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Sample records for channel electron multiplier

  1. Analytical, steady-state model of gain saturation in channel electron multipliers

    CERN Document Server

    Giudicotti, L

    2002-01-01

    By using the transmission line modeling (TLM) technique we derive a simple model describing the saturation of the gain in channel electron multipliers and show that it generalizes and extends a previous steady-state model due to Shikhaliev. Then by introducing a physically consistent rational approximation of the non-linear gain equation we derive an exact, steady-state, analytical solution in which, contrary to other empirical assumptions about the functional dependence of the internal voltage are not required. The model is then used to simulate a multianode microchannel plate (MCP) photomultiplier, showing that the computed gain in saturated conditions is qualitatively in agreement with published experimental data. Finally, we discuss the general validity of our model, we suggest possible measurements and comment existing data relevant for its validation.

  2. Photoionisation detection of single {sup 87}Rb-atoms using channel electron multipliers

    Energy Technology Data Exchange (ETDEWEB)

    Henkel, Florian Alexander

    2011-09-02

    Fast and efficient detection of single atoms is a universal requirement concerning modern experiments in atom physics, quantum optics, and precision spectroscopy. In particular for future quantum information and quantum communication technologies, the efficient readout of qubit states encoded in single atoms or ions is an elementary prerequisite. The rapid development in the field of quantum optics and atom optics in the recent years has enabled to prepare individual atoms as quantum memories or arrays of single atoms as qubit registers. With such systems, the implementation of quantum computation or quantum communication protocols seems feasible. This thesis describes a novel detection scheme which enables fast and efficient state analysis of single neutral atoms. The detection scheme is based on photoionisation and consists of two parts: the hyperfine-state selective photoionisation of single atoms and the registration of the generated photoion-electron pairs via two channel electron multipliers (CEMs). In this work, both parts were investigated in two separate experiments. For the first step, a photoionisation probability of p{sub ion}=0.991 within an ionisation time of t{sub ion}=386 ns is achieved for a single {sup 87}Rb-atom in an optical dipole trap. For the second part, a compact detection system for the ionisation fragments was developed consisting of two opposing CEM detectors. Measurements show that single neutral atoms can be detected via their ionisation fragments with a detection efficiency of {eta}{sub atom}=0.991 within a detection time of t{sub det}=415.5 ns. In a future combined setup, this will allow the state-selective readout of optically trapped, single neutral {sup 87}Rb-atoms via photoionisation detection with an estimated detection efficiency {eta}=0.982 and a detection time of t{sub tot} = 802 ns. Although initially developed for single {sup 87}Rb-atoms, the concept of photoionisation detection is in principle generally applicable to any

  3. The gas electron multiplier (GEM)

    CERN Document Server

    Bouclier, Roger; Dominik, Wojciech; Hoch, M; Labbé, J C; Million, Gilbert; Ropelewski, Leszek; Sauli, Fabio; Sharma, A

    1996-01-01

    We describe operating priciples and results obtained with a new detector component: the Gas Electrons Multiplier (GEM). Consisting of a thin composite sheet with two metal layers separated by a thin insulator, and pierced by a regular matrix of open channels, the GEM electrode, inserted on the path of electrons in a gas detector, allows to transfer the charge with an amplification factor approaching ten. Uniform response and high rate capability are demonstrated. Coupled to another device, multiwire or micro-strip chamber, the GEM electrode permit to obtain higher gains or less critical operation; separation of the sensitive (conversion) volume and the detection volume has other advantages, as a built-in delay (useful for triggering purposes) and the possibility of applying high fields on the photo-cathode of ring imaging detectors to improve efficiency. Multiple GEM grids in the same gas volume allow to obtain large amplification factors in a succession of steps, leading to the realization of an effective ga...

  4. Channel electron multiplier operated on a sounding rocket without a cryogenic vacuum pump from 120 - 75 km altitude

    Science.gov (United States)

    Dickson, S.; Gausa, M. A.; Robertson, S. H.; Sternovsky, Z.

    2012-12-01

    We demonstrate that a channel electron multiplier (CEM) can be operated on a sounding rocket in the pulse-counting mode from 120 km to 75 km altitude without the cryogenic evacuation used in the past. Evacuation of the CEM is provided only by aerodynamic flow around the rocket. This demonstration is motivated by the need for additional flights of mass spectrometers to clarify the fate of metallic compounds and ions ablated from micrometeorites and their possible role in the nucleation of noctilucent clouds. The CEMs were flown as guest instruments on the two sounding rockets of the CHAMPS (CHarge And mass of Meteoritic smoke ParticleS) rocket campaign which were launched into the mesosphere in October 2011 from Andøya Rocket Range, Norway. Modeling of the aerodynamic flow around the payload with Direct Simulation Monte-Carlo (DSMC) code showed that the pressure is reduced below ambient in the void beneath an aft-facing surface. An enclosure containing the CEM was placed above an aft-facing deck and a valve was opened on the downleg to expose the CEM to the aerodynamically evacuated region below. The CEM operated successfully from apogee down to ~75 km. A Pirani gauge confirmed pressures reduced to as low as 20% of ambient with the extent of reduction dependent upon altitude and velocity. Additional DSMC simulations indicate that there are alternate payload designs with improved aerodynamic pumping for forward mounted instruments such as mass spectrometers.

  5. Channel electron multiplier operated on a sounding rocket without a cryogenic vacuum pump from 120 to 80 km altitude

    Science.gov (United States)

    Dickson, Shannon; Gausa, Michael; Robertson, Scott; Sternovsky, Zoltan

    2013-04-01

    We demonstrate that a channel electron multiplier (CEM) can be operated on a sounding rocket in the pulse-counting mode from 120 km to 80 km altitude without the cryogenic evacuation used in the past. Evacuation of the CEM is provided only by aerodynamic flow around the rocket. This demonstration is motivated by the need for additional flights of mass spectrometers to clarify the fate of metallic compounds and ions ablated from micrometeorites and their possible role in the nucleation of noctilucent clouds. The CEMs were flown as guest instruments on two sounding rockets to the mesosphere. Modeling of the aerodynamic flow around the payload with Direct Simulation Monte-Carlo (DSMC) code showed that the pressure is reduced below ambient in the void behind (relative to the direction of motion) an aft-facing surface. An enclosure containing the CEM was placed forward of an aft-facing deck and a valve was opened during flight to expose the CEM to the aerodynamically evacuated region behind it. The CEM operated successfully from apogee down to ∼80 km. A Pirani gauge confirmed pressures reduced to as low as 20% of ambient with the extent of reduction dependent upon altitude and velocity. Additional DSMC simulations indicate that there are alternate payload designs with improved aerodynamic pumping for forward mounted instruments such as mass spectrometers.

  6. Gaseous Electron Multiplier (GEM) Detectors

    Science.gov (United States)

    Gnanvo, Kondo

    2017-09-01

    Gaseous detectors have played a pivotal role as tracking devices in the field of particle physics experiments for the last fifty years. Recent advances in photolithography and micro processing techniques have enabled the transition from Multi Wire Proportional Chambers (MWPCs) and Drift Chambers to a new family of gaseous detectors refer to as Micro Pattern Gaseous Detectors (MPGDs). MPGDs combine the basic gas amplification principle with micro-structure printed circuits to provide detectors with excellent spatial and time resolution, high rate capability, low material budget and high radiation tolerance. Gas Electron Multiplier (GEMs) is a well-established MPGD technology invented by F. Sauli at CERN in 1997 and deployed various high energy physics (HEP) and nuclear NP experiment for tracking systems of current and future NP experiments. GEM detector combines an exceptional high rate capability (1 MHz / mm2) and robustness against harsh radiation environment with excellent position and timing resolution performances. Recent breakthroughs over the past decade have allowed the possibility for large area GEMs, making them cost effective and high-performance detector candidates to play pivotal role in current and future particle physics experiments. After a brief introduction of the basic principle of GEM technology, I will give a brief overview of the GEM detectors used in particle physics experiments over the past decades and especially in the NP community at Thomas Jefferson National Laboratory (JLab) and Brookhaven National Laboratory (BNL). I will follow by a review of state of the art of the new GEM development for the next generation of colliders such as Electron Ion Collider (EIC) or High Luminosity LHC and future Nuclear Physics experiments. I will conclude with a presentation of the CERN-based RD51 collaboration established in 2008 and its major achievements regarding technological developments and applications of MPGDs.

  7. Imaging with the gas electron multiplier

    CERN Document Server

    Sauli, Fabio

    2007-01-01

    The Gas Electron Multiplier (GEM), introduced several years ago, is finding numerous applications thanks to its excellent performances in detecting and localizing ionizing radiation. This note summarizes recent developments of the technology, and presents some examples of applications.

  8. Gas Electron multipliers for low energy beams

    CERN Document Server

    Arnold, F; Ropelewski, L; Spanggaard, J; Tranquille, G

    2010-01-01

    Gas Electron Multipliers (GEM) find their way to more and more applications in beam instrumentation. Gas Electron Multiplication uses a very similar physical phenomenon to that of Multi Wire Proportional Chambers (MWPC) but for small profile monitors they are much more cost efficient both to produce and to maintain. This paper presents the new GEM profile monitors intended to replace the MWPCs currently used at CERN’s low energy Antiproton Decelerator (AD). It will be shown how GEMs overcome the documented problems of profile measurements with MWPCs for low energy beams, where the interaction of the beam with the detector has a large influence on the measured profile. Results will be shown of profile measurements performed at 5 MeV using four different GEM prototypes, with discussion on the possible use of GEMs at even lower energies needed at the AD in 2013.

  9. Development of a micro-array-type electron multiplier

    CERN Document Server

    Fukuda, D; Takahashi, H; Nakazawa, M; Kawarabayashi, J; Hirata, Y; Numazawa, T; Haga, T

    1999-01-01

    This paper describes the development of a micro-array-type electron multiplier (MAEM) and its application to preamplification of a hybrid photo diode (HPD) system. The MAEM consists of several dynode plates fabricated by micromachining techniques. In our simulation of the electron multiplication process in the HPD system, 4500 gain is easily obtained with the total voltage of 6 kV. No spread of electron charges into the neighboring channels is observed in the MAEM device. Consequently, very high position resolution can be achieved if the pixel-type PD is used with the MAEM. The simulation also showed small fluctuation of the electron transit time of 23 ps in the MAEM, thus very high timing resolution can be achieved.

  10. Development of a micro-array-type electron multiplier

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, D. E-mail: fukuda@sophie.q.t.u-tokyo.ac.jp; Inoue, M.; Takahashi, H.; Nakazawa, M.; Kawarabayashi, J.; Hirata, Y.; Numazawa, T.; Haga, T

    1999-10-21

    This paper describes the development of a micro-array-type electron multiplier (MAEM) and its application to preamplification of a hybrid photo diode (HPD) system. The MAEM consists of several dynode plates fabricated by micromachining techniques. In our simulation of the electron multiplication process in the HPD system, 4500 gain is easily obtained with the total voltage of 6 kV. No spread of electron charges into the neighboring channels is observed in the MAEM device. Consequently, very high position resolution can be achieved if the pixel-type PD is used with the MAEM. The simulation also showed small fluctuation of the electron transit time of 23 ps in the MAEM, thus very high timing resolution can be achieved.

  11. The Tynode: A new vacuum electron multiplier

    Energy Technology Data Exchange (ETDEWEB)

    Graaf, Harry van der, E-mail: vdgraaf@nikhef.nl [Delft University of Technology, Delft (Netherlands); Nikhef, Science Park 105, 1098 XG Amsterdam (Netherlands); Akhtar, Hassan; Budko, Neil; Chan, Hong Wah; Hagen, Cornelis W. [Delft University of Technology, Delft (Netherlands); Hansson, Conny C.T. [Delft University of Technology, Delft (Netherlands); Nikhef, Science Park 105, 1098 XG Amsterdam (Netherlands); Nützel, Gert; Pinto, Serge D. [Photonis, Roden (Netherlands); Prodanović, Violeta; Raftari, Behrouz; Sarro, Pasqualina M. [Delft University of Technology, Delft (Netherlands); Sinsheimer, John; Smedley, John [Brookhaven National Laboratory, Upton, NY 11973 (United States); Tao, Shuxia [Eindhoven University of Technology/DIFFER (Netherlands); Theulings, Anne M.M.G. [Delft University of Technology, Delft (Netherlands); Nikhef, Science Park 105, 1098 XG Amsterdam (Netherlands); Vuik, Kees [Delft University of Technology, Delft (Netherlands)

    2017-03-01

    By placing, in vacuum, a stack of transmission dynodes (tynodes) on top of a CMOS pixel chip, a single free electron detector could be made with outstanding performance in terms of spatial and time resolution. The essential object is the tynode: an ultra thin membrane, which emits, at the impact of an energetic electron on one side, a multiple of electrons at the other side. The electron yields of tynodes have been calculated by means of GEANT-4 Monte Carlo simulations, applying special low-energy extensions. The results are in line with another simulation based on a continuous charge-diffusion model. By means of Micro Electro Mechanical System (MEMS) technology, tynodes and test samples have been realized. The secondary electron yield of several samples has been measured in three different setups. Finally, several possibilities to improve the yield are presented.

  12. The Gas Electron Multiplier Chamber Exhibition LEPFest 2000

    CERN Multimedia

    2000-01-01

    The Gas Electron Multiplier (GEM) is a novel device introduced in 1996.Large area detectors based on this technology are in construction for high energy physics detectors.This technology can also be used for high-rate X-ray imaging in medical diagnostics and for monitoring irradiation during cancer treatment

  13. Development and applications of gas electron multiplier detectors

    CERN Document Server

    Sauli, Fabio

    2003-01-01

    An overview of the recent developments in the field of gas electron multiplier (GEM) detectors was presented. Cascading of several GEM foils permits the sustaining of large gains and thereby allows the detection of minimum ionizing particles. The application of GEM included, fast and position sensitive detection in particle physics, medicine, neutron spectrometry, and astrophysics. (Edited abstract) 19 Refs.

  14. Electron capture dissociation of singly and multiply phosphorylated peptides

    DEFF Research Database (Denmark)

    Stensballe, A; Jensen, Ole Nørregaard; Olsen, J V

    2000-01-01

    Analysis of phosphotyrosine and phosphoserine containing peptides by nano-electrospray Fourier transform ion cyclotron resonance (FTICR) mass spectrometry established electron capture dissociation (ECD) as a viable method for phosphopeptide sequencing. In general, ECD spectra of synthetic...... and native phosphopeptides appeared less complex than conventional collision activated dissociation (CAD) mass spectra of these species. ECD of multiply protonated phosphopeptide ions generated mainly c- and z(.)-type peptide fragment ion series. No loss of water, phosphate groups or phosphoric acid from...

  15. Antiproton beam profile measurements using Gas Electron Multipliers

    CERN Document Server

    Duarte Pinto, Serge; Spanggaard, Jens; Tranquille, Gerard

    2011-01-01

    The new beam profile measurement for the Antiproton Decelerator (AD) at CERN is based on a single Gas Electron Multiplier (GEM) with a 2D readout structure. This detector is very light, ~0.4% X_0, as required by the low energy of the antiprotons, 5.3 MeV. This overcomes the problems previously encountered with multi-wire proportional chambers (MWPC) for the same purpose, where beam interactions with the detector severely affect the obtained profiles. A prototype was installed and successfully tested in late 2010, with another five detectors now installed in the ASACUSA and AEgIS beam lines. We will provide a detailed description of the detector and discuss the results obtained. The success of these detectors in the AD makes GEM-based detectors likely candidates for upgrade of the beam profile monitors in all experimental areas at CERN. The various types of MWPC currently in use are aging and becoming increasingly difficult to maintain.

  16. Gas Electron Multiplier Detectors for TREK at J-PARC

    Science.gov (United States)

    Dongwi, Bishoy

    2013-10-01

    Lepton flavor universality is a basic assumption of the Standard Model (SM). The proposed experiment E36 at J-PARC in Japan measures decay widths of stopped K+ using the TREK (Time Reversal Experiment with Kaons) detector system to conduct precision measurements of RK = Γ (K+ -->e+ ν) / Γ (K+ -->μ+ ν) in search of lepton flavor universality violation. The SM prediction for the ratio of leptonic K+ decays is highly precise with an uncertainty of △RK /RK = 4 .10-4 . Any observed deviation from the SM prediction would yield clear indication of New Physics beyond the Standard Model. To test lepton flavor universality violation a total uncertainty for the decay ratio of Ke 2 /Kμ 2 is aimed to be 0 . 25 % (0 . 20 % stat + 0 . 15 % sys). The second portion of the experiment searches for heavy sterile neutrinos (N) in the K+ -->μ+ N decay and allows for further stringent searches for light new particles as a byproduct. Gas Electron Multiplier (GEM) detectors will be constructed for this experiment in order to measure charged tracks of μ+ and e+ from charged K+ decay. I will present Geant4 simulations of the TREK setup augmented with the GEM detectors. This work has been supported by DOE Early Career Award DE-SC0003884.

  17. Investigation of the Decelerating Field of an Electron Multiplier under Negative Ion Impact

    DEFF Research Database (Denmark)

    Larsen, Elfinn; Kjeldgaard, K.

    1973-01-01

    The effect of the decelerating field of an electron multiplier towards negative ions was investigated under standard mass spectrometric conditions. Diminishing of this decelerating field by changing of the potential of the electron multiplier increased the overall sensitivity to negative ions by ...... by a factor of 100. The secondary electron emission coefficient for the negative halogen ions relative to I− were measured on CuBe at the kinetic energies 1.0 and 1.5 keV.......The effect of the decelerating field of an electron multiplier towards negative ions was investigated under standard mass spectrometric conditions. Diminishing of this decelerating field by changing of the potential of the electron multiplier increased the overall sensitivity to negative ions...

  18. The Photon-Assisted Cascaded Electron Multiplier Operation in CF4 for Ion Backflow Suppression

    Science.gov (United States)

    Amaro, F. D.; Veloso, J. F. C. A.; dos Santos, J. M. F.; Breskin, A.; Chechik, R.; Lyashenko, A.

    2008-06-01

    The operation of the recently introduced photon assisted cascaded electron multiplier (PACEM) in CF4 is investigated. The PACEM uses the VUV scintillation produced in the electron avalanches of the first multiplier of the cascade to transfer the signal to the subsequent ones. The VUV scintillation induces the emission of a large number of photoelectrons from a Csl photocathode placed on the top-surface of the second multiplier. The photoelectrons are further multiplied in the subsequent stages of the cascade, resulting in efficient signal amplification. A mesh, set at a fixed voltage, is placed between the first and the second multipliers to block the charge transfer between them, thus suppressing all the ion backflow (IBF) heading to the first cascade element. The PACEM electrically isolates the first multiplier of the cascade and only the ions produced in the electron avalanches of the first element may flow back into the drift region. Operating in CF4, absolute IBFs as low as 1 ion per primary electron are achieved for drift fields of 0.1 kV/cm, while for fields of 0.5 kV/cm the absolute IBF is 10 ions/primary electron. This corresponds to an IBF of 10-4 at gains of 104, for time projection chambers (TPC) operating conditions, and IBFs of 10-5 at gains of 106 for gaseous photomultipliers (GPM) operating conditions.

  19. High dynamic range isotope ratio measurements using an analog electron multiplier

    Czech Academy of Sciences Publication Activity Database

    Williams, P.; Lorinčík, Jan; Franzreb, K.; Herwig, R.

    2013-01-01

    Roč. 45, č. 1 (2013), s. 549-552 ISSN 0142-2421 R&D Projects: GA MŠk ME 894 Institutional support: RVO:67985882 Keywords : Isotope ratios * electron multiplier * dynamic range Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.393, year: 2013

  20. Single electron based binary multipliers with overflow detection ...

    African Journals Online (AJOL)

    Power consumption in the single electron circuit is low irrespective of Bipolar junction transistor (BJT) or Complimentary Metal Oxide Semiconductor (CMOS) circuits. Power consumption can be drastically reduced by reducing the nodes. The processing speed of SED will be nearly close to electronic speed. Noise during ...

  1. The Photon-Assisted Cascaded Electron Multiplier: a concept for potential avalanche-ion blocking

    Science.gov (United States)

    Veloso, J. F. C. A.; Amaro, F. D.; dos Santos, J. M. F.; Breskin, A.; Lyashenko, A.; Chechik, R.

    2006-08-01

    We present a Photon-Assisted Cascaded Electron Multipliers (PACEM) which has a potential for ion back-flow blocking in gaseous radiation detectors: the avalanche from a first multiplication stage propagates to the successive one via its photons, which in turn induce photoelectron emission from a photocathode deposited on the second multiplier stage; the multiplication process may further continue via electron-avalanche propagation. The photonmediated stage allows, by a proper choice of geometry and fields, complete blocking of the ion back-flow into the first element; thus, only ions from the latter will flow back to the drift region. The PACEM concept was validated in a double-MHSP (Micro-Hole & Strip Plate) cascaded multiplier operated in xenon, where the intermediate scintillation stage provided optical gain of ~60. The double-MHSP detector had a total gain above 104 and energy resolution of 18% FWHM for 5.9 keV x-rays.

  2. The Photon-Assisted Cascaded Electron Multiplier: a concept for potential avalanche-ion blocking

    Energy Technology Data Exchange (ETDEWEB)

    Veloso, J F C A [Physics Dept., University of Aveiro, 3810-193 Aveiro (Portugal); Amaro, F D [Physics Dept., University of Coimbra, 3004-516 Coimbra (Portugal); Santos, J M F dos [Physics Dept., University of Coimbra, 3004-516 Coimbra (Portugal); Breskin, A [Dept. of Particle Physics, Weizmann Institute of Science, 76100 Rehovot (Israel); Lyashenko, A [Dept. of Particle Physics, Weizmann Institute of Science, 76100 Rehovot (Israel); Chechik, R [Dept. of Particle Physics, The Weizmann Institute of Science, 76100 Rehovot (Israel)

    2006-08-15

    We present a Photon-Assisted Cascaded Electron Multipliers (PACEM) which has a potential for ion back-flow blocking in gaseous radiation detectors: the avalanche from a first multiplication stage propagates to the successive one via its photons, which in turn induce photoelectron emission from a photocathode deposited on the second multiplier stage; the multiplication process may further continue via electron-avalanche propagation. The photonmediated stage allows, by a proper choice of geometry and fields, complete blocking of the ion back-flow into the first element; thus, only ions from the latter will flow back to the drift region. The PACEM concept was validated in a double-MHSP (Micro-Hole and Strip Plate) cascaded multiplier operated in xenon, where the intermediate scintillation stage provided optical gain of {approx}60. The double-MHSP detector had a total gain above 10{sup 4} and energy resolution of 18% FWHM for 5.9 keV x-rays.

  3. THick Gas Electron Multiplier (THGEM) detector readout based on TDC-FPGAs

    Energy Technology Data Exchange (ETDEWEB)

    Buechele, Maximilian; Fischer, Horst; Gorzellik, Matthias; Grussenmeyer, Tobias; Herrmann, Florian; Joerg, Philipp; Kremser, Paul; Schopferer, Sebastian [Physikalisches Institut, Albert-Ludwigs-Universitaet Freiburg (Germany); Collaboration: THGEM Group of the COMPASS Collaboration

    2014-07-01

    The RD51 program has been investigating a novel photon detector technology called THGEM, aimed to be operated in future Ring Imaging Cherenkov (RICH) Counters. The THGEM design is adopted from the Gas Electron Multiplier (GEM) using Printed Circuit Board (PCB) material. The manufacturing process uses standard PCB drilling and etching techniques which allows to cover large detector areas at gains up to 10{sup 6} in a mechanically robust and very cost-efficient manner. Promising results have also been obtained with a hybrid approach, which combines the THGEM with a Micromega layer to further suppress the ion back flow to the photocathode. In the course of the RICH-1 detector upgrade of the COMPASS experiment at CERN, the existing Multi Wire Proportional Chambers will partly be replaced by a set of THGEMs. For the digital readout, we are designing a front-end board processing 384 detector channels by TDC-FPGAs. The boards reading a single THGEM chamber are connected in a star topology in order to exploit the data rate capability of the optical transceivers interfacing with the downstream data acquisition system.

  4. Design of a new tissue-equivalent proportional counter based on a gas electron multiplier

    Energy Technology Data Exchange (ETDEWEB)

    Farahmand, M. E-mail: m.farahmand@iri.tudelft.nl; Bos, A.J.J.; Huizenga, J.; De Nardo, L.; Eijk, C.W.E. van

    2003-08-21

    By employing a Gas Electron Multiplier a new type of mini multi-element Tissue-Equivalent Proportional Counter (TEPC) has been designed and constructed. In this paper, we describe the design of this novel counter. The first pulse height measurements with this counter for both methane- and propane-based Tissue Equivalent gases are presented. These results show promising properties for application of this novel type TEPC in microdosimetric measurements.

  5. Proton and hydrogen atom detection efficiency of resistance strip magnetic electron multiplier particle-counting system

    Energy Technology Data Exchange (ETDEWEB)

    Wehrenberg, P.J.; Clark, K.C.

    1976-10-01

    The absolute detection efficiency for protons and for hydrogen atoms in the energy range 5--60 keV is determined for a resistance strip magnetic electron multiplier particle-counting system. Significant history-dependent gain variations are discussed. The detector system is suitable for use in coincidence experiments requiring particle-counting rates to 1.0 MHz and timing accuracies of 3.0 nsec. (AIP)

  6. An aging study of a gas electron multiplier with micro-strip gas chamber readout

    CERN Document Server

    Miyamoto, J

    1999-01-01

    We have performed an aging study of a Gas Electron Multiplier (GEM) readout with a Micro-Strip Gas Chamber (MSGC). The GEM is constructed from Kapton and copper, and the MSGC is constructed from semiconductive glass and gold. When the detector (GEM+MSGC) is operated in an argon-dimethyl ether (DME) gas mixture and irradiated with a 5.4 keV photon beam, about 220 mC/cm of charge can be accumulated without degradation of the detector performance. This corresponds to about 20 years of operation at the LHC.

  7. Coupled-Multiplier Accelerator Produces High-Power Electron Beams for Industrial Applications

    Science.gov (United States)

    Hatridge, M.; McIntyre, P.; Roberson, S.; Sattarov, A.; Thomas, E.; Meitzler, Charles

    2003-08-01

    The coupled multiplier is a new approach to efficient generation of MeV d.c. power for accelerator applications. High voltage is produced by a series of modules, each of which consists of a high-power alternator, step-up transformer, and 3-phase multiplier circuit. The alternators are connected mechanically along a rotating shaft, and connected by insulating flexible couplers. This approach differs from all previous d.c. technologies in that power is delivered to the various stages of the system mechanically, rather than through capacitive or inductive electrical coupling. For this reason the capital cost depends linearly on required voltage and power, rather than quadratically as with conventional technologies. The CM technology enables multiple electron beams to be driven within a common supply and insulating housing. MeV electron beam is extremely effective in decomposing organic contaminants in water. A 1 MeV, 100 kW industrial accelerator using the CM technology has been built and is being installed for treatment of wastewater at a petrochemical plant.

  8. Electron transfer in multiply bridged donor-acceptor molecules: Dephasing and quantum coherence.

    Science.gov (United States)

    Goldsmith, Randall H; Wasielewski, Michael R; Ratner, Mark A

    2006-10-19

    We present a simple theoretical treatment of nonadiabatic electron transfer in multiply bridged donor-bridge-acceptor molecules using the density matrix formalism. Destructive interference can result from different signed couplings between bridge sites, with the simplest system being a four-site Joachim-type molecular interferometer. Previous work has shown that deposition of energy on the bridge sites erases the interference and recovers transport. We show that pure local dephasing, a completely elastic process, is also capable of eliminating destructive interference and regaining transport. Destructive interference as a result of system connectivity can explain the familiar ortho-meta-para reactivity of benzene bridges. We also show that pure dephasing can yield a coalescence of ortho, meta, and para effective coupling strengths and suggest a system to observe this effect experimentally.

  9. Gas electron multiplier (GEM) operation with tissue-equivalent gases at various pressures

    Energy Technology Data Exchange (ETDEWEB)

    Farahmand, M. E-mail: m.farahmand@iri.tudelft.nl; Bos, A.J.J.; Eijk, C.W.E. van

    2003-06-21

    We have studied the operation of two different Gas Electron Multiplier (GEM) structures in both methane and propane based Tissue-Equivalent (TE) gases at different pressures varying from 0.1 to 1 atm. This work was motivated to explore the possibility of using a GEM for a new type of Tissue Equivalent Proportional Counter. In methane based TE gas, a maximum safe GEM gain of 1.5x10{sup 3} has been reached while in propane based TE gas this is 6x10{sup 3}. These maxima have been reached at different gas pressures depending on GEM structure and TE gas. Furthermore, we observed a decrease of the GEM gain in time before it becomes stable. Charge up/polarisation effects can explain this.

  10. Construction and performance of a micro-pattern stereo detector with two gas electron multipliers

    Energy Technology Data Exchange (ETDEWEB)

    Barvich, T.; Bluem, P.; Erdmann, M. E-mail: Martin.Erdmann@cern.ch; Fahrer, M.; Kaercher, K.; Kuehn, F.; Moermann, D.; Mueller, Th.; Neuberger, D.; Roederer, F.; Simonis, H.J.; Skiba, A.; Thuemmel, W.H.; Weiler, Th.; Weseler, S

    2002-06-11

    The construction of a micro-pattern gas detector of dimensions 40x10 cm{sup 2} is described. Two gas electron multiplier foils (GEM) provide the internal amplification stages. A two-layer readout structure was used, manufactured using the same technology as the GEM foils. The strips of each layer cross at an effective crossing angle of 6.7 deg. and have a 406 {mu}m pitch. The performance of the detector has been evaluated in a muon beam at CERN using a silicon telescope as reference system. The position resolutions of two orthogonal coordinates are measured to be 50 {mu}m and 1 mm, respectively. The muon detection efficiency for two-dimensional space points reaches 96%.

  11. Performance test of a micro-pattern stereo detector with two gas electron multipliers

    Energy Technology Data Exchange (ETDEWEB)

    Barvich, T.; Bluem, P.; Erdmann, M. E-mail: martin.erdmann@cern.ch; Fahrer, M.; Kaercher, K.; Kuehn, F.; Moermann, D.; Mueller, Th.; Neuberger, D.; Roederer, F.; Simonis, H.J.; Skiba, A.; Thuemmel, W.H.; Weiler, Th.; Weseler, S

    2002-02-01

    We report on the performance of a large micro-pattern detector with two gas electron multiplier foils and a two-layer readout structure at ground potential. The two readout layers each have a 406 {mu}m pitch and cross at an effective angle of 6.7 deg. . This structure allows for two orthogonal coordinates to be determined. Using a muon beam at CERN together with a silicon tracking system, the position resolutions of the two coordinates are measured to be 50 {mu}m and 1 mm respectively (1 standard deviation). The muon detection efficiency for the two-dimensional space points reaches 96%. The detector was found to be well operational over a wide range in the settings of the different electrical fields.

  12. Multi-anode photon-multiplier readout electronics for the LHCb ring imaging Cherenkov detectors

    CERN Document Server

    Smale, N J

    2004-01-01

    A readout system for the Ring Imaging CHerenkov (RICH) detectors of the LHCb experiment has been developed. Two detector technologies for the measurement of Cherenkov photons are considered, the Multi-Anode Photo-Multiplier Tube (MAPMT) and the Hybrid Photon Detector (HPD), both of which meet the RICH requirements. The properties of the MAPMT are evaluated using a controlled single-photon source; a pixel-to-pixel gain variation of ~3 and a typical signal to noise of ~20 is measured. The relative tube efficiency is found to be reduced by ~26 % due to the detailed focusing structure of the MAPMT device. A radiation hard application-specific integrated circuit (ASIC) chip, the Beetle1.2MA0, has been developed to capture and store signals from a pair of MAPMTs. The Beetle1.2MA0 is built on the architecture of the Beetle family that was designed for silicon strip detectors, the difference being a modified front-end amplifier. The 128 input-channels of the Beetle1.2MA0 have a charge-sensitive pre-amplifier followed...

  13. Electron capture and deprotonation processes observed in collisions between Xe8+ and multiply protonated cytochrome-C

    NARCIS (Netherlands)

    Martin, S.; Ortega, C.; Chen, L.; Bredy, R.; Vernier, A.; Dugourd, P.; Antoine, R.; Bernard, J.; Reitsma, G.; Gonzalez Magana, Olmo; Hoekstra, Ronnie; Schlathölter, Thomas

    2014-01-01

    Electron-transfer processes in interaction between highly charged ions and multiply protonated proteins have been studied. Collisions between Xe8+ at 96 keV and protonated cytochrome-C at selected charge state (q from 15+ to 19+) result inmass spectra composed mainly of intact molecular ions. From

  14. Electronic Commerce and Retail Channel Substitution

    NARCIS (Netherlands)

    M.C.W. Janssen (Maarten); R. van der Noll

    2002-01-01

    textabstractWe analyze a market where firms compete in a conventional and an electronic retail channel. Consumers easily compare prices online, but some incur purchase uncertainties on the online channel. We investigate the market shares of the two retail channels and the prices that are charged. We

  15. Properties of the Flight Model Gas Electron Multiplier for the GEMS Mission

    Science.gov (United States)

    Takeuchi, Yoko; Kitaguchi, Takao; Hayato, Asami; Tamagawa, Toru; Iwakiri, Wataru; Asami, Fumi; Yoshikawa, Akifumi; Kaneko, Kenta; Enoto, Teruaki; Black, Kevin; hide

    2014-01-01

    We present the gain properties of the gas electron multiplier (GEM) foil in pure dimethyl ether (DME) at 190 Torr. The GEM is one of the micro pattern gas detectors and it is adopted as a key part of the X-ray polarimeter for the GEMS mission. The X-ray polarimeter is a time projection chamber operating in pure DME gas at 190 Torr. We describe experimental results of (1) the maximum gain the GEM can achieve without any discharges, (2) the linearity of the energy scale for the GEM operation, and (3) the two-dimensional gain variation of the active area. First, our experiment with 6.4 keV X-ray irradiation of the whole GEM area demonstrates that the maximum effective gain is 2 x 10(exp 4) with the applied voltage of 580 V. Second, the measured energy scale is linear among three energies of 4.5, 6.4, and 8.0 keV. Third, the two-dimensional gain mapping test derives the standard deviation of the gain variability of 7% across the active area.

  16. The current status of the Gas Electron Multiplier (GEM) research at Kasetsart University, Thailand

    Science.gov (United States)

    Kumpiranon, P.; Kulasri, K.; Rittirong, A.; Saenboonruang, K.

    2017-06-01

    During the past decade, Gas Electron Multiplier (GEM) detectors have been greatly developed and utilized in numbers of applications including advanced nuclear and particle researches, medical imaging, astrophysics, and neutron detection for national security. Our GEM research group at the Department of Applied Radiation and Isotopes, Faculty of Science, Kasetsart University, Thailand, realized in its excellent properties/potentials and started extensive researches on GEM detectors. To build a strong foundation on our research group, two 10 cm × 10 cm triple GEM detectors were characterized on their important properties including absolute gains and detection uniformity. Moreover, to widen applications of the GEM detector, our group had modified the GEM detector by introducing either solid or gaseous neutron converters to the detector so that the detector could effectively detect neutrons. These modifications included coating a thin film of 10B and natB to the GEM drift cathode for thermal neutron detection and flowing a gas mixture of He/CO2 (80:20 and 70:30) and C4H10/He/CO2 (7:70:23) for fast neutron detection. Results showed that the modified GEM-based neutron detector could detect both types of neutrons with different relative efficiencies and gains depending on thicknesses and types of neutron converters. This article discusses basic knowledge of the GEM detector, construction and testing procedures, results, and discussion.

  17. Gas electron multipliers. Development of large area GEMS and spherical GEMS

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Serge Duarte

    2011-08-15

    Gaseous radiation detectors have been a crucial part of high-energy physics instrumentation since the 1960s, when the first multiwire proportional counters were built. In the 1990s the first micropattern gas detectors (MPGDS) saw the light; with sub-millimeter feature sizes these novel detectors were faster and more accurate than their predecessors. The gas electron multiplier (GEM) is one of the most successful of these technologies. It is a charge multiplication structure made from a copper clad polymer foil, pierced with a regular and dense pattern of holes. I describe the properties and the application of GEMs and GEM. detectors, and the research and development I have done on this technology. Two of the main objectives were the development of large area GEMs ({proportional_to}m{sup 2}) for particle physics experiments and GEMs with a spherical shape for X-ray or neutron diffraction detectors. Both have been realized, and the new techniques involved are finding their way to applications in research and industry. (orig.)

  18. Large Gas Electron Multiplier Trackers for Super Bigbite Spectrometer at Jefferson lab Hall A

    Science.gov (United States)

    Saenboonruang, K.; Gnanvo, K.; Liyanage, N.; Nelyubin, V.; Sacher, S.; Cisbani, E.; Musico, P.; Wojtsekhowski, B.

    2013-04-01

    The 12 GeV upgrade at Jefferson Lab (JLAB) makes many exciting nuclear experiments possible. These experiments also require new high performance instrumentation. The Super Bigbite Spectrometer (SBS) was proposed to perform a series of high precision nucleon form factor experiments at large momentum transfer. The SBS will be capable of operating at a very high luminosity and provide a large solid angle acceptance of 76 msr. SBS will be equipped with a double focal plane polarimeter. Thus, SBS will have three large trackers made of Gas Electron Multiplier (GEM) chambers. The first, second, and third trackers will consist of six, four, and four tracking layers respectively. When completed in 2017, the SBS GEM trackers will form one of the largest sets of GEM chambers in the world. The GEM trackers allow the SBS to operate under high background rates over 500 kHz/cm^2, while providing an excellent spatial resolution of 70 μm. The first tracker will be constructed at the Istituto Nazionale di Fisica Nucleare in Italy, while the second and third trackers will be built at the University of Virginia. In 2012, the first UVa SBS GEM chamber prototype was successfully constructed and tested. The GEM chamber construction details and test results will be presented in this talk.

  19. A how-to approach for a 3D simulation of charge transfer characteristics in a gas electron multiplier (GEM)

    CERN Document Server

    Sharma, A

    1999-01-01

    In this paper a detailed description of how to simulate charge transfer processes in a gaseous device is presented, taking the gas electron multiplier (GEM) as an example. A 3-dimensional simulation of the electric field and avalanche is performed. Results on charge transport are compared to experiment and agree within experimental errors; the avalanche mechanism and positive ion feedback are studied. The procedures used in the simulation are described in detail, and program scripts are appended. (15 refs).

  20. Statistics of electron multiplication in a multiplier phototube; Iterative method; Estadistica de la multiplicacion de electrones en un fotomultiplicador: Metodos iterativos

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, J. F.; Grau, A.

    1985-07-01

    In the present paper an iterative method is applied to study the variation of dynode response in the multiplier phototube. Three different situation are considered that correspond to the following ways of electronic incidence on the first dynode: incidence of exactly one electron, incidence of exactly r electrons and incidence of an average r electrons. The responses are given for a number of steps between 1 and 5, and for values of the multiplication factor of 2.1, 2.5, 3 and 5. We study also the variance, the skewness and the excess of jurtosis for different multiplication factors. (Author) 11 refs.

  1. Simplifying Electron Beam Channeling in Scanning Transmission Electron Microscopy (STEM).

    Science.gov (United States)

    Wu, Ryan J; Mittal, Anudha; Odlyzko, Michael L; Mkhoyan, K Andre

    2017-08-01

    Sub-angstrom scanning transmission electron microscopy (STEM) allows quantitative column-by-column analysis of crystalline specimens via annular dark-field images. The intensity of electrons scattered from a particular location in an atomic column depends on the intensity of the electron probe at that location. Electron beam channeling causes oscillations in the STEM probe intensity during specimen propagation, which leads to differences in the beam intensity incident at different depths. Understanding the parameters that control this complex behavior is critical for interpreting experimental STEM results. In this work, theoretical analysis of the STEM probe intensity reveals that intensity oscillations during specimen propagation are regulated by changes in the beam's angular distribution. Three distinct regimes of channeling behavior are observed: the high-atomic-number (Z) regime, in which atomic scattering leads to significant angular redistribution of the beam; the low-Z regime, in which the probe's initial angular distribution controls intensity oscillations; and the intermediate-Z regime, in which the behavior is mixed. These contrasting regimes are shown to exist for a wide range of probe parameters. These results provide a new understanding of the occurrence and consequences of channeling phenomena and conditions under which their influence is strengthened or weakened by characteristics of the electron probe and sample.

  2. Gaseous electron multiplier-based soft x-ray plasma diagnostics development: Preliminary tests at ASDEX Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Chernyshova, M., E-mail: maryna.chernyshova@ipplm.pl; Malinowski, K.; Czarski, T.; Kowalska-Strzęciwilk, E. [Institute of Plasma Physics and Laser Microfusion, Hery 23, 01-497 Warsaw (Poland); Wojeński, A.; Poźniak, K. T.; Kasprowicz, G.; Krawczyk, R.; Kolasiński, P.; Zabołotny, W.; Zienkiewicz, P. [Institute of Electronic Systems, Warsaw University of Technology, Nowowiejska 15/19, 00-665 Warsaw (Poland); Vezinet, D.; Herrmann, A. [Max Planck Institute for Plasma Physics, Boltzmannstr. 2, 85748 Garching (Germany); Mazon, D.; Jardin, A. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France)

    2016-11-15

    A Gaseous Electron Multiplier (GEM)-based detector is being developed for soft X-ray diagnostics on tokamaks. Its main goal is to facilitate transport studies of impurities like tungsten. Such studies are very relevant to ITER, where the excessive accumulation of impurities in the plasma core should be avoided. This contribution provides details of the preliminary tests at ASDEX Upgrade (AUG) with a focus on the most important aspects for detector operation in harsh radiation environment. It was shown that both spatially and spectrally resolved data could be collected, in a reasonable agreement with other AUG diagnostics. Contributions to the GEM signal include also hard X-rays, gammas, and neutrons. First simulations of the effect of high-energy photons have helped understanding these contributions.

  3. New Efficient Detector for Radiation Therapy Imaging using Gas Electron Multipliers

    OpenAIRE

    Östling, Janina

    2006-01-01

    Currently film is being replaced by electronic detectors for portal imaging in radiation therapy. This development offers obvious advantages such as on-line quality assurance and digital images that can easily be accessed, processed and communicated. In spite of the improvements, the image quality has not been significantly enhanced, partly since the quantum efficiency compared to film is essentially the same, and the new electronic devices also suffer from sensitivity to the harsh radiation ...

  4. An electron-multiplying "Micromegas" grid made in silicon wafer post-processing technology

    CERN Document Server

    Chefdeville, M; Giomataris, Ioanis; van der Graaf, H; Heijne, Erik H M; Van der Putten, S; Salm, C; Schmitz, J; Smits, S; Timmermans, J; Visschers, J L

    2006-01-01

    A technology for manufacturing an aluminium grid onto a silicon wafer has been developed. The grid is fixed parallel and precisely to the wafer (anode) surface at a distance of 50 \\mum by means of insulating pillars. When some 400 V are applied between the grid and (anode) wafer, gas multiplication occurs : primary electrons from the drift space above the grid enter the holes and cause electron avalanches in the high-field region between the grid and the anode. Production and operational characteristics of the device are described. With this newly developed technology, CMOS (pixel) readout chips can be covered with a gas multiplication grid. Such a chip forms, together with the grid, an integrated device which can be applied as readout in a wide field of gaseous detectors.

  5. Simulation and Digitization of a Gas Electron Multiplier Detector Using Geant4 and an Object-Oriented Digitization Program

    Science.gov (United States)

    McMullen, Timothy; Liyanage, Nilanga; Xiong, Weizhi; Zhao, Zhiwen

    2017-01-01

    Our research has focused on simulating the response of a Gas Electron Multiplier (GEM) detector using computational methods. GEM detectors provide a cost effective solution for radiation detection in high rate environments. A detailed simulation of GEM detector response to radiation is essential for the successful adaption of these detectors to different applications. Using Geant4 Monte Carlo (GEMC), a wrapper around Geant4 which has been successfully used to simulate the Solenoidal Large Intensity Device (SoLID) at Jefferson Lab, we are developing a simulation of a GEM chamber similar to the detectors currently used in our lab. We are also refining an object-oriented digitization program, which translates energy deposition information from GEMC into electronic readout which resembles the readout from our physical detectors. We have run the simulation with beta particles produced by the simulated decay of a 90Sr source, as well as with a simulated bremsstrahlung spectrum. Comparing the simulation data with real GEM data taken under similar conditions is used to refine the simulation parameters. Comparisons between results from the simulations and results from detector tests will be presented.

  6. Commercial and cost effective production of Gas Electron Multiplier (GEM) Foils

    Energy Technology Data Exchange (ETDEWEB)

    Crary, David

    2010-05-05

    The nuclear and high energy physics research community is constantly searching for new and improved tracking and radiation detectors. The introduction of micropattern detectors has opened new opportunities for improving the rate capabilities, as well as the spatial and time resolution of particle detectors in these applications. GEM detectors in particular have received enormous interest for use in detectors planned for a number of new and upgraded experiments at many different research facilities. These include both the STAR and PHENIX experiments at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory, experiments at the Thomas Jefferson National Laboratory, Oak Ridge National Laboratory, and at the future electron-positron Linear Collider. At the present time, CERN is not able to supply foils in sufficient quantities to accommodate the needs of these experiments. Compounding this problem, there is a strong interest in GEM foils for numerous other applications, such as in astrophysics, medical imaging and detectors for homeland security. It would therefore be of significant benefit to the research community to develop a commercial source of GEM foils for all of these applications. Tech-Etch is in a unique position to develop this technology for commercial use. Tech-Etch has not only experience in numerous related high precision etched Kapton® products, but it also has strong ties with several research institutions (namely Brookhaven, Yale and MIT) that can help develop and evaluate the performance of the GEM foils produced at Tech-Etch. Additionally, since Tech-Etch is a small company, it also has the capability to produce a large variety of part configurations, as well as the flexibility to shift production methods, equipment, and chemistry to optimize the GEM foil manufacturing process without being constrained by existing work running on high volume continuous coil equipment.

  7. Commercial and Cost Effective Production of Gas Electron Multiplier (GEM) Foils

    Energy Technology Data Exchange (ETDEWEB)

    Woody, Craig

    2009-03-31

    The nuclear and high energy physics research community is constantly searching for new and improved tracking and radiation detectors. The introduction of micropattern detectors has opened new opportunities for improving the rate capabilities, as well as the spatial and time resolution of particle detectors in these applications. GEM detectors in particular have received enormous interest for use in detectors planned for a number of new and upgraded experiments at many different research facilities. These include both the STAR and PHENIX experiments at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory, experiments at the Thomas Jefferson National Laboratory, Oak Ridge National Laboratory, and at the future electron-positron Linear Collider. At the present time, CERN is not able to supply foils in sufficient quantities to accommodate the needs of these experiments. Compounding this problem, there is a strong interest in GEM foils for numerous other applications, such as in astrophysics, medical imaging and detectors for homeland security. It would therefore be of significant benefit to the research community to develop a commercial source of GEM foils for all of these applications. Tech-Etch is in a unique position to develop this technology for commercial use. Tech-Etch has not only experience in numerous related high precision etched Kapton® products, but it also has strong ties with several research institutions (namely Brookhaven, Yale and MIT) that can help develop and evaluate the performance of the GEM foils produced at Tech-Etch. Additionally, since Tech-Etch is a small company, it also has the capability to produce a large variety of part configurations, as well as the flexibility to shift production methods, equipment, and chemistry to optimize the GEM foil manufacturing process without being constrained by existing work running on high volume continuous coil equipment.

  8. Preliminary results of the Gas Electron Multiplier (GEM) as real-time beam monitor in hadron therapy

    Energy Technology Data Exchange (ETDEWEB)

    Aza, E., E-mail: eleni.aza@cern.ch [CERN, Geneva 23, 1211 Geneva (Switzerland); AUTH, Department of Physics, 54124 Thessaloniki (Greece); Ciocca, M. [Fondazione CNAO, Strada Campeggi 53, 27100 Pavia (Italy); Murtas, F. [CERN, Geneva 23, 1211 Geneva (Switzerland); LNF-INFN, Via Fermi 40, 00044 Frascati (Italy); Puddu, S. [CERN, Geneva 23, 1211 Geneva (Switzerland); AEC-LHEP, University of Bern, Sidlerstrasse 5, 3012 Bern (Switzerland); Pullia, M. [Fondazione CNAO, Strada Campeggi 53, 27100 Pavia (Italy); Silari, M. [CERN, Geneva 23, 1211 Geneva (Switzerland)

    2017-01-01

    The use of proton and carbon ion beams in cancer therapy (also known as hadron therapy) is progressively growing worldwide due to their improved dose distributions, sparing of healthy tissues and (for carbon ions) increased radiobiological effectiveness especially for radio-resistant tumours. Strict Quality Assurance (QA) protocols need to be followed for guaranteeing the clinical beam specifications. The aim of this study was to assess the performance of a gaseous detector based on the Gas Electron Multiplier (GEM) technology for measuring the beam spot dimensions and the homogeneity of the scanned irradiation field, which are daily QA tasks commonly performed using radiochromic films. Measurements performed at the National Centre for Oncological Hadron Therapy (CNAO) in Pavia (Italy) showed that the detector is able to monitor the 2D beam image on-line with a pad granularity of 2 mm and a response proportional to the number of delivered particles. The dose homogeneity was measured with low deviation from the results obtained with radiochromic films.

  9. Muon Chamber Endcap Upgrade of the CMS Experiment with Gas Electron Multiplier (GEM) Detectors and their Performance

    CERN Document Server

    Gola, Mohit

    2017-01-01

    As the CERN LHC is heading towards a high luminosity phase a very high flux is expected in the endcaps of the CMS Detector. The presence of muons in collision events can be due to rare or new physics so it is important to maintain the high trigger efficiency of the CMS muon system. The CMS Collaboration has proposed to instrument the high-eta region (1.6 lt IetaI lt 2.2) of the muon endcaps with Gas Electron Multiplier (GEM) detectors, referred to as GE1/1 chambers, during the LS2. This technology will help in maintaining optimum trigger performance with maximum selection efficiency of muons even in a high flux environment. We describe plans for a Slice Test to installa few GE1/1 chambers covering 50 degrees in azimuthal angle within the CMS detector in 2017, with subsequent operation during the current Run 2 of the LHC. We show the performance of the GE1/1 chambers to be installed during the slice test, specifically GEM foil leakage currents, chamber gas volume integrity, high voltage circuit performanc...

  10. Experiences with a pre-series of Micro Strip Gas Counters with Gas Electron Multipliers for high rate applications

    CERN Document Server

    Zander, Anette

    2001-01-01

    Micro strip gas chambers (MSGCs) are promising candidates for large scale applications. They combine a good spatial resolution with high granularity and low cost. As a possible extension of the plain MSGC, a Gas Electron Multiplier (GEM) foil may be implemented into the detector in order to increase the safety of operation. It was planned to equip the outer part of the tracking system of the Compact Muon Solenoid (CMS) experiment at the future Large Hadron Collider (LHC) at the Centre de Recherche Nucleaire (CERN) with MSGCs. In the barrel part of the tracker, plain MSGCs were to be used. For the forward part, the MSGC+GEM technology was envisaged. This thesis describes the assembly and test of a pre-series of 18 fully functional MSGC+GEM forward detector modules to determine their radiation hardness and their readiness for mass production. Five of the modules were built at Aachen, thirteen more at the 'Institut für Experimentelle Kernphysik' in Karlsruhe. For the pre-series, two different types of GEM foils...

  11. Test beam studies of Gas Electron Multiplier (GEM) detectors for the upgrade of CMS endcap muon system

    CERN Document Server

    Sharma, Ram Krishna

    2017-01-01

    The High Luminosity LHC (HL-LHC) will provide exceptional high instantaneous and integrated luminosity. The forward region $\\mid \\eta \\mid \\geq 1.5$ of the CMS detector will face extremely high particle rates in tens of $KHz/cm^{2}$ and hence it will affect the momentum resolution and longevity of the muon detectors. To overcome these issues the CMS collaboration has decided to install new large size rate capable Triple Gas Electron Multiplier (GEM) detectors in the forward region of CMS muon system. The first set of Triple GEM detectors will be installed in the GE1/1 region $(1.5 \\leq \\eta \\leq 2.2)$ of muon endcap during the LS2 of the LHC and the next one will be installed in the GE2/1 region $(1.6 \\leq \\eta \\leq 2.5)$, during the LS3. Towards this goal, full-size CMS Triple GEM prototype chambers have been fabricated and put under the test beam at the CERN SPS test beam facility. The GEM detectors were operated with two gas mixtures $Ar/CO_{2}$ (70/30) and $Ar/CO_{2}/CF_{4}$ (40/15/45). In 2014 and 2016, ...

  12. An ionisation gauge using a channel electron multiplier for pressures below 10$\\^{-12}$

    CERN Document Server

    Blechschmidt, Diether

    1973-01-01

    Since new techniques to achieve pressures of below 10/sup -12/ Torr have been developed, gauges with an appropriate low pressure limit are required. Channeltrons, with their high gain, seem to be the best means to construct gauges with high sensitivity. In this paper a new ionisation gauge using a channeltron has been described. (15 refs).

  13. Dictionary Indexing of Electron Channeling Patterns.

    Science.gov (United States)

    Singh, Saransh; De Graef, Marc

    2017-02-01

    The dictionary-based approach to the indexing of diffraction patterns is applied to electron channeling patterns (ECPs). The main ingredients of the dictionary method are introduced, including the generalized forward projector (GFP), the relevant detector model, and a scheme to uniformly sample orientation space using the "cubochoric" representation. The GFP is used to compute an ECP "master" pattern. Derivative free optimization algorithms, including the Nelder-Mead simplex and the bound optimization by quadratic approximation are used to determine the correct detector parameters and to refine the orientation obtained from the dictionary approach. The indexing method is applied to poly-silicon and shows excellent agreement with the calibrated values. Finally, it is shown that the method results in a mean disorientation error of 1.0° with 0.5° SD for a range of detector parameters.

  14. Fenomeni di channeling e volume reflection per protoni a 400 GeV/c in cristalli multipli

    CERN Document Server

    Duranti, Matteo

    2008-01-01

    The H8-RD22 experiment is an international experiment supported mainly by INFN and CERN with the goal of high precision measurement of the channeling and volume reflection effects occurring to charged particles incident on bent crystals. The use of multi-crystal systems to obtain efficient and relatively large deflections was explored by the collaboration as a possible tecnhique for the collimation and reduction of the beam halo in the high luminosity LHC (Large Hadron Collider) phase. The data collected for the Multi Quasi-Mosaic 7 (MQM7) crystal have been analized. This was the first multi crystal using a remote piezoelectric system to align the various crystal of the device. For this crystal the channeling and volume reflection properties have been measured. The design and on the realization of the experimental setup for the measurement of the channeling and volume reflection effects with a lead (Pb) beam is presented. The silicon detectors with high power lasers to simulate the high charge deposit due to ...

  15. Multiplying dimensions

    CERN Multimedia

    2013-01-01

    A few weeks ago, I had a vague notion of what TED was, and how it worked, but now I’m a confirmed fan. It was my privilege to host CERN’s first TEDx event last Friday, and I can honestly say that I can’t remember a time when I was exposed to so much brilliance in such a short time.   TEDxCERN was designed to give a platform to science. That’s why we called it Multiplying Dimensions – a nod towards the work we do here, while pointing to the broader importance of science in society. We had talks ranging from the most subtle pondering on the nature of consciousness to an eighteen year old researcher urging us to be patient, and to learn from our mistakes. We had musical interludes that included encounters between the choirs of local schools and will.i.am, between an Israeli pianist and an Iranian percussionist, and between Grand Opera and high humour. And although I opened the event by announcing it as a day off from physics, we had a quite brill...

  16. Raman scattering of photons by the channeling electrons

    Science.gov (United States)

    Badreeva, D. R.; Kalashnikov, N. P.

    2017-07-01

    The motion of channeling particles in the accompanying coordinate system can be considered as a two-dimensional atom in the case of axial channeling. The transversal motion of the channeling particles is characterized by discrete spectrum. The occupation probability of the transversal motion levels depends on the entrance angle of the charged particles relative to the crystallographic axis. In the scattering of a photon by the ;quasi-bound; electron moving in the axial channeling regime would appear the frequencies ω which are a combination of the incident photon frequency ω0 and the frequency ωNM (ωNM is the transition frequency in transverse quantized motion of the channeling electron: ω =ω0 ±ωMN , where ℏωMN = 2γ2 ΔE⊥NM for the relativistic electron, γ2 = E / (mc2) is the Lorentz factor of the channeling electron). In the article are discussed the criteria for choosing an adequate continuous potential of the crystallographic axis and the quantum characteristics of a transversal motion of the channeling electron. The peculiarities of the Raman scattering spectrum of photons by electrons in the axial channeling regime are analyzed and the differential cross section of this process is found.

  17. Electron-beam guiding by a reduced-density channel

    Science.gov (United States)

    Welch, D. R.; Bieniosek, F. M.; Godfrey, B. B.

    1990-12-01

    A new regime of density-channel guiding of a relativistic electron beam in air has been found using a three-dimensional charged-particle simulation code, and confirmed in a double-pulse electron-beam experiment. The guiding results from the temperature dependence of the electron-neutral momentum-transfer frequency nu(m). The mechanism does not require a deep channel to obtain a significant guiding force. For the 13-kA MEDEA II (and beams of similar parameters), guiding persists 10 nsec into the beam pulse, with the force per channel displacement as high as 4 G/cm.

  18. Electronic government: Rethinking channel management strategies

    NARCIS (Netherlands)

    Ebbers, Wolfgang E.; Pieterson, Willem Jan; Noordman, H.N.

    2008-01-01

    This article explores how an alternative multichannel management strategy can improve the way governments and citizens interact. Improvement is necessary because, based on empirical data from various sources, the conclusion can be drawn that there is a gap between the communication channels

  19. POES MEPED differential flux retrievals and electron channel contamination correction

    Science.gov (United States)

    Peck, E. D.; Randall, C. E.; Green, J. C.; Rodriguez, J. V.; Rodger, C. J.

    2015-06-01

    A correction method to remove proton contamination from the electron channels of the Polar-orbiting Operational Environmental Satellites Medium Energy Proton/Electron Detector (MEPED) is described. Proton contamination estimates are based on measurements in five of the MEPED proton spectral channels. A constrained inversion of the MEPED proton channel response function matrix is used to calculate proton differential flux spectra. In this inversion, the proton energy distribution is described by a weighted combination of exponential, power law, and Maxwellian distributions. Proton contamination in the MEPED electron spectral channels is derived by applying the electron channel proton sensitivities to the proton fluxes from the best fit proton spectra. Once the electron channel measurements are corrected for proton contamination, an inversion of the electron channel response function matrix is used to calculate electron differential flux spectra. A side benefit of the method is that it yields an estimate for the integrated electron flux in the energy range from 300 keV to 2.5 MeV with a center energy at ~800 keV. The final product is a differential spectrum of electron flux covering the energy range from about 10 keV to 2.5 MeV that is devoid of proton contamination except during large solar proton events. Comparisons of corrected MEPED differential fluxes to the Detection of Electromagnetic Emissions Transmitted from Earthquake Regions Instrument for Detecting Particles show that MEPED fluxes are greater than what is expected from altitude-induced particle population changes; this is attributed at least partially to measurement differences in pitch angle range.

  20. Induced resonance evolution of the channeling electron beam

    Science.gov (United States)

    Ambartsumov, Vazgen V.; Kalashnikov, Nikolay P.

    2017-07-01

    The motion of channeling particles in the accompanying coordinate system can be considered as one-dimensional oscillator (in the case of planar channeling) or as a two-dimensional atom (in the case of axial channeling) (Lindhard, 1965; Baryshevskii, 1982; Vorobiev, 1984; Kalashnikov, 1988; Ryabov, 1994). The transversal motion of the channeling particles is characterized by discrete spectrum. The occupation probability of the transversal motion levels depends on the entrance angle of charged particle relative to the crystallographic axis. Passing through the single crystal the charged channeling particle undergoes periodic impact of the lattice atoms (Kalashnikov, 1988; Foot, 2005; Ter-Mikaelyan, 1972; Okorokov et al., 1973) with the main frequency ω = 2 πv/d γ , where d is the lattice constant, v and γ = E/mc2 are the speed and the Lorentz-factor of the channeling particles (Kalashnikov, 1988). If an external periodic action frequency coincides with the transition frequency of the channeling particles from one quantized state of transversal motion in another, then the resonant excitation of channeling particles is possible. This effect is analogous with the excitation of the atomic electrons by the periodic field of monochromatic electromagnetic waves (Ter-Mikaelyan, 1972; Okorokov et al., 1973; Ohtsuki, 1983). The resonance conditions are discussed and the dependence of the occupation probability of the transversal motion levels of the channeling particles (electrons) upon the single crystal thickness is analyzed.

