3,068 research outputs found

    Polymeric Schiff bases. 17 - Azomethine copolymers

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    Chemical synthesis of azomethine copolymers by melt polymerization techniques - polymeric Schiff base

    The direct synthesis of crosslinked polymeric azomethines

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    Char yields of synthesized crosslinked polymeric azomethine

    Die Bedeutung der Fascia stylopharyngea bei intraoralen Blockadetechniken

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    Zusammenfassung: Hintergrund: Mittels transoraler Blockade des Ganglion cervicale superius des Truncus sympathicus kann bei Trigeminusneuralgien durch Ausbreitung eines Opioids bis zum N.mandibularis eine zusĂ€tzliche Schmerzreduktion erzielt werden. Das Vorhandensein der Fascia stylopharyngea senkt möglicherweise die Erfolgsrate. Durch genaue anatomische Untersuchung der Faszie wollen wir auf die EffektivitĂ€t der zusĂ€tzlichen Opioidwirkung rĂŒckschließen. Material und Methode: 103 KopfhĂ€lften wurden untersucht, die Faszie von lateral her aufgesucht. Dabei unterschieden wir 3 Gruppen: GruppeA reprĂ€sentierte vollstĂ€ndig ausgebildete FaszienblĂ€tter, Gruppe BunvollstĂ€ndige Faszien und in GruppeC war die Faszie nicht ausgebildet. Ergebnis: Die Faszie war in 86 vollstĂ€ndig und in 13 FĂ€llen unvollstĂ€ndig ausgebildet. Lediglich in 4 FĂ€llen fehlte sie vollends. Schlussfolgerung: Die Faszie kann die Erfolgsquote der Schmerzreduktion bei Trigeminusneuralgie beeinflusse

    Release Note -- Vbfnlo-2.6.0

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    Vbfnlo is a flexible parton level Monte Carlo program for the simulation of vector boson fusion (VBF), double and triple vector boson (plus jet) production in hadronic collisions at next-to-leading order (NLO) in the strong coupling constant, as well as Higgs boson plus two jet production via gluon fusion at the one-loop level. This note briefly describes the main additional features and processes that have been added in the new release -- Vbfnlo Version 2.6.0. At NLO QCD diboson production (W\gamma, WZ, ZZ, Z\gamma and \gamma\gamma), same-sign W pair production via vector boson fusion and the process W\gamma\gamma j have been implemented (for which one-loop tensor integrals up to six-point functions are included). In addition, gluon induced diboson production can be studied separately at the leading order (one-loop) level. The diboson processes WW, WZ and W\gamma can be run with anomalous gauge boson couplings, and anomalous couplings between a Higgs and a pair of gauge bosons is included in WW, ZZ, Z\gamma and \gamma\gamma diboson production. The code has also been extended to include anomalous gauge boson couplings for single vector boson production via VBF, and a spin-2 model has been implemented for diboson pair production via vector boson fusion.Comment: 14 pages, 6 tables; new code available at http://www-itp.particle.uni-karlsruhe.de/vbfnlo

    Structural relaxation of E' gamma centers in amorphous silica

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    We report experimental evidence of the existence of two variants of the E' gamma centers induced in silica by gamma rays at room temperature. The two variants are distinguishable by the fine features of their line shapes in paramagnetic resonance spectra. These features suggest that the two E' gamma differ for their topology. We find a thermally induced interconversion between the centers with an activation energy of about 34 meV. Hints are also found for the existence of a structural configuration of minimum energy and of a metastable state.Comment: 4 pages, 2 figures, submitted to Phys. Rev. Let

    Proof of the thermodynamical stability of the E' center in SiO2

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    The E' center is a paradigmatic radiation-induced defect in SiO2 whose peculiar EPR and hyperfine activity has been known since over 40 years. This center has been traditionally identified with a distorted, positively-charged oxygen vacancy V_O+. However, no direct proof of the stability of this defect has ever been provided, so that its identification is still strongly incomplete. Here we prove directly that distorted V_O+ is metastable and that it satisfies the key requirements for its identification as E', such as thermal and optical response, and activation-deactivation mechanisms.Comment: RevTeX 4 pages, 2 figure

    HV/HR-CMOS sensors for the ATLAS upgrade—concepts and test chip results

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    In order to extend its discovery potential, the Large Hadron Collider (LHC) will have a major upgrade (Phase II Upgrade) scheduled for 2022. The LHC after the upgrade, called High-Luminosity LHC (HL-LHC), will operate at a nominal leveled instantaneous luminosity of 5× 1034 cm−2 s−1, more than twice the expected Phase I . The new Inner Tracker needs to cope with this extremely high luminosity. Therefore it requires higher granularity, reduced material budget and increased radiation hardness of all components. A new pixel detector based on High Voltage CMOS (HVCMOS) technology targeting the upgraded ATLAS pixel detector is under study. The main advantages of the HVCMOS technology are its potential for low material budget, use of possible cheaper interconnection technologies, reduced pixel size and lower cost with respect to traditional hybrid pixel detector. Several first prototypes were produced and characterized within ATLAS upgrade R&D effort, to explore the performance and radiation hardness of this technology. In this paper, an overview of the HVCMOS sensor concepts is given. Laboratory tests and irradiation tests of two technologies, HVCMOS AMS and HVCMOS GF, are also given

    Radiation-hard active pixel sensors for HL-LHC detector upgrades based on HV-CMOS technology

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    Luminosity upgrades are discussed for the LHC (HL-LHC) which would make updates to the detectors necessary, requiring in particular new, even more radiation-hard and granular, sensors for the inner detector region. A proposal for the next generation of inner detectors is based on HV-CMOS: a new family of silicon sensors based on commercial high-voltage CMOS technology, which enables the fabrication of part of the pixel electronics inside the silicon substrate itself. The main advantages of this technology with respect to the standard silicon sensor technology are: low material budget, fast charge collection time, high radiation tolerance, low cost and operation at room temperature. A traditional readout chip is still needed to receive and organize the data from the active sensor and to handle high-level functionality such as trigger management. HV-CMOS has been designed to be compatible with both pixel and strip readout. In this paper an overview of HV2FEI4, a HV-CMOS prototype in 180 nm AMS technology, will be given. Preliminary results after neutron and X-ray irradiation are shown
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