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  1. Gem Analysis

    NASA Technical Reports Server (NTRS)

    1981-01-01

    World Gem Laboratory, Inc.'s cathodoluminoscope is an instrument that magnifies a specimen and produces heat-generated light emissions that bring out features important in gemological analysis. It can indicate whether a stone can be successfully cut, useful in the study of growth and strain patterns in diamonds, detection of dyes in jade, and analysis of the growth and structure of rubies and sapphires. In combination with other tests these analyses can separate synthetic from natural gems.

  2. Mechanism of GEMS formation

    SciTech Connect

    Bradley, J P; Dai, Z R

    2004-03-10

    GEMS (glass with embedded metal and sulfides) in interplanetary dust particles (IDPs) were examined using 200 keV analytical transmission electron microscopy. The morphologies and crystallography of embedded relict grains reveal that GEMS are pseudomorphs formed by irradiation processing of crystals free-floating in space. Some GEMS retain a compositional and morphological ''memory'' of the crystal from which they formed. Pseudomorphism rules out condensation, annealing, flash heating, or shock melting as alternative mechanisms of GEMS formation. A significant and often dominant fraction of the atoms in GEMS were sputtered deposited from other grains. Therefore, a normal (solar) isotopic composition is not a reliable indicator of whether GEMS formed in the solar system or in presolar interstellar or circumstellar environments.

  3. Not Your Ordinary GEM

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Through Small Business Innovation Research (SBIR) funding from NASA's Stennis Space Center, Geophex devised a new design for broadband electromagnetic sensors. Geophex developed a patented sensing technology, capable not only of coastal monitoring, but also a variety of other functions, including environmental pollution characterization, groundwater contamination detection, archaeological study, and mineral detection. The new technology is offered in several of the company's products the GEM-2, GEM-2A, and the GEM-3. The Geophex products consist of two primary electromagnetic coils, which are stimulated by alternating currents that generate a magnetic field in the object targeted for investigation. GEM-2 is a handheld, lightweight, programmable, digital device. GEM-2A is an airborne version of the sensor. Suspended from a helicopter, the GEM-2A is used to search for mineral deposits and to survey large tracts of land. The GEM-3 is capable of detecting buried landmines and other active munitions. GEM-3 identifies landmines by their brand names. Because each landmine has its own unique electromagnetic response to the broad frequency band emitted by the GEM-3, bomb identification and disposal strategies are made easier.

  4. Origins of GEMS Grains

    NASA Technical Reports Server (NTRS)

    Messenger, S.; Walker, R. M.

    2012-01-01

    Interplanetary dust particles (IDPs) collected in the Earth s stratosphere contain high abundances of submicrometer amorphous silicates known as GEMS grains. From their birth as condensates in the outflows of oxygen-rich evolved stars, processing in interstellar space, and incorporation into disks around new stars, amorphous silicates predominate in most astrophysical environments. Amorphous silicates were a major building block of our Solar System and are prominent in infrared spectra of comets. Anhydrous interplanetary dust particles (IDPs) thought to derive from comets contain abundant amorphous silicates known as GEMS (glass with embedded metal and sulfides) grains. GEMS grains have been proposed to be isotopically and chemically homogenized interstellar amorphous silicate dust. We evaluated this hypothesis through coordinated chemical and isotopic analyses of GEMS grains in a suite of IDPs to constrain their origins. GEMS grains show order of magnitude variations in Mg, Fe, Ca, and S abundances. GEMS grains do not match the average element abundances inferred for ISM dust containing on average, too little Mg, Fe, and Ca, and too much S. GEMS grains have complementary compositions to the crystalline components in IDPs suggesting that they formed from the same reservoir. We did not observe any unequivocal microstructural or chemical evidence that GEMS grains experienced prolonged exposure to radiation. We identified four GEMS grains having O isotopic compositions that point to origins in red giant branch or asymptotic giant branch stars and supernovae. Based on their O isotopic compositions, we estimate that 1-6% of GEMS grains are surviving circumstellar grains. The remaining 94-99% of GEMS grains have O isotopic compositions that are indistinguishable from terrestrial materials and carbonaceous chondrites. These isotopically solar GEMS grains either formed in the Solar System or were completely homogenized in the interstellar medium (ISM). However, the

  5. GEM*: A Molecular Electronic Density-Based Force Field for Molecular Dynamics Simulations.

    PubMed

    Duke, Robert E; Starovoytov, Oleg N; Piquemal, Jean-Philip; Cisneros, G Andrés

    2014-04-08

    GEM*, a force field that combines Coulomb and Exchange terms calculated with Hermite Gaussians with the polarization, bonded, and modified van der Waals terms from AMOEBA is presented. GEM* is tested on an initial water model fitted at the same level as AMOEBA. The integrals required for the evaluation of the intermolecular Coulomb interactions are efficiently evaluated by means of reciprocal space methods. The GEM* water model is tested by comparing energies and forces for a series of water oligomers and MD simulations. Timings for GEM* compared to AMOEBA are presented and discussed.

  6. A Hidden GEM

    ERIC Educational Resources Information Center

    Khan, Samia

    2012-01-01

    The internet abounds with free science education applications. But, on their own, these applications have limited capacity to teach students curricular concepts or skills. The author integrated several free web-based applications into a broader pedagogical approach called T-GEM, in which the teacher guides student investigations. In this article,…

  7. GEM Technical Design Report

    SciTech Connect

    Not Available

    1993-07-31

    The GEM collaboration was formed in June 1991 to develop a major detector for the SSC. The primary physics objectives of GEM are those central to the motivation for the SSC, to study high p{sub T} physics - exemplified by the search for Higgs bosons - and to search for new physics beyond the standard model. The authors present in this Technical Design Report (TDR) a detector with broad capabilities for the discovery and subsequent study of electroweak symmetry breaking, the origin of mass and flavor, and other physics requiring precise measurements of gammas, electrons, and muons - hence the name, GEM. In addition, as a design goal, they have taken care to provide the robustness needed to do the physics that requires high luminosity. Finally, good coverage and hermeticity allow the detection of missing transverse energy, E{sub T}. The GEM design emphasizes clean identification and high resolution measurement of the primary physics signatures for high p{sub T} physics. The approach is to make precise energy measurements that maximize the sensitivity to rare narrow resonances, to detect the elementary interaction products (quarks, leptons, and photons), and to build in the features required to reduce backgrounds.

  8. Giotto Extended Mission (GEM)

    NASA Technical Reports Server (NTRS)

    Wilkins, D. E. B.; Grensemann, M.

    1991-01-01

    The primary objectives of the Giotto Extended Mission (GEM), are to determine the composition and physical state of the Grigg Skjellerup Comet's nucleus; to determine the processes that govern the composition and distribution of neutral and ionized species in the cometary atmosphere. Giotto consists of a single European Space Agency (ESA) spacecraft that was launched in 1985 from Center Spatial Guyanis in French Guiana on an Ariane launch vehicle. After a successful launch into geostationary orbit and a heliocentric transfer trajectory, the spacecraft successfully encountered Halley's Comet in 1986. One month after encountering Halley's Comet, Mar. 1986, the spacecraft was placed in hibernation in a heliocentric orbit slightly less than 1 AU. Between Feb. and Jul. 1990 the spacecraft was successfully reactivated, checked out, and placed on a trajectory course to intercept comet Grigg Skjellerup. The spacecraft has been in hibernation since Jul. 1990. Information is presented in tabular form in the following areas: coverage goals, Deep Space Network Support, frequency assignments, telemetry, command, and tracking support responsibility.

  9. Origin and properties of GEMS

    SciTech Connect

    Dai, Z R; Bradley, J P

    2006-04-11

    GEMS are to the outer solar system what chondrules are to the inner solar system. Ten years after it was first proposed that GEMS are the long-sought interstellar amorphous silicates, ion microprobe measurements have confirmed that some of them are indeed interstellar amorphous silicates. The new challenges are to obtain even higher precision isotope measurements from these submicrometer-sized objects and to clarify how and where they originally formed. Individual GEMS exhibit a strikingly narrow (0.1-0.5 {micro}m diameter) size distribution and they are systematically depleted from solar abundances in S/Si, Mg/Si, Ca/Si and Fe/Si, implying that they formed by a common mechanism. Mineralogical and petrographic evidence suggest that irradiation processing may be that mechanism. Recent nanometer-scale compositional mapping using new-generation transmission electron microscopes reveals that truly pristine GEMS may be relatively rare and new metrics need to be developed to distinguish the primordial properties of GEMS from more recent secondary alteration effects.

  10. GEM - The Global Earthquake Model

    NASA Astrophysics Data System (ADS)

    Smolka, A.

    2009-04-01

    Over 500,000 people died in the last decade due to earthquakes and tsunamis, mostly in the developing world, where the risk is increasing due to rapid population growth. In many seismic regions, no hazard and risk models exist, and even where models do exist, they are intelligible only by experts, or available only for commercial purposes. The Global Earthquake Model (GEM) answers the need for an openly accessible risk management tool. GEM is an internationally sanctioned public private partnership initiated by the Organisation for Economic Cooperation and Development (OECD) which will establish an authoritative standard for calculating and communicating earthquake hazard and risk, and will be designed to serve as the critical instrument to support decisions and actions that reduce earthquake losses worldwide. GEM will integrate developments on the forefront of scientific and engineering knowledge of earthquakes, at global, regional and local scale. The work is organized in three modules: hazard, risk, and socio-economic impact. The hazard module calculates probabilities of earthquake occurrence and resulting shaking at any given location. The risk module calculates fatalities, injuries, and damage based on expected shaking, building vulnerability, and the distribution of population and of exposed values and facilities. The socio-economic impact module delivers tools for making educated decisions to mitigate and manage risk. GEM will be a versatile online tool, with open source code and a map-based graphical interface. The underlying data will be open wherever possible, and its modular input and output will be adapted to multiple user groups: scientists and engineers, risk managers and decision makers in the public and private sectors, and the public-at- large. GEM will be the first global model for seismic risk assessment at a national and regional scale, and aims to achieve broad scientific participation and independence. Its development will occur in a

  11. Leading a successful iGEM team.

    PubMed

    Materi, Wayne

    2012-01-01

    The International Genetically Engineered Machines (iGEM) competition allows undergraduate teams to develop projects in synthetic biology within the context of a large, international Jamboree. Organizing and managing a successful iGEM team is an exercise in advanced agile project development. While many of the principles applicable to such teams are derived from management of agile software teams, iGEM presents several unique challenges.

  12. Der evolutionäre Naturalismus in der Ethik

    NASA Astrophysics Data System (ADS)

    Kaiser, Marie I.

    Charles Darwin hat eindrucksvoll gezeigt, dass der Mensch ebenso wie alle anderen Lebewesen ein Produkt der biologischen Evolution ist. Die sich an Darwin anschließende Forschung hat außerdem plausibel gemacht, dass sich nicht nur viele der körperlichen Merkmale des Menschen, sondern auch (zumindest einige) seiner Verhaltensdispositionen in adaptiven Selektionsprozessen herausgebildet haben. Die Vorstellung, dass auch die menschliche Moralität evolutionär bedingt ist, scheint daher auf den ersten Blick ganz überzeugend. Schließlich hat die Evolutionstheorie in den vergangenen Jahrzehnten in vielen Bereichen (auch außerhalb der Biologie) ihre weitreichende Bedeutung unter Beweis gestellt. Warum sollte, so könnte man beispielsweise fragen, gerade die Fähigkeit des Menschen, moralische Normen aufzustellen und gemäß ihnen zu handeln, nicht evolutionär erklärt werden können? Und warum sollte eine solche evolutionäre Erklärung der menschlichen Moralität irrelevant für die Rechtfertigung moralischer Normen sein? Warum sollte die Ethik eine Bastion der Philosophen bleiben, für die evolutionsbiologische Forschungsergebnisse über den Menschen und seine nächsten Verwandten keinerlei Relevanz besitzen?

  13. GEM: Statistical weather forecasting procedure

    NASA Technical Reports Server (NTRS)

    Miller, R. G.

    1983-01-01

    The objective of the Generalized Exponential Markov (GEM) Program was to develop a weather forecast guidance system that would: predict between 0 to 6 hours all elements in the airways observations; respond instantly to the latest observed conditions of the surface weather; process these observations at local sites on minicomputing equipment; exceed the accuracy of current persistence predictions at the shortest prediction of one hour and beyond; exceed the accuracy of current forecast model output statistics inside eight hours; and be capable of making predictions at one location for all locations where weather information is available.

  14. The GEMS-2 SEIS Experiment

    NASA Astrophysics Data System (ADS)

    Tillier, S.; De Raucourt, S.; Mimoun, D.; Lognonne, P.; Giardini, D.; Christensen, U. R.; Pike, W. T.; Banerdt, B.; Laudet, P.; Kerjean, L.; Hurst, K. J.; Zweifel, P.; Mance, D.; Roll, R.; Bierwirth, M.; Gagnepain-Beyneix, J.; Nibut, T.; Robert, O.; Gabsi, T.; Pot, O.; Lecomte, B.; Schibler, P.; Mocquet, A.; Garcia, R.

    2011-12-01

    The SEIS experiment is the primary payload of the Geophysical Monitoring Station (GEMS) Mission Proposal, submitted to NASA in the frame of the 2010 Discovery program, and recently selected for the phase A study. The objective of the GEMS SEIS experiment is the determination of the deep internal structure of Mars. In particular, geophysical parameters of first importance, such as the state (liquid/solid) and size of the core, as well as structure of the mantle and shape of discontinuities will be determined by the experiment. It will measure seismic activity in a very broad band of signal, from the tidal frequencies (0.05 mHz) up to the short period frequencies (50 Hz), to address the widest range of scientific questions, from the state of the inner core to the meteoritic rate measurement. Infrasound, which might be associated to dust devils and atmospheric discharge, will be also monitored. The instrument integrates a Very Broad Band (VBB) 3 axis seismometer, completed by another trihedron of MEMS short period seismometers, environmental sensors for pressure, wind and temperature, and an infrasound sensor is additionally considered. The sensors will be deployed on the Martian ground by a robotic arm from the Phoenix lander platform and protected by a wind and thermal shield. The sensor assembly, which contains all seismic sensors, the leveling system, as well as house-keeping and temperature measurements, will be deployed on the soil in order to allow the best possible mechanical coupling with the ground motion. Thanks to the wind and thermal shield, together with the sensors' specific containers (vacuum sphere for VBBs), long term VBB bias will be protected from both temperature and pressure variations (as well as passively compensated), allowing the sensor to operate in the rough Martian thermal environment. A dedicated electronics will manage the overall experiment and ultra-low noise, space qualified 24 bits A/D converters will perform the acquisition. The

  15. ROLE OF GEMS IN INDIAN MEDICINE

    PubMed Central

    Murthy, S.R.N.

    1991-01-01

    This paper is the first attempt in introducing the medicinal importance of gems as found in the Sanskrit text ‘Rasaratnasamuccaya’, which has been rendered an English translation here. The modern physicians and gemologists will find this study quite useful in continuing research and, thus, develop a new field of gem medicine. PMID:22556526

  16. The GEM-T2 gravitational model

    NASA Technical Reports Server (NTRS)

    Marsh, J. G.; Lerch, F. J.; Putney, B. H.; Felsentreger, T. L.; Sanchez, B. V.; Klosko, S. M.; Patel, G. B.; Robbins, J. W.; Williamson, R. G.; Engelis, T. E.

    1989-01-01

    The GEM-T2 is the latest in a series of Goddard Earth Models of the terrestrial field. It was designed to bring modeling capabilities one step closer towards ultimately determining the TOPEX/Poseidon satellite's radial position to an accuracy of 10-cm RMS (root mean square). It also improves models of the long wavelength geoid to support many oceanographic and geophysical applications. The GEM-T2 extends the spherical harmonic field to include more than 600 coefficients above degree 36 (which was the limit for its predecessor, GEM-T1). Like GEM-T1, it was produced entirely from satellite tracking data, but it now uses nearly twice as many satellites (31 vs. 17), contains four times the number of observations (2.4 million), has twice the number of data arcs (1132), and utilizes precise laser tracking from 11 satellites. The estimation technique for the solution has been augmented to include an optimum data weighting procedure with automatic error calibration for the gravitational parameters. Results for the GEM-T2 error calibration indicate significant improvement over previous satellite-only models. The error of commission in determining the geoid has been reduced from 155 cm in GEM-T1 to 105 cm for GEM-T2 for the 36 x 36 portion of the field, and 141 cm for the entire model. The orbital accuracies achieved using GEM-T2 are likewise improved. Also, the projected radial error on the TOPEX satellite orbit indicates 9.4 cm RMS for GEM-T2, compared to 24.1 cm for GEM-T1.

  17. GEM Applications Outside High Energy Physics

    NASA Astrophysics Data System (ADS)

    Pinto, Serge Duarte

    2013-04-01

    From its invention in 1997, the Gas Electron Multiplier (GEM) has been applied in nuclear and high energy physics experiments. Over time however, other applications have also exploited the favorable properties of GEMs. The use of GEMs in these applications will be explained in principle and practice. This paper reviews applications in research, beam instrumentation and homeland security. The detectors described measure neutral radiations such as photons, x-rays, gamma rays and neutrons, as well as all kinds of charged radiation. This paper provides an overview of the still expanding range of possibilities of this versatile detector concept.

  18. The GEMS Model of Volunteer Administration.

    ERIC Educational Resources Information Center

    Culp, Ken, III; Deppe, Catherine A.; Castillo, Jaime X.; Wells, Betty J.

    1998-01-01

    Describes GEMS, a spiral model that profiles volunteer administration. Components include Generate, Educate, Mobilize, and Sustain, four sets of processes that span volunteer recruitment and selection to retention or disengagement. (SK)

  19. Data Analysis And Polarization Measurements With GEMS

    NASA Technical Reports Server (NTRS)

    Stohmayer, Tod

    2011-01-01

    The Gravity and Extreme Magnetism SMEX (GEMS) mission was selected by NASA for flight in 2014. GEMS will make the first sensitive survey of X-ray polarization across a wide range of source classes including black hole and neutron star binaries, AGN of different types, rotation and accretion-powered pulsars, magnetars, shell supernova remnants and pulsar wind nebulae. GEMS employs grazing-incidence foil mirrors and novel time-projection chamber (TPC) polarimeters leveraging the photoelectric effect. The GEMS detectors image the charge tracks of photoelectrons produced by 2 - 10 keV X-rays. The initial direction of the photoelectron is determined by the linear polarization of the photon. We present an overview of the data analysis challenges and methods for GEMS, including procedures for producing optimally filtered images of the charge tracks and estimating their initial directions. We illustrate our methods using laboratory measurements of polarized and unpolarized X-rays with flight-like detectors as well as from simulated tracks. We also present detailed simulations exploring the statistics of polarization measurements appropriate for GEMS, and make comparisons with previous work.

  20. η-PHYSICS at GEM

    NASA Astrophysics Data System (ADS)

    Hawranek, Piotr

    Some experimental studies of η-production and η-interactions performed or presently under way by the GEM collaboration at COSY Jülich are reviewed. The Germanium Wall, a stack of annular detectors made of high purity Germanium, was used to measure a series of differential and total cross sections for η-production with proton and deuteron beams on light nuclei. The unique combination of a high resolution magnetic spectrograph (BIG KARL) and 7an electron cooled beam delivered by COSY is ideally suited to perform high precision experiments like the η-mass determination. In a self calibrating experiment three particles from two reactions were detected simultaneously. Kinematical coincidence of 3H and π+ from p + d → 3H + π+ reaction allowed to calibrate the spectrograph and determine the beam momentum with great accuracy. The η-meson was seen clearly as a sharp missing-mass peak on a slowly varying background in the p + d → 3He + X reaction. A new value for the η-mass has been derived with extremely small error bars.

  1. Does Comet WILD-2 contain Gems?

    NASA Technical Reports Server (NTRS)

    Chi, M.; Ishii, H.; Dai, Z. R.; Toppani, A.; Joswiak, D. J.; Leroux, H.; Zolensky, M.; Keller, L. P.; Browning, N. D.

    2007-01-01

    It is expected that Comet Wild-2 dust should resemble anhydrous carbon-rich, chondritic porous (CP) interplanetary dust particles (IDPs) collected in the stratosphere because some CP IDPs are suspected to be from comets. The rarity of carbonaceous grains and presolar silicates, as well as the presence of high-temperature inner solar nebula minerals in the Wild-2 sample (e.g. osbornite and melilite), appear incompatible with most CP IDPs. However, it is premature to draw firm conclusions about the mineralogy of comet Wild-2 because only approx. 1% of the sample has been examined. The most abundant silicates in CP IDPs are GEMS (glass with embedded metal and sulfides). Nonsolar O isotopic compositions confirm that at least some GEMS in IDPs are presolar amorphous silicates. The presence or absence of GEMS in the Wild-2 sample is important because it addresses, (a) the relationship between CP IDPs and comets, and (b) the hypothesis that other GEMS in IDPs formed in the solar nebula. Here we show that most of the GEMSlike materials so far identified in Stardust aerogel were likely impact generated during collection. At the nanometer scale, they are compositionally and crystallographically distinct from GEMS in IDPs.

  2. The GEM Detector projective alignment simulation system

    SciTech Connect

    Wuest, C.R.; Belser, F.C.; Holdener, F.R.; Roeben, M.D.; Paradiso, J.A.; Mitselmakher, G.; Ostapchuk, A.; Pier-Amory, J.

    1993-07-09

    Precision position knowledge (< 25 microns RMS) of the GEM Detector muon system at the Superconducting Super Collider Laboratory (SSCL) is an important physics requirement necessary to minimize sagitta error in detecting and tracking high energy muons that are deflected by the magnetic field within the GEM Detector. To validate the concept of the sagitta correction function determined by projective alignment of the muon detectors (Cathode Strip Chambers or CSCs), the basis of the proposed GEM alignment scheme, a facility, called the ``Alignment Test Stand`` (ATS), is being constructed. This system simulates the environment that the CSCs and chamber alignment systems are expected to experience in the GEM Detector, albeit without the 0.8 T magnetic field and radiation environment. The ATS experimental program will allow systematic study and characterization of the projective alignment approach, as well as general mechanical engineering of muon chamber mounting concepts, positioning systems and study of the mechanical behavior of the proposed 6 layer CSCs. The ATS will consist of a stable local coordinate system in which mock-ups of muon chambers (i.e., non-working mechanical analogs, representing the three superlayers of a selected barrel and endcap alignment tower) are implemented, together with a sufficient number of alignment monitors to overdetermine the sagitta correction function, providing a self-consistency check. This paper describes the approach to be used for the alignment of the GEM muon system, the design of the ATS, and the experiments to be conducted using the ATS.

  3. Development of a GEM Electronic Board (GEB) for triple-GEM detectors

    NASA Astrophysics Data System (ADS)

    Aspell, P.; Dabrowski, M.; Conde Garcia, A.; De Lentdecker, G.; Marinov, A.; De Oliveira, R.; Talvitie, J.; Tuuva, T.; Yang, Y.

    2014-12-01

    Developed for use with triple GEM detectors, the GEM Electronic Board (GEB) forms a crucial part of the electronics readout system being developed as part of the CMS muon upgrade program. The objective of the GEB is threefold; to provide stable powering and ground for the VFAT3 front ends, to enable high-speed communication between 24 VFAT3 front ends and an optohybrid, and to shield the GEM detector from electromagnetic interference. The paper describes the concept and design of a large-size GEB in detail, highlighting the challenges in terms of design and feasibility of this deceptively difficult system component.

  4. Neutron beam imaging with GEM detectors

    NASA Astrophysics Data System (ADS)

    Albani, G.; Croci, G.; Cazzaniga, C.; Cavenago, M.; Claps, G.; Muraro, A.; Murtas, F.; Pasqualotto, R.; Perelli Cippo, E.; Rebai, M.; Tardocchi, M.; Gorini, G.

    2015-04-01

    Neutron GEM-based detectors represent a new frontier of devices in neutron physics applications where a very high neutron flux must be measured such as future fusion experiments (e.g. ITER Neutral beam Injector) and spallation sources (e.g. the European Spallation source). This kind of detectors can be properly adapted to be used both as beam monitors but also as neutron diffraction detectors that could represent a valid alternative for the 3He detectors replacement. Fast neutron GEM detectors (nGEM) feature a cathode composed by one layer of polyethylene and one of aluminium (neutron scattering on hydrogen generates protons that are detected in the gas) while thermal neutron GEM detectors (bGEM) are equipped with a borated aluminium cathode (charged particles are generated through the 10B(n,α)7Li reaction). GEM detectors can be realized in large area (1 m2) and their readout can be pixelated. Three different prototypes of nGEM and one prototype of bGEM detectors of different areas and equipped with different types of readout have been built and tested. All the detectors have been used to measure the fast and thermal neutron 2D beam image at the ISIS-VESUVIO beamline. The different kinds of readout patterns (different areas of the pixels) have been compared in similar conditions. All the detectors measured a width of the beam profile consitent with the expected one. The imaging property of each detector was then tested by inserting samples of different material and shape in the beam. All the samples were correctly reconstructed and the definition of the reconstruction depends on the type of readout anode. The fast neutron beam profile reconstruction was then compared to the one obtained by diamond detectors positioned on the same beamline while the thermal neutron one was compared to the imaged obtained by cadmium-coupled x-rays films. Also efficiency and the gamma background rejection have been determined. These prototypes represent the first step towards the

  5. The GEMS-2 Seis Experiment

    NASA Astrophysics Data System (ADS)

    Mimoun, D.; de Raucourt, S.; Lognonne, P.; Giardini, D.; Christensen, U. R.; Gagnepain-Beyneix, J.; Pike, T.; Nebut, T.; Tillier, S.; Robert, O.; Gabsi, T.; Pot, O.; Lecomte, B.; Escande, N.; Mocquet, A.; Zweifel, P.; Mance, D.; Roll, R.; Bierwirth, M.

    2010-12-01

    of data will be made on the basis of raw compressed data, plus an excerpt of the high frequency events of the day. The proposed instrument has been developed up to PDR in the frame of the ExoMars Humbold payload. Most critical parts have been tested, including shock tests for pivot, electronics components and displacement sensors. TRL 6 is expected at the end of 2011. SEIS has been proposed onboard the GEMS Mission Proposal, submitted to NASA in the frame of the 2010 Discovery AO.

  6. Development of GEMs at Hampton University

    NASA Astrophysics Data System (ADS)

    Liyanage, Anusha; Kohl, Michael; MUSE Collaboration

    2015-10-01

    Two GEM telescopes each consisting of three 10×10 cm2 triple-GEM chambers 30-40 cm apart were built, tested and operated by the Hampton group. They are read out with APV25 frontend chips and FPGA based digitizing electronics developed by INFN Rome. The telescopes served as luminosity monitors for the OLYMPUS experiment at DESY in Hamburg, Germany, with positron and electron beams at 2 GeV. The telescopes have been recycled to serve as the beam particle tracker of the MUSE experiment at the Paul Scherrer Institute in Switzerland. In the identical configuration as in OLYMPUS, the telescope was limiting the accepted trigger rate in the test measurements. Therefore, an effort is ongoing to improve the GEM readout speed to meet the trigger rate at the design intensity of the MUSE experiment. Further, the Hampton group is responsible for the DarkLight phase-I lepton tracker which is in preparation at the low energy-recovering facility (LERF) at the Thomas Jefferson National Accelerator Facility in Newport News, USA, sponsored by the National Science Foundation through a Major Research Instrumentation (MRI) grant. The group's activities on GEM detector development will be summarized, and the achieved performance and the current effort to further improvements will be discussed.

  7. Counseling Gems: Thoughts for the Practitioner.

    ERIC Educational Resources Information Center

    Carnevale, James P.

    This book contains 110 "gems" about counseling situations gleaned from a practitioner's experience as an advisor to practicum students in counseling in which he advised students on different ways to think about counseling situations. The suggestions are organized under eight headings. The first 19 suggestions deal with counseling philosophy and…

  8. Performance of the GEM electromagnetic calorimeter

    SciTech Connect

    Hong Ma

    1993-06-25

    The GEM EM calorimeter is optimized for the best energy, position, angular resolution and jet rejection. The detailed simulation results are presented. In the barrel with LKr, an energy resolution of about 6%/{radical}{direct_sum}0.4%, pointing resolution of 40mrad/{radical}E + 0.5mrad, and jet rejection of a factor of 5 are expected.

  9. Gravitational field modes GEM 3 and 4

    NASA Technical Reports Server (NTRS)

    Lerch, F. J.; Wagner, C. A.; Putney, B. H.; Sandson, M. L.; Brownd, J. E.; Richardson, J. A.; Taylor, W. A.

    1972-01-01

    A refinement in the satellite geopotential solution for a Goddard Earth Model (GEM 3) was obtained. The solution includes the addition of two low inclination satellites, SAS at 3 deg and PEOLE at 15 deg, and is based upon 27 close earth satellites containing some 400,000 observations of electronic, laser, and optical data. In addition, a new combination satellite/gravimetry solution (GEM 4) was derived. The new model includes 61 center of mass tracking station locations with data from GRARR, Laser, MOTS, Baker-Nunn, and NWL Tranet Doppler tracking sites. Improvement was obtained for the zonal coefficients of the new models and is shown by tests on the long period perturbations of the orbits. Individual zonal coefficients agree very closely among different models that contain low inclination satellites. Tests of models with surface gravity data show that the GEM 3 satellite model has significantly better agreement with the gravimetry data than the GEM 1 satellite model, and that it also has better agreement with the gravimetry data than the 1969 SAO Standard Earth 2 model.

  10. Initial Tests of Commercially Manufactured Large GEM Foils and EIC Triple-GEM Detector Design

    NASA Astrophysics Data System (ADS)

    Kraishan, Amani

    2015-10-01

    Tracking detectors exist in many different varieties and operate on different physical principles, depending on the type of particle that has to be tracked, on the desired spatial resolution, and on the area that has to be covered. Gas electron multiplier (GEM) detectors, operating on the principle of electron amplification in gases, provide good spatial resolution for charged particles and can be built with large sensitive areas. Currently CERN is the only main distributor of large area GEM foils, and will be hard pressed to keep up with the increasing demand. To help satisfy the GEM foil demand, the commercialization of large area GEM foils via the single mask process has been established by Tech-Etch of Plymouth, MA, USA. Here we present our initial quality assurance tests of the foil's electrical and geometrical properties for sizes up to 40 X 40 cm2. Using our electrical and optical measurement setup, we also measured 10 X 10 cm2 GEMs produced by CERN and compare it with the Tech-Etch foils. Furthermore, we will present initial R&D design work done toward building a potential triple-GEM tracking detector to be used at a future experiment at an Electron-Ion Collider (EIC) facility.

  11. Gravity model improvement using GEOS-3 (GEM 9 and 10)

    NASA Technical Reports Server (NTRS)

    Lerch, F. J.; Klosko, S. M.; Laubscher, R. E.; Wagner, C. A.

    1977-01-01

    The use of collocation permitted GEM 9 to be a larger field than previous derived satellite models, GEM 9 having harmonics complete to 20 x 20 with selected higher degree terms. The satellite data set has approximately 840,000 observations, of which 200,000 are laser ranges taken on 9 satellites equipped with retroreflectors. GEM 10 is complete to 22 x 22 with selected higher degree terms out to degree and order 30 amounting to a total of 592 coefficients. Comparisons with surface gravity and altimeter data indicate a substantial improvement in GEM 9 over previous satellite solutions; GEM 9 is in even closer agreement with surface data than the previously published GEM 6 solution which contained surface gravity. In particular the free air gravity anomalies calculated from GEM 9 and a surface gravity solution are in excellent agreement for the high degree terms.

  12. Europa Imaging Highlights during GEM

    NASA Technical Reports Server (NTRS)

    1998-01-01

    During the two year Galileo Europa Mission (GEM), NASA's Galileo spacecraft will focus intensively on Jupiter's intriguing moon, Europa. This montage shows samples of some of the features that will be imaged during eight successive orbits. The images in this montage are in order of increasing orbit from the upper left (orbit 11) to the lower right (orbit 19).

    DESCRIPTIONS AND APPROXIMATE RESOLUTIONSTriple bands and dark spots

    1.6 kilometers/pixelConamara Chaos

    1.6 kilometers/pixelMannan'an Crater

    1.6 kilometers/ pixelCilix

    1.6 kilometers/pixelAgenor Linea and Thrace Macula

    2 kilometers/pixelSouth polar terrain

    2 kilometers/pixelRhadamanthys Linea

    1.6 kilometers/pixelEuropa plume search

    7 kilometers/pixel

    1. Triple bands and dark spots were the focus of some images from Galileo's eleventh orbit of Jupiter. Triple bands are multiple ridges with dark deposits along the outer margins. Some extend for thousands of kilometers across Europa's icy surface. They are cracks in the ice sheet and indicate the great stresses imposed on Europa by tides raised by Jupiter, as well as Europa's neighboring moons, Ganymede and Io. The dark spots or 'lenticulae' are spots of localized disruption.

    2. The Conamara Chaos region reveals icy plates which have broken up, moved, and rafted into new positions. This terrain suggests that liquid water or ductile ice was present near the surface. On Galileo's twelfth orbit of Jupiter, sections of this region with resolutions as high as 10 meters per picture element will be obtained.

    3. Mannann'an Crater is a feature newly discovered by Galileo in June 1996. Color and high resolution images (to 40 meters per picture element) from Galileo's fourteenth orbit of Jupiter will offer a close look at the crater and help characterize how impacts affect the icy surface of this moon.

    4. Cilix, a large mound about 1.5 kilometers high, is the center of Europa's coordinate system. Its concave top and what may be flow

  13. On the origins of GEMS grains: A reply

    NASA Astrophysics Data System (ADS)

    Keller, Lindsay P.; Messenger, Scott

    2013-04-01

    The Comment by Bradley challenges our chemical and isotopic measurements of GEMS grains, arguing that pervasive infiltration of silicone oil and sample heating undermine our comparisons with equally uncertain interstellar grain compositions. However, we have already shown that such effects are negligible and cannot account for the extraordinary chemical variability of GEMS grains. Our data are also in excellent agreement with previous GEMS grain chemical analyses, and with GEMS grains in micrometeorites and within IDPs recently collected without the use of silicone oil. The order of magnitude variations in element abundances displayed by GEMS grains rule out a common origin by the extensive chemical and isotopic homogenization of circumstellar grains, as proposed by Bradley. The vast majority of GEMS grains also do not have radial compositional gradients, crystalline "relict" cores, or rims of condensed materials indicative of radiation exposure. The average element abundances of GEMS grains differ significantly and systematically from solar abundances and from those inferred for interstellar silicates based on element depletion patterns. A few GEMS grains have highly anomalous O isotopic compositions consistent with a condensation origin in evolved O-rich stellar envelopes and supernovae. Yet, on average, GEMS grains have O isotopic compositions very near to terrestrial and meteoritic values. These and other observations discussed in our paper place a strict upper limit on the number of GEMS grains that have preserved presolar origins.

  14. GAS eleven node thermal model (GEM)

    NASA Technical Reports Server (NTRS)

    Butler, Dan

    1988-01-01

    The Eleven Node Thermal Model (GEM) of the Get Away Special (GAS) container was originally developed based on the results of thermal tests of the GAS container. The model was then used in the thermal analysis and design of several NASA/GSFC GAS experiments, including the Flight Verification Payload, the Ultraviolet Experiment, and the Capillary Pumped Loop. The model description details the five cu ft container both with and without an insulated end cap. Mass specific heat values are also given so that transient analyses can be performed. A sample problem for each configuration is included as well so that GEM users can verify their computations. The model can be run on most personal computers with a thermal analyzer solution routine.

  15. Gallium Electromagnetic (GEM) Thrustor Concept and Design

    NASA Technical Reports Server (NTRS)

    Polzin, Kurt A.; Markusic, Thomas E.

    2006-01-01

    We describe the design of a new type of two-stage pulsed electromagnetic accelerator, the gallium electromagnetic (GEM) thruster. A schematic illustration of the GEM thruster concept is given in Fig. 1. In this concept, liquid gallium propellant is pumped into the first stage through a porous metal electrode using an electromagneticpump[l]. At a designated time, a pulsed discharge (approx.10-50 J) is initiated in the first stage, ablating the liquid gallium from the porous electrode surface and ejecting a dense thermal gallium plasma into the second state. The presence of the gallium plasma in the second stage serves to trigger the high-energy (approx.500 I), send-stage puke which provides the primary electromagnetic (j x B) acceleration.

  16. GIS Enabled Modeling and Simulation (GEMS)

    DTIC Science & Technology

    2007-06-01

    polygons, visual databases include texture information to provide a visualization of ground and material types. These databases include 3D models ...US Army TEC GIS-Enabled Modeling and Simulation project, and was the lead developer on the building interior semantic information portion of the...GIS Enabled Modeling and Simulation (GEMS) Thomas Stanzione Kevin Johnson MAK Technologies 68 Moulton Street Cambridge, MA 02138 (617) 876

  17. Nebraska NativeGEM (Geospatial Extension Model)

    NASA Technical Reports Server (NTRS)

    Bowen, Brent

    2004-01-01

    This proposal, Nebraska NativeGEM (Geospatial Extension Model) features a unique diversity component stemming from the exceptional reputation NNSGC has built by delivering geospatial science experiences to Nebraska s Native Americans. For 7 years, NNSGC has partner4 with the 2 tribal colleges and 4 reservation school districts in Nebraska to form the Nebraska Native American Outreach Program (NNAOP), a partnership among tribal community leaders, academia, tribal schools, and industry reaching close to 1,OOO Native American youth, over 1,200 community members (Lehrer & Zendajas, 2001).NativeGEM addresses all three key components of Cooperative State Research, Education, and Extension Service (CSREES) goals for advancing decision support, education, and workforce development through the GES. The existing long term commitments that the NNSGC and the GES have in these areas allow for the pursuit of a broad range of activities. NativeGEM builds upon these existing successful programs and collaborations. Outcomes and metrics for each proposed project are detailed in the Approach section of this document.

  18. Comparative verification between GEM model and official aviation terminal forecasts

    NASA Technical Reports Server (NTRS)

    Miller, Robert G.

    1988-01-01

    The Generalized Exponential Markov (GEM) model uses the local standard airways observation (SAO) to predict hour-by-hour the following elements: temperature, pressure, dew point depression, first and second cloud-layer height and amount, ceiling, total cloud amount, visibility, wind, and present weather conditions. GEM is superior to persistence at all projections for all elements in a large independent sample. A minute-by-minute GEM forecasting system utilizing the Automated Weather Observation System (AWOS) is under development.

  19. GEM Building Taxonomy (Version 2.0)

    USGS Publications Warehouse

    Brzev, S.; Scawthorn, C.; Charleson, A.W.; Allen, L.; Greene, M.; Jaiswal, Kishor; Silva, V.

    2013-01-01

    /7/8/IRRE9/10/RSH3+RWO211/FW12/13/ which can be read as (1) Direction = [DX or DY] (the building has the same lateral load-resisting system in both directions); (2) Material = [Unreinforced Masonry + solid fired clay bricks + cement: lime mortar]; (3) Lateral Load-Resisting System = [Wall]; (4) Date of construction = [pre-1939]; (5) Heaight = [exactly 2 storeys]; (6) Occupancy = [residential, unknown type]; (7) Building Position = [unknown = no entry]; (8) Shape of building plan = [unknown = no entry]; (9) Structural irregularity = [regular]; (10) Exterior walls = [unknown = no entry]; (11) Roof = [Shape: pitched and hipped, Roof covering: clay tiles, Roof system material: wood, Roof system type: wood trusses]; (12) Floor = [Floor system: Wood, unknown]; (13) Foundation = [unknown = no entry]. Mapping of GEM Building Taxonomy to selected taxonomies is included in the report -- for example, the above building would be referenced by previous structural taxonomies as: PAGER-STR as UFB or UFB4, by the World Housing Encyclopedia as 7 or 8 and by the European Macroseismic Scale (98) as M5. The Building Taxonomy data model is highly flexible and has been incorporated within a relational database architecture. Due to its ability to represent building typologies using a shorthand form, it is also possible to use the taxonomy for non-database applications, and we discuss possible application of adaptation for Building Information Modelling (BIM) systems, and for the insurance industry. The GEM Building Taxonomy was independently evaluated and tested by the Earthquake Engineering Research Institute (EERI), which received 217 TaxT reports from 49 countries, representing a wide range of building typologies, including single and multi-storey buildings, reinforced and unreinforced masonry, confined masonry, concrete, steel, wood, and earthern buildings used for residential, commercial, industrial, and educational occupancy. Based on these submissions and other feedback, the EERI

  20. Synthesis and biological activity of gem-dichlorocyclopropyl ethers

    SciTech Connect

    Shostakovskii, S.M.; Mochalov, V.N.; Larionov, G.M.

    1986-09-01

    In order to examine the antimicrobial activity of oxygenated cyclopropanes, the authors have synthesized the bis-gem-dichlorocyclopropyl ether of ethylene glycol, the meso- and dl- forms of bis-gem-dichlorocyclopropyl ether, and the gem-dichlorocyclopropyl alkyl ethers. The physiocochemical properties of compounds obtained are presented. The authors conclude that in the case of gem-dichlorocyclopropane compounds, decontamination of microorganisms occurs at the pre-metabolic stage, and results in the denaturation of the protein components of the cell wall and external membranes and of the specific peptides of the peptide-glycan layer.

  1. The Grief Evaluation Measure (GEM): An Initial Validation Study

    ERIC Educational Resources Information Center

    Jordan, John R.; Baker, John; Matteis, Margherite; Rosenthal, Saul; Ware, Eugenia S.

    2005-01-01

    This article describes the development of the Grief Evaluation Measure (GEM), a new instrument designed to screen for the development of a complicated mourning response in a bereaved adult. The GEM provides a quantitative and qualitative assessment of risk factors, including the mourner's loss and medical history, coping resources before and after…

  2. Guidance Exploration Model (GEM) 1978-79. Summary.

    ERIC Educational Resources Information Center

    Pope, M. Candice, Comp.

    The original program goal for development was to provide implementation of a Guidance Exploratory Model (GEM) at the elementary level which combines career education, guidance, exploration and academics. During the planning stages of GEM, monies were received from Title IV-B to purchase books and audio-visual materials to initiate the concept…

  3. The Ozone Layer. UNEP/GEMS Environment Library No. 2.

    ERIC Educational Resources Information Center

    United Nations Environment Programme, Nairobi (Kenya).

    Since the United Nations Environment Program (UNEP) was created, more than a dozen years ago, public understanding of the environmental issues confronting our planet has increased enormously. The Global Environment Monitoring System (GEMS) has provided several environmental assessments. The aim of the UNEP/GEMS Environment Library is to provide…

  4. A Gas Electron Multiplier (GEM) Detector for Fast Neutron Imaging

    NASA Astrophysics Data System (ADS)

    Jewett, C. C.; McMahan, M.; Cerny, J.; Heilbronn, L.; Johnson, M.

    2008-10-01

    We have built a Gas Electron Multiplier (GEM) detector for detection of fast neutrons at Lawrence Berkeley National Laboratory. The detector consists of a 0.0625 inch thick polypropylene neutron converter, three GEM foils and a grid of 16 readout pads on a printed circuit board. In this talk, we present images of the GEM detector, the results of tests with ^60Co, AmBe sources and our neutron beam, and a comparison between the proposed fast neutron GEM detector and a fast neutron ^238U fission chamber we purchased. One of the advantages of the GEM detector over the fission chamber is the fact that it provides the x-y position information of the neutrons.

  5. GEMS X-ray Polarimeter Performance Simulations

    NASA Technical Reports Server (NTRS)

    Baumgartner, Wayne H.; Strohmayer, Tod; Kallman, Tim; Black, J. Kevin; Hill, Joanne; Swank, Jean

    2012-01-01

    The Gravity and Extreme Magnetism Small explorer (GEMS) is an X-ray polarization telescope selected as a NASA small explorer satellite mission. The X-ray Polarimeter on GEMS uses a Time Projection Chamber gas proportional counter to measure the polarization of astrophysical X-rays in the 2-10 keV band by sensing the direction of the track of the primary photoelectron excited by the incident X-ray. We have simulated the expected sensitivity of the polarimeter to polarized X-rays. We use the simulation package Penelope to model the physics of the interaction of the initial photoelectron with the detector gas and to determine the distribution of charge deposited in the detector volume. We then model the charge diffusion in the detector,and produce simulated track images. Within the track reconstruction algorithm we apply cuts on the track shape and focus on the initial photoelectron direction in order to maximize the overall sensitivity of the instrument, using this technique we have predicted instrument modulation factors nu(sub 100) for 100% polarized X-rays ranging from 10% to over 60% across the 2-10 keV X-ray band. We also discuss the simulation program used to develop and model some of the algorithms used for triggering, and energy measurement of events in the polarimeter.

  6. Umsetzung der Unternehmensstrategie mit der Balanced Scorecard

    NASA Astrophysics Data System (ADS)

    Crespo, Isabel; Bergmann, Lars; Portmann, Stefan; Lacker, Thomas; Lacker, Michael; Fleischmann, Jürgen; Kozó, Hans

    Die Balanced Scorecard (BSC) ist ein Ansatz zum strategischen Management, der neben der Ausrichtung des Unternehmens auf finanzielle Zielwerte ebenso großes Gewicht auf so genannte weiche Faktoren legt, die den wirtschaftlichen Erfolg eines Unternehmens erst ermöglichen. Das entscheidende Merkmal der Balanced Scorecard ist dabei, dass sie ein ausgewogenes System strategischer Ziele herstellt, welches das Unternehmen hinsichtlich der vier Perspektiven Finanzen, Kunden, interne Prozesse und Mitarbeiter und Potenziale strategisch ausrichtet (Kaplan u. Norton 1997).

  7. Heavy metals in Ratnapura alluvial gem sediments, Sri Lanka

    NASA Astrophysics Data System (ADS)

    Vithanage, M. S.; Hettiarachchi, J. K.; Rajapaksha, A. U.; Wijesekara, H.; Hewawasam, T.

    2011-12-01

    The valuable gems in Sri Lanka are found from the sedimentary gem deposits in Ratnapura District, which are found as alluvial deposits some are about >50 m deep. Gem bearing gravel layer is taken out from the mine, washed by panning to recover the gem minerals in the heavy mineral fraction, is a common practice in the gem mining area. Gem bearing sediment layer is associated with different heavy minerals in which different trace metals as Co, Cr, Cu, Al, Zr, Pb and As also can be present. During panning, the sediment is washed away and the heavy metals attached to the sediments are released into the environment. Hence we studied the lability and bioavailability of arsenic and other heavy metals from the gem sediments. Sediment samples were collected from 15 small scale gem mines (3 soil layers- top, gem mineral layer and layer below gem bearing gravel layer), air dried and sieved to obtain <63μm fraction. Bioavailable, exchangeable and residual fractions were 0.01M CaCl2, 1M NaOAc, pH 8.2 and microwave digestion using HF, HNO3 and HClO4. Filtered samples were analyzed for As, Co, Zn, Mn, Cu, Ni, Pb and Fe using atomic absorption spectrophotometer (GBC 933AA). Total digestion results in different layers indicated that heavy metals show an increasing pattern with depth. About 4 gem bearing gravel layers were consist of high concentrations of Ni (>150 mg/kg), Cu (>150 mg/kg), Pb (>400 mg/kg), Zn (>600 mg/kg) and Co ions (>100 mg/kg). Arsenite in the gem sediments were low and recorded as <5mg/kg. Total arsenic analysis is under investigation. Highest concentrations for bioavailable and exchangeable (leach to water) metals were Fe>Co>Zn>Mn>Ni>Cu>Pb. Sediments from few gem pits showed considerably high concentrations of metals analyzed. In some places Fe, Ni, Cu, Zn reported high in bioavailable fractions 70, 25, 20, 10 mg/kg respectively. Mobilization of these metals may increase due to changes in the pH and the presence of other ions in the environment. High

  8. Gem and mineral identification using GL Gem Raman and comparison with other portable instruments

    NASA Astrophysics Data System (ADS)

    Culka, Adam; Hyršl, Jaroslav; Jehlička, Jan

    2016-11-01

    Several mainly silicate minerals in their gemstone varieties have been analysed by the Gem Raman portable system by Gemlab R&T, Vancouver, Canada, in order to ascertain the general performance of this relatively non-expensive tool developed exactly for the purpose of gemstone identification. The Raman spectra of gemstones acquired by this system have been subsequently critically compared with the data obtained by several other portable or handheld Raman instruments. The Raman spectra acquired with the Gem Raman instrument were typically of lesser quality when compared with the spectra taken by other instruments. Characteristic features such as steep baseline probably due to the fluorescence of the minerals, Raman bands much broader and therefore less resolved closely located Raman bands, and generally greater shifts of the band positions from the reference values were encountered. Some gemstone groups such as rubies did not provide useful Raman spectra at all. Nevertheless, general identification of gemstones was possible for a selection of gemstones.

  9. GEM-based detectors for thermal and fast neutrons

    NASA Astrophysics Data System (ADS)

    Croci, G.; Claps, G.; Cazzaniga, C.; Foggetta, L.; Muraro, A.; Valente, P.

    2015-06-01

    Lately the problem of 3He replacement for neutron detection stimulated an intense activity research on alternative technologies based on alternative neutron converters. This paper presents briefly the results obtained with new GEM detectors optimized for fast and thermal neutrons. For thermal neutrons, we realized a side-on GEM detector based on a series of boron-coated alumina sheets placed perpendicularly to the incident neutron beam direction. This prototype has been tested at n@BTF photo-production neutron facilty in order to test its effectiveness under a very high flux gamma background. For fast neutrons, we developed new GEM detectors (called nGEM) for the CNESM diagnostic system of the SPIDER NBI prototype for ITER (RFX-Consortium, Italy) and as beam monitor for fast neutrons lines at spallation sources. The nGEM is a Triple GEM gaseous detector equipped with a polyethylene layer used to convert fast neutrons into recoil protons through the elastic scattering process. This paper describes the results obtained by testing a medium size (30 × 25 cm2 active area) nGEM detector at the ISIS spallation source on the VESUVIO beam line.

  10. Complete Tem-Tomography: 3D Structure of Gems Cluster

    NASA Technical Reports Server (NTRS)

    Matsuno, J.; Miyake, A.; Tsuchiyama, A.; Messenger, S.; Nakamura-Messenger, K.

    2015-01-01

    GEMS (glass with embedded metal and sulfide) grains in interplanetary dust particles (IDPs) are considered to be one of the ubiquitous and fundamental building blocks of solids in the Solar System. They have been considered to be interstellar silicate dust that survived various metamorphism or alteration processes in the protoplanetary disk but the elemental and isotopic composition measurements suggest that most of them have been formed in the protoplanetary disk as condensates from high temperature gas. This formation model is also supported by the formation of GEMS-like grains with respect to the size, mineral assemblage, texture and infrared spectrum by condensation experiments from mean GEMS composition materials. Previous GEMS studies were performed only with 2D observation by transmission electron microscopy (TEM) or scanning TEM (STEM). However, the 3D shape and structure of GEMS grains and the spatial distribution of Fe/FeS's has critical information about their formation and origin. Recently, the 3D structure of GEMS grains in ultrathin sections of cluster IDPs was revealed by electron tomography using a TEM/STEM (JEM-2100F, JEOL). However, CT images of thin sections mounted on Cu grids acquired by conventional TEM-tomography are limited to low tilt angles (e. g., less than absolute value of 75 deg. In fact, previous 3D TEM observations of GEMS were affected by some artifacts related to the limited tilt range in the TEM used. Complete tomographic images should be acquired by rotating the sample tilt angle over a range of more than absolute value of 80 deg otherwise the CT images lose their correct structures. In order to constrain the origin and formation process of GEMS grains more clearly, we performed complete electron tomography for GEMS grains. Here we report the sample preparation method we have developed for this study, and the preliminary results.

  11. Method and apparatus for detecting gem-polyhalogenated hydrocarbons

    DOEpatents

    Anderson, deceased, William G.; Anderson, legal representative, Johanna S.

    1990-01-01

    A method and optrode for detecting gem polyhalogenated hydrocarbons in a sample fluid based on a single phase Fujiwara reaction as provided. The method comprises contacting a reaction mixture with a sample fluid which contains the gem-polyhalogenated hydrocarbons. The reaction mixture comprises an aqueous solution of pyridine or derivative thereof and a hindered nitrogen base. Upon contact a fluorescent and/or chromgenic reaction product forms whose fluorescence and/or absorbance is related to the concentration of gem-polyhalogenated hydrocarbons in the sample fluid.

  12. SSC analysis of the GEMs for reactivity control in PRISM

    SciTech Connect

    Slovik, G.C.; Rodnizki, J.

    1992-01-01

    The performance of three Gas Expansion Modules (GEMS) utilized the Advanced Liquid Metal Reactor (ALMR) concept, PRISM, was analyzed using the computer code, SSC. GE has submitted the PRISM design for a Preapplication Safety Evaluation Report (PSER). The draft PSER indicated a potential weakness in the Unscrammed Loss of Flow (ULOF) event, and GE modified the design by adding three GEMs. The PRISM design was analyzed by SSC for two cases. First, the design's original response to a ULOF where one Electro Magnetic (EM) pump fails to produce a coastdown was analyzed. Then the revised design with the GEMs included was analyzed. The original design had little or no safety margin for this case. The peak fuel temperature in the hot channel was predicted to be 1358K, which is above the solidus temperature of the fuel. However, after the GEMs were added, the loss of one EM pump coastdown became a benign event. The GEM feedback was predicted by SSC to dominate the other reactivity feedbacks and the GEMS, essentially, responded like passive control rods. The fuel temperature quickly dropped below operating temperatures, while the margin to sodium boiling was predicted to be greater than 350K.

  13. SSC analysis of the GEMs for reactivity control in PRISM

    SciTech Connect

    Slovik, G.C.; Rodnizki, J.

    1992-12-31

    The performance of three Gas Expansion Modules (GEMS) utilized the Advanced Liquid Metal Reactor (ALMR) concept, PRISM, was analyzed using the computer code, SSC. GE has submitted the PRISM design for a Preapplication Safety Evaluation Report (PSER). The draft PSER indicated a potential weakness in the Unscrammed Loss of Flow (ULOF) event, and GE modified the design by adding three GEMs. The PRISM design was analyzed by SSC for two cases. First, the design`s original response to a ULOF where one Electro Magnetic (EM) pump fails to produce a coastdown was analyzed. Then the revised design with the GEMs included was analyzed. The original design had little or no safety margin for this case. The peak fuel temperature in the hot channel was predicted to be 1358K, which is above the solidus temperature of the fuel. However, after the GEMs were added, the loss of one EM pump coastdown became a benign event. The GEM feedback was predicted by SSC to dominate the other reactivity feedbacks and the GEMS, essentially, responded like passive control rods. The fuel temperature quickly dropped below operating temperatures, while the margin to sodium boiling was predicted to be greater than 350K.

  14. Measurement Of Gas Electron Multiplier (GEM) Detector Characteristics

    NASA Astrophysics Data System (ADS)

    Park, Seongtae; Baldelomar, Edwin; Park, Kwangjune; Sosebee, Mark; White, Andy; Yu, Jaehoon

    2011-06-01

    The High Energy Physics group of the University of Texas at Arlington has been developing gas electron multiplier detectors to use them as sensitive gap detectors in digital hadron calorimeters for the International Linear Collider, a future high energy particle accelerator. For this purpose, we constructed numerous GEM detectors that employ double GEM layers. In this study, two kinds of prototype GEM detectors were tested; one with 28×28 cm2 active area double GEM structure with a 3 mm drift gap, a 1 mm transfer gap and a 1 mm induction gap and the other with two 3×3 cm2 GEM foils in the amplifier stage with a 5 mm drift gap, a 2 mm transfer gap and a 1 mm induction gap. The detectors' characteristics from exposure to high-energy charged particles and other radiations were measured using cosmic rays and 55Fe radioactive source. From the 55Fe tests, we observed two well separated characteristic X-ray emission peaks and confirmed the detectors' functionality. We also measured chamber gains to be over 6000 at a high voltage of 395 V across each GEM electrode. The responses to cosmic rays show the spectra that fit well to Landau distributions as expected from minimum ionizing particles.

  15. Kosmische Katastrophen und der Ursprung der Religion.

    NASA Astrophysics Data System (ADS)

    Hoyle, F.

    This book is a German translation, by V. Delavre, from the English original "The origin of the Universe and the origin of religion", published in 1993. Contents: E. Sens: Die unterbrochene Musikstunde. Einleitung zur deutschen Ausgabe. C. Ryskamp: Einführung. R. N. Anshen: Vorwort. F. Hoyle: Kosmische Katastrophen und der Ursprung der Religion - Die Folgen der Respektabilität; Eiszeiten und Kometen; Die allgemeine Situation in den Nacheiszeiten; Kometen und der Ursprung der Religionen; Der Übergang zu Mittelalter und Neuzeit. Diskussionsbeiträge: Ruth Nanda Anshen, Freeman Dyson, Paul Oscar Kristeller, John Archibald Wheeler, James Schwartz, Roger Shinn, Milton Gatch, Philip Solomon, Norman Newell. F. Hoyle: Schlußwort. A. Tollmann: Nachwort zur deutschen Ausgabe.

  16. 3D Observation of GEMS by Electron Tomography

    NASA Technical Reports Server (NTRS)

    Matsuno, Junya; Miyake, Akira; Tsuchiyama, Akira; Nakamura-Messenger, Keiko; Messenger, Scott

    2014-01-01

    Amorphous silicates in chondritic porous interplanetary dust particles (CP-IDPs) coming from comets are dominated by glass with embedded metal and sulfides (GEMS). GEMS grains are submicron-sized rounded objects (typically 100-500) nm in diameter) with anaometer-sized (10-50 nm) Fe-Ni metal and sulfide grains embedded in an amorphous silicate matrix. Several formation processes for GEMS grains have been proposed so far, but these models are still being debated [2-5]. Bradley et al. proposed that GEMS grains are interstellar silicate dust that survived various metamorphism or alteration processes in the protoplanetary disk and that they are amorphiation products of crystalline silicates in the interstellar medium by sputter-deposition of cosmic ray irradiation, similar to space weathering [2,4]. This consideration is based on the observation of nano-sized crystals (approximately 10 nm) called relict grains in GEMS grains and their shapes are pseudomorphs to the host GEMS grains. On the other hand, Keller and Messenger proposed that most GEMS formed in the protoplanetary disk as condensates from high temperature gas [3,5]. This model is based on the fact that most GEMS grains have solar isotopic compositions and have extremely heterogeneous and non-solar elemental compositions. Keller and Messenger (2011) also reported that amorphous silicates in GEMS grains are surrounded by sulfide grains, which formed as sulfidization of metallic iron grains located on the GEMS surface. The previous studies were performed with 2D observation by using transmission electron microscopy (TEM) or scanning TEM (STEM). In order to understand the structure of GEMS grains described above more clearly, we observed 3D structure of GEMS grains by electron tomography using a TEM/STEM (JEM-2100F, JEOL) at Kyoto University. Electron tomography gives not only 3D structures but also gives higher spatial resolution (approximately a few nm) than that in conventional 2D image, which is restricted by

  17. The Voyager Anomaly and the GEM Theory

    NASA Astrophysics Data System (ADS)

    Brandenburg, J. E.

    For over a decade, the Pioneer Anomaly (PA) was an object of study and remains unresolved. Basically it is a sunward constant acceleration of the spacecraft that appeared unambiguously after the satellites passage beyond Saturn. It now appears possible the PA acceleration is the appearance of second, string-like, solution to the Einstein Equations first discussed in the context of charged finite mass charged particle potentials as part of the GEM theory. The exact solution to the metric equations is similar in form to the Schwartzchild Solution but with a positive sign: grr = (1 + rG/r)-1 where rG is a characteristic radius corresponding to the Schwartzchild radius. Adopting the approximation that for weak fields the metric becomes a Newtonian gravity potential: grr ≅-2ϕ, a string potential form is obtained in the limit grr ≅1-2ϕ, for r < < rG, grr≅r/rG (1-r/rG…). For the choice rG = cTH, this produces an effective gravity acceleration a ≅ c/TH = 8 x 10-10 m/sec2 in agreement with observations. The "turn on" for this potential apparently occurs with the encounter with Jupiter, which raised the spacecraft to above escape velocity. The possible physical meaning of this second metric appearance is found to be a gravitational form of Lenz's law, where objects departing from gravity potentials experience a resistance that keeps them bound at long distances.

  18. Characterization of synthesized and treated gem diamonds

    NASA Astrophysics Data System (ADS)

    Song, Ohsung

    2007-10-01

    Synthesized diamonds have been widely employed as polishing media for precise machining and noble substrates for microelectronics. The recent development of the split sphere press has led to the commercial HPHT (high pressure high temperature) synthesis of bulk gem diamonds from graphite and to the enhancement of low quality natural diamonds. Synthesized and treated diamonds are sometimes traded deceptively as high quality natural diamonds because it is hard to distinguish among these diamonds with conventional gemological characterization methods. Therefore, we need to develop a new identification method that is non-destructive, fast, and inexpensive. We proposed using new methods of UV fluorescence and X-ray Lang topography for checking the local HPHT stress field as well as using a vibrating sample magnetometer for checking ferromagnetic residue in synthesized diamonds to distinguish these diamonds from natural ones. We observe unique differences in the local stress field images in synthesized and treated diamonds using Lang topography and UV fluorescence characterization. Our result implies that our proposed methods may be appropriate for identification of the synthesized and treated diamonds.

  19. Geodesy on GEMS (GEophysical Monitoring Station)

    NASA Astrophysics Data System (ADS)

    Dehant, V.; Folkner, W.; Le Maistre, S.; Rosenblatt, P.; Yseboodt, M.; Asmar, S.; Marty, J. C.; Banerdt, B.

    2011-10-01

    We propose to use the X-band radio link of the GEMS lander on the surface of Mars with the objective to better determine the rotation and interior structure of Mars. This X-band radio link consists in two-way Doppler measurements from a direct radiolink between the Martian Lander and deep space tracking stations on the Earth. On the basis of these measurements, it will be possible to monitor the lander position relative to the Earth and in turn to improve the determination of the Mars' orientation and rotation parameters (MOP), i.e. the rotation rate variations (or Length of Days LOD), the precession rate and the nutations of the rotation axis, and the orientation of Mars around its rotation axis (polar motion). In this study we perform analytical and numerical simulations of these Doppler measurements in order to quantify the precision that can be obtained on the MOP. These simulations permit to build a strategy to be applied to future data processing in order to improve the precision on the MOP determination. As these parameters are related to the interior of the planet as well as to its seasonal angular momentum changes induced by the CO2 sublimation/condensation process, we further discuss the expected improvement in our knowledge of Mars' interior, i.e. state, size, and composition of the Martian core, and of the CO2 mass budget in the Martian atmosphere and ice caps.

  20. Akustikgestaltung in der Fahrzeugentwicklung

    NASA Astrophysics Data System (ADS)

    Pletschen, Bernd

    Die zielgerichtete Entwicklung der Fahrzeugakustik stellt eine hochkomplexe, integrative Aufgabenstellung im Rahmen der Fahrkomfortgestaltung des Automobils dar. Die Wahrnehmung der Komforteigenschaften eines Fahrzeugs erfolgt grundsätzlich als Wahrnehmung der Wirkung dieser Eigenschaften über einen oder mehrere Wahrnehmungskanäle des Menschen: visuell, auditiv, haptisch, olfaktorisch. Die individuelle Wahrnehmung ist hierbei subjektiv und daher mit rein physikalisch objektiven Messgrößen allein nur unvollständig zu beschreiben. Sie hängt einerseits von den Eigenschaften des betrachteten Fahrzeugs oder einer erlebten Situation ab und andererseits außerdem von der Sozialisation des Bewertenden und der Umgebung, in der die Bewertung stattfindet (Wikipedia). Der Fahrkomfort, den ein Fahrzeug Fahrer und Beifahrern bietet, wird also wegen unterschiedlicher Erwartungen des Kunden in den verschiedenen Weltmärkten sehr unterschiedlich erlebt.

  1. Der II. Hauptsatz der Wärmelehre

    NASA Astrophysics Data System (ADS)

    Heintze, Joachim

    Wir haben in (4.44) den II. Hauptsatz als empirische Tatsache folgendermaßen formuliert: (i) Wärmeenergie geht von selbst nur von einem wärmeren Körper auf einen kälteren über, niemals in der umgekehrten Richtung. Nun werden wir beweisen, dass sich aus diesem Prinzip folgende äquivalente Formulierungen für den II. Hauptsatz ableiten lassen: (ii) Es ist unmöglich, ein Perpetuum mobile zweiter Art zu bauen, d. h. eine Maschine, die fortlaufend Wärmeenergie vollständig in mechanische Arbeit umsetzen kann. Eine Wärmekraftmaschine, die einen Kreisprozess mit der höchsten Temperatur Tw und der niedrigsten Temperatur Tk durchläuft, hat höchstens den Carnotschen Wirkungsgrad c = (Tw - Tk)/Tw. Wenn in der Maschine nur reversible Prozesse ablaufen, die gesamte Wärmezufuhr bei der Temperatur Tw erfolgt und ausschließlich bei der Temperatur Tw gekühlt wird, ist ihr Wirkungsgrad = C. Es gibt keine Wärmekraftmaschine, die eine bessere Ausnutzung der Wärmeenergie ermöglicht. (iv) In jedem thermodynamischen System existiert die Zustandsgröße Entropie, definiert durch ihr Differential dS = (dQrev)/T . Entropie kann erzeugt, aber nicht vernichtet werden. Bei Zustandsänderungen, die in einem abgeschlossenen System ablaufen, nimmt die Entropie entweder zu (irreversible Prozesse), oder sie bleibt konstant (reversible Prozesse). Im Anschluss an (iii) werden wir zur Definition der thermodynamischen Temperatur und bei der Diskussion von (iv) zu einem tieferen Verständnis der Entropie gelangen. Es zeigt sich, dass die Entropie das eigentliche Bindeglied zwischen Mechanik und Wärmelehre darstellt. Am Ende des Kapitels werden wir einige Anwendungen des II. Hauptsatzes betrachten.

  2. Development of Resistive Electrode Gas Electron Multiplier (RE-GEM)

    NASA Technical Reports Server (NTRS)

    Yoshikawa, A.; Tamagawa, T.; Iwahashi, T.; Asami, F.; Takeuchi, Y.; Hayato, A.; Hamagaki, H.; Gunji, T.; Akimoto, R.; Nukariya, A.; Hayashi, S.; Ueno, K.; Ochi, A.; Oliveria, R.

    2012-01-01

    We successfully produced Resistive-Electrode Gas Electron Multiplier (RE-GEM) which has resistive electrodes instead of the metal ones which are employed for the standard GEM foils. RE-GEM has a resistive electrode of 25 micron-thick and an insulator layer of 100 micron-thick. The hole structure of RE-GEM is a single conical with the wider and narrower hole diameters of 80 micron and 60 micron, respectively. A hole pitch of RE-GEM is 140 micron. We obtained the maximum gain of about 600 and the typical energy resolution of about 20% (FWHM) at an applied voltage between the resistive electrodes of 620 V, using a collimated 8 keV X-rays from a generator in a gas mixture of 70% Ar and 30% CO2 by volume at the atmospheric pressure. We measured the effective gain as a function of the electric field of the drift region and obtained the maximum gain at an drift field of 0.5 kV/cm.

  3. Continuous health monitoring of graphite epoxy motorcases (GEM)

    NASA Astrophysics Data System (ADS)

    Finlayson, Richard D.; Luzio, Marco A.; Miller, Ronnie K.; Pollock, Adrian A.

    2003-08-01

    With the increasing use of advanced composite materials in aircraft, automobiles, military hardware, and aerospace composites (such as rocket motorcases) a sizable need for composite health assessment measures exist, particularly where there is risk of failure due to high mechanical and thermal stresses. For most epoxy-based laminate composites, even low-momentum impacts can lead to "barely visible impact damage" (BVD), corresponding to a significant weakening of the composite. This weakening can lead to sudden and catastrophic failure when the material is subjected to normal operating loads. Following the explosion of Delta 241 (IIR-1) on Jaunary 17th, 1997, the failure investigation board concluded that an entire fleet of Graphite Epoxy Motorcases (GEMs) should be instrumented with a health monitoring system. This system would provide continuous structural health data on the GEM from initial acceptance testing through final erection on the launch pad. The result presented here contribute significantly to the understanding of the acoustic properties of the GEM casing, and make a substantial advancement in the theoretical phase of the source location algorithm development. When the system is complete it will continuously monitor the structural health of the GEMs, communicate wirelessly with base stations, operate autonomously for extended periods, and fit unobtrusively on the GEM itself.

  4. Innovative genomic collaboration using the GENESIS (GEM.app) platform.

    PubMed

    Gonzalez, Michael; Falk, Marni J; Gai, Xiaowu; Postrel, Richard; Schüle, Rebecca; Zuchner, Stephan

    2015-10-01

    Next-generation sequencing has led to an unparalleled pace of Mendelian disease gene discovery in recent years. To address the challenges of analysis and sharing of large datasets, we had previously introduced the collaborative web-based GEM.app software [Gonzalez et al., ]. Here, we are presenting the results of using GEM.app over nearly 3 years and introducing the next generation of this platform. First, GEM.app has been renamed to GENESIS since it is now part of "The Genesis Project" (501c3), a not-for-profit foundation that is committed to providing the best technology to enable research scientists and to connecting patients and clinicians to genomic information. Second, GENESIS (GEM.app) has grown to nearly 600 registered users from 44 countries, who have collectively achieved 62 gene identifications or published studies that have expanded phenotype/genotype correlations. Our concept of user-driven data sharing and matchmaking is now the main cause for gene discoveries within GENESIS. In many of these findings, researchers from across the globe have been connected, which gave rise to the genetic evidence needed to successfully pinpoint-specific gene mutations that explained patients' disease. Here, we present an overview of the various novel insights that have been made possible through the data-sharing capabilities of GENESIS/GEM.app.

  5. The Bisa GEM-Mars GCM

    NASA Astrophysics Data System (ADS)

    Neary, Lori; Daerden, Frank

    2013-04-01

    GEM-Mars is a three-dimensional general circulation model of the Mars atmosphere extending from the surface to approximately 170 km based on the latest version of the GEM (Global Environmental Mesoscale) model, the operational data assimilation and weather forecasting system for Canada [Côté et al., 1998]. The dynamical core is an implicit two-time-level semi-Lagrangian scheme on an Arakawa C-grid with a terrain-following, log-hydrostatic-pressure vertical coordinate discretized on a Charney-Phillips grid. The model has both a hydrostatic and non-hydrostatic formulation, providing a single platform for simulations on a variety of horizontal scales. The model code is fully parallelized using OMP and MPI. The GCM includes the relevant physical processes such as CO2 condensation, planetary boundary layer mixing, gravity wave drag and surface parameterizations. A simple water cycle, basic gas-phase chemistry and passive tracers are also included in the model. Because of the vertical extent of the model, UV heating, non-LTE effects and molecular diffusion are also included. Dust is prescribed using the MGS scenario for total opacities and a Conrath profile shape. In the dust radiative transfer code, dust optical properties are based on the Wolff et al [2006, 2009] data. Temperatures in the lower and middle atmosphere have been evaluated using TES [Smith, 2004] and MCS [Kleinbohl et al. 2009] data. Winds and atmospheric circulation (mass stream functions) have been compared with the literature and show a good correspondence to other Mars GCMs. In parallel, active lifting and settling of size-distributed dust has also been implemented. The soil model has been improved to better match surface and near-surface temperatures from the Viking Landers, Phoenix [Davy et al. 2010], and TES. Near-surface winds and friction velocities have been compared with the literature and show reasonable performance. Condensation of CO2 in surface ice has been validated using CO2 ice mass

  6. Die Arbeitsunfähigkeit in der Statistik der GKV

    NASA Astrophysics Data System (ADS)

    Busch, Klaus

    Der vorliegende Beitrag gibt anhand der Statistiken des Bundesministeriums für Gesundheit (BMG) einen Überblick über die Arbeitsunfähigkeitsdaten der Gesetzlichen Krankenkassen (GKV). Zunächst werden die Arbeitsunfähigkeitsstatistiken der Krankenkassen und die Erfassung der Arbeitsunfähigkeit erläutert. Hiernach wird auf die Entwicklung der Fehlzeiten auf GKV-Ebene eingegangen. Ebenfalls wird Bezug auf die Unterschiede der Fehlzeiten zwischen den verschiedenen Kassen genommen.

  7. 16 CFR 23.25 - Misuse of the word “gem.”

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... necessary qualifications to properly be termed “gems.” Imitation diamonds and other imitation stones should not be described as “gems.” Not all diamonds or natural stones, including those classified as...

  8. 16 CFR 23.25 - Misuse of the word “gem.”

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... necessary qualifications to properly be termed “gems.” Imitation diamonds and other imitation stones should not be described as “gems.” Not all diamonds or natural stones, including those classified as...

  9. 16 CFR 23.25 - Misuse of the word “gem.”

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... necessary qualifications to properly be termed “gems.” Imitation diamonds and other imitation stones should not be described as “gems.” Not all diamonds or natural stones, including those classified as...

  10. 16 CFR 23.25 - Misuse of the word “gem.”

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... necessary qualifications to properly be termed “gems.” Imitation diamonds and other imitation stones should not be described as “gems.” Not all diamonds or natural stones, including those classified as...

  11. 16 CFR 23.25 - Misuse of the word “gem.”

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... necessary qualifications to properly be termed “gems.” Imitation diamonds and other imitation stones should not be described as “gems.” Not all diamonds or natural stones, including those classified as...

  12. Readout of TPC Tracking Chambers with GEMs and Pixel Chip

    SciTech Connect

    Kadyk, John; Kim, T.; Freytsis, M.; Button-Shafer, J.; Kadyk, J.; Vahsen, S.E.; Wenzel, W.A.

    2007-12-21

    Two layers of GEMs and the ATLAS Pixel Chip, FEI3, have been combined and tested as a prototype for Time Projection Chamber (TPC) readout at the International Linear Collider (ILC). The double-layer GEM system amplifies charge with gain sufficient to detect all track ionization. The suitability of three gas mixtures for this application was investigated, and gain measurements are presented. A large sample of cosmic ray tracks was reconstructed in 3D by using the simultaneous timing and 2D spatial information from the pixel chip. The chip provides pixel charge measurement as well as timing. These results demonstrate that a double GEM and pixel combination, with a suitably modified pixel ASIC, could meet the stringent readout requirements of the ILC.

  13. Environmentally compatible next generation green energetic materials (GEMs).

    PubMed

    Talawar, M B; Sivabalan, R; Mukundan, T; Muthurajan, H; Sikder, A K; Gandhe, B R; Rao, A Subhananda

    2009-01-30

    This paper briefly reviews the literature work reported on the environmentally compatible green energetic materials (GEMs) for defence and space applications. Currently, great emphasis is laid in the field of high-energy materials (HEMs) to increase the environmental stewardship along with the deliverance of improved performance. This emphasis is especially strong in the areas of energetic materials, weapon development, processing, and disposal operations. Therefore, efforts are on to develop energetic materials systems under the broad concept of green energetic materials (GEMs) in different schools all over the globe. The GEMs program initiated globally by different schools addresses these challenges and establishes the framework for advances in energetic materials processing and production that promote compliance with environmental regulations. This review also briefs the principles of green chemistry pertaining to HEMs, followed by the work carried out globally on environmentally compatible green energetic materials and allied ingredients.

  14. Distinction of gem spinels from the himalayan mountain belt.

    PubMed

    Malsy, Anna; Klemmb, Leonhard

    2010-01-01

    Gem spinel deposits in Myanmar, Vietnam and Tajikistan have their formation in association with Himalayan orogenesis. Gem-quality orange, pink, red and purple spinels from deposits at Mogok (Myanmar), Luc Yen (Vietnam), and Kuh-i-Lal (Tajikistan) have been investigated by 'standard' gemological testing and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Microscopic examination yielded apatite and calcite inclusions together with octahedral negative crystals to be most frequently present in Mogok spinels. The presence of dislocation systems and titanite inclusions are indicative inclusion features for spinels from Luc Yen. Trace elements such as Ti, Fe, Ni, Zn, Zr and Sn differ slightly in spinels from the sources investigated. A distinction of spinels from these deposits is therefore possible by trace element chemistry. This is especially helpful for gem spinels, which often show few inclusions or completely lack inclusion features.

  15. [Two Turkish manuscripts on gems (jauhar) and the treatment by means of gems].

    PubMed

    Kutlar, F S

    2001-01-01

    Literary works of the genre called cevâhir-nâme or cevher-nâme are written in order to give information on how gems (cevher-jauhar) are formed, where they are found, their estimated values, how to distinguish them from the imitations, what their particular colours are and on their uses and harmful effects. These literary works are sometimes titled in accordance with the genre they belong to and sometimes they are given different titles. The literary works dealing with the subject of cevher are mostly written in prose and only a few of them are in verse. The Turkish versions of cevâhir-nâme texts started to be written in the 15th century. These texts, covering the earlier knowledge of medicine, give information on gems and perfumes; how they effect human health; and the way they should be used in medical treatment. Therefore, these texts should be discussed in relation with their place in the history of Turkish science. Two cevâhir-nâmes, which were translated into Turkish by Mustafâ bin Seydî and Za'îfî in the 15th and 16th centuries are still available. The translations by Mustafâ bin Seydî and Za'îfî, did not only convey the classical and medieval knowledge on cevhers to the contemporary readers, but they also confirm the fact that this information was a part of the Ottoman social life.