  1. Cherenkov wakefield excitation by relativistic electron beams in plasma channels

    Science.gov (United States)

    Wang, Tianhong; Khudik, Vladimir; Shvets, Gennday

    2017-10-01

    We report on our theoretical investigations of Cherenkov radiation excited by relativistic electron bunches propagating in plasma channels and in polaritonic channels. Two surface plasmons (SPs) modes of the radiation are analyzed: the longitudinal (accelerating) and the transverse (deflecting) ones. Both form Cherenkov cones that are different in the magnitude of the cone angle and the central frequency. We show that the Cherenkov field profile change dramatically depending on the driver velocity and the channel size, and the longitudinal mode forms a reversed Cherenkov radiation cone due to the negative group velocity for sufficiently small air gaps. In addition, we find that when the channel surface is corrugated, a strong deflecting wake is excited by a relativistic electron bunch. A trailing electron bunch experiencing this wake is forced to undergo betatron oscillations and thus to emit radiation. Numerical simulation showed that intense x-ray radiation can be generated.

  2. Bent crystal channeling of 255 MeV electrons

    Science.gov (United States)

    Takabayashi, Y.; Pivovarov, Yu. L.; Tukhfatullin, T. A.

    2018-01-01

    Charged particles channeled in a bent crystal plane are known to be deflected along the bent plane. Such studies have mainly been performed for high-energy positively-charged particles such as protons, and recently for electrons with energies from 855 MeV to 20.35 GeV. In this work, we present experimental results on the bent crystal channeling of electrons for a lower energy region (255 MeV), where the multiple scattering effect in a crystal is expected to be more dominant. Angular distributions of electrons transmitted through a bent Si crystal have been measured, which are in good agreement with the simulation results.

  3. Electron cryo-microscopy structure of the mechanotransduction channel NOMPC.

    Science.gov (United States)

    Jin, Peng; Bulkley, David; Guo, Yanmeng; Zhang, Wei; Guo, Zhenhao; Huynh, Walter; Wu, Shenping; Meltzer, Shan; Cheng, Tong; Jan, Lily Yeh; Jan, Yuh-Nung; Cheng, Yifan

    2017-07-06

    Mechanosensory transduction for senses such as proprioception, touch, balance, acceleration, hearing and pain relies on mechanotransduction channels, which convert mechanical stimuli into electrical signals in specialized sensory cells. How force gates mechanotransduction channels is a central question in the field, for which there are two major models. One is the membrane-tension model: force applied to the membrane generates a change in membrane tension that is sufficient to gate the channel, as in the bacterial MscL channel and certain eukaryotic potassium channels. The other is the tether model: force is transmitted via a tether to gate the channel. The transient receptor potential (TRP) channel NOMPC is important for mechanosensation-related behaviours such as locomotion, touch and sound sensation across different species including Caenorhabditis elegans, Drosophila and zebrafish. NOMPC is the founding member of the TRPN subfamily, and is thought to be gated by tethering of its ankyrin repeat domain to microtubules of the cytoskeleton. Thus, a goal of studying NOMPC is to reveal the underlying mechanism of force-induced gating, which could serve as a paradigm of the tether model. NOMPC fulfils all the criteria that apply to mechanotransduction channels and has 29 ankyrin repeats, the largest number among TRP channels. A key question is how the long ankyrin repeat domain is organized as a tether that can trigger channel gating. Here we present a de novo atomic structure of Drosophila NOMPC determined by single-particle electron cryo-microscopy. Structural analysis suggests that the ankyrin repeat domain of NOMPC resembles a helical spring, suggesting its role of linking mechanical displacement of the cytoskeleton to the opening of the channel. The NOMPC architecture underscores the basis of translating mechanical force into an electrical signal within a cell.

  4. Laser electron collider within a micro-channel

    Science.gov (United States)

    Ji, Liangliang

    2017-10-01

    We propose a laser-electron collider based on a laser-driven micro-channel-plate target. In this unique geometry, electrons accelerated within the channel can collide head-on with the laser reflected from a foil attached onto the rear target surface. The simple scheme allows for efficient generation of gamma-photons and most importantly, the observing of radiation-reaction effect for the first time. It resolves the aligning and time synchronization challenges for laser-electron colliding scenarios involving two light/electron beams. We predict that a single 5PW laser is sufficient to make radiation-reaction effect measurable. A principle-of-proof experiment was conducted at a currently available 200TW laser system. The superior acceleration of electrons with the novel micro-channel structure was confirmed, showing enhanced electron cut-off energies and slope temperatures compared to ordinary flat interfaces. The results set forth the basis for radiation-reaction measurement from laser-electron colliding in upcoming multi-petawatt laser systems.

  5. On the role of correlated double-electron capture in slow multiply charged N/sup 7+/ collisions with He

    Energy Technology Data Exchange (ETDEWEB)

    Nikulin, V.K.; Samoylov, A.V.

    1989-04-28

    A theoretical study is made of single and double-electron capture by totally stripped N/sup 7+/ ions from helium atoms in the collision velocity range /nu/ = 0.05-1 au. The calculation involves two-electron quasimolecular states and Nikitin's multichannel model. Adiabatic states were constructed by the configuration interaction method to derive the parameters of Nikitin's model around the crossings of the diabatic states. The calculation has revealed a new mechanism of single-electron capture. The capture has been shown to occur predominantly into states of the N/sup 6+/ ion (n=4) via correlated double-electron capture. (author).

  6. Operation of gas electron multiplier (GEM) with propane gas at low pressure and comparison with tissue-equivalent gas mixtures

    Energy Technology Data Exchange (ETDEWEB)

    De Nardo, L., E-mail: laura.denardo@unipd.it [University of Padova, Physics and Astronomy Department and PD-INFN, via Marzolo 8, I-35131 Padova (Italy); Farahmand, M., E-mail: majid.farahmand@rivm.nl [Centre for Environmental Safety and Security, National Institute for Public Health and the Environment (RIVM), PO Box 1, NL-3720 BA Bilthoven (Netherlands)

    2016-05-21

    A Tissue-Equivalent Proportional Counter (TEPC), based on a single GEM foil of standard geometry, has been tested with pure propane gas at low pressure, in order to simulate a tissue site of about 1 µm equivalent size. In this work, the performance of GEM with propane gas at a pressure of 21 and 28 kPa will be presented. The effective gas gain was measured in various conditions using a {sup 244}Cm alpha source. The dependence of effective gain on the electric field strength along the GEM channel and in the drift and induction region was investigated. A maximum effective gain of about 5×10{sup 3} has been reached. Results obtained in pure propane gas are compared with gas gain measurements in gas mixtures commonly employed in microdosimetry, that is propane and methane based Tissue-Equivalent gas mixtures.

  7. Characterization of encapsulated quantum dots via electron channeling contrast imaging

    Science.gov (United States)

    Deitz, Julia I.; Carnevale, Santino D.; De Graef, Marc; McComb, David W.; Grassman, Tyler J.

    2016-08-01

    A method for characterization of encapsulated epitaxial quantum dots (QD) in plan-view geometry using electron channeling contrast imaging (ECCI) is presented. The efficacy of the method, which requires minimal sample preparation, is demonstrated with proof-of-concept data from encapsulated (sub-surface) epitaxial InAs QDs within a GaAs matrix. Imaging of the QDs under multiple diffraction conditions is presented, establishing that ECCI can provide effectively identical visualization capabilities as conventional two-beam transmission electron microscopy. This method facilitates rapid, non-destructive characterization of sub-surface QDs giving immediate access to valuable nanostructural information.

  8. Characterization of encapsulated quantum dots via electron channeling contrast imaging

    Energy Technology Data Exchange (ETDEWEB)

    Deitz, Julia I.; McComb, David W. [Department of Materials Science and Engineering, The Ohio State University, Columbus, Ohio 43210 (United States); Carnevale, Santino D. [Department of Electrical and Computer Engineering, The Ohio State University, Columbus, Ohio 43210 (United States); De Graef, Marc [Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States); Grassman, Tyler J., E-mail: grassman.5@osu.edu [Department of Materials Science and Engineering, The Ohio State University, Columbus, Ohio 43210 (United States); Department of Electrical and Computer Engineering, The Ohio State University, Columbus, Ohio 43210 (United States)

    2016-08-08

    A method for characterization of encapsulated epitaxial quantum dots (QD) in plan-view geometry using electron channeling contrast imaging (ECCI) is presented. The efficacy of the method, which requires minimal sample preparation, is demonstrated with proof-of-concept data from encapsulated (sub-surface) epitaxial InAs QDs within a GaAs matrix. Imaging of the QDs under multiple diffraction conditions is presented, establishing that ECCI can provide effectively identical visualization capabilities as conventional two-beam transmission electron microscopy. This method facilitates rapid, non-destructive characterization of sub-surface QDs giving immediate access to valuable nanostructural information.

  9. On a gas electron multiplier based synthetic diagnostic for soft x-ray tomography on WEST with focus on impurity transport studies

    Science.gov (United States)

    Jardin, A.; Mazon, D.; Malard, P.; O'Mullane, M.; Chernyshova, M.; Czarski, T.; Malinowski, K.; Kasprowicz, G.; Wojenski, A.; Pozniak, K.

    2017-08-01

    The tokamak WEST aims at testing ITER divertor high heat flux component technology in long pulse operation. Unfortunately, heavy impurities like tungsten (W) sputtered from the plasma facing components can pollute the plasma core by radiation cooling in the soft x-ray (SXR) range, which is detrimental for the energy confinement and plasma stability. SXR diagnostics give valuable information to monitor impurities and study their transport. The WEST SXR diagnostic is composed of two new cameras based on the Gas Electron Multiplier (GEM) technology. The WEST GEM cameras will be used for impurity transport studies by performing 2D tomographic reconstructions with spectral resolution in tunable energy bands. In this paper, we characterize the GEM spectral response and investigate W density reconstruction thanks to a synthetic diagnostic recently developed and coupled with a tomography algorithm based on the minimum Fisher information (MFI) inversion method. The synthetic diagnostic includes the SXR source from a given plasma scenario, the photoionization, electron cloud transport and avalanche in the detection volume using Magboltz, and tomographic reconstruction of the radiation from the GEM signal. Preliminary studies of the effect of transport on the W ionization equilibrium and on the reconstruction capabilities are also presented.

  10. New gas electron-multiplier detectors for the endcap muon system of the CMS experiment at the high-luminosity LHC design and prototype performance

    CERN Document Server

    Gruchala, Marek Michal

    2016-01-01

    The high luminosity LHC will require new detectors in the CMS endcap muon system to suppress the trigger rate of background events, to maintain high trigger efficiency for low transverse momentum muons, to enhance the robustness of muon detection in the high-flux environment of the endcap, and to extend the geometrical acceptance. We report on the design and recent progress towards implementing a new system of large-area, triple-foil gas electron-multiplier (GEM) detectors that will be installed in the first three of five muon detector stations in each endcap, the first station being closest to the interaction point. The first station will extend the geometric acceptance in pseudo-rapidity to eta lt 3.0 from the current limit of eta lt 2.4. The second and third stations will enhance the performance in the range 1.6 lt eta lt 2.4. We describe the design of the chambers and readout electronics and report on the performance of prototype systems in tests with cosmic ray muons, high-energy particlebeams, a...

  11. Structure of TRPV1 channel revealed by electron cryomicroscopy.

    Science.gov (United States)

    Moiseenkova-Bell, Vera Y; Stanciu, Lia A; Serysheva, Irina I; Tobe, Ben J; Wensel, Theodore G

    2008-05-27

    The transient receptor potential (TRP) family of ion channels participate in many signaling pathways. TRPV1 functions as a molecular integrator of noxious stimuli, including heat, low pH, and chemical ligands. Here, we report the 3D structure of full-length rat TRPV1 channel expressed in the yeast Saccharomyces cerevisiae and purified by immunoaffinity chromatography. We demonstrate that the recombinant purified TRPV1 channel retains its structural and functional integrity and is suitable for structural analysis. The 19-A structure of TRPV1 determined by using single-particle electron cryomicroscopy exhibits fourfold symmetry and comprises two distinct regions: a large open basket-like domain, likely corresponding to the cytoplasmic N- and C-terminal portions, and a more compact domain, corresponding to the transmembrane portion. The assignment of transmembrane and cytoplasmic regions was supported by fitting crystal structures of the structurally homologous Kv1.2 channel and isolated TRPV1 ankyrin repeats into the TRPV1 structure.

  12. Charged particle detection performance of gas electron multiplier detector for the upgrade of CMS endcap muon system at the CERN LHC

    CERN Document Server

    CMS Collaboration

    2015-01-01

    The CMS detector is one of two general-purpose detectors at the CERN LHC. LHC will provide exceptional high instantaneous and integrated luminosities after second long shutdown. The forward region $\\mid \\eta \\mid \\geq 1.5$ of the CMS detector will face extremely high particle rates in 10s of kHz/cm2 and hence it will affect the momentum resolution and longevity of the muon detectors. To overcome these issues, the CMS-GEM collaboration has proposed to install new large size high rate capable triple Gas Electron Multiplier (GEM) detectors in the forward region of CMS muon system. The proposal has been approved recently. The first set of Triple GEM detectors will be installed in the GE1/1 region ($1.6 < \\mid \\eta \\mid < 2.2$) of muon endcap during phase-II upgrade of the LHC. Towards this goal, full size CMS Triple GEM prototype chambers have been fabricated and put under the test beam at the CERN SPS test beam facility. The GEM detectors were operated with two gas mixtures: Ar:CO2 (70:30) and Ar:CO2:CF4 (...

  13. Data acquisition and online control system for new gas-electron multiplier detectors in the endcap muon system of the CMS experiment

    CERN Document Server

    Ruiz Alvarez, Jose David

    2016-01-01

    A new data acquisition and on-line control system is being developed for gas-electron multiplier (GEM) detectors which will be installed in the forward region (1.6 \\( < \\eta < \\) 2.2) of the CMS muon spectrometer during the 2nd long shutdown of the LHC, planned for the period 2018-2019. A prototype system employs the TOTEM VFAT2 ASIC that will eventually be replaced with the VFAT3 ASIC, under development. The front-end ASIC communicates over printed circuit lines with an intermediate on-detector board called the opto-hybrid. Data, trigger, and control information is transmitted via optical fiber between the opto-hybrid and an off-detector readout system using micro-TCA technology. On-line software, implemented in the CMS XDAQ framework, includes applications for latency and HV scans, and system management. We report on the operational status of the prototype system that has been tested using cosmic ray muons and extracted high-energy particle beams. This work is preparatory for the operation of a prot...

  14. Properties of the Channel Electron Multiplier Arrays (CEMAs) for the SOLEX Solar X-Ray Spectrometer/Spectroheliograph

    Science.gov (United States)

    1981-06-15

    FOR THE ____________________ §PECTROMETER/§YECTROHEL, ft S. PERFORMING ORGANIZATION NAME AND ADDRESS 10. MpR A ELIM T. PROJECT. TASK AR t4Mo W R The...amd pr"patioo pbsmewmia 0ui"ev Ga s eaic"iitor devicel amd lotegrated ciftutts; 4WDn- tum eaCtremics, Wason , sad o1.ctroetice; combiamatte. Sclieesm, a

  15. Laser-electron Compton interaction in plasma channels

    Energy Technology Data Exchange (ETDEWEB)

    Pogorelsky, I.V.; Ben-Zvi, I. [Brookhaven National Lab., Upton, NY (United States); Hirose, T. [Tokyo Metropolitan Univ. (Japan). Physics Dept.

    1998-10-01

    A concept of high intensity femtosecond laser synchrotron source (LSS) is based on Compton backscattering of focused electron and laser beams. The short Rayleigh length of the focused laser beam limits the length of interaction to a few picoseconds. However, the technology of the high repetition rate high-average power picosecond lasers required for high put through LSS applications is not developed yet. Another problem associated with the picosecond laser pulses is undesirable nonlinear effects occurring when the laser photons are concentrated in a short time interval. To avoid the nonlinear Compton scattering, the laser beam has to be split, and the required hard radiation flux is accumulated over a number of consecutive interactions that complicates the LSS design. In order to relieve the technological constraints and achieve a practically feasible high-power laser synchrotron source, the authors propose to confine the laser-electron interaction region in the extended plasma channel. This approach permits to use nanosecond laser pulses instead of the picosecond pulses. That helps to avoid the nonlinear Compton scattering regime and allows to utilize already existing technology of the high-repetition rate TEA CO{sub 2} lasers operating at the atmospheric pressure. They demonstrate the advantages of the channeled LSS approach by the example of the prospective polarized positron source for Japan Linear Collider.

  16. Pressure multiplying dispenser

    Science.gov (United States)

    DeFord, Henry S.; Moss, Owen R.

    1986-01-01

    A pressure multiplying dispenser for delivering fluid, preferably as a spray to the atmosphere, from a source of fluid, preferably a spray bottle, is described. The dispenser includes in combination a hollow cylindrical member, a nozzle delivery tube within the cylindrical member and a hollow actuator piston slideable within the cylindrical member which acts to multiply the pressure of a squeeze applied to the spray bottle.

  17. A comparison using Faraday cups with 10(13) Ω amplifiers and a secondary electron multiplier to measure Os isotopes by negative thermal ionization mass spectrometry.

    Science.gov (United States)

    Wang, Guiqin; Sun, Tiantian; Xu, Jifeng

    2017-10-15

    According to the Johnson-Nyquist noise equation, the value of electron noise is proportional to the square root of the resistor value. This relationship gives a theoretical improvement of 100 in the signal/noise ratio by going from 10(11) Ω to 10(13) Ω amplifiers for Faraday detection in thermal ionization mass spectrometry (TIMS). We measured Os isotopes using static Faraday cups with 10(13) Ω amplifiers in negative thermal ionization mass spectrometry (NTIMS) and compared the results with those obtained with 10(11) Ω amplifiers and by peak-hopping on a single secondary electron multiplier (SEM). We analysed large loads of Os (1 μg) at a range of intensities of (187) OsO3 (0.02-10 mV) in addition to small loads of Os (5-500 pg) to compare the results of the three methods. Using 10(13) Ω amplifiers, the long-term reproducibility determined from Merck Os was (187) Os/(188) Os = 0.1211 ± 0.0086 and 0.120229 ± 0.000034 at 0.02 mV and 10 mV of (187) OsO3 intensities. Meanwhile, the analysed JMC Os loadings of 5 and 500 pg showed (187) Os/(188) Os = 0.10669 ± 0.00036 and 0.106807 ± 0.000023. In comparison, the values measured by the SEM were (187) Os/(188) Os = 0.10704 ± 0.00056 and 0.10690 ± 0.00013. All errors are in 2 standard deviation (SD). Both the accuracy and the precision determined using the 10(13) Ω amplifiers and the SEM are identical when the Os amounts are within 10-50 pg. However, the former analysis time can be shortened by approximately two-thirds. The SEM measurement is still the most precise method for Os amounts 50 pg. Copyright © 2017 John Wiley & Sons, Ltd.

  18. Depth oscillations of electronuclear reaction yield initiated by relativistic planar channeled electrons: quantum versus classical calculations

    Science.gov (United States)

    Eikhorn, Yu. L.; Korotchenko, K. B.; Pivovarov, Yu. L.; Tukhfatullin, T. A.

    2017-07-01

    The first experiment on electronuclear reaction initated by axially channeled 700 MeV electrons in a Si crystal [1] revealed remarkable depth oscillations of reaction yield. The effect was satisfactory explained [2] by computer simulations using binary collisions model. In this work the oscillations effect is investigated for planar channeled electrons in a Si crystal using the new computer code BCM-1.0 which allows both classical and quantum calculations of channeled electrons flux density.

  19. Ionic fragmentation channels in electron collisions of small molecular ions

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, Jens

    2009-01-28

    Dissociative Recombination (DR) is one of the most important loss processes of molecular ions in the interstellar medium (IM). Ion storage rings allow to investigate these processes under realistic conditions. At the Heidelberg test storage ring TSR a new detector system was installed within the present work in order to study the DR sub-process of ion pair formation (IPF). The new detector expands the existing electron target setup by the possibility to measure strongly deflected negative ionic fragments. At the TSR such measurements can be performed with a uniquely high energy resolution by independently merging two electron beams with the ion beam. In this work IPF of HD{sup +}, H{sub 3}{sup +} and HF{sup +} has been studied. In the case of HD{sup +} the result of the high resolution experiment shows quantum interferences. Analysis of the quantum oscillations leads to a new understanding of the reaction dynamics. For H{sub 3}{sup +} it was for the first time possible to distinguish different IPF channels and to detect quantum interferences in the data. Finally the IPF of HF{sup +} was investigated in an energy range, where in previous experiments no conclusive results could be obtained. (orig.)

  20. Hidden Abilities Discovered Among Multiply Handicapped Blind Children

    Science.gov (United States)

    Klineman, Janet

    1975-01-01

    The effectiveness of an objective, systematic assessment and individualized programing approach for discovering new channels of learning is illustrated with case study evaluations of multiply handicapped visually impaired children with complex learning and behavioral problems. (SB)

  1. Multiply Connected Universes

    OpenAIRE

    Sidharth, B. G.

    2006-01-01

    It is now generally believed that our observable universe is one amongst a very large number - may be $10^{500}$ - of parallel universes. Following the author's own model in this context, we argue that this conglomeration of universes defines a multiply connected super space.

  2. The Multiplier Effect.

    Science.gov (United States)

    Flowers, William L., Jr.; Harris, John B.

    1981-01-01

    The multiplier effect is discussed as it applies to the field of continuing education. The authors' main point is that one grant or contract can, and should, be used as the basis for building organizational competencies and capabilities that will secure other funds. (Author/CT)

  3. Large-angle channeling radiation from relativistic electrons in optically transparent crystals

    Science.gov (United States)

    Korotchenko, K. B.; Pivovarov, Yu. L.

    2018-02-01

    In the work within the frame of quantum electrodynamics are obtained new formulae describing the large-angle photon emission from channeled electrons with taking into account of the dispersion of refractive index. Calculations based on these formulae show that the spectral and angular distributions of large-angle optical and ultraviolet radiation from planar channeled sub-GeV electrons in optically transparent crystal reflect the band structure of transverse energy levels of channeled electrons. Comparison with ordinary Cherenkov radiation spectrum reveals that channeling (depending on the beam energy) leads to sufficient change of the large-angle emission spectrum.

  4. Microwave Frequency Multiplier

    Science.gov (United States)

    Velazco, J. E.

    2017-02-01

    High-power microwave radiation is used in the Deep Space Network (DSN) and Goldstone Solar System Radar (GSSR) for uplink communications with spacecraft and for monitoring asteroids and space debris, respectively. Intense X-band (7.1 to 8.6 GHz) microwave signals are produced for these applications via klystron and traveling-wave microwave vacuum tubes. In order to achieve higher data rate communications with spacecraft, the DSN is planning to gradually furnish several of its deep space stations with uplink systems that employ Ka-band (34-GHz) radiation. Also, the next generation of planetary radar, such as Ka-Band Objects Observation and Monitoring (KaBOOM), is considering frequencies in the Ka-band range (34 to 36 GHz) in order to achieve higher target resolution. Current commercial Ka-band sources are limited to power levels that range from hundreds of watts up to a kilowatt and, at the high-power end, tend to suffer from poor reliability. In either case, there is a clear need for stable Ka-band sources that can produce kilowatts of power with high reliability. In this article, we present a new concept for high-power, high-frequency generation (including Ka-band) that we refer to as the microwave frequency multiplier (MFM). The MFM is a two-cavity vacuum tube concept where low-frequency (2 to 8 GHz) power is fed into the input cavity to modulate and accelerate an electron beam. In the second cavity, the modulated electron beam excites and amplifies high-power microwaves at a frequency that is a multiple integer of the input cavity's frequency. Frequency multiplication factors in the 4 to 10 range are being considered for the current application, although higher multiplication factors are feasible. This novel beam-wave interaction allows the MFM to produce high-power, high-frequency radiation with high efficiency. A key feature of the MFM is that it uses significantly larger cavities than its klystron counterparts, thus greatly reducing power density and arcing

  5. Relativistic laser hosing instability suppression and electron acceleration in a preformed plasma channel

    Science.gov (United States)

    Huang, T. W.; Zhou, C. T.; Zhang, H.; Wu, S. Z.; Qiao, B.; He, X. T.; Ruan, S. C.

    2017-04-01

    The hosing processes of a relativistic laser pulse, electron acceleration, and betatron radiation in a parabolic plasma channel are investigated in the direct laser acceleration regime. It is shown that the laser hosing instability would result in the generation of a randomly directed off-axis electron beam and radiation source with a large divergence angle. While employing a preformed parabolic plasma channel, the restoring force provided by the plasma channel would correct the perturbed laser wave front and thus suppress the hosing instability. As a result, the accelerated electron beam and the emitted photons are well guided and concentrated along the channel axis. The employment of a proper plasma density channel can stably guide the relativistically intense laser pulse and greatly improve the properties of the electron beam and radiation source. This scheme is of great interest for the generation of high quality electron beams and radiation sources.

  6. Fiscal Multipliers in Ukraine

    OpenAIRE

    Pritha Mitra; Tigran Poghosyan

    2015-01-01

    Amid renewed crisis, falling tax revenues, and rising debt, Ukraine faces serious fiscal consolidation needs. Durable fiscal adjustment can support economic confidence and rebuild buffers but what is its overall impact on growth? How effective are revenue versus spending instruments? Does current or capital spending have a larger impact? Applying a structural vector autoregressive model, this paper finds that Ukraine’s near-term revenue and spending multipliers are well below one. In the me...

  7. Quantum ballistic transport by interacting two-electron states in quasi-one-dimensional channels

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Danhong [Air Force Research Laboratory, Space Vehicles Directorate, Kirtland Air Force Base, New Mexico 87117 (United States); Center for High Technology Materials, University of New Mexico, 1313 Goddard St SE, Albuquerque, New Mexico 87106 (United States); Gumbs, Godfrey [Center for High Technology Materials, University of New Mexico, 1313 Goddard St SE, Albuquerque, New Mexico 87106 (United States); Abranyos, Yonatan [Department of Physics and Astronomy, Hunter College of the City University of New York, 695 Park Avenue, New York, New York 10065 (United States); Pepper, Michael; Kumar, Sanjeev [Department of Electronic and Electrical Engineering, University College London, London, WC1E 7JE (United Kingdom); London Centre for Nanotechnology, 17-19 Gordon Street, London, WC1H 0AH (United Kingdom)

    2015-11-15

    For quantum ballistic transport of electrons through a short conduction channel, the role of Coulomb interaction may significantly modify the energy levels of two-electron states at low temperatures as the channel becomes wide. In this regime, the Coulomb effect on the two-electron states is calculated and found to lead to four split energy levels, including two anticrossing-level and two crossing-level states. Moreover, due to the interplay of anticrossing and crossing effects, our calculations reveal that the ground two-electron state will switch from one anticrossing state (strong confinement) to a crossing state (intermediate confinement) as the channel width gradually increases and then back to the original anticrossing state (weak confinement) as the channel width becomes larger than a threshold value. This switching behavior leaves a footprint in the ballistic conductance as well as in the diffusion thermoelectric power of electrons. Such a switching is related to the triple spin degeneracy as well as to the Coulomb repulsion in the central region of the channel, which separates two electrons away and pushes them to different channel edges. The conductance reoccurrence region expands from the weak to the intermediate confinement regime with increasing electron density.

  8. Multiplying with Neurons

    Science.gov (United States)

    Gabbiani, F.; Krapp, H.; Koch, C.; Laurent, G.

    1998-03-01

    LGMD and DCMD are a pair of identified neurons in the locust brain thought to be involved in visually triggered escape behavior. LGMD integrates visual inputs in its dendritic arbor, converts them into spikes transmitted in a 1:1 manner to DCMD which relays this information to motor centers. We measured the spike activity of DCMD during simulated object approach and observed that its peak occured prior to the expected collision. The time difference between peak activity and collision depended linearly on the ratio of object size to approach velocity, as expected if LGMD/DCMD were detecting the moment in time when the approaching object reaches a fixed angular threshold θ_thresh on the locust's retina. The response of LGMD/DCMD could be fitted by multiplying the angular velocity at which an approaching object is increasing in size over the retina, dot θ, with an exponential function of the object's angular size, θ: f(t) = g(dot θ(t-δ) e^-α θ(t-δ)) where g is a static non-linearity, α a constant related to the angular threshold detected by LGMD/DCMD (θ_thresh = arctan (2/α)) and δ denotes the lag of the neuronal response with respect to the stimulus. This suggests that LGMD/DCMD derives its angular threshold sensitivity by multiplying dot θ with an exponential of θ. A biophysical implementation would be through linear summation of excitatory and inhibitory inputs proportional to log(dot θ) and -α θ, followed by a conversion to spike rate according to the static non-linearity (g circ exp). We have performed several experiments to test this hypothesis.

  9. Identifying threading dislocations in GaN films and substrates by electron channelling.

    Science.gov (United States)

    Kamaladasa, Ranga J; Liu, Fang; Porter, Lisa M; Davis, Robert F; Koleske, Daniel D; Mulholland, Greg; Jones, Kenneth A; Picard, Yoosuf N

    2011-12-01

    Electron channelling contrast imaging of threading dislocations in GaN (0002) substrates and epitaxial films has been demonstrated using a conventional polepiece-mounted backscatter detector in a commercial scanning electron microscope. The influence of accelerating voltage and diffraction vector on contrast features denoting specific threading dislocation types has been studied. As confirmed by coordinated transmission electron microscopy analysis, electron channelling contrast imaging contrast features for edge-type threading dislocations are spatially smaller than mixed-type threading dislocations in GaN. This ability to delineate GaN edge threading dislocations from mixed type was also confirmed by defect-selective etch processing using molten MgO/KOH. This study validates electron channelling contrast imaging as a nondestructive and widely accessible method for spatially mapping and identifying dislocations in GaN with wider applicability for other single-crystal materials. © 2011 The Authors Journal of Microscopy © 2011 Royal Microscopical Society.

  10. Last multipliers on Lie algebroids

    Indian Academy of Sciences (India)

    ∗Stefan cel Mare University, Suceava, România. E-mail: mcrasm@uaic.ro; cristinah@usv.ro. MS received 27 March 2008; revised 4 September .... For example, in dimension 2, the notions of last multiplier and integrating factor are identical and Sophus Lie suggested a method to associate a last multiplier to every sym-.

  11. Electronic Literacies and TESOL Graduate Students from Korea: New Channels for Navigating Cultures of Learning.

    Science.gov (United States)

    Skilton-Sylvester, Ellen

    2001-01-01

    Drawing on the ethnography of communication, addresses the role of electronic channels for meaning making among Korean students in graduate TESOL classes in the United States. Looks at the ways that these electronic literacies provide opportunities for navigating Korean and U.S. cultures of learning. (Author/VWL)

  12. Electron-deficient fullerenes in triple-channel photosystems.

    Science.gov (United States)

    López-Andarias, Javier; Bolag, Altan; Nançoz, Christoph; Vauthey, Eric; Atienza, Carmen; Sakai, Naomi; Martín, Nazario; Matile, Stefan

    2015-05-01

    Fullerenes of increasing electron deficiency are designed, synthesized and evaluated in multicomponent surface architectures to ultimately build gradients in LUMO levels with nine components over 350 meV down to -4.22 eV.

  13. Coulomb blockade in a Si channel gated by an Al single-electron transistor

    OpenAIRE

    Sun, L.; Brown, K. R.; Kane, B. E.

    2007-01-01

    We incorporate an Al-AlO_x-Al single-electron transistor as the gate of a narrow (~100 nm) metal-oxide-semiconductor field-effect transistor (MOSFET). Near the MOSFET channel conductance threshold, we observe oscillations in the conductance associated with Coulomb blockade in the channel, revealing the formation of a Si single-electron transistor. Abrupt steps present in sweeps of the Al transistor conductance versus gate voltage are correlated with single-electron charging events in the Si t...

  14. Enhanced acceleration of injected electrons in a laser-beat-wave-induced plasma channel.

    Science.gov (United States)

    Tochitsky, S Ya; Narang, R; Filip, C V; Musumeci, P; Clayton, C E; Yoder, R B; Marsh, K A; Rosenzweig, J B; Pellegrini, C; Joshi, C

    2004-03-05

    Enhanced energy gain of externally injected electrons by a approximately 3 cm long, high-gradient relativistic plasma wave (RPW) is demonstrated. Using a CO2 laser beat wave of duration longer than the ion motion time across the laser spot size, a laser self-guiding process is initiated in a plasma channel. Guiding compensates for ionization-induced defocusing (IID) creating a longer plasma, which extends the interaction length between electrons and the RPW. In contrast to a maximum energy gain of 10 MeV when IID is dominant, the electrons gain up to 38 MeV energy in a laser-beat-wave-induced plasma channel.

  15. P -wave coupled channel effects in electron-positron annihilation

    Science.gov (United States)

    Du, Meng-Lin; Meißner, Ulf-G.; Wang, Qian

    2016-11-01

    P -wave coupled channel effects arising from the D D ¯, D D¯ *+c .c . , and D*D¯* thresholds in e+e- annihilations are systematically studied. We provide an exploratory study by solving the Lippmann-Schwinger equation with short-ranged contact potentials obtained in the heavy quark limit. These contact potentials can be extracted from the P -wave interactions in the e+e- annihilations, and then be employed to investigate possible isosinglet P -wave hadronic molecules. In particular, such an investigation may provide information about exotic candidates with quantum numbers JPC=1-+ . In the mass region of the D D ¯, D D¯ *+c .c . , and D*D¯* thresholds, there are two quark model bare states, i.e. the ψ (3770 ) and ψ (4040 ), which are assigned as (13D1) and (31S1) states, respectively. By an overall fit of the cross sections of e+e-→D D ¯, D D¯ *+c .c . , D*D¯*, we determine the physical coupling constants to each channel and extract the pole positions of the ψ (3770 ) and ψ (4040 ). The deviation of the ratios from that in the heavy quark spin symmetry (HQSS) limit reflects the HQSS breaking effect due to the mass splitting between the D and the D*. Besides the two poles, we also find a pole a few MeV above the D D¯ *+c .c . threshold which can be related to the so-called G (3900 ) observed earlier by BABAR and Belle. This scenario can be further scrutinized by measuring the angular distribution in the D*D¯* channel with high luminosity experiments.

  16. Fundamental and experimental aspects of diffraction for characterizing dislocations by electron channeling contrast imaging in scanning electron microscope

    OpenAIRE

    Kriaa, H.; Guitton, A.; Maloufi, N.

    2017-01-01

    Nowadays Field Emission Gun-Scanning Electron Microscopes provide detailed crystallographic information with high spatial and angular resolutions, and allow direct observation of crystalline defects, such as dislocations, through an attractive technique called Electron Channeling Contrast Imaging (ECCI). Dislocations play a crucial role in the properties of materials and ECCI has naturally emerged as an adapted tool for characterizing defects in bulk specimen. Nevertheless, fine control of th...

  17. Extremely intense laser-based electron acceleration in a plasma channel

    Science.gov (United States)

    Vranic, Marija; Fonseca, Ricardo A.; Silva, Luis O.

    2018-03-01

    Laser pulses of extreme intensities (I> {10}22 {{W}} {{cm}}-2) are about to become available in the laboratory. The prepulse of such a laser can induce a plasma expansion that generates a low-density channel in near-critical gas jets. We present a study of channel formation and subsequent direct laser acceleration of electrons within the pre-formed channel. Radiation reaction affects the acceleration in several ways. It first interferes with the motion of the return current on the channel walls. In addition, it reduces the radial expelling efficiency of the transverse ponderomotive force, leading to the radiative trapping of particles near the channel axis. These particles then interact with the peak laser intensity and can attain multi-GeV energies.

  18. RADIATIVE ELECTRON CAPTURE BY FAST HIGHLY STRIPPED HEAVY IONS CHANNELED IN A THIN CRYSTAL

    OpenAIRE

    Andriamonje, S; Chevallier, M; Cohen, C; Dural, J.; Gaillard, M; Genre, R.; Hage-ali, M.; Kirsch, R; L'hoir, A.; Mazuy, B.; Mory, J.; Moulin, J; Poizat, J.-C.; Remillieux, J; Schmaus, Didier

    1989-01-01

    Interaction of moving ions with single crystals is known to be very sensitive to the orientation of the incident beam with respect to the crystalline directions of the target. We have shown that channeling conditions strongly modify the slowing down and the charge exchange processes of high energy heavy ions. The reason is that channeled particles are prevented from approaching the target atoms, and then can interact only with loosely bound target electrons. This results not only in drastical...

  19. The CLIC Test Facility (CTF3) which allowed the first electron beam recombination in order to multiply the RF frequency from 3 GHz up to 15 GHz.

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    Photo 0210005_11: The CTF3 linac accelerates an electron beam up to 350 MeV. Photo 0210005_1: At the front, the yellow dipole is used for the spectrometer line. At the back, a doublet of blue quadrupole for the matching. Photo 0210005_03: The CTF3 transfer line between the electron linac and the isochronous ring. Photo 0210005_04: One arc of the EPA isochronous ring. Photo 0210005_06: The CTF3 bunching system. The first RF wave guide feeds the Pre-Buncher while the second RF wave guide feeds the Buncher. They provide a bunched electron beam at 4 MeV. The blue magnet is a solenoid around the Buncher. Photo 0210005_07: A LIL accelerating structure used for CTF3. It is 4.5 meters long and provides an energy gain of 45 MeV. One can see 3 quadrupoles around the RF structure.

  20. Design of a channel board used in an electronic warfare target simulator

    OpenAIRE

    Andersson, Peter

    2006-01-01

    A channel board was designed for a DRFM circuit. The DRFM is implemented in a Virtex-4 FPGA from Xilinx. In the future a similar channel board is intended to be used for target echo generation in ELSI which is an electronic warfare simulator at Saab Bofors Dynamics in Linköping. Besides the DRFM circuit the channel board consists of analog-to-digital converters, digital-to-analog converters, Ethernet plug-in board with a microcontroller, voltage regulators, FPGA configuration memory, voltage ...

  1. Electronic stopping power of slow-light channeling ions in ZnTe from first principles

    Science.gov (United States)

    Li, Chang-kai; Mao, Fei; Wang, Feng; Fu, Yan-long; Ouyang, Xiao-ping; Zhang, Feng-Shou

    2017-05-01

    Nonadiabatic dynamics simulations are performed to investigate the electronic stopping power of a helium ion moving through ZnTe crystalline thin films under channeling conditions. Using ab initio time-dependent density-functional theory, we found by direct simulation that electronic stopping power versus projectile velocity deviates from velocity proportionality and displays a transition between two velocity regimes for helium ions channeling along middle crystalline axes in and channels and also in a channel with low-impact parameters. This transition causes a change in the slope of the energy loss versus ion velocity curve at a characteristic velocity related to the impact parameter and the lattice plane spacing. It may be an indication of extra energy loss channel beyond the electron-hole excitation. To analyze it, we checked the charge transfer between the moving projectiles and host atoms. It is found that the soft transition between two velocity regimes can be attributed to the resonant coherent excitation stimulated by the time-periodic potential experienced by the channeling ion and also the charge exchange in close encounters between Helium ion and host atoms.

  2. Laser-wakefield acceleration of electron beams in a low density plasma channel

    Directory of Open Access Journals (Sweden)

    T. P. A. Ibbotson

    2010-03-01

    Full Text Available The generation of quasimonoenergetic electron beams, with energies greater than 500 MeV, in a laser-plasma accelerator driven by 2.5 J, 80 fs laser pulses guided in a low density plasma channel, is investigated. The laser energy required to achieve electron injection is found to depend strongly on the quality of the input laser focal spot. Simulations show that, although the matched spot size of the plasma channel is greater than the self-focused spot size, the channel assists relativistic self-focusing and enables electron injection to occur at lower plasma densities and laser powers than would be possible without a waveguide.

  3. Positrons vs electrons channeling in silicon crystal: energy levels, wave functions and quantum chaos manifestations

    Science.gov (United States)

    Shul'ga, N. F.; Syshchenko, V. V.; Tarnovsky, A. I.; Solovyev, I. I.; Isupov, A. Yu.

    2018-01-01

    The motion of fast electrons through the crystal during axial channeling could be regular and chaotic. The dynamical chaos in quantum systems manifests itself in both statistical properties of energy spectra and morphology of wave functions of the individual stationary states. In this report, we investigate the axial channeling of high and low energy electrons and positrons near [100] direction of a silicon crystal. This case is particularly interesting because of the fact that the chaotic motion domain occupies only a small part of the phase space for the channeling electrons whereas the motion of the channeling positrons is substantially chaotic for the almost all initial conditions. The energy levels of transverse motion, as well as the wave functions of the stationary states, have been computed numerically. The group theory methods had been used for classification of the computed eigenfunctions and identification of the non-degenerate and doubly degenerate energy levels. The channeling radiation spectrum for the low energy electrons has been also computed.

  4. Cyanated diazatetracene diimides with ultrahigh electron affinity for n-channel field effect transistors

    KAUST Repository

    Ye, Qun

    2013-03-15

    Several diazatetracene diimides with high electron affinity (up to 4.66 eV!) were prepared and well characterized. The LUMO energy level of these electron-deficient molecules was found to be closely related to their material stability. Compound 7 with ultrahigh electron affinity suffered from reduction and hydrolysis in the presence of silica gel or water. The stable compounds 3 and 6 showed n-channel FET behavior with an average electron mobility of 0.002 and 0.005 cm2 V-1 s-1, respectively, using a solution processing method. © 2013 American Chemical Society.

  5. Analysis of FIB-induced damage by electron channelling contrast imaging in the SEM.

    Science.gov (United States)

    Gutierrez-Urrutia, Ivan

    2017-01-01

    We have investigated the Ga+ ion-damage effect induced by focused ion beam (FIB) milling in a [001] single crystal of a 316 L stainless steel by the electron channelling contrast imaging (ECCI) technique. The influence of FIB milling on the characteristic electron channelling contrast of surface dislocations was analysed. The ECCI approach provides sound estimation of the damage depth produced by FIB milling. For comparison purposes, we have also studied the same milled surface by a conventional electron backscatter diffraction (EBSD) approach. We observe that the ECCI approach provides further insight into the Ga+ ion-damage phenomenon than the EBSD technique by direct imaging of FIB artefacts in the scanning electron microscope. We envisage that the ECCI technique may be a convenient tool to optimize the FIB milling settings in applications where the surface crystal defect content is relevant. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

  6. Channeling radiation from relativistic electrons - Study of stacking faults and dislocations

    CERN Document Server

    Pathak, A P; Prakash-Goteti, L N S

    2002-01-01

    The discrete nature of the energy associated with channeled particles and consequent emission of channeling radiation has opened new applications in accelerator and atomic physics. The spontaneous transitions among various energy levels in the transverse space lead to what is known as channeling radiation. One-dimensional hydrogen atom model for continuum planar potential due to single plane is used for the case of planar channeled electrons to estimate the corresponding bound states in the potential well. The effects of extended defects like stacking faults (SFs) and dislocations on transitions among the various levels are studied by calculating the transition probabilities at the faulted region, i.e. at the SF boundary for the case of SF and distorted region of the dislocation. The obstruction and distortion effects of these extended defects are incorporated suitably to obtain initial and final populations of the eigenstates.

  7. Quasi-phase-matched acceleration of electrons in a corrugated plasma channel

    Directory of Open Access Journals (Sweden)

    S. J. Yoon

    2012-08-01

    Full Text Available A laser pulse propagating in a corrugated plasma channel is composed of spatial harmonics whose phase velocities can be subluminal. The phase velocity of a spatial harmonic can be matched to the speed of a relativistic electron resulting in direct acceleration by the guided laser field in a plasma waveguide and linear energy gain over the interaction length. Here we examine the fully self-consistent interaction of the laser pulse and electron beam using particle-in-cell (PIC simulations. For low electron beam densities, we find that the ponderomotive force of the laser pulse pushes plasma channel electrons towards the propagation axis, which deflects the beam electrons. When the beam density is high, the space charge force of the beam drives the channel electrons off axis, providing collimation of the beam. In addition, we consider a ramped density profile for lowering the threshold energy for trapping in a subluminal spatial harmonic. By using a density ramp, the trapping energy for a normalized vector potential of a_{0}=0.1 is reduced from a relativistic factor γ_{0}=170 to γ_{0}=20.

  8. Lattice Location of Radioactive Probes in Semiconductors and Metals by Electron and Positron Channelling

    CERN Multimedia

    2002-01-01

    The channelling effect of decay-electrons and positrons is used for the localization of radioactive impurities implanted into single crystals. Because of the low implantation doses and the variety of different isotopes available at ISOLDE, this technique is especially suited for applications in semiconducting materials. \\\\ \\\\ Channelling measurements in Si, GaAs and GaP implanted with In-, Cd- and Xe-isotopes have demonstrated that impurity lattice sites can be studied directly after implantation without any annealing. The electron-channelling technique can be ideally combined with hyperfine interaction techniques like Moessbauer s This was shown for the formation of In-vacancy complexes in ion-implanted Ni. \\\\ \\\\ We intend to continue the lattice location measurements in semiconductors implanted with various radioactive impurities of Cd, In, Sn, Sb and Te.

  9. Field-reversed bubble in deep plasma channels for high quality electron acceleration

    CERN Document Server

    Pukhov, A; Tueckmantel, T; Thomas, J; Yu, I; Kostyukov, Yu

    2014-01-01

    We study hollow plasma channels with smooth boundaries for laser-driven electron acceleration in the bubble regime. Contrary to the uniform plasma case, the laser forms no optical shock and no etching at the front. This increases the effective bubble phase velocity and energy gain. The longitudinal field has a plateau that allows for mono-energetic acceleration. We observe as low as 10−3 r.m.s. relative witness beam energy uncertainty in each cross-section and 0.3% total energy spread. By varying plasma density profile inside a deep channel, the bubble fields can be adjusted to balance the laser depletion and dephasing lengths. Bubble scaling laws for the deep channel are derived. Ultra-short pancake-like laser pulses lead to the highest energies of accelerated electrons per Joule of laser pulse energy.

  10. Fundamental and experimental aspects of diffraction for characterizing dislocations by electron channeling contrast imaging in scanning electron microscope.

    Science.gov (United States)

    Kriaa, H; Guitton, A; Maloufi, N

    2017-08-29

    Nowadays Field Emission Gun-Scanning Electron Microscopes provide detailed crystallographic information with high spatial and angular resolutions, and allow direct observation of crystalline defects, such as dislocations, through an attractive technique called Electron Channeling Contrast Imaging (ECCI). Dislocations play a crucial role in the properties of materials and ECCI has naturally emerged as an adapted tool for characterizing defects in bulk specimen. Nevertheless, fine control of the channeling conditions is absolutely required to get strong dislocation contrast for achieving comprehensive analysis. In this work, experiment-assisted fundamental aspects of the origin of dislocation contrast are studied. Experimentally, the potential of ECCI is explored in several dislocation configurations in Interstitial-Free steel (Fe - 1% Si) used as a model material. Full interpretations of dislocation contrast in (g, -g) and its evolution along the Kikuchi band are shown. Furthermore, a dislocation dipole is observed and fully characterized for the first time in an SEM.

  11. A Synthesis of Star Calibration Techniques for Ground-Based Narrowband Electron-Multiplying Charge-Coupled Device Imagers Used in Auroral Photometry

    Science.gov (United States)

    Grubbs, Guy II; Michell, Robert; Samara, Marilia; Hampton, Don; Jahn, Jorg-Micha

    2016-01-01

    A technique is presented for the periodic and systematic calibration of ground-based optical imagers. It is important to have a common system of units (Rayleighs or photon flux) for cross comparison as well as self-comparison over time. With the advancement in technology, the sensitivity of these imagers has improved so that stars can be used for more precise calibration. Background subtraction, flat fielding, star mapping, and other common techniques are combined in deriving a calibration technique appropriate for a variety of ground-based imager installations. Spectral (4278, 5577, and 8446 A ) ground-based imager data with multiple fields of view (19, 47, and 180 deg) are processed and calibrated using the techniques developed. The calibration techniques applied result in intensity measurements in agreement between different imagers using identical spectral filtering, and the intensity at each wavelength observed is within the expected range of auroral measurements. The application of these star calibration techniques, which convert raw imager counts into units of photon flux, makes it possible to do quantitative photometry. The computed photon fluxes, in units of Rayleighs, can be used for the absolute photometry between instruments or as input parameters for auroral electron transport models.

  12. The complementary use of electron backscatter diffraction and ion channelling imaging for the characterization of nanotwins

    DEFF Research Database (Denmark)

    Alimadadi, Hossein; da Silva Fanta, Alice Bastos; Pantleon, Karen

    2013-01-01

    On the example of electrodeposited nickel films, it is shown that unique information on twins with dimensions on the nanoscale can be obtained by suitable combination of ion channelling imaging and electron backscatter diffraction analysis, whereas both (routine) single techniques cannot meet...... the requirements for analysis of these films. High‐resolution electron backscatter diffraction is inadequate for full characterization of nanotwins, but image quality maps obtained from electron backscatter diffraction at least yield a qualitative estimation of the location and number of nanotwins. Complementing...... this information with ion channelling imaging provides more representative insights into the microstructure, because it supplements the quantitative investigation of the number and width of twin lamellae with additional crystallographic orientation analysis provided by EBSD. To this end, two methods for adjusting...

  13. Simulation of cooling efficiency via miniaturised channels in multilayer LTCC for power electronics

    Science.gov (United States)

    Pietrikova, Alena; Girasek, Tomas; Lukacs, Peter; Welker, Tilo; Müller, Jens

    2017-03-01

    The aim of this paper is detailed investigation of thermal resistance, flow analysis and distribution of coolant as well as thermal distribution inside multilayer LTCC substrates with embedded channels for power electronic devices by simulation software. For this reason four various structures of internal channels in the multilayer LTCC substrates were designed and simulated. The impact of the volume flow, structures of channels, and power loss of chip was simulated, calculated and analyzed by using the simulation software Mentor Graphics FloEFDTM. The structure, size and location of channels have the significant impact on thermal resistance, pressure of coolant as well as the effectivity of cooling power components (chips) that can be placed on the top of LTCC substrate. The main contribution of this paper is thermal analyze, optimization and impact of 4 various cooling channels embedded in LTCC multilayer structure. Paper investigate, the effect of volume flow in cooling channels for achieving the least thermal resistance of LTCC substrate that is loaded by power thermal chips. Paper shows on the impact of the first chips thermal load on the second chip as well as. This possible new technology could ensure in the case of practical realization effective cooling and increasing reliability of high power modules.

  14. Determination of gas temperature in the plasmatron channel according to the known distribution of electronic temperature

    Directory of Open Access Journals (Sweden)

    Gerasimov Alexander V.

    2013-01-01

    Full Text Available An analytical method to calculate the temperature distribution of heavy particles in the channel of the plasma torch on the known distribution of the electronic temperature has been proposed. The results can be useful for a number of model calculations in determining the most effective conditions of gas blowing through the plasma torch with the purpose of heating the heavy component. This approach allows us to understand full details about the heating of cold gas, inpouring the plasma, and to estimate correctly the distribution of the gas temperature inside the channel.

  15. Analyses of electron runaway in front of the negative streamer channel

    DEFF Research Database (Denmark)

    Babich, L. P.; Bochkov, E. I.; Kutsyk, I. M.

    2017-01-01

    , which allows the electric field to reach magnitudes, required for a generation of significant RE fluxes and associated bremsstrahlung, when the ionization wave propagates in a narrow, ionized channel created by a previous streamer. Under such conditions we compute the production rate of REs per unit......-emitting ionization wave independent of the initial electron concentration. Thus, the streamer coronas of the leaders are probable sources of REs producing the observed high-energy radiation. To prove these predictions, new simulations are planned, which would show explicitly that the pre-ionization in front...... of the channel via REs will lead to the ionization wave propagation self-consistent with REs generation....

  16. Calculating the electron temperature in the lightning channel by continuous spectrum

    Science.gov (United States)

    Xiangcheng, DONG; Jianhong, CHEN; Xiufang, WEI; Ping, YUAN

    2017-12-01

    Based on the theory of plasma continuous radiation, the relationship between the emission intensity of bremsstrahlung and recombination radiation and the plasma electron temperature is obtained. During the development process of a return stroke of ground flash, the intensity of continuous radiation spectrum is separated on the basis of the spectrums with obviously different luminous intensity at two moments. The electron temperature of the lightning discharge channel is obtained through the curve fitting of the continuous spectrum intensity. It is found that electron temperature increases with the increase of wavelength and begins to reduce after the peak. The peak temperature of the two spectra is close to 25 000 K. To be compared with the result of discrete spectrum, the electron temperature is fitted by the O I line and N II line of the spectrum respectively. The comparison shows that the high temperature value is in good agreement with the temperature of the lightning core current channel obtained from the ion line information, and the low temperature at the high band closes to the calculation result of the atomic line, at a low band is lower than the calculation of the atomic line, which reflects the temperature of the luminous channel of the outer corona.

  17. Computer simulation of electron-positron pair production by channeling radiation in amorphous converter

    Science.gov (United States)

    Abdrashitov, S. V.; Bogdanov, O. V.; Dabagov, S. B.; Pivovarov, Yu L.; Tukhfatullin, T. A.

    2016-07-01

    We consider the radiator-converter approach at 200 MeV channeled electrons (the SPARC_LAB LNF facility energies) for the case of using W crystalline radiator and W amorphous converter. A comparison of the positron production by the axial channeling radiation and the bremsstrahlung is performed. The positron stopping in the convertor is studied by means of computer simulations. It is shown that for the maximum yield of positrons the thickness of the W amorphous converter should be taken 0.35 cm in the case of using the axial channeling radiation resulting to total yield of positrons 5 10-3 e+/e- and 0.71 cm in the case of using the bremsstrahlung resulting to total yield of positrons 3.3 10-3 e+/e-.

  18. Multiplied Environmental Literacy. Final Report.

    Science.gov (United States)

    Buethe, Chris

    This booklet presents a pupil-oriented program designed to increase the environmental literacy of teachers and students in Indiana schools through a programmed multiplier effect. Junior and senior high school science teachers were prepared to teach students the meanings of 44 selected environmental terms and related concepts. Those teachers then…

  19. Modeling of high composition AlGaN channel high electron mobility transistors with large threshold voltage

    Energy Technology Data Exchange (ETDEWEB)

    Bajaj, Sanyam, E-mail: bajaj.10@osu.edu; Hung, Ting-Hsiang; Akyol, Fatih; Nath, Digbijoy; Rajan, Siddharth [Department of Electrical and Computer Engineering, The Ohio State University, Columbus, Ohio 43210 (United States)

    2014-12-29

    We report on the potential of high electron mobility transistors (HEMTs) consisting of high composition AlGaN channel and barrier layers for power switching applications. Detailed two-dimensional (2D) simulations show that threshold voltages in excess of 3 V can be achieved through the use of AlGaN channel layers. We also calculate the 2D electron gas mobility in AlGaN channel HEMTs and evaluate their power figures of merit as a function of device operating temperature and Al mole fraction in the channel. Our models show that power switching transistors with AlGaN channels would have comparable on-resistance to GaN-channel based transistors for the same operation voltage. The modeling in this paper shows the potential of high composition AlGaN as a channel material for future high threshold enhancement mode transistors.

  20. Position-sensitive Si pad detectors for electron emission channeling experiments

    CERN Document Server

    Wahl, Ulrich; Czermak, Adam; Jahn, S G; Jalocha, Pawel; Marques, J G; Rudge, Alan; Schopper, Florian; Carvalho-Soares, João; Vantomme, A; Weilhammer, Peter

    2004-01-01

    Position-sensitive detector systems, initially developed for the detection of X-rays, have been adapted for their use in electron emission channeling experiments. Each detection system consists of a 30.8x30.8 mm$^{2}$ 22x22 -pad Si detector, either of 0.3 mm, 0.5 mm or 1 mm thickness, four 128$-$channel preamplifier chips, a backplane trigger circuit, a sampling analog to digital converter, a digital signal processor, and a personal computer for data display and storage. The operational principle of these detection systems is described, and characteristic features such as energy and position resolution and maximum count rate, which have been determined from tests with conversion electrons and $\\beta^-\\!$ -particles in the energy range 40--600 keV, are presented.

  1. Gating machinery of InsP3R channels revealed by electron cryomicroscopy.

    Science.gov (United States)

    Fan, Guizhen; Baker, Matthew L; Wang, Zhao; Baker, Mariah R; Sinyagovskiy, Pavel A; Chiu, Wah; Ludtke, Steven J; Serysheva, Irina I

    2015-11-19

    Inositol-1,4,5-trisphosphate receptors (InsP3Rs) are ubiquitous ion channels responsible for cytosolic Ca(2+) signalling and essential for a broad array of cellular processes ranging from contraction to secretion, and from proliferation to cell death. Despite decades of research on InsP3Rs, a mechanistic understanding of their structure-function relationship is lacking. Here we present the first, to our knowledge, near-atomic (4.7 Å) resolution electron cryomicroscopy structure of the tetrameric mammalian type 1 InsP3R channel in its apo-state. At this resolution, we are able to trace unambiguously ∼85% of the protein backbone, allowing us to identify the structural elements involved in gating and modulation of this 1.3-megadalton channel. Although the central Ca(2+)-conduction pathway is similar to other ion channels, including the closely related ryanodine receptor, the cytosolic carboxy termini are uniquely arranged in a left-handed α-helical bundle, directly interacting with the amino-terminal domains of adjacent subunits. This configuration suggests a molecular mechanism for allosteric regulation of channel gating by intracellular signals.

  2. Structure of the BK potassium channel in a lipid membrane from electron cryomicroscopy.

    Science.gov (United States)

    Wang, Liguo; Sigworth, Fred J

    2009-09-10

    A long-sought goal in structural biology has been the imaging of membrane proteins in their membrane environments. This goal has been achieved with electron crystallography in those special cases where a protein forms highly ordered arrays in lipid bilayers. It has also been achieved by NMR methods in proteins up to 50 kilodaltons (kDa) in size, although milligram quantities of protein and isotopic labelling are required. For structural analysis of large soluble proteins in microgram quantities, an increasingly powerful method that does not require crystallization is single-particle reconstruction from electron microscopy of cryogenically cooled samples (electron cryomicroscopy (cryo-EM)). Here we report the first single-particle cryo-EM study of a membrane protein, the human large-conductance calcium- and voltage-activated potassium channel (BK), in a lipid environment. The new method is called random spherically constrained (RSC) single-particle reconstruction. BK channels, members of the six-transmembrane-segment (6TM) ion channel family, were reconstituted at low density into lipid vesicles (liposomes), and their function was verified by a potassium flux assay. Vesicles were also frozen in vitreous ice and imaged in an electron microscope. From images of 8,400 individual protein particles, a three-dimensional (3D) reconstruction of the BK channel and its membrane environment was obtained at a resolution of 1.7-2.0 nm. Not requiring the formation of crystals, the RSC approach promises to be useful in the structural study of many other membrane proteins as well.

  3. Structure of the channeling electrons wave functions under dynamical chaos conditions

    Energy Technology Data Exchange (ETDEWEB)

    Shul’ga, N.F. [National Science Center “Kharkov Institute of Physics and Technology”, 1, Akademicheskaya St., Kharkov 61108 (Ukraine); V.N. Karazin National University, 4, Svodody Sq., Kharkov 61022 (Ukraine); Syshchenko, V.V., E-mail: syshch@yandex.ru [Belgorod National Research University, 85, Pobedy St., Belgorod 308015 (Russian Federation); Tarnovsky, A.I. [Belgorod National Research University, 85, Pobedy St., Belgorod 308015 (Russian Federation); Isupov, A.Yu. [Laboratory of High Energy Physics, Joint Institute for Nuclear Research, 141980 Dubna, Moscow region (Russian Federation)

    2016-03-01

    The stationary wave functions of fast electrons axially channeling in the silicon crystal near [1 1 0] direction have been found numerically for integrable and non-integrable cases, for which the classical motion is regular and chaotic, respectively. The nodal structure of the wave functions in the quasi-classical region, where the energy levels density is high, is agreed with quantum chaos theory predictions.

  4. Truncated multipliers through power-gating for degrading precision arithmetic

    DEFF Research Database (Denmark)

    Albicocco, Pietro; Cardarilli, Gian Carlo; Nannarelli, Alberto

    2013-01-01

    When reducing the power dissipation of resource constrained electronic systems is a priority, some precision can be traded-off for lower power consumption. In signal processing, it is possible to have an acceptable quality of the signal even introducing some errors. In this work, we apply power-g...... to multipliers to obtain a programmable truncated multiplier. The method consists in disabling the least-significant columns of the multiplier by power-gating logic in the partial products generation and accumulation array.......When reducing the power dissipation of resource constrained electronic systems is a priority, some precision can be traded-off for lower power consumption. In signal processing, it is possible to have an acceptable quality of the signal even introducing some errors. In this work, we apply power-gating...

  5. The Current Collapse in AlGaN/GaN High-Electron Mobility Transistors Can Originate from the Energy Relaxation of Channel Electrons?

    Science.gov (United States)

    Mao, Ling-Feng; Ning, Huan-Sheng; Wang, Jin-Yan

    2015-01-01

    Influence of the energy relaxation of the channel electrons on the performance of AlGaN/GaN high-electron mobility transistors (HEMTs) has been investigated using self-consistent solution to the coupled Schrödinger equation and Poisson equation. The first quantized energy level in the inversion layer rises and the average channel electron density decreases when the channel electric field increases from 20 kV/cm to 120 kV/cm. This research also demonstrates that the energy relaxation of the channel electrons can lead to current collapse and suggests that the energy relaxation should be considered in modeling the performance of AlGaN/GaN HEMTs such as, the gate leakage current, threshold voltage, source-drain current, capacitance-voltage curve, etc.

  6. The Current Collapse in AlGaN/GaN High-Electron Mobility Transistors Can Originate from the Energy Relaxation of Channel Electrons?

