650 research outputs found
Improvement of the efficient referencing and sample positioning system for micro focused synchrotron X-ray techniques
An efficient referencing and sample positioning system is a basic tool for a micro focus beamline at a synchrotron. The seven years ago introduced command line based system was upgraded at SUL-X beamline at ANKA [1]. A new combination of current server client techniques offers direct control and facilitates unexperienced users the handling of this frequently used tool
Structural, vibrational and thermal properties of densified silicates : insights from Molecular Dynamics
Structural, vibrational and thermal properties of densified sodium silicate
(NS2) are investigated with classical molecular dynamics simulations of the
glass and the liquid state. A systematic investigation of the glass structure
with respect to density was performed. We observe a repolymerization of the
network manifested by a transition from a tetrahedral to an octahedral silicon
environment, the decrease of the amount of non-bridging oxygen atoms and the
appearance of three-fold coordinated oxygen atoms (triclusters). Anomalous
changes in the medium range order are observed, the first sharp diffraction
peak showing a minimum of its full-width at half maximum according to density.
The previously reported vibrational trends in densified glasses are observed,
such as the shift of the Boson peak intensity to higher frequencies and the
decrease of its intensity. Finally, we show that the thermal behavior of the
liquid can be reproduced by the Birch-Murnaghan equation of states, thus
allowing us to compute the isothermal compressibility
Phasentransformationen in lithiumhaltigen Natriumborosilikatgrundglasschmelzen zur Verfestigung von HAW
Nano-mineralogy & -geochemistry of karst bauxites (Greece): Implications of the origin of the deposits
Postshock Thermally Induced Transformations in Experimentally Shocked Magnetite
We studied the effect of 973 K heating in argon atmosphere on the magnetic and structural properties of a magnetiteâbearing ore, which was previously exposed to laboratory shock waves between 5 and 30 GPa. For this purpose magnetic properties were studied using temperatureâdependent magnetic susceptibility, magnetic hysteresis and lowâtemperature saturation isothermal remanent magnetization. Structural properties of magnetite were analyzed using Xâray diffraction, highâresolution scanning electron microscopy and synchrotronâassisted Xâray absorption spectroscopy. The shockâinduced changes include magnetic domain size reduction due to brittle and ductile deformation features and an increase in Verwey transition temperature due to lattice distortion. After heating, the crystal lattice is relaxed and apparent crystallite size is increased suggesting a recovery of lattice defects documented by a mosaic recrystallization texture. The structural changes correlate with modifications in magnetic domain state recorded by temperatureâdependent magnetic susceptibility, hysteresis properties and lowâtemperature saturation isothermal remanent magnetization. These alterations in both, magnetic and structural properties of magnetite can be used to assess impactârelated magnetic anomalies in impact structures with a high temperature overprint
Availability analysis of post-combustion carbon capture systems: minimum work input
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