5,747 research outputs found
Incorporation Of Oxygen In Crystalline Zeolitic Chromosilicates: Optical Identification Of Chromium(vi) By Photoacoustic Spectroscopy
Incorporation of oxygen to crystalline zeolitic chromosilicates, with oxidation of anchored CrIII to non-interacting CrVI species, has been confirmed by photoacoustic spectroscopy; the dichromate anion being extracted from the chromosilicate with water and identified by precipitation of AgCrO4 and oxidation to CrO5.1492292
INCORPORATION OF OXYGEN IN CRYSTALLINE ZEOLITIC CHROMOSILICATES - OPTICAL-IDENTIFICATION OF CHROMIUM(VI) BY PHOTOACOUSTIC-SPECTROSCOPY
Incorporation of oxygen to crystalline zeolitic chromosilicates, with oxidation of anchored Cr(III) to non-interacting Cr(VI) species, has been confirmed by photoacoustic spectroscopy; the dichromate anion being extracted from the chromosilicate with water and identified by precipitation of AgCrO4 and oxidation to CrO5.1492292
Thermal, structural and optical properties of {CdS}-Na(86)X composites
Thermal, structural and optical properties of CdS superclusters grown in zeolite Na(86)X are reported. The interest in this work arose in the need to study CdS prepared in the zeolite host, at high concentrations (>19%), in order to observe porosyte behaviour and CdS aggregate properties. The semiconductor-zeolite composite was studied using X-ray diffraction analysis and photoacoustic technique (PAS). The properties of semiconductor CdS embedded in a zeolite matrix were analysed as a function of the CdS concentration by monitoring Cd concentration (atom%) by chemical analysis. The results show that as the concentration of CdS increases, the thermal diffusivity, capacity, conductivity and the band-gap increase up to a point where the zeolite lattice collapses. From this point on, all these thermal properties diminish and the band-gap is the same as for bulk CdS.92142651265
Determination of the muon charge sign with the dipolar spectrometers of the OPERA experiment
The OPERA long-baseline neutrino-oscillation experiment has observed the
direct appearance of in the CNGS beam. Two large muon
magnetic spectrometers are used to identify muons produced in the
leptonic decay and in interactions by measuring their charge and
momentum. Besides the kinematic analysis of the decays, background
resulting from the decay of charmed particles produced in
interactions is reduced by efficiently identifying the muon track. A new method
for the charge sign determination has been applied, via a weighted angular
matching of the straight track-segments reconstructed in the different parts of
the dipole magnets. Results obtained for Monte Carlo and real data are
presented. Comparison with a method where no matching is used shows a
significant reduction of up to 40\% of the fraction of wrongly determined
charges.Comment: 10 pages. Improvements in the tex
System Test of the ATLAS Muon Spectrometer in the H8 Beam at the CERN SPS
An extensive system test of the ATLAS muon spectrometer has been performed in
the H8 beam line at the CERN SPS during the last four years. This spectrometer
will use pressurized Monitored Drift Tube (MDT) chambers and Cathode Strip
Chambers (CSC) for precision tracking, Resistive Plate Chambers (RPCs) for
triggering in the barrel and Thin Gap Chambers (TGCs) for triggering in the
end-cap region. The test set-up emulates one projective tower of the barrel
(six MDT chambers and six RPCs) and one end-cap octant (six MDT chambers, A CSC
and three TGCs). The barrel and end-cap stands have also been equipped with
optical alignment systems, aiming at a relative positioning of the precision
chambers in each tower to 30-40 micrometers. In addition to the performance of
the detectors and the alignment scheme, many other systems aspects of the ATLAS
muon spectrometer have been tested and validated with this setup, such as the
mechanical detector integration and installation, the detector control system,
the data acquisition, high level trigger software and off-line event
reconstruction. Measurements with muon energies ranging from 20 to 300 GeV have
allowed measuring the trigger and tracking performance of this set-up, in a
configuration very similar to the final spectrometer. A special bunched muon
beam with 25 ns bunch spacing, emulating the LHC bunch structure, has been used
to study the timing resolution and bunch identification performance of the
trigger chambers. The ATLAS first-level trigger chain has been operated with
muon trigger signals for the first time
- …