    Directory of Open Access Journals (Sweden)

    Ling-Feng Mao

    Full Text Available Influence of the energy relaxation of the channel electrons on the performance of AlGaN/GaN high-electron mobility transistors (HEMTs has been investigated using self-consistent solution to the coupled Schrödinger equation and Poisson equation. The first quantized energy level in the inversion layer rises and the average channel electron density decreases when the channel electric field increases from 20 kV/cm to 120 kV/cm. This research also demonstrates that the energy relaxation of the channel electrons can lead to current collapse and suggests that the energy relaxation should be considered in modeling the performance of AlGaN/GaN HEMTs such as, the gate leakage current, threshold voltage, source-drain current, capacitance-voltage curve, etc.

  7. When is the government spending multiplier large?

    OpenAIRE

    Lawrence Christiano; Martin Eichenbaum; Sergio Rebelo

    2010-01-01

    We argue that the government-spending multiplier can be much larger than one when the zero lower bound on the nominal interest rate binds. The larger is the fraction of government spending that occurs while the nominal interest rate is zero, the larger is the value of the multiplier. After providing intuition for these results, we investigate the size of the multiplier in a dynamic, stochastic, general equilibrium model. In this model the multiplier effect is substantially larger than one whe...

  8. Electronic Properties of Alkali Metals Loaded into Channel-Type Zeolite L

    Science.gov (United States)

    Thi, P. T.; Nakano, T.; Sakamoto, Y.; Nozue, Y.

    2017-05-01

    Rb metal was loaded into dehydrated Rb-form zeolite L. The loading density of Rb atoms per unit cell, n, was changed up to 7.1. A resonant optical absorption-reflection band is observed at ≈1.0 eV in all samples. A new reflection band appears at ≈1.7 eV for n > 5. The 1.0 and 1.7 eV bands are assigned to the respective excitations from 1s to 1p and from 1p to 1d quantum states of s-electrons one-dimensionally confined in main-channels with an inside diameter of ≈1 nm. A temperature-dependent semiconducting resistivity is observed at n > 2, and is assigned to the inter-channel polaron hopping between metallic 1s and 1p states. Besides, a nearly metallic resistivity with the low thermal activation energy is observed at n > 5. The metallic conductivity is assigned to three-dimensional s-electrons in the 1d state. The metallic property in Rb-loaded zeolite L is more remarkable than those in K-loaded zeolite L. The difference is explained by the smaller ionization energy of Rb atom, which leads to a shallower one-dimensional confinement potential of main-channel and a smaller polaron effect.

  9. Channeling, Volume Reection and Gamma Emission Using 14GeV Electrons in Bent Silicon Crystals

    Energy Technology Data Exchange (ETDEWEB)

    Benson, Brandon [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-14

    High energy electrons can be deflected with very tight bending radius using a bent silicon crystal. This produces gamma radiation. As these crystals can be thin, a series of bent silicon crystals with alternating direction has the potential to produce coherent gamma radiation with reasonable energy of the driving electron beam. Such an electron crystal undulator offers the prospect for higher energy radiation at lower cost than current methods. Permanent magnetic undulators like LCLS at SLAC National Accelerator Laboratory are expensive and very large (about 100 m in case of the LCLS undulator). Silicon crystals are inexpensive and compact when compared to the large magnetic undulators. Additionally, such a high energy coherent light source could be used for probing through materials currently impenetrable by x-rays. In this work we present the experimental data and analysis of experiment T523 conducted at SLAC National Accelerator Laboratory. We collected the spectrum of gamma ray emission from 14 GeV electrons on a bent silicon crystal counting single photons. We also investigated the dynamics of electron motion in the crystal i.e. processes of channeling and volume reflection at 14 GeV, extending and building off previous work. Our single photon spectrum for the amorphous crystal orientation is consistent with bremsstrahlung radiation and the volume reflection crystal orientation shows a trend consistent with synchrotron radiation at a critical energy of 740 MeV. We observe that in these two cases the data are consistent, but we make no further claims because of statistical limitations. We also extended the known energy range of electron crystal dechanneling length and channeling efficiency to 14 GeV.

  10. A multi-channel opto-electronic sensor to accurately monitor heart rate against motion artefact during exercise

    National Research Council Canada - National Science Library

    Alzahrani, Abdullah; Hu, Sijung; Azorin-Peris, Vicente; Barrett, Laura; Esliger, Dale; Hayes, Matthew; Akbare, Shafique; Achart, Jérôme; Kuoch, Sylvain

    2015-01-01

    This study presents the use of a multi-channel opto-electronic sensor (OEPS) to effectively monitor critical physiological parameters whilst preventing motion artefact as increasingly demanded by personal healthcare...

  11. Development of 32-channel silicon drift detectors and digital electronics for X-ray spectroscopy.

    Science.gov (United States)

    Gauthier, C; Goujon, G; Goulon, J; Moguiline, E; Dressler, P; Henck, R; Lampert, M O

    1998-05-01

    The performance of silicon-drift-detector (SDD) arrays and digital electronics designed for X-ray absorption spectroscopy in the fluorescence excitation mode is reported. Different detectors have been manufactured and tested: two single-channel SDDs with different active areas (10 mm(2) and 1 cm(2)) and a monolithic 2 cm(2) SDD with eight readout anodes. The energy resolution varies between 160 and 170 eV FWHM. A new digital multichannel shaping amplifier has been produced. Its performance is presented in comparison with that of a standard commercial shaper.

  12. Characteristics of four-channel Cherenkov-type detector for measurements of runaway electrons in the ISTTOK tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Plyusnin, V. V.; Duarte, P.; Fernandes, H.; Silva, C. [Instituto de Plasmas e FuSao Nuclear - Laboratorio Associado, Association Euratom/IST, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Jakubowski, L.; Zebrowski, J.; Malinowski, K.; Rabinski, M.; Sadowski, M. J. [The Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland)

    2010-10-15

    A diagnostics capable of characterizing the runaway and superthermal electrons has been developing on the ISTTOK tokamak. In previous paper, a use of single-channel Cherenkov-type detector with titanium filter for runaway electron studies in ISTTOK was reported. To measure fast electron populations with different energies, a prototype of a four-channel detector with molybdenum filters was designed. Test-stand studies of filters with different thicknesses (1, 3, 7, 10, 20, 50, and 100 {mu}m) have shown that they should allow the detection of electrons with energies higher than 69, 75, 87, 95, 120, 181, and 260 keV, respectively. First results of measurements with the four-channel detector revealed the possibility to measure reliably different fast electrons populations simultaneously.

  13. groups by their Schur multiplier

    Indian Academy of Sciences (India)

    22

    A CHARACTERIZATION OF FINITE p-GROUPS BY THEIR SCHUR MULTIPLIER. 7. Now consider groups of order p7 of exponent p. By [14] it follows that there is only one capable group. G = 〈x1, ··· ,x5,c1,c2 | [x2,x1]=[x5,x3] = c1, [x3,x1]=[x5,x4] = c2〉 upto isomorphism. By Theorem 2.3 we have |M(G)| = p9 as |X| = |X1| = p9 ...

  14. Measurement of the Electronic Thermal Conductance Channels and Heat Capacity of Graphene at Low Temperature

    Directory of Open Access Journals (Sweden)

    Kin Chung Fong

    2013-10-01

    Full Text Available The ability to transport energy is a fundamental property of the two-dimensional Dirac fermions in graphene. Electronic thermal transport in this system is relatively unexplored and is expected to show unique fundamental properties and to play an important role in future applications of graphene, including optoelectronics, plasmonics, and ultrasensitive bolometry. Here, we present measurements of bipolar thermal conductances due to electron diffusion and electron-phonon coupling and infer the electronic specific heat, with a minimum value of 10k_{B} (10^{-22}  J/K per square micron. We test the validity of the Wiedemann-Franz law and find that the Lorenz number equals 1.32×(π^{2}/3(k_{B}/e^{2}. The electron-phonon thermal conductance has a temperature power law T^{2} at high doping levels, and the coupling parameter is consistent with recent theory, indicating its enhancement by impurity scattering. We demonstrate control of the thermal conductance by electrical gating and by suppressing the diffusion channel using NbTiN superconducting electrodes, which sets the stage for future graphene-based single-microwave photon detection.

  15. EBSD and electron channeling study of anomalous slip in oligocrystals of high chromium ferritic stainless steel.

    Science.gov (United States)

    Hsiao, Zheng-Wen; Wu, Ting-Yi; Chen, Delphic; Kuo, Jui-Chao; Lin, Dong-Yih

    2017-03-01

    In the present study, electron backscatter diffraction (EBSD) and electron channeling contrast imaging (ECCI) techniques were applied to investigate the deformation pattern of coarse ferrite grains after being subjected to 3%, 6%, and 10% tensile deformation. Oligocrystals of Crofer® 22H ferritic steel were obtained as experimental material at 1075°C for 22min annealing. Using kernel average misorientation (KAM) mapping obtained from EBSD, possible slip planes are (110), (101), (12-1) and (32-1) in grain A; (0-11), (-101), (-112), (1-21) in grain B; and (0-11), (1-21) and (11-2) in grain C. Combining ECCI and EBSD techniques enables us to identify two a0[11¯1]/2 edge dislocations that occur on the (110)[1-11] and (32-1)[1-11] slip systems for grain A, thereby breaking down Schmid's law. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Threading dislocation density characterization in III-V photovoltaic materials by electron channeling contrast imaging

    Science.gov (United States)

    Yaung, Kevin Nay; Kirnstoetter, Stefan; Faucher, Joseph; Gerger, Andy; Lochtefeld, Anthony; Barnett, Allen; Lee, Minjoo Larry

    2016-11-01

    Accurate and rapid threading dislocation density (TDD) characterization of III-V photovoltaic materials using electron channeling contrast imaging (ECCI) is demonstrated. TDDs measured using ECCI showed close agreement with those from electron beam-induced current mapping (EBIC) and defect selective etching (DSE). ECCI is shown to be well-suited for measuring TDD values over a range of 5×106-5×108 cm-2. ECCI can distinguish individual dislocations in clusters closer than 0.2 μm, highlighting its excellent spatial resolution compared to DSE and EBIC. Taken together, ECCI is shown to be a versatile and complementary method to rapidly quantify TDD in III-V solar cells.

  17. Monolithic Chip System with a Microfluidic Channel for In Situ Electron Microscopy of Liquids

    DEFF Research Database (Denmark)

    Jensen, Eric; Burrows, Andrew; Mølhave, Kristian

    2014-01-01

    sandwiched microchips with thin membranes. We report on a new microfabricated chip system based on a monolithic design that enables membrane geometry on the scale of a few micrometers. The design is intended to reduce membrane deflection when the system is under pressure, a micro fluidic channel for improved...... flow geometry, and a better space angle for auxiliary detectors such as energy-dispersive X-ray spectroscopy. We explain the system design and fabrication and show the first successful TEM images of liquid samples in the chips.......Electron microscopy of enclosed liquid samples requires the thinnest possible membranes as enclosing windows as well as nanoscale liquid sample thickness to achieve the best possible resolution. Today liquid sample systems for transmission electron microscopy (TEM) are typically made from two...

  18. Search For The Higgs Boson Decaying Into $\\tau$-Leptons In The Di-Electron Channel

    CERN Document Server

    Salfeld-Nebgen, Jakob; Schleper, Peter

    The first dedicated search for Higgs bosons decaying into tau pairs with two electrons and 4 neutrinos in the final state is presented. The search is performed with the CMS detector at the LHC based on an integrated luminosity of 4.9 fb$^{-1}$ and 19.7 fb$^{-1}$ at 7 TeV and 8 TeV, respectively. Events with two reconstructed electrons are selected before extensive multivariate analysis techniques are utilized to achieve an optimal background rejection. The $ee$-channel alone excludes $3.2\\times(\\sigma^H_{SM}\\times BR(H\\rightarrow \\tau\\tau))$ for $m_H = 120$ $GeV/c^2$ and $3.7\\times(\\sigma^H_{SM}\\times BR(H\\rightarrow \\tau\\tau))$ for $m_H = 125$ $GeV/c^2$ at 95\\% confidence level. The $ee$-channel is combined into the official CMS $H\\rightarrow \\tau\\tau$ analysis, to find, for the first time, direct evidence for couplings of the new Higgs-like boson to down-type fermions with 3.2$\\sigma$.

  19. Electronic Communication Channel Use and Health Information Source Preferences Among Latinos in Northern Manhattan.

    Science.gov (United States)

    Hillyer, Grace Clarke; Schmitt, Karen M; Lizardo, Maria; Reyes, Andria; Bazan, Mercedes; Alvarez, Maria C; Sandoval, Rossy; Abdul, Kazeem; Orjuela, Manuela A

    2017-04-01

    Understanding key health concepts is crucial to participation in Precision Medicine initiatives. In order to assess methods to develop and disseminate a curriculum to educate community members in Northern Manhattan about Precision Medicine, clients from a local community-based organization were interviewed during 2014-2015. Health literacy, acculturation, use of Internet, email, and text messaging, and health information sources were assessed. Associations between age and outcomes were evaluated; multivariable analysis used to examine the relationship between participant characteristics and sources of health information. Of 497 interviewed, 29.4 % had inadequate health literacy and 53.6 % had access to the Internet, 43.9 % to email, and 45.3 % to text messaging. Having adequate health literacy was associated with seeking information from a healthcare professional (OR 2.59, 95 % CI 1.54-4.35) and from the Internet (OR 3.15, 95 % CI 1.97-5.04); having ≤ grade school education (OR 2.61, 95 % CI 1.32-5.17) also preferred information from their provider; persons >45 years (OR 0.29, 95 % CI 0.18-0.47) were less likely to use the Internet for health information and preferred printed media (OR 1.64, 95 % CI 1.07-2.50). Overall, electronic communication channel use was low and varied significantly by age with those ≤45 years more likely to utilize electronic channels. Preferred sources of health information also varied by age as well as by health literacy and educational level. This study demonstrates that to effectively communicate key Precision Medicine concepts, curriculum development for Latino community members of Northern Manhattan will require attention to health literacy, language preference and acculturation and incorporate more traditional communication channels for older community members.

  20. Cross-correlation based high resolution electron backscatter diffraction and electron channelling contrast imaging for strain mapping and dislocation distributions in InAlN thin films

    OpenAIRE

    Vilalta-Clemente, A.; Naresh-Kumar, G; Nouf-Allehiani, M.; Gamarra, P.; di Forte-Poisson, M. A.; Trager-Cowan, C.; Wilkinson, A.J.

    2017-01-01

    We describe the development of cross-correlation based high resolution electron backscatter diffraction (HR-EBSD) and electron channelling contrast imaging (ECCI), in the scanning electron microscope (SEM), to quantitatively map the strain variation and lattice rotation and determine the density and identify dislocations in nitride semiconductor thin films. These techniques can provide quantitative, rapid, non-destructive analysis of the structural properties of materials with a spatial resol...

  1. Selective Dirac voltage engineering of individual graphene field-effect transistors for digital inverter and frequency multiplier integrations

    Science.gov (United States)

    Sul, Onejae; Kim, Kyumin; Jung, Yungwoo; Choi, Eunsuk; Lee, Seung-Beck

    2017-09-01

    The ambipolar band structure of graphene presents unique opportunities for novel electronic device applications. A cycle of gate voltage sweep in a conventional graphene transistor produces a frequency-doubled output current. To increase the frequency further, we used various graphene doping control techniques to produce Dirac voltage engineered graphene channels. The various surface treatments and substrate conditions produced differently doped graphene channels that were integrated on a single substrate and multiple Dirac voltages were observed by applying a single gate voltage sweep. We applied the Dirac voltage engineering techniques to graphene field-effect transistors on a single chip for the fabrication of a frequency multiplier and a logic inverter demonstrating analog and digital circuit application possibilities.

  2. Chemical Selectivity and Sensitivity of a 16-Channel Electronic Nose for Trace Vapour Detection

    Directory of Open Access Journals (Sweden)

    Drago Strle

    2017-12-01

    Full Text Available Good chemical selectivity of sensors for detecting vapour traces of targeted molecules is vital to reliable detection systems for explosives and other harmful materials. We present the design, construction and measurements of the electronic response of a 16 channel electronic nose based on 16 differential microcapacitors, which were surface-functionalized by different silanes. The e-nose detects less than 1 molecule of TNT out of 10+12 N2 molecules in a carrier gas in 1 s. Differently silanized sensors give different responses to different molecules. Electronic responses are presented for TNT, RDX, DNT, H2S, HCN, FeS, NH3, propane, methanol, acetone, ethanol, methane, toluene and water. We consider the number density of these molecules and find that silane surfaces show extreme affinity for attracting molecules of TNT, DNT and RDX. The probability to bind these molecules and form a surface-adsorbate is typically 10+7 times larger than the probability to bind water molecules, for example. We present a matrix of responses of differently functionalized microcapacitors and we propose that chemical selectivity of multichannel e-nose could be enhanced by using artificial intelligence deep learning methods.

  3. WIMAGINE: an implantable electronic platform for wireless 64-channel ECoG recording

    Science.gov (United States)

    Foerster, M.; Porcherot, J.; Robinet, S.; D'Errico, R.; Josselin, V.; Sauter, F.; Mestais, C.; Charvet, G.

    2013-05-01

    The WIMAGINE platform was developed as a proof of concept and first functional prototype of an implantable device for recording ECoG signals on a large number of electrodes. The designed system provides the means of recording wirelessly up to 64 ECoG channels. Two ASIC CINESIC32 ensure the amplification and digitization of the neurosignals which are then transmitted to a PC using a ZL70102 transceiver in the MICS band. An MSP430 handles the communication protocol, configures the ASICs and gives access to various sensor information. The electronics are packaged hermetically in a biocompatible titanium housing encapsulated medical grade silicone. The whole device is powered remotely over an inductive link at 13.56MHz and complies with the regulations applicable to class III AIMD.

  4. Operator valued integral multiplier functions | Fourie | Quaestiones ...

    African Journals Online (AJOL)

    In recent years, several papers were devoted to the study of (p, q)-summing sequences of operators and their applications in the theory of Banach spaces. In the present paper we initiate a similar study of “integral multiplier functions”, thereby introducing these spaces of operator valued multiplier functions as normed spaces ...

  5. ON LU FACTORIZATION ALGORITHM WITH MULTIPLIERS

    African Journals Online (AJOL)

    In this paper, we propose a straightforward method based on multipliers derived from modification of. Gaussion elimination algorithm. KEY WORDS: Lower and Upper Triangular Matrices, Multipliers. INTRODUCTION. Let A be a square matrix of order n. An LU factorization or decomposition is a decomposition of the form:.

  6. Characterization of crystallographic defects in SEM by electron channeling assisted by high resolution pseudo-Kikuchi patterns : application to IF-steel, UO2 and TiAl

    OpenAIRE

    Mansour, Haithem

    2016-01-01

    Electron Channeling Contrast Imaging (ECCI) is a Scanning Electron Microscope (SEM) technique used to observe and characterize crystallographic defects. ECCI requires the crystal to be oriented relative to the electron beam with high accuracy (0.1°) in order to control the electron channeling conditions. The SEM techniques used to determine the crystallographic orientation, such as conventional Electron BackScattered Diffraction (EBSD) or Rocking Beam, don’t satisfy the high accuracy required...

  7. Multiply-negatively charged aluminium clusters and fullerenes

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, Noelle

    2008-07-15

    Multiply negatively charged aluminium clusters and fullerenes were generated in a Penning trap using the 'electron-bath' technique. Aluminium monoanions were generated using a laser vaporisation source. After this, two-, three- and four-times negatively charged aluminium clusters were generated for the first time. This research marks the first observation of tetra-anionic metal clusters in the gas phase. Additionally, doubly-negatively charged fullerenes were generated. The smallest fullerene dianion observed contained 70 atoms. (orig.)

  8. Diagnosis and dynamics in a simple low energy medium current electron beam channel

    Science.gov (United States)

    Marghitu, S.; Marghitu, O.; Oproiu, C.; Marin, G.; Scarlat, Fl.

    2004-05-01

    We present a simple experimental setup and an associated method enabling both the non-destructive diagnosis and the calculation of the beam evolution in a low energy medium current electron beam channel, where the space-charge and emittance effects are comparable. The diagnosis makes use of an axially symmetric magnetic lens while a second lens is added to increase the flexibility in the beam processing. The paper emphasizes the three steps involved in the method: the evaluation of the lenses' magnetic field by numerical simulation, the beam diagnosis, and the computation of the beam envelope. The calculation of the magnetic field is based on the finite element method. Subsequently, the beam parameters at the electron source exit - emittance and cross-over radius and position - are found with the modified three gradient method. Finally, the beam dynamics are modeled with the K-V equation adapted for the particular case of axial symmetry. The results obtained in this paper can be used to optimize technological processes, such as welding, hardening, cladding, and surface alloying.

  9. 2-D imaging with cascaded GEM/MHSP multipliers

    CERN Document Server

    Maia, J M; Breskin, Amos; Chechik, R; Veloso, J F C A; Dos Santos, J M F

    2007-01-01

    The imaging properties of cascaded-GEM (Gas Electron Multiplier) and cascaded-GEM/MHSP (Micro-Hole and Strip Plate) gaseous electron multipliers, equipped with 2-D Wedge & Strip (W&S) readout electrodes, are presented. The W&S electrode was capacitively coupled to the electron multiplier through a resistive electrode, to adapt the charge-cloud size to the 1.6 mm readout pitch. The studies were carried out with soft X-rays and single UV-photons in Ar/5%CH4 gas mixture at atmospheric pressure. Spatial resolutions of ~225μm and ~250μm (FWHM) were reached, with 5.9 keV X-rays, in 3-GEM and 2-GEM/MHSP based detectors, respectively. Single photoelectrons, emitted from a CsI photocathode deposited on the top electrode of the first GEM in the cascade, were localized with resolution of ~ 170μm (FWHM) in a 4-GEM gaseous photomultiplier.

  10. An electronic channel switching-based aptasensor for ultrasensitive protein detection

    Energy Technology Data Exchange (ETDEWEB)

    Li Hongbo; Wang Cui [State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China); Wu Zaisheng, E-mail: wuzaisheng@163.com [State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China); Lu Limin; Qiu Liping; Zhou Hui; Shen Guoli [State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China); Yu Ruqin, E-mail: rqyu@hnu.edu.cn [State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China)

    2013-01-03

    Highlights: Black-Right-Pointing-Pointer Target IgE is successfully designed to serve as a barrier to separate enzyme from its substrate. Black-Right-Pointing-Pointer This sensing platform of electronic channel switching-based aptasensor can be simply manipulated. Black-Right-Pointing-Pointer The stable hairpin structure of anti-IgE aptamer is utilized to detect target IgE. Black-Right-Pointing-Pointer The sensor is ultrasensitive sensitivity, excellent selectivity and small volume of sample. Black-Right-Pointing-Pointer It is a powerful platform to be further expanded to detect more kinds of proteins and even cells. - Abstract: Due to the ubiquity and essential of the proteins in all living organisms, the identification and quantification of disease-specific proteins are particularly important. Because the conformational change of aptamer upon its target or probe/target/probe sandwich often is the primary prerequisite for the design of an electrochemical aptameric assay system, it is extremely difficult to construct the electrochemical aptasensor for protein assay because the corresponding aptamers cannot often meet the requirement. To circumvent the obstacles mentioned, an electronic channel switching-based (ECS) aptasensor for ultrasensitive protein detection is developed. The essential achievement made is that an innovative sensing concept is proposed: the hairpin structure of aptamer is designed to pull electroactive species toward electrode surface and makes the surface-immobilized IgE serve as a barrier that separates enzyme from its substrate. It seemingly ensures that the ECS aptasensor exhibits most excellent assay features, such as, a detection limit of 4.44 Multiplication-Sign 10{sup -6} {mu}g mL{sup -1} (22.7 fM, 220 zmol in 10-{mu}L sample) (demonstrating a 5 orders of magnitude improvement in detection sensitivity compared with classical electronic aptasensors) and dynamic response range from 4.44 Multiplication-Sign 10{sup -6} to 4.44 Multiplication

  11. Net electron energy gain induced by superluminal phase velocity and subluminal group velocity of a laser in a plasma channel

    Science.gov (United States)

    Cheng, Li-Hong; Yao, Zheng-Wei; Zhang, Xiao-Bo; Xue, Ju-Kui

    2017-08-01

    We examine electron dynamics induced by laser-plasma interaction in a two-dimensional plasma channel, taking into action the laser phase velocity as well as the group velocity. The coupled effects of phase velocity, group velocity, and plasma channel on electron dynamics are discussed in detail. The superluminal phase velocity and the corresponding subluminal group velocity of the laser result in rich and complex electron dynamics, which are depicted in the plane of the phase velocity and plasma charge density. For weak superluminosity of the phase velocity, the effects of the phase velocity and the group velocity can be neglected. For moderate superluminosity of the phase velocity, a cross-over region can exist, where the highly energetic electron could be found and the net energy gain is several times greater than the energy gain in vacuum. For strong superluminosity of the phase velocity, the dephasing rate increases and thus limits the electron energy gain from the laser. However, the asymmetric laser pulse, attributed by the superluminal phase velocity and the subluminal group velocity, results in the electron getting adjustable net energy gain from the laser. The electron oscillations are no longer limited by the charge density threshold and the electron can always get net energy from the laser. These electron dynamics can also be modified by adjusting the polarization of the laser.

  12. Observation of Top Quark Pairs in the Dilepton Decay Channel using Electrons, Muons and Taus

    Energy Technology Data Exchange (ETDEWEB)

    Hohlmann, Marcus [Chicago U.

    1997-01-01

    This thesis presents a search for top quark pair production via the process p pbar -> t tbar + X -> W+W- b bbar + X -> (l+ nu_l)(l- nubar_l) b bbar + X, where l is either e, mu, or tau. Using a sample of 109+-7 pb of ppbar collisons at sqrt{s}=1.8 TeV collected by the CDF detector at the Fermilab Tevatron we find a clear signal for ttbar production in the ee, mumu, and emu dilepton channels. We observe 9 events where we expect 3.9+-0.7 ttbar events (based on the theoretical production cross section) and 2.1+-0.4 background events. The ttbar production cross section measured from this channel is sigma_{ttbar}=8.5^{+4.1}_{-3.3}(stat)^{+1.6}_{-0.8} (syst) pb. Using a method developed in this thesis to identify hadronically decaying tau leptons we also search for etau and mutau dilepton events from t tbar production and decay. We observe 4 events and expect 2.5+-0.4 background events. In 3 of the 4 events atleast one jet is tagged as due to a b quark decay. We expect 0.28+-0.02 tagged events from background processes. Based on the 4 tau dilepton events we calculate the ttbar production cross section to be sigma_{t tbar } = 10.2^{+16.3}_{-10.2}(stat)+-1.6(syst) pb. The kinematics and topology of the candidate events are generally consistent with the expectations, with two exceptions. Five of the 14 candidate events have unusually large missing transverse energy. One emu event contains an electron with very high Et (182 GeV) and an additional high--Et (23 GeV) isolated positron. In 109 pb we expect (2.4+-0.9)x10^{-6} such ``trilepton" events from t tbar production and decay. Enjoy,Marcus

  13. Transformational Electronics: Towards Flexible Low-Cost High Mobility Channel Materials

    KAUST Repository

    Nassar, Joanna M.

    2014-05-01

    For the last four decades, Si CMOS technology has been advancing with Moore’s law prediction, working itself down to the sub-20 nm regime. However, fundamental problems and limitations arise with the down-scaling of transistors and thus new innovations needed to be discovered in order to further improve device performance without compromising power consumption and size. Thus, a lot of studies have focused on the development of new CMOS compatible architectures as well as the discovery of new high mobility channel materials that will allow further miniaturization of CMOS transistors and improvement of device performance. Pushing the limits even further, flexible and foldable electronics seem to be the new attractive topic. By being able to make our devices flexible through a CMOS compatible process, one will be able to integrate hundreds of billions of more transistors in a small volumetric space, allowing to increase the performance and speed of our electronics all together with making things thinner, lighter, smaller and even interactive with the human skin. Thus, in this thesis, we introduce for the first time a cost-effective CMOS compatible approach to make high-k/metal gate devices on flexible Germanium (Ge) and Silicon-Germanium (SiGe) platforms. In the first part, we will look at the various approaches in the literature that has been developed to get flexible platforms, as well as we will give a brief overview about epitaxial growth of Si1-xGex films. We will also examine the electrical properties of the Si1-xGex alloys up to Ge (x=1) and discuss how strain affects the band structure diagram, and thus the mobility of the material. We will also review the material growth properties as well as the state-of-the-art results on high mobility metal-oxide semiconductor capacitors (MOSCAPs) using strained SiGe films. Then, we will introduce the flexible process that we have developed, based on a cost-effective “trench-protect-release-reuse” approach, utilizing

  14. Study of unexplained hard photon production by electrons channelled in a crystal

    CERN Multimedia

    2002-01-01

    Our preceding experiment (NA33) designed to study the pair creation process in the interaction of high energy $\\gamma$ with a crystal in alignment conditions had revealed the existence of an unexpected peak in the radiation of 150 GeV e$^{-}$ beam for E$_{\\gamma}$/E$_{e^{-}} \\simeq$ 0.85 incident along the axis of a 185 $\\mu$m. Ge crystal and the photon multiplicity for the peak events has been measured to be M $\\simeq$ 5.7.\\\\ In NA42, in a 76 $\\mu$m crystal of the same crystallographic quality, the peak nearly disappears, and the photon multiplicity at x = 0.85 is only M $\\simeq$ 2.0. \\\\ The thickness dependence of the effect shows that the extrapolated multiplicity in the peak in a very thin crystal tends to unity. The high energy radiation peak emitted by axially channeled electrons in a thick crystal is then interpreted by the radiation cooling mechanism. \\\\ The extrapolation to zero thickness of these results will allow us to extract from the data the single $\\gamma$ radiation spectrum. The comparison o...

  15. Economic Multipliers and Mega-Event Analysis

    OpenAIRE

    Victor Matheson

    2004-01-01

    Critics of economic impact studies that purport to show that mega-events such as the Olympics bring large benefits to the communities “lucky” enough to host them frequently cite the use of inappropriate multipliers as a primary reason why these impact studies overstate the true economic gains to the hosts of these events. This brief paper shows in a numerical example how mega-events may lead to inflated multipliers and exaggerated claims of economic benefits.

  16. A low noise front end electronics for micro-channel plate detector with wedge and strip anode

    Science.gov (United States)

    Hu, K.; Li, F.; Liang, F.; Chen, L.; Jin, G.

    2016-03-01

    A low noise Front End Electronics (FEE) for two-dimensional position sensitive Micro-Channel Plate (MCP) detector has been developed. The MCP detector is based on Wedge and Strip Anode (WSA) with induction readout mode. The WSA has three electrodes, the wedge electrode, the strip electrode, and the zigzag electrode. Then, three readout channels are designed in the Printed Circuit Board (PCB). The FEE is calibrated by a pulse generator from Agilent. We also give an analysis of the charge loss from the CSA. The noise levels of the three channels are less than 1 fC RMS at the shaping time of 200 ns. The experimental result shows that the position resolution of the MCP detector coupled with the designed PCB can reach up to 110 μm.

  17. Enhancement-Mode AIGaN/GaN High Electron Mobility Transistors Using a Nano-Channel Arrayy Structure

    Institute of Scientific and Technical Information of China (English)

    LIU Sheng-Hou; Cheng P. Wen; QIN Hua; ZHANG Bao-Shun; CAI Yong; GONG Ru-Min; WANG Jin-Yan; ZENG Chun-Hong; SHI Wen-Hua; FENG Zhi-Hong; WANG Jing-Jing; YIN Jia-Yun

    2011-01-01

    A nano-channel array (NCA) structure is applied to realize enhancement-mode (E-mode) A1GaN/GaN high electron mobility transistors (HEMTs). The fabricated NCA-HEMT,consisting of 1000 channels connected in parallel with a channel width of 64 nm,shows a threshold voltage of 0.15 V and a subthreshold slope of 78mY/dec,compared to -3.92 V and 99mV/dec for a conventional HEMT (C-HEMT),respectively.Both the NCA-HEMT and C-HEMT show similar gate leakage current,indicating no significant degradation in gate leakage characteristics for the NCA-HEMT.The surrounding-field effect and relieved polarization contribute to the very large positive threshold voltage shift,while the work function difference makes it positive.

  18. Multichannel marketing: an experiment on guiding citizens to the electronic channels

    NARCIS (Netherlands)

    Teerling, Marije L.; Pieterson, Willem Jan

    2010-01-01

    Governments have a variety of channels at their disposal to help them interact with their citizens. Having realized that citizens still prefer the traditional channels, governments are now focusing on ways to lead them to the web. Previously, we have shown that citizens prefer the use of soft

  19. Electron gas polarization effect induced by heavy H-like ions of moderate velocities channeled in a silicon crystal

    Energy Technology Data Exchange (ETDEWEB)

    Testa, E. [Institut de Physique Nucleaire de Lyon, CNRS-IN2P3, Universite Claude Bernard Lyon 1, F-69622 Villeurbanne (France); Dauvergne, D. [Institut de Physique Nucleaire de Lyon, CNRS-IN2P3, Universite Claude Bernard Lyon 1, F-69622 Villeurbanne (France)]. E-mail: d.dauvergne@ipnl.in2p3.fr; Braeuning-Demian, A. [Gesellschaft fuer Schwerionen Forschung (GSI), D-64291 Darmstadt (Germany); Bosch, F. [Gesellschaft fuer Schwerionen Forschung (GSI), D-64291 Darmstadt (Germany); Braeuning, H. [Institut fuer Kernphysik, Justus Liebig Universitaet, D-35392 Giessen (Germany); Chevallier, M. [Institut de Physique Nucleaire de Lyon, CNRS-IN2P3, Universite Claude Bernard Lyon 1, F-69622 Villeurbanne (France); Cohen, C. [Institut des Nano-Sciences de Paris, CNRS-UMR75-88, Universites Paris VI et Paris VII, 75251 Paris cedex 05 (France); Gumberidze, A. [Gesellschaft fuer Schwerionen Forschung (GSI), D-64291 Darmstadt (Germany); Hagmann, S. [Gesellschaft fuer Schwerionen Forschung (GSI), D-64291 Darmstadt (Germany); L' Hoir, A. [Institut des Nano-Sciences de Paris, CNRS-UMR75-88, Universites Paris VI et Paris VII, 75251 Paris cedex 05 (France); Kirsch, R. [Institut de Physique Nucleaire de Lyon, CNRS-IN2P3, Universite Claude Bernard Lyon 1, F-69622 Villeurbanne (France); Kozhuharov, C.; Liesen, D.; Mokler, P.H. [Gesellschaft fuer Schwerionen Forschung (GSI), D-64291 Darmstadt (Germany); Poizat, J.-C.; Ray, C. [Institut de Physique Nucleaire de Lyon, CNRS-IN2P3, Universite Claude Bernard Lyon 1, F-69622 Villeurbanne (France); Rozet, J.-P. [Institut des Nano-Sciences de Paris, CNRS-UMR75-88, Universites Paris VI et Paris VII, 75251 Paris cedex 05 (France); Stoehlker, Th.; Toleikis, S. [Gesellschaft fuer Schwerionen Forschung (GSI), D-64291 Darmstadt (Germany); Toulemonde, M. [Centre Interdisciplinaire de Recherche Ions-Lasers, UMR 11, CEA-CNRS, 14040 Caen cedex (France); Verma, P. [Gesellschaft fuer Schwerionen Forschung (GSI), D-64291 Darmstadt (Germany)

    2006-04-15

    We report on the observation of a strong perturbation of the electron gas induced by 20 MeV/u U{sup 91+} ions and 13 MeV/u Pb{sup 81+} ions channeled in silicon crystals. This collective response (wake effect) induces a shift of the continuum energy level by more than 100 eV, which is observed by means of radiative electron capture into the K- and L-shells of the projectiles. We also observe an increase of the REC probability by 20-50% relative to the probability in a non-perturbed electron gas. The energy shift is in agreement with calculations using the linear response theory, whereas the local electron density enhancement is much smaller than predicted by the same model. This shows that, for the small values of the adiabaticity parameter achieved in our experiments, the density fluctuations are not strongly localized in the vicinity of the heavy ions.

  20. Channel height and curvature effects on flow boiling from an electronic chip

    Science.gov (United States)

    Leland, J. E.; Chow, L. C.

    1995-04-01

    Forced convective boiling from a discrete heat source in a curved rectangular channel has been experimentally investigated. The flow area height and radius of curvature of the channel were varied to ascertain the effects of induced buoyancy and secondary flow. For comparison, results were also obtained for a similar heat source in a straight channel. Three configurations encompassing two radii of curvature, 28.6 and 56.4 mm, and three heights, 3.18, 5.56, and 6.35 mm, were studied. An additional channel height of 1.14 mm was investigated for the straight geometry only. Data were obtained for subcoolings of 5, 20, and 35 C and flow velocities of 1-7 m/s. For the straight geometry, critical heat flux (CHF) did not vary much for heights greater than 1.14 mm. The percent increase in curved channel CHF over straight channel CHF was highest for 5 C subcooling. This implies that buoyancy effects are most important when there is significant vapor generation. For a given subcooling and velocity, the radius of curvature had little effect. This implies that secondary flow has little effect under these conditions. A correlation is developed that describes the effects of buoyancy and secondary flow on CHF in the curved channel.

  1. Characterization of Amorphous Oxide Nano-Thick Layers on 316L Stainless Steel by Electron Channeling Contrast Imaging and Electron Backscatter Diffraction.

    Science.gov (United States)

    Dorri, Mahrokh; Turgeon, Stéphane; Brodusch, Nicolas; Cloutier, Maxime; Chevallier, Pascale; Gauvin, Raynald; Mantovani, Diego

    2016-10-01

    Characterization of the topmost surface of biomaterials is crucial to understanding their properties and interactions with the local environment. In this study, the oxide layer microstructure of plasma-modified 316L stainless steel (SS316L) samples was analyzed by a combination of electron backscatter diffraction and electron channeling contrast imaging using low-energy incident electrons. Both techniques allowed clear identification of a nano-thick amorphous oxide layer, on top of the polycrystalline substrate, for the plasma-modified samples. A methodology was developed using Monte Carlo simulations combined with the experimental results to estimate thickness of the amorphous layer for different surface conditions. X-ray photoelectron spectroscopy depth profiles were used to validate these estimations.

  2. Study of electron beams within ISTTOK tokamak by means of a multi-channel Cherenkov detector; their correlation with hard X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Jakubowski, L., E-mail: Lech.Jakubowski@ipj.gov.p [Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland); Malinowski, K.; Sadowski, M.J.; Zebrowski, J. [Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland); Plyusnin, V.V. [Association Euratom/IST, Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Rabinski, M. [Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland); Fernandes, H.; Silva, C.; Duarte, P. [Association Euratom/IST, Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Jakubowski, M.J. [Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland)

    2010-11-11

    The paper describes experimental studies of electron beams emitted from a plasma torus within the ISTTOK tokamak, which were performed by means of a new four-channel detector of the Cherenkov type. A range of electron energy was estimated. There were also measured hard X-rays, and their correlation with the fast run-away electron beams was investigated experimentally.

  3. Electron Channeling Contrast Imaging (ECCI) and Electron Backscatter Diffraction (EBSD) Study of Forsterite Olivine Deformed in the D-DIA Apparatus

    Science.gov (United States)

    Kaboli, S.; Burnley, P. C.

    2016-12-01

    Understanding the rheology of Earth's interior requires a detailed study of microstructure and crystallographic texture on a micro- and nanoscale. Quantitative microstructure characterization of geological materials is commonly performed on thin foils using a transmission electron microscope (TEM). The main drawbacks of TEM include time consuming and destructive thin foil preparation, limited field of view and statistically unreliable results in the case of heterogeneous microstructures which are common in geological materials. Electron channeling contrast imaging (ECCI) is a complementary technique to electron backscatter diffraction (EBSD) for quantitative microstructure characterization of bulk samples in a field emission scanning electron microscope (FE-SEM). The main application of ECCI is in characterization of deformed materials since it allows the warping of the lattice to be imaged based on the electron channeling contrast. In comparison to TEM, the main advantages of using ECCI in SEM include non-destructive bulk sample preparation and statistically reliable results from a large field of view. In this study, in-situ synchrotron x-ray diffraction deformation experiments were conducted on forsterite olivine at a variety of pressures (2-7 GPa) in the D-DIA apparatus. A suitable sample preparation procedure was established using vibratory polishing in conjunction with chemical etching prior to performing ECCI in SEM. ECCI was performed at 5 keV electron beam energy and 8 mm working distance in a JEOL JSM-6700 FE-SEM. The work hardening of forsterite olivine original grains, recrystallization and grain growth were classified based on electron channeling contrast observations in each sample. EBSD crystal orientation mapping was performed on regions of interest to quantify crystallographic texture and identify various microstructure substructures for each experiment. In addition, ECCI and EBSD were performed on the alumina piston in order to examine spatial

  4. Analysis of dislocation configurations in a [0 0 1] fcc single crystal by electron channeling contrast imaging in the SEM.

    Science.gov (United States)

    Gutierrez-Urrutia, Ivan

    2017-04-01

    We have investigated the dislocation configurations in a [0 0 1] single crystal of a face-centered alloy (316L stainless steel) by the electron channeling contrast imaging (ECCI) technique in the scanning electron microscope under controlled diffraction conditions. Specific dislocations such as piled-up dislocations and Lomer-Cottrell dislocations were characterized by the analysis of dislocation contrast and dislocation line trace analysis. The ECCI technique also allows the sound estimation of the local resolved stress acting on gliding dislocations by the analysis of the radius of curvature following a transmission electron microscopy-based geometrical approach. © The Author 2016. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Multiplier-free filters for wideband SAR

    DEFF Research Database (Denmark)

    Dall, Jørgen; Christensen, Erik Lintz

    2001-01-01

    This paper derives a set of parameters to be optimized when designing filters for digital demodulation and range prefiltering in SAR systems. Aiming at an implementation in field programmable gate arrays (FPGAs), an approach for the design of multiplier-free filters is outlined. Design results...

  6. Temperature Effects in Varactors and Multipliers

    Science.gov (United States)

    East, J.; Mehdi, Imran

    2001-01-01

    Varactor diode multipliers are a critical part of many THz measurement systems. The power and efficiencies of these devices limit the available power for THz sources. Varactor operation is determined by the physics of the varactor device and a careful doping profile design is needed to optimize the performance. Higher doped devices are limited by junction breakdown and lower doped structures are limited by current saturation. Higher doped structures typically have higher efficiencies and lower doped structures typically have higher powers at the same operating frequency and impedance level. However, the device material properties are also a function of the operating temperature. Recent experimental evidence has shown that the power output of a multiplier can be improved by cooling the device. We have used a particle Monte Carlo simulation to investigate the temperature dependent velocity vs. electric field in GaAs. This information was then included in a nonlinear device circuit simulator to predict multiplier performance for various temperatures and device designs. This paper will describe the results of this analysis of temperature dependent multiplier operation.

  7. Fourier Multiplier Theorems Involving Type and Cotype

    NARCIS (Netherlands)

    Rozendaal, J.; Veraar, M.C.

    2017-01-01

    In this paper we develop the theory of Fourier multiplier operators (Formula presented.), for Banach spaces X and Y, (Formula presented.) and (Formula presented.) an operator-valued symbol. The case (Formula presented.) has been studied extensively since the 1980s, but far less is known for

  8. Channeling, volume reflection, and volume capture study of electrons in a bent silicon crystal

    Directory of Open Access Journals (Sweden)

    T. N. Wistisen

    2016-07-01

    Full Text Available We present the experimental data and analysis of experiments conducted at SLAC National Accelerator Laboratory investigating the processes of channeling, volume-reflection and volume-capture along the (111 plane in a strongly bent quasimosaic silicon crystal. These phenomena were investigated at 5 energies: 3.35, 4.2, 6.3, 10.5, and 14.0 GeV with a crystal with bending radius of 0.15 m, corresponding to curvatures of 0.053, 0.066, 0.099, 0.16, and 0.22 times the critical curvature, respectively. Based on the parameters of fitting functions we have extracted important parameters describing the channeling process such as the dechanneling length, the angle of volume reflection, the surface transmission, and the widths of the distribution of channeled particles parallel and orthogonal to the plane.

  9. VLSI Implementation of Fault Tolerance Multiplier based on Reversible Logic Gate

    Science.gov (United States)

    Ahmad, Nabihah; Hakimi Mokhtar, Ahmad; Othman, Nurmiza binti; Fhong Soon, Chin; Rahman, Ab Al Hadi Ab

    2017-08-01

    Multiplier is one of the essential component in the digital world such as in digital signal processing, microprocessor, quantum computing and widely used in arithmetic unit. Due to the complexity of the multiplier, tendency of errors are very high. This paper aimed to design a 2×2 bit Fault Tolerance Multiplier based on Reversible logic gate with low power consumption and high performance. This design have been implemented using 90nm Complemetary Metal Oxide Semiconductor (CMOS) technology in Synopsys Electronic Design Automation (EDA) Tools. Implementation of the multiplier architecture is by using the reversible logic gates. The fault tolerance multiplier used the combination of three reversible logic gate which are Double Feynman gate (F2G), New Fault Tolerance (NFT) gate and Islam Gate (IG) with the area of 160μm x 420.3μm (67.25 mm2). This design achieved a low power consumption of 122.85μW and propagation delay of 16.99ns. The fault tolerance multiplier proposed achieved a low power consumption and high performance which suitable for application of modern computing as it has a fault tolerance capabilities.

  10. Channeling and coherent bremsstrahlung effects for relativistic positrons and electrons. [16 to 28 MeV, orientation

    Energy Technology Data Exchange (ETDEWEB)

    Walker, R. L.

    1976-03-22

    Channeling of positrons in single crystals of silicon was observed in transmission and scattering measurements for incident energies from 16 to 28 MeV. In addition, the spectral dependence upon crystal orientation of the forward coherent bremsstrahlung produced by beams of 28-MeV positrons and electrons incident upon a 5 ..mu..m thick single crystal of silicon was measured with a NaI photon spectrometer. Effects of channeling and perhaps of the nonvalidity of the first Born approximation were observed for beam directions near the (111) axis of the crystal, and coherent peaks near 0.5 MeV were observed for a compound interference direction, in agreement with first-order theoretical calculations. 32 fig.

  11. Intensity distributions of reflected surface channeling protons scattered on surfaces of electron-bombarded alkali halide crystals

    Science.gov (United States)

    Fukazawa, Y.; Kihara, K.; Iwamoto, K.; Susuki, Y.

    2013-11-01

    We have examined the surface-channeling of 550 keV protons on electron-bombarded KBr(0 0 1) surfaces at grazing incidence. On the surface, electron-stimulated desorption (ESD) resulting from the irradiation of 5 keV electrons changes the surface morphology. In order to investigate the change of the surface morphology, the luminous intensity distributions observed on a fluorescent screen (scattering patterns) of the reflected protons under the surface-channeling conditions are measured. Normalized specular intensity of the protons oscillates, and the results of computer simulations show that the period of the intensity oscillation agrees with the period of layer-by-layer desorption. The measured period of the oscillation is comparable to the simulated one, i.e., the period of the desorption, however, the measured amplitude of the oscillation is weak. This shows that the layer-by-layer desorption of the experimental surface is observed but is not as remarkable as that of the perfect surface introduced in the simulation.

  12. Intensity distributions of reflected surface channeling protons scattered on surfaces of electron-bombarded alkali halide crystals

    Energy Technology Data Exchange (ETDEWEB)

    Fukazawa, Y., E-mail: yukofu@cc.osaka-kyoiku.ac.jp; Kihara, K.; Iwamoto, K.; Susuki, Y.

    2013-11-15

    We have examined the surface-channeling of 550 keV protons on electron-bombarded KBr(0 0 1) surfaces at grazing incidence. On the surface, electron-stimulated desorption (ESD) resulting from the irradiation of 5 keV electrons changes the surface morphology. In order to investigate the change of the surface morphology, the luminous intensity distributions observed on a fluorescent screen (scattering patterns) of the reflected protons under the surface-channeling conditions are measured. Normalized specular intensity of the protons oscillates, and the results of computer simulations show that the period of the intensity oscillation agrees with the period of layer-by-layer desorption. The measured period of the oscillation is comparable to the simulated one, i.e., the period of the desorption, however, the measured amplitude of the oscillation is weak. This shows that the layer-by-layer desorption of the experimental surface is observed but is not as remarkable as that of the perfect surface introduced in the simulation.

  13. Lack of a peroxiredoxin suppresses the lethality of cells devoid of electron donors by channelling electrons to oxidized ribonucleotide reductase.

    Science.gov (United States)

    Boronat, Susanna; Domènech, Alba; Carmona, Mercè; García-Santamarina, Sarela; Bañó, M Carmen; Ayté, José; Hidalgo, Elena

    2017-06-01

    The thioredoxin and glutaredoxin pathways are responsible of recycling several enzymes which undergo intramolecular disulfide bond formation as part of their catalytic cycles such as the peroxide scavengers peroxiredoxins or the enzyme ribonucleotide reductase (RNR). RNR, the rate-limiting enzyme of deoxyribonucleotide synthesis, is an essential enzyme relying on these electron flow cascades for recycling. RNR is tightly regulated in a cell cycle-dependent manner at different levels, but little is known about the participation of electron donors in such regulation. Here, we show that cytosolic thioredoxins Trx1 and Trx3 are the primary electron donors for RNR in fission yeast. Unexpectedly, trx1 transcript and Trx1 protein levels are up-regulated in a G1-to-S phase-dependent manner, indicating that the supply of electron donors is also cell cycle-regulated. Indeed, genetic depletion of thioredoxins triggers a DNA replication checkpoint ruled by Rad3 and Cds1, with the final goal of up-regulating transcription of S phase genes and constitutive RNR synthesis. Regarding the thioredoxin and glutaredoxin cascades, one combination of gene deletions is synthetic lethal in fission yeast: cells lacking both thioredoxin reductase and cytosolic dithiol glutaredoxin. We have isolated a suppressor of this lethal phenotype: a mutation at the Tpx1-coding gene, leading to a frame shift and a loss-of-function of Tpx1, the main client of electron donors. We propose that in a mutant strain compromised in reducing equivalents, the absence of an abundant and competitive substrate such as the peroxiredoxin Tpx1 has been selected as a lethality suppressor to favor RNR function at the expense of the non-essential peroxide scavenging function, to allow DNA synthesis and cell growth.

  14. Lack of a peroxiredoxin suppresses the lethality of cells devoid of electron donors by channelling electrons to oxidized ribonucleotide reductase.

    Directory of Open Access Journals (Sweden)

    Susanna Boronat

    2017-06-01

    Full Text Available The thioredoxin and glutaredoxin pathways are responsible of recycling several enzymes which undergo intramolecular disulfide bond formation as part of their catalytic cycles such as the peroxide scavengers peroxiredoxins or the enzyme ribonucleotide reductase (RNR. RNR, the rate-limiting enzyme of deoxyribonucleotide synthesis, is an essential enzyme relying on these electron flow cascades for recycling. RNR is tightly regulated in a cell cycle-dependent manner at different levels, but little is known about the participation of electron donors in such regulation. Here, we show that cytosolic thioredoxins Trx1 and Trx3 are the primary electron donors for RNR in fission yeast. Unexpectedly, trx1 transcript and Trx1 protein levels are up-regulated in a G1-to-S phase-dependent manner, indicating that the supply of electron donors is also cell cycle-regulated. Indeed, genetic depletion of thioredoxins triggers a DNA replication checkpoint ruled by Rad3 and Cds1, with the final goal of up-regulating transcription of S phase genes and constitutive RNR synthesis. Regarding the thioredoxin and glutaredoxin cascades, one combination of gene deletions is synthetic lethal in fission yeast: cells lacking both thioredoxin reductase and cytosolic dithiol glutaredoxin. We have isolated a suppressor of this lethal phenotype: a mutation at the Tpx1-coding gene, leading to a frame shift and a loss-of-function of Tpx1, the main client of electron donors. We propose that in a mutant strain compromised in reducing equivalents, the absence of an abundant and competitive substrate such as the peroxiredoxin Tpx1 has been selected as a lethality suppressor to favor RNR function at the expense of the non-essential peroxide scavenging function, to allow DNA synthesis and cell growth.

  15. Higher-order Z/sub 1/ effects and effects of screening by bound K electrons on the electronic stopping of channeled ions

    Energy Technology Data Exchange (ETDEWEB)

    Datz, S.; Gomez del Campo, J.; Dittner, P.F.; Miller, P.D.; Biggerstaff, J.A.

    1977-05-16

    The stopping power in )111) Au for channeling ions which have not changed charge has been measured for bare nuclei for Z = 1 - 5 at 3.5 MeV/amu, and for ions bearing 0, 1, and 2 bound electrons for Z/sub 1/ = 1 - 9 at 2 MeV/amu. An effective screening of approx.0.9e per electron is obtained. For the bare nculei, deviations from simple Z/sub 1/ /sup 2/ scaling are reported. At 2 MeV/amu an increase of 3.5% in S/Z/sub 1/ /sup 2/ is seen from H to He, 3% from He to Li; but no differences are seen from Z/sub 1/ = 5 - 9. However, at 3.5-MeV/amu deviations of as much as 20% per Z/sub 1/ are observed.

  16. Resonant absorption of electromagnetic radiation in a quantum channel due to the scattering of electrons by impurities

    Science.gov (United States)

    Karpunin, V. V.; Margulis, V. A.

    2017-06-01

    We have found an analytical expression for the absorption coefficient of electromagnetic radiation in a quantum channel with a parabolic confinement potential. The calculation has been performed using the second-order perturbation theory taking into account the scattering of a quasi-one-dimensional electron gas by ionized impurities. We have analyzed the dependences of the absorption coefficient on the frequency of the electromagnetic radiation and the magnetic field. The appearance of additional resonant peaks, which are caused by scattering by impurities, has been found.

  17. Digital Predistortion of 75-110GHzW-Band Frequency Multiplier for Fiber Wireless Short Range Access Systems

    DEFF Research Database (Denmark)

    Zhao, Ying; Pang, Xiaodan; Deng, Lei

    2011-01-01

    We present a digital predistortion technique to effectively compensate high nonlinearity of a sextuple multiplier operating at 99.6GHz. An 18.9dB adjacent-channel power ratio (ACPR) improvement is guaranteed and a W-band fiber-wireless system is experimentally investigated.......We present a digital predistortion technique to effectively compensate high nonlinearity of a sextuple multiplier operating at 99.6GHz. An 18.9dB adjacent-channel power ratio (ACPR) improvement is guaranteed and a W-band fiber-wireless system is experimentally investigated....

  18. Multi-channel electronic and vibrational dynamics in polyatomic resonant high-order harmonic generation

    Science.gov (United States)

    Ferré, A.; Boguslavskiy, A. E.; Dagan, M.; Blanchet, V.; Bruner, B. D.; Burgy, F.; Camper, A.; Descamps, D.; Fabre, B.; Fedorov, N.; Gaudin, J.; Geoffroy, G.; Mikosch, J.; Patchkovskii, S.; Petit, S.; Ruchon, T.; Soifer, H.; Staedter, D.; Wilkinson, I.; Stolow, A.; Dudovich, N.; Mairesse, Y.

    2015-01-01

    High-order harmonic generation in polyatomic molecules generally involves multiple channels of ionization. Their relative contribution can be strongly influenced by the presence of resonances, whose assignment remains a major challenge for high-harmonic spectroscopy. Here we present a multi-modal approach for the investigation of unaligned polyatomic molecules, using SF6 as an example. We combine methods from extreme-ultraviolet spectroscopy, above-threshold ionization and attosecond metrology. Fragment-resolved above-threshold ionization measurements reveal that strong-field ionization opens at least three channels. A shape resonance in one of them is found to dominate the signal in the 20–26 eV range. This resonance induces a phase jump in the harmonic emission, a switch in the polarization state and different dynamical responses to molecular vibrations. This study demonstrates a method for extending high-harmonic spectroscopy to polyatomic molecules, where complex attosecond dynamics are expected. PMID:25608712

  19. The power of fiscal multipliers in Croatia

    Directory of Open Access Journals (Sweden)

    Ana Grdović Gnip

    2014-06-01

    Full Text Available This paper investigates fiscal multipliers in Croatia in the period 1996Q1-2011Q4. For this purpose, a Blanchard Perotti three variable baseline SVAR is employed as a no regime-switch model, along with a four variable baseline STVAR as a regime-switch model. Results show that during recessions fiscal multipliers in Croatia tend to be much larger and move in line with Keynesian assumptions, i.e. a positive government spending shock increases output, private consumption and private investment, while oppositely a positive tax shock worsens the same macroeconomic variables. Moreover, during recession times government spending for purchases of goods and services seems to be the most effective fiscal instrument for boosting economic activity.

  20. Dynamics of the microstructure of current channels and the generation of high-energy electrons in nanosecond discharges in air

    Energy Technology Data Exchange (ETDEWEB)

    Karelin, V. I.; Trenkin, A. A., E-mail: trenkin@ntc.vniief.ru; Fedoseev, I. G. [Russian Federal Nuclear Center VNIIEF (Russian Federation)

    2015-12-15

    The results of the three-dimensional numerical simulation of the dynamics of the microstructure of high-voltage nanosecond discharges in air at atmospheric pressure are presented. It is established that the fast (at a time of ≈10 ns) broadening and significant decrease in the gas concentration in the microchannels occur as a result of the ohmic heating of microchannels with the diameter of 1–30 μm. It was shown that the broadening of microchannels in a nanosecond diffusive discharge provides an increase in the ratio of the electric field strength to the gas concentration in microchannels to values sufficient for the generation highenergy electron beams and X-ray bremsstrahlung in them. Features of the dynamics of the system of microchannels and its effect on the efficiency of the generation of high-energy electrons in discharges developing in the microstructuring regime of the current channels are considered.

  1. Channel-resolved subcycle interferences of electron wave packets emitted from H$_2$ in two-color laser fields

    CERN Document Server

    Xie, Xinhua; Kartashov, Daniil; Zhang, Li; Baltuška, Andrius; Kitzler, Markus

    2016-01-01

    We report on the observation of subcycle interferences of electron wave packets released during the strong field ionization of H$_2$ with cycle-shaped two-color laser fields. With a reaction microscope, channel-resolved photoelectron momentum distribution are obtained for different final products originating from single ionization of H$_2$. Our results show that the subcycle interference structures of electron wave packet are very sensitive to the cycle-shape of the two-color laser field. The reason is that the ionization time within an optical cycle is determined by the cycle-shape of the laser field. The subcycle interference structures can be further used to get the subcycle dynamics of molecules during strong field interaction.

  2. Boiling heat transfer in narrow channels with offset strip fins: Application to electronic chipsets cooling

    OpenAIRE

    Pulvirenti, B.; Matalone, A.; Barucca, U.

    2010-01-01

    Abstract An experimental study on saturated flow boiling heat transfer of HFE-7100 in vertical rectangular channels with offset strip fins is presented. The experiments have been carried out at atmospheric pressure, over a wide range of vapour quality and heat fluxes up to 1.8?105 W/m2. The local boiling heat transfer coefficient has been obtained from experiments and analysed by means of Chen superposition method. Some correlations for convective boiling and nucleate boiling heat ...

  3. Subnanometer-resolution electron cryomicroscopy-based domain models for the cytoplasmic region of skeletal muscle RyR channel.

    Science.gov (United States)

    Serysheva, Irina I; Ludtke, Steven J; Baker, Matthew L; Cong, Yao; Topf, Maya; Eramian, David; Sali, Andrej; Hamilton, Susan L; Chiu, Wah

    2008-07-15

    The skeletal muscle Ca(2+) release channel (RyR1), a homotetramer, regulates the release of Ca(2+) from the sarcoplasmic reticulum to initiate muscle contraction. In this work, we have delineated the RyR1 monomer boundaries in a subnanometer-resolution electron cryomicroscopy (cryo-EM) density map. In the cytoplasmic region of each RyR1 monomer, 36 alpha-helices and 7 beta-sheets can be resolved. A beta-sheet was also identified close to the membrane-spanning region that resembles the cytoplasmic pore structures of inward rectifier K(+) channels. Three structural folds, generated for amino acids 12-565 using comparative modeling and cryo-EM density fitting, localize close to regions implicated in communication with the voltage sensor in the transverse tubules. Eleven of the 15 disease-related residues for these domains are mapped to the surface of these models. Four disease-related residues are found in a basin at the interfaces of these regions, creating a pocket in which the immunophilin FKBP12 can fit. Taken together, these results provide a structural context for both channel gating and the consequences of certain malignant hyperthermia and central core disease-associated mutations in RyR1.

  4. Peer Effects: Social Multiplier or Social Norms?

    OpenAIRE

    Liu, Xiaodong; Patacchini, Eleonora; Zenou, Yves

    2013-01-01

    We develop an unified model embedding different behavioral mechanisms of social interactions and design a statistical model selection test to discriminate between them in empirical applications. This framework is applied to study peer effects in education and delinquent behavior for adolescents in the United States. We find that there are strong social multiplier effects in crime while, for education, social norms matter the most. This suggests that, for crime, individual-based policies are m...