  16. Kants Theorie der Sonne: Physikgeschichte

    NASA Astrophysics Data System (ADS)

    Jacobi, Manfred

    2005-01-01

    Im Rahmen seiner Kosmogonie entwickelte der junge Immanuel Kant eine Theorie der Sonne. Sie ist ein einzigartiges Zeugnis seiner intuitiven Vorstellungskraft und beweist auch die Leistungsfähigkeit der damaligen, vorwiegend von Newton geprägten Weltsicht. Entstehung, Aufbau und Dynamik der Sonne werden in Kants Theorie ebenso erklärt wie etwa das Phänomen der Sonnenflecken.

  17. GEMS: a web server for biclustering analysis of expression data.

    PubMed

    Wu, Chang-Jiun; Kasif, Simon

    2005-07-01

    The advent of microarray technology has revolutionized the search for genes that are differentially expressed across a range of cell types or experimental conditions. Traditional clustering methods, such as hierarchical clustering, are often difficult to deploy effectively since genes rarely exhibit similar expression pattern across a wide range of conditions. Biclustering of gene expression data (also called co-clustering or two-way clustering) is a non-trivial but promising methodology for the identification of gene groups that show a coherent expression profile across a subset of conditions. Thus, biclustering is a natural methodology as a screen for genes that are functionally related, participate in the same pathways, affected by the same drug or pathological condition, or genes that form modules that are potentially co-regulated by a small group of transcription factors. We have developed a web-enabled service called GEMS (Gene Expression Mining Server) for biclustering microarray data. Users may upload expression data and specify a set of criteria. GEMS then performs bicluster mining based on a Gibbs sampling paradigm. The web server provides a flexible and an useful platform for the discovery of co-expressed and potentially co-regulated gene modules. GEMS is an open source software and is available at http://genomics10.bu.edu/terrence/gems/.

  18. The Gravity and Extreme Magnetism Small Explorer (GEMS)

    NASA Technical Reports Server (NTRS)

    Kallman, T. R.

    2011-01-01

    The Gravity and Extreme Magnetism Small Explorer (GEMS) was selected by NASA for flight in 2014 to make a sensitive search for X-ray polarization from a wide set of source classes, including stellar black holes, Seyfert galaxies and quasars, blazars, rotation and accretion-powered pulsars, magnetars, shell supernova remnants and pulsar wind nebulae. Among the primary scientific objectives are determining the effects of the spin of black holes and the geometry of supermassive black hole accretion, determining the configurations of the magnetic fields and the X-ray emission of magnetars, and determining the magnetic structure of the supernova shocks in which cosmic rays are accelerated. GEMS will observe 23 targets during a 16 month prime mission, in observations that will be able to reach predicted levels of polarization. The mission can be extended to provide a guest observer phase. The GEMS instrument has time projection chamber polarimeters with high 2-10 keV efficiency at the focus of thin foil mirrors. The 4.5 m focal length mirrors will be deployed on an extended boom. The spacecraft with the instrument is rotated with a period of about 10 minutes to enable measurement and correction of systematic errors. A small Bragg reflection soft X-ray experiment takes advantage of this rotation to obtain a measurement at 0.5 keV. The design of the GEMS instrument and the mission, the expected performance and the planned science program will be discussed.

  19. Estimation of Item Parameters and the GEM Algorithm.

    ERIC Educational Resources Information Center

    Tsutakawa, Robert K.

    The models and procedures discussed in this paper are related to those presented in Bock and Aitkin (1981), where they considered the 2-parameter probit model and approximated a normally distributed prior distribution of abilities by a finite and discrete distribution. One purpose of this paper is to clarify the nature of the general EM (GEM)…

  20. Atmospheric chemical composition of the peculiar carbon giant TU Gem

    NASA Astrophysics Data System (ADS)

    Yakovina, L. A.; Polinovskii, G. A.; Pavlenko, Ya. V.; Kuznetsov, M. K.

    2017-01-01

    The evolutionary status of the bright peculiar carbon giant TU Gemis fairly uncertain. The possibility that this is aCH star—aGalactic halo star with characteristic chemical-composition anomalies—is considered. Unfortunately, data on the atmospheric chemical composition of TUGem are relatively few and are ambiguous. The results of an analysis of a moderate-resolution optical and near-infrared spectrum of TU Gem obtained on the 2-m telescope of Terskol Peak Observatory (Northern Caucasus) is presented. The atmospheric parameters of TU Gem T eff = 3100 K, C/O = 1.10, and [N/Fe] = 0.0 for the derived metallicity [Fe/H] = 0.0 are taken from [1]. The abundances of Na, Mg, Ca, Ti, and Cr are estimated to be normal or slightly enhanced, and the lithium abundance is log N(Li) = +0.1. The abundances of s-process elements are substantially enhanced in the atmosphere of TU Gem, namely, [s/Fe] ≈ 2, for both light and heavy s-process elements. The range of uncertainty in [Fe/H] is 0.0-0.3, and the uncertainties in other estimates are Δ[M/Fe]≈ ±0.3 and Δ[ s/Fe] = ±0.5. The results show that TU Gem is an anomalous carbon giant, but not a CH star.

  1. The Greenhouse Gases. UNEP/GEMS Environment Library No. 1.

    ERIC Educational Resources Information Center

    United Nations Environment Programme, Nairobi (Kenya).

    Since the United Nations Environment Program (UNEP) was created, more than a dozen years ago, public understanding of the environmental issues confronting our planet has increased enormously. The Global Environment Monitoring System (GEMS) has provided several environmental assessments including urban air pollution, climate modification,…

  2. Continuous health monitoring of Graphite Epoxy Motorcases (GEM)

    NASA Astrophysics Data System (ADS)

    Finlayson, Richard D.; Schaafsma, David T.; Shen, H. Warren; Carlos, Mark F.; Miller, Ronnie K.; Shepherd, Brent

    2001-07-01

    Following the explosion of Delta 241 (IIR-1) on January 17th, 1997, the failure investigation board concluded that the Graphite Epoxy Motorcases (GEM's) should be inspected for damage just prior to launch. Subsequent investigations and feedback from industry led to an Aerospace Corporation proposal to instrument the entire fleet of GEM's with a continuous health monitoring system. The period of monitoring would extend from the initial acceptance testing through final erection on the launch pad. As this proposal demonstrates, (along with the increasing use of advanced composite materials in aircraft, automobiles, military hardware, and aerospace components such as rocket motorcases) a sizable need for composite health assessment measures exist. Particularly where continuous monitoring is required for the detection of damage from impacts and other sources of high mechanical and thermal stresses. Even low-momentum impacts can lead to barely visible impact damage (BVID), corresponding to a significant weakening of the composite. This damage, undetectable by visual inspection, can in turn lead to sudden and catastrophic failure when the material is subjected to a normal operating load. There is perhaps no system with as much potential for truly catastrophic failure as a rocket motor. We will present an update on our ongoing efforts with the United States Air Force Delta II Program Office, and The Aerospace Corporation. This will cover the development of a local, portable, surface-mounted, fiberoptic sensor based impact damage monitor designed to operate on a Delta II GEM during transport, storage, and handling. This system is designed to continuously monitor the GEMs, to communicate wirelessly with base stations and maintenance personnel, to operate autonomously for extended periods, and to fit unobtrusively on the GEM itself.

  3. Die Kosmologie der Griechen.

    NASA Astrophysics Data System (ADS)

    Mittelstraß, J.

    Contents: 1. Mythische Eier. 2. Thales-Welten. 3. "Alles ist voller Götter". 4. Griechische Astronomie. 5. "Rettung der Phänomene". 6. Aristotelische Kosmololgie. 7. Aristoteles-Welt und Platon-Welt. 8. Noch einmal: die Göttlichkeit der Welt. 9. Griechischer Idealismus.

  4. GEM1: First-year modeling and IT activities for the Global Earthquake Model

    NASA Astrophysics Data System (ADS)

    Anderson, G.; Giardini, D.; Wiemer, S.

    2009-04-01

    GEM is a public-private partnership initiated by the Organisation for Economic Cooperation and Development (OECD) to build an independent standard for modeling and communicating earthquake risk worldwide. GEM is aimed at providing authoritative, open information about seismic risk and decision tools to support mitigation. GEM will also raise risk awareness and help post-disaster economic development, with the ultimate goal of reducing the toll of future earthquakes. GEM will provide a unified set of seismic hazard, risk, and loss modeling tools based on a common global IT infrastructure and consensus standards. These tools, systems, and standards will be developed in partnership with organizations around the world, with coordination by the GEM Secretariat and its Secretary General. GEM partners will develop a variety of global components, including a unified earthquake catalog, fault database, and ground motion prediction equations. To ensure broad representation and community acceptance, GEM will include local knowledge in all modeling activities, incorporate existing detailed models where possible, and independently test all resulting tools and models. When completed in five years, GEM will have a versatile, penly accessible modeling environment that can be updated as necessary, and will provide the global standard for seismic hazard, risk, and loss models to government ministers, scientists and engineers, financial institutions, and the public worldwide. GEM is now underway with key support provided by private sponsors (Munich Reinsurance Company, Zurich Financial Services, AIR Worldwide Corporation, and Willis Group Holdings); countries including Belgium, Germany, Italy, Singapore, Switzerland, and Turkey; and groups such as the European Commission. The GEM Secretariat has been selected by the OECD and will be hosted at the Eucentre at the University of Pavia in Italy; the Secretariat is now formalizing the creation of the GEM Foundation. Some of GEM's global

  5. The determination of the orbit of the Japanese satellite Ajisai and the GEM-T1 and GEM-T2 gravity field models

    NASA Technical Reports Server (NTRS)

    Sanchez, Braulio V.

    1990-01-01

    The Japanese Experimental Geodetic Satellite Ajisai was launched on August 12, 1986. In response to the TOPEX-POSEIDON mission requirements, the GSFC Space Geodesy Branch and its associates are producing improved models of the Earth's gravitational field. With the launch of Ajisai, precise laser data is now available which can be used to test many current gravity models. The testing of the various gravity field models show improvements of more than 70 percent in the orbital fits when using GEM-T1 and GEM-T2 relative to results obtained with the earlier GEM-10B model. The GEM-T2 orbital fits are at the 13-cm level (RMS). The results of the tests with the various versions of the GEM-T1 model indicate that the addition of satellite altimetry and surface gravity anomalies as additional data types should improve future gravity field models.

  6. Theoretische Konzepte der Physik

    NASA Astrophysics Data System (ADS)

    Longair, Malcolm S.; Simon, B.; Simon, H.

    "Dies ist kein Lehrbuch der theoretischen Physik, auch kein Kompendium der Physikgeschichte ... , vielmehr eine recht anspruchsvolle Sammlung historischer Miniaturen zur Vergangenheit der theoretischen Physik - ihrer "Sternstunden", wenn man so will. Frei vom Zwang, etwas Erschöpfendes vorlegen zu müssen, gelingt dem Autor etwas Seltenes: einen "lebendigen" Zugang zum Ideengebäude der modernen Physik freizulegen, ... zu zeigen, wie Physik in praxi entsteht... Als Vehikel seiner Absichten dienen dem Autor geschichtliche Fallstudien, insgesamt sieben an der Zahl. Aus ihnen extrahiert er das seiner Meinung nach Lehrhafte, dabei bestrebt, mathematische Anachronismen womöglich zu vermeiden... Als Student hätte ich mir diese gescheiten Essays zum Werden unserer heutigen physikalischen Weltsicht gewünscht. Sie sind originell, didaktisch klug und genieren sich auch nicht, von der Faszination zu sprechen, die ... von der Physik ausgeht. Unnötig darauf hinzuweisen, das sie ein gründliches "konventionelles" Studium weder ersetzen wollen noch können, sie vermögen aber, dazu zu ermuntern." #Astronomische Nachrichten (zur englischen Ausgabe)#1

  7. Large gem diamonds from metallic liquid in Earth's deep mantle.

    PubMed

    Smith, Evan M; Shirey, Steven B; Nestola, Fabrizio; Bullock, Emma S; Wang, Jianhua; Richardson, Stephen H; Wang, Wuyi

    2016-12-16

    The redox state of Earth's convecting mantle, masked by the lithospheric plates and basaltic magmatism of plate tectonics, is a key unknown in the evolutionary history of our planet. Here we report that large, exceptional gem diamonds like the Cullinan, Constellation, and Koh-i-Noor carry direct evidence of crystallization from a redox-sensitive metallic liquid phase in the deep mantle. These sublithospheric diamonds contain inclusions of solidified iron-nickel-carbon-sulfur melt, accompanied by a thin fluid layer of methane ± hydrogen, and sometimes majoritic garnet or former calcium silicate perovskite. The metal-dominated mineral assemblages and reduced volatiles in large gem diamonds indicate formation under metal-saturated conditions. We verify previous predictions that Earth has highly reducing deep mantle regions capable of precipitating a metallic iron phase that contains dissolved carbon and hydrogen.

  8. Reshaping and polishing the GeMS MCAO system

    NASA Astrophysics Data System (ADS)

    Garrel, Vincent; Sivo, Gaetano; Marin, Eduardo; Carrasco Damele, Eleazar R.; Montes, Vanessa; Lazo, Manuel; Gigoux, Pedro; Moreno, Cristian; Trujillo, Chadwick A.; Donahue, Jeff; van Dam, Marcos A.; Rigaut, Francois; d'Orgeville, Céline; Kulcsar, Caroline; Juvénal, Remy; Araujo Hauck, Constanza; Ammons, S. Mark; Neichel, Benoit

    2016-07-01

    GeMS, the Gemini South MCAO System, has now been in operation for 3 years with the near infrared imager GSAOI. We first review the performance obtained by the system, the science cases and the current operational model. In the very near future, GeMS will undergo a profound metamorphosis, as we will integrate a new NGS wavefront sensor, replace the current 50W laser with a more robust one and prepare for a new operational model where operations will shift from the mountain to the base facility. Along this major evolution, we are also presenting several improvements on the loop control, calibrations and automatization of this complex system. We discuss here the progress of the different upgrades and what we expect in terms of performance improvements and operational efficiency.

  9. GEM detectors development for radiation environment: neutron tests and simulations

    NASA Astrophysics Data System (ADS)

    Chernyshova, Maryna; Jednoróg, Sławomir; Malinowski, Karol; Czarski, Tomasz; Ziółkowski, Adam; Bieńkowska, Barbara; Prokopowicz, Rafał; Łaszyńska, Ewa; Kowalska-Strzeciwilk, Ewa; Poźniak, Krzysztof T.; Kasprowicz, Grzegorz; Zabołotny, Wojciech; Wojeński, Andrzej; Krawczyk, Rafał D.; Linczuk, Paweł; Potrykus, Paweł; Bajdel, Barcel

    2016-09-01

    One of the requests from the ongoing ITER-Like Wall Project is to have diagnostics for Soft X-Ray (SXR) monitoring in tokamak. Such diagnostics should be focused on tungsten emission measurements, as an increased attention is currently paid to tungsten due to a fact that it became a main candidate for the plasma facing material in ITER and future fusion reactor. In addition, such diagnostics should be able to withstand harsh radiation environment at tokamak during its operation. The presented work is related to the development of such diagnostics based on Gas Electron Multiplier (GEM) technology. More specifically, an influence of neutron radiation on performance of the GEM detectors is studied both experimentally and through computer simulations. The neutron induced radioactivity (after neutron source exposure) was found to be not pronounced comparing to an impact of other secondary neutron reaction products (during the exposure).

  10. Iron-Catalyzed gem-Specific Dimerization of Terminal Alkynes.

    PubMed

    Liang, Qiuming; Osten, Kimberly M; Song, Datong

    2017-03-13

    We report a gem-specific homo- and cross-dimerization of terminal alkynes catalyzed by a well-defined iron(II) complex containing Cp* and picolyl N-heterocyclic carbene (NHC) ligands, and featuring a piano-stool structure. This catalytic system requires no additives and is compatible with a broad range of substrates, including those with polar functional groups such as NH and OH.

  11. Nomogramme der Sickerwasserprognose

    NASA Astrophysics Data System (ADS)

    Schneider, Wilfried; Stöfen, Heinke

    Kurzfassung Modelle zur Sickerwasserprognose stehen in unterschiedlicher Komplexität zur Verfügung. Komplexe Modelle werden aufgrund der schwierigen Handhabung und des enormen Eingabedatenumfangs in der Praxis kaum angewandt. Grobe Abschätzmethoden sind dagegen nicht ausreichend wissenschaftlich fundiert, um damit justiziable Ergebnisse erzielen zu können. Um die Kluft zwischen komplexer und einfacher, jedoch justiziabler sowie wissenschaftlich fundierter Methode zu schmälern, wurden Nomogramme für Sickerwasserprognosen zur Berücksichtigung der Endlichkeit der Quelle entwickelt. Mithilfe der Nomogramme können ohne Modellierungserfahrung schnell und einfach die zu erwartenden Schadstoffkonzentrationen am Ort der Beurteilung abgeschätzt werden, falls die Endlichkeit der Quelle der hauptsächlich zur Abminderung führende Prozess ist. Die Nomogramme basieren auf analytischen Lösungen der eindimensionalen Advektions-Dispersions-Gleichung. Sie berücksichtigen die Prozesse Advektion, Diffusion in Bodenwasser und -luft, Dispersion, lineare Sorption, Abbau 1. Ordnung innerhalb einer aus mehreren Bodenschichten bestehenden Sickerwasserzone, wobei die Endlichkeit der Schadstoffmasse in der Bodenkontamination einbezogen wird. Die Genauigkeit der Nomogramme wird dargestellt. Models of different complexity are available for groundwater risk assessment. In practice complex models are hardly used, due to their difficult handling and large data requirement. Rough estimation methods are not sufficiently scientifically founded to produce justiciable results. To reduce the gap between complex and easy to use but justiciable and scientifically founded methods we developed nomograms for groundwater risk assessment which take into account the finite mass of contaminant in the source. With the help of the nomograms the expected concentrations at the point of compliance (transition between the unsaturated and saturated zone) can be estimated easily, fast and without any

  12. Development of near infrared spectrometer for gem materials study

    NASA Astrophysics Data System (ADS)

    Jindata, W.; Meesiri, W.; Wongkokua, W.

    2015-07-01

    Most of gem materials can be characterized by infrared absorption spectroscopy. Normally, mid infrared absorption technique has been applied for investigating fundamental vibrational modes. However, for some gem materials, such as tourmaline, NIR is a better choice due to differentiation. Most commercial NIR spectrometers employ complicated dispersive grating or Fourier transform techniques. In this work, we developed a filter type NIR spectrometer with the availability of high efficiency and low-cost narrow bandpass NIR interference filters to be taught in a physics laboratory. The instrument was designed for transmission-mode configuration. A 50W halogen lamp was used as NIR source. There were fourteen NIR filters mounted on a rotatory wheel for wavelength selection ranging from 1000-1650 nm with steps of 50 nm. A 1.0 mm diameter of InGaAs photodiode was used as the detector for the spectrometer. Hence, transparent gem materials can be used as samples for experiment. Student can learn vibrational absorption spectroscopy as well as Beer-Lambert law from the development of this instrument.

  13. Targeting SMN to Cajal bodies and nuclear gems during neuritogenesis

    PubMed Central

    Navascues, Joaquin; Berciano, Maria T.; Tucker, Karen E.

    2006-01-01

    Neurite outgrowth is a central feature of neuronal differentiation. PC12 cells are a good model system for studying the peripheral nervous system and the outgrowth of neurites. In addition to the dramatic changes observed in the cytoplasm, neuronal differentiation is also accompanied by striking changes in nuclear morphology. The large and sustained increase in nuclear transcription during neuronal differentiation requires synthesis of a large number of factors involved in pre-mRNA processing. We show that the number and composition of the nuclear subdomains called Cajal bodies and gems changes during the course of N-ras-induced neuritogenesis in the PC12-derived cell line UR61. The Cajal bodies found in undifferentiated cells are largely devoid of the survival of motor neurons (SMN) protein product. As cells shift to a differentiated state, SMN is not only globally upregulated, but is progressively recruited to Cajal bodies. Additional SMN foci (also known as Gemini bodies, gems) can also be detected. Using dual-immunogold labeling electron microscopy and mouse embryonic fibroblasts lacking the coilin protein, we show that gems clearly represent a distinct category of nuclear body. PMID:15164213

  14. Fast readout of GEM detectors for medical imaging

    NASA Astrophysics Data System (ADS)

    Bucciantonio, M.; Amaldi, U.; Kieffer, R.; Malakhov, N.; Sauli, F.; Watts, D.

    2013-08-01

    We describe the design and implementation of a fast data acquisition (DAQ) system for Gas Electron Multiplier (GEM) trackers applied to imaging and dosimetry in hadrontherapy. Within the AQUA project of the TERA foundation a prototype of Proton Range Radiography of 30×30 cm2 active area has been designed and built to provide in-beam integrated density images of the patient before treatment. It makes use of a pair of GEMs to record position and direction of protons emerging from the target. A fast data acquisition rate close to 1 MHz will allow obtaining a good resolution in-beam proton radiography in a few seconds. A dedicated fast front-end circuit for GEM detectors (GEMROC by AGH-Crakow University) is read by the FPGA based DAQ card (GR_DAQ), developed by the AQUA group. The same system is under evaluation (within the ENVISION European project) to realize the in-vivo dosimetry, based on detecting secondary light particles during the treatment of the patient.

  15. Improvement in the geopotential derived from satellite and surface data (GEM 7 and 8)

    NASA Technical Reports Server (NTRS)

    Wagner, C. A.; Lerch, F. J.; Brownd, J. E.; Richardson, J. A.

    1976-01-01

    A refinement was obtained in the earth's gravitational field using satellite and surface data. In addition to a more complete treatment of data previously employed on 27 satellites, the new satellite solution (Goddard Earth Model 7) includes 64,000 laser measurements taken on 7 satellites during the international satellite geodesy experiment (ISAGEX) program. The GEM 7, containing 400 harmonic terms, is complete through degree and order 16. The companion solution GEM 8 combines the same satellite data as in GEM 7 with surface gravimetry over 39% of the earth. The GEM 8 is complete to degree and order 25. Extensive tests on data independent of the solution show that the undulation of the geoidal surface computed by GEM 7 has an accuracy of about 3m (rms). The overall accuracy of the geoid estimated by GEM 8 is estimated to be about 4-1/4m (rms), an improvement of almost 1m over previous solutions.

  16. Effekt einer ad libitum verzehrten fettreduzierten Kost, reich an Obst, Gemüse und Milchprodukten auf den Blutdruck bei Borderline-Hypertonikern

    NASA Astrophysics Data System (ADS)

    Möseneder, Jutta M.

    2002-01-01

    In der randomisierten, multizentrischen DASH-Studie (Dietary Approaches to Stop Hy-pertension), die unter kontrollierten Bedingungen stattfand, führte eine fettreduzierte Mischkost, reich an Obst, Gemüse und Milchprodukten, bei Borderline-Hypertonikern zu einer signifikanten Blutdrucksenkung. Während der Studienphase wurden Körpermasse, Natrium-Aufnahme sowie Alkoholzufuhr aufgrund der bekannten Einflussnahme auf den Blutdruck konstant gehalten. In der eigenen Pilot-Studie sollte untersucht werden, ob das Ergebnis der DASH-Studie (i) mit deutschen Hypertonikern und (ii) unter habituellen Ernährungs- und Lebensbedingungen mit regelmäßig durchgeführter Ernährungsberatung und ad libitum Verzehr anstelle des streng kontrollierten Studienansatzes bestätigt werden kann. Eine Konstanz der Körpermasse, der Natrium-Urinausscheidung (unter diesem Studienansatz valider als die Aufnahme) und des Alkoholkonsums wurde vorausgesetzt. Die Studienpopulation setzte sich aus 53 übergewichtigen Probanden mit einer nicht medikamentös therapierten Borderline-Hypertonie und ohne Stoffwechselerkrankungen zusammen. Die Studienteilnehmer wurden randomisiert entweder der Idealgruppe mit einer fettarmen Kost reich an Milchprodukten, Obst und Gemüse (ähnlich der DASH-Idealgruppe) oder der Kontrollgruppe mit habitueller Ernährungsweise zugeteilt. Über einen Zeitraum von fünf Wochen wurde den Probanden etwa 50% ihres täglichen Lebensmittelbedarfes entsprechend ihrer Gruppenzugehörigkeit kostenfrei zur Verfügung gestellt. Gelegenheitsblutdruckmessungen und 24h-Blutdruckmessungen, Ernährungs- und Aktivitätsprotokolle, Blut- und Urinproben sowie anthropometrische Messungen wurden vor, während und fünf Wochen nach der Interventionsphase durchgeführt. Die Ergebnisse zeigen, dass in der Idealgruppe keine signifikante Blutdrucksenkung beobachtet werden konnte. Dies lässt sich durch die Tatsache erklären, dass die Lebens-mittel- und Nährstoffaufnahme der deutschen

  17. Synthesis of GEMS from Shock-accelerated Crystalline Dust in Superbubbles: Model and Predictions

    NASA Technical Reports Server (NTRS)

    Westphal, Andrew J.; Bradley, John P.

    2005-01-01

    GEMS (Glass Embedded with Metals and Sulfides) are highly enigmatic yet common components of anhydrous IDPs. We have recently proposed a model of GEMS formation from shock-accelerated crystalline dust in superbubbles[1] which explains the three most perplexing properties of GEMS: pseudomorphism[2], their chemistry[3], and their size range. In this Abstract, we briefly review the main points of the model, and suggest tests that will either prove or rule out this hypothesis.

  18. Statistical exploration of gaseous elemental mercury (GEM) measured at Cape Point from 2007 to 2011

    NASA Astrophysics Data System (ADS)

    Venter, A. D.; Beukes, J. P.; van Zyl, P. G.; Brunke, E.-G.; Labuschagne, C.; Slemr, F.; Ebinghaus, R.; Kock, H.

    2015-02-01

    The authors evaluated continuous high resolution gaseous elemental mercury (GEM) data from the Cape Point Global Atmosphere Watch (CPT GAW) station with different statistical analysis techniques. GEM data was evaluated by cluster analysis and the results indicated that two clusters, separated at 0.904 ng m-3, existed. The air mass history for the two-cluster solution was investigated by means of back-trajectory analysis. The air mass back-trajectory net result showed lower GEM concentrations originating from the sparsely populated semi-arid interior of SA and the marine environment, whereas higher GEM concentrations originated predominately along the coast of SA that most likely coincide with trade routes and industrial activities in urban areas along the coast. Considering the net result from the air mass back-trajectories, it is evident that not all low GEM concentrations are from marine origin, and similarly, not all high GEM concentrations have a terrestrial origin. Equations were developed by means of multi-linear regression (MLR) analysis that allowed for the estimation/prediction of atmospheric GEM concentrations from other atmospheric parameters measured at the CPT GAW station. These equations also provided some insight into the relation and interaction of GEM with other atmospheric parameters. Both measured and MLR calculated data confirm a decline in GEM concentrations at CPT GAW over the period evaluated.

  19. Statistical exploration of gaseous elemental mercury (GEM) measured at Cape Point from 2007 to 2011

    NASA Astrophysics Data System (ADS)

    Venter, A. D.; Beukes, J. P.; van Zyl, P. G.; Brunke, E.-G.; Labuschagne, C.; Slemr, F.; Ebinghaus, R.; Kock, H.

    2015-09-01

    The authors evaluated continuous high-resolution gaseous elemental mercury (GEM) data from the Cape Point Global Atmosphere Watch (CPT GAW) station with different statistical analysis techniques. GEM data were evaluated by cluster analysis and the results indicated that two clusters, separated at 0.904 ng m-3, existed. The air mass history for the two-cluster solution was investigated by means of back-trajectory analysis. The air mass back-trajectory net result showed lower GEM concentrations originating from the sparsely populated semi-arid interior of South Africa and the marine environment, whereas higher GEM concentrations originated predominately along the coast of South Africa that most likely coincide with trade routes and industrial activities in urban areas along the coast. Considering the net result from the air mass back-trajectories, it is evident that not all low GEM concentrations are from marine origin, and similarly, not all high GEM concentrations have a terrestrial origin. Equations were developed by means of multi-linear regression (MLR) analysis that allowed for the estimation and/or prediction of atmospheric GEM concentrations from other atmospheric parameters measured at the CPT GAW station. These equations also provided some insight into the relation and interaction of GEM with other atmospheric parameters. Both measured and MLR calculated data confirm a decline in GEM concentrations at CPT GAW over the period evaluated.

  20. A Study of a Mini-Drift GEM Tracking Detector

    DOE PAGES

    Azmoun, B.; DiRuzza, B.; Franz, A.; ...

    2016-06-22

    In this paper, a GEM tracking detector with an extended drift region has been studied as part of an effort to develop new tracking detectors for future experiments at RHIC and for the Electron Ion Collider that is being planned for BNL or JLAB. The detector consists of a triple GEM stack with a 1.6 cm drift region that was operated in a mini TPC type configuration. Both the position and arrival time of the charge deposited in the drift region were measured on the readout plane which allowed the reconstruction of a short vector for the track traversing themore » chamber. The resulting position and angle information from the vector could then be used to improve the position resolution of the detector for larger angle tracks, which deteriorates rapidly with increasing angle for conventional GEM tracking detectors using only charge centroid information. Two types of readout planes were studied. One was a COMPASS style readout plane with 400 μm pitch XY strips and the other consisted of 2 × 10 mm2 chevron pads. The detector was studied in test beams at Fermilab and CERN, along with additional measurements in the lab, in order to determine its position and angular resolution for incident track angles up to 45 degrees. Several algorithms were studied for reconstructing the vector using the position and timing information in order to optimize the position and angular resolution of the detector for the different readout planes. Finally, applications for large angle tracking detectors at RHIC and EIC are also discussed.« less

  1. A Study of a Mini-Drift GEM Tracking Detector

    SciTech Connect

    Azmoun, B.; DiRuzza, B.; Franz, A.; Kiselev, A.; Pak, R.; Phipps, M.; Purschke, M. L.; Woody, C.

    2016-06-22

    In this paper, a GEM tracking detector with an extended drift region has been studied as part of an effort to develop new tracking detectors for future experiments at RHIC and for the Electron Ion Collider that is being planned for BNL or JLAB. The detector consists of a triple GEM stack with a 1.6 cm drift region that was operated in a mini TPC type configuration. Both the position and arrival time of the charge deposited in the drift region were measured on the readout plane which allowed the reconstruction of a short vector for the track traversing the chamber. The resulting position and angle information from the vector could then be used to improve the position resolution of the detector for larger angle tracks, which deteriorates rapidly with increasing angle for conventional GEM tracking detectors using only charge centroid information. Two types of readout planes were studied. One was a COMPASS style readout plane with 400 μm pitch XY strips and the other consisted of 2 × 10 mm2 chevron pads. The detector was studied in test beams at Fermilab and CERN, along with additional measurements in the lab, in order to determine its position and angular resolution for incident track angles up to 45 degrees. Several algorithms were studied for reconstructing the vector using the position and timing information in order to optimize the position and angular resolution of the detector for the different readout planes. Finally, applications for large angle tracking detectors at RHIC and EIC are also discussed.

  2. The Global Enteric Multicenter Study (GEMS): Impetus, Rationale, and Genesis

    PubMed Central

    Levine, Myron M.; Kotloff, Karen L.; Nataro, James P.; Muhsen, Khitam

    2012-01-01

    Diarrheal disease remains one of the top 2 causes of young child mortality in the developing world. Whereas improvements in water/sanitation infrastructure and hygiene can diminish transmission of enteric pathogens, vaccines can also hasten the decline of diarrheal disease morbidity and mortality. From 1980 through approximately 2004, various case/control and small cohort studies were undertaken to address the etiology of pediatric diarrhea in developing countries. Many studies had methodological limitations and came to divergent conclusions, making it difficult to prioritize the relative importance of different pathogens. Consequently, in the first years of the millennium there was no consensus on what diarrheal disease vaccines should be developed or implemented; however, there was consensus on the need for a well-designed study to obtain information on the etiology and burden of more severe forms of diarrheal disease to guide global investment and implementation decisions. Accordingly, the Global Enteric Multicenter Study (GEMS) was designed to overcome drawbacks of earlier studies and determine the etiology and population-based burden of pediatric diarrheal disease. GEMS, which includes one of the largest case/control studies of an infectious disease syndrome ever undertaken (target approximately 12 600 analyzable cases and 12 600 controls), was rolled out in 4 sites in sub-Saharan Africa (Gambia, Kenya, Mali, Mozambique) and 3 in South Asia (Bangladesh, India, Pakistan), with each site linked to a population under demographic surveillance (total approximately 467 000 child years of observation among children <5 years of age). GEMS data will guide investment and help prioritize strategies to mitigate the morbidity and mortality of pediatric diarrheal disease. PMID:23169934

  3. The Global Enteric Multicenter Study (GEMS): impetus, rationale, and genesis.

    PubMed

    Levine, Myron M; Kotloff, Karen L; Nataro, James P; Muhsen, Khitam

    2012-12-01

    Diarrheal disease remains one of the top 2 causes of young child mortality in the developing world. Whereas improvements in water/sanitation infrastructure and hygiene can diminish transmission of enteric pathogens, vaccines can also hasten the decline of diarrheal disease morbidity and mortality. From 1980 through approximately 2004, various case/control and small cohort studies were undertaken to address the etiology of pediatric diarrhea in developing countries. Many studies had methodological limitations and came to divergent conclusions, making it difficult to prioritize the relative importance of different pathogens. Consequently, in the first years of the millennium there was no consensus on what diarrheal disease vaccines should be developed or implemented; however, there was consensus on the need for a well-designed study to obtain information on the etiology and burden of more severe forms of diarrheal disease to guide global investment and implementation decisions. Accordingly, the Global Enteric Multicenter Study (GEMS) was designed to overcome drawbacks of earlier studies and determine the etiology and population-based burden of pediatric diarrheal disease. GEMS, which includes one of the largest case/control studies of an infectious disease syndrome ever undertaken (target approximately 12,600 analyzable cases and 12,600 controls), was rolled out in 4 sites in sub-Saharan Africa (Gambia, Kenya, Mali, Mozambique) and 3 in South Asia (Bangladesh, India, Pakistan), with each site linked to a population under demographic surveillance (total approximately 467,000 child years of observation among children <5 years of age). GEMS data will guide investment and help prioritize strategies to mitigate the morbidity and mortality of pediatric diarrheal disease.

  4. Novel and efficient ADC concept for BlackGEM telescope

    NASA Astrophysics Data System (ADS)

    ter Horst, Rik; Kragt, Jan; Lesman, Dirk; Navarro, Ramon

    2016-07-01

    Ground based telescopes suffer from Atmospheric Dispersion that can be compensated for with an Atmospheric Dispersion Corrector (ADC). In the BlackGEM array of 650 mm diameter telescopes, the ADC is fully integrated in the three-lens field corrector and requires lateral displacement of only one lens for a full correction of the Atmospheric Dispersion. This concept results in a very compact and efficient ADC design without the need for any additional optical components. This paper describes the optical trade-offs, optical design and optimization, as well as the mechanical design and implementation of this novel ADC solution.

  5. Long-term stability test of a triple GEM detector

    NASA Astrophysics Data System (ADS)

    Adak, R. P.; Biswas, S.; Das, S.; Ghosal, D.; Ghosh, S. K.; Mondal, A.; Nag, D.; Nayak, T. K.; Patra, R. N.; Prasad, S. K.; Raha, S.; Sahu, P. K.; Sahu, S.; Swain, S.

    2016-10-01

    The main aim of the study is to perform the long-term stability test of gain of the single mask triple GEM detector. A simple method is used for this long-term stability test using a radioactive X-ray source with high activity. The test is continued till accumulation of charge per unit area > 12.0 mC/mm2. The details of the chamber fabrication, the test set-up, the method of measurement and the test results are presented in this paper.

  6. Study of resolution of the PANDA GEM detector with Garfield

    NASA Astrophysics Data System (ADS)

    Melnychuk, D.; Voss, B.; Zwieglinski, B.

    2014-05-01

    The forward GEM tracker of the P̅ANDA detector at the future FAIR facility will track the particles produced in antiproton-proton annihilations and emitted in the polar angle range 5∘ -22∘. Position resolution at the level of 100 μ m and good time resolution are critical to work under luminosities up to 2×1032 c m -2 s -1. The simulations performed with Garfield program compared several detector layouts and determined the optimal granularity of readout electronics. The time resolution for two possible gas mixtures was also estimated.

  7. Life with quintuplets: transitioning GeMS into regular operations

    NASA Astrophysics Data System (ADS)

    Garrel, Vincent; Van Dam, Marcos A.; Neichel, Benoît; Vidal, Fabrice; Sivo, Gaetano; Marin, Eduardo; Montes, Vanessa; Serio, Andrew; Arriagada, Gustavo; Trujillo, Chadwick; Rambold, William N.; Gigoux, Pedro; Galvez, Ramon; Moreno, Cristian; Araujo Hauck, Constanza; Vucina Parga, Tomislav; Donahue, Jeff; Marchant, Claudio; Gausachs, Gaston; Collao, Fabian; Carrasco Damele, Eleazar R.; Pessev, Peter; Lopez, Ariel

    2014-08-01

    The Gemini Multi-conjugate adaptive optics System (GeMS) at the Gemini South telescope in Cerro Pachon is the first sodium Laser Guide Star (LGS) adaptive optics (AO) system with multiple guide stars. It uses five LGSs and two deformable mirrors (DMs) to measure and compensate for distortions induced by atmospheric turbulence. After its 2012 commissioning phase, it is now transitioning into regular operations. Although GeMS has unique scientific capabilities, it remains a challenging instrument to maintain, operate and upgrade. In this paper, we summarize the latest news and results. First, we describe the engineering work done this past year, mostly during our last instrument shutdown in 2013 austral winter, covering many subsystems: an erroneous reconjugation of the Laser guide star wavefront sensor, the correction of focus field distortion for the natural guide star wavefront sensor and engineering changes dealing with our laser and its beam transfer optics. We also describe our revamped software, developed to integrate the instrument into the Gemini operational model, and the new optimization procedures aiming to reduce GeMS time overheads. Significant software improvements were achieved on the acquisition of natural guide stars by our natural guide star wavefront sensor, on the automation of tip-tilt and higher-order loop optimization, and on the tomographic non-common path aberration compensation. We then go through the current operational scheme and present the plan for the next years. We offered 38 nights in our last semester. We review the current system efficiency in term of raw performance, completed programs and time overheads. We also present our current efforts to merge GeMS into the Gemini base facility project, where night operations are all reliably driven from our La Serena headquarter, without the need for any spotter. Finally we present the plan for the future upgrades, mostly dedicated toward improving the performance and reliability of the

  8. GEMS Project: A Platform to Investigate Multiple Sclerosis Risk

    PubMed Central

    Xia, Zongqi; White, Charles C.; Owen, Emily K.; Von Korff, Alina; Clarkson, Sarah R.; McCabe, Cristin A.; Cimpean, Maria; Winn, Phoebe A.; Hoesing, Ashley; Steele, Sonya U.; Cortese, Irene C. M.; Chitnis, Tanuja; Weiner, Howard L.; Reich, Daniel S.; Chibnik, Lori B.; De Jager, Philip L.

    2015-01-01

    The Genes and Environment in Multiple Sclerosis (GEMS) project establishes a platform to investigate the events leading to MS in at-risk individuals. It has recruited 2,632 first-degree relatives from across the USA. Using an integrated genetic and environmental risk score, we identified subjects with twice the MS risk when compared to the average family member, and we report an initial incidence rate in these subjects that is 30 times greater than that of sporadic MS. We discuss the feasibility of large-scale studies of asymptomatic at-risk subjects that leverage modern tools of subject recruitment to execute collaborative projects. PMID:26583565

  9. The GEM project: An international collaboration to survey galacticradiation emission

    SciTech Connect

    Torres, S.; Canon, V.; Casas, R.; Umana, A.; Tello, C.; Villela,T.; Bersanelli, M.; Bensadoun, M.; deAmici, G.; Limon, M.; Smoot, G.; Witebsky, C.

    1996-05-11

    The GEM (Galactic Emission Mapping) project is an international collaboration established with the aim of surveying the full sky at long wavelengths with a multi-frequency radio telescope. A total of 745 hours of observation at 408 MHz were completed from an Equatorial site in Colombia. The observations cover the celestial band O-h < alpha < 24(h), and -24 degrees 22 minutes < delta < +35 degrees 37 minutes. Preliminary results of this partial survey will be discussed. A review of the instrumental setup and a similar to 10 degrees resolution sky map at 408 MHz is presented.

  10. Copper-Catalyzed SN2'-Selective Allylic Substitution Reaction of gem-Diborylalkanes.

    PubMed

    Zhang, Zhen-Qi; Zhang, Ben; Lu, Xi; Liu, Jing-Hui; Lu, Xiao-Yu; Xiao, Bin; Fu, Yao

    2016-03-04

    A Cu/(NHC)-catalyzed SN2'-selective substitution reaction of allylic electrophiles with gem-diborylalkanes is reported. Different substituted gem-diborylalkanes and allylic electrophiles can be employed in this reaction, and various synthetic valuable functional groups can be tolerated. The asymmetric version of this reaction was initially researched with chiral N-heterocyclic carbene (NHC) ligands.

  11. Overview of the Gems Model of Volunteer Administration (Generate, Educate, Mobilize and Sustain)

    ERIC Educational Resources Information Center

    Culp, Ken, III

    2012-01-01

    To organize and coordinate the efforts of many volunteers, a framework for volunteer engagement is needed. The "GEMS" Model of volunteer administration was developed to assist Extension professionals and volunteer coordinators to effectively administer volunteer programs without delivering the program themselves. The GEMS Model is…

  12. Grundbegriffe der Thermodynamik

    NASA Astrophysics Data System (ADS)

    Heintze, Joachim

    In diesem Kapitel geht es darum, Vorgänge zu analysieren, bei denen der thermische Zustand eines Systems verändert wird: Daher der Name "Thermodynamik". Wir werden zunächst untersuchen, unter welchen Umständen man eine Zustandsänderung im Detail beschreiben kann. Hierbei werden wir zwei grundsätzlich verschiedene Arten, Zustandsänderungen herbeizuführen, kennenlernen: reversible und irreversible Prozesse. Sodann werden wir die Eigenschaften von Zustandsgrößen allgemein definieren und dabei auf eine überaus wichtige neue Zustandsgröße, die Entropie, stoßen.

  13. Possible Gems and Ultra-Fine Grained Polyphase Units in Comet Wild 2.

    NASA Technical Reports Server (NTRS)

    Gainsforth, Z.; Butterworth, A. L.; Jilly-Rehak, C. E.; Westphal, A. J.; Brownlee, D. E.; Joswiak, D.; Ogliore, R. C.; Zolensky, M. E.; Bechtel, H. A.; Ebel, D. S.; Huss, G. R.; Sandford, S. A.; White, A. J.

    2016-01-01

    GEMS and ultrafine grained polyphase units (UFG-PU) in anhydrous IDPs are probably some of the most primitive materials in the solar system. UFG-PUs contain nanocrystalline silicates, oxides, metals and sulfides. GEMS are rounded approximately 100 nm across amorphous silicates containing embedded iron-nickel metal grains and sulfides. GEMS are one of the most abundant constituents in some anhydrous CPIDPs, often accounting for half the material or more. When NASA's Stardust mission returned with samples from comet Wild 2 in 2006, it was thought that UFG-PUs and GEMS would be among the most abundant materials found. However, possibly because of heating during the capture process in aerogel, neither GEMS nor UFG-PUs have been clearly found.

  14. Quality assurance of GEM foils for the upgrade of the ALICE TPC

    NASA Astrophysics Data System (ADS)

    Ball, M.; Ketzer, B.; Ottnad, J.; Ratza, V.; Urban, S.

    2017-01-01

    With the planned upgrade of the ALICE Time Projection Chamber (TPC) the current readout technology will be replaced by a Gas Electron Multiplier (GEM)—based readout technology in order to allow for a continuous operation at high interaction rates up to 50 kHz. A stack of four GEM stages with non-standard field configuration was chosen to achieve a suppression of the ion backflow below 1%, while maintaining a good energy resolution below σ / E= \\unit[12]% for 55 Fe. A discharge probability of 10‑10 for α-particles was confirmed for this low ion backflow field configuration. This is comparable to standard triple GEM detectors in low discharge settings. To upgrade all the Inner and Outer Readout Chambers of ALICE, 576 GEM foils will be needed. Only GEM foils that fullfill the highest quality criteria can be used. Therefore a quality assurance scheme has been developed that includes a large set of quality assurance measurements.

  15. Great Explorations in Math and Science[R] (GEMS[R]) Space Science. What Works Clearinghouse Intervention Report

    ERIC Educational Resources Information Center

    What Works Clearinghouse, 2012

    2012-01-01

    "Great Explorations in Math and Science[R] (GEMS[R]) Space Science" is an instructional sequence for grades 3-5 that covers fundamental concepts, including planetary sizes and distance, the Earth's shape and movement, gravity, and moon phases and eclipses. Part of the "GEMS"[R] core curriculum, "GEMS[R] Space Science"…

  16. PREFACE: Science's gem: diamond science 2009 Science's gem: diamond science 2009

    NASA Astrophysics Data System (ADS)

    Mainwood, Alison; Newton, Mark E.; Stoneham, Marshall

    2009-09-01

    Natural diamond has been valued for its appearance and mechanical properties for at least two thousand years. As a gem stone diamond is unsurpassed. However, scientific work, especially in the last 20 years, has demonstrated that diamond has numerous surprising properties and many unique ones. Some of the extreme properties have been known for many years, but the true scale of diamond's other highly desirable features is still only coming to light as control in the synthesis of diamond, and hence material perfection, improves. The ultimate prize for man-made diamond is surely not in the synthesis of gem stones, but in delivering technological solutions enabled by diamond to the challenges facing our society today. If the special properties are to be exploited to their full potential, at least four crucial factors must be considered. First, there must be sufficient scientific understanding of diamond to make applications effective, efficient and economical. Secondly, the means of fabrication and control of properties have to be achieved so that diamond's role can be optimised. Thirdly, it is not enough that its properties are superior to existing materials: they must be so much better that it is worth initiating new technologies to exploit them. Finally, any substantial applications will have to address the society's major needs worldwide. The clear technology drivers for the 21st century come from the biomedical technologies, the demand for energy subject to global constraints, and the information technologies, where perhaps diamond will provide the major enabling technology [1]. The papers in this volume concern the solid state physics of diamond, and primarily concern the first two factors: understanding, and control of properties. They address many of the outstanding basic problems, such as the identification of existing defects, which affect the material's properties, both desirable and less so. Regarding future substantial applications, one paper discusses

  17. Update: Therapie der Necrobiosis lipoidica.

    PubMed

    Peckruhn, Melanie; Tittelbach, Jörg; Elsner, Peter

    2017-02-01

    Die Necrobiosis lipoidica ist eine seltene granulomatöse Erkrankung von bisher unzureichend geklärter Ätiologie. Häufig stellt die bei Diabetikern gehäuft zu beobachtende und zur Ulzeration neigende Dermatose eine starke Belastung für die Patienten dar. Bezüglich der Therapie existieren aktuell keine deutschen oder europäischen Leitlinien. Gleichzeitig lässt sich unter der aktuellen Standardtherapie, der lokalen oder intraläsionalen Anwendung von Glukokortikoiden, nicht immer ein zufriedenstellendes Ansprechen beobachten. Daher wurde untersucht, ob seit dem Jahr 2000 publizierte Therapiemodalitäten das Therapiespektrum relevant und erfolgversprechend erweitern. Es erfolgte eine Betrachtung aller Arbeiten im oben genannten Zeitraum, bei denen mehr als ein Einzelfallbericht je Therapiemodalität publiziert wurde. Insgesamt wurden in einem systematischen Review die Daten von 16 verschiedenen, seit 2000 publizierten Therapieverfahren in 49 Publikationen analysiert. Im Ergebnis zeigte sich, dass die meisten Erfahrungen bezüglich der topischen PUVA-Therapie, der photodynamischen Therapie (PDT) und der systemischen Therapie mit Fumarsäureestern vorliegen. Allerdings ist auffällig, dass mit steigender Zahl der pro Behandlungsmodalität behandelten Patienten der Anteil der Patienten, bei denen eine Abheilung bzw. eine teilweise Abheilung berichtet wurde, sinkt. Wir interpretieren diese Beobachtung als Publikationsbias. Daher kann für keines der besprochenen Verfahren eine klare Empfehlung als Therapie der zweiten Wahl nach Versagen der lokalen bzw. intraläsionalen Steroidtherapie gegeben werden.

  18. GEM Detectors of Proton Charge Radius (PRad) Experiment

    NASA Astrophysics Data System (ADS)

    Bai, Xinzhan; PRad Collaboration

    2017-01-01

    The PRad experiment (E12-11-106) was recently performed at Jefferson Lab in Hall B. It was designed to measure the proton charge radius with high precision, through the elastic electron proton scattering process, using a non-magnetic-spectrometer method. PRad experiment reached very small ep scattering angles and thus it can see an unprecedented small four-momentum transfer squared region, Q2 from 2 ×10-4 to 0 . 1(GeV / c) 2 . This experiment measures the proton charge radius by extracting the electric form factor of proton with a sub-percent precision. A pair of world's largest GEM detectors, and a high resolution calorimeter(HyCal) were utilized in the experiment. In this talk, we will present the performance of GEM detectors achieved in the experiment, such as efficiency and other characteristics, and preliminary analysis results of the experimental data. This work is supported in part by NSF MRI award PHY-1229153, the U.S. Department of Energy under Contract No. DE-FG02-07ER41528, University of Virginia under Contract No. DE-FG02-03ER41240 and Thomas Jefferson National Laboratory.

  19. Coordinated Chemical and Isotopic Studies of GEMS in IDPS

    NASA Technical Reports Server (NTRS)

    Keller, L. P.; Messenger, S.

    2008-01-01

    Cometary IDPs contain a record of the building blocks of the solar system including presolar grains, molecular cloud material, and materials formed in the early solar nebula [1]. Following their accretion, these materials have remained relatively unaltered because of the lack of parent body hydrothermal alteration. We are using coordinated transmission electron microscope (TEM) and ion microprobe studies to establish the origins of the various components within cometary IDPs. Of particular interest is the nature and abundance of presolar silicates in these IDPs because astronomical observations suggest that crystalline and amorphous silicates are the dominant grain types produced in young main sequence stars and evolved O-rich stars [e.g. 2]. Amorphous silicates (in the form of GEMS grains) are a major component of cometary IDPs and so a major objective of this work is to elucidate their origins. In rare cases, GEMS grains have highly anomalous O isotopic compositions that establish their origins as circumstellar condensates [3]. Here we present data on a systematic study of the silicate components within a primitive IDP.

  20. GEM-type detectors using LIGA and etchable glass technologies

    SciTech Connect

    Ahn, S.K.; Kim, J.G.; Perez-Mendez, V.; Chang, S.; Jackson, K.H.; Kadyk, J.A.; Wenzel, W.A.; Cho, G.

    2001-11-02

    Gas electron multipliers (GEMS) have been made by a deep X-ray lithography technique (LIGA process) using synchrotron radiation on polymethylmethacrylate (PMMA) and by UV processes using a UV etchable glass. Gain, stability and rate capability for these detectors are described.The LIGA detectors described consist of PMMA sheets of various thicknesses, 125mm to 350mm, and have 150mm x 150mm square holes spaced with a pitch of 300mm. Thin copper electrodes are plated on the top and bottom surfaces using a Damascene method, followed by electroless plating of the copper onto a palladium-tin base layer. For various thicknesses of PMMA measurements have been made of absolute gain vs. voltage, time stability of gain, and rate capability. The operating gas mixture was usually Ar/CO2 (70/30) gas, but some tests were also done using P10 gas. We also made GEM-like detectors using the UV etchable glass called Foturan, patterned by exposure to UV light and subsequent etching. A few measurements using these detectors will be reported, including avalanche gain and time stability.

  1. Study of microtearing mode in NSTX with GEM

    NASA Astrophysics Data System (ADS)

    Chowdhury, Jugal; Chen, Yang; Parker, Scott; Wan, Weigang; Canik, John; Guttenfelder, Walter; Smith, David

    2013-10-01

    Anomalous thermal transport of electrons in conventional and spherical tokamaks is believed to be driven mainly by electron temperature gradient modes, and trapped electron modes. Another mode which is electromagnetic and sensitive to collisionality has emerged as another source of electron thermal loss. Earlier it has been believed that this instability is important only for spherical tokamaks both in core (Guttenfelder et al. Phys of Plasmas 19, 022506 (2012), as well as edge pedestal region (Dickinson et al., Plasma Phys. Control. Fusion 55 (2013) 074006). However, recent results indicate that it can equally affect the electron thermal loss in conventional tokamaks (Moradi et al., Nucl. Fusion 53 (2013) 063025)) also. The mode is characterized by the even parity in A∥, and grows on the free energy provided by the electron temperature gradient. In the present work we will carry out a gyrokinetic study of the microtearing mode for NSTX parameters and compare properties of the mode in the core and edge using the nonlinear gyrokinetic electromagnetic code GEM. The scaling with collisionality in the two regimes will be studied. A preliminary comparison of the microtearing mode in local flux tube and global model of GEM will also be presented.

  2. Detailed 3D Simulation of the GEM-based detector

    NASA Astrophysics Data System (ADS)

    Bhattacharya, P.; Biswas, S.; Mohanty, B.; Majumdar, N.; Mukhopadhyay, S.

    2016-10-01

    The operation of Micro Pattern Gaseous Detectors (MPGDs) has often suffered from effects such as distortion of the electric field due to space charge, despite their widespread use in particle-physics and nuclear-physics experiments, astro-particle research, medical imaging, material science etc. To keep distortions due to space-charge at a manageable level, a lower ion feedback is required while maintaining substantial detector gain and good resolution. Thus, a proper optimization of the detector geometry, field configuration and gas mixtures are required to have a higher electron transparency and lower ion backflow. In our work, Garfield simulation framework has been adopted as a tool to evaluate the fundamental features of Gas Electron Multiplier (GEM). Our study begins with the computation of electrostatic field and its variation with different geometrical and electrical parameters using the neBEM toolkit. Different efficient algorithms have been implemented to increase the computational efficiency of the field solver. Finally, ion backflow and electron transparency of single and quadruple GEMs with different geometry and field configurations suitable for the ALICE-TPC, have been studied.

  3. The stable K0 giant star β Gem

    SciTech Connect

    Gray, David F.

    2014-12-01

    A nine-season spectroscopic study of the photosphere of β Gem (K0 III) shows this low-luminosity giant to be stable, with no effective temperature variations above ∼2 K, and no secular temperature variations over the 2002-2010 time span above 0.2 K per year. The radial-velocity variations are consistent with an orbital variation of ∼40 m s{sup –1}. The projected rotation rate is found to be 1.70 ± 0.20 km s{sup –1} with a macroturbulence dispersion of 4.53 ± 0.10 km s{sup –1}. The third-signature plot is also invariant and shows a granulation velocity gradient 20% smaller than the solar gradient. The absolute shift of the third-signature plot gives a blueshift-corrected radial velocity of 3385 ± 70 m s{sup –1}. Bisector mapping of the Fe I λ6253 line yields a flux deficit of 12% ± 1% in area, somewhat smaller than for other giants, but the shape and the position of the peak at 4.8 km s{sup –1} is consistent with other giants. All of the investigated photospheric parameters are consistent with β Gem being a low-luminosity giant in agreement with its absolute magnitude.

  4. E-GEM- European GNSS-R Environmental Monitoring

    NASA Astrophysics Data System (ADS)

    Catarino, Nuno; Bandeiras, Jorge; Peres, Tiago; Silva, Pedro; Camps, Adriano; Carreno, Hugo; Cardellach, Estel; Capron, Bertrand; Fohannessen, Johnny; Danielson, Rick; Guerriero, Leila; Pierdicca, Nazzareno; Sanchez, Nilda; Storvold, Rune; Wickert, Jens

    2016-08-01

    Earth Monitoring with GNSS signals is a promising novel area for Earth Observations systems. The increasing number of sources, together with the low level of requirements (power, size, budget, etc.) and possibility of using COTS hardware, makes these systems potentially very attractive for future space missions, making this a very attractive complementary technology to traditional active radar systems. Since the use of reflected GNSS signals was proposed in 1993, the number of research activities and scientific publications has been steadily increasing, especially in recent years, where the attention devoted to GNSS-R has increased exponentially after NASA has approved the first operational use of GNSS-R from space, the eight-satellite CYGNSS constellation.The European GNSS-R Earth Monitoring project (E- GEM, www.e-gem.eu), started in 2014, is an FP7 funded project which joins many of the European experts in the field of GNSS-R and involves ten of the top European institutions in this field. The goal of this project is quite ambitions, covering both instruments and scientific algorithms developments of for a number of applications.

  5. Proposal to revise ISC-GEM earthquake catalog (Invited)

    NASA Astrophysics Data System (ADS)

    Ishikawa, Y.

    2013-12-01

    It is important to edit the accurate earthquake catalogue for evaluating realistic disaster in the world. ISC released ISC-GEM Global Instrumental catalogue (Version 1) in 31 Jan, 2013 (Version 1.03 on 11 June). It is much better than The Centennial Catalog (Engdahl and Villaseñor, 2002). ISC used Abe's catalogue (1900-1903), Gutenberg Notepads (Abe's adaptation) (1904-1917), BAAS Bulletin (1913-1917) and ISS Bulletin (1918-1963). But, in the early 20 century not all seismic stations in Japan and Taiwan were reported to BAAS Bulletin and ISS Bulletin. We will be able to add new hypocenters to ISC-GEM using these seismological reports. And ISC-GEM adopted the cut-off magnitudes like 1900-1917: Ms≥7.5 (worldwide + smaller shallow events in stable continental areas), 1918-1959: Ms≥6¼, 1960-2009: Ms≥5.5. In this case, everyone thought that most of the deep events would not be included. The catalogue of damaging earthquakes in the world by Utsu was used to check ISC-GEM catalogue. Figure 1 shows the depth--time distribution. The upper one is from ISC-GEM and shows dense distribution after 1960, but sparse before 1940. The lower one is from Utsu catalogue and showed more events before 1920 than the upper one. Several events in and around Taiwan and Japan were selected to determine hypocenters. The other important data is station locations. Locations of seismic stations must be unified by WGS84. For example, in Taiwan, two stations were compared by my new observation as followed, TAI, TAI, 22.99520, 120.19700, 14.0 ISC TAINAN, 22.99372, 120.20522, 13 new Difference 0.00148 -0.00822 TAP, TAP, 25.03930, 121.50600, 6.0 ISC TAIPEI, 25.03755, 121.51472, new Difference 0.00175 -0.00872 The distances from ISC location to new value are about 1km and it is mainly caused by the change of coordinate system from Tokyo Datum or TWD67 to WGS84. The other case, the Shanghai station named Zikawei in China was listed in the station listing of ISC as followed, ZKW, ZKW, 31

  6. Zum Stellenwert der Unterdruck-Instillationstherapie in der Dermatologie.

    PubMed

    Müller, Cornelia Sigrid Lissi; Burgard, Barbara; Zimmerman, Monika; Vogt, Thomas; Pföhler, Claudia

    2016-08-01

    Die Methoden zur Behandlung akuter und chronischer Wunden unterliegen einer steten Weiterentwicklung, Reevaluierung und Anwendung innovativer Therapieformen. Die Vakuumtherapie zur Wundbehandlung gehört zu den etablierten Behandlungsmodalitäten. Ein innovatives Verfahren kombiniert die Vakuumtherapie mit der automatisierten, kontrollierten Zufuhr und Drainage wirkstoffhaltiger Lösungen zur topischen Wundbehandlung im Wundbett und auch wirkstofffrei durch Instillation physiologischer Kochsalzlösung (Unterdruck-Instillationstherapie). Hierdurch können die Effekte der konventionellen Vakuumtherapie mit denen der lokalen Antisepsis kombiniert werden. Hierdurch kommt es zu einer Reduktion der Wundfläche, einer Induktion von Granulationsgewebe sowie einer Reduktion der Keimbesiedelung der Wunden. Bisher publizierte Studien konzentrieren sich auf die Anwendung dieses Therapieverfahrens zur Behandlung orthopädisch-chirurgischer Krankheiten. Die Datenlage bezüglich der Vakuum-Instillationstherapie in der Dermatochirurgie beschränkt sich derzeit auf Fallberichte und Einzelfallerfahrungen. Randomisierte, prospektive Studien zum Vergleich der Vakuum-Instillationstherapie zur Behandlung dermatologischer Krankheitsbilder existieren bislang nicht. Ziele des vorliegenden Artikels sind die Vorstellung der Vakuumtherapie mit Instillation einschließlich ihres Wirkprinzips, deren mögliche Komplikationen, die Diskussion erdenklicher Kontraindikationen sowie eine Übersicht über die aktuell verfügbare Datenlage. Zusammenfassend scheint sich die Evidenz zu verdichten, dass mittels Unterdruck-Instillationstherapie sowohl einfache als auch komplizierte Wunden effizient behandelt werden können, was sich in einer deutlichen Beschleunigung der Wundgranulation mit konsekutiv früher möglichem Defektverschluss äußert.

  7. Performance of GEM Detectors in the DarkLight Experiment at LERF

    NASA Astrophysics Data System (ADS)

    Mohammed Prem Nazeer, Sahara Jesmin; DarkLight Collaboration

    2017-01-01

    The DarkLight experiment has been proposed to search for a heavy photon A' in the mass range of 10-100 MeV/c2 produced in electron-proton collisions. Phase-I of DarkLight has started to take place in 2016 at the Low Energy Recirculator Facility (LERF) at Jefferson Lab. LERF delivered a 100 MeV electron beam onto a windowless hydrogen gas target. The phase-I detector tracks leptons inside the DarkLight solenoid with a set of Gas Electron Multiplier (GEM) detectors, combined with segmented scintillators for triggering. The GEM telescope consists of four 10 × 10 cm2 triple layer GEM chambers with 2D readout strips, mounted in a slightly angled fixed frame about 12 cm tall. The GEM data are read out with analog pipeline front-end cards (APV-25) each of which can process 128 readout channels. Each GEM chamber has 250 channels for each coordinate axis, read out with two APVs on each side, resulting in 2000 readout channels for the GEM stack, processed by 16 APVs. One Multi Purpose Digitizer (MPD) module is used to read out all of the 16 APV-25 cards. The current run status of DarkLight experiment and the performance of GEMs in the experiment will be discussed. This work has been supported by NSF PHY-1436680 and PHY-1505934.

  8. Use of genetically engineered microorganisms (GEMs) for the bioremediation of contaminants.

    PubMed

    Urgun-Demirtas, Meltem; Stark, Benjamin; Pagilla, Krishna

    2006-01-01

    This paper presents a critical review of the literature on the application of genetically engineered microorganisms (GEMs) in bioremediation. The important aspects of using GEMs in bioremediation, such as development of novel strains with desirable properties through pathway construction and the modification of enzyme specificity and affinity, are discussed in detail. Particular attention is given to the genetic engineering of bacteria using bacterial hemoglobin (VHb) for the treatment of aromatic organic compounds under hypoxic conditions. The application of VHb technology may advance treatment of contaminated sites, where oxygen availability limits the growth of aerobic bioremediating bacteria, as well as the functioning of oxygenases required for mineralization of many organic pollutants. Despite the many advantages of GEMs, there are still concerns that their introduction into polluted sites to enhance bioremediation may have adverse environmental effects, such as gene transfer. The extent of horizontal gene transfer from GEMs in the environment, compared to that of native organisms including benefits regarding bacterial bioremediation that may occur as a result of such transfer, is discussed. Recent advances in tracking methods and containment strategies for GEMs, including several biological systems that have been developed to detect the fate of GEMs in the environment, are also summarized in this review. Critical research questions pertaining to the development and implementation of GEMs for enhanced bioremediation have been identified and posed for possible future research.

  9. Large size GEM for Super Bigbite Spectrometer (SBS) polarimeter for Hall A 12 GeV program at JLab

    NASA Astrophysics Data System (ADS)

    Gnanvo, Kondo; Liyanage, Nilanga; Nelyubin, Vladimir; Saenboonruang, Kiadtisak; Sacher, Seth; Wojtsekhowski, Bogdan

    2015-05-01

    We report on the R&D effort in the design and construction of a large size Gas Electron Multiplier (GEM) for the Proton Polarimeter Back Tracker (BT) of the Super Bigbite Spectrometer (SBS) in Hall A at Thomas Jefferson National Laboratory (JLab). The SBS BT GEM trackers consist of two sets of five large GEM chambers of size 60×200 cm2. The GEM chamber is a vertical stack of four GEM modules, each with an active area of 60×50 cm2. We have built and tested several prototypes and the construction of GEM modules for SBS BT is ongoing. We describe in this paper the design and construction of the GEM module prototype as well as the preliminary results on performance from tests carried out in our detector lab and during test beam at Fermi National Laboratory (Fermilab).

  10. Characterization of a scintillating GEM detector with low energy x-rays.

    PubMed

    Seravalli, E; de Boer, M R; Geurink, F; Huizenga, J; Kreuger, R; Schippers, J M; van Eijk, C W E

    2008-11-07

    A two-dimensional position-sensitive dosimetry system based on a scintillating gas detector is being developed with the aim of using it for pre-treatment verification of dose distributions in charged particle therapy. The dosimetry system consists of a chamber filled with an Ar/CF(4) scintillating gas mixture, inside which two cascaded gas electron multipliers (GEMs) are mounted. A GEM is a thin kapton foil with copper cladding structured with a regular pattern of sub-mm holes. In such a system, light quanta are emitted by the scintillating gas mixture during the electron avalanches in the GEM holes when radiation traverses the detector. The light intensity distribution is proportional to the energy deposited in the detector's sensitive volume by the beam. In the present work, we investigated the optimization of the scintillating GEM detector light yield. The light quanta are detected by means of a CCD camera or a photomultiplier tube coupled to a monochromator. The GEM charge signal is measured simultaneously. We have found that with 60 microm diameter double conical GEM holes, a brighter light signal and a higher electric signal are obtained than with 80 microm diameter holes. With an Ar + 8% CF(4) volume concentration, the highest voltage across the GEMs and the largest light and electric signals were reached. Moreover, we have found that the emission spectrum of Ar/CF(4) is independent of (1) the voltages applied across the GEMs, (2) the x-ray beam intensity and (3) the GEM hole diameter. On the other hand, the ratio of Ar to CF(4) peaks in the spectrum changes when the concentration of the latter gas is varied.

  11. Accuracy of the GEM-T2 geopotential from Geosat and ERS 1 crossover altimetry

    NASA Astrophysics Data System (ADS)

    Wagner, C. A.; Klokočník, J.

    1994-05-01

    Extensive analyses of altimetrically determined sea height differences at crossovers have been used to assess the accuracy of the GEM-T2 geopotential. The orbits used were determined with GEM-T2 for Geosat in its 17-day Exact Repeat Mission (ERM) in 1986-1989 and ERS 1 in both its 3-day ERM in 1991-1992 and its 35-day ERM in 1992. The data examined are completely independent of the data used in GEM-T2's development though GEM-T2 had considerable use of Doppler tracking information on Geosat. The test of the radial accuracy of the ERS 1 orbit (98.5° inclination) is especially significant because it is not ``close'' to any other orbit well represented in GEM-T2. The assessment consists of a comparison of observed mean height differences at thousands of distinct geographic locations with error projections from the GEM-T2 covariance matrix which was estimated from other data sources. This first comprehensive, independent test of the purely radial accuracy of an orbit-geopotential model clearly shows that the covariant predictions for GEM-T2 are broadly reliable for this purpose. Thus, the agreement of crossover predictions and observations suggests that the total radial errors for these ERMs, due to only to GEM-T2 (but excluding the effects of initial state error) are about 23 cm for Geosat and 115 cm (rms) for ERS 1. However, there is little detailed agreement of measurements and predictions for ERS 1 and only partial agreement in detail for Geosat. Our 30,000 mean crossover discrepancies for Geosat (derived from ERM cycles 1-44) are also shown to reduce substantially the crossover height differences in cycles 45-61, almost exactly as predicted if these are the true GEM-T2 errors for this orbit.

  12. Magnetopause structure and dynamics: Issues for GEM (geospace environment modeling)

    SciTech Connect

    Elphic, R.C.

    1989-01-01

    Recent multi-spacecraft observations of the magnetopause have allowed us to establish its structure and dynamical behavior. The magnetopause current sheet is thicker than expected, often ten magnetosheath ion gyroradii or more. One very important result has been the confirmation of magnetic reconnection in both its quasi- steady and transient forms. A boundary layer of magnetosheath-like plasma is often, but not always, observed earthward of the magnetopause current layer. There is considerable small-scale magnetic structure within the current layer, suggesting the presence of filamentary currents much smaller than an ion gyroradius. Such micro-structure may be important in particle diffusion and, hence, reconnection. There are many outstanding questions, among them: How does the low latitude boundary layer form. Why is the magnetopause current layer so thick. What is the detailed structure and topology of FTEs. How are quasi-steady and transient reconnection related. The GEM program may help us address these issues. 18 refs., 9 figs.

  13. Gem-quality Turkish purple jade: Geological and mineralogical characteristics

    NASA Astrophysics Data System (ADS)

    Hatipoğlu, Murat; Başevirgen, Yasemin; Chamberlain, Steven C.

    2012-02-01

    In the Harmancık-Bursa region of the western Anatolia (Turkey), an extensive contact metamorphic aureole at the border between the Late Mesozoic coherent metaclastic rocks of blueschist facies and the Early Senozoic intrusive granodiorite stock hosts an interesting and unique gem material with a mineral assemblage consisting mainly of jadeite, quartz, orthoclase, epidote, chloritoid, and phlogopite as identified by X-ray diffraction spectroscopy and polarized-light microscopy. In addition, chemical analyses performed with X-ray fluorescence and inductive-coupled plasma-atomic emission spectroscopy show that the mass of the metamorphic aureole has a silica-rich, calc-alkaline chemical content. Therefore, some rock building elements (such as Al, Ca, Na, K, P, Sr, and B of which characterize an acidic-neutral rock formation) and trace elements (such as Fe, Cr, Mn, Be, Cu, Ga, La, Ni, Pb, and Zn) are remarkable high ratios. Pale purple-colored gem material of this composition appears to be unique to Turkey, also is only found in one narrow provenance in Turkey. Therefore, it is specially called "Turkish (and/or Anatolian) purple jade" on the worldwide gem market. Even though the mineral jadeite is the principal constituent, 40% by volume as determined with petrographic thin-section examination under a polarized-light microscope, the material cannot be considered pure jadeite. Specific gravity measurements of the jade using a hydrostatic balance confirm that it has a heterogeneous structure. The measured average specific gravity of 3.04, is significantly lower than the normal range for characterized jadeites of 3.24-3.43. Turkish purple jade samples were examined in detail using dispersive confocal micro-Raman spectroscopy (DCμRS) as well as other well-known analytical methods. The resulting strong micro-Raman bands that peaked at 1038, 984, 697, 571, 521, 464, 430, 372, 326, 307, 264, and 201 cm -1 are characteristics of the Turkish purple jade. The first most

  14. A spectrophotometric study of IR Gem at outburst and quiescence

    NASA Technical Reports Server (NTRS)

    Feinswog, Laurie; Szkody, Paula; Garnavich, Peter

    1988-01-01

    Optical spectra with 2.5-A resolution obtained throughout the orbit of IR Gem during a five-day sequence beginning at an outburst state and ending at quiescence are compared with B magnitude and IUE spectra obtained throughout other quiescent-state orbits. No obvious second component is found in the emission lines. In contrast to previous results, little high-excitation He II 4686-A emission is noted, and no variation of the equivalent widths of the Balmer emission is found over the orbital cycle. The results suggest that large changes in the excitation level and in the modulation from a heated zone can take place during different quiescent states, possibly due to the interoutburst phase.

  15. Genomic gems: SINE RNAs regulate mRNA production.

    PubMed

    Ponicsan, Steven L; Kugel, Jennifer F; Goodrich, James A

    2010-04-01

    Mammalian short interspersed elements (SINEs) are abundant retrotransposons that have long been considered junk DNA; however, RNAs transcribed from mouse B2 and human Alu SINEs have recently been found to control mRNA production at multiple levels. Upon cell stress B2 and Alu RNAs bind RNA polymerase II (Pol II) and repress transcription of some protein-encoding genes. Bi-directional transcription of a B2 SINE establishes a boundary that places the growth hormone locus in a permissive chromatin state during mouse development. Alu RNAs embedded in Pol II transcripts can promote evolution and proteome diversity through exonization via alternative splicing. Given the diverse means by which SINE encoded RNAs impact production of mRNAs, this genomic junk is proving to contain hidden gems.

  16. Synthesis of enones, pyrazolines and pyrrolines with gem-difluoroalkyl side chains

    PubMed Central

    El Dine, Assaad Nasr; Khalaf, Ali; Grée, Danielle; Tasseau, Olivier; Fares, Fares; Jaber, Nada; Lesot, Philippe

    2013-01-01

    Summary Starting from easily accessible gem-difluoropropargylic derivatives, a DBU-mediated isomerisation affords enones in fair yields with a gem-difluoroalkyl chain. These derivatives were used to prepare pyrazolines and pyrrolines with the desired gem-difluoroalkyl side chain by cyclocondensations in good yields and with excellent stereoselectivity. A one-pot process was also successfully developed for these sequential reactions. By carrying out various types of Pd-catalyzed coupling reactions for compounds with a p-bromophenyl substituent a route to focused chemical libraries was demonstrated. PMID:24204405

  17. Editorial: Reviewer selection process and new areas of expertise in GEMS

    NASA Astrophysics Data System (ADS)

    Liemohn, Michael W.; Balikhin, Michael; Kepko, Larry; Rodger, Alan; Wang, Yuming

    2016-06-01

    One method of selecting potential reviewers for papers submitted to the Journal of Geophysical Research Space Physics is to filter the user database within the Geophysical Electronic Manuscript System (GEMS) by areas of expertise. The list of these areas in GEMS can be self selected by users in their profile settings. The Editors have added 18 new entries to this list, an increase of 33% more than the previous 55 entries. All space physicists are strongly encouraged to update their profile settings in GEMS, especially their areas of expertise selections, and details of how to do this are provided.

  18. Grundlagen der Organisationsgestaltung

    NASA Astrophysics Data System (ADS)

    Spath, Dieter; Koch, Steffen

    In diesem Kapitel werden Grundlagen der Organisationsgestaltung dargestellt. Es scheint nahe liegend, diese Inhalte wie in einem Lehrbuch aufzubereiten. Schließlich handelt es sich um grundlegende Inhalte. Die Neufassung dieses Abschnitts ist aber stärker für Verantwortliche in Unternehmen geschrieben und weniger wissenschaftlich geprägt. Das "Lehrbuchwissen“ wird daher bewusst knapp gehalten. Das betrifft z.B. die Klärung des Organisationsbegriffes und die Fragen nach den Zielsetzungen und den Gestaltungsbereichen von Organisation. Stattdessen widmet sich das Kapitel ausführlicher den Fragen, ob es Trends in der Organisationsgestaltung gibt, welche wichtigen Einflussgrößen existieren und welche übergeordneten und beständigen Leitlinien es gibt.

  19. Haftung in der Medizintechnik

    NASA Astrophysics Data System (ADS)

    Müller, Ute; Lücker, Volker

    Die Unversehrtheit von Leib und Leben ist das größte Rechtsgut unserer Gesellschaft. Dies macht schon das Grundgesetz in Art. 2 Abs. Satz 1 GG deutlich. Die Öffentlichkeit zeigt daher größtes Interesse an Produkten, welche der Gesundheit dienen und Leben retten oder erhalten. Dieses Interesse gilt einerseits der Entwicklung und Bereitstellung leistungsfähiger Medizinprodukte, andererseits zielt es auf deren Sicherheit. Um vor allem letztere zu gewährleisten, nimmt der Gesetzgeber alle Beteiligten in die Pflicht, die auftretenden Risiken auf das geringstmögliche Maß zu begrenzen. Dies spiegelt sich in den rechtlichen Vorgaben ebenso wie in den Haftungsfolgen, die bei Verletzung dieser Vorgaben greifen, wieder. Diese Folgen können dementsprechend gravierend ausfallen, von Geldstrafen bis zu Freiheitsstrafen, von Bußgeldzahlungen bis zum Schadenersatzansprüchen, die schnell ein wirtschaftliches Aus bedeuten können. Den Beteiligten, allen voran den Herstellern, muss deshalb daran gelegen sein, nicht nur die Produkte, sondern auch deren Sicherheit stetig weiter zu entwickeln.

  20. Evaluation der zentralen TUM-Lernplattform

    NASA Astrophysics Data System (ADS)

    Schulze, Elvira; Baume, Matthias; Graf, Stephan; Gergintchev, Ivan

    Die Notwendigkeit der Qualitätssicherung und -kontrolle für innovative universitäre Lehr-/Lernszenarien ist in der Praxis unbestritten. Die Wirksamkeit der Einführung der zentralen Lernplattform CLIX Campus der imc AG an der TUM wurde mittels quantitativer und qualitativer Evaluation überprüft. Als statistische Bewertungsgrundlage wurde der Erreichungsgrad bestimmter Projektziele herangezogen. Aufbauend auf den theoretischen Grundlagen der Evaluation von Bildungsangeboten gibt diese Studie Aufschluss über die Ergebnisse der Datenerhebungen sowie die Einschätzung der Plattform aus Nutzersicht und belegt die wesentliche Bedeutung der durchgängigen IT-Infrastruktur und speziell der einheitlichen Verfügbarkeit der eLearning Angebote.

