WorldWideScience

Sample records for finite detector dead

  1. Simulating detectors dead time

    International Nuclear Information System (INIS)

    Rustom, Ibrahim Farog Ibrahim

    2015-06-01

    Nuclear detectors are used in all aspects of nuclear measurements. All nuclear detectors are characterized by their dead time i.e. the time needed by a detector to recover from a previous incident. A detector dead time influences measurements taken by a detector and specially when measuring high decay rate (>) where is the detector dead time. Two models are usually used to correct for the dead time effect: the paralayzable and the non-paralayzable models. In the current work we use Monte Carlo simulation techniques to simulate radioactivity and the effect of dead time and the count rate of a detector with a dead time =5x10 - 5s assuming the non-paralayzable model. The simulation indicates that assuming a non -paralayzable model could be used to correct for decay rate measured by a detector. The reliability of the non-paralayzable model to correct the measured decay rate could be gauged using the Monte Carlo simulation. (Author)

  2. Dead time of dual detector tools

    International Nuclear Information System (INIS)

    Czubek, J.A.

    1994-01-01

    A theory of the dead time for the dual detector nuclear tool with the analogue signal transmission is given in the paper. At least two different times exist in such tools: the dead time of detectors (for final computation they assumed identical to each other) and the dead time of the signal transmission set-up. A method of two radioactive sources is proposed to measure these two different dead times. When the times used for measuring every countrate needed in the dead time determination algorithm are taken into account, the statistical accuracy of the dead time determination can be obtained. These estimations are performed by the computer simulation method. Two codes have been designed: DEADT2D (DEAD Time for 2 Detectors) and DEADT2DS (DEAD Time for 2 Detectors with Statistics). The first code calculates the dead time based on the recorded countrates only, the second is doing a 'simulation job' and provides information on the statistical distribution of the observed dead times. The theory and the numerical solutions were checked both by the simulation calculations and by the experiments performed with the ODSN-102 tool (the experiments were performed by T. Zorski). (Author)

  3. On determining dead layer and detector thicknesses for a position-sensitive silicon detector

    Science.gov (United States)

    Manfredi, J.; Lee, Jenny; Lynch, W. G.; Niu, C. Y.; Tsang, M. B.; Anderson, C.; Barney, J.; Brown, K. W.; Chajecki, Z.; Chan, K. P.; Chen, G.; Estee, J.; Li, Z.; Pruitt, C.; Rogers, A. M.; Sanetullaev, A.; Setiawan, H.; Showalter, R.; Tsang, C. Y.; Winkelbauer, J. R.; Xiao, Z.; Xu, Z.

    2018-04-01

    In this work, two particular properties of the position-sensitive, thick silicon detectors (known as the "E" detectors) in the High Resolution Array (HiRA) are investigated: the thickness of the dead layer on the front of the detector, and the overall thickness of the detector itself. The dead layer thickness for each E detector in HiRA is extracted using a measurement of alpha particles emitted from a 212Pb pin source placed close to the detector surface. This procedure also allows for energy calibrations of the E detectors, which are otherwise inaccessible for alpha source calibration as each one is sandwiched between two other detectors. The E detector thickness is obtained from a combination of elastically scattered protons and an energy-loss calculation method. Results from these analyses agree with values provided by the manufacturer.

  4. Detector dead-time effects and paralyzability in high-speed quantum key distribution

    International Nuclear Information System (INIS)

    Rogers, Daniel J; Bienfang, Joshua C; Nakassis, Anastase; Xu Hai; Clark, Charles W

    2007-01-01

    Recent advances in quantum key distribution (QKD) have given rise to systems that operate at transmission periods significantly shorter than the dead times of their component single-photon detectors. As systems continue to increase in transmission rate, security concerns associated with detector dead times can limit the production rate of sifted bits. We present a model of high-speed QKD in this limit that identifies an optimum transmission rate for a system with given link loss and detector response characteristics

  5. Dead time of different neutron detectors associated with a pulsed electronics with current collection

    International Nuclear Information System (INIS)

    Bacconnet, Eugene; Duchene, Jean; Duquesne, Henry; Schmitt, Andre

    1968-01-01

    After having outlined that the development of fast neutron reactor physics, notably kinetics, requires highly efficient neutron detectors and pulse measurement chains able to cope with high counting rates, the authors report the measurement of dead time of various neutron detectors which are used in the experimental study of fast neutron reactors. They present the SAITB 1 electronic measurement set, its components, its general characteristics, the protected connection between the detector and the electronics. They present and report the experiment: generalities about detector location and measurements, studied detectors (fission chambers, boron counters), and report the exploitation of the obtained results (principle, data, high-threshold counting gain) [fr

  6. Si(Li) detectors with thin dead layers for low energy x-ray detection

    International Nuclear Information System (INIS)

    Rossington, C.S.; Walton, J.T.; Jaklevic, J.M.

    1990-10-01

    Regions of incomplete charge collection, or ''dead layers'', are compared for Si(Li) detectors fabricated with Au and Pd entrance window electrodes. The dead layers were measured by characterizing the detector spectral response to x-ray energies above and below the Si Kα absorption edge. It was found that Si(Li) detectors with Pd electrodes exhibit consistently thinner effective Si dead layers than those with Au electrodes. Furthermore, it is demonstrated that the minimum thickness required for low resistivity Pd electrodes is thinner than that required for low resistivity Au electrodes, which further reduces the signal attenuation in Pd/Si(Li) detectors. A model, based on Pd compensation of oxygen vacancies in the SiO 2 at the entrance window Si(Li) surface, is proposed to explain the observed differences in detector dead layer thickness. Electrode structures for optimum Si(Li) detector performance at low x-ray energies are discussed. 18 refs., 8 figs., 1 tab

  7. Dead Time Correction at X and Gamma-Rays Detectors - Part 1-Integral Correction

    OpenAIRE

    KARABIDAK, Salih Mustafa

    2013-01-01

    Determination of and compensating for count losses for the correctness of analyses in spectrometric analysis of qualitative and quantitative use of semiconductor detectors are of importance. These counting losses in spectrometry are due to the pulse pile-up, paralyzable and non-paralyzable system dead time or dual and triple combination of these three mechanisms. In this work, a new method is suggested for compensate for counting losses resulting from above-mentioned three factors. For this ...

  8. Minimizing guard ring dead space in silicon detectors with an n-type guard ring at the edge of the detector

    International Nuclear Information System (INIS)

    Palviainen, Tanja; Tuuva, Tuure; Leinonen, Kari

    2007-01-01

    Detectors with n-type silicon with an n + -type guard ring were investigated. In the present work, a new p + /n/n + detector structure with an n + guard ring is described. The guard ring is placed at the edge of the detector. The detector depletion region extends also sideways, allowing for signal collection very close to the n-guard ring. In this kind of detector structure, the dead space of the detector is minimized to be only below the guard ring. This is proved by simulations done using Silvaco/ATLAS software

  9. Minimizing guard ring dead space in silicon detectors with an n-type guard ring at the edge of the detector

    Energy Technology Data Exchange (ETDEWEB)

    Palviainen, Tanja [Lappeenranta University of Technology, P.O. Box 20, FIN-53851 Lappeenranta (Finland)]. E-mail: tanja.palviainen@lut.fi; Tuuva, Tuure [Lappeenranta University of Technology, P.O. Box 20, FIN-53851 Lappeenranta (Finland); Leinonen, Kari [Lappeenranta University of Technology, P.O. Box 20, FIN-53851 Lappeenranta (Finland)

    2007-04-01

    Detectors with n-type silicon with an n{sup +}-type guard ring were investigated. In the present work, a new p{sup +}/n/n{sup +} detector structure with an n{sup +} guard ring is described. The guard ring is placed at the edge of the detector. The detector depletion region extends also sideways, allowing for signal collection very close to the n-guard ring. In this kind of detector structure, the dead space of the detector is minimized to be only below the guard ring. This is proved by simulations done using Silvaco/ATLAS software.

  10. A 65 nm CMOS analog processor with zero dead time for future pixel detectors

    Energy Technology Data Exchange (ETDEWEB)

    Gaioni, L., E-mail: luigi.gaioni@unibg.it [Università di Bergamo, I-24044 Dalmine (Italy); INFN, Sezione di Pavia, I-27100 Pavia (Italy); Braga, D.; Christian, D.C.; Deptuch, G.; Fahim, F. [Fermi National Accelerator Laboratory, Batavia IL (United States); Nodari, B. [Università di Bergamo, I-24044 Dalmine (Italy); INFN, Sezione di Pavia, I-27100 Pavia (Italy); Centre National de Recherche Scientifique, APC/IN2P3, Paris (France); Ratti, L. [Università di Pavia, I-27100 Pavia (Italy); INFN, Sezione di Pavia, I-27100 Pavia (Italy); Re, V. [Università di Bergamo, I-24044 Dalmine (Italy); INFN, Sezione di Pavia, I-27100 Pavia (Italy); Zimmerman, T. [Fermi National Accelerator Laboratory, Batavia IL (United States)

    2017-02-11

    Next generation pixel chips at the High-Luminosity (HL) LHC will be exposed to extremely high levels of radiation and particle rates. In the so-called Phase II upgrade, ATLAS and CMS will need a completely new tracker detector, complying with the very demanding operating conditions and the delivered luminosity (up to 5×10{sup 34} cm{sup −2} s{sup −1} in the next decade). This work is concerned with the design of a synchronous analog processor with zero dead time developed in a 65 nm CMOS technology, conceived for pixel detectors at the HL-LHC experiment upgrades. It includes a low noise, fast charge sensitive amplifier featuring a detector leakage compensation circuit, and a compact, single ended comparator that guarantees very good performance in terms of channel-to-channel dispersion of threshold without needing any pixel-level trimming. A flash ADC is exploited for digital conversion immediately after the charge amplifier. A thorough discussion on the design of the charge amplifier and the comparator is provided along with an exhaustive set of simulation results.

  11. Energy-dependent dead-time correction in digital pulse processors applied to silicon drift detector's X-ray spectra.

    Science.gov (United States)

    Barros, Suelen F; Vanin, Vito R; Malafronte, Alexandre A; Maidana, Nora L; Martins, Marcos N

    2018-03-01

    Dead-time effects in X-ray spectra taken with a digital pulse processor and a silicon drift detector were investigated when the number of events at the low-energy end of the spectrum was more than half of the total, at counting rates up to 56 kHz. It was found that dead-time losses in the spectra are energy dependent and an analytical correction for this effect, which takes into account pulse pile-up, is proposed. This and the usual models have been applied to experimental measurements, evaluating the dead-time fraction either from the calculations or using the value given by the detector acquisition system. The energy-dependent dead-time model proposed fits accurately the experimental energy spectra in the range of counting rates explored in this work. A selection chart of the simplest mathematical model able to correct the pulse-height distribution according to counting rate and energy spectrum characteristics is included.

  12. Design and Test of a 65nm CMOS Front-End with Zero Dead Time for Next Generation Pixel Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Gaioni, L. [INFN, Pavia; Braga, D. [Fermilab; Christian, D. [Fermilab; Deptuch, G. [Fermilab; Fahim. F., Fahim. F. [Fermilab; Nodari, B. [Lyon, IPN; Ratti, L. [INFN, Pavia; Re, V. [INFN, Pavia; Zimmerman, T. [Fermilab

    2017-09-01

    This work is concerned with the experimental characterization of a synchronous analog processor with zero dead time developed in a 65 nm CMOS technology, conceived for pixel detectors at the HL-LHC experiment upgrades. It includes a low noise, fast charge sensitive amplifier with detector leakage compensation circuit, and a compact, single ended comparator able to correctly process hits belonging to two consecutive bunch crossing periods. A 2-bit Flash ADC is exploited for digital conversion immediately after the preamplifier. A description of the circuits integrated in the front-end processor and the initial characterization results are provided

  13. Measurement of the front-end dead-time of the LHCb muon detector and evaluation of its contribution to the muon detection inefficiency

    CERN Document Server

    INSPIRE-00357120; Archilli, F.; Auriemma, G.; Baldini, W.; Bencivenni, G.; Bizzeti, A.; Bocci, V.; Bondar, N.; Bonivento, W.; Bochin, B.; Bozzi, C.; Brundu, D.; Cadeddu, S.; Campana, P.; Carboni, G.; Cardini, A.; Carletti, M.; Casu, L.; Chubykin, A.; Ciambrone, P.; Dané, E.; De Simone, P.; Falabella, A.; Felici, G.; Fiore, M.; Fontana, M.; Fresch, P.; Furfaro, E.; Graziani, G.; Kashchuk, A.; Kotriakhova, S.; Lai, A.; Lanfranchi, G.; Loi, A.; Maev, O.; Manca, G.; Martellotti, G.; Neustroev, P.; Oldeman, R.G.C.; Palutan, M.; Passaleva, G.; Penso, G.; Pinci, D.; Polycarpo, E.; Saitta, B.; Santacesaria, R.; Santimaria, M.; Santovetti, E.; Saputi, A.; Sarti, A.; Satriano, C.; Satta, A.; Schmidt, B.; Schneider, T.; Sciascia, B.; Sciubba, A.; Siddi, B.G.; Tellarini, G.; Vacca, C.; Vazquez-Gomez, R.; Vecchi, S.; Veltri, M.; Vorobyev, A.

    2016-04-06

    A method is described which allows to deduce the dead-time of the front-end electronics of the LHCb muon detector from a series of measurements performed at different luminosities at a bunch-crossing rate of 20 MHz. The measured values of the dead-time range from 70 ns to 100 ns. These results allow to estimate the performance of the muon detector at the future bunch-crossing rate of 40 MHz and at higher luminosity.

  14. On estimating the loss of quantification in PET due to finite detector resolution.

    Science.gov (United States)

    Bice, A N; Wong, D F; Wagner, H N

    1987-01-01

    In positron emission computed tomography, images are reconstructed from projection data of the slice. Such projection data are inherently subject to bias owing to the detection of coincident annihilation photons with detectors of finite resolution. The influence of these unavoidable effects on reconstructed data is reviewed and a straight forward method is outlined for calculating the loss of quantification of small objects owing to finite detector resolution. A sample calculation using idealized point spread functions is presented.

  15. Dead time effects from linear amplifiers and discriminators in single detector systems

    International Nuclear Information System (INIS)

    Funck, E.

    1986-01-01

    The dead-time losses originating from a linear amplifier combined with a discriminator for pulse-height selection are investigated. Measurements are carried out to determine the type of dead time represented by the amplifier-discriminator combination. The corrections involved by feeding the discriminator output pulses into an electronic module producing a blocking time are discussed and practical hints are given to reduce them. (orig.)

  16. Dead regions and electric thickness in the CdTe(Cl) radiation detector

    International Nuclear Information System (INIS)

    Hirasawa, Masahiko

    2001-01-01

    The studies suggested that low resistivity (approximately 10 -1 Ω cm) granular regions were distributed in high resistivity (approximately 10 9 Ω cm) CdTe(Cl). The existence and influence of these low resistivity regions in the radiation detector made of high resistivity CdTe(Cl) are examined by experiments, numerical simulations and analytical calculations in the present paper. (author)

  17. Submillisecond X-ray photon correlation spectroscopy from a pixel array detector with fast dual gating and no readout dead-time.

    Science.gov (United States)

    Zhang, Qingteng; Dufresne, Eric M; Grybos, Pawel; Kmon, Piotr; Maj, Piotr; Narayanan, Suresh; Deptuch, Grzegorz W; Szczygiel, Robert; Sandy, Alec

    2016-05-01

    Small-angle scattering X-ray photon correlation spectroscopy (XPCS) studies were performed using a novel photon-counting pixel array detector with dual counters for each pixel. Each counter can be read out independently from the other to ensure there is no readout dead-time between the neighboring frames. A maximum frame rate of 11.8 kHz was achieved. Results on test samples show good agreement with simple diffusion. The potential of extending the time resolution of XPCS beyond the limit set by the detector frame rate using dual counters is also discussed.

  18. Feynman-α technique for measurement of detector dead time using a 30 kW tank-in-pool research reactor

    International Nuclear Information System (INIS)

    Akaho, E.H.K.; Intsiful, J.D.K.; Maakuu, B.T.; Anim-Sampong, S.; Nyarko, B.J.B.

    2002-01-01

    Reactor noise analysis was carried out for Ghana Research Reactor-1 GHARR-1, a tank-in-pool type reactor using the Feynman-α technique (variance-to-mean method). Measurements made at different detector positions and under subcritical conditions showed that the technique could not be used to determine the prompt decay constant for the reactor which is Be reflected with photo-neutron background. However, for very low dwell times the technique was used to measure the dead time of the detector which compares favourably with the value obtained using the α-conventional method

  19. Feynman-alpha technique for measurement of detector dead time using a 30 kW tank-in-pool research reactor

    CERN Document Server

    Akaho, E H K; Intsiful, J D K; Maakuu, B T; Nyarko, B J B

    2002-01-01

    Reactor noise analysis was carried out for Ghana Research Reactor-1 GHARR-1, a tank-in-pool type reactor using the Feynman-alpha technique (variance-to-mean method). Measurements made at different detector positions and under subcritical conditions showed that the technique could not be used to determine the prompt decay constant for the reactor which is Be reflected with photo-neutron background. However, for very low dwell times the technique was used to measure the dead time of the detector which compares favourably with the value obtained using the alpha-conventional method.

  20. Analysis of the dead layer of a detector of germanium with code ultrapure Monte Carlo SWORD-GEANT; Analisis del dead layer de un detector de germanio ultrapuro con el codigo de Monte Carlo SWORDS-GEANT

    Energy Technology Data Exchange (ETDEWEB)

    Gallardo, S.; Querol, A.; Ortiz, J.; Rodenas, J.; Verdu, G.

    2014-07-01

    In this paper the use of Monte Carlo code SWORD-GEANT is proposed to simulate an ultra pure germanium detector High Purity Germanium detector (HPGe) detector ORTEC specifically GMX40P4, coaxial geometry. (Author)

  1. Effects of detector dead-time on quantitative analyses involving boron and multi-hit detection events in atom probe tomography.

    Science.gov (United States)

    Meisenkothen, Frederick; Steel, Eric B; Prosa, Ty J; Henry, Karen T; Prakash Kolli, R

    2015-12-01

    In atom probe tomography (APT), some elements tend to field evaporate preferentially in multi-hit detection events. Boron (B) is one such element. It is thought that a large fraction of the B signal may be lost during data acquisition and is not reported in the mass spectrum or in the 3-D APT reconstruction. Understanding the relationship between the field evaporation behavior of B and the limitations for detecting multi-hit events can provide insight into the signal loss mechanism for B and may suggest ways to improve B detection accuracy. The present work reports data for nominally pure B and for B-implanted silicon (Si) (NIST-SRM2137) at dose levels two-orders of magnitude lower than previously studied by Da Costa, et al. in 2012. Boron concentration profiles collected from SRM2137 specimens qualitatively confirmed a signal loss mechanism is at work in laser pulsed atom probe measurements of B in Si. Ion correlation analysis was used to graphically demonstrate that the detector dead-time results in few same isotope, same charge-state (SISCS) ion pairs being properly recorded in the multi-hit data, explaining why B is consistently under-represented in quantitative analyses. Given the important role of detector dead-time as a signal loss mechanism, the results from three different methods of estimating the detector dead-time are presented. The findings of this study apply to all quantitative analyses that involve multi-hit data, but the dead-time will have the greatest effect on the elements that have a significant quantity of ions detected in multi-hit events. Published by Elsevier B.V.

  2. DESIGNING A FINITE STATE MACHINE SIMULATOR TO DETECT LOOPS FOR ALICE DETECTOR CONTROL SYSTEM

    CERN Document Server

    Yogatama, Bobbi Winema

    2017-01-01

    This paper present the design and implementation of a Finite State Machine simulator to provoke loops in ALICE Detector Control System (DCS). Loops in a Finite State Machine can be very harmful for the control system and need to be prevented. One way to prevent loops is to simulate the designed Finite State Machine using a simulator that can detect all of the possible conditions that can provoke loops. Further correction can then be made after the loops are detected in the control system. The proposed simulator is able to get the structure of any unknown FSM, get every datapoint elements that are associated with the FSM, and find every possible datapoint combinations that can provoke loops in the FSM. At the end of the project, we tested the simulator on a sample FSM with loops and a real FSM that belongs to the ALICE PHOton Spectrometer (PHOS). The testing results indicate that the simulator is able to detect every possible condition that can cause loops in the FSM.

  3. Figures of merit for detectors in digital radiography. II. Finite number of secondaries and structured backgrounds

    International Nuclear Information System (INIS)

    Pineda, Angel R.; Barrett, Harrison H.

    2004-01-01

    The current paradigm for evaluating detectors in digital radiography relies on Fourier methods. Fourier methods rely on a shift-invariant and statistically stationary description of the imaging system. The theoretical justification for the use of Fourier methods is based on a uniform background fluence and an infinite detector. In practice, the background fluence is not uniform and detector size is finite. We study the effect of stochastic blurring and structured backgrounds on the correlation between Fourier-based figures of merit and Hotelling detectability. A stochastic model of the blurring leads to behavior similar to what is observed by adding electronic noise to the deterministic blurring model. Background structure does away with the shift invariance. Anatomical variation makes the covariance matrix of the data less amenable to Fourier methods by introducing long-range correlations. It is desirable to have figures of merit that can account for all the sources of variation, some of which are not stationary. For such cases, we show that the commonly used figures of merit based on the discrete Fourier transform can provide an inaccurate estimate of Hotelling detectability

  4. Submillisecond X-ray photon correlation spectroscopy?from a pixel array detector with fast?dual gating and no readout dead-time

    OpenAIRE

    Zhang, Qingteng; Dufresne, Eric M.; Grybos, Pawel; Kmon, Piotr; Maj, Piotr; Narayanan, Suresh; Deptuch, Grzegorz W.; Szczygiel, Robert; Sandy, Alec

    2016-01-01

    Small-angle scattering X-ray photon correlation spectroscopy (XPCS) studies were performed using a novel photon-counting pixel array detector with dual counters for each pixel. Each counter can be read out independently from the other to ensure there is no readout dead-time between the neighboring frames. A maximum frame rate of 11.8?kHz was achieved. Results on test samples show good agreement with simple diffusion. The potential of extending the time resolution of XPCS beyond the limit set ...

  5. Finite-element simulations of coupling capacitances in capacitively coupled pixel detectors

    CERN Document Server

    AUTHOR|(SzGeCERN)755510

    2017-01-01

    Capacitively coupled hybrid silicon pixel-detector assemblies are under study for the vertex detector at the proposed future CLIC linear electron-positron collider. The assemblies consist of active CCPDv3 sensors, with 25 μm pixel pitch implemented in a 180 nm High- Voltage CMOS process, which are glued to the CLICpix readout ASIC, with the same pixel pitch and processed in a commercial 65 nm CMOS technology. The signal created in the silicon bulk of the active sensors passes a two-stage amplifier, in each pixel, and gets transferred as a voltage pulse to metal pads facing the readout chip (ROC). The coupling of the signal to the metal pads on the ROC side proceeds through the capacitors formed between the two chips by a thin layer of epoxy glue. The coupling strength and the amount of unwanted cross coupling to neighbouring pixels depends critically on the uniformity of the glue layer, its thickness and on the alignment precision during the flip-chip assembly process. Finite-element calculations of the coup...

  6. A zero dead-time multi-particle time and position sensitive detector based on correlation between brightness and amplitude

    International Nuclear Information System (INIS)

    Urbain, X.; Bech, D.; Van Roy, J.-P.; Géléoc, M.; Weber, S. J.; Huetz, A.; Picard, Y. J.

    2015-01-01

    A new multi-particle time and position sensitive detector using only a set of microchannel plates, a waveform digitizer, a phosphor screen, and a CMOS camera is described. The assignment of the timing information, as taken from the microchannel plates by fast digitizing, to the positions, as recorded by the camera, is based on the COrrelation between the BRightness of the phosphor screen spots, defined as their integrated intensity and the Amplitude of the electrical signals (COBRA). Tests performed by observing the dissociation of HeH, the fragmentation of H 3 into two or three fragments, and the photo-double-ionization of Xenon atoms are presented, which illustrate the performances of the COBRA detection scheme

  7. A zero dead-time multi-particle time and position sensitive detector based on correlation between brightness and amplitude

    Science.gov (United States)

    Urbain, X.; Bech, D.; Van Roy, J.-P.; Géléoc, M.; Weber, S. J.; Huetz, A.; Picard, Y. J.

    2015-02-01

    A new multi-particle time and position sensitive detector using only a set of microchannel plates, a waveform digitizer, a phosphor screen, and a CMOS camera is described. The assignment of the timing information, as taken from the microchannel plates by fast digitizing, to the positions, as recorded by the camera, is based on the COrrelation between the BRightness of the phosphor screen spots, defined as their integrated intensity and the Amplitude of the electrical signals (COBRA). Tests performed by observing the dissociation of HeH, the fragmentation of H3 into two or three fragments, and the photo-double-ionization of Xenon atoms are presented, which illustrate the performances of the COBRA detection scheme.

  8. Measurement of the Dead-Time in a Multichannel Analyser

    DEFF Research Database (Denmark)

    Mortensen, L.; Olsen, J.

    1973-01-01

    By means of two simple measurements three different dead-times are determined: the normal dead-time, a dead-time coming from the pile-up, and a dead-time due to the finite width of the timing pulses.......By means of two simple measurements three different dead-times are determined: the normal dead-time, a dead-time coming from the pile-up, and a dead-time due to the finite width of the timing pulses....

  9. Simultaneous Analysis of Monovalent Anions and Cations with a Sub-Microliter Dead-Volume Flow-Through Potentiometric Detector for Ion Chromatography

    Science.gov (United States)

    Dumanli, Rukiye; Attar, Azade; Erci, Vildan; Isildak, Ibrahim

    2016-01-01

    A microliter dead-volume flow-through cell as a potentiometric detector is described in this article for sensitive, selective and simultaneous detection of common monovalent anions and cations in single column ion chromatography for the first time. The detection cell consisted of less selective anion- and cation-selective composite membrane electrodes together with a solid-state composite matrix reference electrode. The simultaneous separation and sensitive detection of sodium (Na+), potassium (K+), ammonium (NH4+), chloride (Cl−) and nitrate (NO3−) in a single run was achieved by using 98% 1.5 mM MgSO4 and 2% acetonitrile eluent with a mixed-bed ion-exchange separation column without suppressor column system. The separation and simultaneous detection of the anions and cations were completed in 6 min at the eluent flow-rate of 0.8 mL/min. Detection limits, at S/N = 3, were ranged from 0.2 to 1.0 µM for the anions and 0.3 to 3.0 µM for the cations, respectively. The developed method was successfully applied to the simultaneous determination of monovalent anions and cations in several environmental and biological samples. PMID:26786906

  10. Finite

    Directory of Open Access Journals (Sweden)

    W.R. Azzam

    2015-08-01

    Full Text Available This paper reports the application of using a skirted foundation system to study the behavior of foundations with structural skirts adjacent to a sand slope and subjected to earthquake loading. The effect of the adopted skirts to safeguard foundation and slope from collapse is studied. The skirts effect on controlling horizontal soil movement and decreasing pore water pressure beneath foundations and beside the slopes during earthquake is investigated. This technique is investigated numerically using finite element analysis. A four story reinforced concrete building that rests on a raft foundation is idealized as a two-dimensional model with and without skirts. A two dimensional plain strain program PLAXIS, (dynamic version is adopted. A series of models for the problem under investigation were run under different skirt depths and lactation from the slope crest. The effect of subgrade relative density and skirts thickness is also discussed. Nodal displacement and element strains were analyzed for the foundation with and without skirts and at different studied parameters. The research results showed a great effectiveness in increasing the overall stability of the slope and foundation. The confined soil footing system by such skirts reduced the foundation acceleration therefore it can be tended to damping element and relieved the transmitted disturbance to the adjacent slope. This technique can be considered as a good method to control the slope deformation and decrease the slope acceleration during earthquakes.

  11. Accuracy in gamma spectrometry: Pileup, dead time, and fast electornics

    International Nuclear Information System (INIS)

    Lindstrom, R.M.

    1993-01-01

    An important source of inaccuracy in neutron activation analysis is the nonlinear throughput of the counting system, especially at high counting rates. Losses, due to the finite time needed for events to happen, occur in all parts of the spectrometer system: the germanium detector crystal, preamplifier, amplifier, analog-digital converter (ADC), and MCA or computer. The slowest unbuffered units are the ADC and the amplifier, followed by the crystal. Even with modern fast electronics, losses can be important, although compensating circuits can greatly improve accuracy if they are used correctly. The ADC dead time is less of a problem than it was a decade ago. For example, a modern successive-approximation ADC in the author's laboratory takes 6 μs to digitize a gamma ray in the middle of an 8192-channel spectrum, compared with 60 μs for the Wilkinson device that it replaced. Dead-time circuits in MCAs for many years have compensated very well for this dead time. Pulse pileup is as important as ADC dead time. Random coincidence, the accidental arrival of the signal from two nonrelated gamma rays at the amplifier in a time short compared to the shaping time, results in a composite pulse that distorts the spectrum. For accurate spectrometry, each such random-sum pulse should be excluded from the spectrum (pileup rejection), and the system dead time must be adjusted to compensate for the time the system is busy analyzing this rejected event (pileup live-time correction)

  12. Deadly medicine.

    Science.gov (United States)

    Bachrach, Susan

    2007-01-01

    This article discusses the methods the United States Holocaust Memorial Museum used to make an exhibition on the complex history of Nazi eugenics accessible to the museum's mass public and at the same time, provocative for special audiences consisting of professionals and students from the biomedical fields. Deadly Medicine: Creating the Master Race showed how both eugenics and related "euthanasia" programs in Nazi Germany helped pave the road to the Holocaust. The exhibition implicitly evoked the present-day appeal of biological explanations for human behavior and of new visions of human perfection. Educational programs used the exhibition as a springboard for discussions of bioethics and medical ethics.

  13. Deadly progress

    International Nuclear Information System (INIS)

    Nader, R.; Abbotts, J.

    1978-01-01

    Nuclear power plants are safe, they help to get through the future bottle-neck in the field of energy, nuclear power plants provide for cheap electrical power and support economic growth - these are the sedative formulae which have been used for years to close the populations eyes towards the real problems. In this book, the American lawyer Ralph Nader and the nuclear chemist John Abbots not only oppose this myth of atomic safety, but they also defeat this theory with numerous technical, economic, and political details. Having realized the fact that the development of atomic energy can no longer be prevented by warnings of independent experts, but only by massive protests by the population - i.e. the protest by informed persons-, they give an understandable introduction to the techniques of atomic energy, construction of nuclear power plants, radioactive radiation, safety, etc. Furthermore, they inform about the social, political, and economic background of the nuclear power forcing. Nader and Abbots show the uncertainty of science, they bring secret documents about failures already occured and point out the catastrophic consequences of possible defects. The result of the thorough study: A 'technologic Vietnam' impends both USA and all other nuclear power countries, if the population won't struggle against this dead-end programme of the governments. (orig./HP) [de

  14. Love the dead, fear the dead

    DEFF Research Database (Denmark)

    Seebach, Sophie Hooge

    2017-01-01

    The dead are everywhere in the landscape in Acholi, northern Uganda. In the homes, the dead are present through their gravesites, situated next to houses and huts, and as spiritual presences in their family’s daily lives. In the bush, the dead are present as a constant potentiality, in the form o...

  15. The inverse problem of a Gaussian convolution and its application to the finite size of the measurement chambers/detectors in photon and proton dosimetry

    International Nuclear Information System (INIS)

    Ulmer, W; Kaissl, W

    2003-01-01

    A Gaussian convolution kernel K is deduced as a Green's function of a Lie operator series. The deconvolution of a Gaussian kernel is developed by the inverse Green's function K -1 . A practical application is the deconvolution of measured profiles D m (x) of photons and protons with finite detector size to determine the profiles D p (x) of point-detectors or Monte Carlo Bragg curves of protons. The presented algorithms work if D m (x) is either an analytical function or only given in a numerical form. Some approximation methods of the deconvolution are compared (differential operator expansion to analytical adaptations of 2 x 2 cm 2 and 4 x 4 cm 2 profiles, Hermite expansions to measured 6 x 6 cm 2 and 20 x 20 cm 2 profiles and Bragg curves of 80/180 MeV protons, FFT to an analytical 4 x 4 cm 2 profile). The inverse problem may imply ill-posed problems, and, in particular, the use of FFT may be susceptible to them

  16. 32k Channel Readout IC for Single Photon Counting Pixel Detectors with 75μm Pitch, Dead Time of 85 ns, 9 e- rms Offset Spread and 2% rms Gain Spread

    Science.gov (United States)

    Grybos, P.; Kmon, P.; Maj, P.; Szczygiel, R.

    2016-04-01

    This paper presents a readout integrated circuit called UFXC32k, designed for hybrid pixel semiconductor detectors used in X-ray imaging applications. The UFXC32k integrated circuit, designed in a CMOS 130 nm process, contains about 50 million transistors in the area of 9.64 mm × 20.15 mm. The core of the IC is a matrix of 128 × 256 square-shaped pixels of 75 μm pitch. Each pixel contains a charge sensitive amplifier, a shaper, two discriminators, and two 14-bit ripple counters. The analog front-end electronics allow processing of sensor signals of both polarities (holes and electrons). The UFXC32k chip is bumpbonded to a pixel silicon sensor and is fully characterized using X-ray radiation. The measured equivalent noise charge for the standard settings is equal to 123 e- rms (for the peaking time of 40 ns) and each pixel dissipates 26 μW. Thanks to the use of trim blocks working in each pixel independently, an effective offset spread calculated to the input is only 9 e- rms with a gain spread of 2%. The maximum count rate per pixel depends mainly on effective CSA feedback resistance. Dead time in the front end can be set as low as 85 ns. In the continuous readout mode, a user can select the number of bits read out from each pixel to optimize the UFXC32k frame rate, e.g., for a readout of 2 bits/pixel with 200 MHz clock, the frame rate is equal to 23 kHz.

  17. Investigating Aquatic Dead Zones

    Science.gov (United States)

    Testa, Jeremy; Gurbisz, Cassie; Murray, Laura; Gray, William; Bosch, Jennifer; Burrell, Chris; Kemp, Michael

    2010-01-01

    This article features two engaging high school activities that include current scientific information, data, and authentic case studies. The activities address the physical, biological, and chemical processes that are associated with oxygen-depleted areas, or "dead zones," in aquatic systems. Students can explore these dead zones through both…

  18. Dead time corrections using the backward extrapolation method

    Energy Technology Data Exchange (ETDEWEB)

    Gilad, E., E-mail: gilade@bgu.ac.il [The Unit of Nuclear Engineering, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel); Dubi, C. [Department of Physics, Nuclear Research Center NEGEV (NRCN), Beer-Sheva 84190 (Israel); Geslot, B.; Blaise, P. [DEN/CAD/DER/SPEx/LPE, CEA Cadarache, Saint-Paul-les-Durance 13108 (France); Kolin, A. [Department of Physics, Nuclear Research Center NEGEV (NRCN), Beer-Sheva 84190 (Israel)

    2017-05-11

    Dead time losses in neutron detection, caused by both the detector and the electronics dead time, is a highly nonlinear effect, known to create high biasing in physical experiments as the power grows over a certain threshold, up to total saturation of the detector system. Analytic modeling of the dead time losses is a highly complicated task due to the different nature of the dead time in the different components of the monitoring system (e.g., paralyzing vs. non paralyzing), and the stochastic nature of the fission chains. In the present study, a new technique is introduced for dead time corrections on the sampled Count Per Second (CPS), based on backward extrapolation of the losses, created by increasingly growing artificially imposed dead time on the data, back to zero. The method has been implemented on actual neutron noise measurements carried out in the MINERVE zero power reactor, demonstrating high accuracy (of 1–2%) in restoring the corrected count rate. - Highlights: • A new method for dead time corrections is introduced and experimentally validated. • The method does not depend on any prior calibration nor assumes any specific model. • Different dead times are imposed on the signal and the losses are extrapolated to zero. • The method is implemented and validated using neutron measurements from the MINERVE. • Result show very good correspondence to empirical results.

  19. Dead Sea Scrolls

    Science.gov (United States)

    1994-01-01

    A consortium of researchers from Jet Propulsion Laboratory and three other organizations used charged coupled devices (CCDs) and other imaging enhancement technology to decipher previously unreadable portions of the Dead Sea Scrolls. The technique has potentially important implications for archeology.

  20. No Time for Dead Time: Use the Fourier Amplitude Differences to Normalize Dead-time-affected Periodograms

    Science.gov (United States)

    Bachetti, Matteo; Huppenkothen, Daniela

    2018-02-01

    Dead time affects many of the instruments used in X-ray astronomy, by producing a strong distortion in power density spectra. This can make it difficult to model the aperiodic variability of the source or look for quasi-periodic oscillations. Whereas in some instruments a simple a priori correction for dead-time-affected power spectra is possible, this is not the case for others such as NuSTAR, where the dead time is non-constant and long (∼2.5 ms). Bachetti et al. (2015) suggested the cospectrum obtained from light curves of independent detectors within the same instrument as a possible way out, but this solution has always only been a partial one: the measured rms was still affected by dead time because the width of the power distribution of the cospectrum was modulated by dead time in a frequency-dependent way. In this Letter, we suggest a new, powerful method to normalize dead-time-affected cospectra and power density spectra. Our approach uses the difference of the Fourier amplitudes from two independent detectors to characterize and filter out the effect of dead time. This method is crucially important for the accurate modeling of periodograms derived from instruments affected by dead time on board current missions like NuSTAR and Astrosat, but also future missions such as IXPE.

  1. Practicing on Newly Dead

    Directory of Open Access Journals (Sweden)

    Jewel Abraham

    2015-07-01

    Full Text Available A newly dead cadaver simulation is practiced on the physical remains of the dead before the onset of rigor mortis. This technique has potential benefits for providing real-life in-situ experience for novice providers in health care practices. Evolving ethical views in health care brings into question some of the ethical aspects associated with newly dead cadaver simulation in terms of justification for practice, autonomy, consent, and the need of disclosure. A clear statement of policies and procedures on newly dead cadaver simulation has yet to be implemented. Although there are benefits and disadvantages to an in-situ cadaver simulation, such practices should not be carried out in secrecy as there is no compelling evidence that suggests such training as imperative. Secrecy in these practices is a violation of honor code of nursing ethics. As health care providers, practitioners are obliged to be ethically honest and trustworthy to their patients. The author explores the ethical aspects of using newly dead cadaver simulation in training novice nursing providers to gain competency in various lifesaving skills, which otherwise cannot be practiced on a living individual. The author explores multiple views on cadaver simulation in relation to ethical theories and practices such as consent and disclosure to family.

  2. Dead or alive?

    OpenAIRE

    2006-01-01

    Dead or Alive was a painting and sound exhibition in the National Physical Laboratory (NPL) in Richmond. NPL is the UK’s national standards laboratory for metrology and is one of the world’s leading measurement institutes. \\ud \\ud The exhibition took the form of installations consisting of paintings and soundscapes set up in two spaces, an anechoic chamber (dead) and a reverberation chamber (alive). For the exhibition a new body of work was made including a twenty-seven-metre panoramic painti...

  3. Dead reckoner navigation project

    Science.gov (United States)

    Ellis, R.; Sweet, L.

    1981-01-01

    A previous dead reckoner involved a classical gyrocompass, a Hewlett-Packard minicomputer, and a true airspeed sensor. In an effort to bring the cost of this system more in line with the realities of general aviation, recent work was done on replacing the minicomputer with a microcomputer and implementing a fluidic rate sensor in the compass system in place of the directional gyro.

  4. The Dead Sea

    Science.gov (United States)

    2006-01-01

    The Dead Sea is the lowest point on Earth at 418 meters below sea level, and also one of the saltiest bodies of water on Earth with a salinity of about 300 parts-per-thousand (nine times greater than ocean salinity). It is located on the border between Jordan and Israel, and is fed by the Jordan River. The Dead Sea is located in the Dead Sea Rift, formed as a result of the Arabian tectonic plate moving northward away from the African Plate. The mineral content of the Dead Sea is significantly different from that of ocean water, consisting of approximately 53% magnesium chloride, 37% potassium chloride and 8% sodium chloride. In the early part of the 20th century, the Dead Sea began to attract interest from chemists who deduced that the Sea was a natural deposit of potash and bromine. From the Dead Sea brine, Israel and Jordan produce 3.8 million tons potash, 200,000 tons elemental bromine, 45,000 tons caustic soda, 25, 000 tons magnesium metal, and sodium chloride. Both countries use extensive salt evaporation pans that have essentially diked the entire southern end of the Dead Sea. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining

  5. Dead-ice environments

    DEFF Research Database (Denmark)

    Krüger, Johannes; Kjær, Kurt H.; Schomacker, Anders

    2010-01-01

    Kötlujökull transports considerable amounts of supraglacial debris at its snout because of frontal oscillations with frequent ice advances followed by ice-margin stagnation. Kötlujökull provides suitable conditions of studying dead-ice melting and landscape formation in a debris-charged lowland...... under humid, sub-polar conditions? Does this rate differ from rates reported from polar environments of dry continental nature? How will the sedimentary architecture appear in the geological record? How will the final landsystem appear? These key questions are answered in a review of research...... and conclusions on dead-ice melting and landscape formation from Kötlujökull. Processes and landform-sediment associations are linked to the current climate and glacier–volcano interaction....

  6. Dead-ice environments

    DEFF Research Database (Denmark)

    Krüger, Johannes; Kjær, Kurt H.; Schomacker, Anders

    2010-01-01

    Kötlujökull transports considerable amounts of supraglacial debris at its snout because of frontal oscillations with frequent ice advances followed by ice-margin stagnation. Kötlujökull provides suitable conditions of studying dead-ice melting and landscape formation in a debris-charged lowland...... glacier environment. The scientific challenges are to answer the key questions. What are the conditions for dead-ice formation? From which sources does the sediment cover originate? Which melting and reworking processes act in the ice-cored moraines? What is the rate of de-icing in the ice-cored moraines...... under humid, sub-polar conditions? Does this rate differ from rates reported from polar environments of dry continental nature? How will the sedimentary architecture appear in the geological record? How will the final landsystem appear? These key questions are answered in a review of research...

  7. Digital filter based on the Fisher linear discriminant to reduce dead-time paralysis in photon counting

    Science.gov (United States)

    Sullivan, Shane Z.; Schmitt, Paul D.; DeWalt, Emma L.; Muir, Ryan D.; Simpson, Garth J.

    2013-03-01

    Photon counting represents the Poisson limit in signal to noise, but can often be complicated in imaging applications by detector paralysis, arising from the finite rise / fall time of the detector upon photon absorption. We present here an approach for reducing dead-time by generating a deconvolution digital filter based on optimizing the Fisher linear discriminant. In brief, two classes are defined, one in which a photon event is initiated at the origin of the digital filter, and one in the photon event is non-coincident with the filter origin. Linear discriminant analysis (LDA) is then performed to optimize the digital filter that best resolves the coincident and non-coincident training set data.1 Once trained, implementation of the filter can be performed quickly, significantly reducing dead-time issues and measurement bias in photon counting applications. Experimental demonstration of the LDA-filter approach was performed in fluorescence microscopy measurements using a highly convolved impulse response with considerable ringing. Analysis of the counts supports the capabilities of the filter in recovering deconvolved impulse responses under the conditions considered in the study. Potential additional applications and possible limitations are also considered.

  8. The Dead Walk

    Directory of Open Access Journals (Sweden)

    Bill Phillips

    2014-02-01

    Full Text Available Monsters have always enjoyed a significant presence in the human imagination, and religion was instrumental in replacing the physical horror they engendered with that of a moral threat. Zombies, however, are amoral – their motivation purely instinctive and arbitrary, yet they are, perhaps, the most loathed of all contemporary monsters. One explanation for this lies in the theory of the uncanny valley, proposed by robotics engineer Masahiro Mori. According to the theory, we reserve our greatest fears for those things which seem most human, yet are not – such as dead bodies. Such a reaction is most likely a survival mechanism to protect us from danger and disease – a mechanism even more essential when the dead rise up and walk. From their beginnings zombies have reflected western societies’ greatest fears – be they of revolutionary Haitians, women, or communists. In recent years the rise in the popularity of the zombie in films, books and television series reflects our fears for the planet, the economy, and of death itself

  9. Dead zone analysis of ECAL barrel modules under static and dynamic load

    Science.gov (United States)

    Pierre-Emile, T.; Anduze, M.

    2018-03-01

    In the context of ILD project, impact studies of environmental loads on the Electromagnetic CALorimeter (ECAL) have been initiated. The ECAL part considered is the barrel and it consists of several independent modules which are mounted on the Hadronic CALorimeter barrel (HCAL) itself mounted on the cryostat coil and the yoke. The estimate of the gap required between each ECAL modules is fundamental to define the assembly step and avoid mechanical contacts over the barrel lifetime. In the meantime, it has to be done in consideration to the dead spaces reduction and detector hermiticity optimization. Several Finite Element Analysis (FEA) with static and dynamic loads have been performed in order to define correctly the minimum values for those gaps. Due to the implantation site of the whole project in Japan, seismic analysis were carried out in addition to the static ones. This article shows results of these analysis done with the Finite Element Method (FEM) in ANSYS. First results show the impact of HCAL design on the ECAL modules motion in static load. The second study dedicated to seismic approach on a larger model (including yoke and cryostat) gives additional results on earthquake consequences.

  10. Detector Control System for the ATLAS Forward Proton detector

    CERN Document Server

    Czekierda, Sabina; The ATLAS collaboration

    2017-01-01

    The ATLAS Forward Proton (AFP) is a forward detector using a Roman Pot technique, recently installed in the LHC tunnel. It is aiming at registering protons that were diffractively or electromagnetically scattered in soft and hard processes. Infrastructure of the detector consists of hardware placed both in the tunnel and in the control room USA15 (about 330 meters from the Roman Pots). AFP detector, like the other detectors of the ATLAS experiment, uses the Detector Control System (DCS) to supervise the detector and to ensure its safe and coherent operation, since the incorrect detector performance may influence the physics results. The DCS continuously monitors the detector parameters, subset of which is stored in data bases. Crucial parameters are guarded by alarm system. A detector representation as a hierarchical tree-like structure of well-defined subsystems built with the use of the Finite State Machine (FSM) toolkit allows for overall detector operation and visualization. Every node in the hierarchy is...

  11. Youth in Dead End

    Directory of Open Access Journals (Sweden)

    Duygu TANRIKULU

    2011-01-01

    Full Text Available The primary factor to ensure economic and social development and also to build a healthy society is the education system which plays a significant role in human capital formation and shapes the social structure and its outputs. In this context, there are some risks threatening the youth that is trying to position itself on the education-employment line and some critical areas in need of national policy intervention as well. Hence, by analyzing indicators on education and labor force, this study aims to reveal the amount of youth under risk and to identify these critical areas, while targeting to highlight the urgent need for policy development focusing on youth in dead end. Within the study, it is emphasized that the education system causes youth to face with the problems of access and quality, and that there is a significant amount of youth not in education and employment, while underlining the necessity of bringing especially this inactive youth in economy in addition to equipping with required qualifications for their active participation in social life. Thus, in order to hinder human capital loss additionally, there is policy need in two directions, as focusing on the education system to prevent new hopeless generations on the one hand, and on the inclusion of the disadvantaged youth on the other.

  12. Security issues of quantum cryptographic systems with imperfect detectors

    Science.gov (United States)

    Burenkov, Viacheslav

    The laws of quantum physics can be used to secure communications between two distant parties in a scheme called quantum key distribution (QKD), even against a technologically unlimited eavesdropper. While the theoretical security of QKD has been proved rigorously, current implementations of QKD are generally insecure. In particular, mathematical models of devices, such as detectors, do not accurately describe their real-life behaviour. Such seemingly insignificant discrepancies can compromise the security of the entire scheme, especially as novel detector technologies are being developed with little regard for potential vulnerabilities. In this thesis, we study how detector imperfections can impact the security of QKD and how to overcome such technological limitations. We first analyze the security of a high-speed QKD system with finite detector dead time tau. We show that the previously reported sifting approaches are not guaranteed to be secure in this regime. More specifically, Eve can induce a basis-dependent detection efficiency at the receiver's end. Modified key sifting schemes that are basis-independent, and thus secure in the presence of dead time and an active eavesdropper, are discussed and compared. It is shown that the maximum key generation rate is 1/(2tau) for passive basis selection, and 1/tau for active basis selection. The security analysis is also extended to the decoy state BB84 protocol. We then study a relatively new type of single-photon detector called the superconducting nanowire single-photon detector (SNSPD), and discover some unexpected behaviour. We report an afterpulsing effect present when the SNSPD is operated in the high bias current regime. In our standard set-up, the afterpulsing is most likely to occur at around 180 ns following a detection event, for both real counts and dark counts. We characterize the afterpulsing behaviour and speculate that it is not due to the SNSPD itself but rather the associated read-out circuit. We also

  13. Precise measurement of dead time

    International Nuclear Information System (INIS)

    Schoenfeld, E.; Janssen, H.

    1994-01-01

    Four methods are discussed by which dead times of the non-extending type can be determined experimentally. Two methods using statistical pulses were improved by eliminating uncertainties due to counting statistics. However, it was concluded from a comparison of the four methods that those using periodical pulses are not only less time-consuming but are preferable if high-precision values are aimed at. A dead-time unit with quartz oscillator-based dead times of the non-extending type was tested using all of the four methods. Measurements within a period of three years indicated that the unit investigated here has subnanosecond stability for each of the adjusted dead-time values. (orig.)

  14. Anthrax, People and Dead Hippos

    Centers for Disease Control (CDC) Podcasts

    2017-11-07

    Epidemiologist, Dr. Melissa Marx, discuses anthrax deaths in people who ate dead hippos.  Created: 11/7/2017 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 11/7/2017.

  15. And the Dead Remain Behind

    Directory of Open Access Journals (Sweden)

    Peter Read

    2013-08-01

    Full Text Available In most cultures the dead and their living relatives are held in a dialogic relationship. The dead have made it clear, while living, what they expect from their descendants. The living, for their part, wish to honour the tombs of their ancestors; at the least, to keep the graves of the recent dead from disrepair. Despite the strictures, the living can fail their responsibilities, for example, by migration to foreign countries. The peripatetic Chinese are one of the few cultures able to overcome the dilemma of the wanderer or the exile. With the help of a priest, an Australian Chinese migrant may summon the soul of an ancestor from an Asian grave to a Melbourne temple, where the spirit, though removed from its earthly vessel, will rest and remain at peace. Amongst cultures in which such practices are not culturally appropriate, to fail to honour the family dead can be exquisitely painful. Violence is the cause of most failure.

  16. Climate change and dead zones.

    Science.gov (United States)

    Altieri, Andrew H; Gedan, Keryn B

    2015-04-01

    Estuaries and coastal seas provide valuable ecosystem services but are particularly vulnerable to the co-occurring threats of climate change and oxygen-depleted dead zones. We analyzed the severity of climate change predicted for existing dead zones, and found that 94% of dead zones are in regions that will experience at least a 2 °C temperature increase by the end of the century. We then reviewed how climate change will exacerbate hypoxic conditions through oceanographic, ecological, and physiological processes. We found evidence that suggests numerous climate variables including temperature, ocean acidification, sea-level rise, precipitation, wind, and storm patterns will affect dead zones, and that each of those factors has the potential to act through multiple pathways on both oxygen availability and ecological responses to hypoxia. Given the variety and strength of the mechanisms by which climate change exacerbates hypoxia, and the rates at which climate is changing, we posit that climate change variables are contributing to the dead zone epidemic by acting synergistically with one another and with recognized anthropogenic triggers of hypoxia including eutrophication. This suggests that a multidisciplinary, integrated approach that considers the full range of climate variables is needed to track and potentially reverse the spread of dead zones. © 2014 John Wiley & Sons Ltd.