  5. Contributions to a first measurement of the W-boson mass in the electron channel with the ATLAS detector

    CERN Document Server

    AUTHOR|(SzGeCERN)736721

    In this document, I present my contributions to a first measurement of the W-mass in the LHC using 4.7 fb−1 of 7 TeV data, taken in 2011. I focus on the electron decay channel, W → eν. In the first part, I discuss a study regarding the performance of the electromagnetic calorimeter of the ATLAS detector, presenting a novel method to correct the lateral profiles of electron energy deposit, along with various studies of the different Geant4 physics lists versions. In the second part, I introduce the global methodology for the W-mass measurement used in ATLAS, and discuss my contributions in details. I show in a first step the assessment of uncertainties coming from the parton shower modeling in Pythia8, and the optimization of the lepton's transverse momentum fitting range in order to reduce the systematic uncertainty. In a second step, I present an elaborate data-driven method for the estimation of the multijet background in the W → eν channel, as well as the corresponding results in terms of event yie...

  6. Automobile Industry Retail Price Equivalent and Indirect Cost Multipliers

    Science.gov (United States)

    This report develops a modified multiplier, referred to as an indirect cost (IC) multiplier, which specifically evaluates the components of indirect costs that are likely to be affected by vehicle modifications associated with environmental regulation. A range of IC multipliers a...

  7. Searching for Biotic Multipliers of Climate Change.

    Science.gov (United States)

    Urban, Mark C; Zarnetske, Phoebe L; Skelly, David K

    2017-07-01

    As climates change, biologists need to prioritize which species to understand, predict, and protect. One way is to identify key species that are both sensitive to climate change and that disproportionately affect communities and ecosystems. These "biotic multipliers" provide efficient targets for research and conservation. Here, we propose eight mechanistic hypotheses related to impact and sensitivity that suggest that top consumers might often act as biotic multipliers of climate change. For impact, top consumers often affect communities and ecosystems through strong top-down effects. For sensitivity, metabolic theory and data suggest that photosynthesis and respiration differ in temperature responses, potentially increasing the sensitivity of consumers relative to plants. Larger-bodied organisms are typically more thermally sensitive than smaller ones, suggesting how large top consumers might be more sensitive than their smaller prey. In addition, traits related to predation are more sensitive than defensive traits to temperature. Top consumers might also be more sensitive because they often lag behind prey in phenological responses. The combination of low population sizes and demographic traits of top consumers could make them more sensitive to disturbances like climate change, which could slow their recovery. As top consumers are positioned at the top of the food chain, many small effects can accumulate from other trophic levels to affect top consumers. Finally, top consumers also often disperse more frequently and farther than prey, potentially leading to greater sensitivity to climate-induced changes in ranges and subsequent impacts on invaded communities. Overall, we expect that large, ectothermic top consumers and mobile predators might frequently be biotic multipliers of climate change. However, this prediction depends on the particular features of species, habitats, and ecosystems. In specific cases, herbivores, plants, or pathogens might be more

  8. Interatomic Coulombic decay cascades in multiply excited neon clusters

    Science.gov (United States)

    Nagaya, K.; Iablonskyi, D.; Golubev, N. V.; Matsunami, K.; Fukuzawa, H.; Motomura, K.; Nishiyama, T.; Sakai, T.; Tachibana, T.; Mondal, S.; Wada, S.; Prince, K. C.; Callegari, C.; Miron, C.; Saito, N.; Yabashi, M.; Demekhin, Ph. V.; Cederbaum, L. S.; Kuleff, A. I.; Yao, M.; Ueda, K.

    2016-01-01

    In high-intensity laser light, matter can be ionized by direct multiphoton absorption even at photon energies below the ionization threshold. However on tuning the laser to the lowest resonant transition, the system becomes multiply excited, and more efficient, indirect ionization pathways become operative. These mechanisms are known as interatomic Coulombic decay (ICD), where one of the species de-excites to its ground state, transferring its energy to ionize another excited species. Here we show that on tuning to a higher resonant transition, a previously unknown type of interatomic Coulombic decay, intra-Rydberg ICD occurs. In it, de-excitation of an atom to a close-lying Rydberg state leads to electron emission from another neighbouring Rydberg atom. Moreover, systems multiply excited to higher Rydberg states will decay by a cascade of such processes, producing even more ions. The intra-Rydberg ICD and cascades are expected to be ubiquitous in weakly-bound systems exposed to high-intensity resonant radiation. PMID:27917867

  9. Orientational and Translational Ordering of Sub-Monolayer Films of Passivated Multiply-Twinned Gold Clusters

    Energy Technology Data Exchange (ETDEWEB)

    WELLNER,A.; NELLIST,P.D.; PALMER,R.E.; AINDOW,M.; WILCOXON,JESS P.

    2000-07-18

    The influence of the substrate on the translational and orientational ordering in sub-monolayer films of passivated multiply-twinned gold clusters has been investigated using high resolution and dark field transmission electron microscopy. Although clear differences were observed in the degree of translational ordering on amorphous carbon and etched silicon substrates, there was no corresponding variation in the crystallographic orientation of the nanocrystal cores. The results demonstrate that the orientation of passivated clusters with multiply-twinned cores is effectively random with respect to both the superlattice and the substrate.

  10. Fast imaging readout and electronics--a novel high-speed imaging system for micro-channel plates

    CERN Document Server

    Lapington, J S

    2002-01-01

    The band-width of charge division readout anodes used with micro-channel plates (MCP) is usually limited by the speed of the acquisition electronics. We present a novel charge division anode that does not require analogue to digital conversion. The Fast Imaging Readout and Electronics is a new concept in high-speed imaging using an MCP detector. The imaging system described comprises an MCP intensifier coupled to a charge division image readout using high-speed, multichannel electronics. It has a projected spatial resolution of up to 128x128 pixels, though the image format is inherently flexible, and the potential for rates up to 100 million events per second with nanosecond timing resolution. The readout pattern has a planar electrode structure and the collected charge from each event is shared amongst all electrodes, grouped in pairs. The unique design of the readout obviates the need for charge measurement, usually the dominant process determining the event-processing deadtime. Instead, high-speed signal c...

  11. Multipliers on Generalized Mixed Norm Sequence Spaces

    Directory of Open Access Journals (Sweden)

    Oscar Blasco

    2014-01-01

    Full Text Available Given 1≤p,q≤∞ and sequences of integers (nkk and (nk′k such that nk≤nk′≤nk+1, the generalized mixed norm space ℓℐ(p,q is defined as those sequences (ajj such that ((∑j∈Ik‍|aj|p1/pk∈ℓq where Ik={j∈ℕ0 s.t. nk≤jmultipliers (ℓℐ(r,s,ℓ(u,v, for different sequences ℐ and of intervals in ℕ0, are determined.

  12. Multiplier policies for digital signal processing

    Science.gov (United States)

    Taylor, Fred J.; Ma, Gin-Kou

    1990-01-01

    The successful design of digital signal processing (DSP) systems and subsystems is often predicted on realizing fast multiplication in digital hardware. This tutorial provides the reader with a broad perspective of this important field and the pedagogy needed to understand the basic principles of digital multiplication. Both conventional and nonconventional methods of implementing multiplication, representing a mix of speed/complexity tradeoffs, are presented. Some are based on traditional shift/add structures, whereas others strive for greater mathematical sophistication. Topics include stand-alone fixed-point multipliers, cellular arrays, memory intensive policies, homomorphic systems, and modular arithmetic.

  13. Proximity effects in cold gases of multiply charged atoms (Review)

    Science.gov (United States)

    Chikina, I.; Shikin, V.

    2016-07-01

    Possible proximity effects in gases of cold, multiply charged atoms are discussed. Here we deal with rarefied gases with densities nd of multiply charged (Z ≫ 1) atoms at low temperatures in the well-known Thomas-Fermi (TF) approximation, which can be used to evaluate the statistical properties of single atoms. In order to retain the advantages of the TF formalism, which is successful for symmetric problems, the external boundary conditions accounting for the finiteness of the density of atoms (donors), nd ≠ 0, are also symmetrized (using a spherical Wigner-Seitz cell) and formulated in a standard way that conserves the total charge within the cell. The model shows that at zero temperature in a rarefied gas of multiply charged atoms there is an effective long-range interaction Eproxi(nd), the sign of which depends on the properties of the outer shells of individual atoms. The long-range character of the interaction Eproxi is evaluated by comparing it with the properties of the well-known London dispersive attraction ELond(nd) 0 and for the alkali and alkaline-earth elements Eproxi theory through the temperature dependence of the different versions of Eproxi. The anomaly in the thermal proximity effect shows up in the following way: for T ≠ 0 there is no equilibrium solution of TS statistics for single multiply charged atoms in a vacuum when the effect is present. Instability is suppressed in a Wigner-Seitz model under the assumption that there are no electron fluxes through the outer boundary R3 ∝ n-1d of a Wigner-Seitz cell. Eproxi corresponds to the definition of the correlation energy in a gas of interacting particles. This review is written so as to enable comparison of the results of the TF formalism with the standard assumptions of the correlation theory for classical plasmas. The classic example from work on weak solutions (including charged solutions)—the use of semi-impermeable membranes for studies of osmotic pressure—is highly appropriate for

  14. Electron crystallography of PhoE porin, an outer membrane, channel- forming protein from E. coli

    Energy Technology Data Exchange (ETDEWEB)

    Walian, P.J.

    1989-11-01

    One approach to studying the structure of membrane proteins is the use of electron crystallography. Dr. Bing Jap has crystallized PhoE pore-forming protein (porin) from the outer membrane of escherichia coli (E. coli) into monolayer crystals. The findings of this research and those of Jap (1988, 1989) have determined these crystals to be highly ordered, yielding structural information to a resolution of better than 2.8 angstroms. The task of this thesis has been to collect and process the electron diffraction patterns necessary to generate a complete three-dimensional set of high resolution structure factor amplitudes of PhoE porin. Fourier processing of these amplitudes when combined with the corresponding phase data is expected to yield the three-dimensional structure of PhoE porin at better than 3.5 angstroms resolution. 92 refs., 33 figs., 3 tabs. (CBS)

  15. Drawing the geometry of 3d transition metal-boron pairs in silicon from electron emission channeling experiments

    CERN Document Server

    Silva, Daniel; Wahl, Ulrich; Martins Correia, Joao; Augustyns, Valerie; De Lemos Lima, Tiago Abel; Granadeiro Costa, Angelo Rafael; David Bosne, Eric; Castro Ribeiro Da Silva, Manuel; Esteves De Araujo, Araujo Joao Pedro; Da Costa Pereira, Lino Miguel

    2016-01-01

    Although the formation of transition metal-boron pairs is currently well established in silicon processing, the geometry of these complexes is still not completely understood. We investigated the lattice location of the transition metals manganese, iron, cobalt and nickel in n- and p+-type silicon by means of electron emission channeling. For manganese, iron and cobalt, we observed an increase of sites near the ideal tetrahedral interstitial position by changing the doping from n- to p+-type Si. Such increase was not observed for Ni. We ascribe this increase to the formation of pairs with boron, driven by Coulomb interactions, since the majority of iron, manganese and cobalt is positively charged in p+-type silicon while Ni is neutral. We propose that breathing mode relaxation around the boron ion within the pair causes the observed displacement from the ideal tetrahedral interstitial site. We discuss the application of the emission channeling technique in this system and, in particular, how it provides insi...

  16. Electron energy dissipation model of gate dielectric progressive breakdown in n- and p-channel field effect transistors

    Science.gov (United States)

    Lombardo, S.; Wu, E. Y.; Stathis, J. H.

    2017-08-01

    We report the data and a model showing that the energy loss experienced by the carriers flowing through breakdown spots is the primary cause of progressive breakdown spot growth. The experiments are performed in gate dielectrics of metal-oxide-semiconductor (MOS) devices subjected to accelerated high electric field constant voltage stress under inversion conditions. The model is analytical and contains few free parameters of clear physical meaning. This is compared to a large set of data on breakdown transients at various oxide thicknesses, stress voltages, and temperatures, both in cases of n-channel and p-channel transistors and polycrystalline Si/oxynitride/Si and metal gate/high k dielectric/Si gate stacks. The basic idea is that the breakdown transient is due to the growth of one or more filaments in the dielectric promoted by electromigration driven by the energy lost by the electrons traveling through the breakdown spots. Both cases of polycrystalline Si/oxynitride/Si and metal gate/high-k dielectric/Si MOS structures are investigated. The best fit values of the model to the data, reported and discussed in the paper, consistently describe a large set of data. The case of simultaneous growth of multiple progressive breakdown spots in the same device is also discussed in detail.

  17. Design and characterization of a 32-channel heterodyne radiometer for electron cyclotron emission measurements on experimental advanced superconducting tokamak.

    Science.gov (United States)

    Han, X; Liu, X; Liu, Y; Domier, C W; Luhmann, N C; Li, E Z; Hu, L Q; Gao, X

    2014-07-01

    A 32-channel heterodyne radiometer has been developed for the measurement of electron cyclotron emission (ECE) on the experimental advanced superconducting tokamak (EAST). This system collects X-mode ECE radiation spanning a frequency range of 104-168 GHz, where the frequency coverage corresponds to a full radial coverage for the case with a toroidal magnetic field of 2.3 T. The frequency range is equally spaced every 2 GHz from 105.1 to 167.1 GHz with an RF bandwidth of ~500 MHz and the video bandwidth can be switched among 50, 100, 200, and 400 kHz. Design objectives and characterization of the system are presented in this paper. Preliminary results for plasma operation are also presented.

  18. Effects, determination, and correction of count rate nonlinearity in multi-channel analog electron detectors

    Science.gov (United States)

    Reber, T. J.; Plumb, N. C.; Waugh, J. A.; Dessau, D. S.

    2014-04-01

    Detector counting rate nonlinearity, though a known problem, is commonly ignored in the analysis of angle resolved photoemission spectroscopy where modern multichannel electron detection schemes using analog intensity scales are used. We focus on a nearly ubiquitous "inverse saturation" nonlinearity that makes the spectra falsely sharp and beautiful. These artificially enhanced spectra limit accurate quantitative analysis of the data, leading to mistaken spectral weights, Fermi energies, and peak widths. We present a method to rapidly detect and correct for this nonlinearity. This algorithm could be applicable for a wide range of nonlinear systems, beyond photoemission spectroscopy.

  19. Microstructure and Mechanical Properties of Ti Cold-Spray Splats Determined by Electron Channeling Contrast Imaging and Nanoindentation Mapping.

    Science.gov (United States)

    Goldbaum, Dina; Chromik, Richard R; Brodusch, Nicolas; Gauvin, Raynald

    2015-06-01

    Cold spray is a thermo-mechanical process where the velocity of the sprayed particles affects the deformation, bonding, and mechanical properties of the deposited material, in the form of splats or coatings. At high strain rates, the impact stresses are converted into heat, a phenomenon known as adiabatic shear, which leads to grain re-crystallization. Grain re-crystallization and growth are shown to have a direct impact on the mechanical properties of the cold-sprayed material. The present study ties the microstructural features within the cold-sprayed Ti splats and the substrate to the bonding mechanism and mechanical properties. High-resolution electron channeling contrast imaging, electron backscatter diffraction mapping, and nanoindentation were used to correlate the microstructure to the mechanical properties distribution within the titanium cold-spray splats. The formation of nanograins was observed at the titanium splat/substrate interface and contributed to metallurgical bonding. An increase in grain re-crystallization within the splat and substrate materials was observed with pre-heating of the substrate. In the substrate material, the predominant mechanism of deformation was twinning. A good relationship was found between the hardness and distribution of the twins within the substrate and the size distribution of the re-crystallized grains within the splats.

  20. Gaseous Electron Multiplier (GEM), foil holes deformation studies

    CERN Document Server

    Suhaj, Adam; CERN. Geneva. PH Department

    2015-01-01

    GEM detectors play an important role in the upcoming high-luminosity LHC upgrade in 2018 where they will be exposed to high doses of radiation in the muon endcap region. A series of tensile tests were performed on neutron irradiated and non-irradiated GEM foils where the shape of the holes was thoroughly examined. It was found that the GEM foil does not deform much at lower loads but the deformation gets exponentially bigger after applying more than a 60 N force. Both sets of samples behaved similarly at lower loads up to 40 N after which the holes of the irradiated samples started to deform more rapidly than the non-irradiated ones. The failure point of the non-irradiated samples occurred consistently at around 135 N while the irradiated samples experienced failure at around 85 N with two outliers failing at 120 and 135 N.

  1. Studying discharges in the Gas Electron Multiplies in Alice Detector

    CERN Document Server

    EُlGedawy, Omar

    2016-01-01

    Characterizing discharges is very important in the operation of the GEM detector. Once the discharges happen, a current will go through the GEM, the voltages across the GEM foils sides drop, charge amplification cannot take place anymore, resulting in a loss of signal. So the goal is to understand how the discharges evolve and propagate, in order to find requirements on the voltage settings, which allow to decrease the discharge probability.

  2. Impact parameter dependent electron capture by decelerated U{sup 91+} ions at 20 MeV/u using crystal channeling conditions

    Energy Technology Data Exchange (ETDEWEB)

    Dauvergne, D. E-mail: d.dauvergne@ipnl.in2p3.fr; Braeuning-Demian, A.; Bosch, F.; Braeuning, H.; Chevallier, M.; Cohen, C.; Gumberidze, A.; L' Hoir, A.; Kirsch, R.; Kozhuharov, C.; Liesen, D.; Mokler, P.H.; Poizat, J.C.; Ray, C.; Stoehlker, Th.; Tarisien, M.; Testa, E.; Toleikis, S.; Toulemonde, M

    2003-05-01

    We present results of an experiment using decelerated U{sup 91+} ions, extracted from the GSI-ESR storage ring, and transmitted through a thin silicon crystal in channeling conditions. Charge state at emergence, secondary electron multiplicity and X-rays are measured simultaneously. These conditions allow to study the competition between mechanical electron capture (MEC) and radiative electron capture (REC) as a function of impact parameter. We observe that REC is the dominant charge exchange process for the best channeled ions, i.e. those travelling always far from the silicon target core electrons. For ions with high transverse energy, MEC into highly excited states is counterbalanced by enhanced ionization arising from a succession of close collisions along atomic rows.

  3. Suppression of surface-originated gate lag by a dual-channel AlN/GaN high electron mobility transistor architecture

    Energy Technology Data Exchange (ETDEWEB)

    Deen, David A., E-mail: david.deen@alumni.nd.edu; Storm, David F.; Scott Katzer, D.; Bass, R.; Meyer, David J. [Naval Research Laboratory, Electronics Science and Technology Division, Washington, DC 20375 (United States)

    2016-08-08

    A dual-channel AlN/GaN high electron mobility transistor (HEMT) architecture is demonstrated that leverages ultra-thin epitaxial layers to suppress surface-related gate lag. Two high-density two-dimensional electron gas (2DEG) channels are utilized in an AlN/GaN/AlN/GaN heterostructure wherein the top 2DEG serves as a quasi-equipotential that screens potential fluctuations resulting from distributed surface and interface states. The bottom channel serves as the transistor's modulated channel. Dual-channel AlN/GaN heterostructures were grown by molecular beam epitaxy on free-standing hydride vapor phase epitaxy GaN substrates. HEMTs fabricated with 300 nm long recessed gates demonstrated a gate lag ratio (GLR) of 0.88 with no degradation in drain current after bias stressed in subthreshold. These structures additionally achieved small signal metrics f{sub t}/f{sub max} of 27/46 GHz. These performance results are contrasted with the non-recessed gate dual-channel HEMT with a GLR of 0.74 and 82 mA/mm current collapse with f{sub t}/f{sub max} of 48/60 GHz.

  4. Stimulus versus Austerity: The Asymmetric Government Spending Multiplier

    OpenAIRE

    Barnichon, Régis; MATTHES, Christian

    2015-01-01

    Despite intense scrutiny estimates of the government spending multiplier remain highly uncertain with values ranging from 0.5 to 2. While a fiscal consolidation is generally assumed to have the same (mirror-image) effect as a fiscal expansion, we show that relaxing this assumption is crucial to understanding the effects of fiscal policy. The government spending multiplier is substantially below 1 for fiscal expansions, but the multiplier is substantially above 1 for fiscal consolidations.

  5. Hadamard Multipliers and Abel Dual of Hardy Spaces

    Directory of Open Access Journals (Sweden)

    Paweł Mleczko

    2016-01-01

    Full Text Available The paper is devoted to the study of Hadamard multipliers of functions from the abstract Hardy classes generated by rearrangement invariant spaces. In particular the relation between the existence of such multiplier and the boundedness of the appropriate convolution operator on spaces of measurable functions is presented. As an application, the description of Hadamard multipliers into H∞ is given and the Abel type theorem for mentioned Hardy spaces is proved.

  6. Multipliers on weighted Hardy spaces over certain totally disconnected groups

    Directory of Open Access Journals (Sweden)

    Toshiyuki Kitada

    1988-01-01

    Full Text Available In this note, we consider the multipliers on weighted H1 spaces over totally disconnected locally compact abelian groups with a suitable sequence of open compact subgroups (Vilenkin groups. We first show an (H1,L1 multiplier result from which Onneweer's theorem follows. We also give an (H1,H1 multiplier result under a condition of Baernstein-Sawyer type.

  7. Four-gate transistor analog multiplier circuit

    Science.gov (United States)

    Mojarradi, Mohammad M. (Inventor); Blalock, Benjamin (Inventor); Cristoloveanu, Sorin (Inventor); Chen, Suheng (Inventor); Akarvardar, Kerem (Inventor)

    2011-01-01

    A differential output analog multiplier circuit utilizing four G.sup.4-FETs, each source connected to a current source. The four G.sup.4-FETs may be grouped into two pairs of two G.sup.4-FETs each, where one pair has its drains connected to a load, and the other par has its drains connected to another load. The differential output voltage is taken at the two loads. In one embodiment, for each G.sup.4-FET, the first and second junction gates are each connected together, where a first input voltage is applied to the front gates of each pair, and a second input voltage is applied to the first junction gates of each pair. Other embodiments are described and claimed.

  8. Digital predistortion of 75–110 GHz W-band frequency multiplier for fiber wireless short range access systems

    DEFF Research Database (Denmark)

    Zhao, Ying; Deng, Lei; Pang, Xiaodan

    2011-01-01

    We present a W-band fiber-wireless transmission system based on a nonlinear frequency multiplier for high-speed wireless short range access applications. By implementing a baseband digital signal predistortion scheme, intensive nonlinear distortions induced in a sextuple frequency multiplier can...... be effectively pre-compensated. Without using costly W-band components, a transmission system with 26km fiber and 4m wireless transmission operating at 99.6GHz is experimentally validated. Adjacent-channel power ratio (ACPR) improvements for IQ-modulated vector signals are guaranteed and transmission...

  9. Efek Multiplier Zakat terhadap Pendapatan di Provinsi DKI Jakarta

    OpenAIRE

    Al Arif, M Nur Rianto

    2012-01-01

    The aim of this research is to analyse the multiplier effect of zakâh revenue in DKI Jakarta. A study case at Badan Amil Zakat, Infak, and Sadaqah (BAZIS) DKI Jakarta. Least square method is used to analyze the data. The coefficients will be used to calculate the multiplier effect of zakâh-revenue and it will be compared with the economy without zakah revenue. The results showed 2,522 multiplier effects of zakâh-revenue and 3.561 multiplier effect ofeconomic income without zakâh-revenue. Thi...

  10. Reconfigurable Low Energy Multiplier for Multimedia System Design

    National Research Council Canada - National Science Library

    Kim, Suhwan

    2000-01-01

    This paper proposes a reconfigurable pipelined multiplier architecture that achieves high performance and very low energy dissipation by adapting its structure to computational requirements over time...

  11. A gas secondary electron detector

    CERN Document Server

    Drouart, A; Alamanos, N; Auger, F; Besson, P; Bougamont, E; Bourgeois, P; Lobo, G; Pollacco, E C; Riallot, M

    2002-01-01

    A new Secondary Electron gas Detector (SED) is under development to be used in conjunction with an emissive foil to detect low energy heavy ions as an alternative to micro-channel plates. It could measure position and time of flight. Secondary electrons are accelerated to 10 keV so that they can cross through the 0.9 mu m Mylar entrance window. The electrons then are multiplied in the isobutane gas of the detector at 4-10 Torr. A time resolution of 150 ps and a spatial resolution of 3 mm have been obtained by using californium fission fragments on a prototype detector of 7x7 cm sup 2. The advantage of the SED against MCP is that its size is not limited. Our final goal is to build a large size detector (15x40 cm sup 2) that will operate at the focal plane of the VAMOS magnetic spectrometer at GANIL.

  12. Micromechanisms of brittle fracture: STM, TEM and electron channeling analysis. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Gerberich, W.W.

    1997-01-01

    The original thrust of this grant was to apply newly developed techniques in scanning tunneling and transmission electron microscopy to elucidate the mechanism of brittle fracture. This grant spun-off several new directions in that some of the findings on bulk structural materials could be utilized on thin films or intermetallic single crystals. Modeling and material evaluation efforts in this grant are represented in a figure. Out of this grant evolved the field the author has designated as Contact Fracture Mechanics. By appropriate modeling of stress and strain distribution fields around normal indentations or scratch tracks, various measures of thin film fracture or decohesion and brittle fracture of low ductility intermetallics is possible. These measures of fracture resistance in small volumes are still evolving and as such no standard technique or analysis has been uniformly accepted. For brittle ceramics and ceramic films, there are a number of acceptable analyses such as those published by Lawn, Evans and Hutchinson. For more dissipative systems involving metallic or polymeric films and/or substrates, there is still much to be accomplished as can be surmised from some of the findings in the present grant. In Section 2 the author reviews the funding history and accomplishments associated mostly with bulk brittle fracture. This is followed by Section 3 which covers more recent work on using novel techniques to evaluate fracture in low ductility single crystals or thin films using micromechanical probes. Basically Section 3 outlines how the recent work fits in with the goals of defining contact fracture mechanics and gives an overview of how the several examples in Section 4 (the Appendices) fit into this framework.

  13. Search for electroweak top quark production in the electron + jets channel in the D0 experiment at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Busato, Emmanuel [Paris Univ. (France)

    2005-04-01

    The top quark, whose mass approaches the electroweak symmetry breaking scale, is by far the heaviest known elementary particle. New physics is therefore expected to have its most important effect in the top sector. The Tevatron is, currently, the only collider able to produce the top quark. Among all possible production processes in the standard model, the top-antitop pair production via strong interaction, first observed in 1995, is the one with the largest cross section. The production via electroweak interaction (known as single top production), more difficult to extract from the background because of a lower cross section and of a lower signal to background ratio, has never been observed. In this thesis, we have searched for these processes by studying proton-antiproton collisions at $\\sqrt{s}$ =1.96 TeV produced by the Tevatron and detected with the DØ detector. The experimental study of the top quark is very sensitive to the quality of the data taken by the calorimeter. This detector showed, at the beginning of the Run II, rather important noise problems. Having identified the origin of the noise, new treatments at the offline level were implemented and their effects studied. It has been shown that these treatments reduce very significantly the effect of the noise in the reconstruction of physical quantities without notable degradation of the signal. Within the standard model, the top quark decays into W b with a branching ratio close to 100%. Leptonic decays of the into electron + neutrino have been used to identify the from the top decay. The main backgrounds to the single top signal ( +jets and QCD) are made essentially of light quark jets in the final state. Two ..-tagging algorithms have therefore been applied in order to improve the signal to background ratio. No evidence for electroweak top quark production has been found. Upper limits at the 95 % confidence level on the observed (expected) cross sections have be computed. They are found to be 14

  14. Building Atomic Models of the Ion Channels Based on Low Resolution Electron Microscopy Maps and Homology Modeling.

    Science.gov (United States)

    Novoseletsky, Valery; Malak, Olfat A; Loussouarn, Gildas; Sokolova, Olga S

    2018-01-01

    Voltage-gated potassium channels play pivotal roles in excitable and non-excitable cells. For many decades, structural properties and molecular mechanisms of these channels were inferred from functional observations. At the turn of the twenty-first century, structural biology revealed major aspects in the structural basis of ion channel organization, permeation, and gating. Among the available tools, homology modeling associated with low resolution microscopy helps in delineating the different structural elements of voltage-gated channels. Here, we describe in detail the methodology of homology modeling, using the 3D structure of the Kv2.1ΔCTA ion channel as a reference.

  15. Quasi-molecular electron promotion beyond the 1s$\\sigma$ and 2p$\\pi$ channels in slow collisions of He$^{2+}$ and He

    CERN Document Server

    Schmidt, L Ph H; Goihl, C; Jahnke, T; Schmidt-Böcking, H; Dörner, R

    2015-01-01

    The electron emission pattern of transfer-ionization in collisions of He$^{2+}$ with He was investigated for impact velocities between 0.53 a.u. and 0.77 a.u. (7 keV/u - 15 keV/u) employing recoil-ion momentum spectroscopy. This process is known to be dominated by the promotion of the 2p$\\pi$ molecular orbital into the continuum which results in "banana" shaped areas of high electron momentum densities extending from the target to the projectile in velocity space in the collision plain. Asymmetries are explained by a coherent superposition of the 2p$\\pi$ channel of the quasi molecular promotion with the 1s$\\sigma$ channel. Here we report on an additional contribution of higher angular momentum molecular states for close collisions which emerge at smaller impact velocities. They show up as highly structured electron emission patterns in the plane perpendicular to the direction of impact.

  16. An Innovative Approach of Binary Double Stage Multiplier for Real Time Applications

    Science.gov (United States)

    Kalyani Lakshmi, T.; Nayeemuddin, D.; Samba Siva Nayak, R.; Singh, Yadu, Dr.; Lokaiah, P.; Subbarao, A. V.

    2017-08-01

    In today’s world of portable and super fast electronic gadgets, speed is major concern point. Multiplication is used in many applications such as Fourier transform, discrete cosine transform, and digital filtering. If the multipliers too slow, the performance of entire circuits will be reduced. On VLSI implementation level, the area also becomes quite important as more area means more system cost. So, speed and area are two important parameters in VLSI Design. This paper presents the design a Double Stage multiplier for 32*32 binary bit number multiplication. The proposed system consists of 2 stages of operation. The two stages of operation is used to complete the operation of multiplier. By extending the bits of generator an additional product of Double Stage multiplier is obtained. By lowering the complexity of the product of partial reduction we can reduce the area and delay. So, multiplication operation is performed by the Double Stage is efficient with the less area and it reduces delay i.e., speed is increased.

  17. A Multi-Channel Opto-Electronic Sensor to Accurately Monitor Heart Rate against Motion Artefact during Exercise

    Directory of Open Access Journals (Sweden)

    Abdullah Alzahrani

    2015-10-01

    Full Text Available This study presents the use of a multi-channel opto-electronic sensor (OEPS to effectively monitor critical physiological parameters whilst preventing motion artefact as increasingly demanded by personal healthcare. The aim of this work was to study how to capture the heart rate (HR efficiently through a well-constructed OEPS and a 3-axis accelerometer with wireless communication. A protocol was designed to incorporate sitting, standing, walking, running and cycling. The datasets collected from these activities were processed to elaborate sport physiological effects. t-test, Bland-Altman Agreement (BAA, and correlation to evaluate the performance of the OEPS were used against Polar and Mio-Alpha HR monitors. No differences in the HR were found between OEPS, and either Polar or Mio-Alpha (both p > 0.05; a strong correlation was found between Polar and OEPS (r: 0.96, p < 0.001; the bias of BAA 0.85 bpm, the standard deviation (SD 9.20 bpm, and the limits of agreement (LOA from −17.18 bpm to +18.88 bpm. For the Mio-Alpha and OEPS, a strong correlation was found (r: 0.96, p < 0.001; the bias of BAA 1.63 bpm, SD 8.62 bpm, LOA from −15.27 bpm to +18.58 bpm. These results demonstrate the OEPS to be capable of carrying out real time and remote monitoring of heart rate.

  18. Polarization-mediated Debye-screening of surface potential fluctuations in dual-channel AlN/GaN high electron mobility transistors

    Science.gov (United States)

    Deen, David A.; Miller, Ross A.; Osinsky, Andrei V.; Downey, Brian P.; Storm, David F.; Meyer, David J.; Scott Katzer, D.; Nepal, Neeraj

    2016-12-01

    A dual-channel AlN/GaN/AlN/GaN high electron mobility transistor (HEMT) architecture is proposed, simulated, and demonstrated that suppresses gate lag due to surface-originated trapped charge. Dual two-dimensional electron gas (2DEG) channels are utilized such that the top 2DEG serves as an equipotential that screens potential fluctuations resulting from surface trapped charge. The bottom channel serves as the transistor's modulated channel. Two device modeling approaches have been performed as a means to guide the device design and to elucidate the relationship between the design and performance metrics. The modeling efforts include a self-consistent Poisson-Schrodinger solution for electrostatic simulation as well as hydrodynamic three-dimensional device modeling for three-dimensional electrostatics, steady-state, and transient simulations. Experimental results validated the HEMT design whereby homo-epitaxial growth on free-standing GaN substrates and fabrication of the same-wafer dual-channel and recessed-gate AlN/GaN HEMTs have been demonstrated. Notable pulsed-gate performance has been achieved by the fabricated HEMTs through a gate lag ratio of 0.86 with minimal drain current collapse while maintaining high levels of dc and rf performance.

  19. Multiplier convergent series and uniform convergence of mapping ...

    Indian Academy of Sciences (India)

    j=1 Aj (xj ) converges uniformly with respect to (xj ) in any M ∈ M. Moreover, in the last section we give some applications for mapping series. 2. The space of multiplier convergent series. First, we define the frame property of complex sequence set λ, which is important in studying multiplier convergent series. DEFINITION 2.1.

  20. Multipliers for the absolute Euler summability of Fourier series

    Indian Academy of Sciences (India)

    In this paper, the author has investigated necessary and sufficient conditions for the absolute Euler summability of the Fourier series with multipliers. These conditions are weaker than those obtained earlier by some workers. It is further shown that the multipliers are best possible in certain sense.

  1. Circuit multiplies pulse width modulation, exhibits linear transfer function

    Science.gov (United States)

    Carlson, A. W.; Furciniti, A.

    1967-01-01

    Modulation multiplier provides a simple means of multiplying the width modulation of a pulse train by a constant factor. It operates directly on a pulse width modulated input signal to generate an output pulse train having a greater degree of width modulation than the input signal.

  2. An algebra of absolutely continuous functions and its multipliers

    Indian Academy of Sciences (India)

    Introduction. Let I = [0, 1] be the compact topological semigroup with max multiplication and usual topology. C(I),Lp(I), 1 ≤ p ≤ ∞ are the associated Banach algebras. Larsen [5] obtained multipliers for the Banach algebra L1(I). Baker, Pym and Vasudeva [1] obtain characterizations of multipliers from Lp(I) to Lr(I), 1 ≤ r, ...

  3. Novel intramolecular photoinduced electron transfer-based probe for the Human Ether-a-go-go-Related Gene (hERG) potassium channel.

    Science.gov (United States)

    Liu, Zhenzhen; Zhou, Yubin; Du, Lupei; Li, Minyong

    2015-12-21

    Drug induced long QT syndrome is a high risk event in clinic, which mainly results from their high affinity to the Human Ether-a-go-go-Related Gene (hERG) potassium channel. Therefore, evaluation of the drug's inhibitory activity against the hERG potassium channel is a required step in drug discovery and development. In this study, we developed a series of novel conformation-mediated intramolecular photoinduced electron transfer fluorogenic probes for the hERG potassium channel. After careful evaluation, probes N4 and N6 showed good activity and may have a promising application in the cell-based hERG potassium channel inhibitory activity assay, as well as potential hERG-associated cardiotoxicity evaluation. Compared with other assay methods, such as patch clamp assay, radio-ligand competitive binding assay, fluorescence polarization and potential-sensitive fluorescent probes, this method is convenient and can also selectively measure the inhibitory activity in the native state of the hERG potassium channel. Meanwhile, these probes can also be used for hERG potassium channel imaging without complex washing steps.

  4. Beyond Linear Delay Multipliers in Air Transport

    Directory of Open Access Journals (Sweden)

    Seddik Belkoura

    2017-01-01

    Full Text Available Delays are considered one of the most important burdens of air transport, both for their social and environmental consequences and for the cost they cause for airlines and passengers. It is therefore not surprising that a large effort has been devoted to study how they propagate through the system. One of the most important indicators to assess such propagation is the delay multiplier, a ratio between outbound and inbound average delays; in spite of its widespread utilisation, its simplicity precludes capturing all details about the dynamics behind the diffusion process. Here we present a methodology that extracts a more complete relationship between the in- and outbound delays, distinguishing a linear and a nonlinear phase and thus yielding a richer description of the system’s response as a function of the delay magnitude. We validate the methodology through the study of a historical data set of flights crossing the European airspace and show how its most important airports have heterogeneous ways of reacting to extreme delays and that this reaction strongly depends on some of their global properties.

  5. Negative probability of random multiplier in turbulence

    Science.gov (United States)

    Bai, Xuan; Su, Weidong

    2017-11-01

    The random multiplicative process (RMP), which has been proposed for over 50 years, is a convenient phenomenological ansatz of turbulence cascade. In the RMP, the fluctuation in a large scale is statistically mapped to the one in a small scale by the linear action of an independent random multiplier (RM). Simple as it is, the RMP is powerful enough since all of the known scaling laws can be included in this model. So far as we know, however, a direct extraction for the probability density function (PDF) of RM has been absent yet. The reason is the deconvolution during the process is ill-posed. Nevertheless, with the progress in the studies of inverse problems, the situation can be changed. By using some new regularization techniques, for the first time we recover the PDFs of the RMs in some turbulent flows. All the consistent results from various methods point to an amazing observation-the PDFs can attain negative values in some intervals; and this can also be justified by some properties of infinitely divisible distributions. Despite the conceptual unconventionality, the present study illustrates the implications of negative probability in turbulence in several aspects, with emphasis on its role in describing the interaction between fluctuations at different scales. This work is supported by the NSFC (No. 11221062 and No. 11521091).

  6. Optimizing strassen matrix multiply on GPUs

    KAUST Repository

    ul Hasan Khan, Ayaz

    2015-06-01

    © 2015 IEEE. Many core systems are basically designed for applications having large data parallelism. Strassen Matrix Multiply (MM) can be formulated as a depth first (DFS) traversal of a recursion tree where all cores work in parallel on computing each of the NxN sub-matrices that reduces storage at the detriment of large data motion to gather and aggregate the results. We propose Strassen and Winograd algorithms (S-MM and W-MM) based on three optimizations: a set of basic algebra functions to reduce overhead, invoking efficient library (CUBLAS 5.5), and parameter-tuning of parametric kernel to improve resource occupancy. On GPUs, W-MM and S-MM with one recursion level outperform CUBLAS 5.5 Library with up to twice as faster for large arrays satisfying N>=2048 and N>=3072, respectively. Compared to NVIDIA SDK library, S-MM and W-MM achieved a speedup between 20x to 80x for the above arrays. The proposed approach can be used to enhance the performance of CUBLAS and MKL libraries.

  7. Comparative analysis of hot-electron transport in AlGaN/GaN and AlGaN/AlN/GaN 2DEG channels

    Energy Technology Data Exchange (ETDEWEB)

    Ardaravicius, L.; Ramonas, M.; Kiprijanovic, O.; Liberis, J.; Matulionis, A. [Semiconductor Physics Institute, A. Gostauto 11, 01108 Vilnius (Lithuania); Eastman, L.F.; Shealy, J.R.; Chen, X.; Sun, Y.J. [Cornell University, 425 Philips Hall, Ithaca, NY 14853 (United States)

    2005-04-01

    Nanosecond-pulsed current-voltage measurements were used to study hot-electron transport in undoped AlGaN/GaN and AlGaN/AlN/GaN two-dimensional electron gas channels biased up to 200 kV/cm. Voltage pulses of 1 ns were applied in order to minimize channel heating. The current saturated at 100 kV/cm in the AlN-interbarrier-contained structures; the estimated saturated drift velocity was about 1.1 x 10{sup 7} cm/s. No saturation of the current was observed in AlGaN/GaN channels in the field range below 200 kV/cm. Monte Carlo simulation of hot-electron transport was carried out with electron gas degeneracy and hot phonons taken into account. A fairly good fit of the experimental results with the Monte Carlo simulation data was obtained in the electric field range up to 30 kV/cm. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. Ion beam and performance characteristics in the presence of multiply charged ions in annular and cylindrical type Hall thruster plasmas

    Science.gov (United States)

    Kim, Holak; Lim, Youbong; Seon, Jongho; Choe, Wonho; Korea Advanced Institute of Science and Technology (KAIST) Collaboration; Kyung Hee University Collaboration

    2014-10-01

    Operation performance and ion beam characteristics in the presence of multiply charged ions in cylindrical Hall thruster (CHT) and annular Hall thruster (AHT) plasmas are compared under identical conditions such as channel diameter, channel depth, and propellant flow rate. According to our previous results, the propellant utilization of the 200 W class CHT well exceeds unity [1,2] and the papers suggest that this may be related to the presence of multiply charged ions. In this work, we report the large fractions of Xe2+ and Xe3+ ions measured in the CHT plasma, which are about 16--26% and 6--7%, respectively. The measured values of specific impulse and thrust are higher by 1.4 times in CHT than in AHT at 300 V of the anode voltage, and it is found that the high fraction of multiply charged ions is responsible for the higher values of specific impulse and thrust. The details of the comparison of the overall performance and beam characteristics associated with multiply charged ions in AHT and CHT will be presented. This work was partly supported by the Space Core Technology Program (Grant No. 2014M1A3A3A02034510) and the Korea Institute of Materials Science (KIMS) (Grant No. 10043470).

  9. The Catalan Economy towards the New European Energy Policy: Through Accounting of Greenhouse Emission Multipliers

    Directory of Open Access Journals (Sweden)

    Laia Pié

    2017-12-01

    Full Text Available The aim of this paper is to study the effect that implementing the agreement signed by the European Union at the end of 2008 will have on reducing greenhouse gas emissions in Catalonia. Emission multipliers and the impact of reducing emissions by 10%, in sectors not covered by the EU ETS (EU Emissions Trading System and reducing those that are covered by 21%, are analysed. More specifically, the effects on the endogenous income of the multiplier model (production, factorial and private income is studied, while reducing and increasing endogenous income and the decomposition of emission multipliers into open, own and circular effects is analysed to include the different channels of the process of generating CO2 equivalent emissions. The empirical application is for the Catalan economy and uses economic and environmental data for the year 2001. The results show that increases in greenhouse gas emissions will essentially depend on the account that receives the exogenous inflow in demand. Greenhouse gas emissions in Catalonia are affected very differently at the sectoral level and the effects of production activities, factors of production and consumption on air pollution are very heterogeneous. The analytical approach used in this paper provides interesting results that can help to design and implement policies to reduce emissions.

  10. Development of multi-channel apparatus for electron-atom Compton scattering to study the momentum distribution of atoms in a molecule.

    Science.gov (United States)

    Yamazaki, Masakazu; Hosono, Masaki; Tang, Yaguo; Takahashi, Masahiko

    2017-06-01

    We have developed multi-channel apparatus for electron-atom Compton scattering to study the momentum distribution of atoms in a molecule. It combines the features of both a spherical electron energy analyzer and a large-area position sensitive detector, thereby having an ability to cover almost completely the azimuthal angle range available for quasi-elastic electron Rutherford backscattering at an angle of 135°. Details and performance of the apparatus are reported, together with experimental results measured for Xe and CH4 at an incident electron energy of 2 keV. In particular, it is shown that the instrumental sensitivity is remarkably high, which has increased the signal count rate by nearly three orders of magnitude compared to existing setups. This technical progress would be useful for advancing atomic momentum spectroscopy studies.

  11. Sociophysics of sexism: normal and anomalous petrie multipliers

    Science.gov (United States)

    Eliazar, Iddo

    2015-07-01

    A recent mathematical model by Karen Petrie explains how sexism towards women can arise in organizations where male and female are equally sexist. Indeed, the Petrie model predicts that such sexism will emerge whenever there is a male majority, and quantifies this majority bias by the ‘Petrie multiplier’: the square of the male/female ratio. In this paper—emulating the shift from ‘normal’ to ‘anomalous’ diffusion—we generalize the Petrie model to a stochastic Poisson model that accommodates heterogeneously sexist men and woman, and that extends the ‘normal’ quadratic Petrie multiplier to ‘anomalous’ non-quadratic multipliers. The Petrie multipliers span a full spectrum of behaviors which we classify into four universal types. A variation of the stochastic Poisson model and its Petrie multipliers is further applied to the context of cyber warfare.

  12. Gauss-Bonnet dark energy by Lagrange multipliers

    Science.gov (United States)

    Capozziello, Salvatore; Makarenko, Andrey N.; Odintsov, Sergei D.

    2013-04-01

    A string-inspired effective theory of gravity, containing Gauss-Bonnet invariant interacting with a scalar field, is considered in view of obtaining cosmological dark energy solutions. A Lagrange multiplier is inserted into the action in order to achieve the cosmological reconstruction by selecting suitable forms of couplings and potentials. Several cosmological exact solutions (including dark energy of quintessence, phantom, or Little Rip type) are derived in the presence and in the absence of the Lagrange multiplier showing the difference in the two dynamical approaches. In the models that we consider, the Lagrange multiplier behaves as a sort of dust fluid that realizes the transitions between matter-dominated and dark energy epochs. The relation between Lagrange multipliers and Noether symmetries is discussed.

  13. EFEK MULTIPLIER ZAKAT TERHADAP PENDAPATAN DI PROVINSI DKI JAKARTA

    Directory of Open Access Journals (Sweden)

    M. Nur Rianto Al Arif

    2016-02-01

    Full Text Available The aim of this research is to analyse the multiplier effect of zakâh revenue in DKI Jakarta. A study case at Badan Amil Zakat, Infak, and Sadaqah (BAZIS DKI Jakarta. Least square method is used to analyze the data. The coefficients will be used to calculate the multiplier effect of zakâh-revenue and it will  be compared with the economy without zakah revenue. The results showed 2,522 multiplier effects of zakâh-revenue and 3.561 multiplier effect ofeconomic income without zakâh-revenue. This suggests that the management of zakat in BAZIS Jakarta still can have a significant influence on the economy.DOI: 10.15408/aiq.v4i1.2533

  14. Instructional Computing Project Uses "Multiplier Effect" to Train Florida Teachers.

    Science.gov (United States)

    Roblyer, M. D.; Castine, W. H.

    1987-01-01

    Reviews the efforts undertaken in the Florida Model Microcomputer Trainer Project (FMMTP) and its statewide impact. Outlines its procedural strategies, trainer curriculum, networking system, and the results of its multiplier effect. (ML)

  15. Efek Multiplier Zakat Terhadap Pendapatan di Propinsi DKI Jakarta

    Directory of Open Access Journals (Sweden)

    M. Nur Rianto Al Arif

    2015-10-01

    Full Text Available The aim of this research is to analyze the multiplier effect of zakah revenue in DKI Jakarta, a study case at Badan Amil Zakat, Infak, and Shadaqah (BAZIS DKI Jakarta. Least square methods is used to analyze the data. The coefficient will be used to calculate the multiplier effect of zakah revenue and it will be compared with the economy without zakah revenue. The result showed 2,522 multiplier effects of zakah revenue and 3,561 multiplier effect of economic income without zakah revenue. This suggest that the management of zakah in BAZIS DKI Jakarta still can have a significant influence on the economyDOI: 10.15408/aiq.v4i1.2079

  16. Operational Safety Requirements Neutron Multiplier Facility in 329 Building

    Energy Technology Data Exchange (ETDEWEB)

    EA. Lepel

    1992-10-01

    The operational safety requirements (OSRs) presented in this report define the conditions, safe boundaries and management control needed for safely operating the Neutron Multiplier Facility in the 329 Building Annex.

  17. Isometric multipliers of a vector valued Beurling algebra on a ...

    Indian Academy of Sciences (India)

    Abstract. Let (S, ω) be a weighted abelian semigroup, let Mω(S) be the semigroup of ω-bounded multipliers of S, and let A be a strictly convex commutative Banach algebra with identity. It is shown that T is an onto isometric multiplier of l1(S,ω, A) if and only if there exists an invertible σ ∈ Mω(S), a unitary point a ∈ A, and a k ...

  18. Fiscal Multipliers and Public Debt Dynamics in Consolidations

    OpenAIRE

    Salto, Matteo; Boussard, Jocelyn; de Castro Fernández, Francisco

    2013-01-01

    The success of a consolidation in reducing the debt ratio depends crucially on the value of the multiplier, which measures the impact of consolidation on growth, and on the reaction of sovereign yields to such a consolidation. We present a theoretical framework that formalizes the re spo nse of the public debt ratio to fiscal consolidations in relation to the value of fiscal multipliers, the starting debt level and the cyclical elasticity of the budget balance. We also assess the role of ...

  19. Design and characterization of a 64 channels ASIC front-end electronics for high-flux particle beam detectors

    Science.gov (United States)

    Fausti, F.; Mazza, G.; Attili, A.; Mazinani, M. Fadavi; Giordanengo, S.; Lavagno, M.; Manganaro, L.; Marchetto, F.; Monaco, V.; Sacchi, R.; Vignati, A.; Cirio, R.

    2017-09-01

    A new wide-input range 64-channels current-to-frequency converter ASIC has been developed and characterized for applications in beam monitoring of therapeutic particle beams. This chip, named TERA09, has been designed to extend the input current range, compared to the previous versions of the chip, for dealing with high-flux pulsed beams. A particular care was devoted in achieving a good conversion linearity over a wide bipolar input current range. Using a charge quantum of 200 fC, a linearity within ±2% for an input current range between 3 nA and 12 μA is obtained for individual channels, with a gain spread among the channels of about 3%. By connecting all the 64 channels of the chip to a common input, the current range can be increased 64 times preserving a linearity within ±3% in the range between and 20 μA and 750 μA.

  20. The qualitative f-ratio method applied to electron channelling-induced x-ray imaging with an annular silicon drift detector in a scanning electron microscope in the transmission mode.

    Science.gov (United States)

    Brodusch, Nicolas; Gauvin, Raynald

    2017-09-01

    Electron channelling is known to affect the x-ray production when an accelerated electron beam is applied to a crystalline material and is highly dependent on the local crystal orientation. This effect, unless very long counting time are used, is barely noticeable on x-ray energy spectra recorded with conventional silicon drift detectors (SDD) located at a small elevation angle. However, the very high count rates provided by the new commercially available annular SDDs permit now to observe this effect routinely and may, in some circumstances, hide the true elemental x-ray variations due to the local true specimen composition. To circumvent this issue, the recently developed f-ratio method was applied to display qualitatively the true net intensity x-ray variations in a thin specimen of a Ti-6Al-4V alloy in a scanning electron microscope in transmission mode. The diffraction contrast observed in the x-ray images was successfully cancelled through the use of f-ratios and the true composition variations at the grain boundaries could be observed in relation to the dislocation alignment prior to the β-phase nucleation. The qualitative effectiveness in removing channelling effects demonstrated in this work makes the f-ratio, in its quantitative form, a possible alternative to the ZAF method in channelling conditions. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

  1. Citizens and service channels: channel choice and channel management implications

    NARCIS (Netherlands)

    Pieterson, Willem Jan

    2010-01-01

    The arrival of electronic channels in the 1990s has had a huge impact on governmental service delivery. The new channels have led to many new opportunities to improve public service delivery, not only in terms of citizen satisfaction, but also in cost reduction for governmental agencies. However,

  2. First direct electron microscopic visualization of a tight spatial coupling between GABAA-receptors and voltage-sensitive calcium channels

    DEFF Research Database (Denmark)

    Hansen, G H; Belhage, B; Schousboe, A

    1992-01-01

    Using cerebellar granule neurons in culture it was demonstrated that exposure of the cells to the GABAA receptor agonist 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol (THIP) leads to an increase in the number of voltage-gated calcium channels as revealed by quantitative preembedding indirect imm...... of THIP-treated cultures. This suggests that primarily low affinity GABAA-receptors are closely associated with Ca2+ channels and this may be important for the ability of these receptors to mediate an inhibitory action on transmitter release even under extreme depolarizing conditions....

  3. Single-top production t-channel cross section measurement in the electron+jets final state at ATLAS with 35 pb{sup -1}of data

    Energy Technology Data Exchange (ETDEWEB)

    Khoriauli, Gia

    2012-07-15

    The cross section of the Standard Model electroweak production of a single top quark in the t-channel has been measured using the LHC proton-proton collision data at {radical}(s)=7 TeV, 35 pb{sup -1} of integrated luminosity, recorded by the ATLAS detector during the year 2010. The measurement has been based on a selection of the collision events with an electron and one b-tagged hadronic jet in the central region of the detector and one extra jet in the forward region of the detector. These requirements are dictated by the topology of the final state particles in the t-channel process. They helped to optimize an expected fraction of the t-channel process, according to a study based on Monte-Carlo simulation, in the selected events and suppress the contribution of the background processes. The main background processes such as production of hadronic jets via the strong interaction and production of a single W boson with associated hadronic jets are measured by means of data driven methods developed in this work. The measured cross section of single top quark production in the t-channel process is 59{sup +44}{sub -39}(stat.){sup +63}{sub -39}(syst.) pb. The measured upper limit on the cross section is 226 pb at the 95% confidence level. The results are in agreement with the latest theoretical prediction of the t-channel cross section of the Standard Model production of a single top quark calculated at NNLO, 64.6{sup +3.3}{sub -2.6} pb, considering m {sub t-quark}=172.5 GeV.

  4. An electron paramagnetic resonance spectroscopy investigation of the retention mechanisms of Mn and Cu in the nanopore channels of three zeolite minerals

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Daniel R.; Schulthess, Cristian P.; Amonette, James E.; Walter, Eric D.

    2012-12-01

    The adsorption mechanisms of divalent cations in zeolite nanopore channels can vary as a function of their pore dimensions. The nanopore inner-sphere enhancement (NISE) theory predicts that ions may dehydrate inside small nanopore channels in order to adsorb more closely to the mineral surface if the nanopore channel is sufficiently small. The results of an electron paramagnetic resonance (EPR) spectroscopy study of Mn and Cu adsorption on the zeolite minerals zeolite Y (large nanopores), ZSM-5 (intermediate nanopores), and mordenite (small nanopores) are presented. The Cu and Mn cations both adsorbed via an outer-sphere mechanism on zeolite Y based on the similarity between the adsorbed spectra and the aqueous spectra. Conversely, Mn and Cu adsorbed via an inner-sphere mechanism on mordenite based on spectrum asymmetry and peak broadening of the adsorbed spectra. However, Mn adsorbed via an outer-sphere mechanism on ZSM-5, whereas Cu adsorbed on ZSM-5 shows a high degree of surface interaction that indicates that it is adsorbed closer to the mineral surface. Evidence of dehydration and immobility was more readily evident in the spectrum of mordenite than ZSM-5, indicating that Cu was not as close to the surface on ZSM-5 as it was when adsorbed on mordenite. Divalent Mn cations are strongly hydrated and are held strongly only in zeolites with small nanopore channels. Divalent Cu cations are also strongly hydrated, but can dehydrate more easily, presumably due to the Jahn-Teller effect, and are held strongly in zeolites with medium sized nanopore channels or smaller.

  5. Multiplier Accounting of Indian Mining Industry: The Application

    Science.gov (United States)

    Hussain, Azhar; Karmakar, Netai Chandra

    2017-10-01

    In the previous paper (Hussain and Karmakar in Inst Eng India Ser, 2014. doi: 10.1007/s40033-014-0058-0), the concepts of input-output transaction matrix and multiplier were explained in detail. Input-output multipliers are indicators used for predicting the total impact on an economy due to changes in its industrial demand and output which is calculated using transaction matrix. The aim of this paper is to present an application of the concepts with respect to the mining industry, showing progress in different sectors of mining with time and explaining different outcomes from the results obtained. The analysis shows that a few mineral industries saw a significant growth in their multiplier values over the years.

  6. A Frequency Multiplier Based on Time Recursive Processing

    Directory of Open Access Journals (Sweden)

    D. M. Perisic

    2017-12-01

    Full Text Available This paper describes a digital frequency multiplier for a pulse rate. The multiplier is based on the recursive processing of the input and output periods and their time differences. Special emphasis is devoted to the techniques which provide the development of multipliers based on this principle. The circuit is defined by two system parameters. One is the ratio of two clock frequencies and the other is a division factor of a binary counter. The realization of the circuit is described. The region of the system parameters for the stable circuit is presented. The different aspects of applications and limitations in realization of the circuit are considered. All mathematical analyses are made using a Z transform approach. It is shown that the circuit can be also used in tracking and prediction applications. Computer simulations are performed to prove the correctness of the math and the whole approach.

  7. Radial multipliers on amalgamated free products of II-factors

    DEFF Research Database (Denmark)

    Möller, Sören

    2014-01-01

    Let ℳi be a family of II1-factors, containing a common II1-subfactor 풩, such that [ℳi : 풩] ∈ ℕ0 for all i. Furthermore, let ϕ: ℕ0 → ℂ. We show that if a Hankel matrix related to ϕ is trace-class, then there exists a unique completely bounded map Mϕ on the amalgamated free product of the ℳi...... with amalgamation over 풩, which acts as a radial multiplier. Hereby, we extend a result of Haagerup and the author for radial multipliers on reduced free products of unital C*- and von Neumann algebras....

  8. Channeling of high-power radio waves under conditions of strong anomalous absorption in the presence of an averaged electron heating source

    Science.gov (United States)

    Vas'kov, V. V.; Ryabova, N. A.

    2010-02-01

    Strong anomalous absorption of a high-power radio wave by small-scale plasma inhomogeneities in the Earth’s ionosphere can lead to the formation of self-consistent channels (solitons) in which the wave propagates along the magnetic field, but has a soliton-like intensity distribution across the field. The structure of a cylindrical soliton as a function of the wave intensity at the soliton axis is analyzed. Averaged density perturbations leading to wave focusing were calculated using the model proposed earlier by Vas’kov and Gurevich (Geomagn. Aéron. 16, 1112 (1976)), in which an averaged electron heating source was used. It is shown that, under conditions of strong electron recombination, the radii of individual solitons do not exceed 650 m.

  9. Single-top production t-channel cross section measurement in the electron+jets final state at ATLAS with $35 pb^{−1}$ of data

    CERN Document Server

    Khoriauli, Gia; Wermes, Norbert

    The cross section of the Standard Model electroweak production of a single top quark in the t-channel has been measured using the LHC proton-proton collision data at $sqrt{s} = 7$ TeV, $35 pb^{−1}$ of integrated luminosity, recorded by the ATLAS detector during the year 2010. The measurement has been based on a selection of the collision events with an electron and one b-tagged hadronic jet in the central region of the detector and one extra jet in the forward region of the detector. These requirements are dictated by the topology of the final state particles in the t-channel process. They helped to optimize an expected fraction of the t-channel process, according to a study based on Monte-Carlo simulation, in the selected events and suppress the contribution of the background processes. The main background processes such as production of hadronic jets via the strong interaction and production of a single W boson with associated hadronic jets are measured by means of data driven methods developed in this wo...

  10. Impact of strain on electronic and transport properties of 6 nm hydrogenated germanane nano-ribbon channel double gate field effect transistor

    Science.gov (United States)

    Meher Abhinav, E.; Sundararaj, Anuraj; Gopalakrishnan, Chandrasekaran; Kasmir Raja, S. V.; Chokhra, Saurabh

    2017-11-01

    In this work, chair like fully hydrogenated germanane (CGeH) nano-ribbon 6 nm short channel double gate field effect transistor (DG-FET) has been modeled and the impact of strain on the I–V characteristics of CGeH channel has been examined. The bond lengths, binding and formation energies of various hydrogenated geometries of buckled germanane channel were calculated using local density approximation (LDA) with Perdew–Zunger (PZ) and generalized gradient approximation (GGA) with Perdew Burke Ernzerhof (PBE) parameterization. From four various geometries, chair like structure is found to be more stable compared to boat like obtuse, stiruup structure and table like structure. The bandgap versus width, bandgap versus strain characteristics and I–V characteristics had been analyzed at room temperature using density functional theory (DFT). Using self consistent calculation it was observed that the electronic properties of nano-ribbon is independent of length and band structure, but dependent on edge type, strain [Uni-axial (ε xx ), bi-axial (ε xx   =  ε yy )] and width of the ribbon. The strain engineered hydrogenated germanane (GeH) showed wide direct bandgap (2.3 eV) which could help to build low noise electronic devices that operates at high frequencies. The observed bi-axial compression has high impact on the device transport characteristics with peak to valley ratio (PVR) of 2.14 and 380% increase in peak current compared to pristine CGeH device. The observed strain in CGeH DG-FET could facilitate in designing novel multiple-logic memory devices due to multiple negative differential resistance (NDR) regions.

  11. Investigation of planar channeling radiation on diamond and quartz crystals at electron energies between 14 and 34 MeV and probing the influence of ultrasonic waves on channeling radiation

    Energy Technology Data Exchange (ETDEWEB)

    Azadegan, B.

