is crucial to increase the maximum-available optical energy for optoacoustic excitation and pressure generation. All of these structure-originated characteristics manifest the CNT-PDMS composite films as excellent optoacoustic transmitters for high-amplitude and high-frequency ultrasound generation.

  6. Upper mesospheric lunar tides over middle and high latitudes during sudden stratospheric warming events

    Science.gov (United States)

    Chau, J. L.; Hoffmann, P.; Pedatella, N. M.; Matthias, V.; Stober, G.

    2015-04-01

    In recent years there have been a series of reported ground- and satellite-based observations of lunar tide signatures in the equatorial and low latitude ionosphere/thermosphere around sudden stratospheric warming (SSW) events. This lower atmosphere/ionosphere coupling has been suggested to be via the E region dynamo. In this work we present the results of analyzing 6 years of hourly upper mesospheric winds from specular meteor radars over a midlatitude (54°N) station and a high latitude (69°N) station. Instead of correlating our results with typical definitions of SSWs, we use the definition of polar vortex weaking (PVW) used by Zhang and Forbes. This definition provides a better representation of the strength in middle atmospheric dynamics that should be responsible for the waves propagating to the E region. We have performed a wave decomposition on hourly wind data in 21 day segments, shifted by 1 day. In addition to the radar wind data, the analysis has been applied to simulations from Whole Atmosphere Community Climate Model Extended version and the thermosphere-ionosphere-mesosphere electrodynamics general circulation model. Our results indicate that the semidiurnal lunar tide (M2) enhances in northern hemispheric winter months, over both middle and high latitudes. The time and magnitude of M2 are highly correlated with the time and associated zonal wind of PVW. At middle/high latitudes, M2 in the upper mesosphere occurs after/before the PVW. At both latitudes, the maximum amplitude of M2 is directly proportional to the strength of PVW westward wind. We have found that M2 amplitudes could be comparable to semidiurnal solar tide amplitudes, particularly around PVW and equinoxes. Besides these general results, we have also found peculiarities in some events, particularly at high latitudes. These peculiarities point to the need of considering the longitudinal features of the polar stratosphere and the upper mesosphere and lower thermosphere regions. For

  7. Microlensing by Multiple Planets in High Magnification Events

    CERN Document Server

    Gaudi, B S; Sackett, P D; Sackett, Penny D.

    1998-01-01

    Microlensing is increasingly gaining recognition as a powerful method for the detection and characterization of extra-solar planetary systems. Naively, one might expect that the probability of detecting the influence of more than one planet on any single microlensing light curve would be small. Recently, however, Griest & Safizadeh (1998) have shown that, for a subset of events, those with minimum impact parameter $u_{min} \\lsim 0.1$ (high magnification events), the detection probability is nearly 100% for Jovian mass planets with projected separations in the range 0.6--1.6 of the primary Einstein ring radius $R_E$, and remains substantial outside this zone. In this Letter, we point out that this result implies that, regardless of orientation, all Jovian mass planets with separations near 0.6--1.6$R_E$ dramatically affect the central region of the magnification pattern, and thus have a significant probability of being detected (or ruled out) in high magnification events. The probability, averaged over all...

  8. The influence of temperature dynamics and dynamic finite ion Larmor radius effects on seeded high amplitude plasma blobs

    Science.gov (United States)

    Held, M.; Wiesenberger, M.; Madsen, J.; Kendl, A.

    2016-12-01

    Thermal effects on the perpendicular convection of seeded pressure blobs in the scrape-off layer of magnetised fusion plasmas are investigated. Our numerical study is based on a four field full-F gyrofluid model, which entails the consistent description of high fluctuation amplitudes and dynamic finite Larmor radius effects. We find that the maximal radial blob velocity increases with the square root of the initial pressure perturbation and that a finite Larmor radius contributes to highly compact blob structures that propagate in the poloidal direction. An extensive parameter study reveals that a smooth transition to this compact blob regime occurs when the finite Larmor radius effect strength, defined by the ratio of the magnetic field aligned component of the ion diamagnetic to the \\boldsymbol{E}× \\boldsymbol{B} vorticity, exceeds unity. The maximal radial blob velocities agree excellently with the inertial velocity scaling law over more than an order of magnitude. We show that the finite Larmor radius effect strength affects the poloidal and total particle transport and present an empirical scaling law for the poloidal and total blob velocities. Distinctions to the blob behaviour in the isothermal limit with constant finite Larmor radius effects are highlighted.

  9. Pulsation and Long-Term Variability of the High-Amplitude δ Scuti Star AD Canis Minoris

    Institute of Scientific and Technical Information of China (English)

    Pongsak Khokhuntod; Jian-Ning Fu; Chayan Boonyarak; Kanokwan Marak; Li Chen; Shi-Yang Jiang

    2007-01-01

    Time-series photometry was made for the large-amplitude δ Scuti star AD CMi in 2005 and 2006.High-quality photometric data provided in the literature were used to analyze the pulsation of the star,with the derived multiple frequencies fitted to our new data.Besides the dominant frequency and its harmonics,one low frequency(2.27402 cd-1)is discovered,which provides a reasonable interpretation for the long-noticed luminosity variation at the maximum and minimum light.Combining the nine new times of light maxima determined from the new data with the 64 times collected from the literature.we analyzed the long-term variability of AD CMi with the O-C technique.The results provide the updated value of period of 0.122974478 days.and seem to be in favor of the model of combination of the evolutionary effect and light-time effect of a binary system.of which some parameters are hereby deduced.

  10. Teaching and Assessment of High-Velocity, Low-Amplitude Techniques for the Spine in Predoctoral Medical Education.

    Science.gov (United States)

    Channell, Millicent King

    2016-09-01

    Although national didactic criteria have been set for predoctoral education and assessment in osteopathic manipulative treatment, there is no criterion standard for teaching methods and assessments of osteopathic manipulative treatment competence in colleges of osteopathic medicine. This issue is more pressing with the creation of the single graduate medical education accreditation system by the American Osteopathic Association and Accreditation Council for Graduate Medical Education, which introduced the creation of "osteopathic recognition" for residencies that want to incorporate osteopathic principles and practice into their programs. Residencies with osteopathic recognition may include both osteopathic and allopathic graduates. Increased standardization at the predoctoral level, however, is recommended as osteopathic principles and practice training applications are expanded. The objectives of this article are to review the standards for teaching osteopathic medical students high-velocity, low-amplitude (HVLA) techniques for the spine; to review and discuss the methods used to assess medical students' proficiency in using HVLA; and to propose baseline standards for teaching and assessing HVLA techniques among medical students.

  11. Pulsation and Long-Term Variability of the High-Amplitude δ Scuti Star AD Canis Minoris

    Science.gov (United States)

    Khokhuntod, Pongsak; Fu, Jian-Ning; Boonyarak, Chayan; Marak, Kanokwan; Chen, Li; Jiang, Shi-Yang

    2007-06-01

    Time-series photometry was made for the large-amplitude δ Scuti star AD CMi in 2005 and 2006. High-quality photometric data provided in the literature were used to analyze the pulsation of the star, with the derived multiple frequencies fitted to our new data. Besides the dominant frequency and its harmonics, one low frequency (2.27402 c d-1) is discovered, which provides a reasonable interpretation for the long-noticed luminosity variation at the maximum and minimum light. Combining the nine new times of light maxima determined from the new data with the 64 times collected from the literature, we analyzed the long-term variability of AD CMi with the O-C technique. The results provide the updated value of period of 0.122974478 days, and seem to be in favor of the model of combination of the evolutionary effect and light-time effect of a binary system, of which some parameters are hereby deduced.

  12. The Kep-Cont Mission: Continuing the observation of high-amplitude variable stars in the Kepler field of view

    CERN Document Server

    Molnár, L; Kolenberg, K; Borkovits, T; Antoci, V; Vida, K; Ngeow, C C; Guzik, J A; Plachy, E; Castanheira, B

    2013-01-01

    As a response to the Kepler white paper call, we propose to keep Kepler pointing to its current field of view and continue observing thousands of large amplitude variables (Cepheid, RR Lyrae and delta Scuti stars among others) with high cadence in the Kep-Cont Mission. The degraded pointing stability will still allow observation of these stars with reasonable (better than millimag) precision. The Kep-Cont mission will allow studying the nonradial modes in Blazhko-modulated and first overtone RR Lyrae stars and will give a better view on the period jitter of the only Kepler Cepheid in the field. With continued continuous observation of the Kepler RR Lyrae sample we may get closer to the origin of the century-old Blazhko problem. Longer time-span may also uncover new dynamical effects like apsidal motion in eclipsing binaries. A continued mission will have the advantage of providing unprecedented, many-years-long homogeneous and continuous photometric data of the same targets. We investigate the pragmatic detai...

  13. Patient-centered outcomes of high-velocity, low-amplitude spinal manipulation for low back pain: a systematic review.

    Science.gov (United States)

    Goertz, C M; Pohlman, K A; Vining, R D; Brantingham, J W; Long, C R

    2012-10-01

    Low back pain (LBP) is a well-recognized public health problem with no clear gold standard medical approach to treatment. Thus, those with LBP frequently turn to treatments such as spinal manipulation (SM). Many clinical trials have been conducted to evaluate the efficacy or effectiveness of SM for LBP. The primary objective of this paper was to describe the current literature on patient-centered outcomes following a specific type of commonly used SM, high-velocity low-amplitude (HVLA), in patients with LBP. A systematic search strategy was used to capture all LBP clinical trials of HVLA using our predefined patient-centered outcomes: visual analogue scale, numerical pain rating scale, Roland-Morris Disability Questionnaire, and the Oswestry Low Back Pain Disability Index. Of the 1294 articles identified by our search, 38 met our eligibility criteria. Like previous SM for LBP systematic reviews, this review shows a small but consistent treatment effect at least as large as that seen in other conservative methods of care. The heterogeneity and inconsistency in reporting within the studies reviewed makes it difficult to draw definitive conclusions. Future SM studies for LBP would benefit if some of these issues were addressed by the scientific community before further research in this area is conducted.

  14. Asteroseismology of KIC\\,11754974: a high-amplitude SX\\,Phe pulsator in a 343-day binary system

    CERN Document Server

    Murphy, S J; Kurtz, D W; Suarez, J C; Handler, G; Balona, L A; Smalley, B; Uytterhoeven, K; Szabo, R; Thygesen, A O; Elkin, V; Breger, M; Grigahcene, A; Guzik, J A; Nemec, J M; Southworth, J

    2013-01-01

    The candidate SX Phe star KIC 11754974 shows a remarkably high number of combination frequencies in the Fourier amplitude spectrum: 123 of the 166 frequencies in our multi-frequency fit are linear combinations of independent modes. Predictable patterns in frequency spacings are seen in the Fourier transform of the light curve. We present an analysis of 180 d of short-cadence Kepler photometry and of new spectroscopic data for this evolved, late A-type star. We infer from the 1150-d, long-cadence light curve, and in two different ways, that our target is the primary of a 343-d, non-eclipsing binary system. According to both methods, the mass function is similar, f(M)=0.0207 +/- 0.0003 Msun. The observed pulsations are modelled extensively, using separate, state-of-the-art, time-dependent convection (TDC) and rotating models. The models match the observed temperature and low metallicity, finding a mass of 1.50-1.56 Msun. The models suggest the whole star is metal-poor, and that the low metallicity is not just a...

  15. A novel high amplitude piezoceramic actuator for applications in magnetic resonance elastography: a compliant mechanical amplifier approach

    Science.gov (United States)

    Arani, Arvin; Eskandari, Amiraslan; Ouyang, Puren; Chopra, Rajiv

    2017-08-01

    Piezoceramic actuators are capable of precise positioning with high force, but suffer from limited displacement range, which has hindered their application in the field of magnetic resonance elastography (MRE). The objective of this study was to investigate the feasibility of using a mechanical amplifier in combination with a piezoceramic actuator for the application of endorectal prostate MRE. A five-bar symmetric structure was designed in ANSYS® and manufactured out of brass. Laser vibrometer measurements were used to characterize the amplitude of the CMA actuator while attached to masses in the 0-325 g range and over operating frequencies of 90-500 Hz. The response of the CMA was investigated while mechanically coupled to a balloon type endorectal coil. The resonant frequency of the prototype CMA actuator was predicted within 10% error using ANSYS simulations. The amplification ratio of the CMA actuator was measured to be 10 with the laser vibrometer and 7.6 ± 1.7 (max: 9.2, min: 6.5) using MRE, at a vibration frequency of 200 Hz. Laser vibrometer data also showed that the CMA actuator’s performance did not change whether it was connected to an empty or inflated endorectal. The feasibility of performing endorectal prostate MRE with a CMA actuator was successfully demonstrated in a human volunteer.

  16. A photometric monitoring of bright high-amplitude delta Scuti stars. II. Period updates for seven stars

    CERN Document Server

    Derekas, A; Székely, P; Alfaro, E J; Csák, B; Mészáros, S; Rodríguez, E; Rolland, A; Sarneczky, K; Szabó, G M; Szatmary, K; Varadi, M; Kiss, C; Meszaros, Sz.; Szabo, Gy.M.; Kiss, Cs.

    2003-01-01

    We present new photometric data for seven high-amplitude delta Scuti stars. The observations were acquired between 1996 and 2002, mostly in the Johnson photometric system. For one star (GW UMa), our observations are the first since the discovery of its pulsational nature from the Hipparcos data.The primary goal of this project was to update our knowledge on the period variations of the target stars. For this, we have collected all available photometric observations from the literature and constructed decades-long O-C diagrams of the stars. This traditional method is useful because of the single-periodic nature of the light variations. Text-book examples of slow period evolution (XX Cyg, DY Her, DY Peg) and cyclic period changes due to light-time effect (LITE) in a binary system (SZ Lyn) are updated with the new observations. For YZ Boo, we find a period decrease instead of increase. The previously suggested LITE-solution of BE Lyn (Kiss & Szatmary 1995) is not supported with the new O-C diagram. Instead o...

  17. Protostring scattering amplitudes

    Science.gov (United States)

    Thorn, Charles B.

    2016-11-01

    We calculate some tree-level scattering amplitudes for a generalization of the protostring, which is a novel string model implied by the simplest string bit models. These bit models produce a light-cone world sheet which supports s integer moded Grassmann fields. In the generalization we supplement this Grassmann world-sheet system with d =24 -s transverse coordinate world-sheet fields. The protostring corresponds to s =24 and the bosonic string to s =0 . The interaction vertex is a simple overlap with no operator insertions at the break/join point. Assuming that s is even we calculate the multistring scattering amplitudes by bosonizing the Grassmann fields, each pair equivalent to one compactified bosonic field, and applying Mandelstam's interacting string formalism to a system of s /2 compactified and d uncompactified bosonic world-sheet fields. We obtain all amplitudes for open strings with no oscillator excitations and for closed strings with no oscillator excitations and zero winding number. We then study in detail some simple special cases. Multistring processes with maximal helicity violation have much simpler amplitudes. We also specialize to general four-string amplitudes and discuss their high energy behavior. Most of these models are not covariant under the full Lorentz group O (d +1 ,1 ). The exceptions are the bosonic string whose Lorentz group is O (25 ,1 ) and the protostring whose Lorentz group is O (1 ,1 ). The models in between only enjoy an O (1 ,1 )×O (d ) spacetime symmetry.

  18. High resolution modelling of extreme precipitation events in urban areas

    Science.gov (United States)

    Siemerink, Martijn; Volp, Nicolette; Schuurmans, Wytze; Deckers, Dave

    2015-04-01

    The present day society needs to adjust to the effects of climate change. More extreme weather conditions are expected, which can lead to longer periods of drought, but also to more extreme precipitation events. Urban water systems are not designed for such extreme events. Most sewer systems are not able to drain the excessive storm water, causing urban flooding. This leads to high economic damage. In order to take appropriate measures against extreme urban storms, detailed knowledge about the behaviour of the urban water system above and below the streets is required. To investigate the behaviour of urban water systems during extreme precipitation events new assessment tools are necessary. These tools should provide a detailed and integral description of the flow in the full domain of overland runoff, sewer flow, surface water flow and groundwater flow. We developed a new assessment tool, called 3Di, which provides detailed insight in the urban water system. This tool is based on a new numerical methodology that can accurately deal with the interaction between overland runoff, sewer flow and surface water flow. A one-dimensional model for the sewer system and open channel flow is fully coupled to a two-dimensional depth-averaged model that simulates the overland flow. The tool uses a subgrid-based approach in order to take high resolution information of the sewer system and of the terrain into account [1, 2]. The combination of using the high resolution information and the subgrid based approach results in an accurate and efficient modelling tool. It is now possible to simulate entire urban water systems using extreme high resolution (0.5m x 0.5m) terrain data in combination with a detailed sewer and surface water network representation. The new tool has been tested in several Dutch cities, such as Rotterdam, Amsterdam and The Hague. We will present the results of an extreme precipitation event in the city of Schiedam (The Netherlands). This city deals with

  19. Cloud Atlas: Discovery of Patchy Clouds and High-amplitude Rotational Modulations in a Young, Extremely Red L-type Brown Dwarf

    Science.gov (United States)

    Lew, Ben W. P.; Apai, Daniel; Zhou, Yifan; Schneider, Glenn; Burgasser, Adam J.; Karalidi, Theodora; Yang, Hao; Marley, Mark S.; Cowan, Nicolas B.; Bedin, Luigi R.; Metchev, Stanimir A.; Radigan, Jacqueline; Lowrance, Patrick J.

    2016-10-01

    Condensate clouds fundamentally impact the atmospheric structure and spectra of exoplanets and brown dwarfs, but the connections between surface gravity, cloud structure, dust in the upper atmosphere, and the red colors of some brown dwarfs remain poorly understood. Rotational modulations enable the study of different clouds in the same atmosphere, thereby providing a method to isolate the effects of clouds. Here, we present the discovery of high peak-to-peak amplitude (8%) rotational modulations in a low-gravity, extremely red (J-K s = 2.55) L6 dwarf WISEP J004701.06+680352.1 (W0047). Using the Hubble Space Telescope (HST) time-resolved grism spectroscopy, we find a best-fit rotational period (13.20 ± 0.14 hr) with a larger amplitude at 1.1 μm than at 1.7 μm. This is the third-largest near-infrared variability amplitude measured in a brown dwarf, demonstrating that large-amplitude variations are not limited to the L/T transition but are present in some extremely red L-type dwarfs. We report a tentative trend between the wavelength dependence of relative amplitude, possibly proxy for small dust grains lofted in the upper atmosphere, and the likelihood of large-amplitude variability. By assuming forsterite as a haze particle, we successfully explain the wavelength-dependent amplitude with submicron-sized haze particle sizes of around 0.4 μm. W0047 links the earlier spectral and later spectral type brown dwarfs in which rotational modulations have been observed; the large amplitude variations in this object make this a benchmark brown dwarf for the study of cloud properties close to the L/T transition.

  20. Events

    Directory of Open Access Journals (Sweden)

    Igor V. Karyakin

    2016-02-01

    Full Text Available The 9th ARRCN Symposium 2015 was held during 21st–25th October 2015 at the Novotel Hotel, Chumphon, Thailand, one of the most favored travel destinations in Asia. The 10th ARRCN Symposium 2017 will be held during October 2017 in the Davao, Philippines. International Symposium on the Montagu's Harrier (Circus pygargus «The Montagu's Harrier in Europe. Status. Threats. Protection», organized by the environmental organization «Landesbund für Vogelschutz in Bayern e.V.» (LBV was held on November 20-22, 2015 in Germany. The location of this event was the city of Wurzburg in Bavaria.

  1. Low-amplitude, high-frequency electromagnetic field exposure causes delayed and reduced growth in Rosa hybrida.

    Science.gov (United States)

    Grémiaux, Alexandre; Girard, Sébastien; Guérin, Vincent; Lothier, Jérémy; Baluška, František; Davies, Eric; Bonnet, Pierre; Vian, Alain

    2016-01-15

    It is now accepted that plants perceive high-frequency electromagnetic field (HF-EMF). We wondered if the HF-EMF signal is integrated further in planta as a chain of reactions leading to a modification of plant growth. We exposed whole small ligneous plants (rose bush) whose growth could be studied for several weeks. We performed exposures at two different development stages (rooted cuttings bearing an axillary bud and 5-leaf stage plants), using two high frequency (900MHz) field amplitudes (5 and 200Vm(-1)). We achieved a tight control on the experimental conditions using a state-of-the-art stimulation device (Mode Stirred Reverberation Chamber) and specialized culture-chambers. After the exposure, we followed the shoot growth for over a one-month period. We observed no growth modification whatsoever exposure was performed on the 5-leaf stage plants. When the exposure was performed on the rooted cuttings, no growth modification was observed on Axis I (produced from the elongation of the axillary bud). Likewise, no significant modification was noted on Axis II produced at the base of Axis I, that came from pre-formed secondary axillary buds. In contrast, Axis II produced at the top of Axis I, that came from post-formed secondary buds consistently displayed a delayed and significant reduced growth (45%). The measurements of plant energy uptake from HF-EMF in this exposure condition (SAR of 7.2 10(-4)Wkg(-1)) indicated that this biological response is likely not due to thermal effect. These results suggest that exposure to electromagnetic field only affected development of post-formed organs.

  2. Financial system loss as an example of high consequence, high frequency events

    Energy Technology Data Exchange (ETDEWEB)

    McGovern, D.E.

    1996-07-01

    Much work has been devoted to high consequence events with low frequency of occurrence. Characteristic of these events are bridge failure (such as that of the Tacoma Narrows), building failure (such as the collapse of a walkway at a Kansas City hotel), or compromise of a major chemical containment system (such as at Bhopal, India). Such events, although rare, have an extreme personal, societal, and financial impact. An interesting variation is demonstrated by financial losses due to fraud and abuse in the money management system. The impact can be huge, entailing very high aggregate costs, but these are a result of the contribution of many small attacks and not the result of a single (or few) massive events. Public awareness is raised through publicized events such as the junk bond fraud perpetrated by Milikin or gross mismanagement in the failure of the Barings Bank through unsupervised trading activities by Leeson in Singapore. These event,s although seemingly large (financial losses may be on the order of several billion dollars), are but small contributors to the estimated $114 billion loss to all types of financial fraud in 1993. This paper explores the magnitude of financial system losses and identifies new areas for analysis of high consequence events including the potential effect of malevolent intent.

  3. Summary of Aqua, Aura, and Terra High Interest Events

    Science.gov (United States)

    Newman, Lauri

    2015-01-01

    Single-obs tracking Sparsely tracked objects are an unfortunate reality of CARA operations Terra vs. 32081: new track with bad data was included in OD solution for secondary object and risk became high CARA and JSpOC discussed tracking and OSAs threw out the bad data. Event no longer presented high risk based on new OD Improvement: CARA now sends JSpOC a flag indicating when a single obs is included, so OSAs can evaluate if manual update to OD is required. Missing ASW OCMsAura vs. 87178, TCA: 317 at 08:04 UTC. Post-maneuver risk (conjunction was identified in OO results)CARA confirmed with JSpOC that ASW OCMs should have been received in addition to OO OCMsJSpOC corrected the manual error in their script that prevented the data from being delivered to CARAJSpOC QAd their other scripts to ensure this error did not exist in other places.

  4. Using Cloud Technology to Support Monitoring During High Profile Events

    Science.gov (United States)

    Patel, Megan; Adighibe, Enyinnaya; Lombardo, Joseph; Loschen, Wayne; Stewart, Miles; Vernon, Michael O.

    2013-01-01

    Objective In May 2012, thousands of protesters, descended on Chicago during the NATO Summit to voice their concern about social and economic inequality. Given the increased numbers of international and domestic visitors to the Windy City and the tension surrounding protesting during the summit, increased monitoring for health events within the city and Chicago metropolitan region was advised. This project represents the first use of cloud technology to support monitoring for a high profile event. Introduction Hospital emergency departments in Cook and surrounding counties currently send data to the Cook County Department of Public Health (CCDPH) instance of ESSENCE on CCDPH servers. The cloud instance of ESSENCE has been enhanced to receive and export all meaningful use data elements in the meaningful use format. The NATO summit provided the opportunity for a demonstration project to assess the ability of an Amazon GovCloud instance of ESSENCE to ingest and process meaningful use data, and to export meaningful use surveillance data to the Cook County Locker in BioSense 2.0. Methods In the three weeks leading up to the NATO Summit, HL7 data extracts were sent to BioSense 2.0 and a data feed was established to the Amazon GovCloud instance of ESSENCE. Queries specific to anticipated health events associated with the summit such as injuries, tear gas exposure, and general exposure, were developed. Several features of the cloud instance of ESSENCE enhanced the ability of CCDPH staff epidemiologists to conduct analyses, including the sharing capabilities of queries and the myESSENCE dashboard feature. The sharing capabilities within the cloud instance of ESSENCE allowed queries to be easily shared with multiple staff epidemiologists and across health jurisdictions. The myESSENCE dashboard feature was used to create dashboards of surveillance results, including time series graphs, maps, and records of interest for relevant queries, that were shared with public health

  5. Neural responses to the mechanical parameters of a high velocity, low amplitude spinal manipulation: effect of preload parameters

    Science.gov (United States)

    Reed, William. R.; Long, Cynthia R.; Kawchuk, Gregory N.; Pickar, Joel G.

    2014-01-01

    Objective The purpose of this study was to determine how the preload that precedes a high velocity low amplitude spinal manipulation (HVLA-SM) affects muscle spindle input from lumbar paraspinal muscles both during and after the HVLA-SM. Methods Primary afferent activity from muscle spindles in lumbar paraspinal muscles were recorded from the L6 dorsal root in anesthetized cats. HVLA-SM of the L6 vertebra was preceded either by no preload or by systematic changes in the preload magnitude, duration, and the presence or absence of a downward incisural point (DIP). Immediate effects of preload on muscle spindle responses to the HVLA-SM were determined by comparing mean instantaneous discharge frequencies (MIF) during the HVLA-SM’s thrust phase with baseline. Longer lasting effects of preload on spindle responses to the HVLA-SM were determined by comparing MIF during slow ramp and hold movement of the L6 vertebra before and following the HVLA-SM. Results The smaller compared to the larger preload magnitude and the longer compared to the shorter preload duration significantly increased (P=0.02 and P=0.04) respectively) muscle spindle responses during the HVLA-SM thrust. The absence of preload had the greatest effect on the change in MIF. Interactions between preload magnitude, duration and DIP often produced statistically significant but arguably physiologically modest changes in the passive signaling properties of the muscle spindle following the manipulation. Conclusion Because preload parameters in this animal model were shown to affect neural responses to an HVLA-SM, preload characteristics should be taken into consideration when judging this intervention’s therapeutic benefit in both clinical efficacy studies and in clinical practice. PMID:24387888

  6. Classification of microseismic events in high stress zone

    Institute of Scientific and Technical Information of China (English)

    CAO An-ye; DOU Lin-ming; YAN Ru-ling; JIANG Heng; LU Cai-ping; DU Tao-tao; LU Zhen-yu

    2009-01-01

    For the purpose of having a better understanding of failure mechanisms of rock fracturing in mines, the equivalent point source models of tensile, shear and explosive seismic events were established, and the relationship between far-field seismic dis-placements of the waves and the corresponding equivalent forces were analyzed as well. Based on the results of a microseismic monitoring carried out in the mining progress of 9202 working face under the upper remnant coal pillar in Sanhejian Mine, the waveform features of the seismic events associated with different failure modes were further analyzed. The results show that the signals corresponding to different failure mechanisms have different radiation patterns of the seismic displacements, and different characteristics in waveform features, such as dominant frequency, energy released, the ratio of S- to P-wave energy, and so on. In addition, the rock burst happened in the high stress zone is mainly the result of the strong shear fracturing in the mining process. The results of this study have significantly improved the understanding of the characteristics of the failures associated with under-ground mining, and will greatly benefit the prevention and control of rock burst hazards in burst-prone mines.

  7. Critical parameters and universal amplitude ratios of two-dimensional spin-S Ising models using high- and low-temperature expansions

    CERN Document Server

    Butera, P

    2003-01-01

    For the study of Ising models of general spin S on the square lattice, we have combined our recently extended high-temperature expansions with the low-temperature expansions derived some time ago by Enting, Guttmann and Jensen. We have computed for the first time various critical parameters and improved the estimates of others. Moreover the properties of hyperscaling and of universality (spin S independence) of exponents and of various dimensionless amplitude combinations have been verified accurately. Assuming the validity of the lattice-lattice scaling, from our estimates of critical amplitudes for the square lattice we have also obtained estimates of the corresponding amplitudes for the spin S Ising model on the triangular, honeycomb, and kagome` lattices.

  8. Large-amplitude Fourier transformed high-harmonic alternating current cyclic voltammetry: kinetic discrimination of interfering Faradaic processes at glassy carbon and at boron-doped diamond electrodes.

    Science.gov (United States)

    Zhang, Jie; Guo, Si-Xuan; Bond, Alan M; Marken, Frank

    2004-07-01

    Significant advantages of Fourier transformed large-amplitude ac higher (second to eighth) harmonics relative to responses obtained with conventional small-amplitude ac or dc cyclic voltammetric methods have been demonstrated with respect to (i) the suppression of capacitive background currents, (ii) the separation of the reversible reduction of [Ru(NH(3))(6)](3+) from the overlapping irreversible oxygen reduction process under conditions where aerobic oxygen remains present in the electrochemical cell, and (iii) the kinetic resolution of the reversible [Ru(NH(3))(6)](3+/2+) process in mixtures of [Fe(CN)(6)](3-) and [Ru(NH(3))(6)](3+) at appropriately treated boron-doped diamond electrodes, even when highly unfavorable [Fe(CN)(6)](3-) to [Ru(NH(3))(6)](3+) concentration ratios are employed. Theoretical support for the basis of kinetic discrimination in large-amplitude higher harmonic ac cyclic voltammetry is provided.

  9. Amplitude dependent closest tune approach

    CERN Document Server

    Tomas Garcia, Rogelio; Franchi, Andrea; Maclean, Ewen Hamish; CERN. Geneva. ATS Department

    2016-01-01

    Recent observations in the LHC point to the existence of an amplitude dependent closest tune approach. However this dynamical behavior and its underlying mechanism remain unknown. This effect is highly relevant for the LHC as an unexpectedly closest tune approach varying with amplitude modifies the frequency content of the beam and, hence, the Landau damping. Furthermore the single particle stability would also be affected by this effect as it would modify how particles with varying amplitudes approach and cross resonances. We present analytic derivations that lead to a mechanism generating an amplitude dependent closest tune approach.

  10. A new delirium phenotype with rapid high amplitude onset and nearly as rapid reversal: Central Coast Australia Delirium Intervention Study

    Directory of Open Access Journals (Sweden)

    Regal PJ

    2015-02-01

    , and 45%/80% for the Delirium Index. General medicine and geriatric medicine groups had similar outcomes.Conclusion: This delirium phenotype selects for a rapid high amplitude critical decline in attention, executive function, IADL, and apathy that recovers almost as rapidly.Keywords: delirium, inattention, executive function, dementia

  11. High frame-rate neutron radiography of dynamic events

    Energy Technology Data Exchange (ETDEWEB)

    Bossi, R.H.; Robinson, A.H.; Barton, J.P.

    1981-11-20

    A system has been developed to perform neutron radiographic analysis of dynamic events having a duration of several milliseconds. The system has been operated in the range of 2000 to 10,000 frames/second. Synchronization has provided high-speed-motion neutron radiographs for evaluation of the firing cycle of 7.62 mm munition rounds within a steel rifle barrel. The system has also been used to demonstrate the ability to produce neutron radiographic movies of two-phase flow. The equipment uses the Oregon State University TRIGA reactor capable of pulsing to 3000 MW peak power, a neutron beam collimator, a scintillator neutron conversion screen coupled to an image intensifier, and a 16 mm high speed movie camera. The peak neutron flux incident at the object position is approximately 4 x 10/sup 11/ n/cm/sup 2/s with a pulse, full width at half maximum, of 9 ms. Special studies have been performed on the scintillator conversion screens and on the effects of statistical limitations on the image quality. Modulation transfer function analysis has been used to assist in the evaluation of the system performance.

  12. ATLAS proton-proton event containing two high energy photons

    CERN Multimedia

    ATLAS Collaboration

    2011-01-01

    An event where two energetic photons ("gammas") are produced in a proton-proton collision in ATLAS. Many events of this type are produced by well-understood Standard Model processes ("backgrounds") which do not involve Higgs particles. A small excess of events of this type with similar masses could indicate evidence for Higgs particle production, but any specific event is most likely to be from the background. The photons are indicated, in the different projections and views, by the clusters of energy shown in yellow.

  13. Ionospheric response to sudden stratospheric warming events at low and high solar activity

    Science.gov (United States)

    Fang, Tzu-Wei; Fuller-Rowell, Tim; Wang, Houjun; Akmaev, Rashid; Wu, Fei

    2014-09-01

    The sensitivity of the ionospheric response to a sudden stratospheric warming (SSW) event has been examined under conditions of low and high solar activity through simulations using the whole atmosphere model (WAM) and the global ionosphere plasmasphere model (GIP). During non-SSW conditions, simulated daytime mean vertical drifts at the magnetic equator show similar solar activity dependence as an empirical model. Model results of ionospheric total electron content (TEC) and equatorial vertical drift for the January 2009 major SSW, which occurred at very low solar activity conditions, show reasonable agreement with observations. The simulations demonstrate that the E region dynamo is capable of creating the semidiurnal variation of vertical drift. WAM and GIP were also run at high solar activity conditions, using the same lower atmosphere conditions as present in the January 2009 SSW event. The simulations indicate that the amplitude and phase of migrating tides in the dynamo region during the event have similar magnitudes for both solar flux conditions. However, comparing the ionospheric responses to a major SSW under low and high solar activity periods, it was found that the changes in the ionospheric vertical drifts and relative changes in TEC decreased with increasing solar activity. The simulations indicate that the F region dynamo becomes more important throughout the daytime and contributes to the upward drift in the afternoon during the event when the solar activity is higher. Our test simulations also confirm that the increase of the ionospheric conductivity associated with increasing solar activity is responsible for the decrease of vertical drift changes during an SSW. In particular, first, the increase in F region conductivity allows the closure of E region currents through the F region, reducing the polarization electric field before noon. Second, the F region dynamo contributes an upward drift postnoon, maintaining upward drifts till after sunset

  14. Single event effects in high-energy accelerators

    Science.gov (United States)

    García Alía, Rubén; Brugger, Markus; Danzeca, Salvatore; Cerutti, Francesco; de Carvalho Saraiva, Joao Pedro; Denz, Reiner; Ferrari, Alfredo; Foro, Lionel L.; Peronnard, Paul; Røed, Ketil; Secondo, Raffaello; Steckert, Jens; Thurel, Yves; Toccafondo, Iacocpo; Uznanski, Slawosz

    2017-03-01

    The radiation environment encountered at high-energy hadron accelerators strongly differs from the environment relevant for space applications. The mixed-field expected at modern accelerators is composed of charged and neutral hadrons (protons, pions, kaons and neutrons), photons, electrons, positrons and muons, ranging from very low (thermal) energies up to the TeV range. This complex field, which is extensively simulated by Monte Carlo codes (e.g. FLUKA) is due to beam losses in the experimental areas, distributed along the machine (e.g. collimation points) and deriving from the interaction with the residual gas inside the beam pipe. The resulting intensity, energy distribution and proportion of the different particles largely depends on the distance and angle with respect to the interaction point as well as the amount of installed shielding material. Electronics operating in the vicinity of the accelerator will therefore be subject to both cumulative damage from radiation (total ionizing dose, displacement damage) as well as single event effects which can seriously compromise the operation of the machine. This, combined with the extensive use of commercial-off-the-shelf components due to budget, performance and availability reasons, results in the need to carefully characterize the response of the devices and systems to representative radiation conditions.

  15. The single event upset environment for avionics at high latitude

    Energy Technology Data Exchange (ETDEWEB)

    Sims, A.J.; Dyer, C.S.; Peerless, C.L. (Defence Research Agency, Farnborough (United Kingdom). Space and Communications Dept.); Johansson, K.; Pettersson, H. (SAAB Military Aircraft, Linkoeping (Sweden)); Farren, J. (AEA Technology, Oxfordshire (United Kingdom). Harwell Lab.)

    1994-12-01

    Modern avionic systems for civil and military applications are becoming increasingly reliant upon embedded microprocessors and associated memory devices. The phenomenon of single event upset (SEU) is well known in space systems and designers have generally been careful to use SEU tolerant devices or to implement error detection and correction (EDAC) techniques where appropriate. In the past, avionics designers have had no reason to consider SEU effects but is clear that the more prevalent use of memory devices combined with increasing levels of IC integration will make SEU mitigation an important design consideration for future avionic systems. To this end, it is necessary to work towards producing models of the avionics SEU environment which will permit system designers to choose components and EDAC techniques which are based on predictions of SEU rates correct to much better than an order of magnitude. Measurements of the high latitude SEU environment at avionics altitude have been made on board a commercial airliner. Results are compared with models of primary and secondary cosmic rays and atmospheric neutrons. Ground based SEU tests of static RAMs are used to predict rates in flight.

  16. Particle production in very high-energy cosmic-ray emulsion chamber events usual and unusual events

    CERN Document Server

    Costa, G; Salles, C; Costa, C G S; Halzen, F; Salles, C

    1995-01-01

    We show that a simple scaling model of very forward particle production, consistent with accelerator and air shower data, can describe all features of the very high-energy interactions recorded with emulsion chambers. This is somewhat surprising after numerous claims that the same data implied large scaling violations or new dynamics. Interestingly, we cannot describe some of the Centauro events, suggesting that these events are anomalous independently of their well-advertised unusual features such as the absence of neutral secondaries.

  17. Generating High-Energy Events with Comets, Asteroids, and Planets

    Science.gov (United States)

    Di Stefano, Rosanne

    2015-08-01

    Many stellar remnants are likely to harbor systems of planetoids: comets, asteroids, and planets. Planetoids also travel freely through interstellar space. A combination of processes can therefore lead to tidal disruption events or collisions between planetoids and compact objects. These collisions can produce events that release a great deal of energy over a short time, and they are potentially detectable, even in external galaxies, by wide-field gamma-ray, X-ray, and optical surveys. We discuss the signatures and the possibility that these events could produce Type Ia supernovae.

  18. Cloud Atlas: Discovery of Patchy Clouds and High-amplitude Rotational Modulations In a Young, Extremely Red L-type Brown Dwarf

    CERN Document Server

    Lew, Ben W P; Zhou, Yifan; Schneider, Glenn; Burgasser, Adam J; Karalidi, Theodora; Yang, Hao; Marley, Mark S; Cowan, N B; Bedin,; R., L; Metchev, Stanimir A; Radigan, Jacqueline; Lowrance, Patrick J

    2016-01-01

    Condensate clouds fundamentally impact the atmospheric structure and spectra of exoplanets and brown dwarfs but the connections between surface gravity, cloud structure, dust in the upper atmosphere, and the red colors of some brown dwarfs remain poorly understood. Rotational modulations enable the study of different clouds in the same atmosphere, thereby providing a method to isolate the effects of clouds. Here we present the discovery of high peak-to-peak amplitude (8%) rotational modulations in a low-gravity, extremely red (J-Ks=2.55) L6 dwarf WISEP J004701.06+680352.1 (W0047). Using the Hubble Space Telescope (HST) time-resolved grism spectroscopy we find a best-fit rotational period (13.20$\\pm$0.14 hours) with a larger amplitude at 1.1 micron than at 1.7 micron. This is the third largest near-infrared variability amplitude measured in a brown dwarf, demonstrating that large-amplitude variations are not limited to the L/T transition but are present in some extremely red L-type dwarfs. We report a tentativ...

  19. Hidden focal EEG seizures during prolonged suppressions and high-amplitude bursts in early infantile epileptic encephalopathy.

    Science.gov (United States)

    Al-Futaisi, Amna; Banwell, Brenda; Ochi, Ayako; Hew, Justine; Chu, Bill; Oishi, Makoto; Otsubo, Hiroshi

    2005-05-01

    We report on a 27-month-old female with atypical early infantile epileptic encephalopathy (EIEE), who developed tonic spasms, partial seizures and myoclonic jerks along with episodic bradycardia at 5 days. We recorded digital electroencephalography (EEG) using either an 11-channel neonatal montage or 19 channel scalp electrodes, at 200 Hz sampling rate, and a single reference for a minimum of 30 min. At 18 days EEG showed suppression-burst (SB) patterns during wakefulness and sleep. Tonic spasms concomitant with bursts recorded as brief, low-amplitude fast waves. EEG at 8 months showed increased amplitude of bursts to 1 mV and extension of suppression periods to 65 s. By increasing recording sensitivity, we detected focal epileptiform discharges of slow rhythmic sharp and slow waves building to 30 microV during suppression periods. Status epilepticus occurred at 16 months. EEG at 27 months returned to the previous SB pattern with rare partial seizures. This report is the first to demonstrate clinically silent focal EEG seizures during prolonged suppression periods in atypical EIEE by off-line digital EEG. Digital EEG sensitivity can reveal covert electrical activity during suppression periods in epileptic neonates and infants.

  20. A review of crustacean sensitivity to high amplitude underwater noise: Data needs for effective risk assessment in relation to UK commercial species.

    Science.gov (United States)

    Edmonds, Nathan J; Firmin, Christopher J; Goldsmith, Denise; Faulkner, Rebecca C; Wood, Daniel T

    2016-07-15

    High amplitude anthropogenic noise is associated with adverse impacts among a variety of organisms but detailed species-specific knowledge is lacking in relation to effects upon crustaceans. Brown crab (Cancer pagurus), European lobster (Homarus gammarus) and Norway lobster (Nephrops norvegicus) together represent the most valuable commercial fishery in the UK (Defra, 2014). Critical evaluation of literature reveals physiological sensitivity to underwater noise among N. norvegicus and closely related crustacean species, including juvenile stages. Current evidence supports physiological sensitivity to local, particle motion effects of sound production in particular. Derivation of correlative relationships between the introduction of high amplitude impulsive noise and crustacean distribution/abundance is hindered by the coarse resolution of available data at the present time. Future priorities for research are identified and argument for enhanced monitoring under current legislative frameworks outlined. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  1. Eliminating the effect of phase shift between injection current and amplitude modulation in DFB-LD WMS for high-precision measurement.

    Science.gov (United States)

    Wei, Wei; Chang, Jun; Liu, Yuanyuan; Chen, Xi; Liu, Zhaojun; Qin, Zengguang; Wang, Qiang

    2016-05-01

    Phase shift between the injection current and amplitude modulation due to the characteristics of diode lasers is discussed in this paper. Phase shift has no apparent regularity, but it has an obvious effect on measurement results, especially for high-precision measurement. A new method is proposed to suppress the influence of this phase shift. Water vapor is chosen as the target gas for experiment in this paper. A new detection system with the new method applied is presented and shows much better performance than the traditional wavelength modulation spectroscopy detection system. Phase shift fluctuation between the injection current and amplitude modulation is suppressed from 0.72 deg to 0.07 deg; accuracy is improved from 0.88 ppm to 0.16 ppm.

  2. Combined passive detection and ultrafast active imaging of cavitation events induced by short pulses of high-intensity ultrasound.

    Science.gov (United States)

    Gateau, Jérôme; Aubry, Jean-François; Pernot, Mathieu; Fink, Mathias; Tanter, Mickaël

    2011-03-01

    The activation of natural gas nuclei to induce larger bubbles is possible using short ultrasonic excitations of high amplitude, and is required for ultrasound cavitation therapies. However, little is known about the distribution of nuclei in tissues. Therefore, the acoustic pressure level necessary to generate bubbles in a targeted zone and their exact location are currently difficult to predict. To monitor the initiation of cavitation activity, a novel all-ultrasound technique sensitive to single nucleation events is presented here. It is based on combined passive detection and ultrafast active imaging over a large volume using the same multi-element probe. Bubble nucleation was induced using a focused transducer (660 kHz, f-number = 1) driven by a high-power electric burst (up to 300 W) of one to two cycles. Detection was performed with a linear array (4 to 7 MHz) aligned with the single-element focal point. In vitro experiments in gelatin gel and muscular tissue are presented. The synchronized passive detection enabled radio-frequency data to be recorded, comprising high-frequency coherent wave fronts as signatures of the acoustic emissions linked to the activation of the nuclei. Active change detection images were obtained by subtracting echoes collected in the unnucleated medium. These indicated the appearance of stable cavitating regions. Because of the ultrafast frame rate, active detection occurred as quickly as 330 μs after the high-amplitude excitation and the dynamics of the induced regions were studied individually.

  3. Numerical Simulation on Seismic Response of the Filled Joint under High Amplitude Stress Waves Using Finite-Discrete Element Method (FDEM

    Directory of Open Access Journals (Sweden)

    Xiaolin Huang

    2016-12-01

    Full Text Available This paper numerically investigates the seismic response of the filled joint under high amplitude stress waves using the combined finite-discrete element method (FDEM. A thin layer of independent polygonal particles are used to simulate the joint fillings. Each particle is meshed using the Delaunay triangulation scheme and can be crushed when the load exceeds its strength. The propagation of the 1D longitude wave through a single filled joint is studied, considering the influences of the joint thickness and the characteristics of the incident wave, such as the amplitude and frequency. The results show that the filled particles under high amplitude stress waves mainly experience three deformation stages: (i initial compaction stage; (ii crushing stage; and (iii crushing and compaction stage. In the initial compaction stage and crushing and compaction stage, compaction dominates the mechanical behavior of the joint, and the particle area distribution curve varies little. In these stages, the transmission coefficient increases with the increase of the amplitude, i.e., peak particle velocity (PPV, of the incident wave. On the other hand, in the crushing stage, particle crushing plays the dominant role. The particle size distribution curve changes abruptly with the PPV due to the fragments created by the crushing process. This process consumes part of wave energy and reduces the stiffness of the filled joint. The transmission coefficient decreases with increasing PPV in this stage because of the increased amount of energy consumed by crushing. Moreover, with the increase of the frequency of the incident wave, the transmission coefficient decreases and fewer particles can be crushed. Under the same incident wave, the transmission coefficient decreases when the filled thickness increases and the filled particles become more difficult to be crushed.

  4. Multi-fluid Approach to High-frequency Waves in Plasmas. II. Small-amplitude Regime in Partially Ionized Media

    Science.gov (United States)

    Martínez-Gómez, David; Soler, Roberto; Terradas, Jaume

    2017-03-01

    The presence of neutral species in a plasma has been shown to greatly affect the properties of magnetohydrodynamic waves. For instance, the interaction between ions and neutrals through momentum transfer collisions causes the damping of Alfvén waves and alters their oscillation frequency and phase speed. When the collision frequencies are larger than the frequency of the waves, single-fluid magnetohydrodynamic approximations can accurately describe the effects of partial ionization, since there is a strong coupling between the various species. However, at higher frequencies, the single-fluid models are not applicable and more complex approaches are required. Here, we use a five-fluid model with three ionized and two neutral components, which takes into consideration Hall’s current and Ohm’s diffusion in addition to the friction due to collisions between different species. We apply our model to plasmas composed of hydrogen and helium, and allow the ionization degree to be arbitrary. By analyzing the corresponding dispersion relation and numerical simulations, we study the properties of small-amplitude perturbations. We discuss the effect of momentum transfer collisions on the ion-cyclotron resonances and compare the importance of magnetic resistivity, and ion–neutral and ion–ion collisions on the wave damping at various frequency ranges. Applications to partially ionized plasmas of the solar atmosphere are performed.

  5. Particle production in very-high-energy cosmic-ray emulsion chamber events: Usual and unusual events

    Science.gov (United States)

    Costa, C. G. S.; Halzen, F.; Salles, C.

    1995-10-01

    We show that a simple scaling model of very forward particle production, consistent with accelerator and air shower data, can describe the overall features of the very-high-energy interactions recorded with emulsion chambers. The rapidity and transverse momentum distribution of the secondaries are quantitatively reproduced. This is somewhat surprising after numerous claims that the same data implied large scaling violations or new dynamics. Interestingly, we cannot describe some of the Centauro events, suggesting that these events are anomalous independently of their well-advertised unusual features such as the absence of neutral secondaries.

  6. Brown Norway rats, a putative schizophrenia model, show increased electroencephalographic activity at rest and decreased event-related potential amplitude, power, and coherence in the auditory sensory gating paradigm.

    Science.gov (United States)

    Tomimatsu, Yoshiro; Hibino, Ryosuke; Ohta, Hiroyuki

    2015-08-01

    In recent schizophrenia clinical research, electroencephalographic (EEG) oscillatory activities induced by a sensory stimulus or behavioral tasks have gained considerable interest as functional and pathophysiological biomarkers. The Brown Norway (BN) rat is a putative schizophrenia model that shows naturally low sensorimotor gating and deficits in cognitive performance, although other phenotypes have not been studied. The present study aimed to investigate the neurophysiological features of BN rats, particularly EEG/event-related potential (ERP). EEG activity was recorded at rest and during the auditory sensory gating paradigm under an awake, freely moving condition. Frequency and ERP analysis were performed along with time-frequency analysis of evoked power and intertrial coherence. Compared with Wistar-Kyoto rats, a well-documented control line, BN rats showed increased EEG power at rest, particularly in the theta and gamma ranges. In ERP analysis, BN rats showed reduced N40-P20 amplitude but normal sensory gating. The rats also showed reduced evoked power and intertrial coherence against auditory stimuli. These results suggest that BN rats show features of EEG/ERP measures clinically relevant to schizophrenia and may provide additional opportunities for translational research.

  7. High Resolution Simulation of a Colorado Rockies Extreme Snow and Rain Event in both a Current and Future Climate

    Science.gov (United States)

    Rasmussen, Roy; Ikeda, Kyoko; Liu, Changhai; Gutmann, Ethan; Gochis, David

    2016-04-01

    Modeling of extreme weather events often require very finely resolved treatment of atmospheric circulation structures in order to produce and localize the large moisture fluxes that result in extreme precipitation. This is particularly true for cool season orographic precipitation processes where the representation of the landform can significantly impact vertical velocity profiles and cloud moisture entrainment rates. This study presents results for high resolution regional climate modeling study of the Colorado Headwaters region using an updated version of the Weather Research and Forecasting (WRF) model run at 4 km horizontal resolution and a hydrological extension package called WRF-Hydro. Previous work has shown that the WRF modeling system can produce credible depictions of winter orographic precipitation over the Colorado Rockies if run at horizontal resolutions warming on total precipitation, snow-rain partitioning and surface hydrological fluxes (evapotranspiration and runoff) will be discussed in the context of how potential changes in temperature impact the amount of precipitation, the phase of precipitation (rain vs. snow) and the timing and amplitude of streamflow responses. The results show using the Pseudo Global Warming technique that intense precipitation rates significantly increased during the event and a significant fraction of the snowfall converts to rain which significantly amplifies the runoff response from one where runoff is produced gradually to one in which runoff is rapidly translated into streamflow values that approach significant flooding risks. Results from a new, CONUS scale high resolution climate simulation of extreme events in a current and future climate will be presented as time permits.

  8. Scattering amplitudes in gauge theories

    CERN Document Server

    Henn, Johannes M

    2014-01-01

    At the fundamental level, the interactions of elementary particles are described by quantum gauge field theory. The quantitative implications of these interactions are captured by scattering amplitudes, traditionally computed using Feynman diagrams. In the past decade tremendous progress has been made in our understanding of and computational abilities with regard to scattering amplitudes in gauge theories, going beyond the traditional textbook approach. These advances build upon on-shell methods that focus on the analytic structure of the amplitudes, as well as on their recently discovered hidden symmetries. In fact, when expressed in suitable variables the amplitudes are much simpler than anticipated and hidden patterns emerge.   These modern methods are of increasing importance in phenomenological applications arising from the need for high-precision predictions for the experiments carried out at the Large Hadron Collider, as well as in foundational mathematical physics studies on the S-matrix in quantum ...

  9. Passionflower Extract Induces High-amplitude Rhythms without Phase Shifts in the Expression of Several Circadian Clock Genes in Vitro and in Vivo.

    Science.gov (United States)

    Toda, Kazuya; Hitoe, Shoketsu; Takeda, Shogo; Shimizu, Norihito; Shimoda, Hiroshi

    2017-06-01

    Circadian rhythms play key roles in the regulation of physiological and behavioral systems including wake-sleep cycles. We evaluated the effects of passionflower (aerial parts of Passiflora incarnata Linnaeus) extract (PFE) on circadian rhythms using NIH3T3 cells and mice. PFE (100 μg/mL) induced high-amplitude rhythms in the expression of period circadian protein (Per) 2, cryptochrome (Cry) 1, superoxide dismutase (SOD) 1, and glutathione peroxidase (GPx) in vitro from 12 h after a treatment with serum-rich medium. Isovitexin 2"-O-glucoside, isoschaftoside, and homoorientin, which were purified from PFE, also significantly enhanced Per2 mRNA expression at 20 h. An oral treatment with PFE (100 mg/kg/day) at zeitgeber time (ZT) 0 h for 15 days improved sleep latencies and sleeping times in the pentobarbital-induced sleep test in mice, similar to muscimol (0.2 mg/kg, i.p.). PFE induced high-amplitude rhythms without obvious phase shifts in serum corticosterone levels and the expression of Per1, Per2, and Cry1 in the liver as well as NIH3T3 cells. However, in the cerebrum, PFE enhanced the circadian expression of brain-muscle ARNT-like protein (Bmal) 1, circadian locomotor output cycles kaput (Clock), and Per1. Regarding this difference, we suggest the involvement of several neurotransmitters that influence the circadian rhythm. Indeed, PFE significantly increased dopamine levels at ZT 18 h, and then affected the mRNA expression of the synthetic and metabolic enzymes such as monoamine oxidase (MAO), catechol-O-methyltransferase (COMT), and glutamic acid decarboxylase (GAD). The results obtained show that PFE positively modulates circadian rhythms by inducing high-amplitude rhythms in the expression of several circadian clock genes.

  10. Azimuthal angular correlations in high transverse momentum dijet events

    CERN Document Server

    CMS Collaboration

    2017-01-01

    The azimuthal angle correlation between the two jets with the largest transverse momenta in inclusive 2-jet topologies, close to the back-to-back configuration, is measured for several regions of the leading jet transverse momentum. Measurements of the same observable requiring the presence of extra jets are also presented. The analysis is based on proton-proton collision data collected with the CMS experiment at a center-of-mass energy of $13~\\mathrm{TeV}$ corresponding to an integrated luminosity of $35.9~\\mathrm{fb}^{-1}$. The results are compared to predictions using Monte Carlo event generators which combine perturbative QCD calculations up to next-to-leading-order accuracy with contributions from parton showers, hadronization, and multiparton interactions.

  11. New approach of determinations of earthquake moment magnitude using near earthquake source duration and maximum displacement amplitude of high frequency energy radiation

    Energy Technology Data Exchange (ETDEWEB)

    Gunawan, H.; Puspito, N. T.; Ibrahim, G.; Harjadi, P. J. P. [ITB, Faculty of Earth Sciences and Tecnology (Indonesia); BMKG (Indonesia)

    2012-06-20

    The new approach method to determine the magnitude by using amplitude displacement relationship (A), epicenter distance ({Delta}) and duration of high frequency radiation (t) has been investigated for Tasikmalaya earthquake, on September 2, 2009, and their aftershock. Moment magnitude scale commonly used seismic surface waves with the teleseismic range of the period is greater than 200 seconds or a moment magnitude of the P wave using teleseismic seismogram data and the range of 10-60 seconds. In this research techniques have been developed a new approach to determine the displacement amplitude and duration of high frequency radiation using near earthquake. Determination of the duration of high frequency using half of period of P waves on the seismograms displacement. This is due tothe very complex rupture process in the near earthquake. Seismic data of the P wave mixing with other wave (S wave) before the duration runs out, so it is difficult to separate or determined the final of P-wave. Application of the 68 earthquakes recorded by station of CISI, Garut West Java, the following relationship is obtained: Mw = 0.78 log (A) + 0.83 log {Delta}+ 0.69 log (t) + 6.46 with: A (m), d (km) and t (second). Moment magnitude of this new approach is quite reliable, time processing faster so useful for early warning.

