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Sample records for wire chambers filled

  1. wire chamber

    CERN Multimedia

    Proportional multi-wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle. Proportional wire chambers allow a much quicker reading than the optical or magnetoscriptive readout wire chambers.

  2. Wire chamber

    CERN Multimedia

    1967-01-01

    Magnetoscriptive readout wire chamber.Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  3. Wire Chamber

    CERN Multimedia

    Magnetoscriptive readout wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  4. wire chamber

    CERN Multimedia

    Was used in ISR (Intersecting Storage Ring) split field magnet experiment. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  5. wire chamber

    CERN Multimedia

    1985-01-01

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  6. wire chamber

    CERN Multimedia

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  7. Wire chamber

    CERN Multimedia

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  8. PS wire chamber

    CERN Multimedia

    1970-01-01

    A wire chamber used at CERN's Proton Synchrotron accelerator in the 1970s. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  9. Charpak hemispherical wire chamber

    CERN Multimedia

    1970-01-01

    pieces. Mesures are of the largest one. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  10. Obelix Wire Chamber

    CERN Multimedia

    1986-01-01

    Two wire chambers made originally for the R807 Experiment at CERN's Intersecting Storage Rings. In 1986 they were used for the PS 201 experiment (Obelix Experiment) at LEAR, the Low Energy Antiproton Ring. The group of researchers from Turin, using the chambers at that time, changed the acquisition system using for the first time 8 bit (10 bit non linear) analog to digital conversion for incoming signals from the chambers. The acquisition system was controlled by 54 CPU and 80 digital signal processors. The power required for all the electronics was 40 kW. For the period, this system was one of the most powerful on-line apparatus in the world. The Obelix Experiment was closed in 1996. To find more about how a wire chamber works, see the description for object CERN-OBJ-DE-038.

  11. Wire chambers revisited.

    Science.gov (United States)

    Ott, R J

    1993-04-01

    Detectors used for radioisotope imaging have, historically, been based on scintillating crystal/photomultiplier combinations in various forms. From the rectilinear scanner through to modern gamma cameras and positron cameras, the basic technology has remained much the same. Efforts to overcome the limitations of this form of technology have foundered on the inability to reproduce the required sensitivity, spatial resolution and sensitive area at acceptable cost. Multiwire proportional chambers (MWPCs) have long been used as position-sensitive charged particle detectors in nuclear and high-energy physics. MWPCs are large-area gas-filled ionisation chambers in which large arrays of fine wires are used to measure the position of ionisation produced in the gas by the passage of charged particles. The important properties of MWPCs are high-spatial-resolution, large-area, high-count-rate performance at low cost. For research applications, detectors several metres square have been built and small-area detectors have a charged particle resolution of 0.4 mm at a count rate of several million per second. Modification is required to MWPCs for nuclear medicine imaging. As gamma rays or X-rays cannot be detected directly, they must be converted into photo- or Compton scatter electrons. Photon-electron conversion requires the use of high atomic number materials in the body of the chamber. Pressurised xenon is the most useful form of "gas only" photon-electron convertor and has been used successfully in a gamma camera for the detection of gamma rays at energies below 100 keV. This camera has been developed specifically for high-count-rate first-pass cardiac imaging. This high-pressure xenon gas MWPC is the key to a highly competitive system which can outperform scintillator-based systems. The count rate performance is close to a million counts per second and the intrinsic spatial resolution is better than the best scintillator-based camera. The MWPC camera produces quantitative

  12. Review of wire chamber aging

    Energy Technology Data Exchange (ETDEWEB)

    Va' Vra, J.

    1986-02-01

    This paper makes an overview of the wire chamber aging problems as a function of various chamber design parameters. It emphasizes the chemistry point of view and many examples are drawn from the plasma chemistry field as a guidance for a possible effort in the wire chamber field. The paper emphasizes the necessity of variable tuning, the importance of purity of the wire chamber environment, as well as it provides a practical list of presently known recommendations. In addition, several models of the wire chamber aging are qualitatively discussed. The paper is based on a summary talk given at the Wire Chamber Aging Workshop held at LBL, Berkeley on January 16-17, 1986. Presented also at Wire Chamber Conference, Vienna, February 25-28, 1986. 74 refs., 18 figs., 11 tabs.

  13. Plasma chemistry in wire chambers

    Energy Technology Data Exchange (ETDEWEB)

    Wise, J.

    1990-05-01

    The phenomenology of wire chamber aging is discussed and fundamentals of proportional counters are presented. Free-radical polymerization and plasma polymerization are discussed. The chemistry of wire aging is reviewed. Similarities between wire chamber plasma (>1 atm dc-discharge) and low-pressure rf-discharge plasmas, which have been more widely studied, are suggested. Construction and use of a system to allow study of the plasma reactions occurring in wire chambers is reported. A proportional tube irradiated by an {sup 55}Fe source is used as a model wire chamber. Condensable species in the proportional tube effluent are concentrated in a cryotrap and analyzed by gas chromatography/mass spectrometry. Several different wire chamber gases (methane, argon/methane, ethane, argon/ethane, propane, argon/isobutane) are tested and their reaction products qualitatively identified. For all gases tested except those containing methane, use of hygroscopic filters to remove trace water and oxygen contaminants from the gas resulted in an increase in the average molecular weight of the products, consistent with results from low-pressure rf-discharge plasmas. It is suggested that because water and oxygen inhibit polymer growth in the gas phase that they may also reduce polymer deposition in proportional tubes and therefore retard wire aging processes. Mechanistic implications of the plasma reactions of hydrocarbons with oxygen are suggested. Unresolved issues in this work and proposals for further study are discussed.

  14. Signal shapes in a TPC wire chamber

    Science.gov (United States)

    Rossegger, S.; Riegler, W.

    2010-11-01

    We study signal shapes in Multi Wire Proportional Chambers (MWPCs) and the influence of the electron distribution around the wire on the ion tail characteristics. Simulations of the ion tail for two different geometries, different voltages and therefore gas gains were performed. These simulations are compared to measurements carried out with the ALICE TPC wire chambers for a Ne/CO 2/N 2 gas mixture, which allows to extract the avalanche spread around the anode wires of the MWPC.

  15. Wire pad chamber for LHCb muon system

    CERN Document Server

    Botchine, B; Lazarev, V A; Sagidova, N; Vorobev, A P; Vorobyov, A; Vorobyov, Alexei

    2000-01-01

    2000-003 Wire pad chambers (WPC) have been proposed for the outer Region 4 of the LHCb Muon System. These are double gap MWPCs with small wire spacing allowing to obtain 99% detection efficiency in a 20 ns time window. The chambers have a rectangular shape with the vertical dimension from 20 cm in Station 1 to 30 cm in Station 5. The horizontal dimensions will be different with the maximal size of 3 meters in Station 5. The wires are in the vertical direction. The short wire length allows to use small wire spacing needed for high time resolution. Also, this helps to obtain the uniform gas gain over the whole chamber area. The WPC has one row of the wire pads formed by grouping wires in separate readout channels. Four WPC prototypes have been built at PNPI and tested in the PS beam at CERN. Here we report on the results from these tests. Also, the results of simulation of the WPC performance are presented.

  16. Readout system for proportional wire chambers

    CERN Document Server

    Berst, J D; Metzger, G; Meyer, J M; Schultz, G

    1974-01-01

    The authors describe a MWPC read-out system intended for the hyperon experiments at CERN. Its structure is like the familiar CAMAC branch highway, but driven by a spark chamber readout module placed in CAMAC. The different parts of the equipment, which may read up to 4096 wires, and the test system are described. (5 refs).

  17. Wire chambers with their magnetostrictive readout

    CERN Multimedia

    1974-01-01

    This set of wire chamber planes shaped as a cylinder sector was installed inside the magnet of a polarized spin target modified to allow as well momentum analysis of the produced particles. The experiment (S126) was set up by the CERN-Trieste Collaboration in the PS beam m9 to measure spin effects in the associated production of of a positive kaon and a positive Sigma by interaction of a positive pion with polarized protons.

  18. Carbon wire chamber at sub-atmospheric pressure

    Science.gov (United States)

    Charles, G.; Audouin, L.; Bettane, J.; Dupre, R.; Genolini, B.; Hammoudi, N.; Imre, M.; Le Ven, V.; Maroni, A.; Mathon, B.; Nguyen Trung, T.; Rauly, E.

    2017-05-01

    Present in many experiments, wire and drift chambers have been used in a large variety of shapes and configurations during the last decades. Nevertheless, their readout elements has not evolved much: tungsten, sometimes gold-plated or aluminum, wires. By taking advantage of the developments in the manufacture of conducting carbon fiber, we could obtain interesting improvements for wire detectors. In this article, we present recent tests and simulations using carbon fibers to readout signal in place of traditional tungsten wires. Unlike metallic wires, their low weight guaranties a reduced quantity of material in the active area.

  19. The Effects of a Hydrogen Environment on the Lifetime of Small-Diameter Drift Chamber Anode Wires

    Energy Technology Data Exchange (ETDEWEB)

    King, J; Smith, T; Kunkle, J; Castelaz, J; Thomson, S; Burstein, Z; Bernstein, A; Rosenberg, L; Hefner, M

    2005-04-29

    Possible deterioration of anode sense wires used in a hydrogen-filled neutron detector is investigated. Wires were loaded with free weights and put into a wire detector environment. Stainless Steel, Tungsten, and Platinum wires did not break after exposure to charge equivalent to many wire lifetimes. Furthermore, exposure to hydrogen gas caused no noticeable surface degradation or change in wire yield strength.

  20. Construction and assembly of the wire planes for the MicroBooNE Time Projection Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Acciarri, R.; Adams, C.; Asaadi, J.; Danaher, J.; Fleming, B. T.; Gardner, R.; Gollapinni, S.; Grosso, R.; Guenette, R.; Littlejohn, B. R.; Lockwitz, S.; Raaf, J. L.; Soderberg, M.; John, J. St.; Strauss, T.; Szelc, A. M.; Yu, B.

    2017-03-01

    In this paper we describe how the readout planes for the MicroBooNE Time Projection Chamber were constructed, assembled and installed. We present the individual wire preparation using semi-automatic winding machines and the assembly of wire carrier boards. The details of the wire installation on the detector frame and the tensioning of the wires are given. A strict quality assurance plan ensured the integrity of the readout planes. The different tests performed at all stages of construction and installation provided crucial information to achieve the successful realization of the MicroBooNE wire planes.

  1. Charge production in thin gap multi-wire chambers

    CERN Document Server

    Mincer, A I; Goldberg, J J; Gernitzky, Y; Lazic, D; Lupu, N Z; Robins, S; Rozen, Y; Tarem, S

    2000-01-01

    Resistive cathode thin gap chambers (TGCs) have been used as particle detectors in high-energy physics experiments for more than a decade. A quantitative understanding of charge production mechanisms in TGCs has been developed and a simulation program produced to accurately describe the expected response from a chamber as a function of its design and operating parameters. This simulation is based upon a description of the processes of electron cluster production, drift and avalanche effects and space charge contributions from residual ions. Improved measurements of chamber performance are presented, and the parameters of the simulation have been fitted to these data yielding values consistent with estimates based on the physical mechanisms involved. Sensitivity of chamber timing and amplification properties to operating parameters is discussed.

  2. A new wire chamber front-end system, based on the ASD-8 B chip

    Energy Technology Data Exchange (ETDEWEB)

    Kruesemann, B.A.M. E-mail: kruesemann@kvi.nl; Bassini, R.; Ellinghaus, F.; Frekers, D.; Hagemann, M.; Hannen, V.M.; Heynitz, H. von; Heyse, J.; Rakers, S.; Sohlbach, H.; Woertche, H.J

    1999-07-11

    The Focal-Plane Polarimeter (FPP) for the Big-Bite Spectrometer van den Berg (Nucl. Instr. and Meth. B 99 (1995) 637ff) at the KVI requires the read-out of four large-area MWPCs and two VDCs with 3872 wires in total. The EUROSUPERNOVA collaboration (SNOVA) developed a digital 16 channel preamplifier front-end board, housing two amplifier-shaper-discriminatorchips ASD-8 B. The main features of this board are a fast single-wire readout, a high integration density, a low power consumption and compatibility to common instrumentation standards. The board represents the first successfully running application of the ASD-8 for wire chamber readout. (author)

  3. A new wire chamber front-end system, based on the ASD-8 B chip

    CERN Document Server

    Kruesemann, B A M; Ellinghaus, F; Frekers, D; Hagemann, M; Hannen, V M; Heynitz, H V; Heyse, J; Rakers, S; Sohlbach, H; Wörtche, H J

    1999-01-01

    The Focal-Plane Polarimeter (FPP) for the Big-Bite Spectrometer van den Berg (Nucl. Instr. and Meth. B 99 (1995) 637ff) at the KVI requires the read-out of four large-area MWPCs and two VDCs with 3872 wires in total. The EUROSUPERNOVA collaboration (SNOVA) developed a digital 16 channel preamplifier front-end board, housing two amplifier-shaper-discriminatorchips ASD-8 B. The main features of this board are a fast single-wire readout, a high integration density, a low power consumption and compatibility to common instrumentation standards. The board represents the first successfully running application of the ASD-8 for wire chamber readout. (author)

  4. Particle tracking in kaon electroproduction with cathode-charge sampling in multi-wire proportional chambers

    CERN Document Server

    Achenbach, P; Bernauer, J C; Böhm, R; Bosnar, D; Bösz, M; Debenjak, L; Distler, M O; Esser, A; Friščić, I; de la Paz, M Gómez Rodríguez; Makek, M; Merkel, H; Müller, U; Nungesser, L; Pochodzalla, J; Potokar, M; Majos, S Sánchez; Schlimme, B S; Širca, S; Weinriefer, M; 10.1016/j.nima.2011.03.039

    2011-01-01

    Wire chambers are routinely operated as tracking detectors in magnetic spectrometers at high-intensity continuous electron beams. Especially in experiments studying reactions with small cross-sections the reaction yield is limited by the background rate in the chambers. One way to determine the track of a charged particle through a multi-wire proportional chamber (MWPC) is the measurement of the charge distribution induced on its cathodes. In practical applications of this read-out method, the algorithm to relate the measured charge distribution to the avalanche position is an important factor for the achievable position resolution and for the track reconstruction efficiency. An algorithm was developed for operating two large-sized MWPCs in a strong background environment with multiple-particle tracks. Resulting efficiencies were determined as a function of the electron beam current and on the signal amplitudes. Because of the different energy-losses of pions, kaons, and protons in the momentum range of the s...

  5. A measurement of the relativistic rise in xenon-filled ionisation chambers for cosmic ray iron

    Science.gov (United States)

    Gregory, J. C.; Parnell, T. A.

    1980-01-01

    The relativistic rise of ionization in a pair of xenon-filled pulse ion chambers was measured for primary iron nuclei during a recent balloon flight. Energy calibration over the range 21.5-60 GeV/n was made with a Freon-12 gas Cerenkov detector. This allowed a comparison with recent calculations of the relativistic rise in xenon counters and an estimate of the ion chamber resolution above 21.5 GeV/n to be made.

  6. Radiated Immunity Testing of a Device with an External Wire: Repeatibility of Reverberation Chamber Results and Correlation with Anechoic Chamber Results

    OpenAIRE

    Canavero, Flavio

    2003-01-01

    We present the experimental radiated immunity results of an electronic device with an external wire obtained in reverberation and anechoic chambers. Repeatability and reproducibility of reverberation chamber measurements are investigated by repeating the test in three reverberation chambers with different characteristics. We show how the current state of the art allows a statistical control of RC measurement repeatability within an industrial installation, and that a statistical correlation w...

  7. Front-end Electronics Test for the LHCb Muon Wire Chambers

    CERN Document Server

    Nobrega, R; Carboni, G; Massafferri, A; Santovetti, E

    2007-01-01

    This document describes the apparatus and procedures implemented to test Multi Wire Proportional Chambers (MWPC) after front-end assembly for the LHCb Muon Detector. Results of measurements of key noise parameters are also described. Given a fully equipped chamber, this system is able to diagnose every channel performing an analysis of front-end output drivers’ response and noise rate versus threshold. Besides, it allows to assess if the noise rate at the experiment threshold region is within appropriate limits. Aiming at an automatic, fast and user-friendly system for mass production tests of MWPC, the project has foreseen as well electronic identification of every chamber and front-end board, and data archiving in such a way to make it available to the Experiment Control System (ECS) while in operation.

  8. Electron attachment of oxygen in a drift chamber filled with xenon + 10% methane

    Energy Technology Data Exchange (ETDEWEB)

    Chiba, Y.; Hayashibara, I.; Ohsugi, T.; Sakanoue, T.; Taketani, A.; Terunuma, N.; Suzuki, Y.; Tsukamoto, A.; Yamamoto, H.; Fukushima, Y.

    1988-06-01

    The existence of O/sub 2/ contamination attenuates the pulse height and degrades its resolution in a drift chamber filled with xenon-methane (90/10) gas. The first measurement of the electron attachment coefficient due to oxygen in such a mixture is reported.

  9. The stability of liquid-filled matrix ionization chamber electronic portal imaging devices for dosimetry purposes

    NARCIS (Netherlands)

    Louwe, R. J. W.; Tielenburg, R.; van Ingen, K. M.; Mijnheer, B. J.; van Herk, M. B.

    2004-01-01

    This study was performed to determine the stability of liquid-filled matrix ionization chamber (LiFi-type) electronic portal imaging devices (EPID) for dosimetric purposes. The short- and long-term stability of the response was investigated, as well as the importance of factors influencing the

  10. A micro-gap, air-filled ionisation chamber as a detector for criticality accident dosimetry.

    Science.gov (United States)

    Murawski, Ł; Zielczyński, M; Golnik, N; Gryziński, M A

    2014-10-01

    A micro-gap air-filled ionisation chamber was designed for criticality dosimetry. The special feature of the chamber is its very small gap between electrodes of only 0.3 mm. This prevents ion recombination at high dose rates and minimises the influence of gas on secondary particles spectrum. The electrodes are made of polypropylene because of higher content of hydrogen in this material, when compared with soft tissue. The difference between neutron and gamma sensitivity in such chamber becomes practically negligible. The chamber's envelope contains two specially connected capacitors, one for polarising the electrodes and the other for collecting the ionisation charge. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Particle tracking in kaon electroproduction with cathode-charge sampling in multi-wire proportional chambers

    Science.gov (United States)

    Achenbach, P.; Ayerbe Gayoso, C.; Bernauer, J. C.; Böhm, R.; Bosnar, D.; Bösz, M.; Debenjak, L.; Distler, M. O.; Esser, A.; Friščić, I.; Gómez Rodríguez de la Paz, M.; Makek, M.; Merkel, H.; Müller, U.; Nungesser, L.; Pochodzalla, J.; Potokar, M.; Sánchez Majos, S.; Schlimme, B. S.; Širca, S.; Weinriefer, M.

    2011-06-01

    Wire chambers are routinely operated as tracking detectors in magnetic spectrometers at high-intensity continuous electron beams. Especially in experiments studying reactions with small cross-sections the reaction yield is limited by the background rate in the chambers. One way to determine the track of a charged particle through a multi-wire proportional chamber (MWPC) is the measurement of the charge distribution induced on its cathodes. In practical applications of this read-out method, the algorithm to relate the measured charge distribution to the avalanche position is an important factor for the achievable position resolution and for the track reconstruction efficiency. An algorithm was developed for operating two large-sized MWPCs in a strong background environment with multiple-particle tracks. Resulting efficiencies were determined as a function of the electron beam current and on the signal amplitudes. Because of the different energy-losses of pions, kaons, and protons in the momentum range of the spectrometer the efficiencies depend also on the particle species.

  12. Experimental research on a boron-coated multi-wire proportional chamber neutron detector

    Science.gov (United States)

    Zhang, Ying; Wang, Yan-Feng; Wang, Xiao-Hu; Tu, Xiao-qing; Zhou, Jian-Rong; Yang, Bo; Sun, Zhi-Jia; Cao, Ping; An, Qi; Gong, Jian

    2017-06-01

    A boron-coated multi-wire proportional chamber (MWPC) neutron detector coupled with a delay line readout system has been investigated to possibly replace the 3He neutron detector. MWPC worked on the gas flow mode with Ar/ CO2 (90%/10%) and its readout system was based on the time-to-digital converter. The detection efficiency for a neutron wavelength of 0.247 nm was approximately 3.5%, and the spatial resolution was 5 mm. Other experimental results, such as gain and counting rate plateau, were also obtained.

  13. Mass production of polymer nano-wires filled with metal nano-particles.

    Science.gov (United States)

    Lomadze, Nino; Kopyshev, Alexey; Bargheer, Matias; Wollgarten, Markus; Santer, Svetlana

    2017-08-17

    Despite the ongoing progress in nanotechnology and its applications, the development of strategies for connecting nano-scale systems to micro- or macroscale elements is hampered by the lack of structural components that have both, nano- and macroscale dimensions. The production of nano-scale wires with macroscale length is one of the most interesting challenges here. There are a lot of strategies to fabricate long nanoscopic stripes made of metals, polymers or ceramics but none is suitable for mass production of ordered and dense arrangements of wires at large numbers. In this paper, we report on a technique for producing arrays of ordered, flexible and free-standing polymer nano-wires filled with different types of nano-particles. The process utilizes the strong response of photosensitive polymer brushes to irradiation with UV-interference patterns, resulting in a substantial mass redistribution of the polymer material along with local rupturing of polymer chains. The chains can wind up in wires of nano-scale thickness and a length of up to several centimeters. When dispersing nano-particles within the film, the final arrangement is similar to a core-shell geometry with mainly nano-particles found in the core region and the polymer forming a dielectric jacket.

  14. CFD Modeling of Chamber Filling in a Micro-Biosensor for Protein Detection.

    Science.gov (United States)

    Islamov, Meiirbek; Sypabekova, Marzhan; Kanayeva, Damira; Rojas-Solórzano, Luis

    2017-10-03

    Tuberculosis (TB) remains one of the main causes of human death around the globe. The mortality rate for patients infected with active TB goes beyond 50% when not diagnosed. Rapid and accurate diagnostics coupled with further prompt treatment of the disease is the cornerstone for controlling TB outbreaks. To reduce this burden, the existing gap between detection and treatment must be addressed, and dedicated diagnostic tools such as biosensors should be developed. A biosensor is a sensing micro-device that consists of a biological sensing element and a transducer part to produce signals in proportion to quantitative information about the binding event. The micro-biosensor cell considered in this investigation is designed to operate based on aptamers as recognition elements against Mycobacterium tuberculosis secreted protein MPT64, combined in a microfluidic-chamber with inlet and outlet connections. The microfluidic cell is a miniaturized platform with valuable advantages such as low cost of analysis with low reagent consumption, reduced sample volume, and shortened processing time with enhanced analytical capability. The main purpose of this study is to assess the flooding characteristics of the encapsulated microfluidic cell of an existing micro-biosensor using Computational Fluid Dynamics (CFD) techniques. The main challenge in the design of the microfluidic cell lies in the extraction of entrained air bubbles, which may remain after the filling process is completed, dramatically affecting the performance of the sensing element. In this work, a CFD model was developed on the platform ANSYS-CFX using the finite volume method to discretize the domain and solving the Navier-Stokes equations for both air and water in a Eulerian framework. Second-order space discretization scheme and second-order Euler Backward time discretization were used in the numerical treatment of the equations. For a given inlet-outlet diameter and dimensions of an in-house built cell chamber

  15. Measurement of the response-ratio of an ionization chamber filled with dry air to that filled with P-10 gas in the calibration of gas monitors.

    Science.gov (United States)

    Yunoki, Akira; Kawada, Yasushi; Hino, Yoshio

    2017-11-13

    We developed a new method to determine the response ratio of an ionization chamber (Ohkura ionization chamber: type I-4096 01/06) filled with dry air to that filled with P-10 gas. The response-ratio was obtained by comparing the output currents of the ionization chamber after introduction of radioactive gasses of identical activities contained in two small vessels. The obtained ratio was 0.690 ± 0.003, which agreed with the results obtained by other methods. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Recent results on a simple scheme for 2D localization of particles in a wire chamber

    CERN Document Server

    Barbosa-Ademarlaudo, F; Lima, H P

    2002-01-01

    A simple scheme for 2D localization of ionizing particles in a multiwire proportional chamber has been proposed, in which a multilayer printed circuit board replaces the usual X and Y cathode wire planes involved in the position encoding. Results are shown that illustrate performance improvements: differential non-linearity <10%, integral non-linearity <0.1% and spatial resolution <1 mm in both directions. Also presented are two image acquisition interfaces for PCs. One of these makes use of the PC's Pentium processor to histogram data in the computer memory, reaching counting rates up to 3x10 sup 5 events per second. In the other one, a logic machine is used instead of a dedicated processor, allowing histogramming rates up to 10 sup 6 events per second into an on-board 1 Mword memory.

  17. Asymmetric and double-cathode-pad wire chambers for the LHCb muon system

    CERN Document Server

    Kachtchouk, A; Riegler, W; Schmidt, B; Schneider, T; Souvorov, V

    2005-01-01

    We present results from two types of Multi-Wire Proportional Chambers (MWPCs) with wire pitch of 1.5 mm and cathode–cathode distance of 5 mm intended for triggering purposes in the LHCb experiment. Both prototypes use cathode readout because this allows arbitrary segmentation in order to achieve the required granularity. One MWPC prototype uses a symmetric wire–cathode distance (2.5/2.5 mm) with double cathode readout, which doubles the signal compared to reading only one cathode. The second prototype uses an asymmetric wire–cathode distance (1.25/3.75 mm) with single cathode readout which also doubles the signal and in addition reduces the width of the induced charge distribution and therefore reduces the crosstalk for small cathode pads. We also performed a dedicated optimization of readout traces and guard traces in order to reduce the pad–pad crosstalk. Both prototypes show a few hundred volts of operating plateau defined as the region with 99% efficiency in a 20 ns time window. Close to the plate...

  18. Precision templates for gluing wire holding pieces to chamber frames; Plantillas de precision para la construccion de detectores de muones

    Energy Technology Data Exchange (ETDEWEB)

    Berdugo, J.; Burgos, C; Cerrada, M.

    1995-07-01

    In the present report we describe the procedure which has been used in order to optimize the precision obtained when positioning forward backward muon chamber sensor wire planes of the L3 experiment at CERN. With templates produced at CIEMAT a precision of about 10 microns. In sizes of the order of 3 meters. has been achieved. (Author) 2 refs.

  19. Tunable polarization filter based on high-birefringence photonic crystal fiber filled with silver wires

    Science.gov (United States)

    Yang, Xianchao; Lu, Ying; Liu, Baolin; Yao, Jianquan

    2017-07-01

    A tunable single polarization filter based on high-birefringence photonic crystal fiber with silver wires symmetrically filled into cladding air holes is designed. The confinement loss of the unwanted polarized mode (x-polarized mode) at 1310- and 1550-nm bands are 371 and 252 dB/cm, whereas another mode confinement loss (y-polarized mode) at the corresponding wavelength as low as 14 and 10 dB/cm, respectively. Moreover, the 20-dB bandwidth can reach 179 (at the 1310-nm band) and 71 nm (at the 1550-nm band) for a propagation distance of 1 mm. The dispersion relations and polarization characteristics are analyzed in detail utilizing the finite element method. Numerical results show that by adjusting the pitch between two adjacent air holes, the diameters of cladding air holes or silver wires near the fiber core, the resonance wavelength and resonance strength can be tuned effectively, which is beneficial for tunable polarization filter devices in the communication wave bands.

  20. Air filled ionization chambers and their response to high LET radiation

    DEFF Research Database (Denmark)

    Kaiser, Franz-Joachim; Bassler, Niels; Tölli, Heikki

    Background Air filled ionization chambers (ICs) are widely used for absolute dosimetry, not only in photon beams but also in beams of heavy charged particles. Within the IC, electron hole pairs are generated by the energy deposition originating from incoming radiation. High-LET particles create...... a high density of charge carriers in the core of particle tracks. As a consequence an increased (so called "initial") recombination of the charge carriers takes place, besides of the general (volume) recombination described by the Boag theory. A theory for a sub-type of initial recombination ("columnar......" recombination) is the Jaffe theory, which was developed in 1913 by Jaffe. He solved a differential equation by applying several simplifications and approximations such as a Gaussian shaped track whose width serves as free parameter. These simplifications and the use of an simplified charge carrier distribution...

  1. Inspection of anode and field wires for the COMPASS drift chamber, DC5, with Environmental Scanning Electron Microscope

    Science.gov (United States)

    Cyuzuzo, Sonia

    2014-09-01

    The COMPASS experiment at CERN uses a secondary pion beam from the Super Proton Synchrotron (SPS) at CERN to explore the spin structure of nucleons. A new drift chamber, DC5, will be integrated into the COMPASS spectrometer to replace an aging straw tube detector. DC5 will detect muon pairs from Drell-Yan scattering of a pion-beam off a transversely polarized proton target. This data will be used to determine the correlation between transverse proton spin and the intrinsic transverse momentum of up-quarks inside the proton, the Sivers effect. DC5 is a large area planar drift chamber with 8 layers of anode-frames made of G10 fiberglass-epoxy. The G10 frames support printed circuit boards for soldering 20 μm diameter anode and 100 μm diameter field wires. The anode planes are sandwiched by 13 graphite coated Mylar cathode planes. To ensure a well-functioning of DC5, the wires were carefully tested. An optical inspection and a spectral analysis was performed with an Environmental Scanning Electron Microscope (ESEM) to verify the composition and dimensions and the integrity of the gold plating on the surface of these wires. The spectra of the wires were studied at 10 and 30 keV. The COMPASS experiment at CERN uses a secondary pion beam from the Super Proton Synchrotron (SPS) at CERN to explore the spin structure of nucleons. A new drift chamber, DC5, will be integrated into the COMPASS spectrometer to replace an aging straw tube detector. DC5 will detect muon pairs from Drell-Yan scattering of a pion-beam off a transversely polarized proton target. This data will be used to determine the correlation between transverse proton spin and the intrinsic transverse momentum of up-quarks inside the proton, the Sivers effect. DC5 is a large area planar drift chamber with 8 layers of anode-frames made of G10 fiberglass-epoxy. The G10 frames support printed circuit boards for soldering 20 μm diameter anode and 100 μm diameter field wires. The anode planes are sandwiched by 13

  2. Heavy ion beam propagation through a gas-filled chamber for inertial confinement fusion

    Energy Technology Data Exchange (ETDEWEB)

    Barboza, Nigel Oswald [Univ. of California, Berkeley, CA (United States)

    1996-10-01

    The work presented here evaluates the dynamics of a beam of heavy ions propagating through a chamber filled with gas. The motivation for this research stems from the possibility of using heavy ion beams as a driver in inertial confinement fusion reactors for the purpose of generating electricity. Such a study is important in determining the constraints on the beam which limit its focus to the small radius necessary for the ignition of thermonuclear microexplosions which are the source of fusion energy. Nuclear fusion is the process of combining light nuclei to form heavier ones. One possible fusion reaction combines two isotopes of hydrogen, deuterium and tritium, to form an alpha particle and a neutron, with an accompanying release of ~17.6 MeV of energy. Generating electricity from fusion requires that we create such reactions in an efficient and controlled fashion, and harness the resulting energy. In the inertial confinement fusion (ICF) approach to energy production, a small spherical target, a few millimeters in radius, of deuterium and tritium fuel is compressed so that the density and temperature of the fuel are high enough, ~200 g/cm3 and ~20 keV, that a substantial number of fusion reactions occur; the pellet microexplosion typically releases ~350 MJ of energy in optimized power plant scenarios.

  3. The stability of liquid-filled matrix ionization chamber electronic portal imaging devices for dosimetry purposes.

    Science.gov (United States)

    Louwe, R J W; Tielenburg, R; van Ingen, K M; Mijnheer, B J; van Herk, M B

    2004-04-01

    This study was performed to determine the stability of liquid-filled matrix ionization chamber (LiFi-type) electronic portal imaging devices (EPID) for dosimetric purposes. The short- and long-term stability of the response was investigated, as well as the importance of factors influencing the response (e.g., temperature fluctuations, radiation damage, and the performance of the electronic hardware). It was shown that testing the performance of the electronic hardware as well as the short-term stability of the imagers may reveal the cause of a poor long-term stability of the imager response. In addition, the short-term stability was measured to verify the validity of the fitted dose-response curve immediately after beam startup. The long-term stability of these imagers could be considerably improved by correcting for room temperature fluctuations and gradual changes in response due to radiation damage. As a result, the reproducibility was better than 1% (1 SD) over a period of two years. The results of this study were used to formulate recommendations for a quality control program for portal dosimetry. The effect of such a program was assessed by comparing the results of portal dosimetry and in vivo dosimetry using diodes during the treatment of 31 prostate patients. The improvement of the results for portal dosimetry was consistent with the deviations observed with the reproducibility tests in that particular period. After a correction for the variation in response of the imager, the average difference between the measured and prescribed dose during the treatment of prostate patients was -0.7%+/-1.5% (1 SD), and -0.6%+/-1.1% (1 SD) for EPID and diode in vivo dosimetry, respectively. It can be concluded that a high stability of the response can be achieved for this type of EPID by applying a rigorous quality control program.

  4. Asymmetric Multi-Wire Proportional Chamber with reduced requirements to mechanical precision

    Science.gov (United States)

    Varga, D.; Hamar, G.; Kiss, G.

    2011-08-01

    An asymmetric-type MWPC prototype with an inclined wire plane has been studied. It has been demonstrated that at proper choice of the negative potential on the field wires the dependence of the gain on the cathode flatness can be completely eliminated for the closer cathode. Such feature allows us to construct MWPCs with thin cathode planes and wires positioned relatively close to one of the cathodes since the requirement to the precision of cathode flatness is largely reduced. The relevance of these two advantages, especially to achieve low material budget, are presented for the prototype of the High pT Trigger Detector (HPTD) for the ALICE VHMPID detector system. A number of such designs are in operation for over a year, and have been tested with cosmic rays as well as in pion beam at the CERN PS.

  5. Towards Quantitative Image Reconstruction Using Monte-Carlo Simulations in Multi-Wire Proportional Chamber-Based Small Animal PET

    Science.gov (United States)

    Gottschlag, Holger; Kösters, Thomas; Vernekohl, Don; Reygers, Klaus; Schäfers, Klaus P.; Wübbeling, Frank; Wessels, Johannes P.

    2013-10-01

    The quadHIDAC is a dedicated high resolution small animal PET scanner based on multi-wire proportional chamber detectors. It provides very high spatial resolution, good sensitivity, and a large field-of-view allowing the examination of more than one animal in a single scan or a whole body scan of larger species in a single bed position. Excellent image quality has been obtained through list-mode-based EM reconstruction using resolution recovery. However, quantitative results on local uptake are still missing due to both (1) lack of energy discrimination and (2) inaccurate characterization of random events recorded by the scanner. In this work we describe how quantification can be achieved through the use of an appropriate Monte Carlo simulation of the quadHIDAC. The complex structure of the quadHIDAC has been completely implemented in a Geant4 simulation. Point sources, line sources, cylindrical phantoms, and voxelized image data have been successfully simulated and compared to real measurements. The magnitude and spatial distribution of scattered and random events could be quantitatively characterized for the different phantom geometries. The simulation provides access to information on single hit distributions resulting in appropriate randoms corrections in image reconstruction. Both randoms and scatter correction is demonstrated to improve quantification. Their accuracy and performance was tested on simulated and measured data. Using simulation-based correction techniques for quantitative image reconstruction, multi-wire proportional chamber-based PET technology may be attractive for future high resolution PET scanners.

  6. 7 CFR 1755.860 - RUS specification for filled buried wires.

    Science.gov (United States)

    2010-01-01

    ... conductors which are used within the RUS program are provided in the following table: American Wire Gauge... American National Standards Institute/Electronic Industries Association (ANSI/EIA) 359-A-84, EIA Standard... Materials specifications (ASTM) A 505-87, Standard Specification for Steel, Sheet and Strip, Alloy, Hot...

  7. A new wire chamber front-end system, based on the ASD-8 B chip

    NARCIS (Netherlands)

    Krusemann, BAM; Bassini, R; Ellinghaus, F; Frekers, D; Hagemann, M; Hannen, VM; von Heynitz, H; Heyse, J; Sohlbach, H; Wortche, HJ

    1999-01-01

    The Focal-Plane Polarimeter (FPP) for the Big-Bite Spectrometer van den Berg (Nucl Instr. and Meth. B 99 (1995) 637ff) at the KVI requires the read-out of four large-area MWPCs and two VDCs with 3872 wires in-total. The EUROSUPERNOVA collaboration (SNOVA) developed a digital 16 channel preamplifier

  8. Mass production of polymer nano-wires filled with metal nano-particles

    OpenAIRE

    Lomadze, Nino; Kopyshev, Alexey; Bargheer, Matias; Wollgarten, Markus; Santer, Svetlana

    2017-01-01

    Despite the ongoing progress in nanotechnology and its applications, the development of strategies for connecting nano-scale systems to micro- or macroscale elements is hampered by the lack of structural components that have both, nano- and macroscale dimensions. The production of nano-scale wires with macroscale length is one of the most interesting challenges here. There are a lot of strategies to fabricate long nanoscopic stripes made of metals, polymers or ceramics but none is suitable fo...

  9. A Freon-filled bubble chamber for neutron detection in inertial confinement fusion experiments.

    Science.gov (United States)

    Ghilea, M C; Meyerhofer, D D; Sangster, T C

    2011-03-01

    Neutron imaging is one of the main methods used in inertial confinement fusion experiments to measure the core symmetry of target implosions. Previous studies have shown that bubble chambers have the potential to obtain higher resolution images of the targets for a shorter source-to-target distance than typical scintillator arrays. A bubble chamber for neutron imaging with Freon 115 as the active medium was designed and built for the OMEGA laser system. Bubbles resulting from spontaneous nucleation were recorded. Bubbles resulting from neutron-Freon interactions were observed at neutron yields of 10(13) emitted from deuterium-tritium target implosions on OMEGA. The measured column bubble density was too low for neutron imaging on OMEGA but agreed with the model of bubble formation. The recorded data suggest that neutron bubble detectors are a promising technology for the higher neutron yields expected at National Ignition Facility.

  10. Dark Matter Limits From a 2L C3F8 Filled Bubble Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Alan Edward [Univ. of Chicago, IL (United States)

    2015-12-01

    The PICO-2L C3F8 bubble chamber search forWeakly Interacting Massive Particle (WIMP) dark matter was operated in the SNOLAB underground laboratory at the same location as the previous CF3I lled COUPP-4kg detector. Neutron calibrations using photoneutron sources in C3F8 and CF3I lled calibration bubble chambers were performed to verify the sensitivity of these target uids to dark matter scattering. This data was combined with similar measurements using a low-energy neutron beam at the University of Montreal and in situ calibrations of the PICO-2L and COUPP-4kg detectors. C3F8 provides much greater sensitivity to WIMP-proton scattering than CF3I in bubble chamber detectors. PICO-2L searched for dark matter recoils with energy thresholds below 10 keV. Radiopurity assays of detector materials were performed and the expected neutron recoil background was evaluated to be 1.6+0:3

  11. Medical Positron Imaging with a Dense Drift Space MultiWire Proportional Chamber.

    Science.gov (United States)

    Del Guerra, A; Lim, C B; Lum, G K; Ortendahl, D; Perez-Mendez, V

    1982-01-01

    A multiplanar positron camera is proposed, made of six MWPC modules, arranged to form the lateral surface of a hexagonal prism. Each 50 x 50 cm(2) module has a single MWPC sandwiched by two 2-cm thick lead glass tube converters. The experimental results for a 15 x 15 cm(2) test module are reported. For 511 keV gamma-rays incident almost perpendicular onto a 1.0-cm thick converter, a detection efficiency of 4.3%, a time resolution of 130 ns (FWHM) and a spatial resolution of 2.8 mm (FWHM) have been measured with a standard Argon-Methane (70-30) mixture at 1.2 atm. The chamber may also be operated in high resolution mode: 1.2-mm (FWHM) spatial resolution has been measured at a 50% lower efficiency. The use of fast delay lines (specific delay 8 ns/cm) for the position read-out ensures a high rate capability. The expected performance of the six-module MWPC camera is discussed and compared with that of a BGO crystal ring camera. The MWPC solution seems very attractive not only for its low cost and simplicity of construction, but also for its fully three-dimensional imaging capability.

  12. Monitored Drift Tube (MDT) chambers for precise measurement of muon trajectories in the ATLAS muon spectrometer.

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    The basic detection component of the chamber is the cylindrical, aluminium, gas-filled MDT with its central tungsten rhenium wire. Each chamber is an assembly of two parallel multilayers of MDTs separated by a spacer frame. The chambers are pictured here in building 887 on the Prévessin site where they are being tested.

  13. Design and performance of a custom ASIC digitizer for wire chamber readout in 65 nm CMOS technology

    Science.gov (United States)

    Lee, M. J.; Brown, D. N.; Chang, J. K.; Ding, D.; Gnani, D.; Grace, C. R.; Jones, J. A.; Kolomensky, Y. G.; von der Lippe, H.; Mcvittie, P. J.; Stettler, M. W.; Walder, J.-P.

    2015-06-01

    We present the design and performance of a prototype ASIC digitizer for integrated wire chamber readout, implemented in 65 nm commercial CMOS technology. Each channel of the 4-channel prototype is composed of two 16-bit Time-to-Digital Converters (TDCs), one 8-bit Analog-to-Digital Converter (ADC), a front-end preamplifier and shaper, plus digital and analog buffers that support a variety of digitization chains. The prototype has a multiplexed digital backend that executes a state machine, distributes control and timing signals, and buffers data for serial output. Laboratory bench tests measure the absolute TDC resolution between 74 ps and 480 ps, growing with the absolute delay, and a relative time resolution of 19 ps. Resolution outliers due to cross-talk between clock signals and supply or reference voltages are seen. After calibration, the ADC displays good linearity and noise performance, with an effective number of bits of 6.9. Under normal operating conditions the circuit consumes 32 mW per channel. Potential design improvements to address the resolution drift and tails are discussed.

  14. Initial recombination in the track of heavy charged particles: numerical solution for air filled ionization chambers.

    Science.gov (United States)

    Kaiser, Franz-Joachim; Bassler, Niels; Tölli, Heikki; Jäkel, Oliver

    2012-03-01

    Modern particle therapy facilities enable sub-millimeter precision in dose deposition. Here, also ionization chambers (ICs) are used, which requires knowledge of the recombination effects. Up to now, recombination is corrected using phenomenological approaches for practical reasons. In this study the effect of the underlying dose distribution on columnar recombination, a quantitative model for initial recombination, is investigated. Jaffé's theory, formulated in 1913 quantifies initial recombination by elemental processes, providing an analytical (closed) solution. Here, we investigate the effect of the underlying charged carrier distribution around a carbon ion track. The fundamental partial differential equation, formulated by Jaffé, is solved numerically taking into account more realistic charge carrier distributions by the use of a computer program (Gascoigne 3D). The investigated charge carrier distributions are based on track structure models, which follow a 1/r(2) behavior at larger radii and show a constant value at small radii. The results of the calculations are compared to the initial formulation and to data obtained in experiments using carbon ion beams. The comparison between the experimental data and the calculations shows that the initial approach made by Jaffé is able to reproduce the effects of initial recombination. The amorphous track structure based charge carrier distribution does not reproduce the experimental data well. A small additional correction in the assessment of the saturation current or charge is suggested by the data. The established model of columnar recombination reproduces the experimental data well, whereas the extensions using track structure models do not show such an agreement. Additionally, the effect of initial recombination on the saturation curve (i.e. Jaffé plot) does not follow a linear behavior as suggested by current dosimetry protocols, therefore higher order corrections (such as the investigated ones) might be

  15. Rebound tonometry over an air-filled anterior chamber in the supine child after intraocular surgery.

    Science.gov (United States)

    Davis, Ryan; Jiramongkolchai, Kim; Silverstein, Evan; Freedman, Sharon F

    2016-04-01

    Intracameral air is a critical component of multiple ophthalmic surgical procedures and is frequently used in pediatric intraocular surgery. Among other benefits, it helps to facilitate postoperative examination in uncooperative children by allowing quick confirmation of a formed anterior chamber. The purpose of this study was to evaluate the usefulness and accuracy of a position-independent rebound tonometer (Icare PRO) in measuring intraocular pressure (IOP) intraoperatively in pediatric eyes with intracameral air compared to a commonly used handheld applanation tonometer (Tono-Pen XL). In this prospective study of sequential children undergoing intraocular surgery, IOP was measured immediately following general anesthesia induction using both Icare PRO rebound tonometry and Tono-Pen XL tonometry, with instrument order randomized, in the supine child's eye(s). At completion of surgery after standard placement of intracameral air IOP was again measured using both instruments. A total of 42 eyes of 30 children were included. Surgeries included glaucoma (25), cataract-related (16), and both (1). Mean preoperative IOP by Tono-Pen XL was 23.52 ± 9.76 mm Hg; by Icare PRO, 20.94 ± 10.01 mm Hg (P = 0.0012). Mean IOP over intracameral air at surgery conclusion by Tono-Pen XL (n = 41) was 12.66 ± 4.90; by Icare PRO (n = 42), 12.96 ± 5.10 mm Hg (P = 0.46). One eye had postoperative IOP unrecordable by Tono-Pen XL but 7.9 mm Hg by Icare PRO. Bland-Altman analysis, which included only paired measurements, showed a preoperative mean difference in IOP (ΔIOPT-I) of 2.58 mm Hg (95% CI, -6.86 to 12.02); postoperative mean ΔIOPT-I of -0.42 mm Hg [95% CI, -7.57 to 6.73]. Position-independent rebound tonometry (Icare PRO) accurately measured IOP in supine children's eyes postoperatively in the presence of intracameral air. Copyright © 2016 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

  16. Georges Charpak and his multiwire chamber

    CERN Multimedia

    1970-01-01

    In 1968, Georges Charpak developed the 'multiwire proportional chamber', a gas-filled box with a large number of parallel detector wires, each connected to individual amplifiers. Linked to a computer, it could achieve a counting rate a thousand times better than existing techniques - without a camera in sight. From left to right, Georges Charpak, Fabio Sauli and Jean-Claude Santiard working on a multiwire chamber in 1970.

  17. Thermal performance of a vapor chamber-based plate of high-power light-emitting diodes filled with Al2O3 nanofluid.

    Science.gov (United States)

    Wang, Jung-Chang; Lin, Cherng-Yuan; Chen, Teng-Chieh

    2013-04-01

    Nanofluid that contains Al2O3 nanoparticles evenly dispersed in deionized water is considered to have superior heat transfer characteristics due to the significant increase in both collision frequency and contact surface area between the nanoparticles and the deionized water. The thermal performance of the vapor chamber-based plate of a high power light-emitting diode (LED) filled with Al2O3 nanofluid was experimentally investigated. The thermal characteristics of the vapor chamber were also compared with those of copper- and aluminum-based plates exposed to the heating source of four single-crystal LEDs. The experimental results show that the effective thermal conductivity of the vapor chamber increased with an increase in heat flux. A higher heating power caused an increase in the temperature variation in the vapor chamber, the illumination of the vapor chamber-, copper-, and aluminum-based plates, and the material resistance of the copper- and aluminum-based plates. In contrast, the spreading, convective, and total thermal resistance all decreased with an increase in heating power for all three base plates. The total thermal resistance of the vapor chamber is mostly due to its spreading thermal resistance, and appeared to be lower than that of the copper- and aluminum-based plates under a heating power of over 5 Watts.

  18. Efficacy of CM-Wire, M-Wire, and Nickel-Titanium Instruments for Removing Filling Material from Curved Root Canals: A Micro-Computed Tomography Study.

    Science.gov (United States)

    Rodrigues, Clarissa Teles; Duarte, Marco Antonio Hungaro; de Almeida, Marcela Milanezi; de Andrade, Flaviana Bombarda; Bernardineli, Norberti

    2016-11-01

    The aim of this ex vivo study was to evaluate the removal of filling material after using CM-wire, M-wire, and nickel-titanium instruments in both reciprocating and rotary motions in curved canals. Thirty maxillary lateral incisors were divided into 9 groups according to retreatment procedures: Reciproc R25 followed by Mtwo 40/.04 and ProDesign Logic 50/.01 files; ProDesign R 25/.06 followed by ProDesign Logic 40/.05 and ProDesign Logic 50/.01 files; and Gates-Glidden drills, Hedström files, and K-files up to apical size 30 followed by K-file 40 and K-file 50 up to the working length. Micro-computed tomography scans were performed before and after each reinstrumentation procedure to evaluate root canal filling removal. Statistical analysis was performed with Kruskal-Wallis, Friedman, and Wilcoxon tests (P material removal were found in the 3 groups of teeth. The use of Mtwo and ProDesign Logic 40/.05 rotary files did not enhance filling material removal after the use of reciprocating files. The use of ProDesign Logic 50/.01 files significantly reduced the amount of filling material at the apical levels compared with the use of reciprocating files. Association of reciprocating and rotary files was capable of removing a large amount of filling material in the retreatment of curved canals, irrespective of the type of alloy of the instruments. The use of a ProDesign Logic 50/.01 file for apical preparation significantly reduced the amount of remnant material in the apical portion when compared with reciprocating instruments. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  19. Cosmic ray tests of a 4.6 m-long test drift chamber for JLC

    CERN Document Server

    Kurihara, Y; Sudo, S; Abe, T; Fujii, K; Ishihara, N; Khalatyan, N; Matsui, T; Nitoh, O; Ohama, T; Okuno, H; Sugiyama, A; Takahashi, K; Watanabe, T; Yoshida, T

    2000-01-01

    Performance of a 4.6 m-long drift chamber filled with a CO sub 2 iso-butane (90:10) mixture was studied using cosmic-ray data, in the course of detector R and D for JLC. After correcting the data for wire displacements due to gravitational and electrostatic forces, a spatial resolution of 100 mu m per wire was achieved over the full length of the chamber. The relation between wire efficiency and oxygen remnant in the chamber gas is also discussed.

  20. Pulsed neutron generators based on the sealed chambers of plasma focus design with D and DT fillings

    Science.gov (United States)

    Yurkov, D. I.; Dulatov, A. K.; Lemeshko, B. D.; Golikov, A. V.; Andreev, D. A.; Mikhailov, Yu V.; Prokuratov, I. A.; Selifanov, A. N.