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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

  2. Greenhouse Gas Emissions Model (GEM) for Medium- and Heavy-Duty Vehicle Compliance

    EPA Pesticide Factsheets

    EPA’s Greenhouse Gas Emissions Model (GEM) is a free, desktop computer application that estimates the greenhouse gas (GHG) emissions and fuel efficiency performance of specific aspects of heavy-duty vehicles.

  3. Discriminating cosmic muons and X-rays based on rise time using a GEM detector

    NASA Astrophysics Data System (ADS)

    Wu, Hui-Yin; Zhao, Sheng-Ying; Wang, Xiao-Dong; Zhang, Xian-Ming; Qi, Hui-Rong; Zhang, Wei; Wu, Ke-Yan; Hu, Bi-Tao; Zhang, Yi

    2016-08-01

    Gas electron multiplier (GEM) detectors have been used in cosmic muon scattering tomography and neutron imaging over the last decade. In this work, a triple GEM device with an effective readout area of 10 cm × 10 cm is developed, and a method of discriminating between cosmic muons and X-rays based on rise time is tested. The energy resolution of the GEM detector is tested by 55Fe ray source to prove the GEM detector has a good performance. Analysis of the complete signal-cycles allows us to get the rise time and pulse heights. The experiment result indicates that cosmic muons and X-rays can be discriminated with an appropriate rise time threshold. Supported by National Natural Science Foundation of China (11135002, 11275235, 11405077, 11575073)

  4. Physics Studies for the CMS muon system upgrade with triple-GEM detectors

    NASA Astrophysics Data System (ADS)

    Caputo, C.

    2014-12-01

    The CMS collaboration considers upgrading the muon forward region with Gas Electron Multiplier (GEM) chambers, which are able to handle the extreme particle rates expected in this region along with a high spatial resolution. This allows to combine tracking and triggering capabilities, resulting in a lower trigger threshold along with improved muon identification and track reconstruction. In the last year the GEM project took a major leap forward by integrating triple-GEM chambers in the official CMS software, allowing physics studies to be carried out. Several benchmark analyses have been studied for the impact of such detector upgrade on the physics performance. In this contribution the status of the CMS upgrade project with the usage of GEM detector will be reviewed, discussing the trigger, the muon reconstruction performance, and the impact on the physics analyses.

  5. Thermal neutron response of a boron-coated GEM detector via GEANT4 Monte Carlo code.

    PubMed

    Jamil, M; Rhee, J T; Kim, H G; Ahmad, Farzana; Jeon, Y J

    2014-10-22

    In this work, we report the design configuration and the performance of the hybrid Gas Electron Multiplier (GEM) detector. In order to make the detector sensitive to thermal neutrons, the forward electrode of the GEM has been coated with the enriched boron-10 material, which works as a neutron converter. A total of 5×5cm(2) configuration of GEM has been used for thermal neutron studies. The response of the detector has been estimated via using GEANT4 MC code with two different physics lists. Using the QGSP_BIC_HP physics list, the neutron detection efficiency was determined to be about 3%, while with QGSP_BERT_HP physics list the efficiency was around 2.5%, at the incident thermal neutron energies of 25meV. The higher response of the detector proves that GEM-coated with boron converter improves the efficiency for thermal neutrons detection.

  6. Fine-pitch glass GEM for high-resolution X-ray imaging

    NASA Astrophysics Data System (ADS)

    Fujiwara, T.; Mitsuya, Y.; Toyokawa, H.

    2016-12-01

    We have developed a fine-pitch glass gas electron multiplier (G-GEM) for high-resolution X-ray imaging. The fine-pitch G-GEM is made of a 400 μm thick photo-etchable glass substrate with 150 μm pitch holes. It is fabricated using the same wet etching technique as that for the standard G-GEM. In this work, we present the experimental results obtained with a single fine-pitch G-GEM with a 50 × 50 mm2 effective area. We recorded an energy resolution of 16.2% and gas gain up to 5,500 when the detector was irradiated with 5.9 keV X-rays. We present a 50 × 50 mm2 X-ray radiograph image acquired with a scintillation gas and optical readout system.

  7. Beam test results of a wedge-shaped MSGC+GEM detector at CERN

    NASA Astrophysics Data System (ADS)

    Benhammou, Y.; Blaes, R.; Brom, J. M.; Drouhin, F.; Fontaine, J. C.; Huss, D.; Jeanneau, F.; Mack, V.; Ripp-Baudot, I.; Schwaller, B.; Zghiche, A.

    2000-03-01

    Test results of Gas Electron Multiplier coupled with a MSGC in October 1997 are described. Several studies have been realized in a beam of Minimum Ionizing Particles (100 GeV/ c muons): signal-to-noise curves for different GEM amplifications and drift fields, spatial resolution, efficiency and cluster size. GEM acts as a simple added element with little disturbance of the system (on the electronics or no degradation of the spatial resolution).

  8. Geostationary Environment Monitoring Spectrometer (gems) Over the Korea Peninsula and Asia-Pacific Region

    NASA Astrophysics Data System (ADS)

    Lasnik, J.; Stephens, M.; Baker, B.; Randall, C.; Ko, D. H.; Kim, S.; Kim, Y.; Lee, E. S.; Chang, S.; Park, J. M.; SEO, S. B.; Youk, Y.; Kong, J. P.; Lee, D.; Lee, S. H.; Kim, J.

    2014-12-01

    Introduction: The Geostationary Environment Monitoring Spectrometer (GEMS) is one of two instruments manifested aboard the South Korean Geostationary Earth Orbit KOrea Multi-Purpose SATellite-2B (GEO-KOMPSAT-2B or GK2B), which is scheduled to launch in 2018. Jointly developed/built by KARI and Ball Aerospace, GEMS is a geostationary UV-Vis hyperspectral imager designed to monitor trans-boundary tropospheric pollution events over the Korean peninsula and Asia-Pacific region. The spectrometer provides high temporal and spatial resolution (3.5 km N/S by 7.2 km E/W) measurements of ozone, its precursors, and aerosols. Over the short-term, hourly measurements by GEMS will improve early warnings for potentially dangerous pollution events and monitor population exposure. Over the 10-year mission-life, GEMS will serve to enhance our understanding of long-term climate change and broader air quality issues on both a regional and global scale. The GEMS sensor design and performance are discussed, which includes an overview of measurement capabilities and the on-orbit concept of operations. GEMS Sensor Overview: The GEMS hyperspectral imaging system consists of a telescope and Offner grating spectrometer that feeds a single CCD detector array. A spectral range of 300-500 nm and sampling of 0.2 nm enables NO2, SO2, HCHO, O3, and aerosol retrieval. The GEMS field of regard (FOR), which extends from 5°S to 45°N in latitude and 75°E to 145°E in longitude, is operationally achieved using an onboard two-axis scan mirror. On-orbit, the radiometric calibration is maintained using solar measurements, which are performed using two onboard diffusers: a working diffuser that is deployed routinely for the purpose of solar calibration, and a reference diffuser that is deployed sparingly for the purpose of monitoring working diffuser performance degradation.

  9. The application of a monolithic triphenylphosphine reagent for conducting Ramirez gem-dibromoolefination reactions in flow

    PubMed Central

    Roper, Kimberley A; Berry, Malcolm B

    2013-01-01

    Summary The application of a monolithic form of triphenylphosphine to the Ramirez gem-dibromoolefination reaction using flow chemistry techniques is reported. A variety of gem-dibromides were synthesised in high purity and excellent yield following only removal of solvent and no further off-line purification. It is also possible to perform the Appel reaction using the same monolith and the relationship between the mechanisms of the two reactions is discussed. PMID:24062843

  10. BoNuS: Development and Use of a Radial TPC using Cylindrical GEMs

    SciTech Connect

    Howard Fenker; Nathan Baillie; Peter Bradshaw; S. Bultmann; Stephen Bueltmann; Volker Burkert; Michael Christy; Gail Dodge; Dipangkar Dutta; Rolf Ent; Josh Evans; Robert Fersch; Kevin Giovanetti; Keith Griffioen; Mikayel Ispiryan; Chandana Jayalath; Narbe Kalantarians; Cynthia Keppel; Sebastian Kuhn; Gabriel Niculescu; Maria-Ioana Niculescu; Svyatoslav Tkachenko; Vladas Tvaskis; Jixie Zhang

    2007-11-28

    To provide new access to information about nucleon structure from electron-neutron interactions, a specialized aystem of target and detector was developed at Jefferson Lab. It allows identification and measurement of spectator protons produced in e X scattering events. The detector is a radial time-projection chamber optimized for the acceptance of low-momentum protons. Gas gain is provided by three cascaded curved Gas Electron Multipliers (GEMs), the first application of GEMs in any configuration other than flat.

  11. Public release of the ISC-GEM Global Instrumental Earthquake Catalogue (1900-2009)

    USGS Publications Warehouse

    Storchak, Dmitry A.; Di Giacomo, Domenico; Bondára, István; Engdahl, E. Robert; Harris, James; Lee, William H.K.; Villaseñor, Antonio; Bormann, Peter

    2013-01-01

    The International Seismological Centre–Global Earthquake Model (ISC–GEM) Global Instrumental Earthquake Catalogue (1900–2009) is the result of a special effort to substantially extend and improve currently existing global catalogs to serve the requirements of specific user groups who assess and model seismic hazard and risk. The data from the ISC–GEM Catalogue would be used worldwide yet will prove absolutely essential in those regions where a high seismicity level strongly correlates with a high population density.

  12. Development of GEM-Based Digital Hadron Calorimetry Using the SLAC KPiX Chip

    SciTech Connect

    White, A.; /Texas U., Arlington /Washington U., Seattle /Unlisted /SLAC

    2012-04-12

    The development of Digital Hadron Calorimetry for the SiD detector Concept for the International Linear Collider is described. The jet energy requirements of the ILC physics program are discussed. The concept of GEM-based digital hadron calorimetry is presented, followed by a description of, and results from, prototype detectors. Plans are described for the construction of 1m{sup 2} GEM-DHCAL planes to be tested as part of a future calorimeter stack.

  13. The Triple GEM Detector Control System for CMS forward muon spectrometer upgrade

    NASA Astrophysics Data System (ADS)

    Ahmed, W.; Abbaneo, D.; Abbrescia, M.; Abdelalim, A. A.; Abi. Akl, M.; Acosta, D.; Ahmad, A.; Ahmed, W.; Aleksandrov, A.; Aly, R.; Altieri, P.; Asawatangtrakuldee, C.; Aspell, P.; Assran, Y.; Awan, I.; Bally, S.; Ban, Y.; Banerjee, S.; Barashko, V.; Barria, P.; Bencze, G.; Beni, N.; Benussi, L.; Bhopatkar, V.; Bianco, S.; Bos, J.; Bouhali, O.; Holme, O.; Braghieri, A.; Braibant, S.; Buontempo, S.; Khan, S. A.; Calabria, C.; Caponero, M.; Caputo, C.; Cassese, F.; Castaneda, A.; Cauwenbergh, S.; Cavallo, F. R.; Celik, A.; Choi, M.; Choi, S.; Christiansen, J.; Cimmino, A.; Colafranceschi, S.; Colaleo, A.; Conde Garcia, A.; Czellar, S.; Dabrowski, M. M.; Lentdecker, G. De.; De Oliveira, R.; de Robertis, G.; Dildick, S.; Dorney, B.; Elmetenawee, W.; Endroczi, G.; Errico, F.; Fenyvesi, A.; Ferry, S.; Furic, I.; Giacomelli, P.; Gilmore, J.; Golovtsov, V.; Guiducci, L.; Guilloux, F.; Gutierrez, A.; Hadjiiska, R. M.; Hassan, A.; Hauser, J.; Hoepfner, K.; Hohlmann, M.; Hoorani, H.; Shah, A. H.; Iaydjiev, P.; Jeng, Y. G.; Kamon, T.; Karchin, P.; Korytov, A.; Krutelyov, S.; Kumar, A.; Kim, H.; Lenzi, T.; Litov, L.; Loddo, F.; Madorsky, A.; Maerschalk, T.; Maggi, M.; Magnani, A.; Mal, P. K.; Mandal, K.; Marchioro, A.; Marinov, A.; Majumdar, N.; Merlin, J. A.; Mitselmakher, G.; Mohanty, A. K.; Mohapatra, A.; Molnar, J.; Muhammad, S.; Mukhopadhyay, S.; Naimuddin, M.; Nuzzo, S.; Oliveri, E.; Pant, L. M.; Paolucci, P.; Park, I.; Passeggio, G.; Pavlov, B.; Philipps, B.; Piccolo, D.; Postema, H.; Puig. Baranac, A.; Radi, A.; Radogna, R.; Raffone, G.; Ranieri, A.; Rashevski, G.; Riccardi, C.; Rodozov, M.; Rodrigues, A.; Ropelewski, L.; RoyChowdhury, S.; Ryu, G.; Ryu, M. S.; Safonov, A.; Salva, S.; Saviano, G.; Sharma, A.; Sharma, R.; Shopova, M.; Sturdy, J.; Sultanov, G.; Swain, S. K.; Szillasi, Z.; Talvitie, J.; Tatarinov, A.; Tuuva, T.; Tytgat, M.; Vai, I.; Van Stenis, M.; Venditti, R.; Verhagen, E.; Verwilligen, P.; Vitulo, P.; Volkov, S.; Vorobyev, A.; Wang, D.; Wang, M.; Yang, U.; Yang, Y.; Yonamine, R.; Zaganidis, N.; Zenoni, F.; Zhang, A.

    2017-02-01

    The CMS experiment at LHC will upgrade its forward muon spectrometer by incorporating Triple-GEM detectors. This upgrade referred to as GEM Endcap (GE1/1), consists of adding two back-to-back Triple-GEM detectors in front of the existing Cathode Strip Chambers (CSC) in the innermost ring of the endcap muon spectrometer. Before the full installation of 144 detectors in 2019–2020, CMS will first install ten single chamber prototypes during the early 2017. This pre-installation is referred as the slice test. These ten detectors will be read-out by VFAT2 chips [1]. On-detector there is also a FPGA mezzanine card which sends VFAT2 data optically to the μTCA back-end electronics. The correct and safe operation of the GEM system requires a sophisticated and powerful online Detector Control System, able to monitor and control many heterogeneous hardware devices. The DCS system developed for the slice test has been tested with CMS Triple-GEM detectors in the laboratory. In this paper we describe the newly developed DCS system and present the first results obtained in the GEM assembly and quality assurance laboratory.

  14. Properties of the flight model gas electron multiplier for the GEMS mission

    NASA Astrophysics Data System (ADS)

    Takeuchi, Yoko; Kitaguchi, Takao; Hayato, Asami; Tamagawa, Toru; Iwakiri, Wataru; Asami, Fumi; Yoshikawa, Akifumi; Kaneko, Kenta; Enoto, Teruaki; Black, Kevin; Hill, Joanne E.; Jahoda, Keith

    2014-07-01

    We present the gain properties of the gas electron multiplier (GEM) foil in pure dimethyl ether (DME) at 190 Torr. The GEM is one of the micro pattern gas detectors and it is adopted as a key part of the X-ray polarimeter for the GEMS mission. The X-ray polarimeter is a time projection chamber operating in pure DME gas at 190 Torr. We describe experimental results of (1) the maximum gain the GEM can achieve without any discharges, (2) the linearity of the energy scale for the GEM operation, and (3) the two-dimensional gain variation of the active area. First, our experiment with 6.4 keV X-ray irradiation of the whole GEM area demonstrates that the maximum effective gain is 2 x 104 with the applied voltage of 580 V. Second, the measured energy scale is linear among three energies of 4.5, 6.4, and 8.0 keV. Third, the two-dimensional gain mapping test derives the standard deviation of the gain variability of 7% across the active area.

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

    NASA Technical Reports Server (NTRS)

    Takeuchi, Yoko; Kitaguchi, Takao; Hayato, Asami; Tamagawa, Toru; Iwakiri, Wataru; Asami, Fumi; Yoshikawa, Akifumi; Kaneko, Kenta; Enoto, Teruaki; Black, Kevin; Hill, Joanne E.; Jahoda, Keith

    2014-01-01

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

  16. iGEMS: an integrated model for identification of alternative exon usage events

    PubMed Central

    Sood, Sanjana; Szkop, Krzysztof J.; Nakhuda, Asif; Gallagher, Iain J.; Murie, Carl; Brogan, Robert J.; Kaprio, Jaakko; Kainulainen, Heikki; Atherton, Philip J.; Kujala, Urho M.; Gustafsson, Thomas; Larsson, Ola; Timmons, James A.

    2016-01-01

    DNA microarrays and RNAseq are complementary methods for studying RNA molecules. Current computational methods to determine alternative exon usage (AEU) using such data require impractical visual inspection and still yield high false-positive rates. Integrated Gene and Exon Model of Splicing (iGEMS) adapts a gene-level residuals model with a gene size adjusted false discovery rate and exon-level analysis to circumvent these limitations. iGEMS was applied to two new DNA microarray datasets, including the high coverage Human Transcriptome Arrays 2.0 and performance was validated using RT-qPCR. First, AEU was studied in adipocytes treated with (n = 9) or without (n = 8) the anti-diabetes drug, rosiglitazone. iGEMS identified 555 genes with AEU, and robust verification by RT-qPCR (∼90%). Second, in a three-way human tissue comparison (muscle, adipose and blood, n = 41) iGEMS identified 4421 genes with at least one AEU event, with excellent RT-qPCR verification (95%, n = 22). Importantly, iGEMS identified a variety of AEU events, including 3′UTR extension, as well as exon inclusion/exclusion impacting on protein kinase and extracellular matrix domains. In conclusion, iGEMS is a robust method for identification of AEU while the variety of exon usage between human tissues is 5–10 times more prevalent than reported by the Genotype-Tissue Expression consortium using RNA sequencing. PMID:27095197

  17. van der Waals torque

    NASA Astrophysics Data System (ADS)

    Esquivel-Sirvent, Raul; Schatz, George

    2014-03-01

    The theory of generalized van der Waals forces by Lifshtz when applied to optically anisotropic media predicts the existence of a torque. In this work we present a theoretical calculation of the van der Waals torque for two systems. First we consider two isotropic parallel plates where the anisotropy is induced using an external magnetic field. The anisotropy will in turn induce a torque. As a case study we consider III-IV semiconductors such as InSb that can support magneto plasmons. The calculations of the torque are done in the Voigt configuration, that occurs when the magnetic field is parallel to the surface of the slabs. The change in the dielectric function as the magnetic field increases has the effect of decreasing the van der Waals force and increasing the torque. Thus, the external magnetic field is used to tune both the force and torque. The second example we present is the use of the torque in the non retarded regime to align arrays of nano particle slabs. The torque is calculated within Barash and Ginzburg formalism in the nonretarded limit, and is quantified by the introduction of a Hamaker torque constant. Calculations are conducted between anisotropic slabs of materials including BaTiO3 and arrays of Ag nano particles. Depending on the shape and arrangement of the Ag nano particles the effective dielectric function of the array can be tuned as to make it more or less anisotropic. We show how this torque can be used in self assembly of arrays of nano particles. ref. R. Esquivel-Sirvent, G. C. Schatz, Phys. Chem C, 117, 5492 (2013). partial support from DGAPA-UNAM.

  18. GEM*STAR: Time for an Alternative Way Forward

    NASA Astrophysics Data System (ADS)

    Vogelaar, R. Bruce

    2011-10-01

    The presumption that nuclear reactors will retain their role in global energy production is constantly being challenged - even more so following recent events at Fukushima. Nuclear energy, despite being ``green,'' has inexorably been coupled in the public mind with three paramount concerns: safety, weapons proliferation, and waste (and then ultimately cost). Over the past four decades, the safety of deployed fleets has greatly improved, yet the capital and political costs of a ``nuclear energy option'' appear insurmountable in several countries. The US approach to civilian nuclear energy has become deeply entrenched, first through choices made by the military, and then by the deployed nuclear reactor fleet. This extends to the research agencies as well, to the point where basic sciences and nuclear energy operate in separate spheres. But technologies and priorities have changed, and the time has arrived where a transformative re-think of nuclear energy is not only possible, but urgent. And nuclear physicists are uniquely positioned to accomplish this. This talk will show that by asking, and answering,``what would an accelerator-driven civilian nuclear energy program look like,'' ADNA Corporation's GEM*STAR design directly addresses all three fundamental concerns: safety, proliferation, and waste - and also the final hurdle: cost. GEM*STAR is not an ``add-on'' (to either Project-X, or GEN III+), but rather a base-line energy production capacity, for either electricity or transport fuel production. It integrates and advances the molten-salt reactor technology developed at ORNL, the MW beam accelerator technologies developed by basic sciences, and a reactor/target design optimized for accelerator driven-systems. The results include: the ability to use LWR spent fuel without reprocessing or additional waste; the ability to use natural uranium; no critical mass ever present; orders-of-magnitude less volatile radioactivity in the core; more efficient use of, and deeper

  19. Quantenphysikalischer Ursprung der Eichidee

    NASA Astrophysics Data System (ADS)

    Bopp, Fritz

    Betrachtet man die Quantenphysik als Zusammenspiel von elementaren Erzeugungs- und Vernichtungsprozessen, so sind Eichfeldtheorien nicht nur möglich, sondern auch notwendig. Die komplex konjugierten Phasenfaktoren jedes Paares von Erzeugungs- und Vernichtungsoperatoren sind nämlich. willkürlich wählbar. Darum müssen Quantenfeldtheorien vollständig phaseninvariant sein. Das ist ohne Eichfelder nicht möglich.Dem steht im Wege, daß die Diracgleichung nicht einmal global vollständig phaseninvariant ist. Multipliziert man nämlich die Komponenten der Erzeugungs- und Vernichtungsoperatoren mit verschiedenen konstanten Phasenfaktoren, so ändern sich die Diracmatrizen. Nur die Diracschen Vertauschungsrelationen bleiben invariant. Doch sind die Diracgleichungen vor und nach der Transformation physikalisch äquivalent. Man kann also sagen: Systeme freier Fermionen werden erst durch die Klasse aller äquivalenten Diracgleichungen vollständig dargestellt.Da die Diracschen Vertauschungsrelationen gegen beliebige unitäre Transformationen invariant sind, ist die Klasse äquivalenter Diracgleichungen U 4-invariant. Unitäre Diagonalmatrizen liefern willkürliche Phasentransformationen der Spinorkomponenten, so daß die zur Gruppe U 4 gehörigen Eichfelder zu eine allgemein phaseninvarianten Theorie führen. Sie ist so eng mit der QED verwandt, daß wir von einer erweiterten Quantenelektrodynamik, EQE, sprechen können.Hier soll nur gezeigt werden, daß die EQE existiert. Dabei liefert die invariante Untergruppe U 1 von U 4 die QED. Die komplementäre Untergruppe SU 4 umschließt vier Untergruppen SU 3, drei Untergruppen O 4 und sechs Untergruppen SU 2. Letztere könnten den drei Paaren von Quarks und den drei Paaren von Leptonen entsprechen, wobei sich die Quarkpaare zu einer Gruppe SU 3 zusammenschließen. Mehr als zweimal drei Paare von elementaren Fermionen gibt es in der EQE nicht. Sie wird zwar kaum mit der vereinigten QED und QCD identisch sein. Doch sollte sie

  20. Zeit im Wandel der Zeit.

    NASA Astrophysics Data System (ADS)

    Aichelburg, P. C.

    Contents: Einleitung(P. C. Aichelburg). 1. Über Zeit, Bewegung und Veränderung (Aristoteles). 2. Ewigkeit und Zeit (Plotin). 3. Was ist die Zeit? (Augustinus). 4. Von der Zeit (Immanuel Kant). 5. Newtons Ansichten über Zeit, Raum und Bewegung (Ernst Mach). 6. Über die mechanische Erklärung irreversibler Vorgänge (Ludwig Boltzmann). 7. Das Maß der Zeit (Henri Poincaré). 8. Dauer und Intuition (Henri Bergson). 9. Die Geschichte des Unendlichkeitsproblems (Bertrand Russell). 10. Raum und Zeit (Hermann Minkowski). 11. Der Unterschied von Zeit und Raum (Hans Reichenbach). 12. Newtonscher und Bergsonscher Zeitbegriff (Norbert Wiener). 13. Die Bildung des Zeitbegriffs beim Kinde (JeanPiaget).14. Eine Bemerkung über die Beziehungen zwischen Relativitätstheorie und der idealistischen Philosophie (Kurt Gödel). 15. Der zweite Hauptsatz und der Unterschied von Vergangenheit und Zukunft (Carl Friedrich v. Weizsäcker). 16. Zeit als physikalischer Begriff (Friedrich Hund). 17. Zeitmessung und Zeitbegriff in der Astronomie (Otto Heckmann). 18. Kann die Zeit rückwärts gehen? (Martin Gardner). 19. Zeit und Zeiten (Ilya Prigogine, Isabelle Stengers). 20. Zeit als dynamische Größe in der Relativitätstheorie (P. C. Aichelburg).

  1. Wade's rules and the stability of AunGem clusters

    NASA Astrophysics Data System (ADS)

    McDermott, Danielle; Newman, Kathie E.

    2015-03-01

    The properties of clusters formed from two connected Gem cage-like clusters, such as experimentally synthesized Au3Ge{18/5-}, are examined using first-principles DFT methods. We focus particularly on AunGe{12/q-} formed from a Wade-rules stable Ge6 cluster, where n = 0-3 and q = 0,2. The geometries, electronic structure, and thermal excitations of these clusters are examined using the SIESTA code. Cluster stability is tested using short molecular dynamics simulations. We find that intercluster bridges between Ge m cages, formed of either Ge-Ge or Au-Ge bonds, can either bind a cluster together or tear it apart depending on the orientation of the bridging atoms with respect to the cages. The properties of neutrally charged AuGe12 and Au2Ge12 are characterized, and we observe that radially directed molecular orbitals stabilize AuGe12 while a geometric asymmetry stabilizes Au2Ge12 and Au3Ge18. A two-dimensional {2/∞}[Au2Ge6] structure is examined and found to be more stable than other periodic [AunGe6] subunits. While no stable neutral isomers of Au3Ge12 are observed in our calculations, our work suggests additional charge stabilizes isomers of both Au2Ge12 and Au3Ge12.

  2. An Interactive Java Statistical Image Segmentation System: GemIdent.

    PubMed

    Holmes, Susan; Kapelner, Adam; Lee, Peter P

    2009-06-01

    Supervised learning can be used to segment/identify regions of interest in images using both color and morphological information. A novel object identification algorithm was developed in Java to locate immune and cancer cells in images of immunohistochemically-stained lymph node tissue from a recent study published by Kohrt et al. (2005). The algorithms are also showing promise in other domains. The success of the method depends heavily on the use of color, the relative homogeneity of object appearance and on interactivity. As is often the case in segmentation, an algorithm specifically tailored to the application works better than using broader methods that work passably well on any problem. Our main innovation is the interactive feature extraction from color images. We also enable the user to improve the classification with an interactive visualization system. This is then coupled with the statistical learning algorithms and intensive feedback from the user over many classification-correction iterations, resulting in a highly accurate and user-friendly solution. The system ultimately provides the locations of every cell recognized in the entire tissue in a text file tailored to be easily imported into R (Ihaka and Gentleman 1996; R Development Core Team 2009) for further statistical analyses. This data is invaluable in the study of spatial and multidimensional relationships between cell populations and tumor structure. This system is available at http://www.GemIdent.com/ together with three demonstration videos and a manual.

  3. Entwicklung und Formulierung der Unternehmensstrategie

    NASA Astrophysics Data System (ADS)

    Crespo, Isabel; Bergmann, Lars; Lacker, Thomas

    Ursprünglich stammt der Begriff "Strategie“ aus dem Altgriechischen: "strategos“ bedeutete "Heer“, "Heeresmacht“ und damit auch "konzentrierte Kraft“; das Wort "agein“ bedeutete "tun, machen, treiben“. Ein Stratege war also eine Person, die ein Heer führte und damit Kraft, Macht und Stärke konzentrierte und einsetzen konnte. Strategie bezeichnete dementsprechend die Maßnahmen, die in dieser Funktion entwickelt wurden. Daher ist es leicht verständlich, dass der Begriff Strategie bis in die Mitte des letzten Jahrhunderts in erster Linie militärisch verstanden wurde. Anschließend wurde der Begriff in weiteren Bereichen, wie beispielsweise der Unternehmensführung, verwendet. Im betriebswirtschaftlichen Sinne bedeutet der Begriff Strategie die langfristig geplante Verhaltensweise eines Unternehmens zur Erreichung seiner Ziele.

  4. Geopotential models of the Earth from satellite tracking, altimeter and surface gravity observations: GEM-T3 and GEM-T3S

    NASA Technical Reports Server (NTRS)

    Lerch, F. J.; Nerem, R. S.; Putney, B. H.; Felsentreger, T. L.; Sanchez, B. V.; Klosko, S. M.; Patel, G. B.; Williamson, R. G.; Chinn, D. S.; Chan, J. C.

    1992-01-01

    Improved models of the Earth's gravitational field have been developed from conventional tracking data and from a combination of satellite tracking, satellite altimeter and surface gravimetric data. This combination model represents a significant improvement in the modeling of the gravity field at half-wavelengths of 300 km and longer. Both models are complete to degree and order 50. The Goddard Earth Model-T3 (GEM-T3) provides more accurate computation of satellite orbital effects as well as giving superior geoidal representation from that achieved in any previous GEM. A description of the models, their development and an assessment of their accuracy is presented. The GEM-T3 model used altimeter data from previous satellite missions in estimating the orbits, geoid, and dynamic height fields. Other satellite tracking data are largely the same as was used to develop GEM-T2, but contain certain important improvements in data treatment and expanded laser tracking coverage. Over 1300 arcs of tracking data from 31 different satellites have been used in the solution. Reliable estimates of the model uncertainties via error calibration and optimal data weighting techniques are discussed.

  5. Mice Deficient in GEM GTPase Show Abnormal Glucose Homeostasis Due to Defects in Beta-Cell Calcium Handling

    PubMed Central

    Gunton, Jenny E.; Sisavanh, Mary; Stokes, Rebecca A.; Satin, Jon; Satin, Leslie S.; Zhang, Min; Liu, Sue M.; Cai, Weikang; Cheng, Kim; Cooney, Gregory J.; Laybutt, D. Ross; So, Trina; Molero, Juan-Carlos; Grey, Shane T.; Andres, Douglas A.

    2012-01-01

    Aims and Hypothesis Glucose-stimulated insulin secretion from beta-cells is a tightly regulated process that requires calcium flux to trigger exocytosis of insulin-containing vesicles. Regulation of calcium handling in beta-cells remains incompletely understood. Gem, a member of the RGK (Rad/Gem/Kir) family regulates calcium channel handling in other cell types, and Gem over-expression inhibits insulin release in insulin-secreting Min6 cells. The aim of this study was to explore the role of Gem in insulin secretion. We hypothesised that Gem may regulate insulin secretion and thus affect glucose tolerance in vivo. Methods Gem-deficient mice were generated and their metabolic phenotype characterised by in vivo testing of glucose tolerance, insulin tolerance and insulin secretion. Calcium flux was measured in isolated islets. Results Gem-deficient mice were glucose intolerant and had impaired glucose stimulated insulin secretion. Furthermore, the islets of Gem-deficient mice exhibited decreased free calcium responses to glucose and the calcium oscillations seen upon glucose stimulation were smaller in amplitude and had a reduced frequency. Conclusions These results suggest that Gem plays an important role in normal beta-cell function by regulation of calcium signalling. PMID:22761801

  6. Physik-Nobelpreis 2004 Von der Freiheit in der Welt der Quarks

    NASA Astrophysics Data System (ADS)

    Bartels, Jochen

    2004-11-01

    Die Schwedische Akademie der Wissenschaften vergab in diesem Jahr den Physik-Nobelpreis zu gleichen Teilen an die amerikanischen Physiker David Gross, David Politzer und Frank Wilczek. Sie würdigte damit ihre theoretischen Arbeiten zur asymptotischen Freiheit in der starken Wechselwirkung.

  7. Grundlagen und Vollzug der amtlichen Lebensmittelkontrolle in der Schweiz

    NASA Astrophysics Data System (ADS)

    Hübner, Philipp; Spinner, Christoph

    In der Schweiz wird die Mehrheit der hoheitlichen Aufgaben von den 26 Kantonen, die zusammen die schweizerische Eidgenossenschaft bilden, autonom vollzogen. So liegt zum Beispiel die Kompetenz in den Bereichen Steuern, Gesundheit, Schulen oder Polizei grundsätzlich bei den Kantonen. Im Gegensatz dazu ist die Lebensmittelgesetzgebung national durch eidgenössische Erlasse harmonisiert. Die Vollzugsaufgaben liegen aber auch in diesem Bereich, abgesehen vom Vollzug an der Grenze und von einer nationalen Vollzugsaufsicht und Weisungsberechtigung, in kantonaler Kompetenz. Die Kantone können anhand kantonaler Erlasse das Bundesrecht präzisieren - insbesondere die organisatorischen Aspekte - und Regelungen im nicht harmonisierten Bereich treffen.

  8. Developments of aerosol retrieval algorithm for Geostationary Environmental Monitoring Spectrometer (GEMS) and the retrieval accuracy test

    NASA Astrophysics Data System (ADS)

    KIM, M.; Kim, J.; Jeong, U.; Ahn, C.; Bhartia, P. K.; Torres, O.

    2013-12-01

    A scanning UV-Visible spectrometer, the GEMS (Geostationary Environment Monitoring Spectrometer) onboard the GEO-KOMPSAT2B (Geostationary Korea Multi-Purpose Satellite) is planned to be launched in geostationary orbit in 2018. The GEMS employs hyper-spectral imaging with 0.6 nm resolution to observe solar backscatter radiation in the UV and Visible range. In the UV range, the low surface contribution to the backscattered radiation and strong interaction between aerosol absorption and molecular scattering can be advantageous in retrieving aerosol optical properties such as aerosol optical depth (AOD) and single scattering albedo (SSA). By taking the advantage, the OMI UV aerosol algorithm has provided information on the absorbing aerosol (Torres et al., 2007; Ahn et al., 2008). This study presents a UV-VIS algorithm to retrieve AOD and SSA from GEMS. The algorithm is based on the general inversion method, which uses pre-calculated look-up table with assumed aerosol properties and measurement condition. To obtain the retrieval accuracy, the error of the look-up table method occurred by the interpolation of pre-calculated radiances is estimated by using the reference dataset, and the uncertainties about aerosol type and height are evaluated. Also, the GEMS aerosol algorithm is tested with measured normalized radiance from OMI, a provisional data set for GEMS measurement, and the results are compared with the values from AERONET measurements over Asia. Additionally, the method for simultaneous retrieve of the AOD and aerosol height is discussed.

  9. Short-Term H α Line Variations in Classical Be Stars: 59 Cyg and OT Gem

    NASA Astrophysics Data System (ADS)

    Paul, K. T.; Shruthi, S. B.; Subramaniam, Annapurni

    2017-03-01

    We present the optical spectroscopic study of two classical Be stars, 59 Cyg and OT Gem obtained over a period of few months in 2009. We detected a rare triple-peak H α emission phase in 59 Cyg and a rapid decrease in the emission strength of H α in OT Gem, which are used to understand their circumstellar disks. We find that 59 Cyg is likely to be rapid rotator, rotating at a fractional critical rotation of ˜0.80. The radius of the H α emission region for 59 Cyg is estimated to be R d/ R ∗ ˜ 10.0, assuming a Keplerian disk, suggesting that it has a large disk. We classify stars which have shown triple-peaks into two groups and find that the triple-peak emission in 59 Cyg is similar to ζ Tau. OT Gem is found to have a fractional critical rotation of ˜0.30, suggesting that it is either a slow rotator or viewed in low inclination. In OT Gem, we observed a large reduction in the radius of the H α emission region from ˜6.9 to ˜1.7 in a period of three months, along with the reduction in the emission strength. Our observations suggest that the disk is lost from outside to inside during this disk loss phase in OT Gem.

  10. Identifying the Source of Gem Diamonds: Requirements for a Certification System

    NASA Astrophysics Data System (ADS)

    Shigley, J. E.

    2002-05-01

    Recent civil conflicts in several countries, in which profits from the sales of gem diamonds have supported the rival factions, have forced the jewelry industry to confront the need to certify the geographic sources of gem diamonds. The goals of this program are to prohibit the sale of so-called "conflict diamonds", and to prevent the loss of consumer confidence. Efforts to identify unique characteristics of gem diamonds have been hampered so far by the absence of chemical or physical features that are diagnostic of particular sources, and the lack of a representative collection of diamonds from major producing areas that would be required for a rigorous scientific study. The jewelry industry has therefore adopted plans to track gem diamonds from the mine through the manufacturing process to the consumer. Practical requirements for implementation of such a certification system will be summarized. Any proposed solutions for determining the sources of gem diamonds by some analytical technique, or for following diamonds from the mine, must take into account the annual production of several tens of millions of carats of rough diamonds, which are transformed during manufacturing into several hundreds of millions of polished gemstones (with an average weight of only about 0.03 carat, or 0.006 gram).

  11. GEM luminosity monitors for the OLYMPUS experiment to determine the effect of two-photon exchange

    NASA Astrophysics Data System (ADS)

    Ates, Ozgur

    The OLYMPUS experiment at DESY acquired its data in two distinct periods between 2012-2013 to measure the ratio of positron-proton and electron-proton elastic scattering cross sections. In light of those measurements, OLYMPUS will be able to quantify the effect of two-photon exchange, which is widely considered to be responsible for the discrepancy between measurements of the proton electric to magnetic form factor ratio with the Rosenbluth separation and polarization transfer methods. In order to control the systematic uncertainties to the sub-percent level, the luminosities were monitored redundantly and with high precision. This was done by measuring the rates for symmetric Moller and Bhabha scattering and by measuring the ep-elastic count rates at forward angles and low momentum transfer with tracking telescopes based on GEM (Gas Electron Multiplier) and MWPC (Multi-Wire Proportional Chamber technology. A total of nine GEM detectors were constructed for the OLYMPUS experiment. Within the scope of this thesis, every single step of construction, testing and installation of the GEM OLYMPUS luminosity monitors are explained in the hardware part of this thesis. Moreover, based on the analysis of the data taken with the GEM luminosity monitors at the OLYMPUS experiment, individual GEM detector performance and preliminary results on the positron/electron luminosity ratio measured with elastic scattering at forward angles are discussed in the analysis part of the thesis.

  12. Verbesserung der Symmetrie von Hirnaufnahmen entlang der Sagittalebene

    NASA Astrophysics Data System (ADS)

    Ens, Konstantin; Wenzel, Fabian; Fischer, Bernd

    Die lokale Symmetrie von Hirnscans entlang der Sagittalebene zu ermitteln und zu modizifieren, ist für eine Reihe neurologischer Anwendungen interessant. Beispielsweise kann der voxelweise Vergleich von rechter und linker Hirnhälfte nur dann Aufschluss über die Lokalisierung von Läsionen geben, wenn durch Transformation ein Hirnscan eine möglichst hohe Symmetrie aufweist. Ein weiteres Anwendungsgebiet ist die Visualisierung von medialen Hirnschnitten, für die die Trennfläche beider Hirnhälfte möglichst eben sein sollte. Diese Arbeit stellt die Entwicklung eines Verfahrens vor, mit dessen Hilfe die Symmetrie von Hirnaufnahmen entlang der Sagittalebene verbessert werden kann. Dies geschieht unter Verwendung von aktiven Konturen, die mit Hilfe einer neuartigen Kostenfunktion gesteuert werden. Experimente am Ende der Arbeit mit strukturellen Kernspinaufnahmen demonstrieren die Leistungsfähigkeit des Verfahrens.

  13. Dialektischer Materialismus in der Quantentheorie

    NASA Astrophysics Data System (ADS)

    Fuchs, Klaus

    Der absolute Determinismus der klassischen Mechanik bietet keine Ansatzpunkte für eine befriedigende Naturphilosophie. Mit der Quantenmechanik werden nicht lediglich die Unzulänglichkeiten einzelner klassischer Begriffe, sondern die des gesamten klassischen Begriffssystems beseitigt.Translated AbstractDialectical Materialism in Quantum TheoryThe absolute determinism of classical mechanics does not provide any base for a satisfactory philosophy of nature. In quantum mechanics the shortcomings of not only some single classical concepts but of the classical description as a whole are removed.

  14. Imaging van der Waals Interactions.

    PubMed

    Han, Zhumin; Wei, Xinyuan; Xu, Chen; Chiang, Chi-Lun; Zhang, Yanxing; Wu, Ruqian; Ho, W

    2016-12-15

    The van der Waals interactions are responsible for a large diversity of structures and functions in chemistry, biology, and materials. Discussion of van der Waals interactions has focused on the attractive potential energy that varies as the inverse power of the distance between the two interacting partners. The origin of the attractive force is widely discussed as being due to the correlated fluctuations of electron charges that lead to instantaneous dipole-induced dipole attractions. Here, we use the inelastic tunneling probe to image the potential energy surface associated with the van der Waals interactions of xenon atoms.

  15. Applications of Mapping and Tomographic Techniques in Gem Sciences

    NASA Astrophysics Data System (ADS)

    Shen, A. H.

    2014-12-01

    Gem Sciences are scientific studies of gemstones - their genesis, provenance, synthesis, enhancement, treatment and identification. As high quality forms of specific minerals, the gemstones exhibit unusual physical properties that are usually unseen in the regular counterparts. Most gemstones are colored by trace elements incorporated in the crystal lattice during various growth stages; forming coloration zones of various scales. Studying the spectral and chemical contrast across color zones helps elucidating the origins of colors. These are done by UV-visible spectrometers with microscope and LA-ICPMS in modern gemological laboratories. In the case of diamonds, their colored zones arise from various structural defects incorporated in different growth zones and are studied with FTIR spectrometers with IR microscope and laser photoluminescence spectrometers. Advancement in modern synthetic techniques such as chemical vapor deposition (CVD) has created some problem for identification. Some exploratory experiments in carbon isotope mapping were done on diamonds using SIMS. The most important issue in pearls is to identify one particular pearl being a cultured one or a natural pearl. The price difference can be enormous. Classical way of such identification is done by x-ray radiographs, which clearly show the bead and the nacre. Modern cultured pearl advancement has eliminated the need for an artificial bead, but a small piece of tissue instead. Nowadays, computer x-ray tomography (CT) scanning devices are used to depict the clear image of the interior of a pearl. In the Chinese jade market, filling fissures with epoxy and/or wax are very commonly seen. We are currently exploring Magnetic Resonance Imaging (MRI) technique to map the distribution of artificial resin within a polycrystalline aggregates.

  16. Decadal predictions with the HiGEM high resolution global coupled climate model: description and basic evaluation

    NASA Astrophysics Data System (ADS)

    Shaffrey, L. C.; Hodson, D.; Robson, J.; Stevens, D. P.; Hawkins, E.; Polo, I.; Stevens, I.; Sutton, R. T.; Lister, G.; Iwi, A.; Smith, D.; Stephens, A.

    2017-01-01

    This paper describes the development and basic evaluation of decadal predictions produced using the HiGEM coupled climate model. HiGEM is a higher resolution version of the HadGEM1 Met Office Unified Model. The horizontal resolution in HiGEM has been increased to 1.25° × 0.83° in longitude and latitude for the atmosphere, and 1/3° × 1/3° globally for the ocean. The HiGEM decadal predictions are initialised using an anomaly assimilation scheme that relaxes anomalies of ocean temperature and salinity to observed anomalies. 10 year hindcasts are produced for 10 start dates (1960, 1965,..., 2000, 2005). To determine the relative contributions to prediction skill from initial conditions and external forcing, the HiGEM decadal predictions are compared to uninitialised HiGEM transient experiments. The HiGEM decadal predictions have substantial skill for predictions of annual mean surface air temperature and 100 m upper ocean temperature. For lead times up to 10 years, anomaly correlations (ACC) over large areas of the North Atlantic Ocean, the Western Pacific Ocean and the Indian Ocean exceed values of 0.6. Initialisation of the HiGEM decadal predictions significantly increases skill over regions of the Atlantic Ocean, the Maritime Continent and regions of the subtropical North and South Pacific Ocean. In particular, HiGEM produces skillful predictions of the North Atlantic subpolar gyre for up to 4 years lead time (with ACC > 0.7), which are significantly larger than the uninitialised HiGEM transient experiments.

  17. Online Condition Monitoring mit der Stresswellenanalyse

    NASA Astrophysics Data System (ADS)

    Bruderreck, Frank

    Die Anforderungen des heutigen Energiemarkts und damit einhergehende veränderte Einsatzbedingungen für ältere Kraftwerksblöcke haben unvorhergesehene Produktionsausfälle in den letzten Jahren erheblich verteuert. Nach der Optimierung der Kraftwerksprozesse und der Steigerung der Wirkungsgrade richten die Energieversorger ihren Blick daher nun verstärkt auch auf die Verfügbarkeit ihrer Anlagen. Zur Verbesserung der Anlagenverfügbarkeit und der Minimierung der Instandhaltungskosten bietet sich der Einsatz von Condition Monitoring Systemen an. Nach der Erprobung eines Systems zur Vibrationsanalyse setzt die Evonik Steag GmbH jetzt in einem Pilotprojekt die Stresswellenanalyse ein, ein Online Condition Monitoring System auf der Basis von Ultraschallsensoren. Dieser Beitrag erläutert an einem Beispiel die Methode und grenzt sie gegen den De-facto-Standard Vibrationsanalyse ab.

  18. Auf der Suche nach dem Unendlichen.

    NASA Astrophysics Data System (ADS)

    Fraser, G.; Lillestøl, E.; Sellevåg, I.

    This book is a German translation by C. Ascheron and J. Urbahn, of "The search for infinity: solving the mysteries of the universe", published in 1994. Diese Buch beschreibt anschaulich die Meilensteine, die der Mensch seit der Antike auf der Suche nach dem Unendlichen erreicht und hinter sich gelassen hat. Es enthält Kurzbiographien der wichtigsten Forscher, verständlich geschriebene Texte sowie Erläuterungen der entscheidenen Fachtermini.

  19. Van der Waals quintessence stars

    SciTech Connect

    Lobo, Francisco S. N.

    2007-01-15

    The van der Waals quintessence equation of state is an interesting scenario for describing the late universe, and seems to provide a solution to the puzzle of dark energy, without the presence of exotic fluids or modifications of the Friedmann equations. In this work, the construction of inhomogeneous compact spheres supported by a van der Waals equation of state is explored. These relativistic stellar configurations shall be denoted as van der Waals quintessence stars. Despite of the fact that, in a cosmological context, the van der Waals fluid is considered homogeneous, inhomogeneities may arise through gravitational instabilities. Thus, these solutions may possibly originate from density fluctuations in the cosmological background. Two specific classes of solutions, namely, gravastars and traversable wormholes are analyzed. Exact solutions are found, and their respective characteristics and physical properties are further explored.

  20. OSG-GEM: Gene Expression Matrix Construction Using the Open Science Grid

    PubMed Central

    Poehlman, William L.; Rynge, Mats; Branton, Chris; Balamurugan, D.; Feltus, Frank A.

    2016-01-01

    High-throughput DNA sequencing technology has revolutionized the study of gene expression while introducing significant computational challenges for biologists. These computational challenges include access to sufficient computer hardware and functional data processing workflows. Both these challenges are addressed with our scalable, open-source Pegasus workflow for processing high-throughput DNA sequence datasets into a gene expression matrix (GEM) using computational resources available to U.S.-based researchers on the Open Science Grid (OSG). We describe the usage of the workflow (OSG-GEM), discuss workflow design, inspect performance data, and assess accuracy in mapping paired-end sequencing reads to a reference genome. A target OSG-GEM user is proficient with the Linux command line and possesses basic bioinformatics experience. The user may run this workflow directly on the OSG or adapt it to novel computing environments. PMID:27499617

  1. A COMSOL-GEMS interface for modeling coupled reactive-transport geochemical processes

    NASA Astrophysics Data System (ADS)

    Azad, Vahid Jafari; Li, Chang; Verba, Circe; Ideker, Jason H.; Isgor, O. Burkan

    2016-07-01

    An interface was developed between COMSOL MultiphysicsTM finite element analysis software and (geo)chemical modeling platform, GEMS, for the reactive-transport modeling of (geo)chemical processes in variably saturated porous media. The two standalone software packages are managed from the interface that uses a non-iterative operator splitting technique to couple the transport (COMSOL) and reaction (GEMS) processes. The interface allows modeling media with complex chemistry (e.g. cement) using GEMS thermodynamic database formats. Benchmark comparisons show that the developed interface can be used to predict a variety of reactive-transport processes accurately. The full functionality of the interface was demonstrated to model transport processes, governed by extended Nernst-Plank equation, in Class H Portland cement samples in high pressure and temperature autoclaves simulating systems that are used to store captured carbon dioxide (CO2) in geological reservoirs.

  2. Use of laser induced breakdown spectroscopy in the determination of gem provenance: beryls

    SciTech Connect

    McManus, Catherine E.; McMillan, Nancy J.; Harmon, Russell S.; Whitmore, Robert C.; De Lucia, Frank C. Jr.; Miziolek, Andrzej W

    2008-11-01

    The provenance of gem stones has been of interest to geologists, gemologists, archeologists, and historians for centuries. Laser induced breakdown spectroscopy (LIBS) provides a minimally destructive tool for recording the rich chemical signatures of gem beryls (aquamarine, goshenite, heliodor, and morganite). Broadband LIBS spectra of 39 beryl (Be3Al2Si6O18) specimens from 11 pegmatite mines in New Hampshire, Connecticut, and Maine (USA) are used to assess the potential of using principal component analysis of LIBS spectra to determine specimen provenance. Using this technique, beryls from the three beryl-bearing zones in the Palermo no. 1 pegmatite (New Hampshire) can be recognized. However, the compositional variation within this single mine is comparable to that in beryls from all three states. Thus, a very large database with detailed location metadata will be required to routinely determine gem beryl provenance.

  3. Use of laser induced breakdown spectroscopy in the determination of gem provenance: beryls.

    PubMed

    McManus, Catherine E; McMillan, Nancy J; Harmon, Russell S; Whitmore, Robert C; De Lucia, Frank C; Miziolek, Andrzej W

    2008-11-01

    The provenance of gem stones has been of interest to geologists, gemologists, archeologists, and historians for centuries. Laser induced breakdown spectroscopy (LIBS) provides a minimally destructive tool for recording the rich chemical signatures of gem beryls (aquamarine, goshenite, heliodor, and morganite). Broadband LIBS spectra of 39 beryl (Be(3)Al(2)Si(6)O(18)) specimens from 11 pegmatite mines in New Hampshire, Connecticut, and Maine (USA) are used to assess the potential of using principal component analysis of LIBS spectra to determine specimen provenance. Using this technique, beryls from the three beryl-bearing zones in the Palermo #1 pegmatite (New Hampshire) can be recognized. However, the compositional variation within this single mine is comparable to that in beryls from all three states. Thus, a very large database with detailed location metadata will be required to routinely determine gem beryl provenance.

  4. Optical characterization of synthetic faceted gem materials grown from hydrothermal solutions

    NASA Astrophysics Data System (ADS)

    Lu, Taijin; Shigley, James E.

    1998-10-01

    Various non-destructive optical characterization techniques have been used to characterize and identify synthetic gem materials grown from hydrothermal solutions, to include ruby, sapphire, emerald, amethyst and ametrine (amethyst-citrine), from their natural counterparts. The ability to observe internal features, such as inclusions, dislocations, twins, color bands, and growth zoning in gem materials is strongly dependent on the observation techniques and conditions, since faceted gemstones have many polished surfaces which can reflect and scatter light in various directions which can make observation difficult. However, diagnostic gemological properties of these faceted synthetic gem materials can be obtained by choosing effective optical characterization methods, and by modifying optical instruments. Examples of some of the distinctive features of synthetic amethyst, ametrine, pink quartz, ruby and emerald are presented to illustrate means of optical characterization of gemstones. The ability to observe defects by light scattering techniques is discussed.

  5. OSG-GEM: Gene Expression Matrix Construction Using the Open Science Grid.

    PubMed

    Poehlman, William L; Rynge, Mats; Branton, Chris; Balamurugan, D; Feltus, Frank A

    2016-01-01

    High-throughput DNA sequencing technology has revolutionized the study of gene expression while introducing significant computational challenges for biologists. These computational challenges include access to sufficient computer hardware and functional data processing workflows. Both these challenges are addressed with our scalable, open-source Pegasus workflow for processing high-throughput DNA sequence datasets into a gene expression matrix (GEM) using computational resources available to U.S.-based researchers on the Open Science Grid (OSG). We describe the usage of the workflow (OSG-GEM), discuss workflow design, inspect performance data, and assess accuracy in mapping paired-end sequencing reads to a reference genome. A target OSG-GEM user is proficient with the Linux command line and possesses basic bioinformatics experience. The user may run this workflow directly on the OSG or adapt it to novel computing environments.

  6. An improved model of the Earth's gravitational field: GEM-T1

    NASA Technical Reports Server (NTRS)

    Marsh, J. G.; Lerch, F. J.; Christodoulidis, D. C.; Putney, B. H.; Felsentreger, T. L.; Sanchez, B. V.; Smith, D. E.; Klosko, S. M.; Martin, T. V.; Pavlis, E. C.

    1987-01-01

    Goddard Earth Model T1 (GEM-T1), which was developed from an analysis of direct satellite tracking observations, is the first in a new series of such models. GEM-T1 is complete to degree and order 36. It was developed using consistent reference parameters and extensive earth and ocean tidal models. It was simultaneously solved for gravitational and tidal terms, earth orientation parameters, and the orbital parameters of 580 individual satellite arcs. The solution used only satellite tracking data acquired on 17 different satellites and is predominantly based upon the precise laser data taken by third generation systems. In all, 800,000 observations were used. A major improvement in field accuracy was obtained. For marine geodetic applications, long wavelength geoidal modeling is twice as good as in earlier satellite-only GEM models. Orbit determination accuracy has also been substantially advanced over a wide range of satellites that have been tested.

  7. Coordinated Chemical and Isotropic Studies of IDPS: Comparison of Circumstellar and Solar GEMS Grains

    NASA Technical Reports Server (NTRS)

    Keller, L. P.; Messenger, S.

    2007-01-01

    Silicate stardust in IDPs and meteorites include forsterite, amorphous silicates, and GEMS grains [1]. Amorphous presolar silicates are much less abundant than expected based on astronomical models [2], possibly destroyed by parent body alteration. A more accurate accounting of presolar silicate mineralogy may be preserved in anhydrous IDPs. Here we present results of coordinated TEM and isotopic analyses of an anhydrous IDP (L2005AL5) that is comprised of crystalline silicates and sulfides, GEMS grains, and equilibrated aggregates embedded in a carbonaceous matrix. Nanometer-scale quantitative compositional maps of all grains in two microtome thin sections were obtained with a JEOL 2500SE. These sections were then subjected to O and N isotopic imaging with the JSC NanoSIMS 50L. Coordinated high resolution chemical maps and O isotopic com-positions were obtained on 11 GEMS grains, 8 crystalline grains, and 6 equilibrated aggregates.

  8. Python based integration of GEM detector electronics with JET data acquisition system

    NASA Astrophysics Data System (ADS)

    Zabołotny, Wojciech M.; Byszuk, Adrian; Chernyshova, Maryna; Cieszewski, Radosław; Czarski, Tomasz; Dalley, Simon; Hogben, Colin; Jakubowska, Katarzyna L.; Kasprowicz, Grzegorz; Poźniak, Krzysztof; Rzadkiewicz, Jacek; Scholz, Marek; Shumack, Amy

    2014-11-01

    This paper presents the system integrating the dedicated measurement and control electronic systems for Gas Electron Multiplier (GEM) detectors with the Control and Data Acquisition system (CODAS) in the JET facility in Culham, England. The presented system performs the high level procedures necessary to calibrate the GEM detector and to protect it against possible malfunctions or dangerous changes in operating conditions. The system also allows control of the GEM detectors from CODAS, setting of their parameters, checking their state, starting the plasma measurement and to reading the results. The system has been implemented using the Python language, using the advanced libraries for implementation of network communication protocols, for object based hardware management and for data processing.

  9. Absence of the Thorpe–Ingold Effect by gem-Diphenyl Groups in Ring-Closing Enyne Metathesis

    PubMed Central

    Kim, Yi Jin; Grimm, Jonathan B.; Lee, Daesung

    2007-01-01

    In tandem ring-closing metathesis of alkynyl silaketals containing two different tethered olefins, the gem-dimethyl group showed the expected Thorpe-Ingold effect, thereby giving good level of group selectivity. Unexpectedly, however, the corresponding gem-diphenyl group did not show any Thorpe-Ingold effect for the ring closure reaction. PMID:18046462

  10. MAXI/GSC detection of a possible X-ray flare from an dMe binary system YY Gem

    NASA Astrophysics Data System (ADS)

    Nakamura, Y.; Kanetou, S.; Tsuboi, Y.; Sasaki, R.; Ueno, S.; Tomida, H.; Nakahira, S.; Kimura, M.; Ishikawa, M.; Nakagawa, Y. E.; Mihara, T.; Sugizaki, M.; Serino, M.; Shidatsu, M.; Sugimoto, J.; Takagi, T.; Matsuoka, M.; Kawai, N.; Arimoto, M.; Yoshii, T.; Tachibana, Y.; Ono, Y.; Fujiwara, T.; Yoshida, A.; Sakamoto, T.; Kawakubo, Y.; Ohtsuki, H.; Tsunemi, H.; Imatani, R.; Negoro, H.; Nakajima, M.; Tanaka, K.; Masumitsu, T.; Ueda, Y.; Kawamuro, T.; Hori, T.; Yamauchi, M.; Itoh, D.; Yamaoka, K.; Morii, M.

    2015-09-01

    MAXI/GSC observed a possible X-ray flare from a dMe binary system YY Gem. The MAXI/GSC nova alert system triggered on the flare-like event from the position consistent with the active binary system YY Gem during a scan transit at 01:29:00 UT on September 24th 2015.

  11. Gemcitabine-loaded albumin nanospheres (GEM-ANPs) inhibit PANC-1 cells in vitro and in vivo

    NASA Astrophysics Data System (ADS)

    Li, Ji; Di, Yang; Jin, Chen; Fu, Deliang; Yang, Feng; Jiang, Yongjian; Yao, Lie; Hao, Sijie; Wang, Xiaoyi; Subedi, Sabin; Ni, Quanxing

    2013-04-01

    With the development of nanotechnology, special attention has been given to the nanomaterial application in tumor treatment. Here, a modified desolvation-cross-linking method was successfully applied to fabricate gemcitabine-loaded albumin nanospheres (GEM-ANPs), with 110 and 406 nm of mean diameter, respectively. The aim of this study was to assess the drug distribution, side effects, and antitumor activity of GEM-ANPs in vivo. The metabolic viability and flow cytometry analysis revealed that both GEM-ANPs, especially 406-nm GEM-ANPs, could effectively inhibit the metabolism and proliferation and promote the apoptosis of human pancreatic carcinoma (PANC-1) in vitro. Intravenous injection of 406-nm GEM-ANPs exhibited a significant increase of gemcitabine in the pancreas, liver, and spleen of Sprague-Dawley rats ( p < 0.05). Moreover, no signs of toxic side effects analyzed by blood parameter changes were observed after 3 weeks of administration although a high dose (200 mg/kg) of GEM-ANPs were used. Additionally, in PANC-1-induced tumor mice, intravenous injection of 406-nm GEM-ANPs also could effectively reduce the tumor volume by comparison with free gemcitabine. With these findings, albumin nanosphere-loading approach might be efficacious to improve the antitumor activity of gemcitabine, and the efficacy is associated with the size of GEM-ANPs.

  12. Science and Math Explorations for Young Children: A GEMS/PEACHES Handbook for Early Childhood Educators, Childcare Providers, and Parents.

    ERIC Educational Resources Information Center

    Barrett, Katharine; Blinderman, Ellen; Boffen, Beatrice; Echols, Jean; House, Patricia A.; Hosoume, Kimi; Kopp, Jaine

    This handbook is designed to help readers understand the educational philosophy and practice of the PEACHES (Primary Explorations for Children and Educators in Science) and GEMS (Great Explorations in Math and Science) programs, and to assist in using GEMS/PEACHES teachers' guides in schools and child care centers. The handbook outlines techniques…

  13. Localization of the human mitogen-induced FTP-binding protein Gem to chromosome 8q22.3

    SciTech Connect

    Kapetanopoulos, A.; Martin, R. de; Vanhove, B.

    1996-05-01

    This report describes the localization of the human mitogen-induced FTP-binding protein Gem to human chromosome 8q22.3 using somatic cell hybrids. The article discusses some possible roles for the gene encoding human Gem. 6 refs., 1 fig.

  14. FPGA-based GEM detector signal acquisition for SXR spectroscopy system

    NASA Astrophysics Data System (ADS)

    Wojenski, A.; Pozniak, K. T.; Kasprowicz, G.; Kolasinski, P.; Krawczyk, R.; Zabolotny, W.; Chernyshova, M.; Czarski, T.; Malinowski, K.

    2016-11-01

    The presented work is related to the Gas Electron Multiplier (GEM) detector soft X-ray spectroscopy system for tokamak applications. The used GEM detector has one-dimensional, 128 channel readout structure. The channels are connected to the radiation-hard electronics with configurable analog stage and fast ADCs, supporting speeds of 125 MSPS for each channel. The digitalized data is sent directly to the FPGAs using fast serial links. The preprocessing algorithms are implemented in the FPGAs, with the data buffering made in the on-board 2Gb DDR3 memory chips. After the algorithmic stage, the data is sent to the Intel Xeon-based PC for further postprocessing using PCI-Express link Gen 2. For connection of multiple FPGAs, PCI-Express switch 8-to-1 was designed. The whole system can support up to 2048 analog channels. The scope of the work is an FPGA-based implementation of the recorder of the raw signal from GEM detector. Since the system will work in a very challenging environment (neutron radiation, intense electro-magnetic fields), the registered signals from the GEM detector can be corrupted. In the case of the very intense hot plasma radiation (e.g. laser generated plasma), the registered signals can overlap. Therefore, it is valuable to register the raw signals from the GEM detector with high number of events during soft X-ray radiation. The signal analysis will have the direct impact on the implementation of photon energy computation algorithms. As the result, the system will produce energy spectra and topological distribution of soft X-ray radiation. The advanced software was developed in order to perform complex system startup and monitoring of hardware units. Using the array of two one-dimensional GEM detectors it will be possible to perform tomographic reconstruction of plasma impurities radiation in the SXR region.

  15. Last glacial maximum constraints on the Earth System model HadGEM2-ES

    NASA Astrophysics Data System (ADS)

    Hopcroft, Peter O.; Valdes, Paul J.

    2015-09-01

    We investigate the response of the atmospheric and land surface components of the CMIP5/AR5 Earth System model HadGEM2-ES to pre-industrial (PI: AD 1860) and last glacial maximum (LGM: 21 kyr) boundary conditions. HadGEM2-ES comprises atmosphere, ocean and sea-ice components which are interactively coupled to representations of the carbon cycle, aerosols including mineral dust and tropospheric chemistry. In this study, we focus on the atmosphere-only model HadGEM2-A coupled to terrestrial carbon cycle and aerosol models. This configuration is forced with monthly sea surface temperature and sea-ice fields from equivalent coupled simulations with an older version of the Hadley Centre model, HadCM3. HadGEM2-A simulates extreme cooling over northern continents and nearly complete die back of vegetation in Asia, giving a poor representation of the LGM environment compared with reconstructions of surface temperatures and biome distributions. The model also performs significantly worse for the LGM in comparison with its precursor AR4 model HadCM3M2. Detailed analysis shows that the major factor behind the vegetation die off in HadGEM2-A is a subtle change to the temperature dependence of leaf mortality within the phenology model of HadGEM2. This impacts on both snow-vegetation albedo and vegetation dynamics. A new set of parameters is tested for both the pre-industrial and LGM, showing much improved coverage of vegetation in both time periods, including an improved representation of the needle-leaf forest coverage in Siberia for the pre-industrial. The new parameters and the resulting changes in global vegetation distribution strongly impact the simulated loading of mineral dust, an important aerosol for the LGM. The climate response in an abrupt 4× pre-industrial CO2 simulation is also analysed and shows modest regional impacts on surface temperatures across the Boreal zone.

  16. Formation of GEMS from shock-accelerated crystalline dust in Superbubbles

    SciTech Connect

    Westphal, A; Bradley, J P

    2004-12-08

    Interplanetary dust particles (IDPs) contain enigmatic sub-micron components called GEMS (Glass with Embedded Metal and Sulfides). The compositions and structures of GEMS indicate that they have been processed by exposure to ionizing radiation but details of the actual irradiation environment(s) have remained elusive. Here we propose a mechanism and astrophysical site for GEMS formation that explains for the first time the following key properties of GEMS; they are stoichiometrically enriched in oxygen and systematically depleted in S, Mg, Ca and Fe (relative to solar abundances), most have normal (solar) oxygen isotopic compositions, they exhibit a strikingly narrow size distribution (0.1-0.5 {micro}m diameter), and some of them contain ''relict'' crystals within their silicate glass matrices. We show that the compositions, size distribution, and survival of relict crystals are inconsistent with amorphization by particles accelerated by diffusive shock acceleration. Instead, we propose that GEMS are formed from crystalline grains that condense in stellar outflows from massive stars in OB associations, are accelerated in encounters with frequent supernova shocks inside the associated superbubble, and are implanted with atoms from the hot gas in the SB interior. We thus reverse the usual roles of target and projectile. Rather than being bombarded at rest by energetic ions, grains are accelerated and bombarded by a nearly monovelocity beam of atoms as viewed in their rest frame. Meyer, Drury and Ellison have proposed that galactic cosmic rays originate from ions sputtered from such accelerated dust grains. We suggest that GEMS are surviving members of a population of fast grains that constitute the long-sought source material for galactic cosmic rays. Thus, representatives of the GCR source material may have been awaiting discovery in cosmic dust labs for the last thirty years.

  17. Metadata for selecting or submitting generic seismic vulnerability functions via GEM's vulnerability database

    USGS Publications Warehouse

    Jaiswal, Kishor

    2013-01-01

    This memo lays out a procedure for the GEM software to offer an available vulnerability function for any acceptable set of attributes that the user specifies for a particular building category. The memo also provides general guidelines on how to submit the vulnerability or fragility functions to the GEM vulnerability repository, stipulating which attributes modelers must provide so that their vulnerability or fragility functions can be queried appropriately by the vulnerability database. An important objective is to provide users guidance on limitations and applicability by providing the associated modeling assumptions and applicability of each vulnerability or fragility function.

  18. DETECTORS AND EXPERIMENTAL METHODS: Study on the TU gas for the GEM-TPC detector

    NASA Astrophysics Data System (ADS)

    Qi, Hui-Rong; Li, Yu-Lan; Li, Jin; Gao, Yuan-Ning; Li, Yuan-Jing

    2009-04-01

    In this paper several different working gas mixtures for GEM-TPC were evaluated based on a Garfield simulation. Among them, Ar:CH4:CF4 = 90:7:3 (named herein TU gas) was selected for a detailed study because of its better performance. Some performances of drift velocity, transverse diffusion, spatial resolution and the effective number of electrons in various electric fields were obtained. The performance of a GEM-TPC prototype working in the TU gas was studied and compared with that in Ar:CH4 = 90:10 (P10 gas).

  19. Divergent Mechanistic Routes for the Formation of gem-Dimethyl Groups in the Biosynthesis of Complex Polyketides

    SciTech Connect

    Poust, S; Phelan, RM; Deng, K; Katz, L; Petzold, CJ; Keasling, JD

    2015-01-07

    The gem-dimethyl groups in polyketide-derived natural products add steric bulk and, accordingly, lend increased stability to medicinal compounds, however, our ability to rationally incorporate this functional group in modified natural products is limited. In order to characterize the mechanism of gem-dimethyl group formation, with a goal toward engineering of novel compounds containing this moiety, the gem-dimethyl group producing polyketide synthase (PKS) modules of yersiniabactin and epothilone were characterized using mass spectrometry. The work demonstrated, contrary to the canonical understanding of reaction order in PKSs, that methylation can precede condensation in gem-dimethyl group producing PKS modules. Experiments showed that both PKSs are able to use dimethylmalonyl acyl carrier protein (ACP) as an extender unit. Interestingly, for epothilone module8, use of dimethylmalonyl-ACP appeared to be the sole route to form a gem-dimethylated product, while the yersiniabactin PKS could methylate before or after ketosynthase condensation.

  20. Differentiation of diastereotopic bromine atoms in SN2 reactions of gem-dibromides.

    PubMed

    Münster, Niels; Harms, Klaus; Koert, Ulrich

    2012-02-11

    A novel directed S(N)2 reaction of conformationally biased gem-dibromides and an arenesulfinate anion is described. The reaction results in the diastereoselective formation of α-bromosulfones. The selectivity originates from pre-coordination of the nucleophile to a free hydroxyl group in the γ-position.

  1. Microstructured boron foil scintillating G-GEM detector for neutron imaging

    NASA Astrophysics Data System (ADS)

    Fujiwara, Takeshi; Bautista, Unico; Mitsuya, Yuki; Takahashi, Hiroyuki; Yamada, Norifumi L.; Otake, Yoshie; Taketani, Atsushi; Uesaka, Mitsuru; Toyokawa, Hiroyuki

    2016-12-01

    In this study, a new simple neutron imaging gaseous detector was successfully developed by combining a micro-structured 10B foil, a glass gas electron multiplier (G-GEM), and a mirror-lens-charge-coupled device (CCD)-camera system. The neutron imaging system consists of a chamber filled with Ar/CF4 scintillating gas mixture. Inside this system, the G-GEM is mounted for gas multiplication. The neutron detection in this system is based on the reaction between 10B and neutrons. A micro-structured 10B is developed to overcome the issue of low detection efficiency. Secondary electrons excite Ar/CF4 gas molecules, and high-yield visible photons are emitted from those excited gas molecules during the gas electron multiplication process in the G-GEM holes. These photons are easily detected by a mirror-lens-CCD-camera system. A neutron radiograph is then simply formed. We obtain the neutron images of different materials with a compact accelerator-driven neutron source. We confirm that the new scintillating G-GEM-based neutron imager works properly with low gamma ray sensitivity and exhibits a good performance as a new simple digital neutron imaging device.

  2. MeerLICHT and BlackGEM: custom-built telescopes to detect faint optical transients

    NASA Astrophysics Data System (ADS)

    Bloemen, Steven; Groot, Paul; Woudt, Patrick; Klein Wolt, Marc; McBride, Vanessa; Nelemans, Gijs; Körding, Elmar; Pretorius, Margaretha L.; Roelfsema, Ronald; Bettonvil, Felix; Balster, Harry; Bakker, Roy; Dolron, Peter; van Elteren, Arjen; Elswijk, Eddy; Engels, Arno; Fender, Rob; Fokker, Marc; de Haan, Menno; Hagoort, Klaas; de Hoog, Jasper; ter Horst, Rik; van der Kevie, Giel; Kozłowski, Stanisław; Kragt, Jan; Lech, Grzegorz; Le Poole, Rudolf; Lesman, Dirk; Morren, Johan; Navarro, Ramon; Paalberends, Willem-Jelle; Paterson, Kerry; Pawłaszek, Rafal; Pessemier, Wim; Raskin, Gert; Rutten, Harrie; Scheers, Bart; Schuil, Menno; Sybilski, Piotr W.

    2016-07-01

    We present the MeerLICHT and BlackGEM telescopes, which are wide-field optical telescopes that are currently being built to study transient phenomena, gravitational wave counterparts and variable stars. The telescopes have 65 cm primary mirrors and a 2.7 square degree field-of-view. The MeerLICHT and BlackGEM projects have different science goals, but will use identical telescopes. The first telescope, MeerLICHT, will be commissioned at Sutherland (South Africa) in the first quarter of 2017. It will co-point with MeerKAT to collect optical data commensurate with the radio observations. After careful analysis of MeerLICHT's performance, three telescopes of the same type will be commissioned in La Silla (Chile) in 2018 to form phase I of the BlackGEM array. BlackGEM aims at detecting and characterizing optical counterparts of gravitational wave events detected by Advanced LIGO and Virgo. In this contribution we present an overview of the science goals, the design and the status of the two projects.

  3. Simulation of space-charge effects in an ungated GEM-based TPC

    NASA Astrophysics Data System (ADS)

    Böhmer, F. V.; Ball, M.; Dørheim, S.; Höppner, C.; Ketzer, B.; Konorov, I.; Neubert, S.; Paul, S.; Rauch, J.; Vandenbroucke, M.

    2013-08-01

    A fundamental limit to the application of Time Projection Chambers (TPCs) in high-rate experiments is the accumulation of slowly drifting ions in the active gas volume, which compromises the homogeneity of the drift field and hence the detector resolution. Conventionally, this problem is overcome by the use of ion-gating structures. This method, however, introduces large dead times and restricts trigger rates to a few hundred per second. The ion gate can be eliminated from the setup by the use of Gas Electron Multiplier (GEM) foils for gas amplification, which intrinsically suppress the backflow of ions. This makes the continuous operation of a TPC at high rates feasible. In this work, Monte Carlo simulations of the buildup of ion space charge in a GEM-based TPC and the correction of the resulting drift distortions are discussed, based on realistic numbers for the ion backflow in a triple-GEM amplification stack. A TPC in the future P¯ANDA experiment at FAIR serves as an example for the experimental environment. The simulations show that space charge densities up to 65 fC cm-3 are reached, leading to electron drift distortions of up to 10 mm. The application of a laser calibration system to correct these distortions is investigated. Based on full simulations of the detector physics and response, we show that it is possible to correct for the drift distortions and to maintain the good momentum resolution of the GEM-TPC.

  4. Promoting microbiology education through the iGEM synthetic biology competition.

    PubMed

    Kelwick, Richard; Bowater, Laura; Yeoman, Kay H; Bowater, Richard P

    2015-08-01

    Synthetic biology has developed rapidly in the 21st century. It covers a range of scientific disciplines that incorporate principles from engineering to take advantage of and improve biological systems, often applied to specific problems. Methods important in this subject area include the systematic design and testing of biological systems and, here, we describe how synthetic biology projects frequently develop microbiology skills and education. Synthetic biology research has huge potential in biotechnology and medicine, which brings important ethical and moral issues to address, offering learning opportunities about the wider impact of microbiological research. Synthetic biology projects have developed into wide-ranging training and educational experiences through iGEM, the International Genetically Engineered Machines competition. Elements of the competition are judged against specific criteria and teams can win medals and prizes across several categories. Collaboration is an important element of iGEM, and all DNA constructs synthesized by iGEM teams are made available to all researchers through the Registry for Standard Biological Parts. An overview of microbiological developments in the iGEM competition is provided. This review is targeted at educators that focus on microbiology and synthetic biology, but will also be of value to undergraduate and postgraduate students with an interest in this exciting subject area.

  5. Evolution in boron-based GEM detectors for diffraction measurements: from planar to 3D converters

    NASA Astrophysics Data System (ADS)

    Albani, Giorgia; Perelli Cippo, Enrico; Croci, Gabriele; Muraro, Andrea; Schooneveld, Erik; Scherillo, Antonella; Hall-Wilton, Richard; Kanaki, Kalliopi; Höglund, Carina; Hultman, Lars; Birch, Jens; Claps, Gerardo; Murtas, Fabrizio; Rebai, Marica; Tardocchi, Marco; Gorini, Giuseppe

    2016-11-01

    The so-called ‘3He-crisis’ has motivated the neutron detector community to undertake an intense R&D programme in order to develop technologies alternative to standard 3He tubes and suitable for neutron detection systems in future spallation sources such as the European spallation source (ESS). Boron-based GEM (gas electron multiplier) detectors are a promising ‘3He-free’ technology for thermal neutron detection in neutron scattering experiments. In this paper the evolution of boron-based GEM detectors from planar to 3D converters with an application in diffraction measurements is presented. The use of 3D converters coupled with GEMs allows for an optimization of the detector performances. Three different detectors were used for diffraction measurements on the INES instrument at the ISIS spallation source. The performances of the GEM-detectors are compared with those of conventional 3He tubes installed on the INES instrument. The conceptual detector with the 3D converter used in this paper reached a count rate per unit area of about 25% relative to the currently installed 3He tube. Its timing resolution is similar and the signal-to-background ratio (S/B) is 2 times lower.

  6. Data Quality Monitoring System for New GEM Muon Detectors for the CMS Experiment Upgrade

    NASA Astrophysics Data System (ADS)

    King, Robert; CMS Muon group Team

    2017-01-01

    The Gas Electron Multiplier (GEM) detectors are novel detectors designed to improve the muon trigger and tracking performance in CMS experiment for the high luminosity upgrade of the LHC. Partial installation of GEM detectors is planned during the 2016-2017 technical stop. Before the GEM system is installed underground, its data acquisition (DAQ) electronics must be thoroughly tested. The DAQ system includes several commercial and custom-built electronic boards running custom firmware. The front-end electronics are radiation-hard and communicate via optical fibers. The data quality monitoring (DQM) software framework has been designed to provide online verification of the integrity of the data produced by the detector electronics, and to promptly identify potential hardware or firmware malfunctions in the system. Local hits reconstruction and clustering algorithms allow quality control of the data produced by each GEM chamber. Once the new detectors are installed, the DQM will monitor the stability and performance of the system during normal data-taking operations. We discuss the design of the DQM system, the software being developed to read out and process the detector data, and the methods used to identify and report hardware and firmware malfunctions of the system.

  7. The Use of Computers and Simulation in the Development and Management of GEM.

    ERIC Educational Resources Information Center

    Duncan, Glenn E.; Bauch, Jerold P.