  12. Aggressive Students and High School Dropout: An Event History Analysis

    Science.gov (United States)

    Orozco, Steven R.

    2016-01-01

    Aggressive students often struggle in multiple domains of their school functioning and are at increased risk for high school dropout. Research has identified a variety of warning flags which are strong predictors of high school dropout. While it is known that aggressive students exhibit many of these warning flags, there is little research which…

  13. Amplitude Equalization of 40 Gb/s RZ-DPSK Signals using Saturation of Four-Wave Mixing in a Highly Nonlinear Fiber

    DEFF Research Database (Denmark)

    Geng, Yan; Peucheret, Christophe; Jeppesen, Palle

    2006-01-01

    We report the first experimental demonstration of amplitude equalization of 40 Gb/s RZ-DPSK signals using saturation of FWM in a HNLF. We show effective power penalty reduction after wavelength conversion of an amplitude distorted signal......We report the first experimental demonstration of amplitude equalization of 40 Gb/s RZ-DPSK signals using saturation of FWM in a HNLF. We show effective power penalty reduction after wavelength conversion of an amplitude distorted signal...

  14. Technical Note: Is radiation important for the high amplitude variability of the MOC in the North Atlantic?

    Directory of Open Access Journals (Sweden)

    D. Nof

    2007-09-01

    Full Text Available Radiation is of fundamental importance to climate modeling and it is customary to assume that it is also important for the variability of North Atlantic Deep Water (NADW formation and the meridional overturning cell (MOC. Numerous articles follow this scenario and incorporate radiation into the calculation. Using relatively old heat-flux maps based on measurements taken in the nineteen sixties, Sandal and Nof (2007 recently suggested that, even though the radiation terms are of the same order as the other heat-flux terms, they are not important for the variability of the NADW and the MOC. They proposed that only sensible and latent heat fluxes are important for the long-term variability of the convection, i.e., for processes such as Heinrich events, which supposedly correspond to turning convection on-and-off in the Atlantic.

    Here, we place this suggestion on a firmer ground by presenting new and accurate up-to-date heat flux maps that also suggest that the radiation is of no major consequence to the NADW variability. Also, we attribute the relative importance of sensible and latent heat fluxes and the contrasting negligible role of radiation to the fact that the latent and sensible heat fluxes are primarily proportional to the difference between the sea surface and the air temperature whereas the radiation is primarily proportional to the sea surface temperature, i.e., radiation is approximately independent of the atmospheric temperature. Due the small heat capacity ratio of air/water (1/4, the difference between the ocean temperature and the air temperature varies dramatically between the state of active and inactive MOC, whereas the ocean temperature by itself varies very modestly between a state of active and inactive convection.

  15. High-impact hydrologic events and atmospheric rivers in California: An investigation using the NCEI Storm Events Database

    Science.gov (United States)

    Young, Allison M.; Skelly, Klint T.; Cordeira, Jason M.

    2017-04-01

    Atmospheric rivers (ARs) are long, narrow corridors of enhanced integrated water vapor and integrated vapor transport that can result in high-impact hydrologic events (HIHEs) including floods, flash floods, and debris flows. This study examined the relationship between HIHEs and ARs in California for 10 water years by using the National Centers for Environmental Information Storm Events Database and a catalog of landfalling ARs provided by Rutz et al. Results illustrated that HIHEs related to floods and debris flows are commonly associated with ARs during the cold season across Northern California, whereas HIHEs related to flash floods are commonly not associated with ARs during the warm season across Southern California. Composite analyses illustrated that HIHEs associated with landfalling ARs are associated with synoptic-scale flow patterns that support southwesterly water vapor flux that aligns favorably with California coastal topography to maximize upslope flow and orographic precipitation.

  16. High Resolution, Long - Slit Spectroscopy of VY CMa: The Evidence for Localized High Mass Loss Events

    CERN Document Server

    Humphreys, R M; Ruch, G; Wallerstein, G; Humphreys, Roberta M.; Davidson, Kris; Ruch, Gerald; Wallerstein, George

    2004-01-01

    High spatial and spectral resolution spectroscopy of the OH/IR supergiant VY CMa and its circumstellar ejecta reveals evidence for high mass loss events from localized regions on the star occurring over the past 1000 years. The reflected absorption lines and the extremely strong K I emission lines show a complex pattern of velocities in the ejecta. We show that the large, dusty NW arc, expanding at 50 km/sec with respect to the embedded star, is kinematically distinct from the surrounding nebulosity and was ejected about 400 years ago. Other large, more filamentary loops were probably expelled as much as 800 to 1000 years ago while knots and small arcs close to the star resulted from more recent events 100 to 200 years ago. The more diffuse, uniformly distributed gas and dust is surprisingly stationary with little or no velocity relative to the star. This is not what we would expect for the circumstellar material from an evolved red supergiant with a long history of mass loss. We therefore suggest that the hi...

  17. Test of Antonovsky's postulate: high sense of coherence helps people avoid negative life events.

    Science.gov (United States)

    Hochwälder, Jacek

    2015-04-01

    This study tested Antonovsky's postulate that a high sense of coherence (SOC) helps people avoid negative life events. It was assumed that negative life events that were uncontrollable would not show this effect, while those events that potentially could be controlled would show a significant relationship with SOC. 1,012 female nurses (M age=46.9 yr.; SD=8.9) participated in this longitudinal study and were divided into groups with low, moderate, and high SOC. Sixteen negative life events were categorized into uncontrollable and controllable events, with the controllable events divided into three sub-categories. Five one-way analyses of variance (ANOVAs) for independent measures followed up with post hoc tests were performed, with the number of experienced events in a given category by each participant (at Time 2) as the dependent variable and the three SOC groups (formed at Time 1) as the independent variable. The results indicated that the high SOC group reported fewer controllable negative life events, while there was no significant relationship between the SOC level and uncontrollable negative life events. The findings support the postulate in Antonovsky's model, with the distinction between controllable and uncontrollable negative life events.

  18. A high-speed DAQ framework for future high-level trigger and event building clusters

    Science.gov (United States)

    Caselle, M.; Ardila Perez, L. E.; Balzer, M.; Dritschler, T.; Kopmann, A.; Mohr, H.; Rota, L.; Vogelgesang, M.; Weber, M.

    2017-03-01

    Modern data acquisition and trigger systems require a throughput of several GB/s and latencies of the order of microseconds. To satisfy such requirements, a heterogeneous readout system based on FPGA readout cards and GPU-based computing nodes coupled by InfiniBand has been developed. The incoming data from the back-end electronics is delivered directly into the internal memory of GPUs through a dedicated peer-to-peer PCIe communication. High performance DMA engines have been developed for direct communication between FPGAs and GPUs using "DirectGMA (AMD)" and "GPUDirect (NVIDIA)" technologies. The proposed infrastructure is a candidate for future generations of event building clusters, high-level trigger filter farms and low-level trigger system. In this paper the heterogeneous FPGA-GPU architecture will be presented and its performance be discussed.

  19. Mechanism associated with the Space Shuttle main engine oxidizer valve/duct system anomalous high amplitude discrete acoustical excitation

    Science.gov (United States)

    Schutzenhofer, L. A.; Jones, J. H.; Jewell, R. E.; Ryan, R. S.

    1980-01-01

    Anomalous high frequency pressure fluctuations in the Space Shuttle main engine have been experienced during hot firings. Through diagnostic analysis of hot firing engine data, it was determined that this excitation originated at the main oxidizer valve. The intensity of these fluctuations was such that the main oxidizer valve was partially consumed in fire, experienced fretting, and had seal damage. Delineated in this paper are the associated dynamical phenomena and the methodologies leading toward understanding the excitation mechanism. The results presented demonstrate that the source of the anomalous frequencies was suppressed by a simple fix and all main oxidizer valve damage was terminated.

  20. Frequency and amplitude characteristics of a high-repetition-rate hybrid TEA-CO/sub 2/ laser

    Energy Technology Data Exchange (ETDEWEB)

    Lachambre, J.L.; Lavigne, P.; Verreault, M.; Otis, G.

    1978-02-01

    The envelope and frequency characteristics of the output pulse of a high-repetition-rate hybrid TEA-CO/sub 2/ laser are presented. Both the intrapulse and interpulse laser frequency stability are experimentally determined at repetition rates up to 300 Hz. The recovery of the CW laser signal following the generation of the TEA laser pulse is analyzed theoretically and experimentally. Short term reproducibilities of + or - 2 MHz are observed at a pulse repetition rate of 300 Hz with initial chirp rates of about 1.5 MHz/microsec. Improvements and limits on power and repetition rate are discussed.

  1. Amplitudes, acquisition and imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bloor, Robert

    1998-12-31

    Accurate seismic amplitude information is important for the successful evaluation of many prospects and the importance of such amplitude information is increasing with the advent of time lapse seismic techniques. It is now widely accepted that the proper treatment of amplitudes requires seismic imaging in the form of either time or depth migration. A key factor in seismic imaging is the spatial sampling of the data and its relationship to the imaging algorithms. This presentation demonstrates that acquisition caused spatial sampling irregularity can affect the seismic imaging and perturb amplitudes. Equalization helps to balance the amplitudes, and the dealing strategy improves the imaging further when there are azimuth variations. Equalization and dealiasing can also help with the acquisition irregularities caused by shot and receiver dislocation or missing traces. 2 refs., 2 figs.

  2. Forecasting extreme wave events in moderate and high sea states

    Science.gov (United States)

    Magnusson, Anne Karin; Reistad, Magnar; Bitner-Gregersen, Elzbieta Maria

    2013-04-01

    Empirical studies on measurements have not yet come to conclusive relations between occurrence of rogue waves and - parameters which could be forecasted . Theoretical and tank experiments have demonstrated that high spectral peakedness and low spectral width combined (high Benjamin-Feir instability index, Onorato et al., 2006) give higher probability of rogue wave occurrence. Directional spread seems to reduce the probability of occurrence of rogue waves in these studies. Many years of experience with forecasting and discussions with people working in ocean environment indicate that rogue waves may as well occur in crossing seas. This was also indicated in a study in the Maxwave project (Toffoli et al., 2003) and the EXTREME SEAS project (Toffoli et al., 2011). We have here experimented with some indexes describing both high BFI and crossing seas and run the WAM model for some North Sea storm cases. Wave distributions measured at Ekofisk are analysed in the different cases. References • Onorato, M., Osborne, A., Serio, M., Cavaleri, L., Brandini, C., and Stansberg, C.: Extreme waves, modulational instability and second order theory: wave flume experiments on irregular waves,Europ. J. Mech. B/Fluids, 25, 586-601, 2006. • Toffoli, A., Lefevre, J.M., Monbaliu, J., Savina, H., and Bitner-Gregersen, E., "Freak Waves:Clues for Prediction in Ship Accidents?", Proc. ISOPE'2003 Conf. Hawai, USA, 2003. • Toffoli A., Bitner-Gregersen E. M., Osborne A. R., Serio M. Monbaliu J., Onorato M. (2011) Extreme Waves in Random Crossing Seas: Laboratory Experiments and Numerical Simulations. Geophys. Res. Lett., Vol. 38, L06605, 5 pp. doi: 10.1029/2011.

  3. TOFPET2: a high-performance ASIC for time and amplitude measurements of SiPM signals in time-of-flight applications

    Science.gov (United States)

    Di Francesco, A.; Bugalho, R.; Oliveira, L.; Pacher, L.; Rivetti, A.; Rolo, M.; Silva, J. C.; Silva, R.; Varela, J.

    2016-03-01

    We present a readout and digitization ASIC featuring low-noise and low-power for time-of flight (TOF) applications using SiPMs. The circuit is designed in standard CMOS 110 nm technology, has 64 independent channels and is optimized for time-of-flight measurement in Positron Emission Tomography (TOF-PET). The input amplifier is a low impedance current conveyor based on a regulated common-gate topology. Each channel has quad-buffered analogue interpolation TDCs (time binning 20 ps) and charge integration ADCs with linear response at full scale (1500 pC). The signal amplitude can also be derived from the measurement of time-over-threshold (ToT). Simulation results show that for a single photo-electron signal with charge 200 (550) fC generated by a SiPM with 320 pF capacitance the circuit has 24 (30) dB SNR, 75(39) ps r.m.s. resolution, and 4(8) mW power consumption. The event rate is 600 kHz per channel, with up to 2 MHz dark counts rejection.

  4. High-amplitude supergiant V5112 Sgr: enrichment of the envelope with heavy s-process metals

    CERN Document Server

    Klochkova., V G

    2013-01-01

    High-resolution (R=60000) echelle spectroscopy of the post-AGB supergiant V5112 Sgr performed in 1996-2012 with the 6-m telescope BTA has revealed peculiarities of the star optical spectrum and has allowed the variability of the velocity field in the stellar atmosphere and envelope to be studied in detail. An asymmetry and splitting of strong absorption lines with a low lower-level excitation potential have been detected for the first time. The effect is maximal in BaII lines whose profile is split into three components. The profile shape and positions of the split lines change with time. The blue components of the split absorption lines are shown to be formed in a structured circumstellar envelope, suggesting an efficient dredge-up of the heavy metals produced during the preceding evolution of this star into the envelope. The envelope expansion velocities have been estimated to be 20 and 30 km/s. The mean radial velocity from diffuse bands in the spectrum of V5112 Sgr coincides with that from the short-wavel...

  5. Comparing Self-Regulation-Associated Event Related Potentials in Preschool Children with and without High Levels of Disruptive Behavior.

    Science.gov (United States)

    Grabell, Adam S; Olson, Sheryl L; Tardif, Twila; Thompson, Meaghan C; Gehring, William J

    2016-11-28

    Deficient self-regulation plays a key role in the etiology of early onset disruptive behavior disorders and signals risk for chronic psychopathology. However, to date, there has been no research comparing preschool children with and without high levels of disruptive behavior using Event Related Potentials (ERPs) associated with specific self-regulation sub-processes. We examined 15 preschool children with high levels of disruptive behavior (35 % female) and 20 peers with low disruptive behavior (50 % female) who completed a Go/No-go task that provided emotionally valenced feedback. We tested whether 4 ERP components: the Error Related Negativity, the Error Positivity, the Feedback Related Negativity, and the No-go N2, differed in preschool children with and without high levels of disruptive behavior. Preschoolers with high levels of disruptive behavior showed less differentiation between the Error Positivity and corresponding waveforms following correct responses at posterior sites. Preschoolers with high and low disruptive behavior also showed differences in Go/No-go N2 waveform amplitudes across electrodes. These findings suggest that preschool children with high levels of disruptive behavior may show abnormal brain activity during certain self-regulation sub-processes, informing potential advances in conceptualizing and treating early disruptive behavior.

  6. Flare vs. Shock Acceleration of High-energy Protons in Solar Energetic Particle Events

    Science.gov (United States)

    Cliver, E. W.

    2016-12-01

    Recent studies have presented evidence for a significant to dominant role for a flare-resident acceleration process for high-energy protons in large (“gradual”) solar energetic particle (SEP) events, contrary to the more generally held view that such protons are primarily accelerated at shock waves driven by coronal mass ejections (CMEs). The new support for this flare-centric view is provided by correlations between the sizes of X-ray and/or microwave bursts and associated SEP events. For one such study that considered >100 MeV proton events, we present evidence based on CME speeds and widths, shock associations, and electron-to-proton ratios that indicates that events omitted from that investigation’s analysis should have been included. Inclusion of these outlying events reverses the study’s qualitative result and supports shock acceleration of >100 MeV protons. Examination of the ratios of 0.5 MeV electron intensities to >100 MeV proton intensities for the Grechnev et al. event sample provides additional support for shock acceleration of high-energy protons. Simply scaling up a classic “impulsive” SEP event to produce a large >100 MeV proton event implies the existence of prompt 0.5 MeV electron events that are approximately two orders of magnitude larger than are observed. While classic “impulsive” SEP events attributed to flares have high electron-to-proton ratios (≳5 × 105) due to a near absence of >100 MeV protons, large poorly connected (≥W120) gradual SEP events, attributed to widespread shock acceleration, have electron-to-proton ratios of ˜2 × 103, similar to those of comparably sized well-connected (W20-W90) SEP events.

  7. Reward processing deficits and impulsivity in high-risk offspring of alcoholics: A study of event-related potentials during a monetary gambling task

    Science.gov (United States)

    Kamarajan, Chella; Pandey, Ashwini K.; Chorlian, David B.; Manz, Niklas; Stimus, Arthur T.; Bauer, Lance O.; Hesselbrock, Victor M.; Schuckit, Marc A.; Kuperman, Samuel; Kramer, John; Porjesz, Bernice

    2015-01-01

    Background Individuals at high risk to develop alcoholism often manifest neurocognitive deficits as well as increased impulsivity. The goal of the present study is to elucidate reward processing deficits, externalizing disorders, and impulsivity as elicited by electrophysiological, clinical and behavioral measures in subjects at high risk for alcoholism from families densely affected by alcoholism in the context of brain maturation across age groups and gender. Methods Event-related potentials (ERPs) and current source density (CSD) during a monetary gambling task (MGT) were measured in 12–25 year old offspring (N = 1864) of families in the Collaborative Study on the Genetics of Alcoholism (COGA) Prospective study; the high risk (HR, N = 1569) subjects were from families densely affected with alcoholism and the low risk (LR, N = 295) subjects were from community families. Externalizing disorders and impulsivity scores were also compared between LR and HR groups. Results HR offspring from older (16–25 years) male and younger (12–15 years) female subgroups showed lower P3 amplitude than LR subjects. The amplitude decrement was most prominent in HR males during the loss condition. Overall, P3 amplitude increase at anterior sites and decrease at posterior areas were seen in older compared to younger subjects, suggesting frontalization during brain maturation. The HR subgroups also exhibited hypofrontality manifested as weaker CSD activity during both loss and gain conditions at frontal regions. Further, the HR subjects had higher impulsivity scores and increased prevalence of externalizing disorders. P3 amplitudes during the gain condition were negatively correlated with impulsivity scores. Conclusions Older male and younger female HR offspring, compared to their LR counterparts, manifested reward processing deficits as indexed by lower P3 amplitude and weaker CSD activity, along with higher prevalence of externalizing disorders and higher impulsivity scores

  8. LHC collision event at CMS showing two high energy photons (CMS Higgs search)

    CERN Multimedia

    CMS Collaboration

    2011-01-01

    11sec animation of a Higgs->GammaGamma candidate in CMS. Real CMS proton-proton collision events in which two high energy photons (dashed orange lines and towers) are observed. The event shows characteristics expected from the decay of a Higgs boson but is also consistent with background Standard Model physics processes.

  9. LHC collision event at CMS showing four high energy electrons (CMS Higgs search)

    CERN Multimedia

    CMS Collaboration

    2011-01-01

    11sec animation of a Higgs->ZZ->4e candidate in CMS. Real CMS proton-proton collision events in which 4 high energy electrons (orange lines and towers) are observed. The event shows characteristics expected from the decay of a Higgs boson but is also consistent with background Standard Model physics processes.

  10. Cultural Terms for Communication Events among Some American High School Adolescents.

    Science.gov (United States)

    Baxter, Leslie A.; Goldsmith, Daena

    1990-01-01

    Examines the natural language descriptions employed by American high school adolescents in talking about the kinds of communication events they experience in everyday life. Finds that adolescents describe communication events through use of setting, participant, speech act, and purpose marker terms. Differentiates nine basic clusters of…

  11. LHC collision event at CMS showing four high energy muons (CMS Higgs search)

    CERN Multimedia

    CMS Collaboration

    2011-01-01

    11sec animation of a Higgs->ZZ->4mu candidate being created CMS . Real CMS proton-proton collision events in which 4 high energy muons (light blue lines) are observed. The event shows characteristics expected from the decay of a Higgs boson but is also consistent with background Standard Model physics processes.

  12. Thoracic compression myelopathy due to the progression of dystrophic scoliosis, the presence of a paraspinal tumor, and high and excessive amplitude movement of the shoulder.

    Science.gov (United States)

    Kurosawa, Takashi; Yurube, Takashi; Kakutani, Kenichiro; Maeno, Koichiro; Uno, Koki; Kurosaka, Masahiro; Nishida, Kotaro

    2017-01-01

    The authors present a case of 45-year-old man with neurofibromatosis type 1 (NF-1) and thoracic scoliosis, previously undergoing fusion surgery, who developed myelopathy. This patient further complained of lightning pain when he extended and horizontally abducted the convex-side shoulder. Radiological examination revealed the progression of dystrophic scoliosis with opened spinal canals and the presence of a neurofibroma behind the spinal cord at the apical levels. Delayed development of spinal instability can occur due to dystrophy even postoperatively in patients with NF-1. After tumor resection, he had rapid recovery from myelopathy and no recurrence of radiating pain despite shoulder movement. These findings provide a speculation that high, intense amplitude movement of the shoulder toward the spinal canal causes the impingement on the neurofibroma, resulting in indirect compression of the exposed spinal cord. This is the first report describing thoracic compression myelopathy associated with paraspinal displacement of the scapula.

  13. Nuclear Jacobi and Poincaré transitions at high spins and temperatures: Account of dynamic effects and large-amplitude motion

    Science.gov (United States)

    Mazurek, K.; Dudek, J.; Maj, A.; Rouvel, D.

    2015-03-01

    We present a theoretical analysis of the competition between the so-called nuclear Jacobi and Poincaré shape transitions as a function of spin at high temperatures. The latter condition implies the method of choice, a realistic version of the nuclear liquid drop model, here the Lublin-Strasbourg drop model. We address specifically the fact that the Jacobi and Poincaré shape transitions are accompanied by the flattening of the total nuclear energy landscape as a function of the relevant deformation parameters, which enforces large-amplitude oscillation modes that need to be taken into account. For that purpose we introduce an approximate form of the collective Schrödinger equation whose solutions are used to calculate the most probable deformations associated with the nuclear Jacobi and Poincaré transitions. We discuss selected aspects of the new description focusing on the critical-spin values for both types of these transitions.

  14. Search for high-amplitude Delta Scuti and RR Lyrae stars in Sloan Digital Sky Survey Stripe 82 using principal component analysis

    CERN Document Server

    Süveges, M; Váradi, M; Mowlavi, N; Becker, A C; Ivezić, Ž; Beck, M; Nienartowicz, K; Rimoldini, L; Dubath, P; Bartholdi, P; Eyer, L

    2012-01-01

    We propose a robust principal component analysis (PCA) framework for the exploitation of multi-band photometric measurements in large surveys. Period search results are improved using the time series of the first principal component due to its optimized signal-to-noise ratio.The presence of correlated excess variations in the multivariate time series enables the detection of weaker variability. Furthermore, the direction of the largest variance differs for certain types of variable stars. This can be used as an efficient attribute for classification. The application of the method to a subsample of Sloan Digital Sky Survey Stripe 82 data yielded 132 high-amplitude Delta Scuti variables. We found also 129 new RR Lyrae variables, complementary to the catalogue of Sesar et al., 2010, extending the halo area mapped by Stripe 82 RR Lyrae stars towards the Galactic bulge. The sample comprises also 25 multiperiodic or Blazhko RR Lyrae stars.

  15. Nuclear Jacobi and Poincar\\'e Transitions at High Spins and Temperatures: Account~of~Dynamic~Effects~and~Large-Amplitude Motion

    CERN Document Server

    Mazurek, K; Maj, A; Rouvel, D

    2013-01-01

    We present a theoretical analysis of the competition between so-called nuclear Jacobi and Poincar\\'e shape transitions in function of spin - at high temperatures. The latter condition implies the method of choice - a realistic version of the nuclear Liquid Drop Model (LDM), here: the Lublin-Strasbourg Drop (LSD) model. We address specifically the fact that the Jacobi and Poincar\\'e shape transitions are accompanied by the flattening of total nuclear energy landscape as function of the relevant deformation parameters what enforces large amplitude oscillation modes that need to be taken into account. For that purpose we introduce an approximate form of the collective Schr\\"odinger equation whose solutions are used to calculate the most probable deformations associated with both types of transitions and discuss the physical consequences in terms of the associated critical-spin values and transitions themselves.

  16. Search for anomalous production of events with a high energy lepton and photon at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Loginov, Andrey Borisovich [State Scientific Center of the Russian Federation. Inst. for Theoretical and Experimental Physics, Moscow (Russian Federation)

    2006-01-01

    We present results of a search for the anomalous production of events containing a high-transverse momentum charged lepton (ℓ, either e or μ) and photon (γ), accompanied by missing transverse energy (ET), and/or additional leptons and photons, and jets (X). We use the same kinematic selection criteria as in a previous CDF search, but with a substantially larger data set, 305 pb-1, a p$\\bar{p}$ collision energy of 1.96 TeV, and the upgraded CDF II detector. We find 42 ℓγET events versus a standard model expectation of 37.3 ± 5.4 events. The level of excess observed in Run I, 16 events with an expectation of 7.6 ± 0.7 events (corresponding to a 2.7 σ effect), is not supported by the new data. In the signature of ℓℓγ + X we observe 31 events versus an expectation of 23.0 ± 2.7 events. In this sample we find no events with an extra photon or ET and so find no events like the one eeγγ ET event observed in Run I.

  17. Temporal and spatial variations of high-impact weather events in China during 1959-2014

    Science.gov (United States)

    Shi, Jun; Wen, Kangmin; Cui, Linli

    2017-07-01

    The variation and trend in the frequency and duration of four types of high-impact weather (HIW) events were examined using daily surface climate data and linear regression method, and results show that for both the frequency and the duration, the trends of hot weather events were not significant in most parts of China, though for the China as a whole, they had increased with rates of 0.4 days and 0.1 spells of hot weather per decade respectively. The frequency of cold weather events had decreased significantly in most parts of China, particularly in northern, northeastern, and western China, where it increased at rates of 2-8 days per decade in most stations, but the duration of cold weather events were not significant in most parts of China. The frequency of gale weather events had decreased in almost all of China, with a rate of 3.7 days per decade for the China as a whole, and the duration of gale weather events had decreased mainly in northeastern and northern China, western Xinjiang, southwestern Sichuan, and some coastal areas of Liaoning, Shandong, Zhejiang, and Fujian. The frequency of rainstorm weather events was not significant in most parts of China, and the duration of rainstorm weather events was not significant in the whole of China. With global climate change, there would be an increase in the hot and rainstorm weather events, so mitigation/adaptation strategies for such weather events are essential for local government and social public.

  18. Real topological string amplitudes

    Science.gov (United States)

    Narain, K. S.; Piazzalunga, N.; Tanzini, A.

    2017-03-01

    We discuss the physical superstring correlation functions in type I theory (or equivalently type II with orientifold) that compute real topological string amplitudes. We consider the correlator corresponding to holomorphic derivative of the real topological amplitude G_{χ } , at fixed worldsheet Euler characteristic χ. This corresponds in the low-energy effective action to N=2 Weyl multiplet, appropriately reduced to the orientifold invariant part, and raised to the power g' = -χ + 1. We show that the physical string correlator gives precisely the holomorphic derivative of topological amplitude. Finally, we apply this method to the standard closed oriented case as well, and prove a similar statement for the topological amplitude F_g.

  19. The European ASAMPSA_E project : towards guidance to model the impact of high amplitude natural hazards in the probabilistic safety assessment of nuclear power plants. Information on the project progress and needs from the geosciences.

    Science.gov (United States)

    Raimond, Emmanuel; Decker, Kurt; Guigueno, Yves; Klug, Joakim; Loeffler, Horst

    2015-04-01

    The Fukushima nuclear accident in Japan resulted from the combination of two correlated extreme external events (earthquake and tsunami). The consequences, in particular flooding, went beyond what was considered in the initial engineering design design of nuclear power plants (NPPs). Such situations can in theory be identified using probabilistic safety assessment (PSA) methodology. PSA results may then lead industry (system suppliers and utilities) or Safety Authorities to take appropriate decisions to reinforce the defence-in-depth of the NPP for low probability event but high amplitude consequences. In reality, the development of such PSA remains a challenging task. Definitions of the design basis of NPPs, for example, require data on events with occurrence probabilities not higher than 10-4 per year. Today, even lower probabilities, down to 10-8, are expected and typically used for probabilistic safety analyses (PSA) of NPPs and the examination of so-called design extension conditions. Modelling the combinations of natural or man-made hazards that can affect a NPP and affecting some meaningful probability of occurrence seems to be difficult. The European project ASAMPSAE (www.asampsa.eu) gathers more than 30 organizations (industry, research, safety control) from Europe, US and Japan and aims at identifying some meaningful practices to extend the scope and the quality of the existing probabilistic safety analysis developed for nuclear power plants. It offers a framework to discuss, at a technical level, how "extended PSA" can be developed efficiently and be used to verify if the robustness of Nuclear Power Plants (NPPs) in their environment is sufficient. The paper will present the objectives of this project, some first lessons and introduce which type of guidance is being developed. It will explain the need of expertise from geosciences to support the nuclear safety assessment in the different area (seismotectonic, hydrological, meteorological and biological

  20. Medical costs associated with cardiovascular events among high-risk patients with hyperlipidemia

    Directory of Open Access Journals (Sweden)

    Bonafede MM

    2015-06-01

    Full Text Available Machaon M Bonafede,1 Barbara H Johnson,1 Akshara Richhariya,2 Shravanthi R Gandra2 1Outcomes Research, Truven Health Analytics, Cambridge, MA, USA; 2Global Health Economics, Amgen, Thousand Oaks, CA, USA Objectives: This study descriptively examined acute and longer term direct medical costs associated with a major cardiovascular (CV event among high-risk coronary heart disease risk-equivalent (CHD-RE patients. It also gives a firsthand look at fatal versus nonfatal CV events. Methods: The MarketScan® Commercial Claims and Encounters Database was used to identify adults with a CV event in 2006–2012 with hyperlipidemia or lipid-lowering therapy use in the 18 months prior to one of the following inpatient CV events: myocardial infarction, ischemic stroke, unstable angina, transient ischemic attack, percutaneous coronary intervention, or coronary artery bypass graft (CABG. Patients were required to have a preindex diagnosis of at least one of the following: peripheral arterial disease, abdominal aortic aneurysm, carotid artery disease, or diabetes. A subset analysis was conducted with patients with data linkable to the Social Security Administration Master Death File. Direct medical costs were reported for each quarter following a CV event, for up to 36 months after the first CV event. Results: In total, 38,609 CHD-RE patients were included, mean age 57 years, 31% female. CABG, myocardial infarction, and percutaneous coronary intervention were the most frequent and most expensive first CV events, accounting for >75% of all first CV events with mean first quarter costs ranging from $17,454 (nonfatal transient ischemic attack to $125,690 (fatal CABG. Overall, 15% of those with a first CV event went on to have a second event during the 36-month study period with mean first quarter nonfatal and fatal costs similar to first event levels. Third CV events were rare, happening in less than 3% of patients. Conclusion: CV events among CHD-RE patients were

  1. Method for critical software event execution reliability in high integrity software

    Energy Technology Data Exchange (ETDEWEB)

    Kidd, M.E. [Sandia National Labs., Albuquerque, NM (United States)

    1997-11-01

    This report contains viewgraphs on a method called SEER, which provides a high level of confidence that critical software driven event execution sequences faithfully exceute in the face of transient computer architecture failures in both normal and abnormal operating environments.

  2. Air Shower Events of High-Energy Cosmic Rays Measured at Seoul, South Korea

    Science.gov (United States)

    Cho, Wooram; Shin, Jae-Ik; Kim, Hongki; Lee, Seulgi; Lim, Sunin; Nam, Sinwoo; Yang, Jongmann; Cheon, Byunggu; Bang, Hyungchan; Kwon, Youngjoon

    2011-09-01

    The COsmic ray Research and Education Array (COREA) collaboration has installed an array of six detector stations at two high schools in and near Seoul, Korea for measurement of air-shower events from high-energy cosmic rays. Three stations are installed at each site, where each station consists of four plastic scintillation detectors covering an area of 2m2. In this presentation, we report the currenst status of the COREA project, describing the experimental equipment and measurement of coincident events.

  3. A high-efficiency self-powered wireless sensor node for monitoring concerning vibratory events

    Science.gov (United States)

    Xu, Dacheng; Li, Suiqiong; Li, Mengyang; Xie, Danpeng; Dong, Chuan; Li, Xinxin

    2017-09-01

    This paper presents a self-powered wireless alarming sensor node (SWASN), which was designed to monitor the occurrence of concerning vibratory events. The major components of the sensor node include a vibration-threshold-triggered energy harvester (VTTEH) that powers the sensor node, a dual threshold voltage control circuit (DTVCC) for power management and a radio frequency (RF) signal transmitting module. The VTTEH generates significant electric energy only when the input vibration reaches certain amplitude. Thus, the VTTEH serves as both the power source and the vibration-event-sensing element for the sensor node. The DTVCC was specifically designed to utilize the limited power supply from the VTTEH to operate the sensor node. Constructed with only voltage detectors and MOSFETs, the DTVCC achieved low power consumption, which was 65% lower compared with the power management circuit designed in our previous work. Meanwhile, a RF transmit circuit was constructed based on the commercially available CC1110-F32 wireless transceiver chip and a compact planar antenna was designed to improve the signal transmission distance. The sensor node was fabricated and was characterized both in the laboratory and in the field. Experimental results showed that the SWASN could automatically send out alarming signals when the simulated concerning event occurred. The waiting time between two consecutive transmission periods is less than 125 s and the transmission distance can reach 1.31 km. The SWASN will have broad applications in field surveillances.

  4. Constructing An Event Based Aerosol Product Under High Aerosol Loading Conditions

    Science.gov (United States)

    Levy, R. C.; Shi, Y.; Mattoo, S.; Remer, L. A.; Zhang, J.

    2016-12-01

    High aerosol loading events, such as the Indonesia's forest fire in Fall 2015 or the persistent wintertime haze near Beijing, gain tremendous interests due to their large impact on regional visibility and air quality. Understanding the optical properties of these events and further being able to simulate and predict these events are beneficial. However, it is a great challenge to consistently identify and then retrieve aerosol optical depth (AOD) from passive sensors during heavy aerosol events. Some reasons include:1). large differences between optical properties of high-loading aerosols and those under normal conditions, 2) spectral signals of optically thick aerosols can be mistaken with surface depending on aerosol types, and 3) Extremely optically thick aerosol plumes can also be misidentified as clouds due to its high optical thickness. Thus, even under clear-sky conditions, the global distribution of extreme aerosol events is not well captured in datasets such as the MODIS Dark-Target (DT) aerosol product. In this study, with the synthetic use of OMI Aerosol Index, MODIS cloud product, and operational DT product, the heavy smoke events over the seven sea region are identified and retrieved over the dry season. An event based aerosol product that would compensate the standard "global" aerosol retrieval will be created and evaluated. The impact of missing high AOD retrievals on the regional aerosol climatology will be studied using this newly developed research product.

  5. High-order rational harmonic mode-locking and pulse-amplitude equalization of SOAFL via reshaped gain-switching FPLD pulse injection.

    Science.gov (United States)

    Lin, Gong-Ru; Kang, Jung-Jui; Lee, Chao-Kuei

    2010-04-26

    The 40-GHz rational harmonic mode-locking (RHML) and pulse-amplitude equalization of a semiconductor optical amplifier based fiber-ring laser (SOAFL) is demonstrated by the injection of a reshaped 10-GHz gain-switching FPLD pulse. A nonlinearly biased Mach-Zehnder modulator (MZM) is employed to detune the shape of the double-peak pulse before injecting the SOA, such that a pulse-amplitude equalized 4th-order RHML-SOAFL can be achieved by reshaping the SOA gain within one modulation period. An optical injection mode-locking model is constructed to simulate the compensation of uneven amplitudes between adjacent RHML pulse peaks before and after pulse-amplitude equalization. The indirect gain compensation technique greatly suppresses the clock amplitude jitter from 45% to 3.5% when achieving 4th-order RHML, and the amplitude fluctuation of sub-rational harmonic modulating envelope is attenuated by 45 dB. After pulse-amplitude equalization, the pulsewidth of the optical-injection RHML-SOAFL is 8 ps, which still obeys the trend predicted by the inverse square root of repetition rate. The phase noise contributed by the residual ASE noise of the RHML-SOAFL is significantly decreased from -84 to -90 dBc/Hz after initiating the pulse-amplitude equalization, corresponding to the timing jitter reduction from 0.5 to 0.28 ps.

  6. High-amplitude, centennial-scale climate oscillations during the last glacial in the western Third Pole as recorded in the Guliya ice cap

    Science.gov (United States)

    Thompson, L. G.; Yao, T.; Mosley-Thompson, E.; Wu, G.; Davis, M. E.; Tian, L.; Lin, P. N.

    2015-12-01

    The Guliya ice cap, located in the Kunlun Mountains in the western Third Pole (TP) region near the northern limit of the southwest monsoon influence, may be the only non-polar ice field that provides detailed histories of climate and environment over the last glacial cycle. A continuous climate record from an ice core drilled in 1992 contains Eemian ice, and basal temperatures measured that year confirmed that the record was not being removed from the bottom. The δ18O record throughout Marine Isotope Stage 2 (MIS2) displays the occurrence of high-amplitude (~20‰) episodes of ~200-year periodicity, and the aerosol records suggest snow cover, regional vegetation and fire frequency that vary in synchrony. These oscillations might reflect the movement of the northernmost penetration of the monsoon precipitation through the Late Glacial Stage, which is restricted by the topographic barrier posed by the Kunlun range, and might also reflect solar-driven nonlinearities in the climate system such as sudden shifts in the jet stream. Recent model simulations suggest that glacial cooling over China was significantly amplified by stationary waves, and the Guliya MIS2 oscillations could reflect cyclical variability in these waves. These results are supported by clumped isotope thermometry of carbonates from the Chinese Loess Plateau, which indicate a 6 to 7oC decrease in Last Glacial Maximum summer temperatures. These studies will lead to a better understanding of the mechanisms driving such high-frequency, high-amplitude oscillations. A review of the 2015 Sino-American cooperative ice core drilling program on Guliya is presented. This program will serve as a flagship for the TP Environment Program, an international, multidisciplinary collaboration among professionals and students in 14 countries designed to investigate environmental changes across the TP. The rapidly warming TP contains ~46,000 glaciers that collectively hold one of Earth's largest stores of fresh water that

  7. Protostring Scattering Amplitudes

    CERN Document Server

    Thorn, Charles B

    2016-01-01

    We calculate some tree level scattering amplitudes for a generalization of the protostring, which is a novel string model implied by the simplest string bit models. These bit models produce a lightcone worldsheet which supports $s$ integer moded Grassmann fields. In the generalization we supplement this Grassmann worldsheet system with $d=24-s$ transverse coordinate worldsheet fields. The protostring corresponds to $s=24$ and the bosonic string to $s=0$. The interaction vertex is a simple overlap with no operator insertions at the break/join point. Assuming that $s$ is even we calculate the multi-string scattering amplitudes by bosonizing the Grassmann fields, each pair equivalent to one compactified bosonic field, and applying Mandelstam's interacting string formalism to a system of $s/2$ compactified and $d$ uncompactified bosonic worldsheet fields. We obtain all amplitudes for open strings with no oscillator excitations and for closed strings with no oscillator excitations and zero winding number. We then ...

  8. Scattering amplitudes in gauge theories

    Energy Technology Data Exchange (ETDEWEB)

    Henn, Johannes M. [Institute for Advanced Study, Princeton, NJ (United States). School of Natural Sciences; Plefka, Jan C. [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik

    2014-03-01

    First monographical text on this fundamental topic. Course-tested, pedagogical and self-contained exposition. Includes exercises and solutions. At the fundamental level, the interactions of elementary particles are described by quantum gauge field theory. The quantitative implications of these interactions are captured by scattering amplitudes, traditionally computed using Feynman diagrams. In the past decade tremendous progress has been made in our understanding of and computational abilities with regard to scattering amplitudes in gauge theories, going beyond the traditional textbook approach. These advances build upon on-shell methods that focus on the analytic structure of the amplitudes, as well as on their recently discovered hidden symmetries. In fact, when expressed in suitable variables the amplitudes are much simpler than anticipated and hidden patterns emerge. These modern methods are of increasing importance in phenomenological applications arising from the need for high-precision predictions for the experiments carried out at the Large Hadron Collider, as well as in foundational mathematical physics studies on the S-matrix in quantum field theory. Bridging the gap between introductory courses on quantum field theory and state-of-the-art research, these concise yet self-contained and course-tested lecture notes are well-suited for a one-semester graduate level course or as a self-study guide for anyone interested in fundamental aspects of quantum field theory and its applications. The numerous exercises and solutions included will help readers to embrace and apply the material presented in the main text.

  9. Low-amplitude high frequency vibration down-regulates myostatin and atrogin-1 expression, two components of the atrophy pathway in muscle cells.

    Science.gov (United States)

    Ceccarelli, Gabriele; Benedetti, Laura; Galli, Daniela; Prè, Deborah; Silvani, Giulia; Crosetto, Nicola; Magenes, Giovanni; Cusella De Angelis, Maria Gabriella

    2014-05-01

    Whole body vibration (WBV) is a very widespread mechanical stimulus used in physical therapy, rehabilitation and fitness centres. It has been demonstrated that vibration induces improvements in muscular strength and performance and increases bone density. We investigated the effects of low-amplitude, high frequency vibration (HFV) at the cellular and tissue levels in muscle. We developed a system to produce vibrations adapted to test several parameters in vitro and in vivo. For in vivo experiments, we used newborn CD1 wild-type mice, for in vitro experiments, we isolated satellite cells from 6-day-old CD1 mice, while for proliferation studies, we used murine cell lines. Animals and cells were treated with high frequency vibration at 30 Hz. We analyzed the effects of mechanical stimulation on muscle hypertrophy/atrophy pathways, fusion enhancement of myoblast cells and modifications in the proliferation rate of cells. Results demonstrated that mechanical vibration strongly down-regulates atrophy genes both in vivo and in vitro. The in vitro experiments indicated that mechanical stimulation promotes fusion of satellite cells treated directly in culture compared to controls. Finally, proliferation experiments indicated that stimulated cells had a decreased growth rate compared to controls. We concluded that vibration treatment at 30 Hz is effective in suppressing the atrophy pathway both in vivo and in vitro and enhances fusion of satellite muscle cells.

  10. Large Amplitude Variations of an L/T Transition Brown Dwarf: Multi-Wavelength Observations of Patchy, High-Contrast Cloud Features

    CERN Document Server

    Radigan, Jacqueline; Lafrenière, David; Artigau, Etienne; Marley, Mark; Saumon, Didier

    2012-01-01

    We present multiple-epoch photometric monitoring in the $J$, $H$, and $K_s$ bands of the T1.5 dwarf 2MASS J21392676+0220226 (2M2139), revealing persistent, periodic ($P=7.72\\pm$0.05 hr) variability with a peak-to-peak amplitude as high as 26% in the $J$-band. The light curve shape varies on a timescale of days, suggesting that evolving atmospheric cloud features are responsible. Using interpolations between model atmospheres with differing cloud thicknesses to represent a heterogeneous surface, we find that the multi-wavelength variations and the near-infrared spectrum of 2M2139 can be reproduced by either (1)cool, thick cloud features sitting above a thinner cloud layer, or (2)warm regions of low condensate opacity in an otherwise cloudy atmosphere, possibly indicating the presence of holes or breaks in the cloud layer. We find that temperature contrasts between thick and thin cloud patches must be greater than 175 K and as high as 425 K. We also consider whether the observed variability could arise from an ...

  11. Optimization of high count rate event counting detector with Microchannel Plates and quad Timepix readout

    Energy Technology Data Exchange (ETDEWEB)

    Tremsin, A.S., E-mail: ast@ssl.berkeley.edu; Vallerga, J.V.; McPhate, J.B.; Siegmund, O.H.W.

    2015-07-01

    Many high resolution event counting devices process one event at a time and cannot register simultaneous events. In this article a frame-based readout event counting detector consisting of a pair of Microchannel Plates and a quad Timepix readout is described. More than 10{sup 4} simultaneous events can be detected with a spatial resolution of ~55 µm, while >10{sup 3} simultaneous events can be detected with <10 µm spatial resolution when event centroiding is implemented. The fast readout electronics is capable of processing >1200 frames/sec, while the global count rate of the detector can exceed 5×10{sup 8} particles/s when no timing information on every particle is required. For the first generation Timepix readout, the timing resolution is limited by the Timepix clock to 10–20 ns. Optimization of the MCP gain, rear field voltage and Timepix threshold levels are crucial for the device performance and that is the main subject of this article. These devices can be very attractive for applications where the photon/electron/ion/neutron counting with high spatial and temporal resolution is required, such as energy resolved neutron imaging, Time of Flight experiments in lidar applications, experiments on photoelectron spectroscopy and many others.

  12. High-Performance Monitoring Architecture for Large-Scale Distributed Systems Using Event Filtering

    Science.gov (United States)

    Maly, K.

    1998-01-01

    Monitoring is an essential process to observe and improve the reliability and the performance of large-scale distributed (LSD) systems. In an LSD environment, a large number of events is generated by the system components during its execution or interaction with external objects (e.g. users or processes). Monitoring such events is necessary for observing the run-time behavior of LSD systems and providing status information required for debugging, tuning and managing such applications. However, correlated events are generated concurrently and could be distributed in various locations in the applications environment which complicates the management decisions process and thereby makes monitoring LSD systems an intricate task. We propose a scalable high-performance monitoring architecture for LSD systems to detect and classify interesting local and global events and disseminate the monitoring information to the corresponding end- points management applications such as debugging and reactive control tools to improve the application performance and reliability. A large volume of events may be generated due to the extensive demands of the monitoring applications and the high interaction of LSD systems. The monitoring architecture employs a high-performance event filtering mechanism to efficiently process the large volume of event traffic generated by LSD systems and minimize the intrusiveness of the monitoring process by reducing the event traffic flow in the system and distributing the monitoring computation. Our architecture also supports dynamic and flexible reconfiguration of the monitoring mechanism via its Instrumentation and subscription components. As a case study, we show how our monitoring architecture can be utilized to improve the reliability and the performance of the Interactive Remote Instruction (IRI) system which is a large-scale distributed system for collaborative distance learning. The filtering mechanism represents an Intrinsic component integrated

  13. Occurrence of weak, sub-micron, tropospheric aerosol events at high Arctic latitudes

    Science.gov (United States)

    O'Neill, N. T.; Pancrati, O.; Baibakov, K.; Eloranta, E.; Batchelor, R. L.; Freemantle, J.; McArthur, L. J. B.; Strong, K.; Lindenmaier, R.

    2008-07-01

    Numerous fine mode (sub-micron) aerosol optical events were observed during the summer of 2007 at the High Arctic atmospheric observatory (PEARL) located at Eureka, Nunavut, Canada. Half of these events could be traced to forest fires in southern and eastern Russia and the Northwest Territories of Canada. The most notable findings were that (a) a combination of ground-based measurements (passive sunphotometry, high spectral resolution lidar) could be employed to determine that weak (near sub-visual) fine mode events had occurred, and (b) this data combined with remote sensing imagery products (MODIS, OMI-AI, FLAMBE fire sources), Fourier transform spectroscopy and back trajectories could be employed to identify the smoke events.

  14. Event reconstruction performance of the ALICE High Level Trigger for p + p collisions

    CERN Document Server

    Richter, M; Alt, T; Appelshauser, H; Arend, A; Becker, B; Bottger, S; Breitner, T; Busching, H; Cicalo, C; Chattopadhyay, S; Cleymans, J; Das, I; Djuvsland, O; Erdal, H; Fearick, R; Gorbunov, S; Haaland, O S; Hille, P T; Kalcher, S; Kanaki, K; Kebschull, U; Kisel, I; Kretz, M; Lara, C; Lindal, S; Lindenstruth, V; Masoodi, A A; Ovrebekk, G; Panse, R; Peschek, J; Ploskon, M; Pocheptsov, T; Rascanu, T; Ronchetti, F; Rohr, D; Rohrich, D; Skaali, B; Steinbeck, T; Szostak, A; Thader, J; Tveter, T S; Ullaland, K; Vilakazi, Z; Weis, R; Zelnicek, P

    2011-01-01

    The ALICE High Level Trigger comprises a large computing cluster, dedicated interfaces and software applications. It allows on-line event reconstruction of the full data stream of the ALICE experiment at up to 25 GByte/s. The commissioning campaign has passed an important phase since the startup of the Large Hadron Collider in November 2009. The system has been transferred into continuous operation with focus on the event reconstruction and first simple trigger applications. The paper reports for t he first time on the achieved event reconstruction performance in the ALICE central barrel region.

  15. DOES YOUR EVENT LOG FIT THE HIGH-LEVEL PROCESS MODEL?

    Directory of Open Access Journals (Sweden)

    A. K. Begicheva

    2015-01-01

    Full Text Available Process mining is a relatively new field of computer science, which deals with process discovery and analysis based on event logs. In this paper we consider the problem of models and event logs conformance checking. Conformance checking is intensively studied in the frame of process mining research, but only models and event logs of the same granularity were considered in the literature. Here we present and justify the method of checking conformance between a high-level model (e.g. built by an expert and a low-level log (generated by a system.The article is published in the author’s wording.

  16. A method for critical software event execution reliability in high assurance systems

    Energy Technology Data Exchange (ETDEWEB)

    Kidd, M.E.C.

    1997-03-01

    This paper presents a method for Critical Software Event Execution Reliability (Critical SEER). The Critical SEER method is intended for high assurance software that operates in an environment where transient upsets could occur, causing a disturbance of the critical software event execution order, which could cause safety or security hazards. The method has a finite automata based module that watches (hence SEER) and tracks the critical events and ensures they occur in the proper order or else a fail safe state is forced. This method is applied during the analysis, design and implementation phases of software engineering.

  17. Study by MOA of extra-solar planets in gravitational microlensing events of high magnification

    OpenAIRE

    Bond, I. A.; Rattenbury, N. J.; Skuljan, J.; Abe, F.; Dodd, R. J.; Hearnshaw, J. B.; Honda, M.; Jugaku, J.; Kilmartin, P. M.; Marles, A.; Masuda, K.; Matsubara, Y.; Muraki, Y.(Solar-Terrestrial Environment Laboratory, Nagoya University, Japan); Nakamura, T.; Nankivell, G.

    2001-01-01

    A search for extra-solar planets was carried out in three gravitational microlensing events of high magnification, MACHO 98-BLG-35, MACHO 99-LMC-2, and OGLE 00-BUL-12. Photometry was derived from observational images by the MOA and OGLE groups using an image subtraction technique. For MACHO 98-BLG-35, additional photometry derived from the MPS and PLANET groups was included. Planetary modeling of the three events was carried out in a super-cluster computing environment. The estimated probabil...

  18. Crossing historical and sedimentary archives to reconstruct an extreme flood event calendar in high alpine areas

    Science.gov (United States)

    Wilhelm, B.; Giguet-Covex, C.; Arnaud, F.; Allignol, F.; Legaz, A.; Melo, A.

    2010-09-01

    Torrential flood hazard is expected to increase in the context of global warming. However, long time-series of climate and gauge data at high-elevation sites are too sparse to assess reliably recurrence times of such events in high mountain areas. Historical documents are an alternative which provide valuable information. However, historic archives are by nature subjective and variable in quality owing to hazard perception and vulnerability according to the banks land-use throughout time. To overcome these limits, natural archives may be used as complementary records. Among the various natural archives lake sediments have the advantage to be continuous records in which particular events are preserved such as earthquakes and especially flood events. Furthermore an objective magnitude of these events can be assessed from the thickness of noteworthy event-triggered deposits. However if the recognition of major event-triggered deposits can be simple, a high-resolution dating of these events is more difficult over the historical period due to a lack of chronological markers. In this paper, we present a sediment record study of a French high alpine lake where an important effort was undertaken to date precisely 56 flood events over the last three centuries from the use of historical archives. The caesium and the lead were measured to detect the fallouts of the Chernobyl accident (1986), the atmospheric nuclear weapons tests (1955-1963) and the use of leaded gasoline which culminated in the 70's. In parallel local and regional historical archives were going through in order to correlate the thickest sediment deposits triggered by major floods and earthquakes with their potential triggering historic events. Thus we were able to associate 12 historic flood and 4 earthquake dates to particular sediment deposits. The resulting flood calendar is very well-constrained thanks to 19 chronological marks over the last 270 years, i.e. one mark by 14 years. This method permitted so

  19. A course in amplitudes

    Science.gov (United States)

    Taylor, Tomasz R.

    2017-05-01

    This a pedagogical introduction to scattering amplitudes in gauge theories. It proceeds from Dirac equation and Weyl fermions to the two pivot points of current developments: the recursion relations of Britto, Cachazo, Feng and Witten, and the unitarity cut method pioneered by Bern, Dixon, Dunbar and Kosower. In ten lectures, it covers the basic elements of on-shell methods.

  20. Excitation of high-radial-order Laguerre–Gaussian modes in a solid-state laser using a lower-loss digitally controlled amplitude mask

    Science.gov (United States)

    Bell, T.; Hasnaoui, A.; Ait-Ameur, K.; Ngcobo, S.

    2017-10-01

    In this paper we experimentally demonstrate selective excitation of high-radial-order Laguerre–Gaussian (LG p or LG{}p,0) modes with radial order p = 1–4 and azimuthal order l = 0 using a diode-pump solid-state laser (DPSSL) that is digitally controlled by a spatial light modulator (SLM). We encoded an amplitude mask containing p-absorbing rings, of various incompleteness (segmented) on grey-scale computer-generated digital holograms, and displayed them on an SLM which acted as an end mirror of the diode-pumped solid-state digital laser. The various incomplete (α) p-absorbing rings were digitally encoded to match the zero-intensity nulls of the desired LG p mode. We show that the creation of LG p , for p = 1 to p = 4, only requires an incomplete circular p-absorbing ring that has a completeness of ≈37.5%, giving the DPSSL resonator a lower pump threshold power while maintaining the same laser characteristics (such as beam propagation properties).

  1. Study of event-by-event fluctuations in the charged particle ratio in high energy heavy-ion collisions

    CERN Document Server

    Zhou Dai Mei; Liu Zhi Yi; Lu Zhong Dao; Sá Ben-Hao

    2002-01-01

    Using a hadron and string cascade model, JPCIAE, and the corresponding Monte Carlo event generator, the behavior of the charged particle ratio event-by-event fluctuations in subsystem depending on energy, centrality, resonance decay and rapidity interval was investigated for Pb+Pb collisions at SPS and ALICE energies, and for Au+Au collisions at RHIC energies. The model results of charged particle ratio event-by-event fluctuations as a function of the rapidity interval in Pb+Pb collisions at SPS energies were comparable with the preliminary NA49 data. It turned out that the charged particle ratio fluctuation has no strong energy, centrality, resonance decay and rapidity interval dependences. (13 refs).