    2007-11-15

    Measurements of planar channeling radiation (CR) have been performed at the electron beam of ELBE within an energy range between 14 and 34 MeV and for thicknesses of the diamond crystals between 42.5 and 500 {mu}m. Absolute CR photon yields have for the first time been obtained for the above given ranges of electron energy and crystal thickness. The square-root dependence of the planar CR photon yield on the thickness of diamond crystals has been confirmed. A systematic quantitative investigation of the influence of the crystal thickness on the CR line shape has for the first time been performed. The mean-squared multiple-scattering angle effective for planar CR observed in forward direction has been found to be weaker as assumed from scattering in amorphous targets. Scaling laws deduced from the measured CR data are of advantage for the operation of a CR source. The second part of this thesis deals with the possibility of stimulation of CR emission by means of ultrasonic vibrations excited in a piezoelectric single crystal. Since the knowledge of the CR spectra generated on undisturbed quartz crystals is a necessary precondition for some investigation of the influence of US, planar CR has for the first time been measured at medium electron energies for a variety of planes in quartz. As a consequence of the hexagonal structure of this crystal, relative intense CR could be registered even out of planes with indices larger than one. On the base of the non-linear optics method, occupation functions and spectral distributions of planar CR have been calculated for channeling of 20 MeV electrons in the (01 anti 15) plane of a 20 {mu}m thick quartz crystal at resonant influence of ultrasound (US). The resonance frequencies have been deduced from the measurements of CR spectra performed on quartz. First experimental investigations of the influence of US on CR started at ELBE aimed at the study of the effect of non-resonant ultrasonic vibrations excited in a 500 {mu}m thick

  12. Familiar Sports and Activities Adapted for Multiply Impaired Persons.

    Science.gov (United States)

    Schilling, Mary Lou, Ed.

    1984-01-01

    Means of adapting some familiar and popular physical activities for multiply impaired persons are described. Games reviewed are dice baseball, one base baseball, in-house bowling, wheelchair bowling, ramp bowling, swing-ball bowling, table tennis, shuffleboard, beanbag bingo and tic-tac-toe, balloon basketball, circle football, and wheelchair…

  13. Problems with Accurate Atomic Lfetime Measurements of Multiply Charged Ions

    Energy Technology Data Exchange (ETDEWEB)

    Trabert, E

    2009-02-19

    A number of recent atomic lifetime measurements on multiply charged ions have reported uncertainties lower than 1%. Such a level of accuracy challenges theory, which is a good thing. However, a few lessons learned from earlier precision lifetime measurements on atoms and singly charged ions suggest to remain cautious about the systematic errors of experimental techniques.

  14. Potential energy curves for neutral and multiply charged carbon ...

    Indian Academy of Sciences (India)

    physics pp. 49–55. Potential energy curves for neutral and multiply charged carbon monoxide. PRADEEP KUMAR1 and N SATHYAMURTHY1,2,3,∗. 1Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208 016, India. 2Indian Institute of Science Education and Research Mohali, MGSIPAP Complex,.

  15. Detection of differential item functioning using Lagrange multiplier tests

    NARCIS (Netherlands)

    Glas, Cornelis A.W.

    1998-01-01

    Abstract: In the present paper it is shown that differential item functioning can be evaluated using the Lagrange multiplier test or Rao’s efficient score test. The test is presented in the framework of a number of IRT models such as the Rasch model, the OPLM, the 2-parameter logistic model, the

  16. Detection of differential item functioning using Lagrange multiplier tests

    NARCIS (Netherlands)

    Glas, Cornelis A.W.

    1996-01-01

    In this paper it is shown that differential item functioning can be evaluated using the Lagrange multiplier test or C. R. Rao's efficient score test. The test is presented in the framework of a number of item response theory (IRT) models such as the Rasch model, the one-parameter logistic model, the

  17. Orientation and Mobility for Multiply Handicapped Blind Children.

    Science.gov (United States)

    Wood, Thomas A.

    A research project was conducted to investigate sensory, concept, and locomotion skills in severely multiply handicapped children. The project involved the development of evaluation and teaching materials to be utilized by classroom teachers and paraprofessionals with multi-handicapped children with severe visual deficits. The programed…

  18. Multipliers for the absolute Euler summability of Fourier series

    Indian Academy of Sciences (India)

    Springer Verlag Heidelberg #4 2048 1996 Dec 15 10:16:45

    Multipliers; absolute summability; summability of factored Fourier series; absolute Euler summability. 1. ... In 1968, Mohanty and Mohapatra [12] began the study of absolute Euler summability of. Fourier series by proving the ..... (q > 0) summable. In the case when δ is non-zero real number, we define f (t ) =.. log δ k.

  19. The evolution of unconditional strategies via the 'multiplier effect'.

    Science.gov (United States)

    McNamara, John M; Dall, Sasha R X

    2011-03-01

    Ostensibly, it makes sense in a changeable world to condition behaviour and development on information when it is available. Nevertheless, unconditional behavioural and life history strategies are widespread. Here, we show how intergenerational effects can limit the evolutionary value of responding to reliable environmental cues, and thus favour the evolutionary persistence of otherwise paradoxical unconditional strategies. While cue-ignoring genotypes do poorly in the wrong environments, in the right environment they will leave many copies of themselves, which will themselves leave many copies, and so on, leading genotypes to accumulate in habitats in which they do well. We call this 'The Multiplier Effect'. We explore the consequences of the multiplier effect by focussing on the ecologically important phenomenon of natal philopatry. We model the environment as a large number of temporally varying breeding sites connected by natal dispersal between sites. Our aim is to identify which aspects of an environment promote the multiplier effect. We show, if sites remain connected through some background level of 'accidental' dispersal, unconditional natal philopatry can evolve even when there is density dependence (with its accompanying kin competition effects), and cues that are only mildly erroneous. Thus, the multiplier effect may underpin the evolution and maintenance of unconditional strategies such as natal philopatry in many biological systems. © 2011 Blackwell Publishing Ltd/CNRS.

  20. A CMOS four-quadrant analog current multiplier

    NARCIS (Netherlands)

    Wiegerink, Remco J.

    1991-01-01

    A CMOS four-quadrant analog current multiplier is described. The circuit is based on the square-law characteristic of an MOS transistor and is insensitive to temperature and process variations. The circuit is insensitive to the body effect so it is not necessary to place transistors in individual

  1. Robust formation control of marine surface craft using Lagrange multipliers

    DEFF Research Database (Denmark)

    Ihle, Ivar-Andre F.; Jouffroy, Jerome; Fossen, Thor I.

    2006-01-01

    This paper presents a formation modelling scheme based on a set of inter-body constraint functions and Lagrangian multipliers. Formation control for a °eet of marine craft is achieved by stabilizing the auxiliary constraints such that the desired formation con¯guration appears. In the proposed...

  2. Quantum noise frequency correlations of multiply scattered light

    DEFF Research Database (Denmark)

    Lodahl, Peter

    2006-01-01

    Frequency correlations in multiply scattered light that are present in quantum fluctuations are investigated. The speckle correlations for quantum and classical noise are compared and are found to depend markedly differently on optical frequency, which was confirmed in a recent experiment....... Furthermore, novel mesoscopic correlations are predicted that depend on the photon statistics of the incoming light....

  3. The role of the Jacobi last multiplier and isochronous systems

    Indian Academy of Sciences (India)

    Abstract. We employ Jacobi's last multiplier (JLM) to study planar differential systems. In particu- lar, we examine its role in the transformation of the temporal variable for a system of ODEs originally analysed by Calogero–Leyvraz in course of their identification of isochronous systems. We also show that JLM simplifies to a ...

  4. Multipliers of Ap((0 ,((0 ,((0,∞)) with order convolution

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Introduction. The algebra Ap(G) of elements in L1(G) whose Fourier transforms belong to Lp( ˆG) and the multipliers for these algebras have been studied by various authors [1,7–9]. Let. I = (0, ∞) be the locally compact idempotent commutative topological semigroup with the usual topology and max multiplication and ˆI be ...

  5. A LOW-PHASE NOISE FREQUENCY MULTIPLIER CHAIN ...

    African Journals Online (AJOL)

    ABSTRACT. In this paper a low phase-noise frequency multiplier chain from lOMHz to 480MHz, built in two stages and intended for use as a base for the synthesis of frequencies upto the far infrared. (FIR) region, is presented. Different methods of frequency multiplication were used and the associated circuit diagrams given.

  6. Multiplying Is More than Math--It's Also Good Management

    Science.gov (United States)

    Foster, Elise; Wiseman, Liz

    2015-01-01

    Studying more than 400 educational leaders, the authors propose a new model for leadership and management rooted in the belief that there is latent intelligence inside schools and educational organizations. Their findings suggest two dramatically different types of leaders, Multipliers and Diminishers. The five disciplines that distinguish…

  7. A multi-channel THz and infrared spectrometer for femtosecond electron bunch diagnostics by single-shot spectroscopy of coherent radiation

    Energy Technology Data Exchange (ETDEWEB)

    Wesch, Stephan; Schmidt, Bernhard; Behrens, Christopher; Delsim-Hashemi, Hossein; Schmueser, Peter

    2011-08-15

    The high peak current required in free-electron lasers (FELs) is realized by longitudinal compression of the electron bunches to sub-picosecond length. In this paper, a frequency-domain diagnostic method is described that is capable of resolving structures in the femtosecond regime. A novel in-vacuum spectrometer has been developed for spectroscopy of coherent radiation in the THz and infrared range. The spectrometer is equipped with five consecutive dispersion gratings and 120 parallel readout channels; it can be operated either in short wavelength mode (5-44 {mu}m) or in long wavelength mode (45-430 {mu}m). Fast parallel readout permits the spectroscopy of coherent radiation from single electron bunches. Test measurements at the soft X-ray free-electron laser FLASH, using coherent transition radiation, demonstrate excellent performance of the spectrometer. The high sensitivity down to a few micrometers allows study of short bunch features caused for example by microbunching e ects in magnetic chicanes. The device is planned for use as an online bunch profile monitor during regular FEL operation. (orig.)

  8. Applications of mesoscopic physics to novel correlations and fluctuations of speckle patterns: Imaging and tomography with multiply scattered classical waves. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Shechao Charles

    1995-02-01

    This is the final report on the grant, entitled `applications of mesoscopic physics to novel correlations and fluctuations of speckle patterns: imaging and tomography with multiply scattered classical waves`, which expired on September 14, 1994. The author summarizes the highlights of this research program, and lists the publications supported by this grant. The report is divided into sections, titled: application of mesoscopic fluctuations theory to correlations and fluctuations of multiply scattered light; quantum transport in localized electronic systems; electron-phonon inelastic scattering rate and the temperature scaling exponent in integer quantum Hall effect; high frequency quantum transport in quantum well devices.

  9. Expression of calcium channel CaV1.3 in cat spinal cord: light and electron microscopic immunohistochemical study

    DEFF Research Database (Denmark)

    Zhang, Mengliang; Møller, Morten; Broman, Jonas

    2008-01-01

    In spinal neurons, plateau potentials serve to amplify neuronal input signals. To a large extent, the underlying persistent inward current is mediated by a subtype of the L-type calcium channel (Ca(V)1.3). In the present investigation, we have studied its distribution and cellular localization...... enlargements and the phrenic nucleus in cervical, Clarke's nucleus in lower thoracic and upper lumbar, and Onuf's nucleus in upper sacral segments. At the ultrastructural level, Ca(V)1.3-immunoreactive products were found in neuronal somata and dendrites of different sizes. In the soma, they were predominantly...

  10. Design of multichannel DWDM fiber Bragg grating filters by Lagrange multiplier constrained optimization.

    Science.gov (United States)

    Lee, Cheng-Ling; Lee, Ray-Kuang; Kao, Yee-Mou

    2006-11-13

    We present the synthesis of multi-channel fiber Bragg grating (MCFBG) filters for dense wavelength-division-multiplexing (DWDM) application by using a simple optimization approach based on a Lagrange multiplier optimization (LMO) method. We demonstrate for the first time that the LMO method can be used to constrain various parameters of the designed MCFBG filters for practical application demands and fabrication requirements. The designed filters have a number of merits, i.e., flat-top and low dispersion spectral response as well as single stage. Above all, the maximum amplitude of the index modulation profiles of the designed MCFBGs can be substantially reduced under the applied constrained condition. The simulation results demonstrate that the LMO algorithm can provide a potential alternative for complex fiber grating filter design problems.

  11. Modeling of Noise and Resistance of Semimetal Hg1-xCdxTe Quantum Well used as a Channel for THz Hot-Electron Bolometer.

    Science.gov (United States)

    Melezhik, E O; Gumenjuk-Sichevska, J V; Sizov, F F

    2016-12-01

    Noise characteristics and resistance of semimetal-type mercury-cadmium-telluride quantum wells (QWs) at the liquid nitrogen temperature are studied numerically, and their dependence on the QW parameters and on the electron concentration is established. The QW band structure calculations are based on the full 8-band k.p Hamiltonian. The electron mobility is simulated by the direct iterative solution of the Boltzmann transport equation, which allows us to include correctly all the principal scattering mechanisms, elastic as well as inelastic.We find that the generation-recombination noise is strongly suppressed due to the very fast recombination processes in semimetal QWs. Hence, the thermal noise should be considered as a main THz sensitivity-limiting mechanism in those structures. Optimization of a semimetal Hg1-xCdxTe QW to make it an efficient THz bolometer channel should include the increase of electron concentration in the well and tuning the molar composition x close to the gapless regime.

  12. Characterization of photo-multiplier tube as ex-vessel radiation detector in tokamak

    Science.gov (United States)

    Jo, Jungmin; Cheon, MunSeong; Kim, Junghee; An, YoungHwa; Park, Seungil; Chung, Kyoung-Jae; Hwang, Y. S.

    2017-09-01

    Feasibility of using conventional photo-multiplier tubes (PMTs) without a scintillator as an ex-vessel radiation detector in a tokamak environment is studied. Basic irradiation tests using standard gamma ray sources and a d-d neutron generator showed that the PMT is responding both to gamma photons and neutrons, possibly due to the direct generation of secondary electrons inside the PMT by the impingement of high energy photons. Because of the selective sensitivity of the PMT to hard x-ray and neutrons in ohmic and neutral beam injected plasmas, respectively, it is shown that the PMT with certain configuration can be utilized either to monitor the fluctuation in the fusion neutron generation rate or to study the behavior of runaway electrons in tokamaks.

  13. Contact Resistance and Channel Conductance of Graphene Field-Effect Transistors under Low-Energy Electron Irradiation

    Directory of Open Access Journals (Sweden)

    Filippo Giubileo

    2016-11-01

    Full Text Available We studied the effects of low-energy electron beam irradiation up to 10 keV on graphene-based field effect transistors. We fabricated metallic bilayer electrodes to contact mono- and bi-layer graphene flakes on SiO2, obtaining specific contact resistivity ρ c ≈ 19 k Ω · µ m 2 and carrier mobility as high as 4000 cm2·V−1·s−1. By using a highly doped p-Si/SiO2 substrate as the back gate, we analyzed the transport properties of the device and the dependence on the pressure and on the electron bombardment. We demonstrate herein that low energy irradiation is detrimental to the transistor current capability, resulting in an increase in contact resistance and a reduction in carrier mobility, even at electron doses as low as 30 e−/nm2. We also show that irradiated devices recover their pristine state after few repeated electrical measurements.

  14. On the nature of transport in near-critical dissipative-trapped-electron-mode turbulence: effect of a sudominant diffusive channel

    Energy Technology Data Exchange (ETDEWEB)

    Mier, Jose Angel [Universidad Carlos III, Madrid, Spain; Sanchez, Raul [ORNL; Garcia, Luis [Universidad Carlos III, Madrid, Spain; Newman, David E [University of Alaska; Carreras, Benjamin A [BACV Solutions, Inc., Oak Ridge

    2008-01-01

    The change in nature of radial transport in numerical simulations of near-critical dissipative-trapped-electron-mode turbulence is characterized as the relative strength of an additional diffusive transport channel (subdominant to turbulence) is increased from zero. In its absence, radial transport exhibits the lack of spatial and temporal scales characteristic of self-organized-critical systems. This dynamical regime survives up to diffusivity values which, for the system investigated here, greatly exceeds the expected neoclassical value. These results, obtained using a novel Lagrangian method, complete and extend previous works based instead on the use of techniques imported from the study of cellular automata [J. A. Mier et al., Phys. Plasmas 13, 102308 (2006)]. They also shed further light on why some features of self-organized criticality seem to be observed in magnetically confined plasmas in spite of the presence of mechanisms which apparently violate the conditions needed for its establishment.

  15. Zn-vapor diffused Er:Yb:LiNbO 3 channel waveguides fabricated by means of SiO 2 electron cyclotron resonance plasma deposition

    Science.gov (United States)

    Pernas, P. L.; Hernández, M. J.; Ruíz, E.; Cantelar, E.; Nevado, R.; Morant, C.; Lifante, G.; Cussó, F.

    2000-07-01

    We report here the fabrication method and operation of Zinc-vapor diffused channel waveguides on Erbium/Ytterbium (Er/Yb)-doped Lithium Niobate (LiNbO 3). electron cyclotron resonance (ECR) plasma deposition technique, UV photolithography and Reactive Ion Etching (RIE) are used to define an SiO 2 mask for pattern transfer. The whole process is performed at low temperatures eliminating typical LiO 2 out-diffusion problems and achieving low surface damage. The flexibility of the fabrication technology has been shown to be potentially applicable to integrated optics. EDAX measurements reveal good confinement and homogeneity of the diffused regions. Atomic Force Microscopy (AFM) surface characterization shows the swelling of the diffused areas, consistent with the topoepitaxial growth of a Zn xLi yNb zO w layer.

  16. Intergrown new zeolite beta polymorphs with interconnected 12-ring channels solved by combining electron crystallography and single-crystal X-ray diffraction

    KAUST Repository

    Yu, Zhengbao

    2012-10-09

    Two new polymorphs of zeolite beta, denoted as SU-78A and SU-78B, were synthesized by employing dicyclohexylammonium hydroxides as organic structure-directing agents. The structure was solved by combining transmission electron microscopy and single-crystal X-ray diffraction. SU-78 is an intergrowth of SU-78A and SU-78B and contains interconnected 12-ring channels in three directions. The two polymorphs are built from the same building layer, similar to that for the zeolite beta family. The layer stacking in SU-78, however, is different from those in zeolite beta polymorph A, B, and C, showing new zeolite framework topologies. SU-78 is thermally stable up to 600 °C. © 2012 American Chemical Society.

  17. Spot Pricing When Lagrange Multipliers Are Not Unique

    DEFF Research Database (Denmark)

    Feng, Donghan; Xu, Zhao; Zhong, Jin

    2012-01-01

    on multipliers cannot generate a unique clearing price. Although such situations are rare, they can cause significant uncertainties and complexities in market dispatch. In practice, this situation is solved through simple empirical methods, which may cause additional operations or biased allocation. Based...... on a strict extension of the principles of spot pricing and surplus allocation, we propose a new pricing methodology that can yield unique, impartial, and robust solution. The new method has been analyzed and compared with other pricing approaches in accordance with spot pricing theory. Case studies support......Classical spot pricing theory is based on multipliers of the primal problem of an optimal market dispatch, i.e., the solution of the dual problem. However, the dual problem of market dispatch may yield multiple solutions. In these circumstances, spot pricing or any standard pricing practice based...

  18. Dynamic effects of fiscal policy and fiscal multipliers in Croatia

    Directory of Open Access Journals (Sweden)

    Milan Deskar-Škrbić

    2013-06-01

    Full Text Available The aim of this paper is to analyze the effects of discretionary measures of fiscal policy on the economic activity and to estimate the size of fiscal multipliers in Croatia. Econometric framework is based on the structural VAR model (SVAR, with Blanchard-Perotti identification method that uses information on institutional characteristics of fiscal system. The analysis is conducted on quarterly data for total expenditures and indirect taxes of central, central consolidated and general consolidated government and aggregate demand for the period from 2004-2012. The results show that our initial assumptions about the difference in the size of the multiplier of government expenditures and indirect tax revenues between three levels of government consolidation have been confirmed.

  19. Electron collisions with phenol: Total, integral, differential, and momentum transfer cross sections and the role of multichannel coupling effects on the elastic channel

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Romarly F. da [Instituto de Física “Gleb Wataghin,” Universidade Estadual de Campinas, 13083-859 Campinas, São Paulo (Brazil); Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, 09210-580 Santo André, São Paulo (Brazil); Oliveira, Eliane M. de; Lima, Marco A. P. [Instituto de Física “Gleb Wataghin,” Universidade Estadual de Campinas, 13083-859 Campinas, São Paulo (Brazil); Bettega, Márcio H. F. [Departamento de Física, Universidade Federal do Paraná, CP 19044, 81531-990 Curitiba, Paraná (Brazil); Varella, Márcio T. do N. [Instituto de Física, Universidade de São Paulo, CP 66318, 05315-970 São Paulo, São Paulo (Brazil); Jones, Darryl B. [School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide SA 5001 (Australia); Brunger, Michael J. [School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide SA 5001 (Australia); Institute of Mathematical Sciences, University of Malaya, 50603 Kuala Lumpur (Malaysia); Blanco, Francisco [Departamento de Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid, Ciudad Universitaria, 2840 Madrid (Spain); Colmenares, Rafael [Hospital Ramón y Cajal, 28034 Madrid (Spain); and others

    2015-03-14

    We report theoretical and experimental total cross sections for electron scattering by phenol (C{sub 6}H{sub 5}OH). The experimental data were obtained with an apparatus based in Madrid and the calculated cross sections with two different methodologies, the independent atom method with screening corrected additivity rule (IAM-SCAR), and the Schwinger multichannel method with pseudopotentials (SMCPP). The SMCPP method in the N{sub open}-channel coupling scheme, at the static-exchange-plus-polarization approximation, is employed to calculate the scattering amplitudes at impact energies ranging from 5.0 eV to 50 eV. We discuss the multichannel coupling effects in the calculated cross sections, in particular how the number of excited states included in the open-channel space impacts upon the convergence of the elastic cross sections at higher collision energies. The IAM-SCAR approach was also used to obtain the elastic differential cross sections (DCSs) and for correcting the experimental total cross sections for the so-called forward angle scattering effect. We found a very good agreement between our SMCPP theoretical differential, integral, and momentum transfer cross sections and experimental data for benzene (a molecule differing from phenol by replacing a hydrogen atom in benzene with a hydroxyl group). Although some discrepancies were found for lower energies, the agreement between the SMCPP data and the DCSs obtained with the IAM-SCAR method improves, as expected, as the impact energy increases. We also have a good agreement among the present SMCPP calculated total cross section (which includes elastic, 32 inelastic electronic excitation processes and ionization contributions, the latter estimated with the binary-encounter-Bethe model), the IAM-SCAR total cross section, and the experimental data when the latter is corrected for the forward angle scattering effect [Fuss et al., Phys. Rev. A 88, 042702 (2013)].

  20. Using of the Algorithm of Lagrange Multipliers in Image Restoration

    OpenAIRE

    Stojanovic, Igor; Kraljevski, Ivan; Chungurski, Slavco

    2010-01-01

    This paper presents a method based on algorithm of Lagrange multipliers. The method is use for the removal of blur in an X-ray caused by uniform linear motion. This method assumes that linear motion corresponds to an integral number of pixels. The resolution of the restored image remains at very high level. The main contribution of the method was found on the Improvement in Signal to Noise Ration (ISNR) that has been increase significantly compared to the classic techniques.

  1. Study of multi anode photo multiplier tubes at low gains

    CERN Document Server

    Eisenhardt, S; Bibby, J; Libby, J

    2001-01-01

    We describe a preliminary study of the signal shape of the Multianode Photo Multiplier Tubes (MaPMT) at low gain. We investigate the feasibility of running the MaPMT at gains of around 30000 e which would allow to use front-end chips that have been developed for silicon detectors or micro strip gas chambers. In addition we have investigated the focusing properties of an improved design of the MaPMT.

  2. Radial multipliers on reduced free products of operator algebras

    DEFF Research Database (Denmark)

    Haagerup, Uffe; Møller, Søren

    2012-01-01

    Let AiAi be a family of unital C¿C¿-algebras, respectively, of von Neumann algebras and ¿:N0¿C¿:N0¿C. We show that if a Hankel matrix related to ¿ is trace-class, then there exists a unique completely bounded map M¿M¿ on the reduced free product of the AiAi, which acts as a radial multiplier. Her...

  3. Quantum Chemistry on the time axis: electron correlations and rearrangements on femtosecond and attosecond scales

    CERN Document Server

    Nicolaides, Cleanthes A

    2015-01-01

    Recent developments toward the production and laboratory use of pulses of high intensity, and/or of very high frequency, and/or of ultrashort duration, make possible experiments which can produce time-resolved data on ultrafast transformations involving motions of electrons. The formulation, quantitative understanding and prediction of related new phenomena entail the possibility of computing and applying solutions of the many-electron time-dependent Schroedinger equation, for arbitrary electronic structures, including the dominant effects of Rydberg series, of multiply excited states and of the multi-channel continuous spectrum. To this purpose, we have proposed and applied to many prototypical cases the state-specific expansion approach (SSEA). (Mercouris, Komninos and Nicolaides, Adv. Quantum Chem. 60, 333 (2010)). The paper explains briefly the SSEA, and outlines four of its applications to recently formulated problems concerning time-resolved electronic processes, where electron correlations are crucial....

  4. Rapid imaging of misfit dislocations in SiGe/Si in cross-section and through oxide layers using electron channeling contrast

    Science.gov (United States)

    Mukherjee, Kunal; Wacaser, Brent A.; Bedell, Stephen W.; Sadana, Devendra K.

    2017-06-01

    Electron channeling contrast imaging (ECCI) is emerging as a technique for rapid and high-resolution characterization of individual crystalline defects in a scanning electron microscope. However, the application of ECCI to semiconductor materials has been limited to bare samples in plan-view geometry. In this paper, two modalities of this technique are demonstrated with relevance to semiconductor manufacturing and failure analysis: (1) The use of ECCI to reveal misfit dislocation defects along a cleaved cross-section of a SiGe compositionally graded buffer grown on Si and (2) plan-view imaging of misfit dislocations in metamorphic SiGe/Si layers covered by amorphous oxide layers, where the partial loss of contrast due to the oxide layers is quantified and the effect of the beam accelerating voltage is studied. These results demonstrate the power of ECCI in inspecting crystallographic defects non-destructively over large areas, which is highly desirable for substrate quality control in manufacturing of products based on crystalline materials.

  5. Dual-channel cathodic electrochemiluminescence of luminol induced by injection of hot electrons on a niobate semiconductor modified electrode.

    Science.gov (United States)

    Xu, Huifeng; Ye, Hongzhi; Zhu, Xi; Liang, Shijing; Guo, Longhua; Lin, Zhenyu; Liu, Xianxiang; Chen, Guonan

    2013-01-07

    In this paper, a new niobate semiconductor photocatalyst Sr(0.4)H(1.2)Nb(2)O(6)·H(2)O (HSN) nanoparticle was applied to investigate the cathodic electrochemiluminescent (ECL) behavior of luminol for the first time. The results presented here demonstrated that there were two ECL peaks of luminol at the cathodic potential attributed to immobilization of HSN on the electrode surface. It is implied that HSN can be electrically excited and injected electrons into aqueous electrolytes from this electrode under a quite low potential that only excites luminol. A mechanism for this luminol-ECL system on HSN/GCE has been proposed. Additionally, this HSN/GCE has lots of advantages, such as high stability, good anti-interference ability, simple instrumentation, rapid procedure and ultrasensitive ECL response. It is envisioned that this HSN/GCE has further applications in biosensors.

  6. Auditing the multiply-related concepts within the UMLS.

    Science.gov (United States)

    Mougin, Fleur; Grabar, Natalia

    2014-10-01

    This work focuses on multiply-related Unified Medical Language System (UMLS) concepts, that is, concepts associated through multiple relations. The relations involved in such situations are audited to determine whether they are provided by source vocabularies or result from the integration of these vocabularies within the UMLS. We study the compatibility of the multiple relations which associate the concepts under investigation and try to explain the reason why they co-occur. Towards this end, we analyze the relations both at the concept and term levels. In addition, we randomly select 288 concepts associated through contradictory relations and manually analyze them. At the UMLS scale, only 0.7% of combinations of relations are contradictory, while homogeneous combinations are observed in one-third of situations. At the scale of source vocabularies, one-third do not contain more than one relation between the concepts under investigation. Among the remaining source vocabularies, seven of them mainly present multiple non-homogeneous relations between terms. Analysis at the term level also shows that only in a quarter of cases are the source vocabularies responsible for the presence of multiply-related concepts in the UMLS. These results are available at: http://www.isped.u-bordeaux2.fr/ArticleJAMIA/results_multiply_related_concepts.aspx. Manual analysis was useful to explain the conceptualization difference in relations between terms across source vocabularies. The exploitation of source relations was helpful for understanding why some source vocabularies describe multiple relations between a given pair of terms. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  7. Determination of Ultimate Torque for Multiply Connected Cross Section Rod

    Directory of Open Access Journals (Sweden)

    V. L. Danilov

    2015-01-01

    Full Text Available The aim of this work is to determine load-carrying capability of the multiply cross-section rod. This calculation is based on the model of the ideal plasticity of the material, so that the desired ultimate torque is a torque at which the entire cross section goes into a plastic state.The article discusses the cylindrical multiply cross-section rod. To satisfy the equilibrium equation and the condition of plasticity simultaneously, two stress function Ф and φ are introduced. By mathematical transformations it has been proved that Ф is constant along the path, and a formula to find its values on the contours has been obtained. The paper also presents the rationale of the line of stress discontinuity and obtained relationships, which allow us to derive the equations break lines for simple interaction of neighboring circuits, such as two lines, straight lines and circles, circles and a different sign of the curvature.After substitution into the boundary condition at the end of the stress function Ф and mathematical transformations a formula is obtained to determine the ultimate torque for the multiply cross-section rod.Using the doubly connected cross-section and three-connected cross-section rods as an example the application of the formula of ultimate torque is studied.For doubly connected cross-section rod, the paper offers a formula of the torque versus the radius of the rod, the aperture radius and the distance between their centers. It also clearly demonstrates the torque dependence both on the ratio of the radii and on the displacement of hole. It is shown that the value of the torque is more influenced by the displacement of hole, rather than by the ratio of the radii.For the three-connected cross-section rod the paper shows the integration feature that consists in selection of a coordinate system. As an example, the ultimate torque is found by two methods: analytical one and 3D modeling. The method of 3D modeling is based on the Nadai

  8. On Lagrange Multipliers in Work with Quality and Reliability Assurance

    DEFF Research Database (Denmark)

    Vidal, Rene Victor Valqui; Becker, P.

    1986-01-01

    In optimizing some property of a system, reliability say, a designer usually has to accept certain constraints regarding cost, completion time, volume, weight, etc. The solution of optimization problems with boundary constraints can be helped substantially by the use of Lagrange multipliers...... techniques (LMT). With representative examples of increasing complexity, the wide applicability of LMT is illustrated. Two particular features are put in focus. First, an easy to follow yet powerful new graphical approach is presented, Second, the concept of Fuller-Polya maps is shown to be helpful...

  9. Ionization and bound-state relativistic quantum dynamics in laser-driven multiply charged ions

    Energy Technology Data Exchange (ETDEWEB)

    Hetzheim, Henrik

    2009-01-14

    The interaction of ultra-strong laser fields with multiply charged hydrogen-like ions can be distinguished in an ionization and a bound dynamics regime. Both are investigated by means of numerically solving the Dirac equation in two dimensions and by a classical relativistic Monte-Carlo simulation. For a better understanding of highly nonlinear physical processes the development of a well characterized ultra-intense relativistic laser field strength has been driven forward, capable of studying e.g. the magnetic field effects of the laser resulting in an additional electron motion in the laser propagation direction. A novel method to sensitively measure these ultra-strong laser intensities is developed and employed from the optical via the UV towards the XUV frequency regime. In the bound dynamics field, the determination of multiphoton transition matrixelements has been investigated between different bound states via Rabi oscillations. (orig.)

  10. The gain in Thick GEM multipliers and its time-evolution

    CERN Document Server

    Alexeev, M; Bradamante, F; Bressan, A; Buechele, M; Chiosso, M; Ciliberti, P; Dalla Torre, S; Dasgupta, S; Denisov, O; Duic, V; Finger, M; Finger Jr, M; Fischer, H; Gobbo, B; Gregori, M; Herrmann, F; Koenigsmann, K; Levorato, S; Maggiora, A; Makke, N; Martin, A; Menon, G; Novakova, K; Novy, J; Panzieri, D; Pereira, F A; Santos, C A; Sbrizzai, G; Schiavon, P; Schopferer, S; Slunecka, M; Sozzi, F; Steiger, L; Sulc, M; Takekawa, S; Tessarotto, F; Veloso, J F C A

    2016-01-01

    In the context of a project to upgrade the gas photon detectors of COMPASS RICH-1, we have performed an R&D programme aimed to develop photon detectors based on multi-layer arrangements of thick GEM electron multipliers coupled to a CsI photoconverter. For this purpose, thick GEMs have been characterised in detail including the gain performance, its dependance on the geometrical parameters and its time-evolution, a feature exhibited by the gas detectors with open insulator surfaces. The variation due to this evolution drammatically depends on the parameters themselves. In the present article we summarise the outcomes of the studies dedicated to the thick GEM gain and its evolution versus time. We also include a qualitative model which accounts for the peculiar details of the observed thick GEM gain time-evolution.

  11. Interaction of singly and multiply charged ions with a lithium-fluoride surface

    CERN Document Server

    Wirtz, L

    2001-01-01

    Charge transfer between slow ions and an ionic crystal surface still poses a considerable challenge to theory due to the intrinsic many-body character of the system. For the neutralization of multiply charged ions in front of metal surfaces, the Classical Over the Barrier (COB) model is a widely used tool. We present an extension of this model to ionic crystal surfaces where the localization of valence electrons at the anion sites and the lack of cylindrical symmetry of the ion-surface system impede a simple analytical estimate of electron transfer rates. We use a classical trajectory Monte Carlo approach to calculate electron transfer rates for different charge states of the projectile ion. With these rates we perform a Monte Carlo simulation of the neutralization of slow Ne10+ ions in vertical incidence on an LiF surface. Capture of one or several electrons may lead to a local positive charge up of the surface. The projectile dynamics depends on the balance between the repulsion due to this charge and the a...

  12. Performance enhancement in p-channel charge-trapping flash memory devices with Si/Ge super-lattice channel and band-to-band tunneling induced hot-electron injection

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Li-Jung [Department of Engineering and System Science, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Rd., Hsinchu 30013, Taiwan, ROC (China); Chang-Liao, Kuei-Shu, E-mail: Lkschang@ess.nthu.edu.tw [Department of Engineering and System Science, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Rd., Hsinchu 30013, Taiwan, ROC (China); Jian, Yi-Chuen; Wang, Tien-Ko [Department of Engineering and System Science, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Rd., Hsinchu 30013, Taiwan, ROC (China); Tsai, Ming-Jinn [Electronics and Opto-electronics Research Laboratories, Industrial Technology Research Institute, 195, Sec. 4, Chung Hsing Rd., Chutung, Hsinchu 31040, Taiwan, ROC (China)

    2013-04-30

    P-channel charge-trapping flash memory devices with Si, SiGe, and Si/Ge super-lattice channel are investigated in this work. A Si/Ge super-lattice structure with extremely low roughness and good crystal structure is obtained by precisely controlling the epitaxy thickness of Ge layer. Both programming and erasing (P/E) speeds are significantly improved by employing this Si/Ge super-lattice channel. Moreover, satisfactory retention and excellent endurance characteristics up to 10{sup 6} P/E cycles with 3.8 V memory window show that the degradation on reliability properties is negligible when super-lattice channel is introduced. - Highlights: ► A super-lattice structure is proposed to introduce more Ge content into channel. ► Super-lattice structure possesses low roughness and good crystal structure. ► P-channel flash devices with Si, SiGe, and super-lattice channel are investigated. ► Programming/erasing speeds are significantly improved. ► Reliability properties can be kept for device with super-lattice channel.

  13. Compliant displacement-multiplying apparatus for microelectromechanical systems

    Energy Technology Data Exchange (ETDEWEB)

    Kota, Sridhar (9391 Quail Ridge Run, Brighton, MI 48114); Rodgers, M. Steven (12216 Papaya Ct., NE., Albuquerque, NM 87111); Hetrick, Joel A. (818 S. Gammon, Apartment 4, Madison, WI 53719)

    2001-01-01

    A pivotless compliant structure is disclosed that can be used to increase the geometric advantage or mechanical advantage of a microelectromechanical (MEM) actuator such as an electrostatic comb actuator, a capacitive-plate electrostatic actuator, or a thermal actuator. The compliant structure, based on a combination of interconnected flexible beams and cross-beams formed of one or more layers of polysilicon or silicon nitride, can provide a geometric advantage of from about 5:1 to about 60:1 to multiply a 0.25-3 .mu.m displacement provided by a short-stroke actuator so that such an actuator can be used to generate a displacement stroke of about 10-34 .mu.m to operate a ratchet-driven MEM device or a microengine. The compliant structure has less play than conventional displacement-multiplying devices based on lever arms and pivoting joints, and is expected to be more reliable than such devices. The compliant structure and an associated electrostatic or thermal actuator can be formed on a common substrate (e.g. silicon) using surface micromachining.

  14. The stoichiometry of the TMEM16A ion channel determined in intact plasma membranes of COS-7 cells using liquid-phase electron microscopy.

    Science.gov (United States)

    Peckys, Diana B; Stoerger, Christof; Latta, Lorenz; Wissenbach, Ulrich; Flockerzi, Veit; de Jonge, Niels

    2017-08-01

    TMEM16A is a membrane protein forming a calcium-activated chloride channel. A homodimeric stoichiometry of the TMEM16 family of proteins has been reported but an important question is whether the protein resides always in a dimeric configuration in the plasma membrane or whether monomers of the protein are also present in its native state within in the intact plasma membrane. We have determined the stoichiometry of the human (h)TMEM16A within whole COS-7 cells in liquid. For the purpose of detecting TMEM16A subunits, single proteins were tagged by the streptavidin-binding peptide within extracellular loops accessible by streptavidin coated quantum dot (QD) nanoparticles. The labeled proteins were then imaged using correlative light microscopy and environmental scanning electron microscopy (ESEM) using scanning transmission electron microscopy (STEM) detection. The locations of 19,583 individual proteins were determined of which a statistical analysis using the pair correlation function revealed the presence of a dimeric conformation of the protein. The amounts of detected label pairs and single labels were compared between experiments in which the TMEM16A SBP-tag position was varied, and experiments in which tagged and non-tagged TMEM16A proteins were present. It followed that hTMEM16A resides in the plasma membrane as dimer only and is not present as monomer. This strategy may help to elucidate the stoichiometry of other membrane protein species within the context of the intact plasma membrane in future. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Enhancement of absorption and resistance of motion utilizing a multi-channel opto-electronic sensor to effectively monitor physiological signs during sport exercise

    Science.gov (United States)

    Alzahrani, Abdullah; Hu, Sijung; Azorin-Peris, Vicente; Barrett, Laura; Esliger, Dale; Hayes, Matthew; Akbare, Shafique; Achart, Jérôme; Kuoch, Sylvain

    2015-03-01

    This study presents an effective engineering approach for human vital signs monitoring as increasingly demanded by personal healthcare. The aim of this work is to study how to capture critical physiological parameters efficiently through a well-constructed electronic system and a robust multi-channel opto-electronic patch sensor (OEPS), together with a wireless communication. A unique design comprising multi-wavelength illumination sources and a rapid response photo sensor with a 3-axis accelerometer enables to recover pulsatile features, compensate motion and increase signal-to-noise ratio. An approved protocol with designated tests was implemented at Loughborough University a UK leader in sport and exercise assessment. The results of sport physiological effects were extracted from the datasets of physical movements, i.e. sitting, standing, waking, running and cycling. t-test, Bland-Altman and correlation analysis were applied to evaluate the performance of the OEPS system against Acti-Graph and Mio-Alpha.There was no difference in heart rate measured using OEPS and both Acti-Graph and Mio-Alpha (both p<0.05). Strong correlations were observed between HR measured from the OEPS and both the Acti-graph and Mio-Alpha (r = 0.96, p<0.001). Bland-Altman analysis for the Acti-Graph and OEPS found the bias 0.85 bpm, the standard deviation 9.20 bpm, and the limits of agreement (LOA) -17.18 bpm to +18.88 bpm for lower and upper limits of agreement respectively, for the Mio-Alpha and OEPS the bias is 1.63 bpm, standard deviation SD8.62 bpm, lower and upper limits of agreement, - 15.27 bpm and +18.58 bpm respectively. The OEPS demonstrates a real time, robust and remote monitoring of cardiovascular function.

  16. Diamond Heat-Spreader for Submillimeter-Wave Frequency Multipliers

    Science.gov (United States)

    Lin, Robert H.; Schlecht, Erich T.; Chattopadhyay, Goutam; Gill, John J.; Mehdi, Imran; Siegel, Peter H.; Ward, John S.; Lee, Choonsup; Thomas, Bertrand C.; Maestrini, Alain

    2010-01-01

    The planar GaAs Shottky diode frequency multiplier is a critical technology for the local oscillator (LO) for submillimeter- wave heterodyne receivers due to low mass, tenability, long lifetime, and room-temperature operation. The use of a W-band (75-100 GHz) power amplifier followed by a frequency multiplier is the most common for submillimeter-wave sources. Its greatest challenge is to provide enough input power to the LO for instruments onboard future planetary missions. Recently, JPL produced 800 mW at 92.5 GHz by combining four MMICs in parallel in a balanced configuration. As more power at W-band is available to the multipliers, their power-handling capability be comes more important. High operating temperatures can lead to degradation of conversion efficiency or catastrophic failure. The goal of this innovation is to reduce the thermal resistance by attaching diamond film as a heat-spreader on the backside of multipliers to improve their power-handling capability. Polycrystalline diamond is deposited by hot-filament chemical vapor deposition (CVD). This diamond film acts as a heat-spreader to both the existing 250- and 300-GHz triplers, and has a high thermal conductivity (1,000-1,200 W/mK). It is approximately 2.5 times greater than copper (401 W/mK) and 20 times greater than GaAs (46 W/mK). It is an electrical insulator (resistivity approx. equals 10(exp 15) Ohms-cm), and has a low relative dielectric constant of 5.7. Diamond heat-spreaders reduce by at least 200 C at 250 mW of input power, compared to the tripler without diamond, according to thermal simulation. This superior thermal management provides a 100-percent increase in power-handling capability. For example, with this innovation, 40-mW output power has been achieved from a 250-GHz tripler at 350-mW input power, while the previous triplers, without diamond, suffered catastrophic failures. This breakthrough provides a stepping-stone for frequency multipliers-based LO up to 3 THz. The future work

  17. Measurement of the production cross section for W + γ in the electron channel in √s = 1.8 TeV $\\bar{p}$p collisions

    Energy Technology Data Exchange (ETDEWEB)

    Benjamin, Douglas P. [Tufts Univ., Medford, MA (United States)

    1993-11-01

    The production cross section times decay branching ratio for W+ γ in the electron decay channel in √s = 1.8 TeV $\\bar{p}$-p collisions has been measured using W → eγ data sample obtained from the CDF 1988--1989 Tevatron collider run. For photons in the central region ($\\bar{η}$$\\bar{γ}$ < 1.1) of the CDF detector with transverse energies E$T\\atop{γ}$ 5.0 GeV and lepton-photon angular separation ΔRℓγ > 0.7, eight electron Wγ candidates were observed. From these events, the production cross section times decay branching ratio for the electron sample was measured to be a σ • B(Wγ)exp = 17.0$+13.6\\atop{-13.4}$(stat. + syst.)pb. The Wγ cross section is sensitive to the anomalous couplings of the W boson. Using the Wγ cross section measurement, the absence of an excess of large ET photons accompanying the production of a W boson enables one to obtain direct limits on anomalous WWγ couplings. The experimental limits on the anomalous couplings was measured to be -7.2 < Δκ < +7.7 (λ = 0) and -3.5 < λ < +3.4 (Δκ = 0) at 95% CL. These experimental limits impose contraints on possible internal structure of the W boson with compositeness scale sensitivity ΛW ≥ 1 TeV for saturation of unitarity, corresponding to probing a distance scale of order LW ≤ 2.0 x 10-4 fm. The experimental limits on anomalous WWγ couplings place bounds on the higher-order electromagnetic moments of the W boson -- the magnetic dipole and electric quadrupole moments and the W boson mean-squared charge radius. The experimental results presented in this thesis are in good agreement with Standard Model expectations.

  18. Array Multipliers for High Throughput in Xilinx FPGAs with 6-Input LUTs

    Directory of Open Access Journals (Sweden)

    E. George Walters

    2016-09-01

    Full Text Available Multiplication is the dominant operation for many applications implemented on field-programmable gate arrays (FPGAs. Although most current FPGA families have embedded hard multipliers, soft multipliers using lookup tables (LUTs in the logic fabric remain important. This paper presents a novel two-operand addition circuit (patent pending that combines radix-4 partial-product generation with addition and shows how it can be used to implement two’s-complement array multipliers. The circuit is specific to modern Xilinx FPGAs that are based on a 6-input LUT architecture. Proposed pipelined multipliers use 42%–52% fewer LUTs, and some versions can be clocked up to 23% faster than delay-optimized LogiCORE IP multipliers. This allows 1.72–2.10-times as many multipliers to be implemented in the same logic fabric and potentially offers 1.86–2.58-times the throughput by increasing the clock frequency.

  19. Deflation Expectation Financial System and Decline in Money Multiplier(in Japanese)

    OpenAIRE

    IIDA Yasuyuki

    2005-01-01

    The money multiplier is in a continuous downward trend now since the bubble burst, and, in addition, the trend has accelerated after 2000. It is said that the monetary policy is difficult because the money multiplier has declined. To think about the monetary policy for the future, we should think about the cause of the decline of the money multiplier. I want to verify two typical hypotheses "Deflation Expectation Hypothesis" and "Financial System Hypothesis" for the decision of the money mult...

  20. Extended generalized Lagrangian multipliers for magnetohydrodynamics using adaptive multiresolution methods

    Directory of Open Access Journals (Sweden)

    Domingues M. O.

    2013-12-01

    Full Text Available We present a new adaptive multiresoltion method for the numerical simulation of ideal magnetohydrodynamics. The governing equations, i.e., the compressible Euler equations coupled with the Maxwell equations are discretized using a finite volume scheme on a two-dimensional Cartesian mesh. Adaptivity in space is obtained via Harten’s cell average multiresolution analysis, which allows the reliable introduction of a locally refined mesh while controlling the error. The explicit time discretization uses a compact Runge–Kutta method for local time stepping and an embedded Runge-Kutta scheme for automatic time step control. An extended generalized Lagrangian multiplier approach with the mixed hyperbolic-parabolic correction type is used to control the incompressibility of the magnetic field. Applications to a two-dimensional problem illustrate the properties of the method. Memory savings and numerical divergences of magnetic field are reported and the accuracy of the adaptive computations is assessed by comparing with the available exact solution.

  1. Electromagnetic Radiation in Multiply Connected Robertson-Walker Cosmologies

    CERN Document Server

    Tomaschitz, R

    1993-01-01

    Maxwell's equations on a topologically nontrivial cosmological background are studied. The cosmology is locally determined by a Robertson-Walker line element, but the spacelike slices are open hyperbolic manifolds, whose topology and geometry may vary in time. In this context the spectral resolution of Maxwell's equations in terms of horospherical elementary waves generated at infinity of hyperbolic space is given. The wave fronts are orthogonal to bundles of unstable geodesic rays, and the eikonal of geometric optics appears just as the phase of the horospherical waves. This fact is used to attach to the unstable geodesic rays a quantum mechanical momentum. In doing so the quantized energy-momentum tensor of the radiation field is constructed in a geometrically and dynamically transparent way, without appealing to the intricacies of the second quantization. In particular Planck's radiation formula, and the bearing of the multiply connected topology on the fluctuations in the temperature of the background rad...

  2. Evaluation of interventions to reduce multiply controlled vocal stereotypy.

    Science.gov (United States)

    Scalzo, Rachel; Henry, Kelsey; Davis, Tonya N; Amos, Kally; Zoch, Tamara; Turchan, Sarah; Wagner, Tara

    2015-07-01

    This study examined four interventions targeted at decreasing multiply controlled vocal stereotypy for a 12-year-old boy diagnosed with autism spectrum disorder and a severe intellectual disability. These interventions included Noncontingent Music, Differential Reinforcement of Other Behaviors, Self-Recording, and Functional Communication Training (FCT). In addition to measuring vocal stereotypy during each condition, task engagement and challenging behavior were also monitored. Across conditions, vocal stereotypy did not vary significantly from baseline except in FCT, when it decreased significantly. Task engagement was higher in this condition as well. It is hypothesized that FCT provided an enriched environment by increasing social interaction and access to desired items as well as removal of less preferred activities. For these reasons, there was a decrease in the need for the participant to engage in vocal stereotypy and challenging behavior and increase in his ability to engage in a task. © The Author(s) 2015.

  3. Lagrange multiplier for perishable inventory model considering warehouse capacity planning

    Science.gov (United States)

    Amran, Tiena Gustina; Fatima, Zenny

    2017-06-01

    This paper presented Lagrange Muktiplier approach for solving perishable raw material inventory planning considering warehouse capacity. A food company faced an issue of managing perishable raw materials and marinades which have limited shelf life. Another constraint to be considered was the capacity of the warehouse. Therefore, an inventory model considering shelf life and raw material warehouse capacity are needed in order to minimize the company's inventory cost. The inventory model implemented in this study was the adapted economic order quantity (EOQ) model which is optimized using Lagrange multiplier. The model and solution approach were applied to solve a case industry in a food manufacturer. The result showed that the total inventory cost decreased 2.42% after applying the proposed approach.

  4. Strength of the reversible, garbage-free 2 k ±1 multiplier

    DEFF Research Database (Denmark)

    Rotenberg, Eva; Cranch, James; Thomsen, Michael Kirkedal

    2013-01-01

    Recently, a reversible garbage-free 2 k ±1 constant-multiplier circuit was presented by Axelsen and Thomsen. This was the first construction of a garbage-free, reversible circuit for multiplication with non-trivial constants. At the time, the strength, that is, the range of constants obtainable...... by cascading these circuits, was unknown. In this paper, we show that there exist infinitely many constants we cannot multiply by using cascades of 2 k ±1-multipliers; in fact, there exist infinitely many primes we cannot multiply by. Using these results, we further provide an algorithm for determining whether...

  5. A study on the geometry of dislocation patterns in the surrounding of nanoindents in a TWIP steel using electron channeling contrast imaging and discrete dislocation dynamics simulations

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, J.-I.; Zaefferer, S., E-mail: s.zaefferer@mpie.de; Raabe, D.

    2015-06-11

    Electron channeling contrast imaging under controlled diffraction conditions (cECCI) enables observation of crystal defects, especially dislocations, stacking faults and nano-twins, close to the surface of bulk samples. In this work cECCI has been employed to observe defects around nanoindents into the surface of {100}-, {110}-, {111}-oriented grains in a Fe–22Mn–0.65C (wt%) TWIP steel sample (fcc crystal structure, stacking fault energy ~20 mJ/m²) using a cone-spherical indenter. The dislocation patterns show four- and two-fold symmetries for the {100}- and {110}-orientation, and a three-fold symmetry for the {111}-orientation which is, however, difficult to observe. Discrete dislocation dynamics (DDD) simulations of the indentation were carried out to complement the static experimental investigations. The simulations were carried out with both, cross-slip disabled and enabled conditions, where the former were found to match to the experimental results better, as may be expected for an fcc material with low stacking fault energy. The 3-dimensional geometry of the dislocation patterns of the different indents was analysed and discussed with respect to pattern formation mechanisms. The force–displacement curves obtained during indentation showed a stronger strain hardening for the {111} oriented crystal than that for the other orientations. This is in contrast to the behaviour of, for example, copper and is interpreted to be due to planar slip. Irrespective of orientation and indentation depth the radius of the plastically deformed area was found to be approximately 4 times larger than that of the indenter contact area.

  6. High-harmonic electron bunching in the field of a signal wave and the use of this effect in cyclotron masers with frequency multiplication

    Directory of Open Access Journals (Sweden)

    I. V. Bandurkin

    2005-01-01

    Full Text Available A method of organizing electron-wave interaction at the multiplied frequency of the signal wave is proposed. This type of electron-wave interaction provides multiplied-frequency electron bunching, which leads to formation of an intense harmonic of the electron current at a selected multiplied frequency of the signal wave. This effect is attractive for the use in klystron-type cyclotron masers with frequency multiplication as a way to increase the output frequency and improve the selectivity.

  7. Relations between bilinear multipliers on Rn,Tn Rn,Tn Rn,Tn and Zn ...

    Indian Academy of Sciences (India)

    Carro and Gillespie [5] and Grafakos [11]. Also, for some other transference results in the bilinear setting, see [2, 3] and [6]. In the same paper de Leeuw observed that periodic multipliers on R are precisely the ones which are multipliers on Z and vice versa. In §3 we investigate the bilinear analogue of these results.

  8. On-Chip Power-Combining for High-Power Schottky Diode Based Frequency Multipliers

    Science.gov (United States)

    Siles Perez, Jose Vicente (Inventor); Chattopadhyay, Goutam (Inventor); Lee, Choonsup (Inventor); Schlecht, Erich T. (Inventor); Jung-Kubiak, Cecile D. (Inventor); Mehdi, Imran (Inventor)

    2015-01-01

    A novel MMIC on-chip power-combined frequency multiplier device and a method of fabricating the same, comprising two or more multiplying structures integrated on a single chip, wherein each of the integrated multiplying structures are electrically identical and each of the multiplying structures include one input antenna (E-probe) for receiving an input signal in the millimeter-wave, submillimeter-wave or terahertz frequency range inputted on the chip, a stripline based input matching network electrically connecting the input antennas to two or more Schottky diodes in a balanced configuration, two or more Schottky diodes that are used as nonlinear semiconductor devices to generate harmonics out of the input signal and produce the multiplied output signal, stripline based output matching networks for transmitting the output signal from the Schottky diodes to an output antenna, and an output antenna (E-probe) for transmitting the output signal off the chip into the output waveguide transmission line.

  9. Improved 64-bit Radix-16 Booth Multiplier Based on Partial Product Array Height Reduction

    DEFF Research Database (Denmark)

    Antelo, Elisardo; Montuschi, Paolo; Nannarelli, Alberto

    2016-01-01

    In this paper, we describe an optimization for binary radix-16 (modified) Booth recoded multipliers to reduce the maximum height of the partial product columns to n/4 for [Formula: see text] unsigned operands. This is in contrast to the conventional maximum height of (n+1)/4. Therefore......, a reduction of one unit in the maximum height is achieved. This reduction may add flexibility during the design of the pipelined multiplier to meet the design goals, it may allow further optimizations of the partial product array reduction stage in terms of area/delay/power and/or may allow additional addends...... to be included in the partial product array without increasing the delay. The method can be extended to Booth recoded radix-8 multipliers, signed multipliers, combined signed/unsigned multipliers, and other values of n....

  10. Upgrading PhotoMultiplier Tube bases for FNAL E1039

    Science.gov (United States)

    Salinas, Roy; SeaQuest Collaboration

    2017-09-01

    Experiment 1039 at Fermilab National Laboratory is designed to study the spin structure within the nucleon. To effectively work towards a better understanding of the ``spin crisis'' concerning the quarks and gluons within the nucleon, E1039 will employ a polarized target and a 120 GeV proton beam. The E906/SeaQuest spectrometer will be reused for E1039 since it was designed to measure Drell-Yan events from interactions with quarks in the nucleon sea. The spectrometer consists of several detectors with multiple planes of scintillating hodoscopes, tracking chambers, and two large dipole magnets. An issue arose in the later stages of Experiment 906 regarding the scintillating PhotoMultiplier Tubes(PMTs) high current bases for the first two hodoscope stations. Heat produced in the PMT bases created damage to components on the primary circuit board resulting in failures after years of running. Multiple solutions focused on thermally connecting the daughter cards to the metal shielding pipe while also providing electrical isolation of the high voltages present. Comparisons of thermally conductive adhesive and epoxy were studied with several heat spreaders. This poster will cover the options considered and the chosen solution to the upgrade to the hodoscope PMT bases. Supported by U.S. D.O.E. Medium Energy Nuclear Physics under Grant DE-FG02-03ER41243.

  11. Time-division-multiplex control scheme for voltage multiplier rectifiers

    Directory of Open Access Journals (Sweden)

    Bin-Han Liu

    2017-03-01

    Full Text Available A voltage multiplier rectifier with a novel time-division-multiplexing (TDM control scheme for high step-up converters is proposed in this study. In the proposed TDM control scheme, two full-wave voltage doubler rectifiers can be combined to realise a voltage quadrupler rectifier. The proposed voltage quadrupler rectifier can reduce transformer turn ratio and transformer size for high step-up converters and also reduce voltage stress for the output capacitors and rectifier diodes. An N-times voltage rectifier can be straightforwardly produced by extending the concepts from the proposed TDM control scheme. A phase-shift full-bridge (PSFB converter is adopted in the primary side of the proposed voltage quadrupler rectifier to construct a PSFB quadrupler converter. Experimental results for the PSFB quadrupler converter demonstrate the performance of the proposed TDM control scheme for voltage quadrupler rectifiers. An 8-times voltage rectifier is simulated to determine the validity of extending the proposed TDM control scheme to realise an N-times voltage rectifier. Experimental and simulation results show that the proposed TDM control scheme has great potential to be used in high step-up converters.

  12. On an Integrated Transfer Matrix method for multiply connected mufflers

    Science.gov (United States)

    Vijayasree, N. K.; Munjal, M. L.

    2012-04-01

    The commercial automotive mufflers are generally of a complicated shape with multiply connected parts and complex acoustic elements. The analysis of such complex mufflers has always been a great challenge. In this paper, an Integrated Transfer Matrix method has been developed to analyze complex mufflers. Integrated transfer matrix relates the state variables across the entire cross-section of the muffler shell, as one moves along the axis of the muffler, and can be partitioned appropriately in order to relate the state variables of different tubes constituting the cross-section. The paper presents a generalized one-dimensional (1-D) approach, using the transfer matrices of simple acoustic elements, which are available from the literature. The present approach is robust and flexible owing to its capability to construct an overall matrix of the muffler with the transfer matrices of individual acoustic elements and boundary conditions, which can then be used to evaluate the transmission loss, insertion loss, etc. Results from the present approach have been validated through comparisons with the available experimental and three-dimensional finite element method (FEM) based results. The results show good agreement with both measurements and FEM analysis up to the cut-off frequency.

  13. Multiply-Imputed Synthetic Data: Advice to the Imputer

    Directory of Open Access Journals (Sweden)

    Loong Bronwyn

    2017-12-01

    Full Text Available Several statistical agencies have started to use multiply-imputed synthetic microdata to create public-use data in major surveys. The purpose of doing this is to protect the confidentiality of respondents’ identities and sensitive attributes, while allowing standard complete-data analyses of microdata. A key challenge, faced by advocates of synthetic data, is demonstrating that valid statistical inferences can be obtained from such synthetic data for non-confidential questions. Large discrepancies between observed-data and synthetic-data analytic results for such questions may arise because of uncongeniality; that is, differences in the types of inputs available to the imputer, who has access to the actual data, and to the analyst, who has access only to the synthetic data. Here, we discuss a simple, but possibly canonical, example of uncongeniality when using multiple imputation to create synthetic data, which specifically addresses the choices made by the imputer. An initial, unanticipated but not surprising, conclusion is that non-confidential design information used to impute synthetic data should be released with the confidential synthetic data to allow users of synthetic data to avoid possible grossly conservative inferences.

  14. The Distribution of Lightning Channel Lengths in Northern Alabama Thunderstorms

    Science.gov (United States)

    Peterson, H. S.; Koshak, W. J.

    2010-01-01

    Lightning is well known to be a major source of tropospheric NOx, and in most cases is the dominant natural source (Huntreiser et al 1998, Jourdain and Hauglustaine 2001). Production of NOx by a segment of a lightning channel is a function of channel segment energy density and channel segment altitude. A first estimate of NOx production by a lightning flash can be found by multiplying production per segment [typically 104 J/m; Hill (1979)] by the total length of the flash s channel. The purpose of this study is to determine average channel length for lightning flashes near NALMA in 2008, and to compare average channel length of ground flashes to the average channel length of cloud flashes.

  15. Permeability criteria for effective function of passive countercurrent multiplier.

    Science.gov (United States)

    Layton, H E; Knepper, M A; Chou, C L

    1996-01-01

    The urine concentrating effect of the mammalian renal inner medulla has been attributed to countercurrent multiplication of a transepithelial osmotic difference arising from passive absorption of NaCl from thin ascending limbs of long loops of Henle. This study assesses, both mathematically and experimentally, whether the permeability criteria for effective function of this passive hypothesis are consistent with transport properties measured in long loops of Henle of chinchilla. Mathematical simulations incorporating loop of Henle transepithelial permeabilities idealized for the passive hypothesis generated a steep inner medullary osmotic gradient, confirming the fundamental feasibility of the passive hypothesis. However, when permeabilities measured in chinchilla were used, no inner medullary gradient was generated. A key parameter in the apparent failure of the passive hypothesis is the long-loop descending limb (LDL) urea permeability, which must be small to prevent significant transepithelial urea flux into inner medullary LDL. Consequently, experiments in isolated perfused thin LDL were conducted to determine whether the urea permeability may be lower under conditions more nearly resembling those in the inner medulla. LDL segments were dissected from 30-70% of the distance along the inner medullary axis of the chinchilla kidney. The factors tested were NaCl concentration (125-400 mM in perfusate and bath), urea concentration (5-500 mM in perfusate and bath), calcium concentration (2-8 mM in perfusate and bath), and protamine concentration (300 micrograms/ml in perfusate). None of these factors significantly altered the measured urea permeability, which exceeded 20 x 10(-5) cm/s for all conditions. Simulation results show that this moderately high urea permeability in LDL is an order of magnitude too high for effective operation of the passive countercurrent multiplier.