    Georgia Educational Models (GEM) will proceed to utilize computers and simulation to their fullest cost effectiveness potential simultaneously in operation and in research, while avoiding both the restrictions and duplications which come from doctrinaire insistence on maintaining an artificial separation between management and research uses of…

  8. Development and Test of a GEM-Based TEPC System for In-Phantom Dose Measurements

    SciTech Connect

    C-K Chris Wang

    2007-03-13

    The objectives of this project include: (1) to construct a minature tissue equivalent proportional counter (TEPC) using a gas-electron-multiplier (GEM) foil, and (2) to conduct neutron and gamma-ray dose measurements with the detector embedded in a phantom

  9. Experiential Engineering through iGEM--An Undergraduate Summer Competition in Synthetic Biology

    ERIC Educational Resources Information Center

    Mitchell, Rudolph; Dori, Yehudit Judy; Kuldell, Natalie H.

    2011-01-01

    Unlike students in other engineering disciplines, undergraduates in biological engineering typically have limited opportunity to develop design competencies, and even fewer chances to implement their designed projects. The international Genetically Engineered Machines (iGEM) competition is a student Synthetic Biology competition that, in 2009,…

  10. An improved model of the Earth's gravity field - GEM-T3

    NASA Technical Reports Server (NTRS)

    Nerem, R. S.; Lerch, F. J.; Putney, B. H.; Klosko, S. M.; Patel, G. B.; Williamson, R. G.; Pavlis, E. C.

    1992-01-01

    An improved model of the Earth's gravitational field is developed from a combination of conventional satellite tracking, satellite altimeter measurements, and surface gravimetric data (GEM-T3). This model gives improved performance for the computation of satellite orbital effects as well as a superior representation of the geoid from that achieved in any previous Goddard Earth Model. The GEM-T3 model uses altimeter data directly to define the orbits, geoid, and dynamic height fields. Altimeter data acquired during the GEOS-3 (1975-1976), SEASAT (1978), and GEOSAT (1986-1987) missions were used to compute GEM-T3. In order to accommodate the non-gravitational signal mapped by these altimeters, spherical harmonic models of the dynamic height of the ocean surface were recovered for each mission simultaneously with the gravitational field. The tracking data utilized in the solution includes more than 1300 arcs of data encompassing 31 different satellites. The observational data base is highly dependent on SLR, but also includes TRANET Doppler, optical, S-Band average range-rate and satellite-to-satellite tracking acquired between ATS-6 and GEOS-3. The GEM-T3 model has undergone extensive error calibration.

  11. Open source large-scale high-resolution environmental modelling with GEMS

    NASA Astrophysics Data System (ADS)

    Baarsma, Rein; Alberti, Koko; Marra, Wouter; Karssenberg, Derek

    2016-04-01

    Many environmental, topographic and climate data sets are freely available at a global scale, creating the opportunities to run environmental models for every location on Earth. Collection of the data necessary to do this and the consequent conversion into a useful format is very demanding however, not to mention the computational demand of a model itself. We developed GEMS (Global Environmental Modelling System), an online application to run environmental models on various scales directly in your browser and share the results with other researchers. GEMS is open-source and uses open-source platforms including Flask, Leaflet, GDAL, MapServer and the PCRaster-Python modelling framework to process spatio-temporal models in real time. With GEMS, users can write, run, and visualize the results of dynamic PCRaster-Python models in a browser. GEMS uses freely available global data to feed the models, and automatically converts the data to the relevant model extent and data format. Currently available data includes the SRTM elevation model, a selection of monthly vegetation data from MODIS, land use classifications from GlobCover, historical climate data from WorldClim, HWSD soil information from WorldGrids, population density from SEDAC and near real-time weather forecasts, most with a ±100m resolution. Furthermore, users can add other or their own datasets using a web coverage service or a custom data provider script. With easy access to a wide range of base datasets and without the data preparation that is usually necessary to run environmental models, building and running a model becomes a matter hours. Furthermore, it is easy to share the resulting maps, timeseries data or model scenarios with other researchers through a web mapping service (WMS). GEMS can be used to provide open access to model results. Additionally, environmental models in GEMS can be employed by users with no extensive experience with writing code, which is for example valuable for using models

  12. A geopotential model from satellite tracking, altimeter, and surface gravity data: GEM-T3

    NASA Technical Reports Server (NTRS)

    Lerch, F. J.; Nerem, R. S.; Putney, B. H.; Felsentreger, T. L.; Sanchez, B. V.; Marshall, J. A.; Klosko, S. M.; Patel, G. B.; Williamson, R. G.; Chinn, D. S.

    1994-01-01

    An improved model of Earth's gravitational field, Goddard Earth Model T-3 (GEM-T3), has been developed from a combination of satellite tracking, satellite altimeter, and surface gravimetric data. GEM-T3 provides a significant improvement in the modeling of the gravity field at half wavelengths of 400 km and longer. This model, complete to degree and order 50, yields more accurate satellite orbits and an improved geoid representation than previous Goddard Earth Models. GEM-T3 uses altimeter data from GEOS 3 (1975-1976), Seasat (1978) and Geosat (1986-1987). Tracking information used in the solution includes more than 1300 arcs of data encompassing 31 different satellites. The recovery of the long-wavelength components of the solution relies mostly on highly precise satellite laser ranging (SLR) data, but also includes Tracking Network (TRANET) Doppler, optical, and satellite-to-satellite tracking acquired between the ATS 6 and GEOS 3 satellites. The main advances over GEM-T2 (beyond the inclusion of altimeter and surface gravity information which is essential for the resolution of the shorter wavelength geoid) are some improved tracking data analysis approaches and additional SLR data. Although the use of altimeter data has greatly enhanced the modeling of the ocean geoid between 65 deg N and 60 deg S latitudes in GEM-T3, the lack of accurate detailed surface gravimetry leaves poor geoid resolution over many continental regions of great tectonic interest (e.g., Himalayas, Andes). Estimates of polar motion, tracking station coordinates, and long-wavelength ocean tidal terms were also made (accounting for 6330 parameters). GEM-T3 has undergone error calibration using a technique based on subset solutions to produce reliable error estimates. The calibration is based on the condition that the expected mean square deviation of a subset gravity solution from the full set values is predicted by the solutions' error covariances. Data weights are iteratively adjusted until

  13. Twisted Van der Waals Systems

    NASA Astrophysics Data System (ADS)

    Gani, Satrio; Rossi, Enrico

    Van der Waals systems formed by two-dimensional (2D) crystals and nanostructures possess electronic properties that make them extremely interesting for basic science and for possible technological applications. By tuning the relative angle (the twist angle) between the layers, or nanostructures, forming the Van der Waals systems experimentalists have been able to control the stacking configuration of such systems. We study the dependence on the twist angle of the electronic properties of two classes of Van der Waals systems: double layers formed by two, one-atom thick, layers of a metal dichalcogenide such as molybdenum disulfide (MoS2), and graphene nanoribbons on a hexagonal boron nitride substrate. We present results that show how, for both classes of systems, the electronic properties can be strongly tuned via the twist angle. Work supported by ACS-PRF-53581-DNI5 and NSF-DMR-1455233.

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

    SciTech Connect

    Crary, David

    2010-05-05

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

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

    SciTech Connect

    Woody, Craig

    2009-03-31

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

  16. ISC-GEM: Global Instrumental Earthquake Catalogue (1900-2009) I. Location and Seismicity Patterns

    NASA Astrophysics Data System (ADS)

    Bondar, I.; Engdahl, E. R.; Villasenor, A.; Storchak, D. A.

    2012-12-01

    We present the final results of a two-year project sponsored by the GEM (Global Earthquake Model) Foundation. The ISC-GEM global catalogue consists of some 19 thousand instrumentally recorded, moderate to large earthquakes, spanning 110 years of seismicity. We relocated all events in the catalogue using a two-tier approach. The EHB location methodology (Engdahl et al., 1998) was applied first to obtain improved hypocentres with special focus on the depth determination. The locations were further refined in the next step by fixing the depths to those from the EHB analysis and applying the new ISC location algorithm (Bondár and Storchak, 2011) that reduces location bias by accounting for correlated travel-time prediction error structure. To facilitate the relocation effort, some 900,000 seismic P and S wave arrival-time data were added to the ISC database for the period between 1904 and 1963, either from original station bulletins in the ISC archive or by digitizing the scanned images of the ISS bulletin (Villaseñor and Engdahl, 2005; 2007). Although no substantial amount of new phase data were acquired for the modern period (1964-2009), the number of phases used in the location has still increased by 3 million, owing to fact that both the EHB and ISC locators use all ak135 (Kennett et al., 1995) phases in the location. We show that the relocation effort yielded substantially improved locations, especially in the first half of the 20th century; we demonstrate significant improvements in focal depth estimates in subduction zones and other seismically active regions; and we show that the ISC-GEM catalogue provides an improved view of 110 years of global seismicity of the Earth. The ISC-GEM Global Instrumental Earthquake Catalogue represents the final product of one of the ten global components in the GEM program, and will be made available to researchers at the ISC (www.isc.ac.uk) website.

  17. Coronellis Cosmos in der Melker Stiftsbibliothek.

    NASA Astrophysics Data System (ADS)

    Glaßner, Gottfried; Pärr, Nora

    2009-06-01

    Die Melker Stiftsbibliothek besitzt ein Globenpaar des berühmten venezianischen Globenbauers Vincenzo Coronelli (1650-1718), einen Erdglobus von 1688 und einen Himmelsglobus von 1693. Wie und wann die beiden Globen nach Melk gekommen sind, ist nicht bekannt. Dass sie zur ursprünglichen Ausstattung der 1735 fertig gestellten Barockbibliothek gehörten, wird aber aus der zentralen Stellung deutlich, die dem Globus (Erdglobus und Armillarphäre) in dem von Paul Troger 1732 gemalten Deckenfresko zukommt. Mehrfach begegnet das Motiv des Globus als Attribut der Weisheit bzw. Philosophie, der Geographie bzw. Geometrie und der Astronomie in den beiden Hauptsälen wie auch in der Deckenmalerei von Johann Bergl in der Oberen Bibliothek (1768) und in der Kuppel des Gartenpavillons (1764).

  18. Use of the HadGEM2 climate-chemistry model to investigate interannual variability in methane sources

    NASA Astrophysics Data System (ADS)

    Hayman, Garry; O'Connor, Fiona; Clark, Douglas; Huntingford, Chris; Gedney, Nicola

    2013-04-01

    . Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M.Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 2007. [3] Rigby, M., et al.: Renewed growth of atmospheric methane. Geophysical Research Letters, 35, L22805, doi:10.1029/2008GL036037, 2008. [4] Bousquet, P., et al.: Contribution of anthropogenic and natural sources to atmospheric methane variability, Nature, 443, 439-443, doi:10.1038/nature05132, 2006. [5] Collins, W. J., et al.: Development and evaluation of an Earth-System model - HadGEM2, Geoscientific Model Development, 4, 1051-1075, doi:10.5194/gmd-4-1051-2011, 2011. [6] Lamarque, J.-F., et al.: Historical (1850-2000) gridded anthropogenic and biomass burning emissions of reactive gases and aerosols: methodology and application, Atmospheric Chemistry and Physics, 10, 7017-7039, doi:10.5194/acp-10-7017-2010, 2010. [7] van der Werf, G. R., et al.: Global fire emissions and the contribution of deforestation, savanna, forest, agricultural, and peat fires (1997-2009), Atmospheric Chemistry and Physics, 10, 11707-11735, doi:10.5194/acp-10-11707-2010, 2010. [8] Fung, I., et al.: Three-dimensional model synthesis of the Global Methane Cycle. Journal of Geophysical Research, 96, 13,033-13,065, 1991. [9] Best, M. J., et al.: The Joint UK Land Environment Simulator (JULES), model description - Part 1: Energy and water fluxes, Geoscientific Model Development, 4, 677-699, doi:10.5194/gmd-4-677-2011, 2011. [10] Clark, D.B., et al.: The Joint UK Land Environment Simulator (JULES), Model description - Part 2: Carbon fluxes and vegetation. Geoscientific Model Development, 4, 701-722, doi:10.5194/gmd-4-701-2011, 2011. [11] Gedney, N., et al.: Climate feedback from wetland methane emissions. Geophysical Research Letters, 31, L20503, 2004.

  19. Synthesis of Alkylidene(gem-Difluorocyclopropanes) from Propargyl Glycolates by a One-Pot Difluorocyclopropenation/Ireland-Claisen Rearrangement Sequence.

    PubMed

    Ernouf, Guillaume; Brayer, Jean-Louis; Folléas, Benoît; Demoute, Jean-Pierre; Meyer, Christophe; Cossy, Janine

    2017-03-24

    A one-pot difluorocyclopropenation/Ireland-Claisen rearrangement sequence applied to readily available propargyl glycolates was developed as a route toward functionalized alkylidene(gem-difluorocyclopropanes). This strategy conveniently avoids the isolation of the unstable 3,3-difluorocyclopropenylcarbinyl glycolates arising from the difluorocyclopropenation. The Ireland-Claisen rearrangement proceeds with high diastereoselectivity and chirality transfer to afford alkylidene(gem-difluorocyclopropanes) incorporating a quaternary stereocenter and a protected glycolic acid moiety, which are useful building blocks for the preparation of functionalized gem-difluorocyclopropanes.

  20. Ancillary Services Provided from DER

    SciTech Connect

    Campbell, J.B.

    2005-12-21

    Distributed energy resources (DER) are quickly making their way to industry primarily as backup generation. They are effective at starting and then producing full-load power within a few seconds. The distribution system is aging and transmission system development has not kept up with the growth in load and generation. The nation's transmission system is stressed with heavy power flows over long distances, and many areas are experiencing problems in providing the power quality needed to satisfy customers. Thus, a new market for DER is beginning to emerge. DER can alleviate the burden on the distribution system by providing ancillary services while providing a cost adjustment for the DER owner. This report describes 10 types of ancillary services that distributed generation (DG) can provide to the distribution system. Of these 10 services the feasibility, control strategy, effectiveness, and cost benefits are all analyzed as in the context of a future utility-power market. In this market, services will be provided at a local level that will benefit the customer, the distribution utility, and the transmission company.

  1. PLC-controlled cryostats for the BlackGEM and MeerLICHT detectors

    NASA Astrophysics Data System (ADS)

    Raskin, Gert; Morren, Johan; Pessemier, Wim; Bloemen, Steven; Klein-Wolt, Marc; Roelfsema, Ronald; Groot, Paul; Aerts, Conny

    2016-08-01

    BlackGEM is an array of telescopes, currently under development at the Radboud University Nijmegen and at NOVA (Netherlands Research School for Astronomy). It targets the detection of the optical counterparts of gravitational waves. The first three BlackGEM telescopes are planned to be installed in 2018 at the La Silla observatory (Chile). A single prototype telescope, named MeerLICHT, will already be commissioned early 2017 in Sutherland (South Africa) to provide an optical complement for the MeerKAT radio array. The BlackGEM array consists of, initially, a set of three robotic 65-cm wide-field telescopes. Each telescope is equipped with a single STA1600 CCD detector with 10.5k x 10.5k 9-micron pixels that covers a 2.7 square degrees field of view. The cryostats for housing these detectors are developed and built at the KU Leuven University (Belgium). The operational model of BlackGEM requires long periods of reliable hands-off operation. Therefore, we designed the cryostats for long vacuum hold time and we make use of a closed-cycle cooling system, based on Polycold PCC Joule-Thomson coolers. A single programmable logic controller (PLC) controls the cryogenic systems of several BlackGEM telescopes simultaneously, resulting in a highly reliable, cost-efficient and maintenance-friendly system. PLC-based cryostat control offers some distinct advantages, especially for a robotic facility. Apart of temperature monitoring and control, the PLC also monitors the vacuum quality, the power supply and the status of the PCC coolers (compressor power consumption and temperature, pressure in the gas lines, etc.). Furthermore, it provides an alarming system and safe and reproducible procedures for automatic cool down and warm up. The communication between PLC and higher-level software takes place via the OPC-UA protocol, offering a simple to implement, yet very powerful interface. Finally, a touch-panel display on the PLC provides the operator with a user-friendly and robust

  2. Segmentierung der Papille in Fundusaufnahmen Aktives Kreisbogen-Modell

    NASA Astrophysics Data System (ADS)

    Schmidt, Torsten; Doering, Axel

    In der vorliegenden Arbeit präsentieren wir einen praxistauglichen Algorithmus zur automatischen Segmentierung der Disc-Grenze der Papille in Fundusaufnahmen. Ausgehend von einem lokalisierten Papillenpunkt werden Grauwertverläufe in horizontaler und vertikaler Richtung mittels einer Energiefunktion ausgewertet. In einem iterativen Prozess wird die Ellipse der tatsächlichen Disc-Grenze angenähert. Der Papillenrand konnte im Testdatensatz in 88% der Aufnahmen erfolgreich segmentiert werden. Der Algorithmus ist robust gegenüber der Lage des Startpunktes innerhalb der Papille und soll als Unterstützung bei der Glaukombefundung eingesetzt werden.

  3. Progress on the realization of a new GEM based neutron diagnostic concept for high flux neutron beams

    SciTech Connect

    Croci, G.; Tardocchi, M.; Rebai, M.; Cippo, E. Perelli; Gorini, G.; Cazzaniga, C.; Palma, M. Dalla; Pasqualotto, R.; Tollin, M.; Grosso, G.; Muraro, A.; Murtas, F.; Claps, G.; Cavenago, M.

    2014-08-21

    Fusion reactors will need high flux neutron detectors to diagnose the deuterium-deuterium and deuterium-tritium. A candidate detection technique is the Gas Electron Multiplier (GEM). New GEM based detectors are being developed for application to a neutral deuterium beam test facility. The proposed detection system is called Close-contact Neutron Emission Surface Mapping (CNESM). The diagnostic aims at providing the map of the neutron emission due to interaction of the deuterium beam with the deuterons implanted in the beam dump surface. This is done by placing a detector in close contact, right behind the dump. CNESM uses nGEM detectors, i.e. GEM detectors equipped with a cathode that also serves as neutron-proton converter foil. After the realization and test of several small area prototypes, a full size prototype has been realized and tested with laboratory sources. Test on neutron beams are foreseen for the next months.

  4. Large size GEM for Super Bigbite Spectrometer (SBS) polarimeter for Hall A 12GeV program at JLab

    SciTech Connect

    Gnanvo, Kondo; Liyanage, Nilanga; Nelyubin, Vladimir; Saenboonruang, Kiadtisak; Sacher, Seth; Wojtsekhowski, Bogdan

    2015-05-01

    We report on the R&D effort in the design and construction of a large size GEM chamber for the Proton Polarimeter of the Super Bigbite Spectrometer (SBS) in Hall A at Thomas Jefferson National Laboratory (JLab). The SBS Polarimeter trackers consist of two sets of four large chambers of size 200 cm x 60 cm2. Each chamber is a vertical stack of four GEM modules with an active area of 60 cm x 50 cm. We have built and tested several GEM modules and we describe in this paper the design and construction of the final GEM as well as the preliminary results on performances from tests carried out in our detector lab and with test beams at (Fermilab).

  5. Large size GEM for Super Bigbite Spectrometer (SBS) polarimeter for Hall A 12GeV program at JLab

    DOE PAGES

    Gnanvo, Kondo; Liyanage, Nilanga; Nelyubin, Vladimir; ...

    2015-05-01

    We report on the R&D effort in the design and construction of a large size GEM chamber for the Proton Polarimeter of the Super Bigbite Spectrometer (SBS) in Hall A at Thomas Jefferson National Laboratory (JLab). The SBS Polarimeter trackers consist of two sets of four large chambers of size 200 cm x 60 cm2. Each chamber is a vertical stack of four GEM modules with an active area of 60 cm x 50 cm. We have built and tested several GEM modules and we describe in this paper the design and construction of the final GEM as well asmore » the preliminary results on performances from tests carried out in our detector lab and with test beams at (Fermilab).« less

  6. A study of film and foil materials for the GEM detector proposed for the CMS muon system upgrade

    NASA Astrophysics Data System (ADS)

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

    2014-04-01

    During the next shutdown of the LHC at CERN, the CMS experiment plans to start installing GEM detectors in the endcap (high pseudorapidity) region. These muon detectors have excellent spatial and temporal resolution as well as a high chemical stability and radiation hardness. A report is given on preliminary results of materials studies that aimed to fully characterize the GEM detector components before and after the exposure to a high-radiation environment.

  7. Reduction experiment of FeO-bearing amorphous silicate: application to origin of metallic iron in GEMS

    SciTech Connect

    Matsuno, Junya; Tsuchiyama, Akira; Miyake, Akira; Noguchi, Ryo; Ichikawa, Satoshi

    2014-09-10

    Glass with embedded metal and sulfides (GEMS) are amorphous silicates included in anhydrous interplanetary dust particles (IDPs) and can provide information about material evolution in our early solar system. Several formation processes for GEMS have been proposed so far, but these theories are still being debated. To investigate a possible GEMS origin by reduction of interstellar silicates, we synthesized amorphous silicates with a mean GEMS composition and performed heating experiments in a reducing atmosphere. FeO-bearing amorphous silicates were heated at 923 K and 973 K for 3 hr, and at 1023 K for 1-48 hr at ambient pressure in a reducing atmosphere. Fe grains formed at the interface between the silicate and the reducing gas through a reduction. In contrast, TEM observations of natural GEMS show that metallic grains are uniformly embedded in amorphous silicates. Therefore, the present study suggests that metallic inclusions in GEMS could not form as reduction products and that other formation process such as condensation or irradiation are more likely.

  8. The development and evaluation of mini-GEMs - short, focused, online e-learning videos in geriatric medicine.

    PubMed

    Garside, Mark J; Fisher, James M; Blundell, Adrian G; Gordon, Adam L

    2016-04-06

    Mini Geriatric E-Learning Modules (Mini-GEMs) are short, focused, e-learning videos on geriatric medicine topics, hosted on YouTube, which are targeted at junior doctors working with older people. This study aimed to explore how these resources are accessed and used. The authors analyzed the viewing data from 22 videos published over the first 18 months of the Mini-GEM project. We conducted a focus group of U.K. junior doctors considering their experiences with Mini-GEMS. The Mini-GEMs were viewed 10,291 times over 18 months, equating to 38,435 minutes of total viewing time. The average viewing time for each video was 3.85 minutes. Learners valued the brevity and focused nature of the Mini-GEMs and reported that they watched them in a variety of settings to supplement clinical experiences and consolidate learning. Watching the videos led to an increase in self-reported confidence in managing older patients. Mini-GEMs can effectively disseminate clinical teaching material to a wide audience. The videos are valued by junior doctors due to their accessibility and ease of use.

  9. Data Management and Other Logistical Challenges for the GEMS: The Data Coordinating Center Perspective

    PubMed Central

    Biswas, Kousick; Carty, Christina; Horney, Rebecca; Nasrin, Dilruba; Farag, Tamer H.; Kotloff, Karen L.; Levine, Myron M.

    2012-01-01

    The Cooperative Studies Program Coordinating Center provided the data management, administrative, and statistical support to the Global Enteric Multicenter Study (GEMS). The GEMS study, the largest epidemiological study in the diarrheal disease area among children <5 years of age, was carried out in 4 African countries and 3 Asian countries. Given the geographical and geopolitical differences among the countries, the administration of a centralized data management operation was a major challenge. The sheer volume of the data that were collected, regular transfer of the data to a centralized database, and the cleaning of the same also posed some challenges. This paper outlines the details of the support that the data coordinating center provided and the challenges faced during the course of the study. PMID:23169938

  10. First measurements with new high-resolution gadolinium-GEM neutron detectors

    NASA Astrophysics Data System (ADS)

    Pfeiffer, D.; Resnati, F.; Birch, J.; Etxegarai, M.; Hall-Wilton, R.; Höglund, C.; Hultman, L.; Llamas-Jansa, I.; Oliveri, E.; Oksanen, E.; Robinson, L.; Ropelewski, L.; Schmidt, S.; Streli, C.; Thuiner, P.

    2016-05-01

    European Spallation Source instruments like the macromolecular diffractometer (NMX) require an excellent neutron detection efficiency, high-rate capabilities, time resolution, and an unprecedented spatial resolution in the order of a few hundred micrometers over a wide angular range of the incoming neutrons. For these instruments solid converters in combination with Micro Pattern Gaseous Detectors (MPGDs) are a promising option. A GEM detector with gadolinium converter was tested on a cold neutron beam at the IFE research reactor in Norway. The μTPC analysis, proven to improve the spatial resolution in the case of 10B converters, is extended to gadolinium based detectors. For the first time, a Gd-GEM was successfully operated to detect neutrons with a measured efficiency of 11.8% at a wavelength of 2 Åand a position resolution better than 250 μm.

  11. Going beyond "ABC" to include "GEM": critical reflections on progress in the HIV/AIDS epidemic.

    PubMed

    Dworkin, Shari L; Ehrhardt, Anke A

    2007-01-01

    A considerable number of studies have sought to identify what factors accounted for substantial reductions in HIV seroprevalence after several countries deployed "ABC" (abstinence, be faithful, condom use) strategies. After much public discourse and research on ABC success stories, the Joint United Nations Programme on HIV/AIDS 2004 epidemic report indicated that nearly 50% of infected people worldwide were women, up from 35% in 1985. In light of the feminization of HIV/AIDS, we critically assess the limitations of ABC strategies. We provide 3 additional prevention strategies that focus on gender relations, economics, and migration (GEM) and can speak to the new face of the epidemic. Pressing beyond ABC, GEM strategies provide the basis for a stronger central platform from which national efforts against HIV/AIDS can proceed to reduce transmission risks.

  12. Energy calibration of a GEM-TPC prototype with 83mKr

    NASA Astrophysics Data System (ADS)

    Schmitz, Roman

    2012-05-01

    A GEM-TPC has been built as a 10% scale prototype for the P¯ANDA experiment and as a full-scale prototype for the CBELSA/TAPS experiment (Fabbietti L, et al: Nucl Instrum Methods A 628:204, 2011). The intrinsic suppression of ion backflow into the drift volume makes it suitable for high rate/background environments. The GEM-TPC has been used as an inner tracking update for the FOPI experiment at GSI where cosmic and beam tests were performed. For calibration purposes a 83Rb source has been produced at the Bonn HISKP Cyclotron. Using the isomeric 83mKr evaporated by the source, a relative channel-wise gain calibration as well as gain estimation for different high voltage settings could be performed.

  13. Energy calibration of a GEM-TPC prototype with 83mKr

    NASA Astrophysics Data System (ADS)

    Schmitz, Roman

    A GEM-TPC has been built as a 10% scale prototype for the P¯ANDA experiment and as a full-scale prototype for the CBELSA/TAPS experiment (Fabbietti L, et al: Nucl Instrum Methods A 628:204, 2011). The intrinsic suppression of ion backflow into the drift volume makes it suitable for high rate/background environments. The GEM-TPC has been used as an inner tracking update for the FOPI experiment at GSI where cosmic and beam tests were performed. For calibration purposes a 83Rb source has been produced at the Bonn HISKP Cyclotron. Using the isomeric 83mKr evaporated by the source, a relative channel-wise gain calibration as well as gain estimation for different high voltage settings could be performed.

  14. Studies on GEM modules for a Large Prototype TPC for the ILC

    NASA Astrophysics Data System (ADS)

    Tsionou, Dimitra

    2017-02-01

    The International Linear Collider (ILC) is a future electron-positron collider with centre of mass energy of 500-1000 GeV. The International Large Detector (ILD) is one of two detector concepts at the ILC. Its high precision tracking system consists of Silicon sub-detectors and a Time Projection Chamber (TPC) equipped with micro-pattern gas detectors (MPGDs). Within the framework of the LCTPC collaboration, a Large Prototype (LP) TPC has been built as a demonstrator. This prototype has been equipped with Gas Electron Multiplier (GEM) modules and studied with electron beams of energies 1-6 GeV at the DESY test beam facility. The performance of the prototype detector and the extrapolation to the ILD TPC is presented here. In addition, ongoing optimisation studies and R&D activities in order to prepare the next GEM module iteration are discussed.

  15. GEM detector development for tokamak plasma radiation diagnostics: SXR poloidal tomography

    NASA Astrophysics Data System (ADS)

    Chernyshova, Maryna; Malinowski, Karol; Ziółkowski, Adam; Kowalska-Strzeciwilk, Ewa; Czarski, Tomasz; Poźniak, Krzysztof T.; Kasprowicz, Grzegorz; Zabołotny, Wojciech; Wojeński, Andrzej; Kolasiński, Piotr; Krawczyk, Rafał D.

    2015-09-01

    An increased attention to tungsten material is related to a fact that it became a main candidate for the plasma facing material in ITER and future fusion reactor. The proposed work refers to the studies of W influence on the plasma performances by developing new detectors based on Gas Electron Multiplier GEM) technology for tomographic studies of tungsten transport in ITER-oriented tokamaks, e.g. WEST project. It presents current stage of design and developing of cylindrically bent SXR GEM detector construction for horizontal port implementation. Concept to overcome an influence of constraints on vertical port has been also presented. It is expected that the detecting unit under development, when implemented, will add to the safe operation of tokamak bringing creation of sustainable nuclear fusion reactors a step closer.

  16. Large gem diamonds from metallic liquid in Earth’s deep mantle

    NASA Astrophysics Data System (ADS)

    Smith, Evan M.; Shirey, Steven B.; Nestola, Fabrizio; Bullock, Emma S.; Wang, Jianhua; Richardson, Stephen H.; Wang, Wuyi

    2016-12-01

    The redox state of Earth’s convecting mantle, masked by the lithospheric plates and basaltic magmatism of plate tectonics, is a key unknown in the evolutionary history of our planet. Here we report that large, exceptional gem diamonds like the Cullinan, Constellation, and Koh-i-Noor carry direct evidence of crystallization from a redox-sensitive metallic liquid phase in the deep mantle. These sublithospheric diamonds contain inclusions of solidified iron-nickel-carbon-sulfur melt, accompanied by a thin fluid layer of methane ± hydrogen, and sometimes majoritic garnet or former calcium silicate perovskite. The metal-dominated mineral assemblages and reduced volatiles in large gem diamonds indicate formation under metal-saturated conditions. We verify previous predictions that Earth has highly reducing deep mantle regions capable of precipitating a metallic iron phase that contains dissolved carbon and hydrogen.

  17. Fast data transmission from serial data acquisition for the GEM detector system

    NASA Astrophysics Data System (ADS)

    Kolasinski, Piotr; Pozniak, Krzysztof T.; Czarski, Tomasz; Byszuk, Adrian; Chernyshova, Maryna; Kasprowicz, Grzegorz; Krawczyk, Rafal D.; Wojenski, Andrzej; Zabolotny, Wojciech

    2015-09-01

    This article proposes new method of storing data and transferring it to PC in the X-ray GEM detector system. The whole process is performed by FPGA chips (Spartan-6 series from Xilinx). Comparing to previous methods, new approach allows to store much more data in the system. New, improved implementation of the communication algorithm significantly increases transfer rate between system and PC. In PC data is merged and processed by MATLAB. The structure of firmware implemented in the FPGAs is described.

  18. Evaluation of the modal aerosol model GMXe in the chemistry-climate model GEM-AC

    NASA Astrophysics Data System (ADS)

    Semeniuk, K.; Lupu, A.; Kaminski, J. W.; McConnell, J. C.; O'Neill, N. T.; Tost, H.

    2012-12-01

    We evaluate a modal aerosol model, GMXe, implemented in the atmospheric chemistry-climate model GEM-AC, against global ground-based observations of optical depths and speciated aerosol concentrations. The Global Environmental Multiscale Atmospheric Chemistry model (GEM-AC) is a global, tropospheric-stratospheric chemistry, general circulation model based on the GEM model developed by the Meteorological Service of Canada for operational weather forecasting. Gas-phase chemistry consists in detailed reactions of Ox, NOx, HOx, CO, CH4, NMVOCs, ClOx and BrOx. Tracers are advected using the semi-Lagrangian scheme native to GEM. The vertical transport includes parameterized subgrid scale turbulence and deep convection. Dry deposition is implemented as a flux boundary condition in the vertical diffusion equation. Wet removal comprises both in-cloud and below-cloud scavenging. The Global Modal-aerosol eXtension (GMXe) handles aerosol microphysics and gas-aerosol partitioning. The aerosol size distribution is described by the superposition of 4 hydrophilic and 3 hydrophobic interacting lognormal modes (nucleation, Aitken, accumulation and coarse). Aerosol dynamics includes nucleation, coagulation, and condensation/evaporation. Gas-aerosol partitioning is calculated by the thermodynamic equilibrium model ISORROPIA. The model was run for one year on a 1.5°×1.5° global grid with 73 hybrid levels from the surface to 0.15 hPa. We used aerosol emissions for year 2000 from AeroCom I. The output is compared with aerosol optical depth observations from AERONET, and with measured surface concentrations of sulfate, nitrate and ammonium from CASTNET, EMEP and EANET.

  19. Performance of the full size nGEM detector for the SPIDER experiment

    NASA Astrophysics Data System (ADS)

    Muraro, A.; Croci, G.; Albani, G.; Claps, G.; Cavenago, M.; Cazzaniga, C.; Dalla Palma, M.; Grosso, G.; Murtas, F.; Pasqualotto, R.; Perelli Cippo, E.; Rebai, M.; Tardocchi, M.; Tollin, M.; Gorini, G.

    2016-03-01

    The ITER neutral beam test facility under construction in Padova will host two experimental devices: SPIDER, a 100 kV negative H/D RF beam source, and MITICA, a full scale, 1 MeV deuterium beam injector. SPIDER will start operations in 2016 while MITICA is expected to start during 2019. Both devices feature a beam dump used to stop the produced deuteron beam. Detection of fusion neutrons produced between beam-deuterons and dump-implanted deuterons will be used as a means to resolve the horizontal beam intensity profile. The neutron detection system will be placed right behind the beam dump, as close to the neutron emitting surface as possible thus providing the map of the neutron emission on the beam dump surface. The system uses nGEM neutron detectors. These are Gas Electron Multiplier detectors equipped with a cathode that also serves as neutron-proton converter foil. The cathode is designed to ensure that most of the detected neutrons at a point of the nGEM surface are emitted from the corresponding beamlet footprint (with dimensions of about 40×22 mm2) on the dump front surface. The size of the nGEM detector for SPIDER is 352 mm×200 mm. Several smaller size prototypes have been successfully made in the last years and the experience gained on these detectors has led to the production of the full size detector for SPIDER during 2014. This nGEM has a read-out board made of 256 pads (arranged in a 16×16 matrix) each with a dimension of 22 mm×13 mm. This paper describes the production of this detector and its tests (in terms of beam profile reconstruction capability, uniformity over the active area, gamma rejection capability and time stability) performed on the ROTAX beam-line at the ISIS spallation source (Didcot-UK).

  20. GEM: a dynamic tracking model for mesoscale eddies in the ocean

    NASA Astrophysics Data System (ADS)

    Li, Qiu-Yang; Sun, Liang; Lin, Sheng-Fu

    2016-12-01

    The Genealogical Evolution Model (GEM) presented here is an efficient logical model used to track dynamic evolution of mesoscale eddies in the ocean. It can distinguish between different dynamic processes (e.g., merging and splitting) within a dynamic evolution pattern, which is difficult to accomplish using other tracking methods. To this end, the GEM first uses a two-dimensional (2-D) similarity vector (i.e., a pair of ratios of overlap area between two eddies to the area of each eddy) rather than a scalar to measure the similarity between eddies, which effectively solves the "missing eddy" problem (temporarily lost eddy in tracking). Second, for tracking when an eddy splits, the GEM uses both "parent" (the original eddy) and "child" (eddy split from parent) and the dynamic processes are described as the birth and death of different generations. Additionally, a new look-ahead approach with selection rules effectively simplifies computation and recording. All of the computational steps are linear and do not include iteration. Given the pixel number of the target region L, the maximum number of eddies M, the number N of look-ahead time steps, and the total number of time steps T, the total computer time is O(LM(N + 1)T). The tracking of each eddy is very smooth because we require that the snapshots of each eddy on adjacent days overlap one another. Although eddy splitting or merging is ubiquitous in the ocean, they have different geographic distributions in the North Pacific Ocean. Both the merging and splitting rates of the eddies are high, especially at the western boundary, in currents and in "eddy deserts". The GEM is useful not only for satellite-based observational data, but also for numerical simulation outputs. It is potentially useful for studying dynamic processes in other related fields, e.g., the dynamics of cyclones in meteorology.

  1. GEMS (Gravity Electro-Magnetism Strong) SU(5) Theory and The Prediction of Exchange Boson Masses

    NASA Astrophysics Data System (ADS)

    Brandenburg, John

    2012-10-01

    The GEMS SU(5) [1] theory includes short range Nuclear Forces in the GEM unification theory [2], where the importance of the square root of the proton-electron mass ratio: σ = 42.8503 was found. The creation of mass by a Higgs field coupling must, by the Equivalence Principle, be viewed in the context of General Relativity. This is done here using Kaluza-Klein theory in a Feynman-Hawkings path integral formalism. GEM theory, quantum concepts of virtual particles, and ZPF (Zero Point Fluctuation) allow understanding of the Strong Force and Weak forces as the extension of electrodynamics in the quantum limit. The Strong and Weak forces are found to be associated with EM models of the electron and proton as finite sized structures respectively. Higher order Mie resonances off the EM ``mass at a distance'' structures associated with the electron, proton and fifth dimension generate the quanta with masses of the pion mπ = 2 me /α 140.0 MeV and Z boson: mZ = 2σ mp = 80.4 GeV. The ηc meson mη = 2980 GeV is identified with the 5^th dimension compactification force mediated by the Radion field. Another particle associated with this mass inducing field is the ``Radion'' or Higgs scattering quanta off the fifth dimension with a mass σmη 128.6 GeV which is the Higgs Boson. A GEMS SU(5) Georgi-Glashow model, is proposed, where the unification energy is now the Planck energy.[0pt] [1] Brandenburg, J.E. (2012)., STAIF II Conference Albuquerque NM[0pt] [2] Brandenburg, J.E. (2007). IEEE Transactions On Plasma Science, Vol. 35, No. 4., p845.

  2. CSC large panel R&D summary for the SSC GEM muon subsystem

    SciTech Connect

    Pratuch, S.M.; Clements, J.W.; Spellman, G.P.

    1994-05-01

    The GEM Detector uses 1,128 Cathode Strip Chamber (CSC) muon detectors requiring a total of approximately 10,000 precision panels in the CSC assemblies. These panels must be fabricated to extreme tolerances in order to meet the physics requirement. A fabrication technique used to produce two large panels, nominally 1 by 3 meters, is described and the resulting panel precision is reported.

  3. Quantitative analysis of trace element concentrations in some gem-quality diamonds

    NASA Astrophysics Data System (ADS)

    McNeill, J.; Pearson, D. G.; Klein-Ben David, O.; Nowell, G. M.; Ottley, C. J.; Chinn, I.

    2009-09-01

    The geochemical signature of diamond-forming fluids can be used to unravel diamond-forming processes and is of potential use in the detection of so-called 'conflict' diamonds. While fluid-rich fibrous diamonds can be analyzed by a variety of techniques, very few data have been published for fluid-poor, gem-quality diamonds because of their very low impurity levels. Here we present a new ICPMS-based (ICPMS: inductively coupled plasma mass spectrometry) method for the analysis of trace element concentrations within fluid-poor, gem-quality diamonds. The method employs a closed-system laser ablation cell. Diamonds are ablated and the products trapped for later pre-concentration into solutions that are analyzed by sector-field ICPMS. We show that our limits of quantification for a wide range of elements are at the sub-pg to low pg level. The method is applied to a suite of 10 diamonds from the Cullinan Mine (previously known as Premier), South Africa, along with other diamonds from Siberia (Mir and Udachnaya) and Venezuela. The concentrations of a wide range of elements for all the samples (expressed by weight in the solid) are very low, with rare earth elements along with Y, Nb, Cs ranging from 0.01 to 2 ppb. Large ion lithophile elements (LILE) such as Rb and Ba vary from 1 to 30 ppb. Ti ranges from ppb levels up to 2 ppm. From the combined, currently small data set we observe two kinds of diamond-forming fluids within gem diamonds. One group has enrichments in LILE over Nb, whereas a second group has normalized LILE abundances more similar to those of Nb. These two groups bear some similarity to different groups of fluid-rich diamonds, providing some supporting evidence of a link between the parental fluids for both fluid-inclusion-rich and gem diamonds.

  4. 100+ years of instrumental seismology: the example of the ISC-GEM Global Earthquake Instrumental Catalogue

    NASA Astrophysics Data System (ADS)

    Storchak, Dmitry; Di Giacomo, Domenico

    2015-04-01

    Systematic seismological observations of earthquakes using seismic instruments on a global scale began more than 100 years ago. Since then seismologists made many discoveries about the Earth interior and the physics of the earthquakes, also thanks to major developments in the seismic instrumentation deployed around the world. Besides, since the establishment of the first global networks (Milne and Jesuit networks), seismologists around the world stored and exchanged the results of routine observations (e.g., picking of arrival times, amplitude-period measurements, etc.) or more sophisticated analyses (e.g., moment tensor inversion) in seismological bulletins/catalogues. With a project funded by the GEM Foundation (www.globalquakemodel.org), the ISC and the Team of International Experts released a new global earthquake catalogue, the ISC-GEM Global Instrumental Earthquake Catalogue (1900 2009) (www.isc.ac.uk/iscgem/index.php), which, differently from previous global seismic catalogues, has the unique feature of covering the entire period of instrumental seismology with locations and magnitude re-assessed using modern approaches for the global earthquakes selected for processing (in the current version approximately 21,000). During the 110 years covered by the ISC-GEM catalogue many seismological developments occurred in terms of instrumentation, seismological practice and knowledge of the physics of the earthquakes. In this contribution we give a brief overview of the major milestones characterizing the last 100+ years of instrumental seismology that were relevant for the production of the ISC-GEM catalogue and the major challenges we faced to obtain a catalogue as homogenous as possible.

  5. GEM Detectors and Preliminary Analysis of Proton Charge Radius (PRad) Experiment at Jefferson Lab

    NASA Astrophysics Data System (ADS)

    Bai, Xinzhan; PRad Collaboration

    2016-09-01

    The PRad experiment (E12-11-106) was recently performed at Jefferson Lab in Hall B, it was designed to measure the proton charge radius through the elastic electron proton scattering process, using a non-magnetic-spectrometer method. The experiment reaches very low ep scattering angles and thus an unprecedented low four-momentum transfer squared region, Q2 from 2 ×10-4 to 0 . 1(GeV / c) 2 . The experiment measures the proton charge radius by extracting the electric form factor of proton with a sub-percent precision. Gas Electron Multiplier (GEM) detectors have contributed to reach the experimental goal. A pair of world largest GEM detectors, and a high resolution calorimeter(HyCal) were utilized in the experiment. In this talk, we will present the performance of GEM detectors approached in the experiment, such as efficiency and other characteristics, and preliminary analysis of the experimental data. This work is supported in part by NSF MRI Award PHY-1229153, the U.S. Department of Energy under Contract No. DE-FG02-07ER41528, Thomas Jefferson National Laboratory, and PRad Collaboration.

  6. Pathobiology of aging mice and GEM: background strains and experimental design.

    PubMed

    Brayton, C F; Treuting, P M; Ward, J M

    2012-01-01

    The use of induced and spontaneous mutant mice and genetically engineered mice (and combinations thereof) to study cancers and other aging phenotypes to advance improved functional human life spans will involve studies of aging mice. Genetic background contributes to pathology phenotypes and to causes of death as well as to longevity. Increased recognition of expected phenotypes, experimental variables that influence phenotypes and research outcomes, and experimental design options and rationales can maximize the utility of genetically engineered mice (GEM) models to translational research on aging. This review aims to provide resources to enhance the design and practice of chronic and longevity studies involving GEM. C57BL6, 129, and FVB/N strains are emphasized because of their widespread use in the generation of knockout, transgenic, and conditional mutant GEM. Resources are included also for pathology of other inbred strain families, including A, AKR, BALB/c, C3H, C57L, C58, CBA, DBA, GR, NOD.scid, SAMP, and SJL/J, and non-inbred mice, including 4WC, AB6F1, Ames dwarf, B6, 129, B6C3F1, BALB/c,129, Het3, nude, SENCAR, and several Swiss stocks. Experimental strategies for long-term cross-sectional and longitudinal studies to assess causes of or contributors to death, disease burden, spectrum of pathology phenotypes, longevity, and functional healthy life spans (health spans) are compared and discussed.

  7. Performance Verification of the Gravity and Extreme Magnetism Small Explorer GEMS X-Ray Polarimeter

    NASA Technical Reports Server (NTRS)

    Enoto, Teruaki; Black, J. Kevin; Kitaguchi, Takao; Hayato, Asami; Hill, Joanne E.; Jahoda, Keith; Tamagawa, Toru; Kanako, Kenta; Takeuchi, Yoko; Yoshikawa, Akifumi; Kenward, David

    2014-01-01

    olarimetry is a powerful tool for astrophysical observations that has yet to be exploited in the X-ray band. For satellite-borne and sounding rocket experiments, we have developed a photoelectric gas polarimeter to measure X-ray polarization in the 2-10 keV range utilizing a time projection chamber (TPC) and advanced micro-pattern gas electron multiplier (GEM) techniques. We carried out performance verification of a flight equivalent unit (1/4 model) which was planned to be launched on the NASA Gravity and Extreme Magnetism Small Explorer (GEMS) satellite. The test was performed at Brookhaven National Laboratory, National Synchrotron Light Source (NSLS) facility in April 2013. The polarimeter was irradiated with linearly-polarized monochromatic X-rays between 2.3 and 10.0 keV and scanned with a collimated beam at 5 different detector positions. After a systematic investigation of the detector response, a modulation factor greater than or equal to 35% above 4 keV was obtained with the expected polarization angle. At energies below 4 keV where the photoelectron track becomes short, diffusion in the region between the GEM and readout strips leaves an asymmetric photoelectron image. A correction method retrieves an expected modulation angle, and the expected modulation factor, approximately 20% at 2.7 keV. Folding the measured values of modulation through an instrument model gives sensitivity, parameterized by minimum detectable polarization (MDP), nearly identical to that assumed at the preliminary design review (PDR).

  8. Identification of critical substorm-expansion-phase phenomena: Problems addressable with GEM observations

    SciTech Connect

    Lyons, L.R.

    1994-09-01

    Understanding the physics of the substorm process is currently a crucial topic in magnetospheric physics. Fundamental to this understanding is the determination of what phenomena occur in the magnetosphere during the expansion phase, where these phenomena occur, and how they propagate during the expansion phase. Satellite observations have given researchers important point measurements of what happens; however there is potential for enhancing the use of ground-based observations to study the substorm phenomena. Such enhanced use of ground-based measurements is already taking place as part of the GEM (Geospace Environment Modeling) boundary-layer campaign and is planned to continue throughout the tail/substorm campaign. This report identifies expansion-phase phenomena observed locally within the nightside magnetosphere and from the ground, believed to be of fundamental importance for understanding large-scale substorm processes. The phenomena observed in situ are related to the phenomena observed from the ground. The primary goal is to identify outstanding questions that could be addressed during the GEM tail/substorm campaign using ground-based data from GEM observing periods in coordination with available satellite observations.

  9. ULTRAVIOLET SPECTROSCOPY OF PQ Gem AND V405 Aur FROM THE HST AND IUE SATELLITES

    SciTech Connect

    Sanad, M. R.

    2015-10-20

    Ultraviolet spectra of two intermediate polars (IPs), PQ Gem and V405 Aur, observed with Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph and Faint Object Spectrograph and International Ultraviolet Explorer (IUE) satellites were analyzed during the period between 1994–2000. We estimated the reddening of the two systems from the 2200 Å feature. Six spectra of the two systems revealing modulations of line fluxes at different times are presented. PQ Gem and V405 Aur are featured by spectral lines in different ionization states. This paper focuses on the third ionized carbon emission line at 1550 Å and the first ionized helium emission line at 1640 Å produced in the optically thin outer region of the accretion curtain for the two systems by calculating spectral line fluxes. From HST and IUE data, we deduced ultraviolet luminosities and ultraviolet accretion rates for the two binary stars. The average temperature of the accretion streams for PQ Gem and V405 Aur are ∼4500 K and 4100 K, respectively. The results reveal that there are modulations in fluxes of spectral lines, ultraviolet luminosities, and ultraviolet accretion rates with time for both systems. These modulations are referred to the changes of both density and temperature as a result of the variations of mass transfer rate from the secondary star to the primary star. The current results are consistent with an accretion curtain model for IPs.

  10. 5-(Dimethoxymethyl)-2′-Deoxyuridine: A Novel Gem Diether Nucleoside with Anti-Orthopoxvirus Activity

    PubMed Central

    Fan, Xuesen; Zhang, Xinying; Zhou, Longhu; Keith, Kathy A.; Kern, Earl R.; Torrence, Paul F.

    2014-01-01

    To provide potential new leads for the treatment of orthopoxvirus infections, the 5-position of the pyrimidine nucleosides have been modified with a gem diether moiety to yield the following new nucleosides: 5-(dimethoxymethyl)-2′-deoxyuridine (2b), 5-(diethoxymethyl)-2′-deoxyuridine (3b), 5-formyl-2′-deoxyuridine ethylene acetal (4b), and 5-formyl-2′-deoxyuridine propylene acetal (5b). These were evaluated in human foreskin fibroblast cells challenged with the vaccinia virus or cowpox virus. Of the four gem diether nucleosides, only the dimethyl gem diether congener showed significant antiviral activity against both viruses. This antiviral activity did not appear to be related to the decomposition to the 5-formyl-2′-deoxyuridine, which was itself devoid of anti-orthopoxvirus activity in these assays. Moreover, at the pH of the in vitro assays, 2b was very stable with a decomposition (to aldehyde) half-life of >15 d. The anti-orthopoxvirus activity of pyrimidine may be favored by the introduction of hydrophilic moieties to the 5-position side chain. PMID:16722657

  11. Hexatic phase and cluster crystals of two-dimensional GEM4 spheres

    NASA Astrophysics Data System (ADS)

    Prestipino, Santi; Saija, Franz

    2014-11-01

    Two-dimensional crystals of classical particles are very peculiar in that melting may occur in two steps, in a continuous fashion, via an intermediate hexatic fluid phase exhibiting quasi-long-range orientational order. On the other hand, three-dimensional spheres repelling each other through a fast-decaying bounded potential of generalized-exponential shape (GEM4 potential) can undergo freezing into cluster crystals, allowing for more that one particle per lattice site. We hereby study the combined effect of low spatial dimensionality and extreme potential softness, by investigating the phase behavior of the two-dimensional (2D) GEM4 system. Using a combination of density-functional theory and numerical free-energy calculations, we show that the 2D GEM4 system displays one ordinary and several cluster triangular-crystal phases, and that only the ordinary crystal first melts into a hexatic phase. Upon heating, the difference between the various cluster crystals fades away, eventually leaving a single undifferentiated cluster phase with a pressure-modulated site occupancy.

  12. A simulation study on angular and micro pattern effects in GEM detectors.

    PubMed

    Kim, H G; Jamil, M; Rhee, J T; Ahmad, Farzana; Jeon, Y J

    2016-04-01

    A useful approach for the enhancement of thermal neutrons detection has been reported here. This technique, based on the angular and micro pattern effects, has been developed and applied to the boron-coated ((10)B) Gas Electron multiplier (GEM) detector. In the angular effect case, as a general rule, the detector device is turned at an angle which improves the device response per unit area of the detector. While for the latter case, a regular pattern in the form of micrometer deep grooves is fabricated onto the converter coating, consequently it enhances the capture probability of the detector. For the current study, both of these techniques using a (10)B-coated GEM detector have been simulated for low energy neutrons. For the evaluation of detector response thermal neutrons in the energy ranges from 25meV to 100meV were transported onto the detector surface. For this work, FLUKA MC code has been utilized. The output in both cases has been estimated as a function of incident thermal neutron energies. By employing both techniques, the angle and the micro pattern dependent efficiencies for (10)B-coated GEM detectors are presented, which indicate an improved efficiency response of the device. We anticipate that by using these modifications can lead a further forward step in the development and improvement of thermal neutron detection technology.

  13. A Test of GEMS Astrometric Precision for Exoplanet Detection and Mass Measurement

    NASA Astrophysics Data System (ADS)

    Ammons, S. Mark; Marois, Christian; Macintosh, Bruce; Konopacky, Quinn; Neichel, Benoit; Galicher, Raphael; Bendek, Eduardo; Guyon, Olivier

    2014-08-01

    Precision astrometry is so far the only mainstream exoplanet detection technique that has yet to find a new planet. The unique capabilities of GeMS and GSAOI may finally be what we have been waiting for: the combination of a large aperture and wide-field AO correction for stable high-resolution wide-field diffraction-limited imaging. As part of this program, we have observed the astrometric calibrator star TYC 7122-00041-1 to demonstrate GeMS' long-term astrometric precision of < 0.4 mas in sparse fields (Ammons et al. 2013). Here, we propose two more epochs on the closest brown dwarf pair at 2 pc, WISE J1049-53 (Luhman 2013), newly discovered with Gemini in 2013 to be the third closest system known. GEMS will in one year obtain the best available projected relative orbits and a < 1% trigonometric distance, enabling precision masses and luminosity measurements for both L/T transition components of WISE 1049-53.

  14. The HadGEM2-ES implementation of CMIP5 centennial simulations

    SciTech Connect

    Jones, C. D.; Hughes, JK; Bellouin, N; Hardimann, SC; Jones, GS; Knight, J; Liddicoat, S; O'Connor, FM; Andres, Robert Joseph; Bell, C; Boo, K-O; Bozzo, A; Butchart, N; Cadule, P; Corbin, KD; Doutriaux-Boucher, M; Friedlingstein, P; Gornall, J; Gray, L; Halloran, PR; Hurtt, G; Ingram, WJ; Lamarque, J-F; Law, RM; Meinshausen, M; Osprey, S; Palin, E J; Parsons Chini, L; Raddatz, T; Sanderson, M G; Sellar, A A; Schurer, A; Valdes, P; Wood, N; Woodward, S; Yoshioka, M; Zerroukat, M

    2011-01-01

    The scientific understanding of the Earth s climate system, including the central question of how the climate system is likely to respond to human-induced perturbations, is comprehensively captured in GCMs and Earth System Models (ESM). Diagnosing the simulated climate response, and comparing responses across different models, is crucially dependent on transparent assumptions of how the GCM/ESM has been driven especially because the implementation can involve subjective decisions and may differ between modelling groups performing the same experiment. This paper outlines the climate forcings and setup of the Met Office Hadley Centre ESM, HadGEM2-ES for the CMIP5 set of centennial experiments. We document the prescribed greenhouse gas concentrations, aerosol precursors, stratospheric and tropospheric ozone assumptions, as well as implementation of land-use change and natural forcings for the HadGEM2-ES historical and future experiments following the Representative Concentration Pathways. In addition, we provide details of how HadGEM2-ES ensemble members were initialised from the control run and how the palaeoclimate and AMIP experiments, as well as the emissiondriven RCP experiments were performed.

  15. Performance verification of the Gravity and Extreme Magnetism Small explorer (GEMS) x-ray polarimeter

    NASA Astrophysics Data System (ADS)

    Enoto, Teruaki; Black, J. Kevin; Kitaguchi, Takao; Hayato, Asami; Hill, Joanne E.; Jahoda, Keith; Tamagawa, Toru; Kaneko, Kenta; Takeuchi, Yoko; Yoshikawa, Akifumi; Marlowe, Hannah; Griffiths, Scott; Kaaret, Philip E.; Kenward, David; Khalid, Syed

    2014-07-01

    Polarimetry is a powerful tool for astrophysical observations that has yet to be exploited in the X-ray band. For satellite-borne and sounding rocket experiments, we have developed a photoelectric gas polarimeter to measure X-ray polarization in the 2-10 keV range utilizing a time projection chamber (TPC) and advanced micro-pattern gas electron multiplier (GEM) techniques. We carried out performance verification of a flight equivalent unit (1/4 model) which was planned to be launched on the NASA Gravity and Extreme Magnetism Small Explorer (GEMS) satellite. The test was performed at Brookhaven National Laboratory, National Synchrotron Light Source (NSLS) facility in April 2013. The polarimeter was irradiated with linearly-polarized monochromatic X-rays between 2.3 and 10.0 keV and scanned with a collimated beam at 5 different detector positions. After a systematic investigation of the detector response, a modulation factor >=35% above 4 keV was obtained with the expected polarization angle. At energies below 4 keV where the photoelectron track becomes short, diffusion in the region between the GEM and readout strips leaves an asymmetric photoelectron image. A correction method retrieves an expected modulation angle, and the expected modulation factor, ~20% at 2.7 keV. Folding the measured values of modulation through an instrument model gives sensitivity, parameterized by minimum detectable polarization (MDP), nearly identical to that assumed at the preliminary design review (PDR).

  16. A Cylindrical GEM Detector with Analog Readout for the BESIII Experiment

    SciTech Connect

    Cibinetto, G.

    2015-07-01

    Inner Trackers (IT) are key detectors in Particle Physics experiments; excellent spatial resolution, radiation transparency and hardness, and operability under high occupancies are main requirements. We aim to design, build and commission by 2017 a Cylindrical GEM (CGEM) detector candidate to be the new IT of the BESIII spectrometer, hosted on BEPC2 in IHEP, Beijing; BESIII data taking will last until at least 2020. The IT itself will represent an evolution w.r.t. the state of the art of GEM detectors, since the use of new kind of mechanical supports for the GEM foils will reduce the total radiation length of the detector and improve its tracking performance; an innovative design of the CGEM anode will allow for smaller capacitance and hence for bigger signals. The relatively strong BESIII magnetic field requires a new analogue readout; full custom front-end electronics, including a dedicated ASIC, will be designed and produced for optimal data collection. Prototype Beam Test results showing the measurement of the spatial resolution in a 1 Tesla magnetic field will be presented among with the mechanical design and simulations. (authors)

  17. Technological aspects of GEM detector design and assembling for soft x-ray application

    NASA Astrophysics Data System (ADS)

    Kowalska-Strzeciwilk, E.; Chernyshova, M.

    2016-09-01

    Various types of Micro Pattern Gas Detectors (MPGDs) found applications as tracking detectors in high energy particle physics experiments and as well as imaging detectors, especially for soft X-rays. These detectors offer several advantages like high count rate capability, good spatial and energy resolution, low cost and possibility of constructing large area detectors with very small dead area. Construction, like the triple Gas Electron Multiplier (GEM) detector has become a standard detector, which is widely used for different imaging applications. Some examples of such applications are: monitoring the impurity in plasma, imaging system for mapping of some parameters like pigment distributions using X-ray fluorescence technique[1], proton range radiography system for quality assurance in hadron therapy. Measuring of the Soft X-Ray (SXR) radiation of magnetic fusion plasma is a standard way of accessing valuable information, for example, about particle transport and MHD. The paper is focused on the design of GEM based soft Xray radiation detecting system which is under development. It is dedicated to study soft X-ray emission of plasma radiation with focus on tungsten emission lines energy region. The paper presents the designing, construction and assembling of a prototype of two triple-GEM detectors for soft-X ray application on the WEST device.

  18. Organe der Osmoregulation und Exkretion

    NASA Astrophysics Data System (ADS)

    Møbjerg, Nadja

    Die meisten Schädeltiere sind in der Lage, die Wasser- und Ionenkonzentration ihres Innenmilieus zu regulieren, sind also im Hinblick auf ihren Ionenhaushalt weitgehend unabhängig von der Umgebung. Sie halten die Konzentration von Wasser und anorganischen Ionen in ihren Körperflüssigkeiten (interstitielle Flüssigkeit und Blut) innerhalb enger Grenzen konstant (Osmoregulierer). Schleim aale (Myxinoida) können zwar die Konzentration einzelner anorganischer Ionen regulieren, sind aber insgesamt der hohen Osmolarität des Meerwassers angepasst, also isoosmostisch zu diesem. Isoosmotisch oder leic ht hyperosmostisch zur Umgebung sind auch marine Neoselachier und Latimeria chalumnae (Actinistia), die dazu organische Osmolyte (Harnstoff und Trimethylaminoxid) im Blut akkumulieren (Osmokonformer). Bei anderen aquatischen Schädeltieren sind die Körperflüssigkeiten zur Umgebung hypoosmotisch (im Meerwasser) — sie halten Wasser zurück und scheiden anorganiche Ionen aus — oder hyperosmotisch (im Süßwasser), indem sie Wasser abgeben und anorganische Ionen aufnehmen.

  19. ISC-GEM: Global Instrumental Earthquake Catalogue (1900-2009), II. Location and seismicity patterns

    NASA Astrophysics Data System (ADS)

    Bondár, I.; Engdahl, E. Robert; Villaseñor, A.; Harris, James; Storchak, D.

    2015-02-01

    We present the final results of a two-year project sponsored by the Global Earthquake Model (GEM) Foundation. The ISC-GEM global catalogue consists of some 19 thousand instrumentally recorded, moderate to large earthquakes, spanning 110 years of seismicity. We relocated all events in the catalogue using a two-tier approach. The EHB location methodology (Engdahl et al., 1998) was applied first to obtain improved hypocentres with special focus on the depth determination. The locations were further refined in the next step by fixing the depths to those from the EHB analysis and applying the new International Seismological Centre (ISC) location algorithm (Bondár and Storchak, 2011) that reduces location bias by accounting for correlated travel-time prediction error structure. To facilitate the relocation effort, some one million seismic P and S wave arrival-time data were added to the ISC database for the period between 1904 and 1970, either from original station bulletins in the ISC archive or by digitizing the scanned images of the International Seismological Summary (ISS) bulletin (Villaseñor and Engdahl, 2005, 2007). Although no substantial amount of new phase data were acquired for the modern period (1964-2009), the number of phases used in the location has still increased by three millions, owing to fact that both the EHB and ISC locators use most well-recorded ak135 (Kennett et al., 1995) phases in the location. We show that the relocation effort yielded substantially improved locations, especially in the first half of the 20th century; we demonstrate significant improvements in focal depth estimates in subduction zones and other seismically active regions; and we show that the ISC-GEM catalogue provides an improved view of 110 years of global seismicity of the Earth. The ISC-GEM Global Instrumental Earthquake Catalogue represents the final product of one of the ten global components in the GEM program, and is available to researchers at the ISC (http://www.isc.ac.uk).

  20. Quantitative Analyse und Visualisierung der Herzfunktionen

    NASA Astrophysics Data System (ADS)

    Sauer, Anne; Schwarz, Tobias; Engel, Nicole; Seitel, Mathias; Kenngott, Hannes; Mohrhardt, Carsten; Loßnitzer, Dirk; Giannitsis, Evangelos; Katus, Hugo A.; Meinzer, Hans-Peter

    Die computergestützte bildbasierte Analyse der Herzfunktionen ist mittlerweile Standard in der Kardiologie. Die verfügbaren Produkte erfordern meist ein hohes Maß an Benutzerinteraktion und somit einen erhöhten Zeitaufwand. In dieser Arbeit wird ein Ansatz vorgestellt, der dem Kardiologen eine größtenteils automatische Analyse der Herzfunktionen mittels MRT-Bilddaten ermöglicht und damit Zeitersparnis schafft. Hierbei werden alle relevanten herzphysiologsichen Parameter berechnet und mithilfe von Diagrammen und Graphen visualisiert. Diese Berechnungen werden evaluiert, indem die ermittelten Werte mit manuell vermessenen verglichen werden. Der hierbei berechnete mittlere Fehler liegt mit 2,85 mm für die Wanddicke und 1,61 mm für die Wanddickenzunahme immer noch im Bereich einer Pixelgrösse der verwendeten Bilder.

  1. Amplituden der Kernphasen im Bereich der Kaustik B und Untersuchung der Struktur der Übergangszone zum inneren Erdkern mit spektralen Amplituden der diffraktierten Phase PKP(BC)

    NASA Astrophysics Data System (ADS)

    Wolf, Michael D. C.

    2002-04-01

    Das Ziel dieser Arbeit ist es, die Strukturen im äueren Erdkern zu untersuchen und Rückschlüsse auf die sich daraus ergebenden Konsequenzen für geodynamische Modellvorstellungen zu ziehen. Die Untersuchung der Kernphasenkaustik B mit Hilfe einer kumulierten Amplituden-Entfernungskurve ist Gegenstand des ersten Teils. Dazu werden die absoluten Amplituden der PKP-Phasen im Entfernungsbereich von 142 ° bis 147 ° bestimmt und mit den Amplituden synthetischer Seismogramme verglichen. Als Datenmaterial dienen die Breitbandregistrierungen des Deutschen Seismologischen Re-gionalnetzes (GRSN 1 ) und des Arrays Gräfenberg (GRF). Die verwendeten Wellen-formen werden im WWSSN-SP-Frequenzbereich gefiltert. Als Datenbasis dienen vier Tiefherdbeben der Subduktionszone der Neuen Hebriden (Vanuatu Island) und vier Nuklearexplosionen, die auf dem Mururoa und Fangataufa Atoll im Südpazifik stattgefunden haben. Beide Regionen befinden sich vom Regionalnetz aus gesehen in einer Epizentraldistanz von ungefähr 145 °. Die Verwendung eines homogen instrumentierten Netzes von Detektoren und die Anwendung von Stations- und Magnitudenkorrekturen verringern den Hauptteil der Streuung bei den Amplitudenwerten. Dies gilt auch im Vergleich zu Untersuchungen von langperiodischen Amplituden im Bereich der Kernphasenkaustik (Häge, 1981). Ein weiterer Grund für die geringe Streuung ist die ausschlieliche Verwendung von Ereignissen mit kurzer impulsiver Herdzeitfunktion. Erst die geringe Streuung der Amplitudenwerte ermöglicht eine Interpretation der Daten. Die theoretischen Amplitudenkurven der untersuchten Erdmodelle zeigen im Bereich der Kaustik B einen gleichartigen Kurvenverlauf. Bei allen Berechnungen wird ein einheitliches Modell für die Güte der P- und S-Wellen verwendet, das sich aus den Q-Werten der Modelle CIT112 und PREM 2 zusammensetzt. Die mit diesem Q-Modell berechneten Amplituden liegen in geringem Mae oberhalb der gemessenen Amplituden. Dies braucht nicht ber

  2. The GAPs, GEFs, GDIs and…now, GEMs: New kids on the heterotrimeric G protein signaling block.

    PubMed

    Ghosh, Pradipta; Rangamani, Padmini; Kufareva, Irina

    2017-03-13

    The canonical process of activation of heterotrimeric G proteins by G protein coupled receptors (GPCRs) is well studied. Recently, a rapidly emerging paradigm has revealed the existence of a new, non-canonical set of cytosolic G protein modulators, guanine exchange modulators (GEMs). Among G proteins regulators, GEMs are uniquely capable of initiating pleiotropic signals: these bifunctional modulators can activate cAMP inhibitory (Gi) proteins and inhibit cAMP-stimulatory (Gs) proteins through a single short evolutionarily conserved module. A prototypical member of the GEM family, GIV/Girdin, integrates signals downstream of a myriad of cell surface receptors, e.g., growth factor RTKs, integrins, cytokine, GPCRs, etc., and translates these signals into G protein activation or inhibition. By their pleiotropic action, GIV and other GEMs modulate several key pathways within downstream signaling network. Unlike canonical G protein signaling that is finite and is triggered directly and exclusively by GPCRs, the temporal and spatial features of non-canonical activation of G protein via GIV-family of cytosolic GEMs are unusually relaxed. GIV uses this relaxed circuitry to integrate, reinforce and compartmentalize signals downstream of both growth factors and G proteins in a way that enables it to orchestrate cellular phenotypes in a sustained manner. Mounting evidence suggests the importance of GIV and other GEMs as disease modulators and their potential to serve as therapeutic targets; however, a lot remains unknown within the layers of the proverbial onion that must be systematically peeled. This perspective summarizes the key concepts of the GEM-dependent G protein signaling paradigm and discusses the multidisciplinary approaches that are likely to revolutionize our understanding of this paradigm from the atomic level to systems biology.

  3. Friedrich Möglich - sein Beitrag zum Aufbau der Physik in der DDR. Friedrich Möglich - langjähriger Mitherausgeber und Chefredakteur der Annalen der Physik

    NASA Astrophysics Data System (ADS)

    Rompe, Robert

    Friedrich Möglich, ein Schüler von Max von Laue und Erwin Schrödinger, übernahm 1947 die Chefredaktion der Annalen der Physik.Translated AbstractFriedrich Möglich - His Contributions to the Formation of Physics in GDRFriedrich Möglich a student of Max von Laue and Erwin Schrödinger took over as editor in chief of Annalen der Physik in 1947.

  4. Tycho Brahe - Instrumentenbauer und Meister der Beobachtungstechnik

    NASA Astrophysics Data System (ADS)

    Wolfschmidt, Gudrun

    Vor der Erfindung des Fernrohrs war der dänische Astronom Tycho Brahe (1546 - 1601) der bedeutendste beobachtende Astronom. Von seinem Observatorium Uraniborg auf der - damals dänischen - Insel Hven ist heute noch der Grundriß erkennbar, von Stjerneborg sind die Fundamente erhalten, die Kuppeln in den 1950er Jahren ergänzt. In der Astronomie-Ausstellung im Deutschen Museum gibt es ein Modell der Sternwarte Uraniborg und der zugehörigen Instrumente (Maßstab 1:10); das größere Modell wurde dem Technischen Museum in Malmö geschenkt. Die Instrumente, die er in den Observatorien Uraniborg und Stjerneborg benutzte, sind nicht erhalten. Aber es gibt gute Beschreibungen der Instrumente (Halbkreis, Quadranten, Sextanten, Armillarsphären, Triquetrum, Himmelsglobus) in seinem Buch Astronomiae instauratae mechanica (Wandsbek 1598). Eine Nachbildung des großen hölzernen Quadranten kann man im Runden Turm in Kopenhagen sehen. Zwei Sextanten, hergestellt für Tycho um 1600 von Jost Bürgi und Erasmus Habermel, gibt es noch im Nationalmuseum für Technik in Prag. Ähnlichkeiten von Tychos Instrumenten mit Groß-Instrumenten aus dem islamischen Kulturkreis sind auffällig. Tycho Brahes Meßgeräte markieren einen großen Fortschritt in der Entwicklung astronomischer Instrumente und Meßtechniken und bilden die Grundlage für den weiteren Fortschritt der Positionsastronomie und der damit verbundenen Tabellenwerke. Die Nachwirkungen sind bis ins 17. und 18. Jahrhundert nachweisbar.

  5. Untersuchung der Richtwirkung der Einkopplung von ebenen Wellen in eine Leitung

    NASA Astrophysics Data System (ADS)

    Magdowski, M.; Vick, R.

    2013-07-01

    Elektrische Leitungen und Kabel stellen häufig die Haupteinfallstore für elektromagnetische Felder in die daran angeschlossenen Geräte und Systeme dar. Für die Einkopplung einer ebenen Welle kann der in eine Leitung eingekoppelte Strom unter bestimmten Voraussetzungen mit Hilfe der Leitungstheorie sehr effizient bestimmt werden. Er hängt dabei von den Abmessungen der Leitung, den Leitungsabschlüssen sowie der Amplitude, der Wellenlänge und der Einfallsrichtung der ebenen Welle ab. In dieser Arbeit wird die Abhängigkeit der Einkopplung von der Einfallsrichtung näher untersucht. Dazu werden Richtdiagramme der Einkopplung berechnet, dargestellt und hinsichtlich der mittleren und maximalen Einkopplung über alle Einfallsrichtungen und Polarisationen ausgewertet. Die Ergebnisse werden genutzt, um die maximale Direktivität der Einkopplung in eine Leitung zu bestimmen. Fasst man die Einkopplung externer Felder in eine Leitung als einen Störfestigkeitstest auf, so kann die maximale Direktivität benutzt werden, um einen Vergleich zwischen unterschiedlichen Messumgebungen wie Absorberhallen und Modenverwirbelungskammern herzustellen.

  6. Modelling two-way interactions between atmospheric pollution and weather using high-resolution GEM-MACH

    NASA Astrophysics Data System (ADS)

    Makar, Paul; Gong, Wanmin; Pabla, Balbir; Cheung, Philip; Milbrandt, Jason; Gravel, Sylvie; Moran, Michael; Gilbert, Samuel; Zhang, Junhua; Zheng, Qiong

    2013-04-01

    The Global Environmental Multiscale (GEM) model is the source of the Canadian government's operational numerical weather forecast guidance, and GEM-MACH is the Canadian operational air-quality forecast model. GEM-MACH comprises GEM and the 'Modelling Air-quality and Chemistry' module, a gas-phase, aqueous-phase and aerosol chemistry and microphysics subroutine package called from within GEM's physics module. The present operational GEM-MACH model is "on-line" (both chemistry and meteorology are part of the same modelling structure) but is not fully coupled (weather variables are provided as inputs to the chemistry, but the chemical variables are not used to modify the weather). In this work, we describe modifications made to GEM-MACH as part of the 2nd phase of the Air Quality Model Evaluation International Initiative, in order to bring the model to a fully coupled status and present the results of initial tests comparing uncoupled and coupled versions of the model to observations for a high-resolution forecasting system. Changes to GEM's cloud microphysics and radiative transfer packages were carried out to allow two-way coupling. The cloud microphysics package used here is the Milbrandt-Yau 2-moment (MY2) bulk microphysics scheme, which solves prognostic equations for the total droplet number concentration and the mass mixing ratios of six hydrometeor categories. Here, we have replaced the original cloud condensation nucleation parameterization of MY2 (empirically relating supersaturation and CCN number) with the aerosol activation scheme of Abdul-Razzak and Ghan (2002). The latter scheme makes use of the particle size and speciation distribution of GEM-MACH's chemistry code as well as meteorological inputs to predict the number of aerosol particles activated to form cloud droplets, which is then used in the MY2 microphysics. The radiative transfer routines of GEM assume a default constant concentration aerosol profile between the surface and 1500m, and a single

  7. Towards an automatic system for monitoring of CN2 and wind speed profiles with GeMS

    NASA Astrophysics Data System (ADS)

    Masciadri, Elena; Neichel, Benoit; Guesalaga, Andres; Turchi, Alessio

    2016-07-01

    Wide Field Adaptive Optics (WFAO) systems represent the more sophisticated AO systems available today at large telescopes. One critical aspect for these WFAO systems in order to deliver an optimised performance is the knowledge of the vertical spatiotemporal distribution of the CN2 and the wind speed. Previous studies (Cortes et al., 2012[1]) already proved the ability of GeMS (the Gemini Multi-Conjugated AO system) in retrieving CN2 and wind vertical stratification using the telemetry data. To assess the reliability of the GeMS wind speed estimates a preliminary study (Neichel et al., 2014[2]) compared wind speed retrieved from GeMS with that obtained with the atmospherical model Meso-Nh on a small sample of nights providing promising results. The latter technique is very reliable for the wind speed vertical stratification. The model outputs gave, indeed, an excellent agreement with a large sample of radiosoundings ( 50) both in statistical terms and on individual flights (Masciadri et al., 2013[3]). Such a tool can therefore be used as a valuable reference in this exercise of cross calibrating GeMS on-sky wind estimates with model predictions. The main results of Neichel et al. (2014) analysis showed that, on a great number of cases, GeMS could reconstruct very good wind speed estimates. At the same time it has been put in evidence, on a number of cases, not negligible discrepancies from the atmospherical model. However we observed that these discrepancies strongly decreased or even disappear if GeMS data reduction is done with the a priori knowledge of the wind speed stratification provided by the model Meso-Nh. Basically the a priori knowledge helped the data reduction of GeMS acquisitions. In this contribution we achieved a two-fold results: (1) we extended analysis on a much richer statistical sample ( 43 nights), we confirmed the preliminary results and we found an even better correlation between GeMS observations and the atmospherical model with basically

  8. Idealized climate change simulations with a high-resolution physical model: HadGEM3-GC2

    NASA Astrophysics Data System (ADS)

    Senior, Catherine A.; Andrews, Timothy; Burton, Chantelle; Chadwick, Robin; Copsey, Dan; Graham, Tim; Hyder, Pat; Jackson, Laura; McDonald, Ruth; Ridley, Jeff; Ringer, Mark; Tsushima, Yoko

    2016-06-01

    Idealized climate change simulations with a new physical climate model, HadGEM3-GC2 from The Met Office Hadley Centre are presented and contrasted with the earlier MOHC model, HadGEM2-ES. The role of atmospheric resolution is also investigated. The Transient Climate Response (TCR) is 1.9 K/2.1 K at N216/N96 and Effective Climate Sensitivity (ECS) is 3.1 K/3.2 K at N216/N96. These are substantially lower than HadGEM2-ES (TCR: 2.5 K; ECS: 4.6 K) arising from a combination of changes in the size of climate feedbacks. While the change in the net cloud feedback between HadGEM3 and HadGEM2 is relatively small, there is a change in sign of its longwave and a strengthening of its shortwave components. At a global scale, there is little impact of the increase in atmospheric resolution on the future climate change signal and even at a broad regional scale, many features are robust including tropical rainfall changes, however, there are some significant exceptions. For the North Atlantic and western Europe, the tripolar pattern of winter storm changes found in most CMIP5 models is little impacted by resolution but for the most intense storms, there is a larger percentage increase in number at higher resolution than at lower resolution. Arctic sea-ice sensitivity shows a larger dependence on resolution than on atmospheric physics.

  9. STRONG VARIABLE ULTRAVIOLET EMISSION FROM Y GEM: ACCRETION ACTIVITY IN AN ASYMPTOTIC GIANT BRANCH STAR WITH A BINARY COMPANION?