    2015-11-01

    Development of neutron generators using plasma focus (PF) chambers is being conducted in the All-Russia Scientific Research Institute of Automatics (VNIIA) during more than 25 years. PF is a source of soft and hard x-rays and neutrons 2.5 MeV (D) or 14 MeV (DT). Pulses of x-rays and neutrons have a duration of about several tens of nanoseconds, which defines the scope of such generators—the study of ultrafast processes. VNIIA has developed a series of pulse neutron generators covering the range of outputs 107-1012 n/pulse with resources on the order of 103-104 switches, depending on purposes. Generators have weights in the range of 30-700 kg, which allows referring them to the class of transportable generators. Generators include sealed PF chambers, whose manufacture was mastered by VNIIA vacuum tube production plant. A number of optimized PF chambers, designed for use in generators with a certain yield of neutrons has been developed. The use of gas generator based on gas absorber of hydrogen isotopes, enabled to increase the self-life and resource of PF chambers. Currently, the PF chambers withstand up to 1000 switches and have the safety of not less than 5 years. Using a generator with a gas heater, significantly increased security of PF chambers, because deuterium-tritium mixture is released only during work, other times it is in a bound state in the working element of the gas generator.

  1. Monitored Drift Chambers in the ATLAS Detector

    CERN Document Server

    Herten, G

    Monitored Drift Chambers (MDT) are used in the ATLAS Detector to measure the momentum of high energy muons. They consist of drift tubes, which are filled with an Ar-CO2 gas mixture at 3 bar gas pressure. About 1200 drift chambers are required for ATLAS. They are up to 6 m long. Nevertheless the position of every wire needs to be known with a precision of 20 µm within a chamber. In addition, optical alignment sensors are required to measure the relative position of adjacent chambers with a precision of 30µm. This gigantic task seems impossible at first instance. Indeed it took many years of R&D to invent the right tools and methods before the first chamber could be built according to specifications. Today, at the time when 50% of the chambers have been produced, we are confident that the goal for ATLAS can be reached. The mechanical precision of the chambers could be verified with the x-ray tomograph at CERN. This ingenious device, developed for the MDT system, is able to measure the wire position insid...

  2. Detecting management and fertilization effects on the carbon balance of winter oilseed rape with manual closed chamber measurements: Can we outrange gap-filling uncertainty and spatiotemporal variability?

    Science.gov (United States)

    Huth, Vytas; Moffat, Antje Maria; Calmet, Anna; Andres, Monique; Laufer, Judit; Pehle, Natalia; Rach, Bernd; Gundlach, Laura; Augustin, Jürgen

    2017-04-01

    Winter oilseed rape is the dominant biofuel crop in the young moraine landscape in North-Eastern Germany. However, studies on the effect of rapeseed cropping on net ecosystem exchange of CO2 (NEE) and the soil carbon (SC) balance are scarce. SC balance estimates are usually derived from long-term soil sampling field trials where rapeseed is part of different crop rotations. The estimated annual differences linked to rapeseed cropping are rather small (varying between losses of 40 g C m-2 and gains of up to 100 g C m-2). Testing management effects on the NEE and SC balance of cropping systems is best done by comparing plots with different treatments at the same site under the same climate. The soil sampling approach is in the need of field trials that run over decades, which has the disadvantage that management strategies of practical farming may have already changed when the results are derived. Continuous eddy covariance measurements of NEE would require large fields in flat terrain for each of the treatments, which is especially complicated in the heterogeneous landscapes of glacigenic origin of North-Eastern Germany. The common approach of using the chamber technique to derive NEE, however, is subject to the local soil and plant stand heterogeneities due to its tiny footprint. This technique might also disturb the ecosystem, the measurements are usually discontinuous requiring elaborate gap-filling techniques, and it has mostly been used on organic soils where large respiratory C losses occur. Therefore, our aim was to answer, if a combined approach of the eddy covariance and the chamber technique can detect the relatively small NEE and SC differences of rapeseed cropping on mineral soils within a shorter period of time than conventional soil sampling field trials can. We tested the new experimental design taking the advantages of both techniques into account: The eddy covariance tower measuring the NEE dynamics during the year; the chamber measurements to

  3. Command Wire Sensor Measurements

    Science.gov (United States)

    2012-09-01

    NPS anechoic chamber is located in Spanagel Hall, Room 604. Although the chamber was built for instruction purposes only, it can be used for research...thesis is to investigate the wire scattering behavior and clutter characteristics through measurements performed in the NPS anechoic chamber. The...research has successfully resolved the various multipath components within the anechoic chamber. The transmit-receive coupling between the antennas was

  4. Prototype multiwire proportional chamber

    CERN Multimedia

    1975-01-01

    Chambers of this type were initially developed within the Alpha project (finally not approved). They were designed such to minimize the radiation length with a view to a mass spectrometer of high resolution meant to replace the Omega detector. The chambers were clearly forerunners for the (drift) chambers later built for R606 with the novel technique of crimping the wires. See also photo 7510039X.

  5. Divergent NEE balances from manual-chamber CO2 fluxes linked to different measurement and gap-filling strategies: A source for uncertainty of estimated terrestrial C sources and sinks?

    DEFF Research Database (Denmark)

    Huth, Vytas; Vaidya, Shrijana; Hoffmann, Mathias

    2017-01-01

    -study comparisons and meta analyses. The aim of this study was to compare common approaches for quantifying CO2 exchange at three methodological levels. (1) The first level included two different CO2 flux measurement methods: one via measurements during mid-day applying net coverages (mid-day approach) and one via......Manual closed-chamber measurements are commonly used to quantify annual net CO2 ecosystem exchange (NEE) in a wide range of terrestrial ecosystems. However, differences in both the acquisition and gap filling of manual closed-chamber data are large in the existing literature, complicating inter...... of the agricultural field diverged strongly (–200 to 425 g CO2-C m−2). NEE balances were most similar to previous studies when derived from sunrise measurements and indirect GPP modeling. Overall, the large variation in NEE balances resulting from different data-acquisition or gap-filling strategies indicates...

  6. Production and test of the LHCb Muon Chamber

    CERN Multimedia

    2005-01-01

    - The Muon System of LHCb - The Multi-Wire Proportional Chambers for LHCb - Wire tension meter - Wire pitch measurement - Gas leakage test - Test with cosmic rays - Production and test summary - Gap gain uniformity - Production and test summary

  7. DELPHI Barrel Muon Chamber Module

    CERN Multimedia

    1989-01-01

    The module was used as part of the muon identification system on the barrel of the DELPHI detector at LEP, and was in active use from 1989 to 2000. The module consists of 7 individual muons chambers arranged in 2 layers. Chambers in the upper layer are staggered by half a chamber width with respect to the lower layer. Each individual chamber is a drift chamber consisting of an anode wire, 47 microns in diameter, and a wrapped copper delay line. Each chamber provided 3 signal for each muon passing through the chamber, from which a 3D space-point could be reconstructed.

  8. Making MUSIC: A multiple sampling ionization chamber

    Energy Technology Data Exchange (ETDEWEB)

    Shumard, B. [Argonne National Laboratory, Building 203 H-113, Argonne, IL 60439 (United States)]. E-mail: shumard@phy.anl.gov; Henderson, D.J. [Argonne National Laboratory, Building 203 H-113, Argonne, IL 60439 (United States); Rehm, K.E. [Argonne National Laboratory, Building 203 H-113, Argonne, IL 60439 (United States); Tang, X.D. [Argonne National Laboratory, Building 203 H-113, Argonne, IL 60439 (United States)

    2007-08-15

    A multiple sampling ionization chamber (MUSIC) was developed for use in conjunction with the Atlas scattering chamber (ATSCAT). This chamber was developed to study the ({alpha}, p) reaction in stable and radioactive beams. The gas filled ionization chamber is used as a target and detector for both particles in the outgoing channel (p + beam particles for elastic scattering or p + residual nucleus for ({alpha}, p) reactions). The MUSIC detector is followed by a Si array to provide a trigger for anode events. The anode events are gated by a gating grid so that only ({alpha}, p) reactions where the proton reaches the Si detector result in an anode event. The MUSIC detector is a segmented ionization chamber. The active length of the chamber is 11.95 in. and is divided into 16 equal anode segments (3.5 in. x 0.70 in. with 0.3 in. spacing between pads). The dead area of the chamber was reduced by the addition of a Delrin snout that extends 0.875 in. into the chamber from the front face, to which a mylar window is affixed. 0.5 in. above the anode is a Frisch grid that is held at ground potential. 0.5 in. above the Frisch grid is a gating grid. The gating grid functions as a drift electron barrier, effectively halting the gathering of signals. Setting two sets of alternating wires at differing potentials creates a lateral electric field which traps the drift electrons, stopping the collection of anode signals. The chamber also has a reinforced mylar exit window separating the Si array from the target gas. This allows protons from the ({alpha}, p) reaction to be detected. The detection of these protons opens the gating grid to allow the drift electrons released from the ionizing gas during the ({alpha}, p) reaction to reach the anode segment below the reaction.

  9. Laboratory aging studies for the HERA-B muon chambers

    CERN Document Server

    Danilov, M; Titov, M; Zaitsev, Y

    2002-01-01

    The severe radiation environment of the HERA-B experiment leads to a maximum accumulated charge on a wire, within the muon detector, of 200 mC/cm wire. For operation in this high-intensity environment, the main criteria for the gas choice turned out to be stability against aging. We report recent results of laboratory aging studies performed by irradiating proportional wire chambers filled with Ar/CF sub 4 /CH sub 4 (74:20:6), Ar/CF sub 4 /CH sub 4 (67:30:3), and Ar/CF sub 4 /CO sub 2 (65:30:5) mixtures. The penetration of water and oxygen through the walls of plastic tubes has also been investigated. Water can be introduced indirect to the gas mixture by using polyamide (nylon) pipes for gas supply lines.

  10. Study of high-pressure hydrogen-operated wire chambers designed for a precision measurement of the singlet mu p capture rate

    CERN Document Server

    Maev, E M; Case, T A; Crowe, K M; Dick, P U; Dijksman, A; Egger, J; Fetisov, A A; Ganzha, V A; Herold, W D; Hartmann, F J; Kammel, P; Krivchitch, A G; Maev, O E; Petitjean, C; Petrov, G E; Prieels, R; Sadetsky, S M; Schapkin, G N; Schmidt, R; Semenchuk, G G; Soroka, M; Vorobyov, A A; Voropaev, N I

    2002-01-01

    This work was carried out as part of a project aiming at a greatly improved measurement of the muon capture rate from the singlet state of the mu p atom. The experiment will be performed at the intense muon beam of PSI using a new experimental method allowing high precision measurements of the lifetime of muons stopped in ultra-pure deuterium-depleted hydrogen (protium). The basic element of the detector is a time projection chamber operating in hydrogen gas at 10 bar pressure. The arrival times and trajectories of the incoming muons and the outgoing decay electrons are measured with this device providing effective suppression of background. The system of chambers and electronics is designed for the large muon stop rates required for attaining high statistical accuracy. During four beam periods at PSI, data were taken. Also, various studies of the MWPC performance in hydrogen were made including ageing studies of the chambers under irradiation with stopped muons and with alpha and beta sources. It was demonst...

  11. Filler-wire positioner for electron beam welding

    Science.gov (United States)

    Beaupre, W. M.; Fueg, L. B.; Phillips, J. A.

    1970-01-01

    Miniaturized positioner is installed in any electron beam vacuum chamber for use with wire feed applications requiring filler wire. Horizontal and vertical control of the positioner is maintained from a console while chamber is under vacuum. Device permits more positive positioning of welding filler wire.

  12. Physicist makes muon chamber sing

    CERN Document Server

    2007-01-01

    This Monitored Drift Tube detector, consisting of argon-CO2-filled aluminium tubes with a wire down the centre of each, will track muons in ATLAS; Tiecke used a single tube from one of these detectors to create the pipes in his organ. Particle physicists can make good musicians; but did you know particle detectors can make good music? That's what NIKHEF physicist Henk Tiecke learned when he used pipes cut from the ATLAS Monitored Drift Tube detector (MDT) to build his own working Dutch-style barrel organ in the autumn of 2005. 'I like to work with my hands,' said Tiecke, who worked as a senior physicist at NIKHEF, Amsterdam, on ZEUS until his retirement last summer. Tiecke had already constructed his barrel organ when he visited some colleagues in the ATLAS muon chambers production area at Nikhef in 2005. He noticed that the aluminium tubes they were using to build the chambers were about three centimetres in diameter-just the right size for a pipe in a barrel organ. 'The sound is not as nice as from wooden...

  13. Setup optimization toward accurate ageing studies of gas filled detectors

    Energy Technology Data Exchange (ETDEWEB)

    Abuhoza, A., E-mail: a.abuhoza@gsi.de [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt 64291 (Germany); National Center for Mathematics and Physics, KACST, P.O. Box 6086, Riyadh 11442 (Saudi Arabia); Goethe-Universität, Frankfurt (Germany); Schmidt, H.R. [Eberhard-Karls-Universität, Tübingen (Germany); Biswas, S.; Frankenfeld, U.; Hehner, J.; Schmidt, C.J. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt 64291 (Germany)

    2013-08-01

    An infrastructure has been set up at the GSI detector laboratory to study the influence of construction materials on the ageing properties of gas filled detectors, such as multi-wire proportional chamber (MWPC), gas electron multiplier (GEM). Optimization of an ageing setup was performed by observing the variation of the normalized gain obtained using two identical MWPCs. An accuracy in the relative gain measurement below 1% has been achieved by monitoring environmental conditions and by systematic improvements of the measuring equipment. Ageing test of fiberglass G11 has been performed.

  14. Central Drift Chamber for rare kaon decay spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, S.; Blackmore, E.W.; Bryman, D.A.; Cresswell, J.; Numao, T.

    1986-02-01

    Design of the Central Drift Chamber for BNL experiment 787 and measurement of a rare kaon decay are discussed. A jet chamber type cell with 6 sense wires and no interspersed field wires has been designed to achieve good spatial resolution and efficiency in a 1 T magnetic field. Results of the testing of a prototype chamber are presented.

  15. Geology and preliminary dating of the hominid-bearing sedimentary fill of the Sima de los Huesos Chamber, Cueva Mayor of the Sierra de Atapuerca, Burgos, Spain.

    Science.gov (United States)

    Bischoff, J L; Fitzpatrick, J A; León, L; Arsuagà, J L; Falgueres, C; Bahain, J J; Bullen, T

    1997-01-01

    Sediments of the Sima de los Huesos vary greatly over distances of a few meters. This is typical of interior cave facies, and caused by cycles of cut and fill. Mud breccias containing human bones, grading upwards to mud containing bear bones, fill an irregular surface cut into basal marks and sands. The lack of Bedding and the chaotic abundance of fragile speleothem clasts in the fossiliferous muds suggests that the deposit was originally a subterranean pond facies, and that after emplacement of the human remains, underwent vigorous post-depositional rotation and collapse and brecciation, caused by underlying bedrock dissolution and undermining. The fossiliferous deposits are capped by flowstone and guano-bearing muds which lack large-mammal fossils. U-series and radiocarbon dating indicates the capping flowstones formed from about 68 ka to about 25 ka. U-series analyses of speleothem clasts among the human fossils indicate that all are at, or close to, isotopic equilibrium (> 350 ka). The distribution of U-series dates for 25 bear bones (154 +/- 66 ka) and for 16 human bones (148 +/- 34 ka) is similar and rather broad. Because the human bones seem to be stratigraphically older than chose of the bears, the results would indicate that most of the bones have been accumulating uranium irregularly with time. Electron spin resonance (ESR) analyses of six selected bear bones indicates dates of 189 +/- 28 ka, for which each is cordant with their corresponding U-series date (181 +/- 41 ka). Combined ESR and U-series dates for these samples yielded 200 +/- 4 ka. Such agreement is highly suggestive that uranium uptake in these bones was close to the early-uptake (EU) model, and the dates are essentially correct. Another three selected samples yielded combined ESR U-series dates of 320 +/- 4 ka with a modeled intermediate-mode of uranium uptake. The dating results, therefore, seem to provide a firm minimum age of about 200 ka for the human entry: and suggestive evidence of

  16. The CLEO III drift chamber

    CERN Document Server

    Peterson, D; Briere, R A; Chen, G; Cronin-Hennessy, D; Csorna, S; Dickson, M; Dombrowski, S V; Ecklund, K M; Lyon, A; Marka, S; Meyer, T O; Patterson, J R; Sadoff, A; Thies, P; Thorndike, E H; Urner, D

    2002-01-01

    The CLEO group at the Cornell Electron Storage Ring has constructed and commissioned a new central drift chamber. With 9796 cells arranged in 47 layers ranging in radius from 13.2 to 79 cm, the new drift chamber has a smaller outer radius and fewer wires than the drift chamber it replaces, but allows the CLEO tracking system to have improved momentum resolution. Reduced scattering material in the chamber gas and in the inner skin separating the drift chamber from the silicon vertex detector provides a reduction of the multiple scattering component of the momentum resolution and an extension of the usable measurement length into the silicon. Momentum resolution is further improved through quality control in wire positioning and symmetry of the electric fields in the drift cells which have provided a reduction in the spatial resolution to 88 mu m (averaged over the full drift range).

  17. Beam Profiling through Wire Chambing Tracking

    CERN Document Server

    Nash, W

    2013-01-01

    This note describes the calibration of the Delay Wire Chambers (DWCs) used during test runs of CALICE’s Tungsten Digital Hadron Calorimeter (W-DHCAL) prototype in CERN’s SPS beam line (10 – 300 GeV).

  18. The KLOE drift chamber

    CERN Document Server

    Adinolfi, M; Ambrosino, F; Andryakov, A; Antonelli, A; Antonelli, M; Anulli, F; Bacci, C; Bankamp, A; Barbiellini, G; Bellini, F; Bencivenni, G; Bertolucci, Sergio; Bini, C; Bloise, C; Bocci, V; Bossi, F; Branchini, P; Bulychjov, S A; Cabibbo, G; Calcaterra, A; Caloi, R; Campana, P; Capon, G; Carboni, G; Cardini, A; Casarsa, M; Cataldi, G; Ceradini, F; Cervelli, F; Cevenini, F; Chiefari, G; Ciambrone, P; Conetti, S; Conticelli, S; Lucia, E D; Robertis, G D; Sangro, R D; Simone, P D; Zorzi, G D; Dell'Agnello, S; Denig, A; Domenico, A D; Donato, C D; Falco, S D; Doria, A; Drago, E; Elia, V; Erriquez, O; Farilla, A; Felici, G; Ferrari, A; Ferrer, M L; Finocchiaro, G; Forti, C; Franceschi, A; Franzini, P; Gao, M L; Gatti, C; Gauzzi, P; Giovannella, S; Golovatyuk, V; Gorini, E; Grancagnolo, F; Grandegger, W; Graziani, E; Guarnaccia, P; Von Hagel, U; Han, H G; Han, S W; Huang, X; Incagli, M; Ingrosso, L; Jang, Y Y; Kim, W; Kluge, W; Kulikov, V; Lacava, F; Lanfranchi, G; Lee-Franzini, J; Lomtadze, F; Luisi, C; Mao Chen Sheng; Martemyanov, M; Matsyuk, M; Mei, W; Merola, L; Messi, R; Miscetti, S; Moalem, A; Moccia, S; Moulson, M; Müller, S; Murtas, F; Napolitano, M; Nedosekin, A; Panareo, M; Pacciani, L; Pagès, P; Palutan, M; Paoluzi, L; Pasqualucci, E; Passalacqua, L; Passaseo, M; Passeri, A; Patera, V; Petrolo, E; Petrucci, Guido; Picca, D; Pirozzi, G; Pistillo, C; Pollack, M; Pontecorvo, L; Primavera, M; Ruggieri, F; Santangelo, P; Santovetti, E; Saracino, G; Schamberger, R D; Schwick, C; Sciascia, B; Sciubba, A; Scuri, F; Sfiligoi, I; Shan, J; Silano, P; Spadaro, T; Spagnolo, S; Spiriti, E; Stanescu, C; Tong, G L; Tortora, L; Valente, E; Valente, P; Valeriani, B; Venanzoni, G; Veneziano, Stefano; Wu, Y; Xie, Y G; Zhao, P P; Zhou, Y

    2001-01-01

    The tracking detector of the KLOE experiment is 4 m diameter, 3.3 m length drift chamber, designed to contain a large fraction of the decays of low-energy K sub L produced at the Frascati DAPHINE phi-factory. The chamber is made by a thin carbon fiber structure and operated with a helium-based gas mixture in order to minimise conversion of low-energy photons and multiple scattering inside the sensitive volume. The tracking information is provided by 58 layers of stereo wires defing 12,582 cells, 2x2 cm sup 2 in size in the 12 innermost layers and 3x3 cm sup 2 in the outer ones. Details of the chamber design, calibration procedure and tracking performances are presented.

  19. Test chamber

    NARCIS (Netherlands)

    Leferink, Frank Bernardus Johannes

    2009-01-01

    A test chamber for measuring electromagnetic radiation emitted by an apparatus to be tested or for exposing an apparatus to be tested to an electromagnetic radiation field. The test chamber includes a reverberation chamber made of a conductive tent fabric. To create a statistically uniform field in

  20. Test chamber

    NARCIS (Netherlands)

    Leferink, Frank Bernardus Johannes

    1999-01-01

    A test chamber for measuring electromagnetic radiation emitted by an apparatus to be tested or for exposing an apparatus to be tested to an electromagnetic radiation field. The test chamber includes a reverberation chamber made of a conductive tent fabric. To create a statistically uniform field in

  1. Shielding Effectiveness Measurements using a Reverberation Chamber

    NARCIS (Netherlands)

    Leferink, Frank Bernardus Johannes; Bergsma, J.G.; Bergsma, Hans; van Etten, Wim

    2006-01-01

    Shielding effectiveness measurements have been performed using a reverberation chamber. The reverberation chamber methodology as we1l as the measurement setup is described and some results are given. Samples include glass reinforced plastic panels, aluminum panels with many holes, wire mesh, among

  2. micro strip gas chamber

    CERN Multimedia

    1998-01-01

    About 16 000 Micro Strip Gas Chambers like this one will be used in the CMS tracking detector. They will measure the tracks of charged particles to a hundredth of a millimetre precision in the region near the collision point where the density of particles is very high. Each chamber is filled with a gas mixture of argon and dimethyl ether. Charged particles passing through ionise the gas, knocking out electrons which are collected on the aluminium strips visible under the microscope. Such detectors are being used in radiography. They give higher resolution imaging and reduce the required dose of radiation.

  3. Central drift chamber for rare kaon decay spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, S.; Blackmore, E.W.; Bryman, D.A.; Cresswell, J.; Numao, T.

    1985-10-01

    Design of the central drift chamber for BNL experiment 787 and measurement of the decay K/sup +/ ..-->.. ..pi../sup +/ nu anti nu are discussed. A jet chamber type cell with 6 sense wires and no interspersed field wires has been designed to achieve good spatial resolution and efficiency in a 1 T magnetic field. Results of the testing of a prototype chamber are presented.

  4. Multiwire proportional chamber development

    Science.gov (United States)

    Doolittle, R. F.; Pollvogt, U.; Eskovitz, A. J.

    1973-01-01

    The development of large area multiwire proportional chambers, to be used as high resolution spatial detectors in cosmic ray experiments is described. A readout system was developed which uses a directly coupled, lumped element delay-line whose characteristics are independent of the MWPC design. A complete analysis of the delay-line and the readout electronic system shows that a spatial resolution of about 0.1 mm can be reached with the MWPC operating in the strictly proportional region. This was confirmed by measurements with a small MWPC and Fe-55 X-rays. A simplified analysis was carried out to estimate the theoretical limit of spatial resolution due to delta-rays, spread of the discharge along the anode wire, and inclined trajectories. To calculate the gas gain of MWPC's of different geometrical configurations a method was developed which is based on the knowledge of the first Townsend coefficient of the chamber gas.

  5. Ussing Chamber

    NARCIS (Netherlands)

    Westerhout, J.; Wortelboer, H.; Verhoeckx, K.

    2015-01-01

    The Ussing chamber system is named after the Danish zoologist Hans Ussing, who invented the device in the 1950s to measure the short-circuit current as an indicator of net ion transport taking place across frog skin (Ussing and Zerahn, Acta Physiol Scand 23:110-127, 1951). Ussing chambers are

  6. Physicist makes muon chamber sing

    CERN Multimedia

    2007-01-01

    1. This Monitored Drift Tube detector, consisting of argon-CO2-filled aluminium tubes with a wire down the centre of each, will track muons in ATLAS; Tiecke used a single tube from one of these detectors to create the pipes in his organ.

  7. A Cosmic Ray Measurement Facility for ATLAS Muon Chambers

    CERN Document Server

    Biebel, O; Boutemeur, M; Brandt, A; Dubbert, J; Duckeck, G; Elmsheuser, J; Fiedler, F; Hertenberger, R; Kortner, O; Nunnemann, T; Rauscher, F; Schaile, A D; Schieferdecker, P; Staude, A; Stiller, W; Ströhmer, R; Vertesi, R

    2003-01-01

    Monitored Drift Tube (MDT) chambers will constitute the large majority of precision detectors in the Muon Spectrometer of the ATLAS experiment at the Large Hadron Collider at CERN. For commissioning and calibration of MDT chambers, a Cosmic Ray Measurement Facility is in operation at Munich University. The objectives of this facility are to test the chambers and on-chamber electronics, to map the positions of the anode wires within the chambers with the precision needed for standalone muon momentum measurement in ATLAS, and to gain experience in the operation of the chambers and on-line calibration procedures. Until the start of muon chamber installation in ATLAS, 88 chambers built at the Max Planck Institute for Physics in Munich have to be commissioned and calibrated. With a data taking period of one day individual wire positions can be measured with an accuracy of 8.3 micrometers in the chamber plane and 27 micrometers in the direction perpendicular to that plane.

  8. Magnetic wires in MEMS and bio-medical applications

    Energy Technology Data Exchange (ETDEWEB)

    Barbic, Mladen E-mail: mladen@caltech.edu

    2002-08-01

    Magnetic wires of appropriate design have special features making them useful to micro-electromechanical systems and bio-medical applications. Several applications that exploit the properties of magnetic wires are reviewed including: (a) a magnetic micro-manipulation technique that utilizes integrated micro-coils and magnetic micro-wires for localized positioning of micron-sized magnetic objects, (b) integrated micro-coil/micro-wire system operating as a micro-fluidic micro-motor, (c) mechanical tweezers using magneto-static interaction between two magnetic micro-wires, and (d) ultra-high gradient magnetic separation system based on porous membranes partially filled with magnetic wires.

  9. The Mark II Vertex Drift Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, J.P.; Baggs, R.; Fujino, D.; Hayes, K.; Hoard, C.; Hower, N.; Hutchinson, D.; Jaros, J.A.; Koetke, D.; Kowalski, L.A.

    1989-03-01

    We have completed constructing and begun operating the Mark II Drift Chamber Vertex Detector. The chamber, based on a modified jet cell design, achieves 30 {mu}m spatial resolution and <1000 {mu}m track-pair resolution in pressurized CO{sub 2} gas mixtures. Special emphasis has been placed on controlling systematic errors including the use of novel construction techniques which permit accurate wire placement. Chamber performance has been studied with cosmic ray tracks collected with the chamber located both inside and outside the Mark II. Results on spatial resolution, average pulse shape, and some properties of CO{sub 2} mixtures are presented. 10 refs., 12 figs., 1 tab.

  10. A Laser Based Instrument for MWPC Wire Tension Measurement

    CERN Document Server

    Baldini, W; Evangelisti, F; Germani, S; Landi, L; Savrié, M; Graziani, G; Lenti, M; Lenzi, M; Passaleva, G; Carboni, G; De Capua, S; Kachtchouk, A

    2007-01-01

    A fast and simple method for the measurement of the mechanical tension of wires of Multi Wires Proportional Chambers (MWPCs) is described. The system is based on commercial components and does not require any electrical connection to the wires or electric or magnetic field. It has been developed for the quality control of MWPCs of the Muon Detector of the LHCb experiment in construction at CERN. The system allows a measurement of the wire tension with a precision better than 0.5% within 3-4 seconds per wire

  11. Large-Scale Production of Monitored Drift Tube Chambers for the ATLAS Muon Spectrometer

    CERN Document Server

    Bauer, F.; Kortner, O; Kroha, H; Manz, A; Mohrdieck, S; Richter, R; Zhuravlov, V

    2016-01-01

    Precision drift tube chambers with a sense wire positioning accuracy of better than 20 microns are under construction for the ATLAS muon spectrometer. 70% of the 88 large chambers for the outermost layer of the central part of the spectrometer have been assembled. Measurements during chamber construction of the positions of the sense wires and of the sensors for the optical alignment monitoring system demonstrate that the requirements for the mechanical precision of the chambers are fulfilled.

  12. The world's largest time projection chamber

    CERN Multimedia

    Maximilien Brice

    2006-01-01

    Peter Glassel, the technical coordinator for the ALICE time projection chamber, is seen sitting inside the detector; the largest in the world at nearly 100 cubic metres. Thousands of wires are connected to read out electronic data produced as particles are created in lead-lead collisions at the centre of the detector. These particles will cause the medium within the time projection chamber to ionise along their tracks allowing the particle paths to be recreated.

  13. Purging device for suppression chamber

    Energy Technology Data Exchange (ETDEWEB)

    Yoshino, Koichi.

    1987-11-14

    Purpose: To completely drive out air or the like in the suppression chamber in a short period of time thereby protect bent pipes from embrittled rupture. Constitution: Nitrogen gases, etc. entering through the inlet penetration to the inside of a reactor container are guided downwardly through communication pipeways, and the released downwardly in a stable manner while the blowing speed being retained by blowing mechanisms. Released nitrogen gases, etc. diffuse along the water surface of the suppression chamber and fill the inside of the chamber from below. Air, etc. in the suppression chamber prior to the supply of nitrogen gas, etc. is discharged through the exit penetration from the purging discharge pipe smoothly to the outside. In this way, air is replaced with nitrogen gas, etc., the released nitrogen is not directly blown to bent pipe, the operation is simplified, and the charge/discharge operation can be made in a short time efficiently. (Kamimura, M.).

  14. Aging tests of full scale CMS muon cathode strip chambers

    Energy Technology Data Exchange (ETDEWEB)

    D. Acosta et al.

    2003-10-15

    Two CMS production Cathode Strip Chambers were tested for aging effects in the high radiation environment at the Gamma Irradiation Facility at CERN. The chambers were irradiated over a large area: in total, about 2.1 m{sup 2} or 700 m of wire in each chamber. The 40% Ar+50%CO{sub 2}+10%CF{sub 4} gas mixture was provided by an open-loop gas system for one of the chambers and by closed-loop recirculating gas system for the other. After accumulating 0.3-0.4 C per centimeter of a wire, which is equivalent to operation during about 30-50 years at the peak LHC luminosity, no significant changes in gas gain, chamber efficiency, and wire signal noise were observed for either of the two chambers. The only consistent signs of aging were a small increase in dark current from {approx}2 nA to {approx}10 nA per plane of 600 wires and a decrease of strip-to-strip resistance from 1000 G{Omega} to 10-100 G{Omega}. Disassembly of the chambers revealed deposits on the cathode planes, while the anode wires remained fairly clean.

  15. Time Projection Chamber at TRIUMF

    Energy Technology Data Exchange (ETDEWEB)

    Bryman, D.; Leitch, M.; Navon, I.; Numao, T.; Schlatter, P.; Dixit, M.S.; Hargrove, C.K.; Mes, H.; Bennett, A.; Macdonald, J.A.

    1984-01-01

    The Time Projection Chamber at TRIUMF is being used to search for muon-electron conversion. The best spatial resolution in the TPC, sigma approx. = 200 ..mu..m, occurs at the minimum drift length and for an optimum track-to-anode crossing angle determined by the magnetic field. The observed resolution is dependent on the diffusion of the drifting electrons, the track-to-anode crossing angle, vector E X vector B effects near the anode wire and the discrete nature of the ionization process. Distortion due to positive ions leaking back into the drift volume from the anode wire region have been nearly eliminated by the use of a pulsed dual grid system.

  16. Automatic wire twister.

    Science.gov (United States)

    Smith, J F; Rodeheaver, G T; Thacker, J G; Morgan, R F; Chang, D E; Fariss, B L; Edlich, R F

    1988-06-01

    This automatic wire twister used in surgery consists of a 6-inch needle holder attached to a twisting mechanism. The major advantage of this device is that it twists wires significantly more rapidly than the conventional manual techniques. Testing has found that the ultimate force required to disrupt the wires twisted by either the automatic wire twister or manual techniques did not differ significantly and was directly related to the number of twists. The automatic wire twister reduces the time needed for wire twisting without altering the security of the twisted wire.

  17. Stretched Wire Mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Bowden, Gordon; /SLAC

    2005-09-06

    Stretched wires are beginning to play an important role in the alignment of accelerators and synchrotron light sources. Stretched wires are proposed for the alignment of the 130 meter long LCLS undulator. Wire position technology has reached sub-micron resolution yet analyses of perturbations to wire straightness are hard to find. This paper considers possible deviations of stretched wire from the simple 2-dimensional catenary form.

  18. Development of a portable and fast wire tension measurement system for MWPC's construction

    OpenAIRE

    Pan, Jing-Hui; Ma, Chang-Li; Gong, Xue-Yu; Sun, Zhi-Jia; Wang, Yan-Feng; Yin, Chen-Yan; Gong, Lei

    2016-01-01

    In a multi-wire proportional chamber detector(MWPC), the anode and signal wires must maintain suitable tensions, which is very important for the detector's stable and perfect performance. As a result, wire tension control and measurement is essential in MWPC's construction. The thermal neutron detector of multi-functional reflectometer at China Spallation Neutron Source is designed using a high pressure $^{3}$He MWPC detector, and in the construction of the detector, we developed a wire tensi...

  19. MEG II drift chamber characterization with the silicon based cosmic ray tracker at INFN Pisa

    Energy Technology Data Exchange (ETDEWEB)

    Venturini, M., E-mail: marco.venturini@pi.infn.it [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa (Italy); Baldini, A.M. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Baracchini, E. [ICEPP, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Cei, F.; D' Onofrio, A. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Dipartimento di Fisica, dell' Università di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Dussoni, S.; Galli, L.; Grassi, M. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Nicolò, D. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Dipartimento di Fisica, dell' Università di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Signorelli, G. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy)

    2016-07-11

    High energy physics experiments at the high intensity frontier place ever greater demands on detectors, and in particular on tracking devices. In order to compare the performance of small size tracking prototypes, a high resolution cosmic ray tracker has been assembled to provide an external track reference. It consists of four spare ladders of the external layers of the Silicon Vertex Tracker of the BaBar experiment. The test facility, operating at INFN Sezione di Pisa, provides the detector under test with an external track with an intrinsic resolution of 15–30 μm. The MEG II tracker is conceived as a unique volume wire drift chamber filled with He–isobutane 85–15%. The ionization density in this gas mixture is about 13 clusters/cm and this results in a non-negligible bias of the impact parameters for tracks crossing the cell close to the anode wire. We present the telescope performance in terms of tracking efficiency and resolution and the results of the characterization of a MEG II drift chamber prototype.

  20. MEG II drift chamber characterization with the silicon based cosmic ray tracker at INFN Pisa

    Science.gov (United States)

    Venturini, M.; Baldini, A. M.; Baracchini, E.; Cei, F.; D`Onofrio, A.; Dussoni, S.; Galli, L.; Grassi, M.; Nicolò, D.; Signorelli, G.

    2016-07-01

    High energy physics experiments at the high intensity frontier place ever greater demands on detectors, and in particular on tracking devices. In order to compare the performance of small size tracking prototypes, a high resolution cosmic ray tracker has been assembled to provide an external track reference. It consists of four spare ladders of the external layers of the Silicon Vertex Tracker of the BaBar experiment. The test facility, operating at INFN Sezione di Pisa, provides the detector under test with an external track with an intrinsic resolution of 15-30 μm. The MEG II tracker is conceived as a unique volume wire drift chamber filled with He-isobutane 85-15%. The ionization density in this gas mixture is about 13 clusters/cm and this results in a non-negligible bias of the impact parameters for tracks crossing the cell close to the anode wire. We present the telescope performance in terms of tracking efficiency and resolution and the results of the characterization of a MEG II drift chamber prototype.

  1. Construction of monitored drift tube chambers for ATLAS end-cap muon spectrometer at IHEP (Protvino)

    CERN Document Server

    Bensinger, J; Borisov, A; Fakhrutdinov, R M; Goryatchev, S; Goryachev, V N; Gushchin, V; Hashemi, K S; Kojine, A; Kononov, A I; Larionov, A; Paramoshkina, E; Pilaev, A; Skvorodnev, N; Tchougouev, A; Wellenstein, H

    2002-01-01

    Trapezoidal-shaped Monitored Drift Tube (MDT) chambers will be used in end-caps of ATLAS muon spectrometer. Design and construction technology of such chambers in IHEP (Protvino) is presented. X-ray tomography results confirm desirable 20 mum precision of wire location in the chamber.

  2. TU-F-BRE-03: Application of a Novel Mass-Density Compensation Optimization Method to Improve the Response of a Liquid-Filled Ionization Chamber in Nonstandard Fields

    Energy Technology Data Exchange (ETDEWEB)

    Kamio, Y [CHUM - Notre Dame, Montreal, QC (Canada); Bouchard, H [National Physical Laboratory, Teddington, Middlesex (United Kingdom)

    2014-06-15

    Purpose: To improve the response of the microLion detector (PTW 31018) in small field conditions by optimizing the density of the detector's non-sensitive components using a novel method based on the detector's dose response function. Methods: The central values h(0,0) of the perturbation functions for the microLion detector and a volume of water equivalent to its sensitive volume were calculated using the Monte Carlo user code egs-chamber by scoring the dose absorbed by a 6 MV photon pencil beam incident on their centroids. Values of h(0,0) were plotted as a function of the density of the microLion's graphite electrode with the detector placed in the axial orientation. The optimized density was found by finding the minimal value of h(0,0). Results: A density of 1.37 g/cm3 was found to minimize the perturbation function of the microLion detector. The modified microLion's response was then evaluated in small square fields with sides in the range of 5 – 40 mm and found to be consistent with highly watere-quivalent detectors such as a scintillating detector (Exradin W1) and a generic alanine detector in both axial and radial orientations. Conclusion: This work illustrates a novel method which can used to optimize the design of radiation detectors in small fields. This method should also work with other optimization parameters (e.g. thickness of electrode). Density-compensated detectors have the potential to eliminate the need to evaluate nonstandard field correction factors as described by the IAEA-AAPM formalism (Alfonso et al.) and simplify future dosimetry protocols for SRS/SBRT modalities. Finally, we also expect an improvement in the response of density-compensated detectors for composite IMRT fields.

  3. Dielectron analysis in p-p collisions at 3.5 GeV with the HADES spectrometer. {omega}-meson line shape and a new electronics readout for the multi-wire drift chambers

    Energy Technology Data Exchange (ETDEWEB)

    Tarantola Peloni, Attilio

    2011-06-15

    . Conclusions are given in chapter four. The final part of this work is dedicated to the HADES upgrade, whose goal is among others the achievement of a reliable and fast data acquisition of the Multiwire Drift Chambers (MDCs). Chapter five presents my contribution to this successful project during the three years of my stay at GSI. (orig.)

  4. Wire bonding in microelectronics

    CERN Document Server

    Harman, George G

    2010-01-01

    Wire Bonding in Microelectronics, Third Edition, has been thoroughly revised to help you meet the challenges of today's small-scale and fine-pitch microelectronics. This authoritative guide covers every aspect of designing, manufacturing, and evaluating wire bonds engineered with cutting-edge techniques. In addition to gaining a full grasp of bonding technology, you'll learn how to create reliable bonds at exceedingly high yields, test wire bonds, solve common bonding problems, implement molecular cleaning methods, and much more. Coverage includes: Ultrasonic bonding systems and technologies, including high-frequency systems Bonding wire metallurgy and characteristics, including copper wire Wire bond testing Gold-aluminum intermetallic compounds and other interface reactions Gold and nickel-based bond pad plating materials and problems Cleaning to improve bondability and reliability Mechanical problems in wire bonding High-yield, fine-pitch, specialized-looping, soft-substrate, and extreme-temperature wire bo...

  5. A combination drift chamber/pad chamber for very high readout rates

    Energy Technology Data Exchange (ETDEWEB)

    Spiegel, L.; Cataldi, G.; Elia, V.; Mazur, P.; Murphy, C.T.; Smith, R.P.; Yang, W. [Fermi National Accelerator Lab., Batavia, IL (United States); Alexopoulos, T.; Durandet, C.; Erwin, A.; Jennings, J. [Wisconsin Univ., Madison, WI (United States); Antoniazzi, L.; Introzzi, G.; Lanza, A.; Liguori, G.; Torre, P. [Pavia Univ. (Italy)]|[Istituto Nazionale di Fisica Nucleare, Rome (Italy); Arenton, M.; Conetti, S.; Cox, B.; Dukes, E.; Golovatyuk, V.; Hanlet, P.; McManus, A.; Nelson, K.; Recagni, M.; Segal, J.; Sun, J. [Virginia Univ., Charlottesville, VA (United States); Ballagh, C.; Bingham, H.; Kaeding, T.; Lys, J.; Misawa, S. [California Univ., Berkeley, CA (United States); Blankman, A.; Borodin, S.; Kononenko, W.; Newcomer, M.; Selove, W.; Trojak, T.; VanBerg, R.; Zhang, S.N. [Pennsylvania Univ., Philadelphia, PA (United States); Block, M.; Corti, G.; LeCompte, T.; Rosen, J.; Yao, T. [Northwestern Univ., Evanston, IL (United States); Boden, A.; Cline, D.; Ramachandran, S.; Rhoades, J.; Tokar, S. [California Univ., Los Angeles, CA (United States); Budagov, J.; Tsyganov, E. [Joint Inst. for Nuclear Research, Dubna (USSR); Cao, Z.L.; He, M.; Wang, C.; Wei, C.; Zhang, N. [Shandong Univ., Jinan, SD (China); Chen, T.Y.; Yao, N. [Nanjing Univ., JS (China); Clark, K.; Jenkins, M. [University of South Alabama, Mobile, AL (United States); Cooper, M. [Vanier Inst. of the Family, Ottawa, ON (Canada); Creti, P.; Gorini, E.; Grancagnolo, F.; Panareo, M. [Lecce Univ. (Italy)]|[Istituto Nazionale di Fisica Nucleare, Rome (Italy); Fortney, L.; Kowald, W. [Duke Univ., Durham, NC (United States); Haire, M.; Judd, D.; Turnbull, L.; Wagoner, D. [Texas A and M Univ., Prairie View, TX (United States); Lau, K.; Mo, G. [Houston Univ., TX (United States); Trischuk, J. [McGill Univ., Montreal, PQ (Canada)

    1991-11-01

    Six medium-sized ({approx}1 {times} 2 m{sup 2}) drift chambers with pad and stripe readout have been constructed for and are presently operating in Fermi National Accelerator Laboratory experiment E-771. Each chamber module actually represents a pair of identical planes: two sets of anode wires, two sets of stripes, and two sets of pads. The wire planes are read out separately and represent X measurements in the coordinate system of the experiment. The twin stripe and pad planes are internally paired within the chamber modules; stripe signals represent Y measurements and pad signals combination X and Y measurements. Signals which develop on the stripes and pads are mirror (but inverted) images of what is seen on the wires. In addition to being used in the off-line pattern recognition, pad signals are also used as inputs to an on-line high transverse momentum (pt) trigger processor. While the techniques involved in the design and construction of the chambers are not novel, they may be of interest to experiments contemplating very large area, high rate chambers for future spectrometers.

  6. Laser Wire Stripper

    Science.gov (United States)

    1983-01-01

    NASA-developed space shuttle technology is used in a laser wire stripper designed by Raytheon Company. Laser beams cut through insulation on a wire without damaging conductive metal, because laser radiation that melts plastic insulation is reflected by the metal. The laser process is fast, clean, precise and repeatable. It eliminates quality control problems and the expense of rejected wiring.

  7. Doriot Climatic Chambers

    Data.gov (United States)

    Federal Laboratory Consortium — The Doriot Climatic Chambers are two, 60-feet long, 11-feet high, 15-feet wide chambers that are owned and operated by NSRDEC. The Doriot Climatic Chambers are among...

  8. Flicking-wire drag tensioner

    Science.gov (United States)

    Dassele, M. A.; Fairall, H.

    1978-01-01

    Wire-drag system improves wire profile and applies consistent drag to wire. Wire drag is continuously adjustable from zero drag to tensile strength of wire. No-sag wire drag is easier to thread than former system and requires minimal downtime for cleaning and maintenance.

  9. Directed Energy Anechoic Chamber

    Data.gov (United States)

    Federal Laboratory Consortium — The Directed Energy Anechoic Chamber comprises a power anechoic chamber and one transverse electromagnetic cell for characterizing radiofrequency (RF) responses of...

  10. Effect of wire shape on wire array discharge

    Energy Technology Data Exchange (ETDEWEB)

    Shimomura, N.; Tanaka, Y.; Yushita, Y.; Nagata, M. [University of Tokushima, Department of Electrical and Electronic Engineering, Tokushima (Japan); Teramoto, Y.; Katsuki, S.; Akiyama, H. [Kumamoto University, Department of Electrical and Computer Engineering, Kumamoto (Japan)

    2001-09-01

    Although considerable investigations have been reported on z-pinches to achieve nuclear fusion, little attention has been given from the point of view of how a wire array consisting of many parallel wires explodes. Instability existing in the wire array discharge has been shown. In this paper, the effect of wire shape in the wire array on unstable behavior of the wire array discharge is represented by numerical analysis. The claws on the wire formed in installation of wire may cause uniform current distribution on wire array. The effect of error of wire diameter in production is computed by Monte Carlo Method. (author)

  11. NA48: Wiring up for Change

    CERN Multimedia

    2001-01-01

    The NA48 Collaboration is rebuilding its drift chambers ready for the experiment to start up again this coming July. An intricate task involving the soldering of over 24,000 wires! The future of the NA48 experiment is coming right down to the wire, that is, the wires which the Collaboration is installing in the clean room of Hall 887 on the Prévessin site. Six days a week, technicians are working in shifts to rebuild the experiment's drift chambers. The original chambers were damaged when a section of a vacuum tube imploded at the end of 1999. A year ago, CERN gave the green light for this essential part of the spectrometer to be rebuilt, so the NA48 experiment, which studies CP violation (see box), still has a bright future ahead of it. Three years of data-taking ahead The NA48 experiment aims to penetrate the secrets of CP (Charge Parity) violation. Charge and parity are two parameters which distinguish a particle from an antiparticle. In other words, an electron possesses a negative electric ...

  12. The great advance in the technology of particle detectors during the year was the discovery of the properties of multiwire proportional chambers and drift chambers

    CERN Multimedia

    CERN PhotoLab

    1968-01-01

    In these chambers each wire is an independent proportional counter with its own amplifier and logic circuit. The low cost of the associated electronics makes realistic moderately large systems, with thousands of wires. The resolution time of each wire is of the order of 100 ns, with 3mm spacing. Roger Bouclier is working on an early model tested in a PS beam-line.

  13. Polyurethane spray coating of aluminum wire bonds to prevent corrosion and suppress resonant oscillations

    CERN Document Server

    Izen, Joseph; The ATLAS collaboration; Kurth, Matthew Glenn

    2015-01-01

    Unencapsulated aluminum wedge wire bonds are common in particle-physics pixel and strip detectors. Industry-favored bulk encapsulation is eschewed due to the range of operating temperatures and radiation. Wire bond failures are a persistent, source of tracking detector failure Unencapsulated bonds are vulnerable to condensation-induced corrosion, particularly when halides are present. Oscillations from periodic Lorenz forces are documented as another source of wire bond failure. Spray application of polyurethane coatings, performance of polyurethane-coated wire bonds after climate chamber exposure, and resonant properties of PU-coated wire bonds and their resistance to periodic Lorenz forces will be described.

  14. Single Wire Detector Performance Over One Year of Operation

    CERN Document Server

    Hervas Aguilar, David Alberto

    2014-01-01

    Abstract When ionizing radiation passes through gas chambers in single wire detectors gas molecules separate into ions and electrons. By applying a strong localized electric field near the single wire an avalanche of electrons is created and it can be collected. The current produced in the wire is then proportional to the energy of the particle detected. Nevertheless, many factors can contribute to detector aging effects which are visible in a loss of gain caused by deposition of contaminants on the collecting wire. This study consists on novel data analysis techniques used to process large amounts of data produced by two simultaneously running single wire detectors. Aging effects are analyzed while environmental fluctuations are corrected for. A series of scripts carry out data filtering, data matching, corrections, and finally trend plotting by using ROOT’s extensive libraries developed at CERN.

  15. Wire + Arc Additive Manufacturing

    OpenAIRE

    Williams, Stewart W.; Martina, Filomeno; Addison, Adrian C.; Ding, Jialuo; Pardal, Goncalo; Colegrove, Paul A.

    2016-01-01

    Depositing large components (>10 kg) in titanium, aluminium, steel and other metals is possible using Wire + Arc Additive Manufacturing. This technology adopts arc welding tools and wire as feedstock for additive manufacturing purposes. High deposition rates, low material and equipment costs, and good structural integrity make Wire+Arc Additive Manufacturing a suitable candidate for replacing the current method of manufacturing from solid billets or large forgings, especially with regards to ...

  16. Photovoltaic Wire Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project will investigate a new architecture for photovoltaic devices based on nanotechnology: photovoltaic wire. The...

  17. Central tracking chamber with inflated cathode-strip foils

    Science.gov (United States)

    Blackmore, E. W.; Bryman, D. A.; Kuno, Y.; Lim, C.; Numao, T.; Padley, P.; Redlinger, G.; Soluk, R.; McPherson, R. A.

    1998-02-01

    A new cylindrical low-mass central drift chamber has been constructed for the K+ → π +ν overlineν experiment at BNL (E787). The chamber consists of twelve layers of axial wire cells and six layers of thin cathode-strip foils, four of which are supported by differential gas pressure. The momentum resolution (RMS) for muons and pions in the range 150-250 MeV/ c is found to be about 0.9%.

  18. 1998 wire development workshop proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-04-01

    This report consists of vugraphs of the presentations at the conference. The conference was divided into the following sessions: (1) First Generation Wire Development: Status and Issues; (2) First Generation Wire in Pre-Commercial Prototypes; (3) Second Generation Wire Development: Private Sector Progress and Issues; (4) Second Generation Wire Development: Federal Laboratories; and (5) Fundamental Research Issues for HTS Wire Development.

  19. The CAST Time Projection Chamber

    CERN Document Server

    Autiero, D.; Carmona, J.M.; Cebrian, S.; Chesi, E.; Davenport, M.; Delattre, M.; Di Lella, L.; Formenti, F.; Irastorza, I.G.; Gomez, H.; Hasinoff, M.; Lakic, B.; Luzon, G.; Morales, J.; Musa, L.; Ortiz, A.; Placci, A.; Rodriguez, A.; Ruz, J.; Villar, J.A.; Zioutas, K.