  16. Configurable multiplier modules for an adaptive computing system

    Directory of Open Access Journals (Sweden)

    O. A. Pfänder

    2006-01-01

    Full Text Available The importance of reconfigurable hardware is increasing steadily. For example, the primary approach of using adaptive systems based on programmable gate arrays and configurable routing resources has gone mainstream and high-performance programmable logic devices are rivaling traditional application-specific hardwired integrated circuits. Also, the idea of moving from the 2-D domain into a 3-D design which stacks several active layers above each other is gaining momentum in research and industry, to cope with the demand for smaller devices with a higher scale of integration. However, optimized arithmetic blocks in course-grain reconfigurable arrays as well as field-programmable architectures still play an important role. In countless digital systems and signal processing applications, the multiplication is one of the critical challenges, where in many cases a trade-off between area usage and data throughput has to be made. But the a priori choice of word-length and number representation can also be replaced by a dynamic choice at run-time, in order to improve flexibility, area efficiency and the level of parallelism in computation. In this contribution, we look at an adaptive computing system called 3-D-SoftChip to point out what parameters are crucial to implement flexible multiplier blocks into optimized elements for accelerated processing. The 3-D-SoftChip architecture uses a novel approach to 3-dimensional integration based on flip-chip bonding with indium bumps. The modular construction, the introduction of interfaces to realize the exchange of intermediate data, and the reconfigurable sign handling approach will be explained, as well as a beneficial way to handle and distribute the numerous required control signals.

  17. The Origins of the SPAR-H Method's Performance Shaping Factor Multipliers

    Energy Technology Data Exchange (ETDEWEB)

    Ronald L. Boring; Harold S. Blackman

    2007-08-01

    The Standardized Plant Analysis Risk-Human Reliability Analysis (SPAR-H) method has proved to be a reliable, easy-to-use method for human reliability analysis. Calculation of human error probability (HEP) rates is especially straightforward, starting with pre-defined nominal error rates for cognitive vs. action oriented tasks, and incorporating performance shaping factor (PSF) multipliers upon those nominal error rates. SPAR-H uses eight PSFs with multipliers typically corresponding to nominal, degraded, and severely degraded human performance for individual PSFs. Additionally, some PSFs feature multipliers to reflect enhanced performance. Although SPAR-H enjoys widespread use among industry and regulators, current source documents on SPAR-H such as NUREG/CR-6883 do not provide a clear account of the origin of these multipliers. The present paper redresses this shortcoming and documents the historic development of the SPAR-H PSF multipliers, from the initial use of nominal error rates, to the selection of the eight PSFs, to the mapping of multipliers to available data sources such as a Technique for Human Error Rate Prediction (THERP). Where error rates were not readily derived from THERP and other sources, expert judgment was used to extrapolate appropriate values. In documenting key background information on the multipliers, this paper provides a much needed cross-reference for human reliability practitioners and researchers of SPAR-H to validate analyses and research findings.

  18. Effect of the equity multiplier indicator in companies according the sectors

    Directory of Open Access Journals (Sweden)

    Lenka Lízalová

    2013-01-01

    Full Text Available Managers carry out the demand of the owners to maximise the rentability of invested capital with regards to the taken risk. The tool that evaluates the suitability to indebt in order to reach a higher rentability is the equity multiplier indicator. An analysis of the multiplier was carried out on 10 years of data from 456 Czech companies. Based on the data from these companies the influence of two components of the multiplier, which characterise the influence of indebtedness on the return on equity, was analysed. These components are “financial leverage” and “interest burden”, these having an antagonistic effect. The low variability of the equity multiplier is apparent in the companies of the administrative and support service sector and it is also relatively low in the companies of the agriculture, forestry and fishing sector; on the contrary, in for example the professional, scientific and technical activities and the sector of water, sewage and waste there are companies with higher variability of the equity multiplier. The paper identifies companies (in view of their sector specialization inclining to a larger utility of debts to increase the return on equity. The largest equity is reached in companies of the construction sector; the lowest effect of the multiplier is to be found in companies of the agriculture sector. The resulting value of the multiplier is to a large extent determined by the financial leverage indicator, to a lower extent and at the same time negatively by the interest burden indicator.

  19. Analysis of multiplier effects of ICT sectors – a Croatian case

    Directory of Open Access Journals (Sweden)

    Damira Keček

    2016-04-01

    Full Text Available The impact of Information and Communication Technology (ICT on economic growth and development has nowadays proven to be significant for almost all national economies. In this paper, a quantitative analysis of the impact of ICT on Croatian economic growth is performed using the input-output (IO method. The direct and indirect effects of ICT sectors are analysed. Subsequently, simple output multipliers and simple value added multipliers are then calculated. The results indicate that there are no significant differences between the ICT multipliers for the Croatian economy in 2010 and multipliers of other sectors. The largest values of multipliers of all ICT sectors are attributed to the one of ICT service sector. Moreover, significant changes were also not observed when comparing ICT multipliers for the Croatian economy in 2004 and 2010. In addition to Croatia, multiplier analysis of ICT sectors was conducted for the group of new and long-standing European Union member states. The conclusion is that, in new member states, the implementation and usage of ICT has a lower contribution to economic growth and development.

  20. A study of Channeling, Volume Reflection and Volume Capture of 3.35 - 14.0 GeV Electrons in a bent Silicon Crystal

    Energy Technology Data Exchange (ETDEWEB)

    Wistisen, T. N. [Aarhus Univ. (Denmark); Uggerhoj, U. I. [Aarhus Univ. (Denmark); Wienands, U. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Markiewicz, T. W. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Noble, R. J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Benson, B. L. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Smith, T. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Bagli, E. [Univ. of Ferrara (Italy); Bandiera, L. [Univ. of Ferrara (Italy); Germogli, G. [Univ. of Ferrara (Italy); Guidi, V. [Univ. of Ferrara (Italy); Mazzolari, A. [Univ. of Ferrara (Italy); Holtzapple, R. [California Polytechnic State Univ. (CalPoly), San Luis Obispo, CA (United States); Tucker, S. [California Polytechnic State Univ. (CalPoly), San Luis Obispo, CA (United States)

    2015-12-03

    We present the experimental data and analysis of experiments conducted at SLAC National Accelerator Laboratory investigating the processes of channeling, volume-reflection and volume-capture along the (111) plane in a strongly bent quasi-mosaic silicon crystal. Additionally, these phenomena were investigated at 5 energies: 3.35, 4.2, 6.3, 10.5 and 14.0 GeV with a crystal with bending radius of 0.15m, corresponding to curvatures of 0.070, 0.088, 0.13, 0.22 and 0.29 times the critical curvature respectively. We have extracted important parameters describing the channeling process such as the dechanneling length, the angle of volume reflection, the surface transmission and the widths of the distribution of channeled particles parallel and orthogonal to the plane.

  1. A two-dimensional fully analytical model with polarization effect for off-state channel potential and electric field distributions of GaN-based field-plated high electron mobility transistor

    Science.gov (United States)

    Mao, Wei; She, Wei-Bo; Yang, Cui; Zhang, Chao; Zhang, Jin-Cheng; Ma, Xiao-Hua; Zhang, Jin-Feng; Liu, Hong-Xia; Yang, Lin-An; Zhang, Kai; Zhao, Sheng-Lei; Chen, Yong-He; Zheng, Xue-Feng; Hao, Yue

    2014-08-01

    In this paper, we present a two-dimensional (2D) fully analytical model with consideration of polarization effect for the channel potential and electric field distributions of the gate field-plated high electron mobility transistor (FP-HEMT) on the basis of 2D Poisson's solution. The dependences of the channel potential and electric field distributions on drain bias, polarization charge density, FP structure parameters, AlGaN/GaN material parameters, etc. are investigated. A simple and convenient approach to designing high breakdown voltage FP-HEMTs is also proposed. The validity of this model is demonstrated by comparison with the numerical simulations with Silvaco—Atlas. The method in this paper can be extended to the development of other analytical models for different device structures, such as MIS-HEMTs, multiple-FP HETMs, slant-FP HEMTs, etc.

  2. CORDIC TECHNIQUES FOR FIXED ANGLE OF ROTATION IN MULTIPLYING OPERATION OF QUATERNIONS

    Directory of Open Access Journals (Sweden)

    N. A. Petrovsky

    2015-01-01

    Full Text Available The article contains a number of solutions for the key element of paraunitary filter banks based on quaternionic algebra (Q-PUBF – the multiplier of quaternions with usage of CORDIC (Coordinate Rotation Digital Computer techniques for the fixed angle of rotation where, unlike known solutions, 4D rotation control parameters are represented by nonlinear function of shifts number of input operands of the microrotation operation. Suggested approach of the multiplier designing on a quaternion-constant allows reaching the maximum performance of the multiplier scheme with low use of resources, for example, of FPGA.

  3. Implementation gap between the theory and practice of biodiversity offset multipliers

    DEFF Research Database (Denmark)

    Bull, Joseph William; Lloyd, Samuel P.; Strange, Niels

    2017-01-01

    Emerging policies worldwide require biodiversity gains as compensation for losses associated with economic development, seeking to achieve “no net loss” (NNL). Multipliers – factors by which gains are larger than associated losses – can be crucial for true NNL. Here, we review the theoretical...... when considering, for example, ecological uncertainties. We propose even larger multipliers required to satisfy previously ignored considerations – including prospect theory, taboo trades, and power relationships. Conversely, our data analyses show that multipliers are smaller in practice, regularly...

  4. Efeitos multiplicadores da economia florestal brasileira Multiplier effects of the Brazilian forestry economy

    Directory of Open Access Journals (Sweden)

    Sebastião Renato Valverde

    2003-06-01

    contributing for the generation of these indicators, when one extra monetary unit is spent by the final consumers demanding for products of this particular sector. The results showed that forestry is one of the Brazilian economic sectors presenting the greatest multiplying effects for the social-economic indicators. It surpassed other sectors such as the automobilistic electric and electronic, machinery and equipment and chemicals and petroleum industries.

  5. Multiply Surface-Functionalized Nanoporous Carbon for Vehicular Hydrogen Storage

    Energy Technology Data Exchange (ETDEWEB)

    Pfeifer, Peter [Univ. of Missouri, Columbia, MO (United States). Dept. of Physics; Gillespie, Andrew [Univ. of Missouri, Columbia, MO (United States). Dept. of Physics; Stalla, David [Univ. of Missouri, Columbia, MO (United States). Dept. of Physics; Dohnke, Elmar [Univ. of Missouri, Columbia, MO (United States). Dept. of Physics

    2017-02-20

    The purpose of the project “Multiply Surface-Functionalized Nanoporous Carbon for Vehicular Hydrogen Storage” is the development of materials that store hydrogen (H2) by adsorption in quantities and at conditions that outperform current compressed-gas H2 storage systems for electric power generation from hydrogen fuel cells (HFCs). Prominent areas of interest for HFCs are light-duty vehicles (“hydrogen cars”) and replacement of batteries with HFC systems in a wide spectrum of applications, ranging from forklifts to unmanned areal vehicles to portable power sources. State-of-the-art compressed H2 tanks operate at pressures between 350 and 700 bar at ambient temperature and store 3-4 percent of H2 by weight (wt%) and less than 25 grams of H2 per liter (g/L) of tank volume. Thus, the purpose of the project is to engineer adsorbents that achieve storage capacities better than compressed H2 at pressures less than 350 bar. Adsorption holds H2 molecules as a high-density film on the surface of a solid at low pressure, by virtue of attractive surface-gas interactions. At a given pressure, the density of the adsorbed film is the higher the stronger the binding of the molecules to the surface is (high binding energies). Thus, critical for high storage capacities are high surface areas, high binding energies, and low void fractions (high void fractions, such as in interstitial space between adsorbent particles, “waste” storage volume by holding hydrogen as non-adsorbed gas). Coexistence of high surface area and low void fraction makes the ideal adsorbent a nanoporous monolith, with pores wide enough to hold high-density hydrogen films, narrow enough to minimize storage as non-adsorbed gas, and thin walls between pores to minimize the volume occupied by solid instead of hydrogen. A monolith can be machined to fit into a rectangular tank (low pressure, conformable tank), cylindrical tank

  6. ACE Strategy with Virtual Channels

    Directory of Open Access Journals (Sweden)

    T. Tichy

    2008-12-01

    Full Text Available Cochlear implant is an electronic device, which can mediate hearing sensations to profoundly deaf people. Contemporary cochlear implants are sophisticated electronic devices; however, their performance could still be improved. This paper describes an experiment we made in that direction: additional 21 virtual channels were implemented by sequential stimulation of adjacent intracochlear electrodes, and the ACE strategy with virtual channels (ACEv, Advanced Combination Encoder strategy with virtual channels for the Nucleus® 24 Cochlear Implant System was created and verified in a clinical test with four patients.

  7. Hybrid Si/TMD 2D electronic double channels fabricated using solid CVD few-layer-MoS2 stacking for Vth matching and CMOS-compatible 3DFETs

    KAUST Repository

    Chen, Min Cheng

    2014-12-01

    Stackable 3DFETs such as FinFET using hybrid Si/MoS2 channels were developed using a fully CMOS-compatible process. Adding several molecular layers (3-16 layers) of the transition-metal dichalcogenide (TMD), MoS2 to Si fin and nanowire resulted in improved (+25%) Ion,n of the FinFET and nanowire FET (NWFET). The PFETs also operated effectively and the N/P device Vth are low and matched perfectly. The proposed heterogeneous Si/TMD 3DFETs can be useful in future electronics. © 2014 IEEE.

  8. Paley's multiplier method does not accurately predict adult height in children with bone sarcoma

    National Research Council Canada - National Science Library

    Gilg, Magdalena Maria; Wibmer, Christine; Andreou, Dimosthenis; Avian, Alexander; Sovinz, Petra; Maurer-Ertl, Werner; Tunn, Per-Ulf; Leithner, Andreas

    2014-01-01

    .... Paley's multiplier is used for height prediction in healthy children, and has been suggested as a method to make growth predictions for children with osteosarcoma and Ewing's sarcoma when considering...

  9. DNA-Cryptography-Based Obfuscated Systolic Finite Field Multiplier for Secure Cryptosystem in Smart Grid

    Science.gov (United States)

    Chen, Shaobo; Chen, Pingxiuqi; Shao, Qiliang; Basha Shaik, Nazeem; Xie, Jiafeng

    2017-05-01

    The elliptic curve cryptography (ECC) provides much stronger security per bits compared to the traditional cryptosystem, and hence it is an ideal role in secure communication in smart grid. On the other side, secure implementation of finite field multiplication over GF(2 m ) is considered as the bottle neck of ECC. In this paper, we present a novel obfuscation strategy for secure implementation of systolic field multiplier for ECC in smart grid. First, for the first time, we propose a novel obfuscation technique to derive a novel obfuscated systolic finite field multiplier for ECC implementation. Then, we employ the DNA cryptography coding strategy to obfuscate the field multiplier further. Finally, we obtain the area-time-power complexity of the proposed field multiplier to confirm the efficiency of the proposed design. The proposed design is highly obfuscated with low overhead, suitable for secure cryptosystem in smart grid.

  10. Karatsuba-Ofman Multiplier with Integrated Modular Reduction for GF(2m

    Directory of Open Access Journals (Sweden)

    CUEVAS-FARFAN, E.

    2013-05-01

    Full Text Available In this paper a novel GF(2m multiplier based on Karatsuba-Ofman Algorithm is presented. A binary field multiplication in polynomial basis is typically viewed as a two steps process, a polynomial multiplication followed by a modular reduction step. This research proposes a modification to the original Karatsuba-Ofman Algorithm in order to integrate the modular reduction inside the polynomial multiplication step. Modular reduction is achieved by using parallel linear feedback registers. The new algorithm is described in detail and results from a hardware implementation on FPGA technology are discussed. The hardware architecture is described in VHDL and synthesized for a Virtex-6 device. Although the proposed field multiplier can be implemented for arbitrary finite fields, the targeted finite fields are recommended for Elliptic Curve Cryptography. Comparing other KOA multipliers, our proposed multiplier uses 36% less area resources and improves the maximum delay in 10%.

  11. On the existence of conservation law multiplier for partial differential equations

    Science.gov (United States)

    Zhang, Zhi-Yong

    2015-02-01

    In this paper, we use the property of nonlinear self-adjointness with differential substitution to study the existence of conservation law multiplier for partial differential equations (PDEs). Firstly, we give a sufficient and necessary condition for the existence of the multipliers involving only independent and dependent variables, which is the nonlinear self-adjointness of the studying PDEs. Secondly, a necessary condition for the existence of the multipliers involving derivatives is given for the general evolution PDEs, which is the nonlinear self-adjointness with differential substitution. Finally, applications of multiplier and nonlinear self-adjointness with differential substitution methods to nonlinear telegraph equations and a class of Korteweg-de Vries (KdV) type equations are performed and different types of conservation laws are constructed.

  12. Cost-efficient design of a quantum multiplier-accumulator unit

    Science.gov (United States)

    Babu, Hafiz Md. Hasan

    2017-01-01

    This paper proposes a cost-efficient quantum multiplier-accumulator unit. The paper also presents a fast multiplication algorithm and designs a novel quantum multiplier device based on the proposed algorithm with the optimum time complexity as multiplier is the major device of a multiplier-accumulator unit. We show that the proposed multiplication technique has time complexity O((3 log2n)+1), whereas the best known existing technique has O(n log2 n), where n is the number of qubits. In addition, our design proposes three new quantum circuits: a circuit representing a quantum full-adder, a circuit known as quantum ANDing circuit, which performs the ANDing operation and a circuit presenting quantum accumulator. Moreover, the proposed quantum multiplier-accumulator unit is the first ever quantum multiplier-accumulator circuit in the literature till now, which has reduced garbage outputs and ancillary inputs to a great extent. The comparative study shows that the proposed quantum multiplier performs better than the existing multipliers in terms of depth, quantum gates, delays, area and power with the increasing number of qubits. Moreover, we design the proposed quantum multiplier-accumulator unit, which performs better than the existing ones in terms of hardware and delay complexities, e.g., the proposed (n× n)—qubit quantum multiplier-accumulator unit requires O(n2) hardware and O(log2n) delay complexities, whereas the best known existing quantum multiplier-accumulator unit requires O(n3) hardware and O((n-1)2 +1+n) delay complexities. In addition, the proposed design achieves an improvement of 13.04, 60.08 and 27.2% for 4× 4, 7.87, 51.8 and 27.1% for 8× 8, 4.24, 52.14 and 27% for 16× 16, 2.19, 52.15 and 27.26% for 32 × 32 and 0.78, 52.18 and 27.28% for 128 × 128-qubit multiplications over the best known existing approach in terms of number of quantum gates, ancillary inputs and garbage outputs, respectively. Moreover, on average, the proposed design gains an

  13. Solution of second order linear fuzzy difference equation by Lagrange's multiplier method

    Directory of Open Access Journals (Sweden)

    Sankar Prasad Mondal

    2016-06-01

    Full Text Available In this paper we execute the solution procedure for second order linear fuzzy difference equation by Lagrange's multiplier method. In crisp sense the difference equation are easy to solve, but when we take in fuzzy sense it forms a system of difference equation which is not so easy to solve. By the help of Lagrange's multiplier we can solved it easily. The results are illustrated by two different numerical examples and followed by two applications.

  14. $L^p$-results for fractional integration and multipliers for the Jacobi transform

    OpenAIRE

    Johansen, Troels Roussau

    2011-01-01

    We use precise asymptotic expansions for Jacobi functions $\\phi^{(\\alpha,\\beta)}_\\lambda$ parameters $\\alpha$, $\\beta$ satisfying $\\alpha>1/2$, $\\alpha>\\beta>-1/2$, to generalizing classical H\\"ormander-type multiplier theorem for the spherical transform on a rank one Riemannian symmetric space (by Clerc/Stein and Stanton/Tomas) to the framework of Jacobi analysis. In particular, multiplier results for the spherical transform on Damek--Ricci spaces are subsumed by this approach, and it yields...

  15. A 260-340 GHz Dual Chip Frequency Tripler for THz Frequency Multiplier Chains

    Science.gov (United States)

    Maestrini, Alain; Tripon-Canseliet, Charlotte; Ward, John S.; Gill, John J.; Mehdi, Imran

    2006-01-01

    We designed and fabricated a fix-tuned balanced frequency tripler working in the 260-340 GHz band to be the first stage of a x3x3x3 multiplier chain to 2.7 THz. The design of a dual-chip version of this multiplier featuring an input splitter / output combiner as part of the input / output matching networks of both chips - with no degradation of the expected bandwidth and efficiency- will be presented.

  16. Analysis of multiplier effects of ICT sectors – a Croatian case

    OpenAIRE

    Keček, Damira; Žajdela Hrustek, Nikolina; Dušak, Vesna

    2016-01-01

    The impact of Information and Communication Technology (ICT) on economic growth and development has nowadays proven to be significant for almost all national economies. In this paper, a quantitative analysis of the impact of ICT on Croatian economic growth is performed using the input-output (IO) method. The direct and indirect effects of ICT sectors are analysed. Subsequently, simple output multipliers and simple value added multipliers are then calculated. The results indicate that there ar...

  17. SIMAC - A phosphoproteomic strategy for the rapid separation of mono-phosphorylated from multiply phosphorylated peptides

    DEFF Research Database (Denmark)

    Thingholm, Tine E; Jensen, Ole N; Robinson, Phillip J

    2008-01-01

    spectrometric analysis, such as immobilized metal affinity chromatography or titanium dioxide the coverage of the phosphoproteome of a given sample is limited. Here we report a simple and rapid strategy - SIMAC - for sequential separation of mono-phosphorylated peptides and multiply phosphorylated peptides from...... and an optimized titanium dioxide chromatographic method. More than double the total number of identified phosphorylation sites was obtained with SIMAC, primarily from a three-fold increase in recovery of multiply phosphorylated peptides....

  18. Isometric multipliers of Lp (G, X) Lp (G, X) Lp (G, X)

    Indian Academy of Sciences (India)

    We use the characterization of isometries of L p ( G , X ) onto itself to characterize the isometric, invertible, left multipliers of L p ( G , X ) for 1 ≤ < ∞, ≠ 2, under the assumption that is not the l p -direct sum of two non-zero subspaces. In fact we prove that if is an isometric left multiplier of L p ( G , X ) onto itself then ...

  19. An electron-multiplying ''Micromegas'' grid made in silicon wafer post-processing technology

    NARCIS (Netherlands)

    Chefdeville, M.A.; Colas, P.; Giomataris, Y.; van der Graaf, H.; Heijne, E.H.M.; van der Putten, S.; Salm, Cora; Schmitz, Jurriaan; Smits, Sander M.; Timmermans, J.; Timmermans, J.; Visschers, J.L.

    2005-01-01

    A technology for manufacturing an aluminium grid onto a silicon wafer has been developed. The grid is fixed parallel and precisely to the wafer (anode) surface at a distance of 50 mm by means of insulating pillars. When some 400V are applied between the grid and (anode) wafer, gas multiplication

  20. An electron-multiplying 'Micromegas' grid made in silicon wafer post-processing technology

    NARCIS (Netherlands)

    Chefdeville, M.; Chefdeville, M.A.; Colas, P.; Giomataris, Y.; van der Graaf, H.; Heijne, E.H.M.; van der Putten, S.; Salm, Cora; Schmitz, Jurriaan; Smits, Sander M.; Timmermans, J.; Visschers, J.L.

    A technology for manufacturing an aluminium grid onto a silicon wafer has been developed. The grid is fixed parallel and precisely to the wafer (anode) surface at a distance of 50 μm by means of insulating pillars. When some 400 V are applied between the grid and (anode) wafer, gas multiplication

  1. A novel Tissue-Equivalent Proportional Counter based on a Gas Electron Multiplier

    NARCIS (Netherlands)

    Farahmand, M.

    2004-01-01

    Ionising radiation causes a wide variety of effects in biological targets. In experimental microdosimetry these effects are studied by investigating the statistical distribution of energy deposition events at the microscopic level employing a Tissue-Equivalent Proportional Counter (TEPC). A TEPC is

  2. Improved Quantization Error Compensation Method for Fixed-Width Booth Multipliers

    Directory of Open Access Journals (Sweden)

    Xiaolong Ma

    2014-01-01

    Full Text Available A novel quantization error (QE compensation method is proposed in design of high accuracy fixed-width radix-4 Booth multipliers, which will effectively reduce the QE and save the area of multipliers when they are employed in cognitive radio (CR detector and digital signal processor (DSP. The truncated partial-products of the proposed multipliers are finely divided into three sections: reserved section, adaptive compensation section, and constant compensation section. The QE compensation carries of the multipliers are generated by applying probability estimation based on a shrunken minor truncated section which is a combination of the constant compensation and adaptive compensation. The proposed compensation method not only reduces the QE of the fixed-width Booth multipliers, but also avoids the exhaustive computing resources (time and memory during getting the compensation carries by statistical simulation. The proposed method can achieve higher accuracy than the existing works under the same area and power budgets. Simulation and experiment results show that the improved compensation method has the minimum power-delay products compared with the existing methods under the same area and can save up to 30% area for realization of full-width radix-4 Booth multipliers.

  3. The search for new physics in the diphoton decay channel and the upgrade of the Tile-Calorimeter electronics of the ATLAS detector.

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00508435

    The discovery of the Higgs boson at the Large Hadron Collider in Switzerland marks the beginning of a new era: Physics beyond the Standard Model (SM). A model is proposed to describe numerous Run I features observed with both the ATLAS and CMS experiments. The model introduces a heavy scalar estimated to be around 270 GeV and an intermediate scalar which can decay into both dark matter and SM particles. Three different final state searches, linked by the new hypothesis, are presented. These are the $hh\\rightarrow\\gamma\\gamma b\\overline{b}, \\gamma\\gamma + E^{miss}_{T}$ and high mass diphoton channels. No significant excesses were observed in any channel using the available datasets and limits were set on the relevant cross sections times branching ratios. The lack of statistics in the $\\gamma\\gamma b\\overline{b}$ analysis prevents any conclusive statement in regard to the excess observed with Run I data. Observing no excess in the $\\gamma\\gamma + E^{miss}_{T}$ channel with the current amount of data is also c...

  4. Nanoscale Vacuum Channel Transistor.

    Science.gov (United States)

    Han, Jin-Woo; Moon, Dong-Il; Meyyappan, M

    2017-04-12

    Vacuum tubes that sparked the electronics era had given way to semiconductor transistors. Despite their faster operation and better immunity to noise and radiation compared to the transistors, the vacuum device technology became extinct due to the high power consumption, integration difficulties, and short lifetime of the vacuum tubes. We combine the best of vacuum tubes and modern silicon nanofabrication technology here. The surround gate nanoscale vacuum channel transistor consists of sharp source and drain electrodes separated by sub-50 nm vacuum channel with a source to gate distance of 10 nm. This transistor performs at a low voltage (3 microamperes). The nanoscale vacuum channel transistor can be a possible alternative to semiconductor transistors beyond Moore's law.

  5. Potential energy curves for neutral and multiply charged carbon ...

    Indian Academy of Sciences (India)

    Potential energy curves of various electronic states of CO+ (0 ≤ ≤ 6) are generated at MRCI/CASSCF level using cc-pvQZ basis set and the results are compared with available experimental and theoretical data. Author Affiliations. Pradeep Kumar1 N Sathyamurthy1 2 3. Department of Chemistry, Indian Institute of ...

  6. Ionic Channels in Thunderclouds

    Science.gov (United States)

    Losseva, T. V.; Fomenko, A. S.; Nemtchinov, I. V.

    2007-12-01

    We proceed to study the formation and propagation of ionic channels in thunderclouds in the framework of the model of the corona discharge wave propagation (Fomenko A.S., Losseva T.V., Nemtchinov I.V. The corona discharge waves in thunderclouds and formation of ionic channels // 2004 Fall Meeting. EOS Trans. AGU. 2004. V. 85. ¹ 47. Suppl. Abstract AE23A-0835.). In this model we proposed a hypothesis that the structure of a thundercloud becomes nonuniform due to corona discharge on the drops and ice particles and formation of ionic channels with higher conductivity than the surrounding air. When the onset strength of corona discharge becomes smaller than the electric field strength the corona discharge increases concentrations of ions in a small part of the cloud (a hot spot). An additional charge at opposite ends of the hot spot forms due to polarization process. The increased electric field initiates corona discharge in other parts of the cloud on ice particles and water drops with smaller sizes. The corona discharge front moves as a wave with the velocity of the order of ion drift and formes a highly conductive channel. We model this non-stationary problem with Poisson equation which is solved simultaneously with a simplified set of kinetic equations for ions, small charged particles and electrons (at high electric fields), including ionization due to electronic impact, attachment and formation of positive ions. By applying 3D numerical simulations we obtain the parameters of formed ionic channels with respect to onset electric fields both from large particles (in hot spot) and from small particles (surrounding hot spot), microscopic currents from particles with different sizes and the external electric field in the cloud. The interaction of ionic channels is also investigated. This work was supported by Russian Foundation of Basic Research (Project No 07-05-00998-à).

  7. Production of extended plasma channels in atmospheric air by amplitude-modulated UV radiation of GARPUN-MTW Ti : sapphire—KrF laser. Part 2. Accumulation of plasma electrons and electric discharge control

    Science.gov (United States)

    Zvorykin, V. D.; Ionin, Andrei A.; Levchenko, A. O.; Mesyats, Gennadii A.; Seleznev, L. V.; Sinitsyn, D. V.; Smetanin, Igor V.; Sunchugasheva, E. S.; Ustinovskii, N. N.; Shutov, A. V.

    2013-04-01

    The problem of the production of extended (~1 m) plasma channels is studied in atmospheric air by amplitude-modulated laser pulses of UV radiation, which are a superposition of a subpicosecond USP train amplified in a regenerative KrF amplifier with an unstable confocal resonator and a quasi-stationary lasing pulse. The USPs possess a high (0.2-0.3 TW) peak power and efficiently ionise oxygen molecules due to multiphoton ionisation, and the quasi-stationary lasing pulse, which has a relatively long duration (~100 ns), maintains the electron density at a level ne = (3-5) × 1014 cm—3 by suppressing electron attachment to oxygen. Experiments in laser triggering of high-voltage electric discharges suggest that the use of combined pulses results in a significant lowering of the breakdown threshold and enables controlling the discharge trajectory with a higher efficiency in comparison with smooth pulses. It was shown that controlled breakdowns may develop with a delay of tens of microseconds relative to the laser pulse, which is many orders of magnitude greater than the lifetime of free electrons in the laser-induced plasma. We propose a mechanism for this breakdown, which involves speeding-up of the avalanche ionisation of the air by negative molecular oxygen ions with a low electron binding energy (~0.5 eV) and a long lifetime (~1 ms), which are produced upon cessation of the laser pulse.

  8. Welding multiple plies with an electron beam

    Science.gov (United States)

    Kiluk, F. J.

    1980-01-01

    Method for electron-beam welding of multi-ply metal sheets eliminates ply separation and minimizes porosity. Method was developed for assembling bellows made of four plies of iron/nickel alloy sheets. Method consists of making successive stitch welds with electron beam until weld seam is completely filled in and all plies have been penetrated.

  9. A 2.5-2.7 THz Room Temperature Electronic Source

    Science.gov (United States)

    Maestrini, Alain; Mehdi, Imran; Lin, Robert; Siles, Jose Vicente; Lee, Choonsup; Gill, John; Chattopadhyay, Goutam; Schlecht, Erich; Bertrand, Thomas; Ward, John

    2011-01-01

    We report on a room temperature 2.5 to 2.7 THz electronic source based on frequency multipliers. The source utilizes a cascade of three frequency multipliers with W-band power amplifiers driving the first stage multiplier. Multiple-chip multipliers are utilized for the two initial stages to improve the power handling capability and a sub-micron anode is utilized for the final stage tripler. Room temperature measurements indicate that the source can put out a peak power of about 14 microwatts with more than 4 microwatts in the 2.5 to 2.7 THz range.

  10. A custom readout electronics for the BESIII CGEM detector

    Science.gov (United States)

    Da Rocha Rolo, M.; Alexeev, M.; Amoroso, A.; Baldini Ferroli, R.; Bertani, M.; Bettoni, D.; Bianchi, F.; Bugalho, R.; Calcaterra, A.; Canale, N.; Capodiferro, M.; Carassiti, V.; Cerioni, S.; Chai, J. Y.; Chiozzi, S.; Cibinetto, G.; Cossio, F.; Cotta Ramusino, A.; De Mori, F.; Destefanis, M.; Di Francesco, A.; Dong, J.; Evangelisti, F.; Farinelli, R.; Fava, L.; Felici, G.; Fioravanti, E.; Garzia, I.; Gatta, M.; Greco, M.; Lavezzi, L.; Leng, C. Y.; Li, H.; Maggiora, M.; Malaguti, R.; Marcello, S.; Marciniewski, P.; Melchiorri, M.; Mezzadri, G.; Mignone, M.; Morello, G.; Pacetti, S.; Patteri, P.; Pellegrino, J.; Pelosi, A.; Rivetti, A.; Savrié, M.; Scodeggio, M.; Soldani, E.; Sosio, S.; Spataro, S.; Tskhadadze, E.; Varela, J.; Verma, S.; Wheadon, R.; Yan, L.

    2017-07-01

    For the upgrade of the inner tracker of the BESIII spectrometer, planned for 2018, a lightweight tracker based on an innovative Cylindrical Gas Electron Multiplier (CGEM) detector is now under development. The analogue readout of the CGEM enables the use of a charge centroid algorithm to improve the spatial resolution to better than 130 μm while loosening the pitch strip to 650 μm, which allows to reduce the total number of channels to about 10 000. The channels are readout by 160 dedicated integrated 64-channel front-end ASICs, providing a time and charge measurement and featuring a fully-digital output. The energy measurement is extracted either from the time-over-threshold (ToT) or the 10-bit digitisation of the peak amplitude of the signal. The time of the event is generated by quad-buffered low-power TDCs, allowing for rates in excess of 60 kHz per channel. The TDCs are based on analogue interpolation techniques and produce a time stamp (or two, if working in ToT mode) of the event with a time resolution better than 50 ps. The front-end noise, based on a CSA and a two-stage complex conjugated pole shapers, dominate the channel intrinsic time jitter, which is less than 5 ns r.m.s. The time information of the hit can be used to reconstruct the track path, operating the detector as a small TPC and hence improving the position resolution when the distribution of the cloud, due to large incident angle or magnetic field, is very broad. Event data is collected by an off-detector motherboard, where each GEM-ROC readout card handles 4 ASIC carrier FEBs (512 channels). Configuration upload and data readout between the off-detector electronics and the VME-based data collector cards are managed by bi-directional fibre optical links. This paper covers the design of a custom front-end electronics for the readout of the new inner tracker of the BESIII experiment, addressing the relevant design aspects of the detector electronics and the front-end ASIC for the CGEM readout

  11. Theory of low-energy electron-molecule collision physics in the coupled-channel method and application to e-CO/sub 2/ scattering. [0. 01 to 10 eV, potentials, partial waves

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, M.A.

    1976-08-01

    A theory of electron-molecule scattering based on the fixed-nuclei approximation in a body-fixed reference frame is formulated and applied to e-CO/sub 2/ collisions in the energy range from 0.07 to 10.0 eV. The procedure used is a single-center coupled-channel method which incorporates a highly accurate static interaction potential, an approximate local exchange potential, and an induced polarization potential. Coupled equations are solved by a modification of the integral equations algorithm; several partial waves are required in the region of space near the nuclei, and a transformation procedure is developed to handle the consequent numerical problems. The potential energy is converged by separating electronic and nuclear contributions in a Legendre-polynomial expansion and including a large number of the latter. Formulas are derived for total elastic, differential, momentum transfer, and rotational excitation cross sections. The Born and asymptotic decoupling approximations are derived and discussed in the context of comparison with the coupled-channel cross sections. Both are found to be unsatisfactory in the energy range under consideration. An extensive discussion of the technical aspects of calculations for electron collisions with highly nonspherical targets is presented, including detailed convergence studies and a discussion of various numerical difficulties. The application to e-CO/sub 2/ scattering produces converged results in good agreement with observed cross sections. Various aspects of the physics of this collision are discussed, including the 3.8 eV shape resonance, which is found to possess both p and f character, and the anomalously large low-energy momentum transfer cross sections, which are found to be due to ..sigma../sub g/ symmetry. Comparison with static and static-exchange approximations are made.

  12. Search for excited and exotic electrons in the egamma decay channel in pp collisions at sqrt[s] = 1.96 TeV.

    Science.gov (United States)

    Acosta, D; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Ambrose, D; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arisawa, T; Arguin, J-F; Artikov, A; Ashmanskas, W; Attal, A; Azfar, F; Azzi-Bacchetta, P; Bacchetta, N; Bachacou, H; Badgett, W; Barbaro-Galtieri, A; Barker, G J; Barnes, V E; Barnett, B A; Baroiant, S; Barone, M; Bauer, G; Bedeschi, F; Behari, S; Belforte, S; Bellettini, G; Bellinger, J; Ben-Haim, E; Benjamin, D; Beretvas, A; Bhatti, A; Binkley, M; Bisello, D; Bishai, M; Blair, R E; Blocker, C; Bloom, K; Blumenfeld, B; Bocci, A; Bodek, A; Bolla, G; Bolshov, A; Booth, P S L; Bortoletto, D; Boudreau, J; Bourov, S; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Burkett, K; Busetto, G; Bussey, P; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canepa, A; Casarsa, M; Carlsmith, D; Carron, S; Carosi, R; Cavalli-Sforza, M; Castro, A; Catastini, P; Cauz, D; Cerri, A; Cerri, C; Cerrito, L; Chapman, J; Chen, C; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chu, M L; Chuang, S; Chung, J Y; Chung, W-H; Chung, Y S; Ciobanu, C I; Ciocci, M A; Clark, A G; Clark, D; Coca, M; Connolly, A; Convery, M; Conway, J; Cooper, B; Cordelli, M; Cortiana, G; Cranshaw, J; Cuevas, J; Culbertson, R; Currat, C; Cyr, D; Dagenhart, D; Da Ronco, S; D'Auria, S; de Barbaro, P; De Cecco, S; De Lentdecker, G; Dell'Agnello, S; Dell'Orso, M; Demers, S; Demortier, L; Deninno, M; De Pedis, D; Derwent, P F; Dionisi, C; Dittmann, J R; Doksus, P; Dominguez, A; Donati, S; Donega, M; Donini, J; D'Onofrio, M; Dorigo, T; Drollinger, V; Ebina, K; Eddy, N; Ely, R; Erbacher, R; Erdmann, M; Errede, D; Errede, S; Eusebi, R; Fang, H-C; Farrington, S; Fedorko, I; Feild, R G; Feindt, M; Fernandez, J P; Ferretti, C; Field, R D; Fiori, I; Flanagan, G; Flaugher, B; Flores-Castillo, L R; Foland, A; Forrester, S; Foster, G W; Franklin, M; Freeman, J C; Frisch, H; Fujii, Y; Furic, I; Gajjar, A; Gallas, A; Galyardt, J; Gallinaro, M; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D W; Gerchtein, E; Giagu, S; Giannetti, P; Gibson, A; Gibson, K; Ginsburg, C; Giolo, K; Giordani, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, D; Goldstein, J; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Gotra, Y; Goulianos, K; Gresele, A; Griffiths, M; Grosso-Pilcher, C; Grundler, U; Guenther, M; da Costa, J Guimaraes; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B-Y; Handler, R; Happacher, F; Hara, K; Hare, M; Harr, R F; Harris, R M; Hartmann, F; Hatakeyama, K; Hauser, J; Hays, C; Hayward, H; Heider, E; Heinemann, B; Heinrich, J; Hennecke, M; Herndon, M; Hill, C; Hirschbuehl, D; Hocker, A; Hoffman, K D; Holloway, A; Hou, S; Houlden, M A; Huffman, B T; Huang, Y; Hughes, R E; Huston, J; Ikado, K; Incandela, J; Introzzi, G; Iori, M; Ishizawa, Y; Issever, C; Ivanov, A; Iwata, Y; Iyutin, B; James, E; Jang, D; Jarrell, J; Jeans, D; Jensen, H; Jeon, E J; Jones, M; Joo, K K; Jun, S; Junk, T; Kamon, T; Kang, J; Karagoz Unel, M; Karchin, P E; Kartal, S; Kato, Y; Kemp, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, M S; Kim, S B; Kim, S H; Kim, T H; Kim, Y K; King, B T; Kirby, M; Kirsch, L; Klimenko, S; Knuteson, B; Ko, B R; Kobayashi, H; Koehn, P; Kong, D J; Kondo, K; Konigsberg, J; Kordas, K; Korn, A; Korytov, A; Kotelnikov, K; Kotwal, A V; Kovalev, A; Kraus, J; Kravchenko, I; Kreymer, A; Kroll, J; Kruse, M; Krutelyov, V; Kuhlmann, S E; Kuznetsova, N; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, J; Lancaster, M; Lander, R; Lannon, K; Lath, A; Latino, G; Lauhakangas, R; Lazzizzera, I; Le, Y; Lecci, C; Lecompte, T; Lee, J; Lee, J; Lee, S W; Lefevre, R; Leonardo, N; Leone, S; Lewis, J D; Li, K; Lin, C; Lin, C S; Lindgren, M; Liss, T M; Litvintsev, D O; Liu, T; Liu, Y; Lockyer, N S; Loginov, A; Loreti, M; Loverre, P; Lu, R-S; Lucchesi, D; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Macqueen, D; Madrak, R; Maeshima, K; Maksimovic, P; Malferrari, L; Manca, G; Marginean, R; Martin, M; Martin, A; Martin, V; Martínez, M; Maruyama, T; Matsunaga, H; Mattson, M; Mazzanti, P; McFarland, K S; McGivern, D; McIntyre, P M; McNamara, P; NcNulty, R; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miller, L; Miller, R; Miller, J S; Miquel, R; Miscetti, S; Mitselmakher, G; Miyamoto, A; Miyazaki, Y; Moggi, N; Mohr, B; Moore, R; Morello, M; Mukherjee, A; Mulhearn, M; Muller, T; Mumford, R; Munar, A; Murat, P; Nachtman, J; Nahn, S; Nakamura, I; Nakano, I; Napier, A; Napora, R; Naumov, D; Necula, V; Niell, F; Nielsen, J; Nelson, C; Nelson, T; Neu, C; Neubauer, M S; Newman-Holmes, C; Nicollerat, A-S; Nigmanov, T; Nodulman, L; Norniella, O; Oesterberg, K; Ogawa, T; Oh, S H; Oh, Y D; Ohsugi, T; Okusawa, T; Oldeman, R; Orava, R; Orejudos, W; Pagliarone, C; Palencia, E; Palmonari, F; Paoletti, R; Papadimitriou, V; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Pauly, T; Paus, C; Pellett, D; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pitts, K T; Plager, C; Pompos, A; Pondrom, L; Pope, G; Poukhov, O; Prakoshyn, F; Pratt, T; Pronko, A; Proudfoot, J; Ptohos, F; Punzi, G; Rademacker, J; Rakitine, A; Rappoccio, S; Ratnikov, F; Ray, H; Reichold, A; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Rimondi, F; Rinnert, K; Ristori, L; Robertson, W J; Robson, A; Rodrigo, T; Rolli, S; Rosenson, L; Roser, R; Rossin, R; Rott, C; Russ, J; Ruiz, A; Ryan, D; Saarikko, H; Sabik, S; Safonov, A; St Denis, R; Sakumoto, W K; Salamanna, G; Saltzberg, D; Sanchez, C; Sansoni, A; Santi, L; Sarkar, S; Sato, K; Savard, P; Savoy-Navarro, A; Schlabach, P; Schmidt, E E; Schmidt, M P; Schmitt, M; Scodellaro, L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semeria, F; Sexton-Kennedy, L; Sfiligoi, I; Shapiro, M D; Shears, T; Shepard, P F; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Siegrist, J; Siket, M; Sill, A; Sinervo, P; Sisakyan, A; Skiba, A; Slaughter, A J; Sliwa, K; Smirnov, D; Smith, J R; Snider, F D; Snihur, R; Somalwar, S V; Spalding, J; Spezziga, M; Spiegel, L; Spinella, F; Spiropulu, M; Squillacioti, P; Stadie, H; Stefanini, A; Stelzer, B; Stelzer-Chilton, O; Strologas, J; Stuart, D; Sukhanov, A; Sumorok, K; Sun, H; Suzuki, T; Taffard, A; Tafirout, R; Takach, S F; Takano, H; Takashima, R; Takeuchi, Y; Takikawa, K; Tanaka, M; Tanaka, R; Tanimoto, N; Tapprogge, S; Tecchio, M; Teng, P K; Terashi, K; Tesarek, R J; Tether, S; Thom, J; Thompson, A S; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tollefson, K; Tomura, T; Tonelli, D; Tönnesmann, M; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tseng, J; Tsuchiya, R; Tsuno, S; Tsybychev, D; Turini, N; Turner, M; Ukegawa, F; Unverhau, T; Uozumi, S; Usynin, D; Vacavant, L; Vaiciulis, A; Varganov, A; Vataga, E; Vejcik, S; Velev, G; Veszpremi, V; Veramendi, G; Vickey, T; Vidal, R; Vila, I; Vilar, R; Vollrath, I; Volobouev, I; von der Mey, M; Wagner, P; Wagner, R G; Wagner, R L; Wagner, W; Wallny, R; Walter, T; Yamashita, T; Yamamoto, K; Wan, Z; Wang, M J; Wang, S M; Warburton, A; Ward, B; Waschke, S; Waters, D; Watts, T; Weber, M; Wester, W C; Whitehouse, B; Wicklund, A B; Wicklund, E; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolter, M; Worcester, M; Worm, S; Wright, T; Wu, X; Würthwein, F; Wyatt, A; Yagil, A; Yang, U K; Yao, W; Yeh, G P; Yi, K; Yoh, J; Yoon, P; Yorita, K; Yoshida, T; Yu, I; Yu, S; Yu, Z; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zetti, F; Zhou, J; Zsenei, A; Zucchelli, S

    2005-03-18

    We present a search for excited and exotic electrons (e(*)) decaying to an electron and a photon, both with high transverse momentum. We use 202 pb(-1) of data collected in pp collisions at sqrt[s] = 1.96 TeV with the Collider Detector at Fermilab II detector. No signal above standard model expectation is seen for associated ee(*) production. We discuss the e(*) sensitivity in the parameter space of the excited electron mass M(e(*)) and the compositeness energy scale Lambda. In the contact interaction model, we exclude 132 GeV/c(2)

  13. Object-Relational Management of Multiply Represented Geographic Entities

    DEFF Research Database (Denmark)

    Friis-Christensen, Anders; Jensen, Christian Søndergaard

    2003-01-01

    Multiple representation occurs when information about the same geographic entity is represented electronically more than once. This occurs frequently in practice, and it invariably results in the occurrence of inconsistencies among the different representations. We propose to resolve this situation...... by introducing a multiple representation management system (MRMS), the schema of which includes rules that specify how to identify representations of the same entity, rules that specify consistency requirements, and rules used to restore consistency when necessary. In this paper, we demonstrate by means...

  14. MARKETING CHANNELS

    Directory of Open Access Journals (Sweden)

    Ljiljana Stošić Mihajlović

    2014-07-01

    Full Text Available Marketing channel is a set of entities and institutions, completion of distribution and marketing activities, attend the efficient and effective networking of producers and consumers. Marketing channels include the total flows of goods, money and information taking place between the institutions in the system of marketing, establishing a connection between them. The functions of the exchange, the physical supply and service activities, inherent in the system of marketing and trade. They represent paths which products and services are moving after the production, which will ultimately end up buying and eating by the user.

  15. Estimation of multiply digital process control system extractive distillation stability

    Directory of Open Access Journals (Sweden)

    V. S. Kudryashov

    2016-01-01

    Full Text Available An approach to stability analysis of digital control systems associated non-stationary object on the example of the rectification process. Object modeling with cross-connections and the control scheme of the described system, discrete transfer functions in the shift operators. The equations of connection for each output of the closed-loop system. To solve this problem developed an algorithm for estimating the margin of stability of multivariable digital control systems based on the discrete root criterion, comprising the following main stages: obtaining of the characteristic polynomial of the closed-loop system for each output; computation of eigenvalues of the system matrix in the state space to determine roots of the characteristic equation and the stability of the system; determination of the stability and margin of stability by the deviation of maximum module of the root from the boundary of the high variability. To obtain the characteristic polynomial of a as discrete models of controllers and channels of IP object-use the transfer function of the first order with transport delay. The simulation was performed at different parameters of the control object, which is characterized by a stable and an unstable state of the system. VA-den analysis of the numerical values of the roots and character of their location on the complex plane, which to you-water that the system is stable or unstable. To confirm the obtained results were calculated and presented dynamic characteristics of the closed-loop system under different conditions, which confirm the initial assessment, the root criterion. To determine the factor stability of multivariable digital systems is proposed to use the deviation of the maximum root of the characteristic equation from the stability boundary. The obtained results apply to the class of symmetric multivariable control objects. The approach to assessing the sustainability of multivariable system regulation can be effectively

  16. Rapid, single-molecule assays in nano/micro-fluidic chips with arrays of closely spaced parallel channels fabricated by femtosecond laser machining.

    Science.gov (United States)

    Canfield, Brian K; King, Jason K; Robinson, William N; Hofmeister, William H; Davis, Lloyd M

    2014-08-20

    Cost-effective pharmaceutical drug discovery depends on increasing assay throughput while reducing reagent needs. To this end, we are developing an ultrasensitive, fluorescence-based platform that incorporates a nano/micro-fluidic chip with an array of closely spaced channels for parallelized optical readout of single-molecule assays. Here we describe the use of direct femtosecond laser machining to fabricate several hundred closely spaced channels on the surfaces of fused silica substrates. The channels are sealed by bonding to a microscope cover slip spin-coated with a thin film of poly(dimethylsiloxane). Single-molecule detection experiments are conducted using a custom-built, wide-field microscope. The array of channels is epi-illuminated by a line-generating red diode laser, resulting in a line focus just a few microns thick across a 500 micron field of view. A dilute aqueous solution of fluorescently labeled biomolecules is loaded into the device and fluorescence is detected with an electron-multiplying CCD camera, allowing acquisition rates up to 7 kHz for each microchannel. Matched digital filtering based on experimental parameters is used to perform an initial, rapid assessment of detected fluorescence. More detailed analysis is obtained through fluorescence correlation spectroscopy. Simulated fluorescence data is shown to agree well with experimental values.

  17. Hardware Design and Implementation of Fixed-Width Standard and Truncated 4×4, 6×6, 8×8 and 12×12-BIT Multipliers Using Fpga

    Science.gov (United States)

    Rais, Muhammad H.

    2010-06-01

    This paper presents Field Programmable Gate Array (FPGA) implementation of standard and truncated multipliers using Very High Speed Integrated Circuit Hardware Description Language (VHDL). Truncated multiplier is a good candidate for digital signal processing (DSP) applications such as finite impulse response (FIR) and discrete cosine transform (DCT). Remarkable reduction in FPGA resources, delay, and power can be achieved using truncated multipliers instead of standard parallel multipliers when the full precision of the standard multiplier is not required. The truncated multipliers show significant improvement as compared to standard multipliers. Results show that the anomaly in Spartan-3 AN average connection and maximum pin delay have been efficiently reduced in Virtex-4 device.

  18. Economic Multipliers and Sectoral Linkages: Ghana and the New Oil Sector

    Directory of Open Access Journals (Sweden)

    Dennis Nchor

    2016-01-01

    Full Text Available The study seeks to assess the structure of the economy of Ghana in terms of changes in the economic structure before and after the production of oil in commercial quantities. This is viewed with regards to economic multipliers, sectoral interdependence and trade concentration. The results show that changes occurred with regards to multipliers and sectoral interdependence. The output multipliers of most sectors have declined. The results also show that the agricultural sector experienced an initial decline in its growth while industry experienced an increase. The performance of the services sector was relatively stable for the period covered by the study. There is a decline in the level of trade concentration though on a whole the concentration index is still high. The study employed input-output modeling techniques and the data was obtained from the Ghana statistical service and the World Development Indicators.

  19. Calculation of simultaneous chemical and phase equilibrium by the methodof Lagrange multipliers

    DEFF Research Database (Denmark)

    Tsanas, Christos; Stenby, Erling Halfdan; Yan, Wei

    2017-01-01

    The purpose of this work is to develop a general, reliable and efficient algorithm, which is able to deal with multiple reactions in multiphase systems. We selected the method of Lagrange multipliers to minimize the Gibbs energy of the system, under material balance constraints. Lagrange multipli......The purpose of this work is to develop a general, reliable and efficient algorithm, which is able to deal with multiple reactions in multiphase systems. We selected the method of Lagrange multipliers to minimize the Gibbs energy of the system, under material balance constraints. Lagrange...... iteration in the inner loop and non-ideality updated in the outer loop, thus giving an overall linear convergence rate. Stability analysis is used to introduce additional phases sequentially so as to obtain the final multiphase solution. The procedure was successfully tested on vapor-liquid equilibrium (VLE......) and vapor-liquid-liquid equilibrium (VLLE) of reaction systems....

  20. Perbandingan Metode Gaussian Particle Swarm Optimization (GPSO dan Lagrange Multiplier pada Masalah Economic Dispatch

    Directory of Open Access Journals (Sweden)

    Siti Komsiyah

    2012-06-01

    Full Text Available On electric power system operation, economic planning problem is one variable to take into account due to operational cost efficiency. Economic Dispatch problem of electric power generation is discussed in this study to manage the output division on several units based on the the required load demand, with minimum operating cost yet is able to satisfy equality and inequality constraint of all units and system. In this study the Economic Dispatch problem which has non linear cost function is solved using swarm intelligent method is Gaussian Particle Swarm Optimization (GPSO and Lagrange Multiplier. GPSO is a population-based stochastic algorithms which their moving is inspired by swarm intelligent and probabilities theories. To analize its accuracy, the Economic Dispatch solution by GPSO method is compared with Lagrange Multiplier method. From the test result it is proved that GPSO method gives economic planning calculation better than Lagrange Multiplier does.

  1. Design of Low Power Multiplier with Energy Efficient Full Adder Using DPTAAL

    Directory of Open Access Journals (Sweden)

    A. Kishore Kumar

    2013-01-01

    Full Text Available Asynchronous adiabatic logic (AAL is a novel lowpower design technique which combines the energy saving benefits of asynchronous systems with adiabatic benefits. In this paper, energy efficient full adder using double pass transistor with asynchronous adiabatic logic (DPTAAL is used to design a low power multiplier. Asynchronous adiabatic circuits are very low power circuits to preserve energy for reuse, which reduces the amount of energy drawn directly from the power supply. In this work, an 8×8 multiplier using DPTAAL is designed and simulated, which exhibits low power and reliable logical operations. To improve the circuit performance at reduced voltage level, double pass transistor logic (DPL is introduced. The power results of the proposed multiplier design are compared with the conventional CMOS implementation. Simulation results show significant improvement in power for clock rates ranging from 100 MHz to 300 MHz.

  2. Proposal for electro-optic multiplier based on dual transverse electro-optic Kerr effect.

    Science.gov (United States)

    Li, Changsheng

    2008-10-20

    A novel electro-optic multiplier is proposed, which can perform voltage multiplication operation by use of the Kerr medium exhibiting dual transverse electro-optic Kerr effect. In this kind of Kerr medium, electro-optic phase retardation is proportional to the square of its applied electric field, and orientations of the field-induced birefringent axes are only related to the direction of the field. Based on this effect, we can design an electro-optic multiplier by selecting the crystals of 6/mmm, 432, and m3m classes and isotropic Kerr media such as glass. Simple calculation demonstrates that a kind of glass-ceramic material with a large Kerr constant can be used for the design of the proposed electro-optic multiplier.

  3. Functional communication training for the treatment of multiply determined challenging behavior in two boys with autism.

    Science.gov (United States)

    Sigafoos, J; Meikle, B

    1996-01-01

    Functional communication training was used to replace multiply determined problem behavior in two boys with autism. Experiment 1 involved a functional analysis of several topographies of problem behavior using a variation of the procedures described by Iwata, Dorsey, Slifer, Bauman, and Richman. Results suggested that aggression, self-injury, and disruption were multiply determined (i.e., maintained by both attention and access to preferred objects). Experiment 2 involved a multiple-baseline design across subjects. The focus of intervention was to replace aggression, self-injury, and disruption with functionally equivalent communicative alternatives. Both boys were taught alternative "mands" to recruit attention and request preferred objects. Acquisition of these alternative communication skills was associated with concurrent decreases in aggression, self-injury, and disruption. Results suggest that multiply determined challenging behavior can be decreased by teaching an alternative communication skill to replace each assessed function of the problem behavior.

  4. Schedulling Economical Thermal Power Plant 500 KV Java-Bali System Using Lagrange Multiplier

    Science.gov (United States)

    Sartika, N.; Abdullah, A. G.; Hakim, D. L.

    2017-03-01

    The highest cost of electricity generation operation is fuel cost. Therefore, it is necessary to optimize the thermal generator scheduling. The present study aimed at obtaining the schedule and load sharing of the electric power generation, in order to gain the minimum fuel cost, with regard to inequality and equality constraints. The data tested was the thermal generation system of 500 kV Java-Bali using daily loads. This study employed a lagrange multiplier method to perform the economic scheduling. This method is one of mathematical techniques commonly used to solve economic dispatch problems. The results of the optimation of lagrange multiplier were compared with the real condition in the field. Based on the optimation results, it was found that the lagrange multiplier method is more economical than the real condition of system.

  5. Low Voltage Floating Gate MOS Transistor Based Four-Quadrant Multiplier

    Directory of Open Access Journals (Sweden)

    R. Srivastava

    2014-12-01

    Full Text Available This paper presents a four-quadrant multiplier based on square-law characteristic of floating gate MOSFET (FGMOS in saturation region. The proposed circuit uses square-difference identity and the differential voltage squarer proposed by Gupta et al. to implement the multiplication function. The proposed multiplier employs eight FGMOS transistors and two resistors only. The FGMOS implementation of the multiplier allows low voltage operation, reduced power consumption and minimum transistor count. The second order effects caused due to mobility degradation, component mismatch and temperature variations are discussed. Performance of the proposed circuit is verified at ±0.75 V in TSMC 0.18 µm CMOS, BSIM3 and Level 49 technology by using Cadence Spectre simulator.

  6. The role of AlGaN buffers and channel thickness in the electronic transport properties of Al x In1- x N/AlN/GaN heterostructures

    Science.gov (United States)

    Amirabbasi, M.

    2016-01-01

    We try to theoretically analyze the reported experimental data of the Al x In1- x N/AlN/GaN heterostructures grown by MOCVD and quantitatively investigate the effects of AlGaN buffers and the GaNchannel thickness on the electrical transport properties of these systems. Also, we obtain the most important effective parameters of the temperature-dependent mobility in the range 35-300 K. Our results show that inserting a 1.1 μm thick Al0.04Ga0.96N buffer enhances electron mobility by decreasing the effect of phonons, the interface roughness, and dislocation and crystal defect scattering mechanisms. Also, as the channel thickness increases from 20 nm to 40 nm, the electron mobility increases from 2200 to 2540 cm2/(V s) and from 870 to 1000 cm2/(V s) at 35 and 300 K respectively, which is attributed to the reduction in the dislocation density and the strain-induced field. Finally, the reported experimental data show that inserting a 450 nm graded AlGaN layer before an Al0.04Ga0.96N buffer causes a decrease in the electron mobility, which is attributed to the enhancement of the lateral size of roughness, the dislocation density, and the strain-induced field in this sample.

  7. Multiply charged ion dissociation in Fourier transform ion cyclotron resonance mass spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Qinyuan; Bakhtair, R.; Sherman, M.G.; Hofstadler, S.A.; Smith, R.D. [Pacific Northwest Laboratory, Richland, WA (United States)

    1994-12-31

    Bimolecular ions of up to MDa size with thousands of charges have recently been trapped and studied in this laboratory using electrospray ionization (ESI) and Fourier transform ion cyclotron resonance mass spectrometer (FTICRMS). For structural analysis, multiply charged ions generated by ESI can be dissociated at the interface, by collision induced dissociation (CID) or Surface induced dissociation (SID). However, charge exchange with the surface and charge partition among the fragments significantly complicate the SID and CID spectra of multiply charged large ions. High resolution FTICR is an ideal solution to this problem.

  8. Conformal mapping of unbounded multiply connected regions onto logarithmic spiral slit with infinite straight slit

    Science.gov (United States)

    Yunus, Arif A. M.; Murid, Ali H. M.

    2017-04-01

    This paper presents a boundary integral equation method with the adjoint generalized Neumann kernel for conformal mapping of unbounded multiply connected regions. The canonical region is the entire complex plane bounded by an infinite straight slit on the line Im ω = 0 and finite logarithmic spiral slits. Some linear boundary integral equations are constructed from a boundary relationship satisfied by an analytic function on a multiply connected region. These integral equations are uniquely solvable. The kernel involved in these integral equations is the adjoint generalized Neumann kernel.