    SciTech Connect

    Sahai, Raghvendra; Neill, James D.; Gil de Paz, Armando; Sanchez Contreras, Carmen

    2011-10-20

    Binarity is believed to dramatically affect the history and geometry of mass loss in asymptotic giant branch (AGB) and post-AGB stars, but observational evidence of binarity is sorely lacking. As part of a project to look for hot binary companions to cool AGB stars using the Galaxy Evolution Explorer archive, we have discovered a late-M star, Y Gem, to be a source of strong and variable UV emission. Y Gem is a prime example of the success of our technique of UV imaging of AGB stars in order to search for binary companions. Y Gem's large and variable UV flux makes it one of the most prominent examples of a late-AGB star with a mass accreting binary companion. The UV emission is most likely due to emission associated with accretion activity and a disk around a main-sequence companion star. The physical mechanism generating the UV emission is extremely energetic, with an integrated luminosity of a few x L{sub sun} at its peak. We also find weak CO J = 2-1 emission from Y Gem with a very narrow line profile (FWHM of 3.4 km s{sup -1}). Such a narrow line is unlikely to arise in an outflow and is consistent with emission from an orbiting, molecular reservoir of radius 300 AU. Y Gem may be the progenitor of the class of post-AGB stars which are binaries and possess disks but no outflows.

  10. Sequence polymorphisms of Der f 1, Der p 1, Der f 2 and Der p 2 from Korean house dust mite isolates.

    PubMed

    Jeong, Kyoung Yong; Lee, In-Yong; Yong, Tai-Soon; Lee, Jae-Hyun; Kim, Eun-Jin; Lee, Joo-Shil; Hong, Chein-Soo; Park, Jung-Won

    2012-09-01

    Amino acid sequence variations have possible influences on the allergenicity of allergens and may be important factors in allergen standardization. This study was undertaken to investigate the sequence polymorphisms of group 1 and 2 allergens from Korean isolates of the house dust mites Dermatophagoides farinae and D. pteronyssinus. cDNA sequences encoding group 1 and 2 allergens were amplified by RT-PCR and compared the deduced amino acid sequences. Der f 1.0101, which appeared in 64.0 % of the 50 sequences analyzed, was found to be predominant. Among the Der p 1 sequences, Der p 1.0102 and 1.0105 were predominant (58 %). Among the Der f 2 sequences, Der f 2.0102 (40.7 %) and a new variant with Gly at position 42 (27.8 %) were predominant. The deduced amino acid sequences of 60 Der p 2 clones were examined, and 28 variants with 1-5 amino acid substitutions were found. Interestingly, all of the Der p 2 sequences had Thr instead of Lys at position 49. Two variants (Leu40, Thr49, and Asn114 (26.6 %); Val40, Thr49, and Asn114 (20.0 %)) were found to be the most predominant forms of Der p 2. Der p 1 has a high rate of sporadic substitutions and the group 2 allergens show a more regular pattern with orderly associations of amino acid substitutions. Der f 1 and Der p 2 from Korean mite isolates have unique amino acid sequence polymorphisms. These findings provide important data for house dust mite allergen standardization.

  11. Von Humboldt bis Einstein. Berlin als Weltzentrum der exakten Wissenschaften.

    NASA Astrophysics Data System (ADS)

    Meschkowski, H.

    Contents: 1. Die Anfänge. 2. Die Ära Dirichlet-Jacobi. 3. Der Ausbau der experimentellen Naturwissenschaften. 4. Alexander von Humboldt. 5. Berlin wird "Weltzentrum" der Mathematik. 6. Die Ära Helmholtz. 7. Neue Arbeitsweisen der Astronomie. 8. Chemie: Forschung und Industrie. 9. Max Planck. 10. Ins technische Zeitalter. 11. Zur Mathematik der zwanziger Jahre. 12. Albert Einstein. 13. Fortschritte der Grundlagenforschung. 14. Erwin Schrödinger: Physiker, Philosoph und Poet. 15. Zum Schluß.

  12. Der Kalte Krieg in der Peripherie Griechische Physiker und Atomenergie nach dem Zweiten Weltkrieg

    NASA Astrophysics Data System (ADS)

    Vlahakis, George N.

    Die vorliegende Arbeit analysiert Ansichten griechischer Physiker zur Atomenergie und deren mögliche Anwendung nach dem Zweiten Weltkrieg, insbesondere während des Kalten Kriegs. Einerseits werden Ansichten von Physik- Professoren griechischer Universitäten präsentiert - beispielsweise von Dimitrios Hondros, der Student von Arnold Sommerfeld und Mitarbeiter von Peter Debye in München war, und andererseits wird die Politik der griechischen Regierung für die Etablierung eines Forschungsinstitutes diskutiert, das der Entwicklung der Atomenergie dienen sollte; ebenfalls wird eine öffentliche Meinungsumfrage zu diesen Thema, die in den Tageszeitungen der damaligen Zeit präsentiert wurde, diskutiert.

  13. Ambient water quality in aquifers used for drinking-water supplies, Gem County, southwestern Idaho, 2015

    USGS Publications Warehouse

    Bartolino, James R.; Hopkins, Candice B.

    2016-12-20

    In recent years, the rapid population growth in Gem County, Idaho, has been similar to other counties in southwestern Idaho, increasing about 54 percent from 1990 to 2015. Because the entire population of the study area depends on groundwater for drinking water supply (either from self-supplied domestic, community, or municipal-supply wells), this population growth, along with changes in land use (including potential petroleum exploration and development), indicated to the public and local officials the need to assess the quality of groundwater used for human consumption. To this end, the U.S. Geological Survey, in cooperation with Gem County and the Idaho Department of Environmental Quality, assessed the quality of groundwater from freshwater aquifers used for domestic supply in Gem County. A total of 47 domestic or municipal wells, 1 spring, and 2 surface-water sites on the Payette River were sampled during September 8–November 19, 2015. The sampled water was analyzed for a variety of constituents, including major ions, trace elements, nutrients, bacteria, radionuclides, dissolved gasses, stable isotopes of water and methane, and either volatile organic compounds (VOCs) or pesticides.To better understand analytical results, a conceptual hydrogeologic framework was developed in which three hydrogeologic units were described: Quaternary-Tertiary deposits (QTd), Tertiary Idaho Group rocks (Tig), and Tertiary-Cretaceous igneous rocks (TKi). Water levels were measured in 30 wells during sampling, and a groundwater-level altitude map was constructed for the QTd and Tig units showing groundwater flow toward the Emmett Valley and Payette River.Analytical results indicate that groundwater in Gem County is generally of good quality. Samples collected from two wells contained water with fluoride concentrations greater than the U.S. Environmental Protection Agency (EPA) Maximum Contaminant Level (MCL) of 4 milligrams per liter (mg/L), six wells contained arsenic at

  14. The GEM Theory of the Unification of Gravitation and Electro-Magnetism

    NASA Astrophysics Data System (ADS)

    Brandenburg, J. E.

    2012-01-01

    The GEM (Gravity Electro-Magnetism), theory is presented as an alloy of Sakharov and Kaluza-Klein approaches to field unification. GEM uses the concept of gravity fields as Poynting fields to postulate that the non-metric portion of the EM stress tensor becomes the metric tensor in strong fields leading to "self-censorship". Covariant formulation of the GEM theory is accomplished through definition of the spacetime metric tensor as a portion of the EM stress tensor normalized by its own trace: gab = 4(FcaFcb )/(FabFab), it is found that this results in a massless ground state vacuum and a Newtonian gravitation potential f=1/2 E2/B2 =GM/r , where E, B and F are part of the vacuum Zero Point Fluctuation (ZPF) and M and r are the mass and distance from the center of a gravitating body and G is the Newton gravitation constant. It is found that a Lorentz flat-space metric is recovered in the limit of a vacuum full spectrum ZPF. The vacuum ZPF energy and vacuum quantities G, h, c, gives birth to particles quantities mp, me, e,-e in a process triggered by the appearance of the Kaluza-Klein fifth dimension, where also the EM and gravity forces split from each other in a process correlated to the splitting apart of protons and electrons. The separate appearance of the proton and electron occurs as the splitting of a light-like spacetime interval of zero-length into a finite space-like portion containing three subdimensions identified with the quarks and a time-like portion identified with the electron. The separation of mass with charge for the electron and proton pair comes about from a U(1) symmetry with a rotation in imaginary angle. A logarithmic variation of charge with mass for the proton-electron pair results and leads to the formula ln(ro/rp) = s, where s = (mp/me)1/2 , where mp and me are the electron and proton masses respectively and where ro =e2/moc2 , and where mo = (mpme)1/2 and where rp is the Planck length . This leads to the formula G=e2/mo2aexp(-2s)=6

  15. Multiplexed barcoded CRISPR-Cas9 screening enabled by CombiGEM

    PubMed Central

    Wong, Alan S. L.; Choi, Gigi C. G.; Cui, Cheryl H.; Pregernig, Gabriela; Milani, Pamela; Adam, Miriam; Perli, Samuel D.; Kazer, Samuel W.; Gaillard, Aleth; Hermann, Mario; Shalek, Alex K.; Fraenkel, Ernest; Lu, Timothy K.

    2016-01-01

    The orchestrated action of genes controls complex biological phenotypes, yet the systematic discovery of gene and drug combinations that modulate these phenotypes in human cells is labor intensive and challenging to scale. Here, we created a platform for the massively parallel screening of barcoded combinatorial gene perturbations in human cells and translated these hits into effective drug combinations. This technology leverages the simplicity of the CRISPR-Cas9 system for multiplexed targeting of specific genomic loci and the versatility of combinatorial genetics en masse (CombiGEM) to rapidly assemble barcoded combinatorial genetic libraries that can be tracked with high-throughput sequencing. We applied CombiGEM-CRISPR to create a library of 23,409 barcoded dual guide-RNA (gRNA) combinations and then perform a high-throughput pooled screen to identify gene pairs that inhibited ovarian cancer cell growth when they were targeted. We validated the growth-inhibiting effects of specific gene sets, including epigenetic regulators KDM4C/BRD4 and KDM6B/BRD4, via individual assays with CRISPR-Cas–based knockouts and RNA-interference–based knockdowns. We also tested small-molecule drug pairs directed against our pairwise hits and showed that they exerted synergistic antiproliferative effects against ovarian cancer cells. We envision that the CombiGEM-CRISPR platform will be applicable to a broad range of biological settings and will accelerate the systematic identification of genetic combinations and their translation into novel drug combinations that modulate complex human disease phenotypes. PMID:26864203

  16. GEM-based TPC with CCD imaging for directional dark matter detection

    NASA Astrophysics Data System (ADS)

    Phan, N. S.; Lauer, R. J.; Lee, E. R.; Loomba, D.; Matthews, J. A. J.; Miller, E. H.

    2016-11-01

    The most mature directional dark matter experiments at present all utilize low-pressure gas Time Projection Chamber (TPC) technologies. We discuss some of the challenges for this technology, for which balancing the goal of achieving the best sensitivity with that of cost effective scale-up requires optimization over a large parameter space. Critical for this are the precision measurements of the fundamental properties of both electron and nuclear recoil tracks down to the lowest detectable energies. Such measurements are necessary to provide a benchmark for background discrimination and directional sensitivity that could be used for future optimization studies for directional dark matter experiments. In this paper we describe a small, high resolution, high signal-to-noise GEM-based TPC with a 2D CCD readout designed for this goal. The performance of the detector was characterized using alpha particles, X-rays, gamma-rays, and neutrons, enabling detailed measurements of electron and nuclear recoil tracks. Stable effective gas gains of greater than 1 × 105 were obtained in 100 Torr of pure CF4 by a cascade of three standard CERN GEMs each with a 140 μm pitch. The high signal-to-noise and sub-millimeter spatial resolution of the GEM amplification and CCD readout, together with low diffusion, allow for excellent background discrimination between electron and nuclear recoils down below ∼10 keVee (∼23 keVr fluorine recoil). Even lower thresholds, necessary for the detection of low mass WIMPs for example, might be achieved by lowering the pressure and utilizing full 3D track reconstruction. These and other paths for improvements are discussed, as are possible fundamental limitations imposed by the physics of energy loss.

  17. Multiplexed barcoded CRISPR-Cas9 screening enabled by CombiGEM.

    PubMed

    Wong, Alan S L; Choi, Gigi C G; Cui, Cheryl H; Pregernig, Gabriela; Milani, Pamela; Adam, Miriam; Perli, Samuel D; Kazer, Samuel W; Gaillard, Aleth; Hermann, Mario; Shalek, Alex K; Fraenkel, Ernest; Lu, Timothy K

    2016-03-01

    The orchestrated action of genes controls complex biological phenotypes, yet the systematic discovery of gene and drug combinations that modulate these phenotypes in human cells is labor intensive and challenging to scale. Here, we created a platform for the massively parallel screening of barcoded combinatorial gene perturbations in human cells and translated these hits into effective drug combinations. This technology leverages the simplicity of the CRISPR-Cas9 system for multiplexed targeting of specific genomic loci and the versatility of combinatorial genetics en masse (CombiGEM) to rapidly assemble barcoded combinatorial genetic libraries that can be tracked with high-throughput sequencing. We applied CombiGEM-CRISPR to create a library of 23,409 barcoded dual guide-RNA (gRNA) combinations and then perform a high-throughput pooled screen to identify gene pairs that inhibited ovarian cancer cell growth when they were targeted. We validated the growth-inhibiting effects of specific gene sets, including epigenetic regulators KDM4C/BRD4 and KDM6B/BRD4, via individual assays with CRISPR-Cas-based knockouts and RNA-interference-based knockdowns. We also tested small-molecule drug pairs directed against our pairwise hits and showed that they exerted synergistic antiproliferative effects against ovarian cancer cells. We envision that the CombiGEM-CRISPR platform will be applicable to a broad range of biological settings and will accelerate the systematic identification of genetic combinations and their translation into novel drug combinations that modulate complex human disease phenotypes.

  18. Application of GEM-based detectors in full-field XRF imaging

    NASA Astrophysics Data System (ADS)

    Dąbrowski, W.; Fiutowski, T.; Frączek, P.; Koperny, S.; Lankosz, M.; Mendys, A.; Mindur, B.; Świentek, K.; Wiącek, P.; Wróbel, P. M.

    2016-12-01

    X-ray fluorescence spectroscopy (XRF) is a commonly used technique for non-destructive elemental analysis of cultural heritage objects. It can be applied to investigations of provenance of historical objects as well as to studies of art techniques. While the XRF analysis can be easily performed locally using standard available equipment there is a growing interest in imaging of spatial distribution of specific elements. Spatial imaging of elemental distrbutions is usually realised by scanning an object with a narrow focused X-ray excitation beam and measuring characteristic fluorescence radiation using a high energy resolution detector, usually a silicon drift detector. Such a technique, called macro-XRF imaging, is suitable for investigation of flat surfaces but it is time consuming because the spatial resolution is basically determined by the spot size of the beam. Another approach is the full-field XRF, which is based on simultaneous irradiation and imaging of large area of an object. The image of the investigated area is projected by a pinhole camera on a position-sensitive and energy dispersive detector. The infinite depth of field of the pinhole camera allows one, in principle, investigation of non-flat surfaces. One of possible detectors to be employed in full-field XRF imaging is a GEM based detector with 2-dimensional readout. In the paper we report on development of an imaging system equipped with a standard 3-stage GEM detector of 10 × 10 cm2 equipped with readout electronics based on dedicated full-custom ASICs and DAQ system. With a demonstrator system we have obtained 2-D spatial resolution of the order of 100 μm and energy resolution at a level of 20% FWHM for 5.9 keV . Limitations of such a detector due to copper fluorescence radiation excited in the copper-clad drift electrode and GEM foils is discussed and performance of the detector using chromium-clad electrodes is reported.

  19. First Year K-12 Teachers as High Leverage Point to Implement GEMS Space Science Curriculum Sequence

    NASA Astrophysics Data System (ADS)

    Slater, Timothy F.; Mendez, B. J.; Schultz, G.; Wierman, T.

    2013-01-01

    The recurring challenge for curriculum developers is how to efficiently prepare K-12 classroom teachers to use new curricula. First-year teachers, numbering nearly 250,000 in the US each year, have the greatest potential to impact the largest number of students because they have potential to be in the classroom for thirty years. At the same time, these novice teachers are often the most open minded about adopting curricular innovation because they are not yet deeply entrenched in existing practices. To take advantage of this high leverage point, a collaborative of space scientists and science educators at the University of California, Berkeley’s Lawrence Hall of Science and Center for Science Education at the Space Sciences Laboratory with experts from the Astronomical Society of the Pacific, the University of Wyoming, and the CAPER Center for Astronomy & Physics Education experimented with a unique professional development model focused on helping master teachers work closely with pre-service teachers during their student teaching internship field experience. The Advancing Mentor and Novice Teachers in Space Science (AMANTISS) team first identified master teachers who supervise novice, student teachers and trained these master teachers to use the GEMS Space Science Curriculum Sequence. Then, these master teachers were mentored in coaching interning student teachers assigned to them in using GEMS materials. Evaluation showed that novice teachers mentored by the master teachers felt knowledgeable after teaching the GEMS units. However, they seemed relatively less confident about the solar system and objects beyond the solar system. Overall, mentees felt strongly at the end of the year that they have acquired good strategies for teaching the various topics, suggesting that the support they received while teaching and working with a mentor was of real benefit to them. Funding provided in part by NASA ROSES AMANTISS NNX09AD51G

  20. Topika und deren Einsatz in der Dermatologie.

    PubMed

    Wohlrab, Johannes

    2016-11-01

    Grundkenntnisse zur Zusammensetzung und den regulatorischen Hintergründen von Topika gehören zu den alltäglich benötigten Herausforderungen dermatologisch-ärztlichen Handelns. Ein professioneller und indikationsgerechter Umgang bei der Auswahl, Verordnung und Anwendung topischer Präparate ist somit Voraussetzung für eine verantwortungsvolle fachärztliche Tätigkeit. Dabei bereiten die regulatorische Zuordnung (Arzneimittel, Medizinprodukt, Kosmetikum), die Feststellung der Erstattungsfähigkeit durch die GKV und die unzureichende Kennzeichnung des Vehikelsystems einzelner Präparate nicht selten Probleme. Bestreben sollte es sein, neben der Wahl des geeigneten Wirkstoffs und der geeigneten Konzentration ein an die Indikation der Therapie angepasstes galenisches System auszuwählen, um dessen Eigenwirkung für den therapeutischen Effekt nutzen zu können. Bei der Verschreibung von Rezepturarzneimitteln sollte nach Möglichkeit immer auf eine standardisierte Rezeptur (Magistralrezeptur) zurückgegriffen werden. Durch die Vielzahl der möglichen Inhaltsstoffe und der sich daraus ergebenden Komplexität eines galenischen Systems ist eine willkürliche Manipulation durch qualitative oder quantitative Veränderungen einzelner Komponenten mit hohen Risiken für eine Instabilität und damit für Sicherheit und Sinnhaftigkeit verbunden. Eine optimierte Anwendung von Topika setzt zudem Grundlagenkenntnisse zur Pharmakokinetik und zur evidenzbasierten Therapieplanung voraus.

  1. A Continuously Running High-Rate GEM-TPC for P¯ANDA

    NASA Astrophysics Data System (ADS)

    Böhmer, F. V.; Angerer, H.; Dørheim, S.; Höppner, C.; Ketzer, B.; Konorov, I.; Neubert, S.; Paul, S.; Vandenbroucke, M.; Zhang, X.; Berger, M.; Cusanno, F.; Fabbietti, L.; Lalik, R.; Beck, R.; Kaiser, D.; Lang, M.; Schmitz, R.; Walther, D.; Winnebeck, A.; Zenke, F.; Arora, R.; Averbeckt, R.; Hehner, J.; Herrmannt, N.; Kleipa, V.; Kunkel, J.; Leifelst, Y.; Mladen, K.; Schmidt, C.; Schwab, S.; Soyk, D.; Voss, B.; Voss, J.; Weinert, J.; Zmeskal, J.

    2011-06-01

    The P¯ANDA fixed target experiment planned at FAIR will investigate fundamental questions of non-perturbative QCD. It makes use of a cooled antiproton beam (momentum: 1.5 to 15 GeV/c) and will reach luminosities of up to 2ṡ10 cm s, yielding a p¯p-annihilation rate of 2ṡ10 s. One option for the central tracker of P¯ANDA is a cylindrical, ungated, continuously running TPC with GEM-based gas amplification stage.

  2. The BlackGEM array in search of black hole mergers: integrated performance modelling

    NASA Astrophysics Data System (ADS)

    Roelfsema, Ronald; Klein Wolt, Marc; Bloemen, Steven; Groot, Paul; Bettonvil, Felix; Balster, Harry; Dolron, Peter; van Elteren, Arjen; Engels, Arno; de Haan, Menno; ter Horst, Rik; Kragt, Jan; Navarro, Ramon; Nelemans, Gijs; Paalberends, Willem Jelle; Pal, Sari; Raskin, Gert; Rutten, Harrie; Scheers, Bart; Schuil, Menno; Sybilski, Piotr

    2016-07-01

    The Radboud University Nijmegen in collaboration with the NOVA Optical Infrared Instrumentation group at ASTRON is currently leading the development and realization of the BlackGEM observing facility. The BlackGEM science team aims to be the first to catch the optical counterpart of a gravitational wave event. The BlackGEM project will put an array of three medium-sized optical telescopes at the La Silla site of the European Southern Observatory in Chile. It is uniquely equipped to achieve a combination of wide-field and high sensitivity through its array-like approach. Each BlackGEM unit telescope is a modified Dall-Kirkham-type telescope consisting of a 65cm primary mirror, a 21cm spherical secondary mirror and a triplet corrector lens. The spatial resolution on the sky will be 0.56 asec/pixel and the total field-of-view per telescope is 2.7 square degrees. The main requirement is to achieve a 5-sigma sensitivity of 23rd magnitude within a 5-minute exposure under 15 m/s wind gust conditions. This demands a very stable optical system with tight control of all the error contributions. This has been realized with a spreadsheet based integrated instrument model. The model contains all relevant telescope instrument parameters and environmental conditions. The spreadsheet is partly used for performance calculations and partly used to combine and integrate the output from several other sources. The spreadsheet model calculates the overall performance based on an Exposure Time Calculator using the Noise Equivalent Area metric (NEA). The NEA is further budgeted over 7 main High Level Requirements. The spreadsheet model is coupled to 1) a ZEMAX telescope optical model 2) a telescope FEM analysis to predict the optomechanical response under various gravity, temperature and wind load conditions, 3) a Matlab Simulink thermal model to predict the transient temperature behaviour of the most important telescope elements and 4) a Matlab Simulink control model to predict the

  3. GEMMA and GEMINI, two dedicated mixed-signal ASICs for Triple-GEM detectors readout

    NASA Astrophysics Data System (ADS)

    Pezzotta, A.; Croci, G.; Costantini, A.; De Matteis, M.; Tagnani, D.; Corradi, G.; Murtas, F.; Gorini, G.; Baschirotto, A.

    2016-03-01

    GEMMA and GEMINI, two integrated-circuit front-ends for the Triple-GEM detector are presented. These two ASICs aim to improve detector readout performance in terms of count rate, adaptability, portability and power consumption. GEMMA target is to embed counting, timing and spectroscopic measurements in a single 8-channel device, managing a detector capacitance up to 15 pF. On the other hand, GEMINI is dedicated to counting measurements, embedding 16 channels with a detector capacitance up to 40 pF. Both prototypes, fabricated in 130 nm and 180 nm CMOS respectively, feature an automatic on-chip calibration circuit, compensating for process/temperature variations.

  4. Modeling of serial data acquisition structure for GEM detector system in Matlab

    NASA Astrophysics Data System (ADS)

    Kolasinski, Piotr; Pozniak, Krzysztof T.; Czarski, Tomasz; Chernyshova, Maryna; Kasprowicz, Grzegorz; Krawczyk, Rafal D.; Wojenski, Andrzej; Zabolotny, Wojciech; Byszuk, Adrian

    2016-09-01

    This article presents method of modeling in Matlab hardware architecture dedicated for FPGA created by languages like VHDL or Verilog. Purposes of creating such type of model with its advantages and disadvantages are described. Rules presented in this article were exploited to create model of Serial Data Acquisition algorithm used in X-ray GEM detector system. Result were compared to real working model implemented in VHDL. After testing of basic structure, other two structures were modeled to see influence parameters of the structure on its behavior.

  5. Heterologous Expression of Der Homologs in an Escherichia coli der Mutant and Their Functional Complementation

    PubMed Central

    Choi, Eunsil; Kang, Nalae; Jeon, Young; Pai, Hyun-Sook

    2016-01-01

    ABSTRACT The unique Escherichia coli GTPase Der (double Era-like GTPase), which contains tandemly repeated GTP-binding domains, has been shown to play an essential role in 50S ribosomal subunit biogenesis. The depletion of Der results in the accumulation of precursors of 50S ribosomal subunits that are structurally unstable at low Mg2+ concentrations. Der homologs are ubiquitously found in eubacteria. Conversely, very few are conserved in eukaryotes, and none is conserved in archaea. In the present study, to verify their conserved role in bacterial 50S ribosomal subunit biogenesis, we cloned Der homologs from two gammaproteobacteria, Klebsiella pneumoniae and Salmonella enterica serovar Typhimurium; two pathogenic bacteria, Staphylococcus aureus and Neisseria gonorrhoeae; and the extremophile Deinococcus radiodurans and then evaluated whether they could functionally complement the E. coli der-null phenotype. Only K. pneumoniae and S. Typhimurium Der proteins enabled the E. coli der-null strain to grow under nonpermissive conditions. Sucrose density gradient experiments revealed that the expression of K. pneumoniae and S. Typhimurium Der proteins rescued the structural instability of 50S ribosomal subunits, which was caused by E. coli Der depletion. To determine what allows their complementation, we constructed Der chimeras. We found that only Der chimeras harboring both the linker and long C-terminal regions could reverse the growth defects of the der-null strain. Our findings suggest that ubiquitously conserved essential GTPase Der is involved in 50S ribosomal subunit biosynthesis in various bacteria and that the linker and C-terminal regions may participate in species-specific recognition or interaction with the 50S ribosomal subunit. IMPORTANCE In Escherichia coli, Der (double Era-like GTPase) is an essential GTPase that is important for the production of mature 50S ribosomal subunits. However, to date, its precise role in ribosome biogenesis has not been

  6. Quality Control of the Large-area GEM detectors at Production Sites for the CMS Muon Endcap Upgrade

    NASA Astrophysics Data System (ADS)

    Rahmani, Mehdi; CMS Collaboration

    2017-01-01

    GEM (Gas Electron Multipliers) detectors will be installed in the high-eta region of the CMS muon system by the year 2019. With precise tracking and fast trigger information, these detectors will significantly improve the CMS muon triggering after the second long shutdown of the LHC. There are six sites, external to CERN, where at total of 160 1-meter long GEM detectors will be produced. We present the detector construction and discuss the critical quality control (QC) procedures implemented for chamber commissioning. Some of the most important QCs discussed are: current leakage tests, gas leak tests, gain measurements, high voltage test and response uniformity test. We discuss the criteria that are used to accept or reject a GEM detector based on the QC results. The production and QC status will be presented as well.

  7. 10 cm x 10 cm Single Gas Electron Multiplier (GEM) X-ray Fluorescence Detector for Dilute Elements

    NASA Astrophysics Data System (ADS)

    Shaban, E. H.; Siddons, D. P.; Seifu, D.

    2014-03-01

    We have built and tested a 10 cm × 10 cm single Gas Electron Multiplier (GEM) X-ray detector to probe dilute amounts of Fe in a prepared sample. The detector uses Argon/Carbon Dioxide (75/25) gas mixture flowing at a slow rate through a leak proof Plexi-glass enclosure held together by O-rings and screws. The Fluorescence X-ray emitted by the element under test is directed through a Mylar window into the drift region of the detector where abundant gas is flowing. The ionized electrons are separated, drifted into the high electric field of the GEM, and multiplied by impact ionization. The amplified negatively charged electrons are collected and further amplified by a Keithley amplifier to probe the absorption edge of the element under test using X-ray absorption spectroscopy technique. The results show that the GEM detector provided good results with less noise as compared with a Silicon drift detector (SDD).

  8. Mountain Gem Russet: A medium to late season potato variety with high early and full season yield potential and excellent fresh market characteristics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mountain Gem Russet is a medium to late maturing variety with both high early and full season yields of oblong-long, medium-russeted tubers having higher protein content than those of standard potato varieties. Mountain Gem Russet has greater resistance to tuber late blight, tuber malformations and ...

  9. The promotion of gonadal cell divisions by the Caenorhabditis elegans TRPM cation channel GON-2 is antagonized by GEM-4 copine.

    PubMed Central

    Church, Diane L; Lambie, Eric J

    2003-01-01

    The initiation of postembryonic cell divisions by the gonadal precursors of C. elegans requires the activity of gon-2. gon-2 encodes a predicted cation channel (GON-2) of the TRPM subfamily of TRP proteins and is likely to mediate the influx of Ca(2+) and/or Mg(2+). We report here that mutations in gem-4 (gon-2 extragenic modifier) are capable of suppressing loss-of-function alleles of gon-2. gem-4 encodes a member of the copine family of Ca(2+)-dependent phosphatidylserine binding proteins. Overall, our data indicate that GEM-4 antagonizes GON-2. This antagonism could be mediated by a direct inhibition of GON-2 by GEM-4, since both proteins are predicted to be localized to the plasma membrane. Alternatively, GEM-4 could affect GON-2 activity levels by either promoting endocytosis or inhibiting exocytosis of vesicles that carry GON-2. It is also possible that GEM-4 and GON-2 act in parallel to each other. Mutation of gem-4 does not suppress the gonadal defects produced by inactivation of gon-4, suggesting that gon-4 either acts downstream of gem-4 and gon-2 or acts in a parallel regulatory pathway. PMID:14573470

  10. Gillespie eco-evolutionary models (GEMs) reveal the role of heritable trait variation in eco-evolutionary dynamics.

    PubMed

    DeLong, John P; Gibert, Jean P

    2016-02-01

    Heritable trait variation is a central and necessary ingredient of evolution. Trait variation also directly affects ecological processes, generating a clear link between evolutionary and ecological dynamics. Despite the changes in variation that occur through selection, drift, mutation, and recombination, current eco-evolutionary models usually fail to track how variation changes through time. Moreover, eco-evolutionary models assume fitness functions for each trait and each ecological context, which often do not have empirical validation. We introduce a new type of model, Gillespie eco-evolutionary models (GEMs), that resolves these concerns by tracking distributions of traits through time as eco-evolutionary dynamics progress. This is done by allowing change to be driven by the direct fitness consequences of model parameters within the context of the underlying ecological model, without having to assume a particular fitness function. GEMs work by adding a trait distribution component to the standard Gillespie algorithm - an approach that models stochastic systems in nature that are typically approximated through ordinary differential equations. We illustrate GEMs with the Rosenzweig-MacArthur consumer-resource model. We show not only how heritable trait variation fuels trait evolution and influences eco-evolutionary dynamics, but also how the erosion of variation through time may hinder eco-evolutionary dynamics in the long run. GEMs can be developed for any parameter in any ordinary differential equation model and, furthermore, can enable modeling of multiple interacting traits at the same time. We expect GEMs will open the door to a new direction in eco-evolutionary and evolutionary modeling by removing long-standing modeling barriers, simplifying the link between traits, fitness, and dynamics, and expanding eco-evolutionary treatment of a greater diversity of ecological interactions. These factors make GEMs much more than a modeling advance, but an important

  11. First demonstration of VUV-photon detection in liquid xenon with THGEM and GEM-based Liquid Hole Multipliers

    NASA Astrophysics Data System (ADS)

    Erdal, E.; Arazi, L.; Rappaport, M. L.; Shchemelinin, S.; Vartsky, D.; Breskin, A.

    2017-02-01

    The bubble-assisted Liquid Hole-Multiplier (LHM) is a recently-introduced detection concept for noble-liquid time projection chambers. In this ;local dual-phase; detection element, a gas bubble is supported underneath a perforated electrode (e.g., Thick Gas Electron Multiplier - THGEM, or Gas Electron Multiplier - GEM). Electrons drifting through the holes induce large electroluminescence signals as they pass into the bubble. In this work we report on recent results of THGEM and GEM electrodes coated with cesium iodide and immersed in liquid xenon, allowing - for the first time - the detection of primary VUV scintillation photons in addition to ionization electrons.

  12. Tuning efficiency of the 4-exo-trig cyclization by the electronic effect: ring closure of 3,3-difluoro-4-pentenyl carbon radicals and synthesis of a gem-difluorocyclobutane nucleoside.

    PubMed

    Kumamoto, Hiroki; Kawahigashi, Sachiko; Wakabayashi, Hiromi; Nakano, Tomohiko; Miyaike, Tomoko; Kitagawa, Yasuyuki; Abe, Hiroshi; Ito, Mika; Haraguchi, Kazuhiro; Balzarini, Jan; Baba, Masanori; Tanaka, Hiromichi

    2012-11-18

    4-exo-trig Cyclization reaction of a 4-pentenyl carbon radical containing the gem-difluoromethylene moiety adjacent to a radical accepting α,β-unsaturated ester was found to proceed efficiently to furnish a novel gem-difluorocyclobutane derivative. The cyclized product could be transformed into a gem-difluoromethylene analogue of oxetanocin T.

  13. The Shape of Long Outbursts in U Gem Type Dwarf Novae from AAVSO Data

    NASA Technical Reports Server (NTRS)

    Cannizzo, John K.

    2012-01-01

    We search the American Association of Variable Star Observers (AAVSO) archives of the two best studied dwarf novae in an attempt to find light curves for long out bursts that are extremely well-characterized. The systems are U Gem and S8 Cyg. Our goal is to search for embedded precursors such as those that have been found recently in the high fidelity Kepler data for superoutbursts of some members of the 8U UMa subclass of dwarf novae. For the vast majority of AAV80 data, the combination of low data cadence and large errors associated with individual measurements precludes one from making any strong statement about the shape of the long outbursts. However, for a small number of outbursts, extensive long term monitoring with digital photometry yields high fidelity light curves. We report the finding of embedded precursors in two of three candidate long outbursts. This reinforces van Paradijs' finding that long outbursts in dwarf novae above the period gap and superoutbursts in systems below the period gap constitute a unified class. The thermal-tidal instability to account for superoutbursts in the SU UMa stars predicts embedded precursors only for short orbital period dwarf novae, therefore the presence of embedded precursors in long orbital period systems - U Gem and SS Cyg - argues for a more general mechanism to explain long outbursts.

  14. Trace elemental analysis of Indian natural moonstone gems by PIXE and XRD techniques.

    PubMed

    Venkateswara Rao, R; Venkateswarulu, P; Kasipathi, C; Sivajyothi, S

    2013-12-01

    A selected number of Indian Eastern Ghats natural moonstone gems were studied with a powerful nuclear analytical and non-destructive Proton Induced X-ray Emission (PIXE) technique. Thirteen elements, including V, Co, Ni, Zn, Ga, Ba and Pb, were identified in these moonstones and may be useful in interpreting the various geochemical conditions and the probable cause of their inceptions in the moonstone gemstone matrix. Furthermore, preliminary XRD studies of different moonstone patterns were performed. The PIXE technique is a powerful method for quickly determining the elemental concentration of a substance. A 3MeV proton beam was employed to excite the samples. The chemical constituents of moonstones from parts of the Eastern Ghats geological formations of Andhra Pradesh, India were determined, and gemological studies were performed on those gems. The crystal structure and the lattice parameters of the moonstones were estimated using X-Ray Diffraction studies, trace and minor elements were determined using the PIXE technique, and major compositional elements were confirmed by XRD. In the present work, the usefulness and versatility of the PIXE technique for research in geo-scientific methodology is established.

  15. A verification of the gyrokinetic microstability codes GEM, GYRO, and GS2

    SciTech Connect

    Bravenec, R. V.; Chen, Y.; Wan, W.; Parker, S.; Candy, J.

    2013-10-15

    A previous publication [R. V. Bravenec et al., Phys. Plasmas 18, 122505 (2011)] presented favorable comparisons of linear frequencies and nonlinear fluxes from the Eulerian gyrokinetic codes gyro[J. Candy and R. E. Waltz, J. Comput. Phys. 186, 545 (2003)] and gs2[W. Dorland et al., Phys. Rev. Lett. 85, 5579 (2000)]. The motivation was to verify the codes, i.e., demonstrate that they correctly solve the gyrokinetic-Maxwell equations. The premise was that it is highly unlikely for both codes to yield the same incorrect results. In this work, we add the Lagrangian particle-in-cell code gem[Y. Chen and S. Parker, J. Comput. Phys. 220, 839 (2007)] to the comparisons, not simply to add another code, but also to demonstrate that the codes' algorithms do not matter. We find good agreement of gem with gyro and gs2 for the plasma conditions considered earlier, thus establishing confidence that the codes are verified and that ongoing validation efforts for these plasma parameters are warranted.

  16. A Test of GEMS Astrometric Precision for Exoplanet Detection and Mass Measurement

    NASA Astrophysics Data System (ADS)

    Ammons, S. Mark; Marois, Christian; Macintosh, Bruce; Konopacky, Quinn; Neichel, Benoit; Galicher, Raphael; Bendek, Eduardo; Guyon, Olivier

    2013-08-01

    Precision astrometry is so far the only mainstream exoplanet detection technique that has yet to find a new planet. The unique capabilities of GeMS and GSAOI may finally be what we have been waiting for: the combination of a large aperture and wide-field AO correction for stable high-resolution wide-field diffraction-limited imaging. As part of a multi-year program starting in 2013A, we are observing SCR 1845 and Mu Arae in 2013A to (1) astrometrically verify the presence and measure the dynamical mass of the nearby brown dwarf companion orbiting SCR 1845 (Biller et al. 2006) and (2) measure the dynamical mass of mu Arae e, an RV discovery of 1.9 MJUP with a signal of approximately 0.5 mas (Pepe et al. 2008). Here, due to visibility constraints on SCR 1845 and Mu Arae, we propose four new epochs on the closest brown dwarf pair at 2 pc, WISE J1049-53 (Luhman 2013), newly discovered with Gemini in 2013 to be the third closest system known. GEMS will in one year obtain the best available projected relative orbits and a < 1% trigonometric distance, enabling precision masses and luminosity measurements for both L/T transition components.

  17. THE SHAPE OF LONG OUTBURSTS IN U GEM TYPE DWARF NOVAE FROM AAVSO DATA

    SciTech Connect

    Cannizzo, John K.

    2012-10-01

    We search the American Association of Variable Star Observers (AAVSO) archives of the two best-studied dwarf novae in an attempt to find light curves for long outbursts that are extremely well characterized. The systems are U Gem and SS Cyg. Our goal is to search for embedded precursors such as those that have been found recently in the high-fidelity Kepler data for superoutbursts (SOs) of some members of the SU UMa subclass of dwarf novae. For the vast majority of AAVSO data, the combination of low data cadence and large errors associated with individual measurements precludes one from making any strong statement about the shape of the long outbursts. However, for a small number of outbursts, extensive long-term monitoring with digital photometry yields high-fidelity light curves. We report the discovery of embedded precursors in two of three candidate long outbursts. This is the first time that such embedded precursors have been found in dwarf novae above the period gap in other than kepler data, and reinforces van Paradijs' finding that long outbursts in dwarf novae above the period gap and SOs in systems below the period gap constitute a unified class. The thermal-tidal instability to account for SOs in the SU UMa stars predicts embedded precursors only for short orbital period dwarf novae, therefore the presence of embedded precursors in long orbital period systems-U Gem and SS Cyg-argues for a more general mechanism to explain long outbursts.

  18. ORANGE: A high sensitivity particle tracker based on optically read out GEM

    NASA Astrophysics Data System (ADS)

    Marafini, M.; Patera, V.; Pinci, D.; Sarti, A.; Sciubba, A.; Spiriti, E.

    2017-02-01

    GEM-based detectors had a noticeable development in last years and have successfully been employed in different fields from High Energy Physics to imaging applications. Light production associated to the electron multiplication allows to perform an optical readout of these devices. The big progress achieved in CMOS-based photosensors makes possible to develop a high sensitivity, high granularity and low noise readout. In this paper we present the results obtained by reading out the light produced by a triple-GEM structure by means of a 4 mega-pixel CMOS sensor having a noise level less than two photons per pixel. The choice of a CF4 rich gas mixture (He/CF4 60/40) and a detailed optimisation of the electric fields allowed to reach a light-yield high enough to obtain very visible signals from minimum ionizing particles. In a test performed with 450 MeV electron beam, 800 photons per millimeter were collected and a space resolution of about 75 μ m was obtained.

  19. Qualitätsmanagement in der Lebensmittelindustrie

    NASA Astrophysics Data System (ADS)

    Thorn, Volker

    Die wesentlichen Kunden der Lebensmittelindustrie sind der Einzel- und Großhandel und die Verbraucher. Jedes Unternehmen kann mittel- und langfristig nur existieren, wenn seine Kunden zufrieden sind. Kunden sind zufrieden, wenn ihre Erwartungen, die sie an Produkt, Service und Preis stellen, erfüllt werden. Also die bestimmte erwartete Qualität (Leistung) sichergestellt wird. Trotz aller Bemühungen und Anstrengungen der Anbieter, Qualitätsprodukte auf den Markt zu bringen, kames in den letzten Jahren immer wieder zu Lebensmittelskandalen.

  20. Favourite Gems

    ERIC Educational Resources Information Center

    Barnes, John

    2011-01-01

    Mathematics is full of surprises and beauty. In this article, the author discusses three favourite topics that he finds both amazing and amusing: (1) the problem of the possibility of subdividing a rectangle into a number of different squares; (2) the arrangement formed when several soap bubbles meet; and (3) circles and spheres.

  1. Werner Heisenberg zum 100. Geburtstag: Pionier der Quantenmechanik

    NASA Astrophysics Data System (ADS)

    Jacobi, Manfred

    2001-11-01

    Werner Heisenberg war eine der prägendsten Gestalten der Physik des 20. Jahrhunderts. Zu seinen wichtigsten Verdiensten gehören die Grundlegung der Quantenmechanik, die Formulierung der Unschärferelationen sowie die Beteiligung an der Ausarbeitung der Kopenhagener Deutung der Quantenmechanik. Darüber hinaus lieferte er Arbeiten von fundamentalem Charakter zur Theorie des Atomkerns, zur kosmischen Strahlung und zur Quantenfeldtheorie. Während des Krieges war er an den Arbeiten des Uranvereins beteiligt, der die Möglichkeit einer Entwicklung von Kernwaffen untersuchte, jedoch über Vorarbeiten zur Reaktorphysik nicht hinauskam. Wegen dieser Tätigkeit wurde er bei Kriegsende für einige Monate in England interniert. Nach seiner Rückkehr widmete er sich vor allem dem Aufbau der Physik in Deutschland, die während der NS-Zeit nahezu ihrer gesamten Substanz beraubt worden war.

  2. GEM – Meeting the Challenge of Maize Diversification by Capturing Useful Alleles and Traits from Exotic Germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Germplasm Enhancement of Maize (GEM) Project was conceived as a public and private research partnership dedicated to diversifying the genetic base of U.S. maize production. It is coordinated by USDA-ARS and university personnel located at Iowa State University and North Carolina State University...

  3. The general ensemble biogeochemical modeling system (GEMS) and its applications to agriculture systems in the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The General Ensemble Biogeochemical Modeling System (GEMS) was developed for a proper integration of well-established ecosystem biogeochemical models with various spatial databases to simulate biogeochemical cycles over large areas. Major driving variables include land cover and land use, climate, s...

  4. GEnomes Management Application (GEM.app): A new software tool for large-scale collaborative genome analysis

    PubMed Central

    Gonzalez, Michael A.; Acosta Lebrigio, Rafael F.; Van Booven, Derek; Ulloa, Rick H.; Powell, Eric; Speziani, Fiorella; Tekin, Mustafa; Schule, Rebecca; Zuchner, Stephan

    2015-01-01

    Novel genes are now identified at a rapid pace for many Mendelian disorders, and increasingly, for genetically complex phenotypes. However, new challenges have also become evident: (1) effectively managing larger exome and/or genome datasets, especially for smaller labs; (2) direct hands-on analysis and contextual interpretation of variant data in large genomic datasets; and (3) many small and medium-sized clinical and research-based investigative teams around the world are generating data that, if combined and shared, will significantly increase the opportunities for the entire community to identify new genes. To address these challenges we have developed GEnomes Management Application (GEM.app), a software tool to annotate, manage, visualize, and analyze large genomic datasets (https://genomics.med.miami.edu/). GEM.app currently contains ~1,600 whole exomes from 50 different phenotypes studied by 40 principal investigators from 15 different countries. The focus of GEM.app is on user-friendly analysis for non-bioinformaticians to make NGS data directly accessible. Yet, GEM.app provides powerful and flexible filter options, including single family filtering, across family/phenotype queries, nested filtering, and evaluation of segregation in families. In addition, the system is fast, obtaining results within 4 seconds across ~1,200 exomes. We believe that this system will further enhance identification of genetic causes of human disease. PMID:23463597

  5. Building a large-area GEM-based readout chamber for the upgrade of the ALICE TPC

    NASA Astrophysics Data System (ADS)

    Gasik, P.

    2017-02-01

    A large Time Projection Chamber (TPC) is the main device for tracking and charged-particle identification in the ALICE experiment at the CERN LHC. After the second long shutdown in 2019-2020, the LHC will deliver Pb beams colliding at an interaction rate up to 50 kHz, which is about a factor of 100 above the present read-out rate of the TPC. To fully exploit the LHC potential the TPC will be upgraded based on the Gas Electron Multiplier (GEM) technology. A prototype of an ALICE TPC Outer Read-Out Chamber (OROC) was equipped with twelve large-size GEM foils as amplification stage to demonstrate the feasibility of replacing the current Multi Wire Proportional Chambers with the new technology. With a total area of ∼0.76 m2 it is the largest GEM-based detector built to date. The GEM OROC was installed within a test field cage and commissioned with radioactive sources.

  6. Tapping the Source: A Listing of Groundwater Education Materials Available through the Groundwater Education in Michigan (GEM) Program. Updated.

    ERIC Educational Resources Information Center

    Michigan State Univ., East Lansing. Inst. of Water Research.

    Established in 1988 through the cooperative efforts of the Institute of Water Research at Michigan State University and the W. K. Kellogg Foundation, the Groundwater Education in Michigan (GEM) program helps people understand the relationship between their actions and the quality of their environment, particularly groundwater. The program has a…

  7. Girls in Engineering, Mathematics and Science, GEMS: A Science Outreach Program for Middle-School Female Students

    ERIC Educational Resources Information Center

    Dubetz, Terry A.; Wilson, Jo Ann

    2013-01-01

    Girls in Engineering, Mathematics and Science (GEMS) is a science and math outreach program for middle-school female students. The program was developed to encourage interest in math and science in female students at an early age. Increased scientific familiarity may encourage girls to consider careers in science and mathematics and will also help…

  8. The Germplasm Enhancement of Maize (GEM) project: A Public-Private Partnership (PPP) to increase genetic diversity in US maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Germplasm Enhancement of Maize (GEM) Project is a mission-oriented, cooperative research effort of the United States Department of Agriculture – Agricultural Research Service (USDA-ARS), land grant universities, private industry, and international agricultural research centers to broaden the ger...

  9. Structure-function analysis of the yeast mitochondrial Rho GTPase, Gem1p: implications for mitochondrial inheritance.

    PubMed

    Koshiba, Takumi; Holman, Holly A; Kubara, Kenji; Yasukawa, Kai; Kawabata, Shun-ichiro; Okamoto, Koji; MacFarlane, Jane; Shaw, Janet M

    2011-01-07

    Mitochondria undergo continuous cycles of homotypic fusion and fission, which play an important role in controlling organelle morphology, copy number, and mitochondrial DNA maintenance. Because mitochondria cannot be generated de novo, the motility and distribution of these organelles are essential for their inheritance by daughter cells during division. Mitochondrial Rho (Miro) GTPases are outer mitochondrial membrane proteins with two GTPase domains and two EF-hand motifs, which act as receptors to regulate mitochondrial motility and inheritance. Here we report that although all of these domains are biochemically active, only the GTPase domains are required for the mitochondrial inheritance function of Gem1p (the yeast Miro ortholog). Mutations in either of the Gem1p GTPase domains completely abrogated mitochondrial inheritance, although the mutant proteins retained half the GTPase activity of the wild-type protein. Although mitochondrial inheritance was not dependent upon Ca(2+) binding by the two EF-hands of Gem1p, a functional N-terminal EF-hand I motif was critical for stable expression of Gem1p in vivo. Our results suggest that basic features of Miro protein function are conserved from yeast to humans, despite differences in the cellular machinery mediating mitochondrial distribution in these organisms.

  10. Gem1 and ERMES do not directly affect phosphatidylserine transport from ER to mitochondria or mitochondrial inheritance.

    PubMed

    Nguyen, Tammy T; Lewandowska, Agnieszka; Choi, Jae-Yeon; Markgraf, Daniel F; Junker, Mirco; Bilgin, Mesut; Ejsing, Christer S; Voelker, Dennis R; Rapoport, Tom A; Shaw, Janet M

    2012-06-01

    In yeast, a protein complex termed the ER-Mitochondria Encounter Structure (ERMES) tethers mitochondria to the endoplasmic reticulum. ERMES proteins are implicated in a variety of cellular functions including phospholipid synthesis, mitochondrial protein import, mitochondrial attachment to actin, polarized mitochondrial movement into daughter cells during division, and maintenance of mitochondrial DNA (mtDNA). The mitochondrial-anchored Gem1 GTPase has been proposed to regulate ERMES functions. Here, we show that ERMES and Gem1 have no direct role in the transport of phosphatidylserine (PS) from the ER to mitochondria during the synthesis of phosphatidylethanolamine (PE), as PS to PE conversion is not affected in ERMES or gem1 mutants. In addition, we report that mitochondrial inheritance defects in ERMES mutants are a secondary consequence of mitochondrial morphology defects, arguing against a primary role for ERMES in mitochondrial association with actin and mitochondrial movement. Finally, we show that ERMES complexes are long-lived, and do not depend on the presence of Gem1. Our findings suggest that the ERMES complex may have primarily a structural role in maintaining mitochondrial morphology.

  11. Characterization of a GEM-based scintillation detector with He-CF4 gas mixture in clinical proton beams

    NASA Astrophysics Data System (ADS)

    Nichiporov, D.; Coutinho, L.; Klyachko, A. V.

    2016-04-01

    Accurate, high-spatial resolution dosimetry in proton therapy is a time consuming task, and may be challenging in the case of small fields, due to the lack of adequate instrumentation. The purpose of this work is to develop a novel dose imaging detector with high spatial resolution and tissue equivalent response to dose in the Bragg peak, suitable for beam commissioning and quality assurance measurements. A scintillation gas electron multiplier (GEM) detector based on a double GEM amplification structure with optical readout was filled with a He/CF4 gas mixture and evaluated in pristine and modulated proton beams of several penetration ranges. The detector’s performance was characterized in terms of linearity in dose rate, spatial resolution, short- and long-term stability and tissue-equivalence of response at different energies. Depth-dose profiles measured with the GEM detector in the 115-205 MeV energy range were compared with the profiles measured under similar conditions using the PinPoint 3D small-volume ion chamber. The GEM detector filled with a He-based mixture has a nearly tissue equivalent response in the proton beam and may become an attractive and efficient tool for high-resolution 2D and 3D dose imaging in proton dosimetry, and especially in small-field applications.

  12. Progress on The GEMS (Gravity Electro-Magnetism-Strong) Theory of Field Unification and Its Application to Space Problems

    SciTech Connect

    Brandenburg, J. E.

    2008-01-21

    Progress on the GEMS (Gravity Electro-Magnetism-Strong), theory is presented as well as its application to space problems. The GEMS theory is now validated through the Standard Model of physics. Derivation of the value of the Gravitation constant based on the observed variation of {alpha} with energy: results in the formula G congruent with ({Dirac_h}/2{pi})c/M{sub {eta}}{sub c}{sup 2} exp(-1/(1.61{alpha})), where {alpha} is the fine structure constant,({Dirac_h}/2{pi}), is Planck's constant, c, is the speed of light, and M{sub {eta}}{sub c} is the mass of the {eta}{sub cc} Charmonium meson that is shown to be identical to that derived from the GEM postulates. Covariant formulation of the GEM theory is now possible through definition of the spacetime metric tensor as a portion of the EM stress tensor normalized by its own trace: g{sub ab} = 4(F{sup c}{sub a}F{sub cb})/(F{sup ab}F{sub ab}), it is found that this results in a massless ground state vacuum and a Newtonian gravitation potential {phi} = 1/2 E{sup 2}/B{sup 2}. It is also found that a Lorentz or flat-space metric is recovered in the limit of a full spectrum ZPF.

  13. Oxygen isotope systematics of gem corundum deposits in Madagascar: relevance for their geological origin

    NASA Astrophysics Data System (ADS)

    Giuliani, Gaston; Fallick, Anthony; Rakotondrazafy, Michel; Ohnenstetter, Daniel; Andriamamonjy, Alfred; Ralantoarison, Théogène; Rakotosamizanany, Saholy; Razanatseheno, Marie; Offant, Yohann; Garnier, Virginie; Dunaigre, Christian; Schwarz, Dietmar; Mercier, Alain; Ratrimo, Voahangy; Ralison, Bruno

    2007-02-01

    The oxygen isotopic composition of gem corundum was measured from 22 deposits and occurrences in Madagascar to provide a gemstone geological identification and characterization. Primary corundum deposits in Madagascar are hosted in magmatic (syenite and alkali basalt) and metamorphic rocks (gneiss, cordieritite, mafic and ultramafic rocks, marble, and calc-silicate rocks). In both domains the circulation of fluids, especially along shear zones for metamorphic deposits, provoked in situ transformation of the corundum host rocks with the formation of metasomatites such as phlogopite, sakenite, and corundumite. Secondary deposits (placers) are the most important economically and are contained in detrital basins and karsts. The oxygen isotopic ratios (18O/16O) of ruby and sapphire from primary deposits are a good indicator of their geological origin and reveal a wide range of δ18O (Vienna Standard Mean Ocean Water) between 1.3 and 15.6‰. Metamorphic rubies are defined by two groups of δ18O values in the range of 1.7 to 2.9‰ (cordieritite) and 3.8 to 6.1‰ (amphibolite). “Magmatic” rubies from pyroxenitic xenoliths contained in the alkali basalt of Soamiakatra have δ18O values ranging between 1.3 and 4.7‰. Sapphires are classified into two main groups with δ18O in the range of 4.7 to 9.0‰ (pyroxenite and feldspathic gneiss) and 10.7 to 15.6‰ (skarn in marble from Andranondambo). The δ18O values for gem corundum from secondary deposits have a wide spread between -0.3 and 16.5‰. The ruby and sapphire found in placers linked to alkali basalt environments in the northern and central regions of Madagascar have consistent δ18O values between 3.5 and 6.9‰. Ruby from the placers of Vatomandry and Andilamena has δ18O values of 5.9‰, and between 0.5 and 4.0‰, respectively. The placers of the Ilakaka area are characterized by a huge variety of colored sapphires and rubies, with δ18O values between -0.3 and 16.5‰, and their origin is debated. A

  14. Application of the GEM Inventory Data Capture Tools for Dynamic Vulnerability Assessment and Recovery Modelling

    NASA Astrophysics Data System (ADS)

    Verrucci, Enrica; Bevington, John; Vicini, Alessandro

    2014-05-01

    A set of open-source tools to create building exposure datasets for seismic risk assessment was developed from 2010-13 by the Inventory Data Capture Tools (IDCT) Risk Global Component of the Global Earthquake Model (GEM). The tools were designed to integrate data derived from remotely-sensed imagery, statistically-sampled in-situ field data of buildings to generate per-building and regional exposure data. A number of software tools were created to aid the development of these data, including mobile data capture tools for in-field structural assessment, and the Spatial Inventory Data Developer (SIDD) for creating "mapping schemes" - statistically-inferred distributions of building stock applied to areas of homogeneous urban land use. These tools were made publically available in January 2014. Exemplar implementations in Europe and Central Asia during the IDCT project highlighted several potential application areas beyond the original scope of the project. These are investigated here. We describe and demonstrate how the GEM-IDCT suite can be used extensively within the framework proposed by the EC-FP7 project SENSUM (Framework to integrate Space-based and in-situ sENSing for dynamic vUlnerability and recovery Monitoring). Specifically, applications in the areas of 1) dynamic vulnerability assessment (pre-event), and 2) recovery monitoring and evaluation (post-event) are discussed. Strategies for using the IDC Tools for these purposes are discussed. The results demonstrate the benefits of using advanced technology tools for data capture, especially in a systematic fashion using the taxonomic standards set by GEM. Originally designed for seismic risk assessment, it is clear the IDCT tools have relevance for multi-hazard risk assessment. When combined with a suitable sampling framework and applied to multi-temporal recovery monitoring, data generated from the tools can reveal spatio-temporal patterns in the quality of recovery activities and resilience trends can be

  15. C-4 gem-dimethylated oleanes of Gymnema sylvestre and their pharmacological activities.

    PubMed

    Di Fabio, Giovanni; Romanucci, Valeria; Zarrelli, Mauro; Giordano, Michele; Zarrelli, Armando

    2013-12-04

    Gymnema sylvestre R. Br., one of the most important medicinal plants of the Asclepiadaceae family, is a herb distributed throughout the World, predominantly in tropical countries. The plant, widely used for the treatment of diabetes and as a diuretic in Indian proprietary medicines, possesses beneficial digestive, anti-inflammatory, hypoglycemic and anti-helmentic effects. Furthermore, it is believed to be useful in the treatment of dyspepsia, constipation, jaundice, hemorrhoids, cardiopathy, asthma, bronchitis and leucoderma. A literature survey revealed that some other notable pharmacological activities of the plant such as anti-obesity, hypolipidemic, antimicrobial, free radical scavenging and anti-inflammatory properties have been proven too. This paper aims to summarize the chemical and pharmacological reports on a large group of C-4 gem-dimethylated pentacyclic triterpenoids from Gymnema sylvestre.

  16. The 2.3 GHz continuum survey of the GEM project

    NASA Astrophysics Data System (ADS)

    Tello, C.; Villela, T.; Torres, S.; Bersanelli, M.; Smoot, G. F.; Ferreira, I. S.; Cingoz, A.; Lamb, J.; Barbosa, D.; Perez-Becker, D.; Ricciardi, S.; Currivan, J. A.; Platania, P.; Maino, D.

    2013-08-01

    Context. Determining the spectral and spatial characteristics of the radio continuum of our Galaxy is an experimentally challenging endeavour for improving our understanding of the astrophysics of the interstellar medium. This knowledge has also become of paramount significance for cosmology, since Galactic emission is the main source of astrophysical contamination in measurements of the cosmic microwave background (CMB) radiation on large angular scales. Aims: We present a partial-sky survey of the radio continuum at 2.3GHz within the scope of the Galactic Emission Mapping (GEM) project, an observational program conceived and developed to reveal the large-scale properties of Galactic synchrotron radiation through a set of self-consistent surveys of the radio continuum between 408MHz and 10GHz. Methods: The GEM experiment uses a portable and double-shielded 5.5-m radiotelescope in altazimuthal configuration to map 60-degree-wide declination bands from different observational sites by circularly scanning the sky at zenithal angles of 30° from a constantly rotating platform. The observations were accomplished with a total power receiver, whose front-end high electron mobility transistor (HEMT) amplifier was matched directly to a cylindrical horn at the prime focus of the parabolic reflector. The Moon was used to calibrate the antenna temperature scale and the preparation of the map required direct subtraction and destriping algorithms to remove ground contamination as the most significant source of systematic error. Results: We used 484 h of total intensity observations from two locations in Colombia and Brazil to yield 66% sky coverage from to . The observations in Colombia were obtained with a horizontal HPBW of and a vertical HPBW of . The pointing accuracy was and the RMS sensitivity was 11.42 mK. The observations in Brazil were obtained with a horizontal HPBW of and a vertical HPBW of . The pointing accuracy was and the RMS sensitivity was 8.24 mK. The zero

  17. Conceptual design and development of GEM based detecting system for tomographic tungsten focused transport monitoring

    NASA Astrophysics Data System (ADS)

    Chernyshova, M.; Czarski, T.; Malinowski, K.; Kowalska-Strzęciwilk, E.; Poźniak, K.; Kasprowicz, G.; Zabołotny, W.; Wojeński, A.; Kolasiński, P.; Mazon, D.; Malard, P.

    2015-10-01

    Implementing tungsten as a plasma facing material in ITER and future fusion reactors will require effective monitoring of not just its level in the plasma but also its distribution. That can be successfully achieved using detectors based on Gas Electron Multiplier (GEM) technology. This work presents the conceptual design of the detecting unit for poloidal tomography to be tested at the WEST project tokamak. The current stage of the development is discussed covering aspects which include detector's spatial dimensions, gas mixtures, window materials and arrangements inside and outside the tokamak ports, details of detector's structure itself and details of the detecting module electronics. It is expected that the detecting unit under development, when implemented, will add to the safe operation of tokamak bringing the creation of sustainable nuclear fusion reactors a step closer. A shorter version of this contribution is due to be published in PoS at: 1st EPS conference on Plasma Diagnostics

  18. Overview of large area triple-GEM detectors for the CMS forward muon upgrade

    NASA Astrophysics Data System (ADS)

    Abbaneo, D.; Abbas, M.; Abbrescia, M.; Abi Akl, M.; Aboamer, O.; Acosta, D.; Ahmad, A.; Ahmed, W.; Aleksandrov, A.; Altieri, P.; Asawatangtrakuldee, C.; Aspell, P.; Assran, Y.; Awan, I.; Bally, S.; Ban, Y.; Banerjee, S.; Barashko, V.; Barria, P.; Bencze, G.; Beni, N.; Benussi, L.; Bhopatkar, V.; Bianco, S.; Bos, J.; Bouhali, O.; Braghieri, A.; Braibant, S.; Buontempo, S.; Calabria, C.; Caponero, M.; Caputo, C.; Cassese, F.; Castaneda, A.; Cauwenbergh, S.; Cavallo, F. R.; Celik, A.; Choi, M.; Choi, S.; Christiansen, J.; Cimmino, A.; Colafranceschi, S.; Colaleo, A.; Garcia, A. Conde; Czellar, S.; Dabrowski, M. M.; De Lentdecker, G.; De Oliveira, R.; de Robertis, G.; Dildick, S.; Dorney, B.; Endroczi, G.; Errico, F.; Fenyvesi, A.; Ferry, S.; Furic, I.; Giacomelli, P.; Gilmore, J.; Golovtsov, V.; Guiducci, L.; Guilloux, F.; Gutierrez, A.; Hadjiiska, R. M.; Hauser, J.; Hoepfner, K.; Hohlmann, M.; Hoorani, H.; Iaydjiev, P.; Jeng, Y. G.; Kamon, T.; Karchin, P.; Korytov, A.; Krutelyov, S.; Kumar, A.; Kim, H.; Lee, J.; Lenzi, T.; Litov, L.; Loddo, F.; Madorsky, A.; Maerschalk, T.; Maggi, M.; Magnani, A.; Mal, P. K.; Mandal, K.; Marchioro, A.; Marinov, A.; Majumdar, N.; Merlin, J. A.; Mitselmakher, G.; Mohanty, A. K.; Mohapatra, A.; Molnar, J.; Muhammad, S.; Mukhopadhyay, S.; Naimuddin, M.; Nuzzo, S.; Oliveri, E.; Pant, L. M.; Paolucci, P.; Park, I.; Passeggio, G.; Pavlov, B.; Philipps, B.; Piccolo, D.; Postema, H.; Puig Baranac, A.; Radi, A.; Radogna, R.; Raffone, G.; Ranieri, A.; Rashevski, G.; Riccardi, C.; Rodozov, M.; Rodrigues, A.; Ropelewski, L.; RoyChowdhury, S.; Ryu, G.; Ryu, M. S.; Safonov, A.; Salva, S.; Saviano, G.; Sharma, A.; Sharma, A.; Sharma, R.; Shah, A. H.; Shopova, M.; Sturdy, J.; Sultanov, G.; Swain, S. K.; Szillasi, Z.; Talvitie, J.; Tatarinov, A.; Tuuva, T.; Tytgat, M.; Vai, I.; Stenis, M. Van; Venditti, R.; Verhagen, E.; Verwilligen, P.; Vitulo, P.; Volkov, S.; Vorobyev, A.; Wang, D.; Wang, M.; Yang, U.; Yang, Y.; Yonamine, R.; Zaganidis, N.; Zenoni, F.; Zhang, A.

    2017-02-01

    In order to cope with the harsh environment expected from the high luminosity LHC, the CMS forward muon system requires an upgrade. The two main challenges expected in this environment are an increase in the trigger rate and increased background radiation leading to a potential degradation of the particle ID performance. Additionally, upgrades to other subdetectors of CMS allow for extended coverage for particle tracking, and adding muon system coverage to this region will further enhance the performance of CMS. Following an extensive R&D program, CMS has identified triple-foil gas electron multiplier (GEM) detectors as a solution for the first muon station in the region 1.6 < | η | < 2.2, while continuing R&D is ongoing for additional regions.

  19. 3D field calculation of the GEM prototype magnet and comparison with measurements

    SciTech Connect

    Lari, R.J.

    1983-10-28

    The proposed 4 GeV Electron Microtron (GEM) is designed to fill the existing buildings left vacant by the demise of the Zero Gradient Synchrotron (ZGS) accelerator. One of the six large dipole magnets is shown as well as the first 10 electron orbits. A 3-orbit prototype magnet has been built. The stepped edge of the magnet is to keep the beam exiting perpendicular to the pole. The end guards that wrap around the main coils are joined together by the 3 shield plates. The auxiliary coils are needed to keep the end guards and shield plates from saturating. A 0.3 cm Purcell filter air gap exists between the pole and the yoke. Can anyone question this being a truly three-dimensional magnetostatic problem. The computer program TOSCA, developed at the Rutherford Appleton Laboratory by the Computing Applications Group, was used to calculate this magnet and the results have been compared with measurements.

  20. Re-investigation of the Ponzio reaction for the preparation of gem-dinitro compounds

    SciTech Connect

    Honey, P.J.; Millar, R.W.; Coombes, R.G.

    1995-12-01

    Many aromatic nitro compounds can be prepared using mixtures of nitric and sulphuric acids, but, this medium usually results in the destruction of the substrate for aliphatic compounds. Hence a variety of less aggressive nitrating agents in nonacidic media are employed. This talk presents some recent work to re-investigate the Ponzio reaction for the conversion of oximes to the gem-nitro group. The effect of varying the reaction media, and of changing the nitrating species from N{sub 2}O{sub 4} to N{sub 2}O{sub 5} will also be presented. The reaction mechanism will be discussed with reference to CIDNP nmr studies. Where relevant the results will be compared with other aliphatic nitration methods.

  1. Application of the GEM-T2 gravity field to altimetric satellite orbit computation

    NASA Technical Reports Server (NTRS)

    Haines, Bruce J.; Born, George H.; Williamson, Ronald G.; Koblinsky, Chester I.

    1994-01-01

    As part of a continuing effort to provide improved orbits for use with existing altimeter data, we have recomputed ephemerides for both the Seasat and Geosat Exact Repeat altimeter missions. The orbits were computed in a consistent fashion, using the Goddard Earth Model T2 (GEM-T2) gravity field along with available ground-based tracking data. Such an approach allows direct comparisons of sea level between the two altimeter systems. Evaluation of the resulting ephemerides indicates that root-mean-square accuracies of 30-50 cm have been achieved for the radial component of the orbits for both satellites. An exception occurs for the last year of the Geosat Exact Repeat Mission, when the rms radial orbit accuracy degrades to the 1-m level at times owing to the inability to adequately model the drag force arising from the increased solar activity.

  2. Design and optimization of resistive anode for a two-dimensional imaging GEM detector

    NASA Astrophysics Data System (ADS)

    Ju, Xu-Dong; Dong, Ming-Yi; Zhao, Yi-Chen; Zhou, Chuan-Xing; Qun, Ou-Yang

    2016-08-01

    A resistive anode for two-dimensional imaging detectors, which consists of a series of high resistivity pads surrounded by low resistivity strips, can provide good spatial resolution while reducing the number of electronics channels required. The optimization of this kind of anode has been studied by both numerical simulations and experimental tests. It is found that to obtain good detector performance, the resistance ratio of the pads to the strips should be larger than 5, the nonuniformity of the pad surface resistivity should be less than 20%, a smaller pad width leads to a smaller spatial resolution, and when the pad width is 6 mm, the spatial resolution (σ) can reach about 105 μm. Based on the study results, a 2-D GEM detector prototype with optimized resistive anode is constructed and a good imaging performance is achieved. Supported by National Natural Science Foundation of China (11375219) and CAS Center for Excellence in Particle Physics (CCEPP)

  3. Gas scintillation glass GEM detector for high-resolution X-ray imaging and CT

    NASA Astrophysics Data System (ADS)

    Fujiwara, T.; Mitsuya, Y.; Fushie, T.; Murata, K.; Kawamura, A.; Koishikawa, A.; Toyokawa, H.; Takahashi, H.

    2017-04-01

    A high-spatial-resolution X-ray-imaging gaseous detector has been developed with a single high-gas-gain glass gas electron multiplier (G-GEM), scintillation gas, and optical camera. High-resolution X-ray imaging of soft elements is performed with a spatial resolution of 281 μm rms and an effective area of 100×100 mm. In addition, high-resolution X-ray 3D computed tomography (CT) is successfully demonstrated with the gaseous detector. It shows high sensitivity to low-energy X-rays, which results in high-contrast radiographs of objects containing elements with low atomic numbers. In addition, the high yield of scintillation light enables fast X-ray imaging, which is an advantage for constructing CT images with low-energy X-rays.

  4. Dst Index in the 2008 GEM Modeling Challenge - Model Performance for Moderate and Strong Magnetic Storms

    NASA Technical Reports Server (NTRS)

    Rastaetter, Lutz; Kuznetsova, Maria; Hesse, Michael; Chulaki, Anna; Pulkkinen, Antti; Ridley, Aaron J.; Gombosi, Tamas; Vapirev, Alexander; Raeder, Joachim; Wiltberger, Michael James; Mays, M. L.; Fok, Mei-Ching H.; Weigel, Robert S.; Welling, Daniel T.

    2010-01-01

    The GEM 2008 modeling challenge efforts are expanding beyond comparing in-situ measurements in the magnetosphere and ionosphere to include the computation of indices to be compared. The Dst index measures the largest deviations of the horizontal magnetic field at 4 equatorial magnetometers from the quiet-time background field and is commonly used to track the strength of the magnetic disturbance of the magnetosphere during storms. Models can calculate a proxy Dst index in various ways, including using the Dessler-Parker Sckopke relation and the energy of the ring current and Biot-Savart integration of electric currents in the magnetosphere. The GEM modeling challenge investigates 4 space weather events and we compare models available at CCMC against each other and the observed values of Ost. Models used include SWMF/BATSRUS, OpenGGCM, LFM, GUMICS (3D magnetosphere MHD models), Fok-RC, CRCM, RAM-SCB (kinetic drift models of the ring current), WINDMI (magnetosphere-ionosphere electric circuit model), and predictions based on an impulse response function (IRF) model and analytic coupling functions with inputs of solar wind data. In addition to the analysis of model-observation comparisons we look at the way Dst is computed in global magnetosphere models. The default value of Dst computed by the SWMF model is for Bz the Earth's center. In addition to this, we present results obtained at different locations on the Earth's surface. We choose equatorial locations at local noon, dusk (18:00 hours), midnight and dawn (6:00 hours). The different virtual observatory locations reveal the variation around the earth-centered Dst value resulting from the distribution of electric currents in the magnetosphere during different phases of a storm.

  5. Application of model output statistics to the GEM-AQ high resolution air quality forecast

    NASA Astrophysics Data System (ADS)

    Struzewska, J.; Kaminski, J. W.; Jefimow, M.

    2016-11-01

    The aim of the presented work was to analyse the impact of data stratification on the efficiency of the Model Output Statistics (MOS) methodology as applied to a high-resolution deterministic air quality forecast carried out with the GEM-AQ model. The following parameters forecasted by the GEM-AQ model were selected as predictors for the MOS equation: pollutant concentration, air temperature in the lowest model layer, wind speed in the lowest model layer, temperature inversion and the precipitation rate. A representative 2-year series were used to construct regression functions. Data series were divided into two subsets. Approximately 75% of the data (first 3 weeks of each month) were used to estimate the regression function parameters. Remaining 25% (last week of each month) were used to test the method (control period). The subsequent 12 months were used for method verification (verification period). A linear model fitted the function based on forecasted parameters to the observations. We have assumed four different temperature-based data stratification methods (for each method, separate equations were constructed). For PM10 and PM2.5, SO2 and NO2 the best correction results were obtained with the application of temperature thresholds in the cold season and seasonal distribution combined with temperature thresholds in the warm season. For the PM10, PM2.5 and SO2 the best results were obtained using a combination of two stratification methods separately for cold and warm seasons. For CO, the systematic bias of the forecasted concentrations was partly corrected. For ozone more sophisticated methods of data stratification did not bring a significant improvement.

  6. Impact Features on Europa: Results of the Galileo Europa Mission (GEM)

    NASA Astrophysics Data System (ADS)

    Moore, J. M.; Asphaug, E.; Morrison, D.; Sullivan, R. J.; Chapman, C. R.; Greeley, R.; Klemaszewski, J. E.; Kadel, S.; Chuang, F.; Moreau, J.; Williams, K. K.; Geissler, P. E.; McEwen, A. S.; Turtle, E. A.; Phillips, C. B.; Tufts, B. R.; Head, J. W.; Pappalardo, R. T.; Collins, G. C.; Neukum, G.; Wagner, R.; Klaasen, K. P.; Breneman, H. H.; McGee, K. P.; Senske, D. A.; Granahan, J.; Belton, M. J. S.; Galileo SSI Team

    1998-09-01

    The Galileo Orbiter, during the GEM phase of this mission, has examined a number of impact features on Europa at considerably better resolution and coverage than was possible from either Voyager or during the Galileo nominal mission. The new data allow us to describe the morphology and infer the geology of the largest impact features on Europa, which are probes into the crust. The GEM observations allow us to construct a suite of primary impact features on Europa; a comprehensive "family" portrait and ordering (by size on one axis and morphologic variations within a given size bin along the other). We have also made detailed description of individual impact features including topography (from stereo), crater-related materials deposits, cross-cutting relations, and material-related color variations. We observe two basic types of large impact features: (1) "classic" impact craters that grossly resemble well-preserved lunar craters of similar size but are more topographically subdued (e.g., Pwyll); and (2) very flat circular features that lack the basic topographic structures of impact craters such as raised rims, a central depression, or central peaks, and which largely owe their identification as impact features to the field of secondary craters radially sprayed about them (e.g., Callanish). One of our preliminary conclusions are that Callanish and Tyre display non-"classic" impact features morphologies and a series of large concentric structural rings cutting impact-feature-related materials. Impact simulations suggest that Callanish and Tyre would not be produced by impact into a solid ice target, but may be explained by impact into an ice layer 10 to 15 km thick overlying a low viscosity material such as water.

  7. GEM-CEDAR Challenge: Comparing Ionospheric Models with Poynting Flux from DMSP Observations

    NASA Technical Reports Server (NTRS)

    Rastaetter, Lutz; Kuznetsova, Maria; Shim, Ja-Soon; Hesse, Michael; Knipp, Delores J.; Weimer, Daniel R.; Fuller-Rowell, Timothy J.; Ridley, Aaron J.; Raeder, Joachim; Maruyama, Naomi; Kilcomons, Liam; Wittberger, Michael James

    2011-01-01

    As part to the GEM-CEDAR challenge we are extending the model-data comparisons to electrodynamic in-situ measurements in low-Earth orbit. We use DMSP observations of electric and magnetic fields to compute Poynting Flux values along the satellite track in high latitudes including the auroral zones and the polar cap. Models of the ionosphere that include electrodynamic parameters have been run for five events selected for the GEM-CEDAR modeling challenge for which DMSP data are available for comparison. Combined with a magnetic field model we use the modeled electric fields to compute Poynting Flux and Joule Dissipation values from outputs of CTIPe, TIE-GCM, the ionospheric electrodynamics solvers of the SWMF, LFM and OpenGGCM magnetosphere-ionosphere coupled models, and the Weimer electric field model. The online metrics analysis tool at the Community Coordinated Modeling Center (CCMC) has been updated to handle the analysis of separate short segments of available data (high-latitude sections of the satellite orbit) with model outputs to analyze how well auroral patterns are being reproduced by the models. We present initial results from the new analysis tool in terms of model yields (ratio of the difference between maximum and minimum values of model results to the observation), timing/location errors of local maxima in the inbound and outbound auroral crossings as well as cross-correlations for individual passes. We collect the information for many DMSP passes and present an analysis for model performance during quiet and geomagnetically disturbed time periods using half-orbit integrated values as well.

  8. Modellbasierte interindividuelle Registrierung an der lateralen Schädelbasis

    NASA Astrophysics Data System (ADS)

    Riechmann, M.; Lohnstein, P. U.; Raczkowsky, J.; Klenzner, T.; Schipper, J.; Wörn, H.