  2. TANAMI counterparts to IceCube high-energy neutrino events

    CERN Document Server

    Krauß, Felicia; Baxter, Claire; Kadler, Matthias; Mannheim, Karl; Ojha, Roopesh; Gräfe, Christina; Müller, Cornelia; Wilms, Joern; Carpenter, Bryce; Schulz, Robert; TANAMI, on behalf of the

    2015-01-01

    Since the discovery of a neutrino flux in excess of the atmospheric background by the IceCube Collaboration, searches for the astrophysical sources have been ongoing. Due to the steeply falling background towards higher energies, the PeV events detected in three years of IceCube data are the most likely ones to be of extraterrestrial origin. Even excluding the PeV events detected so far, the neutrino flux is well above the atmospheric background, so it is likely that a number of sub-PeV events originate from the same astrophysical sources that produce the PeV events. We study the high-energy properties of AGN that are positionally coincident with the neutrino events from three years of IceCube data and show the results for event number 4. IC 4 is a event with a low angular error (7.1$^\\circ$) and a large deposited energy of 165 TeV. We use multiwavelength data, including Fermi/LAT and X-ray data, to construct broadband spectra and present parametrizations of the broadband spectral energy distributions with lo...

  3. Relations between Strong High-Frequency Microwave Bursts and Proton Events

    Science.gov (United States)

    Grechnev, Victor V.; Meshalkina, Nataliya S.; Chertok, Ilya M.; Kiselev, Valentin I.

    2013-12-01

    Proceeding from close association between solar eruptions, flares, shock waves, and CMEs, we analyze relations between bursts at 35 GHz recorded with the Nobeyama Radio Polarimeters during 1990-2012, on the one hand, and solar energetic particle (SEP) events, on the other hand. Most west to moderately east solar events with strong bursts at 35 GHz produced near-Earth proton enhancements of J (E > 100 MeV) > 1 pfu. The strongest and hardest of those caused ground-level enhancements. There is a general, although scattered, correspondence between proton enhancements and peak fluxes at 35 GHz, especially pronounced if the 35 GHz flux exceeds 104 sfu and the microwave peak frequency is high. These properties indicate emission from numerous high-energy electrons in very strong magnetic fields suggesting a high rate of energy release in the flare-CME formation process. Flaring above the sunspot umbrae appears to be typical of such events. Irrespective of the origin of SEPs, these circumstances demonstrate significant diagnostic potential of high-frequency microwave bursts and sunspot-associated flares for space weather forecasting. Strong prolonged bursts at 35 GHz promptly alert to hazardous SEP events with hard spectra. A few exceptional events with moderate bursts at 35 GHz and strong proton fluxes look challenging, and should be investigated.

  4. Observation of High Iron Charge States at Low Energies in Solar Energetic Particle Events

    Science.gov (United States)

    Guo, Z.; Möbius, E.; Klecker, B.; Bochsler, P.; Connell, J. J.; Kartavykh, Y. Y.; Mason, G. M.; Popecki, M. A.

    2014-04-01

    The ionic charge states of solar energetic particles (SEPs) provide direct information about the source plasma, the acceleration environment, and their transport. Recent studies report that both gradual and impulsive SEP events show mean iron charge states langQ Ferang ~ 10-14 at low energies E nuc-1, consistent with their origin from typical corona material at temperatures 1-2 MK. Observed increases of langQ Ferang up to 20 at energies 0.1-0.5 MeV nuc-1 in impulsive SEPs are attributed to stripping during acceleration. However, Q Fe > 16 is occasionally found in the solar wind, particularly coming from active regions, in contrast to the exclusively reported langQ Ferang = 14 throughout the entire SEPICA and STOF energy range have been identified. Four of the nine events are impulsive events identified through velocity dispersion that are consistent with source temperatures >=2 MK up to ~4 MK. The other five events show evidence of interplanetary acceleration. Four of them involve re-acceleration of impulsive material, whose original energy dependent charge states appear re-distributed to varying extent bringing higher charge states to lower energy. One event, which shows flat but elevated langQ Ferang ~ 14.2 over the entire energy range, can be associated with interplanetary acceleration of high temperature material. This event may exemplify a rare situation when a second shock plows through high temperature coronal mass ejection material.

  5. Synoptic typing of high ozone events in Arizona (2011-2013)

    Science.gov (United States)

    Wood, Jessica

    This thesis examines the synoptic characteristics associated with ozone exceedance events in Arizona during the time period of 2011 to 2013. Finding explanations and sources to the ground level ozone in this state is crucial to maintaining the state's adherence to federal air quality regulations. This analysis utilizes ambient ozone concentration data, surface meteorological conditions, upper air analyses, and HYSPLIT modeling to analyze the synoptic characteristics of ozone events. Based on these data and analyses, five categories were determined to be associated with these events. The five categories all exhibit distinct upper air patterns and surface conditions conducive to the formation of ozone, as well as distinct potential transport pathways of ozone from different nearby regions. These findings indicate that ozone events in Arizona can be linked to synoptic-scale patterns and potential regional transport of ozone. These results can be useful in the forecasting of high ozone pollution and influential on the legislative reduction of ozone pollution.

  6. Effect of Sampling Rates on the Quantification of Forces, Durations, and Rates of Loading of Simulated Side Posture High-Velocity, Low-Amplitude Lumbar Spine Manipulation☆

    Science.gov (United States)

    Gudavalli, Maruti Ram; DeVocht, James; Tayh, Ali; Xia, Ting

    2013-01-01

    Objective Quantification of chiropractic high-velocity, low-amplitude spinal manipulation (HVLA-SM) may require biomechanical equipment capable of sampling data at high rates. However, there are few studies reported in the literature regarding the minimal sampling rate required to record the HVLA-SM force-time profile data accurately and precisely. The purpose of this study was to investigate the effect of different sampling rates on the quantification of forces, durations, and rates of loading of simulated side posture lumbar spine HVLA-SM delivered by doctors of chiropractic. Methods Five doctors of chiropractic (DCs) and 5 asymptomatic participants were recruited for this study. Force-time profiles were recorded during (i) 52 simulated HVLA-SM thrusts to a force transducer placed on a force plate by 2 DCs and (ii) 12 lumbar side posture HVLA-SM on 5 participants by 3 DCs. Data sampling rate of the force plate remained the same at 1000 Hz, whereas the sampling rate of the force transducer varied at 50, 100, 200, and 500 Hz. The data were reduced using custom-written MATLAB (Mathworks, Inc, Natick, MA) and MathCad (version 15; Parametric Technologies, Natick, MA) programs and analyzed descriptively. Results The average differences in the computed durations and rates of loading are smaller than 5% between 50 and 1000 Hz sampling rates. The differences in the computed preloads and peak loads are smaller than 3%. Conclusions The small differences observed in the characteristics of force-time profiles of simulated manual HVLA-SM thrusts measured using various sampling rates suggest that a sampling rate as low as 50 to 100 Hz may be sufficient. The results are applicable to the manipulation performed in this study: manual side posture lumbar spine HVLA-SM. PMID:23790603

  7. Effect of sampling rates on the quantification of forces, durations, and rates of loading of simulated side posture high-velocity, low-amplitude lumbar spine manipulation.

    Science.gov (United States)

    Gudavalli, Maruti Ram; DeVocht, James; Tayh, Ali; Xia, Ting

    2013-06-01

    Quantification of chiropractic high-velocity, low-amplitude spinal manipulation (HVLA-SM) may require biomechanical equipment capable of sampling data at high rates. However, there are few studies reported in the literature regarding the minimal sampling rate required to record the HVLA-SM force-time profile data accurately and precisely. The purpose of this study was to investigate the effect of different sampling rates on the quantification of forces, durations, and rates of loading of simulated side posture lumbar spine HVLA-SM delivered by doctors of chiropractic. Five doctors of chiropractic (DCs) and 5 asymptomatic participants were recruited for this study. Force-time profiles were recorded during (i) 52 simulated HVLA-SM thrusts to a force transducer placed on a force plate by 2 DCs and (ii) 12 lumbar side posture HVLA-SM on 5 participants by 3 DCs. Data sampling rate of the force plate remained the same at 1000 Hz, whereas the sampling rate of the force transducer varied at 50, 100, 200, and 500 Hz. The data were reduced using custom-written MATLAB (Mathworks, Inc, Natick, MA) and MathCad (version 15; Parametric Technologies, Natick, MA) programs and analyzed descriptively. The average differences in the computed durations and rates of loading are smaller than 5% between 50 and 1000 Hz sampling rates. The differences in the computed preloads and peak loads are smaller than 3%. The small differences observed in the characteristics of force-time profiles of simulated manual HVLA-SM thrusts measured using various sampling rates suggest that a sampling rate as low as 50 to 100 Hz may be sufficient. The results are applicable to the manipulation performed in this study: manual side posture lumbar spine HVLA-SM. Copyright © 2013 The Authors. Published by Mosby, Inc. All rights reserved.

  8. Weak Boson Production Amplitude Zeros; Equalities of the Helicity Amplitudes

    CERN Document Server

    Mamedov, F

    2002-01-01

    We investigate the radiation amplitude zeros exhibited by many Standard Model amplitudes for triple weak gauge boson production processes. We show that $WZ\\gamma$ production amplitudes have especially rich structure in terms of zeros, these amplitudes have zeros originating from several different sources. It is also shown that TYPE I current null zone is the special case of the equality of the specific helicity amplitudes.

  9. Optimal Blood Pressure Goals in Patients With Hypertension at High Risk for Cardiovascular Events.

    Science.gov (United States)

    Aronow, Wilbert S

    2016-01-01

    Existing epidemiologic and clinical trial data suggest that the blood pressure in patients with hypertension at high risk for cardiovascular events because of coronary artery disease, diabetes mellitus, chronic kidney disease, stroke, or heart failure should be reduced to blood pressure be reduced to 140-145 mm Hg if tolerated in patients aged 80 years and older. Studies from patients with coronary artery disease, diabetes mellitus, chronic kidney disease, stroke, and heart failure will be discussed that support a blood pressure goal of high risk for cardiovascular events.

  10. High-speed event detector for embedded nanopore bio-systems.

    Science.gov (United States)

    Huang, Yiyun; Magierowski, Sebastian; Ghafar-Zadeh, Ebrahim; Wang, Chengjie

    2015-08-01

    Biological measurements of microscopic phenomena often deal with discrete-event signals. The ability to automatically carry out such measurements at high-speed in a miniature embedded system is desirable but compromised by high-frequency noise along with practical constraints on filter quality and sampler resolution. This paper presents a real-time event-detection method in the context of nanopore sensing that helps to mitigate these drawbacks and allows accurate signal processing in an embedded system. Simulations show at least a 10× improvement over existing on-line detection methods.

  11. Periods and Superstring Amplitudes

    CERN Document Server

    Stieberger, S

    2016-01-01

    Scattering amplitudes which describe the interaction of physical states play an important role in determining physical observables. In string theory the physical states are given by vibrations of open and closed strings and their interactions are described (at the leading order in perturbation theory) by a world-sheet given by the topology of a disk or sphere, respectively. Formally, for scattering of N strings this leads to N-3-dimensional iterated real integrals along the compactified real axis or N-3-dimensional complex sphere integrals, respectively. As a consequence the physical observables are described by periods on M_{0,N} - the moduli space of Riemann spheres of N ordered marked points. The mathematical structure of these string amplitudes share many recent advances in arithmetic algebraic geometry and number theory like multiple zeta values, single-valued multiple zeta values, Drinfeld, Deligne associators, Hopf algebra and Lie algebra structures related to Grothendiecks Galois theory. We review the...

  12. Light Meson Distribution Amplitudes

    CERN Document Server

    Arthur, R.; Brommel, D.; Donnellan, M.A.; Flynn, J.M.; Juttner, A.; de Lima, H.Pedroso; Rae, T.D.; Sachrajda, C.T.; Samways, B.

    2010-01-01

    We calculated the first two moments of the light-cone distribution amplitudes for the pseudoscalar mesons ($\\pi$ and $K$) and the longitudinally polarised vector mesons ($\\rho$, $K^*$ and $\\phi$) as part of the UKQCD and RBC collaborations' $N_f=2+1$ domain-wall fermion phenomenology programme. These quantities were obtained with a good precision and, in particular, the expected effects of $SU(3)$-flavour symmetry breaking were observed. Operators were renormalised non-perturbatively and extrapolations to the physical point were made, guided by leading order chiral perturbation theory. The main results presented are for two volumes, $16^3\\times 32$ and $24^3\\times 64$, with a common lattice spacing. Preliminary results for a lattice with a finer lattice spacing, $32^3\\times64$, are discussed and a first look is taken at the use of twisted boundary conditions to extract distribution amplitudes.

  13. Quantitative Seismic Amplitude Analysis

    OpenAIRE

    Dey, A. K.

    2011-01-01

    The Seismic Value Chain quantifies the cyclic interaction between seismic acquisition, imaging and reservoir characterization. Modern seismic innovation to address the global imbalance in hydrocarbon supply and demand requires such cyclic interaction of both feed-forward and feed-back processes. Currently, the seismic value chain paradigm is in a feed-forward mode. Modern seismic data now have the potential to yield the best images in terms of spatial resolution, amplitude accuracy, and incre...

  14. High-velocity Hα Absorption Events in B8 Ia - A2 Ia Supergiant Stars

    Science.gov (United States)

    Morrison, Nancy D.; Markova, N.; Rother, S. J.

    2009-12-01

    Late B- and early A-type supergiants are notorious for the time variability of their Hα line profiles, but the physical cause of the variations is poorly understood. Usually, the line is filled in by emission, and the blue absorption wing does not extend to the terminal wind speed, which is roughly defined by the blue edges of the ultraviolet resonance lines. On rare occasions, however, the blue wing of Hα goes strongly into absorption over a wide velocity range, from the photospheric velocity almost all the way to the terminal wind speed. This phenomenon was first described by Kaufer et al. (1996, A&A, 314, 599), who denoted it by the term, "High-Velocity Absorption Event." In this report, high-resolution spectra from Ritter Observatory will be combined with published spectra to examine the temporal recurrence behavior and strength distribution of high-velocity absorption events and their incidence as a function of stellar parameters for the available sample of stars. All B8- and A0-type, Ia-class, stars in the sample that have been sufficiently well observed, as well as one A2-type star, show the events. However, there is some evidence that hyperluminous stars (luminosity class Ia+) do not show the events. In one of the most extensively observed stars in the sample (Rigel, B8 Ia), there is no clear periodicity in the recurrence times of the events. In addition to the strong events discovered by Kaufer et al. (1996), there is a broad distribution of more frequent, weaker events. Ritter Observatory receives operating support from the National Science Foundation Program for Research and Education with Small Telescopes (PREST) award AST-0440784.

  15. Star Formation and Exoplanetary Systems in the National Science Olympiad Astronomy Event for High School Students

    Science.gov (United States)

    Komacek, Thaddeus D.; Young, Donna; Schroeder, Dustin M.; Van Hecke, Mark A.

    2014-11-01

    Science Olympiad is one of the nation’s largest secondary school science competitions, reaching over 240,000 students on more than 6,000 teams. The competition covers various aspects of science and technology, exposing students to a variety of career options in STEM. 9 of Science Olympiad’s 46 events (with 23 for both middle and high school) have a focus on Earth and Space Science, including process skills and knowledge of a variety of subjects, including: Astrophysics, Planetary Sciences, Oceanography, Meteorology, Remote Sensing, and Geologic Mapping, among others. The Astronomy event is held for students from 9th - 12th grade, and covers topics based upon stellar evolution and/or galactic astronomy. For the 2014-2015 competition season, Astronomy will focus on star formation and exoplanets in concert with stellar evolution, bringing recent and groundbreaking research to light for young potential astronomers and planetary scientists. The event tests students on their “understanding of the basic concepts of mathematics and physics relating to stellar evolution and star and planet formation,” including qualitative responses, DS9 image analysis, and quantitative problem solving. We invite any members of the exoplanet and star formation communities that are interested in developing event materials to contact the National event supervisors, Donna Young (donna@aavso.org) and Tad Komacek (tkomacek@lpl.arizona.edu). We also encourage you to contact your local regional or state Science Olympiad tournament directors to help supervise events and run competitions in your area.

  16. Major Solar Eruptions and High Energy Particle Events during Solar Cycle 24

    CERN Document Server

    Gopalswamy, N; Akiyama, S; Makela, P; Yashiro, S

    2014-01-01

    We report on a study of all major solar eruptions that occurred on the front-side of the Sun during the rise to peak phase of cycle 24 (first 62 months) in order to understand the key factors affecting the occurrence of large solar energetic particle events (SEPs) and the ground levels enhancement (GLE) events. The eruptions involve major flares with soft X-ray peak flux >/= 5.0 x10-5 Wm-2 (i.e., flare size >/= M5.0) and accompanying coronal mass ejections (CMEs). The selection criterion was based on the fact that the only front-side GLE in cycle 24 (GLE 71) had a flare size of M5.1. Only ~37% of the major eruptions from the western hemisphere resulted in large SEP events. Almost the same number of large SEP events was produced in weaker eruptions (flare size events. On the other hand, the CME speed is a better indicator of SEP and GLE events because it is consistently high supporting the shock acceleration mechanism for SEP...

  17. Effects of Cervical High-Velocity Low-Amplitude Techniques on Range of Motion, Strength Performance, and Cardiovascular Outcomes: A Review.

    Science.gov (United States)

    Galindez-Ibarbengoetxea, Xabier; Setuain, Igor; Andersen, Lars L; Ramírez-Velez, Robinson; González-Izal, Miriam; Jauregi, Andoni; Izquierdo, Mikel

    2017-07-21

    Cervical high-velocity low-amplitude (HVLA) manipulation technique is among the oldest and most frequently used chiropractic manual therapy, but the physiologic and biomechanics effects were not completely clear. This review aims to describe the effects of cervical HVLA manipulation techniques on range of motion, strength, and cardiovascular performance. A systematic search was conducted of the electronic databases from January 2000 to August 2016: PubMed (n = 131), ScienceDirect (n = 101), Scopus (n = 991), PEDro (n = 33), CINAHL (n = 884), and SciELO (n = 5). Two independent reviewers conducted the screening process to determine article eligibility. The intervention that included randomized controlled trials was thrust, or HVLA, manipulative therapy directed to the cervical spine. Methodological quality was assessed using the Cochrane risk-of-bias tool. The initial search rendered 2145 articles. After screening titles and abstracts, 11 articles remained for full-text review. The review shows that cervical HVLA manipulation treatment results in a large effect size (d > 0.80) on increasing cervical range of motion and mouth opening. In patients with lateral epicondylalgia, cervical HVLA manipulation resulted in increased pain-free handgrip strength, with large effect sizes (1.44 and 0.78, respectively). Finally, in subjects with hypertension the blood pressure seemed to decrease after cervical HVLA manipulation. Higher quality studies are needed to develop a stronger evidence-based foundation for HVLA manipulation techniques as a treatment for cervical conditions.

  18. Validation of the cat as a model for the human lumbar spine during simulated high-velocity, low-amplitude spinal manipulation.

    Science.gov (United States)

    Ianuzzi, Allyson; Pickar, Joel G; Khalsa, Partap S

    2010-07-01

    High-velocity, low-amplitude spinal manipulation (HVLA-SM) is an efficacious treatment for low back pain, although the physiological mechanisms underlying its effects remain elusive. The lumbar facet joint capsule (FJC) is innervated with mechanically sensitive neurons and it has been theorized that the neurophysiological benefits of HVLA-SM are partially induced by stimulation of FJC neurons. Biomechanical aspects of this theory have been investigated in humans while neurophysiological aspects have been investigated using cat models. The purpose of this study was to determine the relationship between human and cat lumbar spines during HVLA-SM. Cat lumbar spine specimens were mechanically tested, using a displacement-controlled apparatus, during simulated HVLA-SM applied at L5, L6, and L7 that produced preload forces of approximately 25% bodyweight for 0.5 s and peak forces that rose to 50-100% bodyweight within approximately 125 ms, similar to that delivered clinically. Joint kinematics and FJC strain were measured optically. Human FJC strain and kinematics data were taken from a prior study. Regression models were established for FJC strain magnitudes as functions of factors species, manipulation site, and interactions thereof. During simulated HVLA-SM, joint kinematics in cat spines were greater in magnitude compared with humans. Similar to human spines, site-specific HVLA-SM produced regional cat FJC strains at distant motion segments. Joint motions and FJC strain magnitudes for cat spines were larger than those for human spine specimens. Regression relationships demonstrated that species, HVLA-SM site, and interactions thereof were significantly and moderately well correlated for HVLA-SM that generated tensile strain in the FJC. The relationships established in the current study can be used in future neurophysiological studies conducted in cats to extrapolate how human FJC afferents might respond to HVLA-SM. The data from the current study warrant further

  19. Oscillations in the hadron scattering amplitude at high energy and small momentum transfer; Oscillations dans l`amplitude de diffusion hadronique a haute energie et petites moments de transfer

    Energy Technology Data Exchange (ETDEWEB)

    Gauron, Pierre; Basarab Nicolescu [Theoretical Physics Division, Inst. de Physique Nucleaire, Paris-11 Univ., 91 - Orsay (France); Selyugin, O.V. [Lab. of Theoretical Physics, Joint Inst. for Nuclear Research, Dubna (Russian Federation)

    1999-10-01

    We show that the high precision dN/dt UA4/2 data at {radical} = 541 GeV are compatible with the presence of Auberson-Kinoshita-Martin (AKM) type of oscillations at very small momentum transfer. These oscillations seem to be periodic in {radical}|t|, the corresponding period being {approx_equal} 2 {center_dot}10{sup -2} GeV. The existence of such visible oscillations suggests a general mechanism of saturation of axiomatic bounds. As an illustration the consequences for extracting the parameter {rho} = ReF/ImF from dN/dt data are also discussed. (authors) 1 ref., 2 figs.

  20. A high performance real-time plasma control and event detection DSP based VME system

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, A.P. E-mail: pinto@ci.uc.pt; Correia, Carlos; Varandas, Carlos

    2002-06-01

    This paper describes the digital signal processors module of a high performance system, specially designed for real-time plasma control and event detection on the next generation fusion experiments with long duration discharges. The system is composed of a commercial CPU board and several on-site developed intelligent modules inserted in the same VME crate.

  1. Earliest Memories and Recent Memories of Highly Salient Events--Are They Similar?

    Science.gov (United States)

    Peterson, Carole; Fowler, Tania; Brandeau, Katherine M.

    2015-01-01

    Four- to 11-year-old children were interviewed about 2 different sorts of memories in the same home visit: recent memories of highly salient and stressful events--namely, injuries serious enough to require hospital emergency room treatment--and their earliest memories. Injury memories were scored for amount of unique information, completeness…

  2. Did cultural and artistic education in the Netherlands increase student participation in high cultural events?

    NARCIS (Netherlands)

    Damen, M.-L.; van Klaveren, C.

    2010-01-01

    This study examines whether Cultural and Artistic Education that was implemented by the Dutch Ministry of Education, Culture and Science in 1999 caused students to participate more in high cultural events. A unique feature of the intervention was that students were free to choose the type of cultura

  3. Amplitude image processing by diffractive optics.

    Science.gov (United States)

    Cagigal, Manuel P; Valle, Pedro J; Canales, V F

    2016-02-22

    In contrast to the standard digital image processing, which operates over the detected image intensity, we propose to perform amplitude image processing. Amplitude processing, like low pass or high pass filtering, is carried out using diffractive optics elements (DOE) since it allows to operate over the field complex amplitude before it has been detected. We show the procedure for designing the DOE that corresponds to each operation. Furthermore, we accomplish an analysis of amplitude image processing performances. In particular, a DOE Laplacian filter is applied to simulated astronomical images for detecting two stars one Airy ring apart. We also check by numerical simulations that the use of a Laplacian amplitude filter produces less noisy images than the standard digital image processing.

  4. Low-Amplitude Anisotropic Wave Train Events during Passage of Interplanetary Magnetic Clouds / Mazas Amplitūdas Anizotropiju Viļņu Parādību Secība Starpplanētu Magnētisko Mākoņu Rašanās Laikā

    Science.gov (United States)

    Agarwal, R.; Mishra, R. K.

    2013-04-01

    The work presents a continuation in the series related to the long-term space observations made by ground-based neutron monitoring stations. The cosmic ray intensity variation is considered as affected by interplanetary magnetic clouds during low-amplitude anisotropic wave train (LAAWT) events. It was observed that the solar wind velocity is higher than normal (> 300 km/s) while the interplanetary magnetic field (IMF) strength is lower than normal on the arrival of magnetic cloud during LAAWT events. The proton density is found to remain significantly low at high solar-wind velocity, which was expected. The north/south component of interplanetary magnetic field turns southward one day before the arrival of cloud and remains in this direction after that. The cosmic ray intensity is found to increase with the solar wind velocity. It is noteworthy that the cosmic ray intensity significantly increases before and 90 h after the arrival of such a cloud, and decreases gradually after its passage. The north/south component of IMF (Bz) is found to significantly correlate with latitude angle (Ө) and disturbance storm time index Dst, whereas the geomagnetic activity index (Ap) significantly anti-correlates with these parameters, decreasing with (Ө) and Dst increasing on the arrival of interplanetary magnetic cloud during LAAWT events. Raksts ir turpinājums darbu sērijai par dažādām parādībām kosmosā, kas balstītas uz novērojumiem un datiem, iegūtiem dažādos laika periodos pasaules neitronu monitoringa stacijās (Deep River, Tokija, Maskava, u.c.). Rakstā apskatītās kosmisko staru intensitātes izmaiņas tiek pamatotas ar starpplanētu magnētisko mākoņu parādīšanos. Tiek parādītas saules vēja, magnētiskā lauka spēka, vētru pertubāciju indeksa un citu parametru atkarība no magnētisko mākoņu parādīšanās. Tiek atzīmēts, ka kosmisko staru intensitāte strauji pieaug pirms mākoņu parādīšanās un 90 stundu laikā pēc tiem, un pak

  5. High Background Ozone Events in the Houston-Galveston-Brazoria Area: Effects from Central American Fires

    Science.gov (United States)

    Lei, R.; Wang, S. C.; Yang, S.; Wang, Y.; Talbot, R. W.

    2016-12-01

    The policy-relevant background (PRB) ozone is defined by the U.S. Environmental Protection Agency (EPA) as the surface ozone mixing ratio that would occur over the U.S. without North American anthropogenic emission influences. PRB ozone over the Houston-Galveston-Brazoria (HGB) area may be affected by foreign sources due to its unique geographical location and meteorology. Our monitoring data revealed several high ozone events over HGB area which might be caused by Central American fire during the years of 2013-2015. To qualify the effects from Central American fire, we estimated the US, Central American and worldwide background over HGB area during those events using the GEOS-Chem global 3-D model. Anomalies in fire emissions leading to high PRB ozone were mapped through spatiotemporal sampling of the Fire INventory from NCAR (FINN) along background trajectories of air masses affecting the HGB area prior to and during the selected high PRB ozone days. Daily HGB PRB ozone estimated by researchers at the Texas Commission on Environmental Quality (TCEQ) was used as the data source to validate model results. Results showed that contribution of emission from Central American to HGB PRB ozone could be tripled during fire events compared to non-impacted fire days. Besides fire emissions from Central American, different types of meteorological events (e.g., cold fronts and thunderstorms) and high local photochemical production (e.g., heat waves and stagnation) are also found associated with high PRB ozone in HGB area during these events. Thus we imply that synthetic contribution from foreign sources and local meteorology to HGB PRB ozone warrants further investigated.

  6. CMS High Level Trigger for boosted $t\\bar{t}$ events

    CERN Document Server

    Celli, Federico

    2016-01-01

    In this work we studied the efficiency of a new CMS high level trigger path for boosted topology $t\\bar{t}$ events, available during the 2016 LHC run at 13 TeV. We found out that this trigger was affected by a prescale factor bug that did not allow us to register about 18.4% of candidate $t\\bar{t}$ events, leading to an apparent loss in the trigger efficiency. This work has also pointed out that as soon as this issue is solved we will be able to use the new trigger path with good performances, increasing the statistics in future measurements.

  7. Altered spontaneous brain activity pattern in patients with high myopia using amplitude of low-frequency fluctuation: a resting-state fMRI study

    Directory of Open Access Journals (Sweden)

    Huang X

    2016-11-01

    Full Text Available Xin Huang,1,2,* Fu-Qing Zhou,3,* Yu-Xiang Hu,1 Xiao-Xuan Xu,1 Xiong Zhou,4 Yu-Lin Zhong,1 Jun Wang,4 Xiao-Rong Wu1 1Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, 2Department of Ophthalmology, The First People’s Hospital of Jiujiang City, Jiujiang, 3Department of Radiology, The First Affiliated Hospital of Nanchang University, Jiangxi Province Medical Imaging Research Institute, 4Second Department of Respiratory Disease, Jiangxi Provincial People’s Hospital, Nanchang, Jiangxi, People’s Republic of China *These authors contributed equally to this work Objective: Many previous reports have demonstrated significant neural anatomy changes in the brain of high myopic (HM patients, whereas the spontaneous brain activity changes in the HM patients at rest are not well studied. Our objective was to use amplitude of low-frequency fluctuation (ALFF method to investigate the changes in spontaneous brain activity in HM patients and their relationships with clinical features. Methods: A total of 38 patients with HM (17 males and 21 females and 38 healthy controls (HCs (17 males and 21 females closely matched in age, sex, and education underwent resting-state functional magnetic resonance imaging scans. The ALFF method was used to assess local features of spontaneous brain activity. The relationship between the mean ALFF signal values in many brain regions and the clinical features in HM patients was calculated by correlation analysis. Results: Compared with HCs, the HM patients had significantly lower ALFF in the right inferior and middle temporal gyrus, left middle temporal gyrus, left inferior frontal gyrus/putamen, right inferior frontal gyrus/putamen/insula, right middle frontal gyrus, and right inferior parietal lobule and higher ALFF values in the bilateral midcingulate cortex, left postcentral gyrus, and left precuneus/inferior parietal lobule. However, no relationship was found between the mean ALFF

  8. Spin rotation and birefringence effect for a particle in a high energy storage ring and measurement of the real part of the coherent elastic zero-angle scattering amplitude, electric and magnetic polarizabilities

    CERN Document Server

    Baryshevsky, V G

    2005-01-01

    In the present paper the equations for the spin evolution of a particle in a storage ring are analyzed considering contributions from the tensor electric and magnetic polarizabilities of the particle. Study of spin rotation and birefringence effect for a particle in a high energy storage ring provides for measurement as the real part of the coherent elastic zero-angle scattering amplitude as well as tensor electric and magnetic polarizabilities. We proposed the method for measurement the real part of the elastic coherent zero-angle scattering amplitude of particles and nuclei in a storage ring by the paramagnetic resonance in the periodical in time nuclear pseudoelectric and pseudomagnetic fields.

  9. Phenomenon of energy concentration in high-energy family events of cosmic rays

    CERN Document Server

    Wang He; Dai Zhi Qiang; Xue Liang; Feng Cun Feng; Zhang Xue Yao; Li Jin; Zhang Nai Jian; He Mao; Wang Cheng Rui; Ren Jing Ru; Lu Sui Ling

    2002-01-01

    The phenomenon of energy concentration in high-energy family events of cosmic rays is studied by comparing the results of family events of total visible energies 100-400 TeV observed in the Kanbala emulsion chamber experiment with the Monte Carlo simulation data. The simulation is made by the program CORSIKA in which QGSJET is applied as the hadronic interaction model, and the chemical composition of primary cosmic rays is obtained from the rigidity-cut model and the extrapolation of new results of direct measurements. This shows that the whole distribution tendency of the rate of energy concentration of simulated family events is basically consistent with that of the experiment

  10. High-energy heavy ion testing of VLSI devices for single event upsets and latch up

    Indian Academy of Sciences (India)

    S B Umesh; S R Kulkarni; R Sandhya; G R Joshi; R Damle; M Ravindra

    2005-08-01

    Several very large scale integrated (VLSI) devices which are not available in radiation hardened version are still required to be used in spacecraft systems. Thus these components need to be tested for highenergy heavy ion irradiation to find out their tolerance and suitability in specific space applications. This paper describes the high-energy heavy ion radiation testing of VLSI devices for single event upset (SEU) and single event latch up (SEL). The experimental set up employed to produce low flux of heavy ions viz. silicon (Si), and silver (Ag), for studying single event effects (SEE) is briefly described. The heavy ion testing of a few VLSI devices is performed in the general purpose scattering chamber of the Pelletron facility, available at Nuclear Science Centre, New Delhi. The test results with respect to SEU and SEL are discussed.

  11. Phenomenon of Energy Concentration in High-Energy Family Events of Cosmic Rays

    Institute of Scientific and Technical Information of China (English)

    王河; 王永刚; 戴志强; 薛良; 冯存峰; 张学尧; 李金玉; 张乃健; 何瑁; 王承瑞; 任敬儒; 陆穗苓

    2002-01-01

    The phenomenon of energy concentration in high-energy family events of cosmic rays is studied by comparing the results of family events of total visible energies 100-400 TeV observed in the Kanbala emulsion chamber experiment with the Monte Carlo simulation data. The simulation is made by the program CORSIKA in which QGSJET is applied as the hadronic interaction model, and the chemical composition of primary cosmic rays is obtained from the rigidity-cut model and the extrapolation of new results of direct measurements. This shows that the whole distribution tendency of the rate of energy concentration of simulated family events is basically consistent with that of the experiment.

  12. Characteristic Paths of Extratropical Cyclones that Cause High Wind Events in the Northeast United States

    Science.gov (United States)

    Booth, J. F.; Rieder, H. E.; Lee, D.; Kushnir, Y.

    2014-12-01

    This study analyzes the association between wintertime high wind events (HWEs) in the northeast United States US and extratropical cyclones. Sustained wind maxima in the Daily Summary Data from the National Climatic Data Center's Integrated Surface Database are analyzed for 1979-2012. For each station, a Generalized Pareto Distribution (GPD) is fit to the upper tail of the daily maximum wind speed data, and probabilistic return levels at intervals of 1, 3 and 5-years are derived from the GPD fit. At each interval, wind events meeting the return level criteria are termed HWEs. The HWEs occurring on the same day are grouped into multi-station events allowing the association with extratropical cyclones, which are tracked in the European Center for Medium-Range Weather Forecast ERA-Interim reanalysis. Using hierarchical clustering analysis, this study finds that the HWEs are most often associated with cyclones travelling from southwest to northeast, usually originating west of the Appalachian Mountains. The results show that a storm approaching from the southwest is four times more likely to cause strong surface winds than a Nor'easter. A series of sensitivity analyses confirms the robustness of this result. Next, the relationship between the strength of the wind events and the corresponding storm minimum sea level pressure is analyzed. No robust relationship between these quantities is found for strong wind events. Nevertheless, subsequent analysis shows that a relationship between deeper storms and stronger winds emerges if the analysis is extended to the entire set of wintertime storms.

  13. Warmer and wetter winters: characteristics and implications of an extreme weather event in the High Arctic

    Science.gov (United States)

    Hansen, Brage B.; Isaksen, Ketil; Benestad, Rasmus E.; Kohler, Jack; Pedersen, Åshild Ø.; Loe, Leif E.; Coulson, Stephen J.; Larsen, Jan Otto; Varpe, Øystein

    2014-11-01

    One predicted consequence of global warming is an increased frequency of extreme weather events, such as heat waves, droughts, or heavy rainfalls. In parts of the Arctic, extreme warm spells and heavy rain-on-snow (ROS) events in winter are already more frequent. How these weather events impact snow-pack and permafrost characteristics is rarely documented empirically, and the implications for wildlife and society are hence far from understood. Here we characterize and document the effects of an extreme warm spell and ROS event that occurred in High Arctic Svalbard in January-February 2012, during the polar night. In this normally cold semi-desert environment, we recorded above-zero temperatures (up to 7 °C) across the entire archipelago and record-breaking precipitation, with up to 98 mm rainfall in one day (return period of >500 years prior to this event) and 272 mm over the two-week long warm spell. These precipitation amounts are equivalent to 25 and 70% respectively of the mean annual total precipitation. The extreme event caused significant increase in permafrost temperatures down to at least 5 m depth, induced slush avalanches with resultant damage to infrastructure, and left a significant ground-ice cover (˜5-20 cm thick basal ice). The ground-ice not only affected inhabitants by closing roads and airports as well as reducing mobility and thereby tourism income, but it also led to high starvation-induced mortality in all monitored populations of the wild reindeer by blocking access to the winter food source. Based on empirical-statistical downscaling of global climate models run under the moderate RCP4.5 emission scenario, we predict strong future warming with average mid-winter temperatures even approaching 0 °C, suggesting increased frequency of ROS. This will have far-reaching implications for Arctic ecosystems and societies through the changes in snow-pack and permafrost properties.

  14. Empagliflozin and Cerebrovascular Events in Patients With Type 2 Diabetes Mellitus at High Cardiovascular Risk.

    Science.gov (United States)

    Zinman, Bernard; Inzucchi, Silvio E; Lachin, John M; Wanner, Christoph; Fitchett, David; Kohler, Sven; Mattheus, Michaela; Woerle, Hans J; Broedl, Uli C; Johansen, Odd Erik; Albers, Gregory W; Diener, Hans Christoph

    2017-05-01

    In the EMPA-REG OUTCOME trial (Empagliflozin Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients), empagliflozin added to standard of care in patients with type 2 diabetes mellitus and high cardiovascular risk reduced the risk of 3-point major adverse cardiovascular events, driven by a reduction in cardiovascular mortality, with no significant difference between empagliflozin and placebo in risk of myocardial infarction or stroke. In a modified intent-to-treat analysis, the hazard ratio for stroke was 1.18 (95% confidence interval, 0.89-1.56; P=0.26). We further investigated cerebrovascular events. Patients were randomized to empagliflozin 10 mg, empagliflozin 25 mg, or placebo; 7020 patients were treated. Median observation time was 3.1 years. The numeric difference in stroke between empagliflozin and placebo in the modified intent-to-treat analysis was primarily because of 18 patients in the empagliflozin group with a first event >90 days after last intake of study drug (versus 3 on placebo). In a sensitivity analysis based on events during treatment or ≤90 days after last dose of drug, the hazard ratio for stroke with empagliflozin versus placebo was 1.08 (95% confidence interval, 0.81-1.45; P=0.60). There were no differences in risk of recurrent, fatal, or disabling strokes, or transient ischemic attack, with empagliflozin versus placebo. Patients with the largest increases in hematocrit or largest decreases in systolic blood pressure did not have an increased risk of stroke. In patients with type 2 diabetes mellitus and high cardiovascular risk, there was no significant difference in the risk of cerebrovascular events with empagliflozin versus placebo. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01131676. © 2017 The Authors.

  15. Determinants of the Price of High-Tech Metals: An Event Study

    Energy Technology Data Exchange (ETDEWEB)

    Wanner, Markus, E-mail: markus.wanner@mrm.uni-augsburg.de; Gaugler, Tobias; Gleich, Benedikt; Rathgeber, Andreas [University of Augsburg, Institute for Materials Resource Management (Germany)

    2015-06-15

    The growing demand for high-tech products has resulted in strong growth in demand for certain minor metals. In combination with production concentrated in China, this caused strong and unpredicted price movements in recent years. As a result, manufacturing companies have to cope with additional risks. However, the detailed reasons for the price development are only partially understood. Therefore, we analyzed empirically which determinants can be assigned to price movements and performed an event study on the high-tech metals neodymium, indium, and gallium. Based on our dataset of news items, we were able to find coinciding events to almost 90% of all price jumps (recall). We showed that if any information about these events occurred with a probability of over 50% there would also be a price jump within 10 days (precision). However, the classical set of price determinants has to be extended for these specific markets, as we found unorthodox factors like holidays or weather that may be indicators for price movements. Therefore, we hope that our study supports industry for instance in performing more informed short-term planning of metals purchasing based on information about specific events.

  16. On the angular distribution of IceCube high-energy events

    CERN Document Server

    Marcos, R de la Fuente

    2015-01-01

    The detection of high-energy astrophysical neutrinos of extraterrestrial origin by the IceCube neutrino observatory in Antarctica has opened a unique window to the cosmos that may help to probe both the distant Universe and our cosmic backyard. The arrival directions of these high-energy events have been interpreted as uniformly distributed on the celestial sphere. Here, we revisit the topic of the putative isotropic angular distribution of these events applying Monte Carlo techniques to investigate a possible anisotropy. A modest evidence for anisotropy is found. An excess of events appears projected towards a section of the Local Void, where the density of galaxies with radial velocities below 3000 km/s is rather low, suggesting that this particular group of somewhat clustered sources are located either very close to the Milky Way or perhaps beyond 40 Mpc. The results of further analyses of the subsample of southern hemisphere events favour an origin at cosmological distances with the arrival directions of ...

  17. Existence domains of arbitrary amplitude nonlinear structures in two-electron temperature space plasmas. II. High-frequency electron-acoustic solitons

    Energy Technology Data Exchange (ETDEWEB)

    Maharaj, S. K. [South African National Space Agency (SANSA) Space Science, P.O. Box 32, Hermanus 7200 (South Africa); Bharuthram, R. [University of the Western Cape, Modderdam Road, Bellville 7530 (South Africa); Singh, S. V. [Indian Institute of Geomagnetism, New Panvel (West), Navi Mumbai 410218 (India); School of Chemistry and Physics, University of KwaZulu-Natal, Private Bag X54001, Durban 4000 (South Africa); Lakhina, G. S. [Indian Institute of Geomagnetism, New Panvel (West), Navi Mumbai 410218 (India)

    2012-12-15

    A three-component plasma model composed of ions, cool electrons, and hot electrons is adopted to investigate the existence of large amplitude electron-acoustic solitons not only for the model for which inertia and pressure are retained for all plasma species which are assumed to be adiabatic but also neglecting inertial effects of the hot electrons. Using the Sagdeev potential formalism, the Mach number ranges supporting the existence of large amplitude electron-acoustic solitons are presented. The limitations on the attainable amplitudes of electron-acoustic solitons having negative potentials are attributed to a number of different physical reasons, such as the number density of either the cool electrons or hot electrons ceases to be real valued beyond the upper Mach number limit, or, alternatively, a negative potential double layer occurs. Electron-acoustic solitons having positive potentials are found to be supported only if inertial effects of the hot electrons are retained and these are found to be limited only by positive potential double layers.

  18. ARTUS - A Framework for Event-based Data Analysis in High Energy Physics

    CERN Document Server

    Berger, Joram; Friese, Raphael; Haitz, Dominik; Hauth, Thomas; Müller, Thomas; Quast, Günter; Sieber, Georg

    2015-01-01

    ARTUS is an event-based data-processing framework for high energy physics experiments. It is designed for large-scale data analysis in a collaborative environment. The architecture design choices take into account typical challenges and are based on experiences with similar applications. The structure of the framework and its advantages are described. An example use case and performance measurements are presented. The framework is well-tested and successfully used by several analysis groups.

  19. Mobilisation or dilution? Nitrate response of karst springs to high rainfall events

    Directory of Open Access Journals (Sweden)

    M. Huebsch

    2014-04-01

    Full Text Available Nitrate (NO3- contamination of groundwater associated with agronomic activity is of major concern in many countries. Where agriculture, thin free draining soils and karst aquifers coincide, groundwater is highly vulnerable to nitrate contamination. As residence times and denitrification potential in such systems are typically low, nitrate can discharge to surface waters unabated. However, such systems also react quickest to agricultural management changes that aim to improve water quality. In response to storm events, nitrate concentrations can alter significantly, i.e., rapidly decreasing or increasing concentrations. The current study examines the response of a specific karst spring situated on a grassland farm in south Ireland to rainfall events utilising high-resolution nitrate and discharge data together with on-farm borehole groundwater fluctuation data. Specifically, the objectives of the study are to formulate a scientific hypothesis of possible scenarios relating to nitrate responses during storm events, and to verify this hypothesis using additional case studies from the literature. This elucidates the controlling key factors that lead to mobilisation and/or dilution of nitrate concentrations during storm events. These were land use, hydrological condition and karstification, which in combination can lead to differential responses of mobilised and/or diluted nitrate concentrations. Furthermore, the results indicate that nitrate response in karst is strongly dependent on nutrient source, whether mobilisation and/or dilution occur and the pathway taken. This will have consequences for the delivery of nitrate to a surface water receptor. The current study improves our understanding of nitrate responses in karst systems and therefore can guide environmental modellers, policy makers and drinking water managers with respect to the regulations of the European Union (EU Water Framework Directive (WFD. In future, more research should focus on

  20. Mobilisation or dilution? Nitrate response of karst springs to high rainfall events

    Science.gov (United States)

    Huebsch, M.; Fenton, O.; Horan, B.; Hennessy, D.; Richards, K. G.; Jordan, P.; Goldscheider, N.; Butscher, C.; Blum, P.

    2014-11-01

    Nitrate (NO3-) contamination of groundwater associated with agronomic activity is of major concern in many countries. Where agriculture, thin free draining soils and karst aquifers coincide, groundwater is highly vulnerable to nitrate contamination. As residence times and denitrification potential in such systems are typically low, nitrate can discharge to surface waters unabated. However, such systems also react quickest to agricultural management changes that aim to improve water quality. In response to storm events, nitrate concentrations can alter significantly, i.e. rapidly decreasing or increasing concentrations. The current study examines the response of a specific karst spring situated on a grassland farm in South Ireland to rainfall events utilising high-resolution nitrate and discharge data together with on-farm borehole groundwater fluctuation data. Specifically, the objectives of the study are to formulate a scientific hypothesis of possible scenarios relating to nitrate responses during storm events, and to verify this hypothesis using additional case studies from the literature. This elucidates the controlling key factors that lead to mobilisation and/or dilution of nitrate concentrations during storm events. These were land use, hydrological condition and karstification, which in combination can lead to differential responses of mobilised and/or diluted nitrate concentrations. Furthermore, the results indicate that nitrate response in karst is strongly dependent on nutrient source, whether mobilisation and/or dilution occur and on the pathway taken. This will have consequences for the delivery of nitrate to a surface water receptor. The current study improves our understanding of nitrate responses in karst systems and therefore can guide environmental modellers, policy makers and drinking water managers with respect to the regulations of the European Union (EU) Water Framework Directive (WFD). In future, more research should focus on the high

  1. A Simulation of an Event Building Network for the CMS High Energy Physics Experiment

    CERN Document Server

    Aziz, S; Brigljevic, V; Bruno, G; Cano, E; Csilling, A; Cittolin, S; Erhan, S; Gigi, D; Glege, F; Gulmini, M; Gutleber, J; Jacobs, C; Kozlovszky, M; Larsen, H; Litmaath, M; Magrans, I; Maron, G; Meijers, F; Meschi, E; Murray, S; O'Dell, V; Oh, A; Orsini, L; Pollet, L; Racz, A; Samyn, D; Scharff-Hansen, P; Sphicas, P; Schwick, C; Suzuki, I; Toniolo, N; Zangrando, L

    2003-01-01

    A simulation of the event building network of the Data Acquisition System of the CMS experiment at the Large Hadron Collider at CERN has been developed. The simulation of this highly complex system allows the validation of the system design and the optimization of its performance. The correctness of the simulation model is verified using measurements from test set-ups and a forecast for the full-scale system is made.

  2. Affective and behavioral changes following exposure to traumatic events: the moderating effect of religiosity on avoidance behavior among students studying under a high level of terror event exposure.

    Science.gov (United States)

    Korn, Liat; Zukerman, Gil

    2011-12-01

    The goals of this study were to examine the development of affective and behavioral changes following exposure to traumatic events among Israeli students studying under a high level of terror event exposure and to assess the effects of religiosity on those changes development. A questionnaire was administered to 770 students in the Ariel University Center in Judea and Samaria. Higher levels of terror exposure were associated with higher levels of avoidance behavior, subjective feelings of insecurity, and emotional distress. Higher religiosity moderated avoidance behavior, even when controlling for the level of objective exposure to terror events exposure, but had no influence on subjective sense of insecurity, or the level of emotional distress. These findings suggest that religiosity moderates behavioral changes development after traumatic event exposure mainly by reducing avoidance behavior.

  3. Relations between strong high-frequency microwave bursts and proton events

    CERN Document Server

    Grechnev, V; Chertok, I; Kiselev, V

    2013-01-01

    Proceeding from close association between solar eruptions, flares, shock waves, and CMEs, we analyze relations between bursts at 35 GHz recorded with the Nobeyama Radio Polarimeters during 1990-2012, on the one hand, and solar energetic particle (SEP) events, on the other hand. Most west to moderately east solar events with strong bursts at 35 GHz produced near-Earth proton enhancements of J(E > 100 MeV) > 1 pfu. The strongest and hardest those caused ground level enhancements. There is a general, although scattered, correspondence between proton enhancements and peak fluxes at 35 GHz, especially pronounced if the 35 GHz flux exceeds 10^4 sfu and the microwave peak frequency is high. These properties indicate emission from numerous high-energy electrons in very strong magnetic fields suggesting a high rate of energy release in the flare-CME formation process. Flaring above the sunspot umbrae appears to be typical of such events. Irrespective of the origin of SEPs, these circumstances demonstrate significant d...

  4. Actin evolution in ciliates (Protist, Alveolata) is characterized by high diversity and three duplication events.

    Science.gov (United States)

    Yi, Zhenzhen; Huang, Lijuan; Yang, Ran; Lin, Xiaofeng; Song, Weibo

    2016-03-01

    Ciliates possess two distinct nuclear genomes and unique genomic features, including highly fragmented chromosomes and extensive chromosomal rearrangements. Recent transcriptomic surveys have revealed that ciliates have several multi-copy genes providing an ideal template to study gene family evolution. Nonetheless, this process remains little studied in ciliated protozoa and consequently, the evolutionary patterns that govern it are not well understood. In this study, we focused on obtaining fine-scale information relative to ciliate species divergence for the first time. A total of 230 actin gene sequences were derived from this study, among which 217 were from four closely related Pseudokeronopsis species and 13 from other hypotrichous ciliates. Our investigation shows that: (1) At least three duplication events occurred in ciliates: diversification of three actin genes (Actin I, II, III) happened after the divergence of ciliate classes but before that of subclasses. And several recent and genus-specific duplications were followed within Actin I (Sterkiella, Oxytricha, Uroleptus, etc.), Actin II (Sterkiella), respectively. (2) Within the genus Pseudokeronopsis, Actin I gene duplication events happened after P. carnea and P. erythrina diverged. In contrast, in the morphologically similar species P. flava and P. rubra, the duplication event preceded diversification of the two species. The Actin II gene duplication events preceded divergence of the genus Pseudokeronopsis. (3) Phylogenetic analyses revealed that actin is suitable for resolving ciliate classes, but may not be used to infer lower taxon relationships.

  5. Complex Event Detection on High-Density RFID Event Streams%高密度RFID事件流上的复杂事件检测

    Institute of Scientific and Technical Information of China (English)

    徐传飞; 林树宽; 乔建忠; 于戈

    2012-01-01

    由于高密度事件流具有实时性和海量性特点,应用已有的复杂事件检测技术处理时,存在时间效率不高、占用内存空间较大等不足.针对这些问题,提出了一种基于哈希链表结构的复杂事件检测算法.该算法设计有效的哈希映射分类来保存中间结果,加快了匹配过程,同时,提出高效的更新机制及时删除内存中过期的数据.针对常见的事件流的乱序现象,对原有自动机处理机制进行了改进.实验和分析证明,复杂事件流检测方法具有理论上的可行性和操作上的高效性与正确性.%The high-density event stream contains mass events which arrive in real time.Existing complex event detection techniques are inefficient and more memory is needed when processing high-density event streams.In order to solve these problems,a new complex event detection algorithm based on Hash structure was proposed.The effective Hash mapping structure is designed in the algorithm to store intermediate data,which improves detection efficiency.Besides,updating mechanism to delete efficiently the overdue events from the memory was also proposed.Furthermore,auto deal mechanism was improved so as to detect complex events over out of order event streams.The feasibility,efficiency and correctness of our algorithms are demonstrated by the theoretical analysis and experiments.

  6. Measles outbreaks in high schools closely associated with sporting events in Niigata, Japan.

    Science.gov (United States)

    Sasaki, Asami; Suzuki, Hiroshi; Sakai, Takatugu; Sato, Maki; Shobugawa, Yugo; Saito, Reiko

    2007-08-01

    Due to high vaccine coverage in Niigata, we had no outbreaks of measles from 1997 to 2003 but an opportunity to study the role of sporting events in the propagation of an epidemic was experienced in the spring of the latter year. Mandatory measles case reports were requested from all high schools in Niigata, which covered a school year, date of onset, club activity, vaccination status, and hospitalization. With national marathon and kendo (Japanese fencing) meetings for high school students, measles outbreaks occurred at 27 high schools with 192 patients (186 students and 6 teachers) in Niigata. Of 64 unvaccinated patients, 14 (21.9%) were hospitalized and 6 (6.2%) of 97 vaccinated patients. Mostly single cases were encountered at high schools in which index cases had a vaccination history, whereas at a high school in which index cases had no vaccination history, the total number of cases per school increased, mostly within more than 3 cases (p<0.05). We conclude that sporting events, even if outdoors, might be a risk factor for measles infections. Appropriate actions to control outbreaks should be performed promptly in collaboration with related personnel and institutions.

  7. Simulation of High Impact Rainfall Events Over Southeastern Hilly Region of Bangladesh Using MM5 Model

    Directory of Open Access Journals (Sweden)

    M. N. Ahasan

    2013-01-01

    Full Text Available Simulation of high impact rainfall events over southeastern hilly region of Bangladesh has been carried out using Fifth-Generation PSU/NCAR Mesoscale Model (MM5 conducting two historical rainfall events, namely, 21 June, 2004 and 11 July, 2004. These extraordinary rainfall events were localized over the Rangamati region and recorded 304 mm and 337 mm rainfall on 21 June, 2004 and 11 July, 2004, respectively, over Rangamati within a span of 24 h. The model performance was evaluated by examining the different predicted and derived parameters. It is found that the seasonal monsoon trough has northerly position compared to normal and pass through Bangladesh extending up to northeast India for both cases. The heat low was found to be intense (996 hPa with strong north-south pressure gradient (12–15 hPa. The analysis of the geopotential height field at 200 hPa shows that the Tibetan high is shifted towards south by 7-8° latitudes with axis along 22–25°N for both cases. The analysis of the wind field shows that the areas of high impact rainfall exhibit strong convergence of low level monsoon circulation (~19–58 knots. The strong southwesterlies were found to exist up to 500 hPa level in both cases. The lower troposphere (925–500 hPa was characterized by the strong vertical wind shear (~9–18 ms−1 and high relative vorticity (~20–40 × 10−5 s−1. The analysis also shows that the areas of high impact rainfall events and neighbourhoods are characterized by strong low level convergence and upper level divergence. The strong southwesterly flow causes transportation of large amount of moisture from the Bay of Bengal towards Bangladesh, especially over the areas of Rangamati and neighbourhoods. The high percentage of relative humidity extends up to the upper troposphere along a narrow vertical column. Model produced details structure of the spatial patterns of rainfall over Bangladesh reasonably well though there are some

  8. High resolution genome wide binding event finding and motif discovery reveals transcription factor spatial binding constraints.