    2007-01-01

    One of the three X-ray detectors of the CAST experiment searching for solar axions is a Time Projection Chamber (TPC) with a multi-wire proportional counter (MWPC) as a readout structure. Its design has been optimized to provide high sensitivity to the detection of the low intensity X-ray signal expected in the CAST experiment. A low hardware threshold of 0.8 keV is safely set during normal data taking periods, and the overall efficiency for the detection of photons coming from conversion of solar axions is 62 %. Shielding has been installed around the detector, lowering the background level to 4.10 x 10^-5 counts/cm^2/s/keV between 1 and 10 keV. During phase I of the CAST experiment the TPC has provided robust and stable operation, thus contributing with a competitive result to the overall CAST limit on axion-photon coupling and mass.

  20. Transport in quantum wires

    Indian Academy of Sciences (India)

    This motivated us to study the LL model of a quantum wire, with Fermi liquid leads and the unusual feature of ... of quantized conductance even in clean quantum wires and a novel odd–even effect in the presence of a .... But in one dimension, it is well-known that the FL theory breaks down, and the ground state is a ...

  1. Commercial and Industrial Wiring.

    Science.gov (United States)

    Kaltwasser, Stan; Flowers, Gary

    This module is the third in a series of three wiring publications, includes additional technical knowledge and applications required for job entry in the commercial and industrial wiring trade. The module contains 15 instructional units that cover the following topics: blueprint reading and load calculations; tools and equipment; service;…

  2. Design and implementation of wire tension measurement system for MWPCs used in the STAR iTPC upgrade

    Science.gov (United States)

    Wang, Xu; Shen, Fuwang; Wang, Shuai; Feng, Cunfeng; Li, Changyu; Lu, Peng; Thomas, Jim; Xu, Qinghua; Zhu, Chengguang

    2017-07-01

    The STAR experiment at RHIC is planning to upgrade the Time Projection Chamber which lies at the heart of the detector. We have designed an instrument to measure the tension of the wires in the multi-wire proportional chambers (MWPCs) which will be used in the TPC upgrade. The wire tension measurement system causes the wires to vibrate and then it measures the fundamental frequency of the oscillation via a laser based optical platform. The platform can scan the entire wire plane, automatically, in a single run and obtain the wire tension on each wire with high precision. In this paper, the details about the measurement method and the system setup will be described. In addition, the test results for a prototype MWPC to be used in the STAR-iTPC upgrade will be presented.

  3. Limits to Drift Chamber Resolution

    CERN Document Server

    Riegler, Werner

    1998-01-01

    ATLAS (A Large Toroidal LHC Apparatus) will be a general-purpose experiment at the Large Hadron Collider that will be operational at CERN in the year 2004. The ATLAS muon spectrometer aims for a momentum resolution of 10% for a transverse momentum of pT=1TeV. The precision tracking devices in the muon system will be high pressure drift tubes (MDTs) with a single wire resolution of 1100 chambers covering an area of ≈ 2500m2. The high counting rates in the spectrometer as well as the aim for excellent spatial resolution and high efficiency put severe constraints on the MDT operating parameters. This work describes a detailed study of all the resolution limiting factors in the ATLAS environment. A ’full chain’ simulation of the MDT response to photons and charged particles as well as quantitative comparisons with measurements was performed. The good agreement between simulation and measurements resulted in a profound understanding of the drift chamber processes and the individual contributions to the spat...

  4. Gated grid system used with a time projection chamber

    Science.gov (United States)

    Bryman, D. A.; Leitch, M.; Navon, I.; Numao, T.; Schlatter, P.; Dixit, M. S.; Hargrove, C. K.; Mes, H.; MacDonald, J. A.; Skegg, R.; Spuller, J.; Burnham, R. A.; Hasinoff, M.; Poutissou, J.-M.; Azuelos, G.; Depommier, P.; Martin, J.-P.; Poutissou, R.; Blecher, M.; Gotow, K.; Carter, A. L.

    1985-01-01

    A gated grid system has been developed for the TRIUMF time projection chamber to suppress drift field distortions caused by positive produced at the endcap proportional wires. Good spatial resolution in the TPC has been thereby maintained over a large range of counting rates.

  5. Gated grid system used with a time projection chamber

    Energy Technology Data Exchange (ETDEWEB)

    Bryman, D.A.; Leitch, M.; Navon, I.; Numao, T.; Schlatter, P. (British Columbia Univ., Vancouver (Canada). TRIUMF Facility; Victoria Univ., British Columbia (Canada)); Dixit, M.S.; Hargrove, C.K.; Mes, H. (National Research Council of Canada, Ottawa, Ontario); MacDonald, J.A.

    1985-01-15

    A gated grid system has been developed for the TRIUMF time projection chamber to suppress drift field distortions caused by positive ions produced at the endcap proportional wires. Good spatial resolution in the TPC has been thereby maintained over a large range of counting rates.

  6. Fast and High Accuracy Wire Scanner

    CERN Document Server

    Koujili, M; Koopman, J; Ramos, D; Sapinski, M; De Freitas, J; Ait Amira, Y; Djerdir, A

    2009-01-01

    Scanning of a high intensity particle beam imposes challenging requirements on a Wire Scanner system. It is expected to reach a scanning speed of 20 m.s-1 with a position accuracy of the order of 1 μm. In addition a timing accuracy better than 1 millisecond is needed. The adopted solution consists of a fork holding a wire rotating by a maximum of 200°. Fork, rotor and angular position sensor are mounted on the same axis and located in a chamber connected to the beam vacuum. The requirements imply the design of a system with extremely low vibration, vacuum compatibility, radiation and temperature tolerance. The adopted solution consists of a rotary brushless synchronous motor with the permanent magnet rotor installed inside of the vacuum chamber and the stator installed outside. The accurate position sensor will be mounted on the rotary shaft inside of the vacuum chamber, has to resist a bake-out temperature of 200°C and ionizing radiation up to a dozen of kGy/year. A digital feedback controller allows maxi...

  7. Development of a portable and fast wire tension measurement system for MWPC construction

    Science.gov (United States)

    Pan, Jing-Hui; Ma, Chang-Li; Gong, Xue-Yu; Sun, Zhi-Jia; Wang, Yan-Feng; Yin, Chen-Yan; Gong, Lei

    2016-09-01

    In a multi-wire proportional chamber detector (MWPC), the anode and signal wires must maintain suitable tension, which is very important for the detector’s stable and accurate performance. As a result, wire tension control and measurement is essential in MWPC construction. A high pressure 3He MWPC detector is to be used as the thermal neutron detector of the multi-functional reflectometer at China Spallation Neutron Source, and in the construction of the detector, we have developed a wire tension measurement system. This system is accurate, portable and time-saving. With it, the wire tension on an anode wire plane has been tested. The measurement results show that the wire tension control techniques used in detector manufacture are reliable. Supported by National Natural Science Foundation of China (A050506), State Key Laboratory of Particle Detection and Electronics and Key Laboratory of China Academy of Engineering Physics (Y490KF40HD)

  8. The spherical drift chamber used at LURE for protein crystallography; last developments, performances, and results (invited) (abstract)

    Science.gov (United States)

    Kahn, R.; Fourme, R.; Bosshard, R.; Lewit-Bentley, A.; Prangé, T.

    1989-07-01

    We have developed at LURE a multiwire proportional chamber with a spherical drift space. The wire chamber consists of two cathode planes, comprising 512 wires with a spacing of 1 mm, set on both sides of the anodic plane. The drift space, a gas filled region bounded by two spherically curved electrodes 144 mm apart, offers several advantages: high quantum efficiency, no parallax effect, equivalent spatial resolution in both directions, and smoothing of the pulsed structure of the synchrotron radiation. The gaseous mixture of argon-xenon (58%), ethane (40%), and ethyl alcohol (2%) is circulated in a closed circuit and is continuously purified. Ethyl alcohol, which avoids electrical discharges and sparks, is essential to operate the instrument at high counting rates (>300 000 events/s). The signal processing, which makes use of one amplifier per cathode wire and of fast priority encoders, determines both coordinates with a resolution of 1 mm and a dead time of 240 ns. Each encoded event is stored into a 512×512 16 bit CAMAC histogramming memory. The experiment is controlled by a PDP11/34 linked to a VAX by a direct memory access channel. A complete set of programs, which performs the data collection and an off line data reduction, is operational. The adaptation of madnes, a general software package which performs an on line data reduction, is under way. Data, collected on a lysozyme crystal to 3.4-Å resolution, give a reliability factor based on intensities of equivalent reflections of 4.7% without absorption corrections; the variation of the detector efficiency is memory linked to a micro VAX.

  9. The BaBar Level 1 Drift-Chamber Trigger Upgrade With 3D Tracking

    Energy Technology Data Exchange (ETDEWEB)

    Chai, X.D.; /Iowa U.

    2005-11-29

    At BABAR, the Level 1 Drift Chamber trigger is being upgraded to reduce increasing background rates while the PEP-II luminosity keeps improving. This upgrade uses the drift time information and stereo wires in the drift chamber to perform a 3D track reconstruction that effectively rejects background events spread out along the beam line.

  10. Study of the cross-talk between different gaps of the LHCb Muon chambers

    CERN Document Server

    Martellotti, G; Penso, G; Pinci, D

    2009-01-01

    During the tests before the installation phase of the Multi-Wire Proportional Chambers (MWPC) on the Muon Detector of LHCb an effect of cross talk between the different gas-gaps was found. In this note we present the results of a detailed study of this effect performed on different chambers.

  11. Ultrathin Nanocrystalline Magnetic Wires

    Directory of Open Access Journals (Sweden)

    Horia Chiriac

    2017-02-01

    Full Text Available The magnetic characteristics of FINEMET type glass-coated nanowires and submicron wires are investigated by taking into account the structural evolution induced by specific annealing all the way from a fully amorphous state to a nanocrystalline structure. The differences between the magnetic properties of these ultrathin wires and those of the thicker glass-coated microwires and “conventional” wires with similar structures have been emphasized and explained phenomenologically. The domain wall propagation in these novel nanowires and submicron wires, featuring a combination between an amorphous and a crystalline structure, has also been studied, given the recent interest in the preparation and investigation of new materials suitable for the development of domain wall logic applications.

  12. Dual wire weld feed proportioner

    Science.gov (United States)

    Nugent, R. E.

    1968-01-01

    Dual feed mechanism enables proportioning of two different weld feed wires during automated TIG welding to produce a weld alloy deposit of the desired composition. The wires are fed into the weld simultaneously. The relative feed rates of the wires and the wire diameters determine the weld deposit composition.

  13. The time projection chamber at triumf

    Science.gov (United States)

    Bryman, D.; Leitch, M.; Navon, I.; Numao, T.; Schlatter, P.; Dixit, M. S.; Hargrove, C. K.; Mes, H.; Bennett, A.; Macdonald, J. A.; Skegg, R.; Spuller, J.; Burnham, A.; Hasinoff, M.; Poutissou, J.-M.; Azuelos, G.; Depommier, P.; Martin, J.-P.; Poutissou, R.; Blecher, M.; Gotow, K.; Carter, A. L.

    1984-02-01

    The time projection chamber at TRIUMF is being used to search for muon-electron conversion. The best spatial resolution in the TPC, σ≂200 μm, occurs at the minimum drift length and for an optimum track-to-anode crossing angle determined by the magnetic field. The observed resolution is dependent on th diffusion of the drifting electrons, the track-to-anode crossing angle, E↘×B↘ effects near the anode wire and the discrete nature of the ionization process. Distortions due to positive ions leaking back into the drift volume from the anode wire region have been nearly eliminated by the use of a pulsed dual grid system.

  14. Copper wire bonding

    CERN Document Server

    Chauhan, Preeti S; Zhong, ZhaoWei; Pecht, Michael G

    2014-01-01

    This critical volume provides an in-depth presentation of copper wire bonding technologies, processes and equipment, along with the economic benefits and risks.  Due to the increasing cost of materials used to make electronic components, the electronics industry has been rapidly moving from high cost gold to significantly lower cost copper as a wire bonding material.  However, copper wire bonding has several process and reliability concerns due to its material properties.  Copper Wire Bonding book lays out the challenges involved in replacing gold with copper as a wire bond material, and includes the bonding process changes—bond force, electric flame off, current and ultrasonic energy optimization, and bonding tools and equipment changes for first and second bond formation.  In addition, the bond–pad metallurgies and the use of bare and palladium-coated copper wires on aluminum are presented, and gold, nickel and palladium surface finishes are discussed.  The book also discusses best practices and re...

  15. The operation of a track sensitive hydrogen target in a 500 l neon hydrogen bubble chamber

    CERN Document Server

    Ayres, J F; Damerell, A R; Fisher, Colin M; Fitzharris, E W; Foster, J H; Gottfeldt, P; Mack, B; Mortimer, A R; Seager, P; Stokoe, J R; Williams, P R; Leutz, H; Tischhauser, Johann; Wenninger, Horst

    1973-01-01

    A 20 l hydrogen filled track sensitive target has been successfully operated in the 1.5 m cryogenic bubble chamber at The Rutherford High Energy Laboratory. The chamber is filled with a mixture of neon and hydrogen at a concentration of 45 mol eon giving a radiation length of 860 mm. Satisfactory track quality in both target and chamber is achieved and 65000 pictures have been obtained in a 4 GeV/c pi /sup +/ beam. (7 refs).

  16. A gating grid driver for time projection chambers

    Science.gov (United States)

    Tangwancharoen, S.; Lynch, W. G.; Barney, J.; Estee, J.; Shane, R.; Tsang, M. B.; Zhang, Y.; Isobe, T.; Kurata-Nishimura, M.; Murakami, T.; Xiao, Z. G.; Zhang, Y. F.; SπRIT Collaboration

    2017-05-01

    A simple but novel driver system has been developed to operate the wire gating grid of a Time Projection Chamber (TPC). This system connects the wires of the gating grid to its driver via low impedance transmission lines. When the gating grid is open, all wires have the same voltage allowing drift electrons, produced by the ionization of the detector gas molecules, to pass through to the anode wires. When the grid is closed, the wires have alternating higher and lower voltages causing the drift electrons to terminate at the more positive wires. Rapid opening of the gating grid with low pickup noise is achieved by quickly shorting the positive and negative wires to attain the average bias potential with N-type and P-type MOSFET switches. The circuit analysis and simulation software SPICE shows that the driver restores the gating grid voltage to 90% of the opening voltage in less than 0.20 μs, for small values of the termination resistors. When tested in the experimental environment of a time projection chamber larger termination resistors were chosen so that the driver opens the gating grid in 0.35 μs. In each case, opening time is basically characterized by the RC constant given by the resistance of the switches and terminating resistors and the capacitance of the gating grid and its transmission line. By adding a second pair of N-type and P-type MOSFET switches, the gating grid is closed by restoring 99% of the original charges to the wires within 3 μs.

  17. A gating grid driver for time projection chambers

    Energy Technology Data Exchange (ETDEWEB)

    Tangwancharoen, S.; Lynch, W.G.; Barney, J.; Estee, J. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Shane, R. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Tsang, M.B., E-mail: tsang@nscl.msu.edu [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Zhang, Y. [Department of Physics, Tsinghua University, Beijing 100084 (China); Isobe, T.; Kurata-Nishimura, M. [RIKEN Nishina Center, Hirosawa 2-1, Wako, Saitama 351-0198 (Japan); Murakami, T. [Department of Physics, Kyoto University, Kita-shirakawa, Kyoto 606–8502 (Japan); Xiao, Z.G. [Department of Physics, Tsinghua University, Beijing 100084 (China); Zhang, Y.F. [College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China)

    2017-05-01

    A simple but novel driver system has been developed to operate the wire gating grid of a Time Projection Chamber (TPC). This system connects the wires of the gating grid to its driver via low impedance transmission lines. When the gating grid is open, all wires have the same voltage allowing drift electrons, produced by the ionization of the detector gas molecules, to pass through to the anode wires. When the grid is closed, the wires have alternating higher and lower voltages causing the drift electrons to terminate at the more positive wires. Rapid opening of the gating grid with low pickup noise is achieved by quickly shorting the positive and negative wires to attain the average bias potential with N-type and P-type MOSFET switches. The circuit analysis and simulation software SPICE shows that the driver restores the gating grid voltage to 90% of the opening voltage in less than 0.20 µs, for small values of the termination resistors. When tested in the experimental environment of a time projection chamber larger termination resistors were chosen so that the driver opens the gating grid in 0.35 µs. In each case, opening time is basically characterized by the RC constant given by the resistance of the switches and terminating resistors and the capacitance of the gating grid and its transmission line. By adding a second pair of N-type and P-type MOSFET switches, the gating grid is closed by restoring 99% of the original charges to the wires within 3 µs.

  18. Streamer chamber: pion decay

    CERN Multimedia

    1992-01-01

    The real particles produced in the decay of a positive pion can be seen in this image from a streamer chamber. Streamer chambers consist of a gas chamber through which a strong pulsed electric field is passed, creating sparks as a charged particle passes through it. A magnetic field is added to cause the decay products to follow curved paths so that their charge and momentum can be measured.

  19. Electromagnetic reverberation chambers

    CERN Document Server

    Besnier, Philippe

    2013-01-01

    Dedicated to a complete presentation on all aspects of reverberation chambers, this book provides the physical principles behind these test systems in a very progressive manner. The detailed panorama of parameters governing the operation of electromagnetic reverberation chambers details various applications such as radiated immunity, emissivity, and shielding efficiency experiments.In addition, the reader is provided with the elements of electromagnetic theory and statistics required to take full advantage of the basic operational rules of reverberation chambers, including calibration proc

  20. Refrigeration Test Chamber

    Data.gov (United States)

    Federal Laboratory Consortium — The enclosed and environmentally controlled chamber is able to test four units (single-phase) simultaneously at conditions ranging from tundra to desert temperatures...

  1. DORIOT CLIMATIC CHAMBERS

    Data.gov (United States)

    Federal Laboratory Consortium — The Doriot Climatic Chambers reproduce environmental conditions occurring anywhere around the world. They provide an invaluable service by significantly reducing the...

  2. The physics of Resistive Plate Chambers

    CERN Document Server

    Riegler, Werner

    2004-01-01

    Over the last 3 years we investigated theoretical aspects of Resistive Plate Chambers (RPC) in order to clarify some of the outstanding questions on space charge effects, high efficiency of small gap RPCs, charge spectra, signal shape and time resolution. In a series of reports we analyzed RPC performance including all detector aspects covering primary ionization, avalanche multiplication, space charge effects, signal induction in presence of resistive materials, crosstalk along detectors with long strips and front-end electronics. Using detector gas parameters entirely based on theoretical predictions and physical models for avalanche development and space charge effects we are able to reproduce measurements for 2 and 0.3 mm RPCs to very high accuracy without any additional assumptions. This fact gives a profound insight into the workings of RPCs and also underlines the striking difference in operation regime when compared to wire chambers. A summary of this work as well as recent results on three-dimensiona...

  3. The Bern Infinitesimal Bubble Chamber (BIBC)

    CERN Multimedia

    CERN PhotoLab

    1977-01-01

    The chamber body was machined from a block of aluminium. The visible volume was cylindrical with 65 mm diameter and 35 mm depth. It was filled with propane or freon. It was meant as vertex detector in the search of short-lived particles. It was also used with in-line holography resulting in 8 µm bubble size and 9 cm depth of the field. See E. Ramseyer, B. Hahn and E. Hugentobler, Nucl. Instrum. Methods 201 (1982) 335.

  4. The Mobile Chamber

    Science.gov (United States)

    Scharfstein, Gregory; Cox, Russell

    2012-01-01

    A document discusses a simulation chamber that represents a shift from the thermal-vacuum chamber stereotype. This innovation, currently in development, combines the capabilities of space simulation chambers, the user-friendliness of modern-day electronics, and the modularity of plug-and-play computing. The Mobile Chamber is a customized test chamber that can be deployed with great ease, and is capable of bringing payloads at temperatures down to 20 K, in high vacuum, and with the desired metrology instruments integrated to the systems control. Flexure plans to lease Mobile Chambers, making them affordable for smaller budgets and available to a larger customer base. A key feature of this design will be an Apple iPad-like user interface that allows someone with minimal training to control the environment inside the chamber, and to simulate the required extreme environments. The feedback of thermal, pressure, and other measurements is delivered in a 3D CAD model of the chamber's payload and support hardware. This GUI will provide the user with a better understanding of the payload than any existing thermal-vacuum system.

  5. DELPHI time projection chamber

    CERN Multimedia

    1989-01-01

    The time projection chamber is inserted inside the central detector of the DELPHI experiment. Gas is ionised in the chamber as a charged particle passes through, producing an electric signal from which the path of the particle can be found. DELPHI, which ran from 1989 to 2000 on the LEP accelerator, was primarily concerned with particle identification.

  6. BEBC bubble chamber

    CERN Multimedia

    CERN PhotoLab

    1972-01-01

    Looking up into the interior of BEBC bubble chamber from the expansion cylinder. At the top of the chamber two fish-eye lenses are installed and three other fish-eye ports are blanked off. In the centre is a heat exchanger.

  7. Climatic chamber ergometer

    CSIR Research Space (South Africa)

    Atkins, AR

    1968-01-01

    Full Text Available The design and calibration of an ergometer for exercising subjects during calorimetric studies in the climate chamber, are described. The ergometer is built into the climatic chamber and forms an integral part of the whole instrumentation system foe...

  8. Wire core reactor for NTP

    Science.gov (United States)

    Harty, R. B.

    1991-01-01

    The development of the wire core system for Nuclear Thermal Propulsion (NTP) that took place from 1963 to 1965 is discussed. A wire core consists of a fuel wire with spacer wires. It's an annular flow core having a central control rod. There are actually four of these, with beryllium solid reflectors on both ends and all the way around. Much of the information on the concept is given in viewgraph form. Viewgraphs are presented on design details of the wire core, the engine design, engine weight vs. thrust, a technique used to fabricate the wire fuel element, and axial temperature distribution.

  9. Modern wiring practice

    CERN Document Server

    Steward, W E

    2012-01-01

    Continuously in print since 1952, Modern Wiring Practice has now been fully revised to provide an up-to-date source of reference to building services design and installation in the 21st century. This compact and practical guide addresses wiring systems design and electrical installation together in one volume, creating a comprehensive overview of the whole process for contractors and architects, as well as electricians and other installation engineers. Best practice is incorporated throughout, combining theory and practice with clear and accessible explanation, all

  10. Wiring and lighting

    CERN Document Server

    Kitcher, Chris

    2013-01-01

    Wiring and Lighting provides a comprehensive guide to DIY wiring around the home. It sets out the regulations and legal requirements surrounding electrical installation work, giving clear guidelines that will enable the reader to understand what electrical work they are able to carry out, and what the testing and certification requirements are once the work is completed. Topics covered include: Different types of circuits; Types of cables and cable installation under floors and through joists; Isolating, earthing and bonding; Accessory boxes and fixings; Voltage bands; Detailed advice on safe

  11. Electric wiring domestic

    CERN Document Server

    Coker, A J

    1992-01-01

    Electric Wiring: Domestic, Tenth Edition, is a clear and reliable guide to the practical aspects of domestic electric wiring. Intended for electrical contractors, installation engineers, wiremen and students, its aim is to provide essential up to date information on modern methods and materials in a simple, clear, and concise manner. The main changes in this edition are those necessary to bring the work into line with the 16th Edition of the Regulations for Electrical Installations issued by the Institution of Electrical Engineers. The book begins by introducing the basic features of domestic

  12. Validation and performance of the CMS barrel Muon drift chambers with cosmic rays

    CERN Document Server

    Meneguzzo, Anna Teresa

    2004-01-01

    The production of the 250 muon barrel Drift Tube chambers for the CMS experiment at the LHC has started in 2001. In each assembly site the produced chambers equipped with the final front-end electronics and the Low and High Voltage boards are checked in a cosmic rays facility. While the wire position is measured and recorded at construction time, all electrical connections and the quality and performance of the chambers and of the local trigger devices can only 9be checked with real tracks. The methods used and the behavior of the first 22 chambers built in Legnaro (Padova) INFN National Lab (LNL) are reported and compared with Test Beam results. The mean noise level at nominal conditions is 20Hz/m/wire, with an RMS of 5Hz/m/wire. The detection efficiency of each layer is above 98%. The wires with noise above 2 S.D. is less than 0.1% of the total. Due to HV problems the number of wire not connected is less than 0.1%. The wire position accuracy is better than 70mm. The resolution is 200-250mm per layer.

  13. Percutaneous Kirschner wire (K-wire) fixation for humerus shaft ...

    African Journals Online (AJOL)

    In the present study, Kirschner wires (K-wire) were used to achieve a closed intramedullary fixation of humeral shaft fractures. The objective of this study was to evaluate the efficacy of intramedullary K-wires for the treatment of humeral shaft fracture in children. Patients and Methods: This prospective study was conducted in ...

  14. Wiring for space applications program

    Science.gov (United States)

    Hammoud, Ahmad

    1994-01-01

    The insulation testing and analysis consists of: identifying and prioritizing NASA wiring requirements; selecting candidate wiring constructions; developing test matrix and formulating test program; managing, coordinating, and conducting tests; and analyzing and documenting data, establishing guidelines and recommendations.

  15. Debate: Wired versus Wireless.

    Science.gov (United States)

    Meeks, Glenn; Nair, Prakash

    2000-01-01

    Debates the issue of investing in wiring schools for desktop computer networks versus using laptops and wireless networks. Included are cost considerations and the value of technology for learning. Suggestions include using wireless networks for existing schools, hardwiring computers for new construction, and not using computers for elementary…

  16. Wired vs. Wireless.

    Science.gov (United States)

    Fielding, Randall

    2000-01-01

    Presents a debate on which technology will be in tomorrow's classrooms and the pros and cons of wiring classrooms and using a wireless network. Concluding comments address the likelihood, and desirability, of placing computers throughout the entire educational process and what types of computers and capabilities are needed. (GR)

  17. Wired to freedom

    DEFF Research Database (Denmark)

    Jepsen, Kim Sune Karrasch; Bertilsson, Margareta

    2017-01-01

    dimension of life science through a notion of public politics adopted from the political theory of John Dewey. We show how cochlear implantation engages different social imaginaries on the collective and individual levels and we suggest that users share an imaginary of being “wired to freedom” that involves...

  18. Gaseous wire detectors

    Energy Technology Data Exchange (ETDEWEB)

    Va' vra, J.

    1997-08-01

    This article represents a series of three lectures describing topics needed to understand the design of typical gaseous wire detectors used in large high energy physics experiments; including the electrostatic design, drift of electrons in the electric and magnetic field, the avalanche, signal creation, limits on the position accuracy as well as some problems one encounters in practical operations.

  19. 3D Wire 2015

    DEFF Research Database (Denmark)

    Jordi, Moréton; F, Escribano; J. L., Farias

    This document is a general report on the implementation of gamification in 3D Wire 2015 event. As the second gamification experience in this event, we have delved deeply in the previous objectives (attracting public areas less frequented exhibition in previous years and enhance networking) and have...

  20. Practical wiring in SI units

    CERN Document Server

    Miller, Henry A

    2013-01-01

    Practical Wiring, Volume 1 is a 13-chapter book that first describes some of the common hand tools used in connection with sheathed wiring. Subsequent chapters discuss the safety in wiring, cables, conductor terminations, insulating sheathed wiring, conductor sizes, and consumer's control equipments. Other chapters center on socket outlets, plugs, lighting subcircuits, lighting accessories, bells, and primary and secondary cells. This book will be very valuable to students involved in this field of interest.

  1. Wire EDM for Refractory Materials

    Science.gov (United States)

    Zellars, G. R.; Harris, F. E.; Lowell, C. E.; Pollman, W. M.; Rys, V. J.; Wills, R. J.

    1982-01-01

    In an attempt to reduce fabrication time and costs, Wire Electrical Discharge Machine (Wire EDM) method was investigated as tool for fabricating matched blade roots and disk slots. Eight high-strength nickel-base superalloys were used. Computer-controlled Wire EDM technique provided high quality surfaces with excellent dimensional tolerances. Wire EDM method offers potential for substantial reductions in fabrication costs for "hard to machine" alloys and electrically conductive materials in specific high-precision applications.

  2. ALICE Time Projection Chamber

    CERN Multimedia

    Lippmann, C

    2013-01-01

    The Time Projection Chamber (TPC) is the main device in the ALICE 'central barrel' for the tracking and identification (PID) of charged particles. It has to cope with unprecedented densities of charges particles.

  3. Vacuum chamber 'bicone'

    CERN Multimedia

    1977-01-01

    This chamber is now in the National Museum of History and Technology, Smithsonian Institution, Washington, DC, USA, where it was exposed in an exhibit on the History of High Energy Accelerators (1977).

  4. Precise gain measurement of the LHCb muon chambers

    CERN Document Server

    Dané, E; Pinci, D; Sarti, A

    2006-01-01

    The muon detector of the LHCb experiment, which will operate at the Large Hadron Collider (LHC) at CERN, consists of five muon tracking stations placed along the beam axis and equipped mainly with multi-wire proportional chambers (MWPC). In the present paper we report the results of a precise measurement of the gain of the MWPC’s as a function of the anode voltage. A precise evaluation of the primary ionization current (of about 5 pA) was performed. The absolute gain of the chambers was deduced as a function of the anode voltage and compared with the prediction of the Diethorn formula.

  5. Central tracking chamber with inflated cathode-strip foils

    Energy Technology Data Exchange (ETDEWEB)

    Blackmore, E.W.; Bryman, D.A.; Kuno, Y.; Lim, C.; Numao, T.; Padley, P.; Redlinger, G.; Soluk, R. [TRIUMF, Vancouver, BC (Canada); McPherson, R.A. [Joseph Henry Laboratories, Princeton University, Princeton, NJ 08544 (United States)

    1998-02-21

    A new cylindrical low-mass central drift chamber has been constructed for the K{sup +}{yields}{pi}{sup +}{nu} anti {nu} experiment at BNL (E787). The chamber consists of twelve layers of axial wire cells and six layers of thin cathode-strip foils, four of which are supported by differential gas pressure. The momentum resolution (RMS) for muons and pions in the range 150-250 MeV/c is found to be about 0.9%. (orig.). 16 refs.

  6. Technology, Applications, and Process Challenges of Dual Chamber Systems.

    Science.gov (United States)

    Werk, Tobias; Ludwig, Imke S; Luemkemann, Joerg; Mahler, Hanns-Christian; Huwyler, Joerg; Hafner, Mathias

    2016-01-01

    Dual-chamber systems provide an option as a drug and device combination product, when home care and emergency lyophilized products are intended. Nevertheless, until today, there are only a few products on the market, due to the challenges and limitations in manufacturability, product formulation, and product stability in a dual-chamber configuration, as well as economic considerations. This review serves to describe currently available dual-chamber systems and to discuss factors to be considered for appropriate selection and establishing fill-finish processes. Copyright © 2016. Published by Elsevier Inc.

  7. A ring-shaped recombination chamber for hadron therapy dosimetry.

    Science.gov (United States)

    Jakubowska, E; Zielczyński, M; Golnik, N; Gryziński, M A; Krzemiński, Ł

    2014-10-01

    An innovative recombination chamber has been designed for estimation of stray radiation doses and quality factors in hadron therapy. The chamber allows for determination of absorbed dose and recombination index of radiation quality in phantoms at small distances from simulated organs. The chamber body and electrodes are ring shaped, so the beam may be directed through the empty centre of the ring. The ionisation of the filling gas is caused by secondary or scattered radiation and can be related to the dose absorbed in the tissues close to the irradiated target volume. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. Close cathode chamber: Low material budget MWPC

    Science.gov (United States)

    Varga, Dezső; Kiss, Gábor; Hamar, Gergő; Bencédi, Gyula

    2013-01-01

    Performance of asymmetric-type MWPC-s are presented. In this structure, referred to as Close Cathode Chamber in an earlier study, the material budget is significantly reduced on one hand by the elimination of external support frame, on the other hand by thin detector walls. In this paper it is demonstrated that the outline is compatible with large size detectors (1 m wire length), maintaining mechanical and operation stability, with total weight of 3 kg (including support structure) for a half square meter surface. The detection efficiency and response time is shown to be sufficient for L0 triggering in the ALICE VHMPID layout. Reduced sensitivity to cathode deformations (due to internal overpressure as mechanical strain) is directly demonstrated. On small sized chambers, improvement of position resolution with analog readout is evaluated, reaching 0.09 mm RMS with 2 mm wide cathode segments. Simulation results on signal time evolutions are presented. With the above studies, comparison of classical MWPC-s and the Close Cathode Chamber design is performed in all major aspects.

  9. A high-precision X-ray tomograph for quality control of the ATLAS Muon Monitored Drift Tube Chambers

    CERN Document Server

    Schuh, S; Banhidi, Z; Fabjan, Christian Wolfgang; Lampl, W; Marchesotti, M; Rangod, Stephane; Sbrissa, E; Smirnov, Y; Voss, Rüdiger; Woudstra, M; Zhuravlov, V

    2004-01-01

    A dedicated X-ray tomograph has been developed at CERN to control the required wire placement accuracy of better than 20mum of the 1200 Monitored Drift Tube Chambers which make up most of the precision chamber part of the ATLAS Muon Spectrometer. The tomograph allows the chamber wire positions to be measured with a 2mum statistical and 2mum systematic uncertainty over the full chamber cross-section of 2.2 multiplied by 0.6m**2. Consistent chamber production quality over the 4-year construction phase is ensured with a similar to 15% sampling rate. Measurements of about 70 of the 650 MDT chambers so far produced have been essential in assessing the validity and consistency of the various construction procedures.

  10. Target Chamber Manipulator

    Science.gov (United States)

    Tantillo, Anthony; Watson, Matthew

    2015-11-01

    A system has been developed to allow remote actuation of sensors in a high vacuum target chamber used with a particle accelerator. Typically, sensors of various types are placed into the target chamber at specific radial and angular positions relative to the beam line and target. The chamber is then evacuated and the experiments are performed for those sensor positions. Then, the chamber is opened, the sensors are repositioned to new angles or radii, and the process is repeated, with a separate pump-down cycle for each set of sensor positions. The new sensor positioning system allows scientists to pre-set the radii of up to a dozen sensors, and then remotely actuate their angular positions without breaking the vacuum of the target chamber. This reduces the time required to reposition sensors from 6 hours to 1 minute. The sensors are placed into one of two tracks that are separately actuated using vacuum-grade stepping motors. The positions of the sensors are verified using absolute optical rotary encoders, and the positions are accurate to 0.5 degrees. The positions of the sensors are electronically recorded and time-stamped after every change. User control is through a GUI using LabVIEW.

  11. Crack sealer fill characteristics.

    Science.gov (United States)

    2010-06-01

    Laboratory testing was conducted to determine the extent of crack fill for crack sealers composed of methyl methacrylate, : epoxy, urethane, and high molecular weight methacrylate. The test specimens consisted of eight-inch long concrete : cylinders ...

  12. Dual wire welding torch and method

    Science.gov (United States)

    Diez, Fernando Martinez; Stump, Kevin S.; Ludewig, Howard W.; Kilty, Alan L.; Robinson, Matthew M.; Egland, Keith M.

    2009-04-28

    A welding torch includes a nozzle with a first welding wire guide configured to orient a first welding wire in a first welding wire orientation, and a second welding wire guide configured to orient a second welding wire in a second welding wire orientation that is non-coplanar and divergent with respect to the first welding wire orientation. A method of welding includes moving a welding torch with respect to a workpiece joint to be welded. During moving the welding torch, a first welding wire is fed through a first welding wire guide defining a first welding wire orientation and a second welding wire is fed through a second welding wire guide defining a second welding wire orientation that is divergent and non-coplanar with respect to the first welding wire orientation.

  13. Tension-filled Governance?

    DEFF Research Database (Denmark)

    Celik, Tim Holst

    on the statesituated tension-filled functional relationship between legitimation and accumulation, the study both historically and theoretically reworks this approach and reapplies it for the post-1970s/1990s governance period. It asks whether and to what extent governance has served as a distinctive post- 1970s/1990s...... state-facilitated way of bridging/altering the tension-filled relationship between legitimation and fiscal accumulation in Western European liberal-capitalist democratic polities....

  14. Intermontane valley fills

    OpenAIRE

    Mey, Jürgen (Diplom-Geologe)

    2017-01-01

    Sedimentary valley fills are a widespread characteristic of mountain belts around the world. They transiently store material over time spans ranging from thousands to millions of years and therefore play an important role in modulating the sediment flux from the orogen to the foreland and to oceanic depocenters. In most cases, their formation can be attributed to specific fluvial conditions, which are closely related to climatic and tectonic processes. Hence, valley-fill deposits constitute v...

  15. Simulation for output signal of BES-III MDC The MDC is stated for Main Drift Chamber

    CERN Document Server

    Wang Zheng; Sheng Hua Yi; Zhuang Bao An; Jiang Xiao Shan

    2002-01-01

    Small cell drift chamber is adopted in the design of BES III-the upgrade version of the BES detector, for its lower electron diffusion and better spatial resolution. The authors did Monte Carlo study for BES-III drift chamber using GARFIELD7, and got the characteristics of the output signals of the sense wires. This become the theoretical basis for the design of drift chamber readout electronics

  16. Filling a Conical Cavity

    Science.gov (United States)

    Nye, Kyle; Eslam-Panah, Azar

    2016-11-01

    Root canal treatment involves the removal of infected tissue inside the tooth's canal system and filling the space with a dense sealing agent to prevent further infection. A good root canal treatment happens when the canals are filled homogeneously and tightly down to the root apex. Such a tooth is able to provide valuable service for an entire lifetime. However, there are some examples of poorly performed root canals where the anterior and posterior routes are not filled completely. Small packets of air can be trapped in narrow access cavities when restoring with resin composites. Such teeth can cause trouble even after many years and lead the conditions like acute bone infection or abscesses. In this study, the filling of dead-end conical cavities with various liquids is reported. The first case studies included conical cavity models with different angles and lengths to visualize the filling process. In this investigation, the rate and completeness at which a variety of liquids fill the cavity were observed to find ideal conditions for the process. Then, a 3D printed model of the scaled representation of a molar with prepared post spaces was used to simulate the root canal treatment. The results of this study can be used to gain a better understanding of the restoration for endodontically treated teeth.

  17. Polyurethane spray coating of aluminum wire bonds to prevent corrosion and suppress resonant oscillations

    CERN Document Server

    INSPIRE-00092738; Kurth, Matthew; Boyd, Rusty

    2016-01-01

    Unencapsulated aluminum wedge wire bonds are common in particle physics pixel and strip detectors. Industry-favored bulk encapsulation is eschewed due to the range of operating temperatures and radiation. Wire bond failures are a persistent source of tracking-detector failure. Unencapsulated bonds are vulnerable to condensation-induced corrosion, particularly when halides are present. Oscillations from periodic Lorentz forces are documented as another source of wire bond failure. Spray application of polyurethane coatings, performance of polyurethane-coated wire bonds after climate chamber exposure, and resonant properties of polyurethane-coated wire bonds and their resistance to periodic Lorentz forces are under study for use in a future High Luminosity Large Hadron Collider detector such as the ATLAS Inner Tracker upgrade.

  18. A Contact-Less 2-Dimensional Laser Sensor for 3-Dimensional Wire Position and Tension Measurements

    Science.gov (United States)

    Prall, Matthias; Hannen, Volker M.; Johren, Raphael; Ortjohann, Hans-Werner; Reinhardt, Martina; Weinheimer, Christian

    2010-04-01

    We have developed a contact-less two-dimensional laser sensor which combines position and tension measurements of wires with a diameter of order 0.2 mm. The sensor consists of commercially available laser pointers, lenses, color filters and photodiodes. In our application we have used this laser sensor in conjunction with an automated three-dimensional coordinate measuring machine (CMM). The device allows for a position measurement of wires in three dimensions with an accuracy of about 10 ¿m. At the same time the wire tension can be determined with an accuracy of 0.04 N. The device is operated at a distance of 150 mm from the wire. For each position measurement, the laser sensor is moved by the automated CMM into a plane, where the coordinates at which the wires intersect with this plane are determined. The position of the plane itself (the third coordinate) is given by the third axis of the CMM which is perpendicular to this plane. The precision of the device was determined using stainless steel wires with a diameter of 0.2 mm and a tension of 5 N. We use the sensor for quality assurance of the wire electrode modules for the KATRIN neutrino mass experiment. These modules are comprised of two layers of wires, which are 70 mm apart. In general, the device presented here is well suited for the measurement of any complex wire chamber geometry.

  19. Metering Wheel-Wire Track Wire Boom Deployment Mechanism

    Science.gov (United States)

    Granoff, Mark S.

    2014-01-01

    The NASA MMS Spin Plane Double Probe (SDP) Deployer utilizes a helical path, rotating Metering Wheel and a spring loaded Wire "Holding" Track to pay out a "fixed end" 57 meter x 1.5 mm diameter Wire Boom stored between concentric storage cylinders. Unlike rotating spool type storage devices, the storage cylinders remain stationary, and the boom wire is uncoiled along the length of the cylinder via the rotation of the Metering Wheel. This uncoiling action avoids the need for slip-ring contacts since the ends of the wire can remain stationary. Conventional fixed electrical connectors (Micro-D type) are used to terminate to operational electronics.

  20. Development of a 150 m/sup 2/ proportional chamber system with a 1 million bit buffer The EMI for BEBC

    CERN Document Server

    Brand, C; Chesi, Enrico Guido; Föth, H; Gilgrass, A; Hilke, H J; Jacobs, D; Lazeyras, Pierre; Sacquin, Yu

    1976-01-01

    For the identification of muons behind the Big European Bubble Chamber (BEBC) a detector wall of 6 m*25 m is required. The authors describe the construction of the wire chambers, the electronics and the performance of the first chambers. The 50 modular 3 m*1 m chambers contain 75000 wires and 10000 cathode stripes, grouped into 20000 electronic channels to give a variable space resolution. Geometrical acceptance is maximized by the suppression of support lines and spacers. The electronics can buffer up to 1023 events without dead time losses and without limitation on the number of hits per event. Ar /CO/sub 2/ mixtures have given good results. (6 refs).

  1. Reduction in wire tension caused by wire clamping and wire tensioner removal: an experimental Ilizarov frame study.

    Science.gov (United States)

    La Russa, Valentina; Skallerud, Bjørn; Klaksvik, Jomar; Foss, Olav A

    2011-03-01

    The stability of an external ring fixator mainly depends on wire tension. Wire fixators should maintain the tension during both wire clamping to the ring and removal of the tensioner device. In the present study the loss in wire tension related to fixator clamping and wire tensioner removal using three different wire fixator designs was studied. The fixators were based on two different cannulated bolts and a washer. Effects from two different pretension levels in combination with three different bolt torque levels upon loss in wire tension were described. Emitted wire vibration frequency was used to assess the corresponding wire tension. Wire tension was determined after each wire fixator tightening and after the removal of the wire tensioner. Increased bolt torque led to a small decrease in tension for both pretension levels. A considerable higher tension loss was measured when removing the wire tensioner. In all cases, the combination of a new cannulated bolt and a washer maintained the highest tension.

  2. Structural evolution of a Ta-filament during hot-wire chemical vapour deposition of Silicon investigated by electron backscatter diffraction

    CSIR Research Space (South Africa)

    Oliphant, CJ

    2012-03-01

    Full Text Available In this study we investigate the structural changes of a burnt-out tantalum filament that was operated at typical hydrogenated nanocrystalline silicon synthesis conditions in our hot-wire chemical vapour deposition chamber. Scanning electron...

  3. The construction technique of the high granularity and high transparency drift chamber of MEG II

    Science.gov (United States)

    Chiarello, G.; Chiri, C.; Corvaglia, A.; Grancagnolo, F.; Miccoli, A.; Panareo, M.; Pinto, C.; Spedicato, M.; Tassielli, G. F.

    2017-07-01

    The MEG experiment searches for the charged lepton flavor violating decay, μ +→ e+γ. MEG has already determined the world best upper limit on the branching ratio BRrobot, designed and built at the INFN Lecce and University of Salento laboratories, consists of: ṡ a semiautomatic wiring machine with a high precision on wire mechanical tensioning (better than 0.5 g) and on wire positioning (20 μ m) for simultaneous wiring of multiwire layers; ṡ a contact-less infrared laser soldering tool; ṡ an automatic handling system for storing and transporting the multi-wire layers. The drift chamber is currently under construction at INFN and should be completed by the end of summer 2017 to be then delivered to PSI for commissioning.

  4. LEP Vacuum Chamber

    CERN Multimedia

    1983-01-01

    This is a cut-out of a LEP vacuum chamber for dipole magnets showing the beam channel and the pumping channel with the getter (NEG) strip and its insulating supports. A water pipe connected to the cooling channel can also be seen at the back.The lead radiation shield lining is also shown. See also 8305563X.

  5. Scanning bubble chamber pictures

    CERN Multimedia

    1974-01-01

    These were taken at the 2 m hydrogen bubble chamber. The photo shows an early Shiva system where the pre-measurements needed to qualify the event were done manually (cf photo 7408136X). The scanning tables were located in bld. 12. Gilberte Saulmier sits on foreground, Inge Arents at centre.

  6. Heavy liquid bubble chamber

    CERN Multimedia

    CERN PhotoLab

    1965-01-01

    The CERN Heavy liquid bubble chamber being installed in the north experimental hall at the PS. On the left, the 1180 litre body; in the centre the magnet, which can produce a field of 26 800 gauss; on the right the expansion mechanism.

  7. Rocket Combustion Chamber Coating

    Science.gov (United States)

    Holmes, Richard R. (Inventor); McKechnie, Timothy N. (Inventor)

    2001-01-01

    A coating with the ability to protect (1) the inside wall (i.e., lining) of a rocket engine combustion chamber and (2) parts of other apparatuses that utilize or are exposed to combustive or high temperature environments. The novelty of this invention lies in the manner a protective coating is embedded into the lining.

  8. Chamber Profile Measurement System.

    Science.gov (United States)

    1980-10-01

    travel with the proper electronics. Other features of tihe gage assembly are: 1. Micrometer controlled down chamber positioning of the master template to...pressure sensitive "stiff stick" for infinitely varying the rate of travel from zero to maximum. A manual vernier control is incorporated to permit fine

  9. LEP vacuum chamber, prototype

    CERN Multimedia

    CERN PhotoLab

    1983-01-01

    Final prototype for the LEP vacuum chamber, see 8305170 for more details. Here we see the strips of the NEG pump, providing "distributed pumping". The strips are made from a Zr-Ti-Fe alloy. By passing an electrical current, they were heated to 700 deg C.

  10. Wiring regulations in brief

    CERN Document Server

    Tricker, Ray

    2012-01-01

    Tired of trawling through the Wiring Regs?Perplexed by Part P?Confused by cables, conductors and circuits?Then look no further! This handy guide provides an on-the-job reference source for Electricians, Designers, Service Engineers, Inspectors, Builders, Students, DIY enthusiastsTopic-based chapters link areas of working practice - such as cables, installations, testing and inspection, special locations - with the specifics of the Regulations themselves. This allows quick and easy identification of the official requirements relating to the situati

  11. Mounting an ISR intersection chamber in the Split Field Magnet(SFM)

    CERN Multimedia

    1977-01-01

    The Split Field Magnet (SFM) was the largest spectrometer for particles from beam-beam collisions in the ISR. It could determine particle momenta in a large solid angle, but was designed mainly for the analysis of forward travelling particles.As the magnet was working on the ISR circulating beams, its magnetic field had to be such as to restore the correct proton orbit.The SFM, therefore, produced zero field at the crossing point and fields of opposite signs upstream and downstream of it and was completed by 2 large and 2 small compensator magnets. The gradient effects were corrected by magnetic channels equipped with movable flaps. The useful magnetic field volume was 28 m3, the induction in the median plane 1.14 T, the gap heigth 1.1 m, the length 10.5 m, the weight about 1000 ton.Concerning the detectors, the SFM was the first massive application of multiwire proportional chambers (about 70000 wires) which filled the main and the large compensator magnets. In the course of the years different types of vacu...

  12. Sag Compensation System for Assembly of MDT-Chambers for the ATLAS Experiment

    CERN Document Server

    Barashkou, A V; Chepurnov, V F; Evtoukhovitch, P G; Glonti, G L; Gongadze, A L; Ilyushenka, Y N; Kotov, S A; Kruchonak, V G; Tskhadadze, E G

    2005-01-01

    The description of a system of the devices created for compensation of the gravitational deflection of the drift chamber during its assembly is presented. By means of this system during stage-by-stage gluing of layers of tube drift detectors to the chamber the transversal deflection considerably decreases and by that high accuracy of mutual position of separate tubes is provided. The devices were applied at assembly of 74 MDT-chambers of the ATLAS experiment. Design values of deformation of the chambers as well as the results of measurement of transversal deflections obtained during the assembly with the use of the system of sag compensation are given. Testing of chambers on the X-ray tomograph at CERN has shown that the accuracy of the positions of separate signal wires inside the assembled chambers is within the limits of the required 20 $\\mu$m.

  13. Corrosion of Wires on Wooden Wire-Bound Packaging Crates

    Science.gov (United States)

    Samuel L. Zelinka; Stan Lebow

    2015-01-01

    Wire-bound packaging crates are used by the US Army to transport materials. Because these crates may be exposed to harsh environments, they are dip-treated with a wood preservative (biocide treatment). For many years, zinc-naphthenate was the most commonly used preservative for these packaging crates and few corrosion problems with the wires were observed. Recently,...

  14. Multiphase CFD Simulation of Solid Propellant Combustion in a Small Gun Chamber

    National Research Council Canada - National Science Library

    Bougamra, Ahmed; Lu, Huilin

    2014-01-01

    ..., the combustion chamber and the launching tube (the barrel of the gun). We can assume that the two cylinders have the same diameter because for small gun using rimless ammunition the diameters are almost the same (see Figure 1). The breech contains the primer, a small space filled with black powder. The space defined by the combustion chamber, sealed by the proj...

  15. Study of the response of low pressure ionization chambers

    CERN Document Server

    Nebot Del Busto, E; Effinger, E; Grishin, V; Herranz Alvarez, J

    2012-01-01

    The Beam Loss Monitoring System (BLM) of the Large Hadron Collider (LHC) is based on parallel plate Ionization Chambers (IC) with active volume 1.5l and a nitrogen filling gas at 0.1 bar overpressure. At the largest loss locations, the ICs generate signals large enough to saturate the read-out electronics. A reduction of the active volume and filling pressure in the ICs would decrease the amount of charge collected in the electrodes, and so provide a higher saturation limit using the same electronics. This makes Little Ionization Chambers (LIC) with both reduced pressure and small active volume a good candidate for these high radiation areas. In this contribution we present measurements performed with several LIC monitors with reduced active volume and various filling pressures. These detectors were tested under various conditions with different beam setups, with standard LHC ICs used for calibration purposes

  16. Most Wired 2006: measuring value.

    Science.gov (United States)

    Solovy, Alden

    2006-07-01

    As the Most Wired hospitals incorporate information technology into their strategic plans, they combine a"balanced scorecard"approach with classic business analytics to measure how well IT delivers on their goals. To find out which organizations made this year's 100 Most Wired list, as well as those named in other survey categories, go to the foldout section.