  17. Dead sea asphalts: historical aspects

    Energy Technology Data Exchange (ETDEWEB)

    Nissenbaum, A.

    1978-05-01

    Asphalts are present in the Dead Sea basin in three forms: (1) huge blocks, up to 100 tons in weight, composed of extremely pure (>99.99%) solid asphalt occasionally found floating on the lake, (2) veins, seepages, and cavity and fissure fillings in Lower Cretaceous to Holocene rocks, and (3) ozocerite veins on the eastern shore of the lake. Dead Sea asphalts probably have been documented over a longer period of time than any other hydrocarbon deposit--from antiquity to the 19th century. Major uses of asphalt from the Dead Sea have been as an ingredient in the embalming process, for medicinal purposes, for fumigation, and for agriculture. The first known war for control of a hydrocarbon deposit was in the Dead Sea area in 312 B.C. between the Seleucid Syrians and the Nabatean Arabs who lived around the lake. Surface manifestations of asphalt are linked closely to tectonic activity. In the lake itself, the asphalt is associated with diapirs During certain historic periods, tectonic and diapiric activity caused frequent liberation to the Dead Sea surface of semiliquid asphalt associated with large amounts of hydrogen sulfide gas. When the tectonic activity was attenuated, as in the 19th and 20th centuries, the rate of asphalt seepage to the bottom sediments of the Dead Sea was much slower and the asphalt solidified on the lake bottom. The release of asphalt to the surface became much more sporadic, and may have resulted in part from earthquakes. Thus, future asphalt prospecting in the Dead Sea area should be conducted along the boundaries of diapirs or their associated faults.

  18. Radiation detectors

    International Nuclear Information System (INIS)

    2013-01-01

    This sixth chapter presents the operational principles of the radiation detectors; detection using photographic emulsions; thermoluminescent detectors; gas detectors; scintillation detectors; liquid scintillation detectors; detectors using semiconductor materials; calibration of detectors; Bragg-Gray theory; measurement chain and uncertainties associated to measurements

  19. Single photon detector design features

    Science.gov (United States)

    Zaitsev, Sergey V.; Kurochkin, Vladimir L.; Kurochkin, Yury V.

    2016-12-01

    In the report are discussed the laboratory test results of SPAD detectors with InGaAs / InP avalanche photodiodes, operating in Geiger mode. Device operating in synchronous mode with the dead timer setting for proper working conditions of photodiodes. The report materials will showing the functional block diagram of the detector, real operating signals in the receiver path and clock circuits and main results of measurements. The input signal of the synchronous detector is the clock, which determines the time positions of expected photons arrival. Increasing the clock speed 1-300 MHz or getting more time positions of the time grid, we provide increased capacity for time position code of signals, when QKD information transmitted over the nets. At the same time, the maximum attainable speed of photon reception is limited by diode dead time. Diode quantum noise are minimized by inclusion of a special time interval - dead time 0.1-10 usec, after each received and registered a photon. The lowest attainable value of the dead time is determined as a compromise between transients in electrical circuits, passive avalanche «quenching» circuit and thermal transients cooling crystal diode, after each avalanche pass though photodiode. Achievable time and speed parameters are discussed with specific examples of detectors.

  20. A detector for neutron imaging

    CERN Document Server

    Britton, C L; Wintenberg, A L; Warmack, R J; McKnight, T E; Frank, S S; Cooper, R G; Dudney, N J; Veith, G M; Stephan, A C

    2004-01-01

    A bright neutron source such as the Spallation Neutron Source (SNS) places extreme requirements on detectors including excellent 2-D spatial imaging and high dynamic range. Present imaging detectors have either shown position resolutions that are less than acceptable or they exhibit excessive paralyzing dead times due to the brightness of the source. High neutron detection efficiency with good neutron- gamma discrimination is critical for applications in neutron scattering research where the usefulness of the data is highly dependent on the statistical uncertainty associated with each detector pixel.. A detector concept known as MicroMegas (MicroMEsh GAseous Structure) has been developed at CERN in Geneva for high- energy physics charged-particle tracking applications and has shown great promise for handling high data rates with a rather low-cost structure. We are attempting to optimize the MicroMegas detector concept for thermal neutrons and have designed a 1-D neutron strip detector which we have tested In ...

  1. Investigation about semiconductor gamma ray detector - Evaluation of Ge(Li) detectors life expectation

    International Nuclear Information System (INIS)

    1980-06-01

    A list of germanium lithium gamma ray detectors has been drawn up by a working group after investigations in various laboratories. Authors analyse the historical account of each detector and try to give an answer about some questions as: - detectors life expectation, - deficiencies and death reasons, - influence of detector type and volume. Differents parameters are also collected by the working group for future works (standard geometry, low level measurements, etc.). In the list, the characteristics of 228 detectors, collected between january 1965 and december 1977 are put together. The principal conclusions of the authors are: - with a probability of 95%, half of the detectors is dead before 6.1 years, - the average age of dead population (33% of detectors) is 3.9 years, - resolution and efficiency evolution are good indicators of possible deficiency, - the fiability of vertical cryostat is better than the other systems [fr

  2. Test data analysis on trapezoidal MSGC detectors

    International Nuclear Information System (INIS)

    Bergdolt, A.M.; Brom, J.M.; Coffin, J.; Djama, F.; Eberle, H.; Kachelhoffer, T.; Pallares, A.; Pralavorio, P.; Sigward, M.H.; Todorov, T.; Zghiche, A.; Barthe, S.; Schunck, J.P.

    1996-01-01

    This paper describes the analysis of experimental data obtained during the october tests at CERN with the trapezoidal MSGC detectors. The resolution and efficiency of the MSGC detectors have been estimated using the track reconstruction from eight planes of the silicon detector (also called telescope). A 100 μm residue is obtained, compatible with a 35 μm resolution, due to multiple coulomb-scattering. The efficiency out of the dead region is about 80%

  3. The Right to be Dead

    DEFF Research Database (Denmark)

    Sabra, Jakob Borrits; Troyer, John Eric

    2018-01-01

    -mortem handling of their exponentially increased digital data. The European Union Court of Justice ruled that a person has a Right to be Forgotten on the world wide web. The Future Cemetery asks: Does a person have the Right to be Dead on this information superhighway? Our essay pursues these specific lines...

  4. (Li) detector characteristics on the accuracy in X-ray analysis using the

    African Journals Online (AJOL)

    A study has been carried out to show how variations in Si(Li) detector characteristics affect the accuracy of X-ray spectra evaluation. The detector characteristics investigated are Be window thickness, Au layer, Si dead layer and Si Detector Sensitive volume. For each of the detector parameters, different thickness values ...

  5. 7 CFR 322.29 - Dead bees.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Dead bees. 322.29 Section 322.29 Agriculture..., DEPARTMENT OF AGRICULTURE BEES, BEEKEEPING BYPRODUCTS, AND BEEKEEPING EQUIPMENT Importation and Transit of Restricted Articles § 322.29 Dead bees. (a) Dead bees imported into or transiting the United States must be...

  6. Global risk of deadly heat

    Science.gov (United States)

    Mora, Camilo; Dousset, Bénédicte; Caldwell, Iain R.; Powell, Farrah E.; Geronimo, Rollan C.; Bielecki, Coral R.; Counsell, Chelsie W. W.; Dietrich, Bonnie S.; Johnston, Emily T.; Louis, Leo V.; Lucas, Matthew P.; McKenzie, Marie M.; Shea, Alessandra G.; Tseng, Han; Giambelluca, Thomas W.; Leon, Lisa R.; Hawkins, Ed; Trauernicht, Clay

    2017-07-01

    Climate change can increase the risk of conditions that exceed human thermoregulatory capacity. Although numerous studies report increased mortality associated with extreme heat events, quantifying the global risk of heat-related mortality remains challenging due to a lack of comparable data on heat-related deaths. Here we conducted a global analysis of documented lethal heat events to identify the climatic conditions associated with human death and then quantified the current and projected occurrence of such deadly climatic conditions worldwide. We reviewed papers published between 1980 and 2014, and found 783 cases of excess human mortality associated with heat from 164 cities in 36 countries. Based on the climatic conditions of those lethal heat events, we identified a global threshold beyond which daily mean surface air temperature and relative humidity become deadly. Around 30% of the world's population is currently exposed to climatic conditions exceeding this deadly threshold for at least 20 days a year. By 2100, this percentage is projected to increase to ~48% under a scenario with drastic reductions of greenhouse gas emissions and ~74% under a scenario of growing emissions. An increasing threat to human life from excess heat now seems almost inevitable, but will be greatly aggravated if greenhouse gases are not considerably reduced.

  7. Electronic fingerprinting of the dead.

    Science.gov (United States)

    Rutty, G N; Stringer, K; Turk, E E

    2008-01-01

    To date, a number of methods exist for the capture of fingerprints from cadavers that can then be used in isolation as a primary method for the identification of the dead. We report the use of a handheld, mobile wireless unit used in conjunction with a personal digital assistant (PDA) device for the capture of fingerprints from the dead. We also consider a handheld single-digit fingerprint scanner that utilises a USB laptop connection for the electronic capture of cadaveric fingerprints. Both are single-operator units that, if ridge detail is preserved, can collect a 10-set of finger pad prints in approximately 45 and 90 s, respectively. We present our observations on the restrictions as to when such devices can be used with cadavers. We do, however, illustrate that the images are of sufficient quality to allow positive identification from finger pad prints of the dead. With the development of mobile, handheld, biometric, PDA-based units for the police, we hypothesize that, under certain circumstances, devices such as these could be used for the accelerated acquisition of fingerprint identification data with the potential for rapid near-patient identification in the future.

  8. Analysis of Excitation and Dead Vibration Modes of Quartz Resonators

    Directory of Open Access Journals (Sweden)

    Zi-Gui Huang

    2014-01-01

    Full Text Available This study uses the finite element method (FEM to analyze the excitation and dead vibration modes of two-dimensional quartz plates. We first simplify three-dimensional quartz plates with plane strain simplification and then compare the modes of the simplified three-dimensional plates to those of two-dimensional plates. We then analyze quartz vibrating elements of AT-cut plates and SC-cut plates. To understand the regularity of the resonance frequency of plates that are excitable by voltage loading, we compare the natural vibrations of quartz plates with the excitation frequency generated after the plates are excited by voltage loading.

  9. Real-time dynamic simulation of angular velocity and suppression of dead zone in IFOG

    Science.gov (United States)

    Gu, Hong; Huan, Yunpeng; Wang, Ansu; Luan, Jinwen

    2015-02-01

    The mechanism of the dead zone in closed-loop IFOGs is theoretically analyzed. The digital closed-loop transfer model for fiber-optic gyroscope is modified and the electronic cross-coupling interference from the feedback channel in the output signal of the detector in the forward channel is added. Using this model, we achieve a real-time dynamic simulation for the dead zone. The simulation results are basically consistent with experiment results. Before the electronic cross-coupling has been eliminated, the dead zone of the high-precision fiber-optic gyro is about , while the medium precision fiber-optic gyro is . After modifying the modulator circuit boards, the dead zone and the noise of the IFOG are of the same order of magnitude, better than and , respectively.

  10. Are Brain Dead Individuals Dead? Grounds for Reasonable Doubt.

    Science.gov (United States)

    Brugger, E Christian

    2016-06-01

    According to the biological definition of death, a human body that has not lost the capacity to holistically organize itself is the body of a living human individual. Reasonable doubt against the conclusion that it has lost the capacity exists when the body appears to express it and no evidence to the contrary is sufficient to rule out reasonable doubt against the conclusion that the apparent expression is a true expression (i.e., when the conclusion that what appears to be holistic organization is in fact holistic organization remains a reasonable explanatory hypothesis in light of the best evidence to the contrary). This essay argues that the evidence and arguments against the conclusion that the signs of complex bodily integration exhibited in ventilated brain dead bodies are true expressions of somatic integration are unpersuasive; that is, they are not adequate to exclude reasonable doubt against the conclusion that BD bodies are dead. Since we should not treat as corpses what for all we know might be living human beings, it follows that we have an obligation to treat BD individuals as if they were living human beings. © The Author 2016. Published by Oxford University Press, on behalf of the Journal of Medicine and Philosophy Inc. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. Analog processor for electroluminescent detector

    International Nuclear Information System (INIS)

    Belkin, V.S.

    1988-01-01

    Analog processor for spectrometric channel of soft X-ray radiation electroluminescent detector is described. Time internal spectrometric measurer (TIM) with 1 ns/chan quick action serves as signal analyzer. Analog processor restores signals direct component, integrates detector signals and generates control pulses on the TIM input, provides signal discrimination by amplitude and duration, counts number of input pulses per measuring cycle. Flowsheet of analog processor and its man characteristics are presented. Analog processor dead time constitutes 0.5-5 ms. Signal/noise relation is ≥ 500. Scale integral nonlinearity is < 2%

  12. finite induc

    Indian Academy of Sciences (India)

    com. Email: singh_shivaraj@rediffmail.com. In this article we provide a solution to a problem in the famous analysis book [1] by Rudin. It does not use trans- finite induction, and readers may find it more transpar- ent than the treatment in [2]. Here is ...

  13. A Minor Modification of Leading Edge Discriminator Circuitry with a Delay Line for Baseline Restoration of Scintillation Detectors

    International Nuclear Information System (INIS)

    Izumi, N

    2003-01-01

    Multi-channel neutron time-of-flight detector arrays LaNSA, T-ion, Medusa, and Mandala, have been used for neutron spectroscopy in inertial confinement fusion experiments. These multi-channel neutron detector arrays consist of many identical scintillation detectors (842 ∼ 1024 channel), data acquisition electronics (discriminators, time-to digital converters, and controller). Each detector element is operated in neutron counting mode. Time-of-flight of individual detected neutrons are recorded by time to digital converters. The energy of each detected neutrons is determined from its time-of-flight. The accurate time measurement (Δt ∼ 0.5 ns) and straightforward statistical features of the data obtained with these systems provides good integrity and reliability. The elements detector used in these systems are organic scintillators coupled with photo multiplier tubes. A scintillation detector operated in particle-counting mode requires finite recovery time after each detection event. The recovery time is determined by the time responses of scintillators, photo multiplier tubes, and the dead times of following discriminators and time-to digital converters. The harsh gamma ray background environment of fast ignitor experiments requires detectors that have fast recovery times. In high intensity laser experiments (I > 10 19 W/cm 2 ), strong gamma ray bursts are produced by relativistic laser plasma interactions. Prior to the neutron signal, these strong gamma ray bursts hit the detectors and interfere with the detection of following neutron signals. In these situations, the recovery time of the system after preceding gamma ray bursts is determined mainly by the base line shift of the PMT signal (due to slower decay components of scintillators ''after glow''). Discriminators cannot detect following signal pulses until the proceeding burst decays below its threshold voltage. The base line shift caused by the after glow prolongs the recovery time of the discriminators

  14. A Generalized Finite Source Calibration Factor: A Natural Improvement to the Finite Source Correction Factor for Uranium Holdup Measurements

    International Nuclear Information System (INIS)

    Gunn, C.A.; Oberer, R.B.; Chiang, L.G.; Ceo, R.N.

    2003-01-01

    This paper proposes refinements to the finite source correction factor used in holdup measurements. Specifically it focuses on a more general method to estimate the average detector response for a finite source. This proposed method for the average detector response is based directly on the Generalized Geometry Holdup (GGH) assay method. First, the finite source correction factor as originally proposed is reviewed in this paper. Following this review the GGH assay method is described. Lastly, a new finite area calibration factor based on GGH is then proposed for finite point and line sources. As an alternative to the direct use of the finite arca calibration factor, finite source correction factors are also derived from this calibration factor. This new correction factor can be used in a manner similar to the finite source correction factor as currently implemented

  15. Is Schrödinger's cat dead oa alive?

    Directory of Open Access Journals (Sweden)

    Wojciech Grygiel

    2005-12-01

    Full Text Available The Schrödinger's Cat paradox was proposed in 1935 by Edwin Schrodinger, one of the founders of quantum mechanics, as an attempt to visualize the macroscopic realization of a quantum superposition state. A cat is placed in a sealed box together with a vial of poison. A two-state particle (e.g. an electron is sent into a detector in the box resulting either in a broken or an intact vial and a dead or live cat, respectively. The main problem consists in whether the superposition state of a microscopic particle can be transferred upon the macroscopic cat, that is, whether the cat can exist in a superposition state, being simultaneously dead and alive. Since the standard Copenhagen interpretation is unable to assign any reality to the quantum superposition state, the paradox finds no resolution within the regime of this interpretation. Von Neumann's insistence on the uniform treatment of both microscopic (quantum and macroscopic (classical objects according to the laws of quantum mechanics provides a more consistent framework for the resolution of the paradox. In particular, the discovery of the phenomenon of decoherence, whereby the disappearance of the quantum interferences at the macro level is accounted for, suggests the onset of an extremely efficient interference relaxation process (10-23 s upon the interaction of the two state particle with the detector. As a result, Schrodinger's cat can exist macroscopically either as dead or alive and never as a combination of both. Decoherence not only aids the resolution of the Schrodinger's Cat paradox but also sheds light upon the mechanisms by which the macro-world emerges from the microscopic quantum realm.

  16. Occurrence of organohalogens at the Dead Sea Basin

    Science.gov (United States)

    Tubbesing, Christoph; Kotte, Karsten; Keppler, Frank; Krause, Torsten; Bahlmann, Enno; Schöler, Heinfried

    2013-04-01

    Most arid and semi-arid regions are characterized by evaporites, which are assured sources for volatile organohalogens (VOX) [1]. These compounds play an important role in tropospheric and stratospheric chemistry. The Dead Sea between Israel and Jordan is the world's most famous and biggest all-season water covered salt lake. In both countries chemical plants like the Dead Sea Works and the Arab Potash Company are located at the southern part of the Dead Sea and mine various elements such as bromine and magnesium. Conveying sea water through constructed evaporation pans multifarious salts are enriched and precipitated. In contrast, the Northern basin and main part of the Dead Sea has remained almost untouched by industrial salt production. Its fresh water supply from the Jordan River is constantly decreasing, leading to further increased salinity. During a HALOPROC campaign (Natural Halogenation Processes in the Environment) we collected various samples including air, soils, sediments, halophytic plants, ground- and seawater from the Northern and Southern basin of the Israeli side of the Dead Sea. These samples were investigated for the occurrence of halocarbons using different analytical techniques. Most samples were analyzed for volatile organohalogens such as haloalkanes using gas chromatography- mass spectrometry (GC-MS). Interestingly, there is a strong enrichment of trihalomethanes (THM), especially all chlorinated and brominated ones and also the iodinated compound dichloroiodomethane were found in the Southern basin. In addition, volatile organic carbons (VOC) such as ethene and some other alkenes were analyzed by a gas chromatography-flame ionisation detector (GC-FID) to obtain further information about potential precursors of halogenated compounds. Halophytic plants were investigated for their potential to release chloromethane and bromomethane but also for their stable carbon and hydrogen isotope composition. For this purpose, a plant chamber was

  17. Detector Mount Design for IGRINS

    Directory of Open Access Journals (Sweden)

    Jae Sok Oh

    2014-06-01

    Full Text Available The Immersion Grating Infrared Spectrometer (IGRINS is a near-infrared wide-band high-resolution spectrograph jointly developed by the Korea Astronomy and Space Science Institute and the University of Texas at Austin. IGRINS employs three HAWAII-2RG Focal Plane Array (H2RG FPA detectors. We present the design and fabrication of the detector mount for the H2RG detector. The detector mount consists of a detector housing, an ASIC housing, a Field Flattener Lens (FFL mount, and a support base frame. The detector and the ASIC housing should be kept at 65 K and the support base frame at 130 K. Therefore they are thermally isolated by the support made of GFRP material. The detector mount is designed so that it has features of fine adjusting the position of the detector surface in the optical axis and of fine adjusting yaw and pitch angles in order to utilize as an optical system alignment compensator. We optimized the structural stability and thermal characteristics of the mount design using computer-aided 3D modeling and finite element analysis. Based on the structural and thermal analysis, the designed detector mount meets an optical stability tolerance and system thermal requirements. Actual detector mount fabricated based on the design has been installed into the IGRINS cryostat and successfully passed a vacuum test and a cold test.

  18. Coincidence-counting corrections for accidental coincidences, set dead time and intrinsic dead time

    International Nuclear Information System (INIS)

    Wyllie, H.A.

    1998-01-01

    An equation is derived for calculating the radioactivity of a source from the results of coincidence counting, taking into account dead-time losses and accidental coincidences. The corrections allow for the extension of the set dead time in the p channel by the intrinsic dead time. Experimental verification shows improvement over a previous equation. (author)

  19. MTR2: a discriminator and dead-time module used in counting systems

    Energy Technology Data Exchange (ETDEWEB)

    Bouchard, J

    2000-03-01

    In the field of radioactivity measurement, there is a constant need for highly specialized electronic modules such as ADCs, amplifiers, discriminators, dead-time modules, etc. But sometimes it is almost impossible to find on the market the modules having the performances corresponding to our needs. The purpose of the module presented here, called MTR2 (Module de Temps-mort Reconductible), is to process, in terms of pulse height discrimination and dead-time corrections, the pulses delivered by the detectors used in counting systems. This dead-time, of the extendible type, is triggered by both the positive and negative parts of the incoming pulse and the dead-time corrections are made according to the live-time method. This module, which has been developed and tested at LPRI, can be used alone in simple counting channels or in more complex systems such as coincidence systems. The philosophy governing the choice and the implementation of this type of dead-time as well as the system used for the dead-time corrections is presented. The electronic scheme and the performances are also presented. This module is available in the NIM standard.

  20. MTR2: a discriminator and dead-time module used in counting systems

    International Nuclear Information System (INIS)

    Bouchard, J.

    2000-01-01

    In the field of radioactivity measurement, there is a constant need for highly specialized electronic modules such as ADCs, amplifiers, discriminators, dead-time modules, etc. But sometimes it is almost impossible to find on the market the modules having the performances corresponding to our needs. The purpose of the module presented here, called MTR2 (Module de Temps-mort Reconductible), is to process, in terms of pulse height discrimination and dead-time corrections, the pulses delivered by the detectors used in counting systems. This dead-time, of the extendible type, is triggered by both the positive and negative parts of the incoming pulse and the dead-time corrections are made according to the live-time method. This module, which has been developed and tested at LPRI, can be used alone in simple counting channels or in more complex systems such as coincidence systems. The philosophy governing the choice and the implementation of this type of dead-time as well as the system used for the dead-time corrections is presented. The electronic scheme and the performances are also presented. This module is available in the NIM standard

  1. Detector trends

    International Nuclear Information System (INIS)

    Charpak, G.

    1986-01-01

    The author describes briefly the development of detectors for high energy physics experiments. Especially considered are semiconductor microstrip detectors, drift tubes, holographic bubble chambers, scintillating fiber optics, and calorimeters. (HSI).

  2. Detector Unit

    CERN Multimedia

    1960-01-01

    Original detector unit of the Instituut voor Kernfysisch Onderzoek (IKO) BOL project. This detector unit shows that silicon detectors for nuclear physics particle detection were already developed and in use in the 1960's in Amsterdam. Also the idea of putting 'strips' onto the silicon for high spatial resolution of a particle's impact on the detector were implemented in the BOL project which used 64 of these detector units. The IKO BOL project with its silicon particle detectors was designed, built and operated from 1965 to roughly 1977. Detector Unit of the BOL project: These detectors, notably the ‘checkerboard detector’, were developed during the years 1964-1968 in Amsterdam, The Netherlands, by the Natuurkundig Laboratorium of the N.V. Philips Gloeilampen Fabrieken. This was done in close collaboration with the Instituut voor Kernfysisch Onderzoek (IKO) where the read-out electronics for their use in the BOL Project was developed and produced.

  3. Infrared detectors

    CERN Document Server

    Rogalski, Antonio

    2010-01-01

    This second edition is fully revised and reorganized, with new chapters concerning third generation and quantum dot detectors, THz detectors, cantilever and antenna coupled detectors, and information on radiometry and IR optics materials. Part IV concerning focal plane arrays is significantly expanded. This book, resembling an encyclopedia of IR detectors, is well illustrated and contains many original references … a really comprehensive book.-F. Sizov, Institute of Semiconductor Physics, National Academy of Sciences, Kiev, Ukraine

  4. Particle identification with the fast COMPASS RICH-1 detector

    International Nuclear Information System (INIS)

    Abbon, P.; Alexeev, M.; Angerer, H.; Birsa, R.; Bordalo, P.; Bradamante, F.; Bressan, A.; Chiosso, M.; Ciliberti, P.; Colantoni, M.L.; Dafni, T.; Dalla Torre, S.; Delagnes, E.; Denisov, O.; Deschamps, H.; Diaz, V.; Dibiase, N.; Duic, V.; Eyrich, W.; Ferrero, A.

    2010-01-01

    A new photon detection system for the COMPASS RICH-1 detector has been designed and installed. In the central region, the project is based on multi-anode photo-multiplier technology accompanied by charge sensitive, high resolution and dead-time free time digitization. In the outer area, only the readout electronics for the existing photon detectors has been replaced. Details on the detector upgrade and its performance are presented.

  5. Raising the Dead without a Red Sea-Dead Sea project? Hydro-economics and governance

    Directory of Open Access Journals (Sweden)

    D. E. Rosenberg

    2011-04-01

    Full Text Available Seven decades of extractions have dramatically reduced Jordan River flows, lowered the Dead Sea level, opened sink holes, and caused other environmental problems. The fix Jordan, Israel, and the Palestinians propose would build an expensive multipurpose conveyance project from the Red Sea to the Dead Sea that would also generate hydropower and desalinate water. This paper compares the Red-Dead project to alternatives that may also raise the Dead Sea level. Hydro-economic model results for the Jordan-Israel-Palestinian inter-tied water systems show two restoration alternatives are more economically viable than the proposed Red-Dead project. Many decentralized new supply, wastewater reuse, conveyance, conservation, and leak reduction projects and programs in each country can together increase economic benefits and reliably deliver up to 900 MCM yr−1 to the Dead Sea. Similarly, a smaller Red-Dead project that only generates hydropower can deliver large flows to the Dead Sea when the sale price of generated electricity is sufficiently high. However, for all restoration options, net benefits fall and water scarcity rises as flows to the Dead Sea increase. This finding suggests (i each country has no individual incentive to return water to the Dead Sea, and (ii outside institutions that seek to raise the Dead must also offer countries direct incentives to deliver water to the Sea besides building the countries new infrastructure.

  6. 3D IC for future HEP detectors

    International Nuclear Information System (INIS)

    Thom, J; Badman, R; Lipton, R; Johnson, M; Spiegel, L; Deptuch, G; Ye, Z; Heintz, U; Narain, M; Triphati, M; Kenney, C; Parker, S; Siddons, D P

    2014-01-01

    Three dimensional integrated circuit technologies offer the possibility of fabricating large area arrays of sensors integrated with complex electronics with minimal dead area, which makes them ideally suited for applications at the LHC upgraded detectors and other future detectors. We describe ongoing R and D efforts to demonstrate functionality of components of such detectors. This includes the study of integrated 3D electronics with active edge sensors to produce ''active tiles'' which can be tested and assembled into arrays of arbitrary size with high yield

  7. New class of neutron detectors

    International Nuclear Information System (INIS)

    Czirr, J.B.

    1997-01-01

    An optimized neutron scattering instrument design must include all significant components, including the detector. For example, useful beam intensity is limited by detector dead time; detector pixel size determines the optimum beam diameter, sample size, and sample to detector distance; and detector efficiency vs. wavelength determines the available energy range. As an example of the next generation of detectors that could affect overall instrumentation design, we will describe a new scintillator material that is potentially superior to currently available scintillators. We have grown and tested several small, single crystal scintillators based upon the general class of cerium-activated lithium lanthanide borates. The outstanding characteristic of these materials is the high scintillation efficiency-as much as five times that of Li-glass scintillators. This increase in light output permits the practical use of the exothermic B (n, alpha) reaction for low energy neutron detection. This reaction provides a four-fold increase in capture cross section relative to the Li (n, alpha) reaction, and the intriguing possibility of demanding a charged-particle/gamma ray coincidence to reduce background detection rates. These new materials will be useful in the thermal and epithermal energy ran at reactors and pulsed neutron sources

  8. Dead pixel replacement in LWIR microgrid polarimeters.

    Science.gov (United States)

    Ratliff, Bradley M; Tyo, J Scott; Boger, James K; Black, Wiley T; Bowers, David L; Fetrow, Matthew P

    2007-06-11

    LWIR imaging arrays are often affected by nonresponsive pixels, or "dead pixels." These dead pixels can severely degrade the quality of imagery and often have to be replaced before subsequent image processing and display of the imagery data. For LWIR arrays that are integrated with arrays of micropolarizers, the problem of dead pixels is amplified. Conventional dead pixel replacement (DPR) strategies cannot be employed since neighboring pixels are of different polarizations. In this paper we present two DPR schemes. The first is a modified nearest-neighbor replacement method. The second is a method based on redundancy in the polarization measurements.We find that the redundancy-based DPR scheme provides an order-of-magnitude better performance for typical LWIR polarimetric data.

  9. Surviving Sepsis: Taming a Deadly Immune Response

    Science.gov (United States)

    ... Issues Subscribe August 2014 Print this issue Surviving Sepsis Taming a Deadly Immune Response En español Send ... Mouth? Looking at Lupus Wise Choices Signs of Sepsis Sepsis can be hard to spot, because its ...

  10. A nondispersive X-ray spectrometer with dead time correction of great accuracy

    International Nuclear Information System (INIS)

    Guillon, H.; Friant, A.

    1976-01-01

    Processing the analog signals from an energy dispersive X-ray spectrometer requires a great number of functions to be assembled. Instead of using function modules, it was decided to build a unit intended for working out digital-input data to the mini-computer, from the signals delivered by the Si(Li) detector. The unit contains six cards intended for the following functions: main amplifier, stabilizer of the threshold level and pile-up detector, amplitude encoder, pulse generator and fast amplifier, chronometer with dead time correction and high voltage polarization [fr

  11. Generalized energy detector for weak random signals via vibrational resonance

    Science.gov (United States)

    Ren, Yuhao; Pan, Yan; Duan, Fabing

    2018-03-01

    In this paper, the generalized energy (GE) detector is investigated for detecting weak random signals via vibrational resonance (VR). By artificially injecting the high-frequency sinusoidal interferences into an array of GE statistics formed for the detector, we show that the normalized asymptotic efficacy can be maximized when the interference intensity takes an appropriate non-zero value. It is demonstrated that the normalized asymptotic efficacy of the dead-zone-limiter detector, aided by the VR mechanism, outperforms that of the GE detector without the help of high-frequency interferences. Moreover, the maximum normalized asymptotic efficacy of dead-zone-limiter detectors can approach a quarter of the second-order Fisher information for a wide range of non-Gaussian noise types.

  12. Final Size Planar Edgeless Silicon Detectors for the TOTEM Experiment

    CERN Document Server

    Noschis, E; Anelli, G; Avati, V; Berardi, V; Boccone, V; Bozzo, M; Brucken, E; Buzzo, A; Catanesi, M G; Cereseto, R; Cuneo, S; Da Vià, C; Deile, M; Dinapoli, R; Eggert, K; Egorov, N; Eremin, I; Ferro, F; Hasi, J; Haug, F; Heino, J; Jarron, P; Kalliopuska, J; Kaspar, J; Kok, A; Kozlov, Y; Kundrat, W; Kurvinen, K; Lauhakangas, R; Lokajícek, M; Luntama, T; Macina, D; Macri, M; Minutoli, S; Mirabito, L; Morelli, A; Musico, P; Negri, M; Niewiadomski, H; Oljemark, F; Orava, R; Oriunno, M; Österberg, K; Perrot, A L; Puppo, R; Radermacher, E; Radicioni, E; Saarikko, H; Santroni, A; Sette, G; Sidorov, A; Siegrist, P; Smotlacha, J; Snoeys, W; Taylor, C; Watts, S; Whitmoree, J

    2006-01-01

    The TOTEM experiment will detect leading protons scattered in angles of microradians from the interaction point at the Large Hadron Collider. This will be achieved using detectors with a minimized dead area at the edge. The collaboration has developed an innovative structure at the detector edge reducing the conventional dead width to less than 100 microns, still using standard planar fabrication technology. In this new development, the current of the surface is decoupled from the sensitive volume current within a few tens of micrometers. The basic working principle is explained in this paper. Final size detectors have been produced using this approach. The current-voltage and current-temperature characteristics of the detectors were studied and the detectors were successfully tested in a coasting beam experiment.

  13. Dead Trees Bring Life to Forest Critters

    Science.gov (United States)

    Thomas Nicholls; Mike Ostry

    2003-01-01

    What good is a dying or dead tree in a forest? Dead and dying trees don't awe us with their beauty; they just stand or lie there on the forest floor, offering no promise of lumber or other wood products we need. But if we look more closely at such trees, we may see lots of life in them: a raccoon family huddled in a burrow, a downy woodpecker excavating another...

  14. Dead reckoning and distributed interactive simulation

    Science.gov (United States)

    Lin, Kuo-Chi

    1995-04-01

    This paper analyzes the use of dead reckoning in Distributed Interactive Simulation. The purpose of dead reckoning is to reduce the updates required by each simulator on the network to better utilize the available bandwidth. Extrapolation formulas are derived and discussed based on network communication traffic and the amount of computation performed by simulators. Smoothing and delay compensation algorithms are also discussed. Numerical and human perspective experiment are conducted. A software tool that assesses the performance of the read reckoning algorithm is introduced.

  15. Accurate efficiency characterization of a BEGe detector in the low-energy range using empirical and Monte Carlo simulation approaches

    International Nuclear Information System (INIS)

    Mekarski, Pawel; Weihua Zhang; Chuanlei Liu; Kurt Ungar, Kurt

    2017-01-01

    The efficiencies of a broad energy germanium detector were characterized down to energies below 10 keV. The K shell X-ray absorption in germanium was seen as a sharp drop in efficiency around 11 keV. This feature was used to determine the thickness of this detector's dead layer. By comparing efficiency simulations with different dead layer thicknesses to those determined from empirical measurements, the best fit dead layer thickness was determined to be 5.7 ± 1.5 µm. Additional measurements, taken with a collimator, made analytical calculations of the efficiency possible and these results also supported the dead layer thickness determination. (author)

  16. Locally Finite Root Supersystems

    OpenAIRE

    Yousofzadeh, Malihe

    2013-01-01

    We introduce the notion of locally finite root supersystems as a generalization of both locally finite root systems and generalized root systems. We classify irreducible locally finite root supersystems.

  17. Transmutation detectors

    Czech Academy of Sciences Publication Activity Database

    Viererbl, L.; Lahodová, Z.; Klupák, V.; Sus, F.; Kučera, Jan; Kůs, P.; Marek, M.

    2011-01-01

    Roč. 632, č. 1 (2011), s. 109-111 ISSN 0168-9002 Institutional research plan: CEZ:AV0Z10480505 Keywords : Transmutation detector * Activation method * Neutron detector * Neutron fluence Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.207, year: 2011

  18. Vapor Detector

    Science.gov (United States)

    Waddell, H. M.; Garrard, G. C.; Houston, D. W.

    1982-01-01

    Detector eliminates need for removing covers to take samples. Detector is canister consisting of screw-in base and clear plastic tube that contains two colors of silica gel. Monoethylhydrazine and nitrogen tetroxide vapors are visually monitored with canister containing color-changing gels.

  19. Cryogenic detectors

    International Nuclear Information System (INIS)

    Zehnder, A.

    1987-01-01

    Presently the development of new large scale detector systems, used in very high energy physics experiments, is very active. In the low energy range, the introduction of charge coupled devices allows improved spacial and energy resolution. In the keV region, high resolution can only be achieved via the well established diffraction spectrometers with the well-known disadvantage of a small throughput. There exist no efficient detectors for non-ionizing radiation such as coherent nuclear scattering of weakly interacting particles. The development of high resolution solid state detectors in the keV-region with the possibility of nuclear recoil detection is therefore highly desired. Such detectors applied in astro and particle physics would thus allow one to obtain new information not achievable otherwise. Three types of cryogenic detectors exist: Calorimeters/Bolometers. This type is sensitive to the produced excess phonons and measures the deposited energy by detecting the heat pulses. Excess charge carriers should be used to produce phonons. Tunneling junctions. This type is sensitive to excess charge produced by the Cooper pair breakup. Excess phonons should be used to break up Cooper pairs. Superheated superconducting granules (SSG). An SSG detector consists of granules, the metastability of which is disturbed by radiation. The Meissner effect then causes a change in the field distribution of the applied external field, which can be detected. The present paper discusses the basic principle of calorimetric and tunneling junction detectors and some of their applications. 26 refs., 7 figs., 1 tab

  20. Surface barrier silicon detectors with a large active area

    International Nuclear Information System (INIS)

    Kim, Y.; Husimi, K.; Ikeda, Y.; Kim, C.; Ohkawa, S.; Sakai, T.

    1985-01-01

    Surface barrier silicon detectors with a large active area have been produced by using high resistive n-type silicon crystals, diameters of which are 3 to 5 inches. High quality detectors with a low leakage current and a low noise were achieved by developing the improved surface treatment. Characteristics of detectors obtained are good in energy resolution compared with conventional large area Si(Li) detectors. It has also been confirmed that local dead region is not found from measuring results of photo-pulse injection

  1. Detectors - Electronics

    International Nuclear Information System (INIS)

    Bregeault, J.; Gabriel, J.L.; Hierle, G.; Lebotlan, P.; Leconte, A.; Lelandais, J.; Mosrin, P.; Munsch, P.; Saur, H.; Tillier, J.

    1998-01-01

    The reports presents the main results obtained in the fields of radiation detectors and associated electronics. In the domain of X-ray gas detectors for the keV range efforts were undertaken to rise the detector efficiency. Multiple gap parallel plate chambers of different types as well as different types of X → e - converters were tested to improve the efficiency (values of 2.4% at 60 KeV were reached). In the field of scintillators a study of new crystals has been carried out (among which Lutetium orthosilicate). CdTe diode strips for obtaining X-ray imaging were studied. The complete study of a linear array of 8 CdTe pixels has been performed and certified. The results are encouraging and point to this method as a satisfying solution. Also, a large dimension programmable chamber was used to study the influence of temperature on the inorganic scintillators in an interval from -40 deg. C to +150 deg. C. Temperature effects on other detectors and electronic circuits were also investigated. In the report mentioned is also the work carried out for the realization of the DEMON neutron multidetector. For neutron halo experiments different large area Si detectors associated with solid and gas position detectors were realized. In the frame of a contract with COGEMA a systematic study of Li doped glasses was undertaken aiming at replacing with a neutron probe the 3 He counters presently utilized in pollution monitoring. An industrial prototype has been realised. Other studies were related to integrated analog chains, materials for Cherenkov detectors, scintillation probes for experiments on fundamental processes, gas position sensitive detectors, etc. In the field of associated electronics there are mentioned the works related to the multidetector INDRA, data acquisition, software gamma spectrometry, automatic gas pressure regulation in detectors, etc

  2. Virtually Dead: Digital Public Mortuary Archaeology

    Directory of Open Access Journals (Sweden)

    Howard Williams

    2015-12-01

    Full Text Available Over recent decades, the ethics, politics and public engagements of mortuary archaeology have received sustained scrutiny, including how we handle, write about and display the archaeological dead. Yet the burgeoning use of digital media to engage different audiences in the archaeology of death and burial have so far escaped attention. This article explores categories and strategies by which digital media create virtual communities engaging with mortuary archaeology. Considering digital public mortuary archaeology (DPMA as a distinctive theme linking archaeology, mortality and material culture, we discuss blogs, vlogs and Twitter as case studies to illustrate the variety of strategies by which digital media can promote, educate and engage public audiences with archaeological projects and research relating to death and the dead in the human past. The article then explores a selection of key critical concerns regarding how the digital dead are currently portrayed, identifying the need for further investigation and critical reflection on DPMA’s aims, objectives and aspired outcomes.

  3. Dead Zone Accretion Flows in Protostellar Disks

    Science.gov (United States)

    Turner, Neal; Sano, T.

    2008-01-01

    Planets form inside protostellar disks in a dead zone where the electrical resistivity of the gas is too high for magnetic forces to drive turbulence. We show that much of the dead zone nevertheless is active and flows toward the star while smooth, large-scale magnetic fields transfer the orbital angular momentum radially outward. Stellar X-ray and radionuclide ionization sustain a weak coupling of the dead zone gas to the magnetic fields, despite the rapid recombination of free charges on dust grains. Net radial magnetic fields are generated in the magnetorotational turbulence in the electrically conducting top and bottom surface layers of the disk, and reach the midplane by ohmic diffusion. A toroidal component to the fields is produced near the midplane by the orbital shear. The process is similar to the magnetization of the solar tachocline. The result is a laminar, magnetically driven accretion flow in the region where the planets form.

  4. Dead sea transform fault system reviews

    CERN Document Server

    Garfunkel, Zvi; Kagan, Elisa

    2014-01-01

    The Dead Sea transform is an active plate boundary connecting the Red Sea seafloor spreading system to the Arabian-Eurasian continental collision zone. Its geology and geophysics provide a natural laboratory for investigation of the surficial, crustal and mantle processes occurring along transtensional and transpressional transform fault domains on a lithospheric scale and related to continental breakup. There have been many detailed and disciplinary studies of the Dead Sea transform fault zone during the last?20 years and this book brings them together.This book is an updated comprehensive coverage of the knowledge, based on recent studies of the tectonics, structure, geophysics, volcanism, active tectonics, sedimentology and paleo and modern climate of the Dead Sea transform fault zone. It puts together all this new information and knowledge in a coherent fashion.

  5. DUMAND detector

    CERN Multimedia

    This object is one of the 256 other detectors of the DUMAND (Deep Underwater Muon And Neutrino Detection) experiment. The goal of the experiment was the construction of the first deep ocean high energy neutrino detector, to be placed at 4800 m depth in the Pacific Ocean off Keahole Point on the Big Island of Hawaii. A few years ago, a European conference with Cosmic experiments was organized at CERN as they were projects like DUMAND in Hawaii. Along with the conference, a temporary exhibition was organised as well. It was a collaboration of institutions from Germany, Japan, Switzerland and the U.S.A. CERN had borrowed equipment and objects from different institutes around the world, including this detector of the DUMAND experiment. Most of the equipment were sent back to the institutes, however this detector sphere was offered to a CERN member of the personnel.

  6. Detector applications

    International Nuclear Information System (INIS)

    Pehl, R.H.

    1977-10-01

    Semiconductor detectors are now applied to a very wide range of problems. The combination of relatively low cost, excellent energy resolution, and simultaneous broad energy-spectrum analysis is uniquely suited to many applications in both basic and applied physics. Alternative techniques, such as magnetic spectrometers for charged-particle spectroscopy, while offering better energy resolution, are bulky, expensive, and usually far more difficult to use. Furthermore, they do not directly provide the broad energy-spectrum measurements easily accomplished using semiconductor detectors. Scintillation detectors, which are approximately equivalent to semiconductor detectors in convenience and cost, exhibit 10 to 100 times worse energy resolution. However, their high efficiency and large potential size recommend their use in some measurements

  7. Radiation detector

    International Nuclear Information System (INIS)

    Gillies, W.

    1980-01-01

    The radiation detector for measuring e.g. a neutron flux consists of a central emitter, an insulating shell arranged around it, and a tube-shaped collector enclosing both. The emitter itself is composed of a great number of stranded, spiral wires of small diameter giving a defined flexibility to the detector. For emitter material Pt, Rh, V, Co, Ce, Os or Ta may be used. (DG) [de

  8. Particle detectors

    CERN Multimedia

    CERN. Geneva

    2001-01-01

    The lecture series will present an overview of the basic techniques and underlying physical principles of particle detectors, applied to current and future high energy physics experiments. Illustrating examples, mainly from the field of collider experiments, will demonstrate the performance and limitations of the various techniques. After an introduction the following topics will be covered: Tracking (gas, solid state based) - Scintillation and light detection Calorimetry - Particle Identification - Electronics and Data Acquisition - Detector Systems

  9. Smoke detectors

    International Nuclear Information System (INIS)

    Bryant, J.; Howes, J.H.; Smout, D.W.S.

    1979-01-01

    A smoke detector is described which provides a smoke sensing detector and an indicating device and in which a radioactive substance is used in conjunction with two ionisation chambers. The system includes an outer electrode, a collector electrode and an inner electrode which is made of or supports the radioactive substance which, in this case, is 241 Am. The invention takes advantage of the fact that smoke particles can be allowed to enter freely the inner ionisation chamber. (U.K.)

  10. Bulk micromegas detectors for large TPC applications

    CERN Document Server

    Bouchez, J; Cavata, Ch; Colas, P; De La Broise, X; Delbart, A; Giganon, Arnaud; Giomataris, Ioanis; Graffin, P; Mols, J Ph; Pierre, F; Ritou, J L; Sarrat, A; Virique, E; Zito, M; Radicioni, E; De Oliveira, R; Dumarchez, J; Abgrall, N; Bene, P; Blondel, A; Cervera-Villanueva, Anselmo; Ferrère, D; Maschiocchi, F; Perrin, E; Richeux, J P; Schroeter, R; Jover, G; Lux,; Rodriguez, A Y; Sánchez, F

    2007-01-01

    A large volume TPC will be used in the near future in a variety of experiments including T2K. The bulk Micromegas detector for this TPC is built using a novel production technique particularly suited for compact and robust low mass detectors. The capability to pave a large surface with a simple mounting solution and small dead space between modules is of particular interest for these applications. We have built several large bulk Micromegas detectors and we have tested them in the former HARP field cage setup with a magnetic field. Cosmic ray data have been acquired in a variety of experimental conditions. Good detector performances and space point resolution have been achieved.

  11. Large bulk Micromegas detectors for TPC applications

    CERN Document Server

    Anvar, S; Boyer, M; Beucher, J; Calvet, D; Colas, P; De La Broise, X; Delagnes, E; Delbart, A; Druillole, F; Emery, S; Giganti, C; Giomataris, I; Mazzucato, E; Monmarthe, E; Nizery, F; Pierre, F; Ritou, J L; Sarrat, A; Zito, M; Catanesi, M G; Radicioni, E; De Oliveira, R; Blondel, A; Di Marco, M; Ferrere, D; Perrin, E; Ravonel, M; Jover, G; Lux, T; Rodriguez, A Y; Sanchez, F; Cervera, A; Hansen, C; Monfregola, L

    2009-01-01

    A large volume TPC will be used in the near future in a variety of experiments including T2K. The bulk Micromegas detector for this TPC is built using a novel production technique particularly suited for compact, thin and robust low mass detectors. The capability to pave a large surface with a simple mounting solution and small dead space is of particular interest for these applications. We have built several large bulk Micromegas detectors () and we have tested one in the former HARP field cage with a magnetic field. Prototypes cards of the T2K front end electronics, based on the AFTER ASIC chip, have been used in this TPC test for the first time. Cosmic ray data have been acquired in a variety of experimental conditions. Good detector performances, space point resolution and energy loss measurement have been achieved.

  12. Optimization of MC model of HPGe detector efficiency

    International Nuclear Information System (INIS)

    Kovacik, A.

    2009-01-01

    Peak efficiency of HPGe detector is limited by several factors such as the probability of interaction of gamma quanta in the detector, sample geometry, measurement geometry and energy of emitted gamma quanta. Computer modelling using Monte Carlo is one of the options with which to evaluate the effectiveness of the detector for an optional shape and composition of the sample. The accuracy of this method is limited by accurate knowledge of the size and composition of all materials of detector, including dead layers in the active volume of germanium crystal, which is a quantity which cannot be directly measured. This work, among other things, investigated the effect of the thickness of dead layers at peak efficiency and look for their small size, by comparing modelled and experimentally determined efficiency. (author)

  13. Photon detectors

    International Nuclear Information System (INIS)

    Va'vra, J.

    1995-10-01

    J. Seguinot and T. Ypsilantis have recently described the theory and history of Ring Imaging Cherenkov (RICH) detectors. In this paper, I will expand on these excellent review papers, by covering the various photon detector designs in greater detail, and by including discussion of mistakes made, and detector problems encountered, along the way. Photon detectors are among the most difficult devices used in physics experiments, because they must achieve high efficiency for photon transport and for the detection of single photo-electrons. For gaseous devices, this requires the correct choice of gas gain in order to prevent breakdown and wire aging, together with the use of low noise electronics having the maximum possible amplification. In addition, the detector must be constructed of materials which resist corrosion due to photosensitive materials such as, the detector enclosure must be tightly sealed in order to prevent oxygen leaks, etc. The most critical step is the selection of the photocathode material. Typically, a choice must be made between a solid (CsI) or gaseous photocathode (TMAE, TEA). A conservative approach favors a gaseous photocathode, since it is continuously being replaced by flushing, and permits the photon detectors to be easily serviced (the air sensitive photocathode can be removed at any time). In addition, it can be argued that we now know how to handle TMAE, which, as is generally accepted, is the best photocathode material available as far as quantum efficiency is concerned. However, it is a very fragile molecule, and therefore its use may result in relatively fast wire aging. A possible alternative is TEA, which, in the early days, was rejected because it requires expensive CaF 2 windows, which could be contaminated easily in the region of 8.3 eV and thus lose their UV transmission

  14. Tunnel Diode Discriminator with Fixed Dead Time

    DEFF Research Database (Denmark)

    Diamond, J. M.

    1965-01-01

    A solid state discriminator for the range 0.4 to 10 V is described. Tunnel diodes are used for the discriminator element and in a special fixed dead time circuit. An analysis of temperature stability is presented. The regulated power supplies are described, including a special negative resistance...

  15. Swimming obstructed by dead-water

    NARCIS (Netherlands)

    Ganzevles, S.P.M; Nuland, F.S.W.; Maas, L.; Toussaint, H.M.

    2009-01-01

    In nautical literature, ‘dead-water’ refers to the obstructive effect encountered by ships moving in stratified water due to the ship generating waves on an interface that separates different water masses. To investigate the hypothesis that open water swimming may also be obstructed by an encounter

  16. Swimming obstructed by dead-water

    NARCIS (Netherlands)

    Ganzevles, S.P.; Nuland, F.S.; Maas, L.R.; Toussaint, H.M.

    2009-01-01

    In nautical literature, 'dead-water' refers to the obstructive effect encountered by ships moving in stratified water due to the ship generating waves on an interface that separates different water masses. To investigate the hypothesis that open water swimming may also be obstructed by an encounter

  17. Cheatgrass Dead Zones in Northern Nevada

    Science.gov (United States)

    Reports of areas of cheatgrass die-off are becoming more frequent. In 2009, we investigated cheatgrass die-off in north-central Nevada. Dead zones ranged from several to hundreds of acres in size and were largely unvegetated and covered by cheatgrass litter with a distinct gray cast. We collected re...

  18. Dinosaurs of India: Dead but Alive

    Indian Academy of Sciences (India)

    Table of contents. Dinosaurs of India: Dead but Alive · Fossils · Evolution and O2 PAL · The Science in Dinosaurs · Origin/ Extinction of Dinosaurs · PowerPoint Presentation · India –94my + 50my · Icehouse /Greenhouse through time · Global Mean Annual Temperature Distributions at 100 my · Global Mean Annual ...

  19. Shaped detector

    International Nuclear Information System (INIS)

    Carlson, R.W.