    Bei chirurgischen Eingriffen an der lateralen Schädelbasis wird in der zur Zeit gängigen Praxis das Knochengewebe unter optischer Kontrolle großflächig ablativ entfernt, um den Operationssitus freizulegen und konventionell operieren zu können. Prinzipiell soll dabei die Schonung vital und funktional bedeutender Strukturen berücksichtigt werden. Zur weiteren Minimierung der Traumatisierung und zur Erhaltung der strukturellen anatomischen Integrität soll eine alternative endoskopische Operationstechnik entwickelt werden, bei der der Situs durch dünne im Knochen liegende Bohrkanäle erreicht wird. Im Rahmen der Evaluierung der generellen Eignung der geometrischen Ausprägungen der humanen lateralen Schädelbasis wurden Methoden entwickelt, die anhand virtueller Modelle die Zugänglichkeit der anatomischen Zielstrukturen bestimmen können. Ein dabei auftretendes Problem ist die interindividuelle Vergleichbarkeit der Ergebnisse, da aufgrund der anatomischen Variationen eine zuverlässige interindividuelle Registrierung nicht trivial ist. Diese Arbeit beschreibt ein modellbasiertes Verfahren zur automatischen Registrierung mehrerer Felsenbeine zu einander über die prägnante Geometrie der Cochlea.

  9. Checkpoint-Inhibitoren in der Immuntherapie: Ein Meilenstein in der Behandlung des malignen Melanoms.

    PubMed

    Wilden, Sophia M; Lang, Berenice M; Mohr, Peter; Grabbe, Stephan

    2016-07-01

    Seit Jahrzehnten ist bekannt, dass Tumoren vom Immunsystem erkannt und zerstört werden können. Diese, vor allem in Tierversuchen gewonnene Erkenntnis konnte jedoch in der Vergangenheit nicht zum Nutzen unserer Patienten umgesetzt werden, da immunonkologische Therapieansätze in den letzten Jahrzehnten in der Anwendung beim Menschen stets versagt haben. Daher hat, mit Ausnahme der adjuvanten Interferontherapie, keines dieser Verfahren den Einzug in die klinische Versorgung gefunden. Langzeitüberleben unter guter Lebensqualität war dabei sehr wenigen Patienten vorbehalten. Mit den neuen immunologischen Therapieansätzen wird jedoch sowohl das Langzeitüberleben als auch die Lebensqualität onkologischer Patienten neu definiert. Auf die neuen "Immun-Checkpoint-Inhibitoren" spricht erstmals ein relevanter Teil der behandelten Patienten an und diese zeigen in der Regel langandauernde Remissionen bis hin zur Heilung. Schon jetzt ist klar, dass die Immuntherapie in Zukunft eine der wesentlichen Therapiesäulen bei der Behandlung des metastasierten Melanoms und auch vieler anderer fortgeschrittener Tumoren bilden wird. In dieser Übersicht werden die wichtigsten neuen Therapiemodalitäten besprochen und sowohl deren Wirkprinzip als auch klinische Daten zum Therapieansprechen und zu erwartenden Nebenwirkungen der Therapie referiert.

  10. Synthesis and Electronic Structure of Ru2(Xap)4(Y-gem-DEE) Type Compounds: Effect of Cross-Conjugation.

    PubMed

    Forrest, William P; Choudhuri, Mohommad M R; Kilyanek, Stefan M; Natoli, Sean N; Prentice, Boone M; Fanwick, Phillip E; Crutchley, Robert J; Ren, Tong

    2015-08-03

    Reported in this Article are the preparation and characterization of a series of new Ru2(II,III) compounds bearing one cross-conjugated σ-geminal-diethynylethene ligand (gem-DEE), namely, Ru2(Xap)4(Y-gem-DEE) (Xap = N,N'-anilinopyridinate (ap) or 2-(3,5-dimethoxy)anilinopyridinate (DiMeOap), and Y = Si(i)Pr3 (1) or H (2)) and [Ru2(ap)4]2(μ-gem-DEE) (3). Compounds 1-3 were characterized by spectroscopic and voltammetric techniques as well as the single crystal X-ray diffraction study of 2a. The X-ray structural data of 2a and the spectroscopic/voltammetric data of compounds 1 and 2 indicate that the gem-DEE ligands are similar to simple alkynyls in their effects on the molecular and electronic structures of the Ru2(Xap)4 moiety. Similar to the previously studied [Ru2(ap)4]2(μ-C2n) type compounds, dimer 3 exhibits pairwise 1e(-) oxidations and reductions, albeit the potential splits within the pair (ΔE1/2) are significantly smaller than those of [Ru2(ap)4]2(μ-C4). The electronic absorption spectra of the reduced and oxidized derivatives of 1a and 3 were determined using spectroelectrochemistry methods. No discernible intervalence charge transfer transition (IVCT) was detected in the near-IR spectrum for either 3(-) or 3(+), suggesting that the Ru2-Ru2 coupling in these mixed-valence states is weak. DFT calculations on a model compound of 3 yielded six singly occupied molecular orbitals (SOMOs), which have Ru2 contributions similar to those previously calculated for the [Ru2(ap)4]2(μ-C2n) type compounds. Among six SOMOs, SOMO-2 is the only one containing substantial dπ-π(gem-DEE) character across the entire Ru2-μ-gem-DEE-Ru2 linkage, which explains the weakened Ru2-Ru2 coupling.

  11. Integrable extended van der Waals model

    NASA Astrophysics Data System (ADS)

    Giglio, Francesco; Landolfi, Giulio; Moro, Antonio

    2016-10-01

    Inspired by the recent developments in the study of the thermodynamics of van der Waals fluids via the theory of nonlinear conservation laws and the description of phase transitions in terms of classical (dissipative) shock waves, we propose a novel approach to the construction of multi-parameter generalisations of the van der Waals model. The theory of integrable nonlinear conservation laws still represents the inspiring framework. Starting from a macroscopic approach, a four parameter family of integrable extended van der Waals models is indeed constructed in such a way that the equation of state is a solution to an integrable nonlinear conservation law linearisable by a Cole-Hopf transformation. This family is further specified by the request that, in regime of high temperature, far from the critical region, the extended model reproduces asymptotically the standard van der Waals equation of state. We provide a detailed comparison of our extended model with two notable empirical models such as Peng-Robinson and Soave's modification of the Redlich-Kwong equations of state. We show that our extended van der Waals equation of state is compatible with both empirical models for a suitable choice of the free parameters and can be viewed as a master interpolating equation. The present approach also suggests that further generalisations can be obtained by including the class of dispersive and viscous-dispersive nonlinear conservation laws and could lead to a new type of thermodynamic phase transitions associated to nonclassical and dispersive shock waves.

  12. Sterically Controlled Cu-Catalyzed or Transition-Metal-Free Cross-Coupling of gem-Difluoroalkenes with Tertiary, Secondary, and Primary Alkyl Grignard Reagents.

    PubMed

    Dai, Wenpeng; Shi, Hongyan; Zhao, Xianghu; Cao, Song

    2016-09-02

    A robust copper-catalyzed or transition-metal-free cross-coupling of gem-difluoroalkenes with tertiary, secondary, and primary alkyl Grignard reagents has been developed. Remarkably, the tertiary and secondary alkylation of gem-difluoroalkenes proceeded very smoothly in the presence of 25 mol % of CuCN or under transition-metal-free conditions, affording the tertiary and secondary alkyl-substituted fluoroalkenes in good to excellent yields with excellent Z stereoselectivity.

  13. Kommunikationsanforderungen an verteilte Echtzeitsysteme in der Fertigungsautomatisierung

    NASA Astrophysics Data System (ADS)

    Just, Roman; Trsek, Henning

    Kommunikationssysteme der Automatisierung müssen hohe zeitliche Anforderungen erfüllen, damit die entsprechenden industriellen Anwendungen realisiert werden können. Im Gegensatz zum IT-Bereich sind diese Anforderungen jedoch häufig nicht genau bekannt, was insbesondere beim Einsatz von drahtlosen Technologien Probleme bereiten kann1. In dieser Arbeit werden Verkehrsmuster einer realen Anlage aus dem Bereich der Fertigungsautomatisierung bestimmt. Die Zwischenankunfts- und Latenzzeiten einzelner Sensorund Aktorsignale ermöglichen Rückschlüsse auf zeitliche Anforderungen und Charakteristiken der untersuchten Anwendung. Im Anschluss werden die erzielten Erkenntnisse hinsichtlich ausgewählter Kommunikationsanforderungen analysiert und aktuell gültige Anforderungen von realen Automatisierungsanlagen abgeleitet. Weiterhin werden sie zukünftig zur Entwicklung realitätsnaher Simulationsmodelle genutzt.

  14. Peptides containing acylated C-terminal gem diamines: novel irreversible inactivators of the cysteine and serine proteinases.

    PubMed

    Gilmore, B F; Lynas, J F; Harriott, P; Healy, A; Walker, B

    2006-05-01

    This study reports on the synthesis of peptides containing C-terminal acylated gem-diamines and their utilization for the preparation of irreversible inactivators of the serine and cysteine proteinases. We have succeeded in obtaining an inhibitor Acetyl-Val-Pro-g-Val-CO-O-C(6)H(4)-NO(2) of neutrophil and pancreatic elastases that functions in a time-dependent manner, indicative of the action of an irreversible inactivator, functioning, most probably, through the formation of a long-lived acyl enzyme intermediate. In addition, we have demonstrated the irreversible inhibition of the cysteine proteinase bovine cathepsin B, by chloroacetyl and bromoacetyl derivatives of a dipeptide gem-diamine, Cbz-Phe-g-Ala-CO-CH(2)Hal (Hal = Br, Cl).

  15. Precision astrometry with adaptive optics: constraints on the mutual orbit of Luhman 16AB from GeMS

    NASA Astrophysics Data System (ADS)

    Ammons, S. Mark; Garcia, E. Victor; Salama, Maissa; Neichel, Benoit; Lu, Jessica; Marois, Christian; Macintosh, Bruce; Savransky, Dmitry; Bendek, Eduardo; Guyon, Olivier; Marin, Eduardo; Garrel, Vincent; Sivo, Gaetano

    2016-07-01

    ELTs equipped with MCAO systems will be powerful astrometric tools in the next two decades. With sparse-field precisions exceeding 30 uas for V > 18, the ELTs will surpass even GAIA's per-epoch precision for faint stars (V > 12). We present results from an ongoing astrometry program with Gemini GeMS and discuss synergies with WFIRST and GAIA. First, we present a fit to the relative orbit of the individual L/T components of Luhman16 AB, the nearest brown dwarf binary known. Exploiting GeMS' wide field of view to image reference stars, we are able to track the relative motion to better than 0.2 mas. We find that a mutual Keplerian orbit with no perturbing planets fits the binary separation to within the measurement errors, ruling out companions down to 14 earth masses for certain orbits and periods.

  16. The GED4GEM project: development of a Global Exposure Database for the Global Earthquake Model initiative

    USGS Publications Warehouse

    Gamba, P.; Cavalca, D.; Jaiswal, K.S.; Huyck, C.; Crowley, H.

    2012-01-01

    In order to quantify earthquake risk of any selected region or a country of the world within the Global Earthquake Model (GEM) framework (www.globalquakemodel.org/), a systematic compilation of building inventory and population exposure is indispensable. Through the consortium of leading institutions and by engaging the domain-experts from multiple countries, the GED4GEM project has been working towards the development of a first comprehensive publicly available Global Exposure Database (GED). This geospatial exposure database will eventually facilitate global earthquake risk and loss estimation through GEM’s OpenQuake platform. This paper provides an overview of the GED concepts, aims, datasets, and inference methodology, as well as the current implementation scheme, status and way forward.

  17. Zenon Environmental, Inc.: ZenoGem{trademark} biological and ultrafiltration technology. Innovative technology evaluation report; Superfund innovative technology evaluation

    SciTech Connect

    1999-04-01

    Zenon Environmental Inc. (Zenon), of Burlington, Ontario, Canada had developed an innovative wastewater treatment technology called the ZenoGem{trademark} technology. The ZenoGem{trademark} technology integrates biological treatment with membrane-based ultrafiltration to treat wastewater with high concentrations of organic contaminants that cause elevated concentrations of chemical oxygen demand (COD). The Superfund Innovative Technology Evaluation (SITE) demonstration occurred between September and December 1994 at the Nascolite Superfund site (Nascolite) in Millville, Cumberland County, New Jersey. During the SITE demonstration, critical and noncritical measurements were evaluated. Critical measurements consisted of sample analyses and process measurements that directly impacted meeting the project`s primary technical objective. Critical measurements included collection of liquid and air samples for MMA and VOC analyses; liquid samples to evaluate COD; and flow rate measurements of the influent and effluent liquid streams. Noncritical, or system condition measurements, provided information on operating ranges, reliability, variability, cost-effectiveness, and full-scale remediation potential of the technology.

  18. GEM:A Mission Concept for Monitoring Point Sources Emissions of CO2 and CH4 from Space

    NASA Astrophysics Data System (ADS)

    Prunet, P.; Jeansou, E.; Camy-Peyret, C.; Ernst, R.; Tesmer, V.; Bordeleau, M.; Payen, L.; Lecuyot, A.

    2016-08-01

    GEM (Gas Emission Mission) is a carbon dioxide and methane point source detection concept analysed in the context of ESA's "Space and Energy" initiative [1]. Starting from a consultation of user needs from the Energy Sectors, mission objectives have been derived for the detection and quantification of surface fluxes at local scales. A new EO concept has been proposed: GEM, a GHG mission based on a SWIR spectro-imager to measure anthropogenic emissions of CO2 and CH4 for GHG emission inventory and leaks detection and with a SWIR optical sensor. A preliminary study of the system including instruments, platform, launch, ground segment, programmatics, costs and feasibility assessment was performed, as well as a cost/benefit analysis.

  19. VizieR Online Data Catalog: Radial velocities of 1 Gem (Lane+, 2014)

    NASA Astrophysics Data System (ADS)

    Lane, B. F.; Muterspaugh, M. W.; Griffin, R. F.; Scarfe, C. D.; Fekel, F. C.; Williamson, M. H.; Eaton, J. A.; Shao, M.; Colavita, M. M.; Konacki, M.

    2016-05-01

    Extensive radial-velocity measurements of the 1 Gem system have been obtained in four separate campaigns spanning 40yr, including data from eight different instruments. Between 1969 and 2009 R.F.G. acquired a total of 128 observations of 1 Gem using the original radial-velocity spectrometer at Cambridge; a second-generation, computerized instrument at Palomar; the CORAVEL spectrometer at Haute Provence Observatory (OHP), and most recently, the Cambridge CORAVEL. The "Cambridge CORAVEL" operates at the Coude focus of the 36inch reflector on the home site of the Cambridge Observatories, Madingley Road, Cambridge, England. The Cambridge and Palomar data are referred to as data set A, while the OHP data are labeled set B. The data for components A and Ba are provided in Table1. A series of observations of 1 Gem has been obtained by C.D.S. with the Dominion Astrophysical Observatory (DAO) radial-velocity spectrometer. Observations were begun early in 1980 and continued until the end of 2003. The DAO velocities of components A and Ba are listed in Table2. The total number of acceptable velocities from DAO radial-velocity scanner observations is 123 of the primary star and 107 of the brighter component of the close pair. The third component was not detectable in the DAO traces. We identify the DAO observations as data set C. >From 1983 through 2009 F.C.F. obtained observations at the Kitt Peak National Observatory (KPNO) with the 0.9m coude feed telescope, coude spectrograph, and several different CCD detectors. All of the spectrograms were acquired with a Texas Instruments (TI) CCD except for five that were obtained in 1983 with an RCA CCD and a single observation in 2008 September with a Tektronix CCD. All those observations were centered near 6430Å and had typical signal-to-noise ratios of about 250. The numerous TI CCD spectra have a wavelength range of just 84Å and a resolution of 0.21Å. The 86 velocities of component A and 80 of component Ba are listed in Table3

  20. Cosmic ray tests of a GEM-based TPC prototype operated in Ar-CF4-isobutane gas mixtures: II

    NASA Astrophysics Data System (ADS)

    Kobayashi, M.; Yonamine, R.; Tomioka, T.; Aoza, A.; Bito, H.; Fujii, K.; Higashi, T.; Hiramatsu, K.; Ikematsu, K.; Ishikawa, A.; Kato, Y.; Kuroiwa, H.; Matsuda, T.; Nitoh, O.; Ohta, H.; Sakai, K.; Settles, R. D.; Sugiyama, A.; Tsuji, H.; Watanabe, T.; Yamaoka, H.; Yazu, T.

    2014-12-01

    The spatial resolution along the pad-row direction was measured with a GEM-based TPC prototype for the future linear collider experiment in order to understand its performance for tracks with finite projected angles with respect to the pad-row normal. The degradation of the resolution due to the angular pad effect was confirmed to be consistent with the prediction of a simple calculation taking into account the cluster-size distribution and the avalanche fluctuation.

  1. Alpha-substituted organic peroxides: synthetic strategies for a biologically important class of gem-dihydroperoxide and perketal derivatives.

    PubMed

    Zmitek, Katja; Zupan, Marko; Iskra, Jernej

    2007-12-21

    In this paper we review the recent developments in the synthesis of alpha-substituted hydroperoxides. Alpha-substituted hydroperoxides are interesting compounds due to their chemistry and bioactivity and as intermediates for the synthesis of other peroxides, of which cyclic peroxides are of major importance. Although the emphasis of this report will be on the derivatives of gem-dihydroperoxides, perketals, as well as the less studied nitrogen and sulfur derivatives, will also be covered.

  2. Efficient thermoelectric van der Pauw measurements

    NASA Astrophysics Data System (ADS)

    de Boor, Johannes; Schmidt, Volker

    2011-07-01

    The development of powerful thermoelectric materials requires fast and simple characterization techniques. We combine three measurements to obtain a complete thermoelectric characterization. The electrical conductivity is measured by the van der Pauw method, while ZT is determined directly by means of a Harman measurement. Finally, exploiting the analogy between electrical and thermal physics, a thermal van der Pauw measurement is performed and the sample Seebeck coefficient and thermal conductivity can be determined. No temperature differences need to be measured; all quantities can be deduced from voltage measurements concurrently on the same sample which allows for quick and convenient material screening.

  3. Request to Monitor U Gem and SS Cyg for Radio Observations

    NASA Astrophysics Data System (ADS)

    Templeton, Matthew R.

    2007-11-01

    Dr. Elmar Koerding, University of Southampton, England, and his collaborators have requested our assistance in a continuing project to monitor two dwarf novae - U Geminorum and SS Cygni - in support of radio observations with the Jodrell Bank MERLIN Array and NRAO Very Large Array (VLA) telescopes. This new campaign is a continuation of the project described in AAVSO Alert Notice 345. Koerding and collaborators are attempting to detect and characterize radio emission from dwarf novae during outbursts. Rapid optical detection of an outburst onset will be used to trigger target-of-opportunity (TOO) observations with the MERLIN Array in the UK and with the VLA in New Mexico. Observations of SS Cyg during the first campaign yielded important new results, and a paper on those observations will be submitted for publication in late 2007. Continuous optical monitoring and rapid reporting of observations of U Gem and SS Cyg is requested beginning 2007 November 5 (JD 2454410). This campaign will continue for at least several months, until a total of four outbursts are detected in either of these systems and TOO observations are obtained with the VLA and MERLIN. Rapid reporting of observations is critical to the success of this campaign. Observers are requested to report their observations to the AAVSO International Database within one (1) hour, especially if an object appears to be in transition to outburst. Quiescent (including "fainter-than" (upper-limit) observations) and full outburst observations are also important as they can be used to constrain when an outburst begins and and ends. Both visual and CCD observations are requested, but CCD time-series observations should only be performed if the data can be reduced and submitted immediately if an outburst has not yet been reported. Once an outburst has been detected and acknowledged by the radio observatories, filtered time-series observations will then be very useful. The outburst threshold (the magnitude at which the

  4. Space Weather Effects on Radio Propagation: Study of the CEDAR, GEM and ISTP Storm Events

    NASA Astrophysics Data System (ADS)

    Blagoveshchensky, D.

    On three high-latitude HF radio paths of North-west Russia, impact of 14 geomagnetic storms from a list of CEDAR, GEM and ISTP storms within 1997-99 on radio propagation conditions have been investigated. These conditions were estimated through variations o the MOF and LOF (the maximum and lowestf operation frequencies) on each path before, during and after a storm. Geophysical data of Dst, Bz, AE as well as some riometer data by observatory Sodankyla, Finland, were attracted for an analysis. It was shown that the storm impact on the ionosphere and radio propagation for each storm has an individual character. Nevertheless, there are common tendencies in variation of the propagation parameters for all storms. Thus, the frequency range ? = MOF - LOF is getting wider several hours before a storm, then it is sharply narrow during a storm-time and further it is expanded again several hours after storm ending. These regularities may be useful for the HF radio communication organization at the high latitudes. On the radio path with a reflection point at the geomagnetic latitude F? = 66o , the full time interval when the path is destroyed throughout a storm depends on a local time LT. For the day-time storms an average value td e s is 30%, for the night storm t des is only 20%. The fact is established that the ionization increase in the F2 layer several hours (4 hours during the day-time and 2 hours during the night) before the storm expansion phase onset may be considered as a reliable forerunner of the storm expansion phase development. By present experimental data, it was revealed that at the high latitudes not only the traditional mechanism of the solar energy transfer into the upper atmosphere through the magnetosphere tail, plasma sheet and auroral ionosphere operates but a quite another mechanism also exists - through the diurnal cusp and enter sheet of the magnetosphere. Thus, considered CEDAR, GEM and ISTP storms are distinguished essentially one from the other by

  5. Dynamic nature of cleavage bodies and their spatial relationship to DDX1 bodies, Cajal bodies, and gems.

    PubMed

    Li, Lei; Roy, Ken; Katyal, Sachin; Sun, Xuejun; Bléoo, Stacey; Godbout, Roseline

    2006-03-01

    DDX1 bodies, cleavage bodies, Cajal bodies (CBs), and gems are nuclear suborganelles that contain factors involved in RNA transcription and/or processing. Although all four nuclear bodies can exist as distinct entities, they often colocalize or overlap with each other. To better understand the relationship between these four nuclear bodies, we examined their spatial distribution as a function of the cell cycle. Here, we report that whereas DDX1 bodies, CBs and gems are present throughout interphase, CPSF-100-containing cleavage bodies are predominantly found during S and G2 phases, whereas CstF-64-containing cleavage bodies are primarily observed during S phase. All four nuclear bodies associate with each other during S phase, with cleavage bodies colocalizing with DDX1 bodies, and cleavage bodies/DDX1 bodies residing adjacent to gems and CBs. Although inhibitors of RNA transcription had no effect on DDX1 bodies or cleavage bodies, inhibitors of DNA replication resulted in loss of CstF-64-containing cleavage bodies. A striking effect on nuclear structures was observed with latrunculin B, an inhibitor of actin polymerization, resulting in the formation of needlelike nuclear spicules made up of CstF-64, CPSF-100, RNA, and RNA polymerase II. Our results suggest that cleavage body components are highly dynamic in nature.

  6. A spontaneous Escherichia coli K12 mutant which inhibits the excision-reintegration process of Mu gem2ts.

    PubMed

    Di Lallo, G; Fabozzi, G; Ghelardini, P; Paolozzi, L

    1997-09-01

    Escherichia coli K12 strains lysogenic for Mu gem2ts with the prophage inserted in a target gene (i.e., lacZ::Mu gem2ts lysogenic strains) revert to Lac+ by prophage precise excision with a relatively high frequency (about 1 x 10(-6)). The revertants obtained are still lysogens with the prophage inserted elsewhere in the bacterial chromosome. We have observed that, with the time of storage in stabs, bacterial cultures lysogenic for Mu gem2ts lose the ability to excise the prophage. The mutation responsible for this effect was co-transducible with the gyrB gene. After the removal of the prophage by P1 vir transduction from these strains, one randomly chosen clone, R3538, was further analyzed. It shows an increment of DNA supercoiling of plasmid pAT153, used as a reporter, and a reduced beta-galactosidase activity. On the other hand, R3538 is totally permissive to both lytic and lysogenic cycles of bacteriophage Mu.

  7. A two deformable-mirror concept to improve the laser efficiency of Gemini South MCAO (GeMS)

    NASA Astrophysics Data System (ADS)

    Béchet, Clémentine; Guesalaga, Andrés; Neichel, Benoit; Fesquet, Vincent; Guzman, Dani

    2013-12-01

    Gem's is the first laser-based multi-conjugate adaptive optics offeredto the astronomical community. Its asterism of 5 laser guide stars hasrecently proved to provide very uniform turbulence correction over the85''x85'' observation field, opening the new era of wide-field highangular resolution studies from the ground. Good AO performance requireshowever good wavefront sensing measurements from the laser guide stars,which directly depends on the quality of the laser spot image. Theoptimization of the lasers launched out of the telescope requires tofollow frequent and constraining calibrations and alignments procedures(quasi-static aberrations), in order to guarantee satisfying amplitudeand phase of the beam. These complex and time-consuming procedures willstrongly penalize the availability of Gem's.A laser beam shaping concept has been recently suggested to overcomesuch issues. It consists in applying, in the beam transfer optics, afield-conjugation thanks to 2 deformable mirrors. We review thisconcept. In particular, we discuss the criterion to be optimized and thedesired amplitude and phase shapes at the output of the Gemini beamtransfer optics. We deduce the control to be applied to the mirrors fromthe optimization of the signal-to-noise ratio of the wavefront sensingin Gem's. An iterative algorithm is used to estimate the phases, with aweighted least-squares unwrapper to avoid branch points. This algorithmefficiency is demonstrated with adequate beam shaping simulations.Discussion is made about how to implement such concept at Gemini.

  8. Development of a Walking Safety Scale for Older Adults, Part I: Content Validity of the GEM Scale

    PubMed Central

    Boudreault, Renée; Rousseau, Jacqueline; Bourbonnais, Daniel; Nadeau, Sylvie; Dubé, François

    2008-01-01

    Purpose: The Grille d’évaluation de la sécurité à la marche (GEM scale) is a performance-based tool developed to fill the need for an objective assessment of walking safety for older adults. It underwent a three-phase process of content validation. Method: A mailed questionnaire was used to assess the representativeness of the walking items (5-point pertinence scale). Subsequently, two physiotherapist focus groups (n = 20) were held to further evaluate the relevance of the scale and the walking items. Finally, a pilot study was completed with 3 raters administering the GEM scale to 12 hospitalized patients. Results: Comments and descriptive statistics (percentages) were analyzed from the questionnaire results and focus groups. On completion of the pilot study, which assessed 12 patients on the GEM scale, additional analyses were performed to address the theoretical background, the administration manual, the walking items, the scoring scale, and interpretation of the scale. Following each step, modifications were made to reflect the results of the analyses. Conclusion: The three-phase content-validation process demonstrated the relevance of this instrument and its representativeness as a walking safety assessment tool for older adults. PMID:20145759

  9. Dynamic Nature of Cleavage Bodies and Their Spatial Relationship to DDX1 Bodies, Cajal Bodies, and Gems

    PubMed Central

    Li, Lei; Roy, Ken; Katyal, Sachin; Sun, Xuejun; Bléoo, Stacey; Godbout, Roseline

    2006-01-01

    DDX1 bodies, cleavage bodies, Cajal bodies (CBs), and gems are nuclear suborganelles that contain factors involved in RNA transcription and/or processing. Although all four nuclear bodies can exist as distinct entities, they often colocalize or overlap with each other. To better understand the relationship between these four nuclear bodies, we examined their spatial distribution as a function of the cell cycle. Here, we report that whereas DDX1 bodies, CBs and gems are present throughout interphase, CPSF-100-containing cleavage bodies are predominantly found during S and G2 phases, whereas CstF-64-containing cleavage bodies are primarily observed during S phase. All four nuclear bodies associate with each other during S phase, with cleavage bodies colocalizing with DDX1 bodies, and cleavage bodies/DDX1 bodies residing adjacent to gems and CBs. Although inhibitors of RNA transcription had no effect on DDX1 bodies or cleavage bodies, inhibitors of DNA replication resulted in loss of CstF-64-containing cleavage bodies. A striking effect on nuclear structures was observed with latrunculin B, an inhibitor of actin polymerization, resulting in the formation of needlelike nuclear spicules made up of CstF-64, CPSF-100, RNA, and RNA polymerase II. Our results suggest that cleavage body components are highly dynamic in nature. PMID:16371507

  10. Some epidemiologic, clinical, microbiologic, and organizational assumptions that influenced the design and performance of the Global Enteric Multicenter Study (GEMS).

    PubMed

    Farag, Tamer H; Nasrin, Dilruba; Wu, Yukun; Muhsen, Khitam; Blackwelder, William C; Sommerfelt, Halvor; Panchalingam, Sandra; Nataro, James P; Kotloff, Karen L; Levine, Myron M

    2012-12-01

    The overall aim of the Global Enteric Multicenter Study-1 (GEMS-1) is to identify the etiologic agents associated with moderate-to-severe diarrhea (MSD) among children <5 years of age, and thereby the attributable pathogen-specific population-based incidence of MSD, to guide investments in research and public health interventions against diarrheal disease. To accomplish this, 9 core assumptions were vetted through widespread consultation: (1) a limited number of etiologic agents may be responsible for most MSD; (2) a definition of MSD can be crafted that encompasses cases that might otherwise be fatal in the community without treatment; (3) MSD seen at sentinel centers is a proxy for fatal diarrheal disease in the community; (4) matched case/control is the appropriate epidemiologic design; (5) methods across the sites can be standardized and rigorous quality control maintained; (6) a single 60-day postenrollment visit to case and control households creates mini-cohorts, allowing comparisons; (7) broad support for GEMS-1 messages can be achieved by incorporating advice from public health spokespersons; (8) results will facilitate the setting of investment and intervention priorities; and (9) wide acceptance and dissemination of the GEMS-1 results can be achieved.

  11. Some Epidemiologic, Clinical, Microbiologic, and Organizational Assumptions That Influenced the Design and Performance of the Global Enteric Multicenter Study (GEMS)

    PubMed Central

    Farag, Tamer H.; Nasrin, Dilruba; Wu, Yukun; Muhsen, Khitam; Blackwelder, William C.; Sommerfelt, Halvor; Panchalingam, Sandra; Nataro, James P.; Kotloff, Karen L.; Levine, Myron M.

    2012-01-01

    The overall aim of the Global Enteric Multicenter Study–1 (GEMS-1) is to identify the etiologic agents associated with moderate-to-severe diarrhea (MSD) among children <5 years of age, and thereby the attributable pathogen-specific population-based incidence of MSD, to guide investments in research and public health interventions against diarrheal disease. To accomplish this, 9 core assumptions were vetted through widespread consultation: (1) a limited number of etiologic agents may be responsible for most MSD; (2) a definition of MSD can be crafted that encompasses cases that might otherwise be fatal in the community without treatment; (3) MSD seen at sentinel centers is a proxy for fatal diarrheal disease in the community; (4) matched case/control is the appropriate epidemiologic design; (5) methods across the sites can be standardized and rigorous quality control maintained; (6) a single 60-day postenrollment visit to case and control households creates mini-cohorts, allowing comparisons; (7) broad support for GEMS-1 messages can be achieved by incorporating advice from public health spokespersons; (8) results will facilitate the setting of investment and intervention priorities; and (9) wide acceptance and dissemination of the GEMS-1 results can be achieved. PMID:23169935

  12. Performance of a large size triple GEM detector at high particle rate for the CBM Experiment at FAIR

    NASA Astrophysics Data System (ADS)

    Adak, Rama Prasad; Kumar, Ajit; Dubey, Anand Kumar; Chattopadhyay, Subhasis; Das, Supriya; Raha, Sibaji; Samanta, Subhasis; Saini, Jogender

    2017-02-01

    In CBM Experiment at FAIR, dimuons will be detected by a Muon Chamber (MUCH) consisting of segmented absorbers of varying widths and tracking chambers sandwiched between the absorber-pairs. In this fixed target heavy-ion collision experiment, operating at highest interaction rate of 10 MHz for Au+Au collision, the inner region of the 1st detector will face a particle rate of 1 MHz/cm2. To operate at such a high particle density, GEM technology based detectors have been selected for the first two stations of MUCH. We have reported earlier the performance of several small-size GEM detector prototypes built at VECC for use in MUCH. In this work, we report on a large GEM prototype tested with proton beam of momentum 2.36 GeV/c at COSY-Jülich Germany. The detector was read out using nXYTER operated in self-triggering mode. An efficiency higher than 96% at ΔVGEM = 375.2 V was achieved. The variation of efficiency with the rate of incoming protons has been found to vary within 2% when tested up to a maximum rate of 2.8 MHz/cm2. The gain was found to be stable at high particle rate with a maximum variation of ∼9%.

  13. Numerische Berechnung von Wirbelstromproblemen mit der Cell-Methode

    NASA Astrophysics Data System (ADS)

    Frenner, K.; Rucker, W. M.

    2006-09-01

    In dieser Arbeit wird die Cell-Methode auf die quasistatischen Maxwellgleichungen angewendet. Dabei werden für die notwendige Transformation vom Primärgitter auf das duale Gitter reziproke Basisvektoren verwendet. Anhand der Felddiffusion der magnetischen Induktion in einen zylindrischen Leiter werden Ergebnisse der Cell-Methode mit einer analytischen Vergleichsrechnung präsentiert.

  14. TÜV - Zertifizierungen in der Life Science Branche

    NASA Astrophysics Data System (ADS)

    Schaff, Peter; Gerbl-Rieger, Susanne; Kloth, Sabine; Schübel, Christian; Daxenberger, Andreas; Engler, Claus

    Life Sciences [1] (Lebenswissenschaften) sind ein globales Innovationsfeld mit Anwendungen der Bio- und Medizinwissenschaften, der Pharma-, Chemie-, Kosmetik- und Lebensmittelindustrie. Diese Branche zeichnet sich durch eine stark interdisziplinäre Ausrichtung aus, mit Anwendung wissenschaftlicher Erkenntnisse und Einsatz von Ausgangsstoffen aus der modernen Biologie, Chemie und Humanmedizin sowie gezielter marktwirtschaftlich orientierter Arbeit.

  15. Darwin, Engels und die Rolle der Arbeit in der biologischen und kulturellen Evolution des Menschen

    NASA Astrophysics Data System (ADS)

    Reichholf, Josef H.

    Im Jahre 1876, 5 Jahre nach Erscheinen von Darwins Buch über die Evolution des Menschen und die sexuelle Selektion (Darwin 1871), veröffentlichte Friedrich Engels den berühmt gewordenen Essay "Anteil der Arbeit an der Menschwerdung des Affen“ (Engels 1876). Die Kernfrage darin lautet in Kurzform: Warum hat der Mensch eigentlich ein Bedürfnis nach Arbeit? Engels Antwort wird nachfolgend näher betrachtet und vom gegenwärtigen Kenntnisstand aus beurteilt. Wie sich zeigen wird, beantworten seine Überlegungen die Frage nicht wirklich. Sie ist weiterhin offen. Es können lediglich einige zusätzliche Anhaltspunkte zur Diskussion gestellt werden. Angesichts des drängenden Problems millionenfacher Arbeitslosigkeit und der Forderungen nach einem "Grundrecht auf Arbeit“ kommt den Überlegungen zum möglichen Ursprung des Bedürfnisses nach Arbeit mehr als nur akademisches Interesse zu.

  16. Evaluation of SUNY satellite-to-irradiance model performance using ECMWF GEMS daily aerosol optical depth reanalysis data

    NASA Astrophysics Data System (ADS)

    Itterly, Kyle F.

    The current version of the State University of New York (SUNY) radiative transfer model (RTM) uses climatological monthly averages derived from a National Renewable Energy Labs (NREL) gridded dataset to parameterize aerosol optical depth (AOD), water vapor and ozone. This is mostly due to the limited availability of high spatially and temporally resolved observations. Several global chemical transport models are analyzed and compared in depth to determine which daily AOD dataset should be implemented into the SUNY Model. After thorough comparison, the chemical transport model chosen was the Global and regional Earth-system Monitoring using satellite and in-situ data (GEMS) model developed by the European Center for Medium Range Weather Forecasts (ECMWF). Using daily AOD values instead of monthly climatological values, the SUNY Model better captures events of extreme aerosol loadings, which greatly improves the accuracy in calculations of direct normal irradiance (DNI) and to a lesser extent, global horizontal irradiance (GHI). In clear-sky conditions with the sun directly overhead, a change in AOD from 0.1 to 0.5 is found to cause a 55% (20%) decrease in DNI (GHI) for Desert Rock, Nevada in January. A calibration scheme is applied to the daily GEMS AOD reanalysis data. For each site, the monthly means of the GEMS daily AOD are corrected by a factor to match the currently used monthly climatological AOD in order to avoid large errors caused by changing the magnitude of the monthly average AOD. The performance of the SUNY model improved significantly for many of the stations analyzed in this work after applying the daily-calibrated GEMS AOD. The Root Mean Squared Error (RMSE) was the most notable statistical improvement, which measures the model’s precision compared to the observed measurements from a ground station, and many other statistical improvements are also evident. All 7 SURFRAD locations showed improvements in DNI RMSE after using the calibrated GEMS

  17. THE PHASES DIFFERENTIAL ASTROMETRY DATA ARCHIVE. IV. THE TRIPLE STAR SYSTEMS 63 Gem A AND HR 2896

    SciTech Connect

    Muterspaugh, Matthew W.; Fekel, Francis C.; Williamson, M.; Lane, Benjamin F.; Hartkopf, William I.; Kulkarni, S. R.; Konacki, Maciej; Burke, Bernard F.; Colavita, M. M.; Shao, M. E-mail: blane@draper.co E-mail: maciej@ncac.torun.p

    2010-12-15

    Differential astrometry measurements from the Palomar High-precision Astrometric Search for Exoplanet Systems (PHASES) are used to constrain the astrometric orbit of the previously known {approx}<2 day subsystem in the triple system 63 Gem A and have detected a previously unknown two-year Keplerian wobble superimposed on the visual orbit of the much longer period (213 years) binary system HR 2896. 63 Gem A was already known to be triple from spectroscopic work, and absorption lines from all three stars can be identified and their individual Doppler shifts measured; new velocities for all three components are presented to aid in constraining the orbit and measuring the stellar masses. In fact, 63 Gem itself is a sextuple system: the hierarchical triple (Aa1-Aa2)-Ab (in which Aa1 and Aa2 orbit each other with a rapid period just under 2 days, and Ab orbits these every two years), plus three distant common proper motion companions. The very small astrometric perturbation caused by the inner pair in 63 Gem A stretches the limits of current astrometric capabilities, but PHASES observations are able to constrain the orientation of the orbit. The two bright stars comprising the HR 2896 long-period (213 year) system have a combined spectral type of K0III and the newly detected object's mass estimate places it in the regime of being an M dwarf. The motion of the stars are slow enough that their spectral features are always blended, preventing Doppler studies. The PHASES measurements and radial velocities (when available) have been combined with lower precision single-aperture measurements covering a much longer time frame (from eyepiece measurements, speckle interferometry, and adaptive optics) to improve the characterization of the long-period orbits in both binaries. The visual orbits of the short- and long-period systems are presented for both systems and used to calculate two possible values of the mutual inclinations between inner and outer orbits of 152{sup 0} {+-} 12

  18. Anti-Oncogenic gem-Dihydroperoxides Induce Apoptosis in Cancer Cells by Trapping Reactive Oxygen Species

    PubMed Central

    Kuranaga, Yuki; Yamada, Nami; Kashiwaya, Maiko; Nakamura, Moeko; Cui, Lei; Kumazaki, Minami; Shinohara, Haruka; Sugito, Nobuhiko; Taniguchi, Kohei; Ito, Yuko; Nakayama, Tatsushi; Uno, Bunji; Itoh, Akichika; Akao, Yukihiro

    2016-01-01

    Organic gem-dihydroperoxides (DHPs) and their derived peroxides have attracted a great deal of attention as potential anti-cancer agents. However, the precise mechanism of their inhibitory effect on tumors is unknown. To determine the mechanism of the inhibitory effects of DHPs, we examined the effects of DHPs on leukemia K562 cells. As a result, certain DHPs used in this study exhibited growth-inhibitory activity according to a clear structure-activity relationship. The most potent DHP, 12AC3O, induced apoptosis in K562 cells, but not in peripheral blood monocytes (PBMCs) or fibroblast cells. 12AC3O induced apoptosis through the intrinsic mitochondrial pathway and thereafter through the extrinsic pathway. The activity of the former pathway was partly attenuated by a JNK inhibitor. Interestingly, 12AC3O induced apoptosis by trapping a large amount of ROS, leading to an extremely lower intracellular ROS level compared with that in the cells in the steady-state condition. These results suggest that an appropriate level of intracellular ROS was necessary for the maintenance of cancer cell growth. DHPs may have a potential to be a novel anti-cancer agent with minimum adverse effects on normal cells. PMID:26760996

  19. Preparation and properties of gem-dichlorocyclopropane derivatives of long-chain fatty esters.

    PubMed

    Jie, M S; Wong, C F

    1992-01-01

    Methyl oleate (18:1) and linoleate (18:2) were readily transformed to the corresponding gem-dichlorocyclopropane derivatives in high yield, using triethylbenzylammonium chloride as the phase-transfer catalyst in the presence of aqueous NaOH and CHCl3. Reaction of dichlorocarbene with methyl 12-hydroxystearate furnished methyl 12-chlorostearate (49%) and 12-O-formylstearate (19%). The hydroxy group in methyl ricinoleate was protected (O-tetrahydropyran-2'-yl) prior to dichlorocyclopropanation of the ethylenic bond. Removal of the protecting group allowed the hydroxy group to be converted to a chloride, O-acetyl, azido or O-formyl function. Treatment of methyl ricinoleate with thionyl chloride, followed by the reaction with dichlorocarbene gave the corresponding 12-chloro-dichlorocyclopropane derivative. The dichlorocyclopropane derivative of oleic acid was transformed to a C19 allenic fatty acid when treated with t-butyl lithium. However, the remaining dichlorocyclopropane derivatives containing an additional functional group in the alkyl chain, failed to yield the corresponding allenic derivatives. All derivatives were characterized by a combination of spectroscopic and chromatographic techniques, including infrared, 1H nuclear magnetic resonance (NMR), and 13C NMR spectroscopy.

  20. Diagnostic Microbiologic Methods in the GEMS-1 Case/Control Study

    PubMed Central

    Panchalingam, Sandra; Antonio, Martin; Hossain, Anowar; Mandomando, Inacio; Ochieng, Ben; Oundo, Joseph; Ramamurthy, T.; Tamboura, Boubou; Zaidi, Anita K. M.; Petri, William; Houpt, Eric; Murray, Patrick; Prado, Valeria; Vidal, Roberto; Steele, Duncan; Strockbine, Nancy; Sansonetti, Philippe; Glass, Roger I.; Robins-Browne, Roy M.; Tauschek, Marija; Svennerholm, Ann-Marie; Kotloff, Karen; Levine, Myron M.; Nataro, James P.

    2012-01-01

    To understand the etiology of moderate-to-severe diarrhea among children in high mortality areas of sub-Saharan Africa and South Asia, we performed a comprehensive case/control study of children aged <5 years at 7 sites. Each site employed an identical case/control study design and each utilized a uniform comprehensive set of microbiological assays to identify the likely bacterial, viral and protozoal etiologies. The selected assays effected a balanced consideration of cost, robustness and performance, and all assays were performed at the study sites. Identification of bacterial pathogens employed streamlined conventional bacteriologic biochemical and serological algorithms. Diarrheagenic Escherichia coli were identified by application of a multiplex polymerase chain reaction assay for enterotoxigenic, enteroaggregative, and enteropathogenic E. coli. Rotavirus, adenovirus, Entamoeba histolytica, Giardia enterica, and Cryptosporidium species were detected by commercially available enzyme immunoassays on stool samples. Samples positive for adenovirus were further evaluated for adenovirus serotypes 40 and 41. We developed a novel multiplex assay to detect norovirus (types 1 and 2), astrovirus, and sapovirus. The portfolio of diagnostic assays used in the GEMS study can be broadly applied in developing countries seeking robust cost-effective methods for enteric pathogen detection. PMID:23169941

  1. Vanadium-rich ruby and sapphire within Mogok Gemfield, Myanmar: implications for gem color and genesis

    NASA Astrophysics Data System (ADS)

    Zaw, Khin; Sutherland, Lin; Yui, Tzen-Fu; Meffre, Sebastien; Thu, Kyaw

    2015-01-01

    Rubies and sapphires are of both scientific and commercial interest. These gemstones are corundum colored by transition elements within the alumina crystal lattice: Cr3+ yields red in ruby and Fe2+, Fe3+, and Ti4+ ionic interactions color sapphires. A minor ion, V3+ induces slate to purple colors and color change in some sapphires, but its role in coloring rubies remains enigmatic. Trace element and oxygen isotope composition provide genetic signatures for natural corundum and assist geographic typing. Here, we show that V can dominate chromophore contents in Mogok ruby suites. This raises implications for their color quality, enhancement treatments, geographic origin, exploration and exploitation and their comparison with rubies elsewhere. Precise LA-ICP-MS analysis of ruby and sapphire from Mogok placer and in situ deposits reveal that V can exceed 5,000 ppm, giving V/Cr, V/Fe and V/Ti ratios up to 26, 78, and 97 respectively. Such values significantly exceed those found elsewhere suggesting a localized geological control on V-rich ruby distribution. Our results demonstrate that detailed geochemical studies of ruby suites reveal that V is a potential ruby tracer, encourage comparisons of V/Cr-variation between ruby suites and widen the scope for geographic typing and genesis of ruby. This will allow more precise comparison of Asian and other ruby fields and assist confirmation of Mogok sources for rubies in historical and contemporary gems and jewelry.

  2. Impact of famous CEDAR, GEM and ISTP geomagnetic Storms on HF Radio Propagation

    NASA Astrophysics Data System (ADS)

    Blagoveshchensky, D.; Sergeeva, M.

    The mighty geomagnetic storms due to the extraordinary Sun s activity cause as a rule some impacts in these areas radiation effects on human and satellites commercial airlines outages electric power and other geomagnetic effects navigation and communication GPS effects ionospheric disturbances HF communication effects Therefore our scientific understanding of this activity is very important Joint efforts for example within the framework of the CAWSES enable progress in our ability to i identify critical inputs to specify the geospace environment at a level needed to minimize impacts on technology human society and life and ii support the development of robust models that predict conditions in geospace based on understanding of the Sun-Earth system and all of its interacting components In this study influence of 14 geomagnetic storms from a list of CEDAR GEM and ISTP storms within 1997-99 on radio propagation conditions have been investigated These conditions were estimated through variations of the MOF and LOF the maximum and lowest operation frequencies on each path from three high-latitude HF radio paths of North-west Russia before during and after a storm It was shown that the storm impact on the ionosphere and radio propagation for each storm has an individual character Nevertheless the common character of the certain manifestations during storm-time was revealed For example the frequency range MOF - LOF is getting wider several hours before a storm then it is sharply narrow during a storm-time and further it is expanded again several

  3. A new front-end ASIC for GEM detectors with time and charge measurement capabilities

    NASA Astrophysics Data System (ADS)

    Ciciriello, F.; Corsi, F.; De Robertis, G.; Felici, G.; Loddo, F.; Marzocca, C.; Matarrese, G.; Ranieri, A.

    2016-07-01

    A 32 channel CMOS front-end ASIC has been designed to read out the GEM detectors intended to be used for beam monitoring in a new proton-therapy facility currently under construction. In order to improve the spatial resolution by exploiting charge centroid algorithms, the analog channels, based on the classic CSA+shaper architecture, are equipped with a peak detector (PD) which works as an analog memory during the read-out phase. The outputs of the PDs are multiplexed towards an integrated 8-bit subranging ADC. An accurate trigger signal marks the arrival of a valid event and is generated by fast-ORing the outputs of 32 voltage discriminators which compare the shaper outputs with a programmable threshold. The digital part of the ASIC manages the read-out of the channels, the A/D conversion and the configuration of the ASIC. A 100 Mbit/s LVDS serial link is used for data communication. The sensitivity of the analog channel is 15 mV/fC and the dynamic range is 80 fC. The simulated ENC is about 650 e- for a detector capacitance of 10 pF. © 2001 Elsevier Science. All rights reserved

  4. Spectroscopic study of inclusions in gem corundum from Mercaderes, Cauca, Colombia

    NASA Astrophysics Data System (ADS)

    Zeug, Manuela; Rodríguez Vargas, Andrés Ignacio; Nasdala, Lutz

    2017-03-01

    Mineral inclusions in gem corundum from Mercaderes, Cauca, Colombia, were investigated non-destructively using Raman and photoluminescence spectroscopy, with special focus lying on phases containing radioactive elements. Besides abundant rutile, the minerals zircon, apatite, feldspar, and an epidote-group species, most probably allanite-(Ce), were found. The latter is detected easily from its characteristic Nd3+ emission pattern, which may prove useful in future provenance studies. Zircon inclusions range from well crystalline to moderately radiation damaged [FWHM (full width at half band maximum) of the ν 3(SiO4) Raman band 1.8-10.9 cm-1]. Both the zircon inclusions and their neighbouring host corundum are affected by compressive stress, which is assigned to (1) heterogeneous volume expansion of the host-inclusion couple upon pressure release during the uplift following primary growth and (2) volume expansion of the zircon inclusion due to the accumulation of self-irradiation damage. Internal stress of zircon inclusions averages 1.1 GPa. Heat treatment of corundum leads to structural reconstitution of zircon (narrowed zircon Raman bands with FWHMs in the range 1.8-2.7 cm-1) and accompanying stress release in the adjacent corundum (indicated by downshifts of the R 1 emission of Cr3+). The observation of broadened Raman band of zircon inclusions therefore allows one to exclude high-temperature enhancement of the host corundum.

  5. UVBY photometry of the chemically peculiar stars HD 15980, HR 1094, 33 Gem, and HD 115708

    NASA Astrophysics Data System (ADS)

    Adelman, Saul J.

    1999-01-01

    Differential Strömgren uvby photometry obtained with the Four College Automated Photoelectric Telescope shows that the hot HgMn star 33 Gem is photometrically constant. The Si star HD 15980 is found to be a variable whose period is significantly greater than 2 years. The unusual magnetic chemically peculiar Co star HR 1094 is discovered to be a low amplitude photometric variable with the magnetic field period of Hill & Blake, 2.9761 days. The ephemeris for the magnetic chemically peculiar star HD 115708 of Wade et al. is confirmed with the error in its period of 5.07622 days being greatly reduced. The {u}, {v}, {b}, and {y} light curves for both HR 1094 and HD 115708 exhibit differences which indicate complex elemental photospheric abundance distributions. Tables 3-6 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html

  6. Resistance heating of the gasket in a gem-anvil high pressure cell

    NASA Astrophysics Data System (ADS)

    Balzaretti, N. M.; Gonzalez, E. J.; Piermarini, G. J.; Russell, T. P.

    1999-11-01

    Resistance heating of the gasket strip in a gem-anvil high pressure cell was successful in obtaining sample temperatures up to 1100 °C, under pressures up to 4.0 GPa. The heating capabilities, as well as the mechanical and chemical stability, of several different gasket strips (two Ni-based alloys, Ta, Pt/Rh, and a Re/Mo alloy) with different design shapes, and two different single-crystal anvil materials (diamond and cubic zirconia) were investigated. Two gasket-strip designs were found to provide optimum uniform heating conditions while decreasing the required current needed to achieve 1100 °C. Two anvil systems were investigated to reduce the temperature increase of the pressure cell body. Cubic zirconia anvils reduced the cell-body temperature to 100 °C at sample temperatures up to 1100 °C. However, zirconia anvils often failed during heating and almost always failed during cooling. Diamond anvils with cubic zirconia mounting plates also permitted temperatures up to 1100 °C to be reached without anvil failure. However, the cell-body temperature increased to 300 °C. A sealed vacuum-type chamber was employed to eliminate the problem with gasket and anvil oxidation. The optimized operating parameters reported here provide a routine method for high temperature-high pressure studies. The method was used to densify and sinter nanosize amorphous silicon nitride and γ-alumina powders at high temperatures and high pressures.

  7. Effects from switching on PIC simulations: Geospace Environmental Modeling (GEM) reconnection setup revisited

    NASA Astrophysics Data System (ADS)

    Bourdin, P. A.; Nakamura, T.; Narita, Y.

    2015-12-01

    Electromagnetic Parcile-In-Cell (PIC) simulations are widely used to study plasma phenomena where kinetic scales are coupled to fluid scales. One of these phenomena is the evolution of magnetic reconnection. Switch-on effects have been described earlier for magneto-/hydrodynamic (MHD and HD) simulations, where oscillations are ignited by the initial condition and the usual instantaneous way of starting a simulation run. Here we revisit the GEM setup (a Harris current sheet) and demonstrate the immediate generation of oscillations propagating perpendicular to the magnetic shear layer (in Bz). Also we show how these oscillations do not dissipate quickly and will later be mode-converted to generate wave power, first in By, much later also in Bx (pointing along the shear direction). One needs to take care not to interpret these oscillations as physical wave modes associated with the nature of reconnection. We propose a method to prevent such switch-on effects from the beginning, that should be considered for implementation in other PIC simulation codes as well.

  8. Kepler Observations of V447 Lyr: an Eclipsing U Gem Cataclysmic Variable

    NASA Technical Reports Server (NTRS)

    Ramsay, Gavin; Cannizzo, John K.; Howell, Steve B.; Wood, Matt A.; Still, Martin; Barclay, Thomas; Smale, Alan

    2012-01-01

    We present the results of an analysis of Kepler data covering 1.5 yr of the dwarf nova V447 Lyr. We detect eclipses of the accretion disc by the mass donating secondary star every 3.74 h which is the binary orbital period. V447 Lyr is therefore the first dwarf nova in the Kepler field to show eclipses.We also detect five long outbursts and six short outbursts showing V447 Lyr is a U Gem-type dwarf nova. We show that the orbital phase of the mid-eclipse occurs earlier during outbursts compared to quiescence and that the width of the eclipse is greater during outburst. This suggests that the bright spot is more prominent during quiescence and that the disc is larger during outburst than quiescence. This is consistent with an expansion of the outer disc radius due to the presence of high viscosity material associated with the outburst, followed by a contraction in quiescence due to the accretion of low angular momentum material. We note that the long outbursts appear to be triggered by a short outburst, which is also observed in the super-outbursts of SU UMa dwarf novae as observed using Kepler.

  9. Fault-tolerant drive electronics for a Xinetics deformable mirror at GeMS DM0

    NASA Astrophysics Data System (ADS)

    Barberio, Michael J.

    2016-07-01

    Gemini South is replacing one of the (3) CILAS DMs with a 349-actuator Xinetics DM in its GeMS MCAO system. Xinetics mirrors operate over a 40-100V dynamic range and require that inter-actuator stroke differences are limited to half-scale; each actuator must be within 30V of its neighbor to prevent mechanical stress and possible face sheet separation. A robust way to implement this protection is to use high power transient voltage suppressors (TVSs) as a 2D-mesh between the amplifiers and mirror, but this has system implications. A sustained clamp condition dissipates significant power in the devices, and if an actuator fails as short (which occurred once with the DM in a thermal chamber), the system is subject to a cascade failure event as multiple outputs drive the shorted actuator through the TVS network. This latter risk is readily resolved by using series fuses to the DM. In this third-generation driver, current sensing and logic inhibit amplifier outputs after a sustained TVS clamp condition or shorted output, and LED indicators show the location. Redundant thermal sensing is used on modular TVS row and column boards. A second 2D-mesh of high impedance resistors after the fuses will hold an unpowered channel to the average voltage of its neighbors, with a negligible influence function. A Failure Modes and Effects Analysis shows significant fault tolerance.

  10. Diagnostic microbiologic methods in the GEMS-1 case/control study.

    PubMed

    Panchalingam, Sandra; Antonio, Martin; Hossain, Anowar; Mandomando, Inacio; Ochieng, Ben; Oundo, Joseph; Ramamurthy, T; Tamboura, Boubou; Zaidi, Anita K M; Petri, William; Houpt, Eric; Murray, Patrick; Prado, Valeria; Vidal, Roberto; Steele, Duncan; Strockbine, Nancy; Sansonetti, Philippe; Glass, Roger I; Robins-Browne, Roy M; Tauschek, Marija; Svennerholm, Ann-Marie; Berkeley, Lynette Y; Kotloff, Karen; Levine, Myron M; Nataro, James P

    2012-12-01

    To understand the etiology of moderate-to-severe diarrhea among children in high mortality areas of sub-Saharan Africa and South Asia, we performed a comprehensive case/control study of children aged <5 years at 7 sites. Each site employed an identical case/control study design and each utilized a uniform comprehensive set of microbiological assays to identify the likely bacterial, viral and protozoal etiologies. The selected assays effected a balanced consideration of cost, robustness and performance, and all assays were performed at the study sites. Identification of bacterial pathogens employed streamlined conventional bacteriologic biochemical and serological algorithms. Diarrheagenic Escherichia coli were identified by application of a multiplex polymerase chain reaction assay for enterotoxigenic, enteroaggregative, and enteropathogenic E. coli. Rotavirus, adenovirus, Entamoeba histolytica, Giardia enterica, and Cryptosporidium species were detected by commercially available enzyme immunoassays on stool samples. Samples positive for adenovirus were further evaluated for adenovirus serotypes 40 and 41. We developed a novel multiplex assay to detect norovirus (types 1 and 2), astrovirus, and sapovirus. The portfolio of diagnostic assays used in the GEMS study can be broadly applied in developing countries seeking robust cost-effective methods for enteric pathogen detection.

  11. A Triple-GEM Detector with Pixel Readout for High-Rate Beam Tracking in COMPASS

    NASA Astrophysics Data System (ADS)

    Nagel, T.; Austregesilo, A.; Haas, F.; Ketzer, B.; Konorov, I.; Krämer, M.; Mann, A.; Paul, S.

    2008-06-01

    For its physics program with a high-intensity hadron beam of 2 · 107 particles/s, the COMPASS experiment at CERN requires tracking of charged particles scattered by very small angles with respect to the incident beam direction. While good resolution in time and space is mandatory, the challenge is imposed by the high beam intensity, requiring radiation-hard detectors which add very little material to the beam path in order to minimise secondary interactions. To this end, a set of triple-GEM detectors with pixel readout in the beam region and 2-D strip readout in the periphery is currently being built. The pixel size has been chosen to be 1×1 mm2, which constitutes a compromise between the spatial resolution achievable and the number of readout channels. Surrounding the pixel area, a 2-D strip readout with a pitch of 400 μm has been realised on the same printed circuit foil. In total an active area of 10 × 10 cm2 is covered using 2048 readout channels. Analogue readout by the APV25 ASIC has been chosen in order to profit from amplitude measurements which help to improve the spatial resolution by clustering neighbouring hit strips or pixels. A detector prototype has been tested successfully in the 5 · 107 particles/s COMPASS muon beam, as well as in a focused hadron beam. The design of the detector and first results concerning its performance as a beam tracker will be presented.

  12. Spectroscopic study of inclusions in gem corundum from Mercaderes, Cauca, Colombia

    NASA Astrophysics Data System (ADS)

    Zeug, Manuela; Rodríguez Vargas, Andrés Ignacio; Nasdala, Lutz

    2016-10-01

    Mineral inclusions in gem corundum from Mercaderes, Cauca, Colombia, were investigated non-destructively using Raman and photoluminescence spectroscopy, with special focus lying on phases containing radioactive elements. Besides abundant rutile, the minerals zircon, apatite, feldspar, and an epidote-group species, most probably allanite-(Ce), were found. The latter is detected easily from its characteristic Nd3+ emission pattern, which may prove useful in future provenance studies. Zircon inclusions range from well crystalline to moderately radiation damaged [FWHM (full width at half band maximum) of the ν 3(SiO4) Raman band 1.8-10.9 cm-1]. Both the zircon inclusions and their neighbouring host corundum are affected by compressive stress, which is assigned to (1) heterogeneous volume expansion of the host-inclusion couple upon pressure release during the uplift following primary growth and (2) volume expansion of the zircon inclusion due to the accumulation of self-irradiation damage. Internal stress of zircon inclusions averages 1.1 GPa. Heat treatment of corundum leads to structural reconstitution of zircon (narrowed zircon Raman bands with FWHMs in the range 1.8-2.7 cm-1) and accompanying stress release in the adjacent corundum (indicated by downshifts of the R 1 emission of Cr3+). The observation of broadened Raman band of zircon inclusions therefore allows one to exclude high-temperature enhancement of the host corundum.

  13. First performance of the GeMS + GMOS system - 1. Imaging

    NASA Astrophysics Data System (ADS)

    Hibon, Pascale; Garrel, Vincent; Neichel, Benoit; Prout, Benjamin; Rigaut, Francois; Koning, Alice; Carrasco, Eleazar R.; Gimeno, German; Pessev, Peter

    2016-09-01

    During the commissioning of the Gemini MCAO System (GeMS), we had the opportunity to obtain data with the Gemini Multi-Object Spectrograph (GMOS), the most utilized instrument at Gemini South Observatory, in 2012 March and May. Several globular clusters were observed in imaging mode that allowed us to study the performance of this new and untested combination. GMOS is a visible instrument, hence pushing MCAO towards the visible. We report here on the results with the GMOS instruments, derive photometric performance in term of full width at half-maximum (FWHM) and throughput. In most of the cases, we obtained an improvement factor of at least 2 against the natural seeing. This result also depends on the natural guide star constellation selected for the observations and we then study the impact of the guide star selection on the FWHM performance. We also derive a first astrometric analysis showing that the GeMS+GMOS system provide an absolute astrometric precision better than 8 mas and a relative astrometric precision lower than 50 mas.

  14. GEM-CEDAR Study of Ionospheric Energy Input and Joule Dissipation

    NASA Technical Reports Server (NTRS)

    Rastaetter, Lutz; Kuznetsova, Maria M.; Shim, Jasoon

    2012-01-01

    We are studying ionospheric model performance for six events selected for the GEM-CEDAR modeling challenge. DMSP measurements of electric and magnetic fields are converted into Poynting Flux values that estimate the energy input into the ionosphere. Models generate rates of ionospheric Joule dissipation that are compared to the energy influx. Models include the ionosphere models CTIPe and Weimer and the ionospheric electrodynamic outputs of global magnetosphere models SWMF, LFM, and OpenGGCM. This study evaluates the model performance in terms of overall balance between energy influx and dissipation and tests the assumption that Joule dissipation occurs locally where electromagnetic energy flux enters the ionosphere. We present results in terms of skill scores now commonly used in metrics and validation studies and we can measure the agreement in terms of temporal and spatial distribution of dissipation (i.e, location of auroral activity) along passes of the DMSP satellite with the passes' proximity to the magnetic pole and solar wind activity level.

  15. Multichannel reconfigurable measurement system for hot plasma diagnostics based on GEM-2D detector

    NASA Astrophysics Data System (ADS)

    Wojenski, A. J.; Kasprowicz, G.; Pozniak, K. T.; Byszuk, A.; Chernyshova, M.; Czarski, T.; Jablonski, S.; Juszczyk, B.; Zienkiewicz, P.

    2015-12-01

    In the future magnetically confined fusion research reactors (e.g. ITER tokamak), precise determination of the level of the soft X-ray radiation of plasma with temperature above 30 keV (around 350 mln K) will be very important in plasma parameters optimization. This paper presents the first version of a designed spectrography measurement system. The system is already installed at JET tokamak. Based on the experience gained from the project, the new generation of hardware for spectrography measurements, was designed and also described in the paper. The GEM detector readout structure was changed to 2D in order to perform measurements of i.e. laser generated plasma. The hardware structure of the system was redesigned in order to provide large number of high speed input channels. Finally, this paper also covers the issue of new control software, necessary to set-up a complete system of certain complexity and perform data acquisition. The main goal of the project was to develop a new version of the system, which includes upgraded structure and data transmission infrastructure (i.e. handling large number of measurement channels, high sampling rate).

  16. Mars methane emission and transport scenarios using the GEM-Mars GCM

    NASA Astrophysics Data System (ADS)

    Neary, Lori; Daerden, Frank; Kaminski, J. W.; McConnell, J. C.

    2010-05-01

    The observation of methane (Formisano et al., 2004; Krasnopolsky et al., 2004; Mumma et al., 2009) in the Martian atmosphere has raised questions about its source and origin as well as its chemical behaviour. The photochemical lifetime of methane is on the order of several hundred years which would give a well-mixed, uniform distribution but measurements suggest locally enhanced "plumes". The GEM-Mars three-dimensional global chemistry-climate model is used to investigate the possible emission rates and lifetime of methane. The model simulations have a horizontal resolution of 4x4 degrees with 101 vertical levels up to approximately 140 km. References Formisano, V., S. Atreya, T. Encrenaz, N. Ignatiev, and M. Giuranna (2004), Detection of Methane in the Atmosphere of Mars, Science 306, 1758 (2004). Krasnopolsky, V. A., J. P. Maillard, and T. C. Owen (2004), Icarus 172, 537. Mumma, M.J., G.L. Villanueva, R.E. Novak, T. Hewagama, B.P. Bonev, M.A. DiSanti, A.M. Mandell, and M.D. Smith (2009), Strong Release of Methane on Mars in Northern Summer 2003. Science, 2009. 323: p. 1041-1045.

  17. Note on a van der Waals Gas.

    ERIC Educational Resources Information Center

    Bauman, Robert P.; Harrison, Joseph G.

    1996-01-01

    Discusses the difficulties with the standard model for introduction of attractive forces into the van der Waals equation. Presents an analysis in terms of force and time delays and an alternative analysis for more advanced students in terms of energy. (JRH)

  18. Die Evolution der Religiosität

    NASA Astrophysics Data System (ADS)

    Voland, Eckart

    Ein konsequent darwinischer Blick auf den Menschen bedeutet, auch im Denken, Fühlen und Handeln biologische Anpassungsgeschichte zu suchen, denn auch die psychischen und mentalen Eigenheiten des Homo sapiens unterliegen der natürlichen Selektion. Lässt sich die religiöse Lebenspraxis von Menschen daher auch aus einer Fitnessperspektive betrachten?

  19. The Forced van der Pol Equation

    ERIC Educational Resources Information Center

    Fay, Temple H.

    2009-01-01

    We report on a study of the forced van der Pol equation x + [epsilon](x[superscript 2] - 1)x + x = F cos[omega]t, by solving numerically the differential equation for a variety of values of the parameters [epsilon], F and [omega]. In doing so, many striking and interesting trajectories can be discovered and phenomena such as frequency entrainment,…

  20. The structure of the GemC1 coiled coil and its interaction with the Geminin family of coiled-coil proteins

    SciTech Connect

    Caillat, Christophe; Fish, Alexander; Pefani, Dafni-Eleftheria; Taraviras, Stavros; Lygerou, Zoi; Perrakis, Anastassis

    2015-10-31

    The GemC1 coiled-coil structure has subtle differences compared with its homologues Geminin and Idas. Co-expression experiments in cells and biophysical stability analysis of the Geminin-family coiled coils suggest that the GemC1 coiled coil alone is unstable. GemC1, together with Idas and Geminin, an important regulator of DNA-replication licensing and differentiation decisions, constitute a superfamily sharing a homologous central coiled-coil domain. To better understand this family of proteins, the crystal structure of a GemC1 coiled-coil domain variant engineered for better solubility was determined to 2.2 Å resolution. GemC1 shows a less typical coiled coil compared with the Geminin homodimer and the Geminin–Idas heterodimer structures. It is also shown that both in vitro and in cells GemC1 interacts with Geminin through its coiled-coil domain, forming a heterodimer that is more stable that the GemC1 homodimer. Comparative analysis of the thermal stability of all of the possible superfamily complexes, using circular dichroism to follow the unfolding of the entire helix of the coiled coil, or intrinsic tryptophan fluorescence of a unique conserved N-terminal tryptophan, shows that the unfolding of the coiled coil is likely to take place from the C-terminus towards the N-terminus. It is also shown that homodimers show a single-state unfolding, while heterodimers show a two-state unfolding, suggesting that the dimer first falls apart and the helices then unfold according to the stability of each protein. The findings argue that Geminin-family members form homodimers and heterodimers between them, and this ability is likely to be important for modulating their function in cycling and differentiating cells.

  1. The Rotation and Interior Structure Experiment (RISE) on the Mars Geophysical Monitoring and Sounding (GEMS) Mission

    NASA Astrophysics Data System (ADS)

    Folkner, W. M.; Asmar, S. W.; Dehant, V. M.; Banerdt, B.

    2011-12-01

    The Geophysical Monitoring and Sounding (GEMS) mission provides unique and critical information about the fundamental processes of terrestrial planet formation and evolutions. GEMS begins the geophysical exploration of the Martian interior using seismic and thermal measurements and rotational dynamics, providing information about the initial accretion of the planet, the formation and differentiation of its core and crust, and the subsequent evolution of the interior. One of the mission's investigations is the Rotation and Interior Structure Experiment (RISE), which uses the spacecraft X-band communication link to receive Doppler and ranging observables. The objective of RISE is to determine the mineralogy, temperature, and state of the deep interior of Mars, complementing information provided by seismology. The mineralogy and temperature of the deep interior will provide key information on the accretion of the planet, and can be used to test theories of terrestrial planet accretion and thermal evolution. The interior structure will be inferred by the effect on variations in the orientation of Mars with respect to inertial space. The precession, nutation, and polar motion of Mars result from the interaction of the interior mass distribution with the gravity of the Sun. RISE will provide improved estimates of Mars' precession and nutation, polar motion, and length-of-day variations by monitoring the Doppler shift due to the rotation of Mars on the radio signal between the spacecraft and tracking stations. RISE will reduce the uncertainty in the precession rate and therefore also in the moment of inertia by a factor of ten or more. The moment of inertia can be used as a constraint on the core size and density, core temperature and mineralogy. The improved accuracy of the moment of inertia can constraint the core size and eliminate many, if not most, possible composition ratios. In addition, the measurements of the nutation of Mars will determine whether the Martian

  2. Mcidas and GemC1 are key regulators for the generation of multiciliated ependymal cells in the adult neurogenic niche.

    PubMed

    Kyrousi, Christina; Arbi, Marina; Pilz, Gregor-Alexander; Pefani, Dafni-Eleftheria; Lalioti, Maria-Eleni; Ninkovic, Jovica; Götz, Magdalena; Lygerou, Zoi; Taraviras, Stavros

    2015-11-01

    Multiciliated cells are abundant in the epithelial surface of different tissues, including cells lining the walls of the lateral ventricles in the brain and the airway epithelium. Their main role is to control fluid flow and defects in their differentiation are implicated in many human disorders, such as hydrocephalus, accompanied by defects in adult neurogenesis and mucociliary disorder in the airway system. Here we show that Mcidas, which is mutated in human mucociliary clearance disorder, and GemC1 (Gmnc or Lynkeas), previously implicated in cell cycle progression, are key regulators of multiciliated ependymal cell generation in the mouse brain. Overexpression and knockdown experiments show that Mcidas and GemC1 are sufficient and necessary for cell fate commitment and differentiation of radial glial cells to multiciliated ependymal cells. Furthermore, we show that GemC1 and Mcidas operate in hierarchical order, upstream of Foxj1 and c-Myb transcription factors, which are known regulators of ependymal cell generation, and that Notch signaling inhibits GemC1 and Mcidas function. Our results suggest that Mcidas and GemC1 are key players in the generation of multiciliated ependymal cells of the adult neurogenic niche.

  3. Synthesis of Bis(oxazoline) Ligands Possessing C-5 gem-Disubstitution and Their Application in Asymmetric Friedel-Crafts Alkylations.

    PubMed

    O'Reilly, Steven; Aylward, Miriam; Keogh-Hansen, Caoimhe; Fitzpatrick, Brian; McManus, Helen A; Müller-Bunz, Helge; Guiry, Patrick J

    2015-10-16

    A series of eight novel bis(oxazoline) ligands incorporating gem-disubstitution on one of the oxazoline rings were prepared from (S)-valine. These ligands are designed as a cost-effective alternative to similar ligands possessing an oxazolinyl C(5)-tert-butyl group derived from expensive (S)-tert-leucine. Four of the ligands possess a C(4)-gem-dimethyl group and four a C(4)-gem-diphenyl group adjacent to the C(5)-isopropyl substituent. Zinc complexes of ligands 11a-h, along with non-C(4)-gem-disubstituted analogues 1a-g, were effective in the Friedel-Crafts alkylation of both indole (up to 74% ee) and 2-methoxyfuran (up to 95% ee) with a series of nitroalkenes. Three of the ligands (11a-c), an iron dichloride complex of ligand 11d and two zinc dichloride complexes, were characterized by X-ray crystallography, one with ligand 11d and the second a bis-tert-butyl-substituted N-methylamine ligand. A direct comparison of the latter structures clearly illustrates the gem-dimethyl effect.

  4. Development of 2D imaging of SXR plasma radiation by means of GEM detectors

    NASA Astrophysics Data System (ADS)

    Chernyshova, M.; Czarski, T.; Jabłoński, S.; Kowalska-Strzeciwilk, E.; Poźniak, K.; Kasprowicz, G.; Zabołotny, W.; Wojeński, A.; Byszuk, A.; Burza, M.; Juszczyk, B.; Zienkiewicz, P.

    2014-11-01

    Presented 2D gaseous detector system has been developed and designed to provide energy resolved fast dynamic plasma radiation imaging in the soft X-Ray region with 0.1 kHz exposure frequency for online, made in real time, data acquisition (DAQ) mode. The detection structure is based on triple Gas Electron Multiplier (GEM) amplification structure followed by the pixel readout electrode. The efficiency of detecting unit was adjusted for the radiation energy region of tungsten in high-temperature plasma, the main candidate for the plasma facing material for future thermonuclear reactors. Here we present preliminary laboratory results and detector parameters obtained for the developed system. The operational characteristics and conditions of the detector were designed to work in the X-Ray range of 2-17 keV. The detector linearity was checked using the fluorescence lines of different elements and was found to be sufficient for good photon energy reconstruction. Images of two sources through various screens were performed with an X-Ray laboratory source and 55Fe source showing a good imaging capability. Finally offline stream-handling data acquisition mode has been developed for the detecting system with timing down to the ADC sampling frequency rate (~13 ns), up to 2.5 MHz of exposure frequency, which could pave the way to invaluable physics information about plasma dynamics due to very good time resolving ability. Here we present results of studied spatial resolution and imaging properties of the detector for conditions of laboratory moderate counting rates and high gain.

  5. GeMS MCAO observations of the Galactic globular cluster NGC 2808: the absolute age

    NASA Astrophysics Data System (ADS)

    Massari, D.; Fiorentino, G.; McConnachie, A.; Bono, G.; Dall'Ora, M.; Ferraro, I.; Iannicola, G.; Stetson, P. B.; Turri, P.; Tolstoy, E.

    2016-02-01

    Context. Globular clusters are the oldest stellar systems in the Milky Way, and they probe the early epoch of the Galaxy formation. However, the uncertainties on their absolute age are still too large to soundly constrain how the Galactic structures have assembled. Aims: The aim of this work is to obtain an accurate estimate of the absolute age of the globular cluster NGC 2808 using deep IR data obtained with the multi-conjugate adaptive optics system operating at the Gemini South telescope (GeMS). Methods: This exquisite photometry, combined with that obtained in V and I-bands with HST, allowed us to detect the faint Main Sequence Knee feature in NGC 2808 colour magnitude diagram. The difference between this point and the main sequence turn-off is a good age estimator that provides ages with unprecedented accuracy. Results: We find that NGC 2808 has an age of t = 10.9 ± 0.7 (intrinsic) ±0.45 (metallicity term) Gyr. A possible contamination by He-enhanced population could make the cluster up to 0.25 Gyr older. Although this age estimate agrees with the age coming from the classical turn-off method (t = 11.0 Gyr), its uncertainty is a factor ~3 better, since it avoids systematics in reddening, distance assumptions, and photometric zero point determination. The final absolute age indicates that NGC 2808 is slightly younger than other Galactic globular clusters with similar metallicity. Tables of the photometry are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/586/A51

  6. Serial data acquisition for the X-ray plasma diagnostics with selected GEM detector structures

    NASA Astrophysics Data System (ADS)

    Czarski, T.; Chernyshova, M.; Pozniak, K. T.; Kasprowicz, G.; Zabolotny, W.; Kolasinski, P.; Krawczyk, R.; Wojenski, A.; Zienkiewicz, P.