  17. Space-filling Curves

    Indian Academy of Sciences (India)

    mathematics and computer applications for the last 20 years. He has been a National Science. Talent awardee of. NCERT in mathematics. GENERAL I ARTICLE. Space-filling Curves. ReMittal. In this article some Peano curves are exhibited and some of their recent applications are dis- cussed. A C++ program to draw the ...

  18. Anechoic Radio Frequency Test Chamber

    Data.gov (United States)

    Federal Laboratory Consortium — This chamber is used for characterization test of such systems as communications gear, tanks, radar, missiles, and helicopters. The dimensions of the chamber are 114...

  19. Radiation Hydrodynamic Parameter Study of Inertial Fusion Energy Reactor Chambers

    Science.gov (United States)

    Sacks, Ryan; Moses, Gregory

    2014-10-01

    Inertial fusion energy reactors present great promise for the future as they are capable of providing baseline power with no carbon footprint. Simulation work regarding the chamber response and first wall insult is performed with the 1-D radiation hydrodynamics code BUCKY. Simulation with differing chamber parameters are implemented to study the effect of gas fill, gas mixtures and chamber radii. Xenon and argon gases are of particular interest as shielding for the first wall due to their high opacity values and ready availability. Mixing of the two gases is an attempt to engineer a gas cocktail to provide the maximum amount of shielding with the least amount of cost. A parameter study of different chamber radii shows a consistent relationship with that of first wall temperature (~1/r2) and overpressure (~1/r3). This work is performed under collaboration with Lawrence Livermore National Laboratory.

  20. Percutaneous cerclage wiring, does it disrupt femoral blood supply? A cadaveric injection study.

    Science.gov (United States)

    Apivatthakakul, T; Phaliphot, J; Leuvitoonvechkit, S

    2013-02-01

    A percutaneous cerclage wiring technique has been developed to reduce iatrogenic soft tissue and vascular disruption associated with classic cerclage fixation. The purpose of this study was to evaluate the extent of femoral vascular disruption resulting iatrogenically from the application of two percutaneous cerclage wire loops. Pairs of cerlage wire loops were percutaneously inserted on 18 fresh cadaveric femurs. The position of the wire loops varied. The wire loops were either inserted 10 and 15cm, 10 and 20cm, or 15 and 20cm distal to the tip of the greater trochanter. Each study group had 6 cadavers. Contralateral femurs without cerclage wiring were used as controls. Liquid contrast-gelatin was injected into the common femoral artery. Using axial and 3D CT scan images the superficial femoral artery (SFA), deep femoral artery (DFA), perforating arteries and their anastomotic patterns as well as endosteal perfusion were identified and their patency was graded. Percutaneous cerclage wiring did not disrupt femoral endosteal blood supply and maintained the integrity of all of the superficial femoral arteries. Four specimens demonstrated maintenance of all 4 perforators, 11 showed disruption of 1 perforator, and 3 showed disruption of 2 perforators. One deep femoral artery was disrupted after its first perforator branched off; however, perfusion was maintained by fill from an alternative anastamosis. There was no significant difference between disruption of deep femoral arteries and perforating arteries (P=1.000), location of wiring (P=0.905) or spacing between wire loops (P=1.000). Percutaneous cerclage wiring resulted in minimal disruption of the femoral blood supply. When partial disruption occurred the SFA, DFA, and their associated perforators compensated to maintain femoral perfusion through their anastomoses. The location of the cerclage wire and the distance between the wire loops in the proximal femur showed no significant difference in the rate of

  1. Position reconstruction in drift chambers operated with Xe, $CO_{2}$ (15\\%)

    CERN Document Server

    Adler, C; Appelshäuser, H; Bielcikova, J; Blume, C; Braun-Munzinger, P; Bucher, D; Busch, O; Catanescu, V; Ciobanu, M; Daues, H W; Emschermann, D; Fateev, O V; Foka, P; Garabatos, C; Gunji, T; Herrmann, N; Inuzuka, M; Ivanov, M; Kislov, E; Lindenstruth, V; Lippmann, C; Ludolphs, W; Mahmoud, T; Petracek, V; Petrovici, M; Radomski, S; Rusanov, I; Sandoval, A; Santo, R; Schicker, R; Schwarz, K; Simon, R S; Smykov, L P; Soltveit, H K; Stachel, J; Stelzer, H; Tsiledakis, G; Vulpescu, B; Wessels, J P; Windelband, B; Yurevich, V; Zanevsky, Yu; Zaudtke, O

    2005-01-01

    We present measurements of position and angular resolution of drift chambers operated with a Xe, CO2 (15%) mixture. The results are compared to Monte Carlo simulations and important systematic effects - in particular the dispersive nature of the absorption of transition radiation and non-linearities - are discussed. The measurements were carried out with prototype drift chambers of the ALICE Transition Radiation Detector, but our findings can be generalized to other drift chambers with similar geometry, where the electron drift is perpendicular to the wire planes.

  2. Microstructure Filled Hohlraums

    Energy Technology Data Exchange (ETDEWEB)

    Moore, A. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Thomas, C. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reese, T. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-02-24

    We propose replacing the gas fill in a hohlraum with a low average density, variable uniformity 3D printed structure. This creates a bimodal hohlraum which acts like a vacuum hohlraum initially during the picket, but could protect the capsule from glint or direct illumination, and then once expanded, homogenizes to behave like a variable z gas-fill during peak portion of the drive. This is motivated by a two main aims: 1) reduction of the Au bubble velocity to improve inner beam propagation, and 2) the introduction of a low density, high-Z, x-ray converter to improve x-ray production in the hohlraum and uniformity of the radiation field seen by the capsule.

  3. Vacuum Chambers for LEP sections

    CERN Multimedia

    1983-01-01

    The picture shows sections of the LEP vacuum chambers to be installed in the dipole magnets (left) and in the quadrupoles (right). The dipole chamber has three channels: the beam chamber, the pumping duct where the NEG (non-evaporabe getter) is installed and the water channel for cooling (on top in the picture). The pumping duct is connected to the beam chamber through holes in the separating wall. The thick lead lining to shield radiation can also be seen. These chambers were manufactured as extruded aluminium alloy profiles.

  4. [Primary cancellous bone formation around micro-chambered beads].

    Science.gov (United States)

    Draenert, M E; Draenert, Y; Draenert, K; Pohlemann, T; Erler, M

    2014-01-01

    The question has been raised whether benign bone defects in patients can be treated with bone forming osteoconductive ceramics achieving primarily a cancellous bone scaffold, which is under load from the beginning. Ten reconstructions were performed in 9patients (6women and 3male), with a mean age of 49 (25-65)years, suffering a high variety of epi- and metaphyseal defects, four tibial fractures, two calcaneal fractures, one pathological phalangeal fracture, one chondroma of the distal femur and two open-wedge osteotomies were filled with micro-chambered ceramic beads of 4 and 6mm in diameter. The mean follow up was 22 (7- 8)months. X-rays and CT-scans formed the basis for the evaluation of the reconstruction of the cancellous bone scaffolds. All cancellous structures were rebuilt, if completely filled with bone-forming elements. If the filling was incomplete, no physiological cancellous bone scaffold resulted. The β-TCP micro-chambered beads were completely reabsorbed or sandwich-like incorporated at the time of evaluation. The HA micro-chambered beads revealed a contrast enhancement and were integrated in the osseous construction of the bone scaffold. Primary cancellous bone formation can be achieved with osteoconductive ceramic micro-chambered beads and can be combined with any osteosynthesis for stable fixation. Copyright © 2013 SECOT. Published by Elsevier Espana. All rights reserved.

  5. Construction and test of new precision drift-tube chambers for the ATLAS muon spectrometer

    Science.gov (United States)

    Kroha, H.; Kortner, O.; Schmidt-Sommerfeld, K.; Takasugi, E.

    2017-02-01

    ATLAS muon detector upgrades aim for increased acceptance for muon triggering and precision tracking and for improved rate capability of the muon chambers in the high-background regions of the detector with increasing LHC luminosity. The small-diameter Muon Drift Tube (sMDT) chambers have been developed for these purposes. With half of the drift-tube diameter of the MDT chambers and otherwise unchanged operating parameters, sMDT chambers share the advantages of the MDTs, but have an order of magnitude higher rate capability and can be installed in detector regions where MDT chambers do not fit in. The chamber assembly methods have been optimized for mass production, minimizing construction time and personnel. Sense wire positioning accuracies of 5 μm have been achieved in serial production for large-size chambers comprising several hundred drift tubes. The construction of new sMDT chambers for installation in the 2016/17 winter shutdown of the LHC and the design of sMDT chambers in combination with new RPC trigger chambers for replacement of the inner layer of the barrel muon spectrometer are in progress.

  6. Damping insert materials for settling chambers of supersonic wind tunnels

    Science.gov (United States)

    Wu, Jie; Radespiel, Rolf

    2017-03-01

    This study describes the application of a novel damping insert material for reducing the flow fluctuations in a tandem nozzle supersonic wind tunnel. This new damping material is composed of multi-layer stainless steel wired meshes. The influences of the multi-layer mesh, such as the quantity of the mesh layer and the installed location in the settling chamber, to the freestream quality have been investigated. A Pitot probe instrumented with a Kulite pressure sensor and a hot-wire probe are employed to monitor the flow fluctuation in the test section of the wind tunnel. Thereafter, a combined modal analysis is applied for the disturbance qualification. Additionally, the transient Mach number in the test section is measured. The disturbance qualification indicates that the multi-layer mesh performs well in providing reduction of vorticity reduction and acoustic fluctuations. Comparable flow quality of the freestream was also obtained using a combination of flexible damping materials. However, the life-span of the new damping materials is much longer. The time transient of the Mach number measured in the test section indicates that the mean flow is rather constant over run time. Furthermore, the time-averaged pressure along the settling chamber is recorded and it shows the distribution of pressure drop by settling chamber inserts.

  7. Influence of counting chamber type on CASA outcomes of equine semen analysis.

    Science.gov (United States)

    Hoogewijs, M K; de Vliegher, S P; Govaere, J L; de Schauwer, C; de Kruif, A; van Soom, A

    2012-09-01

    Sperm motility is considered to be one of the key features of semen analysis. Assessment of motility is frequently performed using computer-assisted sperm analysis (CASA). Nevertheless, no uniform standards are present to analyse a semen sample using CASA. We hypothesised that the type of counting chamber used might influence the results of analysis and aimed to study the effect of chamber type on estimated concentration and motility of an equine semen sample assessed using CASA. Commonly used disposable Leja chambers of different depths were compared with disposable and reusable ISAS chambers, a Makler chamber and a World Health Organization (WHO) motility slide. Motility parameters and concentrations obtained with CASA using these different chambers were analysed. The NucleoCounter was used as gold standard for determining concentration. Concentration and motility parameters were significantly influenced by the chamber type used. Using the NucleoCounter as the gold standard for determining concentration, the correlation coefficients were low for all of the various chambers evaluated, with the exception of the 12 µm deep Leja chamber. Filling a chamber by capillary forces resulted in a lower observed concentration and reduced motility parameters. All chambers evaluated in this study resulted in significant lower progressive motility than the WHO prepared slide, with the exception of the Makler chamber, which resulted in a slight, but statistically significant, increase in progressive motility estimates. Computer-assisted sperm analysis can only provide a rough estimate of sperm concentration and overestimation is likely when drop-filled slides with a coverslip are used. Motility estimates using CASA are highly influenced by the counting chamber; therefore, a complete description of the chamber type used should be provided in semen reports and in scientific articles. © 2011 EVJ Ltd.

  8. Posterior chamber pseudophakia.

    Science.gov (United States)

    Simcoe, C W

    1982-01-01

    Anatomically, the most physiological type of implant is that of the posterior chamber of the eye. After a brief historical review of these implants, two models differing by their loops are compared, these being either in the form of a J with narrow extremities or in the form of a C. The latter model possesses definite advantages. Firstly, the point of pressure on the lens capsule is less concentrated, reducing the pressure exerted by the loops and thus avoiding rupture of the zonular ciliaris, Secondly, contact in the form of an are prevents movement of the implant around its axis, a factor favorizing capsule slipping. Thirdly, the improved pressure distribution of the loops resulting from their greater flexibility also prevents the "windscreen wiper syndrome", providing improved stability of the implant. The technique employed avoids all contact taking place with the endothelium. The upper loop is placed in position after closure of the incision. Results in 1532 cases were very positive, and studies are currently being conducted with an implant with four loops in which the optic is within the posterior chamber, and which could be positioned after intracapsular extraction. A system of irrigation-aspiration is described which employs a fine curved canula that is easier to manage and permits improved cleaning of the capsule. Emphasis is placed on the need for narrow, deep, corneal sutures to reduce postoperative astigmatism.

  9. Council Chamber exhibition

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    To complete the revamp of CERN’s Council Chamber, a new exhibition is being installed just in time for the June Council meetings.   Panels will showcase highlights of CERN’s history, using some of the content prepared for the exhibitions marking 50 years of the PS, which were displayed in the main building last November. The previous photo exhibition in the Council Chamber stopped at the 1970s. To avoid the new panels becoming quickly out of date, photos are grouped together around specific infrastructures, rather than following a classic time-line. “We have put the focus on the accelerators – the world-class facilities that CERN has been offering researchers over the years, from the well-known large colliders to the lesser-known smaller facilities,” says Emma Sanders, who worked on the content. The new exhibition will be featured in a future issue of the Bulletin with photos and an interview with Fabienne Marcastel, designer of the exhibit...

  10. Cavity Mode Related Wire Breaking of the SPS Wire Scanners and Loss Measurements of Wire Materials

    CERN Document Server

    Caspers, Friedhelm; Jensen, E; Koopman, J; Malo, J F; Roncarolo, F

    2003-01-01

    During the SPS high intensity run 2002 with LHC type beam, the breaking of several of the carbon wires in the wire scanners has been observed in their parking position. The observation of large changes in the wire resistivity and thermionic electron emission clearly indicated strong RF heating that was depending on the bunch length. A subsequent analysis in the laboratory, simulating the beam by two probe antennas or by a powered stretched wire, showed two main problems: i) the housing of the wire scanner acts as a cavity with a mode spectrum starting around 350 MHz and high impedance values around 700 MHz; ii) the carbon wire used so far appears to be an excellent RF absorber and thus dissipates a significant part of the beam-induced power. Different wire materials are compared with the classical cavity mode technique for the determination of the complex permittivity in the range of 2-4 GHz. As a resonator a rectangular TE_01n type device is utilized.

  11. Cavity mode related wire breaking of the SPS Wire Scanners and loss measurements of wire materials

    CERN Document Server

    Roncarolo, Federico

    2003-01-01

    During the SPS high intensity run 2002 with LHC type beam, the breaking of several of the carbon wires in the wire scanners has been observed in their parking position. The observation of large changes in the wire resistivity and thermionic electron emission clearly indicated strong RF heating that was depending on the bunch length. A subsequent analysis in the laboratory, simulating the beam by two probe antennas or by a powered stretched wire, showed two main problems: i) the housing of the wire scanner acts as a cavity with a mode spectrum starting around 350MHz and high impedance values around 700 MHz; ii) the carbon wire used so far appears to be an excellent RF absorber and thus dissipates a significant part of the beam-induced power. Different wire materials are compared with the classical cavity mode technique for the determination of the complex permittivity in the range of 2-4 GHz. As a resonator a rectangular TE01n type device is utilized.

  12. Safety-Enclosure System For MOCVD Process Chamber

    Science.gov (United States)

    Singletery, James, Jr.; Velasquez, Hugo; Warner, Joseph

    1995-01-01

    Safety-enclosure system filled with nitrogen surrounds reaction chamber in which metallo-organic chemical vapor deposition (MOCVD) performed. Designed to protect against explosions and/or escaping toxic gases and particulates. Gas-purification subsystem ensures during loading and unloading of process materials, interior of MOCVD chamber exposed to less than 1 ppm of oxygen and less than 5 ppm of water in nitrogen atmosphere. Toxic byproducts of MOCVD process collected within inert atmosphere. Enclosure strong enough to contain any fragments in unlikely event of explosion.

  13. Modeling birds on wires.

    Science.gov (United States)

    Aydoğdu, A; Frasca, P; D'Apice, C; Manzo, R; Thornton, J M; Gachomo, B; Wilson, T; Cheung, B; Tariq, U; Saidel, W; Piccoli, B

    2017-02-21

    In this paper we introduce a mathematical model to study the group dynamics of birds resting on wires. The model is agent-based and postulates attraction-repulsion forces between the interacting birds: the interactions are "topological", in the sense that they involve a given number of neighbors irrespective of their distance. The model is first mathematically analyzed and then simulated to study its main properties: we observe that the model predicts birds to be more widely spaced near the borders of each group. We compare the results from the model with experimental data, derived from the analysis of pictures of pigeons and starlings taken in New Jersey: two different image elaboration protocols allow us to establish a good agreement with the model and to quantify its main parameters. We also discuss the potential handedness of the birds, by analyzing the group organization features and the group dynamics at the arrival of new birds. Finally, we propose a more refined mathematical model that describes landing and departing birds by suitable stochastic processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Michigan ATLAS MDT Chamber Mass Production

    CERN Document Server

    Diehl, E; Levin, D; McKee, S; Neal, H; Schick, H; Tarle, G; Thun, R; Weaverdyck, C; Xu, Q; Zhao, Z; Zhou, B

    2001-01-01

    This paper describes the ATLAS MDT precision muon chamber construction at the University of Michigan. The chamber assembly facilities, the jigging set up, alignment procedures, and other measurements necessary for chamber assembly are described. The chamber quality assurance monitoring procedures and data for the first year mass production are presented. The chamber gas system assembly facilities, and the chamber leak test procedure together with data also reported. The chamber production database, which monitors chamber production, is also discussed.

  15. Topology Optimized Photonic Wire Splitters

    DEFF Research Database (Denmark)

    Frandsen, Lars Hagedorn; Borel, Peter Ingo; Jensen, Jakob Søndergaard

    2006-01-01

    Photonic wire splitters have been designed using topology optimization. The splitters have been fabricated in silicon-on-insulator material and display broadband low-loss 3dB splitting in a bandwidth larger than 100 nm.......Photonic wire splitters have been designed using topology optimization. The splitters have been fabricated in silicon-on-insulator material and display broadband low-loss 3dB splitting in a bandwidth larger than 100 nm....

  16. Vacuum filling of complex microchannels with liquid metal.

    Science.gov (United States)

    Lin, Yiliang; Gordon, Olivia; Khan, M Rashed; Vasquez, Neyanel; Genzer, Jan; Dickey, Michael D

    2017-09-12

    This paper describes the utilization of vacuum to fill complex microchannels with liquid metal. Microchannels filled with liquid metal are useful as conductors for soft and stretchable electronics, as well as for microfluidic components such as electrodes, antennas, pumps, or heaters. Liquid metals are often injected manually into the inlet of a microchannel using a syringe. Injection can only occur if displaced air in the channels has a pathway to escape, which is usually accomplished using outlets. The positive pressure (relative to atmosphere) needed to inject fluids can also cause leaks or delamination of the channels during injection. Here we show a simple and hands-free method to fill microchannels with liquid metal that addresses these issues. The process begins by covering a single inlet with liquid metal. Placing the entire structure in a vacuum chamber removes the air from the channels and the surrounding elastomer. Restoring atmospheric pressure in the chamber creates a positive pressure differential that pushes the metal into the channels. Experiments and a simple model of the filling process both suggest that the elastomeric channel walls absorb residual air displaced by the metal as it fills the channels. Thus, the metal can fill dead-ends with features as small as several microns and branched structures within seconds without the need for any outlets. The method can also fill completely serpentine microchannels up to a few meters in length. The ability to fill dense and complex geometries with liquid metal in this manner may enable broader application of liquid metals in electronic and microfluidic applications.

  17. HTS Wire Development Workshop: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1994-07-01

    The 1994 High-Temperature Superconducting Wire Development Workshop was held on February 16--17 at the St. Petersburg Hilton and Towers in St. Petersburg, Florida. The meeting was hosted by Florida Power Corporation and sponsored by the US Department of Energy`s Superconductivity Program for Electric Power Systems. The meeting focused on recent high-temperature superconducting wire development activities in the Department of Energy`s Superconductivity Systems program. The meeting opened with a general discussion on the needs and benefits of superconductivity from a utility perspective, the US global competitiveness position, and an outlook on the overall prospects of wire development. The meeting then focused on four important technology areas: Wire characterization: issues and needs; technology for overcoming barriers: weak links and flux pinning; manufacturing issues for long wire lengths; and physical properties of HTS coils. Following in-depth presentations, working groups were formed in each technology area to discuss the most important current research and development issues. The working groups identified research areas that have the potential for greatly enhancing the wire development effort. These areas are discussed in the summary reports from each of the working groups. This document is a compilation of the workshop proceedings including all general session presentations and summary reports from the working groups.

  18. 30 CFR 75.701-4 - Grounding wires; capacity of wires.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Grounding wires; capacity of wires. 75.701-4... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Grounding § 75.701-4 Grounding wires; capacity of wires. Where grounding wires are used to ground metallic sheaths, armors, conduits, frames...

  19. 1 mil gold bond wire study.

    Energy Technology Data Exchange (ETDEWEB)

    Huff, Johnathon; McLean, Michael B.; Jenkins, Mark W.; Rutherford, Brian Milne

    2013-05-01

    In microcircuit fabrication, the diameter and length of a bond wire have been shown to both affect the current versus fusing time ratio of a bond wire as well as the gap length of the fused wire. This study investigated the impact of current level on the time-to-open and gap length of 1 mil by 60 mil gold bond wires. During the experiments, constant current was provided for a control set of bond wires for 250ms, 410ms and until the wire fused; non-destructively pull-tested wires for 250ms; and notched wires. The key findings were that as the current increases, the gap length increases and 73% of the bond wires will fuse at 1.8A, and 100% of the wires fuse at 1.9A within 60ms. Due to the limited scope of experiments and limited data analyzed, further investigation is encouraged to confirm these observations.

  20. Construction and test of high precision drift-tube (sMDT) chambers for the ATLAS muon spectrometer

    CERN Document Server

    Nowak, Sebastian; Kroha, Hubert; Schwegler, Philipp; Sforza, Federico

    2014-01-01

    For the upgrade of the ATLAS muon spectrometer in March 2014 new muon tracking chambers (sMDT) with drift-tubes of 15 mm diameter, half of the value of the standard ATLAS Monitored Drift-Tubes (MDT) chambers, and 10~$\\mu$m positioning accuracy of the sense wires have been constructed. The new chambers are designed to be fully compatible with the present ATLAS services but, with respect to the previously installed ATLAS MDT chambers, they are assembled in a more compact geometry and they deploy two additional tube layers that provide redundant rack information. The chambers are composed of 8 layers of in total 624 aluminium drift-tubes. The assembly of a chamber is completed within a week. A semi-automatized production line is used for the assembly of the drift-tubes prior to the chamber assembly. The production procedures and the quality control tests of the single components and of the complete chambers will be discussed. The wire position in the completed chambers have been measured by using a coordinate me...

  1. Mush Column Magma Chambers

    Science.gov (United States)

    Marsh, B. D.

    2002-12-01

    Magma chambers are a necessary concept in understanding the chemical and physical evolution of magma. The concept may well be similar to a transfer function in circuit or time series analysis. It does what needs to be done to transform source magma into eruptible magma. In gravity and geodetic interpretations the causative body is (usually of necessity) geometrically simple and of limited vertical extent; it is clearly difficult to `see' through the uppermost manifestation of the concentrated magma. The presence of plutons in the upper crust has reinforced the view that magma chambers are large pots of magma, but as in the physical representation of a transfer function, actual magma chambers are clearly distinct from virtual magma chambers. Two key features to understanding magmatic systems are that they are vertically integrated over large distances (e.g., 30-100 km), and that all local magmatic processes are controlled by solidification fronts. Heat transfer considerations show that any viable volcanic system must be supported by a vertically extensive plumbing system. Field and geophysical studies point to a common theme of an interconnected stack of sill-like structures extending to great depth. This is a magmatic Mush Column. The large-scale (10s of km) structure resembles the vertical structure inferred at large volcanic centers like Hawaii (e.g., Ryan et al.), and the fine scale (10s to 100s of m) structure is exemplified by ophiolites and deeply eroded sill complexes like the Ferrar dolerites of the McMurdo Dry Valleys, Antarctica. The local length scales of the sill reservoirs and interconnecting conduits produce a rich spectrum of crystallization environments with distinct solidification time scales. Extensive horizontal and vertical mushy walls provide conditions conducive to specific processes of differentiation from solidification front instability to sidewall porous flow and wall rock slumping. The size, strength, and time series of eruptive behavior

  2. Fluid Dynamics of Bottle Filling

    Science.gov (United States)

    McGough, Patrick; Gao, Haijing; Appathurai, Santosh; Basaran, Osman

    2011-11-01

    Filling of bottles is a widely practiced operation in a large number of industries. Well known examples include filling of ``large'' bottles with shampoos and cleaners in the household products and beauty care industries and filling of ``small'' bottles in the pharmaceutical industry. Some bottle filling operations have recently drawn much attention from the fluid mechanics community because of the occurrence of a multitude of complex flow regimes, transitions, and instabilities such as mounding and coiling that occur as a bottle is filled with a fluid. In this talk, we present a primarily computational study of the fluid dynamical challenges that can arise during the rapid filling of bottles. Given the diversity of fluids used in filling applications, we consider four representative classes of fluids that exhibit Newtonian, shear-thinning, viscoelastic, and yield-stress rheologies. The equations governing the dynamics of bottle filling are solved either in their full 3D but axisymmetric form or using the slender-jet approximation.

  3. Hydrogen Filling Station

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, Robert F; Sabacky, Bruce; Anderson II, Everett B; Haberman, David; Al-Hassin, Mowafak; He, Xiaoming; Morriseau, Brian

    2010-02-24

    future. Project partners also conducted a workshop on hydrogen safety and permitting. This provided an opportunity for the various permitting agencies and end users to gather to share experiences and knowledge. As a result of this workshop, the permitting process for the hydrogen filling station on the Las Vegas Valley Water District’s land was done more efficiently and those who would be responsible for the operation were better educated on the safety and reliability of hydrogen production and storage. The lessons learned in permitting the filling station and conducting this workshop provided a basis for future hydrogen projects in the region. Continuing efforts to increase the working pressure of electrolysis and efficiency have been pursued. Research was also performed on improving the cost, efficiency and durability of Proton Exchange Membrane (PEM) hydrogen technology. Research elements focused upon PEM membranes, electrodes/catalysts, membrane-electrode assemblies, seals, bipolar plates, utilization of renewable power, reliability issues, scale, and advanced conversion topics. Additionally, direct solar-to-hydrogen conversion research to demonstrate stable and efficient photoelectrochemistry (PEC) hydrogen production systems based on a number of optional concepts was performed. Candidate PEC concepts included technical obstacles such as inefficient photocatalysis, inadequate photocurrent due to non-optimal material band gap energies, rapid electron-hole recombination, reduced hole mobility and diminished operational lifetimes of surface materials exposed to electrolytes. Project Objective 1: Design, build, operate hydrogen filling station Project Objective 2: Perform research and development for utilizing solar technologies on the hydrogen filling station and convert two utility vehicles for use by the station operators Project Objective 3: Increase capacity of hydrogen filling station; add additional vehicle; conduct safety workshop; develop a roadmap for

  4. The ALICE time projection chamber

    CERN Multimedia

    Maximilien Brice

    2005-01-01

    This time projection chamber is part of the ALICE detector on the new LHC accelerator at CERN. Particles produced in collisions at the core of the detector will follow paths outward through the various sub-detector layers. If these particles carry a charge, they will ionise the gas contained within this chamber producing an electric signal as the ions drift in the chamber's electric field.

  5. The spatial resolution of the time projection chamber at triumf

    Science.gov (United States)

    Hargrove, C. K.; Mes, H.; Bennett, A.; Bryman, D. A.; Hasinoff, M.; Macdonald, J. A.; Poutissou, J. M.; Numao, T.; Spuller, J.; Azuelos, G.; Poutissou, R.; Blecher, M.; Gotow, K.; Carter, A. L.

    1984-02-01

    The spatial resolution of the time projection chamber at TRIUMF has been investigated. The best resolution, σ ⋍ 200 μ m, occurs at the minimum drift length and for an optimum track to anode crossing angle determined by the magnetic field. The resolution worsens for tracks crossing at larger or smaller angles and for longer drift lengths. The observed resolution is quantitatively reproduced by considering the diffusion of the drifting electrons, the track to anode crossing angle, E × B effects near the anode wire and the discrete nature of the ionization process.

  6. Spatial resolutions of the time projection chamber at TRIUMF

    Energy Technology Data Exchange (ETDEWEB)

    Hargrove, C.K.; Mes, H.; Bennett, A.; Bryman, D.A.; Hasinoff, M.; Macdonald, J.A.; Poutissou, J.M.; Numao, T.; Spuller, J.; Azuelos, G.

    1984-02-01

    The spatial resolution of the time projection chamber at TRIUMF has been investigated. The best resolution, sigmaapprox.=200 ..mu..m, occurs at the minimum drift length and for an optimum track to anode crossing angle determined by the magnetic field. The resolution worsens for tracks crossing at larger or smaller angles and for longer drift lengths. The observed resolution is quantitatively reproduced by considering the diffusion of the drifting electrons, the track to anode crossing angle, ExB effects near the anode wire and the discrete nature of the ionization process.

  7. Portable electron beam weld chamber

    Science.gov (United States)

    Lewis, J. R.; Dimino, J. M.

    1972-01-01

    Development and characteristics of portable vacuum chamber for skate type electron beam welding are discussed. Construction and operational details of equipment are presented. Illustrations of equipment are provided.

  8. Construction and Test of New Precision Drift-Tube Chambers for the ATLAS Muon Spectrometer

    CERN Document Server

    INSPIRE-00218480

    2017-02-11

    ATLAS muon detector upgrades aim for increased acceptance for muon triggering and precision tracking and for improved rate capability of the muon chambers in the high-background regions of the detector with increasing LHC luminosity. The small-diameter Muon Drift Tube (sMDT) chambers have been developed for these purposes. With half of the drift-tube diameter of the MDT chambers and otherwise unchanged operating parameters, sMDT chambers share the advantages of the MDTs, but have an order of magnitude higher rate capability and can be installed in detector regions where MDT chambers do not fit in. The chamber assembly methods have been optimized for mass production, minimizing construction time and personnel. Sense wire positioning accuracies of 5 ?micons have been achieved in serial production for large-size chambers comprising several hundred drift tubes. The construction of new sMDT chambers for installation in the 2016/17 winter shutdown of the LHC and the design of sMDT chambers in combination with new R...

  9. Correlated atomic wires on substrates. II. Application to Hubbard wires

    Science.gov (United States)

    Abdelwahab, Anas; Jeckelmann, Eric; Hohenadler, Martin

    2017-07-01

    In the first part of our theoretical study of correlated atomic wires on substrates, we introduced lattice models for a one-dimensional quantum wire on a three-dimensional substrate and their approximation by quasi-one-dimensional effective ladder models [Abdelwahab et al., preceding paper, Phys. Rev. B 96, 035445 (2017), 10.1103/PhysRevB.96.035445]. In this second part, we apply this approach to the case of a correlated wire with a Hubbard-type electron-electron repulsion deposited on an insulating substrate. The ground-state and spectral properties are investigated numerically using the density-matrix renormalization group method and quantum Monte Carlo simulations. As a function of the model parameters, we observe various phases with quasi-one-dimensional low-energy excitations localized in the wire, namely, paramagnetic Mott insulators, Luttinger liquids, and spin-1 /2 Heisenberg chains. The validity of the effective ladder models is assessed for selected parameters by studying the dependence of results on the number of legs and comparing to the full three-dimensional model. We find that narrow ladder models accurately reproduce the quasi-one-dimensional excitations of the full three-dimensional model but predict only qualitatively whether excitations are localized around the wire or delocalized in the three-dimensional substrate.

  10. Effective point of measurement for parallel plate and cylindrical ion chambers in megavoltage electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Voigts-Rhetz, Philip von; Czarnecki, Damian [University of Applied Sciences Giessen, Technische Hochschule Mittelhessen (Germany). Inst. fuer Mediznische Physik und Strahlenschutz (IMPS); Zink, Klemens [University of Applied Sciences Giessen, Technische Hochschule Mittelhessen (Germany). Inst. fuer Mediznische Physik und Strahlenschutz (IMPS); Marburg Univ. Hospital (Germany). Dept. of Radiotherapy and Radiation Oncology

    2014-10-01

    The presence of an air filled ionization chamber in a surrounding medium introduces several fluence perturbations in high energy photon and electron beams which have to be accounted for. One of these perturbations, the displacement effect, may be corrected in two different ways: by a correction factor p{sub dis} or by the application of the concept of the effective point of measurement (EPOM). The latter means, that the volume averaged ionization within the chamber is not reported to the chambers reference point but to a point within the air filled cavity. Within this study the EPOM was determined for four different parallel plate and two cylindrical chambers in megavoltage electron beams using Monte Carlo simulations. The positioning of the chambers with this EPOM at the depth of measurement results in a largely depth independent residual perturbation correction, which is determined within this study for the first time. For the parallel plate chambers the EPOM is independent of the energy of the primary electrons. Whereas for the Advanced Markus chamber the position of the EPOM coincides with the chambers reference point, it is shifted for the other parallel plate chambers several tenths of millimeters downstream the beam direction into the air filled cavity. For the cylindrical chambers there is an increasing shift of the EPOM with increasing electron energy. This shift is in upstream direction, i.e. away from the chambers reference point toward the focus. For the highest electron energy the position of the calculated EPOM is in fairly good agreement with the recommendation given in common dosimetry protocols, for the smallest energy, the calculated EPOM positions deviate about 30% from this recommendation. (orig.)

  11. A new gaseous detector for tracking: The blade chamber

    Energy Technology Data Exchange (ETDEWEB)

    Ambrosi, G.; Battiston, R.; Levi, G. (Perugia Univ. (Italy) Istituto Nazionale di Fisica Nucleare, Perugia (Italy)); Barillari, T.; Susinno, G. (Calabria Univ., Cosenza (Italy) Istituto Nazionale di Fisica Nucleare, Cosenza (Italy)); Bergsma, F.; Contin, A.; Labbe, J.C.; Laurenti, G.; Mattern, D.; Simonet, G.; Williams, M.C.S.; Zichichi, A. (European Organization for Nuclear Research, Geneva (Switzerland)); Boscherini, D.; Bruni, G.; De Pasquale, S.; Giusti, P.; Maccarrone, G.; Nania, R.; O' Shea, V. (Bologna Univ. (Italy) Istituto Nazionale di Fisica Nucleare, Bologna (Italy)); Castro, H.; Galvez, J.; Rivera, F.; Schioppa, M.; Sharma, A. (World Lab., Geneva (Switzerland)); LAA-LAD Group

    1990-04-15

    As part of the LAA project at CERN a prototype of a streamer-chamber in which a blade, instead of a wire, is used as the amplification electrode has been built. A big advantage is that the blade can be bent to follow a curve so that a chamber can be built with cells ideally matched to the geometry of the experiment. Moreover, a blade is very rugged, it can withstand severe mechanical shocks and it is also resistant to damage by sparks. The drift time has been measured and a spatial resolution of 250{mu}m has been achieved. Left-right ambiguity can be solved by measuring the charge asymmetry on the walls. The coordinate along the blade is read by external pickup strips. (orig.).

  12. Endcap Muon Chamber Calibration and Monitoring Procedures in CMS

    CERN Document Server

    Vickey Boeriu, Oana

    2009-01-01

    The cathode strip chamber (CSC) system is one of the three types of muon detectors used in the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC). It consists of 468 chambers, with a total of $\\sim$218k strips and $\\sim$183k wires, placed onto two endcaps. Calibration tests which monitor the system stability, measure configuration constants that will be downloaded to electronics and calculate the calibration constants needed in the offline reconstruction - like crosstalk, gains, noise and connectivity - are performed regularly. The full chain of acquiring, analyzing and applying the calibration constants was successfully tested recently for the first time on the CSC system, using cosmic-ray data recorded during the Magnet Test and Cosmic Challenge (MTCC).

  13. Preparing for faster filling

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Following the programmed technical stop last week, operators focussed on preparing the machine for faster filling, which includes multibunch injection and a faster pre-cycle phase.   The LHC1 screen shot during the first multibunch injection operation. The LHC operational schedule incorporates a technical stop for preventive maintenance roughly every six weeks of stable operation, during which several interventions on the various machines are carried out. Last week these included the replacement of a faulty magnet in the SPS pre-accelerator, which required the subsequent re-setting of the system of particle extraction and transfer to the LHC. At the end of last week, all the machines were handed back for operation and work could start on accommodating all the changes made into the complex systems in order for normal operation to be resumed. These ‘recovery’ operations continued through the weekend and into this week. At the beginning of this week, operators succeeded in pro...

  14. Monitoring Liquid Argon Time Projection Chambers With A Raspberry Pi Camera

    Science.gov (United States)

    Patteson, Crystal

    2016-03-01

    The MicroBooNE detector is the first of three liquid argon (LAr) time projection chambers (TPCs) that are central to the short-baseline neutrino program at Fermilab. These chambers consist of thousands of stainless steel or beryllium-copper sense wires that detect ionization electrons produced when neutrinos interact with liquid argon nuclei inside the detector. The wires are several hundred microns in diameter to several meters in length. The construction of such LAr TPCs often takes place in an assembly hall, which is different from the detector hall where the experiment will operate, as was the case with MicroBooNE. Since in situ access to the chamber and its wires in the beamline enclosure can be limited, we investigate the possibility of using a Raspberry Pi single-board computer connected to a low-cost camera installed inside the cryostat as a cost-efficient way to verify the integrity of the wires after transport. We also highlight other benefits of this monitoring device implemented in MicroBooNE, including detector hall surveillance and verification of the status of LED indicators on detector electronics. The author would like to thank Dr. Matthew Toups for his encouragement and guidance on this research project.

  15. Bulk-Fill Resin Composites

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Havndrup-Pedersen, Cæcilie; Honoré, Daniel

    2015-01-01

    the restorative procedure. The aim of this study, therefore, was to compare the depth of cure, polymerization contraction, and gap formation in bulk-fill resin composites with those of a conventional resin composite. To achieve this, the depth of cure was assessed in accordance with the International Organization...... for Standardization 4049 standard, and the polymerization contraction was determined using the bonded-disc method. The gap formation was measured at the dentin margin of Class II cavities. Five bulk-fill resin composites were investigated: two high-viscosity (Tetric EvoCeram Bulk Fill, SonicFill) and three low......-viscosity (x-tra base, Venus Bulk Fill, SDR) materials. Compared with the conventional resin composite, the high-viscosity bulk-fill materials exhibited only a small increase (but significant for Tetric EvoCeram Bulk Fill) in depth of cure and polymerization contraction, whereas the low-viscosity bulk...

  16. Plasma arc torch with coaxial wire feed

    Science.gov (United States)

    Hooper, Frederick M

    2002-01-01

    A plasma arc welding apparatus having a coaxial wire feed. The apparatus includes a plasma arc welding torch, a wire guide disposed coaxially inside of the plasma arc welding torch, and a hollow non-consumable electrode. The coaxial wire guide feeds non-electrified filler wire through the tip of the hollow non-consumable electrode during plasma arc welding. Non-electrified filler wires as small as 0.010 inches can be used. This invention allows precision control of the positioning and feeding of the filler wire during plasma arc welding. Since the non-electrified filler wire is fed coaxially through the center of the plasma arc torch's electrode and nozzle, the wire is automatically aimed at the optimum point in the weld zone. Therefore, there is no need for additional equipment to position and feed the filler wire from the side before or during welding.

  17. Ocular dangers of fencing wire.

    Science.gov (United States)

    McAllum, P; Barnes, R; Dickson, J

    2001-07-27

    To invesitgate the incidence and severity of penetrating eye injuries caused by fencing wire in the Waikato region. We reviewed the case notes for all penetrating eye injuries treated at Waikato Hospital during the past six years. Parameters recorded were patient age and sex, mechanism of injury, initial visual acuity, characteristics of injury, surgery performed and final visual outcome. The incidence of penetrating eye injuries in the Waikato region was 3.8 per 100,000 per year, based on an estimated catchment population of 350,000. We found fencing wire to be the third most common cause of penetrating eye injury, accounting for 8.8% of injuries, behind motor vehicle accidents and hammering which accounted for 26.3% and 20.0% of injuries, respectively. The fencing wire injuries involved men exclusively, with an average age of 41.7 years. Fencing wire injuries had worse presenting visual acuity than other injuries, involved the posterior segment of the eye more frequently and were more likely to develop bacterial endophthalmitis. They also underwent more surgical procedures and were more commonly associated with a poor visual outcome. Fencing wire is an important cause of visual loss in the Waikato region. We hope to raise awareness of its potential ocular dangers and to promote the use of appropriate eye protection.

  18. Accumulation chamber as monitoring system for biogas emission from solid waste land filling: preliminary experimental results and elaborations on italian provincial scale; Camera di accumulo portatile per il monitoraggio di emissioni di biogas da discarica: risultati sperimentali ed elaborazioni preliminari a scala provinciale

    Energy Technology Data Exchange (ETDEWEB)

    Capaccioni, B.; Pirillo, L. [Urbino Univ. Carlo Bo, Urbino (Italy). Istituto di Vulcanologia e Geochimica; Didero, M. [Urbino Univ. Carlo Bo, Urbino (Italy). Istituto di Geologia Applicata; Lucci, P.; Scartoni, P. [Area Territorio e Ambiente Provincia di Arezzo, Arezzo (Italy). Servizio Ecologia; Tatano, F. [Urbino Univ. Carlo Bo, Urbino (Italy). Facolta' di Scienze Ambientali

    2005-04-01

    On site CO{sub 2} flux measurements with the static, not stationary accumulation chamber system were experimentally carried out in no. 5 MSW (active and closed) landfills located in the territory of the Province of Arezzo (Tuscany Region). Corresponding CO{sub 2} emission flux maps were contoured and analysed, revealing a possible, preliminary geometrical classification of biogas dispersion: diffuse dispersion (internal), lateral/angular dispersion (internal), and external dispersion. Also specific (volume and surface) biogas emission parameters were calculated and graphically compared for the monitored inactive facilities. [Italian] La metodologia strumentale portatile della camera di accumulo, statica non stazionaria, e' stata adoperata sperimentalmente per la misura on site di flussi puntuali di emissione di CO{sub 2} in cinque discariche (attive e non) per RSU ed assimilabili localizzate nel territorio della Provincia di Arezzo. Si sono elaborate, ed analizzate criticamente, le corrispondenti mappe areali di flusso, che hanno consentito di delineare una possibile classificazione geometrica - ancorche' preliminare - di dispersioni di biogas generabili da discarica: diffuse interne, laterali/angolari interne, esterne. Con riferimento alle discariche inattive d'indagine, si sono altresi' determinati, e rappresentati graficamente, i valori di possibili parametri specifici (volumetrico, superficiale) di dispersione di biogas.

  19. The Big European Bubble Chamber

    CERN Multimedia

    1977-01-01

    The 3.70 metre Big European Bubble Chamber (BEBC), dismantled on 9 August 1984. During operation it was one of the biggest detectors in the world, producing direct visual recordings of particle tracks. 6.3 million photos of interactions were taken with the chamber in the course of its existence.

  20. Characterization of a Reverberation Chamber

    Science.gov (United States)

    2015-10-01

    applied to the same device inside another facility, such as a gigahertz transverse electromagnetic (GTEM) or fully- anechoic chamber for further...and found to be consistent; reflections measured from inside the chamber yielded heavy spiking. The antenna used to transmit power into the room was

  1. National Ignition Facility Target Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Wavrik, R W; Cox, J R; Fleming, P J

    2000-10-05

    On June 11, 1999 the Department of Energy dedicated the single largest piece of the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) in Livermore, California. The ten (10) meter diameter aluminum target high vacuum chamber will serve as the working end of the largest laser in the world. The output of 192 laser beams will converge at the precise center of the chamber. The laser beams will enter the chamber in two by two arrays to illuminate 10 millimeter long gold cylinders called hohlraums enclosing 2 millimeter capsule containing deuterium, tritium and isotopes of hydrogen. The two isotopes will fuse, thereby creating temperatures and pressures resembling those found only inside stars and in detonated nuclear weapons, but on a minute scale. The NIF Project will serve as an essential facility to insure safety and reliability of our nation's nuclear arsenal as well as demonstrating inertial fusion's contribution to creating electrical power. The paper will discuss the requirements that had to be addressed during the design, fabrication and testing of the target chamber. A team from Sandia National Laboratories (SNL) and LLNL with input from industry performed the configuration and basic design of the target chamber. The method of fabrication and construction of the aluminum target chamber was devised by Pitt-Des Moines, Inc. (PDM). PDM also participated in the design of the chamber in areas such as the Target Chamber Realignment and Adjustment System, which would allow realignment of the sphere laser beams in the event of earth settlement or movement from a seismic event. During the fabrication of the target chamber the sphericity tolerances had to be addressed for the individual plates. Procedures were developed for forming, edge preparation and welding of individual plates. Construction plans were developed to allow the field construction of the target chamber to occur parallel to other NIF construction activities. This

  2. Trapping of ultracold polar molecules with a thin-wire electrostatic trap.

    Science.gov (United States)

    Kleinert, J; Haimberger, C; Zabawa, P J; Bigelow, N P

    2007-10-05

    We describe the realization of a dc electric-field trap for ultracold polar molecules, the thin-wire electrostatic trap (TWIST). The thin wires that form the electrodes of the TWIST allow us to superimpose the trap onto a magneto-optical trap (MOT). In our experiment, ultracold polar NaCs molecules in their electronic ground state are created in the MOT via photoassociation, achieving a continuous accumulation in the TWIST of molecules in low-field seeking states. Initial measurements show that the TWIST trap lifetime is limited only by the background pressure in the chamber.

  3. Weyl fermions in cylindrical wires

    Science.gov (United States)

    Erementchouk, Mikhail; Mazumder, Pinaki

    2018-01-01

    The key feature of Weyl semimetals (WSMs) is the presence of topologically protected Dirac cones in a three-dimensional material. We consider the effect of restricting geometry on the spectrum of excitations in WSMs using as a model a cylindrical WSM wire. For the full manifold of hard boundary conditions, we derive the general form of the dispersion equation relating the energy of the excitations and their momentum along the wire. We show that only the special class of boundary conditions, corresponding to decoupled helicities or, equivalently, to pinned directions of the electron spin on the surface, support massless excitations. For a general boundary condition, these excitations acquire mass inversely proportional to the radius of the wire. This demonstrates that boundary phenomena may play a crucial role in formation of excitations in WSM based structures.

  4. BEBC, the Big European Bubble Chamber

    CERN Multimedia

    CERN PhotoLab

    1971-01-01

    The vessel of the Big European Bubble Chamber, BEBC, was installed at the beginning of the 1970s. The large stainless-steel vessel, measuring 3.7 metres in diameter and 4 metres in height, was filled with 35 cubic metres of liquid (hydrogen, deuterium or a neon-hydrogen mixture), whose sensitivity was regulated by means of a huge piston weighing 2 tonnes. During each expansion, the trajectories of the charged particles were marked by a trail of bubbles, where liquid reached boiling point as they passed through it. The first images were recorded in 1973 when BEBC, equipped with the largest superconducting magnet in service at the time, first received beam from the PS. In 1977, the bubble chamber was exposed to neutrino and hadron beams at higher energies of up to 450 GeV after the SPS came into operation. By the end of its active life in 1984, BEBC had delivered a total of 6.3 million photographs to 22 experiments devoted to neutrino or hadron physics. Around 600 scientists from some fifty laboratories through...

  5. Upgrades of the ATLAS Muon Spectrometer with sMDT Chambers

    CERN Document Server

    Ferretti, C

    2016-01-01

    With half the drift-tube diameter of the Monitored Drift Tube (MDT) chambers of the ATLAS muon spectrometer and otherwise unchanged operating parameters, small-diameter Muon Drift Tube (sMDT) chambers provide an order of magnitude higher rate capability and can be installed in detector regions where MDT chambers do not fit. The chamber assembly time has been reduced by a factor of seven to one working day and the sense wire positioning accuracy improved by a factor of two to better than ten microns. Two sMDT chambers have been installed in ATLAS in 2014 to improve the momentum resolution in the barrel part of the spectrometer. The construction of an additional twelve chambers covering the feet regions of the ATLAS detector has started. It will be followed by the replacement of the MDT chambers at the ends of the barrel inner layer by sMDTs improving the Performance at the high expected background rates and providing space for additional RPC trigger chambers.

  6. Upgrades Of The ATLAS Muon Spectrometer With sMDT Chambers

    CERN Document Server

    Ferretti, Claudio; The ATLAS collaboration

    2015-01-01

    The Monitored Drift Tube (MDT) chambers of the ATLAS muon spectrometer demonstrated that they provide very precise and robust tracking over large areas. Goals of ATLAS muon detector upgrades are to increase the acceptance for precision muon momentum measurement and triggering and to improve the rate capability of the muon chambers in the high-background regions when the LHC luminosity increases. Small-diameter Muon Drift Tube (sMDT) chambers have been developed for these purposes. With half the drift-tube diameter of the MDT chambers and otherwise unchanged operating parameters, sMDT chambers share the advantages with the MDTs, but have more than ten times higher rate capability and can be installed in detector regions where MDT chambers do not fit in. The chamber assembly methods have been optimized for mass production, reducing cost and construction time considerably and improving the sense wire positioning accuracy to better than ten microns. Two sMDT chambers have been installed in 2014 to improve the mom...

  7. Upgrades of the ATLAS Muon Spectrometer with sMDT Chambers

    CERN Document Server

    Ferretti, Claudio; The ATLAS collaboration

    2015-01-01

    With half the drift-tube diameter of the Monitored Drift Tube (MDT) chambers of the ATLAS muon spectrometer and otherwise unchanged operating parameters, small-diameter Muon Drift Tube (sMDT) chambers provide an order of magnitude higher rate capability and can be installed in detector regions where MDT chambers do not fit. The chamber assembly time has been reduced by a factor of seven to one working day and the sense wire positioning accuracy improved by a factor of two to better than ten microns. Two sMDT chambers have been installed in ATLAS in 2014 to improve the momentum resolution in the barrel part of the spectrometer. The construction of additional twelve chambers covering the feet regions of the ATLAS detector has started. It will be followed by the replacement of the MDT chambers at the ends of the barrel inner layer by sMDTs improving the Performance at the high expected background rates and providing space for additional RPC trigger chambers.