  9. Wiggler Effects on the Growth Rate of a Raman Free-electron Laser with Axial Magnetic Field or Ion-Channel Guiding

    CERN Document Server

    Maraghechi, Behrouz

    2004-01-01

    A relativistic theory for Raman backscattering in the beam frame of electrons is presented and is used to find the growth rate of a free-electron laser (FEL), in the Raman regime. A one dimensional helical wiggler and an axial magnetic field are considered. The effects of static self-electric and self-magnetic fields, induced by the steady-state charge density and currents of the non-neutral electron beam, are taken into account to find the steady-state trajectories. The wiggler effects on the linear dispersion relations of the space-charge wave and radiation are included in the analysis. A numerical computation is conducted to compare the growth rate of the excited waves with nonrelativistic treatment. It was found that self-field effects increase the growth rate in the group II orbits and decrease it in the group I orbits. However, the wiggler effects on growth rate are stronger and increase the growth rate on both group I and group II orbits. The discontinuity, due to the cyclotron resonance with the radia...

  10. Channel Power in Multi-Channel Environments

    NARCIS (Netherlands)

    M.G. Dekimpe (Marnik); B. Skiera (Bernd)

    2004-01-01

    textabstractIn the literature, little attention has been paid to instances where companies add an Internet channel to their direct channel portfolio. However, actively managing multiple sales channels requires knowing the customers’ channel preferences and the resulting channel power. Two key

  11. Measurement of the Top Quark Pair Production Cross Section in the Electron and Jets Channel at $\\sqrt{s}$ = 7 TeV with the CMS Detector at the LHC

    CERN Document Server

    Klein, Benjamin

    The top quark is the heaviest fundamental particle observed in nature. The high mass leads to its decay before a hadronisation takes place which allows the measurement of its properties from the decay products. Measurements of the properties of the top quark allow for precision tests of the Standard Model of particle physics. Furthermore, top quark production is a dominant background in many searches for physics beyond the Standard Model. The Large Hadron Collider (LHC) is a high-energy particle accelerator at the European Organisation for Nuclear Research (CERN) near Geneva, Switzerland. Proton-proton collisions are recorded and analysed with several large scale detectors, one of them is the Compact Muon Solenoid (CMS) detector. This thesis presents a precision measurement of the top quark pair production cross section in the semi-leptonic electron and jets decay channel with the CMS detector at the LHC. Detailed studies of lepton identification and trigger algorithm efficiencies are summarised as they are c...

  12. Real and financial market interactions in a multiplier-accelerator model: Nonlinear dynamics, multistability and stylized facts.

    Science.gov (United States)

    Cavalli, F; Naimzada, A; Pecora, N

    2017-10-01

    In the present paper, we investigate the dynamics of a model in which the real part of the economy, described within a multiplier-accelerator framework, interacts with a financial market with heterogeneous speculators, in order to study the channels through which the two sectors influence each other. Employing analytical and numerical tools, we investigate stability conditions as well as bifurcations and possible periodic, quasi-periodic, and chaotic dynamics, enlightening how the degree of market interaction, together with the accelerator parameter and the intervention of the fiscal authority, may affect the business cycle and the course of the financial market. In particular, we show that even if the steady state is locally stable, multistability phenomena can occur, with several and complex dynamic structures coexisting with the steady state. Finally, simulations reveal that the proposed model is able to explain several statistical properties and stylized facts observed in real financial markets, including persistent high volatility, fat-tailed return distributions, volatility clustering, and positive autocorrelation of absolute returns.

  13. Real and financial market interactions in a multiplier-accelerator model: Nonlinear dynamics, multistability and stylized facts

    Science.gov (United States)

    Cavalli, F.; Naimzada, A.; Pecora, N.

    2017-10-01

    In the present paper, we investigate the dynamics of a model in which the real part of the economy, described within a multiplier-accelerator framework, interacts with a financial market with heterogeneous speculators, in order to study the channels through which the two sectors influence each other. Employing analytical and numerical tools, we investigate stability conditions as well as bifurcations and possible periodic, quasi-periodic, and chaotic dynamics, enlightening how the degree of market interaction, together with the accelerator parameter and the intervention of the fiscal authority, may affect the business cycle and the course of the financial market. In particular, we show that even if the steady state is locally stable, multistability phenomena can occur, with several and complex dynamic structures coexisting with the steady state. Finally, simulations reveal that the proposed model is able to explain several statistical properties and stylized facts observed in real financial markets, including persistent high volatility, fat-tailed return distributions, volatility clustering, and positive autocorrelation of absolute returns.

  14. Discovery of a faint, star-forming, multiply lensed, Lyman-α blob

    NARCIS (Netherlands)

    Caminha, G. B.; Karman, W.; Rosati, P.; Caputi, K. I.; Arrigoni Battaia, F.; Balestra, I.; Grillo, C.; Mercurio, A.; Nonino, M.; Vanzella, E.

    2016-01-01

    We report the discovery of a multiply lensed Lyman-α blob (LAB) behind the galaxy cluster AS1063 using the Multi Unit Spectroscopic Explorer (MUSE) on the Very Large Telescope (VLT). The background source is at z = 3.117 and is intrinsically faint compared to almost all previously reported LABs. We

  15. Ionization and fragmentation modes of nucleobases after collisions with multiply charged ions

    NARCIS (Netherlands)

    Hoekstra, R.; Morgenstern, R.; Schlathoelter, T.

    2004-01-01

    We studied multiply charged ion (MCI) induced ionization, excitation and fragmentation of the nucleobases uracil and thymine. Ions of different charge state at velocities between 0.2 and 0.4 atomic units were used as projectiles. By means of time-of-flight spectrometry of the collision products in a

  16. Modeling of Schottky Barrier Diode Millimeter-Wave Multipliers at Cryogenic Temperatures

    DEFF Research Database (Denmark)

    Johansen, Tom K.; Rybalko, Oleksandr; Zhurbenko, Vitaliy

    2015-01-01

    We report on the evaluation of Schottky barrier diode GaAs multipliers at cryogenic temperatures. A GaAs Schottky barrier diode model is developed for theoretical estimation of doubler performance. The model is used to predict efficiency of doublers from room to cryogenic temperatures...

  17. Faster multiplier and squaring units for evaluation of powers and monomials: a hardware approach

    Science.gov (United States)

    Srinivasan, Aparna

    2013-03-01

    In processors, especially DSPs, the most recurring operations are those that involve exponents and monomials. In this paper, the use of a multiplier and squaring technique based on Vedic mathematics is suggested. Algorithms for calculation of monomials and exponents that make use of the described hardware are also stated.

  18. Effects of the Implicit or Explicit Use of 1 on Students' Responses When Multiplying Monomials.

    Science.gov (United States)

    Anderson, Ann

    1995-01-01

    Tests of (n=105) ninth-grade algebra students involving the addition and multiplication of monomials found that common, systematic errors made when multiplying monomials were related logically to the symbolism used and the algebraic convention of using an implicit 1 as an exponent. (16 references) (MKR)

  19. Ultra-low-power, class-AB, CMOS four-quadrant current multiplier

    NARCIS (Netherlands)

    Sawigun, C.; Serdijn, W.A.

    2009-01-01

    A class-AB four-quadrant current multiplier constituted by a class-AB current amplifier and a current splitter which can handle input signals in excess of ten times the bias current is presented. The proposed circuit operation is based on the exponential characteristic of BJTs or subthreshold

  20. Composite Field Multiplier based on Look-Up Table for Elliptic Curve Cryptography Implementation

    Directory of Open Access Journals (Sweden)

    Marisa W. Paryasto

    2013-09-01

    Full Text Available Implementing a secure cryptosystem requires operations involving hundreds of bits. One of the most recommended algorithm is Elliptic Curve Cryptography (ECC. The complexity of elliptic curve algorithms and parameters with hundreds of bits requires specific design and implementation strategy. The design architecture must be customized according to security requirement, available resources and parameter choices. In this work we propose the use of composite field to implement finite field multiplication for ECC implementation. We use 299-bit keylength represented in GF((21323 instead of in GF(2299. Composite field multiplier can be implemented using different multiplier for ground-field and for extension field. In this paper, LUT is used for multiplication in the ground-field and classic multiplieris used for the extension field multiplication. A generic architecture for the multiplier is presented. Implementation is done with VHDL with the target device Altera DE2. The work in this paper uses the simplest algorithm to confirm the idea that by dividing field into composite, use different multiplier for base and extension field would give better trade-off for time and area. This work will be the beginning of our more advanced further research that implements composite-field using Mastrovito Hybrid, KOA and LUT.

  1. A low-phase noise frequency multiplier chain | Abdo | Zede Journal

    African Journals Online (AJOL)

    'In this paper a low phase-noise frequency multiplier chain from lOMHz to 480MHz, built in two stages and intended for use as a base for the synthesis of frequencies upto the far infrared (FIR) region, is presented. Different methods of frequency multiplication were used and the associated circuit diagrams given.

  2. A Regularity Criterion for the 3D Incompressible Magnetohydrodynamics Equations in the Multiplier Spaces

    Directory of Open Access Journals (Sweden)

    Chunhong Tian

    2017-01-01

    Full Text Available We are concerned with the regularity criterion for weak solutions to the 3D incompressible MHD equations in this paper. We show that if some partial derivatives of the velocity components and magnetic components belong to the multiplier spaces, then the solution actually is smooth on (0,T.

  3. First Order Linear Homogeneous Fuzzy Ordinary Differential Equation Based on Lagrange Multiplier Method

    Directory of Open Access Journals (Sweden)

    Sankar Prasad Mondal

    2013-11-01

    Full Text Available In this paper the First Order Linear Fuzzy Ordinary Differential Equations are described. Here coefficients and /or initial condition of said differential equation are taken as the Generalized Triangular Fuzzy Numbers (GTFNs.The solution procedure of this Fuzzy Differential Equation is developed by Lagrange Multiplier Method. An imprecise barometric pressure problem is described.

  4. Implementation gap between the theory and practice of biodiversity offset multipliers

    DEFF Research Database (Denmark)

    Bull, Joseph William; Lloyd, Samuel P.; Strange, Niels

    2017-01-01

    Emerging policies worldwide require biodiversity gains as compensation for losses associated with economic development, seeking to achieve “no net loss” (NNL). Multipliers – factors by which gains are larger than associated losses – can be crucial for true NNL. Here, we review the theoretical...

  5. The Development of a Program in Orientation and Mobility for Multiply Impaired Blind Children. Final Report.

    Science.gov (United States)

    Harley, Randall K.; And Others

    In the final report on the project to develop programed instruction in orientation and mobility for use by teachers of multiply impaired blind children, the development of the evaluation scales and programed instruction in four basic areas of precane training, the results of field testing, and the dissemination activities are described. An…

  6. A Special Project to Design a Manual in Orientation and Mobility for Multiply Impaired Blind Children.

    Science.gov (United States)

    Harley, Randall K.

    Described is the development of a programed instruction manual in mobility and orientation skills for multiply handicapped blind children. Detailed are procedures involved in creating a developmental scale to assess five basic areas: use of a seated guide, seating, trailing, protective skills, and route travel. Results are reported for a pilot…

  7. Limitations in THz Power Generation with Schottky Diode Varactor Frequency Multipliers

    DEFF Research Database (Denmark)

    Krozer, Viktor; Loata, G.; Grajal, J.

    2002-01-01

    , at increasing frequencies the power drops with f-3 instead of the f-2 predicted by theory. In this contribution we provide an overview of state-of-the-art results. A comparison with theoretically achievable multiplier performance reveals that the devices employed at higher frequencies are operating...

  8. A Classical Conditioning Procedure for the Hearing Assessment of Multiply Handicapped Persons.

    Science.gov (United States)

    Lancioni, Giulio E.; And Others

    1989-01-01

    Hearing assessments of multiply handicapped children/adolescents were conducted using classical conditioning (with an air puff as unconditioned stimulus) and operant conditioning (with a modified visual reinforcement audiometry procedure or edible reinforcement). Findings indicate that classical conditioning was successful with 21 of the 23…

  9. Evaluation of multiplier effect of housing investments in the city economy

    Science.gov (United States)

    Ovsiannikova, T.; Rabtsevich, O.; Yugova, I.

    2017-01-01

    The given study presents evaluation of the role and significance of housing investments providing stable social and economic development of a city. It also justifies multiplier impact of investments in housing construction on all the sectors of urban economy. Growth of housing investments generates multiplier effect triggering the development of other different interrelated sectors. The paper suggests approach developed by the authors to evaluate the level of city development. It involves defining gross city product on the basis of integral criterion of gross value added of types of economic activities in the city economy. The algorithm of gross value added generation in urban economy is presented as a result of multiplier effect of housing investments. The evaluation of the mentioned effect was shown on the case of the city of Tomsk (Russia). The study has revealed that multiplier effect allows obtaining four rubles of added value out of one ruble of housing investments in the city economy. Methods used in the present study include the ones of the System of National Accounts, as well as methods of statistical and structural analysis. It has been proved that priority investment in housing construction is considered to be the key factor for stable social and economic development of the city. Developed approach is intended for justification of priority directions in municipal and regional investment policy. City and regional governing bodies and potential investors are the ones to apply the given approach.

  10. Energy and intensity distributions of 279 keV multiply scattered ...

    Indian Academy of Sciences (India)

    An inverse response matrix converts the observed pulse-height distribution of a NaI(Tl) scintillation detector to a true photon spectrum. This also results in extraction of intensity and energy distributions of multiply scattered events originating from interactions of 279 keV photons with thick targets of bronze. The observed ...

  11. An Exploration of Social Media Use among Multiply Minoritized LGBTQ Youth

    Science.gov (United States)

    Lucero, Alfie Leanna

    2013-01-01

    This study responds to a need for research in a fast-growing and significant area of study, that of exploring, understanding, and documenting the numerous ways that multiply marginalized LGBTQ youth between the ages of 14 and 17 use social media. The primary research question examined whether social media provide safe spaces for multiply…

  12. The Multiplier Effect: A Strategy for the Continuing Education of School Psychologists

    Science.gov (United States)

    Lesiak, Walter; And Others

    1975-01-01

    Twenty-two school psychologists participated in a year long institute designed to test the use of a multiplier effect in the continuing professional development of school psychologists in Michigan. Results indicated that 550 school psychologists attended two in-service meetings with generally favorable reactions. (Author)

  13. The net multiplier is a new key sector indicator : Reply to De Mesnard's comment

    NARCIS (Netherlands)

    Oosterhaven, Jan

    Most of the comment of de Mesnard applies to a causal interpretation of the net multiplier that is applied to economically impossible exogenous (changes in) total output. This reply shows that this interpretation is incorrect and that his further argumentation is based on a time inconsistent

  14. Multiply periodic states and isolated skyrmions in an anisotropic frustrated magnet

    NARCIS (Netherlands)

    Mostovoy, Maxim; Leonov, Andrey

    2015-01-01

    Multiply periodic states appear in a wide variety of physical contexts, such as the Rayleigh–Bénard convection, Faraday waves, liquid crystals and skyrmion crystals recently observed in chiral magnets. Here we study the phase diagram of an anisotropic frustrated magnet which contains five different

  15. Collision Induced Dissociation of Benzylpyridinium-Substituted Porphyrins: Towards a Thermometer Scale for Multiply Charged Ions?

    Science.gov (United States)

    Brendle, Katrina; Kordel, Max; Schneider, Erik; Wagner, Danny; Bräse, Stefan; Weis, Patrick; Kappes, Manfred M.

    2017-10-01

    We have determined breakdown curves for a range of multiply charged benzylpyridinium-substituted porphyrin cations by collision induced dissociation measurements (CID) as mediated by resonant pulsed radio-frequency (rf) excitation in a helium-filled linear ion trap. Measurements were compared with the predictions of DFT calculations. We find a linear correlation between experimental fragmentation thresholds (in instrumental units of "normalized collision energy") and theoretical dissociation energies, suggesting that these species can be used as calibrants to gauge the fragmentation energetics of closely related systems. We have confirmed this by also studying the fragmentation thresholds of metalloporphyrin-based ions - including multiply negatively charged metalloporphyrin oligomers. Unfortunately, the slope of the linear correlation obtained for benzylpyridinium-substituted porphyrin multications differs significantly from that obtained by us for a set of smaller, singly charged substituted benzylpyridines put forward as "thermometer" ions in previous work. Multiplying the threshold energies in an ad hoc fashion by the ion charge basically reconciles both calibration curves. We conclude that one should use caution when applying small, singly charged benzylpyridines as calibrants to gauge the CID of large, multiply charged ions in ion-trap mass spectrometers.

  16. The impact of founder events on chromosomal variability in multiply mating species

    DEFF Research Database (Denmark)

    Pool, John E; Nielsen, Rasmus

    2008-01-01

    size reductions and recent bottlenecks leading to decreased X/A diversity ratios. Here we use theory and simulation to investigate a separate demographic effect-that of founder events involving multiply mated females-and find that it leads to much stronger reductions in X/A diversity ratios than...

  17. Testing of money multiplier model for Pakistan: does monetary base carry any information?

    Directory of Open Access Journals (Sweden)

    Muhammad Arshad Khan

    2010-02-01

    Full Text Available This paper tests the constancy and stationarity of mechanic version of the money multiplier model for Pakistan using monthly data over the period 1972M1-2009M2. We split the data into pre-liberalization (1972M1-1990M12 and post-liberalization (1991M1-2009M2 periods to examine the impact of financial sector reforms. We first examine the constancy and stationarity of the money multiplier and the results suggest the money multiplier remains non-stationary for the entire sample period and sub-periods. We then tested cointegration between money supply and monetary base and find the evidence of cointegration between two variables for the entire period and two sub-periods. The coefficient restrictions are satisfied only for the post-liberalization period. Two-way long-run causality between money supply and monetary base is found for the entire period and post-liberalization. For the post-liberalization period the evidence of short-run causality running from monetary base to money supply is also identified. On the whole, the results suggest that money multiplier model can serve as framework for conducting short-run monetary policy in Pakistan. However, the monetary authority may consider the co-movements between money supply and reserve money at the time of conducting monetary policy.

  18. Time-area efficient multiplier-free recursive filter architectures for FPGA implementation

    DEFF Research Database (Denmark)

    Shajaan, Mohammad; Sørensen, John Aasted

    1996-01-01

    Simultaneous design of multiplier-free recursive filters (IIR filters) and their hardware implementation in Xilinx field programmable gate array (XC4000) is presented. The hardware design methodology leads to high performance recursive filters with sampling frequencies in the interval 15-21 MHz (...

  19. Time-area efficient multiplier-free filter architectures for FPGA implementation

    DEFF Research Database (Denmark)

    Shajaan, Mohammad; Nielsen, Karsten; Sørensen, John Aasted

    1995-01-01

    Simultaneous design of multiplier-free filters and their hardware implementation in Xilinx field programmable gate array (XC4000) is presented. The filter synthesis method is a new approach based on cascade coupling of low order sections. The complexity of the design algorithm is 𝒪 (filter o...

  20. Pointwise Multipliers on Spaces of Homogeneous Type in the Sense of Coifman and Weiss

    Directory of Open Access Journals (Sweden)

    Yanchang Han

    2014-01-01

    homogeneous type in the sense of Coifman and Weiss, pointwise multipliers of inhomogeneous Besov and Triebel-Lizorkin spaces are obtained. We make no additional assumptions on the quasi-metric or the doubling measure. Hence, the results of this paper extend earlier related results to a more general setting.

  1. A Low-jitter 2.5-to-10 GHz Clock Multiplier Unit in CMOS

    NARCIS (Netherlands)

    van de Beek, R.C.H.; Vaucher, C.S.; Leenaerts, D.M.W.; Klumperink, Eric A.M.; Nauta, Bram

    Abstract— This paper demonstrates a low-jitter clock multiplier unit [1] that generates a 10 GHz output clock from a 2.5 GHz reference clock. An integrated 10 GHz LCoscillator is locked to the input clock, using a simple and fast phase detector circuit. This phase detector overcomes the speed

  2. On Shor's Channel Extension and Constrained Channels

    Science.gov (United States)

    Holevo, A. S.; Shirokov, M. E.

    Several equivalent formulations of the additivity conjecture for constrained channels, which formally is substantially stronger than the unconstrained additivity, are given. To this end a characteristic property of the optimal ensemble for such a channel is derived, generalizing the maximal distance property. It is shown that the additivity conjecture for constrained channels holds true for certain nontrivial classes of channels. After giving an algebraic formulation for Shor's channel extension, its main asymptotic property is proved. It is then used to show that additivity for two constrained channels can be reduced to the same problem for unconstrained channels, and hence, ``global'' additivity for channels with arbitrary constraints is equivalent to additivity without constraints.

  3. KAJIAN EFEK MULTIPLIER PRODUK UNGGULAN BERBASIS KLUSTER UKM PENGOLAHAN IKAN ASAP

    Directory of Open Access Journals (Sweden)

    Yusmar Ardhi Hidayat

    2015-05-01

    Full Text Available The purpose of this research are to analyze scale of production of leading commodities and multiplier effect of cultivation and smoked fish in Wonosari, Bonang Demak. This research applies census method in collecting data from all business unit which identified as leading commodities in Wirosari Village, Bonang, Demak Regency. Regarding survey conducted, there are 18 catfish breeders and 49 smoked fish small business used as respondent. Primary data used in this research are rate of production in basis goods, land area, capital, raw materials, manpower, and income multiplier. To support empirical discussion, tools of analysis used in this research are descriptive statistics and income multiplier. Results of this research are primary commodities in Wonosari Village are smoked fish and fresh cat fish. Total production of smoked fish reaches 6.4 Ton each day for with type of smoked fish such as river cat fish, tongkol, sting-ray, cat fish, and other river fish. Meanwhile total production of catfish breeding reaches 105 Ton in first harvest after 2-3 months. Based on that number, smoked fish business promise higher profit than profits catfish breeding. Tujuan penelitian ini adalah menganalisis tingkat produksi dan efek multiplier produk unggulan budidaya dan pengasapan ikan di Desa Wonosari, Bonang Kabupaten Demak. Penelitian mengunakan metode sensus dengan mencari data dari semua unit usaha yang merupakan produk unggulan di Desa Wirosari, Bonang Kecamatan Demak. Responden yang diperoleh sejumlah 18 pembudidaya ikan dan 49 usaha pengasapan ikan. Data primer yang akan digunakan yaitu data jumlah produksi komoditas unggulan, luas lahan, jumlah modal, bahan baku, tenaga kerja, dan multiplier pendapatan. Alat analisis yang digunakan dalam penelitian ini adalah statistik deskriptif, dan indeks multiplier pendapatan. Hasil penelitian menunjukkan bahwa komoditas unggulan Desa Wonosari Kecamatan Bonang Kabupaten Demak adalah Ikan Asap dan Budidaya Ikan Lele

  4. Multi-MW 22.8 GHz Harmonic Multiplier - RF Power Source for High-Gradient Accelerator R&D

    Energy Technology Data Exchange (ETDEWEB)

    Jay L. Hirshfield

    2012-07-26

    Electrodynamic and particle simulation studies have been carried out to optimize design of a two-cavity harmonic frequency multiplier, in which a linear electron beam is energized by rotating fields near cyclotron resonance in a TE111 cavity in a uniform magnetic field, and in which the beam then radiates coherently at the nth harmonic into a TEn11 output cavity. Examples are worked out in detail for 7th and 2nd harmonic converters, showing RF-to-RF conversion efficiencies of 45% and 88%, respectively at 19.992 GHz (K-band) and 5.712 GHz (C-band), for a drive frequency of 2.856 GHz. Details are shown of RF infrastructure (S-band klystron, modulator) and harmonic converter components (drive cavity, output cavities, electron beam source and modulator, beam collector) for the two harmonic converters to be tested. Details are also given for the two-frequency (S- and C-band) coherent multi-MW test stand for RF breakdown and RF gun studies.

  5. DO PUBLIC AND PRIVATE DEBT LEVELS AFFECT THE SIZE OF FISCAL MULTIPLIERS?

    Directory of Open Access Journals (Sweden)

    Chairul Adi

    2017-09-01

    Full Text Available This paper investigates the effectiveness of fiscal policies – as measured by the impact and cumulative multipliers – and how they interact with public and private debt. Harnessing the moderated panel regression approach, based on the yearly data set of several economies during the period from 1996 to 2012, the analysis is focused on the impact of spending-and-revenue-based fiscal policies on economic growth and how these fiscal instruments interact with public and private indebtedness. The result of spending stimuli advocates the basic Keynesian theory. An increase in public expenditures contemporaneously generates a positive multiplier, of around 0.29 – 0.44 and around 0.45 – 0.58 during two years. Decomposing the expenditures into their elements, this paper documents a stronger impact from public investment than that from government purchases. On the other hand, the revenue stimuli seem to follow the Ricardian Equivalence Hypothesis (REH, arguing that current tax cuts are inconsequential. The impact and cumulative multipliers for this fiscal instrument have mixed results, ranging from -0.21 to 0.05 and -0.26 to 0.06, respectively. Moreover, no robust evidence is found to support the argument that government debt moderates the effectiveness of fiscal policies. The size of the multipliers for both spending and revenue policies remain constant with the level of public debt. On the other hand, private debt appears to show a statistically significant moderating effect on spending stimuli. Its impact on spending multipliers, however, is economically insignificant. The moderation effect of private debt on the revenue stimuli does not seem to exist. Finally, this paper documents that both public and private debt exhibit a negative and statistically significant estimation for economic output.

  6. Elaboration and research of planetary precessional multiplier type K-H-V

    Science.gov (United States)

    Bostan, I.; Dulgheru, V.; Ciobanu, R.

    2016-08-01

    The multiplier is an indispensable part of the micro hydropower plant and high power wind turbine. It helps to increase rotor low speeds limited by the water flow small velocity and by the relative big placement diameter of the blades that participate in the energy conversion. For example, the microhydrostation rotor's speed is (2 - 3) min'1 for water flow velocity V= (1...1,6) m/s and for blade placement diameter D = 4 m. Diversity of requirements forwarded by the beneficiaries of mechanical transmissions consists, in particular, in increasing reliability, efficiency and lifting capacity, and in reducing the mass and dimensions. It becomes more and more difficult to satisfy the mentioned demands by partial updating of traditional transmissions. The target problem can be solved with special effects by developing new types of multipliers based on precessional planetary transmissions with multiple gear, that were developed by the authors. Absolute multiplicity of precessional gear (up to 100% pairs of teeth simultaneously involved in gearing, compared to 5%-7% - in classical gearings) provides increased lifting capacity and small mass and dimensions. To mention that until now precessional planetary transmissions have been researched and applied mainly in reducers. Therefore it was necessary to carry out theoretical research to determine the geometrical parameters of the precessional gear that operates in multiplier mode. Also, it was necessary to develop new conceptual diagrams of precessional transmissions that function under multiplier regime. The majority of precessional planetary transmissions diagrams developed previously operate efficiently in reducer's regime. Depending on the structural diagram, precessional transmissions fall into two main types - K-H-V and 2K-H, from which a wide range of constructive solutions with wide kinematical and functional options that operate in multiplier regime.

  7. Prometeo: A portable test-bench for the upgraded front-end electronics of the ATLAS Tile calorimeter

    CERN Document Server

    Bullock, D; The ATLAS collaboration; Govender, M; Hofsajer, I; Mellado, B; Moreno, P; Reed, R; Ruan, X; Sandrock, C; Solans, C; Suter, R; Usai, G; Valero, A

    2014-01-01

    Prometeo is a portable test-bench for full certification of the front-end electronics of the ATLAS Tile calorimeter, designed for the upgrade phase-II. It is a high-throughput electronic system designed to simultaneously read out all the digitized samples from 12 channels at the LHC bunch crossing frequency and assess the quality of the data in real-time. The core of the system is a Xilinx Virtex 7 evaluation board extended with a dual QSFP FMC module to read out and control the on-detector electronics. The rest of the functionalities of the system are provided by a HV mezzanine board that supplied the HV to the photo-multipliers, an LED board that sends light to illuminate them, and a 12 channel ADC board that samples the analog trigger output of the front- end. The system is connected by ethernet to a GUI client from which QA tests are performed on the electronics such as noise measurements and linearity response to an injected charge.

  8. Voltage-gated Proton Channels

    Science.gov (United States)

    DeCoursey, Thomas E.

    2014-01-01

    Voltage-gated proton channels, HV1, have vaulted from the realm of the esoteric into the forefront of a central question facing ion channel biophysicists, namely the mechanism by which voltage-dependent gating occurs. This transformation is the result of several factors. Identification of the gene in 2006 revealed that proton channels are homologues of the voltage-sensing domain of most other voltage-gated ion channels. Unique, or at least eccentric, properties of proton channels include dimeric architecture with dual conduction pathways, perfect proton selectivity, a single-channel conductance ~103 smaller than most ion channels, voltage-dependent gating that is strongly modulated by the pH gradient, ΔpH, and potent inhibition by Zn2+ (in many species) but an absence of other potent inhibitors. The recent identification of HV1 in three unicellular marine plankton species has dramatically expanded the phylogenetic family tree. Interest in proton channels in their own right has increased as important physiological roles have been identified in many cells. Proton channels trigger the bioluminescent flash of dinoflagellates, facilitate calcification by coccolithophores, regulate pH-dependent processes in eggs and sperm during fertilization, secrete acid to control the pH of airway fluids, facilitate histamine secretion by basophils, and play a signaling role in facilitating B-cell receptor mediated responses in B lymphocytes. The most elaborate and best-established functions occur in phagocytes, where proton channels optimize the activity of NADPH oxidase, an important producer of reactive oxygen species. Proton efflux mediated by HV1 balances the charge translocated across the membrane by electrons through NADPH oxidase, minimizes changes in cytoplasmic and phagosomal pH, limits osmotic swelling of the phagosome, and provides substrate H+ for the production of H2O2 and HOCl, reactive oxygen species crucial to killing pathogens. PMID:23798303

  9. Charged and Neutral Particles Channeling Phenomena Channeling 2008

    Science.gov (United States)

    Dabagov, Sultan B.; Palumbo, Luigi

    2010-04-01

    regime by a buried oxide layer / V. Guidi, A. Mazzolari and V. V. Tikhomirov -- A positron source using channeling in crystals for linear colliders / X. Artru ... [et al.] -- Parametric channeling and collapse of charged particles beams in crystals / M. Vysotskyy and V. Vysotskii.The formation and usage of coherent correlated charged particles states in the physics of channeling in crystals / S. V. Adamenko, V. I. Vysotskii and M. V. Vysotskyy -- Surface channeling of magnetic-charged particles on multilayer surface / S. V. Adamenko and V. I. Vysotskii -- Coherent creation of anti-hydrogen atoms in a crystal by relativistic antiproton / Yu. P. Kunashenko -- Thermal equilibrium of light ions in heavy crystals / E. Tsyganov -- Photon emission of electrons in a crystalline undulator / H. Backe ... [et al.] -- Channeling radiation from relativistic electrons in a crystal target as complementary x-ray and gamma ray source at synchrotron light facilities / K. B. Korotchenko, Yu. L. Pivovarov and T. A. Tukhfatullin -- Diffracted channeling radiation and other compound radiation processes / H. Nitta -- Collective scattering on the atom planes under the condition of full transition / A. R. Mkrtchyan ... [et al.] -- The proposal of the experiment on the research of the diffracted channeling radiation / D. A. Baklanov ... [et al.] -- Positron channeling at the DaOne BTF Facility: the cup experiment / L. Quintieri ... [et al.] -- Radiation spectra of 200 MeV electrons in diamond and silicon crystals at axial and planar orientations / K. Fissum ... [et al.] -- Channeling experiments with electrons at the Mainz Microtron Mami / W. Lauth ... [et al.] -- Dechanneling of positrons by dislocations: effects of anharmonic interactions / J. George and A. P. Pathak -- Diffracted channeling radiation from axially channeled relativistic electrons / K. B. Korotchenko ... [et al.] -- Intensive quasi-monochromatic, directed x-ray radiation of planar channeled positron bunch / L. Gevorgian

  10. Exact solutions for a periodic assembly of bubbles in a Hele-Shaw channel

    CERN Document Server

    Vasconcelos, Giovani L

    2014-01-01

    Exact solutions are reported for a periodic assembly of bubbles steadily co-travelling in a Hele-Shaw channel. The solutions are obtained as conformal mappings from a multiply connected circular domain in an auxiliary complex plane to the flow region in a period cell. The conformal mappings are constructed using the generalized Schwarz-Christoffel formula for multiply connected polygonal domains in terms of products of Schottky-Klein prime functions. It is shown that previous solutions for multiple steady bubbles in a Hele-Shaw cell are all particular cases of the solutions described herein. Examples of specific bubble configurations are discussed.

  11. Analytical admittance characterization of high mobility channel

    Energy Technology Data Exchange (ETDEWEB)

    Mammeri, A. M.; Mahi, F. Z., E-mail: fati-zo-mahi2002@yahoo.fr [Institute of Science and Technology, University of Bechar (Algeria); Varani, L. [Institute of Electronics of the South (IES - CNRS UMR 5214), University of Montpellier (France)

    2015-03-30

    In this contribution, we investigate the small-signal admittance of the high electron mobility transistors field-effect channels under a continuation branching of the current between channel and gate by using an analytical model. The analytical approach takes into account the linearization of the 2D Poisson equation and the drift current along the channel. The analytical equations discuss the frequency dependence of the admittance at source and drain terminals on the geometrical transistor parameters.

  12. WEARABLE ELECTRONICS IN THE NEXT YEARS

    Directory of Open Access Journals (Sweden)

    PRINIOTAKIS George

    2015-05-01

    Full Text Available The term ‘Wearable Technologies’, ‘Wearable Electronics’, or ‘Smart Garments’, is associated to those clothing and soft or hard accessories which integrate electronic components, or which are made of smart textiles. Smart textiles research represents a new model for generating creative and novel solutions for integrating electronics into unusual environments and will result in new discoveries that push the boundaries of science forward. Last few years there are several hundreds or maybe thousands of research teams that works and develop such materials and products. But the key driver of the success of the wearable electronics is the acceptance from the end user. It is estimates that only for the next three years the sales in the wearable will be almost multiply by ten times. The flexible wearable computer industry's patent applications arrived at 429 in the second quarter of 2014, up 27.7% year on year, and witnessed a record high in the report's tracking period starting from the first quarter of 2012. The market has already in the shelf commercial products as wristbands (Fitness/well-being/sports devices, smart jewels, smart watches, mobile health devices, tech clothing, and augmented reality glasses. The recently developed enabling technologies eliminates the barriers and help the scientists and developers to launch new types of "wearable". The life style of a large share of population, the low cost of 3D printing for rapid prototyping locally, the large available platforms, the lower cost of sensors and components give a an impetus for large scale of products. In the same time the direct ordering channels to manufacturers of components facilitates the small producers and the scientists for prototype development. In this article we identify key challenges for the success of the wearable and we provide an outlook over the field and a prediction for the near future.

  13. Helium, Oxygen, Proton, and Electron (HOPE) Mass Spectrometer for the Radiation Belt Storm Probes Mission

    Science.gov (United States)

    Funsten, H. O.; Skoug, R. M.; Guthrie, A. A.; MacDonald, E. A.; Baldonado, J. R.; Harper, R. W.; Henderson, K. C.; Kihara, K. H.; Lake, J. E.; Larsen, B. A.; Puckett, A. D.; Vigil, V. J.; Friedel, R. H.; Henderson, M. G.; Niehof, J. T.; Reeves, G. D.; Thomsen, M. F.; Hanley, J. J.; George, D. E.; Jahn, J.-M.; Cortinas, S.; De Los Santos, A.; Dunn, G.; Edlund, E.; Ferris, M.; Freeman, M.; Maple, M.; Nunez, C.; Taylor, T.; Toczynski, W.; Urdiales, C.; Spence, H. E.; Cravens, J. A.; Suther, L. L.; Chen, J.

    2013-11-01

    The HOPE mass spectrometer of the Radiation Belt Storm Probes (RBSP) mission (renamed the Van Allen Probes) is designed to measure the in situ plasma ion and electron fluxes over 4 π sr at each RBSP spacecraft within the terrestrial radiation belts. The scientific goal is to understand the underlying physical processes that govern the radiation belt structure and dynamics. Spectral measurements for both ions and electrons are acquired over 1 eV to 50 keV in 36 log-spaced steps at an energy resolution Δ E FWHM/ E≈15 %. The dominant ion species (H+, He+, and O+) of the magnetosphere are identified using foil-based time-of-flight (TOF) mass spectrometry with channel electron multiplier (CEM) detectors. Angular measurements are derived using five polar pixels coplanar with the spacecraft spin axis, and up to 16 azimuthal bins are acquired for each polar pixel over time as the spacecraft spins. Ion and electron measurements are acquired on alternate spacecraft spins. HOPE incorporates several new methods to minimize and monitor the background induced by penetrating particles in the harsh environment of the radiation belts. The absolute efficiencies of detection are continuously monitored, enabling precise, quantitative measurements of electron and ion fluxes and ion species abundances throughout the mission. We describe the engineering approaches for plasma measurements in the radiation belts and present summaries of HOPE measurement strategy and performance.

  14. Radio Channel Modeling in Body Area Networks

    NARCIS (Netherlands)

    An, L.; Bentum, Marinus Jan; Meijerink, Arjan; Scanlon, W.G.

    2009-01-01

    A body area network (BAN) is a network of bodyworn or implanted electronic devices, including wireless sensors which can monitor body parameters or to de- tect movements. One of the big challenges in BANs is the propagation channel modeling. Channel models can be used to understand wave propagation

  15. Radio channel modeling in body area networks

    NARCIS (Netherlands)

    An, L.; Bentum, Marinus Jan; Meijerink, Arjan; Scanlon, W.G.

    2010-01-01

    A body area network (BAN) is a network of bodyworn or implanted electronic devices, including wireless sensors which can monitor body parameters or to detect movements. One of the big challenges in BANs is the propagation channel modeling. Channel models can be used to understand wave propagation in

  16. Enhancing shelf life of minimally processed multiplier onion using silicone membrane.

    Science.gov (United States)

    Naik, Ravindra; Ambrose, Dawn C P; Raghavan, G S Vijaya; Annamalai, S J K

    2014-12-01

    The aim of storage of minimal processed product is to increase the shelf life and thereby extend the period of availability of minimally processed produce. The silicone membrane makes use of the ability of polymer to permit selective passage of gases at different rates according to their physical and chemical properties. Here, the product stored maintains its own atmosphere by the combined effects of respiration process of the commodity and the diffusion rate through the membrane. A study was undertaken to enhance the shelf life of minimally processed multiplier onion with silicone membrane. The respiration activity was recorded at a temperature of 30 ± 2 °C (RH = 60 %) and 5 ± 1 °C (RH = 90 %). The respiration was found to be 23.4, 15.6, 10 mg CO2kg(-1)h(-1) at 5 ± 1 °C and 140, 110, 60 mg CO2kg(-1) h(-1) at 30 ± 2° for the peeled, sliced and diced multiplier onion, respectively. The respiration rate for the fresh multiplier onion was recorded to be 5, 10 mg CO2kg(-1) h(-1) at 5 ± 1 °C and 30 ± 1 ° C, respectively. Based on the shelf life studies and on the sensory evaluation, it was found that only the peeled multiplier onion could be stored. The sliced and diced multiplier onion did not have the required shelf life. The shelf life of the multiplier onion in the peel form could be increased from 4-5 days to 14 days by using the combined effect of silicone membrane (6 cm(2)/kg) and low temperature (5 ± 1 °C).

  17. Multiple steadily translating bubbles in a Hele-Shaw channel

    CERN Document Server

    Green, Christopher C

    2013-01-01

    Analytical solutions are constructed for an assembly of any finite number of bubbles in steady motion in a Hele-Shaw channel. The solutions are given in the form of a conformal mapping from a bounded multiply connected circular domain to the flow region exterior to the bubbles. The mapping is written as the sum of two analytic functions---corresponding to the complex potentials in the laboratory and co-moving frames---that map the circular domain onto respective degenerate polygonal domains. These functions are obtained using the generalised Schwarz-Christoffel formula for multiply connected domains in terms of the Schottky-Klein prime function. Our solutions are very general in that no symmetry assumption concerning the geometrical disposition of the bubbles is made. Several examples for various bubble configurations are discussed.

  18. Novel Optimization Method of Active Frequency Multiplier Utilizing Harmonic Terminating Impedances with DGS

    Directory of Open Access Journals (Sweden)

    M. Kasal

    2006-06-01

    Full Text Available A novel method for the optimization of the active frequency multiplier utilizing the harmonic terminating impedances with the defected ground structures (DGS has been developed. Furthermore, a new type of the low-pass filter with DGS for the higher harmonic suppression will be reported. Experimental conversion gains (14.52 dB for the doubler, 5.56 dB for the tripler and 0.43 dB for the quadrupler and real power-added efficiency (32.76 % for the doubler, 10.15 % for the tripler and 1.42 % for the quadrupler have been attained. To our knowledge, in the considered frequency range, these results represent the best performance reported up to date for the active frequency multipliers utilizing the low-cost BJTs.

  19. On-Chip Power-Combining for High-Power Schottky Diode-Based Frequency Multipliers

    Science.gov (United States)

    Chattopadhyay, Goutam; Mehdi, Imran; Schlecht, Erich T.; Lee, Choonsup; Siles, Jose V.; Maestrini, Alain E.; Thomas, Bertrand; Jung, Cecile D.

    2013-01-01

    A 1.6-THz power-combined Schottky frequency tripler was designed to handle approximately 30 mW input power. The design of Schottky-based triplers at this frequency range is mainly constrained by the shrinkage of the waveguide dimensions with frequency and the minimum diode mesa sizes, which limits the maximum number of diodes that can be placed on the chip to no more than two. Hence, multiple-chip power-combined schemes become necessary to increase the power-handling capabilities of high-frequency multipliers. The design presented here overcomes difficulties by performing the power-combining directly on-chip. Four E-probes are located at a single input waveguide in order to equally pump four multiplying structures (featuring two diodes each). The produced output power is then recombined at the output using the same concept.

  20. Effect of cooling on the efficiency of Schottky varactor frequency multipliers at millimeter waves

    Science.gov (United States)

    Louhi, Jyrki; Raiesanen, Antti; Erickson, Neal

    1992-01-01

    The efficiency of the Schottky diode multiplier can be increased by cooling the diode to 77 K. The main reason for better efficiency is the increased mobility of the free carriers. Because of that the series resistance decreases and a few dB higher efficiency can be expected at low input power levels. At high output frequencies and at high power levels, the current saturation decreases the efficiency of the multiplication. When the diode is cooled the maximum current of the diode increases and much more output power can be expected. There are also slight changes in the I-V characteristic and in the diode junction capacitance, but they have a negligible effect on the efficiency of the multiplier.

  1. Studying the capture cross sections of structural elements by measuring neutron balance in multiplying media

    Energy Technology Data Exchange (ETDEWEB)

    Golubev, V.N.; Dulin, V.A.; Kazanskij, Yu.A.

    1986-10-01

    To refine neutron capture cross sections for structural elements used in fast power reactors the neutron balance in multiplying media with neutron multiplication factor K/sub infinity/=1 has been studied at KBR and ERMINE critical assemblies. Reactivity of multiplying cells consisting of uranium and structural elements is measured as well as reactivity coefficients of individual structural materials. Corresponding calculations are performed using the versions of group constants applied in designing the fast reactors in the USSR and France. The CARNAVAL 4 constant version predicts well a fraction of neutron absorptions in steel and nickel for the spectra typical for a power reactor (ERMINE assembly). For softer spectra (KBR assembly) the agreement with experiment is better when the BNAB-78 constant version is used.

  2. Bacillus subtilis Swarmer Cells Lead the Swarm, Multiply, and Generate a Trail of Quiescent Descendants

    Directory of Open Access Journals (Sweden)

    Lina Hamouche

    2017-02-01

    Full Text Available Bacteria adopt social behavior to expand into new territory, led by specialized swarmers, before forming a biofilm. Such mass migration of Bacillus subtilis on a synthetic medium produces hyperbranching dendrites that transiently (equivalent to 4 to 5 generations of growth maintain a cellular monolayer over long distances, greatly facilitating single-cell gene expression analysis. Paradoxically, while cells in the dendrites (nonswarmers might be expected to grow exponentially, the rate of swarm expansion is constant, suggesting that some cells are not multiplying. Little attention has been paid to which cells in a swarm are actually multiplying and contributing to the overall biomass. Here, we show in situ that DNA replication, protein translation and peptidoglycan synthesis are primarily restricted to the swarmer cells at dendrite tips. Thus, these specialized cells not only lead the population forward but are apparently the source of all cells in the stems of early dendrites. We developed a simple mathematical model that supports this conclusion.

  3. Post-2008 Brazilian fiscal policy: an interpretation through the analysis of fiscal multipliers

    Directory of Open Access Journals (Sweden)

    Celso José Costa Junior

    Full Text Available Abstract The global crisis that erupted in 2007 led many countries to embark on countercyclical fiscal policies as a way to cushion the blow of a depressed aggregate demand. Advocates of discretionary measures emphasize that fiscal policy can indeed stimulate the economy. The main goal of this work is to assess whether the fiscal policies pursued by the Brazilian government in the aftermath of the 2008 crisis, succeeded in bringing the economy back on track in a sustainable fashion. To this end, the fiscal multipliers of five different shocks are studied in a small open-economy New Keynesian framework. Our results point to the government spending and public investment as the most effective fiscal tools for combating the crisis. However, the highest fiscal multiplier turned out to be the one associated with excise tax reductions.

  4. Different I/O Standard and Technology Based Thermal Aware Energy Efficient Vedic Multiplier Design for Green Wireless Communication on FPGA

    DEFF Research Database (Denmark)

    Goswami, Kavita; Pandey, Bishwajeet; Kumar, Tanesh

    2017-01-01

    with high speed as compared with traditional array and booth multipliers. Vedic Multiplier contains a total of sixteen algorithms/sutras for predominantly logical operations. This research focuses on thermal aspects and energy efficiency of wireless communications systems with the thermal aware low power......This paper deals with low power multiplier design that plays a significant role in green wireless communications systems. Over the period of time, researchers have proposed various multiplier designs in order to get high speed. Vedic multiplier is considered as one of the low power multiplier along...... design of Vedic Multiplier. Temperature plays an important role on the performance of any device. The primary purpose of this research is to enhance the thermal stability of the wireless communications. Energy efficient IO standards are used to decrease the power dissipation of Vedic Multiplier...

  5. A convolution type characterization for Lp - multipliers for the Heisenberg group

    Directory of Open Access Journals (Sweden)

    R. Radha

    2007-01-01

    Full Text Available It is well known that if m is an Lp - multiplier for the Fourier transform on ℝn(1

  6. Isometric multipliers of Lp(G, X) Lp(G, X) Lp(G, X)

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Abstract. Let G be a locally compact group with a fixed right Haar measure and X a separable Banach space. Let Lp(G, X) be the space of X-valued measurable functions whose norm-functions are in the usual Lp . A left multiplier of Lp(G, X) is a bounded linear operator on Lp(G, X) which commutes with all left translations.

  7. Ad Hoc Microphone Array Beamforming Using the Primal-Dual Method of Multipliers

    DEFF Research Database (Denmark)

    Tavakoli, Vincent Mohammad; Jensen, Jesper Rindom; Heusdens, Richard

    2016-01-01

    In the recent years, there have been increasing amount of researches aiming at optimal beamforming with ad hoc microphone arrays, mostly with fusion-based schemes. However, huge amount of computational complexity and communication overhead impede many of these algorithms from being useful...... the distributed linearly-constrained minimum variance beamformer using the the state of the art primal-dual method of multipliers. We study the proposed algorithm with an experiment....

  8. The unitary cover of a finite group and the exponent of the Schur multiplier

    OpenAIRE

    Sambonet, Nicola

    2013-01-01

    For a finite group we introduce a particular central extension, the unitary cover, having minimal exponent among those satisfying the projective lifting property. We obtain new bounds for the exponent of the Schur multiplier relating to subnormal series, and we discover new families for which the bound is the exponent of the group. Finally, we show that unitary covers are controlled by the Zel'manov solution of the restricted Burnside problem for 2-generator groups.

  9. Integrated MOS four-quadrant analogue multiplier using switched-capacitor technique

    Science.gov (United States)

    Yasumoto, M.; Enomoto, T.

    1982-09-01

    A fully integrated four-quadrant analog multiplier based on switched-capacitor technique for realisation of high-speed and high-density analog LSIs was developed using a MOS VLSI process. Excellent characteristics such as low total harmonic distortion of -50 dB for two input signals of 1 Vp-p, large dynamic range of 80 dB and fast operation speed of 2 MHz clock rate were obtained. Application to convolvers and correlators is also demonstrated.

  10. Occurrence of the Cys311 DRD2 variant in a pedigree multiply affected with panic disorder

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, F.; Hoyne, J.; Diaz, P. [Univ. of South Florida, Tampa, FL (United States)] [and others

    1995-08-14

    Following the detection of the rare DRD2 codon 311 variant (Ser{yields}Cys) in an affected member from a large, multiply affected panic disorder family, we investigated the occurrence of this variant in other family members. The variant occurred in both affected and unaffected individuals. Further screening in panic disorder sib pairs unrelated to this family failed to detect the Cys311 variant. Our data suggests that this variant has no pathogenic role in panic disorder. 18 refs., 1 fig.

  11. A Lagrange multiplier and Hopfield-type barrier function method for the traveling salesman problem.

    Science.gov (United States)

    Dang, Chuangyin; Xu, Lei

    2002-02-01

    A Lagrange multiplier and Hopfield-type barrier function method is proposed for approximating a solution of the traveling salesman problem. The method is derived from applications of Lagrange multipliers and a Hopfield-type barrier function and attempts to produce a solution of high quality by generating a minimum point of a barrier problem for a sequence of descending values of the barrier parameter. For any given value of the barrier parameter, the method searches for a minimum point of the barrier problem in a feasible descent direction, which has a desired property that lower and upper bounds on variables are always satisfied automatically if the step length is a number between zero and one. At each iteration, the feasible descent direction is found by updating Lagrange multipliers with a globally convergent iterative procedure. For any given value of the barrier parameter, the method converges to a stationary point of the barrier problem without any condition on the objective function. Theoretical and numerical results show that the method seems more effective and efficient than the softassign algorithm.

  12. Severity Multipliers as a Methodology to Explore Potential Effects of Climate Change on Stream Bioassessment Programs

    Directory of Open Access Journals (Sweden)

    Sonja C. Jähnig

    2017-04-01

    Full Text Available Given the scientific consensus that climate change is impacting biodiversity, estimates of future climate change effects on stream communities and assessments of potential biases are necessary. Here, we propose a simple technique to approximate changes in invertebrate and fish biomonitoring results. Taxa lists for 60 (invertebrate and 52 (fish sites were each modified by 10 multipliers as stepwise 5% or 10% changes in abundances to simulate potential climate-change severity, reflecting increasing climate change effects. These 10 multipliers were based on the stream zonation preference for invertebrates and the Fish Region Index (FRI values for fish, both reflecting the longitudinal gradient present in river ecosystems. The original and modified taxa lists were analyzed using the standard assessment software for the particular group, followed by analysis of key biomonitoring metrics. For invertebrates, our simulations affected small good quality streams more often negatively while large poor mountain streams showed a tendency to improve. Forty percent of the invertebrate data sites showed a change in the final ecological assessment class when using the multipliers, with the poor quality sites changing more often. For fish, metric changes were variable, but the FRI ratio showed mostly positive responses, i.e., a shift in FRI towards downstream communities. The results are discussed as an example that facilitates the interpretation of potential climate-change effects with varying severity. Further, we discuss the simplified approach and implications for assessment from climate change induced range shifts.

  13. Making of an electronic interferometer to study emissive properties of field-effect microtips. Diffraction and interferences of slow electrons; Construction d`un interferometre electronique pour l`etude des proprietes emissives de micropointes a effet de champ. Diffraction et interferences d`electrons lents

    Energy Technology Data Exchange (ETDEWEB)

    Py, C.

    1993-10-01

    The substitution of hot filaments by field-effect microtips has several advantages in many electronic applications. LETI has already proved the interest of this principle for flat panel displays; many people believe it could also provide novel microwave sources. Moreover, the properties of the emission enable to seek new electron optics applications that were not possible with hot filaments. An interferometry experiment was designed, developed and characterized in order to evaluate the potential of the microtips fabricated in the LETI for such applications. This experiment is composed of a Mollenstedt biprism, of electrostatic lenses and an imaging system composed of deflection plates, a small aperture diaphragm (1 {mu}m) and a channel electron multiplier. Quantum wave effects have been observed, which confirms the good coherence properties of the source. Moreover, this experimental setup enables to better understand the physical phenomenon of the emission of the tips fabricated in the LETI, and to propose some technological improvements for the applications we seek. It is also designed for electron holography applications, and should allow the study of new compact electron optics apparatus taking account of the wave properties of the electrons emitted by microtips. (author). 68 figs. 2 annexes. 41 refs.

  14. Two-phase pressure drops for CANDU fuel bundles in uncrept and crept channels

    Energy Technology Data Exchange (ETDEWEB)

    Sutradhar, S.C. [Atomic Energy of Canada Ltd., Chalk River, Ontario (Canada)

    2001-07-01

    Pressure-drop tests in Freon-134a were performed on aligned and misaligned 37-element CANDU (C6) fuel bundles in uncrept and 3% crept channels. The results indicate that the two-phase pressure-drop profiles are similar in shape, but higher in magnitude, compared with the single-phase pressure-drop profiles. The two-phase multipliers (TPMs) are a strong function of the thermodynamic quality of the fluid. The measured TPMs of the bundles in the uncrept channel are higher than those in the crept channel. The measured TPMs for the aligned bundles agree well with the Beattie correlation. (author)

  15. Prometeo: A portable test-bench for the upgraded front-end electronics of the ATLAS Tile calorimeter

    CERN Document Server

    Bullock, D; The ATLAS collaboration; Hofsajer, I; Govender, M; Mellado, B; Moreno, P; Reed, R; Ruan, X; Sandrock, C; Solans, C; Suter, R; Usai, G; Valero, A

    2014-01-01

    Prometeo is the portable test-bench for the full certification of the front-end electronics of the ATLAS Tile calorimeter designed for the upgrade phase-II. It is a high throughput electronics system designed to simultaneously read-out all the samples from 12 channels at the LHC bunch crossing frequency and assess the quality of the data in real-time. The core of the system is a Xilinx Virtex 7 evaluation board extended with a dual QSFP FMC module to read-out and control the front-end boards. The rest of the functionalities of the system are provided by a HV mezzanine board that to turn on the gain of the photo-multipliers, an LED board that sends light to illuminate them, and a 12 channel ADC board that samples the analog output of the front-end. The system is connected by ethernet to a GUI client from which QA tests are performed on the electronics such as noise measurements and linearity response to an injected charge.

  16. MULTIPLIER EVENT AND TRANSNATIONAL MEETING #6 AS A PART OF THE ESIPP PROJECT

    Directory of Open Access Journals (Sweden)

    Ana Shikaleska

    2017-10-01

    Full Text Available Multiplier Event and Transnational Meeting #6 was held as a part of the ESIPP project in the period from 28- 30 of June in Northampton, England. The Multiplier event was held at King’s Park Conference Centre, on the 28th June. After the registration of the 80 guests, Professor David Preece from the UON introduced the ESIPPproject. Presentations and parent voices from Macedonia, Cyprus and Croatia were presented through videos. In the second part of the event, presentations were introduced by Debby Elley ( mother of two children with autism and from Meike Illing-Whitby ( OT from Germany on the subject “Motor Coordination differences in children with Autism Spectrum Disorder (ASD”. The event finished with evaluations and a plenary. On Thursday 29 June at the UON, the meeting started with introductions and update from the Project Management workstream (David Preece and Paul Bramble, reporting about activity since the last meeting and interim report – feedback and actions to maximise project success. Paul Bramble gave a finances update. Jasmina Troshanska gave an update of Internal QA. After that, Cristina Fernandez gave a dissemination update. The second part of the meeting was feedback & discussion about the Multiplier Event in Croatia, planning for Skopje, Cyprus and Croatia regarding the next Multiplier Events and Transnational Meetings, ME content including publicity/links to policy makers , autism parent training roadmap launch (Cyprus March 18, TM 7-8 dates and locations. Paul Bramble talked about impact indicators. The meeting ended with a session led and facilitated by Gareth Long, external auditor, about maximising impact and sustainability and achieving ESIPP’s goals, and a plenary session. On Friday 30 June, in the Senate Building of UON the second meeting took place. There were two parallel sessions in two separate rooms . In room 1 partners were analysing content and delivery of Parent Training Programme, and in room 2 David

  17. The impact of locally multiply damaged sites (LMDS) induced by ionizing radiation in mammalian cells

    Energy Technology Data Exchange (ETDEWEB)

    Averbeck, D.; Boucher, D. [Institut Curie-Section de Recherche, UMR2027 CNRS, LCR-V28 du CEA, Centre Universitaire, 91405 Orsay Cedex (France)

    2006-07-01

    Monte Carlo calculations have shown that ionising radiations produce a specific type of clustered cell damage called locally multiply damaged sites or LMDS. These lesions consist of closely positioned single-strand breaks, (oxidative) base damage and DNA double-strand breaks (DSB) in between one helical turn of DNA. As specific markers of radiation-induced damage these lesions are likely to condition biological responses and are thus of great interest for radiation protection. Calculations indicate that there should be more LMDS induced by high than by low LET radiation, and they should be absent in un-irradiated cells. Processes like K-shell activation and local Auger electron emission can be expected to add complex DSB or LMDS, producing significant chromosomal damage. In the discussion of the specificity of ionising radiation in comparison to other genotoxic agents, many arguments have been put forward that these lesions should be particularly deleterious for living cells. Complex lesions of that type should represent big obstacles for DNA repair and give rise to high lethality. Moreover, cellular attempts to repair them could accentuate harm, leading to mutations, genetic instability and cancer. In vitro experiments with oligonucleotides containing an artificially introduced set of base damage and SSB in different combinations have shown that depending on the close positioning of the damage on DNA, repair enzymes, and even whole cell extracts, are unable to repair properly and may stimulate mis-repair. Pulsed field gel electrophoresis (PFGE) in conjunction with enzymatic treatments has been used to detect LMDS in mammalian cells after high and low LET radiation. In order to further define the importance of LMDS for radiation induced cellular responses, we studied the induction of LMDS as a function of radiation dose and dose rate in mammalian cells (CHO and MRC5) using {sup 137}Cs gamma-radiation. Using PFGE and specific glycosylases to convert oxidative damage

  18. Input/output Buffer based Vedic Multiplier Design for Thermal Aware Energy Efficient Digital Signal Processing on 28nm FPGA

    DEFF Research Database (Denmark)

    Goswami, Kavita; Pandey, Bishwajeet; Hussain, Dil muhammed Akbar

    2016-01-01

    Multiplier is used for multiplication of a signal and a constant in digital signal processing (DSP). 28nm technology based Vedic multiplier is implemented with use of VHDL HDL, Xilinx ISE, Kintex-7 FPGA and XPower Analyzer. Vedic multiplier gain speed improvements by parallelizing the generation...... of partial products with their concurrent summations. In this work, we are exploring the feasibility of Vedic multiplier in Data Encryption Algorithm, DSP, reliable system, multimedia and fault tolerant systems. In our work, we are using 11 different IO standards from HSTL (High Speed Transistor Logic...... Programmable Gate Array (FPGA) in order to reduce the development cost. The development cost for Application Specific Integrated Circuits (ASICs) are high in compare to FPGA. Selection of the most energy efficient IO standards in place of signal gating is the main design methodology for design of energy...

  19. Pilot Study of Cartilage Repair in the Knee Joint with Multiply Incised Chondral Allograft

    Science.gov (United States)

    Vancsodi, Jozsef; Farkas, Boglarka; Fazekas, Adam; Nagy, Szilvia Anett; Bogner, Peter; Vermes, Csaba; Than, Peter

    2015-01-01

    Background Focal cartilage lesions in the knee joint have limited capacity to heal. Current animal experiments show that incisions of the deep zone of a cartilage allograft allow acceptable integration for the graft. Questions/Purposes We performed this clinical study to determine (1) if the multiply incised cartilage graft is surgically applicable for focal cartilage lesions, (2) whether this allograft has a potential to integrate to the repair site, and (3) if patients show clinical improvement. Patients and Methods Seven patients with 8 chondral lesions were enrolled into the study. Symptomatic lesions between 2 and 8 cm2 were accepted. Additional injuries were allowed but were addressed simultaneously. Grafts were tailored to match and the deep zone of the cartilage was multiply incised to augment the basal integration before securing in place. Rigorous postoperative physiotherapy followed. At 12 and 24 months the patients’ satisfaction were measured and serial magnetic resonance imaging (MRI) was performed in 6 patients. Results Following the implantations no adverse reaction occurred. MRI evaluation postoperatively showed the graft in place in 5 out of 6 patients. In 1 patient, MRI suggested partial delamination at 1 year and graft degeneration at 2 years. Short Form–36 health survey and the Lysholm knee score demonstrated a significant improvement in the first year; however, by 2 years there was a noticeable drop in the scores. Conclusions. Multiply incised pure chondral allograft used for cartilage repair appears to be a relatively safe method. Further studies are necessary to assess its potential in cartilage repair before its clinical use. PMID:26069710

  20. Accurate Alignment of Plasma Channels Based on Laser Centroid Oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Gonsalves, Anthony; Nakamura, Kei; Lin, Chen; Osterhoff, Jens; Shiraishi, Satomi; Schroeder, Carl; Geddes, Cameron; Toth, Csaba; Esarey, Eric; Leemans, Wim

    2011-03-23

    A technique has been developed to accurately align a laser beam through a plasma channel by minimizing the shift in laser centroid and angle at the channel outptut. If only the shift in centroid or angle is measured, then accurate alignment is provided by minimizing laser centroid motion at the channel exit as the channel properties are scanned. The improvement in alignment accuracy provided by this technique is important for minimizing electron beam pointing errors in laser plasma accelerators.