    1981-01-01

    A radiation detector or detector array which has a non-constant spatial response, is disclosed individually and in combination with a tomographic scanner. The detector has a first dimension which is oriented parallel to the plane of the scan circle in the scanner. Along the first dimension, the detector is most responsive to radiation received along a centered segment of the dimension and less responsive to radiation received along edge segments. This non-constant spatial response can be achieved in a detector comprised of a scintillation crystal and a photoelectric transducer. The scintillation crystal in one embodiment is composed of three crystals arranged in layers, with the center crystal having the greatest light conversion efficiency. In another embodiment, the crystal is covered with a reflective substance around the center segment and a less reflective substance around the remainder. In another embodiment, an optical coupling which transmits light from adjacent the center segment with the greatest intensity couples the scintillation crystal and the photoelectric transducer. In yet another embodiment, the photoelectric transducer comprises three photodiodes, one receiving light produced adjacent the central segment and the other two receiving light produced adjacent the edge segments. The outputs of the three photodiodes are combined with a differential amplifier

  20. Some aspects of detectors and electronics for x-ray fluorescence analysis

    International Nuclear Information System (INIS)

    Goulding, F.S.

    1976-08-01

    Some of the less recognized and potentially important parameters of the electronics and detectors used in X-ray fluorescence spectrometers are discussed. Detector factors include window (dead-layer) effects, time-dependent background and excess background. Noise parameters of field-effect transistors and time-variant pulse shaping are also discussed

  1. Estimating the effective system dead time parameter for correlated neutron counting

    Science.gov (United States)

    Croft, Stephen; Cleveland, Steve; Favalli, Andrea; McElroy, Robert D.; Simone, Angela T.

    2017-11-01

    yields consistent results as a function of the order of the moment used to extract the dead time parameter. This latter observation is reassuring in that it suggests the assumptions underpinning the theoretical analysis are fit for practical application purposes. However, we found that the effective dead time parameter obtained is not constant, as might be expected for a parameter that in the dead time model is characteristic of the detector system, but rather, varies systematically with gate width.

  2. Microwave detector

    Science.gov (United States)

    Meldner, H.W.; Cusson, R.Y.; Johnson, R.M.

    1985-02-08

    A microwave detector is provided for measuring the envelope shape of a microwave pulse comprised of high-frequency oscillations. A biased ferrite produces a magnetization field flux that links a B-dot loop. The magnetic field of the microwave pulse participates in the formation of the magnetization field flux. High-frequency insensitive means are provided for measuring electric voltage or current induced in the B-dot loop. The recorded output of the detector is proportional to the time derivative of the square of the envelope shape of the microwave pulse.

  3. Gulf of Mexico dead zone - the last 150 years

    Science.gov (United States)

    Osterman, Lisa; Swarzenski, P.W.; Poore, R.Z.

    2006-01-01

    'Gulf of Mexico Dead Zone-The Last 150 Years' discusses the dead zone that forms seasonally in the northern Gulf of Mexico when subsurface waters become depleted in dissolved oxygen and cannot support most life.

  4. Nilpotent -local finite groups

    Science.gov (United States)

    Cantarero, José; Scherer, Jérôme; Viruel, Antonio

    2014-10-01

    We provide characterizations of -nilpotency for fusion systems and -local finite groups that are inspired by known result for finite groups. In particular, we generalize criteria by Atiyah, Brunetti, Frobenius, Quillen, Stammbach and Tate.

  5. Response function of a p type - HPGe detector

    International Nuclear Information System (INIS)

    Lopez-Pino, Neivy; Cabral, Fatima Padilla; D'Alessandro, Katia; Maidana, Nora Lia; Vanin, Vito Roberto

    2011-01-01

    The response function of a HPGe detector depends on Ge crystal dimensions and dead layers thicknesses; most of them are not given by the manufacturers or change with detector damage from neutrons or contact with the atmosphere and therefore must be experimentally determined. The response function is obtained by a Monte-Carlo simulation procedure based on the Ge crystal characteristics. In this work, a p-type coaxial HPGe detector with 30% efficiency, manufactured in 1989, was investigated. The crystal radius and length and the inner hole dimensions were obtained scanning the capsule both in the radial and axial directions using 4 mm collimated beams from 137 Cs, 207 Bi point sources placed on a x-y table in steps of 2,00 mm. These dimensions were estimated comparing the experimental peak areas with those obtained by simulation using several hole configurations. In a similar procedure, the frontal dead layer thickness was determined using 2 mm collimated beams of the 59 keV gamma-rays from 241 Am and 81 keV from 133 Ba sources hitting the detector at 90 deg and 45 deg with respect to the capsule surface. The Monte Carlo detector model included, besides the crystal, hole and capsules sizes, the Ge dead-layers. The obtained spectra were folded with a gaussian resolution function to account for electronic noise. The comparison of simulated and experimental response functions for 4 mm collimated beams of 60 Co, 137 Cs, and 207 Bi points sources placed at distances of 7, 11 and 17 cm from the detector end cap showed relative deviations of about 10% in general and below 10% in the peak. The frontal dead layer thickness determined by our procedure was different from that specified by the detector manufacturer. (author)

  6. Status of the digital pixel array detector for protein crystallography

    CERN Document Server

    Datte, P; Beuville, E; Endres, N; Druillole, F; Luo, L; Millaud, J E; Xuong, N H

    1999-01-01

    A two-dimensional photon counting digital pixel array detector is being designed for static and time resolved protein crystallography. The room temperature detector will significantly enhance monochromatic and polychromatic protein crystallographic through-put data rates by more than three orders of magnitude. The detector has an almost infinite photon counting dynamic range and exhibits superior spatial resolution when compared to present crystallographic phosphor imaging plates or phosphor coupled CCD detectors. The detector is a high resistivity N-type Si with a pixel pitch of 150x150 mu m, and a thickness of 300 mu m, and is bump bonded to an application specific integrated circuit. The event driven readout of the detector is based on the column architecture and allows an independent pixel hit rate above 1 million photons/s/pixel. The device provides energy discrimination and sparse data readout which yields minimal dead-time. This type of architecture allows a continuous (frameless) data acquisition, a f...

  7. Standing dead tree resources in forests of the United States

    Science.gov (United States)

    Christopher W. Woodall; Karen L. Waddell; Christopher M. Oswalt; James E. Smith

    2013-01-01

    Given the importance of standing dead trees to numerous forest ecosystem attributes/ processes such as fuel loadings and wildlife habitat, the Forest Inventory and Analysis (FIA) Program of the Forest Service, U.S. Department of Agriculture, initiated a consistent nationwide inventory of standing dead trees in 1999. As the first cycle of annual standing dead tree...

  8. The zero inflation of standing dead tree carbon stocks

    Science.gov (United States)

    Christopher W. Woodall; David W. MacFarlane

    2012-01-01

    Given the importance of standing dead trees in numerous forest ecosystem attributes/processes such as carbon (C) stocks, the USDA Forest Service’s Forest Inventory and Analysis (FIA) program began consistent nationwide sampling of standing dead trees in 1999. Modeled estimates of standing dead tree C stocks are currently used as the official C stock estimates for the...

  9. Vertex detectors

    International Nuclear Information System (INIS)

    Lueth, V.

    1992-07-01

    The purpose of a vertex detector is to measure position and angles of charged particle tracks to sufficient precision so as to be able to separate tracks originating from decay vertices from those produced at the interaction vertex. Such measurements are interesting because they permit the detection of weakly decaying particles with lifetimes down to 10 -13 s, among them the τ lepton and charm and beauty hadrons. These two lectures are intended to introduce the reader to the different techniques for the detection of secondary vertices that have been developed over the past decades. The first lecture includes a brief introduction to the methods used to detect secondary vertices and to estimate particle lifetimes. It describes the traditional technologies, based on photographic recording in emulsions and on film of bubble chambers, and introduces fast electronic registration of signals derived from scintillating fibers, drift chambers and gaseous micro-strip chambers. The second lecture is devoted to solid state detectors. It begins with a brief introduction into semiconductor devices, and then describes the application of large arrays of strip and pixel diodes for charged particle tracking. These lectures can only serve as an introduction the topic of vertex detectors. Time and space do not allow for an in-depth coverage of many of the interesting aspects of vertex detector design and operation

  10. Smoke detectors

    International Nuclear Information System (INIS)

    Macdonald, E.

    1976-01-01

    A smoke detector is described consisting of a ventilated ionisation chamber having a number of electrodes and containing a radioactive source in the form of a foil supported on the surface of the electrodes. This electrode consists of a plastic material treated with graphite to render it electrically conductive. (U.K.)

  11. Basic Finite Element Method

    International Nuclear Information System (INIS)

    Lee, Byeong Hae

    1992-02-01

    This book gives descriptions of basic finite element method, which includes basic finite element method and data, black box, writing of data, definition of VECTOR, definition of matrix, matrix and multiplication of matrix, addition of matrix, and unit matrix, conception of hardness matrix like spring power and displacement, governed equation of an elastic body, finite element method, Fortran method and programming such as composition of computer, order of programming and data card and Fortran card, finite element program and application of nonelastic problem.

  12. Potential Evaporite Biomarkers from the Dead Sea

    Science.gov (United States)

    Morris, Penny A.; Wentworth, Susan J.; Thomas-Keprta, Kathie; Allen, Carlton C.; McKay, David S.

    2001-01-01

    The Dead Sea is located on the northern branch of the African-Levant Rift systems. The rift system, according to one model, was formed by a series of strike slip faults, initially forming approximately two million years ago. The Dead Sea is an evaporite basin that receives freshwater from springs and from the Jordan River. The Dead Sea is different from other evaporite basins, such as the Great Salt Lake, in that it possesses high concentrations of magnesium and has an average pH of 6.1. The dominant cation in the Great Salt Lake is sodium, and the pH is 7.7. Calcium concentrations are also higher in the Dead Sea than in the Great Salt Lake. Both basins are similar in that the dominant anion is chlorine and the salinity levels are approximately 20 %. Other common cations that have been identified from the waters of the Dead Sea and the Great Salt Lake include sodium and potassium. A variety of Archea, Bacteria, and a single genus of a green algal, Dunaliella, has been described from the Dead Sea. Earlier studies concentrated on microbial identification and analysis of their unique physiology that allows them to survive in this type of extreme environment. Potential microbial fossilization processes, microbial fossils, and the metallic ions associated with fossilization have not been studied thoroughly. The present study is restricted to identifying probable microbial morphologies and associated metallic ions. XRD (X Ray Diffraction) analysis indicates the presence of halite, quartz, and orthoclase feldspar. In addition to these minerals, other workers have reported potassium chloride, magnesium bromide, magnesium chloride, calcium chloride, and calcium sulfate. Halite, calcium sulfate, and orthoclase were examined in this report for the presence of microbes, microbially induced deposits or microbial alteration. Neither the gypsum nor the orthoclase surfaces possesses any obvious indications of microbial life or fossilization. The sand-sized orthoclase particles are

  13. Composite Finite Sums

    KAUST Repository

    Alabdulmohsin, Ibrahim M.

    2018-03-07

    In this chapter, we extend the previous results of Chap. 2 to the more general case of composite finite sums. We describe what composite finite sums are and how their analysis can be reduced to the analysis of simple finite sums using the chain rule. We apply these techniques, next, on numerical integration and on some identities of Ramanujan.

  14. Finite Amplitude Ocean Waves

    Indian Academy of Sciences (India)

    IAS Admin

    plitude waves and finite amplitude waves. This article provides a brief introduction to finite amplitude wave theories. Some of the general characteristics of waves as well as the importance of finite amplitude wave theories are touched upon. 2. Small Amplitude Waves. The topmost and the lowest levels of the waves are re-.

  15. Anisakis simplex: dangerous--dead and alive?

    Science.gov (United States)

    Audicana, María Teresa; Ansotegui, Ignacio J; de Corres, Luis Fernández; Kennedy, Malcolm W

    2002-01-01

    The risk of infection with Anisakis simplex and related parasites of fish has been recognized for some time, but it is now emerging that ingestion of material from dead parasites in food is also potentially dangerous. The resulting allergic reactions range from rapid onset and potentially lethal anaphylactic reactions to chronic, debilitating conditions. This review discusses the problems and clinical implications associated with A. simplex, other related conditions, and the way in which disease manifestations vary from person to person.

  16. The Development of Micro-Pattern Gas Detectors

    CERN Document Server

    BALOUZA, Samah

    2014-01-01

    This work is aimed to study the electron transparency in 3-D woven mesh that is used in micromegas detector. The importance of calculating the transparency is because it is enter in the gain calibration of the detector. The simulation tool is COMSOL Multiphysics in which it is solved the differential equations by Finite Element Method.

  17. Surviving deadness in the analytic experience.

    Science.gov (United States)

    Koritar, Endre

    2014-12-01

    The transference/countertransference (third space) analysis is considered to be central in the therapeutic effectiveness of the analytic process. Less emphasis has been placed on the actual experiences of analyst and analysand in the conflictual reenactment of third space experience and its resolution. This paper recounts the shared experience of a patient who was silent throughout most of the analysis, and my reaction, in fantasy and enactment, to this disturbing experience-both for him and for myself. I argue that it is the affective re-experiencing of past repressed trauma in the analytic space that has a therapeutic impact, leading to growth in the patient and also the therapist. I contrast Freud's emphasis on insight, making the unconscious conscious, with Ferenczi's suggestion that the therapeutic impact lies in the repetition of past traumatic experience in the analysis but with the possibility of a different outcome with a more benign object, leading to symbolic representation of repressed trauma. Re-experiencing and symbolization, in the third space, of past traumatic experience can be an exit point from the endless repetition of trauma in internal and external object relations, leading to a new beginning in the patient's life. Immersed in the experience of deadness in the analysis, which had become a dead womb, the struggle to remain alive and thinking led to a rupture out of the dead womb, like the Caesura of birth, into aliveness and the ability to mentalize what had previously remained unmentalized.

  18. Current responsivity of semiconductor superlattice THz-photon detectors

    DEFF Research Database (Denmark)

    Ignatov, Anatoly A.; Jauho, Antti-Pekka

    1999-01-01

    The current responsivity of a semiconductor superlattice THz-photon detector is calculated using an equivalent circuit model which takes into account the finite matching efficiency between a detector antenna and the superlattice in the presence of parasitic losses. Calculations performed for curr......The current responsivity of a semiconductor superlattice THz-photon detector is calculated using an equivalent circuit model which takes into account the finite matching efficiency between a detector antenna and the superlattice in the presence of parasitic losses. Calculations performed...... of the responsivity (2–3 A/W in the 1–3 THz-frequency band) range up to several percents of the quantum efficiency e/[h-bar] omega of an ideal superconductor tunnel junction detector. Properly designed semiconductor superlattice detectors may thus demonstrate better room temperature THz-photon responsivity than...

  19. Semiconductor Detectors; Detectores de Semiconductores

    Energy Technology Data Exchange (ETDEWEB)

    Cortina, E.

    2007-07-01

    Particle detectors based on semiconductor materials are among the few devices used for particle detection that are available to the public at large. In fact we are surrounded by them in our daily lives: they are used in photoelectric cells for opening doors, in digital photographic and video camera, and in bar code readers at supermarket cash registers. (Author)

  20. Visualization of deuterium dead layer by atom probe tomography

    KAUST Repository

    Gemma, Ryota

    2012-12-01

    The first direct observation, by atom probe tomography, of a deuterium dead layer is reported for Fe/V multilayered film loaded with D solute atoms. The thickness of the dead layers was measured to be 0.4-0.5 nm. The dead layers could be distinguished from chemically intermixed layers. The results suggest that the dead layer effect occurs even near the interface of the mixing layers, supporting an interpretation that the dead layer effect cannot be explained solely by electronic charge transfer but also involves a modulation of rigidity. © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  1. EUV mirror based absolute incident flux detector

    Science.gov (United States)

    Berger, Kurt W.

    2004-03-23

    A device for the in-situ monitoring of EUV radiation flux includes an integrated reflective multilayer stack. This device operates on the principle that a finite amount of in-band EUV radiation is transmitted through the entire multilayer stack. This device offers improvements over existing vacuum photo-detector devices since its calibration does not change with surface contamination.

  2. Neutron detector

    Science.gov (United States)

    Stephan, Andrew C [Knoxville, TN; Jardret,; Vincent, D [Powell, TN

    2011-04-05

    A neutron detector has a volume of neutron moderating material and a plurality of individual neutron sensing elements dispersed at selected locations throughout the moderator, and particularly arranged so that some of the detecting elements are closer to the surface of the moderator assembly and others are more deeply embedded. The arrangement captures some thermalized neutrons that might otherwise be scattered away from a single, centrally located detector element. Different geometrical arrangements may be used while preserving its fundamental characteristics. Different types of neutron sensing elements may be used, which may operate on any of a number of physical principles to perform the function of sensing a neutron, either by a capture or a scattering reaction, and converting that reaction to a detectable signal. High detection efficiency, an ability to acquire spectral information, and directional sensitivity may be obtained.

  3. Particle detectors

    CERN Document Server

    AUTHOR|(CDS)2068232

    1998-01-01

    The lecture series will present and overview of the basic techniques and underlying physical principles of particle detectors, applied to current and future high energy physics experiments. Illustrating examples, mainly from the field of collider experiments, will demonstrate the performance and limitations of the various techniques. After and introduction we shall concentrate on particle tracking. Wire chambers, drift chambers, micro gaseous tracking devices and solid state trackers will be discussed. It follows and overview of scintillators, photon detection, fiber tracking and nuclear emulsions. One lecture will deal with the various techniques of calorimetry. Finally we shall focus on methods developed for particle identification. These comprise specific energy loss, time of flight Cherenkov and transition radiation detectors.

  4. MUST detector

    International Nuclear Information System (INIS)

    Blumenfeld, Y.; Auger, F.; Sauvestre, J.E.

    1999-01-01

    The IPN-Orsay, in collaboration with the SPhN-Saclay and the DPTA Bruyeres, has built an array of 8 telescopes based on Si-strip technology for the study of direct reactions induced by radioactive beams. The detectors are described, along with the compact high density VXI electronics and the stand-alone data acquisition system developed in the laboratory. One telescope was tested using an 40 Ar beam and the measured performances are discussed. (authors)

  5. Improving the counting efficiency in time-correlated single photon counting experiments by dead-time optimization

    Energy Technology Data Exchange (ETDEWEB)

    Peronio, P.; Acconcia, G.; Rech, I.; Ghioni, M. [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)

    2015-11-15

    Time-Correlated Single Photon Counting (TCSPC) has been long recognized as the most sensitive method for fluorescence lifetime measurements, but often requiring “long” data acquisition times. This drawback is related to the limited counting capability of the TCSPC technique, due to pile-up and counting loss effects. In recent years, multi-module TCSPC systems have been introduced to overcome this issue. Splitting the light into several detectors connected to independent TCSPC modules proportionally increases the counting capability. Of course, multi-module operation also increases the system cost and can cause space and power supply problems. In this paper, we propose an alternative approach based on a new detector and processing electronics designed to reduce the overall system dead time, thus enabling efficient photon collection at high excitation rate. We present a fast active quenching circuit for single-photon avalanche diodes which features a minimum dead time of 12.4 ns. We also introduce a new Time-to-Amplitude Converter (TAC) able to attain extra-short dead time thanks to the combination of a scalable array of monolithically integrated TACs and a sequential router. The fast TAC (F-TAC) makes it possible to operate the system towards the upper limit of detector count rate capability (∼80 Mcps) with reduced pile-up losses, addressing one of the historic criticisms of TCSPC. Preliminary measurements on the F-TAC are presented and discussed.

  6. Improving the counting efficiency in time-correlated single photon counting experiments by dead-time optimization

    Science.gov (United States)

    Peronio, P.; Acconcia, G.; Rech, I.; Ghioni, M.

    2015-11-01

    Time-Correlated Single Photon Counting (TCSPC) has been long recognized as the most sensitive method for fluorescence lifetime measurements, but often requiring "long" data acquisition times. This drawback is related to the limited counting capability of the TCSPC technique, due to pile-up and counting loss effects. In recent years, multi-module TCSPC systems have been introduced to overcome this issue. Splitting the light into several detectors connected to independent TCSPC modules proportionally increases the counting capability. Of course, multi-module operation also increases the system cost and can cause space and power supply problems. In this paper, we propose an alternative approach based on a new detector and processing electronics designed to reduce the overall system dead time, thus enabling efficient photon collection at high excitation rate. We present a fast active quenching circuit for single-photon avalanche diodes which features a minimum dead time of 12.4 ns. We also introduce a new Time-to-Amplitude Converter (TAC) able to attain extra-short dead time thanks to the combination of a scalable array of monolithically integrated TACs and a sequential router. The fast TAC (F-TAC) makes it possible to operate the system towards the upper limit of detector count rate capability (˜80 Mcps) with reduced pile-up losses, addressing one of the historic criticisms of TCSPC. Preliminary measurements on the F-TAC are presented and discussed.

  7. Comet 'Bites the Dust' Around Dead Star

    Science.gov (United States)

    2006-01-01

    [figure removed for brevity, see original site] Infrared Spectrometer Graph This artist's concept illustrates a comet being torn to shreds around a dead star, or white dwarf, called G29-38. NASA's Spitzer Space Telescope observed a cloud of dust around this white dwarf that may have been generated from this type of comet disruption. The findings suggest that a host of other comet survivors may still orbit in this long-dead solar system. The white dwarf G29-38 began life as a star that was about three times as massive as our sun. Its death involved the same steps that the sun will ultimately undergo billions of years from now. According to theory, the G29-38 star became brighter and brighter as it aged, until it bloated up into a dying star called a red giant. This red giant was large enough to engulf and evaporate any terrestrial planets like Earth that happened to be in its way. Later, the red giant shed its outer atmosphere, leaving behind a shrunken skeleton of star, called a white dwarf. If the star did host a planetary system, outer planets akin to Jupiter and Neptune and a remote ring of icy comets would remain. The Spitzer observations provide observational evidence for this orbiting outpost of comet survivors. Astronomers speculate that one such comet was knocked into the inner regions of G29-38, possibly by an outer planet. As the comet approached very close to the white dwarf, it may have been torn apart by the star's tidal forces. Eventually, all that would be left of the comet is a disk of dust. This illustration shows a comet in the process of being pulverized: part of it still exists as a chain of small clumps, while the rest has already spread out into a dusty disk. Comet Shoemaker-Levy 9 broke apart in a similar fashion when it plunged into Jupiter in 1994. Evidence for Comets Found in Dead Star's Dust The graph of data, or spectrum, from NASA's Spitzer Space Telescope indicates that a dead star, or white dwarf, called G29-38, is shrouded by a cloud

  8. [A case of lycanthropy with deadly violence].

    Science.gov (United States)

    Bénézech, M; De Witte, J; Etchepare, J J; Bourgeois, M

    1989-01-01

    After a short historical review of the contemporary medical literature, the authors analyze a new and original observation of lycanthropy. He is a 28 years old man, imprisoned for deadly violence, who has been showing, for many years, the belief of being transformed into a werewolf during depersonalization episodes when he presents a lycanthropic behaviour. Our observation is closer to hysteria and mythomania on an antisocial personality, although it seems difficult to place the mental pathology of this alcoholic recidivist delinquent into a nosographical frame.

  9. Simplified Dead Reckoning on a Tortuous Path

    Science.gov (United States)

    Robertson, David

    An approximation procedure is described, which greatly simplifies dead reckoning on a tortuous path. The journey is divided into N segments of equal length, L. The overall direction is approximately the average direction of the segments. The net distance is approximately NL[1-var() is the variance (in radians squared) of bearings, 7. Propagation of random errors is discussed. In a case study in sub-tropical rainforest the technique gives an estimated position whose associated circle of 68% confidence has a radius of about 10% of the net distance.

  10. De Plein Fouet: Is Strategy Dead?

    Science.gov (United States)

    2015-06-01

    discuss strategy. Judging by the title you chose, I assume you have a point of view.Richard Szafranski (RS): Yes, sir . Le tir de plein fouet is one of...quarters, neither strategic thinking nor strategy is dead in the NGA. RS: I’m not sure that what you’re describing, sir , is a strategy as much as it is the...correcting like a self-driving car . I don’t see that coming, or coming very soon, though. Remember, we exist because we support people in harm’s way

  11. Low power electronics for NEMO detector

    International Nuclear Information System (INIS)

    Lo Presti, Domenico

    2000-01-01

    For the realization of the submarine detector NEMO it is necessary to design an acquisition system which is able to capture the signals coming from photo-multipliers (PMs) of the optical modules (OMs) and to satisfy several specifications: low power consumption; few submarine interconnections for reliability and simplicity of the deployment; flexibility of the system; minimum dead time; high dynamic range; accuracy in order to have good resolution. Here we present a Very Large Scale Integration full-custom solution for the OMs according to the requirements. It foresees to use a switched capacitor analog memory, a trigger and single photon classification system, a PLL and a control unit able to manage the different operation states of the whole system. For such a system we foresee a power dissipation not higher than 200-300 mV in each OM, 20 bit dynamic range and a dead time of about 0.1%

  12. When the dead are alive! The influence of the living dead in the letter of Jude

    Directory of Open Access Journals (Sweden)

    Stephan J. Joubert

    2002-12-01

    Full Text Available This essay investigates the impact of the deceased on  the audience to which the letter of Jude was originally addressed. A construct of the influence of the “living dead” in ancient Babylon, Israel, the Graeco-Roman world and in African tradition serves as a basic cognitive map to come to terms with Jude’s views on the dead. It is argued that, since the wicked dead, who are being physically punished in  the underworld,  are kept alive  in the collective memory of Jude’s community and since their deeds are re-enacted in the sinful behavior  of intruders in their midst, their lives are influenced by  the “presence” of these living dead. On the other hand and, although Jude does not deal with the physical whereabouts of the righteous death, he and his readers know that their postmortem honour is still intact. The righteous in this community is assured that God protects the integrity of the faithful dead.

  13. Ethics of practicing medical procedures on newly dead and nearly dead patients.

    Science.gov (United States)

    Berger, Jeffrey T; Rosner, Fred; Cassell, Eric J

    2002-10-01

    To examine the ethical issues raised by physicians performing, for skill development, medically nonindicated invasive medical procedures on newly dead and dying patients. Literature review; issue analysis employing current normative ethical obligations, and evaluation against moral rules and utilitarian assessments manifest in other common perimortem practices. Practicing medical procedures for training purposes is not uncommon among physicians in training. However, empiric information is limited or absent evaluating the effects of this practice on physician competence and ethics, assessing public attitudes toward practicing medical procedures and requirements for consent, and discerning the effects of a consent requirement on physicians' clinical competence. Despite these informational gaps, there is an obligation to secure consent for training activities on newly and nearly dead patients based on contemporary norms for informed consent and family respect. Paradigms of consent-dependent societal benefits elsewhere in health care support our determination that the benefits from physicians practicing procedures does not justify setting aside the informed consent requirement. Current ethical norms do not support the practice of using newly and nearly dead patients for training in invasive medical procedures absent prior consent by the patient or contemporaneous surrogate consent. Performing an appropriately consented training procedure is ethically acceptable when done under competent supervision and with appropriate professional decorum. The ethics of training on the newly and nearly dead remains an insufficiently examined area of medical training.

  14. Uterus retrieval process from brain dead donors.

    Science.gov (United States)

    Gauthier, Tristan; Piver, Pascal; Pichon, Nicolas; Bibes, Romain; Guillaudeau, Angelique; Piccardo, Alessandro; Pesteil, Francis; Tricard, Jeremy; Gardet, Emmanuel; Laskar, Marc; Lalloué, Fabrice; Marquet, Pierre; Aubard, Yves

    2014-08-01

    To describe the feasibility of human uterus retrieval after donation after brain death. Single-center, prospective study. University hospital. Female brain dead donors. The families of female brain dead donors were informed about consent to uterus donation. A specific organ retrieval procedure was performed. At the end of the procedure the uterus was removed together with the hypogastric vessels, parametria, and vaginal fornix. The tolerance of the uterus to cold ischemia was evaluated with histology and TUNEL reaction up to 24 hours. Rate of uterus donation refusal. Between August 1, 2012 and July 31, 2013, seven uteri were retrieved from 14 female multiorgan donors. No refusal to uterus donation occurred. Our surgical protocol did not interfere with vital organ retrieval and was readily accepted by the other transplantation teams. The hypogastric vessels could be preserved in all cases but for one vein loss in the first retrieval. Histology studies did not find major morphologic changes after 24 hours of cold ischemia. Apoptosis was rare. Uterus retrieval could be part of a reproducible multiorgan procurement procedure. Uterus donation seems readily accepted. This preliminary study is a necessary step before any transplantation project. Copyright © 2014 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  15. Breathing Life Into Dead-Zones

    Directory of Open Access Journals (Sweden)

    Gressel Oliver

    2013-04-01

    Full Text Available The terrestrial planet formation regions of protoplanetary disks are generally sufficiently cold to be con- sidered non-magnetized and, consequently, dynamically inactive. However, recent investigations of these so-called “Dead-Zones” indicate the possibility that disks with strong mean radial temperature gradients can support instabilities associated with disk-normal gradients of the basic Keplerian shear profile. This process, known as the Goldreich-Schubert-Fricke (GSF instability, is the instability of short radial wavelength inertial modes and depends wholly on the presence of vertical gradients of the mean Keplerian (zonal flow. We report here high resolution fully nonlinear axisymmetric numerical studies of this instability and find a number of features including how, in the nonlinear saturated state, unstable discs become globally distorted, with strong vertical oscillations occurring at all radii due to local instability. We find that nonaxisymmetric numerical experiments are accompanied by significant amounts angular momentum transport (α ~ 0001. This instability should be operating in the Dead-Zones of protoplanetary disks at radii greater than 10-15 AU in minimum mass solar nebula models.

  16. A new G-M counter dead time model

    International Nuclear Information System (INIS)

    Lee, S.H.; Gardner, R.P.

    2000-01-01

    A hybrid G-M counter dead time model was derived by combining the idealized paralyzable and non-paralyzable models. The new model involves two parameters, which are the paralyzable and non-paralyzable dead times. The dead times used in the model are very closely related to the physical dead time of the G-M tube and its resolving time. To check the validity of the model, the decaying source method with 56 Mn was used. The corrected counting rates by the new G-M dead time model were compared with the observed counting rates obtained from the measurement and gave very good agreement within 5% up to 7x10 4 counts/s for a G-M tube with a dead time of about 300 μs

  17. Detector development and test facility

    International Nuclear Information System (INIS)

    Reeder, D.D.

    1993-01-01

    Following the ideas presented in the proposal to the DoE, we have begun to acquire the equipment needed to design, develop construct and test the electronic and mechanical features of detectors used in High Energy Physics Experiments. A guiding principle for the effort is to achieve integrated electronic and mechanical designs which meet the demanding specifications of the modern hadron collider environment yet minimize costs. This requires state of the art simulation of signal processing as well as detailed calculations of heat transfer and finite element analysis of structural integrity

  18. Photographic Study Of A Dead-Pressed Explosive

    Science.gov (United States)

    Swallowe, G. M.; Field, J. E.

    1983-03-01

    High speed photography in conjunction with electron microscopy and a pressure measuring technique have been used to investigate the differences between dead-pressed and non-dead-pressed samples of the primary explosive Mercury Fulminate (Hg Ful). Photographs of reaction propagation were taken in transmitted light using a specially adapted drop-weight machine with transparent anvils. The results of these experiments suggested a mechanism for dead-pressing in Hg Ful based on the microscopic internal structure of the compacted explosive.

  19. Respect for the dead and the ethics of anatomy.

    Science.gov (United States)

    Wilkinson, T M

    2014-04-01

    Dead bodies are not persons but nor are they just things. What, ethically speaking, do the living owe the dead when it comes to using their bodies in anatomy? The article begins with the general question of respect for the dead. It distinguishes between why we should respect the dead, how we should respect them, and the weight to be given to respect. It sets out an account of the reason to respect the dead based on their interests. The article then turns to how the dead should be respected and the importance of doing so. Specifically, it considers three ethical issues in anatomy: the role of the family, the use of unclaimed bodies, and the public display of bodies donated for that purpose. This article claims that what it is to respect the dead is substantially determined by their wishes. Nonetheless the article argues that respect is consistent with allowing the family to veto anatomical use even when the deceased has consented because respect for the dead does not require following all their possible wishes. Respect is also consistent with using unclaimed bodies to which no one--deceased or family--has consented because the interests of the dead do not directly require consent and the interests of the family are unlikely to be relevant. Finally, the article does not see anything disrespectful in the public display of the bodies of those who have consented. Copyright © 2013 Wiley Periodicals, Inc.

  20. Supersymmetric theories and finiteness

    International Nuclear Information System (INIS)

    Helayel-Neto, J.A.

    1989-01-01

    We attempt here to present a short survey of the all-order finite Lagrangian field theories known at present in four-and two-dimensional space-times. The question of the possible relevance of these ultraviolet finite models in the formulation of consistent unified frameworks for the fundamental forces is also addressed to. (author)

  1. Designs and finite geometries

    CERN Document Server

    1996-01-01

    Designs and Finite Geometries brings together in one place important contributions and up-to-date research results in this important area of mathematics. Designs and Finite Geometries serves as an excellent reference, providing insight into some of the most important research issues in the field.

  2. Simple Finite Sums

    KAUST Repository

    Alabdulmohsin, Ibrahim M.

    2018-03-07

    We will begin our treatment of summability calculus by analyzing what will be referred to, throughout this book, as simple finite sums. Even though the results of this chapter are particular cases of the more general results presented in later chapters, they are important to start with for a few reasons. First, this chapter serves as an excellent introduction to what summability calculus can markedly accomplish. Second, simple finite sums are encountered more often and, hence, they deserve special treatment. Third, the results presented in this chapter for simple finite sums will, themselves, be used as building blocks for deriving the most general results in subsequent chapters. Among others, we establish that fractional finite sums are well-defined mathematical objects and show how various identities related to the Euler constant as well as the Riemann zeta function can actually be derived in an elementary manner using fractional finite sums.

  3. Particle detectors

    CERN Document Server

    Hilke, Hans Jürgen; Joram, Christian; CERN. Geneva

    1991-01-01

    Lecture 5: Detector characteristics: ALEPH Experiment cut through the devices and events - Discuss the principles of the main techniques applied to particle detection ( including front-end electronics), the construction and performance of some of the devices presently in operartion and a few ideas on the future performance. Lecture 4-pt. b Following the Scintillators. Lecture 4-pt. a : Scintillators - Used for: -Timing (TOF, Trigger) - Energy Measurement (Calorimeters) - Tracking (Fibres) Basic scintillation processes- Inorganic Scintillators - Organic Scintil - Discuss the principles of the main techniques applied to particle detection ( including front-end electronics), the construction and performance of some of the devices presently in operation and a fiew ideas on future developpement session 3 - part. b Following Calorimeters lecture 3-pt. a Calorimeters - determine energy E by total absorption of charged or neutral particles - fraction of E is transformed into measurable quantities - try to acheive sig...

  4. Smoke detectors

    International Nuclear Information System (INIS)

    Bryant, J.

    1979-01-01

    An ionization smoke detector consisting of two electrodes defining an ionization chamber permitting entry of smoke, a radioactive source to ionize gas in the chamber and a potential difference applied across the first and second electrodes to cause an ion current to flow is described. The current is affected by entry of smoke. An auxiliary electrode is positioned in the ionization chamber between the first and second electrodes, and it is arranged to maintain or create a potential difference between the first electrode and the auxiliary electrode. The auxiliary electrode may be used for testing or for adjustment of sensitivity. A collector electrode divides the chamber into two regions with the auxiliary electrode in the outer sensing region. (U.K.)

  5. The Effect of a Finite Measurement Volume on Power Spectra from a Burst Type LDA

    DEFF Research Database (Denmark)

    Buchhave, Preben; Velte, Clara Marika; K. George, William

    2014-01-01

    We analyze the effects of a finite size measurement volume on the power spectrum computed fromdata acquired with a burst-type laser Doppler anemometer. The finite measurement volume causes temporal distortions in acquisition of the data resulting in phenomena such as finite processing time and dead...... time.We compare analytical expressions for the bias and distortion of the velocity power spectrum computed from computer-generated data. We then compare the spectrum from the computer-generated data and a power spectrum from a measurement on a free turbulent jet in air and conclude that we have a valid...

  6. Differential Phase Detector for Precise Phase Alignment

    CERN Document Server

    Olexa, Jakub

    2016-01-01

    This paper presents a differential phase detector circuit, whose phase-to-voltage characteristic has an extremum when its two input signals are exactly in phase. In this condition all its digital signals are of 50 % duty cycle so that the circuit characteristic does not have a dead zone. This feature allows a precise indication of the zero-phase condition, which is independent of the detector power supply and the offset of its ADC readout. Such a detector is used for a phase alignment of two reference clock signals with frequency about 11 kHz in front-ends processing signals from beam position monitors of the Large Hadron Collider (LHC) at CERN. The detector output voltage is digitized with a 24-bit ADC at the rate of the reference signals. The resulting samples are processed in the front-end FPGA and transmitted to the control system using an Ethernet data stream. After a detailed description of the differential phase detector its performance is demonstrated with laboratory measurements. The results show tha...

  7. CLIC Detector Power Requirements

    CERN Document Server

    Gaddi, A

    2013-01-01

    An estimate for the CLIC detector power requirements is outlined starting from the available data on power consumptions of the four LHC experiments and considering the differences between a typical LHC Detector (CMS) and the CLIC baseline detector concept. In particular the impact of the power pulsing scheme for the CLIC Detector electronics on the overall detector consumption is considered. The document will be updated with the requirements of the sub-detector electronics once they are more defined.

  8. Calibration of detector efficiency of neutron detector

    International Nuclear Information System (INIS)

    Guo Hongsheng; He Xijun; Xu Rongkun; Peng Taiping

    2001-01-01

    BF 3 neutron detector has been set up. Detector efficiency is calibrated by associated particle technique. It is about 3.17 x 10 -4 (1 +- 18%). Neutron yield of neutron generator per pulse (10 7 /pulse) is measured by using the detector

  9. Finite elements and approximation

    CERN Document Server

    Zienkiewicz, O C

    2006-01-01

    A powerful tool for the approximate solution of differential equations, the finite element is extensively used in industry and research. This book offers students of engineering and physics a comprehensive view of the principles involved, with numerous illustrative examples and exercises.Starting with continuum boundary value problems and the need for numerical discretization, the text examines finite difference methods, weighted residual methods in the context of continuous trial functions, and piecewise defined trial functions and the finite element method. Additional topics include higher o

  10. 10 CFR 1047.7 - Use of deadly force.

    Science.gov (United States)

    2010-01-01

    ... explosives). (3) Nuclear weapons or nuclear explosive devices. When deadly force reasonably appears to be necessary to prevent the theft, sabotage, or unauthorized control of a nuclear weapon or nuclear explosive device. (4) Special nuclear material. When deadly force reasonably appears to be necessary to prevent the...

  11. Recipe for Hypoxia: Playing the Dead Zone Game

    Science.gov (United States)

    Kastler, Jessica A.

    2009-01-01

    Dead zones--areas experiencing low levels of dissolved oxygen--are growing in shallow ocean waters around the world. Research has shown that dead zones form as a result of a specific type of pollution, called nutrient enrichment or eutrophication, and are found in almost every coastal zone where humans have large populations. Concepts related to…

  12. Dead wood inventory and assessment in South Korea

    Science.gov (United States)

    Jong-Su Yim; Rae Hyun Kim; Sun-Jeong Lee; Yeongmo. Son

    2015-01-01

    Dead wood (DW) plays a critical role not only in maintaining biodiversity but also in stocking carbon under UNFCCC. From the 5th national forest inventory (NFI5; 2006-2010) in South Korea, field data relevant to the DW including standing and downed dead trees by four decay class, etc. were collected. Based on the NFI5 data,...

  13. Quantifying carbon stores and decomposition in dead wood: A review

    Science.gov (United States)

    Matthew B. Russell; Shawn Fraver; Tuomas Aakala; Jeffrey H. Gove; Christopher W. Woodall; Anthony W. D’Amato; Mark J. Ducey

    2015-01-01

    The amount and dynamics of forest dead wood (both standing and downed) has been quantified by a variety of approaches throughout the forest science and ecology literature. Differences in the sampling and quantification of dead wood can lead to differences in our understanding of forests and their role in the sequestration and emissions of CO2, as...

  14. MUON DETECTOR

    CERN Multimedia

    F. Gasparini

    DT As announced in the previous Bulletin MU DT completed the installation of the vertical chambers of barrel wheels 0, +1 and +2. 242 DT and RPC stations are now installed in the negative barrel wheels. The missing 8 (4 in YB-1 and 4 in YB-2) chambers can be installed only after the lowering of the two wheels into the UX cavern, which is planned for the last quarter of the year. Cabling on the surface of the negative wheels was finished in May after some difficulties with RPC cables. The next step was to begin the final commissioning of the wheels with the final trigger and readout electronics. Priority was giv¬en to YB0 in order to check everything before the chambers were covered by cables and services of the inner detectors. Commissioning is not easy since it requires both activity on the central and positive wheels underground, as well as on the negative wheels still on the surface. The DT community is requested to commission the negative wheels on surface to cope with a possible lack of time a...

  15. Cascades of pile-up and dead time

    International Nuclear Information System (INIS)

    Pomme, S.

    2008-01-01

    Count loss through a cascade of pile-up and dead time is studied. Time interval density-distribution functions and throughput factors are presented for counters with a series arrangement of pile-up and extending or non-extending dead time. A counter is considered, where an artificial dead time is imposed on every counted event, in order to control the length and type of dead time. For such a system, it is relatively easy to determine an average count-loss correction factor via a live-time clock gated by the imposed dead-time signal ('live-time mode'), or otherwise to apply a correction factor based on the inversion of the throughput function ('real-time mode'). However, these techniques do not account for additional loss through pulse pile-up. In this work, counting errors associated with neglecting cascade effects are calculated for measurements in live-time and real-time mode

  16. Inflation with finite temperature

    International Nuclear Information System (INIS)

    Bellini, M.; Michoacan, Univ. Michoacana de S.Nicola de Hidalgo

    1998-01-01

    In this work the inflationary scenario of the Universe with finite temperature is studied. In this context, thermal equilibrium is closely maintained at the end of inflation. The example of the de Sitter expansion is developed

  17. Supersymmetry at finite temperature

    International Nuclear Information System (INIS)

    Clark, T.E.; Love, S.T.

    1983-01-01

    Finite-temperature supersymmetry (SUSY) is characterized by unbroken Ward identities for SUSY variations of ensemble averages of Klein-operator inserted imaginary time-ordered products of fields. Path-integral representations of these products are defined and the Feynman rules in superspace are given. The finite-temperature no-renormalization theorem is derived. Spontaneously broken SUSY at zero temperature is shown not to be restored at high temperature. (orig.)

  18. Detector simulation needs for detector designers

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, G.G.

    1987-11-01

    Computer simulation of the components of SSC detectors and of the complete detectors will be very important for the designs of the detectors. The ratio of events from interesting physics to events from background processes is very low, so detailed understanding of detector response to the backgrounds is needed. Any large detector for the SSC will be very complex and expensive and every effort must be made to design detectors which will have excellent performance and will not have to undergo major rebuilding. Some areas in which computer simulation is particularly needed are pattern recognition in tracking detectors and development of shower simulation code which can be trusted as an aid in the design and optimization of calorimeters, including their electron identification performance. Existing codes require too much computer time to be practical and need to be compared with test beam data at energies of several hundred GeV. Computer simulation of the processing of the data, including electronics response to the signals from the detector components, processing of the data by microprocessors on the detector, the trigger, and data acquisition will be required. In this report we discuss the detector simulation needs for detector designers.

  19. Study of the 2004 End-Cap beam tests of the ATLAS detector

    CERN Document Server

    Bieri, Marco

    The ATLAS detector is an all-purpose detector to study high-ener gy proton–proton colli- sions. ATLAS is located at the LHC (Lar ge Hadron Collider) at CERN in Gene va, Switzer - land. Before first data taking, man y beam tests have been carried out in order to fully understand each detector component. The studies in this thesis will concentrate on the 2004 beam test of the entire combined end-cap calorimeter system. The first section of this thesis outlines particle selection in the incoming test beam, eliminating contamination in order to have an accurate calibration environment. The remainder of the thesis focuses on detector calibration and performance studies, including signal-to-ener gy calibration con- stant determination, and various detector ener gy summation methods studying their effect on response. Ov erall detector ener gy sharing characteristics including the response of dead detector regions is also presented.

  20. Micro-facies of Dead Sea sediments

    Science.gov (United States)

    Neugebauer, Ina; Schwab, Markus J.; Brauer, Achim; Frank, Ute; Dulski, Peter; Kitagawa, Hiroyuki; Enzel, Yehouda; Waldmann, Nicolas; Ariztegui, Daniel; Drilling Party, Dsddp

    2013-04-01

    Lacustrine sediments infilling the Dead Sea basin (DSB) provide a rare opportunity to trace changing climates in the eastern Mediterranean-Levant region throughout the Pleistocene and Holocene. In this context, high-resolution investigation of changes in sediment micro- facies allow deciphering short-term climatic fluctuations and changing environmental conditions in the Levant. The Dead Sea is a terminal lake with one of the largest drainage areas in the Levant, located in the Mediterranean climate zone and influenced also by the Saharo-Arabian deserts. Due to drastic climatic changes in this region, an exceptionally large variety of lacustrine sediments has been deposited in the DSB. These sediments, partially the results of changing lake levels, primarily represent changes in precipitation (e.g. Enzel et al., 2008). Evaporites (halite and gypsum) reflect dry climatic conditions during interglacials, while alternated aragonite-detritus (AAD) is deposited during glacial lake level high-stands. Here we present the first micro-facies inventory of a ~450 m long sediment profile from the deepest part of the northern DSB (ICDP site 5017-1, ~300 m water depth). The sediment record comprises the last two glacial-interglacial cycles, with mainly AAD facies in the upper part of the Amora Formation (penultimate glacial) and the last glacial Lisan Formation. The last interglacial Samra and the Holocene Zeelim Formations are predominantly characterized by thick bedded halite deposits, intercalated by partly laminated detrital marl sequences. Representative sections of the different facies types have been analyzed for micro-facies on petrographic thin sections, supported by high-resolution µXRF element scanning, magnetic susceptibility measurements and microscopic fluorescence analysis. Furthermore, Holocene sediments retrieved at the deep basin core site have been compared to their shallow-water counterpart at the western margin of the lake (core DSEn; Migowski et al., 2004

  1. SPECT detector system design based on embedded system

    International Nuclear Information System (INIS)

    Zhang Weizheng; Zhao Shujun; Zhang Lei; Sun Yuanling

    2007-01-01

    A single-photon emission computed tomography detector system based on embedded Linux designed. This system is composed of detector module, data acquisition module, ARM MPU module, network interface communication module and human machine interface module. Its software uses multithreading technology based on embedded Linux. It can achieve high speed data acquisition, real-time data correction and network data communication. It can accelerate the data acquisition and decrease the dead time. The accuracy and the stability of the system can be improved. (authors)

  2. The GRANDE detector

    International Nuclear Information System (INIS)

    Adams, A.; Bond, R.; Coleman, L.; Rollefson, A.; Wold, D.; Bratton, C.B.; Gurr, H.; Kropp, W.; Nelson, M.; Price, L.R.; Reines, F.; Schultz, J.; Sobel, H.; Svoboda, R.; Yodh, G.; Burnett, T.; Chaloupka, V.; Wilkes, R.J.; Cherry, M.; Ellison, S.B.; Guzik, T.G.; Wefel, J.; Gaidos, J.; Loeffler, F.; Sembroski, G.; Wilson, C.; Goodman, J.; Haines, T.J.; Kielczewska, D.; Lane, C.; Steinberg, R.; Lieber, M.; Nagle, D.; Potter, M.; Tripp, R.

    1990-01-01

    In this paper we present a detector facility which meets the requirements outlined above for a next-generation instrument. GRANDE (Gamma Ray and Neutrino DEtector) is an imaging, water Cerenkov detector, which combines in one facility an extensive air shower array and a high-energy neutrino detector. (orig.)

  3. Personal Identity and Resurrection from the Dead

    Directory of Open Access Journals (Sweden)

    Gasparov Igor

    2017-04-01

    Full Text Available The paper examines arguments of the “Christian materialist” Trenton Merricks that he provided in support of the claim that the Christian doctrine of resurrection from the dead is compatible with the materialist understanding of the nature of human beings. In his paper The Resurrection of the Body, Merricks discussed two aspects of the materialist interpretation of the traditional religious doctrine of the bodily resurrection. On the one hand, he analyses and tries to overcome objections against the possibility of the general resurrection in case the materialist understanding of the nature of human personality should be true (mainly the problem of the temporal gap. On the other hand, he provides some reasons why the materialist understanding of human nature is more relevant than its dualist counterpart to the doctrine of the bodily resurrection. The present paper evaluates his arguments and discusses the suggestion that the doctrine of resurrection is not only compatible with materialism, but is also tenable if human beings are identical with their physical bodies. The conclusion of the paper is that Merricks’ apologetic arguments achieve their aims in defending the doctrine of resurrection only partially; the resurrection doctrine appears more tenable if we accept the dualistic conception of human nature.

  4. Autopsies of the real: Resurrecting the dead

    Directory of Open Access Journals (Sweden)

    Valis, Noël

    2011-12-01

    Full Text Available The sense of the real, or the material—the dead body—as an inextricable part of the sacred does not disappear in the secular environment of the nineteenth and twentieth centuries. This article analyzes specific humanitarian narratives centered on the practice of autopsy and mummification, in which the traces of Catholicism act as a kind of spectral discourse of the imagination, where the real is configured in forms of the uncanny, the monstrous or the sacred.

    El sentido de lo real, de lo material —el cuerpo sin vida— como una inextricable parte de lo sagrado, no desaparece del ambiente secular de los siglos XIX y XX. En los relatos analizados en este artículo se estudia cómo en determinadas narrativas humanitarias centradas en la práctica de la autopsia y la momificación, las huellas del catolicismo actúan como una suerte de discurso espectral de la imaginación, en que lo real se configura en formas de lo siniestro, lo monstruoso o lo sagrado.

  5. Entrance window structure of a Si(Li) detector

    International Nuclear Information System (INIS)

    Kalinka, G.

    1994-01-01

    The response function of a Si(Li) detector with a 45 μm thick decompensated front p-Si layer, in order to enhance window effects, has been measured in the 1.2-6 keV X-ray energy region as a function of the so-called photo dead layer thickness in the 14-0.4 μm range by varying the detector bias between 200 and 1000 V. From measured spectrum component (photopeak, tail, shelf, escape and SiK line) intensity data, discrete regions responsible for particular spectrum components have been identified: (i) the Au surface barrier, in addition to characteristic X-rays, contributes only to the shelf, adjacent to it is located (ii) an ''absolute'' Si dead layer, which exists only in the undepleted p-region case, and produces no events except for the internal SiK fluorescence, followed by (iii) an incomplete charge collection region, divided into shelf and tail subregions, beyond which (iv) there is the detector sensitive volume with complete charge collection, resulting in photo- and escape peaks, and a bulk shelf component as well. A model has also been developed for the explanation of the observed dead layer thickness dependence of escape- and SiK line intensity. ((orig.))

  6. EIGER detector: application in macromolecular crystallography.

    Science.gov (United States)

    Casanas, Arnau; Warshamanage, Rangana; Finke, Aaron D; Panepucci, Ezequiel; Olieric, Vincent; Nöll, Anne; Tampé, Robert; Brandstetter, Stefan; Förster, Andreas; Mueller, Marcus; Schulze-Briese, Clemens; Bunk, Oliver; Wang, Meitian

    2016-09-01

    The development of single-photon-counting detectors, such as the PILATUS, has been a major recent breakthrough in macromolecular crystallography, enabling noise-free detection and novel data-acquisition modes. The new EIGER detector features a pixel size of 75 × 75 µm, frame rates of up to 3000 Hz and a dead time as low as 3.8 µs. An EIGER 1M and EIGER 16M were tested on Swiss Light Source beamlines X10SA and X06SA for their application in macromolecular crystallography. The combination of fast frame rates and a very short dead time allows high-quality data acquisition in a shorter time. The ultrafine ϕ-slicing data-collection method is introduced and validated and its application in finding the optimal rotation angle, a suitable rotation speed and a sufficient X-ray dose are presented. An improvement of the data quality up to slicing at one tenth of the mosaicity has been observed, which is much finer than expected based on previous findings. The influence of key data-collection parameters on data quality is discussed.