  8. New Processes for Freeze-Drying in Dual-Chamber Systems.

    Science.gov (United States)

    Werk, T; Ludwig, I S; Luemkemann, J; Huwyler, J; Mahler, H-C; Haeuser, C R; Hafner, M

    2016-01-01

    Dual-chamber systems can offer self-administration and home care use for lyophilized biologics. Only a few products have been launched in dual-chamber systems so far-presumably due to dual-chamber systems' complex and costly drug product manufacturing process. Within this paper, two improved processes (both based on tray filling technology) for freeze-drying pharmaceuticals in dual-chamber systems are described. Challenges with regards to heat transfer were tackled by (1) performing the freeze-drying step in a needle-down orientation in combination with an aluminum block, or (2) freeze-drying the drug product "externally" in a metal cartridge with subsequent filling of the lyophilized cake into the dual-chamber system. Metal-mediated heat transfer was shown to be efficient in both cases and batch (unit-to-unit) homogeneity with regards to sublimation rate was increased. It was difficult to influence ice crystal size using different methods when in use with an aluminum block due to its heat capacity. Using such a metal carrier implies a large heat capacity leading to relatively small ice crystals. Compared to the established process, drying times were reduced by half using the new processes. The drying time was, however, longer for syringes compared to vials due to the syringe design (long and slim). The differences in drying times were less pronounced for aggressive drying cycles. The proposed processes may help to considerably decrease investment costs into dual-chamber system fill-finish equipment. Dual-chamber syringes offer self-administration and home care use for freeze-dried pharmaceuticals. Only a few products have been launched in dual-chamber syringes so far-presumably due to their complex and costly drug product manufacturing process. In this paper two improved processes for freeze-drying pharmaceuticals in dual-chamber syringes are described. The major challenge of freeze-drying is to transfer heat through a vacuum. The proposed processes cope with this

  9. Fracture strength of different soldered and welded orthodontic joining configurations with and without filling material.

    Science.gov (United States)

    Bock, Jens Johannes; Bailly, Jacqueline; Gernhardt, Christian Ralf; Fuhrmann, Robert Andreas Werner

    2008-01-01

    The aim of this study was to compare the mechanical strength of different joints made by conventional brazing, TIG and laser welding with and without filling material. Five standardized joining configurations of orthodontic wire in spring hard quality were used: round, cross, 3 mm length, 9 mm length and 7 mm to orthodontic band. The joints were made by five different methods: brazing, tungsten inert gas (TIG) and laser welding with and without filling material. For the original orthodontic wire and for each kind of joint configuration or connecting method 10 specimens were carefully produced, totalizing 240. The fracture strengths were measured with a universal testing machine (Zwick 005). Data were analyzed by ANOVA (p=0.05) and Bonferroni post hoc test (p=0.05). In all cases, brazing joints were ruptured on a low level of fracture strength (186-407 N). Significant differences between brazing and TIG or laser welding (pwelding with filling material and 3 mm joint length (998 N). Using filling materials, there was a clear tendency to higher mean values of fracture strength in TIG and laser welding. However, statistically significant differences were found only in the 9-mm long joints (pwelded joints was positively influenced by the additional use of filling material. TIG welding was comparable to laser welding except for the impossibility of joining orthodontic wire with orthodontic band.

  10. Proportional chambers of the barrel hadron calorimeter of the L3 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Arefiev, A.; Azemoon, T.; Bachmann, U.; Ball, R.C.; Boehlen, W.E.; Capell, M.; Chen, C.; Chen, H.S.; Chumakov, M.; Galaktionov, Yu.

    1989-02-01

    The design and the mass production of the proportional wire chambers for the barrel part of the uranium-gas sampling hadron calorimeter of the L3 detector at the CERN Large Electron-Positron storage ring (LEP) are described. The chambers meet the specific requirements arising from the limited space available to the calorimeter, the radioactivity of uranium, and the physics criteria of good energy and position resolution for incident hadrons. The mass production techniques employed ensured that all of the 371664 chamber cells have uniform response (with 5% accuracy) to ionizing particles. Over 8000 chambers of the same design, in 53 different sizes, were manufactured and tested at the ITEP (Moscow), at the University of Michigan (Ann Arbor) and at the IHEP (Beijing).

  11. Subchannel Analysis of Wire Wrapped SCWR Assembly

    National Research Council Canada - National Science Library

    Shan, Jianqiang; Wang, Henan; Liu, Wei; Song, Linxing; Chen, Xuanxiang; Jiang, Yang

    2014-01-01

    .... The HPLWR wire wrapped assembly was analyzed. The results show that: (1) the assembly with wire wrap can obtain a more uniform coolant temperature profile than the grid spaced assembly, which will result in a lower peak cladding temperature; (2...

  12. Intermittent Surface Water Connectivity: Fill and Spill vs. Fill ...

    Science.gov (United States)

    Intermittent surface connectivity can influence aquatic systems, since chemical and biotic movements are often associated with water flow. Although often referred to as fill and spill, wetlands also fill and merge. We examined the effects of these connection types on water levels, ion concentrations, and biotic communities of eight prairie pothole wetlands between 1979 and 2015. Fill and spill caused pulsed surface water connections that were limited to periods following spring snow melt. In contrast, two wetlands connected through fill and merge experienced a nearly continuous, 20-year surface water connection and had completely coincident water levels. Fill and spill led to minimal convergence in dissolved ions and macroinvertebrate composition, while these constituents converged under fill and merge. The primary factor determining difference in responses was duration of the surface water connection between wetland pairs. Our findings suggest that investigations into the effects of intermittent surface water connections should not consider these connections generically, but need to address the specific types of connections. In particular, fill and spill promotes external water exports while fill and merge favors internal storage. The behaviors of such intermittent connections will likely be accentuated under a future with more frequent and severe climate extremes. Under the Safe and Sustainable Water Resources National Program, work is being done to qu

  13. First test results of TRD prototypes for CBM with alternating wires

    Energy Technology Data Exchange (ETDEWEB)

    Dillenseger, Pascal; Glaessel, Susanne; Roether, Florian [Institut fuer Kernphysik Frankfurt (Germany)

    2014-07-01

    The CBM (Compressed Baryonic Matter) at FAIR will be dedicated to the exploration of the QCD phase diagram in the region of high net-baryon densities using heavy-ion collisions. The CBM Transition-Radiation Detector (TRD) has to deliver a good tracking and electron identification performance in an unprecedented high particle-density environment. A thin Multi-Wire Proportional Chamber (MWPC) without drift region delivers the required fast detector response for the expected high signal rates. One key challenge is to achieve stability of the gas gain. To reduce its sensitivity to cathode deformations, an alternating wire structure, as proposed for the ALICE VHMPID (Nucl. Instrum. Meth. A698 (2013) 11-18), is exploited. Field wires are introduced between the sense wires to improve the field line distribution and its stability. An asymmetric structure, i.e. one cathode is closer to the wire plane than the other, provides fast removal of positive ions. Prototypes with standard and alternating field wires, symmetric and asymmetric structure, and different pad planes have been build and tested with an {sup 55}Fe source to measure position and pressure dependent gain variations.

  14. Transfer Chamber for DBD Surface Treatment and Analysis

    Science.gov (United States)

    Faust, Jessica; Gershman, Sophia; Daniels, Ryan

    2012-10-01

    Materials that are hydrophobic, smooth, and have low surface tension lead to poor adhesion for printing and coating. Surface modification using atmospheric pressure dielectric barrier discharge (DBD) improves adhesion by activating the surface, increasing its roughness and functionalizing. We have constructed and tested a DBD discharge system that uses a 15kV, 800-1350Hz pulsed dc source and a mixture of gasses at 300-600Torr. Treated surfaces are studied using X-ray photoelectron spectroscopy, Auger electron spectroscopy, and other methods that require high vacuum environment. We designed a portable transfer chamber to move the sample from the atmospheric pressure treatment chamber to a high vacuum surface analysis chamber with minimal interaction with the environment. The transfer chamber was designed to meet the specific requirements of each system; a bellows drive and sample holder to manually move the sample into the transfer chamber; the ability to fill with pure nitrogen gas to prevent contamination of the sample surface; constructed to withstand a range of pressures from 300 to 10-8Torr; the ability to connect compatibly with each system. Proper surface characterization of the sample is crucial to designing an effective treatment system.

  15. Transparency in nanophotonic quantum wires

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Mahi R [Department of Physics and Astronomy, University of Western Ontario, London N6A 3K7 (Canada)

    2009-03-28

    We have studied the quantum optics of a photonic quantum nanowire doped with an ensemble of three-level nanoparticles. The wire is made from two photonic crystals A and B. Crystal A is embedded within crystal B and acts as a photonic nanowire. It is considered that the conduction band of crystal A lies below that of crystal B. As a result, photons are confined in crystal A and are reflected from crystal B. The bound states of the confined photons are calculated using the transfer matrix method. It is found that the number of bound states in the wire depends on the size of the wire and the energy difference between the conduction band extrema of crystals A and B. The absorption coefficient of the system has also been calculated using the Schroedinger equation method. It is considered that the nanoparticles interact with the photonic bound states. Numerical simulations show that when one of the resonance energies lies near the bound state, the system becomes transparent. However, when the resonance energy lies away from the bound state the crystal reverts to an absorbing state. Similarly, when the radius of the dielectric spheres is changed the location of the transparency peak is shifted. This means that the present system can be switched between two states by changing the size of the wire and the transition energy. These findings can be used to make new types of optical devices.

  16. Towards Unconventional Applications of Wire Bonding

    OpenAIRE

    Schröder, Stephan

    2018-01-01

    This thesis presents novel heterogeneous integration approaches of wire materials to fabricated and package MEMS devices by exploring unconventional applications of wire bonding technology. Wire bonding, traditionally endemic in the realm of device packaging to establish electrical die-to-package interconnections, is an attractive back-end technology, offering promising features, such as high throughput, flexibility and placement accuracy. Exploiting the advantages of state-of-the-art wire bo...

  17. Novel Wiring Technologies for Aerospace Applications

    Science.gov (United States)

    Gibson, Tracy L.; Parrish, Lewis M.

    2014-01-01

    Because wire failure in aerospace vehicles could be catastrophic, smart wiring capabilities have been critical for NASA. Through the years, researchers at Kennedy Space Center (KSC) have developed technologies, expertise, and research facilities to meet this need. In addition to aerospace applications, NASA has applied its knowledge of smart wiring, including self-healing materials, to serve the aviation industry. This webinar will discuss the development efforts of several wiring technologies at KSC and provide insight into both current and future research objectives.

  18. Electron transport in stretched monoatomic gold wires.

    Science.gov (United States)

    Grigoriev, A; Skorodumova, N V; Simak, S I; Wendin, G; Johansson, B; Ahuja, R

    2006-12-08

    The conductance of monoatomic gold wires containing 3-7 gold atoms has been obtained from ab initio calculations. The transmission is found to vary significantly depending on the wire stretching and the number of incorporated atoms. Such oscillations are determined by the electronic structure of the one-dimensional (1D) part of the wire between the contacts. Our results indicate that the conductivity of 1D wires can be suppressed without breaking the contact.

  19. Detection of a buried wire with two resistively loaded wire antennas

    NARCIS (Netherlands)

    Vossen, S.H.J.A.; Tijhuis, A.G.; Lepelaars, E.S.A.M.; Zwamborn, A.P.M.

    2002-01-01

    The use of two identical straight thin-wire antennas for the detection of a buried wire is analyzed with the aid of numerical calculations. The buried wire is located below an interface between two homogeneous half-spaces. The detection setup, which is formed by a transmitting and a receiving wire,

  20. One century of Kirschner wires and Kirschner wire insertion techniques : A historical review

    NARCIS (Netherlands)

    Franssen, Bas B. G. M.; Schuurman, Arnold H.; Van der Molen, Aebele Mink; Kon, Moshe

    A century ago, in 1909, Martin Kirschner (1879-942) introduced a smooth pin, presently known as the Kirschner wire (K-wire). The K-wire was initiallly used for skeletal traction and is now currently used for many different goals. The development of the K-wire and its insertion devices were mainly

  1. Vaporization chambers and associated methods

    Science.gov (United States)

    Turner, Terry D.; Wilding, Bruce M.; McKellar, Michael G.; Shunn, Lee P.

    2017-02-21

    A vaporization chamber may include at least one conduit and a shell. The at least one conduit may have an inlet at a first end, an outlet at a second end and a flow path therebetween. The shell may surround a portion of each conduit and define a chamber surrounding the portion of each conduit. Additionally, a plurality of discrete apertures may be positioned at longitudinal intervals in a wall of each conduit, each discrete aperture of the plurality of discrete apertures sized and configured to direct a jet of fluid into each conduit from the chamber. A liquid may be vaporized by directing a first fluid comprising a liquid into the inlet at the first end of each conduit, directing jets of a second fluid into each conduit from the chamber through discrete apertures in a wall of each conduit and transferring heat from the second fluid to the first fluid.

  2. The multigap resistive plate chamber

    Energy Technology Data Exchange (ETDEWEB)

    Zeballos, E. Cerron [European Organization for Nuclear Research (CERN), Geneva (Switzerland); World Lab., Lausanne (Switzerland); Crotty, I. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Hatzifotiadou, D. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); World Lab., Lausanne (Switzerland); Valverde, J. Lamas [European Organization for Nuclear Research (CERN), Geneva (Switzerland); World Lab., Lausanne (Switzerland); Univ. Louis Pasteur, Strasbourg (France); Neupane, S. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); World Lab., Lausanne (Switzerland); Williams, M. C. S. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Zichichi, A. [Univ. of Bologna, Bologna (Italy)

    2015-02-03

    The paper describes the multigap resistive plate chamber (RPC). This is a variant of the wide gap RPC. However it has much improved time resolution, while keeping all the other advantages of the wide gap RPC design.

  3. Home and School Technology: Wired versus Wireless.

    Science.gov (United States)

    Van Horn, Royal

    2001-01-01

    Presents results of informal research on smart homes and appliances, structured home wiring, whole-house audio/video distribution, hybrid cable, and wireless networks. Computer network wiring is tricky to install unless all-in-one jacketed cable is used. Wireless phones help installers avoid pre-wiring problems in homes and schools. (MLH)

  4. Electrochemistry of surface wired cytochrome c and ...

    Indian Academy of Sciences (India)

    Pyrazine unit in the mixed self-assembly promotes the electron transfer in the redox reaction of surface wired Cyt-c. Cyt-c wired on the mixed self-assembly has been used for the amperometric sensing of superoxide. The enzymatically generated superoxide has been successfully detected using the Cyt-c wired electrode.

  5. 49 CFR 393.28 - Wiring systems.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Wiring systems. 393.28 Section 393.28 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY... NECESSARY FOR SAFE OPERATION Lamps, Reflective Devices, and Electrical Wiring § 393.28 Wiring systems...

  6. Customised 2G HTS wire for applications

    Science.gov (United States)

    Samoilenkov, S.; Molodyk, A.; Lee, S.; Petrykin, V.; Kalitka, V.; Martynova, I.; Makarevich, A.; Markelov, A.; Moyzykh, M.; Blednov, A.

    2016-02-01

    Reproducibility of superconducting properties and suitability for specific applications by means of customised finish are two important attributes required from commercial 2G HTS wire. This paper reviews the consistent performance of SuperOx production 2G HTS wire and describes two novel customisation options: surround polyimide varnish insulation and composite bulk materials assembled with 2G HTS wires soldered together.

  7. BEBC Big European Bubble Chamber

    CERN Multimedia

    CERN PhotoLab

    1974-01-01

    A view of the dismantling of the magnet of BEBC, the 3.7 m European Bubble Chamber : iron magnetic shielding ; lower and upper parts of the vacuum enclosure of the magnet; turbo-molecular vacuum pumps for the "fish-eye" windows; the two superconducting coils; a handling platform; the two cryostats suspended from the bar of the travelling crane which has a 170 ton carrying capacity. The chamber proper, not dismantled, is inside the shielding.

  8. Anterior chamber depth during hemodialysis

    Directory of Open Access Journals (Sweden)

    Gracitelli CPB

    2013-08-01

    Full Text Available Carolina Pelegrini Barbosa Gracitelli,1 Francisco Rosa Stefanini,1 Fernando Penha,1 Miguel Ângelo Góes,2 Sérgio Antonio Draibe,2 Maria Eugênia Canziani,2 Augusto Paranhos Junior1 1Ophthalmology Department, 2Division of Nephrology, Federal University of São Paulo – UNIFESP, São Paulo, Brazil Background: Exacerbation of chronic glaucoma or acute glaucoma is occasionally observed in patients undergoing hemodialysis (HD because of anterior chamber depth changes during this therapy. Purpose: To evaluate anterior chamber depth and axial length in patients during HD sessions. Methods: A total of 67 eyes of 35 patients were prospectively enrolled. Axial length and anterior chamber depth were measured using ultrasonic biometry, and these measures were evaluated at three different times during HD sessions. Body weight and blood pressure pre- and post-HD were also measured. Results: There was no difference in the axial length between the three measurements (P = 0.241. We observed a significantly decreased anterior chamber depth (P = 0.002 during HD sessions. Conclusion: Our results support the idea that there is a change in anterior chamber depth in HD sessions. Keywords: anterior chamber, hemodialysis, axial length, acute angle-closure glaucoma

  9. Mechanics of filled carbon nanotubes

    KAUST Repository

    Monteiro, A.O.

    2014-04-01

    The benefits of filling carbon nanotubes (CNTs) with assorted molecular and crystalline substances have been investigated for the past two decades. Amongst the study of new structural phases, defects, chemical reactions and varied types of host-guest interactions, there is one fundamental characterisation aspect of these systems that continues to be overlooked: the mechanical behaviour of filled CNTs. In contrast to their empty counterparts, the mechanics of filled CNTs is a subject where reports appear far and apart, this despite being key to the application of these materials in technological devices. In the following paragraphs, we review the work that has been carried out up to the present on the mechanics of filled CNTs. The studies discussed range from experimental resonant frequency essays performed within electron microscopes to modelling, via molecular dynamics, of three-point bending of nanotubes filled with gases. (C) 2014 Elsevier B.V. All rights reserved.

  10. Investigations on gas-air mixture formation in the ignition chamber of two-stage combustion chamber using high-speed Schlieren imaging

    Directory of Open Access Journals (Sweden)

    Bueschke Wojciech

    2017-01-01

    Full Text Available Combustion of the lean mixtures in the spark ignition engines provides higher thermal efficiency compared to the combustion of the stoichiometric mixture but is more restrictive to the ignition systems. Due to the limitations of conventional ignition systems, advanced concepts are being used, e. g. spark-jet ignition. Presented research has been carried to determine: 1. The impact of fuel injection pressure on the velocity of mixture formation, 2. Fuel distribution inside ignition chamber in defined phases of chamber filling, 3. Influence of chamber back-pressure on gas jet development. Investigations have been carried using the ignition chamber providing optical access. The visualization has been done with Schlieren-method with “Z”-setup basing on two ϕ = 150 mm parabolic mirrors. Images have been recorded with LaVision HSS5 camera with CMOS transducer. The paper contains a comparison of gas penetration parameters for a different injection pressures and chamber backpressures. The injection into the quasi-static air has been compared to the injection in dynamic conditions. It is stated, that both injection pressure and chamber back-pressure influence gas jet-development in the ignition chamber. The regions of the chamber with increased swirling and therefore providing more efficient micromixing have been identified.

  11. Emittance growth due to Tevatron flying wires

    Energy Technology Data Exchange (ETDEWEB)

    Syphers, M; Eddy, Nathan

    2004-06-01

    During Tevatron injection, Flying Wires have been used to measure the transverse beam size after each transfer from the Main Injector in order to deduce the transverse emittances of the proton and antiproton beams. This amounts to 36 + 9 = 45 flies of each of 3 wire systems, with an individual wire passing through each beam bunch twice during a single ''fly''. below they estimate the emittance growth induced by the interaction of the wires with the particles during these measurements. Changes of emittance from Flying Wire measurements conducted during three recent stores are compared with the estimations.

  12. Development of a Grid Ionization Chamber for a Dram of α Ray

    Directory of Open Access Journals (Sweden)

    YANG Lu;WANG Qiang;ZHENG Yu-lai;WANG Guo-bao

    2016-11-01

    Full Text Available This article introduced the parallel grid ionization chamber that used to measure the α radioactivity, which had a independent vacuum system. The system was composed of main body of the chamber, gas-filled and electronics system. Energy resolution was 26 keV for 239Pu, background was 10 counts for one hour from 4 MeV to 6 MeV energy range, the stability of 24 hours was less than 0.5% . The chamber can measure the energy of nuclide and analyze the energy spectrum structure to identify nuclear.

  13. Plasma formation in metallic wire Z pinches

    Science.gov (United States)

    Chittenden; Lebedev; Ruiz-Camacho; Beg; Bland; Jennings; Bell; Haines; Pikuz; Shelkovenko; Hammer

    2000-04-01

    Plasma formation in metallic wire Z pinches is modeled using a two-dimensional resistive magnetohydrodynamics code. Modified Thomas-Fermi equations of state and dense plasma transport coefficients allow the phase transitions from solid to plasma to be approximated. Results indicate the persistence of a two-component structure with a cold, dense core embedded within a much hotter, low density, m=0 unstable corona. Extensive benchmark testing against data from a number of single-wire experiments is presented. Artificial laser schlieren and x-ray back-lighting images generated from the code data are compared directly to experimental results. The results were found to be insensitive to inaccuracies in the equations of state and transport coefficients. Simulations of individual wires in a wire array show different behavior to that observed experimentally due to the absence of three-dimensional effects. Simulations with similar conditions to wires in an array show a general trend in the plasma structure at start of implosion from discrete wires with large m=0 perturbation amplitudes to partially merged wires with smaller perturbation amplitudes as the number of wires is increased. Results for a wire number scan with aluminum wire arrays on the SATURN generator suggest that the observed sharp transition to high x-ray power at around 40 wires corresponds to a sharp decrease in m=0 perturbation amplitude and hence a sharp decrease in the seed perturbation for the Rayleigh-Taylor instability.

  14. Laboratory Characterization of Cemented Rock Fill for Underhand Cut and Fill Method of Mining

    Science.gov (United States)

    Kumar, Dinesh; Singh, Upendra Kumar; Singh, Gauri Shankar Prasad

    2016-10-01

    Backfilling with controlled specifications is employed for improved ground support and pillar recovery in underground metalliferous mine workings. This paper reports the results of a laboratory study to characterise various mechanical properties of cemented rock fill (CRF) formulations for different compaction levels and cement content percentage for use in underhand cut and fill method of mining. Laboratory test set ups and procedures have been described for conducting compressive and bending tests of CRF block samples. A three dimensional numerical modelling study has also been carried out to overcome the limitations arising due to non-standard dimension of test blocks used in flexural loading test and the test setup devised for this purpose. Based on these studies, specific relations have been established between the compressive and the flexural properties of the CRF. The flexural strength of the wire mesh reinforced CRF is also correlated with its residual strength and the Young's modulus of elasticity under flexural loading condition. The test results of flexural strength, residual flexural strength and modulus show almost linear relations with cement content in CRF. The compressive strength of the CRF block samples is estimated as seven times the flexural strength whereas the compressive modulus is four times the flexural modulus. It has been found that the strengths of CRF of low compaction and no compaction are 75 and 60 % respectively to that of the medium compaction CRF. The relation between the strength and the unit weight of CRF as obtained in this study is significantly important for design and quality control of CRF during its large scale application in underhand cut and fill stopes.

  15. Structure and Properties of Coatings Made with Self Shielded Cored Wire

    Directory of Open Access Journals (Sweden)

    Gucwa M.

    2016-09-01

    Full Text Available The welding technologies are widely used for design of protection layer against wear and corrosion. Hardfacing, which is destined for obtaining coatings with high hardness, takes special place in these technologies. One of the most effective way of hardfacing is using self shielded flux cored arc welding (FCAW-S. Chemical composition obtained in flux cored wire is much more rich in comparison to this obtained in solid wire. The filling in flux cored wires can be enriched for example with the mixture of hard particles or phases with specified ratio, which is not possible for solid wires. This is the reason why flux cored wires give various possibilities of application of this kind of filler material for improving surface in mining industry, processing of minerals, energetic etc. In the present paper the high chromium and niobium flux cored wire was used for hardfacing process with similar heat input. The work presents studies of microstructures of obtained coatings and hardness and geometric properties of them. The structural studies were made with using optical microscopy and X-ray diffraction that allowed for identification of carbides and other phases obtained in the structures of deposited materials. Investigated samples exhibit differences in coating structures made with the same heat input 4,08 kJ/mm. There are differences in size, shape and distribution of primary and eutectic carbides in structure. These differences cause significant changes in hardness of investigated coatings.

  16. Slice of LHC dipole wiring

    CERN Multimedia

    Dipole model slice made in 1994 by Ansaldo. The high magnetic fields needed for guiding particles around the Large Hadron Collider (LHC) ring are created by passing 12’500 amps of current through coils of superconducting wiring. At very low temperatures, superconductors have no electrical resistance and therefore no power loss. The LHC is the largest superconducting installation ever built. The magnetic field must also be extremely uniform. This means the current flowing in the coils has to be very precisely controlled. Indeed, nowhere before has such precision been achieved at such high currents. 50’000 tonnes of steel sheets are used to make the magnet yokes that keep the wiring firmly in place. The yokes constitute approximately 80% of the accelerator's weight and, placed side by side, stretch over 20 km!

  17. Sintered wire cesium dispenser photocathode

    Science.gov (United States)

    Montgomery, Eric J; Ives, R. Lawrence; Falce, Louis R

    2014-03-04

    A photoelectric cathode has a work function lowering material such as cesium placed into an enclosure which couples a thermal energy from a heater to the work function lowering material. The enclosure directs the work function lowering material in vapor form through a low diffusion layer, through a free space layer, and through a uniform porosity layer, one side of which also forms a photoelectric cathode surface. The low diffusion layer may be formed from sintered powdered metal, such as tungsten, and the uniform porosity layer may be formed from wires which are sintered together to form pores between the wires which are continuous from the a back surface to a front surface which is also the photoelectric surface.

  18. Genetic Optimization of Wire Antennas

    Directory of Open Access Journals (Sweden)

    Z. Raida

    1998-09-01

    Full Text Available The presented submission describes how genetic algorithms can be applied to the optimization and design of wire antennas. The proposed optimization method is easily programmable and well understandable on one hand, but relatively slowly converging and depending on the parameters of the genetic algorithms on the other hand. The disadvantages of the method are deeply discussed and their elimination is discussed in the paper.

  19. Temperature Changes of Pulp Chamber during In Vitro Laser Welding of Orthodontic Attachments

    Science.gov (United States)

    İşman, Eren; Okşayan, Rıdvan; Sökücü, Oral; Üşümez, Serdar

    2014-01-01

    The use of lasers has been suggested for orthodontists to fabricate or repair orthodontic appliances by welding metals directly in the mouth. This work aimed to evaluate the temperature changes in the pulp chamber during welding of an orthodontic wire to an orthodontic molar band using Nd : YAG laser in vitro. A freshly extracted human third molar with eliminated pulpal tissues was used. J-type thermocouple wire was positioned in the pulp chamber. A conductor gel was used in the transferring of outside temperature changes to the thermocouple wire. An orthodontic band was applied to the molar tooth and bonded using light cured orthodontic cement. Twenty five mm length of 0.6 mm diameter orthodontic stainless steel wires was welded to the orthodontic band using Nd : YAG laser operated at 9.4 watt. Temperature variation was determined as the change from baseline temperature to the highest temperature was recorded during welding. The recorded temperature changes were between 1.8 and 6.8°C (mean: 3.3 ± 1.1°C). The reported critical 5.5°C level was exceeded in only one sample. The results of this study suggest that intraoral use of lasers holds great potential for the future of orthodontics and does not present a thermal risk. Further studies with larger samples and structural analysis are required. PMID:24550714

  20. Temperature Changes of Pulp Chamber during In Vitro Laser Welding of Orthodontic Attachments

    Directory of Open Access Journals (Sweden)

    Eren İşman

    2014-01-01

    Full Text Available The use of lasers has been suggested for orthodontists to fabricate or repair orthodontic appliances by welding metals directly in the mouth. This work aimed to evaluate the temperature changes in the pulp chamber during welding of an orthodontic wire to an orthodontic molar band using Nd : YAG laser in vitro. A freshly extracted human third molar with eliminated pulpal tissues was used. J-type thermocouple wire was positioned in the pulp chamber. A conductor gel was used in the transferring of outside temperature changes to the thermocouple wire. An orthodontic band was applied to the molar tooth and bonded using light cured orthodontic cement. Twenty five mm length of 0.6 mm diameter orthodontic stainless steel wires was welded to the orthodontic band using Nd : YAG laser operated at 9.4 watt. Temperature variation was determined as the change from baseline temperature to the highest temperature was recorded during welding. The recorded temperature changes were between 1.8 and 6.8°C (mean: 3.3 ± 1.1°C. The reported critical 5.5°C level was exceeded in only one sample. The results of this study suggest that intraoral use of lasers holds great potential for the future of orthodontics and does not present a thermal risk. Further studies with larger samples and structural analysis are required.

  1. Emulsion Chamber Technology Experiment (ECT)

    Science.gov (United States)

    Gregory, John C.; Takahashi, Yoshiyuki

    1996-01-01

    The experimental objective of Emulsion Chamber Technology (ECT) was to develop space-borne emulsion chamber technology so that cosmic rays and nuclear interactions may subsequently be studied at extremely high energies with long exposures in space. A small emulsion chamber was built and flown on flight STS-62 of the Columbia in March 1994. Analysis of the several hundred layers of radiation-sensitive material has shown excellent post-flight condition and suitability for cosmic ray physics analysis at much longer exposures. Temperature control of the stack was 20 +/-1 C throughout the active control period and no significant deviations of temperature or pressure in the chamber were observed over the entire mission operations period. The unfortunate flight attitude of the orbiter (almost 90% Earth viewing) prevented any significant number of heavy particles (Z greater than or equal to 10) reaching the stack and the inverted flow of shower particles in the calorimeter has not allowed evaluation of absolute primary cosmic ray-detection efficiency nor of the practical time limits of useful exposure of these calorimeters in space to the level of detail originally planned. Nevertheless, analysis of the observed backgrounds and quality of the processed photographic and plastic materials after the flight show that productive exposures of emulsion chambers are feasible in low orbit for periods of up to one year or longer. The engineering approaches taken in the ECT program were proven effective and no major environmental obstacles to prolonged flight are evident.

  2. Construction and use of small chambers for boron trifluoride; Construction et utilisation de petites chambres au trifluorure de bore

    Energy Technology Data Exchange (ETDEWEB)

    Caillat, R.; Lallemant, C.; Valladas, G

    1949-07-01

    The fabrication of the chambers (the materials used, the fabrication of the parts and their assembly), and their final testing are described in a first part. Then, the preparation of crude boron fluoride, the storing of the crude, the purification of BF{sub 3} by sublimation and condensation, the pumping, drying and filling up of the chambers, their finishing and sealing are described in a second part. The last part describes the use of the chambers for the counting of slow neutrons: amplification system, pulses discrimination and neutrons counting, accuracy. The characteristics of the amplification circuit used with the chamber are described in the appendix. (J.S.)

  3. Wired Widgets: Agile Visualization for Space Situational Awareness

    Science.gov (United States)

    Gerschefske, K.; Witmer, J.

    2012-09-01

    Continued advancement in sensors and analysis techniques have resulted in a wealth of Space Situational Awareness (SSA) data, made available via tools and Service Oriented Architectures (SOA) such as those in the Joint Space Operations Center Mission Systems (JMS) environment. Current visualization software cannot quickly adapt to rapidly changing missions and data, preventing operators and analysts from performing their jobs effectively. The value of this wealth of SSA data is not fully realized, as the operators' existing software is not built with the flexibility to consume new or changing sources of data or to rapidly customize their visualization as the mission evolves. While tools like the JMS user-defined operational picture (UDOP) have begun to fill this gap, this paper presents a further evolution, leveraging Web 2.0 technologies for maximum agility. We demonstrate a flexible Web widget framework with inter-widget data sharing, publish-subscribe eventing, and an API providing the basis for consumption of new data sources and adaptable visualization. Wired Widgets offers cross-portal widgets along with a widget communication framework and development toolkit for rapid new widget development, giving operators the ability to answer relevant questions as the mission evolves. Wired Widgets has been applied in a number of dynamic mission domains including disaster response, combat operations, and noncombatant evacuation scenarios. The variety of applications demonstrate that Wired Widgets provides a flexible, data driven solution for visualization in changing environments. In this paper, we show how, deployed in the Ozone Widget Framework portal environment, Wired Widgets can provide an agile, web-based visualization to support the SSA mission. Furthermore, we discuss how the tenets of agile visualization can generally be applied to the SSA problem space to provide operators flexibility, potentially informing future acquisition and system development.

  4. Removal of root filling materials.

    LENUS (Irish Health Repository)

    Duncan, H.F. Chong, B.S.

    2011-05-01

    Safe, successful and effective removal of root filling materials is an integral component of non-surgical root canal re-treatment. Access to the root canal system must be achieved in order to negotiate to the canal terminus so that deficiencies in the original treatment can be rectified. Since a range of materials have been advocated for filling root canals, different techniques are required for their removal. The management of commonly encountered root filling materials during non-surgical re-treatment, including the clinical procedures necessary for removal and the associated risks, are reviewed. As gutta-percha is the most widely used and accepted root filling material, there is a greater emphasis on its removal in this review.

  5. "Flat-Fish" Vacuum Chamber

    CERN Multimedia

    CERN PhotoLab

    1978-01-01

    The picture shows a "Flat-Fish" vacuum chamber being prepared in the ISR workshop for testing prior to installation in the Split Field Magnet (SFM) at intersection I4. The two shells of each part were hydroformed from 0.15 mm thick inconel 718 sheet (with end parts in inconel 600 for easier manual welding to the arms) and welded toghether with two strips which were attached by means of thin stainless steel sheets to the Split Field Magnet poles in order to take the vertical component of the atmospheric pressure force. This was the thinnest vacuum chamber ever made for the ISR. Inconel material was chosen for its high elastic modulus and strenght at chamber bake-out temperature. In this picture the thin sheets transferring the vertical component of the atmosferic pressure force are attached to a support frame for testing. See also 7712182, 7712179.

  6. Characterization of Turbulent Non-Uniform Exploding Wire Plasma Using High Resolution Interferometry, Schlieren and Shadowography Imaging

    Science.gov (United States)

    Caplinger, J.; Sarkisov, G.; Wallerstein, A. J.; Sotnikov, V.; Lundberg, J.; Reed, Z.

    2014-10-01

    High resolution interferogram, Schlieren, and shadowgraph imaging has been used to characterize an exploding wire plasma. Using an 80 kV high voltage pulse generator with a rise time of 5 ns, exploding wire plasmas are created in aluminum, gold, tin, stainless steel, platinum and silver wires. The plasma is probed over a period of 3-7 ns using a 532 nm frequency doubled Nd:YAG Q-switched laser. The resulting laser radiation is imaged as an interferogram using an air-wedge interferometer, a shadowgraph and as a Schlieren image using two CCDs. Calculations resulting from the interferograms reveal ionizations between 10-20% for Aluminum wires at atmospheric pressure. This is confirmed by the Schlieren images as the refraction caused by neutrals is dominant. Single wire, two parallel wires, and other two wire configurations are investigated. Additionally, influence of chamber pressure on plasma uniformity, shock wave propagation velocity and instabilities is presented. Work supported by the Air Force Research Laboratory.

  7. An electromagnetic micrometer to measure the wire centering in high- resolution aluminium drift tubes

    CERN Document Server

    Cambiaghi, M; Casani, S; Ferrari, R; Gaudio, G; Iuvino, G; Lanza, A; Prata, M J

    1999-01-01

    The muon detector of the Atlas experiment at LHC (CERN) consists of 370000 high-resolution drift tubes assembled in multi-layer chambers. To take full advantage of the single-tube resolution, the high- precision external surface of tube end-plugs is used for positioning a layer before gluing. The wire position in the tube is defined at construction time by means of a locator inserted in the end-plug. To check that the wire is in the nominal position after the tube assembly an electromagnetic micrometer (EMMI) has been developed. EMMI detects the wire position by measuring the electromotive force induced in two sensors symmetrically placed on both sides of the tube when a small sinusoidal current circulates on the wire. An accuracy of two microns on the wire centering has been obtained. The simplicity of this method and the short measuring time allow every drift tube to be checked, thus guaranteeing the precision requested for the Atlas muon detector. (4 refs).

  8. An electromagnetic micrometer to measure the wire centering in high-resolution aluminium drift tubes

    CERN Document Server

    Cambiaghi, M; Casani, S; Ferrari, R; Gaudio, G; Iuvino, G; Lanza, A; Prata, M J

    1999-01-01

    The muon detector of the Atlas experiment at LHC (CERN) consists of 370000 high-resolution drift tubes assembled in multi-layer chambers. To take full advantage of the single-tube resolution, the high- precision external surface of tube end-plugs is used for positioning a layer before gluing. The wire position in the tube is defined at construction time by means of a locator inserted in the end-plug. To check that the wire is in the nominal position after the tube assembly an electromagnetic micrometer (EMMI) has been developed. EMMI detects the wire position by measuring the electromotive force induced in two sensors symmetrically placed on both sides of the tube when a small sinusoidal current circulates on the wire. An accuracy of two microns on the wire centering has been obtained. The simplicity of this method and the short measuring time allow every drift tube to be checked, thus guaranteeing the precision requested for the Atlas muon detector. (4 refs).

  9. The effect of material attributes and process parameters on the powder bed uniformity during a low-dose dosator capsule filling process.

    Science.gov (United States)

    Stranzinger, S; Faulhammer, E; Calzolari, V; Biserni, S; Dreu, R; Šibanc, R; Paudel, A; Khinast, J G

    2017-01-10

    The objective of this work was to assess the effect of process parameters of a dosator nozzle machine on the powder bed uniformity of inhalation powders with various characteristics during a low-dose dosator capsule filling process. Three grades of lactose excipients were extensively characterized and filled into size 3 capsules using different dosing chamber lengths (2.5, 5mm), nozzle diameters (1.9, 3.4mm), powder bed heights (5, 10mm) and filling speeds (500, 3000capsules/h). The fill weight and the weight variability of Lactohale 100 (large particles, good flowability, low cohesion) remained almost the same, regardless of the process parameters throughout the capsule filling run time. Moreover, for this powder an increase in the fill weight at a higher filling speed was observed in all cases. Fill weight variability was significantly higher for lower dosing chamber volumes at a filling speed of 3000 capsules per hour. Lactohale 220 (small particles, poor flowability, high cohesion) delivered entirely different results. After a certain run time, depending on instrumental settings, a 'steady-state' with constant fill weights and low weight variability was achieved. For this highly cohesive powder, a high dosing chamber volume requires a low filling speed in order for the powder to completely fill the dosator nozzle. Moreover, it was established that a dosing chamber length of 2.5mm and a powder bed height of 10mm were required due to the powder's high fill weight variability over time, while the dosator size had no effect on it. In summary, the layer uniformity, the fill weight and the weight variability strongly depend on the powder characteristics and the instrumental settings. The results indicate that Lactohale 220 requires special attention during low-dose capsule filling. The study presents excellent insights into the effect of material attributes and process parameters on the layer uniformity and the quality of end product. Copyright © 2016 Elsevier B

  10. "Cut wires grating – single longitudinal wire" planar metastructure to achieve microwave magnetic resonance in a single wire

    Directory of Open Access Journals (Sweden)

    G. Kraftmakher

    2012-09-01

    Full Text Available Here we present metastructures containing cut-wire grating and a single longitudinal cut-wire orthogonal to grating’s wires. Experimental investigations at microwaves show these structures can provide strong magnetic resonant response of a single nonmagnetic cut-wire in dependence on configuration and sizes in the case when metastructures are oriented along the direction of wave propagation and cut-wires of grating are parallel to the electric field of a plane electromagnetic wave. It is suggested a concept of magnetic response based on antiparallel resonant currents excited by magnetic field of surface polaritons in many spatial LC-circuits created from cut-wire pairs of a grating and section of longitudinal cut-wire. Three separately observed resonant effects connected with grating, LC-circuits and with longitudinal cut-wire have been identified applying measurements in waveguides, cutoff waveguides and free space. To tune and mark resonance split cut-wires are loaded with varactor diodes.

  11. A Vibrating Wire System For Quadrupole Fiducialization

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, Zachary

    2010-12-13

    A vibrating wire system is being developed to fiducialize the quadrupoles between undulator segments in the LCLS. This note provides a detailed analysis of the system. The LCLS will have quadrupoles between the undulator segments to keep the electron beam focused. If the quadrupoles are not centered on the beam axis, the beam will receive transverse kicks, causing it to deviate from the undulator axis. Beam based alignment will be used to move the quadrupoles onto a straight line, but an initial, conventional alignment must place the quadrupole centers on a straight line to 100 {micro}m. In the fiducialization step of the initial alignment, the position of the center of the quadrupole is measured relative to tooling balls on the outside of the quadrupole. The alignment crews then use the tooling balls to place the magnet in the tunnel. The required error on the location of the quadrupole center relative to the tooling balls must be less than 25 {micro}m. In this note, we analyze a system under construction for the quadrupole fiducialization. The system uses the vibrating wire technique to position a wire onto the quadrupole magnetic axis. The wire position is then related to tooling balls using wire position detectors. The tooling balls on the wire position detectors are finally related to tooling balls on the quadrupole to perform the fiducialization. The total 25 {micro}m fiducialization error must be divided between these three steps. The wire must be positioned onto the quadrupole magnetic axis to within 10 {micro}m, the wire position must be measured relative to tooling balls on the wire position detectors to within 15 {micro}m, and tooling balls on the wire position detectors must be related to tooling balls on the quadrupole to within 10 {micro}m. The techniques used in these three steps will be discussed. The note begins by discussing various quadrupole fiducialization techniques used in the past and discusses why the vibrating wire technique is our method

  12. Phosphorus in antique iron music wire.

    Science.gov (United States)

    Goodway, M

    1987-05-22

    Harpsichords and other wire-strung musical instruments were made with longer strings about the beginning of the 17th century. This change required stronger music wire. Although these changes coincided with the introduction of the first mass-produced steel (iron alloyed with carbon), carbon was not found in samples of antique iron harpsichord wire. The wire contained an amount of phosphorus sufficient to have impeded its conversion to steel, and may have been drawn from iron rejected for this purpose. The method used to select pig iron for wire drawing ensured the highest possible phosphorus content at a time when its presence in iron was unsuspected. Phosphorus as an alloying element has had the reputation for making steel brittle when worked cold. Nevertheless, in replicating the antique wire, it was found that lowcarbon iron that contained 0.16 percent phosphorus was easily drawn to appropriate gauges and strengths for restringing antique harpsichords.

  13. Electromagnetic Behaviour of Metallic Wire Structures

    CERN Document Server

    Chui, S T

    2013-01-01

    Despite the recent development and interest in the photonics of metallic wire structures, the relatively simple concepts and physics often remain obscured or poorly explained to those who do not specialize in the field. Electromagnetic Behaviour of Metallic Wire Structures provides a clear and coherent guide to understanding these phenomena without excessive numerical calculations.   Including both background material and detailed derivations of the various different formulae applied, Electromagnetic Behaviour of Metallic Wire Structures describes how to extend basic circuit theory relating to voltages, currents, and resistances of metallic wire networks to include situations where the currents are no longer spatially uniform along the wire. This lays a foundation for a deeper understanding of the many new phenomena observed in meta-electromagnetic materials.   Examples of applications are included to support this new approach making Electromagnetic Behaviour of Metallic Wire Structures a comprehensive and ...

  14. A dual deformable reverberation chamber

    NARCIS (Netherlands)

    Leferink, Frank Bernardus Johannes

    2009-01-01

    There is disclosed an arrangement for measuring the effectiveness of a shielding material against electromagnetic fields. The arrangement comprises a first and a second reverberation chamber sharing a common wall. The common wall is partly made of the shielding material. A first antenna is arranged

  15. LEP vacuum chamber, early prototype

    CERN Multimedia

    CERN PhotoLab

    1978-01-01

    The same vacuum chamber as in 7810256, read the detailed description there. Here, the 4 strip-shaped ion-getter pumps are poised at the entrance to their slots. Ion-getter pumps were not retained, thermal getter pumps were chosen instead (see 8301153 and 8305170).

  16. Bubble chamber: colour enhanced tracks

    CERN Multimedia

    1998-01-01

    This artistically-enhanced image of real particle tracks was produced in the Big European Bubble Chamber (BEBC). Liquid hydrogen is used to create bubbles along the paths of the particles as a piston expands the medium. A magnetic field is produced in the detector causing the particles to travel in spirals, allowing charge and momentum to be measured.

  17. Testing an hydrogen streamer chamber

    CERN Multimedia

    1975-01-01

    A 2x10 cm gap streamer chamber, 35x55 cm2 in surface, was built and tested at CERN. Good tracks of cosmic rays were obtained up to atmospheric pressure, see F. Rohrbach et al, CERN-LAL (Orsay) Collaboration, Nucl. Instr. Methods 141 (1977) 229. Michel Cathenoz stand on the center.

  18. DELPHI's Ring Imaging Cherenkov Chamber

    CERN Multimedia

    1989-01-01

    The hundreds of mirrors around this Ring Imaging Cherenkov Chamber reflect cones of light created by fast moving particles to a detector. The velocity of a particle can be measured by the size of the ring produced on the detector. DELPHI, which ran from 1989 to 2000 on the LEP accelerator, was primarily concerned with particle identification.

  19. A new tubular hot-wire CVD for diamond coating

    Science.gov (United States)

    Motahari, Hamid; Bellah, Samad Moemen; Malekfar, Rasoul

    2017-06-01

    A new tubular hot-wire chemical vapor deposition (HWCVD) system using a tubular quartz vacuum chamber has been fabricated. The filaments in this system can heat the substrate and act as a gas activator and thermally activator for gas species at the same time. The nano- and microcrystalline diamond coatings on the surface of steel AISI 316 substrates have been grown. To assess the results, SEM and FESEM images and Raman spectroscopy investigations have been applied. The results reveal that micro- and nanocrystalline diamond structures have been formed in the coatings, but the disordered diamond and some non-diamond phases, such as graphitic carbons, are also present in the coating layers. The analytical measurements show the growth of diamond films with well-faceted crystals in (111) direction. However, intrinsic stress, secondary nucleation, and poor adhesion are the main issues of future research for this new designed HWCVD.

  20. Differences in CASA output according to the chamber type when analyzing frozen-thawed bull sperm.

    Science.gov (United States)

    Ibănescu, Iulian; Leiding, Claus; Ciornei, Ştefan Gregore; Roșca, Petru; Sfartz, Ioana; Drugociu, Dan

    2016-03-01

    As demonstrated by some authors, the type of analyzing chamber can greatly influence the results of computer-assisted sperm analysis (CASA). This study aimed to compare three of the disposable chamber types currently available on the market and to determine whether the CASA output may be significantly different among them. The semen from five Fleckvieh bulls was analyzed by CASA using three different disposable chambers: Leja (20μm), MofA (20μm) and Minitube (20μm), at three different time points: immediately after filling the chamber, at 6min, and also at 12min after filling. Sperm concentration was also determined using the Nucleocounter® NC-100™ device and the hemocytometer as standard methods. The results showed higher values in terms of total and progressive sperm motility for MofA compared to the other two chambers immediately after filling (pCASA only when the other methods are not available. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Effect of endodontic sealers on bond strength of restorative systems to primary tooth pulp chamber

    Directory of Open Access Journals (Sweden)

    Ülkü Şermet Elbay

    2017-06-01

    Conclusion: Composite materials seemed to bond to pulp chamber dentin in primary teeth with a higher strength than compomer and resin-modified glass ionomer. Metapex and zinc-oxide eugenol canal filling materials reduced the bond strength of all three restorative systems.

  2. Page 1 326 S Prakash et al when the chamber is exposed to a ...

    Indian Academy of Sciences (India)

    filled with NO gas. The quantum yield value for the nitric oxide at different photon wavelengths has been taken from Watanabe et al (1967). Knowing the absolute. Intensity of incident photon beam, one can easily measure the quantum efficiency of the two ion chambers. 3. Payload electronics and data collection.

  3. A comparison of different experimental methods for general recombination correction for liquid ionization chambers

    DEFF Research Database (Denmark)

    Andersson, Jonas; Kaiser, Franz-Joachim; Gomez, Faustino

    2012-01-01

    Radiation dosimetry of highly modulated dose distributions requires a detector with a high spatial resolution. Liquid filled ionization chambers (LICs) have the potential to become a valuable tool for the characterization of such radiation fields. However, the effect of an increased recombination...

  4. IEE wiring regulations explained and illustrated

    CERN Document Server

    Scaddan, Brian

    2013-01-01

    The IEE Wiring Regulations Explained and Illustrated, Second Edition discusses the recommendations of the IEE Regulations for the Electrical Equipment of Buildings for the safe selection or erection of wiring installations. The book emphasizes earthing, bonding, protection, and circuit design of electrical wirings. The text reviews the fundamental requirements for safety, earthing systems, the earth fault loop impedance, and supplementary bonding. The book also describes the different types of protection, such as protection against mechanical damage, overcurrent, under voltage (which prevents

  5. Radiofrequency Wire Recanalization of Chronically Thrombosed TIPS

    Energy Technology Data Exchange (ETDEWEB)

    Majdalany, Bill S., E-mail: bmajdala@med.umich.edu [University of Michigan Health System, Division of Interventional Radiology, Department of Radiology (United States); Elliott, Eric D., E-mail: eric.elliott@osumc.edu [The Ohio State University Wexner Medical Center, Division of Interventional Radiology, Department of Radiology (United States); Michaels, Anthony J., E-mail: Anthony.michaels@osumc.edu; Hanje, A. James, E-mail: James.Hanje@osumc.edu [The Ohio State University Wexner Medical Center, Division of Gastroenterology and Hepatology, Department of Medicine (United States); Saad, Wael E. A., E-mail: wsaad@med.umich.edu [University of Michigan Health System, Division of Interventional Radiology, Department of Radiology (United States)

    2016-07-15

    Radiofrequency (RF) guide wires have been applied to cardiac interventions, recanalization of central venous thromboses, and to cross biliary occlusions. Herein, the use of a RF wire technique to revise chronically occluded transjugular intrahepatic portosystemic shunts (TIPS) is described. In both cases, conventional TIPS revision techniques failed to revise the chronically thrombosed TIPS. RF wire recanalization was successfully performed through each of the chronically thrombosed TIPS, demonstrating initial safety and feasibility in this application.

  6. NEW DIRECTIONS IN THE ROLLED WIRE DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    A. V. Vedeneev

    2004-01-01

    Full Text Available Analysis of the world practice and comparison with the competitors data shows, that for keeping up of RUP “BMZ'' competitiveness it is necessary to carry out works in directions of perfection of the steel wire cord production technology, development of steel wire cord, development of the breaker constructions with the high infiltration of rubber of wire with superstandard diameter and etc.

