1,193 research outputs found
The Infocus Hard X-ray Telescope: Pixellated CZT Detector/Shield Performance and Flight Results
The CZT detector on the Infocus hard X-ray telescope is a pixellated
solid-state device capable of imaging spectroscopy by measuring the position
and energy of each incoming photon. The detector sits at the focal point of an
8m focal length multilayered grazing incidence X-ray mirror which has
significant effective area between 20--40 keV. The detector has an energy
resolution of 4.0keV at 32keV, and the Infocus telescope has an angular
resolution of 2.2 arcminute and a field of view of about 10 arcminutes. Infocus
flew on a balloon mission in July 2001 and observed Cygnus X-1. We present
results from laboratory testing of the detector to measure the uniformity of
response across the detector, to determine the spectral resolution, and to
perform a simple noise decomposition. We also present a hard X-ray spectrum and
image of Cygnus X-1, and measurements of the hard X-ray CZT background obtained
with the SWIN detector on Infocus.Comment: To appear in the proceedings of the SPIE conference "Astronomical
Telescopes and Instrumentation", #4851-116, Kona, Hawaii, Aug. 22-28, 2002.
12 pages, 9 figure
Sulfonated immunoglobulin improves cardiopulmonary functions by promoting IGF-I production in ARDS patients with severe sepsis
The Suzaku Observation of NGC 3516: Complex Absorption and the Broad and Narrow Fe K Lines
We present results from a 150 ksec Suzaku observation of the Seyfert 1.5 NGC
3516 in October 2005. The source was in a relatively highly absorbed state. Our
best-fit model is consistent with the presence of a low-ionization absorber
which has a column density near 5 * 10^{22} cm^{-2} and covers most of the
X-ray continuum source (covering fraction 96-100%). A high-ionization absorbing
component, which yields a narrow absorption feature consistent with Fe K XXVI,
is confirmed. A relativistically broadened Fe K alpha line is required in all
fits, even after the complex absorption is taken into account; an additional
partial-covering component is an inadequate substitute for the continuum
curvature associated with the broad Fe line. A narrow Fe K alpha emission line
has a velocity width consistent with the Broad Line Region. The low-ionization
absorber may be responsible for producing the narrow Fe K alpha line, though a
contribution from additional material out of the line of sight is possible. We
include in our model soft band emission lines from He- and H-like ions of N, O,
Ne and Mg, consistent with photo-ionization, though a small contribution from
collisionally-ionized emission is possible.Comment: Accepted for publication in PASJ (Suzaku second special issue). 36
pages, 10 figure
PV System With Reconnection to Improve Output Under Nonuniform Illumination
Photovoltaic (PV) systems are often nonuniformly illuminated owing to shadows of neighboring buildings, trees, clouds, etc. In order to reduce the effect of shadows on solar panels, we propose the concept of a PV system with reconnection; this system consists of PV arrays that can be reconnected to minimize the mismatch loss, depending on the output of each of its module, measured at regular time intervals. In this study, the relationship between the output improvement with reconnection and the switching interval is shown. For a 3-kW PV system, under conditions of cloudlessness and cloudiness, a sharp difference in the output improvement relative to the switching interval is not observed. However, under the condition of shading, the output improvement sharply decreases relative to the switching interval; the output improvement at a 1-min switching interval is 0.15 kWh·h (+22.4%). For the 90-kW building-integrated photovoltaic system, during the summer solstice, a sharp difference in the output improvement relative to the switching interval is not observed. However, during the vernal equinox and winter solstice, when a large area of the PV system is shaded for a long period of time, the output improvement sharply decreases relative to the switching interval. The output improvement at a 1-min switching interval is 6.5 kWh·d (+2.9%) during the vernal equinox and 2.3 kWh·d (+3.7%) during winter solstice
Design and tests of the hard X-ray polarimeter X-Calibur
X-ray polarimetry promises to give qualitatively new information about
high-energy astrophysical sources, such as binary black hole systems,
micro-quasars, active galactic nuclei, and gamma-ray bursts. We designed, built
and tested a hard X-ray polarimeter X-Calibur to be used in the focal plane of
the InFOCuS grazing incidence hard X-ray telescope. X-Calibur combines a low-Z
Compton scatterer with a CZT detector assembly to measure the polarization of
10-80 keV X-rays making use of the fact that polarized photons Compton scatter
preferentially perpendicular to the electric field orientation. X-Calibur
achieves a high detection efficiency of order unity.Comment: 9 pages, 5 figures, conference proceedings: SPIE 2011 (San Diego
Effect of intravenous administration of freeze-dried sulfonated human normal immunoglobulin for septic patients
- …