  1. Mixed Analog/Digital Matrix-Vector Multiplier for Neural Network Synapses

    DEFF Research Database (Denmark)

    Lehmann, Torsten; Bruun, Erik; Dietrich, Casper

    1996-01-01

    In this work we present a hardware efficient matrix-vector multiplier architecture for artificial neural networks with digitally stored synapse strengths. We present a novel technique for manipulating bipolar inputs based on an analog two's complements method and an accurate current rectifier....../sign detector. Measurements on a CMOS test chip are presented and validates the techniques. Further, we propose to use an analog extension, based on a simple capacitive storage, for enhancing weight resolution during learning. It is shown that the implementation of Hebbian learning and back-propagation learning...

  2. Multiply quantized and fractional skyrmions in a binary dipolar Bose-Einstein condensate under rotation

    Science.gov (United States)

    Dong, Biao; Sun, Qing; Liu, Wu-Ming; Ji, An-Chun; Zhang, Xiao-Fei; Zhang, Shou-Gang

    2017-07-01

    We consider a binary dipolar Bose-Einstein condensate with repulsive contact and dipolar interactions under rotation. Our results show that the interplay among short-range interaction, long-range interaction, and rotation can give rise to a rich variety of topological configurations, including giant skyrmions with multiply topological charges and skyrmion-vortex lattices. In particular, we find that for fixed rotation frequencies, tuning the short- and long-range interactions can derive novel ground-state phases, such as a meron pair composed of two fractional skyrmions and a skyrmion with topological charge Q =2 centered in giant skyrmions.

  3. Applying of the Algorithm of Lagrange Multipliers in the Removal of Blur in Images

    OpenAIRE

    Stojanovic, Igor; Kraljevski, Ivan; Chungurski, Slavco

    2010-01-01

    This paper presents a non-iterative method that finds application in a broad scientific field such as digital image restoration. The method, based on algorithm of Lagrange multipliers, is use for the removal of blur in an X-ray caused by uniform linear motion. This method assumes that linear motion corresponds to an integral number of pixels. The resolution of the restored image remains at very high level. The main contribution of the method was found on the Improvement in Signal to Noise Rat...

  4. Evaluation of countable multipliers within the framework of a matrix of regional social accounting

    Directory of Open Access Journals (Sweden)

    Manuel Alejandro Cardenete

    2003-01-01

    Full Text Available The main goal of this paper is to present a recent Social AccountingMatrix for the region of Andalusia (SAMAND95. Using a variety of available data,such as the Regional Income and Product Accounts, the 1995 Input-Output Table forAndalusia, as well as some national level data, we have constructed a square SAMthat reflects all flows and interactions for the base year. With the database we haveperformed a modeling exercise that allows us to obtain accounting multipliers, and their decomposition into direct, indirect, and induced effects, that show some of thestructural relationship among productive sectors.

  5. The Early Exercise Premium Representation for American Options on Multiply Assets

    Energy Technology Data Exchange (ETDEWEB)

    Klimsiak, Tomasz, E-mail: tomas@mat.umk.pl; Rozkosz, Andrzej, E-mail: rozkosz@mat.umk.pl [Nicolaus Copernicus University, Faculty of Mathematics and Computer Science (Poland)

    2016-02-15

    In the paper we consider the problem of valuation of American options written on dividend-paying assets whose price dynamics follow the classical multidimensional Black and Scholes model. We provide a general early exercise premium representation formula for options with payoff functions which are convex or satisfy mild regularity assumptions. Examples include index options, spread options, call on max options, put on min options, multiply strike options and power-product options. In the proof of the formula we exploit close connections between the optimal stopping problems associated with valuation of American options, obstacle problems and reflected backward stochastic differential equations.

  6. Leveraging, Synergies and Cloning: Thoughts on How Scientists can Multiply their Impact on Education and Public Outreach

    Science.gov (United States)

    Chambers, L. H.

    2011-12-01

    An individual scientist might look at the huge numbers of students and the public who constitute a potential audience for education and public outreach (EPO) and conclude that he/she has no hope to make a difference. This talk will share some strategies that have the potential to multiply a scientist's for maximum effect, and some evidence that indeed one person CAN make a difference. The first strategy is to leverage: that is, find a person or group who already has an ongoing EPO activity that relates to your subject area, and use it as a way to get your information out to an existing, interested audience. This benefits you because you don't have to begin from scratch to build an audience for your information, and it benefits them because they get great new content to keep their audience interested. The second strategy is to synergize: that is, cooperate or coordinate with an existing EPO group, or with colleagues with similar interests. Use your expertise to develop new resources that fit into an existing program. Cooperate with an existing EPO group so they can help you navigate details like review processes, aligning your resource to education standards, and helping tailor your information to the needs of the education audience. The third strategy is to use technology to approximate cloning: that is, to propagate yourself and your information via multiple channels. However, this strategy should not be used until after you have tested and honed your information through a number of in-person interactions with the audience(s) you seek to reach, and have developed some communications skills that help you connect with students and teachers. One lesson that you may learn from such interactions is that scientists aren't like other people. We have a distinct vocabulary, culture, and habits of mind that distinguish us from others. This is a key strength for science, but sometimes a barrier for EPO. By personal contact with non-scientists, we can learn again how to

  7. Measurement of the T quark mass in the electron-muon channel with the D0 detector at the Tevatron; Mesure de la masse du quark top dans le canal electron-muon aupres du detecteur D0 au TeVatron

    Energy Technology Data Exchange (ETDEWEB)

    Arthaud, M

    2008-06-15

    The standard model of particle physics is a theory that describes the elementary components of matter and their interactions. The top quark is the heaviest elementary particle described by this model and its mass is one of its free parameters. The measurement of this mass constrains the Higgs boson mass. At the moment of this study, it can be observed only with the 2 detectors located around the Tevatron which collides protons and antiprotons at a centre of mass energy of {radical}(s) = 1.96 TeV. In this thesis, the Run-II b data collected by the D0 detector between June 2006 and August 2007 (around 1 fb{sup -1}) have been analysed. The top quark is mainly produced by pairs and it decays in almost 100% of the time into a W boson and a bottom quark. In the final state studied here, one of the W bosons decays into an electron and a neutrino and the second one into a muon and a neutrino. Such a final state requires to control tightly the muon transverse momentum precision measurement. Events containing Z and J/{psi} decaying into 2 muons have been studied to adjust the momentum precision in simulated events to one observed in data. During the analysis, 77 top-anti-top events have been selected in the electron-muon channel to determine the top quark mass with a method based on the Monte-Carlo integration of the matrix element describing the production of a top-anti-top pair decaying into an electron and a muon. This yields a top quark mass value of m(top) equals (172 {+-} 4.2 (sta) {+-} 2.5 (syst)) GeV. (author)

  8. Channel nut tool

    Science.gov (United States)

    Olson, Marvin

    2016-01-12

    A method, system, and apparatus for installing channel nuts includes a shank, a handle formed on a first end of a shank, and an end piece with a threaded shaft configured to receive a channel nut formed on the second end of the shaft. The tool can be used to insert or remove a channel nut in a channel framing system and then removed from the channel nut.

  9. Analysis of multiply spliced transcripts in lymphoid tissue reservoirs of rhesus macaques infected with RT-SHIV during HAART.

    Directory of Open Access Journals (Sweden)

    Jesse D Deere

    Full Text Available Highly active antiretroviral therapy (HAART can reduce levels of human immunodeficiency virus type 1 (HIV-1 to undetectable levels in infected individuals, but the virus is not eradicated. The mechanisms of viral persistence during HAART are poorly defined, but some reservoirs have been identified, such as latently infected resting memory CD4⁺ T cells. During latency, in addition to blocks at the initiation and elongation steps of viral transcription, there is a block in the export of viral RNA (vRNA, leading to the accumulation of multiply-spliced transcripts in the nucleus. Two of the genes encoded by the multiply-spliced transcripts are Tat and Rev, which are essential early in the viral replication cycle and might indicate the state of infection in a given population of cells. Here, the levels of multiply-spliced transcripts were compared to the levels of gag-containing RNA in tissue samples from RT-SHIV-infected rhesus macaques treated with HAART. Splice site sequence variation was identified during development of a TaqMan PCR assay. Multiply-spliced transcripts were detected in gastrointestinal and lymphatic tissues, but not the thymus. Levels of multiply-spliced transcripts were lower than levels of gag RNA, and both correlated with plasma virus loads. The ratio of multiply-spliced to gag RNA was greatest in the gastrointestinal samples from macaques with plasma virus loads <50 vRNA copies per mL at necropsy. Levels of gag RNA and multiply-spliced mRNA in tissues from RT-SHIV-infected macaques correlate with plasma virus load.

  10. A Fluid Structure Algorithm with Lagrange Multipliers to Model Free Swimming

    Science.gov (United States)

    Sahin, Mehmet; Dilek, Ezgi

    2017-11-01

    A new monolithic approach is prosed to solve the fluid-structure interaction (FSI) problem with Lagrange multipliers in order to model free swimming/flying. In the present approach, the fluid domain is modeled by the incompressible Navier-Stokes equations and discretized using an Arbitrary Lagrangian-Eulerian (ALE) formulation based on the stable side-centered unstructured finite volume method. The solid domain is modeled by the constitutive laws for the nonlinear Saint Venant-Kirchhoff material and the classical Galerkin finite element method is used to discretize the governing equations in a Lagrangian frame. In order to impose the body motion/deformation, the distance between the constraint pair nodes is imposed using the Lagrange multipliers, which is independent from the frame of reference. The resulting algebraic linear equations are solved in a fully coupled manner using a dual approach (null space method). The present numerical algorithm is initially validated for the classical FSI benchmark problems and then applied to the free swimming of three linked ellipses. The authors are grateful for the use of the computing resources provided by the National Center for High Performance Computing (UYBHM) under Grant Number 10752009 and the computing facilities at TUBITAK-ULAKBIM, High Performance and Grid Computing Center.

  11. Dispersion, Topological Scattering, and Self-Interference in Multiply Connected Robertson-Walker Cosmologies

    CERN Document Server

    Tomaschitz, R

    1994-01-01

    We investigate scattering effects in open Robertson-Walker cosmologies whose spacelike slices are multiply connected hyperbolic manifolds. We work out an example in which the 3-space is infinite and has the topology of a solid torus. The world-lines in these cosmologies are unstable, and classical probability densities evolving under the horospherical geodesic flow show dispersion, as do the densities of scalar wave packets. The rate of dispersion depends crucially on the expansion factor, and we calculate the time evolution of their widths. We find that the cosmic expansion can confine dispersion: The diameter of the domain of chaoticity in the 3-manifold provides the natural, time-dependent length unit in an infinite, multiply connected universe. In a toroidal 3-space manifold this diameter is just the length of the limit cycle. On this scale we find that the densities take a finite limit width in the late stage of the expansion. In the early stage classical densities and conformally coupled fields approach...

  12. Comparative antimicrobial activity of ceftibuten against multiply-resistant microorganisms from Belgium.

    Science.gov (United States)

    Verbist, L; Jacobs, J; Hens, K

    1991-01-01

    To study the activity of ceftibuten, we obtained multiply-resistant isolates from approximately 20 hospitals in Belgium. Against Enterobacteriaceae, all of the tested comparative compounds were more active than cefaclor, and ceftibuten and tigemonam were the most active of the agents tested. Ceftibuten MIC50s were less than or equal to 1 microgram/ml for most enteric bacilli species and 85% of strains were susceptible (less than or equal to 8 micrograms/ml). This level of activity compared favorably to that recorded for cefaclor (less than or equal to 8 micrograms/ml), cefetamet (less than or equal to 4 micrograms/ml), and cefteram (less than or equal to 1 microgram/ml), that is, 37%, 69%, and 59%, respectively. Ceftibuten, cefetamet, cefteram, and tigemonam were highly active against isolates of Haemophilus influenzae and Neisseria gonorrhoeae. None of the comparative agents were as active as cefaclor against staphylococcal isolates. Against streptococci, cefteram was the most active, and tigemonam the least active of the agents. The MIC90s of ceftibuten for strains of Streptococcus pneumoniae and Streptococcus pyogenes were 2 micrograms/ml and 0.5 microgram/ml, respectively. Strains of Streptococcus agalactiae were resistant to both ceftibuten and tigemonam; cefaclor and cefteram inhibited 100% of isolates of this species. Strains of Enterococcus faecalis and Pseudomonas aeruginosa were consistently resistant to all of the compounds. Overall, ceftibuten exhibited potent activity against many multiply-resistant clinical isolates.

  13. Mutations in NRXN1 in a family multiply affected with brain disorders

    DEFF Research Database (Denmark)

    Duong, Linh; Klitten, Laura L; Møller, Rikke S

    2012-01-01

    Mutation of the neurexin1-gene, NRXN1, interrupting the expression of neurexin1 has been associated with schizophrenia, autism, and intellectual disability. We have identified a family multiply affected with psychiatric, neurological, and somatic disorders along with an intricate co-segregation o......Mutation of the neurexin1-gene, NRXN1, interrupting the expression of neurexin1 has been associated with schizophrenia, autism, and intellectual disability. We have identified a family multiply affected with psychiatric, neurological, and somatic disorders along with an intricate co...... to be deleterious to NRXN1. The deletion was passed on from the patient's mother who was clinically characterized by sub-diagnostic autistic traits in addition to type 1 diabetes mellitus. The point mutation was subsequently found in the patient's brother, suffering from a psychotic disorder, which implies...... that the point mutation was inherited from the deceased father, who was diagnosed with schizophrenia. The observations suggest a possible gene-dose effect of NRXN1 mutations on type and severity of mental illness and support the notion that the penetrance and pleiotropy of pathogenic CNVs in general...

  14. Computational Design Scheme for Wind Turbine Drive-Train Based on Lagrange Multipliers

    Directory of Open Access Journals (Sweden)

    Mohammed Saleh

    2017-01-01

    Full Text Available The design optimization of wind turbines and their subsystems will make them competitive as an ideal alternative for energy. This paper proposed a design procedure for one of these subsystems, which is the Wind Turbine Drive-Train (WTDT. The design of the WTDT is based on the load assumptions and considered as the most significant parameter for increasing the efficiency of energy generation. In industry, these loads are supplemented by expert assumptions and manipulated to design the transmission elements. In contrary, in this work, the multibody system approach is used to estimate the static as well as dynamic loads based on the Lagrange multipliers. Lagrange multipliers are numerical parameters associated with the holonomic and nonholonomic constraints assigned in the drive-train model. The proposed scheme includes computational manipulations of kinematic constraints, mapping the generalized forces into Cartesian respective, and enactment of velocity-based constrains. Based on the dynamic model and the obtained forces, the design process of a planetary stage of WTDT is implemented with trade-off’s optimization in terms of gearing parameters. A wind turbine of 1.4 megawatts is introduced as an evaluation study of the proposed procedure, in which the main advantage is the systematic nature of designing complex systems in motion.

  15. Hydrogen bond based smart polymer for highly selective and tunable capture of multiply phosphorylated peptides.

    Science.gov (United States)

    Qing, Guangyan; Lu, Qi; Li, Xiuling; Liu, Jing; Ye, Mingliang; Liang, Xinmiao; Sun, Taolei

    2017-09-06

    Multisite phosphorylation is an important and common mechanism for finely regulating protein functions and subsequent cellular responses. However, this study is largely restricted by the difficulty to capture low-abundance multiply phosphorylated peptides (MPPs) from complex biosamples owing to the limitation of enrichment materials and their interactions with phosphates. Here we show that smart polymer can serve as an ideal platform to resolve this challenge. Driven by specific but tunable hydrogen bonding interactions, the smart polymer displays differential complexation with MPPs, singly phosphorylated and non-modified peptides. Importantly, MPP binding can be modulated conveniently and precisely by solution conditions, resulting in highly controllable MPP adsorption on material surface. This facilitates excellent performance in MPP enrichment and separation from model proteins and real biosamples. High enrichment selectivity and coverage, extraordinary adsorption capacities and recovery towards MPPs, as well as high discovery rates of unique phosphorylation sites, suggest its great potential in phosphoproteomics studies.Capture of low-abundance multiply phosphorylated peptides (MPPs) is difficult due to limitation of enrichment materials and their interactions with phosphates. Here the authors show, a smart polymer driven by specific but tunable hydrogen bonding interactions can differentially complex with MPPs, singly phosphorylated and non-modified peptides.

  16. Allele intersection analysis: a novel tool for multi locus sequence assignment in multiply infected hosts.

    Directory of Open Access Journals (Sweden)

    Wolfgang Arthofer

    Full Text Available Wolbachia are wide-spread, endogenous α-Proteobacteria of arthropods and filarial nematodes. 15-75% of all insect species are infected with these endosymbionts that alter their host's reproduction to facilitate their spread. In recent years, many insect species infected with multiple Wolbachia strains have been identified. As the endosymbionts are not cultivable outside living cells, strain typing relies on molecular methods. A Multi Locus Sequence Typing (MLST system was established for standardizing Wolbachia strain identification. However, MLST requires hosts to harbour individual and not multiple strains of supergroups without recombination. This study revisits the applicability of the current MLST protocols and introduces Allele Intersection Analysis (AIA as a novel approach. AIA utilizes natural variations in infection patterns and allows correct strain assignment of MLST alleles in multiply infected host species without the need of artificial strain segregation. AIA identifies pairs of multiply infected individuals that share Wolbachia and differ in only one strain. In such pairs, the shared MLST sequences can be used to assign alleles to distinct strains. Furthermore, AIA is a powerful tool to detect recombination events. The underlying principle of AIA may easily be adopted for MLST approaches in other uncultivable bacterial genera that occur as multiple strain infections and the concept may find application in metagenomic high-throughput parallel sequencing projects.

  17. Very-large-scale coherent motions in open channel flows

    Science.gov (United States)

    Zhong, Qiang; Hussain, Fazle; Li, Dan-Xun

    2016-11-01

    Very-large-scale coherent structures (VLSSs) - whose characteristic length is of the order of 10 h (h is the water depth) - are found to exist in the log and outer layers near the bed of open channel flows. For decades researchers have speculated that large coherent structures may exist in open channel flows. However, conclusive evidence is still lacking. The present study employed pre-multiplied velocity power spectral and co-spectral analyses of time-resolved PIV data obtained in open channel flows. In all cases, two modes - large-scale structures (of the order of h) and VLSSs - dominate the log and outer layers of the turbulent boundary layer. More than half of TKE and 40% of the Reynolds shear stress in the log and outer layers are contributed by VLSSs. The strength difference of VLSSs between open and closed channel flows leads to pronounced redistribution of TKE near the free surface of open channel flows, which is a unique phenomenon that sets the open channel flows apart from other wall-bounded turbulent flows. Funded by China Postdoctoral Science Foundation (No.2015M580105), National Natural Science Foundation of China (No.51127006).

  18. A Micromechanical RF Channelizer

    Science.gov (United States)

    Akgul, Mehmet

    The power consumption of a radio generally goes as the number and strength of the RF signals it must process. In particular, a radio receiver would consume much less power if the signal presented to its electronics contained only the desired signal in a tiny percent bandwidth frequency channel, rather than the typical mix of signals containing unwanted energy outside the desired channel. Unfortunately, a lack of filters capable of selecting single channel bandwidths at RF forces the front-ends of contemporary receivers to accept unwanted signals, and thus, to operate with sub-optimal efficiency. This dissertation focuses on the degree to which capacitive-gap transduced micromechanical resonators can achieve the aforementioned RF channel-selecting filters. It aims to first show theoretically that with appropriate scaling capacitive-gap transducers are strong enough to meet the needed coupling requirements; and second, to fully detail an architecture and design procedure needed to realize said filters. Finally, this dissertation provides an actual experimentally demonstrated RF channel-select filter designed using the developed procedures and confirming theoretical predictions. Specifically, this dissertation introduces four methods that make possible the design and fabrication of RF channel-select filters. The first of these introduces a small-signal equivalent circuit for parallel-plate capacitive-gap transduced micromechanical resonators that employs negative capacitance to model the dependence of resonance frequency on electrical stiffness in a way that facilitates the analysis of micromechanical circuits loaded with arbitrary electrical impedances. The new circuit model not only correctly predicts the dependence of electrical stiffness on the impedances loading the input and output electrodes of parallel-plate capacitive-gap transduced micromechanical device, but does so in a visually intuitive way that identifies current drive as most appropriate for

  19. Electrons in silicon microstructures.

    Science.gov (United States)

    Howard, R E; Jackel, L D; Mankiewich, P M; Skocpol, W J

    1986-01-24

    Silicon microstructures only a few hundred atoms wide can be fabricated and used to study electron transport in narrow channels. Spatially localized voltage probes as close together as 0.1 micrometer can be used to investigate a variety of physical phenomena, including velocity saturation due to phonon emission, the local potentials caused by scattering from a single trapped electron, and quantum tunneling or hopping among very few electron states.

  20. Nonadiabatic electron heat pump

    OpenAIRE

    Rey, Miguel; Strass, Michael; Kohler, Sigmund; Hänggi, Peter; Sols, Fernando

    2006-01-01

    We investigate a mechanism for extracting heat from metallic conductors based on the energy-selective transmission of electrons through a spatially asymmetric resonant structure subject to ac driving. This quantum refrigerator can operate at zero net electronic current as it replaces hot by cold electrons through two energetically symmetric inelastic channels. We present numerical results for a specific heterostructure and discuss general trends. We also explore the conditions under which the...

  1. Channels of distribution on tourist market

    Directory of Open Access Journals (Sweden)

    Đelić Tanja A.

    2005-01-01

    Full Text Available Changes in distribution channels in tourist industry, made as a result of introducing online CRS and Internet, enabled tourist companies offer their products in electronic way to end-users without using agents. In that way technology improvement results in change of the structure of sale channels in the whole tourist market and online orders are growing, as well as the use of agencies are diminishing.

  2. [Diagnostic value of multiply biopsies and endocervical curettage on cervical lesions].

    Science.gov (United States)

    Zhang, Ling; Du, Hui; Zhang, Wei; Yang, Bin; Wang, Chun; Belinson, Jerome L; Wu, Ruifang

    2015-04-01

    To investigate the value of multiply biopsies and endocervical curettage (ECC) on diagnosing cervical lesions. For the detection of cervical lesions, Shenzhen cervical cancer screening trial II (SHENCCAST II) program combined methods of HPV screening with liquid-based cytology (LBC), any positive indicators was then performed multiply biopsies and ECC under colopscopy. A total of 2,558 clear colposcopic images and pathological diagnoses were reviewed. To analyse the pathological results and primary screening results of the negative colopscopic images for discussing the value of multiply biopsies and ECC. Overall 2,558 women's colposcopic images and sampling results were completed and validated. 69.98% (1,790/2,558) women had normal colposcopy appearances. Among them, 2.23% (40/1,790) were diagnosed as cervical intraepithelial neoplasia II or worse (CIN II+). The odds ratio of high-grade squamous intraepithelial lesion (HSIL) was 28.37 (P=0.000) and atypical squamous cell cannot exclude HSIL (ASC-H) was 15.07 (P=0.001). HPV types 16, 52, 58, 31, 33 and 18 were related to high-grade cervical lesion with the odds ratio of 3.11 (P=0.017). Hybrid capture II (HC-II) DNA test results shown that women with HPV positive were 3.58 times more risky than those of HPV negative, which was related to high-grade cervical lesion (P=0.025). Among the 2,558 women, CIN II+ detective rate from ECC were 40.7% (44/108) in older group (≥40 years) were higher than that of 19.2% (24/125) in younger group (biopsies were 90.7% (98/108) in older group (≥40 years) were higher than that of 88.8% (111/125) in younger group (0.05). The highest risky items of detecting CIN II+ were as follows: (1) HSIL or ASC-H; (2) HPV types 16, 18, 52 and 58 positive (either one); (3) HC-II HPV positive, at least 2 of the 3 items were included among 32 cases of the 40 CIN II+ with normal colposcopy appearances. The results shown that only performed multi-site biopsies with abnormal colposcopy appearances may

  3. [Memory and potassium channels].

    Science.gov (United States)

    Solntseva, E I; Bukanova, Iu V; Skrebitskiĭ, V G

    2003-01-01

    The K(+)-channels of the surface membrane play a crucial role in the generation of electrical activity of a neuron. There is a large diversity of the K(+)-channels that depends on a great number (over 200) of genes encoding channels proteins. An evolutionary conservation of channel's proteins is determined. The K(+)-channels were found to have a great importance in the memory processes. It was shown on different model systems that K(+)-current of the surface membrane decreases during the learning. The antagonists of K(+)-channels were found to improve the learning and memory. It was revealed in electrophysiological experiments that K(+)-channels antagonists can either themselves induce a long-term synaptic potentiation or intensify the synaptic potentiation induced by a tetanization. The disfunction of K(+)-channels is believed to be an important link in the mechanisms of memory disturbances. In animal mutants with K(+)-channels disfunction, learning and memory are deficient. In behavioral experiments, the use of K(+)-channels openers make the learning worse. Amnesia caused by cerebral ischemia is explained by strong activity of K(+)-channels which not only inhibits neuronal excitement but also causes neurodegeneration. The question on the K(+)-channels involvement into pathophysiology of Alzheimer's disease is discussed. Neurotoxic peptide beta-amyloid, which is supposed to be involved into mechanisms of Alzheimer's disease, modulates K(+)-channels function. The effect of beta-amyloid depends on the subtype of K(+)-channels: A-channels are inhibited, and KDR-channels, on the contrary, become stronger. The effect of the cognitive enhancers (vinpocetine, piracetam, tacrine, linopirdine) on K(+)-current also depends on the subtype of K(+)-channels. Slow-inactivating K(+)-currents (IDR, IK(Ca), IM) are inhibited in the presence of these drugs, while fast-in-activating K(+)-current (A-current) remains unchanged or even increases.

  4. Hadamard quantum broadcast channels

    Science.gov (United States)

    Wang, Qingle; Das, Siddhartha; Wilde, Mark M.

    2017-10-01

    We consider three different communication tasks for quantum broadcast channels, and we determine the capacity region of a Hadamard broadcast channel for these various tasks. We define a Hadamard broadcast channel to be such that the channel from the sender to one of the receivers is entanglement-breaking and the channel from the sender to the other receiver is complementary to this one. As such, this channel is a quantum generalization of a degraded broadcast channel, which is well known in classical information theory. The first communication task we consider is classical communication to both receivers, the second is quantum communication to the stronger receiver and classical communication to other, and the third is entanglement-assisted classical communication to the stronger receiver and unassisted classical communication to the other. The structure of a Hadamard broadcast channel plays a critical role in our analysis: The channel to the weaker receiver can be simulated by performing a measurement channel on the stronger receiver's system, followed by a preparation channel. As such, we can incorporate the classical output of the measurement channel as an auxiliary variable and solve all three of the above capacities for Hadamard broadcast channels, in this way avoiding known difficulties associated with quantum auxiliary variables.

  5. Interaction of nanosecond laser pulse with tetramethyl silane (Si(CH34 clusters: Generation of multiply charged silicon and carbon ions

    Directory of Open Access Journals (Sweden)

    Purav M. Badani

    2011-12-01

    Full Text Available Present work reports significantly high levels of ionization, eventually leading to Coulomb explosion of Tetramethyl silane (TMS clusters, on interaction with laser pulses of intensity ∼109 W/cm2. Tetramethyl silane clusters, prepared by supersonic expansion were photoionized at 266, 355 or 532 nm and the resultant ions were detected using time-of-flight mass spectrometer. It is observed that wavelength of irradiation and the size of the cluster are crucial parameters which drastically affect the nature of charge species generated upon photoionization of cluster. The results show that clusters absorb significantly higher energy from the laser field at longer wavelengths (532 nm and generate multiply charged silicon and carbon ions which have large kinetic energies. Further, laser-cluster interaction at different wavelengths has been quantified and charge densities at 266, 355 and 532 nm are found to be 4x 1010, 5x 1010 and 5x 1011 charges/cm3 respectively. These unusual results have been rationalized based on dominance of secondary ionization processes at 532 nm ultimately leading to Coulomb explosion of clusters. In another set of experiments, multiply charged ions of Ar (up to +5 state and Kr (up to +6 state were observed when TMS doped inert gas clusters were photoionized at 532 and 355 nm. The extent of energy absorption at these two wavelengths is clearly manifested from the charge state of the atomic ions generated upon Coulomb disintegration of the doped cluster. These experiments thus demonstrate a novel method for generation of multiply charged atomic ions of inert gases at laser intensity of ∼ 109 W/cm2. The average size of the cluster exhibiting Coulomb explosion phenomena under giga watt intensity conditions has been estimated to be ∼ 6 nm. Experimental results obtained in the present work agree qualitatively with the model proposed earlier [D. Niu, H. Li, F. Liang, L. Wen, X. Luo, B. Wang, and H. Qu, J. Chem. Phys. 122, 151103

  6. In-situ and elementally resolved determination of the thickness uniformity of multi-ply films by confocal micro XRF.

    Science.gov (United States)

    Peng, Song; Liu, Zhiguo; Sun, Tianxi; Wang, Guangfu; Ma, Yongzhong; Ding, Xunliang

    2014-08-01

    Confocal micro X-ray fluorescence (CM-XRF) with quasi-monochromatic excitation based on polycapillary X-ray optics was used to measure the thickness of multi-ply films. The relative errors of measuring an Fe film with a thickness of 16.3 μm and a Cu film with a thickness of 24.5 μm were 7.3% and 0.4%, respectively. The non-destructive and in-situ measurement of the thickness and uniformity of multi-ply films of Cu, Fe and Ni on a silicon surface was performed. CM-XRF was convenient in in-situ and elementally resolved analysis of the thickness of multi-ply films without a cumbersome theoretical correction model. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Modulated electron-multiplied fluorescence lifetime imaging microscope : All-solid-state camera for fluorescence lifetime imaging

    NARCIS (Netherlands)

    Zhao, Q.; Schelen, B.; Schouten, R.

    2012-01-01

    We have built an all-solid-state camera that is directly modulated at the pixel level for frequency-domain fluorescence lifetime imaging microscopy (FLIM) measurements. This novel camera eliminates the need for an image intensifier through the use of an application-specific charge coupled device

  8. USACE Navigation Channels 2012

    Data.gov (United States)

    California Department of Resources — This dataset represents both San Francisco and Los Angeles District navigation channel lines. All San Francisco District channel lines were digitized from CAD files...

  9. Calcium channel blocker overdose

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/002580.htm Calcium-channel blocker overdose To use the sharing features on this page, please enable JavaScript. Calcium-channel blockers are a type of medicine used to ...

  10. A Lagrange Multiplier Test for Testing the Adequacy of the Constant Conditional Correlation GARCH Model

    DEFF Research Database (Denmark)

    Catani, Paul; Teräsvirta, Timo; Yin, Meiqun

    A Lagrange multiplier test for testing the parametric structure of a constant conditional correlation generalized autoregressive conditional heteroskedasticity (CCC-GARCH) model is proposed. The test is based on decomposing the CCC-GARCH model multiplicatively into two components, one of which...... represents the null model, whereas the other one describes the misspeci…cation. A simulation study shows that the test has good …nite sample properties. We compare the test with other tests for misspeci…cation of multivariate GARCH models. The test has high power against alternatives where the misspeci......…cation is in the GARCH parameters and is superior to other tests. The test is not greatly affected by misspeci…cation in the conditional correlations and is therefore well suited for considering misspeci…cation of GARCH equations....

  11. Development of a Novel Two Dimensional Surface Plasmon Resonance Sensor Using Multiplied Beam Splitting Optics

    Directory of Open Access Journals (Sweden)

    Akihide Hemmi

    2013-01-01

    Full Text Available A novel two dimensional surface plasmon resonance (SPR sensor system with a multi-point sensing region is described. The use of multiplied beam splitting optics, as a core technology, permitted multi-point sensing to be achieved. This system was capable of simultaneously measuring nine sensing points. Calibration curves for sucrose obtained on nine sensing points were linear in the range of 0–10% with a correlation factor of 0.996–0.998 with a relative standard deviation of 0.090–4.0%. The detection limits defined as S/N = 3 were 1.98 × 10−6–3.91 × 10−5 RIU. This sensitivity is comparable to that of conventional SPR sensors.

  12. Development of a novel two dimensional surface plasmon resonance sensor using multiplied beam splitting optics.

    Science.gov (United States)

    Hemmi, Akihide; Mizumura, Ryosuke; Kawanishi, Ryuta; Nakajima, Hizuru; Zeng, Hulie; Uchiyama, Katsumi; Kaneki, Noriaki; Imato, Toshihiko

    2013-01-08

    A novel two dimensional surface plasmon resonance (SPR) sensor system with a multi-point sensing region is described. The use of multiplied beam splitting optics, as a core technology, permitted multi-point sensing to be achieved. This system was capable of simultaneously measuring nine sensing points. Calibration curves for sucrose obtained on nine sensing points were linear in the range of 0-10% with a correlation factor of 0.996-0.998 with a relative standard deviation of 0.090-4.0%. The detection limits defined as S/N = 3 were 1.98 × 10(-6) - 3.91 × 10(-5) RIU. This sensitivity is comparable to that of conventional SPR sensors.

  13. Input-constrained model predictive control via the alternating direction method of multipliers

    DEFF Research Database (Denmark)

    Sokoler, Leo Emil; Frison, Gianluca; Andersen, Martin S.

    2014-01-01

    This paper presents an algorithm, based on the alternating direction method of multipliers, for the convex optimal control problem arising in input-constrained model predictive control. We develop an efficient implementation of the algorithm for the extended linear quadratic control problem (LQCP......) with input and input-rate limits. The algorithm alternates between solving an extended LQCP and a highly structured quadratic program. These quadratic programs are solved using a Riccati iteration procedure, and a structure-exploiting interior-point method, respectively. The computational cost per iteration...... is quadratic in the dimensions of the controlled system, and linear in the length of the prediction horizon. Simulations show that the approach proposed in this paper is more than an order of magnitude faster than several state-of-the-art quadratic programming algorithms, and that the difference in computation...

  14. Development of a New Multiplying Assembly for Research, Validation, Evaluation, and Learning

    Energy Technology Data Exchange (ETDEWEB)

    David L. Chichester

    2012-10-01

    A new multiplying test assembly is under development at Idaho National Laboratory (INL) to support research, validation, evaluation, and learning. The item is comprised of two stacked highly-enriched uranium (HEU) cylinders each 11.4 cm in diameter and having a combined height of 8.4 cm. The combined mass is 14.4 kg of HEU. Calculations for the bare configuration of the assembly indicate a multiplication level of >2.5 (keff = 0.62). Reflected configurations of the assembly, using either polyethylene or tungsten, are possible and have the capability of raising its multiplication level to approximately 8. This paper will describe the MCNP calculations performed to assess the assembly's multiplication level under different conditions and describe the resource available at INL to support visiting researchers in their use of the material. We will also describe some preliminary calculations and test activities using the assembly to study neutron multiplicity.

  15. Truss Structure Optimization with Subset Simulation and Augmented Lagrangian Multiplier Method

    Directory of Open Access Journals (Sweden)

    Feng Du

    2017-11-01

    Full Text Available This paper presents a global optimization method for structural design optimization, which integrates subset simulation optimization (SSO and the dynamic augmented Lagrangian multiplier method (DALMM. The proposed method formulates the structural design optimization as a series of unconstrained optimization sub-problems using DALMM and makes use of SSO to find the global optimum. The combined strategy guarantees that the proposed method can automatically detect active constraints and provide global optimal solutions with finite penalty parameters. The accuracy and robustness of the proposed method are demonstrated by four classical truss sizing problems. The results are compared with those reported in the literature, and show a remarkable statistical performance based on 30 independent runs.

  16. iPTF16geu: A multiply imaged, gravitationally lensed type Ia supernova

    Science.gov (United States)

    Goobar, A.; Amanullah, R.; Kulkarni, S. R.; Nugent, P. E.; Johansson, J.; Steidel, C.; Law, D.; Mörtsell, E.; Quimby, R.; Blagorodnova, N.; Brandeker, A.; Cao, Y.; Cooray, A.; Ferretti, R.; Fremling, C.; Hangard, L.; Kasliwal, M.; Kupfer, T.; Lunnan, R.; Masci, F.; Miller, A. A.; Nayyeri, H.; Neill, J. D.; Ofek, E. O.; Papadogiannakis, S.; Petrushevska, T.; Ravi, V.; Sollerman, J.; Sullivan, M.; Taddia, F.; Walters, R.; Wilson, D.; Yan, L.; Yaron, O.

    2017-04-01

    We report the discovery of a multiply imaged, gravitationally lensed type Ia supernova, iPTF16geu (SN 2016geu), at redshift z = 0.409. This phenomenon was identified because the light from the stellar explosion was magnified more than 50 times by the curvature of space around matter in an intervening galaxy. We used high-spatial-resolution observations to resolve four images of the lensed supernova, approximately 0.3 arc seconds from the center of the foreground galaxy. The observations probe a physical scale of ~1 kiloparsec, smaller than is typical in other studies of extragalactic gravitational lensing. The large magnification and symmetric image configuration imply close alignment between the lines of sight to the supernova and to the lens. The relative magnifications of the four images provide evidence for substructures in the lensing galaxy.

  17. Two-dimensional modeling of multiply scattered laser radiation in optically dense aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Zardecki, A.; Gerstl, S.A.W.; Embury, J.F.

    1982-01-01

    The discrete ordinates finite element radiation transport code TWOTRAN is applied to describe the multiple scattering of a laser beam from a reflecting target. For a model scenario involving a 99% relative humidity rural aerosol, we compute the average intensity of the scattered radiation and correction factors to the Lambert-Beer law arising from multiple scattering. As our results indicate, two-dimensional x-y and r-z geometry modeling can reliably describe a realistic three-dimensional scenario. Specific results are presented for the two visual ranges of 1.52 and 0.76 km which show that for sufficiently high aerosol concentrations (e.g., equivalent to V = 0.76 km) the target signature in a distant detector becomes dominated by multiply scattered radiation from interactions of the laser light with the aerosol environment.

  18. Generation of symmetry coordinates for crystals using multiplier representations of the space groups

    DEFF Research Database (Denmark)

    Hansen, Flemming Yssing

    1978-01-01

    Symmetry coordinates play an important role in the normal-mode calculations of crystals. It is therefore of great importance to have a general method, which may be applied for any crystal at any wave vector, to generate these. The multiplier representations of the space groups as given by Kovalev...... and the projection-operator technique provide a basis for such a method. The method is illustrated for the nonsymmorphic D36 space group, and the theoretical background for the representations of space groups in general is reviewed and illustrated on the example above. It is desirable to perform the projection...... of symmetry coordinates in such a way that they may be used for as many wave vectors as possible. We discuss how to achieve this goal. The detailed illustrations should make it simple to apply the theory in any other case....

  19. Elemental analysis with multiply charged 7. 5-MeV nitrogen ions

    Energy Technology Data Exchange (ETDEWEB)

    Gavrilov, F.F.; Puzanov, A.A.; Smirnov, V.Ya.; Ushakov, Yu.A.

    1975-08-01

    A determination of the capabilities of elemental analysis using a beam of multiply charged ions was made. The maximum sensitivity which was achieved in the analysis for bismuth when working with a beam of 7.5-MeV nitrogen ions 0.5 mm in diameter incident on films with a thickness less than 0.3 ..mu..g/cm/sup 2/ was 10/sup -10/ g for an irradiation time of 10 min. In this case, the number of counts at the peak of the L/sub ..cap alpha../ line was 500. The specified energy resolution of the spectrometer makes it possible to separate all neighboring chemical elements heavier than copper. With an improvement in the energy resolution of the spectrometer and the use of ions with greater energy per nucleon, multicomponent specimens containing all elements heavier than carbon can be analyzed and the sensitivity can be increased by several orders of magnitude. (JRD)

  20. Multi-Functional Current Multiplier by High Temperature Superconducting Magnet Energy Storage

    Science.gov (United States)

    Yamada, S.; Hishinuma, Y.; Aso, Y.

    We had been developing a current multiplier by inductive storage (CMIS). The prototype of CMIS consists of 12 storage copper coil with switching units. Coils and feeders are cooled by the liquid nitrogen to reduce the resistivity. Output current pulse with 480 A could be generated, by charging the coils to 40 A. The continuous current pulses of 666 pulses per minute were obtained owing to the fast switching of coil currents by using IGBTs. Two types of the multi-functional CMIS were designed conceptually; one is for mega ampere and the other is for long pulse. The system consists of the superconducting (SC) magnet section with a temperature of 20 K and the IGBT control switch section with a temperature of 77 K. The SC coil is cooled down from 77 to 20 K by a G-M refrigerator. The IGBT control switches are soaked in liquid nitrogen to reduce the total resistance from CMIS coils to the load.

  1. The South African wildlife ranching sector: A Social Accounting Matrix Leontief multiplier analysis

    Directory of Open Access Journals (Sweden)

    Philippus C. Cloete

    2014-10-01

    Research purpose: The purpose of this article is to put into context the relative economic contribution of the wildlife ranching sector, as opposed to other land-use options in South Africa. Motivation for the study: Growth in the wildlife ranching sector at the cost of other traditional farming practices resulted in disagreements amongst various role players about the impact thereof on the national economy. The controversy can most probably be explained by different beliefs, coupled with the lack of a proper understanding and quantification of the wildlife ranching sector’s contribution toward the economy. Research methodology: The study employed a Social Accounting Matrix-based Leontief multiplier analysis for South Africa. Main findings: Results from the multiplier analysis revealed that developments within the wildlife ranching sector are likely to make a relatively more superior contribution towards the economy, especially when compared to similar land-use options such as extensive livestock production. Practical/managerial implications: It has been acknowledged by both academia and private sector that a major need exists for more research on the South African wildlife ranching industry, specifically looking at issues such as the industries, economic and social contributions, potentials and constraints. The research, therefore, contributes toward the depth of economic information and research regarding the South African wildlife sector. Contribution/value added: The research provides valuable information in dealing with the ‘popular belief’, especially amongst some of South Africa’s decision makers, namely, that growth in the wildlife ranching sector is not or does not have the ability to contribute significantly toward economic and socioeconomic factors.

  2. The South African wildlife ranching sector: A Social Accounting Matrix Leontief multiplier analysis

    Directory of Open Access Journals (Sweden)

    Philippus C. Cloete

    2014-02-01

    Full Text Available Orientation: There is startlingly little economic research on the South African wildlife sector which contributes toward disputes regarding the economic contribution of the sector.Research purpose: The purpose of this article is to put into context the relative economic contribution of the wildlife ranching sector, as opposed to other land-use options in South Africa.Motivation for the study: Growth in the wildlife ranching sector at the cost of other traditional farming practices resulted in disagreements amongst various role players about the impact thereof on the national economy. The controversy can most probably be explained by different beliefs, coupled with the lack of a proper understanding and quantification of the wildlife ranching sector’s contribution toward the economy.Research methodology: The study employed a Social Accounting Matrix-based Leontief multiplier analysis for South Africa.Main findings: Results from the multiplier analysis revealed that developments within the wildlife ranching sector are likely to make a relatively more superior contribution towards the economy, especially when compared to similar land-use options such as extensive livestock production.Practical/managerial implications: It has been acknowledged by both academia and private sector that a major need exists for more research on the South African wildlife ranching industry, specifically looking at issues such as the industries, economic and social contributions, potentials and constraints. The research, therefore, contributes toward the depth of economic information and research regarding the South African wildlife sector.Contribution/value added: The research provides valuable information in dealing with the ‘popular belief’, especially amongst some of South Africa’s decision makers, namely, that growth in the wildlife ranching sector is not or does not have the ability to contribute significantly toward economic and socioeconomic factors.

  3. Group-Based Alternating Direction Method of Multipliers for Distributed Linear Classification.

    Science.gov (United States)

    Wang, Huihui; Gao, Yang; Shi, Yinghuan; Wang, Ruili

    2017-11-01

    The alternating direction method of multipliers (ADMM) algorithm has been widely employed for distributed machine learning tasks. However, it suffers from several limitations, e.g., a relative low convergence speed, and an expensive time cost. To this end, in this paper, a novel method, namely the group-based ADMM (GADMM), is proposed for distributed linear classification. In particular, to accelerate the convergence speed and improve global consensus, a group layer is first utilized in GADMM to divide all the slave nodes into several groups. Then, all the local variables (from the slave nodes) are gathered in the group layer to generate different group variables. Finally, by using a weighted average method, the group variables are coordinated to update the global variable (from the master node) until the solution of the global problem is reached. According to the theoretical analysis, we found that: 1) GADMM can mathematically converge at the rate , where is the number of outer iterations and 2) by using the grouping methods, GADMM can improve the convergence speed compared with the distributed ADMM framework without grouping methods. Moreover, we systematically evaluate GADMM on four publicly available LIBSVM datasets. Compared with disADMM and stochastic dual coordinate ascent with alternating direction method of multipliers-ADMM, for distributed classification, GADMM is able to reduce the number of outer iterations, which leads to faster convergence speed and better global consensus. In particular, the statistical significance test has been experimentally conducted and the results validate that GADMM can significantly save up to 30% of the total time cost (with less than 0.6% accuracy loss) compared with disADMM on large-scale datasets, e.g., webspam and epsilon.

  4. A composite experimental dynamic substructuring method based on partitioned algorithms and localized Lagrange multipliers

    Science.gov (United States)

    Abbiati, Giuseppe; La Salandra, Vincenzo; Bursi, Oreste S.; Caracoglia, Luca

    2018-02-01

    Successful online hybrid (numerical/physical) dynamic substructuring simulations have shown their potential in enabling realistic dynamic analysis of almost any type of non-linear structural system (e.g., an as-built/isolated viaduct, a petrochemical piping system subjected to non-stationary seismic loading, etc.). Moreover, owing to faster and more accurate testing equipment, a number of different offline experimental substructuring methods, operating both in time (e.g. the impulse-based substructuring) and frequency domains (i.e. the Lagrange multiplier frequency-based substructuring), have been employed in mechanical engineering to examine dynamic substructure coupling. Numerous studies have dealt with the above-mentioned methods and with consequent uncertainty propagation issues, either associated with experimental errors or modelling assumptions. Nonetheless, a limited number of publications have systematically cross-examined the performance of the various Experimental Dynamic Substructuring (EDS) methods and the possibility of their exploitation in a complementary way to expedite a hybrid experiment/numerical simulation. From this perspective, this paper performs a comparative uncertainty propagation analysis of three EDS algorithms for coupling physical and numerical subdomains with a dual assembly approach based on localized Lagrange multipliers. The main results and comparisons are based on a series of Monte Carlo simulations carried out on a five-DoF linear/non-linear chain-like systems that include typical aleatoric uncertainties emerging from measurement errors and excitation loads. In addition, we propose a new Composite-EDS (C-EDS) method to fuse both online and offline algorithms into a unique simulator. Capitalizing from the results of a more complex case study composed of a coupled isolated tank-piping system, we provide a feasible way to employ the C-EDS method when nonlinearities and multi-point constraints are present in the emulated system.

  5. A molecular perspective on a complex polymorphic inversion system with cytological evidence of multiply reused breakpoints.

    Science.gov (United States)

    Orengo, D J; Puerma, E; Papaceit, M; Segarra, C; Aguadé, M

    2015-06-01

    Genome sequence comparison across the Drosophila genus revealed that some fixed inversion breakpoints had been multiply reused at this long timescale. Cytological studies of Drosophila inversion polymorphism had previously shown that, also at this shorter timescale, some breakpoints had been multiply reused. The paucity of molecularly characterized polymorphic inversion breakpoints has so far precluded contrasting whether cytologically shared breakpoints of these relatively young inversions are actually reused at the molecular level. The E chromosome of Drosophila subobscura stands out because it presents several inversion complexes. This is the case of the E1+2+9+3 arrangement that originated from the ancestral Est arrangement through the sequential accumulation of four inversions (E1, E2, E9 and E3) sharing some breakpoints. We recently identified the breakpoints of inversions E1 and E2, which allowed establishing reuse at the molecular level of the cytologically shared breakpoint of these inversions. Here, we identified and sequenced the breakpoints of inversions E9 and E3, because they share breakpoints at sections 58D and 64C with those of inversions E1 and E2. This has allowed establishing that E9 and E3 originated through the staggered-break mechanism. Most importantly, sequence comparison has revealed the multiple reuse at the molecular level of the proximal breakpoint (section 58D), which would have been used at least by inversions E2, E9 and E3. In contrast, the distal breakpoint (section 64C) might have been only reused once by inversions E1 and E2, because the distal E3 breakpoint is displaced >70 kb from the other breakpoint limits.

  6. Recurrence Relations for Moments of Order Statistics from the Lindley Distribution with General Multiply Type-II Censored Sample

    Directory of Open Access Journals (Sweden)

    Bander Al-Zahrani

    2014-05-01

    Full Text Available In this paper, we derive the recurrence relations for the moments of function of single and two order statistics from Lindley distribution. We also consider the maximum likelihood estimation (MLE of the parameter of the distribution based on multiply type-II censoring. However maximum likelihood estimator does not have an explicit form for the involved parameter. In order to compute the MLE of the parameter, Monte Carlo simulation is used. A comparative study is presented between classical MLE and MLE from multiply type-II censored sample.

  7. The Financial Unlinkage of the Mexican Economy: A Social Accounting Matrix Multiplier Approach for a One-Sector Economy

    Directory of Open Access Journals (Sweden)

    Andrés Blancas

    2003-11-01

    Full Text Available This paper addresses the financial unlinkage in Mexico through an accounting multiplier analysis derived from a SAM for a one-sector economy. Such an analysis provides a useful tool to quantify processes of structural financial change in terms of "stylized parameters". We identify and measure the financial unlinkage with financial backward and forward linkage indices derived from the accounting multipliers. The results can also help to the quality of policy decisions by identifying key and weak financial institutions and by giving a better understanding of how an impact of an initial financial injection travels within a structure.

  8. Channel morphology [Chapter 5

    Science.gov (United States)

    Jonathan W. Long; Alvin L. Medina; Daniel G. Neary

    2012-01-01

    Channel morphology has become an increasingly important subject for analyzing the health of rivers and associated fish populations, particularly since the popularization of channel classification and assessment methods. Morphological data can help to evaluate the flows of sediment and water that influence aquatic and riparian habitat. Channel classification systems,...

  9. KV7 potassium channels

    DEFF Research Database (Denmark)

    Stott, Jennifer B; Jepps, Thomas Andrew; Greenwood, Iain A

    2014-01-01

    Potassium channels are key regulators of smooth muscle tone, with increases in activity resulting in hyperpolarisation of the cell membrane, which acts to oppose vasoconstriction. Several potassium channels exist within smooth muscle, but the KV7 family of voltage-gated potassium channels have been...

  10. Quasi-equilibrium channel model of an constant current arc

    Directory of Open Access Journals (Sweden)

    Gerasimov Alexander V.

    2003-01-01

    Full Text Available The rather simple method of calculation of electronic and gas temperature in the channel of arc of plasma generator is offered. This method is based on self-consistent two-temperature channel model of an electric arc. The method proposed enables to obtain radial allocation of gas and electronic temperatures in a non-conducting zone of an constant current arc, for prescribed parameters of discharge (current intensity and power of the discharge, with enough good precision. The results obtained can be used in model and engineering calculations to estimate gas and electronic temperatures in the channel of an arc plasma generator.

  11. Inland Electronic Navigational Charts (IENC)

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — These Inland Electronic Navigational Charts (IENCs) were developed from available data used in maintenance of Navigation channels. Users of these IENCs should be...

  12. Ion channel pharmacology.

    Science.gov (United States)

    Camerino, Diana Conte; Tricarico, Domenico; Desaphy, Jean-François

    2007-04-01

    Because ion channels are involved in many cellular processes, drugs acting on ion channels have long been used for the treatment of many diseases, especially those affecting electrically excitable tissues. The present review discusses the pharmacology of voltage-gated and neurotransmitter-gated ion channels involved in neurologic diseases, with emphasis on neurologic channelopathies. With the discovery of ion channelopathies, the therapeutic value of many basic drugs targeting ion channels has been confirmed. The understanding of the genotype-phenotype relationship has highlighted possible action mechanisms of other empirically used drugs. Moreover, other ion channels have been pinpointed as potential new drug targets. With regards to therapy of channelopathies, experimental investigations of the intimate drug-channel interactions have demonstrated that channel mutations can either increase or decrease affinity for the drug, modifying its potential therapeutic effect. Together with the discovery of channel gene polymorphisms that may affect drug pharmacodynamics, these findings highlight the need for pharmacogenetic research to allow identification of drugs with more specific effects on channel isoforms or mutants, to increase efficacy and reduce side effects. With a greater understanding of channel genetics, structure, and function, together with the identification of novel primary and secondary channelopathies, the number of ion channel drugs for neurologic channelopathies will increase substantially.

  13. High angle phase modulated low coherence interferometry for path length resolved Doppler measurements of multiply scattered light

    NARCIS (Netherlands)

    Varghese, Babu; Rajan, Vinayakrishnan; van Leeuwen, Ton; Steenbergen, Wiendelt

    2008-01-01

    We describe an improved method for coherence domain path length resolved measurements of multiply scattered photons in turbid media. An electro-optic phase modulator sinusoidally modulates the phase in the reference arm of a low coherence fiber optic Mach–Zehnder interferometer, at a high phase

  14. On the numerical solution of the time-dependent Ginzburg-Landau equations in multiply connected domains

    Energy Technology Data Exchange (ETDEWEB)

    Buscaglia, G.C.; Lopez, A. [Centro Atomico Bariloche and Inst. Balseiro, Bariloche (Argentina); Bolech, C. [Rutgers - the State Univ., Piscataway, NJ (United States). Dept. of Physics and Astronomy

    2000-07-01

    A numerical method for the solution of the time-dependent Ginzburg-Landau equations is detailed. The method is based on the popular technique of gauge invariant variables. Extension of the method to multiply connected domains is addressed. An implementation of the method is made available through the Web. (orig.)

  15. Scale dependence of multiplier distributions for particle concentration, enstrophy, and dissipation in the inertial range of homogeneous turbulence

    Science.gov (United States)

    Hartlep, Thomas; Cuzzi, Jeffrey N.; Weston, Brian

    2017-03-01

    Turbulent flows preferentially concentrate inertial particles depending on their stopping time or Stokes number, which can lead to significant spatial variations in the particle concentration. Cascade models are one way to describe this process in statistical terms. Here, we use a direct numerical simulation (DNS) dataset of homogeneous, isotropic turbulence to determine probability distribution functions (PDFs) for cascade multipliers, which determine the ratio by which a property is partitioned into subvolumes as an eddy is envisioned to decay into smaller eddies. We present a technique for correcting effects of small particle numbers in the statistics. We determine multiplier PDFs for particle number, flow dissipation, and enstrophy, all of which are shown to be scale dependent. However, the particle multiplier PDFs collapse when scaled with an appropriately defined local Stokes number. As anticipated from earlier works, dissipation and enstrophy multiplier PDFs reach an asymptote for sufficiently small spatial scales. From the DNS measurements, we derive a cascade model that is used it to make predictions for the radial distribution function (RDF) for arbitrarily high Reynolds numbers, Re, finding good agreement with the asymptotic, infinite Re inertial range theory of Zaichik and Alipchenkov [New J. Phys. 11, 103018 (2009), 10.1088/1367-2630/11/10/103018]. We discuss implications of these results for the statistical modeling of the turbulent clustering process in the inertial range for high Reynolds numbers inaccessible to numerical simulations.

  16. Trainable Mentally Impaired/Severely Multiply Impaired/Autistic Impaired/Severely Mentally Impaired. Product Evaluation Report 1989-1990.

    Science.gov (United States)

    Claus, Richard N.; And Others

    The evaluation report describes special education services provided to trainable mentally impaired (TMI), autistic impaired (AI), severely multiply impaired (SXI), and severely mentally impaired (SMI) students at and through the Melvin G. Millet Learning Center (Bridgeport, Michigan). The eight program components are described individually and…

  17. Carbon Composites based on multiaxial multiply stitched performs, Part 3: Biaxial Tension, picture frame and compression tests of the preforms

    NARCIS (Netherlands)

    Lomov, S.V.; Barburski, M.; Stoilova, Tz.; Verpoest, I.; Akkerman, Remko; Loendersloot, Richard; ten Thije, R.H.W.

    2005-01-01

    Deformability of bi- and quadri-axial multi-axial multiply stitched preforms is studied in biaxial tension, shear (picture frame test) and compression. The results complement KES-F measurements in the low load range, reported in the Part 2 of the series (Compos A, 34, 2003, 359–70). The biaxial

  18. Study of CP violation in the channel B{sub d}{sup 0} {yields} J/{psi}(ee)K{sub S}{sup 0}, identification and reconstruction of electrons in the LHCb experiment; Etude de la violation de CP dans le canal B{sub d}{sup 0} {yields} J/{psi}(ee)K{sub S}{sup 0}, identification et reconstruction des electrons dans l'experience LHCb

    Energy Technology Data Exchange (ETDEWEB)

    Terrier, H

    2005-04-15

    LHCb experiment has been designed in order to do precise measurements of CP violation and rare decays with B mesons. In 2000, the collaboration decided to modify the spectrometer in order to minimize the amount of matter seen by particles and to optimize the trigger. This thesis was done in this context and is divided into 3 parts. The first part is relative to the electron identification and to the recovery of Bremsstrahlung photons emitted by electrons when they pass through matter. Electron identification is mainly based on information provided by calorimeter system but also uses RICH and muon system. A method based on reference histograms had been developed which combine information provided by these detectors. Electron identification efficiency, for electrons in ECAL acceptance is 95% and the pion mis-identification rates 0.8% with a 65% purity of electron sample. Bremsstrahlung recovery allows the selection of J/{phi} decaying in e{sup +}e{sup -} pair and of B{sub d}{sup 0} {yields} J/{phi}(ee)K{sub S}{sup 0} channel which are described in the second part. The selection of this channel was developed in order to get an acceptable selection efficiency with a good rejection of background. A set of kinematic and topological cuts were designed and total selection efficiency is 0.176%, corresponding to 28000 untagged events reconstructed by year, with a ratio B/S belonging to [0.017;0.069] (at 90% of confidence level) for inclusive bb-bar background. In the third part, B meson flavour tagging is presented. The addition of information provided by the vertex locator allows to reject electron coming from conversion and to improve slightly the performances. The LHCb sensibility to sin(2{beta}) from B{sup 0} {yields} J/{psi}K{sub S}{sup 0} decay is also determined. The statistical error, expected after one year of data collecting, corresponding to an integrated luminosity of 2 fb{sup -1} and bb-bar pair cross section of 0.5 mb, varies from 0.015 to 0.020 according to

  19. ELECTRON-CAPTURE IN HIGHLY-CHARGED ION-ATOM COLLISIONS

    NARCIS (Netherlands)

    MORGENSTERN, R

    1993-01-01

    An attempt is made to identify the most important mechanisms responsible for the rearrangement of electrons during collisions between multiply charged ions and atoms at keV energies. It is discussed to which extent the influence of binding energy, angular momentum of heavy particles and electrons,

  20. CONDUCTIVE CHANNEL FOR ENERGY TRANSMISSION

    Directory of Open Access Journals (Sweden)

    V. V. Apollonov

    2014-01-01

    Full Text Available Laser spark obtained by using a conical optics is much more appropriate to form conducting channels in atmosphere. Only two types of lasers are actively considered to be used in forming high-conductivity channels in atmosphere, controlled by laser spark: pulsed sub-microsecond gas and chemical lasers (CO2, DF and short pulse solid-state and UV lasers. Main advantage of short pulse lasers is their ability in forming of super long ionized channels with a characteristic diameter of ~100  µ  in atmosphere along the  beam propagation direction. At estimated electron densities below  10 ⋅ 16 cm–3 in these filaments and laser wavelengths in the range of 0,5–1,0 mm, the plasma barely absorbs laser radiation.  In this case, the length of the track composed of many filaments is determined by the laser intensity and may reach many kilometers at a femtosecond pulse energy of ~100 mJ. However, these lasers could not be used to form high-conductivity long channels in atmosphere. The ohmic resistance of this type a conducting channels turned out to be very high, and the gas in the channels could not be strongly heated (< 1 J. An electric breakdown controlled by radiation of femtosecond solid-state laser was implemented in only at a length of 3 m with a voltage of 2 MV across the discharge gap (670 kV/m.Not so long ago scientific group from P. N. Lebedev has improved that result, the discharge gap – 1 m had been broken under KrF laser irradiation when switching high-voltage (up to 390 kV/m electric discharge by 100-ns UV pulses. Our previous result  –  16 m long conducting channel controlled by a  laser spark at the voltage  –  3 MV  – was obtained more than 20 years ago in Russia and Japan by using pulsed CO2  laser with energy  –  0,5 kJ. An average electric field strength  was < 190 kV/m. It is still too much for efficient applications.