  7. Experimental setup to detect superconducting wire motion

    OpenAIRE

    K. Ruwali; A. Yamanaka; Y. Teramoto; K. Nakanishi; K. Hosoyama

    2009-01-01

    An experimental setup was designed and fabricated to study superconducting wire motion under the influence of electromagnetic force. Experiments were conducted at 4.2 K by varying the experimental conditions such as the tension to the superconducting wire and different insulating materials at the interface of the superconducting wire and head part. The insulating materials used in the experiments were polyimide film and a high strength polyethylene fiber cloth, Dyneema. Details of the experim...

  8. Minimisation of the wire position uncertainties of the new CERN vacuum wire scanner

    CERN Document Server

    AUTHOR|(CDS)2069346; Barjau Condomines, A

    In the next years the luminosity of the LHC will be significantly increased. This will require a much higher accuracy of beam profile measurement than actually achievable by the current wire scanner. The new fast wire scanner is foreseen to measure small emittance beams throughout the LHC injector chain, which demands a wire travelling speed up to 20 ms-1 and position measurement accuracy of the order of a few microns. The vibrations of the mechanical parts of the system, and particularly the vibrations of the thin carbon wire, were identified as the major error sources of wire position uncertainty. Therefore the understanding of the wire vibrations is a high priority for the design and operation of the new device. This document presents the work performed to understand the main causes of the wire vibrations observed in one of the existing wire scanner and the new proposed design.

  9. Highly efficient resistive plate chambers for high rate environment

    CERN Document Server

    Cwiok, M; Górski, M; Królikowski, J

    1999-01-01

    The full scale prototype of an inverted double gap RPC module for ME-1/1 station of the CMS detector was tested in the gamma irradiation facility at the CERN SPS muon beam. The chamber made of medium resistivity bakelite and filled with "green gas" mixture of C /sub 2/H/sub 2/F/sub 4//iso-butane/SF/sub 6/ has wide efficiency plateau and good timing properties when operated in avalanche mode under continuous irradiation with strong /sup 137/Cs source for rates up to about 5 kHz/cm/sup 2//gap. (10 refs).

  10. Aircraft Wiring Support Equipment Integration Laboratory (AWSEIL)

    Data.gov (United States)

    Federal Laboratory Consortium — Purpose:The Aircraft Wiring Support Equipment Integration Laboratory (AWSEIL) provides a variety of research, design engineering and prototype fabrication services...

  11. submitter Dynamical Models of a Wire Scanner

    CERN Document Server

    Barjau, Ana; Dehning, Bernd

    2016-01-01

    The accuracy of the beam profile measurements achievable by the current wire scanners at CERN is limited by the vibrations of their mechanical parts. In particular, the vibrations of the carbon wire represent the major source of wire position uncertainty which limits the beam profile measurement accuracy. In the coming years, due to the Large Hadron Collider (LHC) luminosity upgrade, a wire traveling speed up to 20 $m s^{−1}$ and a position measurement accuracy of the order of 1 μm will be required. A new wire scanner design based on the understanding of the wire vibration origin is therefore needed. We present the models developed to understand the main causes of the wire vibrations observed in an existing wire scanner. The development and tuning of those models are based on measurements and tests performed on that CERN proton synchrotron (PS) scanner. The final model for the (wire + fork) system has six degrees-of-freedom (DOF). The wire equations contain three different excitation terms: inertia...

  12. LHCb: Performance of the fourgap LHCb Muon Chambers tested with cosmic rays

    CERN Multimedia

    Pinci, D

    2007-01-01

    The LHCb Muon System is composed of five detection stations (M1M5)mainly equipped with a total of 1368 MultiWire Proportional Chambers (MWPC). MWPCs need to ensure a high detection efficiency, a fast response and a good space resolution. We present here the results of detailed studies of the performance of different fourgap chambers, completely equipped with the final FrontEnd Electronics, measured with cosmic rays. Aspects such as time resolution, hit multiplicity and time and space structure of the crosstalk hits were measured. For the first time, both types of chambers, those with anodewirereadout and those with cathodepadreadout, were tested and the results are compared. Results hereby obtained will be used to individuate the optimal working conditions of the apparatus and to achieve a more realistic detector description in the LHCb Monte Carlo simulation.

  13. A ZigBee-based wireless system for monitoring vital signs in hyperbaric chambers: Technical report.

    Science.gov (United States)

    Carmona, Cristian; Alorda, Bartomeu; Gracia, Luis; Perez-Vidal, Carlos; Salinas, Antonio

    2017-01-01

    This paper presents the replacement of a traditional wired communication link of the hyperbaric chambers with a wireless ZigBee-based system. This move allows a reduction in the costs of seals capable of withstanding the internal pressures and gives rise to a more versatile system. The new system is able to capture and process individual vital signs like the electrocardiography signal, and other analog sources, sending the data to an external computer and allowing analysis, representation and sharing with medical staff. This system solves such problems as the attenuation of the signal produced by the metal walls of the hyperbaric chamber and has a coverage area large enough to manage up to six patients with an effective data rate conversion of 2kHz. Furthermore, a battery-based and multiparameter platform is designed for multipatient hyperbaric chambers. Copyright© Undersea and Hyperbaric Medical Society.

  14. Development of a Micro Pixel Chamber for the ATLAS Upgrade

    CERN Document Server

    Ochi, Atsuhiko; Komai, Hidetoshi; Edo, Yuki; Yamaguchi, Takahiro

    2012-01-01

    The Micro Pixel Chamber (μ-PIC) is being developed a sacandidate for the muon system of the ATLAS detector for upgrading in LHC experiments. The μ-PIC is a micro-pattern gaseous detector that doesn’t have floating structure such as wires, mesh, or foil. This detector can be made by printed-circuit-board (PCB) technology, which is commercially available and suited for mass production. Operation tests have been performed under high flux neutrons under similar conditions to the ATLAS cavern. Spark rates are measured using several gas mixtures under 7 MeV neutron irradiation, and good properties were observed using neon, ethane, and CF4 mixture of gases.Using resistive materials as electrodes, we are also developing a new μ-PIC, which is not expected to damage the electrodes in the case of discharge sparks.

  15. Imaging performance of a multiwire proportional-chamber positron camera

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Mandez, V.; Del Guerra, A.; Nelson, W.R.; Tam, K.C.

    1982-08-01

    A new design - fully three-dimensional - Positron Camera is presented, made of six MultiWire Proportional Chamber modules arranged to form the lateral surface of a hexagonal prism. A true coincidence rate of 56000 c/s is expected with an equal accidental rate for a 400 ..mu..Ci activity uniformly distributed in a approx. 3 l water phantom. A detailed Monte Carlo program has been used to investigate the dependence of the spatial resolution on the geometrical and physical parameters. A spatial resolution of 4.8 mm FWHM has been obtained for a /sup 18/F point-like source in a 10 cm radius water phantom. The main properties of the limited angle reconstruction algorithms are described in relation to the proposed detector geometry.

  16. FE modeling of Cu wire bond process and reliability

    NARCIS (Netherlands)

    Yuan, C.A.; Weltevreden, E.R.; Akker, P. van den; Kregting, R.; Vreugd, J. de; Zhang, G.Q.

    2011-01-01

    Copper based wire bonding technology is widely accepted by electronic packaging industry due to the world-wide cost reduction actions (compared to gold wire bond). However, the mechanical characterization of copper wire differs from the gold wire; hence the new wire bond process setting and new bond

  17. THERMO-MECHANICALLY PROCESSED ROLLED WIRE FOR HIGH-STRENGTH ON-BOARD WIRE

    Directory of Open Access Journals (Sweden)

    V. A. Lutsenko

    2011-01-01

    Full Text Available It is shown that at twisting of wire of diameter 1,83 mm, produced by direct wire drawing of thermomechanically processed rolled wire of diameter 5,5 mm of steel 90, metal stratification is completely eliminated at decrease of carbon, manganese and an additional alloying of chrome.

  18. Finite element analysis on the wire breaking rule of 1×7IWS steel wire rope

    Directory of Open Access Journals (Sweden)

    Wenzheng Du

    2017-01-01

    Full Text Available Taking the wire rope of 1×7+IWS structure as the research object, the influences of the number of broken wires on the stress distribution under the same axial load were simulated and analysed, and it also explored the rule of wire breaking of steel wire ropes. Based on the SolidWorks software, the three-dimensional model of the wire rope was established. Importing the model into the ABAQUS, the finite element model of the steel wire rope was established. Firstly 5000 N axial tension was placed on the rope, the stress distribution was simulated and analysed, and the steel wire with the largest stress distribution was found out. Then one steel wire was truncated with the load unchanged, and the finite element simulation was carried out again, and repeated the steps several times. The results show that, with the increase of the number of broken wires, the Von-Mises stress of the wire rope increases sharply, and the stress distribution is concentrated on the rest of the unbroken wires, which brings great challenges to the safety of the wire rope.

  19. Effect of chamber characteristics, loading and analysis time on motility and kinetic variables analysed with the CASA-mot system in goat sperm.

    Science.gov (United States)

    Del Gallego, R; Sadeghi, S; Blasco, E; Soler, C; Yániz, J L; Silvestre, M A

    2017-02-01

    Several factors unrelated to the semen samples could be influencing in the sperm motility analysis. The aim of the present research was to study the effect of four chambers with different characteristics, namely; slide-coverslip, Spermtrack, ISAS D4C10, and ISAS D4C20 on the sperm motility. The filling procedure (drop or capillarity) and analysis time (0, 120 and 240s), depth of chamber (10 or 20μm) and field on motility variables were analysed by use of the CASA-mot system in goat sperm. Use of the drop-filling chambers resulted in greater values than capillarity-filling chambers for all sperm motility and kinetic variables, except for LIN (64.5% compared with 56.3% of motility for drop- and capillarity-filling chambers respectively, PCASA-mot system with a drop-loaded chamber within 2min after filling the chamber. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Metal explosion chambers: designing, manufacturing, application

    Science.gov (United States)

    Stoyanovskii, O. I.; Zlobin, B. S.; Shtertser, A. A.; Meshcheryakov, Y. P.

    2017-10-01

    Designing of explosion chambers is based on research investigations of the chamber body stress-strain state, which is determined by numerical computation and experimentally by the strain gage technique. Studies show that chamber bottoms are the most loaded elements, and maximal stresses arise in chamber poles. Increasing the shell thickness around poles by welding-in an insert is a simple and saving way to solve this problem. There are structural solutions, enabling reliable hermetic closure and preventing leakage of detonation products from the chamber. Explosion chambers are employed in scientific research and in different industrial applications: explosive welding and hardening, synthesis of new materials, disposal of expired ammunition, and etc.

  1. Growing and Analyzing Biofilms in Flow Chambers

    DEFF Research Database (Denmark)

    Tolker-Nielsen, Tim; Sternberg, Claus

    2011-01-01

    This unit describes the setup of flow chamber systems for the study of microbial biofilms, and methods for the analysis of structural biofilm formation. Use of flow chambers allows direct microscopic investigation of biofilm formation. The biofilms in flow chambers develop under hydrodynamic...... conditions, and the environment can be carefully controlled and easily changed. The protocols in this unit include construction of the flow chamber and the bubble trap, assembly and sterilization of the flow chamber system, inoculation of the flow chambers, running of the system, image capture and analysis...

  2. Paleovalley fills: Trunk vs. tributary

    Science.gov (United States)

    Kvale, E.P.; Archer, A.W.

    2007-01-01

    A late Mississippian-early Pennsylvanian eustatic sea level drop resulted in a complex lowstand drainage network being eroded across the Illinois Basin in the eastern United States. This drainage system was filled during the early part of the Pennsylvanian. Distinct differences can be recognized between the trunk and tributary paleovalley fills. Fills preserved within the trunk systems tend to be fluvially dominated and consist of bed-load deposits of coarse- to medium-grained sandstone and conglomerate. Conversely, the incised valleys of tributary systems tend to be filled with dark mudstone, thinly interbedded sandstones, and mudstones and siltstones. These finer grained facies exhibit marine influences manifested by tidal rhythmites, certain traces fossils, and macro- and microfauna. Examples of tributary and trunk systems, separated by no more than 7 km (4.3 mi) along strike, exhibit these styles of highly contrasting fills. Useful analogs for understanding this Pennsylvanian system include the Quaternary glacial sluiceways present in the lower Ohio, White, and Wabash river valleys of Indiana (United States) and the modern Amazon River (Brazil). Both the Amazon River and the Quaternary rivers of Indiana have (or had) trunk rivers that are (were) dominated by large quantities of bed load relative to their tributaries. The trunk valley systems of these analogs aggraded much more rapidly than their tributary valleys, which evolved into lakes because depositional rates along the trunk are (were) so high that the mouths of the tributaries have been dammed by bed-load deposits. These Holocene systems illustrate that sediment yields can significantly influence the nature of fill successions within incised valleys independent of rates of sea level changes or proximity to highstand coastlines. Copyright ?? 2007. The American Association of Petroleum Geologists. All rights reserved.

  3. Gas-Filled Capillary Model

    Science.gov (United States)

    Steinhauer, L. C.; Kimura, W. D.

    2006-11-01

    We have developed a 1-D, quasi-steady-state numerical model for a gas-filled capillary discharge that is designed to aid in selecting the optimum capillary radius in order to guide a laser beam with the required intensity through the capillary. The model also includes the option for an external solenoid B-field around the capillary, which increases the depth of the parabolic density channel in the capillary, thereby allowing for propagation of smaller laser beam waists. The model has been used to select the parameters for gas-filled capillaries to be utilized during the Staged Electron Laser Acceleration — Laser Wakefield (STELLA-LW) experiment.

  4. QENS investigation of filled rubbers

    CERN Document Server

    Triolo, A; Desmedt, A; Pieper, J K; Lo Celso, F; Triolo, R; Negroni, F; Arrighi, V; Qian, H; Frick, B

    2002-01-01

    The polymer segmental dynamics is investigated in a series of silica-filled rubbers. The presence of inert fillers in polymers greatly affects the mechanical and physical performance of the final materials. For example, silica has been proposed as a reinforcing agent of elastomers in tire production. Results from quasielastic neutron scattering and Dynamic Mechanical Thermal Analysis (DMTA) measurements are presented on styrene-ran-butadiene rubber filled with silica. A clear indication is obtained of the existence of a bimodal dynamics, which can be rationalized in terms of the relaxation of bulk rubber and the much slower relaxation of the rubber adsorbed on the filler surface. (orig.)

  5. Initial recombination in the track of heavy charged particles: Numerical solution for air filled ionization chambers

    DEFF Research Database (Denmark)

    Kaiser, Franz-Joachim; Bassler, Niels; Tölli, Heikki

    2012-01-01

    . In this study the effect of the underlying dose distribution on columnar recombination, a quantitative model for initial recombination,is investigated. Material and Methods Jaffe’s theory, formulated in 1913 quantifies initial recombination by elemental processes, providing an analytical (closed) solution. Here...... in the assessment of the saturation current or charge is suggested by the data. Conclusion The established model of columnar recombination reproduces the experimental data well, whereas the extentions using track structure models do not show such an agreement. Additionally, the effect of initial recombination...... on the saturation curve (i.e. Jaffe plot) does not follow a linear behavior as suggested by current dosimetry protocols, therefore higher order corrections (such as the investigated ones) might be necessary....

  6. In-Chamber Longitudinal Culvert Design for Lock Filling and Emptying System

    National Research Council Canada - National Science Library

    Hite, John

    2003-01-01

    .... Some of these improvements include the addition or replacement of the navigation lock. Innovative design and construction techniques are being investigated for reducing construction costs, as well as operation and maintenance costs...

  7. The Eulerian buckling test for orthodontic wires.

    Science.gov (United States)

    De Santis, R; Dolci, F; Laino, A; Martina, R; Ambrosio, L; Nicolais, L

    2008-04-01

    Orthodontic treatment is mainly dependent on the loads developed by metal wires. The load developed by a buckled orthodontic wire is of great concern for molar distalization and cannot be simply derived from mechanical properties measured through classical tests (i.e. tensile, torsion, and bending). A novel testing method, based on the Eulerian approach of a simple supported beam, has been developed in order to measure the load due to buckling of orthodontic wires. Elastic titanium molybdenum alloy (TMA; SDS Ormco) and superelastic Nitinol (3M Unitek) and copper nickel-titanium (NiTi; SDS Ormco) wires, each having a rectangular cross section of 0.016 x 0.022 square inches (0.41 x 0.56 mm(2)), were used. The wires were activated and deactivated by loading and unloading. In order to analyse thermo-mechanical properties in buckling, mechanical tests were assisted by calorimetric measurements through differential scanning calorimetry (DSC). Statistical analysis to determine differences between the samples was undertaken using two-way analysis of variance (ANOVA) and Tukey's post hoc test, and one-way ANOVA to assess differences between the tested wires under similar conditions and different materials. The results suggest that the load due to buckling depends on material composition, wire length, the amount of activation, temperature, and deformation rate. The results can be considered as the lower bound for the loads experienced by teeth as far as a buckled wire is concerned. At a temperature higher than the austenite finish transition temperature, superelastic wires were strongly dependent on temperature and deformation rate. The effect due to an increase of deformation rate was similar to that of a decrease of temperature. Load variations due to temperature of a superelastic wire with a length of 20 mm were estimated to be approximately 4 g/degrees C. The high performance of an applied superelastic wire may be related to the high dynamics of the load in relation to

  8. Sequential push-pull pumping mechanism for washing and evacuation of an immunoassay reaction chamber on a microfluidic CD platform.

    Directory of Open Access Journals (Sweden)

    Tzer Hwai Gilbert Thio

    Full Text Available A centrifugal compact disc (CD microfluidic platform with reservoirs, micro-channels, and valves can be employed for implementing a complete immunoassay. Detection or biosensor chambers are either coated for immuno-interaction or a biosensor chip is inserted in them. On microfluidic CDs featuring such multi-step chemical/biological processes, the biosensor chamber must be repeatedly filled with fluids such as enzymes solutions, buffers, and washing solutions. After each filling step, the biosensor chamber needs to be evacuated by a passive siphoning process to prepare it for the next step in the assay. However, rotational speed dependency and limited space on a CD are two big obstacles to performing such repetitive filling and siphoning steps. In this work, a unique thermo-pneumatic (TP Push-Pull pumping method is employed to provide a superior alternative biosensor chamber filling and evacuation technique. The proposed technique is demonstrated on two CD designs. The first design features a simple two-step microfluidic process to demonstrate the evacuation technique, while the second design shows the filling and evacuation technique with an example sequence for an actual immunoassay. In addition, the performance of the filling and evacuation technique as a washing step is also evaluated quantitatively and compared to the conventional manual bench top washing method. The two designs and the performance evaluation demonstrate that the technique is simple to implement, reliable, easy to control, and allows for repeated push-pulls and thus filling and emptying of the biosensor chamber. Furthermore, by addressing the issue of rotational speed dependency and limited space concerns in implementing repetitive filling and evacuation steps, this newly introduced technique increases the flexibility of the microfluidic CD platform to perform multi-step biological and chemical processes.

  9. LEP vacuum chamber, early prototype

    CERN Multimedia

    CERN PhotoLab

    1978-01-01

    The structure of LEP, with long bending magnets and little access to the vacuum chamber between them, required distributed pumping. This is an early prototype for the LEP vacuum chamber, made from extruded aluminium. The main opening is for the beam. The small channel to the right is for cooling water, to carry away the heat deposited by the synchroton radiation from the beam. The 4 slots in the channel to the left house the strip-shaped ion-getter pumps (see 7810255). The ion-getter pumps depended on the magnetic field of the bending magnets, too low at injection energy for the pumps to function well. Also, a different design was required outside the bending magnets. This design was therefore abandoned, in favour of a thermal getter pump (see 8301153 and 8305170).

  10. Development of multiwire proportional chambers

    CERN Multimedia

    Charpak, G

    1969-01-01

    It has happened quite often in the history of science that theoreticians, confronted with some major difficulty, have successfully gone back thirty years to look at ideas that had then been thrown overboard. But it is rare that experimentalists go back thirty years to look again at equipment which had become out-dated. This is what Charpak and his colleagues did to emerge with the 'multiwire proportional chamber' which has several new features making it a very useful addition to the armoury of particle detectors. In the 1930s, ion-chambers, Geiger- Muller counters and proportional counters, were vital pieces of equipment in nuclear physics research. Other types of detectors have since largely replaced them but now the proportional counter, in new array, is making a comeback.

  11. Contemporary root canal filling strategies

    NARCIS (Netherlands)

    Moinzadeh, A.T.

    2016-01-01

    Currently, clinicians can choose from a wide range of root canal filling materials and techniques, some of which have been evaluated in this thesis. Methacrylate resin-based sealers suffer from polymerization shrinkage stresses. This limitation may partly be overcome by a two-step cementation

  12. Can-Filled Crash Barrier

    Science.gov (United States)

    Wilson, A. H.

    1983-01-01

    Crash barrier composed largely of used aluminum beverage cans protects occupants of cars in collisions with poles or trees. Lightweight, can-filled barrier very effective in softening impact of an automobile in head-on and off-angle collisions. Preliminary results indicate barrier is effective in collisions up to 40 mi/h (64 km/h).

  13. Brain Responses to Filled Gaps

    Science.gov (United States)

    Hestvik, Arild; Maxfield, Nathan; Schwartz, Richard G.; Shafer, Valerie

    2007-01-01

    An unresolved issue in the study of sentence comprehension is whether the process of gap-filling is mediated by the construction of empty categories (traces), or whether the parser relates fillers directly to the associated verb's argument structure. We conducted an event-related potentials (ERP) study that used the violation paradigm to examine…

  14. Wire grid and wire scanner design for the CERN Linac4

    CERN Document Server

    Roncarolo, F; Cheymol, B; Dutriat, C; Duraffourg, M; Focker, G J; Raich, U; Vuitton, C

    2010-01-01

    As part of the CERN LHC injector chain upgrade, LINAC4 [1] will accelerate H- ions from 45 KeV to 160 MeV. A number of wire grids and wire scanners will be used to characterize the beam transverse profile. This paper covers all monitor design aspects intended to cope with the required specifications. In particular, the overall measurement robustness, accuracy and sensitivity must be satisfied for different commissioning and operational scenarios. The physics mechanisms generating the wire signals and the wire resistance to beam induced thermal loads have been considered in order to determine the most appropriate monitor design in terms of wire material and dimensions.

  15. Steer-by-wire innovations and demonstrator

    NARCIS (Netherlands)

    Lupker, H.A.; Zuurbier, J.; Verschuren, R.M.A.F.; Jansen, S.T.H.; Willemsen, D.M.C.

    2002-01-01

    Arguments for 'by-wire' systems include production costs, packaging and traffic safety. Innovations concern both product and development process e.g. combined virtual engineering and Hardware-in-the-loop testing. Three Steer-by-wire systems are discussed: a steering system simulator used as a

  16. Add-On Shielding for Unshielded Wire

    Science.gov (United States)

    Koenig, J. C.; Billitti, J. W.; Tallon, J. M.

    1983-01-01

    Fabrication sequence used to produce compact shields slipped into place from free ends of wires already soldered into connectors at other ends. Single shields are formed into harnesses by connecting grounding jumpers. Technique is especially useful for small diameter wire attached to microminiature connectors.

  17. WIRED magazine announces rave awards nominees

    CERN Multimedia

    2002-01-01

    WIRED Magazine has anounced the nominees for its fourth annual WIRED Rave Awards, celebrating innovation and the individuals transforming commerce and culture. Jeffrey Hangst of the University of Aarhus has been nominated in the science category, for his work on the ATHENA Experiment, CERN (1/2 page).

  18. Kirschner Wire Breakage during Removal Requiring Retrieval

    Directory of Open Access Journals (Sweden)

    Kai Yuen Wong

    2016-01-01

    Full Text Available Kirschner wires (K-wires are widely used for fixation of fractures and dislocations in the hand as they are readily available, reliable, and cost-effective. Complication rates of up to 18% have been reported. However, K-wire breakage during removal is rare. We present one such case illustrating a simple technique for retrieval. A 35-year-old male presented with a distal phalanx fracture of his right middle finger. This open fracture was treated with K-wire fixation. Postoperatively, he developed a pin site infection with associated finger swelling. The K-wire broke during removal with the proximal piece completely retained in his middle phalanx. To minimise risk of osteomyelitis, the K-wire was removed with a novel surgical technique. He had full return of hand function. Intraoperative K-wire breakage has a reported rate of 0.1%. In our case, there was no obvious cause of breakage and the patient denied postoperative trauma. On the other hand, pin site infections are much more common with reported rates of up to 7% in the hand or wrist. K-wire fixation is a simple method for bony stabilisation but can be a demanding procedure with complications often overlooked. It is important to be aware of the potential sequelae.

  19. Emulating Wired Backhaul with Wireless Network Coding

    DEFF Research Database (Denmark)

    Thomsen, Henning; De Carvalho, Elisabeth; Popovski, Petar

    2014-01-01

    , the uplink traffic to the user, remains identical to the one performed in a wired system. In the broadcast phase, the decoding of the downlink traffic can also be guaranteed to remain identical. Hence, our solution claims an emulation of a wired backhaul with wireless network coding with same performance. We...

  20. Wire compensation: Performance, SPS MDs, pulsed system

    CERN Document Server

    Dorda, U

    2008-01-01

    A wire compensation (BBLR) scheme has been proposed in order to improve the long range beam-beam performance of the nominal LHC and its phase 1 and phase 2 upgrades[1]. In this paper we present experimental experience of the CERN SPS wires (BBLR) and report on progress with the RF BBLR.

  1. 75 FR 4584 - Wire Decking From China

    Science.gov (United States)

    2010-01-28

    ... and whether shipped as a kit or packaged separately. Wire decking is produced from carbon or alloy..., zinc or nickel coated), coated (e.g., with paint, epoxy, or plastic), or uncoated (``raw''). The wire... before June 28, 2010, but such final comments must not contain new factual information and must otherwise...

  2. GBO RF Anechoic Chamber & Antenna Test Range

    Data.gov (United States)

    Federal Laboratory Consortium — A shielded anechoic chamber measuring 15 by 15 by 37 feet is located in the Jansky Laboratory at Green Bank. This chamber has been outfitted as a far-field antenna...

  3. Wire scanners in low energy accelerators

    CERN Document Server

    Elmfors, P; Huhtinen, M; Lindroos, M; Olsfors, J; Raich, U

    1997-01-01

    Fast wire scanners are today considered as part of standard instrumentation in high energy synchrotrons. The extension of their use to synchrotrons working at lower energies, where Coulomb scattering can be important and the transverse beam size is large, introduces new complications considering beam heating of the wire, composition of the secondary particle shower and geometrical consideration in the detection set-up. A major problem in treating these effects is that the creation of secondaries in a thin carbon wire by a energetic primary beam is difficult to describe in an analytical way. We are here presenting new results from a full Monte Carlo simulation of this process yielding information on heat deposited in the wire, particle type and energy spectrum of secondaries and angular dependence as a function of primary beam energy. The results are used to derive limits for the use of wire scanners in low energy accelerators.

  4. Design of a Fully Anechoic Chamber

    OpenAIRE

    Rusz, Roman

    2015-01-01

    This thesis deals with fully anechoic chamber design. The main aim of this thesis is to design fully anechoic chamber according to acoustics laws and customers (Honeywell’s) requirements. The fully anechoic chamber will be used for measuring sound and vibration quantities. This work is divided into two main parts. The first part deals with the general anechoic chamber theory and all its related design aspects. The second part, practical part, focus on specific design according to requirements...

  5. Vacuum chamber at intersection I-6

    CERN Multimedia

    1971-01-01

    The vacuum chamber at intersection region I-6, one of these where experiments in colliding-beam physics will be taking place. The "wheels" prevent the thin wall (1.5 mm) of the chamber from collapsing. The chamber is equipped with heating tapes and its wrapped in thermal insulation. Residual gas pressure at this and other similar regions is around 10_11.

  6. Making a Fish Tank Cloud Chamber

    Science.gov (United States)

    Green, Frances

    2012-01-01

    The cloud chambers described here are large, made from readily available parts, simple to set up and always work. With no source in the chamber, background radiation can be observed. A large chamber means that a long rod containing a weakly radioactive material can be introduced, increasing the chance of seeing decays. Details of equipment and…

  7. A Sensitive Cloud Chamber without Radioactive Sources

    Science.gov (United States)

    Zeze, Syoji; Itoh, Akio; Oyama, Ayu; Takahashi, Haruka

    2012-01-01

    We present a sensitive diffusion cloud chamber which does not require any radioactive sources. A major difference from commonly used chambers is the use of a heat sink as its bottom plate. The result of a performance test of the chamber is given. (Contains 8 figures.)

  8. A mathematical model of aerosol holding chambers

    DEFF Research Database (Denmark)

    Zak, M; Madsen, J; Berg, E

    1999-01-01

    A mathematical model of aerosol delivery from holding chambers (spacers) was developed incorporating tidal volume (VT), chamber volume (Vch), apparatus dead space (VD), effect of valve insufficiency and other leaks, loss of aerosol by immediate impact on the chamber wall, and fallout of aerosol...

  9. Growing and analyzing biofilms in flow chambers

    DEFF Research Database (Denmark)

    Tolker-Nielsen, Tim; Sternberg, Claus

    2011-01-01

    This unit describes the setup of flow chamber systems for the study of microbial biofilms, and methods for the analysis of structural biofilm formation. Use of flow chambers allows direct microscopic investigation of biofilm formation. The biofilms in flow chambers develop under hydrodynamic cond...

  10. A Wire Grid Paraboloid for Large Low Frequency Telescopes

    Science.gov (United States)

    Kuiper, Tom

    2017-05-01

    Planetary magnetic fields are usually studied remotely through their electron cyclotron maser (ECM) emission from electrons trapped in their magnetic fields. Jupiter has been well studied since the 1960's because its strong magnetic field allows emissions up to about 40 MHz to be observed. The emission from Earth and other outer planets is mostly below 1 MHz and can only be observed from space. It is reasonable to assume that most exoplanets with ECM must be observed at low frequencies from space. Even optimistic assumptions about the strength of such emission leads one to conclude that very large filled aperture telescopes, with a diameters of a kilometer or more, will be needed.This paper reports on a study of a copper wire reflector with a diameter of 1 km operating between 100 kHz and 3.75 MHz. It would require 200 kg of 0.5 mm diameter copper wire (AWG 24)) to be lifted to and deployed in space. For aluminum, the mass would be about 100 kg. By optimizing the wire spacing the mass can be reduced to 80% of a simple radial-azimuthal arrangement. A relatively flat reflector (0.6 ≤ f/D ≤ 1.0) needs to be anchored at about 5 points from center to ring along 24 radii. Station-keeping CubeSats could serve as anchors. A total of about 100-120 anchors would be needed for an f/D = 1 reflector, adding 200-300 kg. to the mass of the reflector. It would be possible to carry several such reflectors into space in a single payload.The Deep Space Network is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract to the National Aeronautics and Space Administration.

  11. Hot wire needle probe for thermal conductivity detection

    Science.gov (United States)

    Condie, Keith Glenn; Rempe, Joy Lynn; Knudson, Darrell lee; Daw, Joshua Earl; Wilkins, Steven Curtis; Fox, Brandon S.; Heng, Ban

    2015-11-10

    An apparatus comprising a needle probe comprising a sheath, a heating element, a temperature sensor, and electrical insulation that allows thermal conductivity to be measured in extreme environments, such as in high-temperature irradiation testing. The heating element is contained within the sheath and is electrically conductive. In an embodiment, the heating element is a wire capable of being joule heated when an electrical current is applied. The temperature sensor is contained within the sheath, electrically insulated from the heating element and the sheath. The electrical insulation electrically insulates the sheath, heating element and temperature sensor. The electrical insulation fills the sheath having electrical resistance capable of preventing electrical conduction between the sheath, heating element, and temperature sensor. The control system is connected to the heating element and the temperature sensor.

  12. Investigation of a wire plate micro heat pipe array

    Energy Technology Data Exchange (ETDEWEB)

    Launay, Stephane; Sartre, Valerie; Lallemand, Monique [CETHIL, UMR CNRS 5008, INSA, 20, av. A. Einstein, 69621 Cedex, Villeurbanne (France); Mantelli, Marcia B.H.; Paiva, Kleber Vieira de [Mechanical Engineering Department, Federal University of Santa Catarina UFSC, P.O. Box 476, 88040-900, SC, Florianopolis (Brazil)

    2004-05-01

    In the present work, experimental and theoretical investigations have been conducted on a copper/water wire plate micro heat pipe (MHP). The experimental results show that its effective thermal conductivity is improved by a factor 1.3 as compared to the empty MHP array. A numerical model is used to predict the fluid distribution along the MHP axis, the temperature field and the maximum heat flux corresponding to the MHP capillary limit. The 1D, steady-state hydrodynamic model is based on the conservation equations for the liquid and vapour phases. The wall temperatures are calculated from the thermal resistance network of the wall and the liquid film. A good agreement between the theoretical and experimental data is achieved. The effect of various parameters - contact angle, fluid type, corner angle, fill charge - is theoretically investigated. (authors)

  13. Chamber B Thermal/Vacuum Chamber: User Test Planning Guide

    Science.gov (United States)

    Montz, Mike E.

    2012-01-01

    Test process, milestones and inputs are unknowns to first-time users of Chamber B. The User Test Planning Guide aids in establishing expectations for both NASA and non-NASA facility customers. The potential audience for this guide includes both internal and commercial spaceflight hardware/software developers. It is intended to assist their test engineering personnel in test planning and execution. Material covered includes a roadmap of the test process, roles and responsibilities of facility and user, major milestones, facility capabilities, and inputs required by the facility. Samples of deliverables, test article interfaces, and inputs necessary to define test scope, cost, and schedule are included as an appendix to the guide.

  14. A drift chamber tracking system for muon scattering tomography applications

    Science.gov (United States)

    Burns, J.; Quillin, S.; Stapleton, M.; Steer, C.; Snow, S.

    2015-10-01

    Muon scattering tomography (MST) allows the identification of shielded high atomic number (high-Z) materials by measuring the scattering angle of cosmic ray muons passing through an inspection region. Cosmic ray muons scatter to a greater degree due to multiple Coulomb scattering in high-Z materials than low-Z materials, which can be measured as the angular difference between the incoming and outgoing trajectories of each muon. Measurements of trajectory are achieved by placing position sensitive particle tracking detectors above and below the inspection volume. By localising scattering information, the point at which a series of muons scatter can be used to reconstruct an image, differentiating high, medium and low density objects. MST is particularly useful for differentiating between materials of varying density in volumes that are difficult to inspect visually or by other means. This paper will outline the experimental work undertaken to develop a prototype MST system based on drift chamber technology. The planar drift chambers used in this prototype measure the longitudinal interaction position of an ionising particle from the time taken for elections, liberated in the argon (92.5%), carbon dioxide (5%), methane (2.5%) gas mixture, to reach a central anode wire. Such a system could be used to enhance the detection of shielded radiological material hidden within regular shipping cargo.

  15. The Time Projection Chamber of the HARP Experiment

    CERN Document Server

    Lundborg, A

    2002-01-01

    The hadron production experiment HARP aims to measure hadron collision cross sections with a 2-15 GeV particle beam and several targets. This energy regime is in a borderline zone between the low energy region dominated by resonance formation and the high energy domain where perturbative Quantum Chromo Dynamics is applicable. The emphasis of this master thesis is put on the HARP central tracker, the Time Projection Chamber (TPC). In the thesis work, Finite Element Method computations of the electric field in critical regions of the TPC have been performed to provide design input concerning the electrostatic configuration of the field cages and of the wire chamber. A first step in the chain of reconstruction of the information produced by the detector is the equalisation and monitoring of about 4000 analogue signals. An algorithm that processes the raw digitised signals, filters out electronics noise and extracts the pad gain from signal distributions has been produced and analysed for this purpose. The algori...

  16. Fracture strength of different soldered and welded orthodontic joining configurations with and without filling material

    Directory of Open Access Journals (Sweden)

    Jens Johannes Bock

    2008-10-01

    Full Text Available The aim of this study was to compare the mechanical strength of different joints made by conventional brazing, TIG and laser welding with and without filling material. Five standardized joining configurations of orthodontic wire in spring hard quality were used: round, cross, 3 mm length, 9 mm length and 7 mm to orthodontic band. The joints were made by five different methods: brazing, tungsten inert gas (TIG and laser welding with and without filling material. For the original orthodontic wire and for each kind of joint configuration or connecting method 10 specimens were carefully produced, totalizing 240. The fracture strengths were measured with a universal testing machine (Zwick 005. Data were analyzed by ANOVA (p=0.05 and Bonferroni post hoc test (p=0.05. In all cases, brazing joints were ruptured on a low level of fracture strength (186-407 N. Significant differences between brazing and TIG or laser welding (p<0.05, Bonferroni post hoc test were found in each joint configuration. The highest fracture strength means were observed for laser welding with filling material and 3 mm joint length (998 N. Using filling materials, there was a clear tendency to higher mean values of fracture strength in TIG and laser welding. However, statistically significant differences were found only in the 9-mm long joints (p<0.05, Bonferroni post hoc test. In conclusion, the fracture strength of welded joints was positively influenced by the additional use of filling material. TIG welding was comparable to laser welding except for the impossibility of joining orthodontic wire with orthodontic band.

  17. Mechanical evaluation of hip cement spacer reinforcement with stainless steel Kirschner wires, titanium and carbon rods, and stainless steel mesh.

    Science.gov (United States)

    Kaku, Nobuhiro; Tabata, Tomonori; Tsumura, Hiroshi

    2015-04-01

    In two-stage treatments for infections after total hip arthroplasty, antibiotic-loaded cement spacers help treat the infection by antibiotic elution and prevent contraction. However, such spacers are weak and may fracture while awaiting replacement, impairing functionality. We evaluated whether a Kirschner wire (K-wire) mounted into the spacer reinforced its strength along with the effects of the reinforcing material, position, and intensity. Spacers without reinforcing materials constituted the control group. As reinforcing materials, stainless steel K-wires (diameters 3 and 6 mm), titanium alloy and carbon fibers (diameter 3.175 mm), and stainless steel meshes (inner and outer diameters, 6 and 9 mm, respectively) were inserted into the spacer mold before filling with cement. The spacers complied with ISO 7206-4; a compressive load was applied using a testing machine with a velocity of 25.4 mm/min, and the maximum load was recorded. We used 1-3 K-wires positioned on the medial side, lateral side, neck only, and stem only and tested 3 specimens for each condition. The control group withstood the highest load. Stainless steel was the strongest material; 3-mm K-wires in the neck and lateral side withstood a higher load. The computed tomography (CT) imaging revealed a cavity between the K-wires and cement. When K-wires were inserted along the whole length, despite cement fractures, continuity was maintained because of the reinforcing materials. It is difficult to improve the reinforcing strength of spacers using K-wires; however, K-wires prevented dislocation of cement spacer fragments, which can help prevent contraction and facilitate spacer removal during replacement.

  18. A mathematical model of aerosol holding chambers

    DEFF Research Database (Denmark)

    Zak, M; Madsen, J; Berg, E

    1999-01-01

    A mathematical model of aerosol delivery from holding chambers (spacers) was developed incorporating tidal volume (VT), chamber volume (Vch), apparatus dead space (VD), effect of valve insufficiency and other leaks, loss of aerosol by immediate impact on the chamber wall, and fallout of aerosol...... in the chamber with time. Four different spacers were connected via filters to a mechanical lung model, and aerosol delivery during "breathing" was determined from drug recovery from the filters. The formula correctly predicted the delivery of budesonide aerosol from the AeroChamber (Trudell Medical, London...

  19. Space filling curves in steganalysis

    Science.gov (United States)

    Westfeld, Andreas

    2005-03-01

    We introduce a new method to increase the reliability of current steganalytic techniques by optimising the sample order. Space filling curves (e.g., Hilbert curve) take advantage of the correlation of adjacent pixels and thus make the detection of steganographic messages with low change densities more reliable. The findings are applicable, but not limited to LSB steganalysis. An experimental comparison of five different sampling paths reveals that recursive principles achieve by far the best performance. All measures, such as mean distance, median autocorrelation, and the ability to detect even tiny modifications show substantial improvements compared to conventional methods. We elaborate the relationship between those parameters and quantify the effectiveness with a large test database of small images, which are usually hard to detect. Apart from quantitative advances, visualisation of steganalytic measures can also gain from the application of reverse space filling curves.

  20. Compact frontend-electronics and bidirectional 3.3 Gbps optical datalink for fast proportional chamber readout

    CERN Document Server

    Lüders, S; Eichler, R; Grab, C; Meier, B; Streuli, S; Szeker, K; Baumeister, D; Löchner, S; Stange, U; Boesiger, K; Robmann, P; Schmid, B A; Steiner, S; Straumann, U; Truöl, P

    2002-01-01

    The 9600 channels of the multi-wire proportional chamber of the H1 experiment at HERA have to be read out within 96 ns and made available to the trigger system. The tight spatial conditions at the rear end flange require a compact bidirectional readout electronics with minimal power consumption and dead material. A solution using 40 identical optical link modules, each transferring the trigger information with a physical rate of 4x832 Mbps via optical fibers, has been developed and commissioned. The analog pulses from the chamber can be monitored and the synchronization to the global HERA clock signal is ensured.

  1. Compact Frontend-Electronics and Bidirectional 3.3 Gbps Optical Datalink for Fast Proportional Chamber Readout

    CERN Document Server

    Lüders, S

    2001-01-01

    The 9600 channels of the multi-wire proportional chamber of the H1 experiment at HERA have to be read out within 96 ns and made available to the trigger system. The tight spatial conditions at the rear end flange require a compact bidirectional readout electronics with minimal power consumption and dead material. A solution using 40 identical optical link modules, each transferring the trigger information with a physical rate of 4 x 832 Mbps via optical fibers, has been developed and commisioned. The analog pulses from the chamber can be monitored and the synchronization to the global HERA clock signal is ensured.

  2. Particle-filled microporous materials

    Science.gov (United States)

    McAllister, Jerome W.; Kinzer, Kevin E.; Mrozinski, James S.; Johnson, Eric J.; Dyrud, James F.

    1990-01-01

    A microporous particulate-filled thermoplastic polymeric article is provided. The article can be in the form of a film, a fiber, or a tube. The article has a thermoplastic polymeric structure having a plurality of interconnected passageways to provide a network of communicating pores. The microporous structure contains discrete submicron or low micron-sized particulate filler, the particulate filler being substantially non-agglomerated.

  3. A silicon microstrip gas chamber

    Energy Technology Data Exchange (ETDEWEB)

    Van der Marel, J. (Radiation Technology Group, Faculty of Applied Physics, Delft Univ. of Tech. (Netherlands)); Van den Bogaard, A. (Delft Inst. of Microelectronics and Submicrotechnology, Delft Univ. of Tech. (Netherlands)); Van Eijk, C.W.E. (Radiation Technology Group, Faculty of Applied Physics, Delft Univ. of Tech. (Netherlands)); Hollander, R.W. (Radiation Technology Group, Faculty of Applied Physics, Delft Univ. of Tech. (Netherlands)); Okx, W.J.C. (Radiation Technology Group, Faculty of Applied Physics, Delft Univ. of Tech. (Netherlands)); Sarro, P.M. (Delft Inst. of Microelectronics and Submicrotechnology, Delft Univ. of Tech. (Netherlands))

    1994-09-01

    We are manufacturing microstrip gas chambers (MSGC) on silicon with an insulating SiO[sub 2] layer. To study the effect of the sheet resistance of the SiO[sub 2] on the operation of the detector several processes to modify the SiO[sub 2] layer have been investigated: ion implantation, boron and phosphorus diffusion, phosphosilicate glass evaporation and polycrystalline silicon deposition. The dependence of the gas gain on the potentials of the different electrodes and the long term stability have been studied. ((orig.))

  4. In-Situ Wire Damage Detection System

    Science.gov (United States)

    Williams, Martha; Roberson, Luke; Tate, Lanetra; Smith, Trent; Gibson, Tracy; Medelius, Pedro; Jolley, Scott

    2012-01-01

    An In-Situ Wire Damage Detection System (ISWDDS) has been developed that is capable of detecting damage to a wire insulation, or a wire conductor, or to both. The system will allow for realtime, continuous monitoring of wiring health/integrity and reduce the number of false negatives and false positives while being smaller, lighter in weight, and more robust than current systems. The technology allows for improved safety and significant reduction in maintenance hours for aircraft, space vehicles, satellites, and other critical high-performance wiring systems for industries such as energy production and mining. The integrated ISWDDS is comprised of two main components: (1) a wire with an innermost core conductor, an inner insulation film, a conductive layer or inherently conductive polymer (ICP) covering the inner insulation film, an outermost insulation jacket; and (2) smart connectors and electronics capable of producing and detecting electronic signals, and a central processing unit (CPU) for data collection and analysis. The wire is constructed by applying the inner insulation films to the conductor, followed by the outer insulation jacket. The conductive layer or ICP is on the outer surface of the inner insulation film. One or more wires are connected to the CPU using the smart connectors, and up to 64 wires can be monitored in real-time. The ISWDDS uses time domain reflectometry for damage detection. A fast-risetime pulse is injected into either the core conductor or conductive layer and referenced against the other conductor, producing transmission line behavior. If either conductor is damaged, then the signal is reflected. By knowing the speed of propagation of the pulse, and the time it takes to reflect, one can calculate the distance to and location of the damage.

  5. Pupillary block glaucoma following implantation of a posterior chamber pseudophakos in the anterior chamber.

    Directory of Open Access Journals (Sweden)

    Mandal Anil

    2002-01-01

    Full Text Available Pupillary block glaucoma is a common complication of cataract surgery, especially following anterior chamber intraocular lens implantation. We report a case of pupillary block glaucoma with a posterior chamber IOL that was implanted in the anterior chamber following a complicated extracapsular cataract extraction. The case was successfully managed by explantation of the posterior chamber lens, anterior vitrectomy, peripheral iridectomy and secondary anterior chamber intraocular lens implantation. The intraocular pressure was controlled with a single topical antiglaucoma medication.

  6. Front-end electronics and data acquisition system for a multi-wire 3D gas tracker

    Energy Technology Data Exchange (ETDEWEB)

    Łojek, K. [Institute of Physics, Jagiellonian University, 30348 Cracow (Poland); Rozpȩdzik, D., E-mail: dagmara.rozpedzik@uj.edu.pl [Institute of Physics, Jagiellonian University, 30348 Cracow (Poland); Bodek, K. [Institute of Physics, Jagiellonian University, 30348 Cracow (Poland); Perkowski, M. [Institute of Physics, Jagiellonian University, 30348 Cracow (Poland); Instituut voor Kern-en Stralingsfysica, University of Leuven, 3001 Leuven (Belgium); Severijns, N. [Instituut voor Kern-en Stralingsfysica, University of Leuven, 3001 Leuven (Belgium)

    2015-12-01

    This paper presents the design and implementation of the front-end electronics and the data acquisition (DAQ) system for readout of multi-wire drift chambers (MWDC). Apart of the conventional drift time measurement the system delivers the hit position along the wire utilizing the charge division technique. The system consists of preamplifiers, and analog and digital boards sending data to a back-end computer via an Ethernet interface. The data logging software formats the received data and enables an easy access to the data analysis software. The use of specially designed preamplifiers and peak detectors allows the charge-division readout of the low resistance signal wire. The implication of the charge-division circuitry onto the drift time measurement was studied and the overall performance of the electronic system was evaluated in dedicated off-line tests.

  7. Development of GEM-based readout chambers for the upgrade of the ALICE TPC

    Energy Technology Data Exchange (ETDEWEB)

    Deisting, Alexander [Universitaet Heidelberg/Gesellschaft fuer Schwerionenforschung GmbH (Germany); Collaboration: ALICE-Collaboration

    2015-07-01

    The ALICE experiment at the LHC is designed to examine lead-lead (Pb-Pb) collisions in order to probe genuine multi-particle aspects of QCD. Its main tracking detector is a time projection chamber (TPC), being equipped with a multi wire proportional chamber (MWPC) based readout. Since the rate in Pb-Pb collisions will increase to up to 50 kHz in LHC Run3 it is necessary to adapt the TPC to this new environment. A change from the current measurement mode with a gating grid and MWPCs to a continuous readout with new readout chambers is hence foreseen. To match the requirements for Run3 the new chambers should be able to cope with the higher rates and thereby preserve the momentum and dE/dx resolution of the current chambers. In addition the ion back flow (IBF) from the amplification stage into the drift volume should be less then 1%. A solution has been found based on 4 gas electron multiplier foils (GEMs) stacked onto each other. Extensive R and D studies of 4 GEM stacks were performed. In this talk different experimental setups to examine the performance of quadruple GEM stacks in terms of IBF, energy resolution and dE/dx are presented. Emphasis is put on the simultaneous optimisation of the energy resolution and the IBF while studying different kinds of GEM foils in a stack.

  8. Experimental setup to detect superconducting wire motion

    Science.gov (United States)

    Ruwali, K.; Yamanaka, A.; Teramoto, Y.; Nakanishi, K.; Hosoyama, K.

    2009-04-01

    An experimental setup was designed and fabricated to study superconducting wire motion under the influence of electromagnetic force. Experiments were conducted at 4.2 K by varying the experimental conditions such as the tension to the superconducting wire and different insulating materials at the interface of the superconducting wire and head part. The insulating materials used in the experiments were polyimide film and a high strength polyethylene fiber cloth, Dyneema. Details of the experimental setup and the test results are reported in this paper.

  9. Lasing from a single quantum wire

    OpenAIRE

    Hayamizu, Yuhei; Yoshita, Masahiro; Watanabe, Shinichi; Akiyama, Hidefumi; Pfeiffer, Loren N.; West, Ken W.

    2002-01-01

    A laser with an active volume consisting of only a single quantum wire in the 1-dimensional (1-D) ground state is demonstrated. The single wire is formed quantum-mechanically at the T-intersection of a 14 nm Al_{0.07}Ga_{0.93}As quantum well and a 6 nm GaAs quantum well, and is embedded in a 1-D single-mode optical waveguide. We observe single-mode lasing from the quantum wire ground state by optical pumping. The laser operates from 5 to 60 K, and has a low threshold pumping power of 5 mW at ...

  10. Experimental setup to detect superconducting wire motion

    Directory of Open Access Journals (Sweden)

    K. Ruwali

    2009-04-01

    Full Text Available An experimental setup was designed and fabricated to study superconducting wire motion under the influence of electromagnetic force. Experiments were conducted at 4.2 K by varying the experimental conditions such as the tension to the superconducting wire and different insulating materials at the interface of the superconducting wire and head part. The insulating materials used in the experiments were polyimide film and a high strength polyethylene fiber cloth, Dyneema. Details of the experimental setup and the test results are reported in this paper.