    Directory of Open Access Journals (Sweden)

    Yuchun Guo

    Full Text Available An essential component of genome function is the syntax of genomic regulatory elements that determine how diverse transcription factors interact to orchestrate a program of regulatory control. A precise characterization of in vivo spacing constraints between key transcription factors would reveal key aspects of this genomic regulatory language. To discover novel transcription factor spatial binding constraints in vivo, we developed a new integrative computational method, genome wide event finding and motif discovery (GEM. GEM resolves ChIP data into explanatory motifs and binding events at high spatial resolution by linking binding event discovery and motif discovery with positional priors in the context of a generative probabilistic model of ChIP data and genome sequence. GEM analysis of 63 transcription factors in 214 ENCODE human ChIP-Seq experiments recovers more known factor motifs than other contemporary methods, and discovers six new motifs for factors with unknown binding specificity. GEM's adaptive learning of binding-event read distributions allows it to further improve upon previous methods for processing ChIP-Seq and ChIP-exo data to yield unsurpassed spatial resolution and discovery of closely spaced binding events of the same factor. In a systematic analysis of in vivo sequence-specific transcription factor binding using GEM, we have found hundreds of spatial binding constraints between factors. GEM found 37 examples of factor binding constraints in mouse ES cells, including strong distance-specific constraints between Klf4 and other key regulatory factors. In human ENCODE data, GEM found 390 examples of spatially constrained pair-wise binding, including such novel pairs as c-Fos:c-Jun/USF1, CTCF/Egr1, and HNF4A/FOXA1. The discovery of new factor-factor spatial constraints in ChIP data is significant because it proposes testable models for regulatory factor interactions that will help elucidate genome function and the

  9. High resolution genome wide binding event finding and motif discovery reveals transcription factor spatial binding constraints.

    Science.gov (United States)

    Guo, Yuchun; Mahony, Shaun; Gifford, David K

    2012-01-01

    An essential component of genome function is the syntax of genomic regulatory elements that determine how diverse transcription factors interact to orchestrate a program of regulatory control. A precise characterization of in vivo spacing constraints between key transcription factors would reveal key aspects of this genomic regulatory language. To discover novel transcription factor spatial binding constraints in vivo, we developed a new integrative computational method, genome wide event finding and motif discovery (GEM). GEM resolves ChIP data into explanatory motifs and binding events at high spatial resolution by linking binding event discovery and motif discovery with positional priors in the context of a generative probabilistic model of ChIP data and genome sequence. GEM analysis of 63 transcription factors in 214 ENCODE human ChIP-Seq experiments recovers more known factor motifs than other contemporary methods, and discovers six new motifs for factors with unknown binding specificity. GEM's adaptive learning of binding-event read distributions allows it to further improve upon previous methods for processing ChIP-Seq and ChIP-exo data to yield unsurpassed spatial resolution and discovery of closely spaced binding events of the same factor. In a systematic analysis of in vivo sequence-specific transcription factor binding using GEM, we have found hundreds of spatial binding constraints between factors. GEM found 37 examples of factor binding constraints in mouse ES cells, including strong distance-specific constraints between Klf4 and other key regulatory factors. In human ENCODE data, GEM found 390 examples of spatially constrained pair-wise binding, including such novel pairs as c-Fos:c-Jun/USF1, CTCF/Egr1, and HNF4A/FOXA1. The discovery of new factor-factor spatial constraints in ChIP data is significant because it proposes testable models for regulatory factor interactions that will help elucidate genome function and the implementation of combinatorial

  10. PULSE AMPLITUDE DISTRIBUTION RECORDER

    Science.gov (United States)

    Cowper, G.

    1958-08-12

    A device is described for automatica1ly recording pulse annplitude distribution received from a counter. The novelty of the device consists of the over-all arrangement of conventional circuit elements to provide an easy to read permanent record of the pulse amplitude distribution during a certain time period. In the device a pulse analyzer separates the pulses according to annplitude into several channels. A scaler in each channel counts the pulses and operates a pen marker positioned over a drivable recorder sheet. Since the scalers in each channel have the sanne capacity, the control circuitry permits counting of the incoming pulses until one scaler reaches capacity, whereupon the input is removed and an internal oscillator supplies the necessary pulses to fill up the other scalers. Movement of the chart sheet is initiated wben the first scaler reaches capacity to thereby give a series of marks at spacings proportional to the time required to fill the remaining scalers, and accessory equipment marks calibration points on the recorder sheet to facilitate direct reading of the number of external pulses supplied to each scaler.

  11. Investigating the Impact of Off-Nominal Events on High-Density "Green" Arrivals

    Science.gov (United States)

    Callatine, Todd J.; Cabrall, Christopher; Kupfer, Michael; Martin, Lynne; Mercer, Joey; Palmer, Everett A.

    2012-01-01

    Trajectory-based controller tools developed to support a schedule-based terminal-area air traffic management (ATM) concept have been shown effective for enabling green arrivals along Area Navigation (RNAV) routes in moderately high-density traffic conditions. A recent human-in-the-loop simulation investigated the robustness of the concept and tools to off-nominal events events that lead to situations in which runway arrival schedules require adjustments and controllers can no longer use speed control alone to impose the necessary delays. Study participants included a terminal-area Traffic Management Supervisor responsible for adjusting the schedules. Sector-controller participants could issue alternate RNAV transition routes to absorb large delays. The study also included real-time winds/wind-forecast changes. The results indicate that arrival spacing accuracy, schedule conformance, and tool usage and usefulness are similar to that observed in simulations of nominal operations. However, the time and effort required to recover from an off-nominal event is highly context-sensitive, and impacted by the required schedule adjustments and control methods available for managing the evolving situation. The research suggests ways to bolster the off-nominal recovery process, and highlights challenges related to using human-in-the-loop simulation to investigate the safety and robustness of advanced ATM concepts.

  12. High precision locations of long-period events at La Fossa Crater (Vulcano Island, Italy

    Directory of Open Access Journals (Sweden)

    Salvatore Rapisarda

    2009-06-01

    Full Text Available Since the last eruption in 1888-90, the volcanic activity on Vulcano Island (Aeolian Archipelago, Italy has been limited to fumarolic degassing. Fumaroles are mainly concentred at the active cone of La Fossa in the northern sector of the island and are periodically characterized by increases in temperature as well as in the amount of both CO2 and He. Seismic background activity at Vulcano is dominated by micro-seismicity originating at shallow depth (<1-1.5 km under La Fossa cone. This seismicity is related to geothermal system processes and comprises long period (LP events. LPs are generally considered as the resonance of a fluid-filled volume in response to a trigger. We analyzed LP events recorded during an anomalous degassing period (August-October 2006 applying a high precision technique to define the shape of the trigger source. Absolute and high precision locations suggest that LP events recorded at Vulcano during 2006 were produced by a shallow focal zone ca. 200 m long, 40 m wide and N30-40E oriented. Their occurrence is linked to magmatic fluid inputs that by modifying the hydrothermal system cause excitation of a fluid-filled cavity.

  13. Inefficient highly eccentric accretion and the low luminosity of stellar tidal disruption events

    CERN Document Server

    Svirski, Gilad; Krolik, Julian

    2015-01-01

    Models for tidal disruption events (TDEs) in which a supermassive black hole disrupts a star commonly assume that the highly eccentric streams of bound stellar debris promptly form a circular accretion disk at the pericenter scale. However, the bolometric peak luminosity of most TDE candidates, $\\sim10^{44}\\,\\rm{erg\\,s^{-1}}$, implies that we observe only $\\sim1\\%$ of the energy expected from accretion. Moreover, recent numerical simulations (Shiokawa et al. 2015) have shown that dissipation via hydrodynamical shocks is insufficient to circularize debris orbits on the pericenter scale, and the debris flow retains its initial semi-major axis scale throughout the first $\\sim10$ orbits of the event. Motivated by these numerical results, Piran et al. (2015) suggested that the observed optical TDE emission is powered by shocks at the apocenter between freshly infalling material and earlier-arriving matter. This model explains the small radiated energy, the low temperature, and the large radius implied by the obser...

  14. High-Energy-Physics Event Generation with PYTHIA 6.1

    CERN Document Server

    Sjöstrand, Torbjörn; Friberg, C; Lönnblad, L; Miu, G; Mrenna, S; Norrbin, E

    2001-01-01

    PYTHIA version 6 represents a merger of the PYTHIA 5, JETSET 7 and SPYTHIA programs, with many improvements. It can be used to generate high-energy-physics `events', i.e. sets of outgoing particles produced in the interactions between two incoming particles. The objective is to provide as accurate as possible a representation of event properties in a wide range of reactions. The underlying physics is not understood well enough to give an exact description; the programs therefore contain a combination of analytical results and various models. The emphasis in this article is on new aspects, but a few words of general introduction are included. Further documentation is available on the web.

  15. High-molecular-weight adiponectin does not predict cardiovascular events in patients with type 2 diabetes.

    Science.gov (United States)

    Krzyzanowska, Katarzyna; Aso, Yoshimasa; Mittermayer, Friedrich; Inukai, Toshihiko; Brix, Johanna; Schernthaner, Guntram

    2009-04-01

    Low circulating high-molecular-weight (HMW) adiponectin might be associated with increased cardiovascular risk. This study aimed to investigate the relationship between HMW adiponectin and cardiovascular events in patients with type 2 diabetes mellitus (T2DM) with an adverse cardiovascular risk profile. The investigation took place in a specialized outpatient clinic for metabolic diseases and included 147 patients with T2DM following a cross-sectional and a prospective study protocol. Ninety patients had macrovascular disease at baseline defined as preexisting coronary artery disease, previous stroke, or peripheral artery disease. HMW adiponectin measured by enzyme-linked immunosorbent assay (Fujirebio, Tokyo, Japan) and routine clinical parameters were determined in all patients at baseline. The occurrence of new cardiovascular events (myocardial infarction, stroke, and all-cause mortality) during the follow-up period was evaluated. No significant correlations between traditional cardiovascular risk markers and HMW adiponectin could be detected. HMW adiponectin did not differ between subjects with and without macrovascular disease at baseline (3.5 [interquartile range [IQR]: 2.2-5.7] mg/L vs 4.0 [IQR: 2.5-7.1] mg/L). During a follow-up of 19.3 (IQR: 16-25) months, 61 endpoints (41 myocardial infarctions, 10 strokes, and 10 deaths) were observed. A 1-standard-deviation increment of log-transformed HMW adiponectin was not significantly associated with the occurrence of cardiovascular events (Adjusted hazard ratio [HR]: 0.95; 95% confidence interval [CI]: 0.58-1.54; P = 0.835). In conclusion, HMW adiponectin was not related to present macrovascular disease and is not associated with future cardiovascular events in high-risk patients with T2DM. It is unlikely that HMW adiponectin has significant vasoprotective effects in these patients.

  16. Chemical regulation of alpine headwater streams during a storm event (Bogong High Plains, Victoria, Australia)

    Science.gov (United States)

    Karis, Terry; Silvester, Ewen; Rees, Gavin

    2016-11-01

    The headwater streams originating in the Australian Alps are the highest water yielding landscape in South-Eastern Australia and are projected to be impacted by climate change through longer dry periods and more episodic rainfall. In this work we studied the major ion and DOC responses of three alpine peatlands (and the broader catchment containing these systems) to a high intensity (summer) storm event. Despite the high volume of rainfall, major ions in stream waters remained strongly chemostatic throughout the event. This was particularly the case for Ca2+ and Mg2+, as well as the alkalinity by association, and suggests that chemical regulation of these particular cations occurs through rapid equilibration processes. DOC concentrations increased during the storm pulse, leading to a shift in alkalinity partitioning from bicarbonate to organic anions and a decrease in pH, mediated by the CO2 saturation levels in the stream water. Our results suggest that alkalinity generation (Ca2+ and Mg2+ acquisition) and partitioning (DOC export) are decoupled processes that may respond differently to repeat storm events depending on the capacity of these systems to provide these constituents. Under extreme case scenarios depletion of DOC (at constant alkalinity) would lead to a smaller pH dip during a storm pulse, while depletion of alkalinity would lead to a larger pH dip, with buffering controlled by free acid. We have not identified the mechanism for the chemostasis of Ca2+ and Mg2+ (and therefore alkalinity) in this work, but this will be critical to understanding the capacity of these peatlands to respond to repeat and more intense storm events.

  17. Dissemination of a highly virulent pathogen: tracking the early events that define infection.

    Directory of Open Access Journals (Sweden)

    Rodrigo J Gonzalez

    2015-01-01

    Full Text Available The series of events that occurs immediately after pathogen entrance into the body is largely speculative. Key aspects of these events are pathogen dissemination and pathogen interactions with the immune response as the invader moves into deeper tissues. We sought to define major events that occur early during infection of a highly virulent pathogen. To this end, we tracked early dissemination of Yersinia pestis, a highly pathogenic bacterium that causes bubonic plague in mammals. Specifically, we addressed two fundamental questions: (1 do the bacteria encounter barriers in disseminating to draining lymph nodes (LN, and (2 what mechanism does this nonmotile bacterium use to reach the LN compartment, as the prevailing model predicts trafficking in association with host cells. Infection was followed through microscopy imaging in addition to assessing bacterial population dynamics during dissemination from the skin. We found and characterized an unexpected bottleneck that severely restricts bacterial dissemination to LNs. The bacteria that do not pass through this bottleneck are confined to the skin, where large numbers of neutrophils arrive and efficiently control bacterial proliferation. Notably, bottleneck formation is route dependent, as it is abrogated after subcutaneous inoculation. Using a combination of approaches, including microscopy imaging, we tested the prevailing model of bacterial dissemination from the skin into LNs and found no evidence of involvement of migrating phagocytes in dissemination. Thus, early stages of infection are defined by a bottleneck that restricts bacterial dissemination and by neutrophil-dependent control of bacterial proliferation in the skin. Furthermore, and as opposed to current models, our data indicate an intracellular stage is not required by Y. pestis to disseminate from the skin to draining LNs. Because our findings address events that occur during early encounters of pathogen with the immune response

  18. Dominance of statistical fluctuation in the factorial-moment study of chaos in low multiplicity events of high energy collisions

    Institute of Scientific and Technical Information of China (English)

    刘连寿; 傅菁华; 吴元芳

    2000-01-01

    Using Monte Carlo simulation it is shown that in low multiplicity events the single-event factorial moments are saturated by the statistical fluctuations. The diversification of the event-space moments Cp, q of single-event moments with the diminishing of phase space scale, called "erraticity", observed in experiment can readily be reproduced by a flat probability distribution with only statistical fluctuations and therefore it has nothing to do with chaos as suggested. The possibility of studying chaos in high multiplicity events using erraticity analysis is discussed.

  19. EEE - Extreme Energy Events: an astroparticle physics experiment in Italian High Schools

    Science.gov (United States)

    Abbrescia, M.; Avanzini, C.; Baldini, L.; Baldini Ferroli, R.; Batignani, G.; Bencivenni, G.; Bossini, E.; Bressan, E.; Chiavassa, A.; Cicalò, C.; Cifarelli, L.; Coccia, E.; Corvaglia, A.; De Gruttola, D.; De Pasquale, S.; Di Giovanni, A.; D'Incecco, M.; Dreucci, M.; Fabbri, F. L.; Fattibene, E.; Ferrarov, A.; Forster, R.; Frolov, V.; Galeotti, P.; Garbini, M.; Gemme, G.; Gnesi, I.; Grazzi, S.; Gustavino, C.; Hatzifotiadou, D.; La Rocca, P.; Maggiora, A.; Maron, G.; Mazziotta, M. N.; Miozzi, S.; Noferini, F.; Nozzoli, F.; Panareo, M.; Panetta, M. P.; Paoletti, R.; Perasso, L.; Pilo, F.; Piragino, G.; Riggi, F.; Righini, G. C.; Rodriguez Rodriguez, A.; Sartorelli, G.; Scapparone, E.; Schioppa, M.; Scribano, A.; Selvi, M.; Serci, S.; Siddi, E.; Squarcia, S.; Taiuti, M.; Terreni, G.; Vistoli, M. C.; Votano, L.; Williams, M. C. S.; Zani, S.; Zichichi, A.; Zuyeuski, R.

    2016-05-01

    The Extreme Energy Events project (EEE) is aimed to study Extensive Air Showers (EAS) from primary cosmic rays of more than 1018 eV energy detecting the ground secondary muon component using an array of telescopes with high spatial and time resolution. The second goal of the EEE project is to involve High School teachers and students in this advanced research work and to initiate them in scientific culture: to reach both purposes the telescopes are located inside High School buildings and the detector construction, assembling and monitoring - together with data taking and analysis - are done by researchers from scientific institutions in close collaboration with them. At present there are 42 telescopes in just as many High Schools scattered all over Italy, islands included, plus two at CERN and three in INFN units. We report here some preliminary physics results from the first two common data taking periods together with the outreach impact of the project.

  20. Thiazolidinediones and Cardiovascular Events In High-Risk Patients with Type-2 Diabetes Mellitus

    Science.gov (United States)

    Shaya, Fadia T.; Lu, Zhiqiang; Sohn, Kyongsei; Weir, Matthew R.

    2009-01-01

    Context. The use of thiazolidinediones (TZDs) in patients with type-2 diabetes mellitus appears to be associated with an increased risk of myocardial infarction (MI) compared with placebo or other oral antidiabetic drug regimens. Objective. We conducted a study to investigate whether there was a difference in the risk of acute MI and hemorrhagic and non-hemorrhagic stroke between specific TZDs, namely rosiglitazone maleate (Avandia) and pioglitazone (Actos), and other oral antidiabetic agents in a high-risk, largely underrepresented and largely minority Medicaid population. Study Design, Setting, and Patients. We analyzed patient encounter data using propensity-scoring methods and logistic regression to compare the risk of cardiovascular (CV) events in patients with type-2 diabetes in a high-risk population. Main Outcome Measures. Outcomes were identified through International Classification of Disease (ICD-9) codes 410–411 for acute MI; 430–438 for stroke; and revenue (emergency department) codes 450–459 in the case of MI. Results. Using retrospective medical encounter and prescription data analyses, we found that rosiglitazone, compared with other oral antidiabetic agents, was associated with an increased rate of CV events by 20% in a high-risk cohort of diabetic patients. Neither pioglitazone nor the TZD drug class as a whole was associated with an increased CV risk. Conclusion. Rosiglitazone was associated with a significant increase in CV events (MI and stroke) among high-risk patients with type-2 diabetes, whereas pioglitazone was not. We recommend further research to capture risk factors that were not observed in our encounter data. PMID:20140111

  1. Observation of Single Isolated Electrons of High Transverse Momentum in Events with Missing Transverse Energy at the CERN pp Collider

    DEFF Research Database (Denmark)

    Banner, M.; Kofoed-Hansen, O.

    1983-01-01

    We report the results of a search for single isolated electrons of high transverse momentum at the CERN collider. Above 15 GeV/c, four events are found having large missing transverse energy along a direction opposite in azimuth to that of the high-pT electron. Both the configuration of the events...

  2. Initiation of a major calving event captured by high-resolution UAV photogrammetry

    Science.gov (United States)

    Jouvet, Guillaume; Abe, Takahiro; Funk, Martin; Seguinot, Julien; Sugiyama, Shin; Weidmann, Yvo

    2016-04-01

    During the summer 2015 field campaign on Bowdoin glacier (Northwest Greenland), the camera inboard a UAV captured the initiation of a major calving event with 7 centimetre accuracy. Two UAV flights were operated prior to and during the opening of a large crack that formed about 100 metre upstream from the calving front, propagated laterally over more than a kilometre and eventually lead to calving. The post-processing of the resulting aerial images by structure-from-motion and feature-tracking techniques allowed us to infer surface velocity fields before and during crack opening. Detailed analysis of maximum principal stresses computed from both velocity fields indicate that the event was triggered by high vertical shear stresses between a lateral band of slow flow where the glacier is solidly anchored to shallow bedrock, and a central band of fast flow where the glacier is nearly floating due to deeper bedrock. We estimate that the observed event contributed by 5 to 10% to the annual mass loss by calving.

  3. Quantifying braided river morphodynamics through a sequence of high-flow events

    Science.gov (United States)

    Williams, R. D.; Brasington, J.; Vericat, D.; Hicks, D. M.

    2012-04-01

    Quantifying braided river morphology and morphological change is a key task for understanding braided river behaviour. In the last decade, developments in geomatics technologies and associated data processing toolboxes have transformed the potential for producing precise, reach-scale topographic datasets. Moreover, since fast data acquisition rates enable surveys to be undertaken at frequencies that are commensurate with individual flood events, it is now possible to map morphological change for sequences of high-flow events over considerable spatial extents. The application of high-resolution remote sensing technologies to monitor braided river dynamics thus has the potential to provide considerable insight into the relationships between forcing discharges, sediment transport and morphological evolution. In this paper we present a set of Digital Elevation Models (DEMs) that have been produced by monitoring the evolution of a 2.5 x 0.7 km braided study area of the Rees River, New Zealand, through a sequence of ten high-flow events over an eight-month period. We then use the morphological approach to produce a sediment budget for the study area. The morphological evolution of the Rees River braided study area was monitored after each storm event using a combination of two remote sensing methodologies. First, dry areas of the braidplain were surveyed using a Terrestrial Laser Scanner (TLS) mounted on an Argo Amphibious All Terrain Vehicle. Second, since the TLS was not water penetrating, bathymetry was mapped using an empirically calibrated optical method, based on non-metric vertical aerial photos acquired from a helicopter and an acoustic depth survey along primary anabranches. The resulting data were fused together to produce high quality DEMs, with sub-cm and sub-decimetre vertical standard deviations of error for the TLS and optical-empirical bathymetric components respectively. The resulting set of DEMs enabled the quantification of morphological change through

  4. Nitrogen accumulation and partitioning in a High Arctic tundra ecosystem from extreme atmospheric N deposition events.

    Science.gov (United States)

    Choudhary, Sonal; Blaud, Aimeric; Osborn, A Mark; Press, Malcolm C; Phoenix, Gareth K

    2016-06-01

    Arctic ecosystems are threatened by pollution from recently detected extreme atmospheric nitrogen (N) deposition events in which up to 90% of the annual N deposition can occur in just a few days. We undertook the first assessment of the fate of N from extreme deposition in High Arctic tundra and are presenting the results from the whole ecosystem (15)N labelling experiment. In 2010, we simulated N depositions at rates of 0, 0.04, 0.4 and 1.2 g Nm(-2)yr(-1), applied as (15)NH4(15)NO3 in Svalbard (79(°)N), during the summer. Separate applications of (15)NO3(-) and (15)NH4(+) were also made to determine the importance of N form in their retention. More than 95% of the total (15)N applied was recovered after one growing season (~90% after two), demonstrating a considerable capacity of Arctic tundra to retain N from these deposition events. Important sinks for the deposited N, regardless of its application rate or form, were non-vascular plants>vascular plants>organic soil>litter>mineral soil, suggesting that non-vascular plants could be the primary component of this ecosystem to undergo measurable changes due to N enrichment from extreme deposition events. Substantial retention of N by soil microbial biomass (70% and 39% of (15)N in organic and mineral horizon, respectively) during the initial partitioning demonstrated their capacity to act as effective buffers for N leaching. Between the two N forms, vascular plants (Salix polaris) in particular showed difference in their N recovery, incorporating four times greater (15)NO3(-) than (15)NH4(+), suggesting deposition rich in nitrate will impact them more. Overall, these findings show that despite the deposition rates being extreme in statistical terms, biologically they do not exceed the capacity of tundra to sequester pollutant N during the growing season. Therefore, current and future extreme events may represent a major source of eutrophication.

  5. High dose rates obtained outside ISS in June 2015 during SEP event.

    Science.gov (United States)

    Dachev, T P; Tomov, B T; Matviichuk, Yu N; Dimitrov, Pl G; Bankov, N G

    2016-06-01

    The R3DR2 instrument performed measurements in the European Space Agency (ESA) EXPOSE-R2 platform outside the Russian "Zvezda" module of the International Space Station (ISS) in the period 24 October 2014-11 January 2016. It is the Liulin-type deposited energy spectrometer (DES) (Dachev et al., 2015a). Took place in November 2014, this was the first attempt to monitor a small solar energetic particle (SEP) event outside ISS using the Liulin-type DES (Dachev et al., 2015d). In this study, we describe the dosimetric characteristics of the largest SEP event, observed on 22 June 2015 with the R3DR2 instrument outside ISS. The main finding of this study is that SEP protons with a minimum energy of approximately 7MeV at the surface of the R3DR2 detector produced high dose rates, reaching >5000µGyh(-1), while the inner radiation belt maximum dose was at the level of 2200µGyh(-1). If a virtual external vehicle activity (EVA) was performed in the same period of the SEP maximum on 22 June 2015, the doses obtained in the skin of cosmonauts/astronauts can reach 2.84mGy after 6.5h, which is similar to the average absorbed dose inside ISS for 15days (Reitz et al., 2005). A comparison with other extreme events measured with Liulin-type instruments shows that SEPs similar to that observed on 22 June 2015 could be one of the most dangerous events for the cosmonauts/astronauts involved in EVA. Copyright © 2016 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.

  6. CHY formula and MHV amplitudes

    CERN Document Server

    Du, Yi-jian; Wu, Yong-shi

    2016-01-01

    In this paper, we study the relation between the Cachazo-He-Yuan (CHY) formula and the maximal-helicity-violating (MHV) amplitudes of Yang-Mills and gravity in four dimensions. We prove that only one special rational solution of the scattering equations found by Weinzierl support the MHV amplitudes. Namely, localized at this solution, the integrated CHY formula reproduces the Parke-Taylor formula for Yang-Mills amplitudes as well as the Hodges formula for gravitational amplitudes. This is achieved by developing techniques, in a manifestly M\\"obius covariant formalism, to explicitly compute relevant reduced Pfaffians/determinants. We observe and prove two interesting properties (or identities), which facilitate the computations. We also check that all the other $(n-3)!-1$ solutions to the scattering equations do not support the MHV amplitudes, and prove analytically that this is indeed true for the other special rational solution proposed by Weinzierl, that actually supports the anti-MHV amplitudes.

  7. Grassmannian geometry of scattering amplitudes

    CERN Document Server

    Arkani-Hamed, Nima; Cachazo, Freddy; Goncharov, Alexander; Postnikov, Alexander; Trnka, Jaroslav

    2016-01-01

    Outlining a revolutionary reformulation of the foundations of perturbative quantum field theory, this book is a self-contained and authoritative analysis of the application of this new formulation to the case of planar, maximally supersymmetric Yang–Mills theory. The book begins by deriving connections between scattering amplitudes and Grassmannian geometry from first principles before introducing novel physical and mathematical ideas in a systematic manner accessible to both physicists and mathematicians. The principle players in this process are on-shell functions which are closely related to certain sub-strata of Grassmannian manifolds called positroids - in terms of which the classification of on-shell functions and their relations becomes combinatorially manifest. This is an essential introduction to the geometry and combinatorics of the positroid stratification of the Grassmannian and an ideal text for advanced students and researchers working in the areas of field theory, high energy physics, and the...

  8. Propensity and Risk Assessment for Solar Particle Events: Consideration of Integral Fluence at High Proton Energies

    Science.gov (United States)

    Kim, Myung-Hee; Hayat, Matthew J.; Feiveson, alan H.; Cucinotta, Francis A.

    2008-01-01

    For future space missions with longer duration, exposure to large solar particle events (SPEs) with high energy levels is the major concern during extra-vehicular activities (EVAs) on the lunar and Mars surface. The expected SPE propensity for large proton fluence was estimated from a non-homogeneous Poisson model using the historical database for measurements of protons with energy > 30 MeV, Phi(sub 30). The database includes a continuous data set for the past 5 solar cycles. The resultant SPE risk analysis for a specific mission period was made including the 95% confidence level. In addition to total particle intensity of SPE, the detailed energy spectra of protons especially at high energy levels were recognized as extremely important parameter for the risk assessment, since there remains a significant cancer risks from those energetic particles for large events. Using all the recorded proton fluence of SPEs for energies >60 and >100 MeV, Phi(sub 60) and Phi(sub 100), respectively, the expected propensities of SPEs abundant with high energy protons were estimated from the same non-homogeneous Poisson model and the representative cancer risk was analyzed. The dependencies of risk with different energy spectra, for e.g. between soft and hard SPEs, were evaluated. Finally, we describe approaches to improve radiation protection of astronauts and optimize mission planning for future space missions.

  9. Radiation Fields in High Energy Accelerators and their impact on Single Event Effects

    CERN Document Server

    García Alía, Rubén; Wrobel, Frédéric; Brugger, Markus

    Including calculation models and measurements for a variety of electronic components and their concerned radiation environments, this thesis describes the complex radiation field present in the surrounding of a high-energy hadron accelerator and assesses the risks related to it in terms of Single Event Effects (SEE). It is shown that this poses not only a serious threat to the respective operation of modern accelerators but also highlights the impact on other high-energy radiation environments such as those for ground and avionics applications. Different LHC-like radiation environments are described in terms of their hadron composition and energy spectra. They are compared with other environments relevant for electronic component operation such as the ground-level, avionics or proton belt. The main characteristic of the high-energy accelerator radiation field is its mixed nature, both in terms of hadron types and energy interval. The threat to electronics ranges from neutrons of thermal energies to GeV hadron...

  10. Graviton amplitudes from collinear limits of gauge amplitudes

    Energy Technology Data Exchange (ETDEWEB)

    Stieberger, Stephan, E-mail: stephan.stieberger@mpp.mpg.de [Max-Planck-Institut für Physik, Werner-Heisenberg-Institut, 80805 München (Germany); Taylor, Tomasz R. [Department of Physics, Northeastern University, Boston, MA 02115 (United States)

    2015-05-11

    We express all tree-level graviton amplitudes in Einstein's gravity as the collinear limits of a linear combination of pure Yang–Mills amplitudes in which each graviton is represented by two gauge bosons, each of them carrying exactly one half of graviton's momentum and helicity.

  11. On the Period-Amplitude and Amplitude-Period Relationships

    Science.gov (United States)

    Wilson, Robert M.; Hathaway, David H.

    2008-01-01

    Examined are Period-Amplitude and Amplitude-Period relationships based on the cyclic behavior of the 12-month moving averages of monthly mean sunspot numbers for cycles 0.23, both in terms of Fisher's exact tests for 2x2 contingency tables and linear regression analyses. Concerning the Period-Amplitude relationship (same cycle), because cycle 23's maximum amplitude is known to be 120.8, the inferred regressions (90-percent prediction intervals) suggest that its period will be 131 +/- 24 months (using all cycles) or 131 +/- 18 months (ignoring cycles 2 and 4, which have the extremes of period, 108 and 164 months, respectively). Because cycle 23 has already persisted for 142 months (May 1996 through February 2008), based on the latter prediction, it should end before September 2008. Concerning the Amplitude-Period relationship (following cycle maximum amplitude versus preceding cycle period), because cycle 23's period is known to be at least 142 months, the inferred regressions (90-percent prediction intervals) suggest that cycle 24's maximum amplitude will be about less than or equal to 96.1 +/- 55.0 (using all cycle pairs) or less than or equal to 91.0 +/- 36.7 (ignoring statistical outlier cycle pairs). Hence, cycle 24's maximum amplitude is expected to be less than 151, perhaps even less than 128, unless cycle pair 23/24 proves to be a statistical outlier.

  12. Nitrogen accumulation and partitioning in a High Arctic tundra ecosystem from extreme atmospheric N deposition events

    Energy Technology Data Exchange (ETDEWEB)

    Choudhary, Sonal, E-mail: S.Choudhary@sheffield.ac.uk [Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN (United Kingdom); Management School, University of Sheffield, Conduit Road, Sheffield S10 1FL (United Kingdom); Blaud, Aimeric [Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN (United Kingdom); Osborn, A. Mark [Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN (United Kingdom); School of Applied Sciences, RMIT University, PO Box 71, Bundoora, VIC 3083 (Australia); Press, Malcolm C. [School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Manchester Metropolitan University, Manchester, M15 6BH (United Kingdom); Phoenix, Gareth K. [Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN (United Kingdom)

    2016-06-01

    Arctic ecosystems are threatened by pollution from recently detected extreme atmospheric nitrogen (N) deposition events in which up to 90% of the annual N deposition can occur in just a few days. We undertook the first assessment of the fate of N from extreme deposition in High Arctic tundra and are presenting the results from the whole ecosystem {sup 15}N labelling experiment. In 2010, we simulated N depositions at rates of 0, 0.04, 0.4 and 1.2 g N m{sup −2} yr{sup −1}, applied as {sup 15}NH{sub 4}{sup 15}NO{sub 3} in Svalbard (79{sup °}N), during the summer. Separate applications of {sup 15}NO{sub 3}{sup −} and {sup 15}NH{sub 4}{sup +} were also made to determine the importance of N form in their retention. More than 95% of the total {sup 15}N applied was recovered after one growing season (~ 90% after two), demonstrating a considerable capacity of Arctic tundra to retain N from these deposition events. Important sinks for the deposited N, regardless of its application rate or form, were non-vascular plants > vascular plants > organic soil > litter > mineral soil, suggesting that non-vascular plants could be the primary component of this ecosystem to undergo measurable changes due to N enrichment from extreme deposition events. Substantial retention of N by soil microbial biomass (70% and 39% of {sup 15}N in organic and mineral horizon, respectively) during the initial partitioning demonstrated their capacity to act as effective buffers for N leaching. Between the two N forms, vascular plants (Salix polaris) in particular showed difference in their N recovery, incorporating four times greater {sup 15}NO{sub 3}{sup −} than {sup 15}NH{sub 4}{sup +}, suggesting deposition rich in nitrate will impact them more. Overall, these findings show that despite the deposition rates being extreme in statistical terms, biologically they do not exceed the capacity of tundra to sequester pollutant N during the growing season. Therefore, current and future extreme events

  13. Retrospective Analysis of Recent Flood Events With Persistent High Surface Runoff From Hydrological Modelling

    Science.gov (United States)

    Joshi, S.; Hakeem, K. Abdul; Raju, P. V.; Rao, V. V.; Yadav, A.; Diwakar, P. G.; Dadhwal, V. K.

    2014-11-01

    Floods are one of the most common and widespread disasters in India, with an estimated 40Mha of land prone to this natural disaster (National Flood Commission, India). Significant loss of property, infrastructure, livestock, public utilities resulting in large economic losses due to floods are recurrent every year in many parts of India. Flood forecasting and early warning is widely recognized and adopted as non-structural measure to lower the damages caused by the flood events. Estimating the rainfall excess that results into excessive river flow is preliminary effort in riverine flood estimation. Flood forecasting models are in general, are event based and do not fully account for successive and persistent excessive surface runoff conditions. Successive high rainfall events result in saturated soil moisture conditions, favourable for high surface runoff conditions. The present study is to explore the usefulness of hydrological model derived surface runoff, running on continuous times-step, to relate to the occurrence of flood inundation due to persistent and successive high surface runoff conditions. Variable Infiltration Capacity (VIC), a macro-scale hydrological model, was used to simulate daily runoff at systematic grid level incorporating daily meteorological data and land cover data. VIC is a physically based, semi-distributed macroscale hydrological model that represents surface and subsurface hydrologic process on spatially distributed grid cell. It explicitly represents sub-grid heterogeneity in land cover classes, taking their phenological changes into account. In this study, the model was setup for entire India using geo-spatial data available from multiple sources (NRSC, NBSS&LUP, NOAA, and IMD) and was calibrated with river discharge data from CWC at selected river basins. Using the grid-wise surface runoff estimates from the model, an algorithm was developed through a set of thresholds of successive high runoff values in order to identify grids

  14. Adverse respiratory events after general anesthesia in patients at high risk of obstructive sleep apnea syndrome.

    Science.gov (United States)

    Xará, Daniela; Mendonça, Júlia; Pereira, Helder; Santos, Alice; Abelha, Fernando José

    2015-01-01

    Patients with STOP-BANG score >3 have a high risk of Obstructive sleep apnea. The aim of this study was to evaluate early postoperative respiratory complications in adults with STOP-BANG score >3 after general anesthesia. This is a prospective double cohort study matching 59 pairs of adult patients with STOP-BANG score >3 (high risk of obstructive sleep apnea) and patients with STOP-BANG score <3 (low risk of obstructive sleep apnea), similar with respect to gender, age and type of surgery, admitted after elective surgery in the Post-Anaesthesia Care Unit in May 2011. Primary outcome was the development of adverse respiratory events. Demographics data, perioperative variables, and postoperative length of stay in the Post-Anesthesia Care Unit and in hospital were recorded. The Mann-Whitney test, the chi-square test and the Fisher exact test were used for comparisons. Subjects in both pairs of study subjects had a median age of 56 years, including 25% males, and 59% were submitted to intra-abdominal surgery. High risk of obstructive sleep apnea patients had a higher median body mass index (31 versus 24kg/m(2), p<0.001) and had more frequently co-morbidities, including hypertension (58% versus 24%, p<0.001), dyslipidemia (46% versus 17%, p<0.001) and insulin-treated diabetes mellitus (17% versus 2%, p=0.004). These patients were submitted more frequently to bariatric surgery (20% versus 2%, p=0.002). Patients with high risk of obstructive sleep apnea had more frequently adverse respiratory events (39% versus 10%, p<0.001), mild to moderate desaturation (15% versus 0%, p=0.001) and inability to breathe deeply (34% versus 9%, p=0.001). After general anesthesia high risk of obstructive sleep apnea patients had an increased incidence of postoperative respiratory complications. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

  15. [Adverse respiratory events after general anesthesia in patients at high risk of obstructive sleep apnea syndrome].

    Science.gov (United States)

    Xará, Daniela; Mendonça, Júlia; Pereira, Helder; Santos, Alice; Abelha, Fernando José

    2015-01-01

    Patients with STOP-BANG score >3 have a high risk of Obstructive sleep apnea. The aim of this study was to evaluate early postoperative respiratory complications in adults with STOP-BANG score >3 after general anesthesia. This is a prospective double cohort study matching 59 pairs of adult patients with STOP-BANG score >3 (high risk of obstructive sleep apnea) and patients with STOP-BANG score <3 (low risk of obstructive sleep apnea), similar with respect to gender, age and type of surgery, admitted after elective surgery in the Post-Anaesthesia Care Unit in May 2011. Primary outcome was the development of adverse respiratory events. Demographics data, perioperative variables, and postoperative length of stay in the Post-Anesthesia Care Unit and in hospital were recorded. The Mann-Whitney test, the chi-square test and the Fisher exact test were used for comparisons. Subjects in both pairs of study subjects had a median age of 56 years, including 25% males, and 59% were submitted to intra-abdominal surgery. High risk of obstructive sleep apnea patients had a higher median body mass index (31 versus 24kg/m(2), p<0.001) and had more frequently co-morbidities, including hypertension (58% versus 24%, p<0.001), dyslipidemia (46% versus 17%, p<0.001) and insulin-treated diabetes mellitus (17% versus 2%, p=0.004). These patients were submitted more frequently to bariatric surgery (20% versus 2%, p=0.002). Patients with high risk of obstructive sleep apnea had more frequently adverse respiratory events (39% versus 10%, p<0.001), mild to moderate desaturation (15% versus 0%, p=0.001) and inability to breathe deeply (34% versus 9%, p=0.001). After general anesthesia high risk of obstructive sleep apnea patients had an increased incidence of postoperative respiratory complications. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

  16. 'HESPERIA' HORIZON 2020 project: High Energy Solar Particle Events foRecastIng and Analysis

    Science.gov (United States)

    Malandraki, Olga; Klein, Karl-Ludwig; Vainio, Rami; Agueda, Neus; Nunez, Marlon; Heber, Bernd; Buetikofer, Rolf; Sarlanis, Christos; Crosby, Norma; Bindi, Veronica; Murphy, Ronald; Tyka, Allan J.; Rodriguez, Juan

    2016-04-01

    Solar energetic particles (SEPs) are of prime interest for fundamental astrophysics. However, due to their high energies they are a space weather concern for technology in space as well as human space exploration calling for reliable tools with predictive capabilities. The two-year EU HORIZON 2020 project HESPERIA (High Energy Solar Particle Events foRecastIng and Analysis, http://www.hesperia-space.eu/) will produce two novel operational SEP forecasting tools based upon proven concepts (UMASEP, REleASE). At the same time the project will advance our understanding of the physical mechanisms that result into high-energy SEP events through the systematic exploitation of the high-energy gamma-ray observations of the FERMI mission and other novel published datasets (PAMELA, AMS), together with in situ SEP measurements near 1 AU. By using multi-frequency observations and performing simulations, the project will address the chain of processes from particle acceleration in the corona, particle transport in the magnetically complex corona and interplanetary space to their detection near 1 AU. Furthermore, HESPERIA will explore the possibility of incorporating the derived results into future innovative space weather services. Publicly available software to invert neutron monitor observations of relativistic SEPs to physical parameters, giving information on the high-energy processes occurring at or near the Sun during solar eruptions, will be provided for the first time. The results of this inversion software will complement the space-borne measurements at adjacent higher energies. In order to achieve these goals HESPERIA will exploit already existing large datasets that are stored into databases built under EU FP7 projects NMDB and SEPServer. The structure of the HESPERIA project, its main objectives and forecasting operational tools, as well as the added value to SEP research will be presented and discussed. Acknowledgement: This project has received funding from the

  17. Multifactorial determinants of target and novelty-evoked P300 amplitudes in children of addicted parents.

    Directory of Open Access Journals (Sweden)

    Anja S Euser

    Full Text Available BACKGROUND: Although P300 amplitude reductions constitute a persistent finding in children of addicted parents, relatively little is known about the specificity of this finding. The major aim of this study was to investigate the association between parental rearing, adverse life events, stress-reactivity, substance use and psychopathology on the one hand, and P300 amplitude in response to both target and novel distracter stimuli on the other hand. Moreover, we assessed whether risk group status (i.e., having a parental history of Substance Use Disorders [SUD] uniquely contributed to P300 amplitude variation above and beyond these other variables. METHODS: Event-related potentials were recorded in high-risk adolescents with a parental history of SUD (HR;n=80 and normal-risk controls (NR;n=100 while performing a visual Novelty Oddball paradigm. Stress-evoked cortisol levels were assessed and parenting, life adversities, substance use and psychopathology were examined by using self-reports. RESULTS: HR adolescents displayed smaller P300 amplitudes in response to novel- and to target stimuli than NR controls, while the latter only approached significance. Interestingly, the effect of having a parental history of SUD on target-P300 disappeared when all other variables were taken into account. Externalizing problem behavior was a powerful predictor of target-P300. In contrast, risk group status uniquely predicted novelty-P300 amplitude reductions above and beyond all other factors. CONCLUSION: Overall, the present findings suggest that the P300 amplitude reduction to novel stimuli might be a more specific endophenotype for SUD than the target-P300 amplitude. This pattern of results underscores the importance of conducting multifactorial assessments when examining important cognitive processes in at-risk adolescents.

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

    Science.gov (United States)

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

    2016-07-01

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

  19. Coincidence of a high-fluence blazar outburst with a PeV-energy neutrino event

    CERN Document Server

    Kadler, M; Mannheim, K; Ojha, R; Müller, C; Schulz, R; Anton, G; Baumgartner, W; Beuchert, T; Buson, S; Carpenter, B; Eberl, T; Edwards, P G; Glawion, D Eisenacher; Elsässer, D; Gehrels, N; Gräfe, C; Hase, H; Horiuchi, S; James, C W; Kappes, A; Katz, U; Kreikenbohm, A; Kreter, M; Kreykenbohm, I; Langejahn, M; Leiter, K; Litzinger, E; Longo, F; Lovell, J E J; McEnery, J; Phillips, C; Plötz, C; Quick, J; Ros, E; Stecker, F W; Steinbring, T; Stevens, J; Thompson, D J; Trüstedt, J; Tzioumis, A K; Wilms, J; Zensus, J A

    2016-01-01

    The discovery of extraterrestrial very-high-energy neutrinos by the IceCube collaboration has launched a quest for the identification of their astrophysical sources. Gamma-ray blazars have been predicted to yield a cumulative neutrino signal exceeding the atmospheric background above energies of 100 TeV, assuming that both the neutrinos and the gamma-ray photons are produced by accelerated protons in relativistic jets. Since the background spectrum falls steeply with increasing energy, the individual events with the clearest signature of being of an extraterrestrial origin are those at PeV energies. Inside the large positional-uncertainty fields of the first two PeV neutrinos detected by IceCube, the integrated emission of the blazar population has a sufficiently high electromagnetic flux to explain the detected IceCube events, but fluences of individual objects are too low to make an unambiguous source association. Here, we report that a major outburst of the blazar PKS B1424-418 occurred in temporal and pos...

  20. Extreme Energy Events Project: Construction of the detectors and installation in Italian High Schools

    CERN Document Server

    Abbrescia, M; An, S; Antolini, R; Badalà, A; Baldini Ferroli, R; Bencivenni, G; Blanco, F; Bressan, E; Chiavassa, A; Chiri, C; Cifarelli, L; Cindolo, F; Coccia, E; De Pasquale, S; Di Giovanni, A; D’Incecco, M; Fabbri, F L; Frolov, V; Garbini, M; Gustavino, C; Hatzifotiadou, D; Imponente, G; Kim, J; La Rocca, P; Librizzi, F; Maggiora, A; Menghetti, H; Miozzi, S; Moro, R; Panareo, M; Pappalardo, G S; Piragino, G; Riggi, F; Romano, F; Sartorelli, G; Sbarra, C; Selvi, M; Serci, S; Williams, C; Zuyeuski, R

    2008-01-01

    The EEE Project, conceived by its leader Antonino Zichichi, aims to detect Extreme Energy Events of cosmic rays with an array of muon telescopes distributed over the Italian territory. The Project involves Italian High Schools in order to introduce young people to Physics, also countervailing the recent crisis of university scientific classes inscriptions. The detectors for the EEE telescopes are Multigap Resistive Plate Chambers (MRPC) and have been constructed by teams of High School students who went in shift at the CERN laboratories. The mechanics and the electronics were developed by groups of researchers from CERN, the Italian Centro Fermi and INFN. The first group of schools of the EEE Project has inaugurated their telescopes recently. A status report of the Project and the preliminary results are presented.

  1. Physically-based modelling of high magnitude torrent events with uncertainty quantification

    Science.gov (United States)

    Wing-Yuen Chow, Candace; Ramirez, Jorge; Zimmermann, Markus; Keiler, Margreth

    2017-04-01

    High magnitude torrent events are associated with the rapid propagation of vast quantities of water and available sediment downslope where human settlements may be established. Assessing the vulnerability of built structures to these events is a part of consequence analysis, where hazard intensity is related to the degree of loss sustained. The specific contribution of the presented work describes a procedure simulate these damaging events by applying physically-based modelling and to include uncertainty information about the simulated results. This is a first step in the development of vulnerability curves based on several intensity parameters (i.e. maximum velocity, sediment deposition depth and impact pressure). The investigation process begins with the collection, organization and interpretation of detailed post-event documentation and photograph-based observation data of affected structures in three sites that exemplify the impact of highly destructive mudflows and flood occurrences on settlements in Switzerland. Hazard intensity proxies are then simulated with the physically-based FLO-2D model (O'Brien et al., 1993). Prior to modelling, global sensitivity analysis is conducted to support a better understanding of model behaviour, parameterization and the quantification of uncertainties (Song et al., 2015). The inclusion of information describing the degree of confidence in the simulated results supports the credibility of vulnerability curves developed with the modelled data. First, key parameters are identified and selected based on literature review. Truncated a priori ranges of parameter values were then defined by expert solicitation. Local sensitivity analysis is performed based on manual calibration to provide an understanding of the parameters relevant to the case studies of interest. Finally, automated parameter estimation is performed to comprehensively search for optimal parameter combinations and associated values, which are evaluated using the

  2. Large amplitude oscillatory elongation flow

    DEFF Research Database (Denmark)

    Rasmussen, Henrik K.; Laillé, Philippe; Yu, Kaijia

    2008-01-01

    A filament stretching rheometer (FSR) was used for measuring the elongation flow with a large amplitude oscillative elongation imposed upon the flow. The large amplitude oscillation imposed upon the elongational flow as a function of the time t was defined as epsilon(t) =(epsilon) over dot(0)t + ...

  3. Closed string amplitudes as single-valued open string amplitudes

    Energy Technology Data Exchange (ETDEWEB)

    Stieberger, Stephan, E-mail: stephan.stieberger@mpp.mpg.de [Max-Planck-Institut für Physik, Werner-Heisenberg-Institut, 80805 München (Germany); Taylor, Tomasz R. [Department of Physics, Northeastern University, Boston, MA 02115 (United States)

    2014-04-15

    We show that the single trace heterotic N-point tree-level gauge amplitude A{sub N}{sup HET} can be obtained from the corresponding type I amplitude A{sub N}{sup I} by the single-valued (sv) projection: A{sub N}{sup HET}=sv(A{sub N}{sup I}). This projection maps multiple zeta values to single-valued multiple zeta values. The latter represent a subclass of multiple zeta values originating from single-valued multiple polylogarithms at unity. Similar relations between open and closed string amplitudes or amplitudes of different string vacua can be established. As a consequence the α{sup ′}-expansion of a closed string amplitude is dictated by that of the corresponding open string amplitude. The combination of single-valued projections, Kawai–Lewellen–Tye relations and Mellin correspondence reveal a unity of all tree-level open and closed superstring amplitudes together with the maximally supersymmetric Yang–Mills and supergravity theories.

  4. Amplitude path corrections for regional phases in China

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, W.S.; Velasco, A.A.; Taylor, S.R.; Randall, G.E.

    1998-12-31

    The authors investigate the effectiveness of amplitude path corrections for regional phases on seismic event discrimination and magnitude estimation. Waveform data from digital stations in China for regional, shallow (< 50 km) events were obtained from the IRIS Data Management Center (DMC) for years 1986 to 1996 using the USGS Preliminary Determination of Epicenters (PDE) and the Chinese State Seismological Bureau (SSB) catalogs. For each event, the amplitudes for each regional phase (P{sub n}, P{sub g}, S{sub n}, L{sub g}) were measured, as well as the P{sub g} and L{sub g} coda. Measured amplitudes were corrected for source scaling using estimates of m{sub b} and for distance using a power law that accounts for attenuation and spreading. The amplitude residuals were interpolated and mapped as 2-D amplitude correction surfaces. The authors employ several methods to create the amplitude correction surfaces: a waveguide method, and two interpolation methods (Baysian kriging and a circular moving window mean smoother). They explore the sensitivities of the surfaces to the method and to regional propagation, and apply these surfaces to correct amplitude data to reduce scatter in discrimination ratios and magnitude estimates.

  5. A database of high-impact weather events in Greece: a descriptive impact analysis for the period 2001–2011

    Directory of Open Access Journals (Sweden)

    K. Papagiannaki

    2013-03-01

    Full Text Available This paper introduces the development of a database of high-impact weather events that occurred in Greece since 2001. The selected events are related to the occurrence of floods, flash floods, hail, snow/frost, tornados, windstorms, heat waves and lightning with adverse consequences (excluding those related to agriculture. The database includes, among others, the geographical distribution of the recorded events, relevant meteorological data, a brief description of the induced impacts and references in the press. This paper further offers an extensive analysis of the temporal and spatial distribution of high-impact weather events for the period 2001–2011, taking into account the intensity of weather conditions and the consequent impact on the society. Analysis of the monthly distribution of high-impact weather events showed that they are more frequent during October and November. More than 80 people lost their lives, half of which due to flash floods. In what concerns the spatial distribution of high-impact weather events, among the 51 prefectures of the country, Attica, Thessaloniki, Elia and Halkidiki were the most frequently affected areas, mainly by flash floods. Significant was also the share of tornados in Elia, of windstorms in Attica, of lightning and hail events in Halkidiki and of snow/frost events in Thessaloniki.

  6. Amplitude Modulations of Acoustic Communication Signals

    Science.gov (United States)

    Turesson, Hjalmar K.

    2011-12-01

    In human speech, amplitude modulations at 3 -- 8 Hz are important for discrimination and detection. Two different neurophysiological theories have been proposed to explain this effect. The first theory proposes that, as a consequence of neocortical synaptic dynamics, signals that are amplitude modulated at 3 -- 8 Hz are propagated better than un-modulated signals, or signals modulated above 8 Hz. This suggests that neural activity elicited by vocalizations modulated at 3 -- 8 Hz is optimally transmitted, and the vocalizations better discriminated and detected. The second theory proposes that 3 -- 8 Hz amplitude modulations interact with spontaneous neocortical oscillations. Specifically, vocalizations modulated at 3 -- 8 Hz entrain local populations of neurons, which in turn, modulate the amplitude of high frequency gamma oscillations. This suggests that vocalizations modulated at 3 -- 8 Hz should induce stronger cross-frequency coupling. Similar to human speech, we found that macaque monkey vocalizations also are amplitude modulated between 3 and 8 Hz. Humans and macaque monkeys share similarities in vocal production, implying that the auditory systems subserving perception of acoustic communication signals also share similarities. Based on the similarities between human speech and macaque monkey vocalizations, we addressed how amplitude modulated vocalizations are processed in the auditory cortex of macaque monkeys, and what behavioral relevance modulations may have. Recording single neuron activity, as well as, the activity of local populations of neurons allowed us to test both of the neurophysiological theories presented above. We found that single neuron responses to vocalizations amplitude modulated at 3 -- 8 Hz resulted in better stimulus discrimination than vocalizations lacking 3 -- 8 Hz modulations, and that the effect most likely was mediated by synaptic dynamics. In contrast, we failed to find support for the oscillation-based model proposing a

  7. Influence of an extreme high water event on survival, reproduction, and distribution of snail kites in Florida, USA

    Science.gov (United States)

    Bennetts, R.E.; Kitchens, W.M.; Dreitz, V.J.

    2002-01-01

    Hydrology frequently has been reported as the environmental variable having the greatest influence on Florida snail kite (Rostrhamus sociabilis) populations. Although drought has received the most attention, high-water conditions also have been reported to affect kites. Years of high water generally have been reported to be favorable for nesting, although prolonged high water may be detrimental to sustaining suitable habitat. During 1994 and 1995, southern Florida experienced an extreme high water event. This event enabled us to compare survival, nesting success, number of young per successful nest, and spatial distribution of nesting before, during, and after the event. We found no evidence of an effect (either negative or positive) on survival of adult kites. In contrast, juvenile kites experienced the highest survival during the event, although our data suggest greater annual variability than can be explained by the event alone. We found no evidence of an effect of the high water event on nest success or number of young per successful nest. Nest success was highest during the event in the southern portion of the range but was quite similar to other years, both before and after the event. Our data do indicate a substantial shift in the spatial distribution of nesting birds. During the event, nesting activity shifted to higher elevations (i.e., shallower water) in the major nesting areas of the Everglades region. Nesting also occurred in Big Cypress National Preserve during the event, which is typically too dry to support nesting kites. Thus, our data indicate a potential short-term benefit of increased juvenile survival and an expansion of nesting habitat. However, the deterioration of habitat quality from prolonged high water precludes any recommendation for such conditions to be maintained for extended periods. ?? 2002, The Society of Wetland Scientists.

  8. Event-based prospective memory deficits in individuals with high depressive symptomatology: problems controlling attentional resources?

    Science.gov (United States)

    Li, Yanqi Ryan; Loft, Shayne; Weinborn, Michael; Maybery, Murray T

    2014-01-01

    Depression has been found to be related to neurocognitive deficits in areas important to successful prospective memory (PM) performance, including executive function, attention, and retrospective memory. However, research specific to depression and PM has produced a mixed pattern of results. The current study further examined the task conditions in which event-based PM deficits may emerge in individuals with high depressive symptomatology (HDS) relative to individuals with low depressive symptomatology (LDS) and the capacity of HDS individuals to allocate attentional resources to event-based PM tasks. Sixty-four participants (32 HDS, 32 LDS) were required to make a PM response when target words were presented during an ongoing lexical decision task. When the importance of the ongoing task was emphasized, response time costs to the ongoing task, and PM accuracy, did not differ between the HDS and LDS groups. This finding is consistent with previous research demonstrating that event-based PM task accuracy is not always impaired by depression, even when the PM task is resource demanding. When the importance of the PM task was emphasized, costs to the ongoing task further increased for both groups, indicating an increased allocation of attentional resources to the PM task. Crucially, while a corresponding improvement in PM accuracy was observed in the LDS group when the importance of the PM task was emphasized, this was not true for the HDS group. The lack of improved PM accuracy in the HDS group compared with the LDS group despite evidence of increased cognitive resources allocated to PM tasks may have been due to inefficiency in the application of the allocated attention, a dimension likely related to executive function difficulties in depression. Qualitatively different resource allocation patterns may underlie PM monitoring in HDS versus LDS individuals.