    2015-10-01

    The measurement system based on GEM—Gas Electron Multiplier detector is developed for X-ray diagnostics of magnetic confinement tokamak plasmas. The paper is focused on the measurement subject and describes the fundamental data processing to obtain reliable characteristics (histograms) useful for physicists. The required data processing have two steps: 1—processing in the time domain, i.e. events selections for bunches of coinciding clusters, 2—processing in the planar space domain, i.e. cluster identification for the given detector structure. So, it is the software part of the project between the electronic hardware and physics applications. The whole project is original and it was developed by the paper authors. The previous version based on 1-D GEM detector was applied for the high-resolution X-ray crystal spectrometer KX1 in the JET tokamak. The current version considers 2-D detector structures for the new data acquisition system. The fast and accurate mode of data acquisition implemented in the hardware in real time can be applied for the dynamic plasma diagnostics. Several detector structures with single-pixel sensors and multi-pixel (directional) sensors are considered for two-dimensional X-ray imaging. Final data processing is presented by histograms for selected range of position, time interval and cluster charge values. Exemplary radiation source properties are measured by the basic cumulative characteristics: the cluster position distribution and cluster charge value distribution corresponding to the energy spectra. A shorter version of this contribution is due to be published in PoS at: 1st EPS conference on Plasma Diagnostics

  7. Frequency and Characteristics of Familial Melanoma in Spain: The FAM-GEM-1 Study

    PubMed Central

    Márquez-Rodas, Iván; Martín González, Manuel; Nagore, Eduardo; Gómez-Fernández, Cristina; Avilés-Izquierdo, Jose Antonio; Maldonado-Seral, Cayetana; Soriano, Virtudes; Majem-Tarruella, Margarita; Palomar, Virginia; Maseda, Rocio; Martín-Carnicero, Alfonso; Puertolas, Teresa; Godoy, Elena; Cerezuela, Pablo; Ochoa de Olza, Maria; Campos, Begoña; Perez-Ruiz, Elisabeth; Soria, Ainara; Gil-Arnaiz, Irene; Gonzalez-Cao, Maria; Galvez, Elisa; Arance, Ana; Belon, Joaquin; de la Cruz-Merino, Luis; Martín-Algarra, Salvador

    2015-01-01

    Introduction Familial history of melanoma is a well-known risk factor for the disease, and 7% melanoma patients were reported to have a family history of melanoma. Data relating to the frequency and clinical and pathological characteristics of both familial and non-familial melanoma in Spain have been published, but these only include patients from specific areas of Spain and do not represent the data for the whole of Spain. Patients and methods An observational study conducted by the Spanish Group of Melanoma (GEM) analyzed the family history of patients diagnosed with melanoma between 2011 and 2013 in the dermatology and oncology departments. Results In all, 1047 patients were analyzed, and 69 (6.6%) fulfilled criteria for classical familial melanoma (two or more first-degree relatives diagnosed with melanoma). Taking into account other risk factors for familial melanoma, such as multiple melanoma, pancreatic cancer in the family or second-degree relatives with melanoma, the number of patients fulfilling the criteria increased to 165 (15.8%). Using a univariate analysis, we determined that a Breslow index of less than 1 mm, negative mitosis, multiple melanoma, and a history of sunburns in childhood were more frequent in familial melanoma patients, but a multivariate analysis revealed no differences in any pathological or clinical factor between the two groups. Conclusions Similar to that observed in other countries, familial melanoma accounts for 6.6% of melanoma diagnoses in Spain. Although no differences in the multivariate analysis were found, some better prognosis factors, such as Breslow index, seem more frequent in familial melanoma, which reflect a better early detection marker and/or a different biological behavior. PMID:25874698

  8. Thermal properties of gem-quality moganite-rich blue chalcedony

    NASA Astrophysics Data System (ADS)

    Hatipogˇlu, M.; Tuncer, Y.; Kibar, R.; Çetin, A.; Karalı, T.; Can, N.

    2010-11-01

    In this study, thermal properties and thermal decompositions of dehydration behaviour of gem-quality translucent blue chalcedonies, without banding or crystalline centre structure, from the Sarıcakaya-Eskişehir region in Turkey were studied by means of X-ray diffraction (XRD), inductively coupled plasma-atomic emission spectrometry (ICP-AES), Fourier transform infrared (FT-IR), thermoluminescence (TL), and simultaneously two thermal analyses of (DTA/TGA) spectroscopy. X-ray diffraction patterns of the blue chalcedony indicate the presence of two important chalcedonic silica phases with overlapped peaks at 4.26, 3.34, 2.28, 2.13, 1.82, 1.54, 1.38, and 137 Å. During heating from the room temperature to 300 °C, the thermoluminescence pattern of the blue chalcedony shows a characteristic peak at 210 °C. This peak may be due to unusually high traces of the impurities S, Th, Tl, U, and W. During heating from the room temperature to 1400 °C, the TGA pattern of the blue chalcedony indicates that the weight loss is due to the silanol water loss only, and that this loss occurs in a wide temperature range between about 170 and 954 °C. In addition, after making some corrections concerning the artefact mass gain, being due to the drift with buoyancy effect of the atmosphere in its TGA curve, the moganite-rich blue chalcedony shows a relatively lower mass loss of 0.202%. The DTA pattern of the blue chalcedony displays both endothermic and exothermic behaviours because of silica phase transformations. There are one distinctive sharp endotherm and three weaker endotherms at 806 °C. In addition, there is one distinctive sharp exotherm and one weaker exotherm at 1270 °C.

  9. Survival for patients with single and multiple primary melanomas in the GEM study

    PubMed Central

    Kricker, Anne; Armstrong, Bruce K.; Goumas, Chris; Thomas, Nancy E.; From, Lynn; Busam, Klaus; Kanetsky, Peter A.; Gallagher, Richard P.; Marrett, Loraine D.; Groben, Pamela A.; Gruber, Stephen B.; Anton-Culver, Hoda; Rosso, Stefano; Dwyer, Terence; Berwick, Marianne

    2013-01-01

    Objective Little is known about survival after a diagnosis of a second or higher order (multiple) primary melanoma. We aimed to determine whether survival after diagnosis was better in patients with multiple primary melanomas (MPM) than with single primary melanomas (SPM), as suggested in a recent study. Design Survival analysis with median follow-up of 7.6 years (range 0.4-10.6). Setting The Genes, Environment and Melanoma (GEM) study enrolled incident cases of melanoma notified to population-based cancer registries in Australia, Canada, Italy and the USA. MPM were ascertained over a longer period than SPM. Participants 2372 patients with SPM and 1206 with MPM. Main outcome measures Melanoma-specific fatality hazard ratios (HR) and confidence intervals (CI) associated with clinical and pathologic characteristics of SPM, MPM and both together in Cox regression models. Results Thickness was the main determinant of fatality (HR for >4mm=7.68, 95% CI 4.46 to 13.23); other independent predictors were ulceration, mitoses and scalp location. After adjustment for these other predictors, there was little difference in fatality between MPM and SPM (HR for MPM relative to SPM=1.24, 95% CI 0.91 to 1.69; P = .18). Thicker SPM, however, had higher fatality (HR for >4mm=13.56, 95% CI 6.47-28.40) than thicker MPM (HR for >4mm=2.93, 95% CI 1.17-7.30). Conclusion While overall fatalities from SPM and MPM were similar, relative fatality for thick SPM was greater than for thick MPM. This finding may offer support for a difference in outcome between patients with SPM and MPM that is worth further exploration. PMID:23784017

  10. J-GEM follow-up observations of the gravitational wave source GW151226*

    NASA Astrophysics Data System (ADS)

    Yoshida, Michitoshi; Utsumi, Yousuke; Tominaga, Nozomu; Morokuma, Tomoki; Tanaka, Masaomi; Asakura, Yuichiro; Matsubayashi, Kazuya; Ohta, Kouji; Abe, Fumio; Chimasu, Sho; Furusawa, Hisanori; Itoh, Ryosuke; Itoh, Yoichi; Kanda, Yuka; Kawabata, Koji S.; Kawabata, Miho; Koshida, Shintaro; Koshimoto, Naoki; Kuroda, Daisuke; Moritani, Yuki; Motohara, Kentaro; Murata, Katsuhiro L.; Nagayama, Takahiro; Nakaoka, Tatsuya; Nakata, Fumiaki; Nishioka, Tsubasa; Saito, Yoshihiko; Terai, Tsuyoshi; Tristram, Paul J.; Yanagisawa, Kenshi; Yasuda, Naoki; Doi, Mamoru; Fujisawa, Kenta; Kawachi, Akiko; Kawai, Nobuyuki; Tamura, Yoichi; Uemura, Makoto; Yatsu, Yoichi

    2017-02-01

    We report the results of optical-infrared follow-up observations of the gravitational wave (GW) event GW151226 detected by the Advanced LIGO in the framework of J-GEM (Japanese collaboration for Gravitational wave ElectroMagnetic follow-up). We performed wide-field optical imaging surveys with the Kiso Wide Field Camera (KWFC), Hyper Suprime-Cam (HSC), and MOA-cam3. The KWFC survey started at 2.26 d after the GW event and covered 778 deg2 centered at the high Galactic region of the skymap of GW151226. We started the HSC follow-up observations from ˜12 d after the event and covered an area of 63.5 deg2 of the highest probability region of the northern sky with limiting magnitudes of 24.6 and 23.8 for the i and z bands, respectively. MOA-cam3 covered 145 deg2 of the skymap with the MOA-red filter ˜2.5 mon after the GW alert. The total area covered by the wide-field surveys was 986.5 deg2. The integrated detection probability for the observed area was ˜29%. We also performed galaxy-targeted observations with six optical and near-infrared telescopes from 1.61 d after the event. A total of 238 nearby (≤100 Mpc) galaxies were observed with a typical I band limiting magnitude of ˜19.5. We detected 13 supernova candidates with the KWFC survey, and 60 extragalactic transients with the HSC survey. Two thirds of the HSC transients were likely supernovae and the remaining one third were possible active galactic nuclei. With our observational campaign, we found no transients that are likely to be associated with GW151226.

  11. Geochemical and palynological indicators of the paleoecology of the River Gem coal bed, Whitley County, Kentucky

    USGS Publications Warehouse

    Hower, J.C.; Ruppert, L.F.; Eble, C.F.; Graham, U.M.

    1996-01-01

    The River Gem coal bed (upper Westphalian A) was sampled at five sites in a single mine in Whitley County, Kentucky. Previous petrographic and sulfur analyses of the collected interval samples showed that the coal bed could be divided into a basal low-sulfur lithotype, a middle high-sulfur bone lithotype and an upper high-sulfur lithotype. At one location a high-sulfur rider unit is present. In this study we have conducted detailed palynological analyses on all of the interval samples and ash geochemistry on the upper high-sulfur lithotype intervals and two of the basal high-sulfur basal lithotype intervals. Geochemical analyses show that As and Pb are generally high in the high-sulfur upper lithotypes from all five sites. Carbonates, having associated high levels of Ba and Sr, are important in the ash geochemistry of the lower, low-sulfur lithotypes. Ga, Ge and W are enriched in the higher vitrinite lithotypes among the low-sulfur samples. The basal lithotype at each of two sites, which was analyzed in detail, is enriched in yttrium plus the lighter rare earth elements. The basal low-sulfur lithotypes are dominated by arboreous lycopod spores. The middle, low-sulfur portion of the bed is dominated by herbaceous lycopsids (Densosporites) at the base of the unit and becomes increasingly enriched in Lycospora towards the top of the unit indicating that the peat-forming environment became wetter. The greatest arboreous lycopod spore abundances in the upper, high-sulfur portion the bed, along with an overlying marine roof, indicates that peat deposition was terminated by a marine inundation.

  12. Comparison of the HadGEM2 climate-chemistry model against in situ and SCIAMACHY atmospheric methane data

    NASA Astrophysics Data System (ADS)

    Hayman, G. D.; O'Connor, F. M.; Dalvi, M.; Clark, D. B.; Gedney, N.; Huntingford, C.; Prigent, C.; Buchwitz, M.; Schneising, O.; Burrows, J. P.; Wilson, C.; Richards, N.; Chipperfield, M.

    2014-12-01

    Wetlands are a major emission source of methane (CH4) globally. In this study, we evaluate wetland emission estimates derived using the UK community land surface model (JULES, the Joint UK Land Earth Simulator) against atmospheric observations of methane, including, for the first time, total methane columns derived from the SCIAMACHY instrument on board the ENVISAT satellite. Two JULES wetland emission estimates are investigated: (a) from an offline run driven with Climatic Research Unit-National Centers for Environmental Prediction (CRU-NCEP) meteorological data and (b) from the same offline run in which the modelled wetland fractions are replaced with those derived from the Global Inundation Extent from Multi-Satellites (GIEMS) remote sensing product. The mean annual emission assumed for each inventory (181 Tg CH4 per annum over the period 1999-2007) is in line with other recently published estimates. There are regional differences as the unconstrained JULES inventory gives significantly higher emissions in the Amazon (by ~36 Tg CH4 yr-1) and lower emissions in other regions (by up to 10 Tg CH4 yr-1) compared to the JULES estimates constrained with the GIEMS product. Using the UK Hadley Centre's Earth System model with atmospheric chemistry (HadGEM2), we evaluate these JULES wetland emissions against atmospheric observations of methane. We obtain improved agreement with the surface concentration measurements, especially at high northern latitudes, compared to previous HadGEM2 runs using the wetland emission data set of Fung et al. (1991). Although the modelled monthly atmospheric methane columns reproduce the large-scale patterns in the SCIAMACHY observations, they are biased low by 50 part per billion by volume (ppb). Replacing the HadGEM2 modelled concentrations above 300 hPa with HALOE-ACE assimilated TOMCAT output results in a significantly better agreement with the SCIAMACHY observations. The use of the GIEMS product to constrain the JULES-derived wetland

  13. Thermal response in van der Waals heterostructures

    NASA Astrophysics Data System (ADS)

    Naidu Gandi, Appala; Alshareef, Husam N.; Schwingenschlögl, Udo

    2017-01-01

    We solve numerically the Boltzmann transport equations of the phonons and electrons to understand the thermoelectric response in heterostructures of M2CO2 (M: Ti, Zr, Hf) MXenes with transition metal dichalcogenide monolayers. Low frequency optical phonons are found to occur as a consequence of the van der Waals bonding, contribute significantly to the thermal transport, and compensate for the reduced contributions of the acoustic phonons (increased scattering cross-sections in heterostructures), such that the thermal conductivities turn out to be similar to those of the bare MXenes. Our results indicate that the important superlattice design approach of thermoelectrics (to reduce the thermal conductivity) may be effective for two-dimensional van der Waals materials when used in conjunction with intercalation.

  14. Thermal response in van der Waals heterostructures.

    PubMed

    Gandi, Appala Naidu; Alshareef, Husam N; Schwingenschlögl, Udo

    2017-01-25

    We solve numerically the Boltzmann transport equations of the phonons and electrons to understand the thermoelectric response in heterostructures of M2CO2 (M: Ti, Zr, Hf) MXenes with transition metal dichalcogenide monolayers. Low frequency optical phonons are found to occur as a consequence of the van der Waals bonding, contribute significantly to the thermal transport, and compensate for the reduced contributions of the acoustic phonons (increased scattering cross-sections in heterostructures), such that the thermal conductivities turn out to be similar to those of the bare MXenes. Our results indicate that the important superlattice design approach of thermoelectrics (to reduce the thermal conductivity) may be effective for two-dimensional van der Waals materials when used in conjunction with intercalation.

  15. Superlubricity using repulsive van der Waals forces.

    PubMed

    Feiler, Adam A; Bergström, Lennart; Rutland, Mark W

    2008-03-18

    Using colloid probe atomic force microscopy, we show that if repulsive van der Waals forces exist between two surfaces prior to their contact then friction is essentially precluded and supersliding is achieved. The friction measurements presented here are of the same order as the lowest ever recorded friction coefficients in liquid, though they are achieved by a completely different approach. A gold sphere attached to an AFM cantilever is forced to interact with a smooth Teflon surface (templated on mica). In cyclohexane, a repulsive van der Waals force is observed that diverges at short separations. The friction coefficient associated with this system is on the order of 0.0003. When the refractive index of the liquid is changed, the force can be tuned from repulsive to attractive and adhesive. The friction coefficient increases as the Hamaker constant becomes more positive and the divergent repulsive force, which prevents solid-solid contact, gets switched off.

  16. Der Begriff mathematischer Schönheit in einer empirisch informierten Ästhetik der Mathematik

    NASA Astrophysics Data System (ADS)

    Müller-Hill, Eva; Spies, Susanne

    Dieses Zitat des britischen Mathematikers G. H. Hardy bringt pointiert die unter praktizierenden Mathematikern, aber auch unter Philosophen der Mathematik weithin akzeptierte Ansicht zum Ausdruck, dass mathematische Schönheit eine nicht zu vernachlässigende Rolle in der mathematischen Forschungspraxis spielt und sowohl interessante ästhetiktheoretische, epistemische als auch ontologische Aspekte aufweist. Danach beeinflusst also das Verständnis dessen, was mathematische Schönheit ist, auch das Verständnis dessen, was Mathematik ist: "Was sind die Träger mathematischer Schönheit?" ist die Frage nach der Art der Gegenstände, für deren Schönheit Mathematiker sich begeistern und nach der sie streben. "Was sind die Kriterien für mathematische Schönheit?" ist die Frage nach den Kategorien, unter denen Mathematiker ihre Arbeit bewerten. Egal, ob sich das Phänomen mathematischer Schönheit als Ausnahmemerkmal oder als ständiger Begleiter mathematischen Tuns erweist - ein adäquates allgemeines Mathematikverständnis sollte dieses Phänomen berücksichtigen und bestenfalls auch erklären können.

  17. Theory of coherent van der Waals matter.

    PubMed

    Kulić, Igor M; Kulić, Miodrag L

    2014-12-01

    We explain in depth the previously proposed theory of the coherent van der Waals (cvdW) interaction, the counterpart of van der Waals (vdW) force, emerging in spatially coherently fluctuating electromagnetic fields. We show that cvdW driven matter is dominated by many-body interactions, which are significantly stronger than those found in standard van der Waals (vdW) systems. Remarkably, the leading two- and three-body interactions are of the same order with respect to the distance (∝R(-6)), in contrast to the usually weak vdW three-body effects (∝R(-9)). From a microscopic theory we show that the anisotropic cvdW many-body interactions drive the formation of low-dimensional structures such as chains, membranes, and vesicles with very unusual, nonlocal properties. In particular, cvdW chains display a logarithmically growing stiffness with the chain length, while cvdW membranes have a bending modulus growing linearly with their size. We argue that the cvdW anisotropic many-body forces cause local cohesion but also a negative effective "surface tension." We conclude by deriving the equation of state for cvdW materials and propose experiments to test the theory, in particular the unusual three-body nature of cvdW.

  18. Zellulare Nichtlineare Netzwerke: Anwendungen in der Informationstechnologie

    NASA Astrophysics Data System (ADS)

    Tetzlaff, R.

    2007-06-01

    Zellulare Nichtlineare Netzwerke (CNN) wurden 1988 von Chua und Yang (Chua und Yang, 1988) eingeführt. Diese Netzwerke sind dadurch gekennzeichnet, dass eine Zelle, die die kleinste Einheit eines CNN darstellt, nur mit Zellen innerhalb einer bestimmten Umgebung verbunden ist. üblicherweise sind Art und Stärke der Wechselwirkung zwischen zwei Zellen eines CNN translationsinvariant, d.h. sie hängen nur von der relativen Lage beider Zellen zueinander ab. Im Vordergrund aktueller Arbeiten stehen auf derartigen Netzwerken basierende schaltungstechnische Realisierungen mit bis zu 176x144 Zellen, die eine direkte Verbindung zu zweidimensionalen optischen Sensor-Anordnungen aufweisen. Über einen separaten Speicherbereich können die Zellkopplungen eines Netzwerks verändert werden, wodurch eine adaptive Verarbeitung von mehrdimensionalen Sensorsignalen ermöglicht wird. Das kürzlich vorgestellte so genannte EyeRis System (Anafocus Ltd.) enthält zusätzlich noch einen Standardprozessor und stellt (bei einer Größe vergleichbar mit der einer Kreditkarte) daher ein vollständiges superschnelles System zur Informationsverarbeitung dar. In diesem Beitrag sollen, nach einem kurzen Überblick über die Eigenschaften von CNN, aktuelle Realisierungen und exemplarisch eine neuere eigene Anwendung vorgestellt und besprochen werden.

  19. Theory of coherent van der Waals matter

    NASA Astrophysics Data System (ADS)

    Kulić, Igor M.; Kulić, Miodrag L.

    2014-12-01

    We explain in depth the previously proposed theory of the coherent van der Waals (cvdW) interaction, the counterpart of van der Waals (vdW) force, emerging in spatially coherently fluctuating electromagnetic fields. We show that cvdW driven matter is dominated by many-body interactions, which are significantly stronger than those found in standard van der Waals (vdW) systems. Remarkably, the leading two- and three-body interactions are of the same order with respect to the distance (∝R-6) , in contrast to the usually weak vdW three-body effects (∝R-9 ). From a microscopic theory we show that the anisotropic cvdW many-body interactions drive the formation of low-dimensional structures such as chains, membranes, and vesicles with very unusual, nonlocal properties. In particular, cvdW chains display a logarithmically growing stiffness with the chain length, while cvdW membranes have a bending modulus growing linearly with their size. We argue that the cvdW anisotropic many-body forces cause local cohesion but also a negative effective "surface tension." We conclude by deriving the equation of state for cvdW materials and propose experiments to test the theory, in particular the unusual three-body nature of cvdW.

  20. Using simulated maps to interpret the geochemistry, formation and quality of the Blue Gem Coal Bed, Kentucky, USA

    USGS Publications Warehouse

    Geboy, Nicholas J.; Olea, Ricardo A.; Engle, Mark A.; Martin-Fernandez, Jose Antonio

    2013-01-01

    This study presents geostatistical simulations of coal-quality parameters, major oxides and trace metals for an area covering roughly 812 km2 of the Blue Gem coal bed in southeastern Kentucky, USA. The Blue Gem, characterized by low ash yield and low sulfur content, is an important economic resource. Past studies have characterized the Blue Gem's geochemistry, palynology and petrography and inferred a depositional setting of a planar peat deposit that transitioned to slightly domed later in its development. These studies have focused primarily on vertical geochemical trends within the coal bed. Simulated maps of chemical elements derived from 45 measured sample locations across the study area provide an opportunity to observe changes in the horizontal direction within the coal bed. As the Blue Gem coal bed shows significant vertical chemical trends, care was taken in this study to try to select samples from a single, middle portion of the coal. By revealing spatial distribution patterns of elements across the middle of the bed, associations between different components of the coal can be seen. The maps therefore help to provide a picture of the coal-forming peat bog at an instant in geologic time and allow interpretation of a depositional setting in the horizontal direction. Results from this middle portion of the coal suggest an association of SiO2 with both K2O and TiO2 in different parts of the study area. Further, a pocket in the southeast of the study area shows elevated concentrations of elements attributable to observed carbonate-phase minerals (MgO, CaO, Ba and Sr) as well as elements commonly associated with sulfide-phase minerals (Cu, Mo and Ni). Areas of relatively high ash yield are observed in the north and south of the mapped area, in contrast to the low ash yields seen towards the east. Additionally, we present joint probability maps where multiple coal-quality parameters are plotted simultaneously on one figure. This application allows researchers

  1. New error calibration tests for gravity models using subset solutions and independent data - Applied to GEM-T3

    NASA Technical Reports Server (NTRS)

    Lerch, F. J.; Nerem, R. S.; Chinn, D. S.; Chan, J. C.; Patel, G. B.; Klosko, S. M.

    1993-01-01

    A new method has been developed to provide a direct test of the error calibrations of gravity models based on actual satellite observations. The basic approach projects the error estimates of the gravity model parameters onto satellite observations, and the results of these projections are then compared with data residual computed from the orbital fits. To allow specific testing of the gravity error calibrations, subset solutions are computed based on the data set and data weighting of the gravity model. The approach is demonstrated using GEM-T3 to show that the gravity error estimates are well calibrated and that reliable predictions of orbit accuracies can be achieved for independent orbits.

  2. Sensitivity analysis of the GEMS soil organic carbon model to land cover land use classification uncertainties under different climate scenarios in Senegal

    NASA Astrophysics Data System (ADS)

    Dieye, A. M.; Roy, D. P.; Hanan, N. P.; Liu, S.; Hansen, M.; Touré, A.

    2011-07-01

    Spatially explicit land cover land use (LCLU) change information is needed to drive biogeochemical models that simulate soil organic carbon (SOC) dynamics. Such information is increasingly being mapped using remotely sensed satellite data with classification schemes and uncertainties constrained by the sensing system, classification algorithms and land cover schemes. In this study, automated LCLU classification of multi-temporal Landsat satellite data were used to assess the sensitivity of SOC modeled by the Global Ensemble Biogeochemical Modeling System (GEMS). The GEMS was run for an area of 1560 km2 in Senegal under three climate change scenarios with LCLU maps generated using different Landsat classification approaches. This research provides a method to estimate the variability of SOC, specifically the SOC uncertainty due to satellite classification errors, which we show is dependent not only on the LCLU classification errors but also on where the LCLU classes occur relative to the other GEMS model inputs.

  3. Sensitivity analysis of the GEMS soil organic carbon model to land cover land use classification uncertainties under different climate scenarios in senegal

    NASA Astrophysics Data System (ADS)

    Dieye, A. M.; Roy, D. P.; Hanan, N. P.; Liu, S.; Hansen, M.; Touré, A.

    2012-02-01

    Spatially explicit land cover land use (LCLU) change information is needed to drive biogeochemical models that simulate soil organic carbon (SOC) dynamics. Such information is increasingly being mapped using remotely sensed satellite data with classification schemes and uncertainties constrained by the sensing system, classification algorithms and land cover schemes. In this study, automated LCLU classification of multi-temporal Landsat satellite data were used to assess the sensitivity of SOC modeled by the Global Ensemble Biogeochemical Modeling System (GEMS). The GEMS was run for an area of 1560 km2 in Senegal under three climate change scenarios with LCLU maps generated using different Landsat classification approaches. This research provides a method to estimate the variability of SOC, specifically the SOC uncertainty due to satellite classification errors, which we show is dependent not only on the LCLU classification errors but also on where the LCLU classes occur relative to the other GEMS model inputs.

  4. Sensitivity analysis of the GEMS soil organic carbon model to land cover land use classification uncertainties under different climate scenarios in Senegal

    USGS Publications Warehouse

    Dieye, A.M.; Roy, D.P.; Hanan, N.P.; Liu, S.; Hansen, M.; Toure, A.

    2011-01-01

    Spatially explicit land cover land use (LCLU) change information is needed to drive biogeochemical models that simulate soil organic carbon (SOC) dynamics. Such information is increasingly being mapped using remotely sensed satellite data with classification schemes and uncertainties constrained by the sensing system, classification algorithms and land cover schemes. In this study, automated LCLU classification of multi-temporal Landsat satellite data were used to assess the sensitivity of SOC modeled by the Global Ensemble Biogeochemical Modeling System (GEMS). The GEMS was run for an area of 1560 km2 in Senegal under three climate change scenarios with LCLU maps generated using different Landsat classification approaches. This research provides a method to estimate the variability of SOC, specifically the SOC uncertainty due to satellite classification errors, which we show is dependent not only on the LCLU classification errors but also on where the LCLU classes occur relative to the other GEMS model inputs. ?? 2011 Author(s).

  5. Jahre Entwicklung der Instandhaltung - von der ausfallorientierten Instandhaltung zum gemeinsamen TPM und RCM

    NASA Astrophysics Data System (ADS)

    Iske, Friedhelm

    Zur Einleitung meines Beitrages möchte ich von einem Gespräch mit einem Mitarbeiter berichten, das ich als junger Vorgesetzter einer Instandhaltungsgruppe 1988 führte. Der engagierte Mitarbeiter feierte damals sein vierzigjähriges Dienstjubiläum und war stolz auf das von ihm Geleistete sowie auf den besonderen Einsatz seiner Altersgruppe, die nach dem Zweiten Weltkrieg das Werk wieder aufgebaut hatte. Auf meine Frage, was denn damals die erste Aufgabe in der Firma war, bekam ich kurz und knapp und mit einer Selbstverständlichkeit die selbstbewusste Antwort: "Unser Pferd füttern und mit dem Pferd die innerbetrieblichen Transporte erledigen“. Als junger, technisch orientierter Vorgesetzter war ich über diese Antwort sehr überrascht. Gedanklich weit entfernt war die Vorstellung, dass in der Vergangenheit Transporte mit einem Pferd erledigt wurden.

  6. Der Telemanipulator daVinci als mechanisches Trackingsystem

    NASA Astrophysics Data System (ADS)

    Käst, Johannes; Neuhaus, Jochen; Nickel, Felix; Kenngott, Hannes; Engel, Markus; Short, Elaine; Reiter, Michael; Meinzer, Hans-Peter; Maier-Hein, Lena

    Der Telemanipulator daVinci (Intuitive Surgical, Sunnyvale, Kalifornien) ist ein M aster-Slave System für roboterassistierte minimalinvasive Chirurgie. Da er über integrierte Gelenksensoren verfügt, kann er unter Verwendung der daVinci-API als mechanisches Trackingsystem verwendet werden. In dieser Arbeit evaluieren wir die Präzision und Genauigkeit eines daVinci mit Hilfe eines Genauigkeitsphantoms mit bekannten Maßen. Der ermittelte Positionierungsfehler liegt in der Größenordnung von 6 mm und ist somit für einen Großteil der medizinischen Fragestellungen zu hoch. Zur Reduktion des Fehlers schlagen wir daher eine Kalibrierung der Gelenksensoren vor.

  7. Zum Wissenschaftsverständnis der modernen Evolutionsbiologie

    NASA Astrophysics Data System (ADS)

    Sommer, Ralf J.

    Die moderne Evolutionsbiologie hat ihren Ursprung in den Arbeiten von Charles Darwin und Alfred Wallace (Darwin 1963). Der gemeinsame Ausgangspunkt des Evolutionsgedanken ist dabei die Beobachtung, dass die biologische Welt nicht konstant ist. Biologische Systeme und alle darin lebenden Organismen unterliegen über längere Zeiträume hinweg einer stetigen Veränderung. Diese grundlegende Eigenschaft biologischer Systeme macht die Biologie zu einer historischen Wissenschaft und stellt einen wichtigen Gegensatz zu großen Teilen der Physik dar. Obwohl die Aussage von der Veränderlichkeit der Arten heute trivial klingt, war sie im 19. Jahrhundert eine Revolution, da die Konstanz der Arten und der Welt eine vorherrschende Stellung im damaligen Weltbild hatte (Amundson 2005).

  8. Mercury in the Arctic atmosphere: an analysis of eight years of measurements of GEM at Alert (Canada) and a comparison with observations at Amderma (Russia) and Kuujjuarapik (Canada).

    PubMed

    Steffen, Alexandra; Schroeder, William; Macdonald, Rob; Poissant, Laurier; Konoplev, Alexei

    2005-04-15

    Eight years of gaseous elemental mercury (GEM) concentration measurements from Alert, Nunavut, Canada (between 1995 and 2002) is presented. The annual time series shows a distinct repeating seasonal pattern with an overall annual median concentration for this time period of 1.58 (S.D.=0.04 ng m(-3)). Strong seasonal variation was observed throughout the years with springtime displaying strong variability in the GEM and overall lower median concentrations due to the so-called mercury depletion events (MDEs). Summer concentrations are higher than the annual average and show a decrease in variability. Fall and winter concentrations are distributed around the annual median concentrations and show little variability. The relationship between the springtime depression and the summer increase shows a change in the behaviour of mercury between 1995 and 2002. Preliminary results suggest that during this period an increasing amount of the mercury lost from the atmosphere in the spring is not returned to atmosphere in summer. A comparison of GEM concentration data from three sites--Alert (Canada), Amderma (Russia) and Kuujjuarapik (Canada)--demonstrated similar monthly distribution of GEM between Alert and Amderma, with the latter not showing as high summer concentrations. Monthly distribution of GEM at Kuujjuarapik varied considerably from the other two sites. MDEs were found to occur at each site in the spring yet displayed different characteristics. MDEs appear to start at Alert shortly after polar sunrise but in Amderma their initiation is delayed approximately 2 months following polar sunrise. MDEs occur in Kuujjuarapik in the springtime despite an incomplete development of the polar day-night cycle. In spring, as soon as air temperature attained temperatures consistently above 0 degrees C, MDEs ended immediately at all three sites. Continued studies into MDEs are warranted, but clearly an important component of future studies must focus on the origins of the variation

  9. Devices and applications of van der Waals heterostructures

    NASA Astrophysics Data System (ADS)

    Li, Chao; Zhou, Peng; Zhang, David Wei

    2017-03-01

    Van der Waals heterostructures, composed of individual two-dimensional material have been developing extremely fast. Synthesis of van der Waals heterostructures without the constraint of lattice matching and processing compatibility provides an ideal platform for fundamental research and new device exploitation. We review the approach of synthesis of van der Waals heterostructures, discuss the property of heterostructures and thoroughly illustrate the functional van der Waals heterostructures used in novel electronic and photoelectronic device. Project supported by the National Key Research and Development Program (No. 2016YFA0203900) and the National Natural Science Foundation of China (Nos. 61376093, 61622401).

  10. Future change of water vaiables from HadGEM2-AO simulation

    NASA Astrophysics Data System (ADS)

    Kim, Moon-Hyun; Kang, Hyun-Suk; Lee, Johan; Baek, Hee-Jeong; Cho, Chunho

    2013-04-01

    hydrology-atmosphere for water resource planning. Arora et al. (1999) and Oki and Sud (1998) developed a method for routing river flows through GCM grid cells. Accordingly, reliable forecasts are expected to help water managers and users with long lead time decisions, leading to greater water use efficiency and better risk management (Wang, 2012). SO, we analysed hydrological cycle and drought index from precipitation, evaporation, runoff, soil moisture, river outflow, and so on using atmosphere-ocean coupled model which called by HadGEM2-AO. Details and added information by this climate projection system about the future water cycle's change will be presented at the workshop. Acknowledgments: This research has been supported by project NIMR-2013-B-2 of the National Institute of Meteorological Research in Korea Meteorological Administration.

  11. A generalized electrostatic micro-mirror (GEM) model for a two-axis convex piecewise linear shaped MEMS mirror

    NASA Astrophysics Data System (ADS)

    Edwards, C. L.; Edwards, M. L.

    2009-05-01

    MEMS micro-mirror technology offers the opportunity to replace larger optical actuators with smaller, faster ones for lidar, network switching, and other beam steering applications. Recent developments in modeling and simulation of MEMS two-axis (tip-tilt) mirrors have resulted in closed-form solutions that are expressed in terms of physical, electrical and environmental parameters related to the MEMS device. The closed-form analytical expressions enable dynamic time-domain simulations without excessive computational overhead and are referred to as the Micro-mirror Pointing Model (MPM). Additionally, these first-principle models have been experimentally validated with in-situ static, dynamic, and stochastic measurements illustrating their reliability. These models have assumed that the mirror has a rectangular shape. Because the corners can limit the dynamic operation of a rectangular mirror, it is desirable to shape the mirror, e.g., mitering the corners. Presented in this paper is the formulation of a generalized electrostatic micromirror (GEM) model with an arbitrary convex piecewise linear shape that is readily implemented in MATLAB and SIMULINK for steady-state and dynamic simulations. Additionally, such a model permits an arbitrary shaped mirror to be approximated as a series of linearly tapered segments. Previously, "effective area" arguments were used to model a non-rectangular shaped mirror with an equivalent rectangular one. The GEM model shows the limitations of this approach and provides a pre-fabrication tool for designing mirror shapes.

  12. Derivation of the Schwartzchild Metric From the ``Self Censorship'' of the ZPF (Zero Point Energy) in the GEM Theory

    NASA Astrophysics Data System (ADS)

    Brandenburg, John

    2012-10-01

    The GEM theory (1) links the EM stress tensor directly to the metric tensor by the principle of ``self censorship'' of the ZPF (2) where the definition of guv = FuwF^wv/ 4 for Planck scale fields makes the stress tensor vanish even when fields are present. The first order form of the metric is recovered as Lorentzian due to alternating regions of strong electric and magnetic fields similar to that seen in models of spacetime in ``Loop Gravity,'' where the model admits perturbations. The GEM ExB drift models of gravity is used The first order perturbations on the fields are considered to be of the order of the fine structure constant alpha. Radiation fields due to a single charged particle of mass M fall off as 1/r and give the values (G=c=1) gtt = 1-2M/r and grr = (1-2M/r). (1) Brandenburg, J.E. (2012)., (2) STAIF II Conference Albuquerque NM 2.Brandenburg, J.E. (2007). IEEE Transactions On Plasma Science, Vol. 35, No. 4., p845.

  13. Real-time implementation of an LQG tip-tilt controller for regular science observation on GeMS

    NASA Astrophysics Data System (ADS)

    Sivo, Gaetano; Juvénal, Rémy; Kulcsár, Caroline; Garrel, Vincent; Gigoux, Pedro; Raynaud, Henri-François; Marin, Eduardo; Conan, Jean-Marc; Petit, Cyril; Rambold, William; Montes, Vanessa; Moreno, Cristian; Donahue, Jeff; Carrasco, Rodrigo; van Dam, Marcos; Neichel, Benoît; Leboulleux, Lucie; Trujillo, Chad

    2016-07-01

    AO systems aim at detecting and correcting for optical distortions induced by atmospheric turbulences. They are also extremely sensitive to extraneous sources of perturbation such as vibrations, which degrade the performance. The Gemini South telescope has currently two main AO systems: the Gemini Multi Conjugated AO System GeMS and the Gemini Planet Imager GPI. GeMS is operational and regularly used for science observation delivering close to diffraction limit resolution over a large field of view (85×85 arcsec2). Performance limitation due to the use of an integrator for tip-tilt control is here explored. In particular, this type of controller does not allow for the mitigation of vibrations with an arbitrary natural frequency. We have thus implemented a tip-tilt Linear Quadratic Gaussian (LQG) controller with different underlying perturbation models: (i) a sum of autoregressive models of order 2 identified from an estimated power spectrum density (s-AR2) of the perturbation,1 already tested on CANARY2 and routinely used on SPHERE;3 (ii) cascaded ARMA models of order 2 identified using prediction error minimization (c-PEM) as proposed in.4, 5 Both s-AR2 and c-PEM were parameterized to produce tip or tilt state-space models up to order 20 and 30 respectively. We discuss the parallelized implementation in the real time computer and the expected performance. On-sky tests are scheduled during the November 2016 run or the January 2017 run.

  14. Die Deutsche Statistische Gesellschaft in der Weimarer Republik und während der Nazidiktatur

    NASA Astrophysics Data System (ADS)

    Wilke, Jürgen

    Nach anfänglichen Schwierigkeiten durch den 1. Weltkrieg erlangte die Deutsche Statistische Gesellschaft (DStatG) unter dem renommierten Statistiker und Vorsitzenden der DStatG, Friedrich Zahn, durch eine Vielzahl von Aktivitäten hohes Ansehen. Es gab Bestrebungen, Statistiker aus allen Arbeitsfeldern der Statistik in die DStatG zu integrieren, wobei die "Mathematische Statistik" nur zögerlich akzeptiert wurde (Konjunkturforschung, Zeitreihenanalyse). Nach der Machtübernahme 1933 durch Adolf Hitler geriet die DStatG in das Fahrwasser nationalsozialistischer Ideologie und Politik (Führerprinzip, Gleichschaltung des Vereinswesens). Damit war eine personelle Umstrukturierung in der DStatG verbunden. Politisch Missliebige und rassisch Verfolgte mussten die DStatG verlassen (Bernstein, Freudenberg, Gumbel u.a.). Unter den Statistikern gab es alle Abstufungen im Verhalten zum Regime von Ablehnung und zwangsweiser Anpassung über bereitwilliges Mitläufertum bis zu bewusster Täterschaft. Besonders die Bevölkerungsstatistik wurde durch die NS- Rassenpolitik auf lange Sicht diskreditiert. Im Rahmen von Wirtschaftsplanung und Aufrüstung wurden neue zukunftsträchtige statistische Modelle (Grünig, Bramstedt, Leisse) entwickelt.

  15. van der Waals Heterostructures Grown by MBE

    NASA Astrophysics Data System (ADS)

    Hinkle, Christopher

    In this work, we demonstrate the high-quality MBE heterostructure growth of various layered 2D materials by van der Waals epitaxy (VDWE). The coupling of different types of van der Waals materials including transition metal dichalcogenide thin films (e.g., WSe2, WTe2, HfSe2) , insulating hexagonal boron nitride (h-BN), and topological insulators (e.g., Bi2Se3) allows for the fabrication of novel electronic devices that take advantage of unique quantum confinement and spin-based characteristics. The relaxed lattice-matching criteria of van der Waals epitaxy has allowed for high-quality heterostructure growth with atomically abrupt interfaces, allowing us to couple these materials based primarily on their band alignment and electronic properties. We will discuss the impact of sample preparation, surface reactivity, and lattice mismatch of various substrates (sapphire, graphene, TMDs, Bi2Se3) on the growth mode and quality of the films and will discuss our studies of substrate temperature and flux rates on the resultant growth and grain size. Structural and chemical characterization was conducted via reflection high energy electron diffraction (RHEED, X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning tunneling microscopy/spectroscopy (STM/S), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Experimentally determined band alignments have been determined and compared with first-principles calculations allowing the design of novel low-power logic and magnetic memory devices. Initial results from the electrical characterization of these grown thin films and some simple devices will also be presented. These VDWE grown layered 2D materials show significant potential for fabricating novel heterostructures with tunable band alignments and magnetic properties for a variety of nanoelectronic and optoelectronic applications.

  16. Kanban - der Weg ist das Ziel

    NASA Astrophysics Data System (ADS)

    Aull, Florian; Berlak, Joachim; Dickmann, Eva; Dickmann, Philipp; Fischäder, Holm; Gerlach, Joachim; Henneberg, Jens; Kapalla, Klaus; Kress, Oliver; Kuttler, Robert; Schneider, Herfried M.; Schürle, Philipp; Stellpflug, Franz-Josef; Wannenwetsch, Ralph; Wulz, Johannes; Zäh, Michael F.

    Wenn man aktuell Produktionsbereiche in Deutschland und Europa besucht, fallen im Zusammenhang mit modernen Produktionsmethoden immer öfter die Begriffe Kanban (jap. Karte, Signal) und Pull-Produktion, und dies nicht ohne Stolz, da diese mit dem schillernden Vorbild des Toyota Produktionssystems in Zusammenhang stehen. Tatsächlich ist Kanban ein integraler Bestandteil moderner Produktionssysteme. Blickt man aber im Rahmen von Prozessanalysen hinter die Fassaden", d. h. in die tägliche Praxis der Arbeitsprozesse, wird man schnell desillusioniert - die viel gepriesenen klassischen Kanban-Regeln werden im Tagesgeschäft nicht eingehalten.

  17. Komplexität der Geographie

    NASA Astrophysics Data System (ADS)

    Diekert, Volker; Hertrampf, Ulrich

    Das allgemein als Prototyp eines PSPACE-vollständigen Spiels gesehene Geographiespiel wird bezüglich seiner Komplexität genauer untersucht. Das Interesse der theoretischen Informatik an diesem Spiel wurde sehr durch die Darstellung in dem Lehrbuch von Papadimitriou [Pap94] gefördert. Allerdings bestimmt dieses Lehrbuch nicht die Komplexität des Standardspiels sondern verwendet eine Verallgemeinerung. Die Aussage in dem Lehrbuch bleibt damit etwas unbefriedigend und hinter den Möglichkeiten. Wir zeigen hier, dass die komplexitätstheoretische Charakterisierung schon für die Standardvariante des Spiels gilt.

  18. Physik gestern und heute: Visualisierung mit der Schlierenmethode

    NASA Astrophysics Data System (ADS)

    Heering, Peter

    2006-07-01

    Der Name des österreichischen Forschers Ernst Mach ist heute noch mit der Schallgeschwindigkeit verbunden. Diese Auszeichnung resultiert aus Machs Untersuchungen, wie sich Projektile mit Überschallgeschwindigkeit durch die Luft bewegen. Gerade in jüngster Zeit hat die Anwendung derartiger Methoden durch technische Modifikationen wieder einen Aufschwung erfahren.

  19. The Genetic Modifiers of Motor Onset Age (GeM MOA) website: genome-wide association analysis for genetic modifiers of Huntington's disease

    PubMed Central

    Correia, Kevin; Harold, Denise; Kim, Kyung-Hee; Holmans, Peter; Jones, Lesley; Orth, Michael; Myers, Richard H.; Kwak, Seung; Wheeler, Vanessa C.; MacDonald, Marcy E.; Gusella, James F.; Lee, Jong-Min

    2016-01-01

    BACKGROUND Huntington's disease (HD) is a dominantly inherited disease caused by a CAG expansion mutation in HTT. The age at onset of clinical symptoms is determined primarily by the length of this CAG expansion but is also influenced by other genetic and/or environmental factors. OBJECTIVE Recently, through genome-wide association studies (GWAS) aimed at discovering genetic modifiers, we identified loci associated with age at onset of motor signs that are significant at the genome-wide level. However, many additional HD modifiers may exist but may not have achieved statistical significance due to limited power. METHODS In order to disseminate broadly the entire GWAS results and make them available to complement alternative approaches, we have developed the internet website "GeM MOA" where genetic association results can be searched by gene name, SNP ID, or genomic coordinates of a region of interest. RESULTS Users of the Genetic Modifiers of Motor Onset Age (GeM MOA) site can therefore examine support for association between any gene region and age at onset of HD motor signs. GeM MOA's interactive interface also allows users to navigate the surrounding region and to obtain association p-values for individual SNPs. CONCLUSIONS Our website conveys a comprehensive view of the genetic landscape of modifiers of HD from the existing GWAS, and will provide the means to evaluate the potential influence of genes of interest on the onset of HD. GeM MOA is freely available at https://www.hdinhd.org/. PMID:26444025

  20. Measurement characteristics of activity-related psychosocial measures in 8- to 10-year-old African-American girls in the Girls health Enrichment Multisite Study (GEMS)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    BACKGROUND: This paper presents reliability and validity analyses of physical activity-related psychosocial questionnaires completed by 8- to 10-year-old African-American girls at baseline and follow-up assessments of pilot intervention studies in the Girls health Enrichment Multi-site Study (GEMS)....

  1. A micro-TCA based data acquisition system for the Triple-GEM detectors for the upgrade of the CMS forward muon spectrometer

    NASA Astrophysics Data System (ADS)

    Lenzi, T.

    2017-01-01

    The Gas Electron Multiplier (GEM) upgrade project aims at improving the performance of the muon spectrometer of the Compact Muon Solenoid (CMS) experiment which will suffer from the increase in luminosity of the Large Hadron Collider (LHC). The GEM collaboration proposes to instrument the first muon station with Triple-GEM detectors, a technology which has proven to be resistant to high fluxes of particles. The architecture of the readout system is based on the use of the microTCA standard hosting FPGA-based Advanced Mezzanine Card (AMC) and of the Versatile Link with the GBT chipset to link the on-detector electronics to the micro-TCA boards. For the front-end electronics a new ASIC, called VFAT3, is being developed. On the detector, a Xilinx Virtex-6 FPGA mezzanine board, called the OptoHybrid, has to collect the data from 24 VFAT3s and to transmit the data optically to the off-detector micro-TCA electronics, as well as to transmit the trigger data at 40 MHz to the CMS Cathode Strip Chamber (CSC) trigger. The microTCA electronics provides the interfaces from the detector (and front-end electronics) to the CMS DAQ, TTC (Timing, Trigger and Control) and Trigger systems. In this paper, we will describe the DAQ system of the Triple-GEM project and provide results from the latest test beam campaigns done at CERN.

  2. Ohio 4-H Agents' Perceptions of the Level of Importance and Frequency of Use of the Eighteen Components of the GEMS Model of Volunteer Administration.

    ERIC Educational Resources Information Center

    Deppe, Catherine A.; Culp, Ken, III

    2001-01-01

    4-H youth development agents (n=81) identified the importance and frequency of use of the phases in the GEMS (Generate, Educate, Motivate, Sustain) model of volunteer administration. The greatest discrepancy between importance and frequency was in sustaining volunteer involvement. Areas for agents' professional development were identified.…

  3. Great Explorations in Math and Science[R] (GEMS[R]) The Real Reasons for Seasons. What Works Clearinghouse Intervention Report

    ERIC Educational Resources Information Center

    What Works Clearinghouse, 2013

    2013-01-01

    "Great Explorations in Math and Science"[R] ("GEMS"[R]) "The Real Reasons for Seasons" is a curriculum unit for grades 6-8 that focuses on the connections between the Sun and the Earth to teach students the scientific concepts behind the seasons. The unit utilizes models, hands-on investigations, peer-to-peer…

  4. Crystal Structures of Mite Allergens Der f 1 and Der p 1 Reveal Differences in Surface-Exposed Residues that May Influence Antibody Binding

    SciTech Connect

    Chruszcz, Maksymilian; Chapman, Martin D.; Vailes, Lisa D.; Stura, Enrico A.; Saint-Remy, Jean-Marie; Minor, Wladek; Pomés, Anna

    2009-12-01

    The Group 1 mite allergens, Der f 1 and Der p 1, are potent allergens excreted by Dermatophagoides farinae and Dermatophagoides pteronyssinus, respectively. The human IgE antibody responses to the Group 1 allergens show more cross-reactivity than the murine IgG antibody responses which are largely species-specific. Here, we report the crystal structure of the mature form of Der f 1, which was isolated from its natural source, and a new, high-resolution structure of mature recombinant Der p 1. Unlike Der p 1, Der f 1 is monomeric both in the crystalline state and in solution. Moreover, no metal binding is observed in the structure of Der f 1, despite the fact that all amino acids involved in Ca{sup 2+} binding in Der p 1 are completely conserved in Der f 1. Although Der p 1 and Der f 1 share extensive sequence identity, comparison of the crystal structures of both allergens revealed structural features which could explain the differences in murine and human IgE antibody responses to these allergens. There are structural differences between Der f 1 and Der p 1 which are unevenly distributed on the allergens' surfaces. This uneven spatial arrangement of conserved versus altered residues could explain both the specificity and cross-reactivity of antibodies against Der f 1 and Der p 1.

  5. STELLAR CORONAE, SOLAR FLARES: A DETAILED COMPARISON OF {sigma} GEM, HR 1099, AND THE SUN IN HIGH-RESOLUTION X-RAYS

    SciTech Connect

    Huenemoerder, David P.; Phillips, Kenneth J. H.; Sylwester, Janusz; Sylwester, Barbara E-mail: kennethjhphillips@yahoo.com E-mail: bs@cbk.pan.wroc.pl

    2013-05-10

    The Chandra High Energy Transmission Grating Spectrometer (HETG) spectra of the coronally active binary stars {sigma} Gem and HR 1099 are among the highest fluence observations for such systems taken at high spectral resolution in X-rays with this instrument. This allows us to compare their properties in detail to solar flare spectra obtained with the Russian CORONAS-F spacecraft's RESIK instrument at similar resolution in an overlapping bandpass. Here we emphasize the detailed comparisons of the 3.3-6.1 A region (including emission from highly ionized S, Si, Ar, and K) from solar flare spectra to the corresponding {sigma} Gem and HR 1099 spectra. We also model the larger wavelength range of the HETG, from 1.7 to 25 A - having emission lines from Fe, Ca, Ar, Si, Al, Mg, Ne, O, and N-to determine coronal temperatures and abundances. {sigma} Gem is a single-lined coronally active long-period binary which has a very hot corona. HR 1099 is a similar, but shorter period, double-lined system. With very deep HETG exposures we can even study emission from some of the weaker species, such as K, Na, and Al, which are important since they have the lowest first ionization potentials, a parameter well known to be correlated with elemental fractionation in the solar corona. The solar flare temperatures reach Almost-Equal-To 20 MK, comparable to the {sigma} Gem and HR 1099 coronae. During the Chandra exposures, {sigma} Gem was slowly decaying from a flare and its spectrum is well characterized by a collisional ionization equilibrium plasma with a broad temperature distribution ranging from 2 to 60 MK, peaking near 25 MK, but with substantial emission from 50 MK plasma. We have detected K XVIII and Na XI emission which allow us to set limits on their abundances. HR 1099 was also quite variable in X-rays, also in a flare state, but had no detectable K XVIII. These measurements provide new comparisons of solar and stellar coronal abundances, especially at the lowest first ionization

  6. Vollautomatische Segmentierung der Prostata aus 3D-Ultraschallbildern

    NASA Astrophysics Data System (ADS)

    Heimann, Tobias; Simpfendörfer, Tobias; Baumhauer, Matthias; Meinzer, Hans-Peter

    Diese Arbeit beschreibt ein modellbasiertes Verfahren zur Segmentierung der Prostata aus 3D-Ultraschalldaten. Kern der Methode ist ein statistisches Formmodell, das auf Beispieldaten der Prostata trainiert wird. Erster Schritt der Segmentierung ist ein evolutionärer Algorithmus, mit dem das Modell grob im zu segmentierenden Bild positioniert wird. Für die darauf folgende lokale Suche wurden mehrere Varianten des Algorithmus evaluiert, unter anderem Ausreißer-Unterdrückung, freie Deformation und Gewichtung der verwendeten Erscheinungsmodelle nach ihrer Zuverlässigkeit. Alle Varianten wurden auf 35 Ultraschallbildern getestet und mit manuellen Referenzsegmentierungen verglichen. Die beste Variante erreichte eine durchschnittliche Oberflächenabweichung von 1.1 mm.

  7. Scaling laws for van der Waals interactions in nanostructured materials.

    PubMed

    Gobre, Vivekanand V; Tkatchenko, Alexandre

    2013-01-01

    Van der Waals interactions have a fundamental role in biology, physics and chemistry, in particular in the self-assembly and the ensuing function of nanostructured materials. Here we utilize an efficient microscopic method to demonstrate that van der Waals interactions in nanomaterials act at distances greater than typically assumed, and can be characterized by different scaling laws depending on the dimensionality and size of the system. Specifically, we study the behaviour of van der Waals interactions in single-layer and multilayer graphene, fullerenes of varying size, single-wall carbon nanotubes and graphene nanoribbons. As a function of nanostructure size, the van der Waals coefficients follow unusual trends for all of the considered systems, and deviate significantly from the conventionally employed pairwise-additive picture. We propose that the peculiar van der Waals interactions in nanostructured materials could be exploited to control their self-assembly.

  8. GEMS-like material in the matrix of the Paris meteorite and the early stages of alteration of CM chondrites

    NASA Astrophysics Data System (ADS)

    Leroux, H.; Cuvillier, P.; Zanda, B.; Hewins, R. H.

    2015-12-01

    The Paris meteorite is a weakly altered CM chondrite that has been discovered recently (Hewins et al., 2014). Its matrix offers the opportunity to search for well-preserved pristine pre-accretional material, as well as to study the earliest stages of aqueous alteration in the CM parent body. The study of the matrix of Paris has been conducted by analytical transmission electron microscopy on focused ion beam sections extracted from matrix areas showing different degrees of aqueous alteration. The least altered matrix sample consists of amorphous silicate grains, a few hundreds of nm in size, separated from one another by an abundant porosity. The amorphous silicates enclose numerous Fe-sulfide nanograins and their average composition is close to the chondritic composition. They share many similarities with GEMS (glass with embedded metal and sulfides) grains present in chondritic-porous interplanetary dust particles and with primitive type 3.0 carbonaceous chondrites. This first discovery of GEMS-like texture in a CM chondrite suggests that GEMS grains could have been the building blocks of the CM matrices. In more aqueously altered samples, pronounced microstructural heterogeneities were detected at the micrometer scale. The matrix consists mostly of a mixture of amorphous material and Fe-rich, spongy to fine-fibrous, poorly crystalline phyllosilicates. The porosity fraction is significantly reduced and the mixed amorphous-fibrous material frequently forms a continuous groundmass. The close association between these two material types suggests a replacement mechanism due to aqueous alteration. Chemical compositions correlate strongly with the microstructure. The amorphous material has a composition close to the chondritic value while the fine-fibrous phyllosilicate material is Fe-enriched. This Fe enrichment is found to be continuous from weakly to more heavily altered areas, in which the fibrous morphology is coarser and better crystalline. Cronstedtite with

  9. A compilation of field surveys on gaseous elemental mercury (GEM) from contrasting environmental settings in Europe, South America, South Africa and China: separating fads from facts.

    PubMed

    Higueras, Pablo; Oyarzun, Roberto; Kotnik, Joze; Esbrí, José María; Martínez-Coronado, Alba; Horvat, Milena; López-Berdonces, Miguel Angel; Llanos, Willians; Vaselli, Orlando; Nisi, Barbara; Mashyanov, Nikolay; Ryzov, Vladimir; Spiric, Zdravko; Panichev, Nikolay; McCrindle, Rob; Feng, Xinbin; Fu, Xuewu; Lillo, Javier; Loredo, Jorge; García, María Eugenia; Alfonso, Pura; Villegas, Karla; Palacios, Silvia; Oyarzún, Jorge; Maturana, Hugo; Contreras, Felicia; Adams, Melitón; Ribeiro-Guevara, Sergio; Niecenski, Luise Felipe; Giammanco, Salvatore; Huremović, Jasna

    2014-08-01

    Mercury is transported globally in the atmosphere mostly in gaseous elemental form (GEM, [Formula: see text]), but still few worldwide studies taking into account different and contrasted environmental settings are available in a single publication. This work presents and discusses data from Argentina, Bolivia, Bosnia and Herzegovina, Brazil, Chile, China, Croatia, Finland, Italy, Russia, South Africa, Spain, Slovenia and Venezuela. We classified the information in four groups: (1) mining districts where this contaminant poses or has posed a risk for human populations and/or ecosystems; (2) cities, where the concentration of atmospheric mercury could be higher than normal due to the burning of fossil fuels and industrial activities; (3) areas with natural emissions from volcanoes; and (4) pristine areas where no anthropogenic influence was apparent. All the surveys were performed using portable LUMEX RA-915 series atomic absorption spectrometers. The results for cities fall within a low GEM concentration range that rarely exceeds 30 ng m(-3), that is, 6.6 times lower than the restrictive ATSDR threshold (200 ng m(-3)) for chronic exposure to this pollutant. We also observed this behavior in the former mercury mining districts, where few data were above 200 ng m(-3). We noted that high concentrations of GEM are localized phenomena that fade away in short distances. However, this does not imply that they do not pose a risk for those working in close proximity to the source. This is the case of the artisanal gold miners that heat the Au-Hg amalgam to vaporize mercury. In this respect, while GEM can be truly regarded as a hazard, because of possible physical-chemical transformations into other species, it is only under these localized conditions, implying exposure to high GEM concentrations, which it becomes a direct risk for humans.

  10. The structure of the GemC1 coiled coil and its interaction with the Geminin family of coiled-coil proteins.

    PubMed

    Caillat, Christophe; Fish, Alexander; Pefani, Dafni Eleftheria; Taraviras, Stavros; Lygerou, Zoi; Perrakis, Anastassis

    2015-11-01

    GemC1, together with Idas and Geminin, an important regulator of DNA-replication licensing and differentiation decisions, constitute a superfamily sharing a homologous central coiled-coil domain. To better understand this family of proteins, the crystal structure of a GemC1 coiled-coil domain variant engineered for better solubility was determined to 2.2 Å resolution. GemC1 shows a less typical coiled coil compared with the Geminin homodimer and the Geminin-Idas heterodimer structures. It is also shown that both in vitro and in cells GemC1 interacts with Geminin through its coiled-coil domain, forming a heterodimer that is more stable that the GemC1 homodimer. Comparative analysis of the thermal stability of all of the possible superfamily complexes, using circular dichroism to follow the unfolding of the entire helix of the coiled coil, or intrinsic tryptophan fluorescence of a unique conserved N-terminal tryptophan, shows that the unfolding of the coiled coil is likely to take place from the C-terminus towards the N-terminus. It is also shown that homodimers show a single-state unfolding, while heterodimers show a two-state unfolding, suggesting that the dimer first falls apart and the helices then unfold according to the stability of each protein. The findings argue that Geminin-family members form homodimers and heterodimers between them, and this ability is likely to be important for modulating their function in cycling and differentiating cells.

  11. Group epitope mapping considering relaxation of the ligand (GEM-CRL): Including longitudinal relaxation rates in the analysis of saturation transfer difference (STD) experiments

    NASA Astrophysics Data System (ADS)

    Kemper, Sebastian; Patel, Mitul K.; Errey, James C.; Davis, Benjamin G.; Jones, Jonathan A.; Claridge, Timothy D. W.

    2010-03-01

    In the application of saturation transfer difference (STD) experiments to the study of protein-ligand interactions, the relaxation of the ligand is one of the major influences on the experimentally observed STD factors, making interpretation of these difficult when attempting to define a group epitope map (GEM). In this paper, we describe a simplification of the relaxation matrix that may be applied under specified experimental conditions, which results in a simplified equation reflecting the directly transferred magnetisation rate from the protein onto the ligand, defined as the summation over the whole protein of the protein-ligand cross-relaxation multiplied by with the fractional saturation of the protein protons. In this, the relaxation of the ligand is accounted for implicitly by inclusion of the experimentally determined longitudinal relaxation rates. The conditions under which this "group epitope mapping considering relaxation of the ligand" (GEM-CRL) can be applied were tested on a theoretical model system, which demonstrated only minor deviations from that predicted by the full relaxation matrix calculations (CORCEMA-ST) [7]. Furthermore, CORCEMA-ST calculations of two protein-saccharide complexes (Jacalin and TreR) with known crystal structures were performed and compared with experimental GEM-CRL data. It could be shown that the GEM-CRL methodology is superior to the classical group epitope mapping approach currently used for defining ligand-protein proximities. GEM-CRL is also useful for the interpretation of CORCEMA-ST results, because the transferred magnetisation rate provides an additional parameter for the comparison between measured and calculated values. The independence of this parameter from the above mentioned factors can thereby enhance the value of CORCEMA-ST calculations.

  12. Studies of aging and HV break down problems during development and operation of MSGC and GEM detectors for the inner tracking system of HERA-B

    NASA Astrophysics Data System (ADS)

    Bagaturia, Y.; Baruth, O.; Dreis, H. B.; Eisele, F.; Gorbunov, I.; Gradl, S.; Gradl, W.; Hausmann, S.; Hildebrandt, M.; Hott, T.; Keller, S.; Krauss, C.; Lomonosov, B.; Negodaev, M.; Richter, C.; Robmann, P.; Schmidt, B.; Straumann, U.; Truöl, P.; Visbeck, S.; Walter, T.; Werner, C.; Werthenbach, U.; Zech, G.; Zeuner, T.; Ziegler, M.

    2002-09-01

    The results of 5 years of development of the inner tracking system of the HERA-B experiment and first experience from the data taking period of the year 2000 are reported. The system contains 184 chambers, covering a sensitive area of about (20×20) cm2 each. The detector is based on microstrip gas counters (MSGCs) with diamond-like coated (DLC) glass wafers and gas electron multipliers (GEMs). The main problems in the development phase were gas discharges in intense hadron beams and aging in a high radiation dose environment. The observation of gas discharges which damage the electrode structure of the MSGC led to the addition of the GEM as a first amplification step. Spurious sparking at the GEM cannot be avoided completely. It does not affect the GEM itself but can produce secondary damage of the MSGC if the electric field between the GEM and the MSGC is above a threshold depending on the operation conditions. We observed that aging does not only depend on the dose but also on the spot size of the irradiated area. Ar-DME mixtures had to be abandoned whereas a mixture of 70% Ar and 30% CO 2 showed no serious aging effects up to about 40 mC/cm deposited charge on the anodes. X-ray measurements indicate that the DLC of the MSGC is deteriorated by the gas amplification process. As a consequence, long-term gain variations are expected. The Inner Tracker has successfully participated in the data taking at HERA-B during summer 2000.

  13. elecTUM: Umsetzung der eLearning-Strategie der Technischen Universität München

    NASA Astrophysics Data System (ADS)

    Rathmayer, Sabine; Gergintchev, Ivan

    An der TUM wurde ein umfassendes und integriertes eLearning-Konzept umgesetzt, welches Präsenzstudium und eLearning in allen Leistungsbereichen der Universität miteinander verzahnt. Ein besonderer Schwerpunkt lag dabei in der Schaffung einer effizienten und wettbewerbsfähigen integrierten eLearning Infrastruktur in Hinblick auf die noch weiter steigenden Studienanfängerzahlen ab dem Jahr 2011 sowie die Umsetzung von eBologna. Die Etablierung einer hochschulweiten Lernplattform stellte eine wesentliche Basis für die Umsetzung der eLearning-Strategie dar. Die wissenschaftliche und wirtschaftliche Anschlussfähigkeit im Hinblick auf eine Verwertung der Projektergebnisse wurde durch die aktive Beteiligung an einer Vielzahl hochschulübergreifender Arbeitskreise, Fachtagungen und Kooperationen, vor allem über Organisations- und Dienstleistungsmodelle sowie innovative technische Entwicklungen, sichergestellt.

  14. On line separation of overlapped signals from multi-time photons for the GEM-based detection system

    NASA Astrophysics Data System (ADS)

    Czarski, T.; Pozniak, K. T.; Chernyshova, M.; Malinowski, K.; Kasprowicz, G.; Kolasinski, P.; Krawczyk, R.; Wojenski, A.; Zabolotny, W.

    2015-09-01

    The Triple Gas Electron Multiplier (T-GEM) is presented as soft X-ray (SXR) energy and position sensitive detector for high-resolution X-ray diagnostics of magnetic confinement fusion plasmas. Multi-channel measurement system and serial data acquisition for X-ray energy and position recognition is described. Fundamental characteristics are presented for two dimensional detector structure. Typical signals of ADC - Analog to Digital Converter are considered for charge value and position estimation. Coinciding signals for high flux radiation cause the problem for cluster charge identification. The amplifier with shaper determines time characteristics and limits the pulses frequency. Separation of coincided signals was introduced and verified for simulation experiments. On line separation of overlapped signals was implemented applying the FPGA technology with relatively simple firmware procedure. Representative results for reconstruction of coinciding signals are demonstrated.

  15. Study of solid-conversion gaseous detector based on GEM for high energy X-ray industrial CT.

    PubMed

    Zhou, Rifeng; Zhou, Yaling

    2014-01-01

    The general gaseous ionization detectors are not suitable for high energy X-ray industrial computed tomography (HEICT) because of their inherent limitations, especially low detective efficiency and large volume. The goal of this study was to investigate a new type of gaseous detector to solve these problems. The novel detector was made by a metal foil as X-ray convertor to improve the conversion efficiency, and the Gas Electron Multiplier (hereinafter "GEM") was used as electron amplifier to lessen its volume. The detective mechanism and signal formation of the detector was discussed in detail. The conversion efficiency was calculated by using EGSnrc Monte Carlo code, and the transport course of photon and secondary electron avalanche in the detector was simulated with the Maxwell and Garfield codes. The result indicated that this detector has higher conversion efficiency as well as less volume. Theoretically this kind of detector could be a perfect candidate for replacing the conventional detector in HEICT.

  16. Impact of aviation emissions on UTLS and air quality in current and future climate - GEM-AC model simulations

    NASA Astrophysics Data System (ADS)

    Kaminski, J. W.

    2015-12-01

    The objective of this study is to investigate the potential impacts of aviation emissions on the upper troposphere and lower stratosphere (UTLS) and surface air quality. The tool that was used in our study is the GEM-AC (Global Environmental Multiscale with Atmospheric Chemistry) chemical weather model where air quality, free tropospheric and stratospheric chemistry processes are on-line and interactive in a weather forecast model of Environment Canada. In vertical, the model domain is defined on 70 hybrid levels from the surface to ~60km. The gas-phase chemistry includes a comprehensive set of reactions for Ox, NOx, HOx, CO, CH4, NMVOCs, halocarbons, ClOx and BrO. Also, the model can address aerosol microphysics and gas-aerosol partitioning. Aircraft emissions are provided by the AEDT 2006 database developed by the Federal Aviation Administration. Results from model simulations on a global variable grid with 1 degree uniform resolution in the northern hemisphere will be presented.

  17. Digital Database of Selected Aggregate and Related Resources in Ada, Boise, Canyon, Elmore, Gem, and Owyhee Counties, Southwestern Idaho

    USGS Publications Warehouse

    Moyle, Phillip R.; Wallis, John C.; Bliss, James D.; Bolm, Karen D.

    2004-01-01

    The U.S. Geological Survey (USGS) compiled a database of aggregate sites and geotechnical sample data for six counties - Ada, Boise, Canyon, Elmore, Gem, and Owyhee - in southwest Idaho as part of a series of studies in support of the Bureau of Land Management (BLM) planning process. Emphasis is placed on sand and gravel sites in deposits of the Boise River, Snake River, and other fluvial systems and in Neogene lacustrine deposits. Data were collected primarily from unpublished Idaho Transportation Department (ITD) records and BLM site descriptions, published Army Corps of Engineers (ACE) records, and USGS sampling data. The results of this study provides important information needed by land-use planners and resource managers, particularly in the BLM, to anticipate and plan for demand and development of sand and gravel and other mineral material resources on public lands in response to the urban growth in southwestern Idaho.

  18. The Genomes and Metagenomes (GEM) Catalogue (first presentation) and The ISA-GCDML Workshop (second presentation) (GSC8 Meeting)

    ScienceCinema

    Field, Dawn [NERC Centre for Ecology and Hydrology; Sansone, Susanna [EBI

    2016-07-12

    The Genomic Standards Consortium was formed in September 2005. It is an international, open-membership working body which promotes standardization in the description of genomes and the exchange and integration of genomic data. The 2009 meeting was an activity of a five-year funding ''Research Coordination Network'' from the National Science Foundation and was organized held at the DOE Joint Genome Institute with organizational support provided by the JGI and by the University of California - San Diego. Dawn Field of the NERC Centre for Ecology & Hydrology briefly introduces the GEM Catalogue, followed by Susanna Sansone of the European Bioinformatics Institute who talks about the ISA-GCDML workshop at the Genomic Standards Consortium's 8th meeting at the DOE JGI in Walnut Creek, Calif. on Sept. 9, 2009.

  19. Luminescence spectroscopy and microscopy applied to study gem materials: a case study of C centre containing diamonds

    NASA Astrophysics Data System (ADS)

    Hainschwang, Thomas; Karampelas, Stefanos; Fritsch, Emmanuel; Notari, Franck

    2013-06-01

    The methods of luminescence spectroscopy and microscopy are widely used for the analysis of gem materials. This paper gives an overview of the most important applications of the analysis of laser and UV excited luminescence by spectroscopy and visually by microscopy with emphasis on diamond, and specifically natural type Ib diamond, little studied so far. Luminescence based techniques are paramount to the gemmological analysis of diamond, in order to determine whether it is natural, treated or synthetic. The great sensitivity of luminescence helps detect some emitting centres that are undetectable by any other analytical method. Hence, especially for diamond, luminescence is an enabling technology, as illustrated by its pioneering use of imagery for the separation of natural and synthetic diamond, and of spectroscopy for the detection of High Pressure-High Temperature treatment. For all other gemstones the applications are at the moment less numerous, but nevertheless they remain highly important. They provide quickly information on the identification of a gem material, and its treatment. Besides the study of broad band emissions caused by various colour centres, the typical PL-causing trace elements (amongst others) are chromium, manganese, uranium and rare earth elements. In pearls the study of broad band luminescence can be useful, and particularly the study of pink to red porphyrin luminescence in pearls from certain species such as Pinctada and Pteria and others can help identify the pearl-producing mollusc, or if a pearl has been dyed or not. Type Ib diamonds are representative of the importance and complexity of the analysis of luminescence by microscopy and spectroscopy. They show a wide range of sometimes very complex emissions that result in luminescence colours from green to yellow to orange or red. These emissions show generally very inhomogeneous distribution. They are caused by a range of defects, however only a few of them are well characterized.

  20. Berechnung der auftretenden lokalen Kräfte auf der magnetischen Beschichtung eines magnetischen Rasterkraftmikroskops

    NASA Astrophysics Data System (ADS)

    Preisner, T.; Mathis, W.

    2009-05-01

    Die numerische Berechnung entstehender Kraftwirkungen auf Körper aufgrund magnetischer Wechselwirkungen zwischen diesen, ist in Bezug auf die mechanische Deformation dieser Körper ein noch nicht vollständig gelöstes Problem. In dieser Arbeit wird ein Vergleich vorhandener Kraftberechnungsmethoden hinsichtlich der totalen Kraft anhand eines analytisch berechenbaren Beispiels vorgestellt, sowie Unterschiede der lokalen Kraftdichten dieser Methoden in Anwendung auf die magnetische Beschichtung eines magnetischen Rasterkraftmikroskops aufgezeigt. Due to magnetic interactions between magnetic field inducing bodies, force effects occur on the materials. The numerical computation of those occuring forces with respect to a subsequent structural analysis of a deformable material is still a topic of interest in research. In this paper a comparison between several existent force calculation methods regarding the total force is given for an example with two magnetic cubes. Furthermore, differences are shown concerning the local force densities on the magnetic coating of a magnetic force microscope.

  1. Der f 21, a novel allergen from dermatophagoides farina.

    PubMed

    Wu, Yulan; Jiang, Congli; Li, Meng; Yu, Haiqiong; Xiao, Xiaojun; Fan, Xiaoqin; Lin, Jianli; Liu, Xiaoyu; Zhang, Min; Yang, Pingchang; Liu, Zhigang

    2016-01-01

    The Dermatophagoides farina (D. farina) allergens are an important factor contributing to allergic disease. To identify new allergens is important for diagnosis and treatment of allergic diseases. In this study, we sought to characterize the biological activity of Der f 21 of D. farina. The recombinant Der f 21 protein was characterized by western-blot, ELISA and Skin prick test using clinic patient's serum.An allergic asthma mouse model was established with the rDer f 21 as a specific antigen. The results showed that the sera from 28.9% in 38 dust mite allergic children displayed positive results in response to rDer f 21, and 42% in 98 dust mite allergic patients displayed positive response in skin prick test. In addition, Immune inhibition assays showed there was IgE cross-reactivity between rDer f 21 and rDer f 5. Moreover, an allergic asthma mouse model was established. Airway hyperresponsiveness, serum specific IgE, IgG1, eosinophil infiltration in the allergic mice, interleukin-4(IL-4) and interferon-γ (INF-γ) from spleen cells were markedly increased in the allergic mice. The results demonstrate that Der f 21 is a novel allergen.

  2. Direct synthesis of van der Waals solids.

    PubMed

    Lin, Yu-Chuan; Lu, Ning; Perea-Lopez, Nestor; Li, Jie; Lin, Zhong; Peng, Xin; Lee, Chia Hui; Sun, Ce; Calderin, Lazaro; Browning, Paul N; Bresnehan, Michael S; Kim, Moon J; Mayer, Theresa S; Terrones, Mauricio; Robinson, Joshua A

    2014-04-22

    The stacking of two-dimensional layered materials, such as semiconducting transition metal dichalcogenides (TMDs), insulating hexagonal boron nitride (hBN), and semimetallic graphene, has been theorized to produce tunable electronic and optoelectronic properties. Here we demonstrate the direct growth of MoS2, WSe2, and hBN on epitaxial graphene to form large-area van der Waals heterostructures. We reveal that the properties of the underlying graphene dictate properties of the heterostructures, where strain, wrinkling, and defects on the surface of graphene act as nucleation centers for lateral growth of the overlayer. Additionally, we show that the direct synthesis of TMDs on epitaxial graphene exhibits atomically sharp interfaces. Finally, we demonstrate that direct growth of MoS2 on epitaxial graphene can lead to a 10(3) improvement in photoresponse compared to MoS2 alone.

  3. Hyperdislocations in van der Waals Layered Materials.

    PubMed

    Ly, Thuc Hue; Zhao, Jiong; Keum, Dong Hoon; Deng, Qingming; Yu, Zhiyang; Lee, Young Hee

    2016-12-14

    Dislocations are one-dimensional line defects in three-dimensional crystals or periodic structures. It is common that the dislocation networks made of interactive dislocations be generated during plastic deformation. In van der Waals layered materials, the highly anisotropic nature facilitates the formation of such dislocation networks, which is critical for the friction or exfoliation behavior for these materials. By transmission electron microscopy analysis, we found the topological defects in such dislocation networks can be perfectly rationalized in the framework of traditional dislocation theory, which we applied the name "hyperdislocations". Due to the strong pinning effect of hyperdislocations, the state of exfoliation can be easily triggered by 1° twisting between two layers, which also explains the origin of disregistry and frictionlessness for all of the superlubricants that are widely used for friction reduction and wear protection.

  4. Implantate und Verfahren in der Augenheilkunde

    NASA Astrophysics Data System (ADS)

    Neuhann, Tobias H.

    Das in der Medizin mit am häufigsten verwendete Implantat weltweit ist die Intraokulare Linse (IOL). Die Gründe hierfür sind vielschichtig: einmal haben die Operationstechniken in den letzten 30 Jahren eine wesentliche Steigerung an Gleichmäßigkeit, Erfolg und Effizienz erfahren, zum anderen verursachen die gestiegenen Anforderungen des Alltags in den Industrienationen und im Berufsleben den höheren Anspruch an das Sehvermögen. Ist die menschliche Linse Ursache für schlechtes Sehvermögen, besteht meist eine Trübung des Linsenproteins. Diese Trübung nennt wird Volksmund Grauer Star genannt, wissenschaftlich die Katarakt (cataracta). Es gibt unterschiedliche Formen wie angeborene (congenita) oder erworbene, traumatische, krankheitsoder altersbedingte Formen [45]. Wird die eingetrübte Linse nun mittels moderner Operationsverfahren entfernt, muss für Ersatz dieses lichtbrechenden Mediums gesorgt werden [2].

  5. Kernschmelze Der nachhaltige Einfluss von Nuklearwaffen auf Politik und Wirtschaft

    NASA Astrophysics Data System (ADS)

    Greiner, Bernd

    "Was sollen wir von einer Kultur halten, der die Ethik stets als wesentliches Element des menschlichen Lebens galt, die aber - außer in fachlicher oder spieltheoretischer Terminologie - nicht in der Lage war, über die Möglichkeit zu sprechen, nahezu alle Menschen zu töten?" Der Fragesteller gehört zu den berühmtesten Physikern des 20. Jahrhunderts und zu den nach wie vor Umstrittensten. über ihn wurde in den 1960er Jahren ein international viel beachtetes Theaterstück geschrieben, vor wenigen Jahren gar eine Oper.

  6. Einsteins Spuren in den Archiven der Wissenschaft: Physikgeschichte

    NASA Astrophysics Data System (ADS)

    Marx, Werner

    2005-07-01

    Die Erwähnungen und Zitierungen von Einsteins Arbeiten dokumentieren lediglich den quantifizierbaren Anteil von Einsteins Beitrag zur Physik. Gleichwohl belegen sie die außergewöhnliche Resonanz und Langzeitwirkung seiner Arbeiten. Die Häufigkeit der Zitierungen entspricht nicht der allgemeinen Einschätzung ihrer Bedeutung. Insbesondere die Pionierarbeiten werden inzwischen als bekannt vorausgesetzt und nicht mehr explizit zitiert. Interessanterweise ist seine nach 1945 meist zitierte Arbeit nicht eine der Pionierarbeiten zur Quantenphysik oder Relativitätstheorie, sondern jene aus dem Jahr 1935 zum berühmten Einstein-Podolsky-Rosen-Paradoxon.