  11. Understanding the Relationship Between Filling Pattern and Part Quality in Die Casting

    Energy Technology Data Exchange (ETDEWEB)

    Jerald Brevick; R. Allen Miller

    2004-03-15

    The overall objective of this research project was to investigate phenomena involved in the filling of die cavities with molten alloy in the cold chamber die-casting process. It has long been recognized that the filling pattern of molten metal entering a die cavity influences the quality of die-cast parts. Filling pattern may be described as the progression of molten metal filling the die cavity geometry as a function of time. The location, size and geometric configuration of points of metal entry (gates), as well as the geometry of the casting cavity itself, have great influence on filling patterns. Knowledge of the anticipated filling patterns in die-castings is important for designers. Locating gates to avoid undesirable flow patterns that may entrap air in the casting is critical to casting quality - as locating vents to allow air to escape from the cavity (last places to fill). Casting quality attributes that are commonly flow related are non-fills, poor surface finish, internal porosity due to trapped air, cold shuts, cold laps, flow lines, casting skin delamination (flaking), and blistering during thermal treatment.

  12. Chemically etched modulation in wire radius for wire array Z-pinch perturbation studies

    Science.gov (United States)

    Jones, B.; Deeney, C.; McKenney, J. L.; Garrity, J. E.; Lobley, D. K.; Martin, K. L.; Griego, A. E.; Ramacciotti, J. P.; Bland, S. N.; Lebedev, S. V.; Bott, S. C.; Ampleford, D. J.; Palmer, J. B. A.; Rapley, J.; Hall, G.

    2004-11-01

    A technique for manufacturing wires with imposed modulation in radius with axial wavelengths as short as 1 mm is presented. Extruded aluminum 5056 with 15 μm diameter was masked and chemically etched to reduce the radius by ˜20% in selected regions. Characterized by scanning electron microscopy, the modulation in radius is a step function with a ˜10 μm wide conical transition between thick and thin segments, with some pitting in etched regions. Techniques for mounting and aligning these wires in arrays for fast z-pinch experiments will be discussed. Axially mass-modulated wire arrays of this type will allow the study of seeded Rayleigh-Taylor instabilities in z pinches, corona formation, wire initiation with varying current density in the wire core, and correlation of perturbations between adjacent wires. This tool will support magnetohydrodynamics code validation in complex three-dimensional geometries, and perhaps x-ray pulse shaping.

  13. Corrosion susceptibility and nickel release of nickel titanium wires during clinical application.

    Science.gov (United States)

    Petoumeno, Evangelia; Kislyuk, Maya; Hoederath, Hildegard; Keilig, Ludger; Bourauel, Christoph; Jäger, Andreas

    2008-11-01

    Orthodontic wires are exposed to a corrosive intraoral environment and are subject to mechanical and thermal load. This could affect how nickel titanium (NiTi) wires corrode, as they possess temperature- and load-dependent characteristics. It was the scope of this study to determine whether the clinical application of NiTi wires would lead to corrosion defects on the wire surfaces, and whether an influence on the patients' salivary Ni ion concentration would become apparent. A total of 115 wires of different manufacturers (Forestadent Titanol 'Low Force' und 'Martensitic', Ormco Copper Ni-Ti 35 degrees C, Ortho Organizers NiTi) was retrieved after intraoral application lasting 1 to 12 months. The wires were examined after cleaning with a scanning electron microscope. We also analyzed the salivary Ni ion concentration in 18 patients at predefined intervals following a detailed orthodontic treatment protocol during the initial phase of orthodontic therapy. The intervals were: 1) a saliva sample before treatment commenced, 2) after bonding of brackets and bands, 3) 2 weeks after bonding, immediately before and 4) immediately after fitting the archwires, and 5) 4 and 6) 8 weeks after placing the archwires. 16 to 20 brackets and bands were bonded in the upper and lower jaws, while NiTi leveling arches (ODS Euro Arch Opto Therm, 0.40 mm round) were fitted. The saliva samples were quick-frozen and subsequently dried under red light. Dried residuals were dissolved in aqua regia and filled up to 3 ml. The solutions were analyzed using a mass spectrometer (Perkin Elmer Elan 5000). Surface analysis revealed no differences in the degree of corrosion of the different products. In fact, we observed only extremely small and isolated corrosion defects. No statistically-significant differences were noted in the Ni ion concentration at time points 1 (reference value), 3, 5 and 6 (34, 34, 28 and 30 microg/l, respectively). The samples taken immediately after bracket bonding or the Ni

  14. Thermal Performance Evaluation of Walls with Gas Filled Panel Insulation

    Energy Technology Data Exchange (ETDEWEB)

    Shrestha, Som S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Desjarlais, Andre Omer [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Atchley, Jerald Allen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-11-01

    Gas filled insulation panels (GFP) are very light weight and compact (when uninflated) advanced insulation products. GFPs consist of multiple layers of thin, low emittance (low-e) metalized aluminum. When expanded, the internal, low-e aluminum layers form a honeycomb structure. These baffled polymer chambers are enveloped by a sealed barrier and filled with either air or a low-conductivity gas. The sealed exterior aluminum foil barrier films provide thermal resistance, flammability protection, and properties to contain air or a low conductivity inert gas. This product was initially developed with a grant from the U.S. Department of Energy. The unexpanded product is nearly flat for easy storage and transport. Therefore, transportation volume and weight of the GFP to fill unit volume of wall cavity is much smaller compared to that of other conventional insulation products. This feature makes this product appealing to use at Army Contingency Basing, when transportation cost is significant compared to the cost of materials. The objective of this study is to evaluate thermal performance of walls, similar to those used at typical Barracks Hut (B-Hut) hard shelters, when GFPs are used in the wall cavities. Oak Ridge National Laboratory (ORNL) tested performance of the wall in the rotatable guarded hotbox (RGHB) according to the ASTM C 1363 standard test method.

  15. CATS, a low pressure multiwire proportional chamber for secondary beam tracking at GANIL

    CERN Document Server

    Ottini-Hustache, S; Auger, F; Musumarra, A; Alamanos, N; Cahan, B; Gillibert, A; Lagoyannis, A; Maillard, O; Pollacco, E; Sida, J L; Riallot, M

    1999-01-01

    A beam detector system, CATS (Chambre A Trajectoires de Saclay), was designed to provide event-by-event particle tracking in experiments with radioactive beams at GANIL. It consists of two low pressure multiwire proportional chambers with one plane of anode wires placed between two cathode planes (active area: 70x70 mm sup 2), respectively segmented into 28 vertical or horizontal strips (2.54 mm wide). The anode wires deliver a time signal allowing a time of flight measurement with an accuracy between 440 ps and 1.2 ns, depending on the energy loss of incident particles in the detector. The cathode strips are individually read out and the position of incoming particles is reconstructed using a charge centroid finding algorithm. A spatial resolution of 400 mu m (700 mu m) was achieved during in beam experiment, with a counting rate of 1.5x10 sup 5 (10 sup 6) particles per second. (author)

  16. Molecular wires, switches and memories

    Science.gov (United States)

    Chen, Jia

    Molecular electronics, an emerging field, makes it possible to build individual molecules capable of performing functions identical or analogous to present- day conductors, switches, or memories. These individual molecules, with a nano-meter scale characteristic length, can be designed and chemically synthesized with specific atoms, geometries and charge distribution. This thesis focuses on the design, and measurements of molecular wires, and related strategically engineered structures-molecular switches and memories. The experimental system relies on a thermodynamically driven self-assembling process to attach molecules onto substrate surfaces without intervention from outside. The following topics will be discussed: directed nanoscale manipulation of self-assembled molecules using scanning tunneling microscope; investigation on through-bond transport of nanoscale symmetric metal/conjugated self- assembled monolayers (SAM)/metal junctions, where non- Ohmic thermionic emission was observed to be the dominant process, with isocyanide-Pd contacts showing the lowest thermionic barrier of 0.22 eV; the first realization of robust and large reversible switching behavior in an electronic device that utilizes molecules containing redox centers as the active component, exhibiting negative differential resistance (NDR) and large on-off peak-to-valley ratio (PVR); observation of erasable storage of higher conductivity states in these redox- center containing molecular devices, and demonstration of a two-terminal electronically programmable and erasable molecular memory cell with long bit retention time.

  17. Magnetoimpedance simulations in wires and tubes

    CERN Document Server

    Munoz, J L; Kurlyandskaya, G V; Garcia-Arribas, A

    2002-01-01

    Numerical computations have been used to study the magnetoimpedance (MI) effect in magnetic wires and microtubes. Two kinds of wires have been investigated. In the first case, a typical amorphous wire with a core-shell structure is simulated, considering the different magnetization curve of each layer, and in the second case, a non-magnetic wire with a thin deposited layer of magnetic material is studied. The results of the simulations agree in both cases with the experimental behavior usually found for these samples. They also allow us to explain such features as MI saturation and the influence of the resistivities of the conductive and magnetic layers in microtubes, that can improve MI-based devices.

  18. Wire core reactor for nuclear thermal propulsion

    Science.gov (United States)

    Harty, Richard B.; Brengle, Robert G.

    1993-01-01

    Studies have been performed of a compact high-performance nuclear rocket reactor that incorporates a tungsten alloy wire fuel element. This reactor, termed the wire core reactor, can deliver a specific impulse of 1,000 s using an expander cycle and a nozzle expansion ratio of 500 to 1. The core is constructed of layers of 0.8-mm-dia fueled tungsten wires wound over alternate layers of spacer wires, which forms a rugged annular lattice. Hydrogen flow in the core is annular, flowing from inside to outside. In addition to the concepts compact size and good heat transfer, the core has excellent power-flow matching features and can resist vibration and thermal stresses during star-up and shutdown.

  19. Wire Bonder: Kulicke and Soffa Model 4526

    Data.gov (United States)

    Federal Laboratory Consortium — Description:CORAL Name: Wire BonderNeeds Description.Scientific Opportunities / Applications:Wedge bonderSemi-automatic and manual modesIndependent Z-axis control,...

  20. Highly stretchable wrinkled gold thin film wires

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Joshua, E-mail: joshuk7@uci.edu; Park, Sun-Jun; Nguyen, Thao [Department of Chemical Engineering and Materials Science, University of California, Irvine, California 92697 (United States); Chu, Michael [Department of Biomedical Engineering, University of California, Irvine, California 92697 (United States); Pegan, Jonathan D. [Department of Materials and Manufacturing Technology, University of California, Irvine, California 92697 (United States); Khine, Michelle, E-mail: mkhine@uci.edu [Department of Chemical Engineering and Materials Science, University of California, Irvine, California 92697 (United States); Department of Biomedical Engineering, University of California, Irvine, California 92697 (United States)

    2016-02-08

    With the growing prominence of wearable electronic technology, there is a need to improve the mechanical reliability of electronics for more demanding applications. Conductive wires represent a vital component present in all electronics. Unlike traditional planar and rigid electronics, these new wearable electrical components must conform to curvilinear surfaces, stretch with the body, and remain unobtrusive and low profile. In this paper, the piezoresistive response of shrink induced wrinkled gold thin films under strain demonstrates robust conductive performance in excess of 200% strain. Importantly, the wrinkled metallic thin films displayed negligible change in resistance of up to 100% strain. The wrinkled metallic wires exhibited consistent performance after repetitive strain. Importantly, these wrinkled thin films are inexpensive to fabricate and are compatible with roll to roll manufacturing processes. We propose that these wrinkled metal thin film wires are an attractive alternative to conventional wires for wearable applications.

  1. 30 CFR 77.701-3 - Grounding wires; capacity.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Grounding wires; capacity. 77.701-3 Section 77... MINES Grounding § 77.701-3 Grounding wires; capacity. Where grounding wires are used to ground metallic sheaths, armors, conduits, frames, casings, and other metallic enclosures, such grounding wires will be...

  2. 47 CFR 32.2321 - Customer premises wiring.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Customer premises wiring. 32.2321 Section 32... Customer premises wiring. (a) This account shall include all amounts transferred from the former Account 232, Station Connections, inside wiring subclass. (b) Embedded Customer Premises Wiring is that...

  3. Cobalt chromium sublaminar wires for spinal deformity surgery.

    Science.gov (United States)

    Cluck, Michael W; Skaggs, David L

    2006-09-01

    Biomechanical analysis and retrospective chart review. To determine the mechanical properties of cobalt chromium alloy wires and review the clinical application of the wires as sublaminar implants to correct spinal deformity. Sublaminar wires are commonly used as anchors in spinal deformity surgery. In stainless steel instrumentation systems, single strand wires (Luque wires) may be retightened over time to take advantage of stress relaxation while correcting spinal deformity. Because of the mechanical properties of titanium, solid titanium wires are not used as sublaminar wires. Cobalt chromium alloy is a titanium compatible alloy that can be twisted in a similar fashion to stainless steel sublaminar wires. Comparative tensile tests were performed using cobalt chromium alloy wires and Luque stainless steel wires. In addition, 22 consecutive posterior spinal fusions for idiopathic scoliosis were performed using cobalt chromium alloy wires as sublaminar implants. Yield and ultimate tensile loads for the cobalt chromium alloy wires are on average 66% (P cobalt chromium alloy wires were used as sublaminar implants. Mean preoperative lumbar curve was 52 degrees +/- 14 degrees , which corrected to 17 degrees +/- 8 degrees (68% correction, P cobalt chromium alloy wire over steel wire include greater tensile strength and titanium compatibility. Cobalt chromium alloy solid wires may be used as sublaminar implants with titanium spinal instrumentation with excellent clinical results.

  4. Transferring calibration coefficients from ionisation chambers used for diagnostic radiology to transmission chambers.

    Science.gov (United States)

    Yoshizumi, Maíra T; Caldas, Linda V E

    2012-07-01

    In this work, the response of a double volume transmission ionisation chamber, developed at the Instituto de Pesquisas Energéticas e Nucleares, was compared to that of a commercial transmission chamber. Both ionisation chambers were tested in different X-ray beam qualities using secondary standard ionisation chambers as reference dosimeters. These standard ionisation chambers were a parallel-plate and a cylindrical ionisation chambers, used for diagnostic radiology and mammography beam qualities, respectively. The response of both transmission chambers was compared to that of the secondary standard chambers to obtain coefficients of equivalence. These coefficients allow the transmission chambers to be used as reference equipment. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Filling patterns in contrast ventriculography

    Science.gov (United States)

    Ferguson, Lawrence

    1974-01-01

    The filling patterns of a negative contrast material (air), a positive contrast water soluble material (Conray), and a positive contrast water insoluble material (Myodil) were examined in 60 normal ventriculograms. Using a scoring system developed for this study, Conray was found effective for outlining the ipsilateral (injected) lateral ventricle, the third ventricle, the aqueduct of Sylvius, and the fourth ventricle. Air was the most effective for the noninjected lateral ventricle, while Myodil was best for A-P demonstration of the aqueduct. The clinical implications of these findings are discussed. PMID:4545798

  6. Audio wiring guide how to wire the most popular audio and video connectors

    CERN Document Server

    Hechtman, John

    2012-01-01

    Whether you're a pro or an amateur, a musician or into multimedia, you can't afford to guess about audio wiring. The Audio Wiring Guide is a comprehensive, easy-to-use guide that explains exactly what you need to know. No matter the size of your wiring project or installation, this handy tool provides you with the essential information you need and the techniques to use it. Using The Audio Wiring Guide is like having an expert at your side. By following the clear, step-by-step directions, you can do professional-level work at a fraction of the cost.

  7. A Magnetic Sensor with Amorphous Wire

    Directory of Open Access Journals (Sweden)

    Dongfeng He

    2014-06-01

    Full Text Available Using a FeCoSiB amorphous wire and a coil wrapped around it, we have developed a sensitive magnetic sensor. When a 5 mm long amorphous wire with the diameter of 0.1 mm was used, the magnetic field noise spectrum of the sensor was about 30 pT/ÖHz above 30 Hz. To show the sensitivity and the spatial resolution, the magnetic field of a thousand Japanese yen was scanned with the magnetic sensor.

  8. Graphene wire medium: Homogenization and application

    DEFF Research Database (Denmark)

    Andryieuski, Andrei; Chigrin, Dmitry N.; Lavrinenko, Andrei

    2012-01-01

    In this contribution we analyze numerically the optical properties of the graphene wire medium, which unit cell consists of a stripe of graphene embedded into dielectric. We propose a simple method for retrieval of the isofrequency contour and effective permittivity tensor. As an example...... of the graphene wire medium application we demonstrate a reconfigurable hyperlens for the terahertz subwavelength imaging capable of resolving two sources with separation λ0/5 in the far-field....

  9. Subwavelength wire array metamaterial microwave cavities

    Science.gov (United States)

    Al-Rubaiee, M.; Alchalaby, A.; Al-Janabi, H.

    2018-01-01

    Wire array metamaterial cavities and waveguides can be achieved by changing the resonance frequency of one or more unit cell surrounding by unit cells don't support the resonance for certain frequency and hence obtain signal confinement only on the defect wires. Changing the resonance frequency of one or more unit cell was done in this work by changing the length of the unit cell. We validate our approach in experiment and simulation with electromagnetic waves in the microwave range.

  10. Electronic Properties of Quantum Wire Networks

    OpenAIRE

    Kuzmenko, Igor

    2005-01-01

    Quantum wire networks (``quantum crossbars'', QCB) represent a 2D grid formed by superimposed crossing arrays of parallel conducting quantum wires, molecular chains or metallic single-wall carbon nanotubes. QCB coupled only by capacitive interaction in the crosses have similar low-energy, long-wave properties characterized as a crossed sliding Luttinger liquid (CSLL) phase. In this Thesis we develop a theory of interacting Bose excitations (plasmons) in QCB. We analyze spectrum of boson field...

  11. Novel use of the "buddy"wire.

    LENUS (Irish Health Repository)

    O'Hare, A

    2008-12-29

    Summary: During interventional procedures the tortuosity of the vasculature hampers catheter stability. The buddy wire may be used to aid and maintain vascular access.We describe a case of acute subarachnoid haemorrhage secondary to dissecting aneurysm of the vertebral artery.We discuss the value of the buddy wire during balloon occlusion of the vertebral artery not as it is typically used, but to actually prevent the balloon repeatedly entering the posterior inferior cerebellar artery during the procedure.

  12. Charge Transport Along Phenylenevinylene Molecular Wires

    OpenAIRE

    Siebbeles, Laurens; Prins, Paulette; Grozema, Ferdinand

    2006-01-01

    Abstract A model to calculate the mobility of charges along molecular wires is presented. The model is based on the tight-binding approximation and combines a quantum mechanical description of the charge with a classical description of the structural degrees of freedom. It is demonstrated that the average mobility of charge carriers along molecular wires can be obtained by time-propagation of states which are initially localised. The model is used to calculate the mobility of charg...

  13. Wiring System Diagnostic Techniques for Legacy Aircraft

    Science.gov (United States)

    2003-02-01

    Reunions des specialistes des techniques de estion du cycle de vie pour vehicules aeriens vieillissants ] To order the complete compilation report, use...Ageing Mechanisms and Control. Specialists’ Meeting on Life Management Techniques for Ageing Air Vehicles [Les mecanismes vieillissants et le controle...be identified. Additionally, wiring failures tend to be intermittent in nature and can take considerable time to isolate. Wire modifications and

  14. Subchannel Analysis of Wire Wrapped SCWR Assembly

    Directory of Open Access Journals (Sweden)

    Jianqiang Shan

    2014-01-01

    Full Text Available Application of wire wrap spacers in SCWR can reduce pressure drop and obtain better mixing capability. As a consequence, the required coolant pumping power is decreased and the coolant temperature profile inside the fuel bundle is flattened which will obviously decrease the peak cladding temperature. The distributed resistance model for wire wrap was developed and implemented in ATHAS subchannel analysis code. The HPLWR wire wrapped assembly was analyzed. The results show that: (1 the assembly with wire wrap can obtain a more uniform coolant temperature profile than the grid spaced assembly, which will result in a lower peak cladding temperature; (2 the pressure drop in a wire wrapped assembly is less than that in a grid spaced assembly, which can reduce the operating power of pump effectively; (3 the wire wrap pitch has significant effect on the flow in the assembly. Smaller Hwire/Drod will result in stronger cross flow a more uniform coolant temperature profile, and also a higher pressure drop.

  15. Induced Voltage in an Open Wire

    Science.gov (United States)

    Morawetz, K.; Gilbert, M.; Trupp, A.

    2017-07-01

    A puzzle arising from Faraday's law has been considered and solved concerning the question which voltage will be induced in an open wire with a time-varying homogeneous magnetic field. In contrast to closed wires where the voltage is determined by the time variance of the magnetic field and the enclosed area, in an open wire we have to integrate the electric field along the wire. It is found that the longitudinal electric field with respect to the wave vector contributes with 1/3 and the transverse field with 2/3 to the induced voltage. In order to find the electric fields the sources of the magnetic fields are necessary to know. The representation of a spatially homogeneous and time-varying magnetic field implies unavoidably a certain symmetry point or symmetry line which depend on the geometry of the source. As a consequence the induced voltage of an open wire is found to be the area covered with respect to this symmetry line or point perpendicular to the magnetic field. This in turn allows to find the symmetry points of a magnetic field source by measuring the voltage of an open wire placed with different angles in the magnetic field. We present exactly solvable models of the Maxwell equations for a symmetry point and for a symmetry line, respectively. The results are applicable to open circuit problems like corrosion and for astrophysical applications.

  16. The technology of testing the safety of steel wire ropes

    Science.gov (United States)

    Zhang, Xiaochun; Hu, Caiwen

    2005-12-01

    To estimate the security of steel wire rope, the broken wire condition, the capability of the rope to bear weight and the state of stress balance of each wire in the steel wire rope were investigated. The wavelet translation method was applied to analyze the signals of magnetic field leakage from the steel wire rope. The result of the time-frequency analysis of the signals can be used to make certain of he position and the amount of the broken wire. Using the static surveillance method as a basis, a dynamic surveillance method was designed to detect the stress balance of the steel wire rope. This technology makes it possible to check the stress condition of each wire on line. It can be concluded that a wavelet translation analysis and the dynamic surveillance technique are effective methods to detect on line and real-time the broken wire and the stress balance of multistrand wire ropes.

  17. Tests of anechoic chamber for aeroacoustics investigations

    Science.gov (United States)

    Palchikovskiy, V. V.; Bersenev, Yu. V.; Makashov, S. Yu.; Belyaev, I. V.; Korin, I. A.; Sorokin, E. V.; Khramtsov, I. V.; Kustov, O. Yu.

    2016-10-01

    The paper presents the results of qualification tests in the new anechoic chamber of Perm National Research Polytechnic University (PNRPU) built in 2014-2015 and evaluation of the chamber quality in aeroacoustic experiments. It describes design features of the chamber and its sound-absorption lining. The qualification tests were carried out with tonal and broadband noise sources in the frequency range 100 Hz - 20 kHz for two different cases of the source arrangement. In every case, measurements were performed in three directions by traverse microphones. Qualification tests have determined that in the chamber there is a free acoustic field within radius of 2 m for tonal noise and 3 m for broadband noise. There was also evaluated acoustic quality of the chamber by measurements of the jet noise and vortex ring noise. The results of the experiments demonstrate that PNRPU anechoic chamber allows the aeroacoustic measurements to be performed to obtain quantitative results.

  18. Bio-inspired dental fillings

    Science.gov (United States)

    Deyhle, Hans; Bunk, Oliver; Buser, Stefan; Krastl, Gabriel; Zitzmann, Nicola U.; Ilgenstein, Bernd; Beckmann, Felix; Pfeiffer, Franz; Weiger, Roland; Müller, Bert

    2009-08-01

    Human teeth are anisotropic composites. Dentin as the core material of the tooth consists of nanometer-sized calcium phosphate crystallites embedded in collagen fiber networks. It shows its anisotropy on the micrometer scale by its well-oriented microtubules. The detailed three-dimensional nanostructure of the hard tissues namely dentin and enamel, however, is not understood, although numerous studies on the anisotropic mechanical properties have been performed and evaluated to explain the tooth function including the enamel-dentin junction acting as effective crack barrier. Small angle X-ray scattering (SAXS) with a spatial resolution in the 10 μm range allows determining the size and orientation of the constituents on the nanometer scale with reasonable precision. So far, only some dental materials, i.e. the fiber reinforced posts exhibit anisotropic properties related to the micrometer-size glass fibers. Dental fillings, composed of nanostructures oriented similar to the natural hard tissues of teeth, however, do not exist at all. The current X-ray-based investigations of extracted human teeth provide evidence for oriented micro- and nanostructures in dentin and enamel. These fundamental quantitative findings result in profound knowledge to develop biologically inspired dental fillings with superior resistance to thermal and mechanical shocks.

  19. Rice Husk Filled Polymer Composites

    Directory of Open Access Journals (Sweden)

    Reza Arjmandi

    2015-01-01

    Full Text Available Natural fibers from agricultural wastes are finding their importance in the polymer industry due to the many advantages such as their light weight, low cost and being environmentally friendly. Rice husk (RH is a natural sheath that forms around rice grains during their growth. As a type of natural fiber obtained from agroindustrial waste, RH can be used as filler in composites materials in various polymer matrices. This review paper is aimed at highlighting previous works of RH filled polymer composites to provide information for applications and further research in this area. Based on the information gathered, application of RH filled composites as alternative materials in building and construction is highly plausible with both light weight and low cost being their main driving forces. However, further investigations on physical and chemical treatment to further improve the interfacial adhesion with polymeric matrix are needed as fiber-polymer interaction is crucial in determining the final composite properties. Better understanding on how the used polymer blends as the matrix and secondary fillers may affect the properties would provide interesting areas to be explored.

  20. Silicone Gel-Filled Breast Implants

    Science.gov (United States)

    ... Medical Procedures Implants and Prosthetics Breast Implants Silicone Gel-Filled Breast Implants Share Tweet Linkedin Pin it ... options Linkedin Pin it Email Print Description: Silicone gel-filled breast implants have a silicone outer shell ...

  1. Domain walls and spacetime-filling branes

    NARCIS (Netherlands)

    Bergshoeff, E; Wess, J; Ivanov, EA

    1999-01-01

    We discuss branes with one transversal direction (domain walls) and no transversal direction (spacetime-filling branes). In particular, we briefly discuss a relationship between spacetime-filling branes and superstring theories with sixteen supercharges.

  2. 75 FR 60480 - In the Matter of Certain Bulk Welding Wire Containers and Components Thereof and Welding Wire...

    Science.gov (United States)

    2010-09-30

    ... COMMISSION In the Matter of Certain Bulk Welding Wire Containers and Components Thereof and Welding Wire... importation, or the sale within the United States after importation of certain bulk welding wire containers, components thereof, and welding wire by reason of infringement of certain claims of United States Patent Nos...

  3. Use of a tip-edge stage-1 wire to enhance vertical control during straight wire treatment: two case reports.

    Science.gov (United States)

    Taylor, Helen

    2003-02-01

    Vertical control is one of the problems occasionally encountered in Straight wire treatment. Two cases, one with deep overbite and one with anterior open-bite, demonstrate the use of a Tip-Edge stage-1 wire to enhance vertical control in conjunction with Straight wire brackets and superelastic main arch wires.

  4. Vacuum Chamber for the Booster Bending Magnets

    CERN Multimedia

    CERN PhotoLab

    1974-01-01

    To minimize eddy currents, induced by the rising magnetic field, the chamber was made from thin stainless steel of high specific electric resistance. For mechanical stength, it was corrugated in a hydro-forming process. The chamber is curved, to follow the beam's orbital path. Under vacuum, the chamber tends to staighten, the ceramic spacer along half of its length keeps it in place (see also 7402458).

  5. Drift chamber tracking with neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Lindsey, C.S.; Denby, B.; Haggerty, H.

    1992-10-01

    We discuss drift chamber tracking with a commercial log VLSI neural network chip. Voltages proportional to the drift times in a 4-layer drift chamber were presented to the Intel ETANN chip. The network was trained to provide the intercept and slope of straight tracks traversing the chamber. The outputs were recorded and later compared off line to conventional track fits. Two types of network architectures were studied. Applications of neural network tracking to high energy physics detector triggers is discussed.

  6. Bicone vacuum chamber for ISR intersection

    CERN Multimedia

    1975-01-01

    This is one of the bicone chambers made of titanium for experiment R 702. The central corrugated part had a very thin titanium wall (0.28 mm). The first of these chambers collapsed in its central part when baked at 300 C (August 1975). After an intensive effort to develop better quality and reproducible welds for this special material, the ISR workshop was able to build two new chambers of this type. One of them was installed at I 7 for R 702 in 1976 and worked perfectly. It was at that time the most "transparent" intersection vacuum chamber. See also 7609219, 7609221.

  7. Anechoic chamber for VHF and UHF bands

    Science.gov (United States)

    Morikawa, Takao; Sugiura, Akira; Harima, Katsushige; Masuzawa, Hiroshi

    1995-06-01

    Built in 1969, the anechoic chamber of CRL has been used to the fullest by researchers in many fields such as EMI, EMC, antenna design, standard of electric field intensity, and type approval testing. In particular, in the early days of space development in Japan, many satellite-born antennas were developed in this anechoic chamber. However, a quarter of a century has passed since its construction and deteriorated performance due to superannuation sometimes caused difficulties in experiments conducted in the chamber. In 1993, CRL constructed a Measuring Facility for Radio Research (MFRR) and the anechoic chamber for VHF-UHF bands was remodeled as one of the sub-facilities of MFRR. The remodeling work included full replacement of the electromagnetic shielding, absorbers and measurement system. Since the remodeled anechoic chamber is being used not only for EMI tests but also for other purposes, a full-anechoic chamber has been adopted. In addition the chamber has been designed for the frequency range between 30 MHz and 10 GHz. After the remodeling work, the performance of the chamber is greatly improved. The average shielding factor is better than 85 dB for all frequency ranges and the unwanted reflection characteristic is -30 dB for frequencies above 1 GHZ. This paper summarizes the remodeling work, and the specifications and performance of the remodeled anechoic chamber.

  8. Precision Radio Frequency Anechoic Chamber Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Performs measurements and calibration of antennas for satellites and aircraft or groundbased systems. The chamber is primarily used for optimizing antenna...

  9. D0 Central Tracking Chamber Performance Studies

    Energy Technology Data Exchange (ETDEWEB)

    Pizzuto, Domenico [State Univ. of New York (SUNY), Stony Brook, NY (United States)

    1991-01-01

    The performance of the completed DO central tracking chamber was studied using cosmic rays at the State University of New York at Stony Brook. Also studied was a prototype tracking chamber identical in design to the completed DO tracking chamber. The prototype chamber was exposed to a collimated beam of 150 GeV pions at the Fermilab NWA test facility. Results indicate an $R\\Phi$ tracking resolution compatible with the limitations imposed by physical considerations, excellent 2 track resolution, and a high track reconstruction efficiency along with a good rejection power against $\\gamma \\to e^+ e^-$ events.

  10. Biases in methane chamber measurements in peatlands

    Science.gov (United States)

    Juszczak, R.

    2013-03-01

    The paper presents results of CH4 emission measurements at peatland with the application of the dynamic chamber technique. The measurements were conducted in two types of chambers differing in shape, height, volume and technology used to assure their tightness. The study tested how the following factors: 1) forced chamber headspace mixing or its absence, 2) mistakes of the person conducting measurements, 3) improper application of linear technique for calculating CH4 fluxes, and 4) simulated air sampling typical for static chambers, influence the significance of errors and the underestimation rate of CH4 fluxes measured in situ. It was indicated that chamber headspace mixing allows estimating methane fluxes with a smaller error than in the case of measurements conducted without mixing, and CH4 fluxes in such conditions can be 47 to 58% higher (depending on the chamber type) than in a chamber without fans. Using dynamic chambers and a fast analyzer to measure methane fluxes allows shortening the methane measurement process to a few minutes. On the other hand, using static chambers for methane flux measurements may lead to 70% underestimation of the calculated flux.

  11. D0 central tracking chamber performance studies

    Energy Technology Data Exchange (ETDEWEB)

    Pizzuto, Domenico [State Univ. of New York, Stony Brook, NY (United States)

    1991-12-01

    The performance of the completed DO central tracking chamber was studied using cosmic rays at the State University of New York at Stony Brook. Also studied was a prototype tracking chamber identical in design to the completed DO tracking chamber. The prototype chamber was exposed to a collimated beam of 150 GeV pions at the Fermilab NWA test facility. Results indicate an RΦ tracking resolution compatible with the limitations imposed by physical considerations, excellent 2 track resolution, and a high track reconstruction efficiency along with a good rejection power against γ → e + e- events.

  12. The Analysis of the High Speed Wire Drawing Process of High Carbon Steel Wires Under Hydrodynamic Lubrication Conditions

    Directory of Open Access Journals (Sweden)

    Suliga M.

    2015-04-01

    Full Text Available In this work the analysis of the wire drawing process in hydrodynamic dies has been done. The drawing process of φ5.5 mm wire rod to the final wire of φ1.7 mm was conducted in 12 passes, in drawing speed range of 5-25 m/s. For final wires of φ1.7 mm the investigation of topography of wire surface, the amount of lubricant on the wire surface and the pressure of lubricant in hydrodynamic dies were determined. Additionally, in the work selected mechanical properties of the wires have been estimated.

  13. Filling of carbon nanotubes and nanofibres

    Directory of Open Access Journals (Sweden)

    Reece D. Gately

    2015-02-01

    Full Text Available The reliable production of carbon nanotubes and nanofibres is a relatively new development, and due to their unique structure, there has been much interest in filling their hollow interiors. In this review, we provide an overview of the most common approaches for filling these carbon nanostructures. We highlight that filled carbon nanostructures are an emerging material for biomedical applications.

  14. Spin Start Line Effects on the J2X Gas Generator Chamber Acoustics

    Science.gov (United States)

    Kenny, R. Jeremy

    2011-01-01

    The J2X Gas Generator engine design has a spin start line connected near to the turbine inlet vanes. This line provides helium during engine startup to begin turbomachinery operation. The spin start line also acts as an acoustic side branch which alters the chamber's acoustic modes. The side branch effectively creates 'split modes' in the chamber longitudinal modes, in particular below the first longitudinal mode and within the frequency range associated with the injection-coupled response of the Gas Generator. Interaction between the spin start-modified chamber acoustics and the injection-driven response can create a higher system response than without the spin start attached to the chamber. This work reviews the acoustic effects of the spin start line as seen throughout the workhorse gas generator test program. A simple impedance model of the spin start line is reviewed. Tests were run with no initial spin start gas existing in the line, as well as being initially filled with nitrogen gas. Tests were also run with varying spin start line lengths from 0" to 40". Acoustic impedance changes due to different spin start gas constituents and line lengths are shown. Collected thermocouple and static pressure data in the spin start line was used to help estimate the fluid properties along the line length. The side branch impedance model was coupled to a chamber impedance model to show the effects on the overall chamber response. Predictions of the spin start acoustic behavior for helium operation are shown and compared against available data.

  15. Development of GEM-based Read-Out Chambers for the upgrade of the ALICE TPC

    Science.gov (United States)

    Gasik, P.

    2014-04-01

    ALICE at the LHC at CERN is planning a major upgrade of the central barrel detectors, including the TPC, to cope with an increase of the LHC luminosity after 2018. A prototype of an ALICE TPC Inner Read-Out Chamber (IROC) was equipped with three large-size Gas Electron Multiplier (GEM) foils as amplification stage to demonstrate the feasibility of replacing the current readout by Multi-Wire Proportional Chambers (MWPC) with such technology. The GEM IROC was installed within a test field cage with a drift length of 115 mm and commissioned with radioactive sources. The dE/dx resolution of the prototype was evaluated in a test beam campaign at the CERN PS and is comparable to the resolution of the MWPC IROC. Stability under LHC conditions was tested during the ALICE p-Pb beam time, when the prototype was mounted underneath LHC beam pipe, close to the interaction point.

  16. STRS SpaceWire FPGA Module

    Science.gov (United States)

    Lux, James P.; Taylor, Gregory H.; Lang, Minh; Stern, Ryan A.

    2011-01-01

    An FPGA module leverages the previous work from Goddard Space Flight Center (GSFC) relating to NASA s Space Telecommunications Radio System (STRS) project. The STRS SpaceWire FPGA Module is written in the Verilog Register Transfer Level (RTL) language, and it encapsulates an unmodified GSFC core (which is written in VHDL). The module has the necessary inputs/outputs (I/Os) and parameters to integrate seamlessly with the SPARC I/O FPGA Interface module (also developed for the STRS operating environment, OE). Software running on the SPARC processor can access the configuration and status registers within the SpaceWire module. This allows software to control and monitor the SpaceWire functions, but it is also used to give software direct access to what is transmitted and received through the link. SpaceWire data characters can be sent/received through the software interface, as well as through the dedicated interface on the GSFC core. Similarly, SpaceWire time codes can be sent/received through the software interface or through a dedicated interface on the core. This innovation is designed for plug-and-play integration in the STRS OE. The SpaceWire module simplifies the interfaces to the GSFC core, and synchronizes all I/O to a single clock. An interrupt output (with optional masking) identifies time-sensitive events within the module. Test modes were added to allow internal loopback of the SpaceWire link and internal loopback of the client-side data interface.

  17. Forecasting of Corrosion Properties of Steel Wires for Production of Guide Wires for Cardiological Treatment

    National Research Council Canada - National Science Library

    Przondziono, J; Walke, W; Hadasik, E; Młynarski, R

    2013-01-01

    ... of guide wires used in invasive cardiology. The results of static tensile test enabled us to determine the course of flow curve of wires made of X10CrNi 18-8 steel as well as mathematical form of flow stress function...

  18. Modeling and simulation of the fluid flow in wire electrochemical machining with rotating tool (wire ECM)

    Science.gov (United States)

    Klocke, F.; Herrig, T.; Zeis, M.; Klink, A.

    2017-10-01

    Combining the working principle of electrochemical machining (ECM) with a universal rotating tool, like a wire, could manage lots of challenges of the classical ECM sinking process. Such a wire-ECM process could be able to machine flexible and efficient 2.5-dimensional geometries like fir tree slots in turbine discs. Nowadays, established manufacturing technologies for slotting turbine discs are broaching and wire electrical discharge machining (wire EDM). Nevertheless, high requirements on surface integrity of turbine parts need cost intensive process development and - in case of wire-EDM - trim cuts to reduce the heat affected rim zone. Due to the process specific advantages, ECM is an attractive alternative manufacturing technology and is getting more and more relevant for sinking applications within the last few years. But ECM is also opposed with high costs for process development and complex electrolyte flow devices. In the past, few studies dealt with the development of a wire ECM process to meet these challenges. However, previous concepts of wire ECM were only suitable for micro machining applications. Due to insufficient flushing concepts the application of the process for machining macro geometries failed. Therefore, this paper presents the modeling and simulation of a new flushing approach for process assessment. The suitability of a rotating structured wire electrode in combination with an axial flushing for electrodes with high aspect ratios is investigated and discussed.

  19. gamma. -converting plate system for neutrino-deuterium exposures in the FNAL 15-foot bubble chamber

    Energy Technology Data Exchange (ETDEWEB)

    Hanlon, J.; Mann, W.A.; Sommars, S.; Wald, H.

    1978-01-01

    During May 18-20 of this year the hydrogen-filled 15-foot bubble chamber at Fermilab was operated with an array of four half-inch thick stainless steel plates mounted in downstream portions of the fiducial volume. Notes from the test run, and results from a Monte Carlo study of efficiencies of the plate array for detection of photons and positrons in final states produced in a wide-band neutrino--deuterium exposure, are presented.

  20. K-wire position in tension-band wiring technique affects stability of wires and long-term outcome in surgical treatment of olecranon fractures.

    NARCIS (Netherlands)

    Linden, S.C. van der; Kampen, A. van; Jaarsma, R.L.

    2012-01-01

    BACKGROUND: Tension-band wiring (TBW) has been accepted as the treatment of choice for displaced olecranon fractures. The aim of this study was to examine the effect of K-wire position on instability of the K-wires in relation to local complications and radiological and clinical long-term outcome.

  1. Wide-band antennas for reverberation chambers

    NARCIS (Netherlands)

    Vogt-Ardatjew, R.A.; van de Beek, G.S.; Leferink, Frank Bernardus Johannes

    2012-01-01

    Shielding effectiveness measurements in a dual vibrating intrinsic reverberation chamber results in very repeatable results for a large frequency range and large dynamic range. Antennas in reverberation chambers do not need any gain, but the losses should be low and the dimensions should be small.

  2. 21 CFR 866.2120 - Anaerobic chamber.

    Science.gov (United States)

    2010-04-01

    ... and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2120 Anaerobic chamber. (a) Identification. An anaerobic chamber is a device intended for medical purposes to maintain an anaerobic (oxygen...

  3. An ionization chamber with magnetic levitated electrodes

    CERN Document Server

    Kawaguchi, T

    1999-01-01

    A new type of ionization chamber which has magnetically levitated electrodes has been developed. The electrodes are supplied voltages for the repelling of ions by a battery which is also levitated with the electrodes. The characteristics of this ionization chamber are investigated in this paper.

  4. Results from the MAC Vertex chamber

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, H.N.

    1987-05-01

    The design, construction, and performance characteristics of a high precision gaseous drift chamber made of thin walled proportional tubes are described. The device achieved an average spatial resolution of 45 ..mu..m in use for physics analysis with the MAC detector. The B-lifetime result obtained with this chamber is discussed.

  5. Validation of a fully anechoic chamber

    NARCIS (Netherlands)

    Mandaris, Dwi; Moonen, Dominicus Johannes Guilielmus; van de Beek, G.S.; Buesink, Frederik Johannes Karel; Leferink, Frank Bernardus Johannes

    2016-01-01

    This paper describes a technique to characterize the performance of a Fully Anechoic Chamber (FAC) from 500 MHz to 3 GHz based on S-Parameter analysis with antennas and a Vector Network Analyzer (VNA. The measurements have been performed by placing one antenna inside the chamber and performing S11

  6. HVAC&R Equipment Environmental Chambers

    Data.gov (United States)

    Federal Laboratory Consortium — Description:Large "Truck" ChamberThe large "truck" chamber provides controlled air conditions from -7 °C (20 °F) to 65 °C (150 °F).Air-Conditioner and Heat Pump Test...

  7. Modeling and experimentation of a positioning system of SMA wires

    Science.gov (United States)

    Lei, KinFong; Yam, Yeung

    2000-06-01

    This work reports two modeling and control attempts performed on a positioning system comprising of linking SMA wires and an overlooking video system for on-line measurements. The first attempt takes the model by Ikuta and identifies experimentally the parameters of the SMA wire. The identified single wire model is then extended to a system of two SMA wires joining together at their tips, based upon which open loop position control of the linkage is then conducted. The approach, however, becomes too complicated when more SMA wires are involved. The second attempt utilizes a neuro-fuzzy based approach for positioning control of a linkage point joining together four SMA wires. The second approach involves four ANFIS neuro-networks with hybrid learning algorithm trained to model the currents to the SMA wires as functions of present and target positions of the linkage point. Experimentation for both the two-wires and four-wires system yield quite satisfactory performance.

  8. Percutaneous tension band wiring for patellar fractures.

    Science.gov (United States)

    Rathi, Akhilesh; Swamy, M K S; Prasantha, I; Consul, Ashu; Bansal, Abhishek; Bahl, Vibhu

    2012-08-01

    To evaluate outcome of percutaneous tension band wiring for transverse fractures of the patella. 16 men and 7 women aged 27 to 65 (mean, 40) years underwent percutaneous tension band wiring for transverse fractures of the patella with a displacement of >3 mm. Pain, operating time, mobility, functional score, and complications were evaluated. 20 patients underwent successful percutaneous tension band wiring. The remaining 3 patients in whom closed reduction failed underwent open reduction and tension band wiring. The mean operating time was 46 (range, 28-62) minutes. The mean follow-up period was 20 (range, 15-30) months. At the latest follow-up, all patients had regained full extension. The objective score was excellent in 20 patients and good in 3, whereas the subjective score was excellent in 17, good in 5, and fair in one. All patients had radiological union at week 8. One patient had patellofemoral arthritis (secondary to a postoperative articular step). Two patients developed superficial infections, which resolved after antibiotic therapy. Mean thigh muscle wasting was 0.7 (range, 0.4-1) cm. Three patients encountered hardware problems (impingement/irritation of the skin over the knee) necessitating implant removal. Percutaneous tension band wiring is a viable option for transverse fractures of the patella.

  9. EVALUATION OF INDUCTANCE WITH ELECTRICAL WIRES

    Directory of Open Access Journals (Sweden)

    V. Kudry

    2016-08-01

    Full Text Available In this paper proved the possibility of developing passive electronic inductive elements based replace metal wire that is wound inductor, the wire is made of electret. The relative permeability of the electret S  10 000, several orders of magnitude greater than the permeability of conventional insulation materials, i < 10, resulting current in the wire acquires properties bias current. The essence of innovation is to replace the source of of magnetic induction flow that pervades the core of the coil. According to the theory of electrodynamics, current bias, in contrast to conduction current, generated no movement of charge along the wire, but the change of the charge in the local volume.Equivalence bias current and conduction current is manifested in the possibility of forming a magnetic field. The flow through magnetic induction coil core regardless of the current it generates, creates voltage at its ends.The paper also shows the numeric characteristics that determine the effective frequency range, specified the reason why electric a wire with і < 10 can not generate magnetic flux through the core and serve as a passive reactive component.

  10. Wire scanner software and firmware issues

    Energy Technology Data Exchange (ETDEWEB)

    Gilpatrick, John Doug [Los Alamos National Laboratory

    2008-01-01

    The Los Alamos Neutron Science Center facility presently has 110 slow wire scanning profile measurement instruments located along its various beam lines. These wire scanners were developed and have been operating for at least 30 years. While the wire scanners solved many problems to operate and have served the facility well they have increasingly suffered from several problems or limitations, such as maintenance and reliability problems, antiquated components, slow data acquisition, and etc. In order to refurbish these devices, these wire scanners will be replaced with newer versions. The replacement will consist of a completely new beam line actuator, new cables, new electronics and brand new software and firmware. This note describes the functions and modes of operation that LabVIEW VI software on the real time controller and FPGA LabVIEW firmware will be required. It will be especially interesting to understand the overall architecture of these LabVIEW VIs. While this note will endeavor to describe all of the requirements and issues for the wire scanners, undoubtedly, there will be missing details that will be added as time progresses.

  11. The PS Booster Fast Wire Scanner

    CERN Document Server

    Burger, S; Priestnall, K; Raich, U

    2003-01-01

    The very tight emittance budget for LHC type beams makes precise emittance measurements in the injector complex a necessity. The PS machine uses 2 fast wire scanners per transverse plane for emittance measurement of the circulating beams. In order to ease comparison the same type of wire scanners have been newly installed in the upstream machine, the PS Booster, where each of the 4 rings is equipped with 2 wire scanners measuring the horizontal and vertical profiles. Those wire scanners use new and more modern control and readout electronics featuring dedicated intelligent motor movement controllers, which relieves the very stringent real time constraints due to the very high speed of 20m/s. In order to be able to measure primary beams at the very low injection energy of the Booster (50MeV) secondary emission currents from the wire can be measured as well as secondary particle flows at higher primary particle energies during and after acceleration. The solution adopted for the control of the devices is descri...

  12. Forgotten Kirschner Wire Causing Severe Hematuria

    Directory of Open Access Journals (Sweden)

    Santosh Kumar

    2014-01-01

    Full Text Available Kirschner wire (K-wire is commonly used in the treatment of hip fracture and its migration into pelvis leading to bladder injury is a very rare complication. Nonremoval of these devices either because of lack of followup or because of prolonged requirement due to disease process is associated with this complication. We report a case of a patient who presented with acute onset severe hematuria with clot retention secondary to perforation of bladder by a migrated K-wire placed earlier, for the treatment of hip fracture. Initial imaging showed its presence in the soft tissues of the pelvis away from the major vascular structures. Patient was taken for emergency laparotomy and wire was removed after cystotomy. Postoperative period was uneventful and patient was discharged in satisfactory condition. K-wires are commonly used in the management of fracture bones and their migration has been reported in the literature although such migration in the intrapelvic region involving bladder is very rare. Early diagnosis and prompt removal of such foreign bodies are required to avert potentially fatal involvement of major structures.

  13. Dynamics of Anderson localization in disordered wires

    Science.gov (United States)

    Khalaf, E.; Ostrovsky, P. M.

    2017-11-01

    We consider the dynamics of an electron in an infinite disordered metallic wire. We derive exact expressions for the probability of diffusive return to the starting point in a given time. The result is valid for wires with or without time-reversal symmetry and allows for the possibility of topologically protected conducting channels. In the absence of protected channels, Anderson localization leads to a nonzero limiting value of the return probability at long times, which is approached as a negative power of time with an exponent depending on the symmetry class. When topologically protected channels are present (in a wire of either unitary or symplectic symmetry), the probability of return decays to zero at long time as a power law whose exponent depends on the number of protected channels. Technically, we describe the electron dynamics by the one-dimensional supersymmetric nonlinear sigma model. We derive an exact identity that relates any local dynamical correlation function in a disordered wire of unitary, orthogonal, or symplectic symmetry to a certain expectation value in the random matrix ensemble of class AIII, CI, or DIII, respectively. The established exact mapping from a one- to a zero-dimensional sigma model is very general and can be used to compute any local observable in a disordered wire.

  14. Integrated Electrical Wire Insulation Repair System

    Science.gov (United States)

    Williams, Martha; Jolley, Scott; Gibson, Tracy; Parks, Steven

    2013-01-01

    An integrated system tool will allow a technician to easily and quickly repair damaged high-performance electrical wire insulation in the field. Low-melt polyimides have been developed that can be processed into thin films that work well in the repair of damaged polyimide or fluoropolymer insulated electrical wiring. Such thin films can be used in wire insulation repairs by affixing a film of this low-melt polyimide to the damaged wire, and heating the film to effect melting, flow, and cure of the film. The resulting repair is robust, lightweight, and small in volume. The heating of this repair film is accomplished with the use of a common electrical soldering tool that has been modified with a special head or tip that can accommodate the size of wire being repaired. This repair method can furthermore be simplified for the repair technician by providing replaceable or disposable soldering tool heads that have repair film already "loaded" and ready for use. The soldering tool heating device can also be equipped with a battery power supply that will allow its use in areas where plug-in current is not available

  15. The HARP Time Projection Chamber

    CERN Document Server

    Vidal-Sitjes, G

    2003-01-01

    A novel apparatus for the calibration of the HARP Time Projection Chamber has been designed, developed and built. The apparatus consists of a large number of point-like photo-electron sources located at precise positions inside the detector volume. The photo-electron sources are optical quartz fibers on which one end is coated with an aluminum layer of $\\sim$80{\\AA} thickness and are held in place on the High Voltage membrane. The fibers are used to guide UV laser light pulses that generate photoelectrons on the fiber tips and these act as photo-electron emitters. The photoelectrons drift inside the detector and produce the calibration signals. The technique allows to asses $E\\times B$ distortions and to measure drift velocity, ion feedback and time stability in real time. The analog signals generated by the TPC front-end electronics have been characterized. Different methods to extract the amplitude and time of occurrence from the digitized signals have been studied and compared. Fast estimators, like the su...