  7. Fault-tolerant dead reckoning system for a modular vehicle

    Science.gov (United States)

    Hashimoto, Masafumi; Oba, Fuminori; Takahashi, Kazuhiko

    2005-12-01

    A fault-tolerant dead reckoning system is presented for a modular vehicle, which consists of one chassis unit and several wheel units. The units locally estimate the vehicle position based on their own internal sensors. The local estimates are exchanged among the units via an inter-communication system, and they are fused in a decentralized manner. The units can then determine the vehicle position accurately. The decentralized dead reckoning algorithm is formulated based on the information filter and the covariance Intersection method. For enhancing the reliability of the dead reckoning a multi-model based fault detection and diagnosis (FDD) of the internal sensors is incorporated into the dead reckoning system. The units diagnose their sensors with the FDD system, and they apply only the normal sensors for the vehicle localization. In this paper two fault modes (hard fault and noise fault modes) of the sensors are handled; on the hard fault the sensor output is stuck at a constant value. On the noise fault it is disturbed by a large noise. The FDD algorithm is based on the variable structure interacting multiple-model estimator. The fault-tolerant dead reckoning algorithm was implemented on our indoor test-vehicle, which consists of one chassis unit and four wheel units. Experimental results show that our dead reckoning provided better localization accuracy than the conventional one (i.e., the dead reckoning without sensor FDD system) did even though the sensors partially failed.

  8. Prototype of high resolution PET using resistive electrode position sensitive CdTe detectors

    International Nuclear Information System (INIS)

    Kikuchi, Yohei; Ishii, Keizo; Matsuyama, Shigeo; Yamazaki, Hiromichi

    2008-01-01

    Downsizing detector elements makes it possible that spatial resolutions of positron emission tomography (PET) cameras are improved very much. From this point of view, semiconductor detectors are preferable. To obtain high resolution, the pixel type or the multi strip type of semiconductor detectors can be used. However, in this case, there is a low packing ratio problem, because a dead area between detector arrays cannot be neglected. Here, we propose the use of position sensitive semiconductor detectors with resistive electrode. The CdTe detector is promising as a detector for PET camera because of its high sensitivity. In this paper, we report development of prototype of high resolution PET using resistive electrode position sensitive CdTe detectors. We made 1-dimensional position sensitive CdTe detectors experimentally by changing the electrode thickness. We obtained 750 A as an appropriate thickness of position sensitive detectors, and evaluated the performance of the detector using a collimated 241 Am source. A good position resolution of 1.2 mm full width half maximum (FWHM) was obtained. On the basis of the fundamental development of resistive electrode position sensitive detectors, we constructed a prototype of high resolution PET which was a dual head type and was consisted of thirty-two 1-dimensional position sensitive detectors. In conclusion, we obtained high resolutions which are 0.75 mm (FWHM) in transaxial, and 1.5 mm (FWHM) in axial. (author)

  9. 6Li foil thermal neutron detector

    Energy Technology Data Exchange (ETDEWEB)

    Ianakiev, Kiril D [Los Alamos National Laboratory; Swinhoe, Martyn T [Los Alamos National Laboratory; Favalli, Andrea [Los Alamos National Laboratory; Chung, Kiwhan [Los Alamos National Laboratory; Macarthur, Duncan W [Los Alamos National Laboratory

    2010-01-01

    In this paper we report on the design of a multilayer thermal neutron detector based on {sup 6}Li reactive foil and thin film plastic scintillators. The {sup 6}Li foils have about twice the intrinsic efficiency of {sup 10}B films and about four times higher light output due to a unique combination of high energy of reaction particles, low self absorption, and low ionization density of tritons. The design configuration provides for double sided readout of the lithium foil resulting in a doubling of the efficiency relative to a classical reactive film detector and generating a pulse height distribution with a valley between neutron and gamma signals similar to {sup 3}He tubes. The tens of microns thickness of plastic scintillator limits the energy deposited by gamma rays, which provides the necessary neutron/gamma discrimination. We used MCNPX to model a multilayer Li foil detector design and compared it with the standard HLNCC-II (18 {sup 3}He tubes operated at 4 atm). The preliminary results of the {sup 6}Li configuration show higher efficiency and one third of the die-away time. These properties, combined with the very short dead time of the plastic scintillator, offer the potential of a very high performance detector.

  10. Dead-Time Generation in Six-Phase Frequency Inverter

    Directory of Open Access Journals (Sweden)

    Aurelijus Pitrėnas

    2016-06-01

    Full Text Available In this paper control of multi-phase induction drives is discussed. Structure of six-phase frequency inverter is examined. The article deals with dead-time generation circuits in six-phase frequency inverter for transistor control signals. Computer models of dead-time circuits is created using LTspice software package. Simulation results are compared with experimental results of the tested dead-time circuits. Parameters obtained in simulation results are close to the parameters obtained in experimental results.

  11. Adaptive control with variable dead-zone nonlinearities

    Science.gov (United States)

    Orlicki, D.; Valavani, L.; Athans, M.; Stein, G.

    1984-01-01

    It has been found that fixed error dead-zones as defined in the existing literature result in serious degradation of performance, due to the conservativeness which characterizes the determination of their width. In the present paper, variable width dead-zones are derived for the adaptive control of plants with unmodeled dynamics. The derivation makes use of information available about the unmodeled dynamics both a priori as well as during the adaptation process, so as to stabilize the adaptive loop and at the same time overcome the conservativeness and performance limitations of fixed-dead zone adaptive or fixed gain controllers.

  12. Are We the Walking Dead? Burnout as Zombie Apocalypse

    Science.gov (United States)

    Doolittle, Benjamin R.

    2016-01-01

    The Walking Dead, one of the most popular television shows in recent history, uses the plot of a zombie apocalypse as a lens into exploring the human condition. Amidst a particularly dangerous moment, the show’s hero references the human struggle to survive by remarking, “We are the walking dead.” This offhand comment sheds light upon physicians’ struggles in medicine, in particular the high prevalence of burnout and the challenge to cultivate compassion and meaning. This is an important question for our age and for our profession. Are we the walking dead? PMID:28376445

  13. Groundwater-Lake Interaction in the Dead Sea Area

    Science.gov (United States)

    Kiro, Y.; Weinstein, Y.; Starinsky, A.; Yechieli, Y.

    2011-12-01

    The Dead Sea hypersaline water system is unique in terms of its unusual geochemical composition, rapid lake level changes and water composition of the brines discharging along its shoreline. The Dead Sea can be used as a natural lab for studying groundwater-seawater interaction and saline water hydrological circulation along the aquifer-sea boundary. It provides an opportunity to follow the geochemical processes along a flow path from the lake into the aquifer and back into the lake. The lake level has been dropping since the 1960's due to human interference in its water budget, reaching a rate of 1 m/yr in recent years. Saline water circulation in coastal aquifers may be a major process that governs trace element mass balances in coastal areas. This study uses radium isotopes in order to quantify the lake water circulation in the Dead Sea aquifer. There are four naturally-occurring radium isotopes, with half-lives ranging from 3.7 days to 1600 years which are chain products of uranium and thorium isotopes. Radium isotopes are usually enriched in saline groundwater and therefore are good candidates for estimating seawater or hypersaline lake water circulation in the aquifer. Compared to most natural water bodies, the Dead Sea is extremely enriched in radium and barium, where both 226Ra and 228Ra activities and Ba concentration (145, 1-2 dpm/L and 5 mg/L, respectively) are 2-3 orders of magnitude higher than in ocean water, whereas the salinity of the Dead Sea is only 10 times higher. Circulated Dead Sea water in the aquifer contains decreased concentrations of 226Ra (60 dpm/L), Ba (1.5 mg/L), Sr (300 relative to 340 mg/L in the Dead Sea) and Sulfate (250 relative to 392 mg/L). We suggest that the low 226Ra and Ba concentrations are due to precipitation of barite and celestine from the supersaturated Dead Sea water on entering the aquifer. 228Ra and the shorter-lived 224Ra and 223Ra, which have much lower activities in the Dead Sea (up to 1.8, 3 and 0.8 dpm

  14. Finite Discrete Gabor Analysis

    DEFF Research Database (Denmark)

    Søndergaard, Peter Lempel

    2007-01-01

    on the real line to be well approximated by finite and discrete Gabor frames. This method of approximation is especially attractive because efficient numerical methods exists for doing computations with finite, discrete Gabor systems. This thesis presents new algorithms for the efficient computation of finite......, discrete Gabor coefficients. Reconstruction of a signal from its Gabor coefficients is done by the use of a so-called dual window. This thesis presents a number of iterative algorithms to compute dual and self-dual windows. The Linear Time Frequency Toolbox is a Matlab/Octave/C toolbox for doing basic...... discrete time/frequency and Gabor analysis. It is intended to be both an educational and a computational tool. The toolbox was developed as part of this Ph.D. project to provide a solid foundation for the field of computational Gabor analysis....

  15. Products of Finite Groups

    CERN Document Server

    Ballester-Bolinches, Adolfo; Asaad, Mohamed

    2010-01-01

    The study of finite groups factorised as a product of two or more subgroups has become a subject of great interest during the last years with applications not only in group theory, but also in other areas like cryptography and coding theory. It has experienced a big impulse with the introduction of some permutability conditions. The aim of this book is to gather, order, and examine part of this material, including the latest advances made, give some new approach to some topics, and present some new subjects of research in the theory of finite factorised groups.

  16. Probable Carbonate Fossilization Processes Within Dead Sea Microbial Remains

    Science.gov (United States)

    Morris, P. A.; Wentworth, S. J.; Thomas-Keprta, K. L.; Allen, C. C.; McKay, D. S.

    2001-01-01

    Microbial fossilization processes in the Dead Sea is primarily associated with the calcium cation. The putative fossilized microbes do not represent the reported living microbial population. Additional information is contained in the original extended abstract.

  17. Dead zone area at the downstream flow of barrages

    Directory of Open Access Journals (Sweden)

    Mohamed F. Sauida

    2016-12-01

    Full Text Available Flow separation is a natural phenomenon encountered at some cases downstream of barrages. The main flow is divided into current and dead zone flows. The percentage area of dead zone flow must be taken into consideration downstream of barrages, due to its negative effect on flow characteristics. Experimental studies were conducted in the Hydraulic Research Institute (HRI, on a physical regulator model with five vents. Theoretically the separation zone is described as a part of an ellipse which is practically verified by plotting velocity vectors. The results show that the percentage area of dead zone to the area through length of separation depends mainly on the expansion ratio [channel width to width of opened vents], with maximum value of 81% for operated side gates. A statistical analysis was derived, to predict the percentage area of dead zone flow to the area through length of separation.

  18. In the Event of Bioterrorism: Protecting Families from Deadly Diseases

    Science.gov (United States)

    ... Español Text Size Email Print Share In the Event of Bioterrorism: Protecting Families from Deadly Diseases Page ... exposure. Talking to Children about Bioterrorism In the event of bioterrorism, knowing how to talk to your ...

  19. Dead-time free pixel readout architecture for ATLAS front-end IC

    CERN Document Server

    Einsweiler, Kevin F; Kleinfelder, S A; Luo, L; Marchesini, R; Milgrome, O; Pengg, F X

    1999-01-01

    A low power sparse scan readout architecture has been developed for the ATLAS pixel front-end IC. The architecture supports a dual discriminator and extracts the time over threshold (TOT) information along with a 2-D spatial address $9 of the hits associating them with a unique 7-bit beam crossing number. The IC implements level-1 trigger filtering along with event building (grouping together all hits in a beam crossing) in the end of column (EOC) buffer. The $9 events are transmitted over a 40 MHz serial data link with the protocol supporting buffer overflow handling by appending error flags to events. This mixed-mode full custom IC is implemented in 0.8 mu HP process to meet the $9 requirements for the pixel readout in the ATLAS inner detector. The circuits have been tested and the IC provides dead-time-less ambiguity free readout at 40 MHz data rate.

  20. Comparative analysis of movement characteristics during dead-reckoning-based navigation in humans and rats.

    Science.gov (United States)

    Wallace, Douglas G; Choudhry, Sarwat; Martin, Megan M

    2006-11-01

    Human and rat movement organization was investigated as they searched for randomly located rewards without access to visual information. Under dark conditions, rats foraged for randomly located food pellets (Experiment 1). Blindfolded humans were instructed to search for an ostensible hidden coin using a metal detector (Experiment 2). After locating the food pellet, rats carried it back to the refuge, and after a designated searching time, humans were instructed to return to the start location. Although both species exhibited a high degree of similarity in searching path movement organization and ability to return to the start location, disruption of human searching path organization was associated with impairments in returning to the start location. These results support the vestibular "gain" account of movement organization during dead-reckoning-based navigation.

  1. Pulse pile-up and dead time corrections for digitized signals from a BaF{sub 2} calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza, E., E-mail: emilio.mendoza@ciemat.es [CIEMAT, Avda. Complutense 40, 28040 Madrid (Spain); Cano-Ott, D., E-mail: daniel.cano@ciemat.es [CIEMAT, Avda. Complutense 40, 28040 Madrid (Spain); Guerrero, C., E-mail: carlos.guerrero@cern.ch [CERN, Physics Department, Geneva (Switzerland); CIEMAT, Avda. Complutense 40, 28040 Madrid (Spain); Berthoumieux, E., E-mail: Eric.Berthoumieux@cea.fr [CEA/Saclay - IRFU, Gif-sur-Yvette (France); CERN, Physics Department, Geneva (Switzerland)

    2014-12-21

    The pulse pile-up and associated dead time effects in an {sup 243}Am(n,γ) cross section measurement with a BaF{sub 2} Total Absorption Calorimeter at the CERN n{sub T}OF facility have been characterized. In this case, reliable corrections of these effects are crucial because of the complex detector configuration and of the high count rate induced by the sample activity of 50 MBq. The techniques, which have been developed for offline processing of the present data, may be of general interest for the analysis of other experiments using digital acquisition systems.

  2. Integration of a zero dead-volume PDMS rotary switch valve in a miniaturised (bio)electroanalytical system

    DEFF Research Database (Denmark)

    Godino, Neus; del Campo, Francisco Javier; Munoz, Francesc Xavier

    2010-01-01

    reaction products. The system is built using mainly polymeric materials such as PMMA and PDMS and fast prototyping techniques such as milling and moulding. The system also includes a set of microelectrodes, photo-lithographed on a silicon chip. The novelty lies in the design of the rotary microvalve, which...... contains a microreactor so that various reaction and incubation steps can be carried out in isolation from the detection event with zero dead volume. This avoids contamination and fouling of the electrodes by proteins or other organic matter, and extends the useful lifetime of the detector. The system...

  3. GADRAS Detector Response Function.

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, Dean J.; Harding, Lee; Thoreson, Gregory G; Horne, Steven M.

    2014-11-01

    The Gamma Detector Response and Analysis Software (GADRAS) applies a Detector Response Function (DRF) to compute the output of gamma-ray and neutron detectors when they are exposed to radiation sources. The DRF is fundamental to the ability to perform forward calculations (i.e., computation of the response of a detector to a known source), as well as the ability to analyze spectra to deduce the types and quantities of radioactive material to which the detectors are exposed. This document describes how gamma-ray spectra are computed and the significance of response function parameters that define characteristics of particular detectors.

  4. Management of the dead in Tacloban City after Typhoon Haiyan

    OpenAIRE

    Julius Erving Ballera; Vikki Carr de los Reyes; Ma Nemia Sucaldito; Alethea De Guzman; Luis Sy, Jr; Ma Justina Zapanta; Ferchito Avelino; Joselito Feliciano; Enrique Tayag

    2015-01-01

    Introduction: The post-disaster management of the dead involves a series of steps including on-site identification, transfer, storage and examination of bodies and delivery to families for burial. Two weeks after Typhoon Haiyan, a team from the Department of Health (DOH) was tasked with identifying the dead in Tacloban City. Methods: A suitable site for the collection of bodies was identified and an algorithm and standard data collection form developed. The retrieval of bodies was coordi...

  5. The dead donor rule, voluntary active euthanasia, and capital punishment.

    Science.gov (United States)

    Coons, Christian; Levin, Noah

    2011-06-01

    We argue that the dead donor rule, which states that multiple vital organs should only be taken from dead patients, is justified neither in principle nor in practice. We use a thought experiment and a guiding assumption in the literature about the justification of moral principles to undermine the theoretical justification for the rule. We then offer two real world analogues to this thought experiment, voluntary active euthanasia and capital punishment, and argue that the moral permissibility of terminating any patient through the removal of vital organs cannot turn on whether or not the practice violates the dead donor rule. Next, we consider practical justifications for the dead donor rule. Specifically, we consider whether there are compelling reasons to promulgate the rule even though its corresponding moral principle is not theoretically justified. We argue that there are no such reasons. In fact, we argue that promulgating the rule may actually decrease public trust in organ procurement procedures and medical institutions generally - even in states that do not permit capital punishment or voluntary active euthanasia. Finally, we examine our case against the dead donor rule in the light of common arguments for it. We find that these arguments are often misplaced - they do not support the dead donor rule. Instead, they support the quite different rule that patients should not be killed for their vital organs.

  6. Undecidability and finite automata

    NARCIS (Netherlands)

    Endrullis, Jörg; Shallit, Jeffrey; Smith, Tim

    2017-01-01

    Using a novel rewriting problem, we show that several natural decision problems about finite automata are undecidable (i.e., recursively unsolvable). In contrast, we also prove three related problems are decidable. We apply one result to prove the undecidability of a related problem about

  7. Robust RBF Finite Automata

    Czech Academy of Sciences Publication Activity Database

    Šorel, Michal; Šíma, Jiří

    2004-01-01

    Roč. 62, - (2004), s. 93-110 ISSN 0925-2312 R&D Projects: GA AV ČR IAB2030007; GA MŠk LN00A056 Keywords : radial basis function * neural network * finite automaton * Boolean circuit * computational power Subject RIV: BA - General Mathematics Impact factor: 0.641, year: 2004

  8. Inside finite elements

    CERN Document Server

    Weiser, Martin

    2016-01-01

    All relevant implementation aspects of finite element methods are discussed in this book. The focus is on algorithms and data structures as well as on their concrete implementation. Theory is covered as far as it gives insight into the construction of algorithms. Throughout the exercises a complete FE-solver for scalar 2D problems will be implemented in Matlab/Octave.

  9. Finite unified models

    Energy Technology Data Exchange (ETDEWEB)

    Kapetanakis, D. (Technische Univ. Muenchen, Garching (Germany). Physik Dept.); Mondragon, M. (Technische Univ. Muenchen, Garching (Germany). Physik Dept.); Zoupanos, G. (National Technical Univ., Athens (Greece). Physics Dept.)

    1993-09-01

    We present phenomenologically viable SU(5) unified models which are finite to all orders before the spontaneous symmetry breaking. In the case of two models with three families the top quark mass is predicted to be 178.8 GeV. (orig.)

  10. Finite unified models

    International Nuclear Information System (INIS)

    Kapetanakis, D.; Mondragon, M.; Zoupanos, G.

    1993-01-01

    We present phenomenologically viable SU(5) unified models which are finite to all orders before the spontaneous symmetry breaking. In the case of two models with three families the top quark mass is predicted to be 178.8 GeV. (orig.)

  11. Finiteness and GUTs

    International Nuclear Information System (INIS)

    Kapetanakis, D.; Mondragon, M.

    1993-01-01

    It is shown how to obtain phenomenologically viable SU(5) unified models which are finite to all orders before the spontaneous symmetry breaking. A very interesting feature of the models with three families is that they predict the top quark mass to be around 178 GeV. 16 refs

  12. Drift Chambers detectors; Detectores de deriva

    Energy Technology Data Exchange (ETDEWEB)

    Duran, I.; Martinez laso, L.

    1989-07-01

    We present here a review of High Energy Physics detectors based on drift chambers. The ionization, drift diffusion, multiplication and detection principles are described. Most common drift media are analysed, and a classification of the detectors according to its geometry is done. Finally the standard read-out methods are displayed and the limits of the spatial resolution are discussed. (Author) 115 refs.

  13. Exercising is like flogging a dead horse

    International Nuclear Information System (INIS)

    Molhoek, W.

    2003-01-01

    - FR (NPP Gravelines) was conducted (22-23th of May 2001). The main objectives of the INEX series of exercises were focused on: decision making based on limited information and uncertain plant conditions; the use of real time communications with actual equipment and procedures; public information and interaction with media; the use of real weather for real time forecasts. For real further improvement of (nuclear) emergency management and response, not only national and international exercises such as INEX, CONVEX, JINEX etc. are needed, but the efforts to improve personal performance of key-persons involved is crucial. Structural plans to train and exercise individuals and teams should therefore be developed as well. To move the dead horse and create a racehorse need a lot of personal skills and attention. It is also recognized that often the carrot is better than the whip. (author)

  14. Barrier Infrared Detector (BIRD)

    Data.gov (United States)

    National Aeronautics and Space Administration — A recent breakthrough in MWIR detector design, has resulted in a high operating temperature (HOT) barrier infrared detector (BIRD) that is capable of spectral...

  15. The LDC detector concept

    Indian Academy of Sciences (India)

    ), the large detector concept (LDC) is being developed. The main points of the LDC are a large volume gaseous tracking system, combined with high precision vertex detector and an extremely granular calorimeter. The main design force ...

  16. Forward tracking detectors

    Indian Academy of Sciences (India)

    Abstract. Forward tracking is an essential part of a detector at the international linear collider (ILC). The requirements for forward tracking are explained and the proposed solutions in the detector concepts are shown.

  17. Thermal kinetic inductance detector

    Science.gov (United States)

    Cecil, Thomas; Gades, Lisa; Miceli, Antonio; Quaranta, Orlando

    2016-12-20

    A microcalorimeter for radiation detection that uses superconducting kinetic inductance resonators as the thermometers. The detector is frequency-multiplexed which enables detector systems with a large number of pixels.

  18. Calibration and Characterization of the UNCB and Nab Detectors

    Science.gov (United States)

    Zeck, Bryan; UCNB Collaboration; Nab Collaboration

    2017-09-01

    The UCNB and Nab experiments are designed to produce precision measurements of the free neutron decay angular correlations B, a, and b. Measurements of B and a require a coincident detection of the proton and electron produced in neutron decay, while for b, which manifests as a subtle shift in the electron energy spectrum, energy resolution better than 3 keV is desired and excellent fidelity for energy reconstruction is required, including characterization of non-linearity to the 10-4 level. To this end, a thick segmented silicon detector with a 100 nm dead layer and a 100 cm active area has been extensively characterized at LANL. The thin dead layer allows protons accelerated to 30 keV to deposit energy above threshold in the active volume of the detector, and the paired amplifer chain, developed at LANL, has a risetime of approximately 40 ns. Comparison of simulation to experiment reveals a detector resolution better than σ = 2.5 keV. A complete characterization of the detector will be presented. This work has been supported by Grants from the US National Science Foundation and the Department of Energy.

  19. Nonlinear, finite deformation, finite element analysis

    Science.gov (United States)

    Nguyen, Nhung; Waas, Anthony M.

    2016-06-01

    The roles of the consistent Jacobian matrix and the material tangent moduli, which are used in nonlinear incremental finite deformation mechanics problems solved using the finite element method, are emphasized in this paper, and demonstrated using the commercial software ABAQUS standard. In doing so, the necessity for correctly employing user material subroutines to solve nonlinear problems involving large deformation and/or large rotation is clarified. Starting with the rate form of the principle of virtual work, the derivations of the material tangent moduli, the consistent Jacobian matrix, the stress/strain measures, and the objective stress rates are discussed and clarified. The difference between the consistent Jacobian matrix (which, in the ABAQUS UMAT user material subroutine is referred to as DDSDDE) and the material tangent moduli ( C e ) needed for the stress update is pointed out and emphasized in this paper. While the former is derived based on the Jaumann rate of the Kirchhoff stress, the latter is derived using the Jaumann rate of the Cauchy stress. Understanding the difference between these two objective stress rates is crucial for correctly implementing a constitutive model, especially a rate form constitutive relation, and for ensuring fast convergence. Specifically, the implementation requires the stresses to be updated correctly. For this, the strains must be computed directly from the deformation gradient and corresponding strain measure (for a total form model). Alternatively, the material tangent moduli derived from the corresponding Jaumann rate of the Cauchy stress of the constitutive relation (for a rate form model) should be used. Given that this requirement is satisfied, the consistent Jacobian matrix only influences the rate of convergence. Its derivation should be based on the Jaumann rate of the Kirchhoff stress to ensure fast convergence; however, the use of a different objective stress rate may also be possible. The error associated

  20. The LDC detector concept

    Indian Academy of Sciences (India)

    2004. Its goal is to design a complete detector concept for the LDC, based on a gaseous central tracking detector, and on granular calorimetry. The concept is heavily based on the concept of particle flow for event reconstruction. LDC started from the TESLA detector, developed for the TESLA TDR [2] and published in 2001.

  1. Gas filled detectors

    International Nuclear Information System (INIS)

    Stephan, C.

    1993-01-01

    The main types of gas filled nuclear detectors: ionization chambers, proportional counters, parallel-plate avalanche counters (PPAC) and microstrip detectors are described. New devices are shown. A description of the processes involved in such detectors is also given. (K.A.) 123 refs.; 25 figs.; 3 tabs

  2. The CAPRICE RICH detector

    International Nuclear Information System (INIS)

    Basini, G.; De Pascale, M.P.; Golden, R.L.; Barbiellini, G.; Boezio, M.

    1995-01-01

    A compact RICH detector has been developed and used for particle identification in a balloon borne spectrometer to measure the flux of antimatter in the cosmic radiation. This is the first RICH detector ever used in space experiments that is capable of detecting unit charged particles, such as antiprotons. The RICH and all other detectors performed well during the 27 hours long flight

  3. The LDC detector concept

    Indian Academy of Sciences (India)

    and an extremely granular calorimeter. The main design force behind the LDC is the particle flow concept. Keywords. International linear collider; large detector concept. PACS No. 13.66-a. 1. Introduction. The large detector concept (LDC) detector concept group [1] was formed early in. 2004. Its goal is to design a complete ...

  4. The CAPRICE RICH detector

    Energy Technology Data Exchange (ETDEWEB)

    Basini, G. [INFN, Laboratori Nazionali di Frascati, Rome (Italy); Codino, A.; Grimani, C. [Perugia Univ. (Italy)]|[INFN, Perugia (Italy); De Pascale, M.P. [Rome Univ. `Tor Vergata` (Italy). Dip. di Fisica]|[INFN, Sezione Univ. `Tor Vergata` Rome (Italy); Cafagna, F. [Bari Univ. (Italy)]|[INFN, Bari (Italy); Golden, R.L. [New Mexico State Univ., Las Cruces, NM (United States). Particle Astrophysics Lab.; Brancaccio, F.; Bocciolini, M. [Florence Univ. (Italy)]|[INFN, Florence (Italy); Barbiellini, G.; Boezio, M. [Trieste Univ. (Italy)]|[INFN, Trieste (Italy)

    1995-09-01

    A compact RICH detector has been developed and used for particle identification in a balloon borne spectrometer to measure the flux of antimatter in the cosmic radiation. This is the first RICH detector ever used in space experiments that is capable of detecting unit charged particles, such as antiprotons. The RICH and all other detectors performed well during the 27 hours long flight.

  5. Options for reducing HIV transmission related to the dead space in needles and syringes.

    Science.gov (United States)

    Zule, William A; Pande, Poonam G; Otiashvili, David; Bobashev, Georgiy V; Friedman, Samuel R; Gyarmathy, V Anna; Des Jarlais, Don C

    2018-01-15

    When shared by people who inject drugs, needles and syringes with different dead space may affect the probability of HIV and hepatitis C virus (HCV) transmission differently. We measured dead space in 56 needle and syringe combinations obtained from needle and syringe programs across 17 countries in Europe and Asia. We also calculated the amounts of blood and HIV that would remain in different combinations following injection and rinsing. Syringe barrel capacities ranged from 0.5 to 20 mL. Needles ranged in length from 8 to 38 mm. The average dead space was 3 μL in low dead space syringes with permanently attached needles, 13 μL in high dead space syringes with low dead space needles, 45 μL in low dead space syringes with high dead space needles, and 99 μL in high dead space syringes with high dead space needles. Among low dead space designs, calculated volumes of blood and HIV viral burden were lowest for low dead space syringes with permanently attached needles and highest for low dead space syringes with high dead space needles. The dead space in different low dead space needle and syringe combinations varied substantially. To reduce HIV transmission related to syringe sharing, needle and syringe programs need to combine this knowledge with the needs of their clients.

  6. The COMPASS RICH-1 detector upgrade

    International Nuclear Information System (INIS)

    Colantoni, M.L.; Panzieri, D.; Joosten, R.; Naehle, O.; Kolosov, V.N.; Eyrich, W.; Lehmann, A.; Schroeder, W.; Teufel, A.; Fischer, H.; Hagemann, R.; Heinsius, F.H.; Konigsmann, K.; Mutter, A.; Nerling, F.; Schill, C.; Wollny, H.; Kramer, D.; Polak, J.; Sulc, M.; Svec, M.; Silva, L.; Von Harrach, D.; Angerer, H.; Gerassimov, S.; Ketzer, B.; Konorov, I.; Mann, A.; Paul, S.; Finger, M.; Finger, M. Jr.; Slunecka, M.; Steiger, L.; Finger, M.; Finger, M. Jr.; Slunecka, M.; Steiger, L.; Abbon, P.; Dafni, T.; Delagnes, E.; Deschamps, H.; Kunne, F.; Magnon, A.; Neyret, D.; Panebianco, S.; Rebourgeard, P.; Robinet, F.; Alekseev, M.; Busso, L.; Chiosso, M.; Costa, S.; Dibiase, N.; Faso, D.; Ferrero, A.; Maggiora, A.; Alekseev, M.; Busso, L.; Chiosso, M.; Costa, S.; Dibiase, N.; Faso, D.; Ferrero, A.; Maggiora, A.; Apollonio, M.; Birsa, R.; Bradamante, F.; Bressan, A.; Ciliberti, P.; Torre, S. Dalla; Diaz, V.; Duic, V.; Giorgi, M.; Gobbo, B.; Levorato, S.; Martin, A.; Menon, G.; Pagano, P.; Pesaro, G.; Rocco, E.; Schiavon, P.; Sozzi, F.; Tessarotto, F.; Apollonio, M.; Birsa, R.; Bradamante, F.; Bressan, A.; Ciliberti, P.; Torre, S. Dalla; Diaz, V.; Duic, V.; Giorgi, M.; Gobbo, B.; Levorato, S.; Martin, A.; Menon, G.; Pagano, P.; Pesaro, G.; Rocco, E.; Schiavon, P.; Sozzi, F.; Tessarotto, F.

    2008-01-01

    The COMPASS experiment at CERN provides hadron identification in a wide momentum range employing a large size gaseous Ring Imaging Cherenkov detector (RICH). The presence of large uncorrelated background in the COMPASS environment was limiting the efficiency of COMPASS RICH-1 in the very forward regime. A major upgrade of RICH-1 required a new technique for Cherenkov photon detection at count rates of several 10 6 /s per channel in the central detector part, and a read-out system allowing for trigger rates of up to 100 kHz. To cope with these requirements, the photon detectors of the central region have been replaced with a fast photon detection system described here, while, in the peripheral regions, the existing multi-wire proportional chambers with CsI photo-cathodes have been equipped with a new read-out system based on APV preamplifiers and flash ADC chips. The new system consists of multi-anode photo-multiplier tubes (MAPMTs) coupled to individual fused silica lens telescopes, and fast read-out electronics based on the MAD4 amplifier-discriminator and the dead-time free F1 TDC chip. The project was completely designed and implemented in less than two years: The upgraded detector is in operation since the 2006 CERN SPS run. We present the photon detection design, constructive aspects and test studies to characterise the single photon response of the MAPMTs coupled to the read-out system as well as the detector performance based on the 2006 data. (authors)

  7. Assessment and management of dead-wood habitat

    Science.gov (United States)

    Hagar, Joan

    2007-01-01

    The Bureau of Land Management (BLM) is in the process of revising its resource management plans for six districts in western and southern Oregon as the result of the settlement of a lawsuit brought by the American Forest Resource Council. A range of management alternatives is being considered and evaluated including at least one that will minimize reserves on O&C lands. In order to develop the bases for evaluating management alternatives, the agency needs to derive a reasonable range of objectives for key issues and resources. Dead-wood habitat for wildlife has been identified as a key resource for which decision-making tools and techniques need to be refined and clarified. Under the Northwest Forest Plan, reserves were to play an important role in providing habitat for species associated with dead wood (U.S. Department of Agriculture Forest Service and U.S. Department of the Interior Bureau of Land Management, 1994). Thus, the BLM needs to: 1) address the question of how dead wood will be provided if reserves are not included as a management strategy in the revised Resource Management Plan, and 2) be able to evaluate the effects of alternative land management approaches. Dead wood has become an increasingly important conservation issue in managed forests, as awareness of its function in providing wildlife habitat and in basic ecological processes has dramatically increased over the last several decades (Laudenslayer et al., 2002). A major concern of forest managers is providing dead wood habitat for terrestrial wildlife. Wildlife in Pacific Northwest forests have evolved with disturbances that create large amounts of dead wood; so, it is not surprising that many species are closely associated with standing (snags) or down, dead wood. In general, the occurrence or abundance of one-quarter to one-third of forest-dwelling vertebrate wildlife species, is strongly associated with availability of suitable dead-wood habitat (Bunnell et al., 1999; Rose et al., 2001). In

  8. Optimal infrared detector configurations for air target detection

    Science.gov (United States)

    Uda, G.; Barani, G.

    1995-01-01

    The airtarget detection by a thermal camera is a typical problem of 'hot spot detection' and the knowledge of the available energy on the infrared sensor becomes a critical item to analyse. In order to evaluate the performances of an infrared system in search and track threat warning or passive surveillance, it is necessary to compute the Signal to Noise Ratio (SNR) of the system. The maximization of the SNR is an important goal to assure long detection ranges against stealth threats or cruise missiles with very low emissivities. The large number of detectors is just one of the requirements for this kind of application and some energetic considerations lead up to consider particular geometrical array configurations. Usually, in the SNR evaluation it is assumed that all the energy from a target is focused by the optical system on a single detector element of the array. However, the image of a point source on the focal plane has a finite extent (spot) and its energy distribution is given by the Point Spread Function (PSF) of the optics. The interaction of the finite spot size with the array gives rise to a spreading of the energy impinging on the individual detectors, which causes a decrease of performances. In this paper a statistical evaluation of the loss of energy impinging on the detector due to the finite image size of point targets was performed through a Monte Carlo simulation. By considering the maximum of the energy integrated by a single detector, it is possible to compute the effective SNR of the system. A new figure of merit, called Spreading Factor (SF), defined as the ratio between the maximum of the energy integrated by the single detector of the array and the total energy subtended by the PSF, permits to evaluate the capability of a detector array to detect point sources. Some typical detector and system configurations with their technological impacts have been examined.

  9. Supersymmetry at finite temperature

    International Nuclear Information System (INIS)

    Oliveira, M.W. de.

    1986-01-01

    The consequences of the incorporation of finite temperature effects in fields theories are investigated. Particularly, we consider the sypersymmetric non-linear sigma model, calculating the effective potencial in the large N limit. Initially, we present the 1/N expantion formalism and, for the O(N) model of scalar field, we show the impossibility of spontaneous symmetry breaking. Next, we study the same model at finite temperature and in the presence of conserved charges (the O(N) symmetry's generator). We conclude that these conserved charges explicitly break the symmetry. We introduce a calculation method for the thermodynamic potential of the theory in the presence of chemical potentials. We present an introduction to Supersymmetry in the aim of describing some important concepts for the treatment at T>0. We show that Suppersymmetry is broken for any T>0, in opposition to what one expects, by the solution of the Hierachy Problem. (author) [pt

  10. Radiation detectors laboratory

    International Nuclear Information System (INIS)

    Ramirez J, F.J.

    1997-01-01

    The Radiation detectors laboratory was established with the assistance of the International Atomic Energy Agency which gave this the responsibility to provide its services at National and regional level for Latin America and it is located at the ININ. The more expensive and delicate radiation detectors are those made of semiconductor, so it has been put emphasis in the use and repairing of these detectors type. The supplied services by this laboratory are: selection consultant, detectors installation and handling and associated systems. Installation training, preventive and corrective maintenance of detectors and detection systems calibration. (Author)

  11. Using Finite Element Method

    Directory of Open Access Journals (Sweden)

    M.H.R. Ghoreishy

    2008-02-01

    Full Text Available This research work is devoted to the footprint analysis of a steel-belted radial tyre (185/65R14 under vertical static load using finite element method. Two models have been developed in which in the first model the tread patterns were replaced by simple ribs while the second model was consisted of details of the tread blocks. Linear elastic and hyper elastic (Arruda-Boyce material models were selected to describe the mechanical behavior of the reinforcing and rubbery parts, respectively. The above two finite element models of the tyre were analyzed under inflation pressure and vertical static loads. The second model (with detailed tread patterns was analyzed with and without friction effect between tread and contact surfaces. In every stage of the analysis, the results were compared with the experimental data to confirm the accuracy and applicability of the model. Results showed that neglecting the tread pattern design not only reduces the computational cost and effort but also the differences between computed deformations do not show significant changes. However, more complicated variables such as shape and area of the footprint zone and contact pressure are affected considerably by the finite element model selected for the tread blocks. In addition, inclusion of friction even in static state changes these variables significantly.

  12. Proceedings of the symposium on the ecology and management of dead wood in western forests

    Science.gov (United States)

    William F. Laudenslayer; Patrick J. Shea; Bradley E. Valentine; C. Phillip Weatherspoon; Thomas E. Lisle

    2002-01-01

    Dead trees, both snags (standing dead trees) and logs (downed dead trees), are critical elements of healthy and productive forests. The “Symposium on the Ecology and Management of Dead Wood in Western Forests” was convened to bring together forest researchers and managers to share the current state of knowledge relative to the values and interactions of dead wood to...

  13. Radiation detectors laboratory

    International Nuclear Information System (INIS)

    Ramirez J, F.J.

    1996-01-01

    The National Institute for Nuclear Research has established a Radiation detector laboratory that has the possibility of providing to the consultants on the handling and applications of the nuclear radiation detectors. It has special equipment to repair the radiation detectors used in spectroscopy as the hyper pure Germanium for gamma radiation and the Lithium-silica for X-rays. There are different facilities in the laboratory that can become useful for other institutions that use radiation detectors. This laboratory was created to satisfy consultant services, training and repairing of the radiation detectors both in national and regional levels for Latin America. The laboratory has the following sections: Nuclear Electronic Instrumentation; where there are all kind of instruments for the measurement and characterization of detectors like multichannel analyzers of pulse height, personal computers, amplifiers and nuclear pulse preamplifiers, nuclear pulses generator, aleatories, computer programs for radiation spectra analysis, etc. High vacuum; there is a vacuum escape measurer, two high vacuum pumps to restore the vacuum of detectors, so the corresponding measurers and the necessary tools. Detectors cleaning; there is an anaerobic chamber for the detectors handling at inert atmosphere, a smoke extraction bell for cleaning with the detector solvents. Cryogenic; there are vessels and tools for handling liquid nitrogen which is used for cooling the detectors when they required it. (Author)

  14. Vestibular information is required for dead reckoning in the rat.

    Science.gov (United States)

    Wallace, Douglas G; Hines, Dustin J; Pellis, Sergio M; Whishaw, Ian Q

    2002-11-15

    Dead reckoning is an on-line form of spatial navigation used by an animal to identify its present location and return directly to a starting location, even after circuitous outward trips. At present, it is not known which of several self-movement cues (efferent copy from movement commands, proprioceptive information, sensory flow, or vestibular information) are used to compute homeward trajectories. To determine whether vestibular information is important for dead reckoning, the impact of chemical labyrinthectomy was evaluated in a test that demanded on-line computation of a homeward trajectory. Rats were habituated to leave a refuge that was visible from all locations on a circular table to forage for large food pellets, which they carried back to the refuge to eat. Two different probe trials were given: (1) the rats foraged from the same spatial location from a hidden refuge in the light and so were able to use visual cues to navigate; (2) the same procedure took place in the dark, constraining the animals to dead reckon. Although control rats carried food directly and rapidly back to the refuge on both probes, the rats with vestibular lesions were able to do so on the hidden refuge but not on the dark probe. The scores of vestibular reflex tests predicted the dead reckoning deficit. The vestibular animals were also impaired in learning a new piloting task. This is the first unambiguous demonstration that vestibular information is used in dead reckoning and also contributes to piloting.

  15. The Dead Sea, The Lake and Its Setting

    Science.gov (United States)

    Brink, Uri ten

    I cannot think of a subject more befitting the description of interdisciplinary research with societal relevance than the study of the Dead Sea, a terminal lake of the Jordan River in Israel and Jordan. The scientific study of the Dead Sea is intimately connected with politics, religion, archeology, economic development, tourism, and environmental change.The Dead Sea is a relatively closed geologic and limnologic system with drastic physical changes often occurring on human timescales and with a long human history to observe these changes. Research in this unique area covers diverse aspects such as active subsidence and deformation along strike-slip faults; vertical stratification and stability of the water column; physical properties of extremely saline and dense (1234 kg/m3) water; spontaneous precipitation of minerals in an oversaturated environment; origin of the unusual chemical composition of the brine; existence of life in extreme environments; use of lake level fluctuations as a paleoclimatic indicator; and effects on the environment of human intervention versus natural climatic variability. Although the Dead Sea covers a small area on a global scale, it is nevertheless one of the largest natural laboratories for these types of research on Earth. These reasons make the Dead Sea a fascinating topic for the curious mind.

  16. High-energy detector

    Science.gov (United States)

    Bolotnikov, Aleksey E [South Setauket, NY; Camarda, Giuseppe [Farmingville, NY; Cui, Yonggang [Upton, NY; James, Ralph B [Ridge, NY

    2011-11-22

    The preferred embodiments are directed to a high-energy detector that is electrically shielded using an anode, a cathode, and a conducting shield to substantially reduce or eliminate electrically unshielded area. The anode and the cathode are disposed at opposite ends of the detector and the conducting shield substantially surrounds at least a portion of the longitudinal surface of the detector. The conducting shield extends longitudinally to the anode end of the detector and substantially surrounds at least a portion of the detector. Signals read from one or more of the anode, cathode, and conducting shield can be used to determine the number of electrons that are liberated as a result of high-energy particles impinge on the detector. A correction technique can be implemented to correct for liberated electron that become trapped to improve the energy resolution of the high-energy detectors disclosed herein.

  17. Count rate performance of a silicon-strip detector for photon-counting spectral CT

    Energy Technology Data Exchange (ETDEWEB)

    Liu, X., E-mail: olivia@mi.physics.kth.se; Grönberg, F.; Sjölin, M.; Karlsson, S.; Danielsson, M.

    2016-08-11

    A silicon-strip detector is developed for spectral computed tomography. The detector operates in photon-counting mode and allows pulse-height discrimination with 8 adjustable energy bins. In this work, we evaluate the count-rate performance of the detector in a clinical CT environment. The output counts of the detector are measured for x-ray tube currents up to 500 mA at 120 kV tube voltage, which produces a maximum photon flux of 485 Mphotons/s/mm{sup 2} for the unattenuated beam. The corresponding maximum count-rate loss of the detector is around 30% and there are no saturation effects. A near linear relationship between the input and output count rates can be observed up to 90 Mcps/mm{sup 2}, at which point only 3% of the input counts are lost. This means that the loss in the diagnostically relevant count-rate region is negligible. A semi-nonparalyzable dead-time model is used to describe the count-rate performance of the detector, which shows a good agreement with the measured data. The nonparalyzable dead time τ{sub n} for 150 evaluated detector elements is estimated to be 20.2±5.2 ns.

  18. Count rate performance of a silicon-strip detector for photon-counting spectral CT

    Science.gov (United States)

    Liu, X.; Grönberg, F.; Sjölin, M.; Karlsson, S.; Danielsson, M.

    2016-08-01

    A silicon-strip detector is developed for spectral computed tomography. The detector operates in photon-counting mode and allows pulse-height discrimination with 8 adjustable energy bins. In this work, we evaluate the count-rate performance of the detector in a clinical CT environment. The output counts of the detector are measured for x-ray tube currents up to 500 mA at 120 kV tube voltage, which produces a maximum photon flux of 485 Mphotons/s/mm2 for the unattenuated beam. The corresponding maximum count-rate loss of the detector is around 30% and there are no saturation effects. A near linear relationship between the input and output count rates can be observed up to 90 Mcps/mm2, at which point only 3% of the input counts are lost. This means that the loss in the diagnostically relevant count-rate region is negligible. A semi-nonparalyzable dead-time model is used to describe the count-rate performance of the detector, which shows a good agreement with the measured data. The nonparalyzable dead time τn for 150 evaluated detector elements is estimated to be 20.2±5.2 ns.

  19. The Dead Sea Transform and the Dead Sea Basin - Structure and dynamics

    Science.gov (United States)

    Weber, M.; Desire Groups, D A

    2007-12-01

    DESERT and DESIRE, two multi-national, interdisciplinary research efforts by teams from Germany, Israel, Jordan and Palestine focused on the Dead Sea Transform (DST) and the Dead Sea Basin (DSB), respectively. The DST has accommodated left-lateral transform motion of 105 km between the African and Arabian plates since early Miocene (ca. 20 My), creating during this process also the prime example of a pull-apart basin, the DSB. Within DESERT the DST segment between the Dead Sea and the Red Sea called Arava/Araba Fault (AF) was studied with the following results. On plate tectonic scale the AF is a narrow, sub-vertical zone cutting through crust and lithosphere to more than 50 km depth, while the Moho depth increases smoothly from 26 km to 39 km from W to E under the DST. Several faults exist in the upper crust in a ca. 40 km wide zone around the AF, but none has kilometer-size zones of decreased seismic velocities/zones of high electrical conductivities typical for damage zones. Across the sub-vertical AF abrupt changes in lithology can be identified to a depth of 4 kilometers. The AF also acts as a barrier to fluids. The AF is the main active fault of the DST system but it has only accommodated a limited part (up to 60 km) of the overall 105 km of sinistral plate motion. Now inactive fault strands in the vicinity of the present day AF took up lateral motion until about 5 Ma ago, when the main, active fault trace shifted ca. 1 km westward to its present position. In the top few hundred meters of the AF a locally transpressional regime occurs in a 100 to 300 m wide zone of deformed and displaced material, bordered by sub-parallel faults forming positive flower structures. The damage zones of the individual faults are only 5 to 20 m wide. This narrow width is significantly smaller than at other major strike-slip faults of similar magnitude. Most of these findings are corroborated by thermo-mechanical modeling that show shear deformation in the lithosphere under the

  20. Deadly Choices empowering Indigenous Australians through social networking sites.

    Science.gov (United States)

    McPhail-Bell, Karen; Appo, Nathan; Haymes, Alana; Bond, Chelsea; Brough, Mark; Fredericks, Bronwyn

    2017-04-05

    The potential for health promotion through social networking sites (SNSs) is widely recognized. However, while health promotion prides itself in focusing on the social determinants of health, its partiality for persuading individuals to comply with health behaviours dominates the way health promotion utilizes SNSs. This paper contributes to an understanding of collaborative ways SNSs can work for health promotion agendas of self-determination and empowerment in an Indigenous Australia context. An ethnographic study was undertaken with Deadly Choices, an Indigenous-led health promotion initiative. The study involved participant observation of interactions on Deadly Choices SNSs between Deadly Choices and its online community members. Deadly Choices provides an example of SNSs providing a powerful tool to create a safe, inclusive and positive space for Indigenous people and communities to profile their healthy choices, according to Indigenous notions of health and identity. The study found five principles that underpin Deadly Choices' use of SNSs for health promotion. These are: create a dialogue; build community online and offline; incentivise healthy online engagement; celebrate Indigenous identity and culture; and prioritize partnerships. Deadly Choices SNSs empowers Indigenous people and communities to be health promoters themselves, which represents a power shift from health promotion practitioner to Indigenous people and communities and more broadly, an enactment of Indigenous self-determination on SNSs. Mainstream health promotion can learn from Indigenous health promotion practice regarding the use of SNSs for health promotion agendas. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Nuclear radiation detectors

    International Nuclear Information System (INIS)

    Kapoor, S.S.; Ramamurthy, V.S.

    1986-01-01

    The present monograph is intended to treat the commonly used detectors in the field of nuclear physics covering important developments of the recent years. After a general introduction, a brief account of interaction of radiation with matter relevant to the processes in radiation detection is given in Chapter II. In addition to the ionization chamber, proportional counters and Geiger Mueller counters, several gas-filled detectors of advanced design such as those recently developed for heavy ion physics and other types of studies have been covered in Chapter III. Semiconductor detectors are dealt with in Chapter IV. The scintillation detectors which function by sensing the photons emitted by the luminescence process during the interaction of the impinging radiation with the scintillation detector medium are described in Chapter V. The topic of neutron detectors is covered in Chapter VI, as in this case the emphasis is more on the method of neutron detection rather than on detector type. Electronic instrumentation related to signal pulse processing dealt with in Chapter VII. The track etch detectors based on the visualization of the track of the impinging charge particle have also been briefly covered in the last chapter. The scope of this monograph is confined to detectors commonly used in low and medium energy nuclear physics research and applications of nuclear techniques. The monograph is intended for post-graduate students and those beginning to work with the radiation detectors. (author)

  2. Tourism development challenges on the Dead Sea shore

    Directory of Open Access Journals (Sweden)

    Wendt Jan A.

    2016-12-01

    Full Text Available The Dead Sea along with Jerusalem belongs to one of the most well-known spots visited by tourists in Israel. Because of many factors, such as the water level of the Dead Sea at a depth of 430 m b.s.l. (in 2015, average salinity of 26%, hot springs and many healing salts located there, it is a unique tourist attraction on a global level. Its attractiveness is heightened by its proximity to other sites of interest, such as the Jewish fortress at Masada, Jericho, Qumran, where the Dead Sea Scrolls were found, as well as Petra, Madaba and Al-Karak on the Jordanian side of the Dead Sea. High salinity and a microclimate create perfect conditions for the development of health resorts and medical tourism. Extracting healing salts from its waters for the needs of the chemical industry is important for both the economy and medical tourism. However, as a consequence of the agricultural and urban use of the waters of the River Jordan, which flows into the Dead Sea, a persistent decrease in the lake water level has been observed over the last century. This has created a number of economic and political issues. The problems which still have to be resolved are associated with the Red Sea-Dead Sea Conduit (Canal, the division of Jordan’s water resources, conservation of the unique reservoir of the Dead Sea and the threat of hindering the development of tourism within the region. The presentation of these issues is the main aim of this research paper. The study is based on the analysis of changes in tourism flows, results of research studies and the prognosis of changes in the water level of the Dead Sea. It presents an assessment of the effects of this phenomenon on the tourist economy. At the current level of tourism flows within the region, the tourist capacity of local beaches will be exceeded in areas where the most popular tourist resorts are located. Increased expenditure on development of tourism infrastructure in the coastal zone can also be observed

  3. Simplified dead-time compensator for multiple delay SISO systems.

    Science.gov (United States)

    Torrico, Bismark Claure; Correia, Wilkley Bezerra; Nogueira, Fabrício Gonzalez

    2016-01-01

    This paper presents a dead-time compensation structure able to deal with stable and unstable multiple delay single input single output (SISO) systems. The proposed method aims to simplify the primary controller by replacing it for FIR filters placed at the feedback path. Such modification reduces the total number of parameters to be tuned which facilitates the overall design in comparison with other primary controllers normally considered. Simulation results show a better performance for the proposed control approach compared with other dead-time compensator (DTC) recently proposed in the literature. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  4. Homer and the cult of the dead in Helladic times

    Directory of Open Access Journals (Sweden)

    Odysseus Tsagarakis

    1980-12-01

    Full Text Available This paper discusses the Homeric bothros (Odyssey X 517 ff. as a possible source of information for the ritual and function of various bothroi (grave pits which are considered to be an important archaeological source. It seems that the bothroi were, by their nature, best suited to a cult of the dead and served as altars. The paper also discusses the possible reasons for the existence of the cult and argues against the view that fear of the dead motivated the cult in Helladic times.