  9. Detection and Attribution of Simulated Climatic Extreme Events and Impacts: High Sensitivity to Bias Correction

    Science.gov (United States)

    Sippel, S.; Otto, F. E. L.; Forkel, M.; Allen, M. R.; Guillod, B. P.; Heimann, M.; Reichstein, M.; Seneviratne, S. I.; Kirsten, T.; Mahecha, M. D.

    2015-12-01

    Understanding, quantifying and attributing the impacts of climatic extreme events and variability is crucial for societal adaptation in a changing climate. However, climate model simulations generated for this purpose typically exhibit pronounced biases in their output that hinders any straightforward assessment of impacts. To overcome this issue, various bias correction strategies are routinely used to alleviate climate model deficiencies most of which have been criticized for physical inconsistency and the non-preservation of the multivariate correlation structure. We assess how biases and their correction affect the quantification and attribution of simulated extremes and variability in i) climatological variables and ii) impacts on ecosystem functioning as simulated by a terrestrial biosphere model. Our study demonstrates that assessments of simulated climatic extreme events and impacts in the terrestrial biosphere are highly sensitive to bias correction schemes with major implications for the detection and attribution of these events. We introduce a novel ensemble-based resampling scheme based on a large regional climate model ensemble generated by the distributed weather@home setup[1], which fully preserves the physical consistency and multivariate correlation structure of the model output. We use extreme value statistics to show that this procedure considerably improves the representation of climatic extremes and variability. Subsequently, biosphere-atmosphere carbon fluxes are simulated using a terrestrial ecosystem model (LPJ-GSI) to further demonstrate the sensitivity of ecosystem impacts to the methodology of bias correcting climate model output. We find that uncertainties arising from bias correction schemes are comparable in magnitude to model structural and parameter uncertainties. The present study consists of a first attempt to alleviate climate model biases in a physically consistent way and demonstrates that this yields improved simulations of

  10. Modelado del transformador para eventos de alta frecuencia ;Transformer model for high frequency events

    Directory of Open Access Journals (Sweden)

    Verónica Adriana – Galván Sanchez

    2012-07-01

    Full Text Available La función de un transformador es cambiar el nivel de tensión a través de un acoplamiento magnético.Debido a su construcción física, su representación como un circuito y su modelo matemático son muycomplejos. El comportamiento electromagnético del transformador, al igual que todos los elementos de lared eléctrica de potencia, depende de la frecuencia involucrada. Por esta razón cuando se tienenfenómenos de alta frecuencia su modelo debe ser muy detallado para que reproduzca el comportamientodel estado transitorio. En este trabajo se analiza cómo se pasa de un modelo muy simple, a un modelo muydetallado para hacer simulación de eventos de alta frecuencia. Los eventos que se simulan son la operaciónde un interruptor por una falla en el sistema y el impacto de una descarga atmosférica sobre la línea detransmisión a una distancia de 5 km de una subestación de potencia.The transformer’s function is to change the voltage level through a magnetic coupling. Due to its physicalconstruction, its representation as a circuit and its mathematical model are very complex. Theelectromagnetic behavior and all the elements in the power network depend on the involved frequency. So,for high frequency events, its model needs to be very detailed to reproduce the electromagnetic transientbehavior. This work analyzes how to pass from a simple model to a very detailed model to simulated highfrequency events. The simulated events are the switch operation due to a fault in the system and the impactof an atmospheric discharge (direct stroke in the transmission line, five km far away from the substation.

  11. Teleconnection between the North Indian Ocean high swell events and meteorological conditions over the Southern Indian Ocean

    Science.gov (United States)

    Remya, P. G.; Vishnu, S.; Praveen Kumar, B.; Balakrishnan Nair, T. M.; Rohith, B.

    2016-10-01

    The link between North Indian Ocean (NIO) high swell events and the meteorological conditions over the Southern Indian Ocean (SIO) is explored in this article, using a combination of in situ measurements and model simulations for the year 2005. High waves, without any sign in the local winds, sometimes cause severe flooding events along the south-west coast of India, locally known as the Kallakkadal events and cause major societal problems along the coasts. In situ observations report 10 high swell events in NIO during 2005. Our study confirms that these events are caused by the swells propagating from south of 30°S. In all cases, 3-5 days prior to the high swell events in NIO, we observed a severe low pressure system, called the Cut-Off Low (COL) in the Southern Ocean. These COLs are quasistationary in nature, providing strong (˜25 ms-1) and long duration (˜3 days) surface winds over a large fetch; essential conditions for the generation of long-period swells. The intense equator ward winds associated with COLs in the SIO trigger the generation of high waves, which propagate to NIO as swells. Furthermore, these swells cause high wave activity and sometimes Kallakkadal events along the NIO coastal regions, depending on the local topography, angle of incidence, and tidal conditions. Our study shows that such natural hazards along the NIO coasts can be forecasted at least 2 days in advance if the meteorological conditions of the SIO are properly monitored.

  12. An analysis of high-impact, low-predictive skill severe weather events in the northeast U.S

    Science.gov (United States)

    Vaughan, Matthew T.

    An objective evaluation of Storm Prediction Center slight risk convective outlooks, as well as a method to identify high-impact severe weather events with poor-predictive skill are presented in this study. The objectives are to assess severe weather forecast skill over the northeast U.S. relative to the continental U.S., build a climatology of high-impact, low-predictive skill events between 1980--2013, and investigate the dynamic and thermodynamic differences between severe weather events with low-predictive skill and high-predictive skill over the northeast U.S. Severe storm reports of hail, wind, and tornadoes are used to calculate skill scores including probability of detection (POD), false alarm ratio (FAR) and threat scores (TS) for each convective outlook. Low predictive skill events are binned into low POD (type 1) and high FAR (type 2) categories to assess temporal variability of low-predictive skill events. Type 1 events were found to occur in every year of the dataset with an average of 6 events per year. Type 2 events occur less frequently and are more common in the earlier half of the study period. An event-centered composite analysis is performed on the low-predictive skill database using the National Centers for Environmental Prediction Climate Forecast System Reanalysis 0.5° gridded dataset to analyze the dynamic and thermodynamic conditions prior to high-impact severe weather events with varying predictive skill. Deep-layer vertical shear between 1000--500 hPa is found to be a significant discriminator in slight risk forecast skill where high-impact events with less than 31-kt shear have lower threat scores than high-impact events with higher shear values. Case study analysis of type 1 events suggests the environment over which severe weather occurs is characterized by high downdraft convective available potential energy, steep low-level lapse rates, and high lifting condensation level heights that contribute to an elevated risk of severe wind.

  13. Composition and meteorological changes associated with a strong stratospheric intrusion event in the Canadian High Arctic

    Science.gov (United States)

    Zhao, Xiaoyi; Strong, Kimberly; Conway, Stephanie; Tarasick, David; Osman, Mohammed; Richter, Andreas; Blechschmidt, Anne; Manney, Gloria

    2015-04-01

    Stratosphere-troposphere exchange (STE) provides a mechanism for trace gas transport between the lower stratosphere and the troposphere. Intense downward stratospheric intrusions may significantly affect the oxidizing capacity of the troposphere. Most STE events occur in tropical and mid-latitude regions, with less known about STE in the polar regions. In this work, we present an observation and modelling study of a strong stratospheric intrusion in the high Arctic (Eureka, 80°N) in March 2013, which led to an increase of total ozone and BrO columns observed by both ground-based and satellite instruments. The meteorological conditions for this event were similar to those observed for STEs associated with cold fronts. Before the cold front arrived at Eureka, the surface temperature first increased from -25.3°C (25 March 13:00 UTC) to -14.5°C (27 March 20:00 UTC) and then dropped to -36.4°C (29 March 6:00 UTC) after the front passed by. Meanwhile, the ground-level pressure decreased from 103.8 kPa to 101.8 kPa, then rose back to 102.6 kPa. Ozonesonde data (27 March 23:15 UTC) showed unusually high ozone (>100 ppbv) above ~3 km altitude, while the relative humidity profile indicated that the airmass was of stratospheric origin (very low relative humidity). The thermal tropopause height was ~9 km, based on a uniform lapse rate of 3.9 K/km from surface to 9 km. From ECMWF Interim data, the airmass with high relative potential vorticity (4 pvu) extended down to 3 km. In addition, HYSPLIT model ensemble back-trajectories show a clear Rossby wave signature in the upper troposphere during this event, which could explain the intrusion. However, there are no strong downwelling layers along the trajectories, which indicates that the intrusion may have occurred close to Eureka. Trace gas composition data from three ground-based spectrometers and the GOME-2 satellite instrument are presented in this work. Ozone vertical column densities (VCDs) measured by two Zenith

  14. Flavor Composition of the High-Energy Neutrino Events in IceCube

    Science.gov (United States)

    Mena, Olga; Palomares-Ruiz, Sergio; Vincent, Aaron C.

    2014-08-01

    The IceCube experiment has recently reported the observation of 28 high-energy (>30 TeV) neutrino events, separated into 21 showers and 7 muon tracks, consistent with an extraterrestrial origin. In this Letter, we compute the compatibility of such an observation with possible combinations of neutrino flavors with relative proportion (αe∶αμ∶ατ)⊕. Although the 7∶21 track-to-shower ratio is naively favored for the canonical (1∶1∶1)⊕ at Earth, this is not true once the atmospheric muon and neutrino backgrounds are properly accounted for. We find that, for an astrophysical neutrino E-2 energy spectrum, (1∶1∶1)⊕ at Earth is disfavored at 81% C.L. If this proportion does not change, 6 more years of data would be needed to exclude (1∶1∶1)⊕ at Earth at 3σ C.L. Indeed, with the recently released 3-yr data, that flavor composition is excluded at 92% C.L. The best fit is obtained for (1∶0∶0)⊕ at Earth, which cannot be achieved from any flavor ratio at sources with averaged oscillations during propagation. If confirmed, this result would suggest either a misunderstanding of the expected background events or a misidentification of tracks as showers, or even more compellingly, some exotic physics which deviates from the standard scenario.

  15. Verification of ensemble forecasts of Mediterranean high-impact weather events against satellite observations

    Directory of Open Access Journals (Sweden)

    J.-P. Chaboureau

    2012-08-01

    Full Text Available Ensemble forecasts at kilometre scale of two severe storms over the Mediterranean region are verified against satellite observations. In complement to assessing the forecasts against ground-based measurements, brightness temperature (BT images are computed from forecast fields and directly compared to BTs observed from satellite. The so-called model-to-satellite approach is very effective in identifying systematic errors in the prediction of cloud cover for BTs in the infrared window and in verifying the forecasted convective activity with BTs in the microwave range. This approach is combined with the calculation of meteorological scores for an objective evaluation of ensemble forecasts. The application of the approach is shown in the context of two Mediterranean case studies, a tropical-like storm and a heavy precipitating event. Assessment of cloud cover and convective activity using satellite observations in the infrared (10.8 μm and microwave regions (183–191 GHz provides results consistent with other traditional methods using rainfall measurements. In addition, for the tropical-like storm, differences among forecasts occur much earlier in terms of cloud cover and deep convective activity than they do in terms of deepening and track. Further, the underdispersion of the ensemble forecasts of the two high-impact weather events is easily identified with satellite diagnostics. This suggests that such an approach could be a useful method for verifying ensemble forecasts, particularly in data-sparse regions.

  16. A Nuclear Interaction Model for Understanding Results of Single Event Testing with High Energy Protons

    Science.gov (United States)

    Culpepper, William X.; ONeill, Pat; Nicholson, Leonard L.

    2000-01-01

    An internuclear cascade and evaporation model has been adapted to estimate the LET spectrum generated during testing with 200 MeV protons. The model-generated heavy ion LET spectrum is compared to the heavy ion LET spectrum seen on orbit. This comparison is the basis for predicting single event failure rates from heavy ions using results from a single proton test. Of equal importance, this spectra comparison also establishes an estimate of the risk of encountering a failure mode on orbit that was not detected during proton testing. Verification of the general results of the model is presented based on experiments, individual part test results, and flight data. Acceptance of this model and its estimate of remaining risk opens the hardware verification philosophy to the consideration of radiation testing with high energy protons at the board and box level instead of the more standard method of individual part testing with low energy heavy ions.

  17. Survey of TES high albedo events in Mars' northern polar craters

    Science.gov (United States)

    Armstrong, J.C.; Nielson, S.K.; Titus, T.N.

    2007-01-01

    Following the work exploring Korolev Crater (Armstrong et al., 2005) for evidence of crater interior ice deposits, we have conducted a survey of Thermal Emission Spectroscopy (TES) temperature and albedo measurements for Mars' northern polar craters larger than 10 km. Specifically, we identify a class of craters that exhibits brightening in their interiors during a solar longitude, Ls, of 60 to 120 degrees, roughly depending on latitude. These craters vary in size, latitude, and morphology, but appear to have a specific regional association on the surface that correlates with the distribution of subsurface hydrogen (interpreted as water ice) previously observed on Mars. We suggest that these craters, like Korolev, exhibit seasonal high albedo frost events that indicate subsurface water ice within the craters. A detailed study of these craters may provide insight in the geographical distribution of the ice and context for future polar missions. Copyright 2007 by the American Geophysical Union.

  18. Detection and analysis of high-temperature events in the BIRD mission

    Energy Technology Data Exchange (ETDEWEB)

    Zhukov, B.; Briess, K.; Lorenz, E.; Oertel, D.; Skrbek, W. [DLR, Berlin (Germany). Inst. of Space Sensor Technology & Planetary Exploration

    2005-01-01

    The primary mission objective of a new small Bi-spectral InfraRed Detection (BIRD) satellite is detection and quantitative analysis of high-temperature events like fires and volcanoes. An absence of saturation in the BIRD infrared channels makes it possible to improve false alarm rejection as well as to retrieve quantitative characteristics of hot targets, including their effective fire temperature, area and the radiative energy release. Examples are given of detection and analysis of wild and coal seam fires, of volcanic activity as well as of oil fires in Iraq. The smallest fires detected by BIRD, which were verified on ground, had an area of 12 m{sup 2} at daytime and 4 m{sup 2} at night.

  19. Single-event upset studies of a high-speed digital optical data link

    CERN Document Server

    Andrieux, M L; Dinkespiler, B; Evans, G; Gallin-Martel, L; Pearce, M; Rethore, F; Stroynowski, R; Ye, J

    2001-01-01

    The results from a series of neutron and photon irradiation tests of a high-speed digital optical data link based on a commercial serialiser and a vertical cavity surface emitting laser are described, the link was developed as a candidate for the front-end readout of the ATLAS electromagnetic calorimeter. The components at the emitting end of the link were unaffected by neutron and photon irradiation levels exceeding those expected during 10 years of LHC running. However, the link suffered from Single-Event upsets (SEUs) when irradiated with energetic neutrons. A very general method based on the burst generation rate (BGR) model has been developed and is used to extrapolate the error rate observed during tests to that expected at the LHC. A model-independent extrapolation was used to check the BGR approach and the results were consistent once systematic errors were taken into account. (21 refs).

  20. Projected changes to high temperature events for Canada based on a regional climate model ensemble

    Science.gov (United States)

    Jeong, Dae Il; Sushama, Laxmi; Diro, Gulilat Tefera; Khaliq, M. Naveed; Beltrami, Hugo; Caya, Daniel

    2016-05-01

    Extreme hot spells can have significant impacts on human society and ecosystems, and therefore it is important to assess how these extreme events will evolve in a changing climate. In this study, the impact of climate change on hot days, hot spells, and heat waves, over 10 climatic regions covering Canada, based on 11 regional climate model (RCM) simulations from the North American Regional Climate Change Assessment Program for the June to August summer period is presented. These simulations were produced with six RCMs driven by four Atmosphere-Ocean General Circulation Models (AOGCM), for the A2 emission scenario, for the current 1970-1999 and future 2040-2069 periods. Two types of hot days, namely HD-1 and HD-2, defined respectively as days with only daily maximum temperature (Tmax) and both Tmax and daily minimum temperature (Tmin) exceeding their respective thresholds (i.e., period-of-record 90th percentile of Tmax and Tmin values), are considered in the study. Analogous to these hot days, two types of hot spells, namely HS-1 and HS-2, are identified as spells of consecutive HD-1 and HD-2 type hot days. In the study, heat waves are defined as periods of three or more consecutive days, with Tmax above 32 °C threshold. Results suggest future increases in the number of both types of hot days and hot spell events for the 10 climatic regions considered. However, the projected changes show high spatial variability and are highly dependent on the RCM and driving AOGCM combination. Extreme hot spell events such as HS-2 type hot spells of longer duration are expected to experience relatively larger increases compared to hot spells of moderate duration, implying considerable heat related environmental and health risks. Regionally, the Great Lakes, West Coast, Northern Plains, and Maritimes regions are found to be more affected due to increases in the frequency and severity of hot spells and/or heat wave characteristics, requiring more in depth studies for these regions

  1. Very Rapid High-amplitude Gamma-Ray Variability in Luminous Blazar PKS 1510-089 Studied with Fermi-LAT

    Energy Technology Data Exchange (ETDEWEB)

    Saito, S.; Stawarz, L.; Tanaka, Y.T.; Takahashi, T.; Madejski, G.; D' Ammando, F.

    2013-03-20

    Here we report on the detailed analysis of the γ-ray light curve of a luminous blazar PKS 1510-089 observed in the GeV range with the Large Area Telescope (LAT) onboard the Fermi satellite during the period 2011 September - December. By investigating the properties of the detected three major flares with the shortest possible time binning allowed by the photon statistics, we find a variety of temporal characteristics and variability patterns. This includes a clearly asymmetric profile (with a faster flux rise and a slower decay) of the flare resolved on sub-daily timescales, a superposition of many short uncorrelated flaring events forming the apparently coherent longer-duration outburst, and a huge single isolated outburst unresolved down to the timescale of three-hours. In the latter case we estimate the corresponding γ-ray flux doubling timescale to be below one hour, which is extreme and never previously reported for any active galaxy

  2. Elliptical Accretion and Low Luminosity from High Accretion Rate Stellar Tidal Disruption Events

    Science.gov (United States)

    Svirski, Gilad; Piran, Tsvi; Krolik, Julian

    2017-01-01

    Models for tidal disruption events (TDEs) in which a supermassive black hole disrupts a star commonly assume that the highly eccentric streams of bound stellar debris promptly form a circular accretion disk at the pericenter scale. However, the bolometric peak luminosity of most TDE candidates, ˜ 10^{44} {erg s^{-1}}, implies that we observe only ˜1% of the energy expected from radiatively efficient accretion. Even the energy that must be lost to circularize the returning tidal flow is larger than the observed energy. Recently, Piran et al. (2015) suggested that the observed optical TDE emission is powered by shocks at the apocenter between freshly infalling material and earlier arriving matter. This model explains the small radiated energy, the low temperature, and the large radius implied by the observations as well as the t-5/3 light curve. However the question of the system's low bolometric efficiency remains unanswered. We suggest that the high orbital energy and low angular momentum of the flow make it possible for magnetic stresses to reduce the matter's already small angular momentum to the point at which it can fall ballistically into the SMBH before circularization. As a result, the efficiency is only ˜1-10% of a standard accretion disk's efficiency. Thus, the intrinsically high eccentricity of the tidal debris naturally explains why most TDE candidates are fainter than expected.

  3. Combination of various data analysis techniques for efficient track reconstruction in very high multiplicity events

    Science.gov (United States)

    Siklér, Ferenc

    2017-08-01

    A novel combination of established data analysis techniques for reconstructing charged-particles in high energy collisions is proposed. It uses all information available in a collision event while keeping competing choices open as long as possible. Suitable track candidates are selected by transforming measured hits to a binned, three- or four-dimensional, track parameter space. It is accomplished by the use of templates taking advantage of the translational and rotational symmetries of the detectors. Track candidates and their corresponding hits, the nodes, form a usually highly connected network, a bipartite graph, where we allow for multiple hit to track assignments, edges. In order to get a manageable problem, the graph is cut into very many minigraphs by removing a few of its vulnerable components, edges and nodes. Finally the hits are distributed among the track candidates by exploring a deterministic decision tree. A depth-limited search is performed maximizing the number of hits on tracks, and minimizing the sum of track-fit χ2. Simplified but realistic models of LHC silicon trackers including the relevant physics processes are used to test and study the performance (efficiency, purity, timing) of the proposed method in the case of single or many simultaneous proton-proton collisions (high pileup), and for single heavy-ion collisions at the highest available energies.

  4. Angular correlation between IceCube high-energy starting events and starburst sources

    CERN Document Server

    Moharana, Reetanjali

    2016-01-01

    Starburst galaxies and star-forming regions in the Milkyway, with high rate of supernova activities, are candidate sources of high-energy neutrinos. Using a gamma-ray selected sample of these sources we perform statistical analysis of their angular correlation with the four-year sample of high-energy starting events (HESE), detected by the IceCube Neutrino Observatory. We find that the two samples (starburst galaxies and local star-forming regions) are correlated with cosmic neutrinos at $\\sim (2-3)\\sigma$ (pre-trial) significance level, when the full HESE sample with deposited energy $\\gtrsim 20$~TeV is considered. However when we consider the HESE sample with deposited energy $\\gtrsim 60$~TeV, which is almost free of atmospheric neutrino and muon backgrounds, the significance of correlation decreased drastically. We perform a similar study for Galactic sources in the 2FHL catalog as well, obtaining $\\sim (2-3)\\sigma$ (pre-trial) correlation, however the significance of correlation increases with higher cuto...

  5. Positive Amplitudes In The Amplituhedron

    CERN Document Server

    Arkani-Hamed, Nima; Trnka, Jaroslav

    2014-01-01

    The all-loop integrand for scattering amplitudes in planar N = 4 SYM is determined by an "amplitude form" with logarithmic singularities on the boundary of the amplituhedron. In this note we provide strong evidence for a new striking property of the superamplitude, which we conjecture to be true to all loop orders: the amplitude form is positive when evaluated inside the amplituhedron. The statement is sensibly formulated thanks to the natural "bosonization" of the superamplitude associated with the amplituhedron geometry. However this positivity is not manifest in any of the current approaches to scattering amplitudes, and in particular not in the cellulations of the amplituhedron related to on-shell diagrams and the positive grassmannian. The surprising positivity of the form suggests the existence of a "dual amplituhedron" formulation where this feature would be made obvious. We also suggest that the positivity is associated with an extended picture of amplituhedron geometry, with the amplituhedron sitting...

  6. Model selection for amplitude analysis

    CERN Document Server

    Guegan, Baptiste; Stevens, Justin; Williams, Mike

    2015-01-01

    Model complexity in amplitude analyses is often a priori under-constrained since the underlying theory permits a large number of amplitudes to contribute to most physical processes. The use of an overly complex model results in reduced predictive power and worse resolution on unknown parameters of interest. Therefore, it is common to reduce the complexity by removing from consideration some subset of the allowed amplitudes. This paper studies a data-driven method for limiting model complexity through regularization during regression in the context of a multivariate (Dalitz-plot) analysis. The regularization technique applied greatly improves the performance. A method is also proposed for obtaining the significance of a resonance in a multivariate amplitude analysis.

  7. Adverse events among high-risk participants in a home-based walking study: a descriptive study

    Directory of Open Access Journals (Sweden)

    Holleman Robert G

    2007-05-01

    Full Text Available Abstract Background For high-risk individuals and their healthcare providers, finding the right balance between promoting physical activity and minimizing the risk of adverse events can be difficult. More information on the prevalence and influence of adverse events is needed to improve providers' ability to prescribe effective and safe exercise programs for their patients. Methods This study describes the type and severity of adverse events reported by participants with cardiovascular disease or at-risk for cardiovascular disease that occurred during an unsupervised, home-based walking study. This multi-site, randomized controlled trial tested the feasibility of a diet and lifestyle activity intervention over 1.5 years. At month 13, 274 eligible participants (male veterans were recruited who were ambulatory, BMI > 28, and reporting one or more cardiovascular disease risk factors. All participants attended five, face-to-face dietitian-delivered counseling sessions during the six-month intervention. Participants were randomized to three study arms: 1 time-based walking goals, 2 simple pedometer-based walking goals, and 3 enhanced pedometer-based walking goals with Internet-mediated feedback. Two physicians verified adverse event symptom coding. Results Enrolled participants had an average of five medical comorbidities. During 1110 person months of observation, 87 of 274 participants reported 121 adverse events. One serious study-related adverse event (atrial fibrillation was reported; the individual resumed study participation within three days. Non-serious, study related adverse events made up 12% of all symptoms – predominantly minor musculoskeletal events. Serious, non-study related adverse events represented 32% of all symptoms while non-serious, non-study related adverse events made up 56% of symptoms. Cardiovascular disease events represented over half of the non-study related adverse event symptoms followed by musculoskeletal complaints

  8. Subcascade formation and defect cluster size scaling in high-energy collision events in metals

    Science.gov (United States)

    De Backer, A.; Sand, A. E.; Nordlund, K.; Luneville, L.; Simeone, D.; Dudarev, S. L.

    2016-07-01

    It has been recently established that the size of the defects created under ion irradiation follows a scaling law (Sand A. E. et al., EPL, 103 (2013) 46003; Yi X. et al., EPL, 110 (2015) 36001). A critical constraint associated with its application to phenomena occurring over a broad range of irradiation conditions is the limitation on the energy of incident particles. Incident neutrons or ions, with energies exceeding a certain energy threshold, produce a complex hierarchy of collision subcascade events, which impedes the use of the defect cluster size scaling law derived for an individual low-energy cascade. By analyzing the statistics of subcascade sizes and energies, we show that defect clustering above threshold energies can be described by a product of two scaling laws, one for the sizes of subcascades and the other for the sizes of defect clusters formed in subcascades. The statistics of subcascade sizes exhibits a transition at a threshold energy, where the subcascade morphology changes from a single domain below the energy threshold, to several or many sub-domains above the threshold. The number of sub-domains then increases in proportion to the primary knock-on atom energy. The model has been validated against direct molecular-dynamics simulations and applied to W, Fe, Be, Zr and sixteen other metals, enabling the prediction of full statistics of defect cluster sizes with no limitation on the energy of cascade events. We find that populations of defect clusters produced by the fragmented high-energy cascades are dominated by individual Frenkel pairs and relatively small defect clusters, whereas the lower-energy non-fragmented cascades produce a greater proportion of large defect clusters.

  9. The associated charged particle multiplicity of high-p/sub T/ pi /sup 0/ and single-photon events

    CERN Document Server

    Diakonou, M; Albrow, M G; Almehed, S; Benary, O; Bøggild, H; Botner, O; Cnops, A M; Cockerill, D J A; Dagan, S; Dahl-Jensen, Erik; Dahl-Jensen, I; Damgaard, G; Fabjan, Christian Wolfgang; Filippas-Tassos, A; Fokitis, E; Fowler, E C; Hallgren, A; Hansen, K H; Henning, S; Hood, D M; Hooper, J; Jarlskog, G; Karpathopoulos, S; Killian, T; Kourkoumelis, C; Kreisler, M; Lissauer, D; Lörstad, B; Ludlam, T; Mannelli, I; McCubbin, N A; Melin, A; Mjörnmark, U; Møller, R; Molzon, W; Mouzourakis, P; Nielsen, B S; Nielsen, S O; Nilsson, A; Oren, Y; Palmer, R B; Rahm, David Charles; Rehak, P; Resvanis, L K; Rosselt, L; Schistad, B; Stumer, I; Svensson, L; von Dardel, Guy F; Willis, W J

    1980-01-01

    The associated charged particle multiplicities of high-p/sub T/ pi /sup 0/ and single-photon events were measured at the CERN intersecting storage rings using lead/liquid-argon calorimeters and a scintillation counter array placed around the intersection region. The average multiplicity on the trigger side for the single-photon events was found to be significantly lower than that for the pi /sup 0/ events. The away-side multiplicity for both pi /sup 0/ and single- photon events increases with the trigger particle p/sub T/, but, at a fixed p/sub T/, the direct photon sample was found to have a slightly lower average multiplicity. The differences in the event structure can be explained if a large fraction of the single photons are produced via qg to gamma q constituent scattering. (16 refs).

  10. High--cadence observations of spicular-type events on the Sun

    CERN Document Server

    Shetye, J; Scullion, E; Nelson, C J; Kuridze, D; Henriques, V; Woeger, F; Ray, T

    2016-01-01

    Chromospheric observations taken at high cadence and high spatial resolution show a range of spicule like features, including Type I, Type II (as well as RBEs and RREs) and those which seem to appear within a few seconds, which if interpreted as flows would imply mass flow velocities in excess of 1000 km/s. This article seeks to quantify and study rapidly appearing spicular type events. We also compare the MOMFBD and speckle reconstruction techniques in order to understand if such spicules are more favourably observed using a particular technique. We use spectral imaging observations taken with the CRISP on the Swedish 1 m Solar Telescope. Data was sampled at multiple positions within the Halpha line profile for both an ondisk and limb location. The data is host to numerous rapidly appearing features which are observed at different locations within the Halpha line profile. The feature's durations vary between 10 and 20 s and lengths around 3500 km. Sometimes, a time delay in their appearance between the blue ...

  11. High cardiovascular event rates occur within the first weeks of starting hemodialysis.

    Science.gov (United States)

    Eckardt, Kai-Uwe; Gillespie, Iain A; Kronenberg, Florian; Richards, Sharon; Stenvinkel, Peter; Anker, Stefan D; Wheeler, David C; de Francisco, Angel L; Marcelli, Daniele; Froissart, Marc; Floege, Jürgen

    2015-11-01

    Early mortality is high in hemodialysis (HD) patients, but little is known about early cardiovascular event (CVE) rates after HD initiation. To study this we analyzed data in the AROii cohort of incident HD patients from over 300 European Fresenius Medical Care dialysis centers. Weekly rates of a composite of CVEs during the first year and monthly rates of the composite and its constituents (coronary artery, cerebrovascular, peripheral arterial, congestive heart failure, and sudden cardiac death) during the first 2 years after HD initiation were assessed. Of 6308 patients that started dialysis within 7 days, 1449 patients experienced 2405 CVEs over the next 2 years. The first-year CVE rate (30.2/100 person-years; 95% CI, 28.7-31.7) greatly exceeded the second-year rate (19.4/100; 95% CI, 18.1-20.8). Composite CVEs were highest during the first week with increased risk compared with the second year, persisting until the fifth month. Except for sudden cardiac death, temporal patterns of rates for all CVE categories were very similar, with highest rates during the first month and a high-risk period extending to 4 months. Higher or lower cumulative weekly dialysis dose, lower blood flow, and lower net ultrafiltration during dialysis were associated with CVE during the high-risk period, but not during the post high-risk period. Thus, the incidence of CVE in the first weeks after HD initiation is much higher than during subsequent periods which raises concerns that HD initiation may trigger CVEs.

  12. High mass photon pairs in ℓ +ℓ -γγ events at LEP

    Science.gov (United States)

    Adriani, O.; Aguilar-Benitez, M.; Ahlen, S.; Alcaraz, J.; Aloisio, A.; Alverson, G.; Alviggi, M. G.; Ambrosi, G.; An, Q.; Anderhub, H.; Anderson, A. L.; Andreev, V. P.; Antonov, L.; Antreasyan, D.; Arce, P.; Arefiev, A.; Atamanchuk, A.; Azemoon, T.; Aziz, T.; Baba, P. V. K. S.; Bagnaia, P.; Bakken, J. A.; Baksay, L.; Ball, R. C.; Banerjee, S.; Bao, J.; Barillère, R.; Barone, L.; Baschirotto, A.; Battiston, R.; Bay, A.; Becattini, F.; Becker, U.; Behner, F.; Behrens, J.; Bencze, Gy. L.; Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B. L.; Biasini, M.; Biland, A.; Bilei, G. M.; Bizzarri, R.; Blaising, J. J.; Bobbink, G. J.; Bock, R.; Böhm, A.; Borgia, B.; Boseti, M.; Bourilkov, D.; Bourquin, M.; Boutigny, D.; Bouwens, B.; Brambilla, E.; Branson, J. G.; Brock, I. C.; Brooks, M.; Bujak, A.; Burger, J. D.; Burger, W. J.; Busenitz, J.; Cai, X. D.; Capell, M.; Caria, M.; Carlino, G.; Cartacci, A. M.; Castello, R.; Cerrada, M.; Cesaroni, F.; Chang, Y. H.; Chaturvedi, U. K.; Chemarin, M.; Chen, A.; Chena, C.; Chen, G. M.; H. F., Chen; Chen, H. S.; Chen, M.; Chen, W. Y.; Chiefari, G.; Chien, C. Y.; Choi, M. T.; Chung, S.; Civinini, C.; Clare, I.; Clare, R.; Coan, T. E.; Cohn, H. O.; Coignet, G.; Colino, N.; Contin, A.; Cui, X. T.; Cui, X. Y.; Dai, T. S.; D'Alessandro, R.; de Asmundis, R.; Degré, A.; Deiters, K.; Dénes, E.; Denes, P.; DeNotaristefani, F.; Dhina, M.; DiBitonto, D.; Diemoz, M.; Dimitrov, H. R.; Dionisi, C.; Djambazov, L.; Dova, M. T.; Drago, E.; Driever, T.; Duchesneau, D.; Duinker, P.; Duran, I.; Easo, S.; El Mamouni, H.; Engler, A.; Eppling, F. J.; Erné, F. C.; Extermann, P.; Fabbretti, R.; Fabre, M.; Falciano, S.; Fan, S. J.; Fackler, O.; Fay, J.; Felcini, M.; Ferguson, T.; Fernandez, D.; Fernandez, G.; Ferroni, F.; Fesefeldt, H.; Fiandrini, E.; Field, J.; Filthaut, F.; Finocchiaro, G.; Fisher, P. H.; Forconi, G.; Foreman, T.; Freudenreich, K.; Friebel, W.; Fukushima, M.; Gailloud, M.; Galaktionov, Yu.; Gallo, E.; Ganguli, S. N.; Garcia-Abia, P.; Gele, D.; Gentile, S.; Goldfarb, S.; Gong, Z. F.; Gonzalez, E.; Gougas, A.; Goujon, D.; Gratta, G.; Gruenewald, M.; Gu, C.; Guanziroli, M.; Guo, J. K.; Gupta, V. K.; Gurtu, A.; Gustafson, H. R.; Gutay, L. J.; Hangarter, K.; Hasan, A.; Hauschildt, D.; He, C. F.; He, J. T.; Hebbeker, T.; Hebert, M.; Herten, G.; Hervé, A.; Hilgers, K.; Hofer, H.; Hoorani, H.; Hu, G.; Hu, G. Q.; Ille, B.; Ilyas, M. M.; Innocente, V.; Janssen, H.; Jezequel, S.; Jin, B. N.; Kasser, A.; Khan, R. A.; Kamyshkov, Yu.; Kapinos, P.; Kapustinsky, J. S.; Karyotakis, Y.; Kaur, M.; Khokhar, S.; Kienzle-Focacci, M. N.; Kim, J. K.; Kim, S. C.; Kinnison, W. W.; Kirkby, D.; Kirsch, S.; Kittel, W.; Klimentov, A.; König, A. C.; Koffeman, E.; Kornadt, O.; Koutsenko, V.; Koulbardis, A.; Kraemer, R. W.; Kramer, T.; Krastev, V. R.; Krenz, W.; Krivshich, A.; Kuijten, H.; Kumar, K. S.; Kunin, A.; Landi, G.; Lanske, D.; Lanzano, S.; Lebrun, P.; Lecomte, P.; Lecoq, P.; Le Coultre, P.; Lee, D. M.; Leedom, I.; Leggett, C.; Le Goff, J. M.; Leiste, R.; Lenti, M.; Leonardi, E.; Leytens, X.; Li, C.; Li, H. T.; Li, P. J.; Liao, J. Y.; Lin, W. T.; Lin, Z. Y.; Linde, F. L.; Lindemann, B.; Lista, L.; Liu, Y.; Lohmann, W.; Longo, E.; Lu, Y. S.; Lubbers, J. M.; Lübelsmeyer, K.; Luci, C.; Luckey, D.; Ludovici, L.; Luminari, L.; Lustermann, W.; Ma, J. M.; Ma, W. G.; MacDermott, M.; Malhotra, P. K.; Malik, R.; Malinin, A.; Maña, C.; Maolinbay, M.; Marchesini, P.; Marion, F.; Marin, A.; Martin, J. P.; Martinez-Laso, L.; Marzano, F.; Massaro, G. G. G.; Mazumdar, K.; McBride, P.; McMahon, T.; McNally, D.; Merk, M.; Merola, L.; Meschini, M.; Metzger, W. J.; Mi, Y.; Mills, G. B.; Mir, Y.; Mirabelli, G.; Mnich, J.; Möller, M.; Monteleoni, B.; Morand, R.; Morganti, S.; Moulai, N. E.; Mount, R.; Müller, S.; Nadtochy, A.; Nagy, E.; Napolitano, M.; Newman, H.; Neyer, C.; Niaz, M. A.; Nippe, A.; Nowak, H.; Organtini, G.; Pandoulas, D.; Paoletti, S.; Paolucci, P.; Pascala, G.; Passaleva, G.; Patricelli, S.; Paul, T.; Pauluzzi, M.; Paus, C.; Pauss, F.; Pei, Y. J.; Pensotti, S.; Perret-Gallix, D.; Perrier, J.; Pevsner, A.; Piccolo, D.; Pieri, M.; Piroué, P. A.; Plasil, F.; Plyaskin, V.; Pohl, M.; Pojidaev, V.; Postema, H.; Qi, Z. D.; Qian, J. M.; Qureshi, K. N.; Raghavan, R.; Rahal-Callot, G.; Rancoita, P. G.; Rattaggi, M.; Raven, G.; Razis, P.; Read, K.; Ren, D.; Ren, Z.; Rescigno, M.; Reucroft, S.; Ricker, A.; Riemann, S.; Riemers, W.; Rind, O.; Rizvi, H. A.; Rodriguez, F. J.; Röhner, M.; Röhner, S.; Romero, L.; Rose, J.; Rosier-Lees, S.; Rosmalen, R.; Rosselet, Ph.; Rubbia, A.; Rubio, J. A.; Rykaczewski, H.; Sachwitz, M.; Sajan, E.; Salicio, J.; Salicio, J. M.; Sanders, G. S.; Santocchia, A.; Sarakinos, M. S.; Sartorelli, G.; Sassowsky, M.; Sauvage, G.; Schegelsky, V.; Schmitz, D.; Schmitz, P.; Schneegans, M.; Schopper, H.; Schotanus, D. J.; Shotkin, S.; Schreiber, H. J.; Shukla, J.; Schulte, R.; Schulte, S.; Schultze, K.; Schwenke, J.; Schwering, G.; Sciacca, C.; Scott, I.; Sehgal, R.; Seiler, P. G.; Sens, J. C.; Servoli, L.; Sheer, I.; Shen, D. Z.; Shevchenko, S.; Shi, X. R.; Shumilov, E.; Shoutko, V.; Son, D.; Sopczak, A.; Spartiotis, C.; Spickermann, T.; Spillantini, P.; Starosta, R.; Steuer, M.; Stickland, D. P.; Sticozzi, F.; Stone, H.; Strauch, K.; Stringfellow, B. C.; Sudhakar, K.; Sultanov, G.; Sun, L. Z.; Suter, H.; Swain, J. D.; Syed, A. A.; Tang, X. W.; Taylor, L.; Terzi, G.; Ting, Samuel C. C.; Ting, S. M.; Tonutti, M.; Tonwar, S. C.; Tóth, J.; Tsaregorodtsev, A.; Tsipolitis, G.; Tully, C.; Tung, K. L.; Ulbricht, J.; Urbán, L.; Uwer, U.; Valente, E.; Van de Walle, R. T.; Vetlitsky, I.; Viertel, G.; Vikas, P.; Vikas, U.; Vivargent, M.; Vogel, H.; Vogt, H.; Vorobiev, I.; Vorobyov, A. A.; Vuilleumier, L.; Wadhwa, M.; Wallraff, W.; Wang, C.; Wang, C. R.; Wang, G. H.; Wang, X. L.; Wang, Y. F.; Wang, Z. M.; Weber, A.; Weber, J.; Weill, R.; Wenaus, T. J.; Wenninger, J.; White, M.; Willmott, C.; Wittgenstein, F.; Wright, D.; Wu, S. X.; Wysłouch, B.; Xie, Y. Y.; Xu, J. G.; Xu, Z. Z.; Xue, Z. L.; Yan, D. S.; Yang, B. Z.; Yang, C. G.; Yang, G.; Ye, C. H.; Ye, J. B.; Ye, Q.; Yeh, S. C.; Yin, Z. W.; You, J. M.; Yunus, N.; Yzerman, M.; Zaccardelli, C.; Zemp, P.; Zeng, M.; Zeng, Y.; Zhang, D. H.; Zhang, Z. P.; Zhou, B.; Zhou, G. J.; Zhou, J. F.; Zhu, R. Y.; Zichichi, A.; van der Zwaan, B. C. C.; L3 Collaboration

    1992-12-01

    From the analysis of the reactions e +e -→ l+l-( nγ) ( l= e, μ, τ) we observe four events, one e +e -γγ and three μ+μ-γγ, with the invariant mass of the photon pairs close to 60 GeV. These events were selected from a data sample collected in the L3 detector corresponding to 950 000 produced Z 0's. More data are necessary to ascertain the origin of these events.

  13. High prevalence of peripheral arterial disease in patients with previous cerebrovascular or coronary event

    DEFF Research Database (Denmark)

    Mehlsen, Jesper; Wiinberg, Niels; Joergensen, Bjarne S

    2010-01-01

    The presence of peripheral arterial disease (PAD) in patients with other manifestations of cardiovascular disease identifies a population at increased risk of complications both during acute coronary events and on a long-term basis and possibly a population in whom secondary prevention of cardiov...... of cardiovascular events should be addressed aggressively. The present study was aimed at providing a valid estimate on the prevalence of PAD in patients attending their general practitioner and having previously suffered a cardio- or cerebrovascular event....

  14. Particle Distribution Modification by Low Amplitude Modes

    Energy Technology Data Exchange (ETDEWEB)

    White, R. B.; Gorelenkov, N.; Heidbrink, W. W.; Van Zeeland, M. A.

    2009-08-28

    Modification of a high energy particle distribution by a spectrum of low amplitude modes is investigated using a guiding center code. Only through resonance are modes effective in modifying the distribution. Diagnostics are used to illustrate the mode-particle interaction and to find which effects are relevant in producing significant resonance, including kinetic Poincare plots and plots showing those orbits with time averaged mode-particle energy transfer. Effects of pitch angle scattering and drag are studied, as well as plasma rotation and time dependence of the equilibrium and mode frequencies. A specific example of changes observed in a DIII-D deuterium beam distribution in the presence of low amplitude experimentally validated Toroidal Alfven (TAE) eigenmodes and Reversed Shear Alfven (RSAE) eigenmodes is examined in detail. Comparison with experimental data shows that multiple low amplitude modes can account for significant modification of high energy beam particle distributions. It is found that there is a stochastic threshold for beam profile modification, and that the experimental amplitudes are only slightly above this threshold.

  15. OGLE-2016-BLG-0596Lb: High-Mass Planet From High-Magnification Pure-Survey Microlensing Event

    CERN Document Server

    Mróz, P; Udalski, A; Poleski, R; Skowron, J; Szymański, M K; Soszyński, I; Pietrukowicz, P; Kozłowski, S; Ulaczyk, K; Wyrzykowski, Ł; Pawlak, M; Albrow, M D; Cha, S -M; Chung, S -J; Jung, Y K; Kim, D -J; Kim, S -L; Lee, C -U; Lee, Y; Park, B -G; Pogge, R W; Ryu, Y -H; Shin, I -G; Yee, J C; Zhu, W; Gould, A

    2016-01-01

    We report the discovery of a high mass-ratio planet $q=0.012$, i.e., 13 times higher than the Jupiter/Sun ratio. The host mass is not presently measured but can be determined or strongly constrained from adaptive optics imaging. The planet was discovered in a small archival study of high-magnification events in pure-survey microlensing data, which was unbiased by the presence of anomalies. The fact that it was previously unnoticed may indicate that more such planets lie in archival data and could be discovered by similar systematic study. In order to understand the transition from predominantly survey+followup to predominately survey-only planet detections, we conduct the first analysis of these detections in the observational $(s,q)$ plane. Here $s$ is projected separation in units of the Einstein radius. We find some evidence that survey+followup is relatively more sensitive to planets near the Einstein ring, but that there is no statistical difference in sensitivity by mass ratio.

  16. Statistical-noise reduction in correlation analysis of high-energy nuclear collisions with event-mixing

    CERN Document Server

    Ray, R L

    2016-01-01

    The error propagation and statistical-noise reduction method of Reid and Trainor for two-point correlation applications in high-energy collisions is extended to include particle-pair references constructed by mixing two particles from all event-pair combinations within event subsets of arbitrary size. The Reid-Trainor method is also applied to other particle-pair mixing algorithms commonly used in correlation analysis of particle production from high-energy nuclear collisions. The statistical-noise reduction, inherent in the Reid-Trainor event-mixing procedure, is shown to occur for these other event-mixing algorithms as well. Monte Carlo simulation results are presented which verify the predicted degree of noise reduction. In each case the final errors are determined by the bin-wise particle-pair number, rather than by the bin-wise single-particle count.

  17. Pattern recognition of $^{136}$Xe double beta decay events and background discrimination in a high pressure Xenon TPC

    CERN Document Server

    Cebrian, S; Gomez, H; Herrera, D C; Iguaz, F J; Irastorza, I G; Luzon, G; Segui, L; Tomas, A

    2013-01-01

    High pressure gas detectors offer advantages for the detection of rare events, where background reduction is crucial. For the neutrinoless double beta decay of 136Xe a high pressure xenon gas Time Projection Chamber (TPC) combines a good energy resolution and a detailed topological information of each event. The ionization topology of the double beta decay event of 136Xe in gaseous xenon has a characteristic shape defined by the two straggling electron tracks ending up in two higher ionization charge density blobs. With a properly pixelized readout, this topological information is invaluable to perform powerful background discrimination. In this study we carry out detailed simulations of the signal topology, as well as the competing topologies from gamma events that typically compose the background at these energies. We define observables based on graph theory concepts and develop automated discrimination algorithms which reduce the background level in around three orders of magnitude while keeping signal eff...

  18. Statistical-noise reduction in correlation analysis of high-energy nuclear collisions with event-mixing

    Energy Technology Data Exchange (ETDEWEB)

    Ray, R.L., E-mail: ray@physics.utexas.edu; Bhattarai, P.

    2016-06-11

    The error propagation and statistical-noise reduction method of Reid and Trainor for two-point correlation applications in high-energy collisions is extended to include particle-pair references constructed by mixing two particles from all event-pair combinations within event subsets of arbitrary size. The Reid–Trainor method is also applied to other particle-pair mixing algorithms commonly used in correlation analysis of particle production from high-energy nuclear collisions. The statistical-noise reduction, inherent in the Reid–Trainor event-mixing procedure, is shown to occur for these other event-mixing algorithms as well. Monte Carlo simulation results are presented which verify the predicted degree of noise reduction. In each case the final errors are determined by the bin-wise particle-pair number, rather than by the bin-wise single-particle count.

  19. 稳定的保幅高阶广义屏地震偏移成像方法研究%The method of preserved-amplitude seismic migration imaging with stable generalized high order screen

    Institute of Scientific and Technical Information of China (English)

    刘定进; 杨瑞娟; 罗申玥; 王鹏燕; 郑小鹏; 宋林

    2012-01-01

    Wave equation preserved-amplitude seismic migration imaging has a special function that can give true amplitudes as well as the correct locations based on advanced wave theories. The author first starts from the unstable phase shift expression of preserved-amplitude one way wave equation. Based on perturbation theory which is often used in reversed question solution, the author uses the progressive expansion of single square root operator to drive a high-order generalized screen form of preserved-amplitude prestack depth migration equation. To solve the unstable problem in lateral variable speed media caused by computation items of the scattering wavefield, the author proposes a strategy which can effectively improve the stability by math approximation. Then this strategy is applied to the wavefield recursion extrapolation, so a kind of stable preserved-amplitude prestack depth migration operators of high-order generalized screen are obtained. Theoretical model testing and real data processing indicate that this method can not only make scattering energy be focused and migrated to the correct position to improve imaging accuracy but also output the amplitude information which reflects the correct subsurface reflection coefficients. So this method has clearer AVO response and can enhance analytic precision for AVO data.%以先进的波动理论为基础的波动方程保幅地震偏移成像是在给出正确位置的同时也给出真实振幅的一种特殊完善.作者从保幅单程波动方程的非稳态相移公式出发,基于反问题求解中常用的摄动理论,利用单平方根算子的渐进展开,从而推导出保幅叠前深度偏移方程的高阶广义屏形式;针对散射波场计算项对于横向变速介质的不稳定性,通过数学近似提出一个有效提高稳定性的策略,应用到波场递归外推过程中,从而得到一种稳定的保幅高阶广义屏叠前深度偏移算子.理论模型试算和实际资料处理表明,该

  20. Computing Maximally Supersymmetric Scattering Amplitudes

    Science.gov (United States)

    Stankowicz, James Michael, Jr.

    This dissertation reviews work in computing N = 4 super-Yang--Mills (sYM) and N = 8 maximally supersymmetric gravity (mSUGRA) scattering amplitudes in D = 4 spacetime dimensions in novel ways. After a brief introduction and overview in Ch. 1, the various techniques used to construct amplitudes in the remainder of the dissertation are discussed in Ch. 2. This includes several new concepts such as d log and pure integrand bases, as well as how to construct the amplitude using exactly one kinematic point where it vanishes. Also included in this chapter is an outline of the Mathematica package on shell diagrams and numerics.m (osdn) that was developed for the computations herein. The rest of the dissertation is devoted to explicit examples. In Ch. 3, the starting point is tree-level sYM amplitudes that have integral representations with residues that obey amplitude relations. These residues are shown to have corresponding residue numerators that allow a double copy prescription that results in mSUGRA residues. In Ch. 4, the two-loop four-point sYM amplitude is constructed in several ways, showcasing many of the techniques of Ch. 2; this includes an example of how to use osdn. The two-loop five-point amplitude is also presented in a pure integrand representation with comments on how it was constructed from one homogeneous cut of the amplitude. On-going work on the two-loop n-point amplitude is presented at the end of Ch. 4. In Ch. 5, the three-loop four-point amplitude is presented in the d log representation and in the pure integrand representation. In Ch. 6, there are several examples of four- through seven-loop planar diagrams that illustrate how considerations of the singularity structure of the amplitude underpin dual-conformal invariance. Taken with the previous examples, this is additional evidence that the structure known to exist in the planar sector extends to the full theory. At the end of this chapter is a proof that all mSUGRA amplitudes have a pole at

  1. Scattering Amplitudes in Gauge Theories

    CERN Document Server

    Schubert, Ulrich

    2014-01-01

    This thesis is focused on the development of new mathematical methods for computing multi-loop scattering amplitudes in gauge theories. In this work we combine, for the first time, the unitarity-based construction for integrands, and the recently introduced integrand-reduction through multivariate polynomial division. After discussing the generic features of this novel reduction algorithm, we will apply it to the one- and two-loop five-point amplitudes in ${\\cal N}=4$ sYM. The integrands of the multiple-cuts are generated from products of tree-level amplitudes within the super-amplitudes formalism. The corresponding expressions will be used for the analytic reconstruction of the polynomial residues. Their parametric form is known a priori, as derived by means of successive polynomial divisions using the Gr\\"obner basis associated to the on-shell denominators. The integrand reduction method will be exploited to investigate the color-kinematic duality for multi-loop ${\\cal N}=4$ sYM scattering amplitudes. Our a...

  2. Ion-ion coincidence imaging at high event rate using an in-vacuum pixel detector

    Science.gov (United States)

    Long, Jingming; Furch, Federico J.; Durá, Judith; Tremsin, Anton S.; Vallerga, John; Schulz, Claus Peter; Rouzée, Arnaud; Vrakking, Marc J. J.

    2017-07-01

    A new ion-ion coincidence imaging spectrometer based on a pixelated complementary metal-oxide-semiconductor detector has been developed for the investigation of molecular ionization and fragmentation processes in strong laser fields. Used as a part of a velocity map imaging spectrometer, the detection system is comprised of a set of microchannel plates and a Timepix detector. A fast time-to-digital converter (TDC) is used to enhance the ion time-of-flight resolution by correlating timestamps registered separately by the Timepix detector and the TDC. In addition, sub-pixel spatial resolution (algorithm. This performance is achieved while retaining a high event rate (104 per s). The spectrometer was characterized and used in a proof-of-principle experiment on strong field dissociative double ionization of carbon dioxide molecules (CO2), using a 400 kHz repetition rate laser system. The experimental results demonstrate that the spectrometer can detect multiple ions in coincidence, making it a valuable tool for studying the fragmentation dynamics of molecules in strong laser fields.

  3. Time evolution of atmospheric particle number concentration during high-intensity pyrotechnic events

    Science.gov (United States)

    Crespo, Javier; Yubero, Eduardo; Nicolás, Jose F.; Caballero, Sandra; Galindo, Nuria

    2014-10-01

    The Mascletàs are high-intensity pyrotechnic events, typical of eastern Spanish festivals, in which thousands of firecrackers are burnt at ground level in an intense, short-time (festival in Alicante (southeastern Spain). Peak concentrations and dilution times observed throughout the Mascletàs have been compared to those measured when conventional aerial fireworks were launched 2 km away from the monitoring site. The impact of the Mascletàs on the total number concentration of particles larger than 0.3 μm was higher (maximum ˜2·104 cm-3) than that of fireworks (maximum ˜2·103 cm-3). The effect of fireworks depended on whether the dominant meteorological conditions favoured the transport of the plume to the measurement location. However, the time required for particle concentrations to return to background levels is longer and more variable for firework displays (minutes to hours) than for the Mascletàs (<25 min).

  4. Ionosphere data assimilation capabilities for representing the high-latitude geomagnetic storm event in September 2011

    Science.gov (United States)

    Solomentsev, Dmitry; Jacobsen, Knut Stanley; Khattatov, Boris; Khattatov, Vyacheslav; Cherniak, Yakov; Titov, Anton

    2014-12-01

    Severe geomagnetic storms have a strong impact on space communication and satellite navigation systems. Forecasting the appearance of geomagnetically induced disturbances in the ionosphere is one of the urgent goals of the space weather community. The challenge is that the processes governing the distribution of the crucial ionospheric parameters have a rather poor quantitative description, and the models, built using the empirical parameterizations, have limited capabilities for operational purposes. On the other hand, data assimilation techniques are becoming more and more popular for nowcasting the state of the large-scale geophysical systems. We present an example of an ionospheric data assimilation system performance assessment during a strong geomagnetic event, which took place on 26 September 2011. The first-principle model has assimilated slant total electron content measurements from a dense network of ground stations, provided by the Norwegian Mapping Authority. The results have shown satisfactory agreement with independent data and demonstrate that the assimilation model is accurate to about 2-4 total electron content units and can be used for operational purposes in high-latitude regions. The operational system performance assessment is the subject of future work.