  16. Temperature Dependent Wire Delay Estimation in Floorplanning

    DEFF Research Database (Denmark)

    Winther, Andreas Thor; Liu, Wei; Nannarelli, Alberto

    2011-01-01

    Due to large variations in temperature in VLSI circuits and the linear relationship between metal resistance and temperature, the delay through wires of the same length can be different. Traditional thermal aware floorplanning algorithms use wirelength to estimate delay and routability....... In this work, we show that using wirelength as the evaluation metric does not always produce a floorplan with the shortest delay. We propose a temperature dependent wire delay estimation method for thermal aware floorplanning algorithms, which takes into account the thermal effect on wire delay. The experiment...... results show that a shorter delay can be achieved using the proposed method. In addition, we also discuss the congestion and reliability issues as they are closely related to routing and temperature....

  17. A new route to process diamond wires

    Directory of Open Access Journals (Sweden)

    Marcello Filgueira

    2003-06-01

    Full Text Available We propose an original route to process diamond wires, denominated In Situ Technology, whose fabrication involves mechanical conformation processes, such as rotary forging, copper tubes restacking, and thermal treatments, such as sintering and recrystallisation of a bronze 4 wt.% diamond composite. Tensile tests were performed, reaching an ultimate tensile strength (UTS of 230 MPa for the diameter of Æ = 1.84 mm. Scanning electron microscopy showed the diamond crystals distribution along the composite rope during its manufacture, as well as the diamond adhesion to the bronze matrix. Cutting tests were carried out with the processed wire, showing a probable performance 4 times higher than the diamond sawing discs, however its probable performance was about 5 to 8 times less than the conventional diamond wires (pearl system due to the low abrasion resistance of the bronze matrix, and low adhesion between the pair bronze-diamond due to the use of not metallised diamond single crystals.

  18. Golden Jubilee photos - BEBC, the Big European Bubble Chamber

    CERN Multimedia

    2004-01-01

    The vessel of the Big European Bubble Chamber, BEBC, was installed at the beginning of the 1970s. The large stainless-steel vessel, measuring 3.7 metres in diameter and 4 metres in height, was filled with 35 cubic metres of liquid (hydrogen, deuterium or a neon-hydrogen mixture), whose sensitivity was regulated by means of a huge piston weighing 2 tonnes. During each expansion, the trajectories of the charged particles were marked by a trail of bubbles, where liquid reached boiling point as they passed through it. The first images were recorded in 1973 when BEBC, equipped with the largest superconducting magnet in service at the time, first received beam from the PS. In 1977, the bubble chamber was exposed to neutrino and hadron beams at higher energies of up to 450 GeV after the SPS came into operation. By the end of its active life in 1984, BEBC had delivered a total of 6.3 million photographs to 22 experiments devoted to neutrino or hadron physics. Around 600 scient...

  19. Effect of bleaching agents on bonding to pulp chamber dentine.

    Science.gov (United States)

    Timpawat, S; Nipattamanon, C; Kijsamanmith, K; Messer, H H

    2005-04-01

    To determine the effect of intracoronal bleaching agents on adhesion of bonding agents to pulp chamber dentine. Forty extracted human maxillary anterior teeth were randomly divided into four groups of 10 teeth each. Bleaching agents were sealed in pulp chambers for 7 days, as in clinical use. Group 1 (control): distilled water, group 2: 35% hydrogen peroxide, group 3: sodium perborate mixed with water, and group 4: sodium perborate mixed with 35% hydrogen peroxide. Teeth were stored in saline at 37 degrees C for 7 days. After the bleaching agent was removed, teeth were leached in water for a further 7 days prior to bonding. The crown was cut vertically from mesial to distal and the labial pulp chamber dentine was prepared for bonding with Clearfil SE-Bond and filled with resin composite (Clearfil AP-X). The bonded specimens were kept moist at 37 degrees C for 24 h. Microtensile bond strengths were determined using a universal testing machine. Additional teeth were prepared using the same bleaching procedures to investigate the scanning electron microscopic appearance of the dentine surface. Mean values (+/-SD) of microtensile bond strength for the experimental groups were: group 1: 5.29 +/- 2.21 MPa, group 2: 5.99 +/- 1.51 MPa, group 3: 9.17 +/- 1.65 MPa and group 4: 3.99 +/- 1.31 MPa. Dentine treated with sodium perborate in water (group 3) had significantly higher mean bond strength when compared with the other three groups (P sodium perborate plus hydrogen peroxide (group 4). In terms of subsequent bond strength during restoration, sodium perborate mixed with distilled water appears to be the best intracoronal bleaching agent.

  20. Dedicated composite fillings − inlays

    Directory of Open Access Journals (Sweden)

    Šaulić Slobodan

    2003-01-01

    Full Text Available Background. The aim of the study was to evaluate the quality and persistance of esthetics of dedicated inlay by clinical methods. Methods. The paper reviews the clinical significance and technique of preparing particular composite inlays before and after the construction of the metallic framework partial denture. On the basis of indications the total of 30 inlays were placed into cavities under relatively dry working conditions. Six, twelve eighteen and twenty-four months after the placement of filling, control check-up was carried out by Ryge criteria. Results. After two years marginal discoloration as well as the change of the colour occured in 3.3% of inlays. There was neither detectable secondary caries, nor the symtoms of pulpal damage. The requirements to be fulfilled concerning the composite materials in order that they can be implemented for this purpose, were also discussed. Conclusion. From the clinical point of view, purpouse inlays from Herculite XRV lab C8B in combination with Opti Bond System and composite cement Porcelite Dual Cure showed high functional and esthetic values in the observational period of two years.

  1. Charge-signal multiplication mediated by urea wires inside Y-shaped carbon nanotubes.

    Science.gov (United States)

    Lv, Mei; He, Bing; Liu, Zengrong; Xiu, Peng; Tu, Yusong

    2014-07-28

    In previous studies, we reported molecular dynamics (MD) simulations showing that single-file water wires confined inside Y-shaped single-walled carbon nanotubes (Y-SWNTs) held strong and robust capability to convert and multiply charge signals [Y. S. Tu, P. Xiu, R. Z. Wan, J. Hu, R. H. Zhou, and H. P. Fang, Proc. Natl. Acad. Sci. U.S.A. 106, 18120 (2009); Y. Tu, H. Lu, Y. Zhang, T. Huynh, and R. Zhou, J. Chem. Phys. 138, 015104 (2013)]. It is fascinating to see whether the signal multiplication can be realized by other kinds of polar molecules with larger dipole moments (which make the experimental realization easier). In this article, we use MD simulations to study the urea-mediated signal conversion and multiplication with Y-SWNTs. We observe that when a Y-SWNT with an external charge of magnitude 1.0 e (the model of a signal at the single-electron level) is solvated in 1 M urea solutions, urea can induce drying of the Y-SWNT and fill its interiors in single-file, forming Y-shaped urea wires. The external charge can effectively control the dipole orientation of the urea wire inside the main channel (i.e., the signal can be readily converted), and this signal can further be multiplied into 2 (or more) output signals by modulating dipole orientations of urea wires in bifurcated branch channels of the Y-SWNT. This remarkable signal transduction capability arises from the strong dipole-induced ordering of urea wires under extreme confinement. We also discuss the advantage of urea as compared with water in the signal multiplication, as well as the robustness and biological implications of our findings. This study provides the possibility for multiplying signals by using urea molecules (or other polar organic molecules) with Y-shaped nanochannels and might also help understand the mechanism behind signal conduction in both physical and biological systems.

  2. Charge-signal multiplication mediated by urea wires inside Y-shaped carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Mei; Liu, Zengrong [Department of Mathematics, and Institute of Systems Biology, Shanghai University, Shanghai 200444 (China); He, Bing [School of Computer Engineering and Science, Shanghai University, Shanghai 200444 (China); Xiu, Peng, E-mail: xiupeng2011@zju.edu.cn, E-mail: ystu@shu.edu.cn [Department of Engineering Mechanics, and Soft Matter Research Center, Zhejiang University, Hangzhou 310027 (China); Tu, Yusong, E-mail: xiupeng2011@zju.edu.cn, E-mail: ystu@shu.edu.cn [Department of Mathematics, and Institute of Systems Biology, Shanghai University, Shanghai 200444 (China); College of Physics Science and Technology, Yangzhou University, Yangzhou 225009 (China)

    2014-07-28

    In previous studies, we reported molecular dynamics (MD) simulations showing that single-file water wires confined inside Y-shaped single-walled carbon nanotubes (Y-SWNTs) held strong and robust capability to convert and multiply charge signals [Y. S. Tu, P. Xiu, R. Z. Wan, J. Hu, R. H. Zhou, and H. P. Fang, Proc. Natl. Acad. Sci. U.S.A. 106, 18120 (2009); Y. Tu, H. Lu, Y. Zhang, T. Huynh, and R. Zhou, J. Chem. Phys. 138, 015104 (2013)]. It is fascinating to see whether the signal multiplication can be realized by other kinds of polar molecules with larger dipole moments (which make the experimental realization easier). In this article, we use MD simulations to study the urea-mediated signal conversion and multiplication with Y-SWNTs. We observe that when a Y-SWNT with an external charge of magnitude 1.0 e (the model of a signal at the single-electron level) is solvated in 1 M urea solutions, urea can induce drying of the Y-SWNT and fill its interiors in single-file, forming Y-shaped urea wires. The external charge can effectively control the dipole orientation of the urea wire inside the main channel (i.e., the signal can be readily converted), and this signal can further be multiplied into 2 (or more) output signals by modulating dipole orientations of urea wires in bifurcated branch channels of the Y-SWNT. This remarkable signal transduction capability arises from the strong dipole-induced ordering of urea wires under extreme confinement. We also discuss the advantage of urea as compared with water in the signal multiplication, as well as the robustness and biological implications of our findings. This study provides the possibility for multiplying signals by using urea molecules (or other polar organic molecules) with Y-shaped nanochannels and might also help understand the mechanism behind signal conduction in both physical and biological systems.

  3. Quantum conductance in silicon quantum wires

    CERN Document Server

    Bagraev, N T; Klyachkin, L E; Malyarenko, A M; Gehlhoff, W; Ivanov, V K; Shelykh, I A

    2002-01-01

    The results of investigations of electron and hole quantum conductance staircase in silicon quantum wires are presented. The characteristics of self-ordering quantum wells of n- and p-types, which from on the silicon (100) surface in the nonequilibrium boron diffusion process, are analyzed. The results of investigations of the quantum conductance as the function of temperature, carrier concentration and modulation degree of silicon quantum wires are given. It is found out, that the quantum conductance of the one-dimensional channels is observed, for the first time, at an elevated temperature (T >= 77 K)

  4. Laser wire emittance measurement line AT CLIC

    CERN Document Server

    Garcia, H; Blair, G A; Aumeyr, T; Schulte, D; Stulle, F

    2011-01-01

    A precise measurement of the transverse beam size and beam emittances upstream of the final focus is essential for ensuring the full luminosity at future linear colliders. A scheme for the emittance measurements at the RTML line of the CLIC using laser-wire beam profile monitors is described. A lattice of the measurement line is discussed and results of simulations of statistical errors and of their impact on the accuracy of the emittance reconstruction are given. Laser wire systems suitable for CLIC and their main characteristics are discussed.

  5. Transient response of wire bicone antennas

    Science.gov (United States)

    Morgan, J. G.; Lizius, D. W.

    This paper describes the computational analysis of biconical wire antennas without end-caps performed using an extended and improved version of the Thin Wire Time Domain code from the Lawrence Livermore National Laboratory. Special attention is given to the computational algorithm used in the direct time domain analysis of the transient behavior of antennas. It is shown that the time domain numerical predictions are consistent with intuitive expectations and with predictions obtained from the Fourier transform of a frequency domain semianalytical model of a sheet bicone antenna.

  6. Numerical Simulation of Wire-Coating

    DEFF Research Database (Denmark)

    Wapperom, Peter; Hassager, Ole

    1999-01-01

    A finite element program has been used to analyze the wire-coating process of an MDPE melt. The melt is modeled by a nonisothermal Carreau model. The emphasis is on predicting an accurate temperature field. Therefore, it is necessary to include the heat conduction in the metal parts. A comparison...... is made with the results of a simulation that models the heat conduction in the metal head by means of a Biot boundary condition. The influence of the wire velocity, inlet temperature and power-law index will be examined....

  7. EDITORIAL More than a wire More than a wire

    Science.gov (United States)

    Demming, Anna

    2010-10-01

    Nanowires are the natural evolution of the connections in circuits when scaled down to nanometre sizes. On closer inspection, of course, the role of nanowires in developing new technologies is much more than just a current-bearing medium. By sizing the diameters of these objects down to the nanoscale, their properties become increasingly sensitive to factors such as the gas composition, temperature and incident light of their surrounding environment, as well as defects and variations in diameter. What becomes important in modern electronics innovations is not just what is connected, but how. Nanowires had already begun to attract the attention of researchers in the early 1990s as advances in imaging and measurement devices invited researchers to investigate the properties of these one-dimensional structures [1, 2]. This interest has sparked ingenious ways of fabricating nanowires such as the use of a DNA template. A collaboration of researchers at Louisiana Tech University in the US hs provided an overview of various methods to assemble conductive nanowires on a DNA template, including a summary of different approaches to stretching and positioning the templates [3]. Work in this area demonstrates a neat parallel for the role of DNA molecules as the building blocks of life and the foundations of nanoscale device architectures. Scientists at HP Labs in California are using nanowires to shrink the size of logic arrays [4]. One aspect of electronic interconnects that requires particular attention at nanoscale sizes is the effect of defects. The researchers at HP Labs demonstrate that their approach, which they name FPNI (field-programmable nanowire interconnect), is extremely tolerant of the high defect rates likely to be found in these nanoscale structures, and allows reduction in size and power without significantly sacrificing the clock rate. Another issue in scaling down electronics is the trend for an increasing resistivity with decreasing wire width. Researchers

  8. Formation of a Molecular Wire Using the Chemically Adsorbed Monomolecular Layer Having Pyrrolyl Groups

    Directory of Open Access Journals (Sweden)

    Kazufumi Ogawa

    2011-01-01

    Full Text Available A molecular wire containing polypyrrolyl conjugate bonds has been prepared by a chemical adsorption technique using 1,1,1-trichloro-12-pyrrolyl-1-siladodecane (PNN and an electrooxidative polymerization technique, and the conductivity of the molecular wire without any dopant has been measured by using AFM/STM at room temperature. When sample dimension measured was about 0.3 nm (thickness of the conductive portion in the PNN monomolecular layer ×100 μm (the average width of an electric path ×2 mm (the distance between Pt positive electrode and the AFM tip covered with Au, the conductivity of the polymerized PNN molecular wire at room temperature was larger than 1.6 × 105 S/cm both in an atmosphere and in a vacuum chamber of 10−5 Torr. The activation energy obtained by Arrhenius' plots was almost zero in the temperature range between 320 and 450 K.

  9. Wire grid polarizers for visible wavelengths

    Science.gov (United States)

    Johnson, Joshua Hans

    Detailed analysis of wire-grid (WG) polarizers for visible wavelengths is presented. Rigorous coupled-wave analysis (RCWA) is used to model their performance. The optimum choice of metal for the wires is identified, and the effects of different substrate indices of refraction are considered. The polarization properties are considered with changes in the physical parameters, including period, duty cycle, and wire thickness. It is shown that the performance of WG polarizers improves with increasing angle of incidence. The effect of non-square wire profiles is considered, as is the effect of adding additional dielectric layers between the wires and the substrate. The effect of metal oxide layers forming on the wires is also modeled. While most of this work concerns WG polarizers used in transmission, the performance in reflection is also discussed. Several visible-wavelength WG polarizers were fabricated at the Cornell Nanofabrication Facility (CNF) in Ithaca, NY. Electron-beam lithography was used to write the patterns for these devices, and two different methods of pattern transfer were compared. These were the lift-off method and reactive-ion etching (RIE). We found that lift-off could not produce wires thick enough for good polarization properties. RIE could produce much thicker wires with good profiles and was used for all of the experimental work presented here. Two different methods for metal film deposition, evaporation and sputtering were also compared. Films deposited by sputtering were found to have much lower indices of refraction and to not respond to etching as well. Thermally evaporated films performed much better in WG polarizers. Alternative methods for the mass-production of visible-wavelength WG polarizers are also discussed. The performance of the fabricated WG polarizers is compared to theory. When the measured physical parameters are used in RCWA to predict the performance, the measured extinction ratio is found to be much lower than the

  10. Extending the Dynamic Range of a Time Projection Chamber

    Science.gov (United States)

    Estee, Justin; S πRIT Collaboration

    2017-09-01

    The use of Time Projection Chambers (TPCs) in intermediate heavy ion reactions faces some challenges in addressing the energy losses that range from the small energy loss of relativistic pions to the large energy loss of slow moving heavy ions. A typical trade-off can be to set the smallest desired signals to be well within the lower limits of the dynamic range of the electronics while allowing for some larger signals to saturate the electronics. With wire plane anodes, signals from readout pads further away from the track remain unsaturated and allow signals from tracks with saturated pads to be accurately recovered. We illustrate this technique using data from the SAMURAI Pion-Reconstruction and Ion-Tracker (S πRIT) TPC , which recently measured pions and light charged particles in collisions of Sn+Sn isotopes. Our method exploits knowledge of how the induced charge distribution depends on the distance from the track to smoothly extend dynamic range even when some of the pads in the track are saturated. To accommodate the analysis of slow moving heavy ions, we have extended the Bichsel energy loss distributions to handle slower moving ions as well. In this talk, I will discuss a combined approach which successfully extends the dynamic range of the TPC electronics. This work is supported by the U.S. DOE under Grant Nos. DE-SC0014530, DE-NA0002923, US NSF Grant No. PHY-1565546 and the Japan MEXT KAKENHI Grant No. 24105004.

  11. Point and track-finding processors for multiwire chambers

    CERN Document Server

    Hansroul, M

    1973-01-01

    The hardware processors described below are designed to be used in conjunction with multi-wire chambers. They have the characteristic of being based on computational methods in contrast to analogue procedures. In a sense, they are hardware implementations of computer programs. But, being specially designed for their purpose, they are free of the restrictions imposed by the architecture of the computer on which the equivalent program is to run. The parallelism inherent in the algorithms can thus be fully exploited. Combined with the use of fast access scratch-pad memories and the non-sequential nature of the control program, the parallelism accounts for the fact that these processors are expected to execute 2-3 orders of magnitude faster than the equivalent Fortran programs on a CDC 7600 or 6600. As a consequence, methods which are simple and straightforward, but which are impractical because they require an exorbitant amount of computer time can on the contrary be very attractive for hardware implementation. ...

  12. LEP vacuum chamber, cross-section

    CERN Multimedia

    CERN PhotoLab

    1983-01-01

    Cross-section of the final prototype for the LEP vacuum chamber. The elliptic main-opening is for the beam. The small channel to the left is for the cooling water, to carry away the heat deposited by the synchrotron radiation. The square channel to the right houses the Non-Evaporable Getter (NEG) pump. The chamber is made from extruded aluminium. Its outside is clad with lead, to stop the synchrotron radiation emitted by the beam. For good adherence between Pb and Al, the Al chamber was coated with a thin layer of Ni. Ni being slightly magnetic, some resulting problems had to be overcome. See also 8301153.

  13. Weld Development for Aluminum Fission Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Cross, Carl Edward [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Martinez, Jesse Norris [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-05-16

    The Sigma welding team was approached to help fabricate a small fission chamber (roughly ½ inch dia. x ½ inch tall cylinder). These chambers are used as radiation sensors that contain small traces of radionuclides (Cf 252, U 235, and U 238) that serve to ionize gas atoms in addition to external radiation. When a voltage is applied within the chamber, the resulting ion flow can be calibrated and monitored. Aluminum has the advantage of not forming radioactive compounds when exposed to high external radiation (except from minor Na alloy content). Since aluminum has not been used before in this application, this presented an unexplored challenge.

  14. Cloud chamber photographs of the cosmic radiation

    CERN Document Server

    Rochester, George Dixon

    1952-01-01

    Cloud Chamber Photographs of the Cosmic Radiation focuses on cloud chamber and photographic emulsion wherein the tracks of individual subatomic particles of high energy are studied. The publication first offers information on the technical features of operation and electrons and cascade showers. Discussions focus on the relationship in time and space of counter-controlled tracks; techniques of internal control of the cloud chamber; cascade processes with artificially-produced electrons and photons; and nuclear interaction associated with an extensive shower. The manuscript then elaborates on

  15. Performance of a Drift Chamber Candidate for a Cosmic Muon Tomography System

    Energy Technology Data Exchange (ETDEWEB)

    Anghel, V.; Jewett, C.; Jonkmans, G.; Thompson, M. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada); Armitage, J.; Botte, J.; Boudjemline, K.; Erlandson, A.; Oakham, G. [Ottawa-Carleton Institute for Physics, Department of Physics, Carleton University, Ottawa, Ontario (Canada); Bueno, J.; Bryman, D.; Liu, Z. [Advanced Applied Physics Solutions, Vancouver, British Columbia (Canada); Charles, E.; Gallant, G. [Canada Border Services Agency, Ottawa, Ontario (Canada); Cousins, T.; Noel, S. [International Safety Research, Ottawa, Ontario (Canada); Drouin, P.-L.; Waller, D. [Defence Research and Development Canada, Ottawa, Ontario (Canada); Stocki, T. J. [Health Canada, Ottawa, Ontario (Canada)

    2011-12-13

    In the last decade, many groups around the world have been exploring different ways to probe transport containers which may contain illicit Special Nuclear Materials such as uranium. The muon tomography technique has been proposed as a cost effective system with an acceptable accuracy. A group of Canadian institutions (see above), funded by Defence Research and Development Canada, is testing different technologies to track the cosmic muons. One candidate is the single wire Drift Chamber. With the capability of a 2D impact position measurement, two detectors will be placed above and two below the object to be probed. In order to achieve a good 3D image quality of the cargo content, a good angular resolution is required. The simulation showed that 1mrad was required implying the spatial resolution of the trackers must be in the range of 1 to 2 mm for 1 m separation. A tracking system using three prototypes has been built and tested. The spatial resolution obtained is 1.7 mm perpendicular to the wire and 3 mm along the wire.

  16. Performance of a Drift Chamber Candidate for a Cosmic Muon Tomography System

    Science.gov (United States)

    Anghel, V.; Armitage, J.; Botte, J.; Boudjemline, K.; Bueno, J.; Bryman, D.; Charles, E.; Cousins, T.; Drouin, P.-L.; Erlandson, A.; Gallant, G.; Jewett, C.; Jonkmans, G.; Liu, Z.; Noel, S.; Oakham, G.; Stocki, T. J.; Thompson, M.; Waller, D.

    2011-12-01

    In the last decade, many groups around the world have been exploring different ways to probe transport containers which may contain illicit Special Nuclear Materials such as uranium. The muon tomography technique has been proposed as a cost effective system with an acceptable accuracy. A group of Canadian institutions (see above), funded by Defence Research and Development Canada, is testing different technologies to track the cosmic muons. One candidate is the single wire Drift Chamber. With the capability of a 2D impact position measurement, two detectors will be placed above and two below the object to be probed. In order to achieve a good 3D image quality of the cargo content, a good angular resolution is required. The simulation showed that 1mrad was required implying the spatial resolution of the trackers must be in the range of 1 to 2 mm for 1 m separation. A tracking system using three prototypes has been built and tested. The spatial resolution obtained is 1.7 mm perpendicular to the wire and 3 mm along the wire.

  17. Negative differential resistance in a one-dimensional molecular wire ...

    Indian Academy of Sciences (India)

    voltage characteristics of a one-dimensional molecular wire with odd number of atoms. The wire has been modelled ... Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bangalore 560 064, India ...

  18. Radiation of relativistic electrons in a periodic wire structure

    Energy Technology Data Exchange (ETDEWEB)

    Soboleva, V.V., E-mail: sobolevaveronica@mail.ru; Naumenko, G.A.; Bleko, V.V.

    2015-07-15

    We present in this work the experimental investigation of the interaction of relativistic electron field with periodic wire structures. We used two types of the targets in experiments: flat wire target and sandwich wire target that represent the right triangular prism. The measurements were done in millimeter wavelength region (10–40 mm) on the relativistic electron beam with energy of 6.2 MeV in far-field zone. We showed that bunched electron beam passing near wire metamaterial prism generates coherent Cherenkov radiation. The experiments with flat wire target were carried out in two geometries. In the first geometry the electron beam passed close to the flat wire target surface. In the second case the electron beam passed through the flat wire structure with generation of a coherent backward transition radiation (CBTR). The comparison of the Cherenkov radiation intensity and BTR intensity from the flat wire target and from the flat conductive target (conventional BTR) was made.

  19. Electric and Magnetic Forces between Parallel-Wire Conductors.

    Science.gov (United States)

    Morton, N.

    1979-01-01

    Discusses electric and magnetic forces between parallel-wire conductors and derives, in a simple fashion, order of magnitude estimates of the ratio of the likely electrostatic and electromagnetic forces for a simple parallel-wire balance. (Author/HM)

  20. Studying superconducting Nb3Sn wire

    CERN Multimedia

    AUTHOR|(CDS)2099575

    2015-01-01

    Studying superconducting Nb3Sn wire. From the current experience from LHC and HL-LHC we know that the performance requirements for Nb3Sn conductor for future circular collider are challenging and should exceed that of present state-of-the-art materials.

  1. Niobium Titanium and Copper wire samples

    CERN Document Server

    2009-01-01

    Two wire samples, both for carrying 13'000Amperes. I sample is copper. The other is the Niobium Titanium wiring used in the LHC magnets. The high magnetic fields needed for guiding particles around the Large Hadron Collider (LHC) ring are created by passing 12’500 amps of current through coils of superconducting wiring. At very low temperatures, superconductors have no electrical resistance and therefore no power loss. The LHC is the largest superconducting installation ever built. The magnetic field must also be extremely uniform. This means the current flowing in the coils has to be very precisely controlled. Indeed, nowhere before has such precision been achieved at such high currents. Magnet coils are made of copper-clad niobium–titanium cables — each wire in the cable consists of 9’000 niobium–titanium filaments ten times finer than a hair. The cables carry up to 12’500 amps and must withstand enormous electromagnetic forces. At full field, the force on one metre of magnet is comparable ...

  2. Description of CBETA magnet tuning wire holders

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, S. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2017-07-19

    A non-­magnetic insert will be placed directly inside the permanent magnet blocks in every CBETA Halbach magnet in order to hold a set of iron “tuning wires”. These wires have various lengths around the perimeter of the aperture in order to cancel multipole field errors from the permanent magnet blocks.

  3. Wire Separation From Automotive Shredder Residue

    NARCIS (Netherlands)

    Fabrizi, L.; De Jong, T.P.R.; Bevilacqua, P.

    2003-01-01

    The investigation discussed in this article concerned the removal of wires and cables fraction contained in automotive shredder residue (ASR) through a newly invented device, called the nail roll. Series of tests were carried out with three ASR samples of different origin and the influence of the

  4. Commercial and Industrial Wiring. Second Edition.

    Science.gov (United States)

    Kaltwasser, Stan; Flowers, Gary

    This guide is designed to assist teachers conducting a course to prepare students for entry-level employment in the commercial and industrial wiring trade. Included in the guide are 15 instructional units and the following sections of information for teachers: guidelines in using the unit components; academic and workplace skills classifications…

  5. SRB Altitude Switch Assembly Wire Harness Failure

    Science.gov (United States)

    Blanche, Jim

    2002-01-01

    This paper presents an assessment of two wire harness failures that had occurred in Solid Rocket Booster Altitude Switch Assemblies S/N 200001 and S/N 20002. A list of modifications to EDU #4 and modification of qualification units 2000001 and 2000002 are also presented.

  6. Diamagnetism in wire medium metamaterials: Theory and experiment

    Science.gov (United States)

    Yagupov, I.; Filonov, D.; Ageyskiy, A.; Kosulnikov, S.; Hasan, M.; Iorsh, I. V.; Belov, P. A.

    2015-07-01

    A strong diamagnetic response of a wire medium with a finite wire radius is reported. Contrary to the previous works where it was assumed that the wire medium exhibits only an electric response, we show that the nonzero magnetic susceptibility has to be taken into account for a proper effective medium description of the wire medium. Analytical and numerical results are supported by experimental measurements.

  7. A notch-wire composite antenna for polarization diversity reception

    OpenAIRE

    Kuga, Nobuhiro; Arai, H; Goto, N

    1998-01-01

    This paper presents a notch-wire composite antenna for polarization diversity reception in an indoor base-station system, A three-notched disk antenna and a wire antenna are proposed as component antennas for the horizontal and the vertical polarization, respectively. These component antennas are unified as a single composite diversity antenna by mounting the wire antenna on the notched disk. Antenna characteristics are calculated using the method of moments (MoM) with wire grid models and ex...

  8. High-Speed Automated Tester for Vacuum Chamber Feedthrough Connectors and Cables

    Science.gov (United States)

    Swope, Robert H.; Powers, Edward I. (Technical Monitor)

    2000-01-01

    The Goddard Space Flight Center's thermal vacuum laboratory has developed a high-speed automated system for testing the integrity of 37-pin MIL-C-5015 cylindrical electrical feedthrough connectors used on penetration plates of thermal vacuum chambers. The system consists of a desktop PC driving a data acquisition front end. The latter measures the resistance through each pin of the connector and the resistance from each pin to all other pins and the connector shell. In addition to identifying unacceptable feedthroughs, the system is also used for testing cables. In the special case of Type T thermocouples (used almost exclusively at the lab), the difference in resistance between the copper and constantan wires provides positive proof of accidentally reversed connector wiring. Data acquisition time to completely test a cable or feedthrough connector is less than thirty seconds. The system provides a hardcopy printout of the resistance readings. Connectors or cables with fewer wires are tested using simple adapter cables. Initial tests indicate that the performance of a given feedthrough connector can be predicted on the basis of measured resistance readings, reducing ongoing cost of connector replacement. The opportunity to positively certify the integrity of cables, cable connectors and feedthroughs before the start of a thermal vacuum test minimizes the likelihood of a circuit problem that would require returning the chamber to ambient conditions for repair. This system has two principal advantages for the Goddard thermal vacuum laboratory. Its only significant cost was the labor to fabricate the test cable and shorting cable -- about 40 man-hours total. The system was built around a computer and data acquisition unit that were already on hand. The second advantage is that it very quickly tests both of the parameters that are essential.

  9. Reflectivity level of radio anechoic chambers

    DEFF Research Database (Denmark)

    Appel-Hansen, Jørgen

    1973-01-01

    A comparison between the antenna-pattern comparison technique and the free-space voltage standing-wave ratio technique for evaluating the reflectivity level of radio anechoic chambers is presented. Based on an analysis of the two techniques, it is pointed out which parameters influence the measured...... be used to measure the improvements. This work is inspired by the current discussion of finding a figure of merit for anechoic chambers. Based on the results, an evaluation procedure for anechoic chambers is indicated. However, it is pointed out and illustrated by examples that further investigations...... value of the reflectivity level. The comparison is illustrated with experimental results and it is explained why inconsistent and uncorrelated results may be found when the two methods are used. Furthermore, it is demonstrated, by introducing improvements in a chamber, how the reflectivity level can...

  10. RADAR Anechoic Chamber/RCS Measurements Lab

    Data.gov (United States)

    Federal Laboratory Consortium — The RF Anechoic Chamber is 56 feet long by 12 feet high by 13.5 feet wide, with an adjoining electronic computer control room. A double door entrance at one end of...

  11. Developing cloud chambers with high school students

    CERN Document Server

    Ishizuka, Ryo; Sato, Shoma; Zeze, Syoji

    2013-01-01

    The result and outcome of the cloud chamber project, which aims to develop a cloud chamber useful for science education is reported in detail. A project includes both three high school students and a teacher as a part of Super Science High School (SSH) program in our school. We develop a dry ice free cloud chamber using salt and ice (or snow). Technical detail of the chamber is presented. We also argue how the project affects student's cognition, motivation, academic skills and behavior. The research project had been done in very similar way to those of professional researchers, i.e., planning research, applying fund, writing a paper and giving a talk in conferences. From interviews with students, we learn that such style of scientific activity is very effective in promoting student's motivation for learning science.

  12. High Performance Methane Thrust Chamber (HPMTC) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ORBITEC proposes to develop a High-Performance Methane Thrust Chamber (HPMRE) to meet the demands of advanced chemical propulsion systems for deep-space mission...

  13. MAN-IN-SIMULANT TEST (MIST) CHAMBER

    Data.gov (United States)

    Federal Laboratory Consortium — The MIST chamber uses methyl salicylate (oil of wintergreen) vapor as a simulant for HD agent to conduct system level evaluations of chemical protective ensembles....

  14. Chamber Core Structures for Fairing Acoustic Mitigation

    National Research Council Canada - National Science Library

    Lane, Steven A; Henderson, Kyle; Williams, Andrew; Ardelean, Emil

    2007-01-01

    .... A composite chamber core fairing consists of many axial tubes sandwiched between face sheets, tubes that can be used as acoustic dampers to reduce low-frequency interior noise with virtually no added mass...

  15. Developing Cloud Chambers with High School Students

    Science.gov (United States)

    Ishizuka, Ryo; Tan, Nobuaki; Sato, Shoma; Zeze, Syoji

    The result and outcome of the cloud chamber project, which aims to develop a cloud chamber useful for science education is reported in detail. A project includes both three high school students and a teacher as a part of Super Science High School (SSH) program in our school. We develop a dry-ice-free cloud chamber using salt and ice (or snow). Technical details of the chamber are described. We also argue how the project have affected student's cognition, motivation, academic skills and behavior. The research project has taken steps of professional researchers, i.e., in planning research, applying fund, writing a paper and giving a talk in conferences. From interviews with students, we have learnt that such style of scientific activity is very effective in promoting student's motivation for learning science.

  16. Communication and wiring in the cortical connectome

    Science.gov (United States)

    Budd, Julian M. L.; Kisvárday, Zoltán F.

    2012-01-01

    In cerebral cortex, the huge mass of axonal wiring that carries information between near and distant neurons is thought to provide the neural substrate for cognitive and perceptual function. The goal of mapping the connectivity of cortical axons at different spatial scales, the cortical connectome, is to trace the paths of information flow in cerebral cortex. To appreciate the relationship between the connectome and cortical function, we need to discover the nature and purpose of the wiring principles underlying cortical connectivity. A popular explanation has been that axonal length is strictly minimized both within and between cortical regions. In contrast, we have hypothesized the existence of a multi-scale principle of cortical wiring where to optimize communication there is a trade-off between spatial (construction) and temporal (routing) costs. Here, using recent evidence concerning cortical spatial networks we critically evaluate this hypothesis at neuron, local circuit, and pathway scales. We report three main conclusions. First, the axonal and dendritic arbor morphology of single neocortical neurons may be governed by a similar wiring principle, one that balances the conservation of cellular material and conduction delay. Second, the same principle may be observed for fiber tracts connecting cortical regions. Third, the absence of sufficient local circuit data currently prohibits any meaningful assessment of the hypothesis at this scale of cortical organization. To avoid neglecting neuron and microcircuit levels of cortical organization, the connectome framework should incorporate more morphological description. In addition, structural analyses of temporal cost for cortical circuits should take account of both axonal conduction and neuronal integration delays, which appear mostly of the same order of magnitude. We conclude the hypothesized trade-off between spatial and temporal costs may potentially offer a powerful explanation for cortical wiring patterns

  17. ECO fill: automated fill modification to support late-stage design changes

    Science.gov (United States)

    Davis, Greg; Wilson, Jeff; Yu, J. J.; Chiu, Anderson; Chuang, Yao-Jen; Yang, Ricky

    2014-03-01

    One of the most critical factors in achieving a positive return for a design is ensuring the design not only meets performance specifications, but also produces sufficient yield to meet the market demand. The goal of design for manufacturability (DFM) technology is to enable designers to address manufacturing requirements during the design process. While new cell-based, DP-aware, and net-aware fill technologies have emerged to provide the designer with automated fill engines that support these new fill requirements, design changes that arrive late in the tapeout process (as engineering change orders, or ECOs) can have a disproportionate effect on tapeout schedules, due to the complexity of replacing fill. If not handled effectively, the impacts on file size, run time, and timing closure can significantly extend the tapeout process. In this paper, the authors examine changes to design flow methodology, supported by new fill technology, that enable efficient, fast, and accurate adjustments to metal fill late in the design process. We present an ECO fill methodology coupled with the support of advanced fill tools that can quickly locate the portion of the design affected by the change, remove and replace only the fill in that area, while maintaining the fill hierarchy. This new fill approach effectively reduces run time, contains fill file size, minimizes timing impact, and minimizes mask costs due to ECO-driven fill changes, all of which are critical factors to ensuring time-to-market schedules are maintained.

  18. 30 CFR 77.705 - Guy wires; grounding.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Guy wires; grounding. 77.705 Section 77.705... MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Grounding § 77.705 Guy wires; grounding. Guy wires from poles supporting high-voltage transmission lines shall be...

  19. 49 CFR 236.723 - Circuit, double wire; line.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Circuit, double wire; line. 236.723 Section 236.723 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... § 236.723 Circuit, double wire; line. An electric circuit not employing a common return wire; a circuit...

  20. Thermal Aware Floorplanning Incorporating Temperature Dependent Wire Delay Estimation

    DEFF Research Database (Denmark)

    Winther, AndreasThor; Liu, Wei; Nannarelli, Alberto

    2015-01-01

    Temperature has a negative impact on metal resistance and thus wire delay. In state-of-the-art VLSI circuits, large thermal gradients usually exist due to the uneven distribution of heat sources. The difference in wire temperature can lead to performance mismatch because wires of the same length ...

  1. 78 FR 7452 - Steel Wire Garment Hangers From Vietnam; Determinations

    Science.gov (United States)

    2013-02-01

    ... COMMISSION Steel Wire Garment Hangers From Vietnam; Determinations On the basis of the record \\1\\ developed... imports of steel wire garment hangers from Vietnam, provided for in subheading 7326.20.00 of the... countervailing and antidumping duty orders on steel wire garment hangers from Vietnam. Background The Commission...

  2. Basic Wiring. Third Edition. Teacher Edition [and] Student Edition.

    Science.gov (United States)

    Kaltwasser, Stan; Flowers, Gary; Blasingame, Don; Batson, Larry; Ipock, Dan; Carroll, Charles; Friesen, Wade; Fleming, Glenn

    This publication contains both a teacher edition and a student edition of materials for a foundation course in an electrical wiring program. The course introduces basic concepts and skills that are prerequisites to residential wiring and commercial and industrial wiring courses. The contents of the materials are tied to measurable and observable…

  3. Lunar Module Wiring Design Considerations and Failure Modes

    Science.gov (United States)

    Interbartolo, Michael

    2009-01-01

    This slide presentation reviews the considerations for the design of wiring for the Lunar Module. Included are a review of the choice of conductors and insulations, the wire splicing (i.e., crimping, and soldering), the wire connectors, and the fabrication of the wire harnesses. The problems in fabrication include the wires being the wrong length, the damage due to the sharp edges, the requried use of temproary protective covers and inadequate training. The problems in the wire harness installation include damge from sharp eges, work on adjacent harnesses, connector damage, and breaking wires. Engineering suggestions from the Apollo-era in reference to the conductors that are reviewed include: the use of plated conductors, and the use of alloys for stronger wiring. In refernce to insulation, the suggestions from Apollo era include the use of polymer tape-wrap wire insulation due to the light weight, however, other types of modern insulation might be more cost-effective. In reference to wire splices and terminal boards the suggestions from the Apollo Era include the use of crimp splices as superior to solder splices, joining multiple wire to a common point using modular plug-ins might be more reliable, but are heavier than crimp splicing. For connectors, the lessons from the Apollo era indicate that a rear environmental seal that does not require additional potting is preferred, and pins should be crimped or welded to the incoming wires and be removable from the rear of the connector.

  4. 77 FR 1504 - Stainless Steel Wire Rod From India

    Science.gov (United States)

    2012-01-10

    ... COMMISSION Stainless Steel Wire Rod From India Determination On the basis of the record \\1\\ developed in the... antidumping duty order on stainless steel wire rod From India would be likely to lead to continuation or... contained in USITC Publication 4300 (January 2012), entitled Stainless Steel Wire Rod From India...

  5. Kirschner Wires : insertion techniques and bone related consequences

    NARCIS (Netherlands)

    Franssen, B.B.G.M.

    2010-01-01

    The Kirschner (K-) wire was first introduced in 1909 by Martin Kirschner. This is a thin unthreaded wire of surgical steel with a diameter of up to three millimeters and a selection of different tips. The use of K-wires is often promoted as a simple technique because of its easy placement,

  6. Modeling, simulation and parametric optimization of wire EDM ...

    African Journals Online (AJOL)

    In the present work, quadratic mathematical models have been derived to represent the process behavior of wire electrical discharge machining (WEDM) operation. Experiments have been conducted with six process parameters: discharge current, pulse duration, pulse frequency, wire speed, wire tension and dielectric flow ...

  7. Experimental investigation of industrial copper deformed by wire ...

    African Journals Online (AJOL)

    drawing on microstructure and physical properties of industrial copper wires. Copper wires were provided by E.N.I.CA.Biskra (Algeria). We investigated some wires with different strain levels (as received, 1.20, 2.10, and ε = 3.35).

  8. Application of Matteucci Voltage Pulses of Amorphous Wires in ...

    African Journals Online (AJOL)

    In this work the effect of torsion on the Matteucci voltage pulses in amorphous wires has been studied. It has been shown that: Amplitude of the pulses decreases to zero at a twist angle that depends on the chemical composition of the wire. From zero torsion, the amplitude of the Matteucci voltage increases when the wires ...

  9. 77 FR 28404 - Galvanized Steel Wire From China and Mexico

    Science.gov (United States)

    2012-05-14

    ... COMMISSION Galvanized Steel Wire From China and Mexico Determinations On the basis of the record \\1... retarded, by reason of imports from China of galvanized steel wire, provided for in subheadings 7217.20.30... retarded, by reason of imports from Mexico of galvanized steel wire, provided for in subheadings 7217.20.30...

  10. 76 FR 29266 - Galvanized Steel Wire From China and Mexico

    Science.gov (United States)

    2011-05-20

    ... COMMISSION Galvanized Steel Wire From China and Mexico Determinations On the basis of the record \\1... injured by reason of imports from China and Mexico of galvanized steel wire, provided for in subheading... subsidized imports of galvanized steel wire from China and Mexico. Accordingly, effective March 31, 2011, the...

  11. New measurement methods for anechoic chamber characterization

    OpenAIRE

    Gómez Alfageme, Juan José; Sanchez Bote, José Luis; Blanco Martín, Elena

    2008-01-01

    As a continuation of the work presented in 122nd AES Convention, this paper tries to study in depth the anechoic chambers qualification. The purpose of this paper is to find parameters that allow the characterization of this type of enclosures. The proposal that becomes in this work is trying to obtain data of the anechoic chambers absorption by means of the transfer functions between pairs of microphones, or by means of the impulse response between pairs of microphones. Based on the results ...

  12. The Gargamelle heavy liquid bubble chamber

    CERN Multimedia

    CERN PhotoLab

    1970-01-01

    This image shows the Gargamelle heavy liquid bubble chamber. It was used to detect particles in experiments at the PS between 1970 and 1976 before being moved to the SPS. In 1973, while working on the PS, it detected the first neutral current, an interaction vital to the electroweak theory. In 1978 a large fissure appeared in the body of the chamber and Gargamelle was stopped in 1979.

  13. Delayed migration of K-wire into popliteal fossa used for tension band wiring of patellar fracture

    Directory of Open Access Journals (Sweden)

    Meena Sanjay

    2013-06-01

    Full Text Available 【Abstract】Breakage of K-wires and stainless steel wires which are used for fracture fixation is not uncommon, but migration is rare. We report a case of migration of bro-ken K-wire used for patella tension band wiring to the popliteal fossa. The broken hardware was removed surgically. We would like to suggest that K-wire and wire fixation used for treatment of patellar fractures can migrate into the posterior compartment of the knee and cause clini-cal symptoms. Close clinical and radiological follow-up af-ter internal fixation to identify the presence of hardware breakage or movement and removal of wires once fracture has united can avert such complications. Key words: Patella; Fracture fixation, internal; Bone wires

  14. On grouping individual wire segments into equivalent wires or chains, and introduction of multiple domain basis functions

    CSIR Research Space (South Africa)

    Lysko, AA

    2009-06-01

    Full Text Available The paper introduces a method to cover several wire segments with a single basis function, describes related practical algorithms, and gives some results. The process involves three steps: identifying chains of wire segments, splitting the chains...

  15. Forecasting of Corrosion Properties of Steel Wires for Production of Guide Wires for Cardiological Treatment

    Directory of Open Access Journals (Sweden)

    J. Przondziono

    2013-01-01

    Full Text Available The study presents evaluation of the influence of strain in drawing process and of surface modification on resistance to electrochemical corrosion of wires made of stainless steel for production of guide wires used in invasive cardiology. The results of static tensile test enabled us to determine the course of flow curve of wires made of X10CrNi 18-8 steel as well as mathematical form of flow stress function. Resistance to electrochemical corrosion was evaluated on the ground of registered anodic polarisation curves by means of potentiodynamic method. The tests were performed in solution simulating human blood on samples that were electrolytically polished and samples that were polished and then chemically passivated. Exemplary anodic polarisation curves were given. It was proved that with the applied strain, corrosion properties decrease. It was found that chemical passivation improves wire corrosion characteristics. Statistical analysis showed that there is a significant dependence between corrosion properties (polarisation resistance Rp and strain ε applied in drawing process. Functions that present the change Rp=f(ε were selected. The issue is of importance to guide wire manufacturers because application of the suggested methodology will enable us to forecast corrosion characteristics of wire with the required strength drawn with the applied strain.

  16. Research regarding wires elastic deformations influence on joints positioning of a wire-driven robotic arm

    Science.gov (United States)

    Ciofu, C.; Stan, G.

    2016-08-01

    In this paper, we present the influence of driving wires deformation on positioning precision of joints from an elephant's trunk robotic arm. Robotic arms driven by wires have the joint accuracy largely depending on wires rigidity. The joint moment of resistance causes elastic deformation of wires and it is determined by: manipulated object load, weight loads previous to the analyzed joint and inherent resistance moment of joint. Static load analysis emphasizes the particular wires elastic deformation of each driven joint from an elephant's trunk robotic arm with five degrees of freedom. We consider the case of a constant manipulated load. Errors from each driving system of joints are not part of the closed loop system. Thus, precision positioning depends on wires elastic deformation which is about microns and causes angle deviation of joints about tens of minutes of sexagesimal degrees. The closer the joints to base arm the smaller positioning precision of joint. The obtained results are necessary for further compensation made by electronic corrections in the programming algorithm of the elephant's trunk robotic arm to improve accuracy.

  17. Laser peripheral iridotomy changes anterior chamber architecture.

    Science.gov (United States)

    Theinert, Christian; Wiedemann, Peter; Unterlauft, Jan D

    2017-01-19

    The pressure gradient between anterior and posterior chamber in acute angle closure (AAC) and primary angle closure suspects is balanced by a sufficient laser peripheral iridotomy (LPI). The anterior chamber changes induced by LPI in patients with unilateral AAC were examined and compared to healthy eyes to define threshold values, which may help to discriminate between healthy and diseased eyes. Using Scheimpflug photography, anterior chamber depth (ACD), anterior chamber volume (ACV), anterior chamber angle (ACA), and central corneal thickness (CCT) were measured before and after LPI in both eyes of unilateral AAC cases. These measurements were compared to a group of healthy control eyes to determine threshold values for ACD, ACV, and ACA. The ACD, ACV, and ACA increased significantly in the 25 AAC eyes after LPI. The ACD, ACV, ACA, and CCT values in the AAC eyes obtained before LPI were compared to a control group of 59 healthy eyes with wide open chamber angles. The cutoff values revealed by receiver operating characteristic analysis were 2.1 mm for ACD, 90.5 mm2 for ACV, and 27.25° for ACA. Our results confirm the significant changes of the anterior segments architecture induced by LPI in AAC eyes. The found threshold values for ACD, ACV, and ACA may help in daily clinical routine to discriminate between healthy eyes and those in need for a prophylactic LPI.

  18. Selective filling of Photonic Crystal Fibres

    DEFF Research Database (Denmark)

    Nielsen, Kristian; Noordegraaf, Danny; Sørensen, Thorkild

    2005-01-01

    A model for calculating the time necessary for filling one or more specific holes in a photonic crystal fibre is made. This model is verified for water, and its enabling potential is illustrated by a polymer application. Selective filling of the core in an air-guide photonic crystal fibre is demo...

  19. Scaffold Filling under the Breakpoint Distance

    Science.gov (United States)

    Jiang, Haitao; Zheng, Chunfang; Sankoff, David; Zhu, Binhai

    Motivated by the trend of genome sequencing without completing the sequence of the whole genomes, Muñoz et al. recently studied the problem of filling an incomplete multichromosomal genome (or scaffold) I with respect to a complete target genome G such that the resulting genomic distance between I' and G is minimized, where I' is the corresponding filled scaffold. We call this problem the one-sided scaffold filling problem. In this paper, we follow Muñoz et al. to investigate the scaffold filling problem under the breakpoint distance for the simplest unichromosomal genomes. When the input genome contains no gene repetition (i.e., is a fragment of a permutation), we show that the two-sided scaffold filling problem is polynomially solvable. However, when the input genome contains some genes which appear twice, even the one-sided scaffold filling problem becomes NP-complete. Finally, using the ideas for solving the two-sided scaffold filling problem under the breakpoint distance we show that the two-sided scaffold filling problem under the genomic/rearrangement distance is also polynomially solvable.

  20. Influence of template fill in graphoepitaxy DSA

    Science.gov (United States)

    Doise, Jan; Bekaert, Joost; Chan, Boon Teik; Hong, SungEun; Lin, Guanyang; Gronheid, Roel

    2016-03-01

    Directed self-assembly (DSA) of block copolymers (BCP) is considered a promising patterning approach for the 7 nm node and beyond. Specifically, a grapho-epitaxy process using a cylindrical phase BCP may offer an efficient solution for patterning randomly distributed contact holes with sub-resolution pitches, such as found in via and cut mask levels. In any grapho-epitaxy process, the pattern density impacts the template fill (local BCP thickness inside the template) and may cause defects due to respectively over- or underfilling of the template. In order to tackle this issue thoroughly, the parameters that determine template fill and the influence of template fill on the resulting pattern should be investigated. In this work, using three process flow variations (with different template surface energy), template fill is experimentally characterized as a function of pattern density and film thickness. The impact of these parameters on template fill is highly dependent on the process flow, and thus pre-pattern surface energy. Template fill has a considerable effect on the pattern transfer of the DSA contact holes into the underlying layer. Higher fill levels give rise to smaller contact holes and worse critical dimension uniformity. These results are important towards DSA-aware design and show that fill is a crucial parameter in grapho-epitaxy DSA.