  5. Organ donation from brain-dead and circulatory-dead donors: single-institution experiences.

    Science.gov (United States)

    Kenmochi, T; Nishiyama, S; Hayashi, M; Ito, T; Kato, Y; Hoshinaga, K

    2014-05-01

    Although the number of organ donations is extremely small in Japan, organ donation from brain dead (DBD) donors is increasing since the revised Law for Organ Transplantation was enacted on July 17, 2010. In our institution, organ donations had so far been performed from 247 donors (DCD 242, DBD 5), which is the largest number in Japan. In this study, we analyzed the status of organ donation before and after the enforcement of the revised law. After the enforcement of the revised law, the option of organ donation was shown to the more families of potential donors by the doctors or donor coordinators. However, the final number of donors was almost the same. The frequency of DBD donors of all donors increased (33.3%) as compared to 9.1% before the enforcement of the revised law. Reasons for rejection of donation from donor families were mainly based on the lack of understanding of brain death. To increase organ donation, we should promote social recognition of brain death, having the Organ Donation Card, and discussion of organ donation in each family. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Combinatorics of finite sets

    CERN Document Server

    Anderson, Ian

    2011-01-01

    Coherent treatment provides comprehensive view of basic methods and results of the combinatorial study of finite set systems. The Clements-Lindstrom extension of the Kruskal-Katona theorem to multisets is explored, as is the Greene-Kleitman result concerning k-saturated chain partitions of general partially ordered sets. Connections with Dilworth's theorem, the marriage problem, and probability are also discussed. Each chapter ends with a helpful series of exercises and outline solutions appear at the end. ""An excellent text for a topics course in discrete mathematics."" - Bulletin of the Ame

  7. Optical Finite Element Processor

    Science.gov (United States)

    Casasent, David; Taylor, Bradley K.

    1986-01-01

    A new high-accuracy optical linear algebra processor (OLAP) with many advantageous features is described. It achieves floating point accuracy, handles bipolar data by sign-magnitude representation, performs LU decomposition using only one channel, easily partitions and considers data flow. A new application (finite element (FE) structural analysis) for OLAPs is introduced and the results of a case study presented. Error sources in encoded OLAPs are addressed for the first time. Their modeling and simulation are discussed and quantitative data are presented. Dominant error sources and the effects of composite error sources are analyzed.

  8. BATSE spectroscopy detector calibration

    Science.gov (United States)

    Band, D.; Ford, L.; Matteson, J.; Lestrade, J. P.; Teegarden, B.; Schaefer, B.; Cline, T.; Briggs, M.; Paciesas, W.; Pendleton, G.

    1992-01-01

    We describe the channel-to-energy calibration of the Spectroscopy Detectors of the Burst and Transient Source Experiment (BATSE) on the Compton Gamma Ray Observatory (GRO). These detectors consist of NaI(TI) crystals viewed by photomultiplier tubes whose output in turn is measured by a pulse height analyzer. The calibration of these detectors has been complicated by frequent gain changes and by nonlinearities specific to the BATSE detectors. Nonlinearities in the light output from the NaI crystal and in the pulse height analyzer are shifted relative to each other by changes in the gain of the photomultiplier tube. We present the analytical model which is the basis of our calibration methodology, and outline how the empirical coefficients in this approach were determined. We also describe the complications peculiar to the Spectroscopy Detectors, and how our understanding of the detectors' operation led us to a solution to these problems.

  9. SDC detector foundation requirements

    International Nuclear Information System (INIS)

    Western, J.L.; Butalla, M.W.

    1992-01-01

    The Solenoidal Detector Collaboration (SDC) Detector weighs approximately 32,000 metric tons, and its ability to perform to design specifications is directly related to its internal alignment. The limits of the misalignment tolerance envelope in combination with the detector weight impose a set of tolerance limits of performance directly upon the foundation structure. The foundation must accommodate different detector loading conditions during installation, operation, maintenance, and future enhancements. The foundation must also respond to the loading conditions within a restrictive set of displacement limitations in order to maintain the detector's critical alignment, thereby guaranteeing its operational integrity. This paper will present the results of this study, which has been issued to the Architect Engineer/Construction Manager as user requirements of design. The total structural system performance of the combination of both the detector and its foundation will be discussed

  10. Detectors for Particle Radiation

    Science.gov (United States)

    Kleinknecht, Konrad

    1999-01-01

    This textbook provides a clear, concise and comprehensive review of the physical principles behind the devices used to detect charged particles and gamma rays, and the construction and performance of these many different types of detectors. Detectors for high-energy particles and radiation are used in many areas of science, especially particle physics and nuclear physics experiments, nuclear medicine, cosmic ray measurements, space sciences and geological exploration. This second edition includes all the latest developments in detector technology, including several new chapters covering micro-strip gas chambers, silicion strip detectors and CCDs, scintillating fibers, shower detectors using noble liquid gases, and compensating calorimeters for hadronic showers. This well-illustrated textbook contains examples from the many areas in science in which these detectors are used. It provides both a coursebook for students in physics, and a useful introduction for researchers in other fields.

  11. Extreme Dead Sea drying event during the last interglacial from the ICDP Dead Sea Deep Drill Core

    Science.gov (United States)

    Goldstein, S.; Stein, M.; Ben-Avraham, Z.; Agnon, A.; Ariztegui, D.; Brauer, A.; Haug, G.; Ito, E.; Kitagawa, H.; Torfstein, A.; Yasuda, Y.

    2012-04-01

    The ICDP funded Dead Sea Deep Drilling Project (DSDDP) recovered the longest and most complete paleo-environmental record in the Middle East, drilling holes in a deep and a shallow site extending to ~450 meters. The Dead Sea expands during the glacials and contracts during interglacials, and the sediments are an archive of the evolving climatic conditions. During glacials the sediments comprise intervals of marl (aragonite, gypsum and detritus) and during interglacials they are salts and marls. We estimate that the deep site core spans ~200 kyr (to early MIS 7). A dramatic discovery is a ~40 cm interval of rounded pebbles at ~235 m below the lake floor, the only clean pebbly unit in the entire core. It appears to be a beach layer, near the deepest part of the Dead Sea, lying above ~35 meters of mainly salt. If it is a beach layer, it implies an almost complete dry-down of the paleo-Dead Sea. The pebble layer lies within the last interglacial interval. Our initial attempt to estimate the age of the possible dry down shows an intriguing correlation between the salt-mud stratigraphy of the Dead Sea core and the oxygen isotope record of Soreq Cave, whereby excursions to light oxygen in the speleothems correspond to periods of salt deposition. Through this comparison, we estimate that the dry down occurred during MIS 5e. The occurrence of ~35 meters of mainly salt along with the pebble layer demonstrates a severe dry interval during MIS 5. This observation has implications for the Middle East today, where the Dead Sea level is dropping as all the countries in the area use the runoff. GCM models indicate a more arid future in the region. The core shows that the runoff nearly stopped during a past warm period without human intervention.

  12. Study on Silicon detectors

    International Nuclear Information System (INIS)

    Gervino, G.; Boero, M.; Manfredotti, C.; Icardi, M.; Gabutti, A.; Bagnolatti, E.; Monticone, E.

    1990-01-01

    Prototypes of Silicon microstrip detectors and Silicon large area detectors (3x2 cm 2 ), realized directly by our group, either by ion implantation or by diffusion are presented. The physical detector characteristics and their performances determined by exposing them to different radioactive sources and the results of extensive tests on passivation, where new technological ways have been investigated, are discussed. The calculation of the different terms contributing to the total dark current is reported

  13. Noble Gas Detectors

    CERN Document Server

    Aprile, Elena; Bolozdynya, Alexander I; Doke, Tadayoshi

    2006-01-01

    This book discusses the physical properties of noble fluids, operational principles of detectors based on these media, and the best technical solutions to the design of these detectors. Essential attention is given to detector technology: purification methods and monitoring of purity, information readout methods, electronics, detection of hard ultra-violet light emission, selection of materials, cryogenics etc.The book is mostly addressed to physicists and graduate students involved in the preparation of fundamental next generation experiments, nuclear engineers developing instrumentation

  14. History of infrared detectors

    Science.gov (United States)

    Rogalski, A.

    2012-09-01

    This paper overviews the history of infrared detector materials starting with Herschel's experiment with thermometer on February 11th, 1800. Infrared detectors are in general used to detect, image, and measure patterns of the thermal heat radiation which all objects emit. At the beginning, their development was connected with thermal detectors, such as thermocouples and bolometers, which are still used today and which are generally sensitive to all infrared wavelengths and operate at room temperature. The second kind of detectors, called the photon detectors, was mainly developed during the 20th Century to improve sensitivity and response time. These detectors have been extensively developed since the 1940's. Lead sulphide (PbS) was the first practical IR detector with sensitivity to infrared wavelengths up to ˜3 μm. After World War II infrared detector technology development was and continues to be primarily driven by military applications. Discovery of variable band gap HgCdTe ternary alloy by Lawson and co-workers in 1959 opened a new area in IR detector technology and has provided an unprecedented degree of freedom in infrared detector design. Many of these advances were transferred to IR astronomy from Departments of Defence research. Later on civilian applications of infrared technology are frequently called "dual-use technology applications." One should point out the growing utilisation of IR technologies in the civilian sphere based on the use of new materials and technologies, as well as the noticeable price decrease in these high cost technologies. In the last four decades different types of detectors are combined with electronic readouts to make detector focal plane arrays (FPAs). Development in FPA technology has revolutionized infrared imaging. Progress in integrated circuit design and fabrication techniques has resulted in continued rapid growth in the size and performance of these solid state arrays.

  15. Living with the Dead or Communicating with the dead: media practices of continuing bonds among bereaved parents

    DEFF Research Database (Denmark)

    Sandvik, Kjetil; Christensen, Dorthe Refslund

    in the shape of everyday parental activities such as playing with the child, reading bedtime stories, celebrating birthdays or just bearing the dead child in mind, the purpose of which are to keep the dead child as a present part of the parents’ and family’s continuing life. We argue that these practices...... when getting a memory tattoo. Based on observation studies and qualitative contents analysis performed since 2008 on children’s graves and on online memorial sites (Christensen & Sandvik 2013, 2014a, 2014b, 2015a) and furthermore including interviews with bereaved parents (Christensen & Sandvik...

  16. The solenoidal detector collaboration silicon detector system

    International Nuclear Information System (INIS)

    Ziock, H.J.; Gamble, M.T.; Miller, W.O.; Palounek, A.P.T.; Thompson, T.C.

    1992-01-01

    Silicon tracking systems (STS) will be fundamental components of the tracking systems for both planned major SSC experiments. The STS is physically a small part of the central tracking system and the calorimeter of the detector being proposed by the Solenoidal Detector Collaboration (SDC). Despite its seemingly small size, it occupies a volume of more than 5 meters in length and 1 meter in diameter and is an order of magnitude larger than any silicon detector system previously built. The STS will consist of silicon microstrip detectors and possibly silicon pixel detectors. The other two components are an outer barrel tracker, which will consist of straw tubes or scintillating fibers; and an outer intermediate angle tracker, which will consist of gas microstrips. The components are designed to work as an integrated system. Each componenet has specific strengths, but is individually incapable of providing the overall performance required by the physics goals of the SSC. The large particle fluxes, the short times between beam crossing, the high channel count, and the required very high position measurement accuracy pose challenging problems that must be solved. Furthermore, to avoid degrading the measurements, the solutions must be achieved using only a minimal amount of material. An additional constraint is that only low-Z materials are allowed. If that were not difficlut enough, the solutions must also be affordable

  17. detectors

    International Nuclear Information System (INIS)

    Abolins, M.; Barnett, B.A.; Binnie, D.M.

    1984-01-01

    The 4π Detector Working Group tried to address two major questions: can general 4π detectors be built for the SSC that will be able to study rare processes at center-of-mass energies of 40 TeV and at luminosities of 10 33 cm -2 sec -1 ; what are realistic cost estimates for such detectors? The general conclusions of these studies were that these types of detectors could be built, would be able to do physics under these conditions, and would each cost between 200 and 300 million dollars

  18. ALFA Detector Control System

    CERN Document Server

    Oleiro Seabra, Luis Filipe; The ATLAS collaboration

    2015-01-01

    ALFA (Absolute Luminosity For ATLAS) is one of the sub-detectors of ATLAS (A Toroidal LHC Apparatus). The ALFA system is composed by four stations installed in the LHC tunnel 240 m away from the ATLAS interaction point. Each station has a vacuum and ventilation system, movement control and all the required electronics for signal processing. The Detector Control System (DCS) provides control and monitoring of several components and ensures the safe operation of the detector contributing to good Data Quality. This paper describes the ALFA DCS system including a detector overview, operation aspects and hardware control through a SCADA system, WinCC OA.

  19. ALFA Detector Control System

    CERN Document Server

    Oleiro Seabra, Luis Filipe; The ATLAS collaboration

    2015-01-01

    ALFA (Absolute Luminosity For ATLAS) is one of the sub-detectors of ATLAS/LHC. The ALFA system is composed by two stations installed in the LHC tunnel 240 m away from each side of the ATLAS interaction point. Each station has a vacuum and ventilation system, movement control and all the required electronic for signal processing. The Detector Control System (DCS) provides control and monitoring of several components and ensures the safe operation of the detector contributing to good Data Quality. This paper describes the ALFA DCS system including a detector overview, operation aspects and hardware control through a SCADA system, WinCC OA.

  20. Finiteness of corner vortices

    Science.gov (United States)

    Kalita, Jiten C.; Biswas, Sougata; Panda, Swapnendu

    2018-04-01

    Till date, the sequence of vortices present in the solid corners of steady internal viscous incompressible flows was thought to be infinite. However, the already existing and most recent geometric theories on incompressible viscous flows that express vortical structures in terms of critical points in bounded domains indicate a strong opposition to this notion of infiniteness. In this study, we endeavor to bridge the gap between the two opposing stream of thoughts by diagnosing the assumptions of the existing theorems on such vortices. We provide our own set of proofs for establishing the finiteness of the sequence of corner vortices by making use of the continuum hypothesis and Kolmogorov scale, which guarantee a nonzero scale for the smallest vortex structure possible in incompressible viscous flows. We point out that the notion of infiniteness resulting from discrete self-similarity of the vortex structures is not physically feasible. Making use of some elementary concepts of mathematical analysis and our own construction of diametric disks, we conclude that the sequence of corner vortices is finite.

  1. Ground Motion Prediction Atop Geometrically Complex Sedimentary Basins - The Dead Sea Basin

    Science.gov (United States)

    Shani-Kadmiel, S.; Tsesarsky, M.; Louie, J. N.; Gvirtzman, Z.

    2014-12-01

    The Dead Sea Transform (DST) is the source for some of the largest earthquakes in the eastern Mediterranean. Several deep and structurally complex sedimentary basins are associated with the DST. These basins are up to 10 km deep and typically bounded by active fault zones. The low seismicity of the DST combined with the limited instrumental coverage of the seismic network in the area result in a critical knowledge gap. Therefore, it is necessary to complement the limited instrumental data with synthetic data based on computational modeling, in order to study the effects of earthquake ground motion in these sedimentary basins. We performed a 2D ground-motion analysis in the Dead Sea Basin (DSB) using a finite-difference code. Results indicate a complex pattern of ground motion amplification affected by the geometric features in the basin. To distinguish between the individual contributions of each geometrical feature in the basin, we developed a semiquantitative decomposition approach. This approach enabled us to interpret the DSB results as follows: (1) Ground-motion amplification as a result of resonance occurs basin-wide due to a high impedance contrast at the base of the uppermost layer; (2) Steep faults generate a strong edge-effect that further ampli- fies ground motions; (3) Sub-basins cause geometrical focusing that may significantly amplify ground motions; and (4) Salt diapirs diverge seismic energy and cause a de- crease in ground-motion amplitude. We address the significance of ground motion amplification due to geometrical focusing via an analytical and numerical study. We show that effective geometrical focusing occurs for a narrow set of eccentricities and velocity ratios, where seismic energy is converged to a region of ±0.5 km from surface. This mechanism leads to significant ground motion amplification at the center of the basin, up to a factor of 3; frequencies of the modeled spectrum are amplified up to the corner frequency of the source.

  2. Dead Zones in LX-17 and PBX 9502

    Energy Technology Data Exchange (ETDEWEB)

    Souers, P C; Andreski, H G; Batteux, J; Bratton, B; Cabacungan, C; Cook, III, C F; Fletcher, S; Garza, R; Grimsley, D; Handly, J; Hernandez, A; McMaster, P; Molitoris, J D; Palmer, R; Prindiville, J; Rodriguez, J; Schneberk, D; Wong, B; Vitello, P

    2005-09-06

    Pin and X-ray corner-turning data have been taken on ambient LX-17 and PBX 9052, and the results are listed in tables as an aid to future modeling. The results have been modeled at 4 zones/mm with a reactive flow approach that varies the burn rate as a function of pressure. A single rate format is used to simulate failure and detonation in different pressure regimes. A pressure cut-off must also be reached to initiate the burn. Corner-turning and failure are modeled using an intermediate pressure rate region, and detonation occurs at high pressure. The TATB booster is also modeled using reactive flow, and X-ray tomography is used to partition the ram-pressed hemisphere into five different density regions. The model reasonably fits the bare corner-turning experiment but predicts a smaller dead zone with steel confinement, in contradiction with experiment. The same model also calculates the confined and unconfined cylinder detonation velocities and predicts the failure of the unconfined cylinder at 3.75 mm radius. The PBX 9502 shows a smaller dead zone than LX-17. An old experiment that showed a large apparent dead zone in Comp B was repeated with X-ray transmission and no dead zone was seen. This confirms the idea that a variable burn rate is the key to modeling. The model also produces initiation delays, which are shorter than those found in time-to-detonation.

  3. "The Northern Lights" Investigative Reporting Covers Deadly Decisions.

    Science.gov (United States)

    Srour, George

    2001-01-01

    Presents a story package from the high school newspaper "The Northern Lights," called "Deadly Decisions." Includes an editorial, an eyewitness account, a timeline of the coverage itself, an interview with a local TV reporter, photographs, and a graph of the events the stories covered. (SR)

  4. Eating the dead in Madagascar | Campbell | South African Medical ...

    African Journals Online (AJOL)

    They may be supported in societies under stress or in times of famine, to reflect aggression and antisocial behaviour (in cases where the bodies of enemies killed in battle or people who have harmed the family are eaten), or to honour a dead kinsman. It was, for example, noted in Madagascar during the imperial campaigns ...

  5. [Forensic Analysis of 20 Dead Cases Related to Heroin Abuse].

    Science.gov (United States)

    Huang, W Q; Li, L H; Li, Z; Hong, S J

    2016-08-01

    To perform retrospective analysis on 20 dead cases related to heroin abuse, and to provide references for the forensic assessment of correlative cases. Among 20 dead cases related to heroin abuse, general situation, using method of drug, cause of death and result of forensic examination were analyzed by statistical analysis for summarizing the cause of death and pathologic changes. The dead were mostly young adults, with more male than female. The results of histopathological examinations showed non-specific pathological changes. There were four leading causes of death, including acute poisoning of heroin abuse or leakage (13 cases, 65%), concurrent diseases caused by heroin abuse (3 cases, 15%), inspiratory asphyxia caused by taking heroin (2 cases, 10%), and heroin withdrawal syndrome (2 cases, 10%). The forensic identification on dead related to heroin abuse must base on the comprehensive autopsy, and combine with the qualitative and quantitative analysis of heroin and its metabolites in death and the case information, as well as the scene investigation. Copyright© by the Editorial Department of Journal of Forensic Medicine

  6. Dead Metaphor in Selected Advertisements in Nigerian Dailies ...

    African Journals Online (AJOL)

    Dead metaphors and images are often enlivened and empowered by advertisers to help their commUlzication and to achieve bewitching effects. It is interesting to see words and phrases that may be presumed to have been drained of their linguistic strength being brought back to currency and made to act fast in aiding ...

  7. Theory of precipitation effects on dead cylindrical fuels

    Science.gov (United States)

    Michael A. Fosberg

    1972-01-01

    Numerical and analytical solutions of the Fickian diffusion equation were used to determine the effects of precipitation on dead cylindrical forest fuels. The analytical solution provided a physical framework. The numerical solutions were then used to refine the analytical solution through a similarity argument. The theoretical solutions predicted realistic rates of...

  8. Dead Reckoning Localization Technique for Mobile Wireless Sensor Networks

    OpenAIRE

    Rashid, Haroon; Turuk, Ashok Kumar

    2015-01-01

    Full paper at: http://arxiv.org/pdf/1504.06797.pdfThis paper shows how a mobile node can be localized with less than three beacon nodes. It uses a technique known as dead-reckoning for localization of nodes at specific intervals

  9. Stylistic Variation In Three English Translations Of The Dead Sea ...

    African Journals Online (AJOL)

    Since the discovery of the Dead Sea Scrolls in 1947 different English translations were published. In this article the stylistic variation of three of these translations are analysed. It is suggested that the issue of stylistic variation boils down to linguistically inscribed preference in the choice and construction of discourses in the ...

  10. Piecing Together the Past: The Dead Sea Schools.

    Science.gov (United States)

    Ulrich, Eugene; And Others

    1995-01-01

    Illustrates the astonishing coordination of archaeological and scholarly activities surrounding the Dead Sea Scrolls. First discovered by Bedouin nomads in 1947, the Scrolls consist of a few complete manuscripts and over 80,000 fragments. Discusses the early Christian sect that produced the Scrolls, and provides current perspectives on the…

  11. Literary Genres in Poetic Texts from the Dead Sea Scrolls

    Science.gov (United States)

    Pickut, William Douglas

    2017-01-01

    Among the texts of the Dead Sea Scrolls, there are four literary compositions that bear the superscriptional designations shir and mizmor. These designations correspond directly to superscriptional designations provided many times in both the now-canonical Psalter and the various witnesses to those texts unearthed at Qumran. On its face, this fact…

  12. Comparison of burning characteristics of live and dead chaparral fuels

    Science.gov (United States)

    L. Sun; X. Zhou; S. Mahalingam; D.R. Weise

    2006-01-01

    Wildfire spread in living vegetation, such as chaparral in southern California, often causes significant damage to infrastructure and ecosystems. The effects of physical characteristics of fuels and fuel beds on live fuel burning and whether live fuels differ fundamentally from dead woody fuels in their burning characteristics are not well understood. Toward this end,...

  13. Brought in Dead: An Avoidable Delay in Maternal Deaths.

    Science.gov (United States)

    Kumar, Aruna; Agrawal, Neha

    2016-10-01

    Maternal brought in dead are the patient who dies in the need of adequate medical care. These deaths are often not analyzed sincerely as they are not institutional deaths. Our aim is to find out actual life threatening cause of delay leading to death. Patients brought dead to casualty were seen by the doctors on duty in Department of Obstetrics and Gynaecology,Gandhi Medical College, Bhopal round the clock. Cause of death was analyzed by verbal autopsy of attendants and referral letter from the institute. In this analytical study a complete evaluation of brought deaths from January 2011 to Decmeber 2014 was done. A total of 64 brought in deaths were reported in this 4 year duration. Most common cause of death was postpartum hemorrhage (54.68 %) followed by hypertension (15.62 %) and the most common cause of delay was delay in getting adequate treatment (56.25 %). The brought in dead are the indicator of the three delays in getting health care. Challenges appear to be enormous to be tackled. Timely management proves to be critical in preventing maternal death. Thus it appears that community education about pregnancy and its complications, EmOC training at FRU and strict adherence to referral protocol may help us to reduce the brought dead burden.

  14. Gastric necrosis four years after fundoplication causing a dead foetus

    DEFF Research Database (Denmark)

    Thinggaard, Ebbe; Skovsen, Anders Peter; Kildsig, Jeppe

    2014-01-01

    A 31-year-old pregnant woman was admitted and treated for diabetic ketoacidosis. As the patient deteriorated and the viability of the foetus was uncertain a CT scan was done which showed free fluid and air intraabdominally. Surgery was performed. A dead foetus was delivered and a 2 × 5 cm necrotic...

  15. Dead wood in European beech (Fagus sylvatica) forest reserves

    NARCIS (Netherlands)

    Christensen, M.; Hahn, K.; Mountford, E.P.; Ódor, P.; Standovár, T.; Rozenbergar, D.; Diaci, J.; Wijdeven, S.M.J.; Meyer, P.; Winter, S.; Vrska, T.

    2005-01-01

    Data were analysed on the volume of dead wood in 86 beech forest reserves, covering most of the range of European beech forests. The mean volume was 130 m3/ha and the variation among reserves was high, ranging from almost nil to 550 m3/ha. The volume depended significantly on forest type, age since

  16. Bipolar disorder, childhood bereavement, and the return of the dead ...

    African Journals Online (AJOL)

    Upon its head, with red extended mouth and solitary eye of fire, sat the hideous beast whose craft had seduced me into murder ...' From 'The Black Cat', written c. age 35 (Poe 1975:230). Keywords: Edgar Allan Poe; bipolar disorder, childhood bereavement, and the return of the dead; literary criticism; American poetry; ...

  17. Hypoalbuminaemia in brain-dead donors for liver transplantation

    African Journals Online (AJOL)

    Nicky

    Liver transplantation has become established as the treat- ment of choice for most patients with end-stage liver disease and is performed on a routine basis in most major centres throughout the world. The majority of donors for liver trans- plantation are brain-dead cadaver donors following either a severe head injury or a ...

  18. Remembering Important People On The Day Of The Dead

    Science.gov (United States)

    Curriculum Review, 2005

    2005-01-01

    This article describes a project that can help students learn more about historic figures-or remember lost loved ones--with this Day of the Dead project from Frida Kahlo and Diego Rivera. The purpose is to remember the wonderful things the person did, and to celebrate his or her life. Directions for construction, as well as a suggested list of…

  19. The prevalence and challenges of abandoned dead neonates in an ...

    African Journals Online (AJOL)

    %) cases, as depicted in Table 1. The parents/caregivers of 618 (56.5%) dead babies were illiterate and of a low socioeconomic class. Financial constraint experienced by the parents/caregivers of 309. (28.3%) babies, repulsion toward obvious ...

  20. Preparedness of Response to Deadly Outbreaks: Lessons Learnt ...

    African Journals Online (AJOL)

    Some of the lessons learnt included improved work efficiency, built staff resilience to work long hours under stressful conditions and consciously managing aseptic techniques. Conclusion: Exposure to some adverse conditions such as managing work operations in the midst of a deadly outbreak such as Ebola may have a ...

  1. Antimicrobial properties of Dead Sea black mineral mud.

    Science.gov (United States)

    Ma'or, Zeev; Henis, Yigal; Alon, Yaacov; Orlov, Elina; Sørensen, Ketil B; Oren, Aharon

    2006-05-01

    The unique, black, hypersaline mud mined from the Dead Sea shores is extensively used in mud packs, masks, and topical body and facial treatments in spas surrounding the lake, and in cosmetic preparations marketed worldwide, but little is known about its antimicrobiological properties. We performed detailed microbial and chemical analysis of Dead Sea mineral mud compounded in dermatological and cosmetic preparations. Using conventional bacteriological media (with or without salt augmentation), we found surprisingly low numbers of colony-forming microorganisms in the mud. The highest counts (up to 20,000 colonies per gram, mostly consisting of endospore-forming bacteria) were obtained on sheep blood agar. Test microorganisms (i.e. Escherichia coli, Staphylococcus aureus, Propionibacterium acnes, Candida albicans) rapidly lost their viability when added to the mud. Zones of growth inhibition were observed around discs of Dead Sea mud placed on agar plates inoculated with Candida or with Propionibacterium, but not with Staphylococcus or Escherichia. The effect was also found when the mud was sterilized by gamma irradiation. Using (35)S-labeled sulfate as a tracer, bacterial dissimilatory sulfate reduction could be demonstrated at a low rate (0.13 +/- 0.03 nmol/cm(3).d). The antibacterial properties of Dead Sea mud are probably owing to chemical and/or physical phenomena. Possible modes of antimicrobial action of the mud in relation to its therapeutic properties are discussed.

  2. Necrotizing fasciitis: A deadly disease | Cree | East and Central ...

    African Journals Online (AJOL)

    Background: Knowledge of the diagnosis, cause, course and required treatment of this deadly disease among physicians and surgeons around the world is limited. Methods: A study was undertaken at University Teaching Hospital (UTH), Lusaka Zambia to review the incidence, associated pathology, management given, ...

  3. Book Review Lifeblood: How to Change the World, One Dead ...

    African Journals Online (AJOL)

    Book Review Lifeblood: How to Change the World, One Dead Mosquito at a Time By Alex Perry (2011). Melissa Raemaekers. Abstract. Pp xiv + 219. R210. Picador Africa, Pan Macmillan, South Africa. 2011. ISBN 978-1-77010-146-3. February 2012, Vol. 102, No. 2 SAMJ. Full Text: EMAIL FREE FULL TEXT EMAIL FREE ...

  4. Assessment of biofuel potential of dead neem leaves ( Azadirachta ...

    African Journals Online (AJOL)

    Dead leaves of neem trees in the Sahelian urban zone are among the wastes that are underutilized, since it is either buried or burnt, and thus, contribute to increased environmental pollution. Unfortunately, the lack of information on the biomass and energy potentials of these wastes empedes any initiative for its industrial ...

  5. Cowboys and zombies: destabilizing patriarchal discourse in The Walking Dead

    NARCIS (Netherlands)

    Hassler-Forest, D.

    2012-01-01

    The serialized comic book The Walking Dead, written by Robert Kirkman and drawn by Charlie Adlard, has been published by Image Comics from October 2003, and is still being released in monthly instalments as of this writing. It has won numerous awards, including the prestigious Eisner Award for Best

  6. Manufacture and study of very high purity P-type Silicium nuclear detectors

    International Nuclear Information System (INIS)

    Rahab, H.

    1986-04-01

    The purpose of this study is the realization of P-type silicon detectors of very high resistivity. The well-known process of Li ion drifting compensates for the acceptor impurities in the P-type Si of low resistivity used for the manufacturing of Si(Li) detector becomes useless. The last (Si(Li)) present a problem of utilization and storage at low temperature. The obtainment of silicon monocrystals having a resistivity reaching 130.000 Ω cm allows to use them directly in detection of nuclear radiations without compensating them with lithium. In order to familiarise with the techniques of detectors manufacturing in general, we have realized Si(Li) detectors. Afterwards we began the research itself by a study and realization of a great number and different types of detectors from P-type silicon having a resistivity varying from 40.000 to 100.000 Ω cm. The surface barrier detectors (SBD) elaborated after an investigation of different chemical treatments present electrical characteristics and dead layer better than Si(Li) detectors at time t=0. However they present a stability problem. A more profound investigation has to be undertaken in the future to improve the contacts and the surface treatment which are the principal causes of this instability. PIN type detectors made by implantation technique gave way to very promising results in nuclear detection. The resolutions which are obtained on the peaks of energy above 20 KeV, are much comparable to those obtained with the Si(Li) detectors. (For example, we have obtained a resolution of 540 eV on the peak of 59,6 KeV for 241 Am with a high purity Si(p) detector implanted B-AS). However to be used in the low energies field (20 KeV) it is necessary to diminish the dead layer. For this purpose, and implantation at lower energies than those used must be envisaged

  7. Thermodynamic and fluid mechanic analysis of rapid pressurization in a dead-end tube

    Science.gov (United States)

    Leslie, Ian H.

    1989-01-01

    Three models have been applied to very rapid compression of oxygen in a dead-ended tube. Pressures as high as 41 MPa (6000 psi) leading to peak temperatures of 1400 K are predicted. These temperatures are well in excess of the autoignition temperature (750 K) of teflon, a frequently used material for lining hoses employed in oxygen service. These findings are in accord with experiments that have resulted in ignition and combustion of the teflon, leading to the combustion of the stainless steel braiding and catastrophic failure. The system analyzed was representative of a capped off-high-pressure oxygen line, which could be part of a larger system. Pressurization of the larger system would lead to compression in the dead-end line, and possible ignition of the teflon liner. The model consists of a large plenum containing oxygen at the desired pressure (500 to 6000 psi). The plenum is connected via a fast acting valve to a stainless steel tube 2 cm inside diameter. Opening times are on the order of 15 ms. Downstream of the valve is an orifice sized to increase filling times to around 100 ms. The total length from the valve to the dead-end is 150 cm. The distance from the valve to the orifice is 95 cm. The models describe the fluid mechanics and thermodynamics of the flow, and do not include any combustion phenomena. A purely thermodynamic model assumes filling to be complete upstream of the orifice before any gas passes through the orifice. This simplification is reasonable based on experiment and computer modeling. Results show that peak temperatures as high as 4800 K can result from recompression of the gas after expanding through the orifice. An approximate transient model without an orifice was developed assuming an isentropic compression process. An analytical solution was obtained. Results indicated that fill times can be considerably shorter than valve opening times. The third model was a finite difference, 1-D transient compressible flow model. Results from

  8. The Determining Finite Automata Process

    Directory of Open Access Journals (Sweden)

    M. S. Vinogradova

    2017-01-01

    Full Text Available The theory of formal languages widely uses finite state automata both in implementation of automata-based approach to programming, and in synthesis of logical control algorithms.To ensure unambiguous operation of the algorithms, the synthesized finite state automata must be deterministic. Within the approach to the synthesis of the mobile robot controls, for example, based on the theory of formal languages, there are problems concerning the construction of various finite automata, but such finite automata, as a rule, will not be deterministic. The algorithm of determinization can be applied to the finite automata, as specified, in various ways. The basic ideas of the algorithm of determinization can be most simply explained using the representations of a finite automaton in the form of a weighted directed graph.The paper deals with finite automata represented as weighted directed graphs, and discusses in detail the procedure for determining the finite automata represented in this way. Gives a detailed description of the algorithm for determining finite automata. A large number of examples illustrate a capability of the determinization algorithm.

  9. Gigahertz-gated InGaAs/InP single-photon detector with detection efficiency exceeding 55% at 1550 nm

    International Nuclear Information System (INIS)

    Comandar, L. C.; Fröhlich, B.; Dynes, J. F.; Sharpe, A. W.; Lucamarini, M.; Yuan, Z. L.; Shields, A. J.; Penty, R. V.

    2015-01-01

    We report on a gated single-photon detector based on InGaAs/InP avalanche photodiodes (APDs) with a single-photon detection efficiency exceeding 55% at 1550 nm. Our detector is gated at 1 GHz and employs the self-differencing technique for gate transient suppression. It can operate nearly dead time free, except for the one clock cycle dead time intrinsic to self-differencing, and we demonstrate a count rate of 500 Mcps. We present a careful analysis of the optimal driving conditions of the APD measured with a dead time free detector characterization setup. It is found that a shortened gate width of 360 ps together with an increased driving signal amplitude and operation at higher temperatures leads to improved performance of the detector. We achieve an afterpulse probability of 7% at 50% detection efficiency with dead time free measurement and a record efficiency for InGaAs/InP APDs of 55% at an afterpulse probability of only 10.2% with a moderate dead time of 10 ns

  10. ALICE Silicon Strip Detector

    CERN Multimedia

    Nooren, G

    2013-01-01

    The Silicon Strip Detector (SSD) constitutes the two outermost layers of the Inner Tracking System (ITS) of the ALICE Experiment. The SSD plays a crucial role in the tracking of the particles produced in the collisions connecting the tracks from the external detectors (Time Projection Chamber) to the ITS. The SSD also contributes to the particle identification through the measurement of their energy loss.

  11. Performance of GLD detector

    Indian Academy of Sciences (India)

    In order to achieve better jet energy resolution, the so-called particle flow algorithm (PFA) will be employed and there is a general consensus that PFA derives overall ILC detector design. Four detector concepts for the ILC .... However, the world-wide consensus of the performance goal for jet energy resolution is 30%/. √.

  12. Future particle detector systems

    International Nuclear Information System (INIS)

    Clark, Allan G.

    2000-01-01

    Starting with a short summary of the major new experimental physics programs, we attempt to motivate the reasons why existing general-purpose detectors at Hadron Colliders are what they are, why they are being upgraded, and why new facilities are being constructed. The CDF and ATLAS detectors are used to illustrate these motivations. Selected physics results from the CDF experiment provide evidence for limitations on the detector performance, and new physics opportunities motivate both machine and detector upgrades. This is discussed with emphasis on the improved physics reach of the CDF experiment at the Fermilab Tevatron (√(s)=2 TeV). From 2005, the Large Hadron Collider (LHC) at CERN will become operational at a collision energy of √(s)=14 TeV, seven times larger than at the Tevatron Collider. To exploit the physics capability of the LHC, several large detectors are being constructed. The detectors are significantly more complex than those at the Tevatron Collider because of physics and operational constraints. The detector design and technology of the aspects of the large general-purpose detector ATLAS is described

  13. Pixel detector readout chip

    CERN Multimedia

    1991-01-01

    Close-up of a pixel detector readout chip. The photograph shows an aera of 1 mm x 2 mm containing 12 separate readout channels. The entire chip contains 1000 readout channels (around 80 000 transistors) covering a sensitive area of 8 mm x 5 mm. The chip has been mounted on a silicon detector to detect high energy particles.

  14. The LDC detector concept

    Indian Academy of Sciences (India)

    Abstract. In preparation of the experimental program at the international linear collider (ILC), the large detector concept (LDC) is being developed. The main points of the LDC are a large volume gaseous tracking system, combined with high precision vertex detector and an extremely granular calorimeter. The main design ...

  15. The TESLA Detector

    OpenAIRE

    Moenig, Klaus

    2001-01-01

    For the superconducting linear collider TESLA a multi purpose detector has been designed. This detector is optimised for the important physics processes expected at a next generation linear collider up to around 1 TeV and is designed for the specific environment of a superconducting collider.

  16. CHERENKOV RADIATION DETECTOR

    African Journals Online (AJOL)

    ES Obe

    1981-03-01

    Mar 1, 1981 ... Most of Radiation detectors based on the Cherenkov Effect are essentially very bulky and expensive for schools and colleges. An inexpensive yet very compact radiation detector is designed, built and tested. It is used to measure the Cherenkov angles for natural radioactivity from sources as. Cs137.

  17. CMS Detector Posters

    CERN Multimedia

    2016-01-01

    CMS Detector posters (produced in 2000): CMS installation CMS collaboration From the Big Bang to Stars LHC Magnetic Field Magnet System Trackering System Tracker Electronics Calorimetry Eletromagnetic Calorimeter Hadronic Calorimeter Muon System Muon Detectors Trigger and data aquisition (DAQ) ECAL posters (produced in 2010, FR & EN): CMS ECAL CMS ECAL-Supermodule cooling and mechatronics CMS ECAL-Supermodule assembly

  18. Detector Systems at CLIC

    CERN Document Server

    Simon, Frank

    2011-01-01

    The Compact Linear Collider CLIC is designed to deliver e+e- collisions at a center of mass energy of up to 3 TeV. The detector systems at this collider have to provide highly efficient tracking and excellent jet energy resolution and hermeticity for multi-TeV final states with multiple jets and leptons. In addition, the detector systems have to be capable of distinguishing physics events from large beam-induced background at a crossing frequency of 2 GHz. Like for the detector concepts at the ILC, CLIC detectors are based on event reconstruction using particle flow algorithms. The two detector concepts for the ILC, ILD and SID, were adapted for CLIC using calorimeters with dense absorbers limiting leakage through increased compactness, as well as modified forward and vertex detector geometries and precise time stamping to cope with increased background levels. The overall detector concepts for CLIC are presented, with particular emphasis on the main detector and engineering challenges, such as: the ultra-thi...

  19. Drift chamber detectors

    International Nuclear Information System (INIS)

    Duran, I.; Martinez Laso, L.

    1989-01-01

    A review of High Energy Physics detectors based on drift chambers is presented. The ionization, drift diffusion, multiplication and detection principles are described. Most common drift media are analysied, and a classification of the detectors according to its geometry is done. Finally the standard read-out methods are displayed and the limits of the spatial resolution are discussed. (Author)

  20. Drift Chambers detectors

    International Nuclear Information System (INIS)

    Duran, I.; Martinez laso, L.

    1989-01-01

    We present here a review of High Energy Physics detectors based on drift chambers. The ionization, drift diffusion, multiplication and detection principles are described. Most common drift media are analysed, and a classification of the detectors according to its geometry is done. Finally the standard read-out methods are displayed and the limits of the spatial resolution are discussed. (Author) 115 refs

  1. ALICE Photon Multiplicity Detector

    CERN Multimedia

    Nayak, T

    2013-01-01

    Photon Multiplicity Detector (PMD) measures the multiplicity and spatial distribution of photons in the forward region of ALICE on a event-by-event basis. PMD is a pre-shower detector having fine granularity and full azimuthal coverage in the pseudo-rapidity region 2.3 < η < 3.9.

  2. Stanford's big new detector

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    A detector constructed for the Standford Linear Collider is described. It consists of a central drift chamber in the field of a surrounding superconducting solenoid. Furthermore included are a Cherenkov ring imaging detector for particle identification and a liquid argon calorimeter. (HSI).

  3. Developments on RICH detectors

    International Nuclear Information System (INIS)

    Besson, P.; Bourgeois, P.

    1996-01-01

    The RICH (ring imaging Cherenkov) detector which is dedicated to Cherenkov radiation detection is described. An improvement made by replacing photo sensible vapor with solid photocathode is studied. A RICH detector prototype with a CsI photocathode has been built in Saclay and used with Saturne. The first results are presented. (A.C.)

  4. Statistical finite element analysis.

    Science.gov (United States)

    Khalaji, Iman; Rahemifar, Kaamran; Samani, Abbas

    2008-01-01

    A novel technique is introduced for tissue deformation and stress analysis. Compared to the conventional Finite Element method, this technique is orders of magnitude faster and yet still very accurate. The proposed technique uses preprocessed data obtained from FE analyses of a number of similar objects in a Statistical Shape Model framework as described below. This technique takes advantage of the fact that the body organs have limited variability, especially in terms of their geometry. As such, it is well suited for calculating tissue displacements of body organs. The proposed technique can be applied in many biomedical applications such as image guided surgery, or virtual reality environment development where tissue behavior is simulated for training purposes.

  5. Extreme drying event in the Dead Sea basin during MIS5 from the ICDP Dead Sea Deep Drill Core

    Science.gov (United States)

    Goldstein, S. L.; Stein, M.; Ben-Avraham, Z.; Agnon, A.; Ariztegui, D.; Brauer, A.; Haug, G. H.; Ito, E.; Kitagawa, H.; Torfstein, A.; Yasuda, Y.; The Icdp-Dsddp Scientific Party

    2011-12-01

    The ICDP funded Dead Sea Deep Drilling Project (DSDDP) recovered the longest and most complete paleo-environmental record in the Middle East, drilling holes of ~450 and ~350 meters in length in deep (~300 m below the lake level) and shallow sites (~3 mbll) respectively. The Dead Sea expands during the glacials and contracts during interglacials, and the sediments comprise a geological archive of the evolving environmental conditions (e.g. rains, floods, dust-storms, droughts). Dead Sea sediments include inorganic aragonite, allowing for dating by U-series (e.g. Haase-Schramm et al. GCA 2004). The deep site cores were opened and described in June 2011. The cores are composed mainly of alternating intervals of marl (aragonite, gypsum and detritus) during glacials, and salts and marls during interglacials. From this stratigraphy we estimate that the deep site core spans ~200 kyr (to the boundary of MIS 6 and 7). A dramatic discovery is a ~40 cm thick interval of partly rounded pebbles at ~235 m below the lake floor. This is the only clean pebbly unit in the entire core. It appears to be a beach layer, near the deepest part of the Dead Sea, lying above ~35 meters of mainly salt. If it is a beach layer, it implies an almost complete dry-down of the paleo-Dead Sea. The pebble layer lies within the last interglacial interval. Our initial attempt to more precisely estimate the age of the possible dry down shows an intriguing correlation between the salt-mud stratigraphy of the Dead Sea core and the oxygen isotope record of Soreq Cave, whereby excursions to light oxygen in the speleothems correspond to periods of salt deposition. Through this comparison, we estimate that the possible dry down occurred during MIS 5e. The occurrence of ~35 meters of mainly salt along with the pebble layer demonstrates a severe dry interval during MIS 5. This observation has implications for the Middle East today, where the Dead Sea level is dropping as all the countries in the area use the

  6. Nanomechanical resonance detector

    Science.gov (United States)

    Grossman, Jeffrey C; Zettl, Alexander K

    2013-10-29

    An embodiment of a nanomechanical frequency detector includes a support structure and a plurality of elongated nanostructures coupled to the support structure. Each of the elongated nanostructures has a particular resonant frequency. The plurality of elongated nanostructures has a range of resonant frequencies. An embodiment of a method of identifying an object includes introducing the object to the nanomechanical resonance detector. A resonant response by at least one of the elongated nanostructures of the nanomechanical resonance detector indicates a vibrational mode of the object. An embodiment of a method of identifying a molecular species of the present invention includes introducing the molecular species to the nanomechanical resonance detector. A resonant response by at least one of the elongated nanostructures of the nanomechanical resonance detector indicates a vibrational mode of the molecular species.

  7. Advanced far infrared detectors

    International Nuclear Information System (INIS)

    Haller, E.E.

    1993-05-01

    Recent advances in photoconductive and bolometric semiconductor detectors for wavelength 1 mm > λ > 50 μm are reviewed. Progress in detector performance in this photon energy range has been stimulated by new and stringent requirements for ground based, high altitude and space-borne telescopes for astronomical and astrophysical observations. The paper consists of chapters dealing with the various types of detectors: Be and Ga doped Ge photoconductors, stressed Ge:Ga devices and neutron transmutation doped Ge thermistors. Advances in the understanding of basic detector physics and the introduction of modern semiconductor device technology have led to predictable and reliable fabrication techniques. Integration of detectors into functional arrays has become feasible and is vigorously pursued by groups worldwide

  8. Detector R&D

    CERN Document Server

    Behnke, T

    2004-01-01

    The next big project in high energy physics should be a high energy e /sup +/e/sup -/ linear collider, operating at energies up to around 1 TeV. A vigorous R&D program has started to prepare the grounds for a detector at such a machine. The amounts of precision data expected at this machine make a novel approach to the reconstruction of events necessary; the particle flow ansatz. This in turn influences significantly the design of a detector for such an experiment. Apart from work ongoing for the linear collider detector, preparations are under way for an update of the LHC. This requires extremely radiation hard detectors. In this paper the state of the different detector development projects is reviewed. (21 refs).

  9. Design of a highly segmented Endcap at a CLIC detector

    CERN Document Server

    Gerwig, H; Siegrist, N

    2010-01-01

    This technical note describes a possible design for a highly segmented end-cap at a CLIC detector with a strong magnetic field up to 5 Tesla. Reinforcement is horizontal in order to allow an insertion of the muon chambers from the side. Construction issues, assembly questions as well as muon chamber access and support questions have been studied. A FEA analysis to optimize dead space for physics and checking the weakening effect of alignment channels through the end-cap have been performed.

  10. The Solenoidal Detector Collaboration silicon detector system

    International Nuclear Information System (INIS)

    Ziock, H.J.; Gamble, M.T.; Miller, W.O.; Palounek, A.P.T.; Thompson, T.C.

    1992-01-01

    Silicon tracking systems will be fundamental components of the tracking systems for both planned major SSC experiments. Despite its seemingly small size, it occupies a volume of more than 5 meters in length and 1 meter in diameter and is an order of magnitude larger than any silicon detector system previously built. This report discusses its design and operation

  11. Performance of the CMS Phase 1 Pixel Detector

    CERN Document Server

    Akgun, Bora

    2018-01-01

    It is anticipated that the LHC accelerator will reach and exceed the luminosity of L = 2$\\times$10$^{34}$cm$^{-2}$s$^{-1}$ during the LHC Run 2 period until 2023. At this higher luminosity and increased hit occupancies the CMS phase-0 pixel detector would have been subjected to severe dead time and inefficiencies introduced by limited buffers in the analog read-out chip and effects of radiation damage in the sensors. Therefore a new pixel detector has been built and replaced the phase-0 detector in the 2016/17 LHC extended year-end technical stop. The CMS phase-1 pixel detector features four central barrel layers and three end-cap disks in forward and backward direction for robust tracking performance, and a significantly reduced overall material budget including new cooling and powering schemes. The design of the new front-end readout chip comprises larger data buffers, an increased transmission bandwidth, and low-threshold comparators. These improvements allow the new pixel detector to sustain and improve t...

  12. Multi detector input and function generator for polarized neutron experiments

    International Nuclear Information System (INIS)

    De Blois, J.; Beunes, A.J.H.; Ende, P. v.d.; Osterholt, E.A.; Rekveldt, M.T.; Schipper, M.N.; Velthuis, S.G.E. te

    1998-01-01

    In this paper a VME module is described for static or stroboscopic measurements with a neutron scattering instrument, consisting essentially of a series of up to 64 3 He neutron detectors around a sample environment. Each detector is provided with an amplifier and a discriminator to separate the neutrons from noise. To reduce the wiring, the discriminator outputs are connected to the module by coding boxes. Two 16-inputs to one-output coding boxes generate serial output codes on a fiber optic connection. This basically fast connection reduces the dead time introduced by the coding, and the influence of environmental noise. With stroboscopic measurements a periodic function is used to affect the sample surrounded by a field coil. Each detected neutron is labeled with a data label containing the detector number and the time of detection with respect to a time reference. The data time base can be programmed on a linear or a nonlinear scale. An external source or an attribute of the periodic function may generate the time reference pulse. A 12-bit DAC connected to the output of an 8 K, 16-bits memory, where the pattern of the current has been stored before, generates the function. The function memory is scanned by the programmable function time base. Attributes are set by the four remaining bits of the memory. One separate detector input connects a monitor detector in the neutron beam with a 32-bit counter/timer that provides measuring on a preset count, preset time or preset frame. (orig.)

  13. 76 FR 63341 - Culturally Significant Objects Imported for Exhibition Determinations: “The Dead Sea Scrolls...

    Science.gov (United States)

    2011-10-12

    ... for Exhibition Determinations: ``The Dead Sea Scrolls: Life and Faith in Biblical Times'' SUMMARY... objects to be included in the exhibition ``The Dead Sea Scrolls: Life and Faith in Biblical Times...

  14. Analysis of archaeal communities in Gulf of Mexico dead zone sediments.

    Science.gov (United States)

    Sediments may contribute significantly to Louisiana continental shelf “dead zone” hypoxia but limited information hinders comparison of sediment biogeochemistry between norm-oxic and hypoxic seasons. Dead zone sediment cores collected during hypoxia (September 2006) had higher l...

  15. Smoking Out a Deadly Threat: Tobacco Use in the LGBT Community

    Science.gov (United States)

    ... Out a Deadly Threat: Tobacco Use in the LGBT Community Disparities in Lung Health Series "Smoking Out a Deadly Threat: Tobacco Use in the LGBT Community" is part of the American Lung Association's ...