  5. High-energy Neutrino Flares from X-Ray Bright and Dark Tidal Disruption Events

    Science.gov (United States)

    Senno, Nicholas; Murase, Kohta; Mészáros, Peter

    2017-03-01

    X-ray and γ-ray observations by the Swift satellite revealed that a fraction of tidal disruption events (TDEs) have relativistic jets. Jetted TDEs have been considered to be potential sources of very-high-energy cosmic-rays and neutrinos. In this work, using semi-analytical methods, we calculate neutrino spectra of X-ray bright TDEs with powerful jets and dark TDEs with possible choked jets, respectively. We estimate their neutrino fluxes and find that non-detection would give us an upper limit on the baryon loading of the jet luminosity contained in cosmic-rays ξ cr ≲ 20–50 for Sw J1644+57. We show that X-ray bright TDEs make a sub-dominant (≲5%–10%) contribution to IceCube’s diffuse neutrino flux, and study possible contributions of X-ray dark TDEs given that particles are accelerated in choked jets or disk winds. We discuss future prospects for multi-messenger searches of the brightest TDEs.

  6. Early spring, severe frost events, and drought induce rapid carbon loss in high elevation meadows.

    Directory of Open Access Journals (Sweden)

    Chelsea Arnold

    Full Text Available By the end of the 20th century, the onset of spring in the Sierra Nevada mountain range of California has been occurring on average three weeks earlier than historic records. Superimposed on this trend is an increase in the presence of highly anomalous "extreme" years, where spring arrives either significantly late or early. The timing of the onset of continuous snowpack coupled to the date at which the snowmelt season is initiated play an important role in the development and sustainability of mountain ecosystems. In this study, we assess the impact of extreme winter precipitation variation on aboveground net primary productivity and soil respiration over three years (2011 to 2013. We found that the duration of snow cover, particularly the timing of the onset of a continuous snowpack and presence of early spring frost events contributed to a dramatic change in ecosystem processes. We found an average 100% increase in soil respiration in 2012 and 2103, compared to 2011, and an average 39% decline in aboveground net primary productivity observed over the same time period. The overall growing season length increased by 57 days in 2012 and 61 days in 2013. These results demonstrate the dependency of these keystone ecosystems on a stable climate and indicate that even small changes in climate can potentially alter their resiliency.

  7. Large surface radiative forcing from surface-based ice crystal events measured in the High Arctic at Eureka

    Directory of Open Access Journals (Sweden)

    G. Lesins

    2008-09-01

    Full Text Available Ice crystals, also known as diamond dust, are suspended in the boundary layer air under clear sky conditions during most of the Arctic winter in Northern Canada. Occasionally ice crystal events can produce significantly thick layers with optical depths in excess of 2.0 even in the absence of liquid water clouds. Four case studies of high optical depth ice crystal events at Eureka in the Nunavut Territory of Canada during the winter of 2006–2007 are presented. They show that the measured ice crystal surface infrared downward radiative forcing ranged from 8 to 36 W m−2 in the wavelength band from 5.6 to 20 μm for visible optical depths ranging from 0.2 to 1.7. MODIS infrared and visible images and the operational radiosonde wind profile were used to show that these high optical depth events were caused by surface snow being blown off 600 to 800 m high mountain ridges about 20 to 30 km North-West of Eureka and advected by the winds towards Eureka as they settled towards the ground within the highly stable boundary layer. This work presents the first study that demonstrates the important role that surrounding topography plays in determining the occurrence of high optical depth ice crystal events and points to a new source of boundary layer ice crystal events distinct from the classical diamond dust phenomenon.

  8. Sensitivity of the IceCube detector for ultra-high energy electron neutrino events

    Energy Technology Data Exchange (ETDEWEB)

    Voigt, Bernhard

    2008-07-16

    IceCube is a neutrino telescope currently under construction in the glacial ice at South Pole. At the moment half of the detector is installed, when completed it will instrument 1 km{sup 3} of ice providing a unique experimental setup to detect high energy neutrinos from astrophysical sources. In this work the sensitivity of the complete IceCube detector for a diffuse electron-neutrino flux is analyzed, with a focus on energies above 1 PeV. Emphasis is put on the correct simulation of the energy deposit of electromagnetic cascades from charged-current electron-neutrino interactions. Since existing parameterizations lack the description of suppression effects at high energies, a simulation of the energy deposit of electromagnetic cascades with energies above 1 PeV is developed, including cross sections which account for the LPM suppression of bremsstrahlung and pair creation. An attempt is made to reconstruct the direction of these elongated showers. The analysis presented here makes use of the full charge waveform recorded with the data acquisition system of the IceCube detector. It introduces new methods to discriminate efficiently between the background of atmospheric muons, including muon bundles, and cascade signal events from electron-neutrino interactions. Within one year of operation of the complete detector a sensitivity of 1.5.10{sup -8}E{sup -2} GeVs{sup -1}sr{sup -1}cm{sup -2} is reached, which is valid for a diffuse electron neutrino flux proportional to E{sup -2} in the energy range from 16 TeV to 13 PeV. Sensitivity is defined as the upper limit that could be set in absence of a signal at 90% confidence level. Including all neutrino flavors in this analysis, an improvement of at least one order of magnitude is expected, reaching the anticipated performance of a diffuse muon analysis. (orig.)

  9. Factorization of Chiral String Amplitudes

    CERN Document Server

    Huang, Yu-tin; Yuan, Ellis Ye

    2016-01-01

    We re-examine a closed-string model defined by altering the boundary conditions for one handedness of two-dimensional propagators in otherwise-standard string theory. We evaluate the amplitudes using Kawai-Lewellen-Tye factorization into open-string amplitudes. The only modification to standard string theory is effectively that the spacetime Minkowski metric changes overall sign in one open-string factor. This cancels all but a finite number of states: As found in earlier approaches, with enough supersymmetry (e.g., type II) the tree amplitudes reproduce those of the massless truncation of ordinary string theory. However, we now find for the other cases that additional fields, formerly thought to be auxiliary, describe new spin-2 states at the two adjacent mass levels (tachyonic and tardyonic). The tachyon is always a ghost, but can be avoided in the heterotic case.

  10. Factorization of chiral string amplitudes

    Science.gov (United States)

    Huang, Yu-tin; Siegel, Warren; Yuan, Ellis Ye

    2016-09-01

    We re-examine a closed-string model defined by altering the boundary conditions for one handedness of two-dimensional propagators in otherwise-standard string theory. We evaluate the amplitudes using Kawai-Lewellen-Tye factorization into open-string amplitudes. The only modification to standard string theory is effectively that the spacetime Minkowski metric changes overall sign in one open-string factor. This cancels all but a finite number of states: as found in earlier approaches, with enough supersymmetry (e.g., type II) the tree amplitudes reproduce those of the massless truncation of ordinary string theory. However, we now find for the other cases that additional fields, formerly thought to be auxiliary, describe new spin-2 states at the two adjacent mass levels (tachyonic and tardyonic). The tachyon is always a ghost, but can be avoided in the heterotic case.

  11. Shape of Pion Distribution Amplitude

    Energy Technology Data Exchange (ETDEWEB)

    Radyushkin, Anatoly

    2009-11-01

    A scenario is investigated in which the leading-twist pion distribution amplitude $\\varphi_\\pi (x)$ is approximated by the pion decay constant $f_\\pi$ for all essential values of the light-cone fraction $x$. A model for the light-front wave function $\\Psi (x, k_\\perp)$ is proposed that produces such a distribution amplitude and has a rapidly decreasing (exponential for definiteness) dependence on the light-front energy combination $ k_\\perp^2/x(1-x)$. It is shown that this model easily reproduces the fit of recent large-$Q^2$ BaBar data on the photon-pion transition form factor. Some aspects of scenario with flat pion distribution amplitude are discussed.

  12. Nonsinglet pentagons and NMHV amplitudes

    Directory of Open Access Journals (Sweden)

    A.V. Belitsky

    2015-07-01

    Full Text Available Scattering amplitudes in maximally supersymmetric gauge theory receive a dual description in terms of the expectation value of the super Wilson loop stretched on a null polygonal contour. This makes the analysis amenable to nonperturbative techniques. Presently, we elaborate on a refined form of the operator product expansion in terms of pentagon transitions to compute twist-two contributions to NMHV amplitudes. To start with, we provide a novel derivation of scattering matrices starting from Baxter equations for flux-tube excitations propagating on magnon background. We propose bootstrap equations obeyed by pentagon form factors with nonsinglet quantum numbers with respect to the R-symmetry group and provide solutions to them to all orders in 't Hooft coupling. These are then successfully confronted against available perturbative calculations for NMHV amplitudes to four-loop order.

  13. Traumatic Life Events and Psychopathology in a High Risk, Ethnically Diverse Sample of Young Children: A Person-Centered Approach.

    Science.gov (United States)

    Hagan, Melissa J; Sulik, Michael J; Lieberman, Alicia F

    2016-07-01

    Studies of the association between traumatic experiences and psychopathology in early childhood have primarily focused on specific types of events (e.g., sexual abuse) or aggregated different types of events without differentiating among them. We extend this body of work by investigating patterns of traumatic event exposure in a high-risk, ethnically diverse sample of children ages 3-6 (N = 211; 51 % female) and relating these different patterns to parents' reports of child externalizing, internalizing, and post-traumatic stress symptomatology. Using latent class analysis, which divides a heterogeneous population into homogenous subpopulations, we identified three patterns of traumatic events based on parents' responses to an interview-based assessment of trauma exposure in young children: (1) severe exposure, characterized by a combination of family violence and victimization; (2) witnessing family violence without victimization; and (3) moderate exposure, characterized by an absence of family violence but a moderate probability of other events. The severe exposure class exhibited elevated internalizing and post-traumatic stress symptoms relative to the witness to violence and moderate exposure classes, controlling for average number of traumatic events. Results highlight the need for differentiation between profiles of traumatic life event exposure and the potential for person-centered methods to complement the cumulative risk perspective.

  14. Detection of a 1258 Hz high-amplitude kilohertz quasi-periodic oscillation in the ultra-compact X-ray binary 1A 1246-588

    CERN Document Server

    Jonker, P G; Méndez, M; Van der Klis, M

    2007-01-01

    We have observed the ultra-compact low-mass X-ray binary (LMXB) 1A 1246-588 with the Rossi X-ray Timing Explorer (RXTE). In this manuscript we report the discovery of a kilohertz quasi-periodic oscillation (QPO) in 1A 1246-588. The kilohertz QPO was only detected when the source was in a soft high-flux state reminiscent of the lower banana branch in atoll sources. Only one kilohertz QPO peak is detected at a relatively high frequency of 1258+-2 Hz and at a single trial significance of more than 7 sigma. Kilohertz QPOs with a higher frequency have only been found on two occasions in 4U 0614+09. Furthermore, the frequency is higher than that found for the lower kilohertz QPO in any source, strongly suggesting that the QPO is the upper of the kilohertz QPO pair often found in LMXBs. The full-width at half maximum is 25+-4 Hz, making the coherence the highest found for an upper kilohertz QPO. From a distance estimate of ~6 kpc from a radius expansion burst we derive that 1A 1246-588 is at a persistent flux of ~0....

  15. Method of differential-phase/absolute-amplitude QAM

    Science.gov (United States)

    Dimsdle, Jeffrey William

    2007-07-17

    A method of quadrature amplitude modulation involving encoding phase differentially and amplitude absolutely, allowing for a high data rate and spectral efficiency in data transmission and other communication applications, and allowing for amplitude scaling to facilitate data recovery; amplitude scale tracking to track-out rapid and severe scale variations and facilitate successful demodulation and data retrieval; 2.sup.N power carrier recovery; incoherent demodulation where coherent carrier recovery is not possible or practical due to signal degradation; coherent demodulation; multipath equalization to equalize frequency dependent multipath; and demodulation filtering.

  16. Source geometry from exceptionally high resolution long period event observations at Mt Etna during the 2008 eruption

    CERN Document Server

    De Barros, Louis; Lokmer, Ivan; Saccorotti, Gilberto; Zucarello, Luciano; O'Brien, Gareth; Métaxian, Jean-Philippe; Patanè, Domenico; 10.1029/2009GL041273

    2010-01-01

    During the second half of June, 2008, 50 broadband seismic stations were deployed on Mt Etna volcano in close proximity to the summit, allowing us to observe seismic activity with exceptionally high resolution. 129 long period events (LP) with dominant frequencies ranging between 0.3 and 1.2 Hz, were extracted from this dataset. These events form two families of similar waveforms with different temporal distributions. Event locations are performed by cross-correlating signals for all pairs of stations in a two-step scheme. In the first step, the absolute location of the centre of the clusters was found. In the second step, all events are located using this position. The hypocentres are found at shallow depths (20 to 700 m deep) below the summit craters. The very high location resolution allows us to detect the temporal migration of the events along a dike-like structure and 2 pipe shaped bodies, yielding an unprecedented view of some elements of the shallow plumbing system at Mount Etna. These events do not s...

  17. ATLAS High Level Calorimeter Trigger Software Performance for Cosmic Ray Events

    CERN Document Server

    Oliveira Damazio, Denis; The ATLAS collaboration

    2009-01-01

    The ATLAS detector is undergoing intense commissioning effort with cosmic rays preparing for the first LHC collisions next spring. Combined runs with all of the ATLAS subsystems are being taken in order to evaluate the detector performance. This is an unique opportunity also for the trigger system to be studied with different detector operation modes, such as different event rates and detector configuration. The ATLAS trigger starts with a hardware based system which tries to identify detector regions where interesting physics objects may be found (eg: large energy depositions in the calorimeter system). An approved event will be further processed by more complex software algorithms at the second level where detailed features are extracted (full detector granularity data for small portions of the detector is available). Events accepted at this level will be further processed at the so-called event filter level. Full detector data at full granularity is available for offline like processing with complete calib...

  18. High Resolution Imagery of Buck Island Coral Reef Systems Prior to and During Suspected Bleaching Events

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset is a collection of imagery of Buck Island coral reef systems. They are pairs of imagery where one image was acquired during a suspected bleaching event....

  19. High cardiovascular event rates in patients with asymptomatic carotid stenosis: the REACH Registry

    DEFF Research Database (Denmark)

    Aichner, F T; Topakian, R; Alberts, M J

    2009-01-01

    BACKGROUND AND PURPOSE: Data on current cardiovascular event rates in patients with asymptomatic carotid artery stenosis (ACAS) are sparse. We compared the 1-year outcomes of patients with ACAS > or =70% versus patients without ACAS in an international, prospective cohort of outpatients.......26%, P = 0.04), cardiovascular death (2.29% vs. 1.52%, P = 0.002), the composite end-point cardiovascular death/myocardial infarction/stroke (6.03% vs. 4.29%, P events (1.41% vs. 0.81%, P = 0.002). In patients with ACAS, Cox regression analyses identified history of cerebrovascular...... ischaemic events as most important predictor of future stroke (HR 3.21, 95% CI 1.82-5.65, P events. Stroke was powerfully predicted by prior cerebrovascular...

  20. On the detectability of a predicted mesolensing event associated with the high proper motion star VB 10

    CERN Document Server

    Lepine, Sebastien

    2011-01-01

    Extrapolation of the astrometric motion of the nearby low-mass star VB 10 indicates that sometime in late December 2011 or early January 2012, the star will approach to within short angular distance of a background point source. Based on astrometric uncertainties, we estimate a 1 in 2 chance that the distance of closest approach rho_{min} will be less than 100 mas, a 1 in 5 chance that rho_{min} 0.3 AU) orbit, this planet could pass closer to the background source up to several weeks preceding or following the primary event, and produce a secondary event of significantly higher magnification (tens of percent or higher). The secondary events have timescales of several days but detectable, high-magnification peaks lasting only about 5-10 hours. We argue that an intensive, multi-site monitoring campaign using 1-meter class telescopes would be required to detect secondary events due to orbiting planets.

  1. High-energy Neutrino follow-up search of Gravitational Wave Event GW150914 with ANTARES and IceCube

    CERN Document Server

    Adrián-Martínez, S; André, M; Anton, G; Ardid, M; Aubert, J -J; Avgitas, T; Baret, B; Barrios-Martí, J; Basa, S; Bertin, V; Biagi, S; Bormuth, R; Bouwhuis, M C; Bruijn, R; Brunner, J; Busto, J; Capone, A; Caramete, L; Carr, J; Celli, S; Chiarusi, T; Circella, M; Coleiro, A; Coniglione, R; Costantini, H; Coyle, P; Creusot, A; Deschamps, A; De Bonis, G; Distefano, C; Donzaud, C; Dornic, D; Drouhin, D; Eberl, T; Bojaddaini, I El; Elsässer, D; Enzenhöfer, A; Fehn, K; Felis, I; Fusco, L A; Galatà, S; Gay, P; Geißelsöder, S; Geyer, K; Giordano, V; Gleixner, A; Glotin, H; Gracia-Ruiz, R; Graf, K; Hallmann, S; van Haren, H; Heijboer, A J; Hello, Y; Hernández-Rey, J J; Hößl, J; Hofestädt, J; Hugon, C; Illuminati, G; James, C W; de Jong, M; Jongen, M; Kadler, M; Kalekin, O; Katz, U; Kießling, D; Kouchner, A; Kreter, M; Kreykenbohm, I; Kulikovskiy, V; Lachaud, C; Lahmann, R; Lefèvre, D; Leonora, E; Loucatos, S; Marcelin, M; Margiotta, A; Marinelli, A; Martínez-Mora, J A; Mathieu, A; Melis, K; 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McIver, J; McManus, D J; McWilliams, S T; Meacher, D; Meadors, G D; Meidam, J; Melatos, A; Mendell, G; Mendoza-Gandara, D; Mercer, R A; Merilh, E; Merzougui, M; Meshkov, S; Messenger, C; Messick, C; Meyers, P M; Mezzani, F; Miao, H; Michel, C; Middleton, H; Mikhailov, E E; Milano, L; Miller, J; Millhouse, M; Minenkov, Y; Ming, J; Mirshekari, S; Mishra, C; Mitra, S; Mitrofanov, V P; Mitselmakher, G; Mittleman, R; Moggi, A; Mohan, M; Mohapatra, S R P; Montani, M; Moore, B C; Moore, C J; Moraru, D; Moreno, G; Morriss, S R; Mossavi, K; Mours, B; Mow-Lowry, C M; Mueller, C L; Mueller, G; Muir, A W; Mukherjee, Arunava; Mukherjee, D; Mukherjee, S; Mukund, N; Mullavey, A; Munch, J; Murphy, D J; Murray, P G; Mytidis, A; Nardecchia, I; Naticchioni, L; Nayak, R K; Necula, V; Nedkova, K; Nelemans, G; Neri, M; Neunzert, A; Newton, G; Nguyen, T T; Nielsen, A B; Nissanke, S; Nitz, A; Nocera, F; Nolting, D; Normandin, M E N; Nuttall, L K; Oberling, J; Ochsner, E; O'Dell, J; Oelker, E; Ogin, G H; Oh, J J; Oh, S H; Ohme, F; Oliver, M; Oppermann, P; Oram, Richard J; O'Reilly, B; O'Shaughnessy, R; Ott, C D; Ottaway, D J; Ottens, R S; Overmier, H; Owen, B J; Pai, A; Pai, S A; Palamos, J R; Palashov, O; Palomba, C; Pal-Singh, A; Pan, H; Pankow, C; Pannarale, F; Pant, B C; Paoletti, F; Paoli, A; Papa, M A; Paris, H R; Parker, W; Pascucci, D; Pasqualetti, A; Passaquieti, R; Passuello, D; Patricelli, B; Patrick, Z; Pearlstone, B L; Pedraza, M; Pedurand, R; Pekowsky, L; Pele, A; Penn, S; Perreca, A; Phelps, M; Piccinni, O; Pichot, M; Piergiovanni, F; Pierro, V; Pillant, G; Pinard, L; Pinto, I M; Pitkin, M; Poggiani, R; Popolizio, P; Post, A; Powell, J; Prasad, J; Predoi, V; Premachandra, S S; Prestegard, T; Price, L R; Prijatelj, M; Principe, M; Privitera, S; Prix, R; Prodi, G A; Prokhorov, L; Puncken, O; Punturo, M; Puppo, P; Pürrer, M; Qi, H; Qin, J; Quetschke, V; Quintero, E A; Quitzow-James, R; Raab, F J; Rabeling, D S; Radkins, H; Raffai, P; Raja, S; Rakhmanov, M; Rapagnani, P; Raymond, V; Razzano, M; Re, V; Read, J; Reed, C M; Regimbau, T; Rei, L; Reid, S; Reitze, D H; Rew, H; Reyes, S D; Ricci, F; Riles, K; Robertson, N A; Robie, R; Robinet, F; Rocchi, A; Rolland, L; Rollins, J G; Roma, V J; Romano, J D; Romano, R; Romanov, G; Romie, J H; Rosińska, D; Rowan, S; Rüdiger, A; Ruggi, P; Ryan, K; Sachdev, S; Sadecki, T; Sadeghian, L; Salconi, L; Saleem, M; Salemi, F; Samajdar, A; Sammut, L; Sanchez, E J; Sandberg, V; Sandeen, B; Sanders, J R; Sassolas, B; Sathyaprakash, B S; Saulson, P R; Sauter, O; Savage, R L; Sawadsky, A; Schale, P; Schilling, R; Schmidt, J; Schmidt, P; Schnabel, R; Schofield, R M S; Schönbeck, A; Schreiber, E; Schuette, D; Schutz, B F; Scott, J; Scott, S M; Sellers, D; Sengupta, A S; Sentenac, D; Sequino, V; Sergeev, A; Serna, G; Setyawati, Y; Sevigny, A; Shaddock, D A; Shah, S; Shahriar, M S; Shaltev, M; Shao, Z; Shapiro, B; Shawhan, P; Sheperd, A; Shoemaker, D H; Shoemaker, D M; Siellez, K; Siemens, X; Sigg, D; Silva, A D; Simakov, D; Singer, A; Singer, L P; Singh, A; Singh, R; Singhal, A; Sintes, A M; Slagmolen, B J J; Smith, J R; Smith, N D; Smith, R J E; Son, E J; Sorazu, B; Sorrentino, F; Souradeep, T; Srivastava, A K; Staley, A; Steinke, M; Steinlechner, J; Steinlechner, S; Steinmeyer, D; Stephens, B C; Stone, R; Strain, K A; Straniero, N; Stratta, G; Strauss, N A; Strigin, S; Sturani, R; Stuver, A L; Summerscales, T Z; Sun, L; Sutton, P J; Swinkels, B L; Szczepańczyk, M J; Tacca, M; Talukder, D; Tanner, D B; Tápai, M; Tarabrin, S P; Taracchini, A; Taylor, R; Theeg, T; Thirugnanasambandam, M P; Thomas, E G; Thomas, M; Thomas, P; Thorne, K A; Thorne, K S; Thrane, E; Tiwari, S; Tiwari, V; Tokmakov, K V; Tomlinson, C; Tonelli, M; Torres, C V; Torrie, C I; Töyrä, D; Travasso, F; Traylor, G; Trifirò, D; Tringali, M C; Trozzo, L; Tse, M; Turconi, M; Tuyenbayev, D; Ugolini, D; Unnikrishnan, C S; Urban, A L; Usman, S A; Vahlbruch, H; Vajente, G; Valdes, G; van Bakel, N; van Beuzekom, M; Brand, J F J van den; Broeck, C Van Den; Vander-Hyde, D C; van der Schaaf, L; van Heijningen, J V; van Veggel, A A; Vardaro, M; Vass, S; Vasúth, M; Vaulin, R; Vecchio, A; Vedovato, G; Veitch, J; Veitch, P J; Venkateswara, K; Verkindt, D; Vetrano, F; Viceré, A; Vinciguerra, S; Vine, D J; Vinet, J -Y; Vitale, S; Vo, T; Vocca, H; Vorvick, C; Voss, D; Vousden, W D; Vyatchanin, S P; Wade, A R; Wade, L E; Wade, M; Walker, M; Wallace, L; Walsh, S; Wang, G; Wang, H; Wang, M; Wang, X; Wang, Y; Ward, R L; Warner, J; Was, M; Weaver, B; Wei, L -W; Weinert, M; Weinstein, A J; Weiss, R; Welborn, T; Wen, L; Weßels, P; Westphal, T; Wette, K; Whelan, J T; Whitcomb, %S E; White, D J; Whiting, B F; Williams, R D; Williamson, A R; Willis, J L; Willke, B; Wimmer, M H; Winkler, W; Wipf, C C; Wittel, H; Woan, G; Worden, J; Wright, J L; Wu, G; Yablon, J; Yam, W; Yamamoto, H; Yancey, C C; Yap, M J; Yu, H; Yvert, M; Zadrożny, A; Zangrando, L; Zanolin, M; Zendri, J -P; Zevin, M; Zhang, F; Zhang, L; Zhang, M; Zhang, Y; Zhao, C; Zhou, M; Zhou, Z; Zhu, X J; Zucker, M E; Zuraw, S E; Zweizig, J

    2016-01-01

    We present the high-energy-neutrino follow-up observations of the first gravitational wave transient GW150914 observed by the Advanced LIGO detectors on Sept. 14th, 2015. We search for coincident neutrino candidates within the data recorded by the IceCube and ANTARES neutrino detectors. A possible joint detection could be used in targeted electromagnetic follow-up observations, given the significantly better angular resolution of neutrino events compared to gravitational waves. We find no neutrino candidates in both temporal and spatial coincidence with the gravitational wave event. Within 500 s of the gravitational wave event, the number of neutrino candidates detected by IceCube and ANTARES were three and zero, respectively. This is consistent with the expected atmospheric background, and none of the neutrino candidates were directionally coincident with GW150914. We use this non-detection to constrain neutrino emission from the gravitational-wave event.

  2. High-energy neutrino follow-up search of gravitational wave event GW150914 with ANTARES and IceCube

    Science.gov (United States)

    Adrián-Martínez, S.; Albert, A.; André, M.; Anghinolfi, M.; Anton, G.; Ardid, M.; Aubert, J.-J.; Avgitas, T.; Baret, B.; Barrios-Martí, J.; Basa, S.; Bertin, V.; Biagi, S.; Bormuth, R.; Bouwhuis, M. C.; Bruijn, R.; Brunner, J.; Busto, J.; Capone, A.; Caramete, L.; Carr, J.; Celli, S.; Chiarusi, T.; Circella, M.; Coleiro, A.; Coniglione, R.; Costantini, H.; Coyle, P.; Creusot, A.; Deschamps, A.; De Bonis, G.; Distefano, C.; Donzaud, C.; Dornic, D.; Drouhin, D.; Eberl, T.; El Bojaddaini, I.; Elsässer, D.; Enzenhöfer, A.; Fehn, K.; Felis, I.; Fusco, L. A.; Galatà, S.; Gay, P.; Geißelsöder, S.; Geyer, K.; Giordano, V.; Gleixner, A.; Glotin, H.; Gracia-Ruiz, R.; Graf, K.; Hallmann, S.; van Haren, H.; Heijboer, A. J.; Hello, Y.; Hernández-Rey, J. J.; Hößl, J.; Hofestädt, J.; Hugon, C.; Illuminati, G.; James, C. W.; de Jong, M.; Jongen, M.; Kadler, M.; Kalekin, O.; Katz, U.; Kießling, D.; Kouchner, A.; Kreter, M.; Kreykenbohm, I.; Kulikovskiy, V.; Lachaud, C.; Lahmann, R.; Lefèvre, D.; Leonora, E.; Loucatos, S.; Marcelin, M.; Margiotta, A.; Marinelli, A.; Martínez-Mora, J. A.; Mathieu, A.; Melis, K.; Michael, T.; Migliozzi, P.; Moussa, A.; Mueller, C.; Nezri, E.; Pǎvǎlaş, G. E.; Pellegrino, C.; Perrina, C.; Piattelli, P.; Popa, V.; Pradier, T.; Racca, C.; Riccobene, G.; Roensch, K.; Saldaña, M.; Samtleben, D. F. E.; Sánchez-Losa, A.; Sanguineti, M.; Sapienza, P.; Schnabel, J.; Schüssler, F.; Seitz, T.; Sieger, C.; Spurio, M.; Stolarczyk, Th.; Taiuti, M.; Trovato, A.; Tselengidou, M.; Turpin, D.; Tönnis, C.; Vallage, B.; Vallée, C.; Van Elewyck, V.; Vivolo, D.; Wagner, S.; Wilms, J.; Zornoza, J. D.; Zúñiga, J.; Aartsen, M. G.; Abraham, K.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Ahrens, M.; Altmann, D.; Anderson, T.; Ansseau, I.; Anton, G.; Archinger, M.; Arguelles, C.; Arlen, T. C.; Auffenberg, J.; Bai, X.; Barwick, S. W.; Baum, V.; Bay, R.; Beatty, J. J.; Becker Tjus, J.; Becker, K.-H.; Beiser, E.; BenZvi, S.; Berghaus, P.; Berley, D.; Bernardini, E.; Bernhard, A.; Besson, D. Z.; Binder, G.; Bindig, D.; Bissok, M.; Blaufuss, E.; Blumenthal, J.; Boersma, D. J.; Bohm, C.; Börner, M.; Bos, F.; Bose, D.; Böser, S.; Botner, O.; Braun, J.; Brayeur, L.; Bretz, H.-P.; Buzinsky, N.; Casey, J.; Casier, M.; Cheung, E.; Chirkin, D.; Christov, A.; Clark, K.; Classen, L.; Coenders, S.; Collin, G. H.; Conrad, J. M.; Cowen, D. F.; Cruz Silva, A. H.; Daughhetee, J.; Davis, J. C.; Day, M.; de André, J. P. A. M.; De Clercq, C.; del Pino Rosendo, E.; Dembinski, H.; De Ridder, S.; Desiati, P.; de Vries, K. D.; de Wasseige, G.; de With, M.; DeYoung, T.; Díaz-Vélez, J. C.; di Lorenzo, V.; Dujmovic, H.; Dumm, J. P.; Dunkman, M.; Eberhardt, B.; Ehrhardt, T.; Eichmann, B.; Euler, S.; Evenson, P. A.; Fahey, S.; Fazely, A. R.; Feintzeig, J.; Felde, J.; Filimonov, K.; Finley, C.; Flis, S.; Fösig, C.-C.; Fuchs, T.; Gaisser, T. K.; Gaior, R.; Gallagher, J.; Gerhardt, L.; Ghorbani, K.; Gier, D.; Gladstone, L.; Glagla, M.; Glüsenkamp, T.; Goldschmidt, A.; Golup, G.; Gonzalez, J. G.; Góra, D.; Grant, D.; Griffith, Z.; Ha, C.; Haack, C.; Haj Ismail, A.; Hallgren, A.; Halzen, F.; Hansen, E.; Hansmann, B.; Hansmann, T.; Hanson, K.; Hebecker, D.; Heereman, D.; Helbing, K.; Hellauer, R.; Hickford, S.; Hignight, J.; Hill, G. C.; Hoffman, K. D.; Hoffmann, R.; Holzapfel, K.; Homeier, A.; Hoshina, K.; Huang, F.; Huber, M.; Huelsnitz, W.; Hulth, P. O.; Hultqvist, K.; In, S.; Ishihara, A.; Jacobi, E.; Japaridze, G. S.; Jeong, M.; Jero, K.; Jones, B. J. P.; Jurkovic, M.; Kappes, A.; Karg, T.; Karle, A.; Katz, U.; Kauer, M.; Keivani, A.; Kelley, J. L.; Kemp, J.; Kheirandish, A.; Kim, M.; Kintscher, T.; Kiryluk, J.; Klein, S. R.; Kohnen, G.; Koirala, R.; Kolanoski, H.; Konietz, R.; Köpke, L.; Kopper, C.; Kopper, S.; Koskinen, D. J.; Kowalski, M.; Krings, K.; Kroll, G.; Kroll, M.; Krückl, G.; Kunnen, J.; Kunwar, S.; Kurahashi, N.; Kuwabara, T.; Labare, M.; Lanfranchi, J. L.; Larson, M. J.; Lennarz, D.; Lesiak-Bzdak, M.; Leuermann, M.; Leuner, J.; Lu, L.; Lünemann, J.; Madsen, J.; Maggi, G.; Mahn, K. B. M.; Mandelartz, M.; Maruyama, R.; Mase, K.; Matis, H. S.; Maunu, R.; McNally, F.; Meagher, K.; Medici, M.; Meier, M.; Meli, A.; Menne, T.; Merino, G.; Meures, T.; Miarecki, S.; Middell, E.; Mohrmann, L.; Montaruli, T.; Morse, R.; Nahnhauer, R.; Naumann, U.; Neer, G.; Niederhausen, H.; Nowicki, S. C.; Nygren, D. R.; Obertacke Pollmann, A.; Olivas, A.; Omairat, A.; O'Murchadha, A.; Palczewski, T.; Pandya, H.; Pankova, D. V.; Paul, L.; Pepper, J. A.; Pérez de los Heros, C.; Pfendner, C.; Pieloth, D.; Pinat, E.; Posselt, J.; Price, P. B.; Przybylski, G. T.; Quinnan, M.; Raab, C.; Rädel, L.; Rameez, M.; Rawlins, K.; Reimann, R.; Relich, M.; Resconi, E.; Rhode, W.; Richman, M.; Richter, S.; Riedel, B.; Robertson, S.

    2016-06-01

    We present the high-energy-neutrino follow-up observations of the first gravitational wave transient GW150914 observed by the Advanced LIGO detectors on September 14, 2015. We search for coincident neutrino candidates within the data recorded by the IceCube and Antares neutrino detectors. A possible joint detection could be used in targeted electromagnetic follow-up observations, given the significantly better angular resolution of neutrino events compared to gravitational waves. We find no neutrino candidates in both temporal and spatial coincidence with the gravitational wave event. Within ±500 s of the gravitational wave event, the number of neutrino candidates detected by IceCube and Antares were three and zero, respectively. This is consistent with the expected atmospheric background, and none of the neutrino candidates were directionally coincident with GW150914. We use this nondetection to constrain neutrino emission from the gravitational-wave event.

  3. High-cadence observations of spicular-type events on the Sun

    Science.gov (United States)

    Shetye, J.; Doyle, J. G.; Scullion, E.; Nelson, C. J.; Kuridze, D.; Henriques, V.; Woeger, F.; Ray, T.

    2016-05-01

    Context. Chromospheric observations taken at high-cadence and high-spatial resolution show a range of spicule-like features, including Type-I, Type-II (as well as rapid blue-shifted excursions (RBEs) and rapid red-shifted excursions (RREs) which are thought to be on-disk counterparts of Type-II spicules) and those which seem to appear within a few seconds, which if interpreted as flows would imply mass flow velocities in excess of 1000 km s-1. Aims: This article seeks to quantify and study rapidly appearing spicular-type events. We also compare the multi-object multi-frame blind deconvolution (MOMFBD) and speckle reconstruction techniques to understand if these spicules are more favourably observed using a particular technique. Methods: We use spectral imaging observations taken with the CRisp Imaging SpectroPolarimeter (CRISP) on the Swedish 1-m Solar Telescope. Data was sampled at multiple positions within the Hα line profile for both an on-disk and limb location. Results: The data is host to numerous rapidly appearing features which are observed at different locations within the Hα line profile. The feature's durations vary between 10-20 s and lengths around 3500 km. Sometimes, a time delay in their appearance between the blue and red wings of 3-5 s is evident, whereas, sometimes they are near simultaneous. In some instances, features are observed to fade and then re-emerge at the same location several tens of seconds later. Conclusions: We provide the first statistical analysis of these spicules and suggest that these observations can be interpreted as the line-of-sight (LOS) movement of highly dynamic spicules moving in and out of the narrow 60 mÅ transmission filter that is used to observe in different parts of the Hα line profile. The LOS velocity component of the observed fast chromospheric features, manifested as Doppler shifts, are responsible for their appearance in the red and blue wings of Hα line. Additional work involving data at other

  4. LEONA: Transient Luminous Event and Thunderstorm High Energy Emission Collaborative Network in Latin America

    Science.gov (United States)

    Sao Sabbas, F. T.

    2012-12-01

    This project has the goal of establishing the Collaborative Network LEONA, to study the electrodynamical coupling of the atmospheric layers signaled by Transient Luminous Events - TLEs and high energy emissions from thunderstorms. We will develop and install a remotely controlled network of cameras to perform TLE observations in different locations in South America and one neutron detector in southern Brazil. The camera network will allow building a continuous data set of the phenomena studied in this continent. The first two trial units of the camera network are already installed, in Brazil and Peru, and two more will be installed until December 2012, in Argentina and Brazil. We expect to determine the TLE geographic distribution, occurrence rate, morphology, and possible coupling with other geophysical phenomena in South America, such as the South Atlantic Magnetic Anomaly - SAMA. We also expect to study thunderstorm neutron emissions in a region of intense electrical activity, measuring neutron fluxes with high time resolution simultaneously with TLEs and lightning for the first time in South America. Using an intensified high-speed camera for TLE observation during 2 campaigns we expect to be able to determine the duration and spatial- temporal development of the TLEs observed, to study the structure and initiation of sprites and to measure the velocity of development of sprite structures and the sprite delay. The camera was acquired via the FAPESP project DEELUMINOS (2005-2010), which also nucleated our research group Atmospheric Electrodynamical Coupling - ACATMOS. LEONA will nucleate this research in other institutions in Brazil and other countries in South America, providing continuity for this important research in our region. The camera network will be an unique tool to perform consistent long term TLE observation, and in fact is the only way to accumulate a data set for a climatological study of South America, since satellite instrumentation turns off in

  5. Continuous and discrete extreme climatic events affecting the dynamics of a high-arctic reindeer population.

    Science.gov (United States)

    Chan, Kung-Sik; Mysterud, Atle; Øritsland, Nils Are; Severinsen, Torbjørn; Stenseth, Nils Chr

    2005-10-01

    Climate at northern latitudes are currently changing both with regard to the mean and the temporal variability at any given site, increasing the frequency of extreme events such as cold and warm spells. Here we use a conceptually new modelling approach with two different dynamic terms of the climatic effects on a Svalbard reindeer population (the Brøggerhalvøya population) which underwent an extreme icing event ("locked pastures") with 80% reduction in population size during one winter (1993/94). One term captures the continuous and linear effect depending upon the Arctic Oscillation and another the discrete (rare) "event" process. The introduction of an "event" parameter describing the discrete extreme winter resulted in a more parsimonious model. Such an approach may be useful in strongly age-structured ungulate populations, with young and very old individuals being particularly prone to mortality factors during adverse conditions (resulting in a population structure that differs before and after extreme climatic events). A simulation study demonstrates that our approach is able to properly detect the ecological effects of such extreme climate events.

  6. Abrupt Changes at the Permian/Triassic Boundary: Tempo of Events from High-Resolution Cyclostratigraphy

    Science.gov (United States)

    Rampino, M. R.; Prokoph, A.; Adler, A. C.

    2000-01-01

    the nearby Reppwand outcrop section, the same faunal changes occurs over only 0.8 m or about 8,000 years, close to the limit of time-resolution induced by bioturbation and reworking in these sediments. The sharp negative global carbon-isotope shift took place within less than or equal to 40,000 yr, and the isotope excursions persisted for approximately 480,000 yr into the Early Triassic. The results indicate that the severe marine faunal event that marks the P/Tr boundary was very sudden, perhaps less than the resolution window in the GK-1 core, and suggest a catastrophic cause. The wavelet-analysis approach to high-resolution cyclostratigraphy can be applied to other P/Tr boundary sections, and when combined with precise absolute dating and magnetostratigraphic methods promises a significant increase in resolution in determining the correlation and tempo of the end-Permian extinctions and related events worldwide.

  7. Quantitative laryngeal electromyography: turns and amplitude analysis.

    Science.gov (United States)

    Statham, Melissa McCarty; Rosen, Clark A; Nandedkar, Sanjeev D; Munin, Michael C

    2010-10-01

    Laryngeal electromyography (LEMG) is primarily a qualitative examination, with no standardized approach to interpretation. The objectives of our study were to establish quantitative norms for motor unit recruitment in controls and to compare with interference pattern analysis in patients with unilateral vocal fold paralysis (VFP). Retrospective case-control study We performed LEMG of the thyroarytenoid-lateral cricoarytenoid muscle complex (TA-LCA) in 21 controls and 16 patients with unilateral VFP. Our standardized protocol used a concentric needle electrode with subjects performing variable force TA-LCA contraction. To quantify the interference pattern density, we measured turns and mean amplitude per turn for ≥10 epochs (each 500 milliseconds). Logarithmic regression analysis between amplitude and turns was used to calculate slope and intercept. Standard deviation was calculated to further define the confidence interval, enabling generation of a linear-scale graphical "cloud" of activity containing ≥90% of data points for controls and patients. Median age of controls and patients was similar (50.7 vs. 48.5 years). In controls, TA-LCA amplitude with variable contraction ranged from 145-1112 μV, and regression analysis comparing mean amplitude per turn to root-mean-square amplitude demonstrated high correlation (R = 0.82). In controls performing variable contraction, median turns per second was significantly higher compared to patients (450 vs. 290, P = .002). We first present interference pattern analysis in the TA-LCA in healthy adults and patients with unilateral VFP. Our findings indicate that motor unit recruitment can be quantitatively measured within the TA-LCA. Additionally, patients with unilateral VFP had significantly reduced turns when compared with controls.

  8. High-cadence observations of spicular-type events and their wave-signatures

    Science.gov (United States)

    Shetye, Juie

    2016-05-01

    We present, a statistical study of spectral images, taken from the CRISP instrument at the Swedish 1-m Solar Telescope in H-alpha 656.28 nm of fast spicules with Doppler velocities in the range of -41km/s to +41 km/s. Remarkably, many of these spicules display apparent velocities above 500 km/s, very short lifetimes of up to 20 s combined with width or thickness of 100 km and apparent lengths of around 3500 km. Here we present, the other spectral properties of these events in the H-alpha line scan. Most features showed signature in multiple line position as we scan along the line scan. In around 89 % of the cases, there is temporal offset by 3.7 s to 5 s between the red-wing and blue-wing signatures. Another result is that 25% of cases are repetitive i.e. appear at the same location but they are not co-temporal or necessarily periodic in nature. Putting all the evidence together, we interpret the observations as mass motions (of flux tubes) that appear in the field-of-view of CRISP’s 0.0060 nm filters in the line of sight, along their projection as we scan. Further we observed transverse motion associated with these structures, which in some cases could be related to high-frequency kink-waves. We describe some cases showing this motion and the energies associated with them. The current work presented already tests the limits of current telescopes in terms of the temporal and spatial resolution. DKIST VTF instrument, having 3 times more spatial resolution than CRISP and much higher temporal resolution, we can being to understand the nature of such fine-scale transient phenomena in greater details.

  9. Recharge heterogeneity and high intensity rainfall events increase contamination risk for Mediterranean groundwater resources

    Science.gov (United States)

    Hartmann, Andreas; Jasechko, Scott; Gleeson, Tom; Wada, Yoshihide; Andreo, Bartolomé; Barberá, Juan Antonio; Brielmann, Heike; Charlier, Jean-Baptiste; Darling, George; Filippini, Maria; Garvelmann, Jakob; Goldscheider, Nico; Kralik, Martin; Kunstmann, Harald; Ladouche, Bernard; Lange, Jens; Mudarra, Matías; Francisco Martín, José; Rimmer, Alon; Sanchez, Damián; Stumpp, Christine; Wagener, Thorsten

    2017-04-01

    Karst develops through the dissolution of carbonate rock and results in pronounced spatiotemporal heterogeneity of hydrological processes. Karst groundwater in Europe is a major source of fresh water contributing up to half of the total drinking water supply in some countries like Austria or Slovenia. Previous work showed that karstic recharge processes enhance and alter the sensitivity of recharge to climate variability. The enhanced preferential flow from the surface to the aquifer may be followed by enhanced risk of groundwater contamination. In this study we assess the contamination risk of karst aquifers over Europe and the Mediterranean using simulated transit time distributions. Using a new type of semi-distributed model that considers the spatial heterogeneity of karst hydraulic properties, we were able to simulate karstic groundwater recharge including its heterogeneous spatiotemporal dynamics. The model is driven by gridded daily climate data from the Global Land Data Assimilation System (GLDAS). Transit time distributions are calculated using virtual tracer experiments. We evaluated our simulations by independent information on transit times derived from observed time series of water isotopes of >70 karst springs over Europe. The simulations indicate that, compared to humid, mountain and desert regions, the Mediterranean region shows a stronger risk of contamination in Europe because preferential flow processes are most pronounced given thin soil layers and the seasonal abundance of high intensity rainfall events in autumn and winter. Our modelling approach includes strong simplifications and its results cannot easily be generalized but it still highlights that the combined effects of variable climate and heterogeneous catchment properties constitute a strong risk on water quality.

  10. A High-Resolution Porphyrin Nitrogen Isotope Record of an Oceanic Anoxic Event

    Science.gov (United States)

    Pearson, A.; Higgins, M. B.; Robinson, R. S.; Carter, S. J.

    2010-12-01

    Nitrogen isotope values measured in sediments deposited at times of widespread marine suboxic conditions are consistently more depleted in 15N than are modern marine sediments. We measured a high-resolution δ15N record of sedimentary porphyrins from a section spanning the Cenomanian-Turonian Oceanic Anoxic Event (OAE) II to examine changes in the nitrogen cycle recorded in surface waters. We compare these values to δ15N values of three sedimentary fractions: bulk sediment, extractable organic matter (bitumen), and non-extractable organic matter (kerogen). All fractions record similar trends; are offset from each other by consistent differences that are reflective of algal (not cyanobacterial) export; and are depleted in 15N compared to modern sedimentary samples, both before, during, and after the interval defined by the OAE. Prior to the termination of OAE II, there is a slight further negative excursion in δ15N values. In order to interpret these and other depleted δ15N values measured in similar black shales, we invoke a nitrogen isotope model that considers the importance of redox transformations of N under suboxic conditions. This model invokes an ocean in which the deep N reservoir is dominated by NH4+, limited nitrification occurs in the photic zone, and chemocline denitrification acts as a quantitative sink for downwelling nitrate. Although in this model a large component of net production may be fueled by N fixation, N fixation alone cannot generate biomass with δ15N values as depleted as are seen in many Mesozoic OAE sections. We postulate that throughout the Phanerozoic, excursions leading to negative values of d15N reflect relatively low rates of nitrosification relative to the sum of NH4+ utilization and N fixation.

  11. Extreme climatic events: impacts of drought and high temperature on physiological processes in agronomically important plants

    Directory of Open Access Journals (Sweden)

    Urs eFeller

    2014-10-01

    Full Text Available Climate models predict more frequent and more severe extreme events (e.g. heat waves, extended drought periods, flooding in many regions for the next decades. The impact of adverse environmental conditions on crop plants is ecologically and economically relevant. This review is focused on drought and heat effects on physiological status and productivity of agronomically important plants. Stomatal opening represents an important regulatory mechanism during drought and heat stress since it influences simultaneously water loss via transpiration and CO2 diffusion into the leaf apoplast which further is utilized in photosynthesis. Along with the reversible short-term control of stomatal opening, stomata and leaf epidermis may produce waxy deposits and irreversibly down-regulate the stomatal conductance and non-stomatal transpiration. As a consequence photosynthesis will be negatively affected. Rubisco activase - a key enzyme in keeping the Calvin cycle functional – is heat-sensitive and may become a limiting factor at elevated temperature. The accumulated reactive oxygen species during stress represent an additional challenge under unfavorable conditions. Drought and heat cause accumulation of free amino acids which are partially converted into compatible solutes such as proline. This is accompanied by lower rates of both nitrate reduction and de novo amino acid biosynthesis. Protective proteins (e.g. dehydrins, chaperones, antioxidant enzymes or the key enzyme for proline biosynthesis play an important role in leaves and may be present at higher levels under water deprivation or high temperatures. On the whole plant level, effects on long-distance translocation of solutes via xylem and phloem and on leaf senescence (e.g. anticipated, accelerated or delayed senescence are important. The factors mentioned above are relevant for the overall performance of crops under drought and heat and must be considered for genotype selection and breeding programs.

  12. Dynamics of the MAP IOP 15 severe Mistral event: Observations and high-resolution numerical simulations

    Science.gov (United States)

    Guénard, V.; Drobinski, P.; Caccia, J. L.; Tedeschi, G.; Currier, P.

    2006-04-01

    This paper investigates the fundamental processes involved in a severe Mistral event that occurred during the Mesoscale Alpine Program (from 6 to 9 November 1999). The Mistral refers to a violent north/north-westerly wind blowing in south-eastern France from the Rhône valley to the French Riviera. The study is based on measurements from radiosoundings launched from Lyon and Nîmes and from two UHF wind profilers located near Marseille and Toulon allowing a good description of the flow in the complex terrain formed by the south-western Alps. Observational results are compared with RAMS non-hydrostatic numerical simulations performed with 27 km, 9 km and 3 km nested grids. The numerical simulations capture the flow complexity both upstream of the Alps and in the coastal area affected by the Mistral. They correctly reproduce horizontal wind speeds and directions, vertical velocities, virtual potential temperature and relative humidity documented by the observational network. The simulations are used to point out the main dynamical processes generating the Mistral. It is found that flow splitting around the Alps and around the isolated peaks bordering the south-eastern part of the Rhône valley (Mont Ventoux 1909 m, Massif du Lubéron 1425 m) induces the low-level jet observed near Marseille that lasts for 36 hours. The high-resolution simulation indicates that the transient low-level jet lasting for only 9 hours observed at Toulon is due to a gravity wave breaking over local topography (the Sainte Baume 1147 m) where hydraulic jumps are involved. A mountain wake with two opposite-sign potential-vorticity banners is generated. The mesoscale wake explains the westward progression of the large-scale Alpine wake.

  13. Ketamine Dysregulates the Amplitude and Connectivity of High-Frequency Oscillations in Cortical-Subcortical Networks in Humans: Evidence From Resting-State Magnetoencephalography-Recordings.

    Science.gov (United States)

    Rivolta, Davide; Heidegger, Tonio; Scheller, Bertram; Sauer, Andreas; Schaum, Michael; Birkner, Katharina; Singer, Wolf; Wibral, Michael; Uhlhaas, Peter J

    2015-09-01

    Hypofunctioning of the N-methyl-D-aspartate receptor (NMDA-R) has been prominently implicated in the pathophysiology of schizophrenia (ScZ). The current study tested the effects of ketamine, a dissociative anesthetic and NMDA-R antagonist, on resting-state activity recorded with magnetoencephalography (MEG) in healthy volunteers. In a single-blind cross-over design, each participant (n = 12) received, on 2 different sessions, a subanesthetic dose of S-ketamine (0.006 mg/Kg) and saline injection. MEG-data were analyzed at sensor- and source-level in the beta (13-30 Hz) and gamma (30-90 Hz) frequency ranges. In addition, connectivity analysis at source-level was performed using transfer entropy (TE). Ketamine increased gamma-power while beta-band activity was decreased. Specifically, elevated 30-90 Hz activity was pronounced in subcortical (thalamus and hippocampus) and cortical (frontal and temporal cortex) regions, whilst reductions in beta-band power were localized to the precuneus, cerebellum, anterior cingulate, temporal and visual cortex. TE analysis demonstrated increased information transfer in a thalamo-cortical network after ketamine administration. The findings are consistent with the pronounced dysregulation of high-frequency oscillations following the inhibition of NMDA-R in animal models of ScZ as well as with evidence from electroencephalogram-data in ScZ-patients and increased functional connectivity during early illness stages. Moreover, our data highlight the potential contribution of thalamo-cortical connectivity patterns towards ketamine-induced neuronal dysregulation, which may be relevant for the understanding of ScZ as a disorder of disinhibition of neural circuits.

  14. Ketamine Dysregulates the Amplitude and Connectivity of High-Frequency Oscillations in Cortical–Subcortical Networks in Humans: Evidence From Resting-State Magnetoencephalography-Recordings

    Science.gov (United States)

    Rivolta, Davide; Heidegger, Tonio; Scheller, Bertram; Sauer, Andreas; Schaum, Michael; Birkner, Katharina; Singer, Wolf; Wibral, Michael; Uhlhaas, Peter J.

    2015-01-01

    Hypofunctioning of the N-methyl-D-aspartate receptor (NMDA-R) has been prominently implicated in the pathophysiology of schizophrenia (ScZ). The current study tested the effects of ketamine, a dissociative anesthetic and NMDA-R antagonist, on resting-state activity recorded with magnetoencephalography (MEG) in healthy volunteers. In a single-blind cross-over design, each participant (n = 12) received, on 2 different sessions, a subanesthetic dose of S-ketamine (0.006mg/Kg) and saline injection. MEG-data were analyzed at sensor- and source-level in the beta (13–30 Hz) and gamma (30–90 Hz) frequency ranges. In addition, connectivity analysis at source-level was performed using transfer entropy (TE). Ketamine increased gamma-power while beta-band activity was decreased. Specifically, elevated 30–90 Hz activity was pronounced in subcortical (thalamus and hippocampus) and cortical (frontal and temporal cortex) regions, whilst reductions in beta-band power were localized to the precuneus, cerebellum, anterior cingulate, temporal and visual cortex. TE analysis demonstrated increased information transfer in a thalamo-cortical network after ketamine administration. The findings are consistent with the pronounced dysregulation of high-frequency oscillations following the inhibition of NMDA-R in animal models of ScZ as well as with evidence from electroencephalogram-data in ScZ-patients and increased functional connectivity during early illness stages. Moreover, our data highlight the potential contribution of thalamo-cortical connectivity patterns towards ketamine-induced neuronal dysregulation, which may be relevant for the understanding of ScZ as a disorder of disinhibition of neural circuits. PMID:25987642

  15. Employing Helicity Amplitudes for Resummation

    CERN Document Server

    Moult, Ian; Tackmann, Frank J; Waalewijn, Wouter J

    2015-01-01

    Many state-of-the-art QCD calculations for multileg processes use helicity amplitudes as their fundamental ingredients. We construct a simple and easy-to-use helicity operator basis in soft-collinear effective theory (SCET), for which the hard Wilson coefficients from matching QCD onto SCET are directly given in terms of color-ordered helicity amplitudes. Using this basis allows one to seamlessly combine fixed-order helicity amplitudes at any order they are known with a resummation of higher-order logarithmic corrections. In particular, the virtual loop amplitudes can be employed in factorization theorems to make predictions for exclusive jet cross sections without the use of numerical subtraction schemes to handle real-virtual infrared cancellations. We also discuss matching onto SCET in renormalization schemes with helicities in $4$- and $d$-dimensions. To demonstrate that our helicity operator basis is easy to use, we provide an explicit construction of the operator basis, as well as results for the hard m...

  16. Employing Helicity Amplitudes for Resummation

    NARCIS (Netherlands)

    Moult, I.; Stewart, I.W.; Tackmann, F.J.; Waalewijn, W.J.

    2015-01-01

    Many state-of-the-art QCD calculations for multileg processes use helicity amplitudes as their fundamental ingredients. We construct a simple and easy-to-use helicity operator basis in soft-collinear effective theory (SCET), for which the hard Wilson coefficients from matching QCD onto SCET are dire

  17. Extracting amplitudes from photoproduction data

    Science.gov (United States)

    Workman, R. L.

    2011-09-01

    We consider the problems associated with amplitude extraction, from meson photoproduction data, over the first resonance regions. The notion of a complete experiment has motivated the FROST program at Jefferson Lab. Exercises applied to pion photoproduction data illustrate the problems to be confronted in any attempt to extract underlying resonance signals from these data (without introducing a model for the resonant process).