  7. Nanophysik: Wärmeübertrag auf der Nanometerskala

    NASA Astrophysics Data System (ADS)

    Kittel, Achim

    2006-01-01

    Gegen Ende des 19. Jahrhunderts waren die grundlegenden Prozesse des Wärmeaustauschs verstanden. Die Gesetze dienten dann als Grundlage für die Quantenmechanik. Doch gelten diese Gesetze auch auf der Nanometerskala? In den 1970er-Jahren wurde eine Theorie für den Wärmeübertrag im atomaren Bereich entwickelt. Physiker der Universität Oldenburg überprüften deren Vorhersagen und stießen dabei auf signifikante Abweichungen, welche auf einen Zusammenbruch der klassischen, makroskopischen Elektrodynamik hindeuten.

  8. Melker Meilensteine auf dem Weg in ein naturwissenschaftliches Zeitalter - Glanzlichter der Ausstellung zum Internationalen Astronomiejahr 2009 in der Melker Stiftsbibliothek.

    NASA Astrophysics Data System (ADS)

    Beck, Paul G.; Zotti, Georg

    2009-06-01

    Das Mittelalter wird weithin als die dunkle Epoche in der Geschichte der Europäischen Wissenschaften betrachtet, und insbesondere das Leben in den Klöstern galt lange Zeit als frei von jeglichem Interesse für Naturwissenschaften abseits der Medizin. Im Mittelalter galt die Astronomie bloß als Mittel zum Zweck, um religiöse und zivile Kalender erstellen zu können. Durch den Bestand der Handschriftenkammer der Melker Stiftsbibliothek eröffnet sich uns eine neue Sichtweise auf das gegen Ende des Mittelalters wachsende Interesse an den Naturwissenschaften. Dies wurde durch die starke Aufwertung der Klosterbibliothek im Rahmen der 'Melker Reform' im 15. Jahrhundert noch weiter verstärkt. Diese Epoche fällt mit der Frühphase der Universität Wien und der 'ersten Wiener Schule der Astronomie' zusammen. Dieser Artikel beleuchtet ausgewählte astronomischen Werke in der Melker Stiftsbibliothek zwischen dem frühen 9 und dem 18. Jahrhundert. Einen Schwerpunkt stellt das Wirken der Wiener Schule der Astronomie dar, wobei wir u.a. die Melker Abschrift von Peuerbachs Gutachten über den Kometen von 1456 sowie die im Stift Melk durchgeführte Beobachtung der Mondfinsternis von 1457 durch Regiomontanus und Peuerbach beleuchten. Dieser Beitrag ist der einführende Übersichtsartikel zum Ausstellungsprojekt in der Melker Stiftsbibliothek im Rahmen des Internationalen Jahres der Astronomie 2009. The medieval period is commonly seen as a dark epoch for science in Europe. Especially monasteries were seen as institutions without interest in natural sciences except for medicine. Astronomy was allegedly only a tool to construct religious and civil calendars. The inventory of the medieval manuscript collection of the library of the Abbey of Melk allows a new view on the growing interest in the exact sciences towards the end of the medieval ages. This interest was intensified through the increased importance of the monastery library due to the monastery reform

  9. Isotope separation by photodissociation of Van der Waal's molecules

    DOEpatents

    Lee, Yuan T.

    1977-01-01

    A method of separating isotopes based on the dissociation of a Van der Waal's complex. A beam of molecules of a Van der Waal's complex containing, as one partner of the complex, a molecular species in which an element is present in a plurality of isotopes is subjected to radiation from a source tuned to a frequency which will selectively excite vibrational motion by a vibrational transition or through electronic transition of those complexed molecules of the molecular species which contain a desired isotope. Since the Van der Waal's binding energy is much smaller than the excitational energy of vibrational motion, the thus excited Van der Waal's complex dissociate into molecular components enriched in the desired isotope. The recoil velocity associated with vibrational to translational and rotational relaxation will send the separated molecules away from the beam whereupon the product enriched in the desired isotope can be separated from the constituents of the beam.

  10. Ein routine-integrierbares Planungswerkzeug zur operativen Rekonstruktion der Orbita

    NASA Astrophysics Data System (ADS)

    Kleiner, Melanie; Schulze, Dirk; Voss, Pit Jakob; Deserno, Thomas M.

    Bei Frakturen des Orbitabodens kann ein Titangitter zur Rekonstruktion operativ eingesetzt werden. In dieser Arbeit wird ein Planungswerkzeug entwickelt, welches mit Hilfe eines aktiven Konturmodells die Orbita in CT Daten segmentiert, ihr Volumen berechnet und visualisiert. Neben den technischen Integrationsstufen der Funktions- und Präsentationsintegration, welche durch den Einsatz des Medical Imaging Interaction Toolkit (MITK) erreicht werden, sowie der Daten-, und Kontextintegration ist vor allem die Stabilität der eingesetzten Algorithmik für die Routine-Integrierbarkeit wichtig. Erste Stabilitätsuntersuchungen basieren auf 3 von 100 zufällig ausgewählten CT-Datensätzen, wobei das Volumen mit je 50 verschiedenen Startpunkten berechnet wurde. Die so ermittelten Variationskoeffizienten liegen deutlich unterhalb der kritischen 5 % Schwelle.

  11. Demographische Entwicklung in der Metropolregion Berlin-Brandenburg

    NASA Astrophysics Data System (ADS)

    Beyer, Wolf; Bluth, Friedrich

    〝Denn eins ist sicher: Die Rente.`` Der vielzitierte Satz des früheren Arbeits- und Sozialministers Norbert Blüm klingt heute vielen wie Hohn. Der Altersaufbau der deutschen Bevölkerung erinnert grafisch immer mehr an einen Baum auf dünnem Stämmchen als an eine Pyramide. Angesichts dessen rücken demographische Entwicklungen mehr und mehr in den Fokus der Öffentlichkeit. Besonders die neuen Bundesländer sind massiv von Abwanderung und einem nie dagewesenen Geburtenrückgang betroffen.DIPL.-GEOGR. UTE C. BAUERsprach mitFRIEDRICH BLUTHundWOLF BEYERüber die Besonderheiten der demographischen Prozesse in Berlin und Brandenburg. Beyer leitete bis Anfang 2004 das brandenburgische Referat für Raumbeobachtung. Seine Aufgabe bestand darin, Planungsgrundlagen für die Gemeinsame Landesplanung Berlin-Brandenburg(GL) zu schaffen. Dazu zählen auch Bevölkerungsprognosen für die Kreise und Städte Brandenburgs. Bluth ist in der Senatsverwaltung für Stadtentwicklung Berlin beschäftigt und leitet dort die Gruppe 〝Stadtwissen, Stadtentwicklungsmonitoring, Bevölkerungsprognose.``

  12. Modified Van der Waals equation and law of corresponding states

    NASA Astrophysics Data System (ADS)

    Zhong, Wei; Xiao, Changming; Zhu, Yongkai

    2017-04-01

    It is well known that the Van der Waals equation is a modification of the ideal gas law, yet it can be used to describe both gas and liquid, and some important messages can be obtained from this state equation. However, the Van der Waals equation is not a precise state equation, and it does not give a good description of the law of corresponding states. In this paper, we expand the Van der Waals equation into its Taylor's series form, and then modify the fourth order expansion by changing the constant Virial coefficients into their analogous ones. Via this way, a more precise result about the law of corresponding states has been obtained, and the law of corresponding states can then be expressed as: in terms of the reduced variables, all fluids should obey the same equation with the analogous Virial coefficients. In addition, the system of 3 He with quantum effects has also been taken into consideration with our modified Van der Waals equation, and it is found that, for a normal system without quantum effect, the modification on ideal gas law from the Van der Waals equation is more significant than the real case, however, for a system with quantum effect, this modification is less significant than the real case, thus a factor is introduced in this paper to weaken or strengthen the modification of the Van der Waals equation, respectively.

  13. GASTONE64: A new front-end ASIC for the cylindrical GEM Inner Tracker of KLOE-2 experiment at DAΦNE

    NASA Astrophysics Data System (ADS)

    Balla, A.; Bencivenni, G.; Branchini, P.; Budano, A.; Cerioni, S.; Ciambrone, P.; Czerwinski, E.; De Lucia, E.; De Robertis, G.; Di Domenico, A.; Domenici, D.; Jing, D.; Erriquez, O.; Fanizzi, G.; Felici, G.; Gatta, M.; Lacalamita, N.; Liuzzi, R.; Loddo, F.; Mongelli, M.; Morello, G.; Pelosi, A.; Quintieri, L.; Ranieri, A.; Tskhadadze, E.; Valentino, V.

    2013-12-01

    GASTONE64 (Gem Amplifier Shaper Tracking ON Events) is a novel 64-channel mixed analog-digital ASIC developed to readout the cylindrical GEM inner tracking detector of the KLOE-2 apparatus at the e+e-DAΦNE collider. It has been designed in the CMOS 0.35 μm technology and each analog channel is made of preamplifier, shaper and discriminator. The expected input charge ranges between few fC up to 40 fC, the charge sensitivity is 16 mV/fC while the equivalent input noise charge (ENC) is 800 e-+40 e-/pF. The discriminated signals are read-out using a 100 MBit/s LVDS serial data link. The power consumption is about 6 mW/channel.

  14. A comparison of airborne GEMS/SAR with satellite-borne Seasat/SAR radar imagery - The value of archived multiple data sets

    NASA Technical Reports Server (NTRS)

    Hanson, Bradford C.; Dellwig, Louis F.

    1988-01-01

    In a study concerning the value of using radar imagery from systems with diverse parameters, X-band images of the Northern Louisiana Salt dome area generated by the airborne Goodyear electronic mapping system (GEMS) are analyzed in conjunction with imagery generated by the satelliteborne Seasat/SAR. The GEMS operated with an incidence angle of 75 to 85 deg and a resolution of 12 m, whereas the Seasat/SAR operated with an incidence angle of 23 deg and a resolution of 25 m. It is found that otherwise unattainable data on land management activities, improved delineation of the drainage net, better definition of surface roughness in cleared areas, and swamp identification, became accessible when adjustments for the time lapse between the two missions were made and supporting ground data concerning the physical and vegetative characteristics of the terrain were acquired.

  15. Die Anfaenge der Melker Bibliothek - Neue Erkenntnisse zu Handschriften und Fragmenten aus der Zeit vor 1200

    NASA Astrophysics Data System (ADS)

    Glaßner, Christine; Haidinger, Alois

    1996-04-01

    Shortly after Benedictine monks started monastic life in Melk in 1089 the scriptorium was flourishing under abbot Erchenfried (1121-1164). Noteworthy is Cod. 391, a manuscript written in its main part in 1123, but used by the monks as a yearbook with handwritten entries up to the 16th century. This manuscript was also an important source for the publication which dealt with the history of the scriptorium in 12th century. By examining the entries in this book the period of the activity of at least three unknwon writers in this era could be identified. It was the first time that not only the intact volumes but also the manuscripts preserved as fragments in the binding were examined. At the beginning of th 13th century the number of books held in the collection according to the result of this examination was 68. Another remarkable point of the exhibition and of the publication refering to the exhibition was Cod. 412, the oldest manuscript of the monastery, written in early 9th century and containing texts on natural sciences and astronomy by Venerable Bede. Three copies of this manuscript were done during 12th century, one of them probably in Melk, all of them with nearly identical consistency except the catalogue of signs of the zodiac which was ascribed erroneously to Venerable Bede in the Middle Ages: Vatican, Cod. Vat. lat. 643, Zwettl, Cod. 296 (copy of the Vatican manuscript), Klosterneuburg, Cod. 685 (copy of the Zwettl manuscript done in Klosterneuburg). Kurz nach Einführung der Benediktiner in Melk im Jahr 1089 erlebte das Melker Skriptorium unter Abt Erchenfried (1121-1163) seine erste Blüte. Hervorzuheben ist eine im Jahr 1123 angelegte Chronik, die bis in das 16. Jahrhundert durch Annaleneintragungen und andere wichtige Texte zur Geschichte des Klosters ergänzt wurde (Cod. 391). Diese Handschrift ist zugleich eine der wichtigsten Quellen zur Geschichte des Melker Skriptoriums im 12. Jahrhundert, dem sich die Publikation widmet. Mit Hilfe einer genaueren

  16. A Clinical Evaluation of the GemStar® and the AmbIT® Pumps for Patient-Controlled Epidural Analgesia

    PubMed Central

    Sinha, Aneeta; Paech, Michael; Ledger, Rupert; McDonnell, Nolan; Nathan, Elizabeth

    2012-01-01

    Background Patient-controlled analgesia is used for both labor and postoperative analgesia. Objectives This study aimed to assess user satisfaction and functionality of two ambulatory, electronic patient controlled analgesia devices, the GemStar pump Hospira Inc., Illinois, USA) and the ambIT Ambulatory Infusion Therapy pump (Sorenson Medical Products, Utah, USA). Patients and Methods It was a randomized clinical trial of laboring women and postoperative gynecology patients receiving patient-controlled epidural analgesia. Patients were randomized to use one of the pumps and both anesthesiologists and patients completed questionnaires about aspects of pump function, and rated their satisfaction with the equipment. Midwives and high-dependency unit nurses also evaluated the pumps in each clinical setting. Results Forty patients, 20 laboring women and 20 postoperative patients were randomized and completed the study. The pumps were compared by nine anesthesiologists. Patient and staff satisfaction with both devices was high. Patient satisfaction did not significantly differ between groups (median 10 [8, 10] for the GemStar and 10 [9, 10] for the ambIT, P = 0.525]. The median staff satisfaction score was 8 [6, 8] for the GemStar and 7 [5, 8] for the ambIT (P = 0.154). Both patient cohorts rated each pump highly for most aspects of clinical function. Staff rated the ambIT pump more favourably with respect to portability and storage at the bedside whilst the GemStar had better assessments with respect to its consumables and interactions involving the electronic interface. Conclusions Both devices were well-rated by patients and staff, with no significant difference between them for overall satisfaction, and only minor differences with respect to their respective strengths and weaknesses. PMID:24223340

  17. Pattern recognition in the GEM central tracker at luminosity of 10{sup 33} cm{sup {minus}2}s{sup {minus}1}

    SciTech Connect

    Brooks, M.L.; Kinnison, W.W.

    1994-01-01

    A GEANT based pattern recognition algorithm has been developed for simulations of the GEM central tracker. We describe the pattern recognition algorithm and present the results of studies of the track finding efficiency for single isolated tracks and for all tracks present in a Higgs event with minimum bias background at luminosity 10{sup 33} cm{sup {minus}2}s{sup {minus}l}.

  18. Origin of gem corundum in calcite marble: The Revelstoke occurrence in the Canadian Cordillera of British Columbia

    NASA Astrophysics Data System (ADS)

    Dzikowski, Tashia J.; Cempírek, Jan; Groat, Lee A.; Dipple, Gregory M.; Giuliani, Gaston

    2014-06-01

    The calcite marble-hosted gem corundum (ruby, sapphire) occurrence near Revelstoke, British Columbia, Canada, occurs in the Monashee Complex of the Omineca Belt of the Canadian Cordillera. Corundum occurs in thin, folded and stretched layers with green muscovite + Ba-bearing K-feldspar + anorthite (An0.85-1) ± phlogopite ± Na-poor scapolite. Other silicate layers within the marble are composed of: (1) diopside + tremolite ± quartz and (2) garnet (Alm0.7-0.5Grs0.2-0.4) + Na-rich scapolite + diopside + tremolite + Na,K-amphiboles. Non-silicate layers in the marble are either magnetite- or graphite-bearing. Predominantly pink (locally red or purple) opaque to transparent corundum crystals have elevated Cr2O3 (≤ 0.21 wt.%) and variable amounts of TiO2; rare blue rims on the corundum crystals contain higher amounts of TiO2 (≤ 0.53 wt.%) and Fe2O3 (≤ 0.07 wt.%). The associated micas have elevated Cr, V, Ti, and Ba contents. Petrography of the silicate layers show that corundum formed from muscovite at the peak of metamorphism (~ 650-700 °C at 8.5-9 kbar). Because the marble is almost pure calcite (dolomite is very rare), the corundum was preserved because it did not react with dolomite to spinel + calcite during decompression. The scapolite-bearing assemblages formed during or after decompression of the rock at ~ 650 °C and 4-6 kbar. Gem-quality corundum crystals formed especially on borders of the mica-feldspar layers in an assemblage with calcite. Whole rock geochemistry data show that the corundum-bearing silicate (mica-feldspar) layers formed by mechanical mixing of carbonate with the host gneiss protolith; the bulk composition of the silicate layers was modified by Si and Fe depletion during prograde metamorphism. High element mobility is supported by the homogenization of δ18O and δ13C values in carbonates and silicates for the marble and silicate layers. The silicate layers and the gneiss contain elevated contents of Cr and V due to the volcanoclastic

  19. Argon behaviour in gem-quality orthoclase from Madagascar: Experiments and some consequences for 40Ar/39Ar geochronology

    NASA Astrophysics Data System (ADS)

    Arnaud, N. O.; Kelley, S. P.

    1997-08-01

    In order to investigate argon diffusion in as simple a K-feldspar structure as possible, a single crystal of the gem-quality Itrongay K-feldspar from Madagascar has been studied using cycled step heating, ultra-violet (UV) laser depth profiling, in vacuo crushing, Electron Microprobe Analysis (EMPA) and X-ray diffraction (XRD) techniques. The results have been modelled using both the multidomain model and a multipath model invoking pipe or short circuit (SC) diffusion. Cycle heating (both forward and reversed) indicates a very retentive K-feldspar, in which the great majority of argon release conforms to a simple model of volume diffusion with a single domain size, a single activation energy, and is associated with a plateau age of 435 ± 8 Ma. However, the first 1% of argon release exhibits younger ages and the same type of complex behaviour seen in other K-feldspars. Modelling the argon release in terms of multidomains yields good fits to data with four domains of varying activation energies. An alternative model for the argon release, involving not only volume diffusion through the lattice but also SC or pipe diffusion and mass transfer between lattice and rapid diffusion paths, provides a good though less sophisticated model to explain the argon release. Argon concentration/depth profiles of a previously outgassed sample, measured using the UV laser ablation technique, exhibited argon loss in only the upper 5-10 μm. Argon loss calculated from the measured profiles suggests that the low temperature domains outgassed during step heating were within 5-10 μm of the grain surfaces and thus may be artefacts of sample preparation and surface texture effects. In vacuo crushing of an untreated sample released argon with an older age than the plateau value, which was not detected by any of the other analytical techniques. However, previously cycled step heated samples contained very little excess argon, suggesting the existence of traps within the feldspar structure

  20. Evaluation of biomass burning aerosols in the HadGEM3 climate model with observations from the SAMBBA field campaign

    NASA Astrophysics Data System (ADS)

    Johnson, Ben T.; Haywood, James M.; Langridge, Justin M.; Darbyshire, Eoghan; Morgan, William T.; Szpek, Kate; Brooke, Jennifer K.; Marenco, Franco; Coe, Hugh; Artaxo, Paulo; Longo, Karla M.; Mulcahy, Jane P.; Mann, Graham W.; Dalvi, Mohit; Bellouin, Nicolas

    2016-11-01

    We present observations of biomass burning aerosol from the South American Biomass Burning Analysis (SAMBBA) and other measurement campaigns, and use these to evaluate the representation of biomass burning aerosol properties and processes in a state-of-the-art climate model. The evaluation includes detailed comparisons with aircraft and ground data, along with remote sensing observations from MODIS and AERONET. We demonstrate several improvements to aerosol properties following the implementation of the Global Model for Aerosol Processes (GLOMAP-mode) modal aerosol scheme in the HadGEM3 climate model. This predicts the particle size distribution, composition, and optical properties, giving increased accuracy in the representation of aerosol properties and physical-chemical processes over the Coupled Large-scale Aerosol Scheme for Simulations in Climate Models (CLASSIC) bulk aerosol scheme previously used in HadGEM2. Although both models give similar regional distributions of carbonaceous aerosol mass and aerosol optical depth (AOD), GLOMAP-mode is better able to capture the observed size distribution, single scattering albedo, and Ångström exponent across different tropical biomass burning source regions. Both aerosol schemes overestimate the uptake of water compared to recent observations, CLASSIC more so than GLOMAP-mode, leading to a likely overestimation of aerosol scattering, AOD, and single scattering albedo at high relative humidity. Observed aerosol vertical distributions were well captured when biomass burning aerosol emissions were injected uniformly from the surface to 3 km. Finally, good agreement between observed and modelled AOD was gained only after scaling up GFED3 emissions by a factor of 1.6 for CLASSIC and 2.0 for GLOMAP-mode. We attribute this difference in scaling factor mainly to different assumptions for the water uptake and growth of aerosol mass during ageing via oxidation and condensation of organics. We also note that similar agreement

  1. Stanford GEMS Phase 2 Obesity Prevention Trial for Low-Income African-American Girls: Design and Sample Baseline Characteristics

    PubMed Central

    Robinson, Thomas N.; Kraemer, Helena C.; Matheson, Donna M.; Obarzanek, Eva; Wilson, Darrell M.; Haskell, William L.; Pruitt, Leslie A.; Thompson, Nikko S.; Farish Haydel, K; Fujimoto, Michelle; Varady, Ann; McCarthy, Sally; Watanabe, Connie; Killen, Joel D

    2008-01-01

    Objective African-American girls and women are at high risk of obesity and its associated morbidities. Few studies have tested obesity prevention strategies specifically designed for African-American girls. This report describes the design and baseline findings of the Stanford GEMS (Girls health Enrichment Multi-site Studies) trial to test the effect of a 2-year community- and family-based intervention to reduce weight gain in low-income, preadolescent African-American girls. Design Randomized controlled trial with measurements scheduled in girls’ homes at baseline, 6, 12, 18 and 24 months post randomization. Setting Low-income areas of Oakland, CA. Participants Eight, nine and ten year old African-American girls and their parents/caregivers. Interventions Girls are randomized to a culturally-tailored after school dance program and a home/family-based intervention to reduce screen media use versus an information-based community health education active-placebo comparison intervention. Interventions last for 2-years for each participant. Main Outcome Measure Change in body mass index over the two-year study. Results Recruitment and enrollment successfully produced a predominately low-socioeconomic status sample. 261 families were randomized. One girl per family is randomly chosen for the analysis sample. Randomization produced comparable experimental groups with only a few statistically significant differences. The sample had a mean body mass index (BMI) at the 74th percentile on the 2000 CDC BMI reference, and one-third of the analysis sample had a BMI at the 95th percentile or above. Average fasting total cholesterol and LDL-cholesterol were above NCEP thresholds for borderline high classifications. Girls averaged low levels of moderate to vigorous physical activity, more than 3 hours per day of screen media use, and diets high in energy from fat. Conclusions The Stanford GEMS trial is testing the benefits of culturally-tailored after-school dance and screen time

  2. A Derivation of the Newton Gravitation Constant and the Proton Mass From The GEM Unification Theory of Baryo-Genesi

    NASA Astrophysics Data System (ADS)

    Brandenburg, John

    2011-11-01

    A model of combined Sakharov and Kaluza-Klein baryo-genesis from the GEM unification theory, where the deployment of the Kaluza-Klein 5th dimension creates separate EM and gravity fields and also generates lepton and baryon numbers, uses a U(1) mass model with imaginary angle to give an expression ln (ro/rP) =σ relating the lepton-baryon mass splitting parameter σ = (mp/me) 1⁄2 to the hidden dimension size, ro, where mp and me are the electron and proton rest masses respectively, and , in cgs, ro= e2/((mpme)1/2c2) is a deployed hidden dimension size and where rP= (G/c3)1/2 is the Planck Length. This expression can be inverted , without any free parameters, to yield a highly accurate formula for the Newton Gravitation constant ( in cgs) : G=(e2/(mp me))α exp(-2(mp/me) 1⁄2) = 6.668x10-8 dynes-cm2/g2 which is within 1 part per thousand of the measured value, where α is the fine structure constant. The U(1) mass model can be extended without free parameters, where q'/e = α 1/2 is the normalized Planck charge, to find mp = MP σ - q'/e =1.71 x10-24 g which is the proton mass to within 2.5% of its measured value, where MP is the vacuum Planck mass MP=(c/G)1/2. This work is an outgrowth of the GEM unification theory, which is briefly summarized here. Correction of the relationship for the hidden dimension size as it deploys from the Planck scale, using constraints from Big Bang Nucleo-synthesis on quark-quark and quark electron associations yield for G :G= e2/(mp me) α exp( -2((mp/me)1⁄2-0.86/R...)) = 6.67424 x 10-8 dynes-cm2/g2 where R=(mp/me) and which is within 1 part per 105 of the accepted expression G= 6.67428 x 10-8 dynes-cm2/g2. Similar constraints yield the more accurate formula mp =MP σ (- q'/e)(1+0.71/R) =1.683 x 10-24 g for the proton mass. The seeming success of this approach appears to validate the utility of hidden dimension theories in understanding the cosmos.

  3. Hydrogen Cyanide in the Upper Troposphere: GEM-AQ Simulation and Comparison with ACE-FTS Observations

    NASA Technical Reports Server (NTRS)

    Lupu, A.; Kaminski, J. W.; Neary, L.; McConnell, J. C.; Toyota, K.; Rinsland, C. P.; Bernath, P. F.; Walker, K. A.; Boone, C. D.; Nagahama, Y.; Suzuki, K.

    2009-01-01

    We investigate the spatial and temporal distribution of hydrogen cyanide (HCN) in the upper troposphere through numerical simulations and comparison with observations from a space-based instrument. To perform the simulations, we used the Global Environmental Multiscale Air Quality model (GEM-AQ), which is based on the threedimensional Gobal multiscale model developed by the Meteorological Service of Canada for operational weather forecasting. The model was run for the period 2004-2006 on a 1.5deg x 1.5deg global grid with 28 hybrid vertical levels from the surface up to 10 hPa. Objective analysis data from the Canadian Meteorological Centre were used to update the meteorological fields every 24 h. Fire emission fluxes of gas species were generated by using year-specific inventories of carbon emissions with 8-day temporal resolution from the Global Fire Emission Database (GFED) version 2. The model output is compared with HCN profiles measured by the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) instrument onboard the Canadian SCISAT-1 satellite. High values of up to a few ppbv are observed in the tropics in the Southern Hemisphere; the enhancement in HCN volume mixing ratios in the upper troposphere is most prominent in October. Low upper-tropospheric mixing ratios of less than 100 pptv are mostly recorded at middle and high latitudes in the Southern Hemisphere in May-July. Mixing ratios in Northern Hemisphere peak in the boreal summer. The amplitude of the seasonal variation is less pronounced than in the Southern Hemisphere. The comparison with the satellite data shows that in the upper troposphere GEM-AQ perform7s well globally for all seasons, except at northern hi gh and middle latitudes in surnmer, where the model has a large negative bias, and in the tropics in winter and spring, where it exhibits large positive bias. This may reflect inaccurate emissions or possible inaccuracies in the emission profile. The model is able to

  4. Comparison of the passive dynamics of walking on ground, tied-belt and split-belt treadmills, and via the Gait Enhancing Mobile Shoe (GEMS).

    PubMed

    Handzić, Ismet; Reed, Kyle B

    2013-06-01

    This research compares walking over ground, on a split-belt treadmill, on a tied-belt treadmill, and on the Gait Enhancing Mobile Shoe (GEMS) in both humans and simulated on a passive dynamic model. Passive Dynamic Walkers (PDW) have been researched for decades, yet only recently has the model been used significantly in gait rehabilitation. We aim to identify how well the two-dimensional PDW can be used as a kinematic approximation tool for gait analysis. In this work, the PDW was scaled according to an anthropomorphic human model. For comparison, measurements were taken of humans walking in the same four environments. For normal walking, the PDW was found to be a good approximation for symmetric and rhythmic hip position, foot position, and velocity profiles. Tied-belt and split-belt treadmill model estimations revealed that the PDW's lack of dorsiflexion, joint stiffness, and joint damping limited the comparison, however trends between the human and the model agreed. The kinematics of the GEMS showed good agreement in interlimb interactions indicating that the PDW can be used as a good kinematic predictor for the GEMS.

  5. gem-Difluoroolefination of Diazo Compounds with TMSCF3 or TMSCF2Br: Transition-Metal-Free Cross-Coupling of Two Carbene Precursors.

    PubMed

    Hu, Mingyou; Ni, Chuanfa; Li, Lingchun; Han, Yongxin; Hu, Jinbo

    2015-11-18

    A new olefination protocol for transition-metal-free cross-coupling of two carbene fragments arising from two different sources, namely, a nonfluorinated carbene fragment resulting from a diazo compound and a difluorocarbene fragment derived from Ruppert-Prakash reagent (TMSCF3) or TMSCF2Br, has been developed. This gem-difluoroolefination proceeds through the direct nucleophilic addition of diazo compounds to difluorocarbene followed by elimination of N2. Compared to previously reported Cu-catalyzed gem-difluoroolefination of diazo compounds with TMSCF3, which possesses a narrow substrate scope due to a demanding requirement on the reactivity of diazo compounds and in-situ-generated CuCF3, this transition-metal-free protocol affords a general and efficient approach to various disubstituted 1,1-difluoroalkenes, including difluoroacrylates, diaryldifluoroolefins, as well as arylalkyldifluoroolefins. In view of the ready availability of diazo compounds and difluorocarbene reagents and versatile transformations of 1,1-difluoroalkenes, this new gem-difluoroolefination method is expected to find wide applications in organic synthesis.

  6. A Large GEM-TPC Prototype Detector for anda

    NASA Astrophysics Data System (ADS)

    Arora, R.; Angerer, H.; Ball, M.; Beck, R.; Berger, M.; Böhmer, F.; Chen, J.; Cusanno, F.; Dørheim, S.; Fabbietti, L.; Fröppner, J.; Kaiser, D.; Ketzer, B.; Kiš, M.; Fruhauf, J.; Hehner, J.; Herrmann, N.; Hs, C.; Kleipa, V.; Konorov, I.; Kunkel, J.; Kurz, N.; Lang, M.; Leifels, Y.; Münzer, R.; Müllner, P.; Neubert, S.; Paul, S.; Peters, K.; Risch, H.; Schmitz, R.; Schmidt, C.; Schwab, S.; Soyk, D.; Suzuki, K.; Thoma, U.; Uhl, S.; Vandenbroucke, M.; Voss, B.; Voss, J.; Walther, D.; Weinert, J.; Winnebeck, A.; Zmeskal, J.

    The PANDA spectrometer will be a state of the art universal detector for strong interaction studies at the High-Energy Storage Ring (HESR) in the future international Facility for Anti-proton and Ion Research (FAIR) at GSI, Darmstadt. The detector is designed to take advantage of the extraordinary physics potential which will be available utilizing high intensity, phase space cooled anti-proton beams. This facility will provide a cooled anti-proton beam-2with momenta of 1.5-15 GeV/c, a maximal luminosity of 2×1032cms-1 that translates into 2×107 pp annihilations per second. A GEM based Time Projection Chamber (TPC) was one of the central tracker candidates for the PANDA experiment. To check the feasibility of such a detector system, a large prototype GEM-TPC was built and tested inside the FOPI Spectrometer at GSI. A set of three Gas Electron Multiplier (GEM) foils were used as amplification stage instead of Multi Wire Proportional Chambers. In this report, the design, construction, characterization of the prototype-detector system will be discussed in detail along with the results of recent beam tests.

  7. Study on the novel neutron-to-proton convertor for improving the detection efficiency of a triple GEM based fast neutron detector

    NASA Astrophysics Data System (ADS)

    Wang, Xiao-Dong; Yang, He-Run; Ren, Zhong-Guo; Zhang, Jun-We; Yang, Lei; Zhang, Chun-Hui; Ha, Ri-Ba-La; An, Lü-Xing; Hu, Bi-Tao

    2015-02-01

    A high-efficiency fast neutron detector prototype based on a triple Gas Electron Multiplier (GEM) detector, which, coupled with a novel multi-layered high-density polyethylene (HDPE) as a neutron-to-proton converter for improving the neutron detection efficiency, is introduced and tested with the Am-Be neutron source in the Institute of Modern Physics (IMP) at Lanzhou in the present work. First, the developed triple GEM detector is tested by measuring its effective gain and energy resolution with 55Fe X-ray source to ensure that it has a good performance. The effective gain and obtained energy resolution is 5.0×104 and around 19.2%, respectively. Secondly, the novel multi-layered HDPE converter is coupled with the cathode of the triple GEM detector making it a high-efficiency fast neutron detector. Its effective neutron response is four times higher than that of the traditional single-layered conversion technique when the converter layer number is 38. Supported by National Natural Science Foundation of China (11135002, 11305232, 11175076)

  8. CRYSTALLIZATION EXPERIMENTS OF SiO{sub 2}-RICH AMORPHOUS SILICATE: APPLICATION TO SiO{sub 2}-RICH CIRCUMSTELLAR DUST AND GEMS

    SciTech Connect

    Matsuno, Junya; Tsuchiyama, Akira; Koike, Chiyoe; Chihara, Hiroki; Imai, Yuta; Noguchi, Ryo; Ohi, Shugo

    2012-07-10

    Crystallization experiments of relatively SiO{sub 2}-rich amorphous silicates using the mean chemical composition of the silicate portions in GEMS (glass with embedded metal and sulfide), which is a major component in anhydrous interplanetary dust particles and a primitive material of the early solar system, were performed to understand the presence of crystalline silica around young stars and crystallization in GEMS. Olivine crystallized at {approx}900-1400 K, probably prior to pyroxene. Three different polymorphs of pyroxene, protopyroxene, orthopyroxene, and clinopyroxene, were identified at {>=}1000 K. Cristobalite, which is one of the silica polymorphs, crystallized only at high temperatures ({>=}1500 K). We obtained time-temperature-transformation (TTT) crystallization diagrams. These results suggest that crystallization of a silica polymorph is kinetically difficult in a day or so at {approx}900-1400 K even for the SiO{sub 2}-saturated composition, while the crystallization might be possible after metastable olivine crystallization if duration is long enough. The TTT diagram also indicates that the GEMS cooling timescale was {approx}10{sup 5} s if they condensed at 1000 K as amorphous silicates and annealed during cooling after the condensation.

  9. Retrospective Study of Pegaspargase, Gemicitabine, Oxaliplatin and Dexamethasone (Peg-GemOD) as a First-Line Therapy for Advanced-Stage Extranodal NK/T Cell Lymphoma.

    PubMed

    Yao, Yi-Yun; Tang, Yong; Zhuang, Yan; Zou, Li-Fang; Dou, Hong-Ju; Wang, Lei; Zhu, Qi

    2017-03-01

    This study was conducted to retrospectively investigate the efficacy and safety of pegaspargase, gemicitabine, oxaliplatin and dexamethasone (Peg-GemOD) combination chemotherapy as a first-line therapy for advanced-stage extranodal NK/T cell lymphoma (ENKTL). Eighteen patients with newly diagnosed stage III/IV ENKTL were subjected to 3-6 cycles of Peg-GemOD chemotherapy. After 3 cycles of therapy, the overall response rate was 67 % (12/18) with a complete response rate of 28 % (5/18) and a partial response rate of 39 % (7/18). The median overall survival (OS) and progression-free survival (PFS) time were 10 and 8.5 months respectively. For those responders, the median OS and PFS time were significantly better than those of non-responders (median OS, 15 vs. 10 months; P = 0.001 and median PFS, 15 vs. 7 months; P = 0.001). Furthermore, patients with low plasma EBV-DNA levels after induction chemotherapy had a remarkably longer OS and PFS time. The toxicity of Peg-GemOD regimen was acceptable.

  10. Therapeutic efficacy of oral immunization with a non-genetically modified Lactococcus lactis-based vaccine CUE-GEM induces local immunity against Helicobacter pylori infection.

    PubMed

    Liu, Wei; Tan, Zhoulin; Xue, Jinfeng; Luo, Wenjin; Song, Hui; Lv, Xiaobo; Zheng, Tianjing; Xi, Tao; Xing, Yingying

    2016-07-01

    The gastric bacterial pathogen Helicobacter pylori persistently colonizes the gastric mucosa of humans and plays a critical role in the development of gastritis, peptic ulceration and gastric adenocarcinoma. Consequently, the eradication of H. pylori might contribute to the prevention of H. pylori-associated gastric diseases. In this study, a multi-epitope vaccine CTB-UE (CUE) was displayed on the surface of non-genetically modified Lactococcus lactis particles (GEM) to enhance immunogenicity. This particulate vaccine CUE-GEM induced serum and mucosal specific antibody responses against native H. pylori urease and provided potent protection to eliminate H. pylori colonization and relieve gastritis in an H. pylori-infected BALB/c mouse model. The immuno-protective mechanisms are highly associated with CD4(+) Th cell-mediated and humoral immunity, especially local immunity. There might be two main aspects of this association. One aspect is related to the suppression of urease activity by promotion of the production of specific mucosal neutralizing antibody. The other aspect is correlated with alleviating gastritis by regulating the gastric pro-inflammatory cytokine profile, especially IFN-γ and IL-17. These results demonstrated that conjugating antigen vaccines with GEM particles could lead to promising oral therapeutic vaccine formulations against H. pylori infection.

  11. Effectiveness of hospital-based geriatric evaluation and management and home intervention team (GEM-HIT). Rationale and design of a 5-year randomized trial.

    PubMed

    Nikolaus, T; Specht-Leible, N; Bach, M; Wittmann-Jennewein, C; Oster, P; Schlierf, G

    1995-01-01

    In this ongoing randomized controlled trial the effectiveness of an interdisciplinary team implementing hospital-based comprehensive geriatric assessment (CGA) and home intervention is being studied. All patients admitted from home showing functional decline with impairment of any basic activity of daily living are randomly assigned to one of the following courses of treatment: CGA with in-hospital and post discharge management by a home intervention team (HIT), where necessary (group 1): CGA with recommendations and usual care at home (group 2); or usual hospital and home care (group 3). The HIT consists of 3 nurses, 1 geriatrician, 1 physiotherapist, 1 occupational therapist, and 1 social worker. 540 patients will be recruited for the trial, which will assess the effects of GEM-HIT on the following outcomes: health status, functional status, survival, hospital readmission, nursing home placement and costs. The purpose of the GEM-HIT trial is to answer many of the current questions concerning treatment and health care delivery for frail older persons under the specific conditions found in Germany. The large sample size and the broad range of diagnoses included in the study will allow the evaluation of effects of GEM-HIT for subgroups and may help to identify the most effective assessment tools for use within our particular context.

  12. GEM2Net: from gene expression modeling to -omics networks, a new CATdb module to investigate Arabidopsis thaliana genes involved in stress response.

    PubMed

    Zaag, Rim; Tamby, Jean Philippe; Guichard, Cécile; Tariq, Zakia; Rigaill, Guillem; Delannoy, Etienne; Renou, Jean-Pierre; Balzergue, Sandrine; Mary-Huard, Tristan; Aubourg, Sébastien; Martin-Magniette, Marie-Laure; Brunaud, Véronique

    2015-01-01

    CATdb (http://urgv.evry.inra.fr/CATdb) is a database providing a public access to a large collection of transcriptomic data, mainly for Arabidopsis but also for other plants. This resource has the rare advantage to contain several thousands of microarray experiments obtained with the same technical protocol and analyzed by the same statistical pipelines. In this paper, we present GEM2Net, a new module of CATdb that takes advantage of this homogeneous dataset to mine co-expression units and decipher Arabidopsis gene functions. GEM2Net explores 387 stress conditions organized into 18 biotic and abiotic stress categories. For each one, a model-based clustering is applied on expression differences to identify clusters of co-expressed genes. To characterize functions associated with these clusters, various resources are analyzed and integrated: Gene Ontology, subcellular localization of proteins, Hormone Families, Transcription Factor Families and a refined stress-related gene list associated to publications. Exploiting protein-protein interactions and transcription factors-targets interactions enables to display gene networks. GEM2Net presents the analysis of the 18 stress categories, in which 17,264 genes are involved and organized within 681 co-expression clusters. The meta-data analyses were stored and organized to compose a dynamic Web resource.

  13. Van der Waals Effects on semiconductor clusters.

    PubMed

    Li, Haisheng; Chen, Weiguang; Han, Xiaoyu; Li, Liben; Sun, Qiang; Guo, Zhengxiao; Jia, Yu

    2015-09-30

    Van der Waals (vdW) interactions play an important role on semiconductors in nanoscale. Here, we utilized first-principles calculations based on density functional theory to demonstrate the growth mode transition from prolate to multiunit configurations for Gen (n = 10-50) clusters. In agreement with the injected ion drift tube techniques that "clusters with n < 70 can be thought of as loosely bound assemblies of small strongly bound fragments (such as Ge7 and Ge10 )," we found these stable fragments are connected by Ge6 , Ge9 , or Ge10 unit (from bulk diamond), via strong covalent bonds. Our calculated cations usually fragment to Ge7 and Ge10 clusters, in accordance with the experiment results that the spectra Ge7 and Ge10 correspond to the mass abundance spectra. By controlling a germanium cluster with vdW interactions parameters in the program or not, we found that the vdW effects strengthen the covalent bond from different units more strikingly than that in a single unit. With more bonds between units than the threadlike structures, the multiunit structures have larger vdW energies, explaining why the isolated nanowires are harder to produce. © 2015 Wiley Periodicals, Inc.

  14. Van der Waals Interactions Involving Proteins

    NASA Technical Reports Server (NTRS)

    Roth, Charles M.; Neal, Brian L.; Lenhoff, Abraham M.

    1996-01-01

    Van der Waals (dispersion) forces contribute to interactions of proteins with other molecules or with surfaces, but because of the structural complexity of protein molecules, the magnitude of these effects is usually estimated based on idealized models of the molecular geometry, e.g., spheres or spheroids. The calculations reported here seek to account for both the geometric irregularity of protein molecules and the material properties of the interacting media. Whereas the latter are found to fall in the generally accepted range, the molecular shape is shown to cause the magnitudes of the interactions to differ significantly from those calculated using idealized models. with important consequences. First, the roughness of the molecular surface leads to much lower average interaction energies for both protein-protein and protein-surface cases relative to calculations in which the protein molecule is approximated as a sphere. These results indicate that a form of steric stabilization may be an important effect in protein solutions. Underlying this behavior is appreciable orientational dependence, one reflection of which is that molecules of complementary shape are found to exhibit very strong attractive dispersion interactions. Although this has been widely discussed previously in the context of molecular recognition processes, the broader implications of these phenomena may also be important at larger molecular separations, e.g., in the dynamics of aggregation, precipitation, and crystal growth.

  15. Van der Waals Interactions in Aspirin

    NASA Astrophysics Data System (ADS)

    Reilly, Anthony; Tkatchenko, Alexandre

    2015-03-01

    The ability of molecules to yield multiple solid forms, or polymorphs, has significance for diverse applications ranging from drug design and food chemistry to nonlinear optics and hydrogen storage. In particular, aspirin has been used and studied for over a century, but has only recently been shown to have an additional polymorphic form, known as form II. Since the two observed solid forms of aspirin are degenerate in terms of lattice energy, kinetic effects have been suggested to determine the metastability of the less abundant form II. Here, first-principles calculations provide an alternative explanation based on free-energy differences at room temperature. The explicit consideration of many-body van der Waals interactions in the free energy demonstrates that the stability of the most abundant form of aspirin is due to a subtle coupling between collective electronic fluctuations and quantized lattice vibrations. In addition, a systematic analysis of the elastic properties of the two forms of aspirin rules out mechanical instability of form II as making it metastable.

  16. Van der Waals Force Assisted Heat Transfer

    NASA Astrophysics Data System (ADS)

    Sasihithlu, K.; Pendry, J. B.; Craster, R. V.

    2017-02-01

    Phonons (collective atomic vibrations in solids) are more effective in transporting heat than photons. This is the reason why the conduction mode of heat transport in nonmetals (mediated by phonons) is dominant compared to the radiation mode of heat transport (mediated by photons). However, since phonons are unable to traverse a vacuum gap (unlike photons), it is commonly believed that two bodies separated by a gap cannot exchange heat via phonons. Recently, a mechanism was proposed [J. B. Pendry, K. Sasihithlu, and R. V. Craster, Phys. Rev. B 94, 075414 (2016)] by which phonons can transport heat across a vacuum gap - through the Van der Waals interaction between two bodies with gap less than the wavelength of light. Such heat transfer mechanisms are highly relevant for heating (and cooling) of nanostructures; the heating of the flying heads in magnetic storage disks is a case in point. Here, the theoretical derivation for modelling phonon transmission is revisited and extended to the case of two bodies made of different materials separated by a vacuum gap. Magnitudes of phonon transmission, and hence the heat transfer, for commonly used materials in the micro- and nano-electromechanical industry are calculated and compared with the calculation of conduction heat transfer through air for small gaps as well as the heat transfer calculation due to photon exchange.

  17. Van der Waals interactions involving proteins.

    PubMed Central

    Roth, C M; Neal, B L; Lenhoff, A M

    1996-01-01

    Van der Waals (dispersion) forces contribute to interactions of proteins with other molecules or with surfaces, but because of the structural complexity of protein molecules, the magnitude of these effects is usually estimated based on idealized models of the molecular geometry, e.g., spheres or spheroids. The calculations reported here seek to account for both the geometric irregularity of protein molecules and the material properties of the interacting media. Whereas the latter are found to fall in the generally accepted range, the molecular shape is shown to cause the magnitudes of the interactions to differ significantly from those calculated using idealized models, with important consequences. First, the roughness of the molecular surface leads to much lower average interaction energies for both protein-protein and protein-surface cases relative to calculations in which the protein molecule is approximated as a sphere. These results indicate that a form of steric stabilization may be an important effect in protein solutions. Underlying this behavior is appreciable orientational dependence, one reflection of which is that molecules of complementary shape are found to exhibit very strong attractive dispersion interactions. Although this has been widely discussed previously in the context of molecular recognition processes, the broader implications of these phenomena may also be important at larger molecular separations, e.g., in the dynamics of aggregation, precipitation, and crystal growth. Images FIGURE 3 PMID:8789115

  18. EDITORIAL: Gems in nanoscience Gems in nanoscience

    NASA Astrophysics Data System (ADS)

    Demming, Anna

    2011-04-01

    In 1902 R M Wood published the paper 'On a remarkable case of uneven distribution of light in a diffraction grating spectrum' [1]. As was true of so much of his work, interest in his observations took flight, inspiring extensive research into associated new optical phenomena. What is now known as Wood's anomaly has been described as the result of excitations of oscillations in the conducting electron plasma, or 'plasmons'. These quasiparticles have become increasingly attractive to researchers, perhaps less for the dazzling colours they impart to glitzy gemstones over their potential to facilitate medical imaging, as well as integrated optics [2] and the transfer of information and energy at dimensions below the diffraction limit. Excitation of surface plasmons provides a means of enhancing optical near fields, thus empowering a range of signal detecting applications. A range of innovative techniques have been implemented to probe surface plasmon resonances. The evolution of plasmon resonance energy and mean free path as particle dimensions increase from nanostructures to bulk matter has been monitored through ellipsometry, thus providing an insight into the plasmon polariton coupling [3]. Electron energy loss experiments have also proved a valuable tool for mapping surface plasmons with a spatial resolution an order of magnitude better than can be achieved with scanning near-field optical microscopes [4]. The exploitation of surface plasmons is primed to aid advances in medical imaging, diagnosis and therapy. Researchers in the US have developed a protein-enabled strategy to fabricate quantum dot nanoarrays where an increase in surface-plasmon-enhanced fluorescence of up to a factor of 15 has been achieved [5]. Understanding and dexterity in manipulating these enhancements has reached a high level of sophistication, and researchers in London have demonstrated the ability to increase the fluorescence enhancement by a factor of 4 and the decay rate by a factor of almost 30 by tuning the localised surface plasmon resonance of silver particle arrays to the emission wavelength of a locally situated fluorophore [6]. In the US and Belarus researchers have collaborated to investigate the potential of plasmonic nanobubbles, generated by laser activated nanoparticles, for combined diagnostics, therapy, and therapy guidance. Such nanobubbles can be optically tracked in the body, and their rapid expansion and collapse provides a localised mechanical impact on cells that can disrupt the cell membrane [7]. Surface plasmon polaritons at nanostructures allow highly local control of light, which has a range of uses in electronic devices. Photovoltaics researchers in the US and the Netherlands have demonstrated enhanced short circuit current densities compared to cells having flat or randomly textured back contacts using nanostructured plasmonic back contacts, which maximise the interaction with the light [8]. Progress in optoelectronics is another area where surface plasmon polaritons are playing an increasingly important role [9]. In this issue, researchers at the Institut des Sciences Molé culaire d'Orsay demonstrate that it is possible to excite propagating surface plasmon polaritons with a scanning tunnelling microscope, and detect them [2]. Their work also investigates the nature of the excited plasmons and how the intensities of the propagating surface plasmon polaritons and the localized plasmon emission can be enhanced by factors of 2 and 20 respectively by using a silver tip instead of a tungsten one. Wisdom may be worth more than silver and gold, but a little silver and gold can contribute a lot to unearthing new wisdom at the nanoscale. References [1] Wood R M 1902 Nanotechnology 18 296 [2] Wang T, Boer-Duchemin E, Zhang Y, Comtet G and Dujardin G 2011 Nanotechnology 22 175201 [3] Oates T W H and Mücklich A 2005 Nanotechnology 16 2606 [4] Bosman M, Keast V J, Watanabe M, Maaroof A I and Cortie M B 2007 Nanotechnology 18 165505 [5] Zin M T, Leong K, Wong N-Y, Ma H, Sarikaya M and Jen A K-Y 2009 Nanotechnology 20 015305 [6] C

  19. A process-based evaluation of dust-emitting winds in the CMIP5 simulation of HadGEM2-ES

    NASA Astrophysics Data System (ADS)

    Fiedler, Stephanie; Knippertz, Peter; Woodward, Stephanie; Martin, Gill M.; Bellouin, Nicolas; Ross, Andrew N.; Heinold, Bernd; Schepanski, Kerstin; Birch, Cathryn E.; Tegen, Ina

    2016-02-01

    Despite the importance of dust aerosol in the Earth system, state-of-the-art models show a large variety for North African dust emission. This study presents a systematic evaluation of dust emitting-winds in 30 years of the historical model simulation with the UK Met Office Earth-system model HadGEM2-ES for the Coupled Model Intercomparison Project Phase 5. Isolating the effect of winds on dust emission and using an automated detection for nocturnal low-level jets (NLLJs) allow an in-depth evaluation of the model performance for dust emission from a meteorological perspective. The findings highlight that NLLJs are a key driver for dust emission in HadGEM2-ES in terms of occurrence frequency and strength. The annually and spatially averaged occurrence frequency of NLLJs is similar in HadGEM2-ES and ERA-Interim from the European Centre for Medium-Range Weather Forecasts. Compared to ERA-Interim, a stronger pressure ridge over northern Africa in winter and the southward displaced heat low in summer result in differences in location and strength of NLLJs. Particularly the larger geostrophic winds associated with the stronger ridge have a strengthening effect on NLLJs over parts of West Africa in winter. Stronger NLLJs in summer may rather result from an artificially increased mixing coefficient under stable stratification that is weaker in HadGEM2-ES. NLLJs in the Bodélé Depression are affected by stronger synoptic-scale pressure gradients in HadGEM2-ES. Wintertime geostrophic winds can even be so strong that the associated vertical wind shear prevents the formation of NLLJs. These results call for further model improvements in the synoptic-scale dynamics and the physical parametrization of the nocturnal stable boundary layer to better represent dust-emitting processes in the atmospheric model. The new approach could be used for identifying systematic behavior in other models with respect to meteorological processes for dust emission. This would help to improve dust

  20. Left to their own devices: Post-ELSI, ethical equipment and the International Genetically Engineered Machine (iGEM) Competition

    PubMed Central

    Balmer, Andrew S; Bulpin, Kate J

    2013-01-01

    In this article, we evaluate a novel method for post-ELSI (ethical, legal and social implications) collaboration, drawing on ‘human practices' (HP) to develop a form of reflexive ethical equipment that we termed ‘sociotechnical circuits'. We draw on a case study of working collaboratively in the International Genetically Engineered Machine Competition (iGEM) and relate this to the parts-based agenda of synthetic biology. We use qualitative methods to explore the experience of undergraduate students in the Competition, focussing on the 2010 University of Sheffield team. We examine how teams work collaboratively across disciplines to produce novel microorganisms. The Competition involves a HP component and we examine the way in which this has been narrowly defined within the ELSI framework. We argue that this is a much impoverished style of HP when compared with its original articulation as the development of ‘ethical equipment'. Inspired by this more theoretically rich HP framework, we explore the relations established between team members and how these were shaped by the norms, materials and practices of the Competition. We highlight the importance of care in the context of post-ELSI collaborations and report on the implications of our case study for such efforts and for the relation of the social sciences to the life sciences more generally. PMID:24159360

  1. A soft X-ray beam-splitting multilayer optic for the NASA GEMS Bragg Reflection Polarimeter

    SciTech Connect

    Allured, Ryan; Kaaret, Philip; Fernandez-Perea, Monica; Soufli, Regina; Alameda, Jennifer B.; Pivovaroff, Michael J.; Gullikson, Eric M.

    2013-04-12

    A soft X-ray, beam-splitting, multilayer optic has been developed for the Bragg Reflection Polarimeter (BRP) on the NASA Gravity and Extreme Magnetism Small Explorer Mission (GEMS). The optic is designed to reflect 0.5 keV X-rays through a 90° angle to the BRP detector, and transmit 2–10 keV X-rays to the primary polarimeter. The transmission requirement prevents the use of a thick substrate, so a 2 μm thick polyimide membrane was used. Atomic force microscopy has shown the membrane to possess high spatial frequency roughness less than 0.2 nm rms, permitting adequate X-ray reflectance. A multilayer thin film was especially developed and deposited via magnetron sputtering with reflectance and transmission properties that satisfy the BRP requirements and with near-zero stress. Furthermore, reflectance and transmission measurements of BRP prototype elements closely match theoretical predictions, both before and after rigorous environmental testing.

  2. Meeting the Challenge of Earthquake Risk Globalisation: Towards the Global Earthquake Model GEM (Sergey Soloviev Medal Lecture)

    NASA Astrophysics Data System (ADS)

    Zschau, J.

    2009-04-01

    Earthquake risk, like natural risks in general, has become a highly dynamic and globally interdependent phenomenon. Due to the "urban explosion" in the Third World, an increasingly complex cross linking of critical infrastructure and lifelines in the industrial nations and a growing globalisation of the world's economies, we are presently facing a dramatic increase of our society's vulnerability to earthquakes in practically all seismic regions on our globe. Such fast and global changes cannot be captured with conventional earthquake risk models anymore. The sciences in this field are, therefore, asked to come up with new solutions that are no longer exclusively aiming at the best possible quantification of the present risks but also keep an eye on their changes with time and allow to project these into the future. This does not apply to the vulnerablity component of earthquake risk alone, but also to its hazard component which has been realized to be time-dependent, too. The challenges of earthquake risk dynamics and -globalisation have recently been accepted by the Global Science Forum of the Organisation for Economic Co-operation and Development (OECD - GSF) who initiated the "Global Earthquake Model (GEM)", a public-private partnership for establishing an independent standard to calculate, monitor and communicate earthquake risk globally, raise awareness and promote mitigation.

  3. A soft X-ray beam-splitting multilayer optic for the NASA GEMS Bragg Reflection Polarimeter

    DOE PAGES

    Allured, Ryan; Kaaret, Philip; Fernandez-Perea, Monica; ...

    2013-04-12

    A soft X-ray, beam-splitting, multilayer optic has been developed for the Bragg Reflection Polarimeter (BRP) on the NASA Gravity and Extreme Magnetism Small Explorer Mission (GEMS). The optic is designed to reflect 0.5 keV X-rays through a 90° angle to the BRP detector, and transmit 2–10 keV X-rays to the primary polarimeter. The transmission requirement prevents the use of a thick substrate, so a 2 μm thick polyimide membrane was used. Atomic force microscopy has shown the membrane to possess high spatial frequency roughness less than 0.2 nm rms, permitting adequate X-ray reflectance. A multilayer thin film was especially developedmore » and deposited via magnetron sputtering with reflectance and transmission properties that satisfy the BRP requirements and with near-zero stress. Furthermore, reflectance and transmission measurements of BRP prototype elements closely match theoretical predictions, both before and after rigorous environmental testing.« less

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

    NASA Astrophysics Data System (ADS)

    Aza, E.; Ciocca, M.; Murtas, F.; Puddu, S.; Pullia, M.; Silari, M.

    2017-01-01

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

  5. Advanced Communication and Control Solutions of Distributed Energy Resources (DER)

    SciTech Connect

    Asgeirsson, Haukur; Seguin, Richard; Sherding, Cameron; de Bruet, Andre, G.; Broadwater, Robert; Dilek, Murat

    2007-01-10

    This report covers work performed in Phase II of a two phase project whose objective was to demonstrate the aggregation of multiple Distributed Energy Resources (DERs) and to offer them into the energy market. The Phase I work (DE-FC36-03CH11161) created an integrated, but distributed, system and procedures to monitor and control multiple DERs from numerous manufacturers connected to the electric distribution system. Procedures were created which protect the distribution network and personnel that may be working on the network. Using the web as the communication medium for control and monitoring of the DERs, the integration of information and security was accomplished through the use of industry standard protocols such as secure SSL,VPN and ICCP. The primary objective of Phase II was to develop the procedures for marketing the power of the Phase I aggregated DERs in the energy market, increase the number of DER units, and implement the marketing procedures (interface with ISOs) for the DER generated power. The team partnered with the Midwest Independent System Operator (MISO), the local ISO, to address the energy market and demonstrate the economic dispatch of DERs in response to market signals. The selection of standards-based communication technologies offers the ability of the system to be deployed and integrated with other utilities’ resources. With the use of a data historian technology to facilitate the aggregation, the developed algorithms and procedures can be verified, audited, and modified. The team has demonstrated monitoring and control of multiple DERs as outlined in phase I report including procedures to perform these operations in a secure and safe manner. In Phase II, additional DER units were added. We also expanded on our phase I work to enhance communication security and to develop the market model of having DERs, both customer and utility owned, participate in the energy market. We are proposing a two-part DER energy market model--a utility

  6. Stufenweise Integration von eLearning an der Technischen Universität München

    NASA Astrophysics Data System (ADS)

    Pätzold, Sebastian; Graf, Stephan; Gergintchev, Ivan; Pongratz, Hans; Rathmayer, Sabine

    Der vorliegende Beitrag beschreibt als Best Practice Beispiel die stufenweise Integration eines Learning Management Systems (LMS) in die Infrastruktur von Information und Kommunikation (IuK) der Technischen Universität München (TUM). Dabei wird sowohl die Konsolidierung mehrfach angebotener Funktionalitäten und Dienste in den verschiedenen Portalen der Universität als auch die sukzessive Optimierung der Abläufe aufgezeigt. Gleichzeitig wird auf zukünftige weitere Entwicklungen hin zu einer vollständigen Integration der IuK, aber auch auf die Probleme in den unterschiedlichen Stadien der Entwicklung eingegangen.

  7. Examination of Arabian Sea SST biases in the HiGEM high resolution coupled climate model and the CMIP3 multi-model dataset

    NASA Astrophysics Data System (ADS)

    Marathayil, Deepthi; Shaffrey, Len; Turner, Andrew; Slingo, Julia

    2010-05-01

    The Arabian Sea region undergoes a pronounced seasonal cycle relating to upwelling, mixing and monsoon dynamics. Any variations in high temperatures of the region may affect the availability of moisture supply to the Indian summer monsoon. Seasonal analysis has been performed for various ocean and atmosphere data from a present day control run in the Indian Ocean region of the HiGEM High Resolution Global Environment Model. When compared with observed and reanalysis datasets such as HadISST, SODA reanalysis and ARGO floats for SST and ocean potential temperature, we find a significant cold bias of around 2°C in HiGEM boreal winter SST. This bias persists through springtime in the northern Arabian Sea, potentially to the detriment of the subsequent Indian summer monsoon which is deficient in this model. Meridional cross-sections of ocean potential temperature and salinity along 65°E also reveal the existence of a deeper mixed layer extending to 300m with highly saline water in the same area. Near-surface winds in HiGEM reveal very strong northeasterly wind biases during boreal winter, which may be the result of a strong north-south air temperature gradient. Compared to estimates from CRU and ERA40, a large cold bias of more than 8°C is observed in HiGEM surface air temperature over northern India during the same season. We suspect that the cold SST bias in the northern Arabian Sea is due to coupling with the strong wind and evaporation biases in HiGEM. Seasonal analysis of modelled latent heat flux in comparison with NOCS (National Oceanographic Centre Southampton) data also suggests that the evaporation rate in HiGEM is too strong over the northern Arabian Sea during winter. Similar analysis was also carried out for the 20th century simulations from the CMIP3 multi-model dataset. Most of the models show a similar cold bias in the Arabian Sea SST and in northern Indian air temperature during boreal winter. However the mixed layer depth biases show wide variations

  8. Depletion of pro-oncogenic RUNX2 enhances gemcitabine (GEM) sensitivity of p53-mutated pancreatic cancer Panc-1 cells through the induction of pro-apoptotic TAp63

    PubMed Central

    Ozaki, Toshinori; Nakamura, Mizuyo; Ogata, Takehiro; Sang, Meijie; Yoda, Hiroyuki; Hiraoka, Kiriko; Sang, Meixiang; Shimozato, Osamu

    2016-01-01

    Recently, we have described that siRNA-mediated silencing of runt-related transcription factor 2 (RUNX2) improves anti-cancer drug gemcitabine (GEM) sensitivity of p53-deficient human pancreatic cancer AsPC-1 cells through the augmentation of p53 family TAp63-dependent cell death pathway. In this manuscript, we have extended our study to p53-mutated human pancreatic cancer Panc-1 cells. According to our present results, knockdown of mutant p53 alone had a marginal effect on GEM-mediated cell death of Panc-1 cells. We then sought to deplete RUNX2 using siRNA in Panc-1 cells and examined its effect on GEM sensitivity. Under our experimental conditions, RUNX2 knockdown caused a significant enhancement of GEM sensitivity of Panc-1 cells. Notably, GEM-mediated induction of TAp63 but not of TAp73 was further stimulated in RUNX2-depleted Panc-1 cells, indicating that, like AsPC-1 cells, TAp63 might play a pivotal role in the regulation of GEM sensitivity of Panc-1 cells. Consistent with this notion, forced expression of TAp63α in Panc-1 cells promoted cell cycle arrest and/or cell death, and massively increased luciferase activities driven by TAp63-target gene promoters such as p21WAF1 and NOXA. In addition, immunoprecipitation experiments indicated that RUNX2 forms a complex with TAp63 in Panc-1 cells. Taken together, our current observations strongly suggest that depletion of RUNX2 enhances the cytotoxic effect of GEM on p53-mutated Panc-1 cells through the stimulation of TAp63-dependent cell death pathway even in the presence of a large amount of pro-oncogenic mutant p53, and might provide an attractive strategy to treat pancreatic cancer patients with p53 mutations. PMID:27713122

  9. Van der Waals interaction in uniaxial anisotropic media.

    PubMed

    Kornilovitch, Pavel E

    2013-01-23

    Van der Waals interactions between flat surfaces in uniaxial anisotropic media are investigated in the nonretarded limit. The main focus is the effect of nonzero tilt between the optical axis and the surface normal on the strength of the van der Waals attraction. General expressions for the van der Waals free energy are derived using the surface mode method and the transfer-matrix formalism. To facilitate numerical calculations a temperature-dependent three-band parameterization of the dielectric tensor of the liquid crystal 5CB is developed. A solid slab immersed in a liquid crystal experiences a van der Waals torque that aligns the surface normal relative to the optical axis of the medium. The preferred orientation is different for different materials. Two solid slabs in close proximity experience a van der Waals attraction that is strongest for homeotropic alignment of the intervening liquid crystal for all the materials studied. The results have implications for the stability of plate-like colloids in liquid crystal hosts.

  10. Evolutionary design of interfacial phase change van der Waals heterostructures.

    PubMed

    Kalikka, Janne; Zhou, Xilin; Behera, Jitendra; Nannicini, Giacomo; Simpson, Robert E

    2016-10-27

    We use an evolutionary algorithm to explore the design space of hexagonal Ge2Sb2Te5; a van der Waals layered two dimensional crystal heterostructure. The Ge2Sb2Te5 structure is more complicated than previously thought. Predominant features include layers of Ge3Sb2Te6 and Ge1Sb2Te4 two dimensional crystals that interact through Te-Te van der Waals bonds. Interestingly, (Ge/Sb)-Te-(Ge/Sb)-Te alternation is a common feature for the most stable structures of each generation's evolution. This emergent rule provides an important structural motif that must be included in the design of high performance Sb2Te3-GeTe van der Waals heterostructure superlattices with interfacial atomic switching capability. The structures predicted by the algorithm agree well with experimental measurements on highly oriented, and single crystal Ge2Sb2Te5 samples. By analysing the evolutionary algorithm optimised structures, we show that diffusive atomic switching is probable by Ge atoms undergoing a transition at the van der Waals interface from layers of Ge3Sb2Te6 to Ge1Sb2Te4 thus producing two blocks of Ge2Sb2Te5. Evolutionary methods present an efficient approach to explore the enormous multi-dimensional design parameter space of van der Waals bonded heterostructure superlattices.

  11. Materials perspective on Casimir and van der Waals interactions

    NASA Astrophysics Data System (ADS)

    Woods, L. M.; Dalvit, D. A. R.; Tkatchenko, A.; Rodriguez-Lopez, P.; Rodriguez, A. W.; Podgornik, R.

    2016-10-01

    Interactions induced by electromagnetic fluctuations, such as van der Waals and Casimir forces, are of universal nature present at any length scale between any types of systems. Such interactions are important not only for the fundamental science of materials behavior, but also for the design and improvement of micro- and nanostructured devices. In the past decade, many new materials have become available, which has stimulated the need for understanding their dispersive interactions. The field of van der Waals and Casimir forces has experienced an impetus in terms of developing novel theoretical and computational methods to provide new insights into related phenomena. The understanding of such forces has far reaching consequences as it bridges concepts in materials, atomic and molecular physics, condensed-matter physics, high-energy physics, chemistry, and biology. This review summarizes major breakthroughs and emphasizes the common origin of van der Waals and Casimir interactions. Progress related to novel ab initio modeling approaches and their application in various systems, interactions in materials with Dirac-like spectra, force manipulations through nontrivial boundary conditions, and applications of van der Waals forces in organic and biological matter are examined. The outlook of the review is to give the scientific community a materials perspective of van der Waals and Casimir phenomena and stimulate the development of experimental techniques and applications.

  12. A cartography of the van der Waals territories.

    PubMed

    Alvarez, Santiago

    2013-06-28

    The distribution of distances from atoms of a particular element E to a probe atom X (oxygen in most cases), both bonded and intermolecular non-bonded contacts, has been analyzed. In general, the distribution is characterized by a maximum at short E···X distances corresponding to chemical bonds, followed by a range of unpopulated distances--the van der Waals gap--and a second maximum at longer distances--the van der Waals peak--superimposed on a random distribution function that roughly follows a d(3) dependence. The analysis of more than five million interatomic "non-bonded" distances has led to the proposal of a consistent set of van der Waals radii for most naturally occurring elements, and its applicability to other element pairs has been tested for a set of more than three million data, all of them compared to over one million bond distances.

  13. The Economics of van der Waals Force Engineering

    NASA Astrophysics Data System (ADS)

    Pinto, Fabrizio

    2008-01-01

    As micro-electro-mechanical system (MEMS) fabrication continues on an ever-decreasing scale, new technological challenges must be successfully negotiated if Moore's Law is to be an even approximately valid model of the future of device miniaturization. Among the most significant obstacles is the existence of strong surface forces related to quantum mechanical van der Waals interatomic interactions, which rapidly diverge as the distance between any two neutral boundaries decreases. The van der Waals force is a contributing factor in several device failures and limitations, including, for instance, stiction and oscillator non-linearities. In the last decade, however, it has been conclusively shown that van der Waals forces are not just a MEMS limitation but can be engineered in both magnitude and sign so as to enable classes of proprietary inventions which either deliver novel capabilities or improve upon existing ones. The evolution of van der Waals force research from an almost exclusively theoretical field in quantum-electro-dynamics to an enabling nanotechnology discipline represents a useful example of the ongoing paradigm shift from government-centered to private-capital funded R&D in cutting-edge physics leading to potentially profitable products. In this paper, we discuss the reasons van der Waals force engineering may lead to the creation of thriving markets both in the short and medium terms by highlighting technical challenges that can be competitively addressed by this novel approach. We also discuss some notable obstacles to the cultural transformation of the academic research community required for the emergence of a functional van der Waals force engineering industry worldwide.

  14. Curves of growth for van der Waals broadened spectral lines

    NASA Technical Reports Server (NTRS)

    Park, C.

    1980-01-01

    Curves of growth are evaluated for a spectral line broadened by the van der Waals interactions during collisions. The growth of the equivalent widths of such lines is shown to be dependent on the product of the perturber density and the 6/10 power of the van der Waals potential coefficient. When the parameter is small, the widths grow as the 1/2 power of the optical depth as they do for the Voigt profile: but when the parameter is large, they grow as 2/3 power and, hence, faster than the Voigt profile. An approximate analytical expression for the computed growth characteristics is given.

  15. Aufbau und Anpassung der Motorsteuerungs-Software für Otto- und Dieselmotoren

    NASA Astrophysics Data System (ADS)

    Stuhler, Harald; Ricken, Volker; Diener, René

    Die Erfüllung steigender Kundenansprüche und strenger gesetzlicher Vorgaben hinsichtlich der Verringerung des Kraftstoffverbrauchs, der Reduzierung von Schadstoffemissionen, der Erhöhung von Fahrsicherheit, Fahrleistung und Fahrkomfort ist untrennbar mit dem Einzug elektronischer Systeme in moderne Kraftfahrzeuge verbunden. Die elektronischen Systeme bestimmen zunehmend den Kundennutzen und werden für die Differenzierung der Automobilhersteller untereinander immer wichtiger. Daher sind sie ein wesentlicher Erfolgsfaktor moderner Kraftfahrzeuge.

  16. PS3-11: Beyond General Equivalency Mappings (GEMs): Understanding the Implications of ICD 10 in Research

    PubMed Central

    Riordan, Rick

    2013-01-01

    Background/Aims With the implementation of ICD 10 CM and ICD 10 PCS less than two years away, there are still unanswered questions as to how research teams will effectively translate or use ICD 10 codes in research. Approximately 84% of the ICD 10 codes have only approximate matches with 10% having multiple matches and only 5% have exact one-to-one matches between ICD 9 and ICD 10. With the number of codes increasing five-fold, this offers additional opportunities and risks when pulling data. Methods Besides looking at the General Equivalency Mappings and other tools that are used to translate ICD 9 codes to ICD 10 codes, we will examine some common research areas where only approximate matches between ICD 9 and ICD 10 exist. We will also discuss how the finer level of detail that ICD 10 gives allows research teams to pinpoint exactly what type of asthma, Crohn’s disease, and diabetic retinopathy they wish to study without including some of the other cases that do not meet their research criteria. Results There are significant ambiguities and irregularity in several common areas such as diabetes, mental health, asthma, and gastroenterology due to approximate, multiple, or combination matches. Even in the case of exact matches such as an old myocardial infarction where there is an exact match, the definition of when a myocardial infarction becomes “old” is different. Conclusions ICD 10 offers a finer level of detail and a higher level of specificity, thereby allowing research teams to be more targeted when pulling data. On the other hand, research teams need to exercise caution when using GEMs and other tools to translate ICD 9 codes into ICD 10 codes and vice versa, especially if they are looking at data that overlaps the implementation date of October 1, 2014.

  17. Planck's Dusty GEMS. II. Extended [CII] emission and absorption in the Garnet at z = 3.4 seen with ALMA

    NASA Astrophysics Data System (ADS)

    Nesvadba, N.; Kneissl, R.; Cañameras, R.; Boone, F.; Falgarone, E.; Frye, B.; Gerin, M.; Koenig, S.; Lagache, G.; Le Floc'h, E.; Malhotra, S.; Scott, D.

    2016-08-01

    We present spatially resolved ALMA [CII] observations of the bright (flux density S350 = 400 mJy at 350 μm), gravitationally lensed, starburst galaxy PLCK G045.1+61.1 at z = 3.427, the "Garnet". This source is part of our set of "Planck's Dusty GEMS", discovered with the Planck's all-sky survey. Two emission-line clouds with a relative velocity offset of ~600 km s-1 extend towards north-east and south-west, respectively, of a small, intensely star-forming clump with a star-formation intensity of 220 M⊙ yr-1 kpc-2, akin to maximal starbursts. [CII] is also seen in absorption, with a redshift of +350 km s-1 relative to the brightest CO component. [CII] absorption has previously only been found in the Milky Way along sightlines toward bright high-mass star-forming regions, and this is the first detection in another galaxy. Similar to Galactic environments, the [CII] absorption feature is associated with [CI] emission, implying that this is diffuse gas shielded from the UV radiation of the clump, and likely at large distances from the clump. Since absorption can only be seen in front of a continuum source, the gas in this structure can definitely be attributed to gas flowing towards the clump. The absorber could be part of a cosmic filament or merger debris being accreted onto the galaxy. We discuss our results also in light of the on-going debate of the origin of the [CII] deficit in dusty star-forming galaxies. Based on data obtained with ALMA in program 2013.1.01230.S, and with EMIR on the IRAM 30 m telescope in program 223-13.

  18. The BlackGEM Array: Searching for Gravitational Wave Source Counterparts to Study Ultra-Compact Binaries

    NASA Astrophysics Data System (ADS)

    Bloemen, S.; Groot, P.; Nelemans, G.; Klein-Wolt, M.

    2015-07-01

    The rates and physics of ultra-compact binaries consisting of neutron stars and black holes are poorly known, mostly due to the lack of a good sample to study such systems. In two years from now, the LIGO and Virgo interferometers are expected to be able to directly detect the gravitational waves (GW) emitted by such binaries when they merge, opening up a completely new window on the sky to study ultra-compact binaries. The combination of a GW detection with electromagnetic observations would be especially powerful to characterize the systems and the merger events. Unfortunately, however, the electromagnetic counterparts will be hard to find. The sky localization of the GW detections will be rather poor, with typical error boxes spanning ˜100 square degrees, and the optical sources are expected to be faint (˜22nd magnitude) and not long lasting (˜1 day). In this contribution we discuss the possibilities of finding the electromagnetic counterparts of these binaries, thereby paying particular attention to the dedicated BlackGEM array of optical telescopes that will be deployed at the ESO site in La Silla (Chile) in 2015 and 2016. In the first phase, the array will consist of four 60-cm telescopes with a field of view of 2.7 square degrees each. Apart from going after GW triggers, the array will also perform a deep southern sky survey in Sloan u, g, r, i, and z filters, down to 23rd magnitude in the g band, and a survey to characterize the transient and variable sky on timescales of hours and days. The latter will be a valuable resource to search for variable stars across the sky, including eclipsing, reflecting, and beaming binary stars.

  19. Generation of an atlas for commodity chemical production in Escherichia coli and a novel pathway prediction algorithm, GEM-Path.

    PubMed

    Campodonico, Miguel A; Andrews, Barbara A; Asenjo, Juan A; Palsson, Bernhard O; Feist, Adam M

    2014-09-01

    The production of 75% of the current drug molecules and 35% of all chemicals could be achieved through bioprocessing (Arundel and Sawaya, 2009). To accelerate the transition from a petroleum-based chemical industry to a sustainable bio-based industry, systems metabolic engineering has emerged to computationally design metabolic pathways for chemical production. Although algorithms able to provide specific metabolic interventions and heterologous production pathways are available, a systematic analysis for all possible production routes to commodity chemicals in Escherichia coli is lacking. Furthermore, a pathway prediction algorithm that combines direct integration of genome-scale models at each step of the search to reduce the search space does not exist. Previous work (Feist et al., 2010) performed a model-driven evaluation of the growth-coupled production potential for E. coli to produce multiple native compounds from different feedstocks. In this study, we extended this analysis for non-native compounds by using an integrated approach through heterologous pathway integration and growth-coupled metabolite production design. In addition to integration with genome-scale model integration, the GEM-Path algorithm developed in this work also contains a novel approach to address reaction promiscuity. In total, 245 unique synthetic pathways for 20 large volume compounds were predicted. Host metabolism with these synthetic pathways was then analyzed for feasible growth-coupled production and designs could be identified for 1271 of the 6615 conditions evaluated. This study characterizes the potential for E. coli to produce commodity chemicals, and outlines a generic strain design workflow to design production strains.

  20. Web-gestütztes Social Networking am Beispiel der Plattform Wissensmanagement"

    NASA Astrophysics Data System (ADS)

    Lindstaedt, Stefanie; Thurner, Claudia

    Anhand der Plattform Wissensmanagement, der größten deutschsprachigen Community im Themenfeld Wissensmanagement, werden organisationale Rahmenbedingungen, technische Werkzeuge und Rollen der Moderatorin diskutiert, die Bedingungen für den erfolgreichen Betrieb einer Community im Web 2.0 sind. Weiters wird dargestellt, wie Communities für das betriebliche Wissensmanagement eingesetzt werden können.