  16. Study of charge Transport in Silicon Detectors Non-Irradiated and Irradiated

    CERN Document Server

    Leroy, C; Casse, G L; Glaser, M; Grigoriev, E; Lemeilleur, F

    1998-01-01

    The electrical characteristics of silicon detectors (standard planar float zone and MESA detectors) as a function of the particle fluence can be extracted by the application of a model describing the transport of charge carriers generated in the detectors by ionizing particles. The current pulse response induced by $\\alpha$ and $\\beta$ particles in non-irradiated detectors and detectors irradiated up to fluences $\\Phi \\approx 3 \\cdot 10^{14}$ particles/cm$^2$ is reproduced via this model: i) by adding a small n-type region 15 $\\mu$m deep on the $p^+$ side for the detectors at fluences beyond the n to p-type inversion and ii) for the MESA detectors, by considering one additional dead layer of 14 $\\mu$m (observed experimentally) on each side of the detector, and introducing a second (delayed) component to the current pulse response. For both types of detectors, the model gives mobilities decreasing linearily up to fluences of about $5 \\cdot 10^{13}$ particles/cm$^2$ and converging, beyond, to saturation values ...

  17. LHCb: FPGA-based, radiation-tolerant on-detector electronics for the upgrade of the LHCb Outer Tracker Detector

    CERN Multimedia

    Vink, W

    2013-01-01

    The LHCb experiment studies B-decays at the LHC. The Outer Tracker straw tubes detects charged decay particles. The on-detector electronics will be upgraded to be able to digitize and transmit drift-times at every LHC crossing without the need for a hardware trigger. FPGAs have been preferred to application-specific integrated circuits to implement dead-time free TDCs, able to transmit data volumes of up to 36 Gbits/s per readout unit, including the possibility of performing zero suppression. Extensive irradiation tests have been carried out to validate the usage of field-programmable devices in the hostile environment of the LHCb tracking system.

  18. Axial anomaly at finite temperature

    International Nuclear Information System (INIS)

    Chaturvedi, S.; Gupte, Neelima; Srinivasan, V.

    1985-01-01

    The Jackiw-Bardeen-Adler anomaly for QED 4 and QED 2 are calculated at finite temperature. It is found that the anomaly is independent of temperature. Ishikawa's method [1984, Phys. Rev. Lett. vol. 53 1615] for calculating the quantised Hall effect is extended to finite temperature. (author)

  19. Solution of Finite Element Equations

    DEFF Research Database (Denmark)

    Krenk, Steen

    An important step in solving any problem by the finite element method is the solution of the global equations. Numerical solution of linear equations is a subject covered in most courses in numerical analysis. However, the equations encountered in most finite element applications have some special...... features that justify the development of specialized solution algorithms....

  20. Finite strain discrete dislocation plasticity

    NARCIS (Netherlands)

    Deshpande, VS; Needleman, A; Van der Giessen, E

    2003-01-01

    A framework for carrying out finite deformation discrete dislocation plasticity calculations is presented. The discrete dislocations are presumed to be adequately represented by the singular linear elastic fields so that the large deformations near dislocation cores are not modeled. The finite

  1. Massively Parallel Finite Element Programming

    KAUST Repository

    Heister, Timo

    2010-01-01

    Today\\'s large finite element simulations require parallel algorithms to scale on clusters with thousands or tens of thousands of processor cores. We present data structures and algorithms to take advantage of the power of high performance computers in generic finite element codes. Existing generic finite element libraries often restrict the parallelization to parallel linear algebra routines. This is a limiting factor when solving on more than a few hundreds of cores. We describe routines for distributed storage of all major components coupled with efficient, scalable algorithms. We give an overview of our effort to enable the modern and generic finite element library deal.II to take advantage of the power of large clusters. In particular, we describe the construction of a distributed mesh and develop algorithms to fully parallelize the finite element calculation. Numerical results demonstrate good scalability. © 2010 Springer-Verlag.

  2. The HERMES recoil detector

    Energy Technology Data Exchange (ETDEWEB)

    Airapetian, A. [Giessen Univ. (Germany). Physikalisches Inst.; Michigan Univ., Ann Arbor, MI (United States). Randall Laboratory of Physics; Aschenauer, E.C. [DESY, Zeuthen (Germany); Belostotski, S. [B.P. Konstantinov Petersburg Nuclear Physics Insitute, Gatchina (Russian Federation)] [and others; Collaboration: HERMES Recoil Detector Group

    2013-02-15

    For the final running period of HERA, a recoil detector was installed at the HERMES experiment to improve measurements of hard exclusive processes in charged-lepton nucleon scattering. Here, deeply virtual Compton scattering is of particular interest as this process provides constraints on generalised parton distributions that give access to the total angular momenta of quarks within the nucleon. The HERMES recoil detector was designed to improve the selection of exclusive events by a direct measurement of the four-momentum of the recoiling particle. It consisted of three components: two layers of double-sided silicon strip sensors inside the HERA beam vacuum, a two-barrel scintillating fibre tracker, and a photon detector. All sub-detectors were located inside a solenoidal magnetic field with an integrated field strength of 1Tm. The recoil detector was installed in late 2005. After the commissioning of all components was finished in September 2006, it operated stably until the end of data taking at HERA end of June 2007. The present paper gives a brief overview of the physics processes of interest and the general detector design. The recoil detector components, their calibration, the momentum reconstruction of charged particles, and the event selection are described in detail. The paper closes with a summary of the performance of the detection system.

  3. The HERMES recoil detector

    International Nuclear Information System (INIS)

    Airapetian, A.; Belostotski, S.

    2013-02-01

    For the final running period of HERA, a recoil detector was installed at the HERMES experiment to improve measurements of hard exclusive processes in charged-lepton nucleon scattering. Here, deeply virtual Compton scattering is of particular interest as this process provides constraints on generalised parton distributions that give access to the total angular momenta of quarks within the nucleon. The HERMES recoil detector was designed to improve the selection of exclusive events by a direct measurement of the four-momentum of the recoiling particle. It consisted of three components: two layers of double-sided silicon strip sensors inside the HERA beam vacuum, a two-barrel scintillating fibre tracker, and a photon detector. All sub-detectors were located inside a solenoidal magnetic field with an integrated field strength of 1Tm. The recoil detector was installed in late 2005. After the commissioning of all components was finished in September 2006, it operated stably until the end of data taking at HERA end of June 2007. The present paper gives a brief overview of the physics processes of interest and the general detector design. The recoil detector components, their calibration, the momentum reconstruction of charged particles, and the event selection are described in detail. The paper closes with a summary of the performance of the detection system.

  4. Smile detectors correlation

    Science.gov (United States)

    Yuksel, Kivanc; Chang, Xin; Skarbek, Władysław

    2017-08-01

    The novel smile recognition algorithm is presented based on extraction of 68 facial salient points (fp68) using the ensemble of regression trees. The smile detector exploits the Support Vector Machine linear model. It is trained with few hundreds exemplar images by SVM algorithm working in 136 dimensional space. It is shown by the strict statistical data analysis that such geometric detector strongly depends on the geometry of mouth opening area, measured by triangulation of outer lip contour. To this goal two Bayesian detectors were developed and compared with SVM detector. The first uses the mouth area in 2D image, while the second refers to the mouth area in 3D animated face model. The 3D modeling is based on Candide-3 model and it is performed in real time along with three smile detectors and statistics estimators. The mouth area/Bayesian detectors exhibit high correlation with fp68/SVM detector in a range [0:8; 1:0], depending mainly on light conditions and individual features with advantage of 3D technique, especially in hard light conditions.

  5. ATLAS Detector Interface Group

    CERN Multimedia

    Mapelli, L

    Originally organised as a sub-system in the DAQ/EF-1 Prototype Project, the Detector Interface Group (DIG) was an information exchange channel between the Detector systems and the Data Acquisition to provide critical detector information for prototype design and detector integration. After the reorganisation of the Trigger/DAQ Project and of Technical Coordination, the necessity to provide an adequate context for integration of detectors with the Trigger and DAQ lead to organisation of the DIG as one of the activities of Technical Coordination. Such an organisation emphasises the ATLAS wide coordination of the Trigger and DAQ exploitation aspects, which go beyond the domain of the Trigger/DAQ project itself. As part of Technical Coordination, the DIG provides the natural environment for the common work of Trigger/DAQ and detector experts. A DIG forum for a wide discussion of all the detector and Trigger/DAQ integration issues. A more restricted DIG group for the practical organisation and implementation o...

  6. Profile detectors of GANIL

    International Nuclear Information System (INIS)

    Tribouillard, C.

    1997-01-01

    In the design phase of GANIL, which started in 1977, one of the priorities of the project management was equipping the beam lines with a fast and efficient system for visualizing the beam position, thus making possible adjustment of the beam transport lines optics and facilitating beam control. The implantation of some thirty detectors was foreseen in the initial design. The profile detectors are unavoidable tools in displaying the GANIL beams for adaptation and adjustment of the beam line optics. The installed detector assembly (about 190) proves the advantages of these detectors for displaying all the beams extracted from GANIL: transfer and transport lines, beams extracted from SISSI, very high intensity beams (VHIB), secondary ion beams emitted by LISE and SPEG spectrometers targets, different lines of SPIRAL project (HE, BE, ME): This detector assembly must meet the following standard requirements: flange diameter (DN 160) with a standard booster for all the sensors; identical analog electronics for all the detectors with networking; unique visualization system. The new micro-channel plate non-interceptive detectors (the beam profile and ion packet length allow an in-line control of the beam quality and accelerator stability

  7. Dead space and slope indices from the expiratory carbon dioxide tension-volume curve

    NARCIS (Netherlands)

    A.H. Kars (Alice); J.M. Bogaard (Jan); Th. Stijnen (Theo); J. de Vries; A.F.M. Verbraak (Anton); C. Hilvering

    1997-01-01

    textabstractThe slope of phase 3 and three noninvasively determined dead space estimates derived from the expiratory carbon dioxide tension (PCO2) versus volume curve, including the Bohr dead space (VD,Bohr), the Fowler dead space (VD,Fowler) and pre-interface expirate

  8. Application of Optical Flow Sensors for Dead Reckoning, Heading Reference, Obstacle Detection, and Obstacle Avoidance

    Science.gov (United States)

    2015-09-01

    OPTICAL FLOW SENSORS FOR DEAD RECKONING , HEADING REFERENCE, OBSTACLE DETECTION, AND OBSTACLE AVOIDANCE by Tarek M. Nejah September 2015...SENSORS FOR DEAD RECKONING , HEADING REFERENCE, OBSTACLE DETECTION, AND OBSTACLE AVOIDANCE 5. FUNDING NUMBERS 6. AUTHOR(S) Nejah, Tarek M. 7...DISTRIBUTION CODE 13. ABSTRACT (maximum 200 words) A novel approach for dead reckoning , heading reference, obstacle detection, and obstacle

  9. 78 FR 16565 - Culturally Significant Objects Imported for Exhibition Determinations: “The Dead Sea Scrolls...

    Science.gov (United States)

    2013-03-15

    ... Culturally Significant Objects Imported for Exhibition Determinations: ``The Dead Sea Scrolls: Life and Faith in Ancient Times'' Formerly Titled ``The Dead Sea Scrolls: Life and Faith in Biblical Times'' ACTION... exhibition ``The Dead Sea Scrolls: Life and Faith in Biblical Times.'' The referenced notice was corrected on...

  10. 78 FR 62354 - Culturally Significant Objects Imported for Exhibition Determinations: “The Dead Sea Scrolls...

    Science.gov (United States)

    2013-10-18

    ... Culturally Significant Objects Imported for Exhibition Determinations: ``The Dead Sea Scrolls: Life and Faith in Ancient Times'' Formerly Titled ``The Dead Sea Scrolls: Life and Faith in Biblical Times'' ACTION... exhibition ``The Dead Sea Scrolls: Life and Faith in Biblical Times.'' The referenced notice was corrected on...

  11. 77 FR 64373 - Culturally Significant Objects Imported for Exhibition Determinations: “The Dead Sea Scrolls...

    Science.gov (United States)

    2012-10-19

    ... Culturally Significant Objects Imported for Exhibition Determinations: ``The Dead Sea Scrolls: Life and Faith in Ancient Times,'' Formerly Titled ``The Dead Sea Scrolls: Life and Faith in Biblical Times... the exhibition ``The Dead Sea Scrolls: Life and Faith in Biblical Times.'' The referenced notice is...

  12. 78 FR 24462 - Culturally Significant Objects Imported for Exhibition; Determinations: “The Dead Sea Scrolls...

    Science.gov (United States)

    2013-04-25

    ... Culturally Significant Objects Imported for Exhibition; Determinations: ``The Dead Sea Scrolls: Life and Faith in Ancient Times'' Formerly Titled ``The Dead Sea Scrolls: Life and Faith in Biblical Times... the exhibition ``The Dead Sea Scrolls: Life and Faith in Biblical Times.'' The referenced notice was...

  13. El Dia de los Muertos -- Libreto. (The Day of the Dead -- Notebook.)

    Science.gov (United States)

    Espinoza, Delia; Lopez, Santiago, III

    On November 2, all Mexican Americans remember their dead as Mexico does on that same day. Called "El Dia de los Muertos" (Day of the Dead), the dead are remembered posthumously with flowers, candles, music, prayers, chants, and wreaths. The people go to cemeteries to clean tombs, lay fresh or artificial flowers on them, and pray for…

  14. Microclimate and habitat heterogeneity as the major drivers of beetle diversity in dead wood

    Science.gov (United States)

    Sebastian Seibold; Claus Bassler; Roland Brandl; Boris Buche; Alexander Szallies; Simon Thorn; Michael D. Ulyshen; Jorg Muller; Christopher Baraloto

    2016-01-01

    1. Resource availability and habitat heterogeneity are principle drivers of biodiversity, but their individual roles often remain unclear since both factors are usually correlated. The biodiversity of species dependent on dead wood could be driven by either resource availability represented by dead-wood amount or habitat heterogeneity characterized by dead-wood...

  15. 9 CFR 309.3 - Dead, dying, disabled, or diseased and similar livestock.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Dead, dying, disabled, or diseased and... AND VOLUNTARY INSPECTION AND CERTIFICATION ANTE-MORTEM INSPECTION § 309.3 Dead, dying, disabled, or diseased and similar livestock. (a) Livestock found to be dead or in a dying condition on the premises of...

  16. Proportional Derivative Control with Inverse Dead-Zone for Pendulum Systems

    OpenAIRE

    Rubio, José de Jesús; Zamudio, Zizilia; Pacheco, Jaime; Mújica Vargas, Dante

    2013-01-01

    A proportional derivative controller with inverse dead-zone is proposed for the control of pendulum systems. The proposed method has the characteristic that the inverse dead-zone is cancelled with the pendulum dead-zone. Asymptotic stability of the proposed technique is guaranteed by the Lyapunov analysis. Simulations of two pendulum systems show the effectiveness of the proposed technique.

  17. Self-Interaction Chromatography of mAbs: Accurate Measurement of Dead Volumes.

    Science.gov (United States)

    Hedberg, S H M; Heng, J Y Y; Williams, D R; Liddell, J M

    2015-12-01

    Measurement of the second virial coefficient B22 for proteins using self-interaction chromatography (SIC) is becoming an increasingly important technique for studying their solution behaviour. In common with all physicochemical chromatographic methods, measuring the dead volume of the SIC packed column is crucial for accurate retention data; this paper examines best practise for dead volume determination. SIC type experiments using catalase, BSA, lysozyme and a mAb as model systems are reported, as well as a number of dead column measurements. It was observed that lysozyme and mAb interacted specifically with Toyopearl AF-Formyl dead columns depending upon pH and [NaCl], invalidating their dead volume usage. Toyopearl AF-Amino packed dead columns showed no such problems and acted as suitable dead columns without any solution condition dependency. Dead volume determinations using dextran MW standards with protein immobilised SIC columns provided dead volume estimates close to those obtained using Toyopearl AF-Amino dead columns. It is concluded that specific interactions between proteins, including mAbs, and select SIC support phases can compromise the use of some standard approaches for estimating the dead volume of SIC columns. Two other methods were shown to provide good estimates for the dead volume.

  18. A New Virtual Point Detector Concept for a HPGe detector

    International Nuclear Information System (INIS)

    Byun, Jong In; Yun, Ju Yong

    2009-01-01

    For last several decades, the radiation measurement and radioactivity analysis techniques using gamma detectors have been well established. Especially , the study about the detection efficiency has been done as an important part of gamma spectrometry. The detection efficiency depends strongly on source-to-detector distance. The detection efficiency with source-to-detector distance can be expressed by a complex function of geometry and physical characteristics of gamma detectors. In order to simplify the relation, a virtual point detector concept was introduced by Notea. Recently, further studies concerning the virtual point detector have been performed. In previous other works the virtual point detector has been considered as a fictitious point existing behind the detector end cap. However the virtual point detector position for the front and side of voluminous detectors might be different due to different effective central axis of them. In order to more accurately define the relation, therefore, we should consider the virtual point detector for the front as well as side and off-center of the detector. The aim of this study is to accurately define the relation between the detection efficiency and source-to-detector distance with the virtual point detector. This paper demonstrates the method to situate the virtual point detectors for a HPGe detector. The new virtual point detector concept was introduced for three area of the detector and its characteristics also were demonstrated by using Monte Carlo Simulation method. We found that the detector has three virtual point detectors except for its rear area. This shows that we should consider the virtual point detectors for each area when applying the concept to radiation measurement. This concept can be applied to the accurate geometric simplification for the detector and radioactive sources.

  19. Detectors - Electronics; Detecteurs - Electronique

    Energy Technology Data Exchange (ETDEWEB)

    Bregeault, J.; Gabriel, J.L.; Hierle, G.; Lebotlan, P.; Leconte, A.; Lelandais, J.; Mosrin, P.; Munsch, P.; Saur, H.; Tillier, J. [Lab. de Physique Corpusculaire, Caen Univ., 14 (France)

    1998-04-01

    The reports presents the main results obtained in the fields of radiation detectors and associated electronics. In the domain of X-ray gas detectors for the keV range efforts were undertaken to rise the detector efficiency. Multiple gap parallel plate chambers of different types as well as different types of X {yields} e{sup -} converters were tested to improve the efficiency (values of 2.4% at 60 KeV were reached). In the field of scintillators a study of new crystals has been carried out (among which Lutetium orthosilicate). CdTe diode strips for obtaining X-ray imaging were studied. The complete study of a linear array of 8 CdTe pixels has been performed and certified. The results are encouraging and point to this method as a satisfying solution. Also, a large dimension programmable chamber was used to study the influence of temperature on the inorganic scintillators in an interval from -40 deg. C to +150 deg. C. Temperature effects on other detectors and electronic circuits were also investigated. In the report mentioned is also the work carried out for the realization of the DEMON neutron multidetector. For neutron halo experiments different large area Si detectors associated with solid and gas position detectors were realized. In the frame of a contract with COGEMA a systematic study of Li doped glasses was undertaken aiming at replacing with a neutron probe the {sup 3}He counters presently utilized in pollution monitoring. An industrial prototype has been realised. Other studies were related to integrated analog chains, materials for Cherenkov detectors, scintillation probes for experiments on fundamental processes, gas position sensitive detectors, etc. In the field of associated electronics there are mentioned the works related to the multidetector INDRA, data acquisition, software gamma spectrometry, automatic gas pressure regulation in detectors, etc

  20. Not to declare dead someone still alive: Case reports

    Directory of Open Access Journals (Sweden)

    Anđelić Slađana

    2015-01-01

    Full Text Available Introduction. Diagnosing death represents an activity that carries a great deal of public responsibility for medical professionals and is continually exposed to the control of citizens and media. Although this is a taboo subject in medical circles, unfortunately in medical practice there are situations when the physician issues a death diagnosis form without even examining the person or for an already buried person. Such physician’s action is impermissible and it leads to the possibility of professional and criminal law punishment. Case Outline. By giving examples from practice, we wish to point out the need for exceptional caution when confirming and diagnosing death in order to diagnose the true, i.e. rule out apparent death and consequently avoid the mistake of declaring dead someone still alive. Conclusion. When confirming and declaring death, exceptional caution of the physician is necessary so as not to declare dead someone still alive!

  1. Awakening the "Walking Dead": Zombie Pedagogy for Millennials

    Directory of Open Access Journals (Sweden)

    Nancy Dawn Wadsworth

    2017-02-01

    Full Text Available This article lays out the pedagogical benefits of using popular zombie productions, particularly AMC's The Walking Dead, to teach a critical introduction to modern political theory. Based on my undergraduate course: "Political Theory, Climate Change, and the Zombie Apocalypse," the article outlines how The Walking Dead can be used to critique the mythic assumptions built into modern social contract theory; to introduce other political ideologies, including conservatism, anarchism, fascism, and communism; and to consider the political challenges raised by a global problem such as climate change in an increasingly neoliberal environment. Zombie productions are offered as a particularly salient pedagogical tool that can help awaken critical political analysis for the Millennial Generation.

  2. The death effect in literary evaluation: reverence for the dead?

    Science.gov (United States)

    Green, Joseph P; Mohler, Eric W

    It is commonly believed that the value of art and other creative works increases after the death of the artist. In an attempt to examine this so-called death effect we presented a short story to N = 431 undergraduate students asking how much money they would hypothetically spend to purchase a literary work. We experimentally manipulated: 1) whether the author died or moved after publishing a short story, and, 2) the gender of the author. Participants randomly received one of four possible biographical descriptions about the author. We predicted that participants would offer higher purchase prices and subjectively evaluate the work more positively when they believed the author was dead. Results were consistent with this hypothesis perhaps reflecting a certain reverence for the dead. We also found that evaluations of the story were more favorable when the purported gender of the author matched that of the participant.

  3. Pulsed optically pumped atomic clock with zero-dead-time

    Science.gov (United States)

    Lin, Haixiao; Lin, Jinda; Deng, Jianliao; Zhang, Song; Wang, Yuzhu

    2017-12-01

    By alternatively operating two pulsed optically pumped (POP) atomic clocks, the dead time in a single clock can be eliminated, and the local oscillator can be discriminated continuously. A POP atomic clock with a zero-dead-time (ZDT) method is then insensitive to the microwave phase noise. From τ = 0.01 to 1 s, the Allan deviation of the ZDT-POP clock is reduced as nearly τ-1, which is significantly faster than τ-1/2 of a conventional clock. During 1-40 s, the Allan deviation returns to τ-1/2. Moreover, the frequency stability of the ZDT-POP clock is improved by one order of magnitude compared with that of the conventional POP clock. We also analyze the main factors that limit the short-term frequency stability of the POP atomic clock.

  4. The Dead Mother, the Uncanny, and the Holy Ghost

    Directory of Open Access Journals (Sweden)

    Gal Ventura

    2015-01-01

    Full Text Available Recurrent portrayals of dead mothers frequently appeared in French art from 1800 to 1850. This essay focuses on one of the latest manifestations of this image, namely, the French Realist Jules Breton's (1827-1906 painting The Hunger of 1850, in order to examine the psycho-historical elements associated with the mother's death. Through an analysis of the "Uncanny" as formulated by both Ernst Jentsch and Sigmund Freud, we will address the undissolvable link between the structuralization of "homeliness" in the late eighteenth century and the dread it evoked in the early nineteenth century, as two sides of the same coin. We will simultaneously consider the inherent conflictuality embodied by the dead mother according to the French psychoanalyst André Green, who dealt with the experience of "nothingness" that characterizes children of mothers-who-refuse-to-die.

  5. Fuel rod leak detector

    International Nuclear Information System (INIS)

    Womack, R.E.

    1978-01-01

    A typical embodiment of the invention detects leaking fuel rods by means of a radiation detector that measures the concentration of xenon-133 ( 133 Xe) within each individual rod. A collimated detector that provides signals related to the energy of incident radiation is aligned with one of the ends of a fuel rod. A statistically significant sample of the gamma radiation (γ-rays) that characterize 133 Xe is accumulated through the detector. The data so accumulated indicates the presence of a concentration of 133 Xe appropriate to a sound fuel rod, or a significantly different concentration that reflects a leaking fuel rod

  6. Microfluidic Scintillation Detectors

    CERN Multimedia

    Microfluidic scintillation detectors are devices of recent introduction for the detection of high energy particles, developed within the EP-DT group at CERN. Most of the interest for such technology comes from the use of liquid scintillators, which entails the possibility of changing the active material in the detector, leading to an increased radiation resistance. This feature, together with the high spatial resolution and low thickness deriving from the microfabrication techniques used to manufacture such devices, is desirable not only in instrumentation for high energy physics experiments but also in medical detectors such as beam monitors for hadron therapy.

  7. Semiconductor ionizino. radiation detectors

    International Nuclear Information System (INIS)

    1982-01-01

    Spectrometric semiconductor detectors of ionizing radiation with the electron-hole junction, based on silicon and germanium are presented. The following parameters are given for the individual types of germanium detectors: energy range of detected radiation, energy resolution given as full width at half maximum (FWHM) and full width at one tenth of maximum (FWTM) for 57 Co and 60 Co, detection sensitivity, optimal voltage, and electric capacitance at optimal voltage. For silicon detectors the value of FWHM for 239 Pu is given, the sensitive area and the depth of the sensitive area. (E.S.)

  8. Liquid ionizing radiaion detector

    International Nuclear Information System (INIS)

    deGaston, A.N.

    1979-01-01

    A normally nonconducting liquid such as liquid hydrocarbon is encased between a pair of electrodes in an enclosure so that when the liquid is subjected to ionizing radiation, the ion pairs so created measurably increase the conductivity of the fluid. The reduced impedance between the electrodes is detectable with a sensitive ohm-meter and indicates the amount of ionizing radiation. The enclosure, the electrodes and the fluid can be constructed of materials that make the response of the detector suitable for calibrating a large range of radiation energy levels. The detector is especially useful in medical applications where tissue equivalent X ray detectors are desired

  9. Directional radiation detectors

    Science.gov (United States)

    Dowell, Jonathan L.

    2017-09-12

    Directional radiation detectors and systems, methods, and computer-readable media for using directional radiation detectors to locate a radiation source are provided herein. A directional radiation detector includes a radiation sensor. A radiation attenuator partially surrounds the radiation sensor and defines an aperture through which incident radiation is received by the radiation sensor. The aperture is positioned such that when incident radiation is received directly through the aperture and by the radiation sensor, a source of the incident radiation is located within a solid angle defined by the aperture. The radiation sensor senses at least one of alpha particles, beta particles, gamma particles, or neutrons.

  10. Layered semiconductor neutron detectors

    Science.gov (United States)

    Mao, Samuel S; Perry, Dale L

    2013-12-10

    Room temperature operating solid state hand held neutron detectors integrate one or more relatively thin layers of a high neutron interaction cross-section element or materials with semiconductor detectors. The high neutron interaction cross-section element (e.g., Gd, B or Li) or materials comprising at least one high neutron interaction cross-section element can be in the form of unstructured layers or micro- or nano-structured arrays. Such architecture provides high efficiency neutron detector devices by capturing substantially more carriers produced from high energy .alpha.-particles or .gamma.-photons generated by neutron interaction.

  11. Ionization detectors, ch. 3

    International Nuclear Information System (INIS)

    Sevcik, J.

    1976-01-01

    Most measuring devices used in gas chromatography consist of detectors that measure the ionization current. The process is based on the collision of a moving high-energy particle with a target particle that is ionised while an electron is freed. The discussion of the conditions of the collision reaction, the properties of the colliding particles, and the intensity of the applied field point to a unified classification of ionisation detectors. Radioactive sources suitable for use in these detectors are surveyed. The slow-down mechanism, recombination and background current effect are discussed

  12. AntReckoning: Dead Reckoning using Interest Modeling by Pheromones

    OpenAIRE

    Yahyavi , Amir; Huguenin , Kévin; Kemme , Bettina

    2011-01-01

    International audience; In games, the goals and interests of players are key factors in their behavior. However, techniques used by networked games to cope with infrequent updates and message loss, such as dead reckoning, estimate a player's movements based on previous observations only. The estimations are typically done using dynamics of motion, taking only inertia and external factors (e.g., gravity, wind) into account while completely ignoring the player's goals (e.g., chasing other playe...

  13. Strong tracking adaptive Kalman filters for underwater vehicle dead reckoning

    Science.gov (United States)

    Xiao, Kun; Fang, Shao-Ji; Pang, Yong-Jie

    2007-06-01

    To impove underwater vehicle dead reckoning, a developed strong tracking adaptive kalman filter is proposed. The filter is improved with an additional adaptive factor and an estimator of measurement noise covariance. Since the magnitude of fading factor is changed adaptively, the tracking ability of the filter is still enhanced in low velocity condition of underwater vehicles. The results of simulation tests prove the presented filter effective.

  14. Modification in amino acids of Dead Sea Scroll Parchments.

    Science.gov (United States)

    Sobel, H; Ajie, H

    1992-12-01

    Fragments of Dead Sea Scroll Parchments were extracted for collagen and subjected to amino acid analysis. In modern parchment samples, 90% or more of the protein could be extracted in hot aqueous solution as collagen. In the ancient specimens, 70% or less was extractable. The hot-solution insoluble material was analyzed for collagen. In the soluble extract, the quantity of tyrosine, histidine, and methionine was reduced. Dityrosine was detected. The need to extend such studies is discussed.

  15. Interest Modeling in Games: The Case of Dead Reckoning

    OpenAIRE

    Yahyavi, Amir; Huguenin, Kévin; Kemme, Bettina

    2013-01-01

    Special Issue on Network and Systems Support for Games; International audience; In games, the goals and interests of players are key factors in their behavior. However, techniques used by networked games to cope with infrequent updates and message loss, such as dead reckoning, estimate a player's movements based mainly on previous observations. The estimations are typically made by using dynamics of motion, taking only inertia and some external factors (e.g., gravity, wind) into account while...

  16. Vector Graph Assisted Pedestrian Dead Reckoning Using an Unconstrained Smartphone

    OpenAIRE

    Qian, Jiuchao; Pei, Ling; Ma, Jiabin; Ying, Rendong; Liu, Peilin

    2015-01-01

    The paper presents a hybrid indoor positioning solution based on a pedestrian dead reckoning (PDR) approach using built-in sensors on a smartphone. To address the challenges of flexible and complex contexts of carrying a phone while walking, a robust step detection algorithm based on motion-awareness has been proposed. Given the fact that step length is influenced by different motion states, an adaptive step length estimation algorithm based on motion recognition is developed. Heading estimat...

  17. Thermodynamics of the dead zone inner edge in protoplanetary disks

    International Nuclear Information System (INIS)

    Faure, Julien

    2014-01-01

    The dead zone, a quiescent region enclosed in the turbulent flow of a protoplanetary disk, seems to be a promising site for planet formation. Indeed, the development of a density maximum at the dead zone inner edge, that has the property to trap the infalling dust, is a natural outcome of the accretion mismatch at this interface. Moreover, the flow here may be unstable and organize itself into vortical structures that efficiently collect dust grains. The inner edge location is however loosely constrained. In particular, it depends on the thermodynamical prescriptions of the disk model that is considered. It has been recently proposed that the inner edge is not static and that the variations of young stars accretion luminosity are the signature of this interface displacements. This thesis address the question of the impact of the gas thermodynamics onto its dynamics around the dead zone inner edge. MHD simulations including the complex interplay between thermodynamical processes and the dynamics confirmed the dynamical behaviour of the inner edge. A first measure of the interface velocity has been realised. This result has been compared to the predictions of a mean field model. It revealed the crucial role of the energy transport by density waves excited at the interface. These simulations also exhibit a new intriguing phenomenon: vortices forming at the interface follow a cycle of formation-migration-destruction. This vortex cycle may compromise the formation of planetesimals at the inner edge. This thesis claims that thermodynamical processes are at the heart of how the region around the dead zone inner edge in protoplanetary disks works. (author) [fr

  18. Finite element and finite difference methods in electromagnetic scattering

    CERN Document Server

    Morgan, MA

    2013-01-01

    This second volume in the Progress in Electromagnetic Research series examines recent advances in computational electromagnetics, with emphasis on scattering, as brought about by new formulations and algorithms which use finite element or finite difference techniques. Containing contributions by some of the world's leading experts, the papers thoroughly review and analyze this rapidly evolving area of computational electromagnetics. Covering topics ranging from the new finite-element based formulation for representing time-harmonic vector fields in 3-D inhomogeneous media using two coupled sca

  19. Fast photon detection for the COMPASS RICH detector

    CERN Document Server

    Abbon, P; Alekseev, M; Angerer, H; Apollonio, M; Birsa, R; Bordalo, P; Bradamante, Franco; Bressan, A; Busso, L; Chiosso, M; Ciliberti, P; Colantoni, M L; Costa, S; Dalla Torre, S; Dafni, T; Delagnes, E; Deschamps, H; Díaz, V; Dibiase, N; Duic, V; Eyrich, W; Faso, D; Ferrero, A; Finger, M; Finger, M Jr; Fischer, H; Gerassimov, S; Giorgi, M; Gobbo, B; Hagemann, R; Von Harrach, D; Heinsius, F H; Joosten, R; Ketzer, B; Königsmann, K C; Kolosov, V N; Konorov, I; Kramer, Daniel; Kunne, Fabienne; Lehmann, A; Levorato, S; Maggiora, A; Magnon, A; Mann, A; Martin, A; Menon, G; Mutter, A; Nahle, O; Nerling, F; Neyret, D; Pagano, P; Panebianco, S; Panzieri, D; Paul, S; Pesaro, G; Polak, J; Rebourgeard, P; Robinet, F; Rocco, E; Schiavon, Paolo; Schroder, W; Silva, L; Slunecka, M; Sozzi, F; Steiger, L; Sulc, M; Svec, M; Tessarotto, F; Teufel, A; Wollny, H

    2007-01-01

    The COMPASS experiment at the SPS accelerator at CERN uses a large scale Ring Imaging CHerenkov detector (RICH) to identify pions, kaons and protons in a wide momentum range. For the data taking in 2006, the COMPASS RICH has been upgraded in the central photon detection area (25% of the surface) with a new technology to detect Cherenkov photons at very high count rates of several 10^6 per second and channel and a new dead-time free read-out system, which allows trigger rates up to 100 kHz. The Cherenkov photons are detected by an array of 576 visible and ultra-violet sensitive multi-anode photomultipliers with 16 channels each. The upgraded detector showed an excellent performance during the 2006 data taking.

  20. The spectral response of silicon X-ray detectors

    International Nuclear Information System (INIS)

    Eggert, T.

    2004-01-01

    Energy dispersive Silicon Drift Detectors (SDDs) show a superior performance compared with other semiconductor detectors, but low energy X-rays generates an undesirable high background due to incomplete charge collection (ICC) in the entrance window. To investigate the reasons for charge losses, a discrete analytic calculation is performed. All loss mechanisms (partial or full loss of both, photo and/or Auger electrons) due to diffusion into the aluminum dead layer are considered. In order to verify the model, measurements with monochromatic X-rays in the 0.2 to 2 keV energy range were conducted at BESSY II. The observed spectral features like shelf, shoulder, and tail are explained by the model. The main reason for ICC is the escape of thermalized electrons at metalization-silicon-interface

  1. Finite discrete field theory

    International Nuclear Information System (INIS)

    Souza, Manoelito M. de

    1997-01-01

    We discuss the physical meaning and the geometric interpretation of implementation in classical field theories. The origin of infinities and other inconsistencies in field theories is traced to fields defined with support on the light cone; a finite and consistent field theory requires a light-cone generator as the field support. Then, we introduce a classical field theory with support on the light cone generators. It results on a description of discrete (point-like) interactions in terms of localized particle-like fields. We find the propagators of these particle-like fields and discuss their physical meaning, properties and consequences. They are conformally invariant, singularity-free, and describing a manifestly covariant (1 + 1)-dimensional dynamics in a (3 = 1) spacetime. Remarkably this conformal symmetry remains even for the propagation of a massive field in four spacetime dimensions. We apply this formalism to Classical electrodynamics and to the General Relativity Theory. The standard formalism with its distributed fields is retrieved in terms of spacetime average of the discrete field. Singularities are the by-products of the averaging process. This new formalism enlighten the meaning and the problem of field theory, and may allow a softer transition to a quantum theory. (author)

  2. Cooperation Between Dead Reckoning (Path Integration) and External Position Cues

    Science.gov (United States)

    Etienne, Ariane S.; Maurer, Roland; Berlie, Joëlle; Derivaz, Valérie; Georgakopoulos, Joséphine; Griffin, Andrea; Rowe, Tiffany

    Dead reckoning (also called path integration) is the process by which a navigating organism derives its current position relative to an Earthbound reference point from its own locomotion. Dead reckoning requires the continuous estimation of changes in direction and location through self-generated signals and the computation of position on the basis of these signals.(i) Hymenopterous insects measure rotations and translations mainly with the help of optical references such as the Sun and translational visual flow. By contrast, mammals are able to estimate their position on the basis of purely 'internal' information; that is, signals generated in the vestibular system by inertial forces, somatosensory feedback, and efference copies (copies of central commands that control the performance of rotations and translations). Obviously, the assessment of the angular and linear components of locomotion is much more precise if it is assisted by external references than if this is not the case.(ii) Only man-made dead reckoning systems yield precise position information through the twofold integration over time of inertial signals deriving from angular and linear acceleration. On the biological level, all species tested so far seem to rely on a simplified form of path 'integration': in certain test situations, arthropods and mammals (including humans) commit similar systematic errors. This suggests that species from unrelated taxa update position according to a similar algorithm.

  3. Identifying location by dead reckoning and external cues.

    Science.gov (United States)

    Georgakopoulos, J; Etienne, A S

    1994-02-01

    Golden hamsters can orient towards specific points in their environment using location- based visual cues and/or dead reckoning based on vestibular and proprioceptive signals. The relative weight of these different kinds of information was investigated in an apparatus consisting of three identical, square compartments joined by tunnels, with the subject's own nest box at one end. Each compartment contained a feeding site and a weak light spot, the relation between the feeding site and the light spot being different in the three compartments. The animals were trained to hoard food in succession from the three feeding locations, in darkness. During test trials, the light spots were either suppressed or moved to new locations, thus being set in conflict with other kinds of spatial information. In the majority of trials, the subjects proceeded fairly directly to the feeding places, independently of the presence and position of the light spots. This performance may be explained through rote motor learning, which may be initiated with respect to tactile cues previously associated to the goal. However, more flexible, indirect trajectories towards the goal suggest that the subjects kept track of their location within the test space and therefore depended simultaneously on dead reckoning and a map. A control experiment in which the goals were moved along with the visual cues excluded the use of olfactory cues from the food source and confirmed the role of dead reckoning. Copyright © 1994. Published by Elsevier B.V.

  4. Water Quality Modeling in the Dead End Sections of Drinking ...

    Science.gov (United States)

    Dead-end sections of drinking water distribution networks are known to be problematic zones in terms of water quality degradation. Extended residence time due to water stagnation leads to rapid reduction of disinfectant residuals allowing the regrowth of microbial pathogens. Water quality models developed so far apply spatial aggregation and temporal averaging techniques for hydraulic parameters by assigning hourly averaged water demands to the main nodes of the network. Although this practice has generally resulted in minimal loss of accuracy for the predicted disinfectant concentrations in main water transmission lines, this is not the case for the peripheries of a distribution network. This study proposes a new approach for simulating disinfectant residuals in dead end pipes while accounting for both spatial and temporal variability in hydraulic and transport parameters. A stochastic demand generator was developed to represent residential water pulses based on a non-homogenous Poisson process. Dispersive solute transport was considered using highly dynamic dispersion rates. A genetic algorithm was used to calibrate the axial hydraulic profile of the dead-end pipe based on the different demand shares of the withdrawal nodes. A parametric sensitivity analysis was done to assess the model performance under variation of different simulation parameters. A group of Monte-Carlo ensembles was carried out to investigate the influence of spatial and temporal variations

  5. Gulf of Mexico dead zone - 1000 year record

    Science.gov (United States)

    Osterman, L.E.; Poore, R.Z.; Swarzenski, P.W.

    2010-01-01

    An area of oxygen-depleted bottom- and subsurfacewater (hypoxia = dissolved oxygen Since systematic measurement of the extent of the dead zone was begun in 1985, the overall pattern indicates that the area of the dead zone is increasing. Several studies have concluded that the expansion of the Louisiana shelf dead zone is related to increased nutrients (primarily nitrogen, but possibly also phosphorous) in the Mississippi River drainage basin and is responsible for the degradation of Gulf of Mexico marine habitats. The goal of this research is to augment information on the recent expansion of Louisiana shelf hypoxia and to investigate the temporal and geographic extent of the lowoxygen bottom-water conditions prior to 1985 in sediment cores collected from the Louisiana shelf. We use a specific low-oxygen faunal proxy termed the PEB index based on the cumulative percentage of three foraminifers (= % Protononion atlanticum, + % Epistominella vitrea, + % Buliminella morgani) that has been shown statistically to represent the modern seasonal Louisiana hypoxia zone. Our hypothesis is that the increased relative abundance of PEB species in dated sediment cores accurately tracks past seasonal low-oxygen conditions on the Louisiana shelf.

  6. A micron resolution optical scanner for characterization of silicon detectors

    International Nuclear Information System (INIS)

    Shukla, R. A.; Dugad, S. R.; Gopal, A. V.; Gupta, S. K.; Prabhu, S. S.; Garde, C. S.

    2014-01-01

    The emergence of high position resolution (∼10 μm) silicon detectors in recent times have highlighted the urgent need for the development of new automated optical scanners of micron level resolution suited for characterizing microscopic features of these detectors. More specifically, for the newly developed silicon photo-multipliers (SiPM) that are compact, possessing excellent photon detection efficiency with gain comparable to photo-multiplier tube. In a short time, since their invention the SiPMs are already being widely used in several high-energy physics and astrophysics experiments as the photon readout element. The SiPM is a high quantum efficiency, multi-pixel photon counting detector with fast timing and high gain. The presence of a wide variety of photo sensitive silicon detectors with high spatial resolution requires their performance evaluation to be carried out by photon beams of very compact spot size. We have designed a high resolution optical scanner that provides a monochromatic focused beam on a target plane. The transverse size of the beam was measured by the knife-edge method to be 1.7 μm at 1 − σ level. Since the beam size was an order of magnitude smaller than the typical feature size of silicon detectors, this optical scanner can be used for selective excitation of these detectors. The design and operational details of the optical scanner, high precision programmed movement of target plane (0.1 μm) integrated with general purpose data acquisition system developed for recording static and transient response photo sensitive silicon detector are reported in this paper. Entire functionality of scanner is validated by using it for selective excitation of individual pixels in a SiPM and identifying response of active and dead regions within SiPM. Results from these studies are presented in this paper

  7. Multi electrode semiconductors detectors

    CERN Document Server

    Amendolia, S R; Bertolucci, Ennio; Bosisio, L; Bradaschia, C; Budinich, M; Fidecaro, F; Foà, L; Focardi, E; Giazotto, A; Giorgi, M A; Marrocchesi, P S; Menzione, A; Ristori, L; Rolandi, Luigi; Scribano, A; Stefanini, A; Vincelli, M L

    1981-01-01

    Detectors with very high space resolution have been built in this laboratory and tested at CERN in order to investigate their possible use in high energy physics experiments. These detectors consist of thin layers of silicon crystals acting as ionization chambers. Thin electrodes, structured in strips or in more fancy shapes are applied to their surfaces by metal coating. The space resolution which could be reached is of the order of a few microns. An interesting feature of these solid state detectors is that they can work under very high or low external pressure or at very low temperature. The use of these detectors would strongly reduce the dimensions and the cost of high energy experiments. (3 refs).

  8. Multi electrode semiconductor detectors

    International Nuclear Information System (INIS)

    Amendolia, S.R.; Batignani, G.; Bertolucci, E.; Bosisio, L.; Budinich, M.; Bradaschia, C.; Fidecaro, F.; Foa, L.; Focardi, E.; Giazotto, A.; Giorgi, M.A.; Marrocchesi, P.S.; Menzione, A.; Ristori, L.; Rolandi, L.; Scribano, A.; Stefanini, A.; Vincelli, M.L.

    1981-01-01

    Detectors with very high space resolution have been built in the laboratory and tested at CERN in order to investigate their possible use in high energy physics experiments. These detectors consist of thin layers of silicon crystals acting as ionization chambers. Thin electrodes, structured in strips or in more fancy shapes are applied to their surfaces by metal coating. The space resolution which could be reached is of the order of a few microns. An interesting feature of these solid state detectors is that they can work under very high or low external pressure or at very low temperature. The use of these detectors would strongly reduce the dimensions and the cost of high energy experiments. (Auth.)

  9. Infrared Detectors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The end goal of this project is to develop proof-of-concept infrared detectors which can be integrated in future infrared instruments engaged in remote...

  10. ALICE Forward Multiplicity Detector

    CERN Multimedia

    Christensen, C

    2013-01-01

    The Forward Multiplicity Detector (FMD) extends the coverage for multiplicity of charge particles into the forward regions - giving ALICE the widest coverage of the 4 LHC experiments for these measurements.

  11. The pixelated detector

    CERN Multimedia

    Sutton, C

    1990-01-01

    "Collecting data as patterns of light or subatomic particles is vitally important in all the sciences. The new generation of solid-state detectors called pixel devices could transform experimental research at all levels" (4 pages).

  12. Gas-filled detectors

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    This chapter deals with the nature of the interaction of radiation with gas-filled radiation detectors. A description of the theory of operation of the ionization chamber and Geiger-Mueller counter is included

  13. Inverter ratio failure detector

    Science.gov (United States)

    Wagner, A. P.; Ebersole, T. J.; Andrews, R. E. (Inventor)

    1974-01-01

    A failure detector which detects the failure of a dc to ac inverter is disclosed. The inverter under failureless conditions is characterized by a known linear relationship of its input and output voltages and by a known linear relationship of its input and output currents. The detector includes circuitry which is responsive to the detector's input and output voltages and which provides a failure-indicating signal only when the monitored output voltage is less by a selected factor, than the expected output voltage for the monitored input voltage, based on the known voltages' relationship. Similarly, the detector includes circuitry which is responsive to the input and output currents and provides a failure-indicating signal only when the input current exceeds by a selected factor the expected input current for the monitored output current based on the known currents' relationship.

  14. The CLIC Detector Concept

    CERN Document Server

    AUTHOR|(SzGeCERN)779659

    2016-01-01

    CLIC is a concept for a future linear collider that would provide e+e- collisions at up to 3 TeV. The physics aims require a detector system with excellent jet energy and track momentum resolution, highly efficient flavour-tagging and lepton identification capabilities, full geometrical coverage extending to low polar angles and timing information in the order of nanoseconds to reject beam-induced background. To deal with those requirements, an extensive R&D programme is in place to overcome current technological limits. The CLIC detector concept includes a low-mass all-silicon vertex and tracking detector system and fine-grained calorimeters designed for particle flow analysis techniques, surrounded by a 4 T solenoid magnet. An overview of the requirements and design optimisations for the CLIC detector concept is presented.

  15. ATLAS Inner Detector developments

    CERN Document Server

    Barberis, D

    2000-01-01

    The ATLAS Inner Detector consists of three layers of silicon pixels, four double layers of silicon microstrips and a Transition Radiation Tracker (straw tubes). The good performance of the track and vertex reconstruction algorithms is a direct consequence of the small radius (4.3, 10.1 and 13.2 cm), fine pitch ($50 \\times 300~\\mu$m) and low occupancy ($<3 \\times 10^{-4}$ at design luminosity) of the pixel detectors, and of the good tracking capabilities of the SCT and the TRT. The full detector simulation is used to evaluate the performance of the detector and of the reconstruction algorithms. Results are presented on track and vertex reconstruction efficiencies and resolutions, and on the separation between $b$-jets and jets produced by light quarks.

  16. Hybrid photon detectors

    CERN Document Server

    D'Ambrosio, C

    2003-01-01

    Hybrid photon detectors detect light via vacuum photocathodes and accelerate the emitted photoelectrons by an electric field towards inversely polarized silicon anodes, where they are absorbed, thus producing electron-hole pairs. These, in turn, are collected and generate electronic signals on their ohmic contacts. This review first describes the characteristic properties of the main components of hybrid photon detectors: light entrance windows, photocathodes, and silicon anodes. Then, essential relations describing the trajectories of photoelectrons in electric and magnetic fields and their backscattering from the silicon anodes are derived. Depending on their anode configurations, three families of hybrid photon detectors are presented: hybrid photomultiplier tubes with single anodes for photon counting with high sensitivity and for gamma spectroscopy; multi-anode photon detector tubes with anodes subdivided into square or hexagonal pads for position-sensitive photon detection; imaging silicon pixel array t...

  17. Correction for intrinsic and set dead-time losses in radioactivity counting

    International Nuclear Information System (INIS)

    Wyllie, H.A.

    1992-12-01

    Equations are derived for the determination of the intrinsic dead time of the components which precede the paralysis unit in a counting system for measuring radioactivity. The determination depends on the extension of the set dead time by the intrinsic dead time. Improved formulae are given for the dead-time correction of the count rate of a radioactive source in a single-channel system. A variable in the formulae is the intrinsic dead time which is determined concurrently with the counting of the source. The only extra equipment required in a conventional system is a scaler. 5 refs., 2 tabs., 21 figs

  18. FERMILAB: Collider detectors -2

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Last month's edition (April, page 12) included a status report on data collection and preliminary physics results from the 'newcomer' DO detector at Fermilab's Tevatron proton-antiproton collider. This time the spotlight falls in the Veteran' CDF detector, in action since 1985 and meanwhile significantly upgraded. Meanwhile the Tevatron collider continues to improve, with record collision rates

  19. Lepton detector workshop summary

    International Nuclear Information System (INIS)

    Imlay, R.; Iwata, S.; Thorndike, A.

    1976-01-01

    The study group met from June 7 to 11, 1976, with the dual purpose of reviewing an earlier Lepton Detector report in order to resolve some of the remaining design problems and of considering possible alternatives. Since the role of this group was primarily that of providing a critique of the earlier work, the reader is referred to that earlier paper for the general motivation and design of the detector. Problems studied at this session are described

  20. Fiber optic detector

    Energy Technology Data Exchange (ETDEWEB)

    Partin, J.K.; Ward, T.E.; Grey, A.E.

    1990-12-31

    This invention is comprised of a portable fiber optic detector that senses the presence of specific target chemicals by exchanging the target chemical for a fluorescently-tagged antigen that is bound to an antibody which is in turn attached to an optical fiber. Replacing the fluorescently-tagged antigen reduces the fluorescence so that a photon sensing detector records the reduced light level and activates an appropriate alarm or indicator.

  1. The AMANDA Neutrino Detector

    Energy Technology Data Exchange (ETDEWEB)

    Wischnewski, R.; Andres, E.; Askebjer, P.; Barwick, S.; Bay, R.; Bergstroem, L.; Biron, A.; Booth, J.; Botner, O.; Bouchta, A.; Carius, S.; Carlson, M.; Chinowsky, W.; Chirkin, D.; Cowen, D.; Costa, C.; Dalberg, E.; Deyoung, T.; Edsjo, J.; Ekstroem, P.; Goobar, A.; Gray, L.; Hallgren, A.; Halzen, F.; Hardtke, R.; He, Y.; Hill, G.; Hulth, P.; Hundertmark, S.; Jacobsen, J.; Kandhadai, V.; Karle, A.; Kim, J.; Leich, H.; Leuthold, M.; Lindahl, P.; Liss, T.; Liubarsky, I.; Loaiza, P.; LOwder, D.; Marciniewski, P.; Miller, T.; Miocinovic, P.; Mock, P.; Morse, R.; Newcomer, M.; Niessen, P.; Nygren, D.; Perez de los Heros, C.; Porrata, R.; Price, P.; Przybylski, G.; Rhode, W.; Richter, S.; Rodriguez, J.; Romenesko, P.; Ross, D.; Rubinstein, H.; Schmidt, T.; Schneider, E.; Schwarz, R.; Schwendicke, U.; Smoot, G.; Solarz, M.; Sorin, V.; Spiering, C.; Steffen, P.; Stokstad, R.; Streicher, O.; Thollander, L.; Thon, T.; Tilav, S.; Walck, C.; Wiebusch, C.; Woschnagg, K.; Wu, W.; Yodh, G.; Young, S

    1999-03-01

    The first stage of the AMANDA High Energy Neutrino Detector at the South Pole, the 302 PMT array AMANDA-B with an expected effective area for TeV neutrinos of {approx} 10{sup 4} m{sup 2}, has been taking data since 1997. Progress with calibration, investigation of ice properties, as well as muon and neutrino data analysis are described. The next stage 20-string detector AMANDA-II with {approx}800 PMTs will be completed in spring 2000.