  18. Ward identities for amplitudes with reggeized gluons

    Energy Technology Data Exchange (ETDEWEB)

    Bartles, J. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Universidad Tecnica Federico Santa Maria, Valparaiso (Chile). Dept. de Fisica; Lipatov, L.N. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; St. Petersburg Nuclear Physics Institute (Russian Federation); Vacca, G.P. [INFN, Sezione di Bologna (Italy)

    2012-05-15

    Starting from the effective action of high energy QCD we derive Ward identities for Green's functions of reggeized gluons. They follow from the gauge invariance of the effective action, and allow to derive new representations of amplitudes containing physical particles as well as reggeized gluons. We explicitly demonstrate their validity for the BFKL kernel, and we present a new derivation of the kernel.

  19. Characteristics of High-Impact Long-Duration Freezing Rain Events over North America

    Science.gov (United States)

    McCray, Christopher; Gyakum, John; Atallah, Eyad

    2017-04-01

    While even short periods of freezing rain can be hazardous, the most severe economic and public health impacts tend to occur when it persists for many hours. Predicting the precise and often fragile temperature stratification necessary for freezing rain to persist remains an important forecast challenge. To better elucidate the conditions responsible for the most severe impacts, we concentrate on surface observations of long-duration (6 or more hours) freezing rain events over North America from 1979-2015. Furthermore, we analyze cases in which multiple stations observe long-duration events simultaneously. Following these cases over successive days allows us to generate maps of freezing rain "tracks" which are then categorized by their geographic distributions. We then analyze the conditions that lead to the occurrence of freezing rain for each of these categories. The climatology of long-duration freezing rain events is largely controlled by a combination of synoptic patterns and local terrain effects, which help to maintain or replenish cold air at the surface. As with freezing rain in general, long-duration events occur most frequently from southeastern Canada into the northeastern United States, with a maximum in the St. Lawrence River Valley of Quebec. An examination of the longest-duration events at each station shows a broader geographic distribution, with local maxima in the frequency of 18+ h events over Oklahoma and surrounding states in the South Central United States (SCUS) - a region with relatively low annual freezing rain frequencies. Classification of individual events shows us that in many instances, the SCUS and northeastern North America are impacted by long-duration freezing rain during the same cases. Indeed, the category responsible for the greatest number of freezing rain observations over the largest area is one which begins in the SCUS (often Texas or Oklahoma), with freezing rain occurring over a broad southwest-northeast swath (2-3000 km

  20. UKIRT microlensing surveys as a pathfinder for $WFIRST$: The detection of five highly extinguished low-$|b|$ events

    CERN Document Server

    Shvartzvald, Y; Gould, A; Henderson, C B; Howell, S B; Beichman, C

    2016-01-01

    Optical microlensing surveys are restricted from detecting events near the Galactic plane and center, where the event rate is thought to be the highest, due to the high optical extinction of these fields. In the near-infrared (NIR), however, the lower extinction leads to a corresponding increase in event detections and is a primary driver for the wavelength coverage of the $WFIRST$ microlensing survey. During the 2015 and 2016 bulge observing seasons we conducted NIR microlensing surveys with UKIRT in conjunction with and in support of the $Spitzer$ and $Kepler$ microlensing campaigns. Here we report on five highly extinguished ($A_H=0.81-1.97$), low-Galactic latitude ($-0.98\\le b\\le -0.36$) microlensing events discovered from our 2016 survey. Four of them were monitored with an hourly cadence by optical surveys but were not reported as discoveries, likely due to the high extinction. Our UKIRT surveys and suggested future NIR surveys enable the first measurement of the microlensing event rate in the NIR. This...

  1. Strain accumulation model of soils under low-amplitude high-cycle loading%低幅值高循环荷载作用下土体的应变累积模型

    Institute of Scientific and Technical Information of China (English)

    贾鹏飞; 孔令伟; 杨爱武

    2013-01-01

    高速铁路路基上的轨道以及附近区域的结构物承受低幅值、高循环振动荷载的反复作用.在此低幅值、高循环荷载作用下土体会产生不可恢复的应变累积,导致轨道及附近区域结构物发生附加沉降.当前,描述土体的循环变形特征的理论分为两类:一类是基于经典塑性理论的应力-应变滞回模型(例如边界面模型),另一类是基于循环三轴试验经验规律的应变累积模型(例如Bochum累积模型).为了能够预测土体在低幅值、高循环荷载作用下的应变累积行为,在前人对土体在低幅值、高循环荷载作用下大量试验研究的基础上,在经典弹塑性理论的框架下,提出一个土体在低幅值、高循环荷载作用下的应变累积模型.该模型通过用对数律来描述塑性体应变的累积规律,并以此作为应变累积的大小度量,然后通过修正Cam-clay模型的流动准则来描述应变累积的发展方向.最后,通过多组试验结果的模拟,表明所提出的应变累积模型能够较好地预测土体在低幅值、高循环荷载作用下的应变累积行为,具有广泛的应用前景.%High-speed railway track and nearby structures are subjected to low-amplitude and high-cycle loading. Additional settlements of track and structures may be caused by irreversible strain accumulation of soils under the low-amplitude and high-cycle loading. At present, the theories described the deformation characteristics of soils have two kinds, stress-strain hysteretic model based on classical plastic theory, e.g. bounding surface model, and strain accumulation model based on empirical law obtained from the cyclic triaxial tests, e.g. Bochum accumulation model. Based on the existing test studies and classical elastoplastic theory, a strain accumulation model is proposed to predict strain accumulation behavior of soils subjected to low-amplitude and high-cycle loading. The model describes the accumulation law of

  2. Remote measurement of cloud microphysics and its influence in predicting high impact weather events

    Science.gov (United States)

    Bipasha, Paul S.; Jinya, John

    2016-05-01

    observations from A-Train , geostationary and futuristic imaging spectroscopic sensors, a multi-dimensional, and multi-scalar exploration of cloud systems is anticipated leading to accurate prediction of high impact weather events.

  3. Channeling efficiency dependence on bending radius and thermal vibration amplitude of the model for the channeling of high-energy particles in straight and bent crystals implemented in Geant4

    Energy Technology Data Exchange (ETDEWEB)

    Bagli, Enrico [INFN Sezione di Ferrara, Dipartimento di Fisica e Scienze della Terra, Università di Ferrara, Via Saragat 1, 44100 Ferrara (Italy); Asai, Makoto; Dotti, Andrea [SLAC National Accelerator Laboratory, 2575 Sand Hill Rd, Menlo Park, CA 94025 (United States); Guidi, Vincenzo [INFN Sezione di Ferrara, Dipartimento di Fisica e Scienze della Terra, Università di Ferrara, Via Saragat 1, 44100 Ferrara (Italy); Verderi, Marc [Laboratoire Leprince-Ringuet, Ecole Polytechnique, CNRS/IN2P3, F-91128 Palaiseau (France)

    2015-07-15

    Monte Carlo simulations of the interaction of particles with matter are usually done with downloadable toolkits such as Geant4. A model suitable for the implementation into Geant4 for the interaction of high-energy particles in straight and bent crystals was developed and implemented. The model relies on the continuum potential approximation. The variation of the Geant4 model for the description of the orientational effect as a function of the physical parameters for the calculation of the interplanar potential is presented. The simulations are capable of reproducing the variation of the efficiency of channeling as a function of the thermal vibration amplitude and the bending radius of a bent Si strip. The study can be useful for the simulation of the channeling effect in experiments at GeV/c energies.

  4. Latitudinal Responses of F2 Peak Parameters to High-intensity Long-duration Continuous AE Activity (HILDCAA) Events

    Science.gov (United States)

    Spraggs, M. E.

    2015-12-01

    The ionospheric responses to geomagnetic storms form an important part of the space weather study. The ionospheric perturbations may be described as enhancements and depletions compared to the quiet time variations, known as positive and negative phases of the ionospheric storms, respectively. In spite of a significant volume of studies on the ionospheric responses to the geomagnetic storms, understanding of ionospheric storm has not reached a level where it is possible to predict it. Geomagnetic activity may be divided into three categories: substorms, storms of different intensity, and high-intensity long-duration continuous AE activity (HILDCAA) events. This work presents specifically the latitudinal responses of the noontime F region peak parameters (hmF2 and foF2) to HILDCAA events. For this, digisonde data from 51 stations around the world was selected from the Digital Ionogram Data Base (DIDbase) from 2004 to 2012. For the same period 19 HILDCAA events were detected. Preliminary results show a positive effect in the peak parameters of the southern hemisphere and a negative effect in those of the northern hemisphere, suggesting that there is a predominantly northward component of the meridional winds. Additionally, it seems that the events occurring around the summer solstice have meridional wind components that are exclusively northward, while two of the six winter time events have southward components. Wintertime events are also the only ones with a very prominent eastward component of the zonal winds.

  5. Kinematics and amplitude evolution of global coronal extreme ultraviolet waves

    Institute of Scientific and Technical Information of China (English)

    Ting Li; Jun Zhang; Shu-Hong Yang; Wei Liu

    2012-01-01

    With the observations of the Solar-Terrestrial Relations Observatory (STEREO) and the Solar Dynamics Observatory (SDO),we analyze in detail the kinematics of global coronal waves together with their intensity amplitudes (so-called "perturbation profiles").We use a semi-automatic method to investigate the perturbation profiles of coronal waves.The location and amplitude of the coronal waves are calculated over a 30° sector on the sphere,where the wave signal is strongest.The position with the strongest perturbation at each time is considered as the location of the wave front.In all four events,the wave velocities vary with time for most of their lifetime,up to 15 min,while in the event observed by the Atmospheric Imaging Assembly there is an additional early phase with a much higher velocity.The velocity varies greatly between different waves from 216 to 440 km s-1.The velocity of the two waves initially increases,subsequently decreases,and then increases again.Two other waves show a deceleration followed by an acceleration.Three categories of amplitude evolution of global coronal waves are found for the four events.The first is that the amplitude only shows a decrease.The second is that the amplitude initially increases and then decreases,and the third is that the amplitude shows an orderly increase,a decrease,an increase again and then a decrease.All the extreme ultraviolet waves show a decrease in amplitude while propagating farther away,probably because the driver of the global coronal wave (coronal mass ejection) is moving farther away from the solar surface.

  6. High prevalence of peripheral arterial disease in patients with previous cerebrovascular or coronary event

    DEFF Research Database (Denmark)

    Mehlsen, Jesper; Wiinberg, Niels; Joergensen, Bjarne S

    2010-01-01

    The presence of peripheral arterial disease (PAD) in patients with other manifestations of cardiovascular disease identifies a population at increased risk of complications both during acute coronary events and on a long-term basis and possibly a population in whom secondary prevention of cardiov......The presence of peripheral arterial disease (PAD) in patients with other manifestations of cardiovascular disease identifies a population at increased risk of complications both during acute coronary events and on a long-term basis and possibly a population in whom secondary prevention...

  7. Particle physics explanations for ultra-high energy cosmic ray events

    Indian Academy of Sciences (India)

    Manuel Dress

    2004-02-01

    The origin of cosmic ray events with $E\\gtrsim 10^{11}$ GeV remains mysterious. In this talk I briefly summarize several proposed particle physics explanations: a breakdown of Lorentz invariance, the `$Z$-burst' scenario, new hadrons with masses of several GeV as primaries, and magnetic monopoles with mass below 1010 GeV as primaries. I then describe in a little more detail the idea that these events are due to the decays of very massive, long-lived exotic particles.

  8. Cardiovascular Events in Cancer Patients Treated with Highly or Moderately Emetogenic Chemotherapy: Results from a Population-Based Study

    Directory of Open Access Journals (Sweden)

    Thao T. Vo

    2012-01-01

    Full Text Available Studies on cardiovascular safety in cancer patients treated with highly or moderately emetogenic chemotherapy (HEC or MEC, who may have taken the antiemetic, aprepitant, have been limited to clinical trials and postmarketing spontaneous reports. Our study explored background rates of cardiovascular disease (CVD events among HEC- or MEC-treated cancer patients in a population-based setting to contextualize events seen in a new drug development program and to determine at a high level whether rates differed by aprepitant usage. Medical and pharmacy claims data from the 2005–2007 IMPACT National Benchmark Database were classified into emetogenic chemotherapy categories and CVD outcomes. Among 5827 HEC/MEC-treated patients, frequencies were highest for hypertension (16–21% and composites of venous (7–12% and arterial thromboembolic events (4–7%. Aprepitant users generally did not experience higher frequencies of events compared to nonusers. Our study serves as a useful benchmark of background CVD event rates in a population-based setting of cancer patients.

  9. New structures in scattering amplitudes: a review

    CERN Document Server

    Benincasa, Paolo

    2013-01-01

    We review some recent developments in the understanding of field theories in the perturbative regime. In particular, we discuss the notions of analyticity, unitarity and locality, and therefore the singularity structure of scattering amplitudes in general interacting theories. We describe their tree-level structure and their on-shell representations, as well as the links between the tree-level structure itself and the structure of the loop amplitudes. Finally, we describe the on-shell diagrammatics recently proposed both on general grounds and in the remarkable example of planar supersymmetric theories. This review is partially based on lectures given at: Dipartimento di Fisica and INFN, Universit\\`a di Bologna; Departamento de F{\\i}sica de Part{\\i}culas, Universidade de Santiago de Compostela; and as part of the program Strings@ar Lectures on Advanced Topics of High Energy Physics held at the IAFE

  10. Optical twists in phase and amplitude

    DEFF Research Database (Denmark)

    Daria, Vincent R.; Palima, Darwin; Glückstad, Jesper

    2011-01-01

    beams, the far field projection of the twisted optical beam maintains a high photon concentration even at higher values of topological charge. Optical twisters have therefore profound applications to fundamental studies of light and atoms such as in quantum entanglement of the OAM, toroidal traps......Light beams with helical phase profile correspond to photons having orbital angular momentum (OAM). A Laguerre-Gaussian (LG) beam is an example where its helical phase sets a phase-singularity at the optical axis and forms a ring-shaped transverse amplitude profile. Here, we describe a unique beam...... where both phase and amplitude express a helical profile as the beam propagates in free space. Such a beam can be accurately referred to as an optical twister. We characterize optical twisters and demonstrate their capacity to induce spiral motion on particles trapped along the twisters’ path. Unlike LG...

  11. Integrable spin chains and scattering amplitudes

    Energy Technology Data Exchange (ETDEWEB)

    Bartels, J.; Prygarin, A. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Lipatov, L.N. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Petersburg Nuclear Physics Institute (Russian Federation); Sankt-Peterburgskij Univ., St. Petersburg (Russian Federation)

    2011-04-15

    In this review we show that the multi-particle scattering amplitudes in N=4 SYM at large N{sub c} and in the multi-Regge kinematics for some physical regions have the high energy behavior appearing from the contribution of the Mandelstam cuts in the complex angular momentum plane of the corresponding t-channel partial waves. These Mandelstam cuts or Regge cuts are resulting from gluon composite states in the adjoint representation of the gauge group SU(N{sub c}). In the leading logarithmic approximation (LLA) their contribution to the six point amplitude is in full agreement with the known two-loop result. The Hamiltonian for the Mandelstam states constructed from n gluons in LLA coincides with the local Hamiltonian of an integrable open spin chain. We construct the corresponding wave functions using the integrals of motion and the Baxter-Sklyanin approach. (orig.)

  12. High Resolution Modeling in Mountainous Terrain for Water Resource Management: AN Extreme Precipitation Event Case Study

    Science.gov (United States)

    Masarik, M. T.; Watson, K. A.; Flores, A. N.; Anderson, K.; Tangen, S.

    2016-12-01

    The water resources infrastructure of the Western US is designed to deliver reliable water supply to users and provide recreational opportunities for the public, as well as afford flood control for communities by buffering variability in precipitation and snow storage. Thus water resource management is a balancing act of meeting multiple objectives while trying to anticipate and mitigate natural variability of water supply. Currently, the forecast guidance available to personnel managing resources in mountainous terrain is lacking in two ways: the spatial resolution is too coarse, and there is a gap in the intermediate time range (10-30 days). To address this need we examine the effectiveness of using the Weather Research and Forecasting (WRF) model, a state of the art, regional, numerical weather prediction model, as a means to generate high-resolution weather guidance in the intermediate time range. This presentation will focus on a reanalysis and hindcasting case study of the extreme precipitation and flooding event in the Payette River Basin of Idaho during the period of June 2nd-4th, 2010. For the reanalysis exercise we use NCEP's Climate Forecast System Reanalysis (CFSR) and the North American Regional Reanalysis (NARR) data sets as input boundary conditions to WRF. The model configuration includes a horizontal spatial resolution of 3km in the outer nest, and 1 km in the inner nest, with output temporal resolution of 3 hrs and 1 hr, respectively. The hindcast simulations, which are currently underway, will make use of the NCEP Climate Forecast System Reforecast (CFSRR) data. The current state of these runs will be discussed. Preparations for the second of two components in this project, weekly WRF forecasts during the intense portion of the water year, will be briefly described. These forecasts will use the NCEP Climate Forecast System version 2 (CFSv2) operational forecast data as boundary conditions to provide forecast guidance geared towards water resource

  13. Biofilm formation and sanitizer resistance of Escherichia coli 0157:H7 strains isolated from "High Event Period" meat contamination

    Science.gov (United States)

    In the meat industry, a “High Event Period” (HEP) is defined as a time period during which commercial meat plants experience a higher than usual rate of E. coli O157:H7 contamination. Genetic analysis indicated that within a HEP, most of the E. coli O157:H7 strains belong to a singular dominant str...

  14. Variations in airborne bacterial communities at high altitudes over the Noto Peninsula (Japan in response to Asian dust events

    Directory of Open Access Journals (Sweden)

    T. Maki

    2017-10-01

    Full Text Available Aerosol particles, including airborne microorganisms, are transported through the free troposphere from the Asian continental area to the downwind area in East Asia and can influence climate changes, ecosystem dynamics, and human health. However, the variations present in airborne bacterial communities in the free troposphere over downwind areas are poorly understood, and there are few studies that provide an in-depth examination of the effects of long-range transport of aerosols (natural and anthropogenic particles on bacterial variations. In this study, the vertical distributions of airborne bacterial communities at high altitudes were investigated and the bacterial variations were compared between dust events and non-dust events.Aerosols were collected at three altitudes from ground level to the free troposphere (upper level: 3000 or 2500 m; middle level: 1200 or 500 m; and low level: 10 m during Asian dust events and non-dust events over the Noto Peninsula, Japan, where westerly winds carry aerosols from the Asian continental areas. During Asian dust events, air masses at high altitudes were transported from the Asian continental area by westerly winds, and laser imaging detection and ranging (lidar data indicated high concentrations of non-spherical particles, suggesting that dust-sand particles were transported from the central desert regions of Asia. The air samples collected during the dust events contained 10–100 times higher concentrations of microscopic fluorescent particles and optical particle counter (OPC measured particles than in non-dust events. The air masses of non-dust events contained lower amounts of dust-sand particles. Additionally, some air samples showed relatively high levels of black carbon, which were likely transported from the Asian continental coasts. Moreover, during the dust events, microbial particles at altitudes of  >  1200 m increased to the concentrations ranging from 1. 2 × 106 to 6

  15. PFOS and PFOSA in Bottlenose Dolphins: An Investigation into Two Unusually High Mortality Events

    Science.gov (United States)

    Along the Atlantic coast of the United States during 1987 and 1988, bottlenose dolphins (Tursiops truncatus) suffered one of this country's largest marine mammal mass mortality events. An estimated 50% of all near-shore bottlenose died during this short period. Two years later a ...

  16. High Energy Solar Particle Events and their Associated Coronal Mass Ejections

    CERN Document Server

    Manoharan, P K

    2010-01-01

    Intense solar energetic particle (SEP) events data, associated with ground level enhancements (GLEs), occurred during 1989 to 2006 have been obtained from the spectrometers on board GOES spacecraft in the energy range 10-100 MeV. The interplanetary effects of these events and their associated coronal mass ejections (CMEs) have been provided by the LASCO/SOHO coronagraph images in the field of view of 2-30 {\\rsun} and the interplanetary scintillation images from the Ooty Radio Telescope in the heliocentric distance range of $\\sim$40-250 R$_\\odot$. The comparison between the radial evolution of the CME and its associated particle spectrum shows that the spectrum is soft at the onset of the particle event. A flat spectrum is observed at the peak of the particle event and the spectrum becomes steeper as the CME moves farther out into the inner heliosphere. However, the magnitude of change in spectral slopes differs from one CME to the other, suggesting the difference in energy available within the CME to drive th...

  17. Effect of high flow events on spatiotemporal variation of E. coli concentrations in creek sediments

    Science.gov (United States)

    Sediments can harbor large populations of Escherichia coli often times in greater amounts than the overlying water column. Resuspension of sediments during storm events causes the release of E. coli which drastically changes microbial water quality metrics. It is not well known how populations of E....

  18. Muons in air showers at the Pierre Auger Observatory: Mean number in highly inclined events

    NARCIS (Netherlands)

    Aab, A.; Abreu, P.; Aglietta, M.; Ahn, E. J.; Al Samarai, I.; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Aramo, C.; Aranda, V. M.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Badescu, A. M.; Barber, K. B.; Bäuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertaina, M. E.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, M.; Bleve, C.; Blümer, H.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Buitink, S.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Candusso, M.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Chavez, A. G.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Coleman, A.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cooper, M. J.; Cordier, A.; Coutu, S.; Covault, C. E.; Cronin, J.; Curutiu, A.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; de Jong, S. J.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Di Matteo, A.; Diaz, J. C.; Díaz Castro, M. L.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dorofeev, A.; Dorosti Hasankiadeh, Q.; Dova, M. T.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fernandes, M.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipčič, A.; Fox, B. D.; Fratu, O.; Fröhlich, U.; Fuchs, B.; Fujii, T.; Gaior, R.; García, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Gascon Bravo, A.; Gate, F.; Gemmeke, H.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Glaser, C.; Glass, H.; Gómez Berisso, M.; Gómez Vitale, P. F.; Gonçalves, P.; Gonzalez, J. G.; González, N.; Gookin, B.; Gordon, J.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grebe, S.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Hampel, M. R.; Hansen, P.; Harari, D.; Harrison, T. A.; Hartmann, S.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holt, E.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huber, D.; Huege, T.; Insolia, A.; Isar, P. G.; Islo, K.; Jandt, I.; Jansen, S.; Jarne, C.; Josebachuili, M.; Kääpä, A.; Kambeitz, O.; Kampert, K. H.; Kasper, P.; Katkov, I.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Krömer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kunka, N.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Le Coz, S.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Malacari, M.; Maldera, S.; Mallamaci, M.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Mariş, I. C.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martínez Bravo, O.; Martraire, D.; Masías Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, J. J.; Matthews, A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menshikov, A.; Messina, S.; Meyhandan, R.; Mićanović, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morello, C.; Mostafá, M.; Moura, C. A.; Muller, M. A.; Müller, G.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Newton, D.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nožka, L.; Ochilo, L.; Olinto, A.; Oliveira, M.; Olmos-Gilbaja, V. M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Papenbreer, P.; Parente, G.; Parra, A.; Paul, T.; Pech, M.; Pekala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Petermann, E.; Peters, C.; Petrera, S.; Petrov, Y.; Phuntsok, J.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porcelli, A.; Porowski, C.; Prado, R. R.; Privitera, P.; Prouza, M.; Purrello, V.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rizi, V.; Roberts, J.; Rodrigues de Carvalho, W.; Rodriguez Fernandez, G.; Rodriguez Rojo, J.; Rodríguez-Frías, M. D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Roulet, E.; Rovero, A. C.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Saleh, A.; Salesa Greus, F.; Salina, G.; Sánchez, F.; Sanchez-Lucas, P.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarmento, R.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Scholten, O.; Schoorlemmer, H.; Schovánek, P.; Schröder, F. G.; Schulz, A.; Schulz, J.; Schumacher, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Sima, O.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Squartini, R.; Srivastava, Y. N.; Stanič, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Taborda, O. A.; Tapia, A.; Tartare, M.; Tepe, A.; Theodoro, V. M.; Timmermans, C.; Todero Peixoto, C. J.; Toma, G.; Tomankova, L.; Tomé, B.; Tonachini, A.; Torralba Elipe, G.; Torres Machado, D.; Travnicek, P.; Trovato, E.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van den Berg, A. M.; van Velzen, S.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Varner, G.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Verzi, V.; Vicha, J.; Videla, M.; Villaseñor, L.; Vlcek, B.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Widom, A.; Wiencke, L.; Wilczyńska, B.; Wilczyński, H.; Will, M.; Williams, C.; Winchen, T.; Wittkowski, D.; Wundheiler, B.; Wykes, S.; Yamamoto, T.; Yapici, T.; Younk, P.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Zhou, J.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.; Zuccarello, F.; Pierre Auger Collaboration, [No Value

    2015-01-01

    We present the first hybrid measurement of the average muon number in air showers at ultrahigh energies, initiated by cosmic rays with zenith angles between 62° and 80°. The measurement is based on 174 hybrid events recorded simultaneously with the surface detector array and the fluorescence detecto

  19. Associated Electron-Muon Events from High-Energy Hadronic Collisions

    Science.gov (United States)

    Plaag, Robert Emil

    The inclusive reaction p + N (--->) e + (mu) + X was measured at an energy of 38.8 GeV (center of mass). Data representing a total luminosity of 13.4 inverse femtobarns (13.4 x 10('39) cm('-2)) were analyzed. Three associated electron-muon events were observed. The observed signal was 0.02 (+OR-) 0.015 of the Drell-Yan di-muon production. The expected number of e(mu) events from tau lepton pair production and decay was calculated to be 0.5 (+OR-) 0.1. A two sigma upper limit for (lepton family number violating) two body resonant decays to e + (mu) was obtained (physi- cally reasonable model. No prompt e(mu) events attributable to charm production and decay, or bottom production and decay, were seen. This corresponded to a two sigma upper limit for charm pair produc- tion of ) D + (')D (--->) e + K (--->) e + (mu) interpretation of these candidate events was consistent with the lower limit on charm production obtained with the prompt e(mu) rate.

  20. Muons in air showers at the Pierre Auger Observatory: Mean number in highly inclined events

    NARCIS (Netherlands)

    Aab, A.; Abreu, P.; Aglietta, M.; Ahn, E. J.; Al Samarai, I.; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Aramo, C.; Aranda, V. M.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Badescu, A. M.; Barber, K. B.; Bäuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertaina, M. E.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, M.; Bleve, C.; Blümer, H.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Buitink, S.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Candusso, M.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Chavez, A. G.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Coleman, A.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cooper, M. J.; Cordier, A.; Coutu, S.; Covault, C. E.; Cronin, J.; Curutiu, A.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; de Jong, S. J.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Di Matteo, A.; Diaz, J. C.; Díaz Castro, M. L.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dorofeev, A.; Dorosti Hasankiadeh, Q.; Dova, M. T.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fernandes, M.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipčič, A.; Fox, B. D.; Fratu, O.; Fröhlich, U.; Fuchs, B.; Fujii, T.; Gaior, R.; García, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Gascon Bravo, A.; Gate, F.; Gemmeke, H.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Glaser, C.; Glass, H.; Gómez Berisso, M.; Gómez Vitale, P. F.; Gonçalves, P.; Gonzalez, J. G.; González, N.; Gookin, B.; Gordon, J.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grebe, S.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Hampel, M. R.; Hansen, P.; Harari, D.; Harrison, T. A.; Hartmann, S.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holt, E.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huber, D.; Huege, T.; Insolia, A.; Isar, P. G.; Islo, K.; Jandt, I.; Jansen, S.; Jarne, C.; Josebachuili, M.; Kääpä, A.; Kambeitz, O.; Kampert, K. H.; Kasper, P.; Katkov, I.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Krömer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kunka, N.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Le Coz, S.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Malacari, M.; Maldera, S.; Mallamaci, M.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Mariş, I. C.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martínez Bravo, O.; Martraire, D.; Masías Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, J. J.; Matthews, A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menshikov, A.; Messina, S.; Meyhandan, R.; Mićanović, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morello, C.; Mostafá, M.; Moura, C. A.; Muller, M. A.; Müller, G.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Newton, D.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nožka, L.; Ochilo, L.; Olinto, A.; Oliveira, M.; Olmos-Gilbaja, V. M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Papenbreer, P.; Parente, G.; Parra, A.; Paul, T.; Pech, M.; Pekala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Petermann, E.; Peters, C.; Petrera, S.; Petrov, Y.; Phuntsok, J.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porcelli, A.; Porowski, C.; Prado, R. R.; Privitera, P.; Prouza, M.; Purrello, V.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rizi, V.; Roberts, J.; Rodrigues de Carvalho, W.; Rodriguez Fernandez, G.; Rodriguez Rojo, J.; Rodríguez-Frías, M. D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Roulet, E.; Rovero, A. C.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Saleh, A.; Salesa Greus, F.; Salina, G.; Sánchez, F.; Sanchez-Lucas, P.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarmento, R.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Scholten, O.; Schoorlemmer, H.; Schovánek, P.; Schröder, F. G.; Schulz, A.; Schulz, J.; Schumacher, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Sima, O.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Squartini, R.; Srivastava, Y. N.; Stanič, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Taborda, O. A.; Tapia, A.; Tartare, M.; Tepe, A.; Theodoro, V. M.; Timmermans, C.; Todero Peixoto, C. J.; Toma, G.; Tomankova, L.; Tomé, B.; Tonachini, A.; Torralba Elipe, G.; Torres Machado, D.; Travnicek, P.; Trovato, E.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van den Berg, A. M.; van Velzen, S.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Varner, G.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Verzi, V.; Vicha, J.; Videla, M.; Villaseñor, L.; Vlcek, B.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Widom, A.; Wiencke, L.; Wilczyńska, B.; Wilczyński, H.; Will, M.; Williams, C.; Winchen, T.; Wittkowski, D.; Wundheiler, B.; Wykes, S.; Yamamoto, T.; Yapici, T.; Younk, P.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Zhou, J.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.; Zuccarello, F.; Pierre Auger Collaboration, [No Value

    2015-01-01

    We present the first hybrid measurement of the average muon number in air showers at ultrahigh energies, initiated by cosmic rays with zenith angles between 62° and 80°. The measurement is based on 174 hybrid events recorded simultaneously with the surface detector array and the fluorescence detecto

  1. Gauge and Gravity Amplitude Relations

    CERN Document Server

    Carrasco, John Joseph M

    2015-01-01

    In these lectures I talk about simplifications and universalities found in scattering amplitudes for gauge and gravity theories. In contrast to Ward identities, which are understood to arise from familiar symmetries of the classical action, these structures are currently only understood in terms of graphical organizational principles, such as the gauge-theoretic color-kinematics duality and the gravitational double-copy structure, for local representations of multi-loop S-matrix elements. These graphical principles make manifest new relationships in and between gauge and gravity scattering amplitudes. My lectures will focus on arriving at such graphical organizations for generic theories with examples presented from maximal supersymmetry, and their use in unitarity-based multi-loop integrand construction.

  2. Infrared singularities in QCD amplitudes

    CERN Document Server

    Gardi, Einan

    2009-01-01

    We review recent progress in determining the infrared singularity structure of on-shell scattering amplitudes in massless gauge theories. We present a simple ansatz where soft singularities of any scattering amplitude of massless partons, to any loop order, are written as a sum over colour dipoles, governed by the cusp anomalous dimension. We explain how this formula was obtained, as the simplest solution to a newly-derived set of equations constraining the singularity structure to all orders. We emphasize the physical ideas underlying this derivation: the factorization of soft and collinear modes, the special properties of soft gluon interactions, and the notion of the cusp anomaly. Finally, we briefly discuss potential multi-loop contributions going beyond the sum-over-dipoles formula, which cannot be excluded at present.

  3. A high diet quality is associated with lower incidence of cardiovascular events in the Malmo diet and cancer cohort.

    Directory of Open Access Journals (Sweden)

    Joanna Hlebowicz

    Full Text Available AIMS: To investigate if diet quality is related to incidence of cardiovascular (CV events. SUBJECTS AND METHODS: A diet quality index based on the 2005 Swedish Nutrition Recommendations and the Swedish Dietary Guidelines was created and included six dietary components: saturated fatty acids, polyunsaturated fatty acids, fish and shellfish, dietary fiber, fruit and vegetables, and sucrose. The index ranked 17126 participants (59% women of the population-based Malmö Diet and Cancer cohort (Sweden on their dietary intakes. Total index score was categorized as low, medium or high. Cox proportional hazard regression was used to model associations between index score categories and index components with risk of incident CV events, with adjustment for potential confounders. The incidence of first CV events (non-fatal or fatal myocardial infarction or ischemic stroke or death from ischemic heart disease was monitored from baseline (1991-1996 until December 31, 2008; 703 CV events occurred in women and 1093 in men. RESULTS: A high diet quality was associated with decreased risk of CV events when compared to a low diet quality. In multivariate analysis, the risk reduction was 32% (hazard ratio = 0.68, 95% confidence interval: 0.49-0.73 in men and 27% (hazard ratio = 0.73, 95% confidence interval: 0.59-0.91 in women. When examined separately and mutually adjusted for each other, the individual components were either not associated with CV risk or marginally decreased risks were seen. CONCLUSION: High quality diets in line with current recommendations may reduce the risk of CV events. This study illustrates the importance of considering a combination of dietary factors when evaluating diet-disease associations.

  4. Pulse amplitude modulated chlorophyll fluorometer

    Energy Technology Data Exchange (ETDEWEB)

    Greenbaum, Elias; Wu, Jie

    2015-12-29

    Chlorophyll fluorometry may be used for detecting toxins in a sample because of changes in micro algae. A portable lab on a chip ("LOAC") based chlorophyll fluorometer may be used for toxin detection and environmental monitoring. In particular, the system may include a microfluidic pulse amplitude modulated ("PAM") chlorophyll fluorometer. The LOAC PAM chlorophyll fluorometer may analyze microalgae and cyanobacteria that grow naturally in source drinking water.

  5. Physical distress is associated with cardiovascular events in a high risk population of elderly men

    Directory of Open Access Journals (Sweden)

    Klemsdal Tor O

    2009-03-01

    Full Text Available Abstract Background Self-reported health perceptions such as physical distress and quality of life are suggested independent predictors of mortality and morbidity in patients with established cardiovascular disease. This study examined the associations between these factors and three years incidence of cardiovascular events in a population of elderly men with long term hyperlipidemia. Methods We studied observational data in a cohort of 433 men aged 64–76 years from a prospective, 2 × 2 factorial designed, three-year interventional trial. Information of classical risk factors was obtained and the following questionnaires were administered at baseline: Hospital Anxiety and Depression Scale, Physical Symptom Distress Index and Life Satisfaction Index. The occurrence of cardiovascular death, myocardial infarction, cerebrovascular incidences and peripheral arterial disease were registered throughout the study period. Continuous data with skewed distribution was split into tertiles. Hazard ratios (HR were calculated from Cox regression analyses to assess the associations between physical distress, quality of life and cardiovascular events. Results After three years, 49 cardiovascular events were registered, with similar incidence among subjects with and without established cardiovascular disease. In multivariate analyses adjusted for age, smoking, systolic blood pressure, serum glucose, HADS-anxiety and treatment-intervention, physical distress was positively associated (HR 3.1, 95% CI 1.2 – 7.9 for 3rd versus 1st tertile and quality of life negatively associated (HR 2.6, 95% CI 1.1–5.8 for 3rd versus 1st tertile with cardiovascular events. The association remained statistically significant only for physical distress (hazard ratio 2.8 95% CI 1.2 – 6.8, p Conclusion Physical distress, but not quality of life, was independently associated with increased risk of cardiovascular events in an observational study of elderly men predominantly

  6. All-Multiplicity Amplitudes with Massive Scalars

    CERN Document Server

    Forde, D; Forde, Darren; Kosower, David A.

    2005-01-01

    We compute two infinite series of tree-level amplitudes with a massive scalar pair and an arbitrary number of gluons. We provide results for amplitudes where all gluons have identical helicity, and amplitudes with one gluon of opposite helicity. These amplitudes are useful for unitarity-based one-loop calculations in nonsupersymmetric gauge theories generally, and QCD in particular.

  7. Crisis in Amplitude Control Hides in Multistability

    Science.gov (United States)

    Li, Chunbiao; Sprott, Julien Clinton; Xing, Hongyan

    2016-12-01

    A crisis of amplitude control can occur when a system is multistable. This paper proposes a new chaotic system with a line of equilibria to demonstrate the threat to amplitude control from multistability. The new symmetric system has two coefficients for amplitude control, one of which is a partial amplitude controller, while the other is a total amplitude controller that simultaneously controls the frequency. The amplitude parameter rescales the basins of attraction and triggers a state switch among different states resulting in a failure of amplitude control to the desired state.

  8. Implications of high-temperature events and water deficits on protein profiles in wheat (Triticum aestivum L. cv. Vinjett) grain.

    Science.gov (United States)

    Yang, Fen; Jørgensen, Anders D; Li, Huawei; Søndergaard, Ib; Finnie, Christine; Svensson, Birte; Jiang, Dong; Wollenweber, Bernd; Jacobsen, Susanne

    2011-05-01

    Increased climatic variability is resulting in an increase of both the frequency and the magnitude of extreme climate events. Therefore, cereals may be exposed to more than one stress event in the growing season, which may ultimately affect crop yield and quality. Here, effects are reported of interaction of water deficits and/or a high-temperature event (32°C) during vegetative growth (terminal spikelet) with either of these stress events applied during generative growth (anthesis) in wheat. Influence of combinations of stress on protein fractions (albumins, globulins, gliadins and glutenins) in grains and stress-induced changes on the albumin and gliadin proteomes were investigated by 2-DE and MS. The synthesis of individual protein fractions was shown to be affected by both the type and time of the applied stresses. Identified drought or high-temperature-responsive proteins included proteins involved in primary metabolism, storage and stress response such as late embryogenesis abundant proteins, peroxiredoxins and α-amylase/trypsin inhibitors. Several proteins, e.g. heat shock protein and 14-3-3 protein changed in abundance only under multiple high temperatures.

  9. High Resolution Simulations of a Severe Hail Storm and Flooding Event over La Paz city with WRF

    Science.gov (United States)

    Zamuriano, Marcelo; Brönnimann, Stefan

    2016-04-01

    On February 19, 2002 a very local hail storm and a flash flood episode occurred in La Paz city, Bolivia. About 40 millimeters of precipitation in over an hour was observed, it was the strongest rainfall registered until that date. This event caused at least 69 causalities and important damages to the city's infrastructure, being considered as an exceptional natural disaster. It is thought that the vertical humid air motion driven by the high surface temperatures and topographical forcing is the responsible of such event, nevertheless a formal study about the atmospheric features leading to this episode has not been done yet. In order to overcome this issue, a series of high resolution numerical experiments with the WRF-ARW model is conducted using two global datasets: GFS and ECMWF. Several micro-physics schemes are used in a four-nested domain configuration with 2 kilometers as finest resolution, giving more details about the effects topography on this event. Overall, high-resolution simulations improves the spatial distribution of rainfall and represents better the local atmospheric circulation leading to this extreme event.

  10. Calculation of multi-loop superstring amplitudes

    Science.gov (United States)

    Danilov, G. S.

    2016-12-01

    The multi-loop interaction amplitudes in the closed, oriented superstring theory are obtained by the integration of local amplitudes. The local amplitude is represented by a sum over the spinning string local amplitudes. The spinning string local amplitudes are given explicitly through super-Schottky group parameters and through interaction vertex coordinates on the (1| 1) complex, non-split supermanifold. The obtained amplitudes are free from divergences. They are consistent with the world-sheet spinning string symmetries. The vacuum amplitude vanishes along with 1-, 2- and 3-point amplitudes of massless states. The vanishing of the above-mentioned amplitude occurs after the integration of the corresponding local amplitude has been performed over the super-Schottky group limiting points and over interaction vertex coordinate, except for those (3| 2) variables which are fixed due to SL(2)-symmetry.

  11. Performance of a Micro-Strip Gas Chamber for event wise, high rate thermal neutron detection with accurate 2D position determination

    Science.gov (United States)

    Mindur, B.; Alimov, S.; Fiutowski, T.; Schulz, C.; Wilpert, T.

    2014-12-01

    A two-dimensional (2D) position sensitive detector for neutron scattering applications based on low-pressure gas amplification and micro-strip technology was built and tested with an innovative readout electronics and data acquisition system. This detector contains a thin solid neutron converter and was developed for time- and thus wavelength-resolved neutron detection in single-event counting mode, which improves the image contrast in comparison with integrating detectors. The prototype detector of a Micro-Strip Gas Chamber (MSGC) was built with a solid natGd/CsI thermal neutron converter for spatial resolutions of about 100 μm and counting rates up to 107 neutrons/s. For attaining very high spatial resolutions and counting rates via micro-strip readout with centre-of-gravity evaluation of the signal amplitude distributions, a fast, channel-wise, self-triggering ASIC was developed. The front-end chips (MSGCROCs), which are very first signal processing components, are read out into powerful ADC-FPGA boards for on-line data processing and thereafter via Gigabit Ethernet link into the data receiving PC. The workstation PC is controlled by a modular, high performance dedicated software suite. Such a fast and accurate system is crucial for efficient radiography/tomography, diffraction or imaging applications based on high flux thermal neutron beam. In this paper a brief description of the detector concept with its operation principles, readout electronics requirements and design together with the signals processing stages performed in hardware and software are presented. In more detail the neutron test beam conditions and measurement results are reported. The focus of this paper is on the system integration, two dimensional spatial resolution, the time resolution of the readout system and the imaging capabilities of the overall setup. The detection efficiency of the detector prototype is estimated as well.

  12. Genome-wide high-resolution mapping of UV-induced mitotic recombination events in Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Yi Yin

    2013-10-01

    Full Text Available In the yeast Saccharomyces cerevisiae and most other eukaryotes, mitotic recombination is important for the repair of double-stranded DNA breaks (DSBs. Mitotic recombination between homologous chromosomes can result in loss of heterozygosity (LOH. In this study, LOH events induced by ultraviolet (UV light are mapped throughout the genome to a resolution of about 1 kb using single-nucleotide polymorphism (SNP microarrays. UV doses that have little effect on the viability of diploid cells stimulate crossovers more than 1000-fold in wild-type cells. In addition, UV stimulates recombination in G1-synchronized cells about 10-fold more efficiently than in G2-synchronized cells. Importantly, at high doses of UV, most conversion events reflect the repair of two sister chromatids that are broken at approximately the same position whereas at low doses, most conversion events reflect the repair of a single broken chromatid. Genome-wide mapping of about 380 unselected crossovers, break-induced replication (BIR events, and gene conversions shows that UV-induced recombination events occur throughout the genome without pronounced hotspots, although the ribosomal RNA gene cluster has a significantly lower frequency of crossovers.

  13. Conjunction Assessment Late-Notice High-Interest Event Investigation: Space Weather Aspects

    Science.gov (United States)

    Pachura, D.; Hejduk, M. D.

    2016-01-01

    Late-notice events usually driven by large changes in primary (protected) object or secondary object state. Main parameter to represent size of state change is component position difference divided by associated standard deviation (epsilon divided by sigma) from covariance. Investigation determined actual frequency of large state changes, in both individual and combined states. Compared them to theoretically expected frequencies. Found that large changes ( (epsilon divided by sigma) is greater than 3) in individual object states occur much more frequently than theory dictates. Effect is less pronounced in radial components and in events with probability of collision (Pc) greater than 1 (sup -5) (1e-5). Found combined state matched much closer to theoretical expectation, especially for radial and cross-track. In-track is expected to be the most vulnerable to modeling errors, so not surprising that non-compliance largest in this component.

  14. Motivation modulates the P300 amplitude during brain-computer interface use.

    Science.gov (United States)

    Kleih, S C; Nijboer, F; Halder, S; Kübler, A

    2010-07-01

    This study examined the effect of motivation as a possible psychological influencing variable on P300 amplitude and performance in a brain-computer interface (BCI) controlled by event-related potentials (ERP). Participants were instructed to copy spell a sentence by attending to cells of a randomly flashing 7*7 matrix. Motivation was manipulated by monetary reward. In two experimental groups participants received 25 (N=11) or 50 (N=11) Euro cent for each correctly selected character; the control group (N=11) was not rewarded. BCI performance was defined as the overall percentage of correctly selected characters (correct response rate=CRR). Participants performed at an average of 99%. At electrode location Cz the P300 amplitude was positively correlated to self-rated motivation. The P300 amplitude of the most motivated participants was significantly higher than that of the least motivated participants. Highly motivated participants were able to communicate correctly faster with the ERP-BCI than less motivated participants. Motivation modulates the P300 amplitude in an ERP-BCI. Motivation may contribute to variance in BCI performance and should be monitored in BCI settings. Copyright 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  15. High-Energy Electromagnetic Offline Follow-Up of Ligo-Virgo Gravitational-Wave Binary Coalescence Candidate Events

    Science.gov (United States)

    Blackburn, L.; Briggs, M. S.; Camp, J.; Christensen, N.; Connaughton, V.; Jenke, P.; Remillard, R. A.; Veitch, J.

    2015-01-01

    We present two different search methods for electromagnetic counterparts to gravitational-wave (GW) events from ground-based detectors using archival NASA high-energy data from the Fermi Gamma-ray Burst Monitor (GBM) and RXTE All-sky Monitor (ASM) instruments. To demonstrate the methods, we use a limited number of representative GW background noise events produced by a search for binary neutron star coalescence over the last two months of the LIGO-Virgo S6/VSR3 joint science run. Time and sky location provided by the GW data trigger a targeted search in the high-energy photon data. We use two custom pipelines: one to search for prompt gamma-ray counterparts in GBM, and the other to search for a variety of X-ray afterglow model signals in ASM. We measure the efficiency of the joint pipelines to weak gamma-ray burst counterparts, and a family of model X-ray afterglows. By requiring a detectable signal in either electromagnetic instrument coincident with a GW event, we are able to reject a large majority of GW candidates. This reduces the signal-to-noise ratio of the loudest surviving GW background event by around 15-20 percent.

  16. High-Energy Electromagnetic Offline Follow-Up of Ligo-Virgo Gravitational-Wave Binary Coalescence Candidate Events

    Science.gov (United States)

    Blackburn, L.; Briggs, M. S.; Camp, J.; Christensen, N.; Connaughton, V.; Jenke, P.; Remillard, R. A.; Veitch, J.

    2015-01-01

    We present two different search methods for electromagnetic counterparts to gravitational-wave (GW) events from ground-based detectors using archival NASA high-energy data from the Fermi Gamma-ray Burst Monitor (GBM) and RXTE All-sky Monitor (ASM) instruments. To demonstrate the methods, we use a limited number of representative GW background noise events produced by a search for binary neutron star coalescence over the last two months of the LIGO-Virgo S6/VSR3 joint science run. Time and sky location provided by the GW data trigger a targeted search in the high-energy photon data. We use two custom pipelines: one to search for prompt gamma-ray counterparts in GBM, and the other to search for a variety of X-ray afterglow model signals in ASM. We measure the efficiency of the joint pipelines to weak gamma-ray burst counterparts, and a family of model X-ray afterglows. By requiring a detectable signal in either electromagnetic instrument coincident with a GW event, we are able to reject a large majority of GW candidates. This reduces the signal-to-noise ratio of the loudest surviving GW background event by around 15-20 percent.

  17. Studying the Underlying Event in Drell-Yan and High Transverse Momentum Jet Production at the Tevatron

    CERN Document Server

    Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Apresyan, A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Attal, A.; Aurisano, A.; Azfar, F.; Badgett, W.; Barbaro-Galtieri, A.; Barnes, V.E.; Barnett, B.A.; Barria, P.; Bartos, P.; Bauer, G.; Beauchemin, P.H.; Bedeschi, F.; Beecher, D.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Berge, D.; Bhatti, A.; Binkley, M.; Bisello, D.; Bizjak, I.; Blair, R.E.; Blocker, C.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Boisvert, V.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brau, B.; Bridgeman, A.; Brigliadori, L.; Bromberg, C.; Brubaker, E.; Budagov, J.; Budd, H.S.; Budd, S.; Burkett, K.; Busetto, G.; Bussey, P.; Buzatu, A.; Byrum, K.L.; Cabrera, S.; Calancha, C.; Camarda, S.; Campanelli, M.; Campbell, M.; Canelli, F.; Canepa, A.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Carron, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chang, S.H.; Chen, Y.C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Chlebana, F.; Cho, K.; Chokheli, D.; Chou, J.P.; Chung, K.; Chung, W.H.; Chung, Y.S.; Chwalek, T.; Ciobanu, C.I.; Ciocci, M.A.; Clark, A.; Clark, D.; Compostella, G.; Convery, M.E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C.A.; Cox, D.J.; Crescioli, F.; Cuenca Almenar, C.; Cuevas, J.; Culbertson, R.; Cully, J.C.; Dagenhart, D.; Datta, M.; Davies, T.; de Barbaro, P.; De Cecco, S.; Deisher, A.; De Lorenzo, G.; Dell'Orso, M.; Deluca, C.; Demortier, L.; Deng, J.; Deninno, M.; d'Errico, M.; Di Canto, A.; di Giovanni, G.P.; Di Ruzza, B.; Dittmann, J.R.; D'Onofrio, M.; Donati, S.; Dong, P.; Dorigo, T.; Dube, S.; Ebina, Koji; Elagin, A.; Erbacher, R.; Errede, D.; Errede, S.; Ershaidat, N.; Eusebi, R.; Fang, H.C.; Farrington, S.; Fedorko, W.T.; Feild, R.G.; Feindt, M.; Fernandez, J.P.; Ferrazza, C.; Field, R.; Flanagan, G.; Forrest, R.; Frank, M.J.; Franklin, M.; Freeman, J.C.; Furic, I.; Gallinaro, M.; Galyardt, J.; Garberson, F.; Garcia, J.E.; Garfinkel, A.F.; Garosi, P.; Gerberich, H.; Gerdes, D.; Gessler, A.; Giagu, S.; Giakoumopoulou, V.; Giannetti, P.; Gibson, K.; Gimmell, J.L.; Ginsburg, C.M.; Giokaris, N.; Giordani, M.; Giromini, P.; Giunta, M.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldschmidt, N.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; Gonzalez, O.; Gorelov, I.; Goshaw, A.T.; Goulianos, K.; Gresele, A.; Grinstein, S.; Grosso-Pilcher, C.; Group, R.C.; Grundler, U.; Guimaraes da Costa, J.; Gunay-Unalan, Z.; Haber, C.; Hahn, S.R.; Halkiadakis, E.; Han, B.Y.; Han, J.Y.; Happacher, F.; Hara, K.; Hare, D.; Hare, M.; Harr, R.F.; Hartz, M.; Hatakeyama, K.; Hays, C.; Heck, M.; Heinrich, J.; Herndon, M.; Heuser, J.; Hewamanage, S.; Hickman, M.; Hidas, D.; Hill, C.S.; Hirschbuehl, D.; Hocker, A.; Hou, S.; Houlden, M.; Hsu, S.C.; Hughes, R.E.; Hurwitz, M.; Husemann, U.; Hussein, M.; Huston, J.; Incandela, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E.J.; Jha, M.K.; Jindariani, S.; Johnson, W.; Jones, M.; Joo, K.K.; Jun, S.Y.; Jung, J.E.; Junk, T.R.; Kamon, T.; Kar, D.; Karchin, P.E.; Kato, Y.; Kephart, R.; Ketchum, W.; Keung, J.; Khotilovich, V.; Kilminster, B.; Kim, D.H.; Kim, H.S.; Kim, H.W.; Kim, J.E.; Kim, M.J.; Kim, S.B.; Kim, S.H.; Kim, Y.K.; Kimura, N.; Kirsch, L.; Klimenko, S.; Kondo, K.; Kong, D.J.; Konigsberg, J.; Korytov, A.; Kotwal, A.V.; Kreps, M.; Kroll, J.; Krop, D.; Krumnack, N.; Kruse, M.; Krutelyov, V.; Kuhr, T.; Kulkarni, N.P.; Kurata, M.; Kwang, S.; Laasanen, A.T.; Lami, S.; Lammel, S.; Lancaster, M.; Lander, R.L.; Lannon, K.; Lath, A.; Latino, G.; Lazzizzera, I.; LeCompte, T.; Lee, E.; Lee, H.S.; Lee, J.S.; Lee, S.W.; Leone, S.; Lewis, J.D.; Lin, C.J.; Linacre, J.; Lindgren, M.; Lipeles, E.; Lister, A.; Litvintsev, D.O.; Liu, C.; Liu, T.; Lockyer, N.S.; Loginov, A.; Lovas, L.; Lucchesi, D.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; MacQueen, D.; Madrak, R.; Maeshima, K.; Makhoul, K.; Maksimovic, P.; Malde, S.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Margaroli, F.; Marino, C.; Marino, C.P.; Martin, A.; Martin, V.; Martinez, M.; Martinez-Ballarin, R.; Mastrandrea, P.; Mathis, M.; Mattson, M.E.; Mazzanti, P.; McFarland, K.S.; McIntyre, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Menzione, A.; Mesropian, C.; Miao, T.; Mietlicki, D.; Miladinovic, N.; Miller, R.; Mills, C.; Milnik, M.; Mitra, A.; Mitselmakher, G.; Miyake, H.; Moed, S.; Moggi, N.; Mondragon, M.N.; Moon, C.S.; Moore, R.; Morello, M.J.; Morlock, J.; Movilla Fernandez, P.; Mulmenstadt, J.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakamura, K.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Neubauer, M.S.; Neubauer, S.; Nielsen, J.; Nodulman, L.; Norman, M.; Norniella, O.; Nurse, E.; Oakes, L.; Oh, S.H.; Oh, Y.D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Osterberg, K.; Pagan Griso, S.; Pagliarone, C.; Palencia, E.; Papadimitriou, V.; Papaikonomou, A.; Paramanov, A.A.; Parks, B.; Pashapour, S.; Patrick, J.; Pauletta, G.; Paulini, M.; Paus, C.; Peiffer, T.; Pellett, D.E.; Penzo, A.; Phillips, T.J.; Piacentino, G.; Pianori, E.; Pinera, L.; Pitts, K.; Plager, C.; Pondrom, L.; Potamianos, K.; Poukhov, O.; Prokoshin, F.; Pronko, A.; Ptohos, F.; Pueschel, E.; Punzi, G.; Pursley, J.; Rademacker, J.; Rahaman, A.; Ramakrishnan, V.; Ranjan, N.; Redondo, I.; Renton, P.; Renz, M.; Rescigno, M.; Richter, S.; Rimondi, F.; Ristori, L.; Robson, A.; Rodrigo, T.; Rodriguez, T.; Rogers, E.; Rolli, S.; Roser, R.; Rossi, M.; Rossin, R.; Roy, P.; Ruiz, A.; Russ, J.; Rusu, V.; Rutherford, B.; Saarikko, H.; Safonov, A.; Sakumoto, W.K.; Santi, L.; Sartori, L.; Sato, K.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, A.; Schmidt, E.E.; Schmidt, M.A.; Schmidt, M.P.; Schmitt, M.; Schwarz, T.; Scodellaro, L.; Scribano, A.; Scuri, F.; Sedov, A.; Seidel, S.; Seiya, Y.; Semenov, A.; Sexton-Kennedy, L.; Sforza, F.; Sfyrla, A.; Shalhout, S.Z.; Shears, T.; Shepard, P.F.; Shimojima, M.; Shiraishi, S.; Shochet, M.; Shon, Y.; Shreyber, I.; Simonenko, A.; Sinervo, P.; Sisakyan, A.; Slaughter, A.J.; Slaunwhite, J.; Sliwa, K.; Smith, J.R.; Snider, F.D.; Snihur, R.; Soha, A.; Somalwar, S.; Sorin, V.; Squillacioti, P.; Stanitzki, M.; St. Denis, R.; Stelzer, B.; Stelzer-Chilton, O.; Stentz, D.; Strologas, J.; Strycker, G.L.; Suh, J.S.; Sukhanov, A.; Suslov, I.; Taffard, A.; Takashima, R.; Takeuchi, Y.; Tanaka, R.; Tang, J.; Tecchio, M.; Teng, P.K.; Thom, J.; Thome, J.; Thompson, G.A.; Thomson, E.; Tipton, P.; Ttito-Guzman, P.; Tkaczyk, S.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Tourneur, S.; Trovato, M.; Tsai, S.Y.; Tu, Y.; Turini, N.; Ukegawa, F.; Uozumi, S.; van Remortel, N.; Varganov, A.; Vataga, E.; Vazquez, F.; Velev, G.; Vellidis, C.; Vidal, M.; Vila, I.; Vilar, R.; Vogel, M.; Volobouev, I.; Volpi, G.; Wagner, P.; Wagner, R.G.; Wagner, R.L.; Wagner, W.; Wagner-Kuhr, J.; Wakisaka, T.; Wallny, R.; Wang, S.M.; Warburton, A.; Waters, D.; Weinberger, M.; Weinelt, J.; Wester, W.C.; Whitehouse, B.; Whiteson, D.; Wicklund, A.B.; Wicklund, E.; Wilbur, S.; Williams, G.; Williams, H.H.; Wilson, M.G.; Wilson, P.; Winer, B.L.; Wittich, P.; Wolbers, S.; Wolfe, C.; Wolfe, H.; Wright, T.; Wu, X.; Wurthwein, F.; Yagil, A.; Yamamoto, K.; Yamaoka, J.; Yang, U.K.; Yang, Y.C.; Yao, W.M.; Yeh, G.P.; Yi, K.; Yoh, J.; Yorita, K.; Yoshida, T.; Yu, G.B.; Yu, I.; Yu, S.S.; Yun, J.C.; Zanetti, A.; Zeng, Y.; Zhang, X.; Zheng, Y.; Zucchelli, S.