  2. Microsonic detector (MSD)

    International Nuclear Information System (INIS)

    Bober, J.T.; Haridas, P.; Oh, S.H.; Pless, I.A.; Stoughton, T.B.

    1983-01-01

    The microsonic detector (MSD) has good spatial resolution, moderate flux capacity, moderate event rate, and small volume. The MSD is a super clean bubble chamber driven at 10-50 KHz. It would be used in experiments as a vertex detector to detect short lived particles. Its characteristics--active volume, density, absorption length, radiation length, and spatial resolution--are given. The setup is schematicized, and a photograph of a 130 MeV/C photon bremsstrahlung beam is given

  3. Calibration of germanium detectors

    International Nuclear Information System (INIS)

    Bjurman, B.; Erlandsson, B.

    1985-01-01

    This paper describes problems concerning the calibration of germanium detectors for the measurement of gamma-radiation from environmental samples. It also contains a brief description of some ways of reducing the uncertainties concerning the activity determination. These uncertainties have many sources, such as counting statistics, full energy peak efficiency determination, density correction and radionuclide specific-coincidence effects, when environmental samples are investigated at close source-to-detector distances

  4. Cryogenic radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    King, S.E. (Naval Research Lab., Washington, DC (United States)); Welsh, D.J. (Physics Dept., Univ. of South Carolina, Columbia, SC (United States)); Fausch, T. (Walther Meissner Inst. ZTTF, Garching (Germany)); Drukier, A.K. (Physics Dept., Univ. of South Carolina, Columbia, SC (United States)); Kroeger, R.A. (Naval Research Lab., Washington, DC (United States)); Inderhees, S.E. (Naval Research Lab., Washington, DC (United States))

    1993-06-01

    Low temperature detectors promise an order of magnitude improvement over semiconducting devices in energy resolution, spatial resolution and radiation hardness. Within this broad field, bolometers and superconducting tunnel junctions are reviewed and potential applications for accelerator based experiments are examined. Our own experiments using Sn, In, Sn(Sb) and In(Bi) alloy based superconducting grain detectors have demonstrated excellent reproducibility and uniformity. (orig.)

  5. Efficiency calibration of the Ge(Li) detector of the BIPM for SIR-type ampoules

    International Nuclear Information System (INIS)

    Michotte, C.

    1999-01-01

    The absolute full-energy peak efficiency of the Ge(Li) γ-ray spectrometer has been measured between 50 keV and 2 MeV with a relative uncertainty around 1 x 10 -2 and for ampoule-to-detector distances of 20 cm and 50 cm. All the corrections applied (self-attenuation, dead time, pile up, true coincidence summing) are discussed in detail. (authors)

  6. Capturing dynamics with Eiger, a fast-framing X-ray detector

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, I., E-mail: ian.johnson@psi.ch; Bergamaschi, A. [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Buitenhuis, J. [Soft Matter Group, ICS-3, Forschungszentrum Jülich, 52425 Jülich (Germany); Dinapoli, R.; Greiffenberg, D.; Henrich, B.; Ikonen, T. [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Meier, G. [Soft Matter Group, ICS-3, Forschungszentrum Jülich, 52425 Jülich (Germany); Menzel, A.; Mozzanica, A. [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Radicci, V. [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); European Synchrotron Radiation Facility, 38043 Grenoble Cedex (France); Satapathy, D. K. [Department of Physics, Indian Institute of Technology Madras, Chennai 600036 (India); Schmitt, B.; Shi, X. [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland)

    2012-11-01

    A high-frame-rate single-photon-counting pixel detector named Eiger and its suitability for X-ray photon correlation spectroscopy are described. Eiger is the next-generation single-photon-counting pixel detector following the widely used Pilatus detector. Its smaller pixel size of 75 µm × 75 µm, higher frame rate of up to 22 kHz, and practically zero dead-time (∼4 µs) between exposures will further various measurement methods at synchrotron sources. In this article Eiger’s suitability for X-ray photon correlation spectroscopy (XPCS) is demonstrated. By exploiting its high frame rate, complementary small-angle X-ray scattering (SAXS) and XPCS data are collected in parallel to determine both the structure factor and collective diffusion coefficient of a nano-colloid suspension. For the first time, correlation times on the submillisecond time scale are accessible with a large-area pixel detector.

  7. Potential Impact of a New GEM-based Detector on CMS Triggering

    CERN Document Server

    INSPIRE-00212096; Abbaneo, D.; Abbrescia, M.; Abi Akl, M.; Armaingaud, C.; Aspell, P.; Assran, Y.; Bally, S.; Ban, Y.; Barria, P.; Benussi, L.; Bhopatkar, V.; Bianco, S.; Bos, J.; Bouhali, O.; Cai, J.; Calabria, C.; Cauwenbergh, S.; Celik, A.; Christiansen, J.; Colafranceschi, S.; Colaleo, A.; Conde Garcia, A.; De Lentdecker, G.; De Oliveira, R.; de Robertis, G.; Dildick, S.; Ferry, S.; Flanagan, W.; Gilmore, J.; Gutierrez, A.; Hoepfner, K.; Hohlmann, M.; Kamon, T.; Karchin, P.E.; Khotilovich, V.; Krutelyov, S.; Loddo, F.; Maerschalk, T.; Magazzu, G.; Maggi, M.; Maghrbi, Y.; Marchioro, A.; Marinov, A.; Merlin, J.A.; Nuzzo, S.; Oliveri, E.; Philipps, B.; Piccolo, D.; Postema, H.; Radi, A.; Radogna, R.; Raffone, G.; Ranieri, A.; Rodrigues, A.; Ropelewski, L.; Safonov, A.; Sakharov, A.; Salva, S.; Saviano, G.; Sharma, A.; Tatarinov, A.; Teng, H.; Turini, N.; Twigger, J.; Tytgat, M.; van Stenis, M.; Verhagen, E.; Yang, Y.; Zaganidis, N.; Zenoni, F.

    2013-01-01

    With the increases in the LHC instantaneous luminosity, maintaining effective triggering and avoiding dead time will become especially challenging. As the sensitivity of many physics studies, depends critically on the ability to maintain relatively low muon momentum thresholds, the identification of potential improvements in triggering is particularly important. The addition of a new muon detector to the existing CMS muon system in the very forward region allows for a substantial improvement in the performance of muon triggering. Integration of the new detector and the existing Cathode Strip Chamber system can improve the muon trigger momentum resolution due to an increase in the lever arm for the measurement of the muon bending angle.

  8. quadratic spline finite element method

    Directory of Open Access Journals (Sweden)

    A. R. Bahadir

    2002-01-01

    Full Text Available The problem of heat transfer in a Positive Temperature Coefficient (PTC thermistor, which may form one element of an electric circuit, is solved numerically by a finite element method. The approach used is based on Galerkin finite element using quadratic splines as shape functions. The resulting system of ordinary differential equations is solved by the finite difference method. Comparison is made with numerical and analytical solutions and the accuracy of the computed solutions indicates that the method is well suited for the solution of the PTC thermistor problem.

  9. GANIL beam profile detectors

    International Nuclear Information System (INIS)

    Tribouillard, C.

    1997-01-01

    In the design phase of GANIL which started in 1977, one of the priorities of the project management was equipping the beamlines with a fast and efficient system for visualizing the beam position, thus making possible adjustment of the beam transport lines optics and facilitating beam control. The implantation of some thirty detectors was foreseen in the initial design. The assembly of installed detectors (around 190) proves the advantages of these detectors for displaying all the beams extracted from GANIL: transfer and transport lines, beam extracted from SISSI, very high intensity beam, secondary ion beams from the production target of the LISE and SPEG spectrometers, different SPIRAL project lines. All of these detectors are based on standard characteristics: - standard flange diameter (DN 160) with a standard booster for all the sensors; - identical analog electronics for all the detectors, with networking; - unique display system. The new micro-channel plate non-interceptive detectors (beam profile and ion packet lengths) make possible in-line control of the beam quality and accelerator stability. (author)

  10. Gamma ray detector modules

    Science.gov (United States)

    Capote, M. Albert (Inventor); Lenos, Howard A. (Inventor)

    2009-01-01

    A radiation detector assembly has a semiconductor detector array substrate of CdZnTe or CdTe, having a plurality of detector cell pads on a first surface thereof, the pads having a contact metallization and a solder barrier metallization. An interposer card has planar dimensions no larger than planar dimensions of the semiconductor detector array substrate, a plurality of interconnect pads on a first surface thereof, at least one readout semiconductor chip and at least one connector on a second surface thereof, each having planar dimensions no larger than the planar dimensions of the interposer card. Solder columns extend from contacts on the interposer first surface to the plurality of pads on the semiconductor detector array substrate first surface, the solder columns having at least one solder having a melting point or liquidus less than 120 degrees C. An encapsulant is disposed between the interposer circuit card first surface and the semiconductor detector array substrate first surface, encapsulating the solder columns, the encapsulant curing at a temperature no greater than 120 degrees C.

  11. Detectors for CBA

    International Nuclear Information System (INIS)

    Baggett, N.; Gordon, H.A.; Palmer, R.B.; Tannenbaum, M.J.

    1983-05-01

    We discuss some current approaches to a large solid angle detector. An alternative approach for utilizing the high rate of events at CBA is to design special purpose detectors for specific physics goals which can be pursued within a limited solid angle. In many cases this will be the only way to proceed, and then high luminosity has a different significance. The total rate in the restricted acceptance is less likely to be a problem, while the need for high luminosity to obtain sufficient data is obvious. Eight such experiments from studies carried out in the community are surveyed. Such experiments could be run on their own or in combination with others at the same intersection, or even with a large solid angle detector, if a window can be provided in the larger facility. The small solid angle detector would provide the trigger and special information, while the facility would provide back-up information on the rest of the event. We consider some possibilities of refurbishing existing detectors for use at CBA. This discussion is motivated by the fact that there is a growing number of powerful detectors at colliding beam machines around the world. Their builders have invested considerable amounts of time, money and ingenuity in them, and may wish to extend the useful lives of their creations, as new opportunities arise

  12. Radiation detectors for reactors

    International Nuclear Information System (INIS)

    Balagi, V.

    2005-01-01

    Detection and measurement of radiation plays a vital role in nuclear reactors from the point of view of control and safety, personnel protection and process control applications. Various types of radiation are measured over a wide range of intensity. Consequently a variety of detectors find use in nuclear reactors. Some of these devices have been developed in Electronics Division. They include gas-filled detectors such as 10 B-lined proportional counters and chambers, fission detectors and BF 3 counters are used for the measurement of neutron flux both for reactor control and safety, process control as well as health physics instrumentation. In-core neutron flux instrumentation employs the use detectors such as miniature fission detectors and self-powered detectors. In this development effort, several indigenous materials, technologies and innovations have been employed to suit the specific requirement of nuclear reactor applications. This has particular significance in view of the fact that several new types of reactors such as P-4, PWR and AHWR critical facilities, FBTR, PFBR as well as the refurbishment of old units like CIRUS are being developed. The development work has sought to overcome some difficulties associated with the non-availability of isotopically enriched neutron-sensing materials, achieving all-welded construction etc. The present paper describes some of these innovations and performance results. (author)

  13. Protecting Detectors in ALICE

    CERN Document Server

    Mateusz Lechman, Mateusz; Chochula, Peter; Di Mauro, Antonio; Jirden, Lennart Stig; Schindler, Heinrich; Rosinsky, Peter; Moreno, Alberto; Kurepin, Alexander; Pinazza, Ombretta; De Cataldo, Giacinto

    2011-01-01

    ALICE (A Large Ion Collider Experiment) is one of the big LHC (Large Hadron Collider) experiments at CERN in Geneva. It is composed of many sophisticated and complex detectors mounted very compactly around the beam pipe. Each detector is a unique masterpiece of design, engineering and construction and any damage to it could stop the experiment for months or even for years. It is therefore essential that the detectors are protected from any danger and this is one very important role of the Detector Control System (DCS). One of the main dangers for the detectors is the particle beam itself. Since the detectors are designed to be extremely sensitive to particles they are also vulnerable to any excess of beam conditions provided by the LHC accelerator. The beam protection consists of a combination of hardware interlocks and control software and this paper will describe how this is implemented and handled in ALICE. Tools have also been developed to support operators and shift leaders in the decision making related...

  14. Extension of the Dytlewski-style dead time correction formalism for neutron multiplicity counting to any order

    Science.gov (United States)

    Croft, Stephen; Favalli, Andrea

    2017-10-01

    Neutron multiplicity counting using shift-register calculus is an established technique in the science of international nuclear safeguards for the identification, verification, and assay of special nuclear materials. Typically passive counting is used for Pu and mixed Pu-U items and active methods are used for U materials. Three measured counting rates, singles, doubles and triples are measured and, in combination with a simple analytical point-model, are used to calculate characteristics of the measurement item in terms of known detector and nuclear parameters. However, the measurement problem usually involves more than three quantities of interest, but even in cases where the next higher order count rate, quads, is statistically viable, it is not quantitatively applied because corrections for dead time losses are currently not available in the predominant analysis paradigm. In this work we overcome this limitation by extending the commonly used dead time correction method, developed by Dytlewski, to quads. We also give results for pents, which may be of interest for certain special investigations. Extension to still higher orders, may be accomplished by inspection based on the sequence presented. We discuss the foundations of the Dytlewski method, give limiting cases, and highlight the opportunities and implications that these new results expose. In particular there exist a number of ways in which the new results may be combined with other approaches to extract the correlated rates, and this leads to various practical implementations.

  15. Frontier detectors for frontier physics

    International Nuclear Information System (INIS)

    Cervelli, F.; Scribano, A.

    1984-01-01

    These proceedings contain the articles presented at the named meeting. These concern developments of radiation detectors and counting techniques in high energy physics. Especially considered are tracking detectors, calorimeters, time projection chambers, detectors for rare events, solid state detectors, particle identification, and optical readout systems. See hints under the relevant topics. (HSI)

  16. Progress in semiconductor drift detectors

    International Nuclear Information System (INIS)

    Rehak, P.; Walton, J.; Gatti, E.

    1985-01-01

    Progress in testing semiconductor drift detectors is reported. Generally better position and energy resolutions were obtained than resolutions published previously. The improvement is mostly due to new electronics better matched to different detectors. It is shown that semiconductor drift detectors are becoming versatile and reliable detectors for position and energy measurements

  17. The ALICE forward multiplicity detector

    DEFF Research Database (Denmark)

    Holm Christensen, Christian; Gulbrandsen, Kristjan; Sogaard, Carsten

    2007-01-01

    The ALICE Forward Multiplicity Detector (FMD) is a silicon strip detector with 51,200 strips arranged in 5 rings, covering the range $-3.4......The ALICE Forward Multiplicity Detector (FMD) is a silicon strip detector with 51,200 strips arranged in 5 rings, covering the range $-3.4...

  18. Feasibility of conversion electron spectrometry using a Peltier-cooled silicon drift detector

    International Nuclear Information System (INIS)

    Perajarvi, K.; Turunen, J.; Ihantola, S.; Pollanen, R.; Siiskonen, T.; Toivonen, H.; Kamarainen, V.; Pomme, S.

    2014-01-01

    A Peltier-cooled silicon drift detector was successfully applied for conversion electron spectrometry. The energy resolution of the detector for 45 keV electrons was 0.50 keV (FWHM). The approximate thickness of the dead layer was determined to be 140 ± 20 nm Si equivalent. The relative efficiency of the detector was verified to be approximately constant in the energy range of 17-75 keV. This is concordant with the high transparency of the thin dead layer and the sufficient thickness of the detector (450 μm) to stop the electrons. The detector is suitable for use in plutonium analysis of chemically prepared samples. Moreover, it was demonstrated that conversion electron spectrometry is better than alpha spectrometry in preserving its capability to determine the 240 Pu/ 239 Pu isotopic ratio as a function of sample thickness. The investigated measurement technique can be considered a promising new tool in safeguards, complementary to existing methods. (author)

  19. Detectors on the drawing board

    CERN Multimedia

    Katarina Anthony

    2011-01-01

    Linear collider detector developers inside and outside CERN are tackling the next generation of detector technology. While their focus has centred on high-energy linear collider detectors, their innovative concepts and designs will be applicable to any future detector.   A simulated event display in one of the new generation detectors. “While the LHC experiments remain the pinnacle of detector technology, you may be surprised to realise that the design and expertise behind them is well over 10 years old,” says Lucie Linssen, CERN’s Linear Collider Detector (LCD) project manager whose group is pushing the envelope of detector design. “The next generation of detectors will have to surpass the achievements of the LHC experiments. It’s not an easy task but, by observing detectors currently in operation and exploiting a decade’s worth of technological advancements, we’ve made meaningful progress.” The LCD team is curr...

  20. Computation of Schenberg response function by using finite element modelling

    International Nuclear Information System (INIS)

    Frajuca, C; Bortoli, F S; Magalhaes, N S

    2016-01-01

    Schenberg is a detector of gravitational waves resonant mass type, with a central frequency of operation of 3200 Hz. Transducers located on the surface of the resonating sphere, according to a distribution half-dodecahedron, are used to monitor a strain amplitude. The development of mechanical impedance matchers that act by increasing the coupling of the transducers with the sphere is a major challenge because of the high frequency and small in size. The objective of this work is to study the Schenberg response function obtained by finite element modeling (FEM). Finnaly, the result is compared with the result of the simplified model for mass spring type system modeling verifying if that is suitable for the determination of sensitivity detector, as the conclusion the both modeling give the same results. (paper)

  1. Towards time domain finite element analysis of gravity gradient noise

    International Nuclear Information System (INIS)

    Beker, M G; Brand, J F J van den; Hennes, E; Rabeling, D S

    2010-01-01

    Gravity gradient noise generated by seismic displacements constitute a limiting factor for the sensitivity of ground based gravitational wave detectors at frequencies below 10 Hz. We present a finite element framework to calculate the soil response to various excitations. The accompanying gravity gradients as a result of the seismic displacement field can then be evaluated. The framework is first shown to accurately model seismic waves in homogenous media. Calculations of the gravity gradient noise are then shown to be in agreement with previous analytical results. Finally results of gravity gradient noise from a single pulse excitation of a homogenous medium are discussed.

  2. Finite Size Scaling of Perceptron

    OpenAIRE

    Korutcheva, Elka; Tonchev, N.

    2000-01-01

    We study the first-order transition in the model of a simple perceptron with continuous weights and large, bit finite value of the inputs. Making the analogy with the usual finite-size physical systems, we calculate the shift and the rounding exponents near the transition point. In the case of a general perceptron with larger variety of inputs, the analysis only gives bounds for the exponents.

  3. Incompleteness in the finite domain

    Czech Academy of Sciences Publication Activity Database

    Pudlák, Pavel

    2017-01-01

    Roč. 23, č. 4 (2017), s. 405-441 ISSN 1079-8986 EU Projects: European Commission(XE) 339691 - FEALORA Institutional support: RVO:67985840 Keywords : finite domain Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 0.742, year: 2016 https://www.cambridge.org/core/journals/bulletin-of-symbolic-logic/article/incompleteness-in-the-finite-domain/D239B1761A73DCA534A4805A76D81C76

  4. Programming the finite element method

    CERN Document Server

    Smith, I M; Margetts, L

    2013-01-01

    Many students, engineers, scientists and researchers have benefited from the practical, programming-oriented style of the previous editions of Programming the Finite Element Method, learning how to develop computer programs to solve specific engineering problems using the finite element method. This new fifth edition offers timely revisions that include programs and subroutine libraries fully updated to Fortran 2003, which are freely available online, and provides updated material on advances in parallel computing, thermal stress analysis, plasticity return algorithms, convection boundary c

  5. Incompleteness in the finite domain

    Czech Academy of Sciences Publication Activity Database

    Pudlák, Pavel

    2017-01-01

    Roč. 23, č. 4 (2017), s. 405-441 ISSN 1079-8986 EU Projects: European Commission(XE) 339691 - FEALORA Institutional support: RVO:67985840 Keywords : finite domain Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 0.742, year: 2016 https://www.cambridge.org/core/ journals /bulletin-of-symbolic-logic/article/incompleteness-in-the-finite-domain/D239B1761A73DCA534A4805A76D81C76

  6. Detectors for proton counting. Si-APD and scintillation detectors

    International Nuclear Information System (INIS)

    Kishimoto, Shunji

    2008-01-01

    Increased intensity of synchrotron radiation requests users to prepare photon pulse detectors having higher counting rates. As detectors for photon counting, silicon-avalanche photodiode (Si-APD) and scintillation detectors were chosen for the fifth series of detectors. Principle of photon detection by pulse and need of amplification function of the detector were described. Structure and working principle, high counting rate measurement system, bunch of electrons vs. counting rate, application example of NMR time spectroscopy measurement and comments for users were described for the Si-APD detector. Structure of scintillator and photomultiplier tube, characteristics of scintillator and performance of detector were shown for the NaI detector. Future development of photon pulse detectors was discussed. (T. Tanaka)

  7. Reconstruction of Micropattern Detector Signals using Convolutional Neural Networks

    Science.gov (United States)

    Flekova, L.; Schott, M.

    2017-10-01

    Micropattern gaseous detector (MPGD) technologies, such as GEMs or MicroMegas, are particularly suitable for precision tracking and triggering in high rate environments. Given their relatively low production costs, MPGDs are an exemplary candidate for the next generation of particle detectors. Having acknowledged these advantages, both the ATLAS and CMS collaborations at the LHC are exploiting these new technologies for their detector upgrade programs in the coming years. When MPGDs are utilized for triggering purposes, the measured signals need to be precisely reconstructed within less than 200 ns, which can be achieved by the usage of FPGAs. In this work, we present a novel approach to identify reconstructed signals, their timing and the corresponding spatial position on the detector. In particular, we study the effect of noise and dead readout strips on the reconstruction performance. Our approach leverages the potential of convolutional neural network (CNNs), which have recently manifested an outstanding performance in a range of modeling tasks. The proposed neural network architecture of our CNN is designed simply enough, so that it can be modeled directly by an FPGA and thus provide precise information on reconstructed signals already in trigger level.

  8. Space Radar Image of Jerusalem and the Dead Sea

    Science.gov (United States)

    1994-01-01

    This space radar image shows the area surrounding the Dead Sea along the West Bank between Israel and Jordan. This region is of major cultural and historical importance to millions of Muslims, Jews and Christians who consider it the Holy Land. The yellow area at the top of the image is the city of Jericho. A portion of the Dead Sea is shown as the large black area at the top right side of the image. The Jordan River is the white line at the top of the image which flows into the Dead Sea. Jerusalem, which lies in the Judaean Hill Country, is the bright, yellowish area shown along the left center of the image. Just below and to the right of Jerusalem is the town of Bethlehem. The city of Hebron is the white, yellowish area near the bottom of the image. The area around Jerusalem has a history of more than 2,000 years of settlement and scientists are hoping to use these data to unveil more about this region's past. The Jordan River Valley is part of an active fault and rift system that extends from southern Turkey and connects with the east African rift zone. This fault system has produced major earthquakes throughout history and some scientists theorize that an earthquake may have caused the fall of Jericho's walls. The Dead Sea basin is formed by active earthquake faulting and contains the lowest place on the Earth's surface at about 400 meters (1,300 feet) below sea level. It was in caves along the northern shore of the Dead Sea that the Dead Sea Scrolls were found in 1947. The blue and green areas are generally regions of undeveloped hills and the dark green areas are the smooth lowlands of the Jordan River valley. This image is 73 kilometers by 45 kilometers (45 miles by 28 miles) and is centered at 31.7 degrees north latitude, 35.4 degrees east longitude. North is toward the upper left. The colors are assigned to different radar frequencies and polarizations as follows: red is L-band, horizontally transmitted and vertically received; green is L-band, horizontally

  9. ATLAS muon detector

    CERN Multimedia

    Muon detectors from the outer layer of the ATLAS experiment at the Large Hadron Collider. Over a million individual detectors combine to make up the outer layer of ATLAS. All of this is exclusively to track the muons, the only detectable particles to make it out so far from the collision point. How the muon’s path curves in the magnetic field depends on how fast it is travelling. A fast muon curves only a very little, a slower one curves a lot. Together with the calorimeters, the muon detectors play an essential role in deciding which collisions to store and which to ignore. Certain signals from muons are a sure sign of exciting discoveries. To make sure the data from these collisions is not lost, some of the muon detectors react very quickly and trigger the electronics to record. The other detectors take a little longer, but are much more precise. Their job is to measure exactly where the muons have passed, calculating the curvature of their tracks in the magnetic field to the nearest five hundredths of a ...

  10. Lepton detector workshop summary

    International Nuclear Information System (INIS)

    Imlay, R.; Iwata, S.; Jacobs, S.

    1976-01-01

    A discussion is given of the initial detector design, focusing on the cost estimates and on the inner detector modules. With regard to inner modules, the rate problem was examined for the closest elements, and the question whether one should use argon or lead-liquid scintillator calorimeters was discussed. New designs which involved major modifications to the lepton detector are considered. The major motivations for alternative designs were twofold. One was that the original detector looked quite expensive, and a study of the tradeoff of money versus physics had not really been done yet. The second point was that, since the physics region to be explored was totally new ground, one would like to leave as many options open as possible and build a detector that was as flexible as possible. A scaled-down version of the original design, which was strongly favored by this study, appears to save an appreciable amount of money with a small decrease in the initial physics scope. The more modular designs seem quite attractive, but not enough time was spent to demonstrate feasibility

  11. Magnesium borate radiothermoluminescent detectors

    International Nuclear Information System (INIS)

    Kazanskaya, V.A.; Kuzmin, V.V.; Minaeva, E.E.; Sokolov, A.D.

    1974-01-01

    In the report the technology of obtaining polycrystalline magnesium borate activated by dysprosium is described briefly and the method of preparing the tabletted detectors from it is presented. The dependence of the light sum of the samples on the proportion of the components and on the sintering regime has shown that the most sensitive material is obtained at the proportion of boric anhydride and magnesium oxide 2.2-2.4 and at the dysprosium concentration about 1 milligram-atom per gram molecule of the base. The glow curve of such a material has a simple form with one peak the maximum of which is located at 190-200 0 C. The measurement of the main dosimetric characteristics of the magnesium borate tabletted detectors and the comparison with similar parmaeters of the lithium fluoride tabletted detectors have shown that at practically identical effective number the former detectors have the following substantial advantages: the sensitivity is ten-twenty times as large, they are substantially more technological on synthesis of the radiothermoluminophor and during the production of the tabletted detectors, they have a simple glow curve, they do not require the utilization of the thermocycling during the use. (author)

  12. Heterostructure infrared photovoltaic detectors

    Science.gov (United States)

    Rogalski, Antoni

    2000-08-01

    HgCdTe remains the most important material for infrared (IR) photodetectors despite numerous attempts to replace it with alternative materials such as closely related mercury alloys (HgZnTe, HgMnTe), Schottky barriers on silicon, SiGe heterojunctions, GaAs/AlGaAs multiple quantum wells, InAs/GaInSb strained layer superlattices, high temperature superconductors and especially two types of thermal detectors: pyroelectric detectors and silicon bolometers. It is interesting, however, that none of these competitors can compete in terms of fundamental properties. In addition, HgCdTe exhibits nearly constant lattice parameter which is of extreme importance for new devices based on complex heterostructures. The development of sophisticated controllable vapour phase epitaxial growth methods, such as MBE and MOCVD, has allowed fabrication of almost ideally designed heterojunction photodiodes. In this paper, examples of novel devices based on heterostructures operating in the long wavelength, middle wavelength and short wavelength spectral ranges are presented. Recently, more interest has been focused on p-n junction heterostructures. As infrared technology continues to advance, there is a growing demand for multispectral detectors for advanced IR systems with better target discrimination and identification. HgCdTe heterojunction detectors offer wavelength flexibility from medium wavelength to very long wavelength and multicolour capability in these regions. Recent progress in two-colour HgCdTe detectors is also reviewed.

  13. Brain-Dead Donors on Extracorporeal Membrane Oxygenation.

    Science.gov (United States)

    Bronchard, Régis; Durand, Louise; Legeai, Camille; Cohen, Johana; Guerrini, Patrice; Bastien, Olivier

    2017-10-01

    To describe donors after brain death with ongoing extracorporeal membrane oxygenation and to analyze the outcome of organs transplanted from these donors. Retrospective analysis of the national information system run by the French Biomedicine Agency (CRISTAL database). National registry data of all donors after brain death in France and their organ recipients between 2007 and 2013. Donors after brain death and their organ recipients. None. During the study period, there were 22,270 brain-dead patients diagnosed in France, of whom 161 with extracorporeal membrane oxygenation. Among these patients, 64 donors on extracorporeal membrane oxygenation and 10,805 donors without extracorporeal membrane oxygenation had at least one organ retrieved. Donors on extracorporeal membrane oxygenation were significantly younger and had more severe intensive care medical conditions (hemodynamic, biological, renal, and liver insults) than donors without extracorporeal membrane oxygenation. One hundred nine kidneys, 37 livers, seven hearts, and one lung were successfully transplanted from donors on extracorporeal membrane oxygenation. We found no significant difference in 1-year kidney graft survival (p = 0.24) and function between recipients from donors on extracorporeal membrane oxygenation (92.7% [85.9-96.3%]) and matching recipients from donors without extracorporeal membrane oxygenation (95.4% [93.0-97.0%]). We also found no significant difference in 1-year liver recipient survival (p = 0.91): 86.5% (70.5-94.1) from donors on extracorporeal membrane oxygenation versus 80.7% (79.8-81.6) from donors without extracorporeal membrane oxygenation. Brain-dead patients with ongoing extracorporeal membrane oxygenation have more severe medical conditions than those without extracorporeal membrane oxygenation. However, kidney graft survival and function were no different than usual. Brain-dead patients with ongoing extracorporeal membrane oxygenation are suitable for organ procurement.

  14. Resonant power converter comprising adaptive dead-time control

    DEFF Research Database (Denmark)

    2017-01-01

    The invention relates in a first aspect to a resonant power converter comprising: a first power supply rail for receipt of a positive DC supply voltage and a second power supply rail for receipt of a negative DC supply voltage. The resonant power converter comprises a resonant network with an input...... terminal for receipt of a resonant input voltage from a driver circuit. The driver circuit is configured for alternatingly pulling the resonant input voltage towards the positive and negative DC supply voltages via first and second semiconductor switches, respectively, separated by intervening dead...

  15. Some remarks on dead-time losses of coincidences

    International Nuclear Information System (INIS)

    Mueller, J.W.

    1976-01-01

    Dead-time effects for coincident pulses are known to be a very difficult subject. Apart from some trivial cases, no rigorous results are yet known. For all practical applications, approximate solutions are used, the quality of which is difficult to judge. Whereas in general they seem to be sufficiently reliable, their deficiency begins to show up clearly for very high count rates. Unfortunately, the present small note will not really improve this situation. It may, however, provide some guideline for the credibility of the various approaches which have been suggested

  16. Analysis and compensation for the cascade dead-zones in the proportional control valve.

    Science.gov (United States)

    Xu, Bing; Su, Qi; Zhang, Junhui; Lu, Zhenyu

    2017-01-01

    The four-way proportional directional control valve has been widely used as the main stage spring constant for the two-stage proportional control valve (PDV). Since a tradeoff should be made between manufacturing costs and static performance, two symmetry dead-zones are introduced in the main stage spring constant: the center dead-zone caused by the center floating position and the intermediate dead-zone caused by the intermediate position. Though the intermediate dead-zone is much smaller than the center dead-zone, it has significant effect on the dynamic position tracking performance. In this paper, the cascade dead-zones problem in a typical two-stage PDV is analyzed and a cascade dead-zones model is proposed for the main stage spring constant. Then, a cascade dead-zones inverse method is improved with gain estimation and dead-zone detection to compensate the dead-zone nonlinearity. Finally, a digital controller is designed for verification. The comparative experimental results indicate that it is effective to reduce the large position tracking error when the proposed method is applied. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  17. The AFP detector control system

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00514541; The ATLAS collaboration; Caforio, Davide; Czekierda, Sabina; Hajduk, Zbigniew; Olszowska, Jolanta; Sicho, Petr; Zabinski, Bartlomiej

    The ATLAS Forward Proton (AFP) detector is one of the forward detectors of the ATLAS experiment at CERN aiming at measuring momenta and angles of diffractively scattered protons. Silicon Tracking and Time-of-Flight detectors are located inside Roman Pot stations inserted into beam pipe aperture. The AFP detector is composed of two stations on each side of the ATLAS interaction point and is under commissioning. The detector is provided with high and low voltage distribution systems. Each station has vacuum and cooling systems, movement control and all the required electronics for signal processing. Monitoring of environmental parameters, like temperature and radiation, is also available. The Detector Control System (DCS) provides control and monitoring of the detector hardware and ensures the safe and reliable operation of the detector, assuring good data quality. Comparing with DCS systems of other detectors, the AFP DCS main challenge is to cope with the large variety of AFP equipment. This paper describes t...

  18. The AFP Detector Control System

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00514541; The ATLAS collaboration

    2017-01-01

    The ATLAS Forward Proton (AFP) detector is one of the forward detectors of the ATLAS experiment at CERN aiming at measuring momenta and angles of diffractively scattered protons. Silicon Tracking and Time-of-Flight detectors are located inside Roman Pot stations inserted into beam pipe aperture. The AFP detector is composed of two stations on each side of the ATLAS interaction point and is under commissioning. The detector is provided with high and low voltage distribution systems. Each station has vacuum and cooling systems, movement control and all the required electronics for signal processing. Monitoring of environmental parameters, like temperature and radiation, is also available. The Detector Control System (DCS) provides control and monitoring of the detector hardware and ensures the safe and reliable operation of the detector, assuring good data quality. Comparing with DCS systems of other detectors, the AFP DCS main challenge is to cope with the large variety of AFP equipment. This paper describes t...

  19. The ATLAS Inner Detector

    CERN Document Server

    Gray, HM; The ATLAS collaboration

    2012-01-01

    The ATLAS experiment at the LHC is equipped with a charged particle tracking system, the Inner Detector, built on three subdetectors, which provide high precision measurements made from a fine detector granularity. The Pixel and microstrip (SCT) subdetectors, which use the silicon technology, are complemented with the Transition Radiation Tracker. Since the LHC startup in 2009, the ATLAS inner tracker has played a central role in many ATLAS physics analyses. Rapid improvements in the calibration and alignment of the detector allowed it to reach nearly the nominal performance in the timespan of a few months. The tracking performance proved to be stable as the LHC luminosity increased by five orders of magnitude during the 2010 proton run, New developments in the offline reconstruction for the 2011 run will improve the tracking performance in high pile-up conditions as well as in highly boosted jets will be discussed.

  20. Transition Radiation Detectors

    CERN Document Server

    Andronic, A

    2012-01-01

    We review the basic features of transition radiation and how they are used for the design of modern Transition Radiation Detectors (TRD). The discussion will include the various realizations of radiators as well as a discussion of the detection media and aspects of detector construction. With regard to particle identification we assess the different methods for efficient discrimination of different particles and outline the methods for the quantification of this property. Since a number of comprehensive reviews already exist, we predominantly focus on the detectors currently operated at the LHC. To a lesser extent we also cover some other TRDs, which are planned or are currently being operated in balloon or space-borne astro-particle physics experiments.

  1. Improved photon detector

    International Nuclear Information System (INIS)

    Zermeno, A.; Marsh, L.M.

    1981-01-01

    Apparatus and methods used to obtain image information from modulation of a uniform flux. A multi-layered detector apparatus is disclosed which comprises a first conductive layer having two sides, a photoconductive layer thick enough to obtain a desired level of sensitivity and resolution of the detector apparatus when the detector apparatus is exposed to radiation of known energy, one side of the photoconductive layer being integrally affixed to and in electrical contact with one side of the first conductive layer, an insulating layer having two sides that is a phosphor that will emit light when irradiated by x-rays, one side of the insulating layer being affixed to the other side of the photoconductive layer and a transparent conductive layer having two sides, one side of the transparent conductive layer being affixed to the other side of the insulating layer. (author)

  2. Silicon radiation detector

    International Nuclear Information System (INIS)

    Benc, I.; Kerhart, J.; Kopecky, J.; Krca, P.; Veverka, V.; Weidner, M.; Weinova, H.

    1992-01-01

    The silicon radiation detector, which is designed for the detection of electrons with energies above 500 eV and of radiation within the region of 200 to 1100 nm, comprises a PIN or PNN + type photodiode. The active acceptor photodiode is formed by a detector surface of shallow acceptor diffusion surrounded by a collector band of deep acceptor diffusion. The detector surface of shallow P-type diffusion with an acceptor concentration of 10 15 to 10 17 atoms/cm 3 reaches a depth of 40 to 100 nm. One sixth to one eighth of the collector band width is overlapped by the P + collector band at a width of 150 to 300 μm with an acceptor concentration of 10 20 to 10 21 atoms/cm 3 down a depth of 0.5 to 3 μm. This band is covered with a conductive layer, of NiCr for instance. (Z.S.)

  3. The H1 detector

    International Nuclear Information System (INIS)

    Cozzika, G.

    1992-11-01

    The H1 detector presently operating at the HERA e-p collider is described. A general overview of the detector is given with particular emphasis on the calorimeters, the main element of which is a liquid Argon calorimeter enclosed within a large radius solenoid. Calorimetry in the proton direction, close to the beam-pipe is provided by a copper-silicon pad hadronic calorimeter. In the electron direction a lead-scintillator electromagnetic calorimeter closes the solid angle between the rear part of the liquid Argon calorimeter and the beam-pipe. An iron limited streamer tube tail catcher using the return yoke of the solenoid as absorber completes the calorimetry of the detector. The hardware triggers derived from the calorimeters are also described and some performance details of the calorimeters are given

  4. Cryogenic Tracking Detectors

    CERN Multimedia

    Luukka, P R; Tuominen, E M; Mikuz, M

    2002-01-01

    The recent advances in Si and diamond detector technology give hope of a simple solution to the radiation hardness problem for vertex trackers at the LHC. In particular, we have recently demonstrated that operating a heavily irradiated Si detector at liquid nitrogen (LN$_2$) temperature results in significant recovery of Charge Collection Efficiency (CCE). Among other potential benefits of operation at cryogenic temperatures are the use of large low-resistivity wafers, simple processing, higher and faster electrical signal because of higher mobility and drift velocity of carriers, and lower noise of the readout circuit. A substantial reduction in sensor cost could result The first goal of the approved extension of the RD39 program is to demonstrate that irradiation at low temperature in situ during operation does not affect the results obtained so far by cooling detectors which were irradiated at room temperature. In particular we shall concentrate on processes and materials that could significantly reduce th...

  5. Superlattice electroabsorption radiation detector

    International Nuclear Information System (INIS)

    Cooke, B.J.

    1993-06-01

    This paper provides a preliminary investigation of a new class of superlattice electroabsorption radiation detectors that employ direct optical modulation for high-speed, two-dimensional (2-D), high-resolution imaging. Applications for the detector include nuclear radiation measurements, tactical guidance and detection (laser radar), inertial fusion plasma studies, and satellite-based sensors. Initial calculations discussed in this paper indicate that a 1.5-μm (GaAlAs) multi-quantum-well (MQW) Fabry-Perot detector can respond directly to radiation of energies 1 eV to 10 KeV, and indirectly (with scattering targets) up through gamma, with 2-D sample rates on the order of 20 ps

  6. Refining Radchem Detectors: Iridium

    Science.gov (United States)

    Arnold, C. W.; Bredeweg, T. A.; Vieira, D. J.; Bond, E. M.; Jandel, M.; Rusev, G.; Moody, W. A.; Ullmann, J. L.; Couture, A. J.; Mosby, S.; O'Donnell, J. M.; Haight, R. C.

    2013-10-01

    Accurate determination of neutron fluence is an important diagnostic of nuclear device performance, whether the device is a commercial reactor, a critical assembly or an explosive device. One important method for neutron fluence determination, generally referred to as dosimetry, is based on exploiting various threshold reactions of elements such as iridium. It is possible to infer details about the integrated neutron energy spectrum to which the dosimetry sample or ``radiochemical detector'' was exposed by measuring specific activation products post-irradiation. The ability of radchem detectors like iridium to give accurate neutron fluence measurements is limited by the precision of the cross-sections in the production/destruction network (189Ir-193Ir). The Detector for Advanced Neutron Capture Experiments (DANCE) located at LANSCE is ideal for refining neutron capture cross sections of iridium isotopes. Recent results from a measurement of neutron capture on 193-Ir are promising. Plans to measure other iridium isotopes are underway.

  7. Semiconductor Thermal Neutron Detector

    Directory of Open Access Journals (Sweden)

    Toru Aoki

    2014-02-01

    Full Text Available The  CdTe  and  GaN  detector  with  a  Gd  converter  have  been developed  and  investigated  as  a  neutron  detector  for neutron  imaging.  The  fabricated  Gd/CdTe  detector  with  the  25  mm  thick  Gd  was  designed  on  the  basis  of  simulation results  of  thermal  neutron  detection  efficiency  and  spatial  resolution.  The  Gd/CdTe  detector  shows  the  detection  of neutron  capture  gamma  ray  emission  in  the  155Gd(n,  g156Gd,  157Gd(n,  g158Gd  and  113Cd(n,  g114Cd  reactions  and characteristic X-ray emissions due to conversion-electrons generated inside the Gd film. The observed efficient thermal neutron detection with the Gd/CdTe detector shows its promise in neutron radiography application. Moreover, a BGaN detector has also investigated to separate neutron signal from gamma-ray clearly. 

  8. Report of the compact detector subgroup

    International Nuclear Information System (INIS)

    Kirkby, J.; Kondo, T.; Olsen, S.L.

    1988-01-01

    This report discusses different detector designs that are being proposed for Superconducting Super Collider experiments. The detectors discussed are: Higgs particle detector, Solid State Box detector, SMART detector, muon detection system, and forward detector. Also discussed are triggering strategies for these detectors, high field solenoids, barium fluoride option for EM calorimetry, radiation damage considerations, and cost estimates

  9. Failed fuel detector

    International Nuclear Information System (INIS)

    Kogure, Sumio; Seya, Toru; Watanabe, Masaaki.

    1976-01-01

    Purpose: To enhance the reliability of a failed fuel detector which detects radioactivity of nuclear fission products leaked out from fuel elements in cooling water. Constitution: Collected specimen is introduced into a separator and co-existing material considered to be an impediment is separated and removed by ion exchange resins, after which this specimen is introduced into a container housing therein a detector to systematically measure radioactivity. Thereby, it is possible to detect a signal lesser in variation in background, and inspection work also becomes simple. (Kawakami, Y.)

  10. Neutron detector assembly

    International Nuclear Information System (INIS)

    Hanai, Koi; Shirayama, Shinpei.

    1978-01-01

    Purpose: To prevent gamma-ray from leaking externally passing through the inside of a neutron detector assembly. Constitution: In a neutron detector assembly having a protection pipe formed with an enlarged diameter portion which serves also as a spacer, partition plates with predetermined width are disposed at the upper and the lower portions in this expanded portion. A lot of metal particles are filled into spaces formed by the partition plates. In such a structure, the metal particles well-absorb the gamma-rays from above and convert them into heat to provide shielding for the gamma-rays. (Horiuchi, T.)

  11. Detectors for rare events

    International Nuclear Information System (INIS)

    Charpak, G.

    1984-01-01

    This chapter discusses the possibility of combining the advantages of photographic data retrieval with the flexibility of operation of conventional gaseous or liquid detectors operated with electronic data retrieval. Possible applications of the proposed detectors to such problems as nucleon decay, neutrinoelectron interaction, and the search for magnetic monopoles are examined. Topics considered include the photography of ionization patterns, the photography of ionization tracks with the multistep avalanche chambers, and exploiting the stimulated scintillation light. Two processes which give rise to the emission of light when ionizing electrons interact in gases under the influence of an electric field are described

  12. Compton current detector

    International Nuclear Information System (INIS)

    Carvalho Campos, J.S. de.

    1984-01-01

    The project and construction of a Compton current detector, with cylindrical geometry using teflon as dielectric material; for electromagnetic radiation in range energy between 10 KeV and 2 MeV are described. The measurements of Compton current in teflon were obtained using an electrometer. The Compton current was promoted by photon flux proceeding from X ray sources (MG 150 Muller device) and gamma rays of 60 Co. The theory elaborated to explain the experimental results is shown. The calibration curves for accumulated charge and current in detector in function of exposition rates were obtained. (M.C.K.) [pt

  13. Intelligent Detector Design

    Energy Technology Data Exchange (ETDEWEB)

    Graf, N.; Cassell, R.; Johnson, T.; McCormick, J.; /SLAC; Magill, S.; Kuhlmann, S.; /Argonne

    2007-02-13

    At a future e+e- linear collider, precision measurements of jets will be required in order to understand physics at and beyond the electroweak scale. Calorimetry will be used with other detectors in an optimal way to reconstruct particle 4-vectors with unprecedented precision. This Particle Flow Algorithm (PFA) approach is seen as the best way to achieve particle mass resolutions from dijet measurements in the range of {approx} 30%/{radical}E, resulting in innovative methods for choosing the calorimeter technology and optimizing the detector design.

  14. ALICE Transition Radiation Detector

    CERN Multimedia

    Pachmayer, Y

    2013-01-01

    The Transition Radiation Detector (TRD) is the main electron detector in ALICE. In conduction with the TPC and the ITS, it provides the necessary electron identification capability to study: - Production of light and heavy vector mesons as well as the continuum in the di-electron channel, - Semi leptonic decays of hadrons with open charm and open beauty via the single-electron channel using the displaced vertex information provided by the ITS, - Correlated DD and BB pairs via coincidences of electrons in the central barrel and muons in the forward muon arm, - Jets with high Pτ tracks in one single TRD stack.

  15. A neutron activation detector

    International Nuclear Information System (INIS)

    Ambardanishvili, T.S.; Kolomiitsev, M.A.; Zakharina, T.Y.; Dundua, V.J.; Chikhladze, N.V.

    1973-01-01

    The present invention concerns a neutron activation detector made from a moulded and hardened composition. According to the invention, that composition contains an activable substance constituted by at least two chemical elements and/or compounds of at least two chemical elements. Each of these chemical elements is capable of reacting with the neutrons forming radio-active isotopes with vatious levels of energy during desintegration. This neutron detector is mainly suitable for measuring integral thermal neutron and fast neutron fluxes during irradiation of the sample, and also for measuring the intensities of neutron fields [fr

  16. Multiple chamber ionization detector

    International Nuclear Information System (INIS)

    Solomon, E.E.

    1982-01-01

    An ionization smoke detector employs a single radiation source in a construction comprising at least two chambers with a center or node electrode. The radioactive source is associated with this central electrode, and its positioning may be adjusted relative to the electrode to alter the proportion of the source that protrudes into each chamber. The source may also be mounted in the plane of the central electrode, and positioned relative to the center of the electrode. The central electrode or source may be made tiltable relative to the body of the detector

  17. Semiconductor neutron detector

    Science.gov (United States)

    Ianakiev, Kiril D [Los Alamos, NM; Littlewood, Peter B [Cambridge, GB; Blagoev, Krastan B [Arlington, VA; Swinhoe, Martyn T [Los Alamos, NM; Smith, James L [Los Alamos, NM; Sullivan, Clair J [Los Alamos, NM; Alexandrov, Boian S [Los Alamos, NM; Lashley, Jason Charles [Santa Fe, NM

    2011-03-08

    A neutron detector has a compound of lithium in a single crystal form as a neutron sensor element. The lithium compound, containing improved charge transport properties, is either lithium niobate or lithium tantalate. The sensor element is in direct contact with a monitor that detects an electric current. A signal proportional to the electric current is produced and is calibrated to indicate the neutrons sensed. The neutron detector is particularly useful for detecting neutrons in a radiation environment. Such radiation environment may, e.g. include gamma radiation and noise.

  18. The Micro Wire Detector

    Energy Technology Data Exchange (ETDEWEB)

    Adeva, B.; Gomez, F.; Pazos, A.; Pfau, R.; Plo, M. E-mail: maximo.plo@cern.ch; Rodriguez, J.M.; Vazquez, P.; Labbe, J.C

    1999-10-11

    We present the performance of a new proportional gas detector. Its geometry consists of a cathode plane with 70x70 {mu}m{sup 2} apertures, crossed by 25 {mu}m anode strips to which it is attached by 50 {mu}m kapton spacers. In the region where the avalanche takes place, the anode strips are suspended in the gas mixture as in a standard wire chamber. This detector exhibits high rate capability and large gains, introducing very little material. (author)

  19. Occurrence of dead core in catalytic particles containing immobilized enzymes: analysis for the Michaelis-Menten kinetics and assessment of numerical methods.

    Science.gov (United States)

    Pereira, Félix Monteiro; Oliveira, Samuel Conceição

    2016-11-01

    In this article, the occurrence of dead core in catalytic particles containing immobilized enzymes is analyzed for the Michaelis-Menten kinetics. An assessment of numerical methods is performed to solve the boundary value problem generated by the mathematical modeling of diffusion and reaction processes under steady state and isothermal conditions. Two classes of numerical methods were employed: shooting and collocation. The shooting method used the ode function from Scilab software. The collocation methods included: that implemented by the bvode function of Scilab, the orthogonal collocation, and the orthogonal collocation on finite elements. The methods were validated for simplified forms of the Michaelis-Menten equation (zero-order and first-order kinetics), for which analytical solutions are available. Among the methods covered in this article, the orthogonal collocation on finite elements proved to be the most robust and efficient method to solve the boundary value problem concerning Michaelis-Menten kinetics. For this enzyme kinetics, it was found that the dead core can occur when verified certain conditions of diffusion-reaction within the catalytic particle. The application of the concepts and methods presented in this study will allow for a more generalized analysis and more accurate designs of heterogeneous enzymatic reactors.

  20. Status of the KEDR detector

    CERN Document Server

    Anashin, V V; Baibusinov, B O; Balashov, V; Baldin, E M; Barkov, L M; Barladyan, A K; Barnyakov, M Y; Baru, S E; Bedny, I; Beilin, D M; Blinov, A E; Blinov, V E; Bondarev, D V; Bondar, A E; Buzykaev, A R; Cantoni, P; Chilingarov, A G; Dneprovsky, L V; Eidelman, S I; Epifanov, D A; Frabetti, P L; Gaidarev, P B; Groshev, V R; Karpov, S V; Kiselev, V A; Klimenko, S G; Kolachev, G M; Kononov, S A; Kozlov, V N; Kravchenko, E A; Kulikov, V F; Kurdadze, L M; Kuzmin, A S; Kuznecov, S A; Lanni, F; Lelchuk, M Y; Leontiev, L A; Levichev, E B; Malyshev, V M; Manfredi, P F; Maslennikov, A L; Minakov, G D; Nagaslaev, V P; Naumenkov, A I; Nikitin, S A; Nomerotski, A; Onuchin, A P; Oreshkin, S B; Ovechkin, R; Palombo, F; Peleganchuk, S V; Petrosyan, S S; Pivovarov, S V; Poluektov, A O; Pospelov, G E; Protopopov, I Ya; Re, V; Romanov, L V; Root, N I; Ruban, A A; Savinov, G A; Shamov, A G; Shatilov, D; Shubin, M A; Shusharo, A I; Shwartz, B A; Sidorov, V A; Skovpen, Y I; Smakhtin, V P; Snopkov, R G; Sokolov, A V; Soukharev, A M; Talyshev, A A; Tayursky, V A; Telnov, V I; Tikhonov, Yu A; Todyshev, K Y; Usov, Y V; Vorobyev, A I; Yushkov, A N; Zatcepin, A V; Zhilich, V N

    2002-01-01

    KEDR is a general-purpose detector for experiments at the VEPP-4M e sup + e sup - -collider in the energy range 2E=2.0-12 GeV. All detector subsystems (except the aerogel Cherenkov counters) have been installed into the detector at VEPP-4M. Some preliminary data have been taken in the energy region of the J/PSI meson. The tuning of the detector and the VEPP-4M collider is in progress. Preliminary results on the detector performance are presented. The future experimental program for the KEDR detector is discussed.

  1. The Upgraded D0 detector

    Energy Technology Data Exchange (ETDEWEB)

    Abazov, V.M.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adams, D.L.; Adams, M.; Adams, T.; Agelou, M.; Agram, J.-L.; Ahmed, S.N.; Ahn, S.H.; Ahsan, M.; Alexeev, G.D.; Alkhazov, G.; Alton, A.; Alverson, G.; Alves, G.A.; Anastasoaie, M.; Andeen, T.; Anderson, J.T.; Anderson, S.; /Buenos Aires U. /Rio de Janeiro, CBPF /Sao Paulo, IFT /Alberta U.

    2005-07-01

    The D0 experiment enjoyed a very successful data-collection run at the Fermilab Tevatron collider between 1992 and 1996. Since then, the detector has been upgraded to take advantage of improvements to the Tevatron and to enhance its physics capabilities. We describe the new elements of the detector, including the silicon microstrip tracker, central fiber tracker, solenoidal magnet, preshower detectors, forward muon detector, and forward proton detector. The uranium/liquid-argon calorimeters and central muon detector, remaining from Run I, are discussed briefly. We also present the associated electronics, triggering, and data acquisition systems, along with the design and implementation of software specific to D0.

  2. Treatment of psoriatic arthritis at the Dead Sea.

    Science.gov (United States)

    Sukenik, S; Giryes, H; Halevy, S; Neumann, L; Flusser, D; Buskila, D

    1994-07-01

    To evaluate the effectiveness of balneotherapy (mud packs and sulfur baths) on patients with psoriasis and psoriatic arthritis (PsA). One hundred and sixty-six patients with psoriasis and PsA were treated at the Dead Sea for a period of 3 weeks. The patients were divided into 2 groups. Both groups had the regular regimen of bathing in Dead Sea water and exposure to the sun's ultraviolet rays. The study group, which consisted of 146 patients also was treated with mud packs and sulfur baths. The control group, which had no additional therapy, consisted of 20 patients. The main clinical variables assessed were duration of morning stiffness, grip strength, activities of daily living, subjective patient assessment of disease severity, number of active joints, number of effluent joints. Ritchie index, psoriasis area and severity index score, cervical, thoracic, and lumbar spine pain and limitations of movement. Statistically significant improvement was found in most variables in both groups. However, better results were observed in the study group. In 2 variables, reduction of spinal pain and range of movement in the lumbar spine, significant improvement (p balneotherapy can have additional beneficial effects on patients with PsA. Other controlled studies with longer followup periods are needed to verify our results.

  3. Uncovering Cinematic Adaptations of James Joyce’s The Dead

    Directory of Open Access Journals (Sweden)

    Pegah Marandi

    2017-10-01

    Full Text Available The relationship between literature and film is the subject of plentiful analyses and reflections within the general framework of Comparative Literature. A comparison between a literary work and its adaptations shows how filmmakers adhere to the principles of intertextuality. Exploring various adaptations of James Joyce’s The Dead (1914 and comparing them against each other are the main objectives of this research. This study examines how John Huston (1987, Travis Mills and William Ivey Long (2013 adapted James Joyce’s The Dead (1914 culturally, geopolitically, and sociologically. This study demonstrated that Huston’s adaptation was faithful to Joyce’s text in terms of character, costume, culture, and language, whereas Mills and Long’s adaptation was not fully loyal to Joyce especially in terms of character and culture. However, Mills and Long have attempted to create a language similar to Joyce’s. Further, consciousness and interior thoughts as subtle issues precisely shown in the novel were not illustrated wholly in both adaptations. Huston’s creativity was maintained in the last scene, picturing Gabriel’s monologue, whereas Mills and Long’s creativity was shown in creating new postmodern characters and culture.

  4. Daily Living Movement Recognition for Pedestrian Dead Reckoning Applications

    Directory of Open Access Journals (Sweden)

    Alessio Martinelli

    2016-01-01

    Full Text Available Nowadays, activity recognition is a central topic in numerous applications such as patient and sport activity monitoring, surveillance, and navigation. By focusing on the latter, in particular Pedestrian Dead Reckoning navigation systems, activity recognition is generally exploited to get landmarks on the map of the buildings in order to permit the calibration of the navigation routines. The present work aims to provide a contribution to the definition of a more effective movement recognition for Pedestrian Dead Reckoning applications. The signal acquired by a belt-mounted triaxial accelerometer is considered as the input to the movement segmentation procedure which exploits Continuous Wavelet Transform to detect and segment cyclic movements such as walking. Furthermore, the segmented movements are provided to a supervised learning classifier in order to distinguish between activities such as walking and walking downstairs and upstairs. In particular, four supervised learning classification families are tested: decision tree, Support Vector Machine, k-nearest neighbour, and Ensemble Learner. Finally, the accuracy of the considered classification models is evaluated and the relative confusion matrices are presented.

  5. Using and respecting the dead human body: an anatomist's perspective.

    Science.gov (United States)

    Jones, D Gareth

    2014-09-01

    In his stimulating article enquiring into what the living owe the dead, Wilkinson (2013, Clin. Anat. DOI: 10.1002/ca.22263) sought to unpack a range of ethical questions of considerable interest to anatomists. In this, he looked closely at the extent to which we are or are not to respect all the prior wishes of the deceased, and the implications of this for the role of the family in providing consent, the use of unclaimed bodies, and the public display of bodies. Some of his conclusions challenge widely encountered views by anatomists. In this response I have re-visited these topics in an attempt to ground his arguments in the experience of anatomists, by emphasizing the many intimate connections that exist between each of these areas. The following emerge as issues for further debate. I accept that the wishes of the deceased are preeminent, so that authorities should make every effort to abide by these. This reiterates the importance of body bequests over against unclaimed bodies, and provides a context for assessing the role of family consent. This has repercussions for all activities employing dead bodies, from the dissecting room to public plastination exhibitions. In determining the extent to which the wishes of the deceased are followed the input of other interested parties is a relevant consideration. An ethical assessment of the public display of bodies needs to take into account the nature of the plastination process. © 2014 Wiley Periodicals, Inc.

  6. Open ocean dead zones in the tropical North Atlantic Ocean

    Science.gov (United States)

    Karstensen, J.; Fiedler, B.; Schütte, F.; Brandt, P.; Körtzinger, A.; Fischer, G.; Zantopp, R.; Hahn, J.; Visbeck, M.; Wallace, D.

    2015-04-01

    Here we present first observations, from instrumentation installed on moorings and a float, of unexpectedly low (zones are created at shallow depth, just below the mixed layer, in the euphotic zone of cyclonic eddies and anticyclonic-modewater eddies. Both types of eddies are prone to high surface productivity. Net respiration rates for the eddies are found to be 3 to 5 times higher when compared with surrounding waters. Oxygen is lowest in the centre of the eddies, in a depth range where the swirl velocity, defining the transition between eddy and surroundings, has its maximum. It is assumed that the strong velocity at the outer rim of the eddies hampers the transport of properties across the eddies boundary and as such isolates their cores. This is supported by a remarkably stable hydrographic structure of the eddies core over periods of several months. The eddies propagate westward, at about 4 to 5 km day-1, from their generation region off the West African coast into the open ocean. High productivity and accompanying respiration, paired with sluggish exchange across the eddy boundary, create the "dead zone" inside the eddies, so far only reported for coastal areas or lakes. We observe a direct impact of the open ocean dead zones on the marine ecosystem as such that the diurnal vertical migration of zooplankton is suppressed inside the eddies.

  7. Dead zones in colloidal quantum dot photovoltaics: evidence and implications

    KAUST Repository

    Barkhouse, D. Aaron R.

    2010-09-01

    In order to fabricate photovoltaic (PV) cells incorporating light-trapping electrodes, flexible foil substrates, or more than one junction, illumination through the top-contact (i.e.: non-substrate) side of a photovoltaic device is desirable. We investigate the relative collection efficiency for illumination through the top vs. bottom of PbS colloidal quantum dot (CQD) PV devices. The external quantum efficiency spectra of FTO/TiO2/PbS CQD/ITO PV devices with various PbS layer thicknesses were measured for illumination through either the top (ITO) or bottom (FTO) contacts. By comparing the relative shapes and intensities of these spectra with those calculated from an estimation of the carrier generation profile and the internal quantum efficiency as a function of distance from the TiO2 interface in the devices, a substantial dead zone, where carrier extraction is dramatically reduced, is identified near the ITO top contact. The implications for device design, and possible means of avoiding the formation of such a dead zone, are discussed.

  8. Management of the dead in Tacloban City after Typhoon Haiyan

    Directory of Open Access Journals (Sweden)

    Julius Erving Ballera

    2015-11-01

    Full Text Available Introduction: The post-disaster management of the dead involves a series of steps including on-site identification, transfer, storage and examination of bodies and delivery to families for burial. Two weeks after Typhoon Haiyan, a team from the Department of Health (DOH was tasked with identifying the dead in Tacloban City. Methods: A suitable site for the collection of bodies was identified and an algorithm and standard data collection form developed. The retrieval of bodies was coordinated with the Bureau of Fire Protection personnel. Upon receipt of a body, two team members conducted a systematic external examination. Findings were documented, photos were taken and each body was assigned a unique number. Results: The DOH team examined 128 bodies. Of these, the majority (86% were complete bodies; 95% were decomposed and two were skeletonized. Two thirds (66% were adults, sex was identifiable for 92%, and the male to female ratio was 1:1.4. The majority of adults were females. Only 11% were presumptively identified from documents in clothing; 89% remained unidentified. Conclusion: From the limited setting of this study, we describe the process of rapid body processing post-Haiyan. We prioritized rapid processing over more technically complicated means of identification, including DNA testing. Our protocol showed a dignified and efficient way of identifying corpses. As local and regional laboratory capacity increases in the Philippines, the collection of DNA specimens may become part of the identification algorithm.

  9. May we practise endotracheal intubation on the newly dead?

    Science.gov (United States)

    Ardagh, M

    1997-10-01

    Endotracheal intubation (ETI) is a valuable procedure which must be learnt and practised, and performing ETI on cadavers is probably the best way to do this, although lesser alternatives do exist. Performing ETI on a cadaver is viewed with a real and reasonable repugnance and if it is done without proper authorisation it might be illegal. Some form of consent is required. Presumed consent would preferably be governed by statute and should only occur if the community is well informed and therefore in a position of being able to decline. Currently neither statute nor adequate informing exists. Endotracheal intubation on the newly dead may be justifiable according to a Guttman scale if the patient has already consented to organ donation and if further research supports the relevance of the Guttman scale to this question. A "mandated choice" with prior individual consent as a matter of public policy is the best of these solutions, however until such a solution is in place we may not practise endotracheal intubation on the newly dead.

  10. Solid finite elements through three decades

    OpenAIRE

    Venkatesh, DN; Shrinivasa, U

    1994-01-01

    conventionally, solid finite elements have been looked upon as just generalizations of two-dimensional finite elements. In this article we trace their development starting from the days of their inception. Keeping in tune with our perceptions on developing finite elements, without taking recourse to any extra variational techniques, we discuss a few of the techniques which have been applied to solid finite elements. Finally we critically examine our own work on formulating solid finite elemen...

  11. Internal bioerosion in dead and live hard corals in intertidal zone of Hormuz Island (Persian Gulf).

    Science.gov (United States)

    Jafari, Mohammad Ali; Seyfabadi, Jafar; Shokri, Mohammad Reza

    2016-04-30

    Internal macrobioeroders and their erosion rate in three live and dead coral genera (Favia, Platygyra and Porites) from the intertidal zone of the Hormuz Island were studied by collecting five live and five dead colonies from each genus, from which 4 mm cross-sections were cut and photographed. Photos were analyzed using the Coral Point Count with Excel extensions. Totally, 9 taxa were identified: four bivalve species, one sponge, three polychaetes, and one barnacle. Bioerosion rate did not significantly differ among the three live corals, but among the dead ones only Porites was significantly more eroded than Favia. Sponge had the highest role in the erosion of the dead Platygyra, while barnacles were the most effective eroding organism in the live Platygyra. Polychaetes, followed by bivalves, were the most destructive bioeroders on the dead and live Porites. Further, none of the bioeroding organisms had selectively chosen either the dead or live Favia. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Fast Detector Simulation Using Lelaps, Detector Descriptions in GODL

    Energy Technology Data Exchange (ETDEWEB)

    Langeveld, Willy; /SLAC

    2005-07-06

    Lelaps is a fast detector simulation program which reads StdHep generator files and produces SIO or LCIO output files. It swims particles through detectors taking into account magnetic fields, multiple scattering and dE/dx energy loss. It simulates parameterized showers in EM and hadronic calorimeters and supports gamma conversions and decays. In addition to three built-in detector configurations, detector descriptions can also be read from files in the new GODL file format.

  13. Fast photon detection for the COMPASS RICH detector

    International Nuclear Information System (INIS)

    Abbon, P.; Alekseev, M.; Angerer, H.; Apollonio, M.; Birsa, R.; Bordalo, P.; Bradainante, F.; Bressan, A.; Busso, L.; Chiosso, M.; Ciliberti, P.; Colantoni, M.L.; Costa, S.; Dalla Torre, S.; Dafni, T.; Delagnes, E.; Deschamps, H.; Diaz, V.; Dibiase, N.; Duic, V.

    2007-01-01

    Particle identification at high rates is a central aspect of many present and future experiments in high-energy particle physics. The COMPASS experiment at the SPS accelerator at CERN uses a large scale Ring Imaging CHerenkov detector (RICH) to identify pions, kaons and protons in a wide momentum range. For the data taking in 2006, the COMPASS RICH has been upgraded in the central photon detection area (25% of the surface) with a new technology to detect Cherenkov photons at very high count rates of several 10 6 s -1 per channel and a new dead-time free read-out system, which allows trigger rates up to 100 kHz. The Cherenkov photons are detected by an array of 576 visible and ultra-violet sensitive multi-anode photomultipliers with 16 channels each. Lens telescopes of fused silica lenses have been designed and built to focus the Cherenkov photons onto the individual photomultipliers. The read-out electronics of the PMTs is based on the MAD4 amplifier-discriminator chip and the dead-time free high resolution F1-TDC. The 120 ps time resolution of the digital card guarantees negligible background from uncorrelated physical events. In the outer part of the detector, where the particle rates are lower, the present multi-wire proportional chambers (MWPC) with Cesium Iodide photo-cathodes have been upgraded with a new read-out electronic system based on the APV preamplifier and shaper ASIC with analog pipeline and sampling ADCs. The project was fully designed and implemented in the period November 2004 until May 2006. The upgraded detector showed an excellent performance during the 2006 data taking: the number of detected Cherenkov photons per ring was increased from 14 to above 60 at saturation. The time resolution was improved from about 3 microseconds to about one nanosecond which allows an excellent suppression of the background photons from uncorrelated events

  14. Finite and profinite quantum systems

    CERN Document Server

    Vourdas, Apostolos

    2017-01-01

    This monograph provides an introduction to finite quantum systems, a field at the interface between quantum information and number theory, with applications in quantum computation and condensed matter physics. The first major part of this monograph studies the so-called `qubits' and `qudits', systems with periodic finite lattice as position space. It also discusses the so-called mutually unbiased bases, which have applications in quantum information and quantum cryptography. Quantum logic and its applications to quantum gates is also studied. The second part studies finite quantum systems, where the position takes values in a Galois field. This combines quantum mechanics with Galois theory. The third part extends the discussion to quantum systems with variables in profinite groups, considering the limit where the dimension of the system becomes very large. It uses the concepts of inverse and direct limit and studies quantum mechanics on p-adic numbers. Applications of the formalism include quantum optics and ...

  15. Finite element methods for engineers

    CERN Document Server

    Fenner, Roger T

    2013-01-01

    This book is intended as a textbook providing a deliberately simple introduction to finite element methods in a way that should be readily understandable to engineers, both students and practising professionals. Only the very simplest elements are considered, mainly two dimensional three-noded “constant strain triangles”, with simple linear variation of the relevant variables. Chapters of the book deal with structural problems (beams), classification of a broad range of engineering into harmonic and biharmonic types, finite element analysis of harmonic problems, and finite element analysis of biharmonic problems (plane stress and plane strain). Full Fortran programs are listed and explained in detail, and a range of practical problems solved in the text. Despite being somewhat unfashionable for general programming purposes, the Fortran language remains very widely used in engineering. The programs listed, which were originally developed for use on mainframe computers, have been thoroughly updated for use ...

  16. On characters of finite groups

    CERN Document Server

    Broué, Michel

    2017-01-01

    This book explores the classical and beautiful character theory of finite groups. It does it by using some rudiments of the language of categories. Originally emerging from two courses offered at Peking University (PKU), primarily for third-year students, it is now better suited for graduate courses, and provides broader coverage than books that focus almost exclusively on groups. The book presents the basic tools, notions and theorems of character theory (including a new treatment of the control of fusion and isometries), and introduces readers to the categorical language at several levels. It includes and proves the major results on characteristic zero representations without any assumptions about the base field. The book includes a dedicated chapter on graded representations and applications of polynomial invariants of finite groups, and its closing chapter addresses the more recent notion of the Drinfeld double of a finite group and the corresponding representation of GL_2(Z).

  17. Sound radiation from finite surfaces

    DEFF Research Database (Denmark)

    Brunskog, Jonas

    2013-01-01

    A method to account for the effect of finite size in acoustic power radiation problem of planar surfaces using spatial windowing is developed. Cremer and Heckl presents a very useful formula for the power radiating from a structure using the spatially Fourier transformed velocity, which combined...... with spatially windowing of a plane waves can be used to take into account the finite size. In the present paper, this is developed by means of a radiation impedance for finite surfaces, that is used instead of the radiation impedance for infinite surfaces. In this way, the spatial windowing is included...... in the radiation formula directly, and no pre-windowing is needed. Examples are given for the radiation efficiency, and the results are compared with results found in the literature....

  18. The Borexino Detector

    Science.gov (United States)

    Montanari, David

    2010-04-01

    The Borexino detector is a large volume liquid scintillator detector for low energy neutrino spetroscopy currently running underground at the Laboratori Nazionali del Gran Sasso, Italy. Main goal of the experiment is the real-time measurement of sub-MeV solar neutrinos, and particularly of the mono-energetic (862KeV) 7Be electron capture neutrinos, via neutrino-electron scattering in ultra-pure liquid scintillator. We report the description of the detector itself from its construction to the final current configuration. The initial requirements are first presented, then the strategy developed to achieve them: choice of materials and components, purification of the scintillator, cleaning, leak tightness, fluid handling. Every single point is analyzed, particularly the purification plants, that allowed reaching an ultra high pure scintillator and the fluid handling system, a large modular system connecting fluid receiving, purification and fluid delivery processes for every fluid involved. The different phases of the filling follow: from air to water to the final liquid scintillator, mainly focusing on the scintillator filling. The performances of the detector and the results are then presented.

  19. Ionic smoke detectors

    CERN Document Server

    2002-01-01

    Ionic smoke detectors are products incorporating radioactive material. This article summarises the process for their commercialization and marketing, and how the activity is controlled, according to regulations establishing strict design and production requisites to guarantee the absence of radiological risk associated both with their use and their final handling as conventional waste. (Author)

  20. MUON DETECTORS: RPC

    CERN Multimedia

    P. Paolucci

    2012-01-01

    The RPC system is operating with a very high uptime, an average chamber efficiency of about 95% and an average cluster size around 1.8. The average number of active channels is 97.7%. Eight chambers are disconnected and forty are working in single-gap mode due to high-voltage problems. The total luminosity lost due to RPCs in 2012 is 88.46 pb–1. One of the main goals of 2012 was to improve the stability of the endcap trigger that is strongly correlated to the performances of the detector, due to the 3-out-3 trigger logic. At beginning of 2011 the instability of the detector efficiency was about 10%. Detailed studies found that this was mainly due to the strong correlation between the performance of the detector and the atmospheric pressure (P). Figure XXY shows the linear correlation between the average cluster size of the endcap chamber versus P. This effect is expected for gaseous detectors and can be reduced by correcting the applied high-voltage working point (HVapp) according to the followi...

  1. ALICE Silicon Pixel Detector

    CERN Multimedia

    Manzari, V

    2013-01-01

    The Silicon Pixel Detector (SPD) forms the innermost two layers of the 6-layer barrel Inner Tracking System (ITS). The SPD plays a key role in the determination of the position of the primary collision and in the reconstruction of the secondary vertices from particle decays.

  2. Performance of GLD detector

    Indian Academy of Sciences (India)

    Most of the important physics processes to be studied in the international linear collider (ILC) experiment have multi-jets in the final state. In order to achieve better jet energy resolution, the so-called particle flow algorithm (PFA) will be employed and there is a general consensus that PFA derives overall ILC detector design.

  3. Semiconductor detector physics

    International Nuclear Information System (INIS)

    Equer, B.

    1987-01-01

    Comprehension of semiconductor detectors follows comprehension of some elements of solid state physics. They are recalled here, limited to the necessary physical principles, that is to say the conductivity. P-n and MIS junctions are discussed in view of their use in detection. Material and structure (MOS, p-n, multilayer, ..) are also reviewed [fr

  4. Ionization chamber smoke detectors

    International Nuclear Information System (INIS)

    1988-03-01

    One kind of smoke detector, the ionization-type, is regulated by the Atomic Energy Control Board (AECB) because it uses a radioactive substance in its mechanism. Radioactivity and radiation are natural phenomena, but they are not very familiar to the average householder. This has led to a number of questions being asked of the AECB. These questions and AECB responses are outlined

  5. The BABAR Detector

    Energy Technology Data Exchange (ETDEWEB)

    Luth, Vera G

    2001-05-18

    BABAR, the detector for the SLAC PEP-II asymmetric e{sup +}e{sup -} B Factory operating at the {Upsilon}(4S) resonance, was designed to allow comprehensive studies of CP-violation in B-meson decays. Charged particle tracks are measured in a multi-layer silicon vertex tracker surrounded by a cylindrical wire drift chamber. Electromagentic showers from electrons and photons are detected in an array of CsI crystals located just inside the solenoidal coil of a superconducting magnet. Muons and neutral hadrons are identified by arrays of resistive plate chambers inserted into gaps in the steel flux return of the magnet. Charged hadrons are identified by dE/dx measurements in the tracking detectors and in a ring-imaging Cherenkov detector surrounding the drift chamber. The trigger, data acquisition and data-monitoring systems, VME- and network-based, are controlled by custom-designed online software. Details of the layout and performance of the detector components and their associated electronics and software are presented.

  6. The LUCID-2 Detector

    CERN Document Server

    Pinfold, James; The ATLAS collaboration

    2017-01-01

    The LUCID-2 detector is the main online and offline luminosity provider of the ATLAS experiment. It provides over 100 different luminosity measurements from different algorithms for each of the 2808/3546 filled/total LHC bunches. LUCID was entirely redesigned in preparation for LHC Run 2: both the detector and the electronics were upgraded in order to cope with the challenging conditions expected at the LHC center of mass energy of 13 TeV with only 25 ns bunch-spacing. While LUCID-1 used gas as a Cherenkov medium, the LUCID-2 detector is in a new unique way using the quartz windows of small photomultipliers as the Cherenkov medium. The main challenge for a luminometer is to keep the efficiency constant during years of data-taking. LUCID-2 is using an innovative calibration system based on radioactive 207 Bi sources deposited on the quartz window of the readout photomultipliers. This makes it possible to accurately monitor and control the gain of the photomultipliers so that the detector efficiency can be kept...

  7. Electromagnetic radiation detector

    Science.gov (United States)

    Benson, Jay L.; Hansen, Gordon J.

    1976-01-01

    An electromagnetic radiation detector including a collimating window, a cathode member having a photoelectric emissive material surface angularly disposed to said window whereby radiation is impinged thereon at acute angles, an anode, separated from the cathode member by an evacuated space, for collecting photoelectrons emitted from the emissive cathode surface, and a negatively biased, high transmissive grid disposed between the cathode member and anode.

  8. Forward tracking detectors

    Indian Academy of Sciences (India)

    In order to get a forward tracking that fulfils the needs, it has to be implemented in the design of the detectors from the beginning. Past experience shows that this part was often underestimated and upgrades at a later stage could not deliver the required performance because the needed space was already taken by other ...

  9. The LUCID-2 Detector

    CERN Document Server

    Soluk, Richard; The ATLAS collaboration

    2017-01-01

    The LUCID-2 detector is the main online and offline luminosity provider of the ATLAS experiment. It provides over 100 different luminosity measurements from different algorithms for each of the 2808 LHC bunches. LUCID was entirely redesigned in preparation for LHC Run 2: both the detector and the electronics were upgraded in order to cope with the challenging conditions expected at the LHC center of mass energy of 13 TeV with only 25 ns bunch-spacing. While LUCID-1 used gas as a Cherenkov medium, the LUCID-2 detector is in a new unique way using the quartz windows of small photomultipliers as the Cherenkov medium. The main challenge for a luminometer is to keep the efficiency constant during years of data-taking. LUCID-2 is using an innovative calibration system based on radioactive 207 Bi sources deposited on the quartz window of the readout photomultipliers. This makes it possible to accurately monitor and control the gain of the photomultipliers so that the detector efficiency can be kept stable at a perce...

  10. First ALICE detectors installed!

    CERN Multimedia

    2006-01-01

    Detectors to track down penetrating muon particles are the first to be placed in their final position in the ALICE cavern. The Alice muon spectrometer: in the foreground the trigger chamber is positioned in front of the muon wall, with the dipole magnet in the background. After the impressive transport of its dipole magnet, ALICE has begun to fill the spectrometer with detectors. In mid-July, the ALICE muon spectrometer team achieved important milestones with the installation of the trigger and the tracking chambers of the muon spectrometer. They are the first detectors to be installed in their final position in the cavern. All of the eight half planes of the RPCs (resistive plate chambers) have been installed in their final position behind the muon filter. The role of the trigger detector is to select events containing a muon pair coming, for instance, from the decay of J/ or Y resonances. The selection is made on the transverse momentum of the two individual muons. The internal parts of the RPCs, made o...

  11. Adaptive NN Control for Multisteering Plane Aircraft with Dead Zone or Backlash Input Nonlinearity

    OpenAIRE

    Meng, Xiang-fei; Wang, Ying; Lv, Mao-long

    2017-01-01

    Considering that many factors such as actuator input dead zone, backlash, and external disturbance could affect the exactness of trajectory tracking, therewith a robust adaptive neural network control scheme on the basis of control allocation is proposed for the sake of tracking control of multisteering plane aircraft with actuator input dead zone or backlash nonlinearity. First of all, an actuator input dead zone or backlash nonlinearity control assignment model is established and the contro...

  12. Fire Emulator/Detector Evaluator

    Data.gov (United States)

    Federal Laboratory Consortium — Description:The fire emulator/detector evaluator (FE/DE) is a computer-controlled flow tunnel used to re-create the environments surrounding detectors in the early...

  13. Finite connectivity attractor neural networks

    International Nuclear Information System (INIS)

    Wemmenhove, B; Coolen, A C C

    2003-01-01

    We study a family of diluted attractor neural networks with a finite average number of (symmetric) connections per neuron. As in finite connectivity spin glasses, their equilibrium properties are described by order parameter functions, for which we derive an integral equation in replica symmetric approximation. A bifurcation analysis of this equation reveals the locations of the paramagnetic to recall and paramagnetic to spin-glass transition lines in the phase diagram. The line separating the retrieval phase from the spin-glass phase is calculated at zero temperature. All phase transitions are found to be continuous

  14. Finite connectivity attractor neural networks

    Science.gov (United States)

    Wemmenhove, B.; Coolen, A. C. C.

    2003-09-01

    We study a family of diluted attractor neural networks with a finite average number of (symmetric) connections per neuron. As in finite connectivity spin glasses, their equilibrium properties are described by order parameter functions, for which we derive an integral equation in replica symmetric approximation. A bifurcation analysis of this equation reveals the locations of the paramagnetic to recall and paramagnetic to spin-glass transition lines in the phase diagram. The line separating the retrieval phase from the spin-glass phase is calculated at zero temperature. All phase transitions are found to be continuous.

  15. Variational collocation on finite intervals

    International Nuclear Information System (INIS)

    Amore, Paolo; Cervantes, Mayra; Fernandez, Francisco M

    2007-01-01

    In this paper, we study a set of functions, defined on an interval of finite width, which are orthogonal and which reduce to the sinc functions when the appropriate limit is taken. We show that these functions can be used within a variational approach to obtain accurate results for a variety of problems. We have applied them to the interpolation of functions on finite domains and to the solution of the Schroedinger equation, and we have compared the performance of the present approach with others

  16. FINITE ELEMENT ANALYSIS OF STRUCTURES

    Directory of Open Access Journals (Sweden)

    PECINGINA OLIMPIA-MIOARA

    2015-05-01

    Full Text Available The application of finite element method is analytical when solutions can not be applied for deeper study analyzes static, dynamic or other types of requirements in different points of the structures .In practice it is necessary to know the behavior of the structure or certain parts components of the machine under the influence of certain factors static and dynamic . The application of finite element in the optimization of components leads to economic growth , to increase reliability and durability organs studied, thus the machine itself.

  17. The Role of Dead Wood in Maintaining Arthropod Diversity on the Forest Floor

    Energy Technology Data Exchange (ETDEWEB)

    Hanula, James L. [Dept. of Agriculture Forest Service, Athens, GA (United States). Southern Research Station; Horn, Scott [Dept. of Agriculture Forest Service, Athens, GA (United States). Southern Research Station; Wade, Dale D. [Dept. of Agriculture Forest Service, Athens, GA (United States). Southern Research Station

    2006-08-01

    Dead wood is a major component of forests and contributes to overall diversity, primarily by supporting insects that feed directly on or in it. Further, a variety of organisms benefit by feeding on those insects. What is not well known is how or whether dead wood influences the composition of the arthropod community that is not solely dependent on it as a food resource, or whether woody debris influences prey available to generalist predators. One group likely to be affected by dead wood is ground-dwelling arthropods. We studied the effect of adding large dead wood to unburned and frequently burned pine stands to determine if dead wood was used more when the litter and understory plant community are removed. We also studied the effect of annual removal of dead wood from large (10-ha) plots over a 5-year period on ground-dwelling arthropods. In related studies, we examined the relationships among an endangered woodpecker that forages for prey on live trees, its prey, and dead wood in the forest. Finally, the results of these and other studies show that dead wood can influence the abundance and diversity of the ground-dwelling arthropod community and of prey available to generalist predators not foraging directly on dead trees.

  18. The effect of ketoconazole on pulmonary pathology associated with dead Dirofilaria immitis.

    Science.gov (United States)

    Tarish, J; Atwell, R

    1993-01-01

    The involvement of thromboxane and lipoxygenase in the regulation of pulmonary lesions and immune responses was investigated in dogs given ketoconazole and exposed to dead adult Dirofiliara immitis. Immunopathological reactions to the dead filariae were monitored by light and transmission electron microscopy and serology. When compared with control tissues, ketoconazole administration enhanced the level of pulmonary haemorrhage and early parenchymal fibrosis associated with dead adult filariae. Ultrastructurally, alveolar capillaries were filled with erythrocyte aggregations and proteinaceous material. These results suggested that an intact thromboxane and lipoxygenase pathway within the arachidonic acid system is necessary to minimize the effect of dead D. immitis in this pulmonary artery model.

  19. Comparison between morphological and staining characteristics of live and dead eggs of Schistosoma mansoni

    Directory of Open Access Journals (Sweden)

    AK Sarvel

    2006-10-01

    Full Text Available Schistosoma mansoni eggs are classified, according to morphological characteristics, as follows: viable mature and immature eggs; dead mature and immature eggs, shells and granulomas. The scope of this study was to compare the staining characteristics of different morphological types of eggs in the presence of fluorescent labels and vital dyes, aiming at differentiating live and dead eggs. The eggs were obtained from the intestines of infected mice, and put into saline 0.85%. The fluorescent labels were Hoechst 33258 and Acridine Orange + Ethidium Bromide and vital dyes (Trypan Blue 0.4% and Neutral Red 1%. When labelled with the probe Hoechst 33258, some immature eggs, morphologically considered viable, presented fluorescence (a staining characteristic detected only in dead eggs; mature eggs did not present fluorescence, and the other types of dead eggs, morphologically defined, showed fluorescence. As far as Acridine Orange + Ethidium Bromide are concerned, either the eggs considered to be live, or the dead ones, presented staining with green color, and only the hatched and motionless miracidium was stained with an orange color. Trypan Blue was not able to stain the eggs, considered to be dead but only dead miracidia which had emerged out of the shell. Neutral Red stained both live and dead eggs. Only the fluorescent Hoechst 33258 can be considered a useful tool for differentiation between dead and live eggs.

  20. "Dead in bed": a tragic complication of type 1 diabetes mellitus.

    LENUS (Irish Health Repository)

    O'Reilly, M

    2010-12-01

    "Dead in bed" is a tragic description of a particular type of sudden death in type 1 diabetes mellitus (DM). Patients are typically found dead in the early morning, lying in an undisturbed bed, having been well the previous evening. The incidence of "dead in bed" syndrome is not known but studies suggest figures of between 4.7 and 27.3% of all unexplained deaths in type 1 DM. The pathogenesis is unclear but patients typically have a preceding history of recurrent severe hypoglycaemia. We describe two cases of "dead in bed" syndrome which occurred at our institution within a 12-month period.

  1. Steady-state analysis of dead-time effect on bidirectional buck converters

    DEFF Research Database (Denmark)

    Bidoggia, Benoit; Maheshwari, Ram Krishan; Nielsen, Rasmus Ørndrup

    2012-01-01

    analyzed. It has been shown that in a region around zero there is no dead-time effect. The analytical expression of the borders between the areas where the dead-time effect is positive, zero or negative has been given. Moreover it has been shown that between these three areas, there are four other...... between output voltage, input voltage and duty cycle as a function of the output current. In the literature, the dead-time effect has been studied in relation with inverters, active filters, voltage regulated modules and high-precision power amplifiers, and dead-time compensation techniques have been...

  2. Detector Readout of Analog Quantum Simulators

    Science.gov (United States)

    Schwenk, Iris; Tian, Lin; Marthaler, Michael

    An important step in quantum simulation is to measure the many-body correlations of the simulated model. For a practical quantum simulator composed of a finite number of qubits and cavities, in contrast to many-body systems in the thermodynamic limit, a measurement device can generate strong backaction on the simulator, which could prevent the accurate readout of the correlation functions. Here we calculate the readout of a detector coupled to analog quantum simulators. We show that reliable characterization of the many-body correlations of the simulators can be achieved when the coupling operators obey the Wick's theorem. Our results are illustrated with two examples: a simulator for an harmonic oscillator and a simulator for the free electron gas. We also present a method, which under certain constraints, allows for the reconstruction of the ideal correlators from the measurements on a perturbed quantum simulator. This work is in part supported by the National Science Foundation under Award Number 0956064.

  3. Research on intellectualized γ detector

    International Nuclear Information System (INIS)

    Duan Zaiyu; Chen Jianhua; Zhang Guixin

    2006-01-01

    This design makes use of the Time-to-Count measuring method, the SCM and the high-voltage power is supplied into the γ detector, and new-style intellectualized γ detector is designed. The intellectualized γ detector is a sort of intellectualized, miniature, integrative γ radial monitor instrument. The designing project, performance index, and structural design of the detector are introduced. The research is applied into project. (authors)

  4. The status of BAT detector

    Science.gov (United States)

    Lien, Amy; Markwardt, Craig B.; Krimm, Hans Albert; Barthelmy, Scott D.; Cenko, Bradley

    2018-01-01

    We will present the current status of the Swift/BAT detector. In particular, we will report the updated detector gain calibration, the number of enable detectors, and the global bad time intervals with potential calibration issues. We will also summarize the results of the yearly BAT calibration using the Crab nebula. Finally, we will discuss the effects on the BAT survey, such as the sensitivity, localization, and spectral analysis, due to the changes in detector status.

  5. How the Seven Deadly Sins can Lead to Project Failure

    Directory of Open Access Journals (Sweden)

    Harold Kerzner

    2013-01-01

    Full Text Available For more than forty years, the project management landscape has seen textbooks, journal articles and presented papers discussing the causes of project failures. Unfortunately, many of the failure analyses seem to look at failure superficially rather than in depth. When trying to discover the root cause of a failure, we usually look first in the contractor’s company for someone to blame rather than in our own company. If that doesn’t work, then we begin climbing the organizational hierarchy in our own company by focusing on the project team, followed by the project manager. Once we find someone to blame, the search seems to end and we feel comfortable that we have discovered the cause of the failure. It is human nature to begin finger-pointing at the bottom of the organizational hierarchy first, rather than at the top. Yet, more often than not, the real cause of failure is the result of actions (or inactions and decisions made at the top of the organizational chart than at the bottom. It is also human nature to make decisions based upon how we are affected by the Seven Deadly Sins, namely: envy, anger, pride, greed, sloth, lust and gluttony. Decisions made based upon the Seven Deadly Sins, whether they are made at the top or bottom of the organization, can have dire consequences on projects. Sometimes the sins are hidden and not easily recognized by ourselves or others. We simply do not see or feel that were are committing a sin. The Seven Deadly Sins affect all of us sooner or later, even though we refuse to admit it. Some of us may be impacted by just one or two of the sins, whereas others may succumb to all seven. What is unfortunate is that the greatest damage can occur on projects when the sins influence the way that senior levels of management must interface with projects, whether as a project sponsor or as a member of a governance group. Bad decisions at the top, especially if based upon emotions rather than practicality, can place the

  6. Radiation detectors laboratory; Laboratorio de detectores de radiacion

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez J, F.J. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    The Radiation detectors laboratory was established with the assistance of the International Atomic Energy Agency which gave this the responsibility to provide its services at National and regional level for Latin America and it is located at the ININ. The more expensive and delicate radiation detectors are those made of semiconductor, so it has been put emphasis in the use and repairing of these detectors type. The supplied services by this laboratory are: selection consultant, detectors installation and handling and associated systems. Installation training, preventive and corrective maintenance of detectors and detection systems calibration. (Author)

  7. Scalar top study: Detector optimization

    Indian Academy of Sciences (India)

    Previous studies investigated the vertex detector design in scenarios with large mass differences between stop and neutralino, corresponding to large visible energy in the detector. In this study we investigate the tagging performance dependence on the vertex detector design in a scenario with small visible energy for the.

  8. Workshops on radiation imaging detectors

    Energy Technology Data Exchange (ETDEWEB)

    Sochinskii, N.V.; Sun, G.C.; Kostamo, P.; Silenas, A.; Saynatjoki, A.; Grant, J.; Owens, A.; Kozorezov, A.G.; Noschis, E.; Van Eijk, C.; Nagarkar, V.; Sekiya, H.; Pribat, D.; Campbell, M.; Lundgren, J.; Arques, M.; Gabrielli, A.; Padmore, H.; Maiorino, M.; Volpert, M.; Lebrun, F.; Van der Putten, S.; Pickford, A.; Barnsley, R.; Anton, M.E.G.; Mitschke, M.; Gros d' Aillon, E.; Frojdh, C.; Norlin, B.; Marchal, J.; Quattrocchi, M.; Stohr, U.; Bethke, K.; Bronnimann, C.H.; Pouvesle, J.M.; Hoheisel, M.; Clemens, J.C.; Gallin-Martel, M.L.; Bergamaschi, A.; Redondo-Fernandez, I.; Gal, O.; Kwiatowski, K.; Montesi, M.C.; Smith, K

    2005-07-01

    This document gathers the transparencies that were presented at the international workshop on radiation imaging detectors. 9 sessions were organized: 1) materials for detectors and detector structure, 2) front end electronics, 3) interconnected technologies, 4) space, fusion applications, 5) the physics of detection, 6) industrial applications, 7) synchrotron radiation, 8) X-ray sources, and 9) medical and other applications.

  9. Review of semiconductor drift detectors

    Science.gov (United States)

    Gatti, Emilio; Rehak, Pavel

    2005-04-01

    A short review of semiconductor drift detectors is given. The emphasis is given to detectors intended for tracking of fast charged particles for experiments in particle physics and high energy heavy-ion physics. The use and performance of this kind of detector in past, present and future experiments is described together with the experience learned during the design, production and data taking phases.

  10. The 4th concept detector

    Indian Academy of Sciences (India)

    The 4th concept detector consists of four detector subsystems, a small-pixel vertex detector, a high-resolution TPC, a new multiple-readout fiber calorimeter and a new dual-solenoid iron-free muon system. We discuss the design of a comprehensive facility that measures and identifies all partons of the standard model, ...

  11. Workshops on radiation imaging detectors

    International Nuclear Information System (INIS)

    Sochinskii, N.V.; Sun, G.C.; Kostamo, P.; Silenas, A.; Saynatjoki, A.; Grant, J.; Owens, A.; Kozorezov, A.G.; Noschis, E.; Van Eijk, C.; Nagarkar, V.; Sekiya, H.; Pribat, D.; Campbell, M.; Lundgren, J.; Arques, M.; Gabrielli, A.; Padmore, H.; Maiorino, M.; Volpert, M.; Lebrun, F.; Van der Putten, S.; Pickford, A.; Barnsley, R.; Anton, M.E.G.; Mitschke, M.; Gros d'Aillon, E.; Frojdh, C.; Norlin, B.; Marchal, J.; Quattrocchi, M.; Stohr, U.; Bethke, K.; Bronnimann, C.H.; Pouvesle, J.M.; Hoheisel, M.; Clemens, J.C.; Gallin-Martel, M.L.; Bergamaschi, A.; Redondo-Fernandez, I.; Gal, O.; Kwiatowski, K.; Montesi, M.C.; Smith, K.

    2005-01-01

    This document gathers the transparencies that were presented at the international workshop on radiation imaging detectors. 9 sessions were organized: 1) materials for detectors and detector structure, 2) front end electronics, 3) interconnected technologies, 4) space, fusion applications, 5) the physics of detection, 6) industrial applications, 7) synchrotron radiation, 8) X-ray sources, and 9) medical and other applications

  12. TO DETERMINATION OF DAMPING COEFFICIENT OF VERTICAL DEAD STRESS OF EARTH DAMS ON A DEPTH

    Directory of Open Access Journals (Sweden)

    NESTEROVA E. V.

    2015-12-01

    Full Text Available Raising of problem. At the problem solving about determination of deflected mode (DM of build constructions by the finite element method (FEM on accuracy of solving substantial influence is rendered by the sizes of effective area of foundation. It is suggested to develop the criteria of determining the size of effective area. Presently at the calculation of vertical fallouts of earth dams with the trapeziform section (fig. 1, is assumed that the epure of contact pressures has a rectangular form [2, 6]. Thus actual epure of contact pressures on the sole of dam has form of trapezoid (fig. 1. Thus, there is a disparity between actual and accepted in the normative documents in the contact pressures on the sole of earth dams. Purpose. At writing of this article we were pursue a purpose to calculate the value of damping coefficient of vertical dead stress on the depth of foundation, trapeziform loading determined and to foundation attached. About it has been already written not a bit in scientific literature [2; 5; 6; 7; 13]. In our view, for determination of vertical fallouts of foundation of earth dams it is necessary to use the formula of D-1 DBN [7], corrected in it the damping coefficient of vertical stress on a depth, conditioned of dam weight, that is to calculate a trapezoidal form of environmental stress (fig. 1. Conclusion. The damping coefficients of vertical stress calculated by us on a depth (tablas. 1 allow more exactly to determine their values, than coefficients, presented in normative documents [7]. This is caused by more complete, than it takes a place in normative documents, in the light of configuration of the environmental stress.

  13. VMM3, an ASIC for Micropattern Detectors

    CERN Document Server

    Iakovidis, Georgios; The ATLAS collaboration

    2018-01-01

    The VMM is a custom Application Specific Integrated Circuit (ASIC). It will be used in the front- end readout electronics of both the Micromegas and sTGC detectors of the New Small Wheel upgrade of the ATLAS experiment at CERN. It is being developed at Brookhaven National Laboratory and fabricated in the 130nm Global Foundries 8RF-DM process (former IBM 8RF- DM). The 64 channels ASIC has highly configurable parameters and is able to handle signals of opposite polarities and a high range of capacitances while being low noise and low on power consumption. The VMM has four independent data output paths. First is the “precision” (10-bit) amplitude and (effective) 20-bit time stamp read out continuously (250 ns dead-time per channel) or at when a trigger occurs. Second, a serial output called Address in Real Time (ART). This is the address of the channel which had a signal above threshold within the bunch crossing clock. Third, the parallel prompt outputs from all 64 channels in a variety of selectable formats...

  14. Analytical response function for planar Ge detectors

    Science.gov (United States)

    García-Alvarez, Juan A.; Maidana, Nora L.; Vanin, Vito R.; Fernández-Varea, José M.

    2016-04-01

    We model the response function (RF) of planar HPGe x-ray spectrometers for photon energies between around 10 keV and 100 keV. The RF is based on the proposal of Seltzer [1981. Nucl. Instrum. Methods 188, 133-151] and takes into account the full-energy absorption in the Ge active volume, the escape of Ge Kα and Kβ x-rays and the escape of photons after one Compton interaction. The relativistic impulse approximation is employed instead of the Klein-Nishina formula to describe incoherent photon scattering in the Ge crystal. We also incorporate a simple model for the continuous component of the spectrum produced by the escape of photo-electrons from the active volume. In our calculations we include external interaction contributions to the RF: (i) the incoherent scattering effects caused by the detector's Be window and (ii) the spectrum produced by photo-electrons emitted in the Ge dead layer that reach the active volume. The analytical RF model is compared with pulse-height spectra simulated using the PENELOPE Monte Carlo code.

  15. Calibration of the E Si detector in a DE-E telescope with a ^212Pb pin source

    Science.gov (United States)

    Chan, Ka Pang

    2012-10-01

    In nuclear physics experiments, telescopes composed of two or more large area silicon strip detectors are used to identify charged particles. To use the energy loss method for particle identification, a thin (˜0.065mm) silicon detector (DE) is mounted in front of a thicker E detector (˜1.5 mm). The DE Si detector can be calibrated with 8.785, 6.778, 6.288, 5.685 and 5.423 MeV alpha particles emitted from a ^228Th source. However, this method cannot be used to calibrate the E detector as the alpha particles cannot penetrate the front DE detector. We have developed a method to calibrate the E detector by inserting a small irradiated dowel pin between the two Si detectors. The pin source is electroplated with ^212Pb nuclei which emit alpha particles with 8.785 MeV, 6.090 and 6.051 MeV. Insertion of the dowel pin is designed and guided so that the head of the pin lies near the center of the detector at a distance of 2.72 mm away from the surface of the E detector. In addition to providing two strong alpha peaks for calibrations, the close distance and high pixilation of the E detector allows accurate determination of the front dead layer of the E Si strip detector. This technique has been implemented successfully in calibrating the E Si detectors in the NSCL High Resolution Array (HiRA) consisting of 20 closely pack DE-E-CsI telescopes.

  16. Detector and System Developments for LHC Detector Upgrades

    CERN Document Server

    Mandelli, Beatrice; Guida, Roberto; Rohne, Ole; Stapnes, Steinar

    2015-05-12

    The future Large Hadron Collider (LHC) Physics program and the consequent improvement of the LHC accelerator performance set important challenges to all detector systems. This PhD thesis delineates the studies and strategies adopted to improve two different types of detectors: the replacement of precision trackers with ever increasingly performing silicon detectors, and the improvement of large gaseous detector systems by optimizing their gas mixtures and operation modes. Within the LHC tracker upgrade programs, the ATLAS Insertable B-layer (IBL) is the first major upgrade of a silicon-pixel detector. Indeed the overall ATLAS Pixel Detector performance is expected to degrade with the increase of luminosity and the IBL will recover the performance by adding a fourth innermost layer. The IBL Detector makes use of new pixel and front-end electronics technologies as well as a novel thermal management approach and light support and service structures. These innovations required complex developments and Quality Ass...

  17. INDIA: Photon multiplicity detector

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    Full text: The team of Indian scientists from Calcutta's Variable Energy Cyclotron Centre, Bhubaneswar Institute of Physics, Panjab (Chandigarh), Rajasthan (Jaipur) and Jammu in collaboration with GSI Darmstadt have contributed a large and highly granular preshower photon multiplicity detector (PMD) for the WA98 experiment at the CERN SPS proton synchrotron. This experiment studies high energy collisions of lead ions and will measure both charged particle and photon multiplicity in a large overlap region. The motivation for measuring photon multiplicity in ultra-relativistic heavy ion collisions stems from theoretical predictions of changes in the relative production of photons and charged particles in the phase transition of hadronic matter to quarkgluon plasma and its subsequent hadronization. The photon multiplicity detector consists of a matrix of scintillator pads placed in light-tight boxes and mounted behind the lead converter plates. The light from the scintillator pads is transported to the readout system using wavelength shifting (WLS) fibres. Developing on the team's earlier experience with a smaller version for the WA93 experiment (September 1991, page 16), several modifications were incorporated to improve light collection and transport. Use of improved WLS fibres, short WLS pieces to minimize self-absorption, and thermal splicing with long clear fibres were some of the important changes incorporated. Tests showed signficantly improved light collection. The scintillator pads were fabricated at all the five collaborating centres in India and the complicated assembly in the detector box modules carried out at the Variable Energy Cyclotron Centre, Calcutta. More than 400 lead converter plates were machined in Calcutta to rigorous tolerances of 0.2 mm. The assembled detector box modules and lead plates were shipped to CERN in spring 1994 for tests and installation. The WA98 PMD consists of over 50,000 scintillator pads of sizes varying from 15 to

  18. Lattice QCD at finite temperature

    International Nuclear Information System (INIS)

    DeTar, C.

    1988-01-01

    Recent progress in the numerical simulation of QCD at finite temperature is reviewed. Eight topics are treated briefly: (1) T c scaling, (2) Equation of state, (3) Baryon susceptibility, (4) The QCD Phase Diagram, (5) J/Ψ Binding in the Plasma, (6) The Screening Spectrum of the Plasma, (7) Gauge Symmetry Breaking at High T, (8) Progress in Computing Power. (author)

  19. Linguistics, Logic, and Finite Trees

    NARCIS (Netherlands)

    Blackburn, P.; Meyer-Viol, W.

    1993-01-01

    A modal logic is developed to deal with finite ordered binary trees as they are used in (computational) linguistics. A modal language is introduced with operators for the 'mother of', 'first daughter of' and 'second daughter of' relations together with their transitive reflexive closures.

  20. On symmetric pyramidal finite elements

    Czech Academy of Sciences Publication Activity Database

    Liu, L.; Davies, K. B.; Yuan, K.; Křížek, Michal

    2004-01-01

    Roč. 11, 1-2 (2004), s. 213-227 ISSN 1492-8760 R&D Projects: GA AV ČR IAA1019201 Institutional research plan: CEZ:AV0Z1019905 Keywords : mesh generation * finite element method * composite elements Subject RIV: BA - General Mathematics Impact factor: 0.108, year: 2004