    2010-01-01

    We study the underlying event in proton-antiproton collisions by examining the behavior of charged particles (transverse momentum pT > 0.5 GeV/c, pseudorapidity |\\eta| < 1) produced in association with large transverse momentum jets (~2.2 fb-1) or with Drell-Yan lepton-pairs (~2.7 fb-1) in the Z-boson mass region (70 < M(pair) < 110 GeV/c2) as measured by CDF at 1.96 TeV center-of-mass energy. We use the direction of the lepton-pair (in Drell-Yan production) or the leading jet (in high-pT jet production) in each event to define three regions of \\eta-\\phi space; toward, away, and transverse, where \\phi is the azimuthal scattering angle. For Drell-Yan production (excluding the leptons) both the toward and transverse regions are very sensitive to the underlying event. In high-pT jet production the transverse region is very sensitive to the underlying event and is separated into a MAX and MIN transverse region, which helps separate the hard component (initial and final-state radiation) from the beam-beam...

  18. MOA-2008-BLG-379Lb: A Massive Planet from a High Magnification Event with a Faint Source

    CERN Document Server

    Suzuki, D; Sumi, T; Bennett, D P; Bond, I A; Abe, F; Botzler, C S; Freeman, M; Fukagawa, M; Fukui, A; Furusawa, K; Itow, Y; Ling, C H; Masuda, K; Matsubara, Y; Muraki, Y; Ohnishi, K; Rattenbury, N; Saito, To; Shibai, H; Sullivan, D J; Suzuki, K; Sweatman, W L; Takino, S; Tristram, P J; Wada, K; Yock, P C M; Szymański, M K; Kubiak, M; Soszyński, I; Pietrzyński, G; Poleski, R; Ulaczyk, K; Wyrzykowski, Ł

    2013-01-01

    We report analysis of high microlensing event MOA-2008-BLG-379, which has a strong microlensing anomaly at its peak, due to a massive planet with a mass ratio of q = 6.9 x 10^{-3}. Because the faint source star crosses the large resonant caustic, the planetary signal dominates the light curve. This is unusual for planetary microlensing events, and as a result, the planetary nature of this light curve was not immediately noticed. The planetary nature of the event was found when the MOA Collaboration conducted a systematic study of binary microlensing events previously identified by the MOA alert system. We have conducted a Bayesian analysis based on a standard Galactic model to estimate the physical parameters of the lens system. This yields a host star mass of M_L = 0.66_{-0.33}^{+0.29} M_Sun orbited by a planet of mass m_P = 4.8_{-2.4}^{+2.1} M_Jup at an orbital separation of a = 4.1_{-1.5}^{+1.9} AU at a distance of D_L = 3.6 +/- 1.3 kpc. The faint source magnitude of I_S = 21.30 and relatively high lens-so...

  19. Studying the Underlying Event in Drell-Yan and High Transverse Momentum Jet Production at the Tevatron

    CERN Document Server

    Aaltonen, T; Alvarez Gonzalez, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Apresyan, A; Arisawa, T; Artikov, A; Asaadi, J; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Barria, P; Bartos, P; Bauer, G; Beauchemin, P H; Bedeschi, F; Beecher, D; Behari, S; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Berge, D; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Bridgeman, A; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Calancha, C; Camarda, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carls, B; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavaliere, V; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Chung, K; Chung, W H; Chung, Y S; Chwalek, T; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Compostella, G; Convery, M E; Conway, J; Corbo, M; Cordelli, M; Cox, C A; Cox, D J; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cully, J C; Dagenhart, D; Datta, M; Davies, T; de Barbaro, P; De Cecco, S; Deisher, A; De Lorenzo, G; Dell'Orso, M; Deluca, C; Demortier, L; Deng, J; Deninno, M; d'Errico, M; Di Canto, A; di Giovanni, G P; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Dorigo, T; Dube, S; Ebina, Koji; Elagin, A; Erbacher, R; Errede, D; Errede, S; Ershaidat, N; Eusebi, R; Fang, H C; Farrington, S; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Frank, M J; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garberson, F; Garcia, J E; Garfinkel, A F; Garosi, P; Gerberich, H; Gerdes, D; Gessler, A; Giagu, S; Giakoumopoulou, V; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C M; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; Gonzalez, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Group, R C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, S R; Halkiadakis, E; Han, B Y; Han, J Y; Happacher, F; Hara, K; Hare, D; Hare, M; Harr, R F; Hartz, M; Hatakeyama, K; Hays, C; Heck, M; Heinrich, J; Herndon, M; Heuser, J; Hewamanage, S; Hickman, M; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Hou, S; Houlden, M; Hsu, S C; Hughes, R E; Hurwitz, M; Husemann, U; Hussein, M; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; James, E; Jang, D; Jayatilaka, B; Jeon, E J; Jha, M K; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Kar, D; Karchin, P E; Kato, Y; Kephart, R; Ketchum, W; Keung, J; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, H W; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kreps, M; Kroll, J; Krop, D; Krumnack, N; Kruse, M; Krutelyov, V; Kuhr, T; Kulkarni, N P; Kurata, M; Kwang, S; Laasanen, A T; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; LeCompte, T; Lee, E; Lee, H S; Lee, J S; Lee, S W; Leone, S; Lewis, J D; Lin, C J; Linacre, J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, C; Liu, T; Lockyer, N S; Loginov, A; Lovas, L; Lucchesi, D; Lueck, J; Lujan, P; Lukens, P; Lungu, G; Lys, J; Lysak, R; MacQueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis-Katsikakis, A; Margaroli, F; Marino, C; Marino, C P; Martin, A; Martin, V; Martinez, M; Martinez-Ballarin, R; Mastrandrea, P; Mathis, M; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzione, A; Mesropian, C; Miao, T; Mietlicki, D; Miladinovic, N; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyake, H; Moed, S; Moggi, N; Mondragon, M N; Moon, C S; Moore, R; Morello, M J; Morlock, J; Movilla Fernandez, P; Mulmenstadt, J; Mukherjee, A; Muller, Th; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Nett, J; Neu, C; Neubauer, M S; Neubauer, S; Nielsen, J; Nodulman, L; Norman, M; Norniella, O; Nurse, E; Oakes, L; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Osterberg, K; Pagan Griso, S; Pagliarone, C; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramanov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Peiffer, T; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Pianori, E; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Potamianos, K; Poukhov, O; Prokoshin, F; Pronko, A; Ptohos, F; Pueschel, E; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Renton, P; Renz, M; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rodriguez, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Rutherford, B; Saarikko, H; Safonov, A; Sakumoto, W K; Santi, L; Sartori, L; Sato, K; Savoy-Navarro, A; Schlabach, P; Schmidt, A; Schmidt, E E; Schmidt, M A; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sforza, F; Sfyrla, A; Shalhout, S Z; Shears, T; Shepard, P F; Shimojima, M; Shiraishi, S; Shochet, M; Shon, Y; Shreyber, I; Simonenko, A; Sinervo, P; Sisakyan, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soha, A; Somalwar, S; Sorin, V; Squillacioti, P; Stanitzki, M; St. Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Strycker, G L; Suh, J S; Sukhanov, A; Suslov, I; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tang, J; Tecchio, M; Teng, P K; Thom, J; Thome, J; Thompson, G A; Thomson, E; Tipton, P; Ttito-Guzman, P; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Totaro, P; Tourneur, S; Trovato, M; Tsai, S Y; Tu, Y; Turini, N; Ukegawa, F; Uozumi, S; van Remortel, N; Varganov, A; Vataga, E; Vazquez, F; Velev, G; Vellidis, C; Vidal, M; Vila, I; Vilar, R; Vogel, M; Volobouev, I; Volpi, G; Wagner, P; Wagner, R G; Wagner, R L; Wagner, W; Wagner-Kuhr, J; Wakisaka, T; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Weinelt, J; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Wilbur, S; Williams, G; Williams, H H; Wilson, M G; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wolfe, H; Wright, T; Wu, X; Wurthwein, F; Yagil, A; Yamamoto, K; Yamaoka, J; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yi, K; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanetti, A; Zeng, Y; Zhang, X; Zheng, Y; Zucchelli, S

    2010-01-01

    We study the underlying event in proton-antiproton collisions by examining the behavior of charged particles (transverse momentum pT > 0.5 GeV/c, pseudorapidity |\\eta| < 1) produced in association with large transverse momentum jets (~2.2 fb-1) or with Drell-Yan lepton-pairs (~2.7 fb-1) in the Z-boson mass region (70 < M(pair) < 110 GeV/c2) as measured by CDF at 1.96 TeV center-of-mass energy. We use the direction of the lepton-pair (in Drell-Yan production) or the leading jet (in high-pT jet production) in each event to define three regions of \\eta-\\phi space; toward, away, and transverse, where \\phi is the azimuthal scattering angle. For Drell-Yan production (excluding the leptons) both the toward and transverse regions are very sensitive to the underlying event. In high-pT jet production the transverse region is very sensitive to the underlying event and is separated into a MAX and MIN transverse region, which helps separate the hard component (initial and final-state radiation) from the beam-beam...

  20. Automated force controller for amplitude modulation atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Miyagi, Atsushi, E-mail: atsushi.miyagi@inserm.fr, E-mail: simon.scheuring@inserm.fr; Scheuring, Simon, E-mail: atsushi.miyagi@inserm.fr, E-mail: simon.scheuring@inserm.fr [U1006 INSERM, Université Aix-Marseille, Parc Scientifique et Technologique de Luminy, 163 Avenue de Luminy, 13009 Marseille (France)

    2016-05-15

    Atomic Force Microscopy (AFM) is widely used in physics, chemistry, and biology to analyze the topography of a sample at nanometer resolution. Controlling precisely the force applied by the AFM tip to the sample is a prerequisite for faithful and reproducible imaging. In amplitude modulation (oscillating) mode AFM, the applied force depends on the free and the setpoint amplitudes of the cantilever oscillation. Therefore, for keeping the applied force constant, not only the setpoint amplitude but also the free amplitude must be kept constant. While the AFM user defines the setpoint amplitude, the free amplitude is typically subject to uncontrollable drift, and hence, unfortunately, the real applied force is permanently drifting during an experiment. This is particularly harmful in biological sciences where increased force destroys the soft biological matter. Here, we have developed a strategy and an electronic circuit that analyzes permanently the free amplitude of oscillation and readjusts the excitation to maintain the free amplitude constant. As a consequence, the real applied force is permanently and automatically controlled with picoNewton precision. With this circuit associated to a high-speed AFM, we illustrate the power of the development through imaging over long-duration and at various forces. The development is applicable for all AFMs and will widen the applicability of AFM to a larger range of samples and to a larger range of (non-specialist) users. Furthermore, from controlled force imaging experiments, the interaction strength between biomolecules can be analyzed.

  1. Characterization of seismic events during the 2009 eruption of Redoubt Volcano, Alaska

    Science.gov (United States)

    Ketner, Dane; Power, John

    2013-06-01

    Seismic events were automatically detected and characterized throughout the 2009 eruption of Redoubt Volcano, Alaska on a single short period station located 3 km from the volcanic crater. A total of 126,789 individual events were identified from continuous recording of seismic data from January 1 to June 30 (average 29 events per hour) using a short-term average/long-term average detection algorithm. Nine metrics were computed for this suite of events including event duration, inter-event time, event rate, peak amplitude, peak-to-peak amplitude, root-mean-square (RMS) amplitude, peak frequency, center frequency, and frequency index. Eight swarms were identified with event rates exceeding 100 events per hour. The first two occurred in late January and are attributed to high amplitude spasmodic tremor. Five additional swarms were manually repicked including swarms on February 26-27, March 20-23, March 27, March 29, and April 2-4. Three of these swarms immediately preceded major explosions including March 20-23, March 27, and April 2-4. A final swarm on May 2-9 was re-picked using a correlation detection scheme. We identified 146 event families that occurred within this suite of selected events using a cross correlation technique. Seven explosions were each immediately preceded by one or more event families. Events from the dominant family during each of these periods was additionally re-picked using correlation detection. The procession of event metrics and occurrence of event families formed a complex distribution throughout the eruption. A single-station approach was used to gain a fine-scale view of variations in seismic behavior at Redoubt with a focus on potential indicators of impending explosions. These techniques may serve an important role in future real-time eruption monitoring efforts.

  2. Community Response to a Heavy Precipitation Event in High Temperature, Chemosynthetic Biofilms and Sediments

    Science.gov (United States)

    Meyer-Dombard, D. R.; Loiacono, S. T.; Shock, E.

    2012-12-01

    Coordinated analysis of the "Bison Pool" (BP) Environmental Genome and a complementary contextual geochemical dataset of ~75 parameters revealed biogeochemical cycling and metabolic and microbial community shifts in a Yellowstone National Park hot spring ecosystem (1). The >22m outflow of BP is a gradient of decreasing temperature, increasing dissolved oxygen, and changing availability of nutrients. Microbial life at BP transitions from a 92°C chemosynthetic community in the BP source pool to a 56°C photosynthetic mat community. Metagenomic data at BP showed the potential for both heterotrophic and autotrophic carbon metabolism (rTCA and acetyl-CoA cycles) in the highest temperature, chemosynthetic regions (1). This region of the outflow is dominated by Aquificales and Pyrococcus relatives, with smaller contributions of heterotrophic Bacteria. Following a 2h heavy precipitation event we observed an influx of exogenous organic material into the source pool supplied from the meadow surrounding the BP area. We sampled biomass and fluid at several locations within the outflow immediately following the event, and on several occasions for the next eight days. Elemental analysis and carbon and nitrogen isotopic analyses were conducted on biomass and sediment, and dissolved organic and inorganic carbon content and δ13C of fluids were analyzed. DNA and RNA were extracted, and following RT-PCR, nitrogen cycle functional gene expression was evaluated. Previous work at BP has shown that chemosynthetic biomass may carry isotopic signatures of fractionation during carbon fixation, via the acetyl-CoA and rTCA cycles (2). However, the addition of exogenous organic carbon during the rain event had an immediate and dramatic effect on the sediments and biofilms in the chemosynthetic zone of the outflow. Dissolved organic carbon was the highest measured in six years. Chemosynthetic biomass responded by incorporating the organic carbon. Carbon isotopic signatures in chemosynthetic

  3. A novel paleo-bleaching proxy using boron isotopes and high-resolution laser ablation to reconstruct coral bleaching events

    Science.gov (United States)

    Dishon, G.; Fisch, J.; Horn, I.; Kaczmarek, K.; Bijma, J.; Gruber, D. F.; Nir, O.; Popovich, Y.; Tchernov, D.

    2015-10-01

    Coral reefs occupy only ~ 0.1 percent of the ocean's habitat, but are the most biologically diverse marine ecosystem. In recent decades, coral reefs have experienced a significant global decline due to a variety of causes, one of the major causes being widespread coral bleaching events. During bleaching, the coral expels its symbiotic algae, thereby losing its main source of nutrition generally obtained through photosynthesis. While recent coral bleaching events have been extensively investigated, there is no scientific data on historical coral bleaching prior to 1979. In this study, we employ high-resolution femtosecond Laser Ablation Multiple Collector Inductively Coupled Plasma Mass Spectrometry (LA-MC-ICP-MS) to demonstrate a distinct biologically induced decline of boron (B) isotopic composition (δ11B) as a result of coral bleaching. These findings and methodology offer a new use for a previously developed isotopic proxy to reconstruct paleo-coral bleaching events. Based on a literature review of published δ11B data and our recorded vital effect of coral bleaching on the δ11B signal, we also describe at least two possible coral bleaching events since the Last Glacial Maximum. The implementation of this bleaching proxy holds the potential of identifying occurrences of coral bleaching throughout the geological record. A deeper temporal view of coral bleaching will enable scientists to determine if it occurred in the past during times of environmental change and what outcome it may have had on coral population structure. Understanding the frequency of bleaching events is also critical for determining the relationship between natural and anthropogenic causes of these events.

  4. Neural events leading to and associated with detection of sounds under high processing load.

    Science.gov (United States)

    Sabri, Merav; Humphries, Colin; Binder, Jeffrey R; Liebenthal, Einat

    2013-03-01

    The neural events that lead to successful or failed detection of suprathreshold sounds are not well established. In this experiment, event-related potentials (ERPs) and functional magnetic resonance imaging (fMRI) were recorded while participants performed two tasks: a primary difficult duration judgment task on a sequence of tones presented to one ear, and a secondary target detection task on an auditory oddball stream presented to the other ear. The paradigm was designed to elicit competition and variability in detection of auditory targets despite identical input. Successful detection of auditory targets was associated mainly with greater fMRI activity in superior parietal cortex and thalamus. In the ERPs, successful detection was linked with a larger fronto-central negativity at 200-400 ms, and a later centro-posterior positivity. Failure to detect targets was associated with greater fMRI signal in the default mode network, a significantly smaller electrical fronto-central negativity and no late positivity. These findings demonstrate that variability in auditory detection is related to modulation of activity in multimodal parietal and frontal networks active ∼ 200 ms after target onset. Results are consistent with a limited capacity and late selection view of attention.

  5. Stellar Death by Black Hole: How Tidal Disruption Events Unveil the High Energy Universe

    Science.gov (United States)

    Coughlin, Eric Robert

    2017-08-01

    When a star comes very close to a supermassive black hole, the tidal field of the hole can be strong enough to deform and stretch the star into a stream of debris. Half of this stellar debris stream returns to the black hole and forms an accretion disk, briefly lighting up the black hole and, in the most extreme cases, launching relativistic jets. These ``tidal disruption events,'' from the initial stellar destruction to the eventual jet production, are the focus of my thesis, and during this talk I will describe some of the theoretical advances we have made in understanding them. I will also discuss more recent work that shows how this relatively simple picture can be more complicated when the disrupting black hole is part of a binary system. Despite the added complexity, I will argue that there is a timescale over which one expects to see variation in the luminosity of a tidal disruption event from a binary supermassive black hole system. Using these predictions and a set of simulations, I will motivate such an interpretation for the superluminous supernova ASASSN-15lh.

  6. Patients at high risk of adverse events from intravenous contrast media after computed tomography examination

    Energy Technology Data Exchange (ETDEWEB)

    Reddan, Donal [University College Galway Hospitals, Unit 7, Merlin Park Hospital, Galway (Ireland)]. E-mail: donal.reddan@mailn.hse.ie

    2007-05-15

    Adverse reactions to iodinated contrast media (CM) may occur and require prompt recognition and treatment. Although adverse reactions to radiocontrast agents cannot be eliminated, an important first step toward reducing their incidence is to identify patients at greatest risk. Prior to examinations using CM, patients should be adequately assessed by obtaining thorough medical histories and using simple screening tests. Studies have demonstrated that patients with a history of asthma, allergy, hyperthyroidism, and previous reaction to CM are at risk for severe reactions to iodinated CM. Renal adverse reactions reportedly occur more frequently in patients with pre-existing chronic kidney disease, especially those with diabetic nephropathy. Patients with congestive heart failure, dehydration, older age, and those who use nephrotoxic medications are also at risk for developing contrast-associated nephropathy. The occurrence of adverse events may be further increased in patients with multiple risk factors. As the number of patients undergoing computed tomography procedures continues to increase, it is essential for physicians to be able to identify patients at risk for adverse events of CM. Patient-related risk factors are discussed and simple tools for risk stratification presented.

  7. Amplitude recruitment of cochlear potential

    Institute of Scientific and Technical Information of China (English)

    LI Xingqi; SUN Wei; SUN Jianhe; YU Ning; JIANG Sichang

    2001-01-01

    Intracellular recordings were made from outer hair cells (OHC) and the cochlear microphonics (CM) were recorded from scala media (SM) in three turn of guinea pig cochlea,the compound action potential (CAP) were recorded at the round window (RW) before and after the animal were exposed to white noise. The results suggest that the nonlinear properties with “saduration” of Input/output (I/O) function of OHC AC recepter potential and CM were founded; the nonlinear properties with “Low”, “Platean” and “high” of CAP also were investigated. After explosion, the threshold shift of CAP has about 10 dB. The I/O of OHC responses and CM were changed in a linearizing (i.e., nonlinearity loss), the “platean” of I/O CAP disappeared and the growth rate of CAP amplitude were larger than before explosion. The response amplitude recruitment of OHC appears to result from reduction in gain (i.e., hearing loss); It was due to the nonlinear growth function of OHC receptor potentials was changed in linearzing that the basilar membrance motion was changed in linearizing. Since intensity coding in the inner ear depends on an interactions of nonlinear basilar membrance and nerve fibers. So that it must lead to a linearizing of CAP as input responses.

  8. Atmospheric ionization by high-fluence, hard spectrum solar proton events and their probable appearance in the ice core archive

    CERN Document Server

    Melott, Adrian L; Laird, Claude M; Neuenswander, Ben; Atri, Dimitra

    2016-01-01

    Solar energetic particles ionize the atmosphere, leading to production of nitrogen oxides. It has been suggested that some such events are visible as layers of nitrate in ice cores, yielding archives of energetic, high fluence solar proton events (SPEs). There has been controversy, due to slowness of transport for these species down from the upper stratosphere; past numerical simulations based on an analytic calculation have shown very little ionization below the mid stratosphere. These simulations suffer from deficiencies: they consider only soft SPEs and narrow energy ranges; spectral fits are poorly chosen; with few exceptions secondary particles in air showers are ignored. Using improved simulations that follow development of the proton-induced air shower, we find consistency with recent experiments showing substantial excess ionization down to 5 km. We compute nitrate available from the 23 February 1956 SPE, which had a high fluence, hard spectrum, and well-resolved associated nitrate peak in a Greenland...

  9. Search for Dark Matter in events with a hight- p$_T$ photon and high missing transverse momentum in ATLAS

    CERN Document Server

    Ratti, M G

    2016-01-01

    We present the results of a search for new particles in events with a high-pT photon and high missing transverse momentum with the ATLAS experiment at the LHC. The analysis is performed on the data collected by ATLAS at a centre of mass energy of 8TeV and corresponding to a total integrated luminosity of 20.3 fb$^{−1}$. No excess has been found with respect to the Standard Model expectation. A modelindependent upper limit on the fiducial cross section for the production of events with a photon and large missing transverse momentum is set. Exclusion limits on the direct pair production of dark matter candidates are presented.

  10. Implications of high-temperature events and water deficits on protein profiles in wheat (Triticum aestivum L. cv. Vinjett) grain

    DEFF Research Database (Denmark)

    Yang, Fen; Jørgensen, Anders Dysted; Li, Huawei

    2011-01-01

    Increased climatic variability is resulting in an increase of both the frequency and the magnitude of extreme climate events. Therefore, cereals may be exposed to more than one stress event in the growing season, which may ultimately affect crop yield and quality. Here, effects are reported...... and glutenins) in grains and stress-induced changes on the albumin and gliadin proteomes were investigated by 2-DE and MS. The synthesis of individual protein fractions was shown to be affected by both the type and time of the applied stresses. Identified drought or high-temperature-responsive proteins included...... proteins involved in primary metabolism, storage and stress response such as late embryogenesis abundant proteins, peroxiredoxins and alpha-amylase/trypsin inhibitors. Several proteins, e.g. heat shock protein and 14-3-3 protein changed in abundance only under multiple high temperatures....

  11. Encoding negative events under stress: high subjective arousal is related to accurate emotional memory despite misinformation exposure.

    Science.gov (United States)

    Hoscheidt, Siobhan M; LaBar, Kevin S; Ryan, Lee; Jacobs, W Jake; Nadel, Lynn

    2014-07-01

    Stress at encoding affects memory processes, typically enhancing, or preserving, memory for emotional information. These effects have interesting implications for eyewitness accounts, which in real-world contexts typically involve encoding an aversive event under stressful conditions followed by potential exposure to misinformation. The present study investigated memory for a negative event encoded under stress and subsequent misinformation endorsement. Healthy young adults participated in a between-groups design with three experimental sessions conducted 48 h apart. Session one consisted of a psychosocial stress induction (or control task) followed by incidental encoding of a negative slideshow. During session two, participants were asked questions about the slideshow, during which a random subgroup was exposed to misinformation. Memory for the slideshow was tested during the third session. Assessment of memory accuracy across stress and no-stress groups revealed that stress induced just prior to encoding led to significantly better memory for the slideshow overall. The classic misinformation effect was also observed - participants exposed to misinformation were significantly more likely to endorse false information during memory testing. In the stress group, however, memory accuracy and misinformation effects were moderated by arousal experienced during encoding of the negative event. Misinformed-stress group participants who reported that the negative slideshow elicited high arousal during encoding were less likely to endorse misinformation for the most aversive phase of the story. Furthermore, these individuals showed better memory for components of the aversive slideshow phase that had been directly misinformed. Results from the current study provide evidence that stress and high subjective arousal elicited by a negative event act concomitantly during encoding to enhance emotional memory such that the most aversive aspects of the event are well remembered and

  12. Characterization of the High-Speed-Stage Bearing Skidding of Wind Turbine Gearboxes Induced by Dynamic Electricity Grid Events

    Energy Technology Data Exchange (ETDEWEB)

    Helsen, Jan; Guillaume, Patrick; Guo, Yi; Keller, Jonathan

    2016-07-01

    Bearing behavior is an important factor for wind turbine drivetrain reliability. Extreme loads and dynamic excitations pose challenges to the bearing design and therefore its performance. Excessive skidding of the bearing rollers should be avoided because it can cause scuffing failures. Excitations coming from wind and the electricity grid can subject the drivetrain to fluctuating torque and nontorque loads. Wind-induced excitations have been investigated predominantly in literature. However, modern wind turbines are subjected more and more to grid-induced loads because of stricter electricity grid regulations. For example, during fault-ride-through events, turbines are required to stay connected for a longer period of time during the grid failure. This work investigates the influence of electrically induced excitations on the skidding behaviour of the tapered roller bearings on the high-speed stage of a wind turbine gearbox. This skidding behaviour during dynamic events is described as a potential bearing failure initiator by many researchers; however, only limited full-scale dynamic testing is documented. Therefore, a dedicated gridloss-type event is defined in the paper and conducted in a dynamometer test on a full-scale wind turbine nacelle. During the event, a complete electricity grid failure is simulated while the turbine is at rated speed and predefined torque levels. Particular focus is on the characterization of the high-speed shaft tapered roller bearing slip behavior. Strain-gauge bridges in grooves along the circumference of the outer ring are used to characterize the bearing load zone in detail. It is shown that during the torque reversals of the transient event, roller slip can be induced. This indicates the potential of the applied load case to go beyond the preload of the tapered roller bearing. Furthermore, the relation between the applied torque and skidding level is studied.

  13. Characterization of the High-Speed-Stage Bearing Skidding of Wind Turbine Gearboxes Induced by Dynamic Electricity Grid Events: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Helsen, Jan; Guillaume, Patrick; Guo, Yi; Keller, Jonathan

    2016-05-18

    Bearing behavior is an important factor for wind turbine drivetrain reliability. Extreme loads and dynamic excitations pose challenges to the bearing design and therefore its performance. Excessive skidding of the bearing rollers should be avoided because it can cause scuffing failures. Excitations coming from wind and the electricity grid can subject the drivetrain to fluctuating torque and nontorque loads. Wind-induced excitations have been investigated predominantly in literature. However, modern wind turbines are subjected more and more to grid-induced loads because of stricter electricity grid regulations. For example, during fault-ride-through events, turbines are required to stay connected for a longer period of time during the grid failure. This work investigates the influence of electrically induced excitations on the skidding behaviour of the tapered roller bearings on the high-speed stage of a wind turbine gearbox. This skidding behaviour during dynamic events is described as a potential bearing failure initiator by many researchers; however, only limited full-scale dynamic testing is documented. Therefore, a dedicated gridloss-type event is defined in the paper and conducted in a dynamometer test on a full-scale wind turbine nacelle. During the event, a complete electricity grid failure is simulated while the turbine is at rated speed and predefined torque levels. Particular focus is on the characterization of the high-speed shaft tapered roller bearing slip behavior. Strain-gauge bridges in grooves along the circumference of the outer ring are used to characterize the bearing load zone in detail. It is shown that during the torque reversals of the transient event, roller slip can be induced. This indicates the potential of the applied load case to go beyond the preload of the tapered roller bearing. Furthermore, the relation between the applied torque and skidding level is studied.

  14. High-energy neutrino follow-up search of gravitational wave event GW150914 with ANTARES and IceCube

    OpenAIRE

    Adrián-Martínez, S.; Albert, A.; M. André; Anghinolfi, M.; Ardid, M.; Aubert, J.-J.; Avgitas, T.; Baret, B.; Barrios-Martí, J.; Basa, S.; Bertin, V.; Biagi, S.; Bormuth, R.; Bouwhuis, M. C.; Bruijn, R.

    2016-01-01

    We present the high-energy-neutrino follow-up observations of the first gravitational wave transient GW150914 observed by the Advanced LIGO detectors on September 14, 2015. We search for coincident neutrino candidates within the data recorded by the IceCube and Antares neutrino detectors. A possible joint detection could be used in targeted electromagnetic follow-up observations, given the significantly better angular resolution of neutrino events compared to gravitational waves. We find no n...

  15. Early detection of atrial high rate episodes predicts atrial fibrillation and thromboembolic events in patients with cardiac resynchronization therapy

    DEFF Research Database (Denmark)

    Witt, Christoffer Tobias; Kronborg, Mads Brix; Nohr, Ellen Aagaard

    2015-01-01

    BACKGROUND: In patients without any history of atrial fibrillation (AF), detection of subclinical atrial high rate episodes (AHRE) by implanted devices has been associated with an increased thromboembolic risk. The predictive value of AHRE in patients with cardiac resynchronization therapy (CRT...... of AF, detection of early AHRE after CRT implantation is associated with a significantly increased risk of clinical AF and thromboembolic events, particularly AHRE longer than 24 hours....

  16. Snow cover and extreme winter warming events control flower abundance of some, but not all species in high arctic Svalbard.

    Science.gov (United States)

    Semenchuk, Philipp R; Elberling, Bo; Cooper, Elisabeth J

    2013-08-01

    The High Arctic winter is expected to be altered through ongoing and future climate change. Winter precipitation and snow depth are projected to increase and melt out dates change accordingly. Also, snow cover and depth will play an important role in protecting plant canopy from increasingly more frequent extreme winter warming events. Flower production of many Arctic plants is dependent on melt out timing, since season length determines resource availability for flower preformation. We erected snow fences to increase snow depth and shorten growing season, and counted flowers of six species over 5 years, during which we experienced two extreme winter warming events. Most species were resistant to snow cover increase, but two species reduced flower abundance due to shortened growing seasons. Cassiope tetragona responded strongly with fewer flowers in deep snow regimes during years without extreme events, while Stellaria crassipes responded partly. Snow pack thickness determined whether winter warming events had an effect on flower abundance of some species. Warming events clearly reduced flower abundance in shallow but not in deep snow regimes of Cassiope tetragona, but only marginally for Dryas octopetala. However, the affected species were resilient and individuals did not experience any long term effects. In the case of short or cold summers, a subset of species suffered reduced reproductive success, which may affect future plant composition through possible cascading competition effects. Extreme winter warming events were shown to expose the canopy to cold winter air. The following summer most of the overwintering flower buds could not produce flowers. Thus reproductive success is reduced if this occurs in subsequent years. We conclude that snow depth influences flower abundance by altering season length and by protecting or exposing flower buds to cold winter air, but most species studied are resistant to changes. Winter warming events, often occurring

  17. A Simple Engineering Analysis of Solar Particle Event High Energy Tails and Their Impact on Vehicle Design

    Science.gov (United States)

    Singleterry, Robert C., Jr.; Walker, Steven A.; Clowdsley, Martha S.

    2016-01-01

    The mathematical models for Solar Particle Event (SPE) high energy tails are constructed with several di erent algorithms. Since limited measured data exist above energies around 400 MeV, this paper arbitrarily de nes the high energy tail as any proton with an energy above 400 MeV. In order to better understand the importance of accurately modeling the high energy tail for SPE spectra, the contribution to astronaut whole body e ective dose equivalent of the high energy portions of three di erent SPE models has been evaluated. To ensure completeness of this analysis, simple and complex geometries were used. This analysis showed that the high energy tail of certain SPEs can be relevant to astronaut exposure and hence safety. Therefore, models of high energy tails for SPEs should be well analyzed and based on data if possible.

  18. Measurements in a highly polluted Asian mega city: observations of aerosol number size distribution, modal parameters and nucleation events

    Directory of Open Access Journals (Sweden)

    P. Mönkkönen

    2004-09-01

    Full Text Available Diurnal variation of number size distribution (particle size 3–800 nm and modal parameters (geometric standard deviation, geometric mean diameter and modal aerosol particle concentration in a highly polluted urban environment was investigated during October and November 2002 in New Delhi, India. Continuous monitoring for more than two weeks with the time resolution of 10 min was conducted using a Differential Mobility Particle Sizer (twin DMPS. The results indicated clear increase in Aitken mode (25–100 nm particles during traffic peak hours, but towards the evenings there were more Aitken mode particles compared to the mornings. Also high concentrations of accumulation mode particles (>100 nm were detected in the evenings only. In the evenings, biomass/refuse burning and cooking are possible sources beside the traffic. We have also shown that nucleation events are possible in this kind of atmosphere even though as clear nucleation events as observed in rural sites could not be detected. The formation rate of 3 nm particles (J3 of the observed events varied from 3.3 to 13.9 cm−3s−1 and the growth rate varied from 11.6 to 18.1 nmh−1 showing rapid growth and high formation rate, which seems to be typical in urban areas.

  19. Measurements in a highly polluted Asian mega city: observations of aerosol number size distribution, modal parameters and nucleation events

    Directory of Open Access Journals (Sweden)

    P. Mönkkönen

    2005-01-01

    Full Text Available Diurnal variation of number size distribution (particle size 3-800nm and modal parameters (geometric standard deviation, geometric mean diameter and modal aerosol particle concentration in a highly polluted urban environment was investigated during October and November 2002 in New Delhi, India. Continuous monitoring for more than two weeks with the time resolution of 10min was conducted using a Differential Mobility Particle Sizer (twin DMPS. The results indicated clear increase in Aitken mode (25-100nm particles during traffic peak hours, but towards the evenings there were more Aitken mode particles compared to the mornings. Also high concentrations of accumulation mode particles (>100nm were detected in the evenings only. In the evenings, biomass/refuse burning and cooking are possible sources beside the traffic. We have also shown that nucleation events are possible in this kind of atmosphere even though as clear nucleation events as observed in rural sites could not be detected. The formation rate of 3nm particles (J3 of the observed events varied from 3.3 to 13.9cm-3s-1 and the growth rate varied from 11.6 to 18.1nmh-1 showing rapid growth and high formation rate, which seems to be typical in urban areas.

  20. NEW FERMI-LAT EVENT RECONSTRUCTION REVEALS MORE HIGH-ENERGY GAMMA RAYS FROM GAMMA-RAY BURSTS

    Energy Technology Data Exchange (ETDEWEB)

    Atwood, W. B. [Santa Cruz Institute for Particle Physics, Department of Physics and Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064 (United States); Baldini, L. [Universita di Pisa and Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Bregeon, J.; Pesce-Rollins, M.; Sgro, C.; Tinivella, M. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Bruel, P. [Laboratoire Leprince-Ringuet, Ecole polytechnique, CNRS/IN2P3, Palaiseau (France); Chekhtman, A. [Center for Earth Observing and Space Research, College of Science, George Mason University, Fairfax, VA 22030 (United States); Cohen-Tanugi, J. [Laboratoire Univers et Particules de Montpellier, Universite Montpellier 2, CNRS/IN2P3, F-34095 Montpellier (France); Drlica-Wagner, A.; Omodei, N.; Rochester, L. S.; Usher, T. L. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Granot, J. [Department of Natural Sciences, The Open University of Israel, 1 University Road, P.O. Box 808, Ra' anana 43537 (Israel); Longo, F. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy); Razzaque, S. [Department of Physics, University of Johannesburg, Auckland Park 2006 (South Africa); Zimmer, S., E-mail: melissa.pesce.rollins@pi.infn.it, E-mail: nicola.omodei@stanford.edu, E-mail: granot@openu.ac.il [Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm (Sweden)

    2013-09-01

    Based on the experience gained during the four and a half years of the mission, the Fermi-LAT Collaboration has undertaken a comprehensive revision of the event-level analysis going under the name of Pass 8. Although it is not yet finalized, we can test the improvements in the new event reconstruction with the special case of the prompt phase of bright gamma-ray bursts (GRBs), where the signal-to-noise ratio is large enough that loose selection cuts are sufficient to identify gamma rays associated with the source. Using the new event reconstruction, we have re-analyzed 10 GRBs previously detected by the Large Area Telescope (LAT) for which an X-ray/optical follow-up was possible and found four new gamma rays with energies greater than 10 GeV in addition to the seven previously known. Among these four is a 27.4 GeV gamma ray from GRB 080916C, which has a redshift of 4.35, thus making it the gamma ray with the highest intrinsic energy ({approx}147 GeV) detected from a GRB. We present here the salient aspects of the new event reconstruction and discuss the scientific implications of these new high-energy gamma rays, such as constraining extragalactic background light models, Lorentz invariance violation tests, the prompt emission mechanism, and the bulk Lorentz factor of the emitting region.

  1. A novel paleo-bleaching proxy using boron isotopes and high-resolution laser ablation to reconstruct coral bleaching events

    Directory of Open Access Journals (Sweden)

    G. Dishon

    2015-06-01

    Full Text Available Coral reefs occupy only ~0.1% of the oceans habitat, but are the most biologically diverse marine ecosystem. In recent decades, coral reefs have experienced significant global declines due to a variety of causes, one of the major being widespread coral bleaching events. During bleaching the coral expels its symbiotic algae losing its main source of nutrition generally obtained through photosynthesis. While recent coral bleaching events have been extensively investigated, there is no scientific data on historical coral bleaching prior to 1979. In this study, we employ high-resolution femtosecond Laser Ablation Multiple Collector Inductively Coupled Plasma Mass Spectrometry (LA-MC-ICP-MS to demonstrate a distinct biologically-induced decline of boron (B isotopic composition (δ11B as a result of coral bleaching. These findings and methodology offer a new use for a previously developed isotopic proxy to reconstruct paleo-coral bleaching events. Based on a literature review of published δ11B data and our recorded "vital effect" of coral bleaching on the δ11B signal, we also describe at least two possible coral bleaching events since the Last Glacial Maximum. The implementation of this bleaching proxy holds the potential of identifying occurrences of coral bleaching throughout the geological record. A deeper temporal view of coral bleaching will enable scientists to determine if it occurred in the past during times of environmental change and what outcome it may have had on coral population structure.

  2. High Cadence Observations and Analysis of Spicular-type Events Using CRISP Onboard SST

    Science.gov (United States)

    Shetye, J.; Doyle, J. G.; Scullion, E.; Nelson, C. J.; Kuridze, D.

    2016-04-01

    We present spectroscopic and imaging observations of apparent ultra-fast spicule-like features observed with CRisp Imaging SpectroPolarimeter (CRISP) at the Swedish 1-m Solar Telescope (SST). The data shows spicules with an apparent velocity above 500 km s-1, very short lifetimes of up to 20 s and length/height around 3500 km. The spicules are seen as dark absorption structures in the Hα wings ±516 mÅ, ±774 mÅ and ±1032 mÅ which suddenly appear and disappear from the FOV. These features show a time delay in their appearance in the blue and red wings by 3-5 s. We suggest that their appearance/disappearance is due to their Doppler motion in and out of the 60 mÅ filter. See Fig. 1 for the evolution of the event at two line positions.

  3. High-Performance Signal Detection for Adverse Drug Events using MapReduce Paradigm.

    Science.gov (United States)

    Fan, Kai; Sun, Xingzhi; Tao, Ying; Xu, Linhao; Wang, Chen; Mao, Xianling; Peng, Bo; Pan, Yue

    2010-11-13

    Post-marketing pharmacovigilance is important for public health, as many Adverse Drug Events (ADEs) are unknown when those drugs were approved for marketing. However, due to the large number of reported drugs and drug combinations, detecting ADE signals by mining these reports is becoming a challenging task in terms of computational complexity. Recently, a parallel programming model, MapReduce has been introduced by Google to support large-scale data intensive applications. In this study, we proposed a MapReduce-based algorithm, for common ADE detection approach, Proportional Reporting Ratio (PRR), and tested it in mining spontaneous ADE reports from FDA. The purpose is to investigate the possibility of using MapReduce principle to speed up biomedical data mining tasks using this pharmacovigilance case as one specific example. The results demonstrated that MapReduce programming model could improve the performance of common signal detection algorithm for pharmacovigilance in a distributed computation environment at approximately liner speedup rates.

  4. High quality maize centromere 10 sequence reveals evidence of frequent recombination events

    Directory of Open Access Journals (Sweden)

    Thomas Kai Wolfgruber

    2016-03-01

    Full Text Available The ancestral centromeres of maize contain long stretches of the tandemly arranged CentC repeat. The abundance of tandem DNA repeats and centromeric retrotransposons (CR have presented a significant challenge to completely assembling centromeres using traditional sequencing methods. Here we report a nearly complete assembly of the 1.85 Mb maize centromere 10 from inbred B73 using PacBio technology and BACs from the reference genome project. The error rates estimated from overlapping BAC sequences are 7 x 10-6 and 5 x 10-5 for mismatches and indels, respectively. The number of gaps in the region covered by the reassembly was reduced from 140 in the reference genome to three. Three expressed genes are located between 92 and 477 kb of the inferred ancestral CentC cluster, which lies within the region of highest centromeric repeat density. The improved assembly increased the count of full-length centromeric retrotransposons from 5 to 55 and revealed a 22.7 kb segmental duplication that occurred approximately 121,000 years ago. Our analysis provides evidence of frequent recombination events in the form of partial retrotransposons, deletions within retrotransposons, chimeric retrotransposons, segmental duplications including higher order CentC repeats, a deleted CentC monomer, centromere-proximal inversions, and insertion of mitochondrial sequences. Double-strand DNA break (DSB repair is the most plausible mechanism for these events and may be the major driver of centromere repeat evolution and diversity. This repair appears to be mediated by microhomology, suggesting that tandem repeats may have evolved to facilitate the repair of frequent DSBs in centromeres.

  5. Fatigue independent amplitude-frequency correlations in EMG signals

    CERN Document Server

    Siemienski, A; Klajner, P; Siemienski, Adam; Kebel, Alicja; Klajner, Piotr

    2006-01-01

    In order to assess fatigue independent amplitude-frequency correlations in EMG signals we asked nineteen male subjects to perform a series of isometric muscular contractions by extensors of the knee joint. Different amplitudes of the signal were due to randomly varying both the joint moment and the overall amplification factor of the EMG apparatus. Mean and median frequency, RMS and mean absolute value were calculated for every combination of joint moment and amplification at the original sampling rate of 5 kHz and at several simulated lower sampling rates. Negative Spearman and Kendall amplitude-frequency correlation coefficients were found, and they were more pronounced at high sampling rates.

  6. Role of land state in a high resolution mesoscale model for simulating the Uttarakhand heavy rainfall event over India

    Science.gov (United States)

    Rajesh, P. V.; Pattnaik, S.; Rai, D.; Osuri, K. K.; Mohanty, U. C.; Tripathy, S.

    2016-04-01

    In 2013, Indian summer monsoon witnessed a very heavy rainfall event (>30 cm/day) over Uttarakhand in north India, claiming more than 5000 lives and property damage worth approximately 40 billion USD. This event was associated with the interaction of two synoptic systems, i.e., intensified subtropical westerly trough over north India and north-westward moving monsoon depression formed over the Bay of Bengal. The event had occurred over highly variable terrain and land surface characteristics. Although global models predicted the large scale event, they failed to predict realistic location, timing, amount, intensity and distribution of rainfall over the region. The goal of this study is to assess the impact of land state conditions in simulating this severe event using a high resolution mesoscale model. The land conditions such as multi-layer soil moisture and soil temperature fields were generated from High Resolution Land Data Assimilation (HRLDAS) modelling system. Two experiments were conducted namely, (1) CNTL (Control, without land data assimilation) and (2) LDAS, with land data assimilation (i.e., with HRLDAS-based soil moisture and temperature fields) using Weather Research and Forecasting (WRF) modelling system. Initial soil moisture correlation and root mean square error for LDAS is 0.73 and 0.05, whereas for CNTL it is 0.63 and 0.053 respectively, with a stronger heat low in LDAS. The differences in wind and moisture transport in LDAS favoured increased moisture transport from Arabian Sea through a convectively unstable region embedded within two low pressure centers over Arabian Sea and Bay of Bengal. The improvement in rainfall is significantly correlated to the persistent generation of potential vorticity (PV) in LDAS. Further, PV tendency analysis confirmed that the increased generation of PV is due to the enhanced horizontal PV advection component rather than the diabatic heating terms due to modified flow fields. These results suggest that, two

  7. Role of land state in a high resolution mesoscale model for simulating the Uttarakhand heavy rainfall event over India

    Indian Academy of Sciences (India)

    P V Rajesh; S Pattnaik; D Rai; K K Osuri; U C Mohanty; S Tripathy

    2016-04-01

    In 2013, Indian summer monsoon witnessed a very heavy rainfall event (>30 cm/day) over Uttarakhandin north India, claiming more than 5000 lives and property damage worth approximately 40 billionUSD. This event was associated with the interaction of two synoptic systems, i.e., intensified subtropicalwesterly trough over north India and north-westward moving monsoon depression formed over the Bayof Bengal. The event had occurred over highly variable terrain and land surface characteristics. Althoughglobal models predicted the large scale event, they failed to predict realistic location, timing, amount,intensity and distribution of rainfall over the region. The goal of this study is to assess the impactof land state conditions in simulating this severe event using a high resolution mesoscale model. Theland conditions such as multi-layer soil moisture and soil temperature fields were generated from HighResolution Land Data Assimilation (HRLDAS) modelling system. Two experiments were conductednamely, (1) CNTL (Control, without land data assimilation) and (2) LDAS, with land data assimilation(i.e., with HRLDAS-based soil moisture and temperature fields) using Weather Research and Forecasting(WRF) modelling system. Initial soil moisture correlation and root mean square error for LDAS is 0.73and 0.05, whereas for CNTL it is 0.63 and 0.053 respectively, with a stronger heat low in LDAS. Thedifferences in wind and moisture transport in LDAS favoured increased moisture transport from ArabianSea through a convectively unstable region embedded within two low pressure centers over Arabian Seaand Bay of Bengal. The improvement in rainfall is significantly correlated to the persistent generation ofpotential vorticity (PV) in LDAS. Further, PV tendency analysis confirmed that the increased generationof PV is due to the enhanced horizontal PV advection component rather than the diabatic heatingterms due to modified flow fields. These results suggest that, two different synoptic

  8. High-Sensitivity C-Reactive Protein as a Predictor of Cardiovascular Events after ST-Elevation Myocardial Infarction

    Science.gov (United States)

    Ribeiro, Daniel Rios Pinto; Ramos, Adriane Monserrat; Vieira, Pedro Lima; Menti, Eduardo; Bordin, Odemir Luiz; de Souza, Priscilla Azambuja Lopes; de Quadros, Alexandre Schaan; Portal, Vera Lúcia

    2014-01-01

    Background The association between high-sensitivity C-reactive protein and recurrent major adverse cardiovascular events (MACE) in patients with ST-elevation myocardial infarction who undergo primary percutaneous coronary intervention remains controversial. Objective To investigate the potential association between high-sensitivity C-reactive protein and an increased risk of MACE such as death, heart failure, reinfarction, and new revascularization in patients with ST-elevation myocardial infarction treated with primary percutaneous coronary intervention. Methods This prospective cohort study included 300 individuals aged >18 years who were diagnosed with ST-elevation myocardial infarction and underwent primary percutaneous coronary intervention at a tertiary health center. An instrument evaluating clinical variables and the Thrombolysis in Myocardial Infarction (TIMI) and Global Registry of Acute Coronary Events (GRACE) risk scores was used. High-sensitivity C-reactive protein was determined by nephelometry. The patients were followed-up during hospitalization and up to 30 days after infarction for the occurrence of MACE. Student's t, Mann-Whitney, chi-square, and logistic regression tests were used for statistical analyses. P values of ≤0.05 were considered statistically significant. Results The mean age was 59.76 years, and 69.3% of patients were male. No statistically significant association was observed between high-sensitivity C-reactive protein and recurrent MACE (p = 0.11). However, high-sensitivity C-reactive protein was independently associated with 30-day mortality when adjusted for TIMI [odds ratio (OR), 1.27; 95% confidence interval (CI), 1.07-1.51; p = 0.005] and GRACE (OR, 1.26; 95% CI, 1.06-1.49; p = 0.007) risk scores. Conclusion Although high-sensitivity C-reactive protein was not predictive of combined major cardiovascular events within 30 days after ST-elevation myocardial infarction in patients who underwent primary angioplasty and stent

  9. High-Sensitivity C-Reactive Protein as a Predictor of Cardiovascular Events after ST-Elevation Myocardial Infarction

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Daniel Rios Pinto; Ramos, Adriane Monserrat; Vieira, Pedro Lima; Menti, Eduardo; Bordin, Odemir Luiz Jr.; Souza, Priscilla Azambuja Lopes de; Quadros, Alexandre Schaan de; Portal, Vera Lúcia, E-mail: veraportal.pesquisa@gmail.com [Programa de Pós-Graduação em Ciências da Saúde: Cardiologia - Instituto de Cardiologia/Fundação Universitária de Cardiologia, Porto Alegre, RS (Brazil)

    2014-07-15

    The association between high-sensitivity C-reactive protein and recurrent major adverse cardiovascular events (MACE) in patients with ST-elevation myocardial infarction who undergo primary percutaneous coronary intervention remains controversial. To investigate the potential association between high-sensitivity C-reactive protein and an increased risk of MACE such as death, heart failure, reinfarction, and new revascularization in patients with ST-elevation myocardial infarction treated with primary percutaneous coronary intervention. This prospective cohort study included 300 individuals aged >18 years who were diagnosed with ST-elevation myocardial infarction and underwent primary percutaneous coronary intervention at a tertiary health center. An instrument evaluating clinical variables and the Thrombolysis in Myocardial Infarction (TIMI) and Global Registry of Acute Coronary Events (GRACE) risk scores was used. High-sensitivity C-reactive protein was determined by nephelometry. The patients were followed-up during hospitalization and up to 30 days after infarction for the occurrence of MACE. Student's t, Mann-Whitney, chi-square, and logistic regression tests were used for statistical analyses. P values of ≤0.05 were considered statistically significant. The mean age was 59.76 years, and 69.3% of patients were male. No statistically significant association was observed between high-sensitivity C-reactive protein and recurrent MACE (p = 0.11). However, high-sensitivity C-reactive protein was independently associated with 30-day mortality when adjusted for TIMI [odds ratio (OR), 1.27; 95% confidence interval (CI), 1.07-1.51; p = 0.005] and GRACE (OR, 1.26; 95% CI, 1.06-1.49; p = 0.007) risk scores. Although high-sensitivity C-reactive protein was not predictive of combined major cardiovascular events within 30 days after ST-elevation myocardial infarction in patients who underwent primary angioplasty and stent implantation, it was an independent predictor

  10. Sequential amplitude divided angular multiplexing encoding optical system design for high power excimer laser system%连续分振幅式高功率准分子激光角多路编码光路设计

    Institute of Scientific and Technical Information of China (English)

    胡云; 王大辉; 赵学庆

    2016-01-01

    In high power excimer laser system, angular multiplexing technique is employed to achieve both high energy and narrow pulse output. In this article, angular multiplexing technique was introduced, and a multiplexing encoding method was presented. This method encoded seed beam in two steps by sequential amplitude splitting. The optical elements were arranged in rectangle arrays and piled by layers. A specific optical design was made for XeCl high power excimer laser system in this laboratory. This method of angular multiplexing encoding has advantages of compacted space, small encoding error, good compatibility with alignment and measurement, and is also easy to fabricate and assemble. This design is adopted in the system and performs well.%在高功率准分子激光系统中,一般采用光学角多路技术来获得高能量窄脉冲输出。文中介绍了角多路技术原理,提出了一种采用矩形阵列和空间层叠光路结构的连续分振幅两次编码方式,并针对该实验室的XeCl高功率准分子激光系统进行了具体的编码光路设计,给出了设计实例。该方法具有编码结构紧凑,编码精度高,与光路准直、激光参数测量系统等兼容性好,便于加工制作和安装调节等优点,目前已在系统中应用,效果良好。

  11. Relations Between Helicity Coupling Amplitude and L-S Coupling Amplitude

    Institute of Scientific and Technical Information of China (English)

    WU Ning; RUAN Tu-Nan

    2001-01-01

    Relations between helicity coupling amplitude and L-S coupling amplitude are discussed. The equivalence condition for these two kinematic analysis methods and the limitations of the L-S coupling amplitude are also studied in this paper.``

  12. Holonomy-flux spinfoam amplitude

    CERN Document Server

    Perini, Claudio

    2012-01-01

    We introduce a holomorphic representation for the Lorentzian EPRL spinfoam on arbitrary 2-complexes. The representation is obtained via the Ashtekar-Lewandowski-Marolf-Mour\\~ao-Thiemann heat kernel coherent state transform. The new variables are classical holonomy-flux phase space variables $(h,X)\\simeq \\mathcal