152 research outputs found
Charge trapping characteristics of Al2O3/Al-rich Al2O3/SiO2 stacked films fabricated by radio-frequency magnetron co-sputtering
A thin-film structure comprising Al2O3/Al-rich Al2O3/SiO2 was fabricated on Si substrate. We used radio-frequency magnetron co-sputtering with Al metal plates set on an Al2O3 target to fabricate the Al-rich Al2O 3 thin film, which is used as a charge storage layer for nonvolatile Al2O3 memory. We investigated the charge trapping characteristics of the film. When the applied voltage between the gate and the substrate is increased, the hysteresis window of capacitance-voltage (C-V) characteristics becomes larger, which is caused by the charge trapping in the film. For a fabricated Al-O capacitor structure, we clarified experimentally that the maximum capacitance in the C-V hysteresis agrees well with the series capacitance of insulators and that the minimum capacitance agrees well with the series capacitance of the semiconductor depletion layer and stacked insulator. When the Al content in the Al-rich Al2O3 is increased, a large charge trap density is obtained. When the Al content in the Al-O is changed from 40 to 58%, the charge trap density increases from 0 to 18 × 1018 cm-3, which is 2.6 times larger than that of the trap memory using SiN as the charge storage layer. The device structure would be promising for low-cost nonvolatile memory. © 2011 Elsevier B.V. All rights reserved
Reliability and Validity of the Japanese Version of the Basel Assessment of Adherence to Immunosuppressive Medications Scale in Kidney Transplant Recipients
A valid and reliable instrument that can measure adherence is needed to identify nonadherent patients and to improve adherence. However, there is no validated Japanese self-report instrument to evaluate adherence to immunosuppressive medications for transplant patients. The purpose of this study was to determine the reliability and validity of the Japanese version of the Basel Assessment of Adherence to Immunosuppressive Medications Scale (BAASIS).; We translated the BAASIS into Japanese and developed the Japanese version of the BAASIS (J-BAASIS) according to the International Society of Pharmacoeconomics and Outcomes Research task force guidelines. We analyzed the reliability (test-retest reliability and measurement error) and validity of the J-BAASIS (concurrent validity with the medication event monitoring system and the 12-item Medication Adherence Scale) referring to the COSMIN Risk of Bias checklist.; A total of 106 kidney transplant recipients were included in this study. In the analysis of test-retest reliability, Cohen's kappa coefficient was found to be 0.62. In the analysis of measurement error, the positive and negative agreement were 0.78 and 0.84, respectively. In the analysis of concurrent validity with the medication event monitoring system, sensitivity and specificity were 0.84 and 0.90, respectively. In the analysis of concurrent validity with the 12-item Medication Adherence Scale, the point-biserial correlation coefficient for the "medication compliance" subscale was 0.38 (; P; < 0.001).; The J-BAASIS was determined to have good reliability and validity. Using the J-BAASIS to evaluate adherence can help clinicians to identify medication nonadherence and institute appropriate corrective measures to improve transplant outcomes
Suzaku Spectroscopy of the Extended X-Ray Emission in M17
We present the results of a Suzaku spectroscopic study of the soft extended
X-ray emission in the HII region M17. The spectrum of the extended emission was
obtained with a high signal-to-noise ratio in a spatially-resolved manner using
the X-ray Imaging Spectrometer (XIS). We established that the contamination by
unresolved point sources, the Galactic Ridge X-ray emission, the cosmic X-ray
background, and the local hot bubble emission is negligible in the
background-subtracted XIS spectrum of the diffuse emission. Half a dozen of
emission lines were resolved clearly for the first time, including K lines of
highly ionized O, Ne, and Mg as well as L series complex of Fe at 0.5--1.5 keV.
Based on the diagnosis of these lines, we obtained the following results: (1)
the extended emission is an optically-thin thermal plasma represented well by a
single temperature of 3.0 +/- 0.4 MK, (2) the abundances of elements with
emission lines in the diffuse spectrum are 0.1--0.3 solar, while those of
bright discrete sources are 0.3--1.5 solar, (3) the metal abundances relative
to each other in the diffuse emission are consistent with solar except for a Ne
enhancement of a factor of 2, (4) both the plasma temperature and the chemical
composition of the diffuse emission show no spatial variation across the
studied spatial scale of about 5 pc.Comment: PASJ in press. 9 pages, 5 figure
Factors influencing long-term survival after aortic valve replacement.
In the aortic stenosis group, the left ventricular (LV) muscle mass index was a good parameter for predicting the prognosis. Associated mitral valve disease had no influence on long term survival after aortic valve replacement. In the aortic insufficiency group, associated mitral valve disease had a marked influence on the results of aortic valve replacement. In general, the aortic insufficiency group had less clinical improvement postoperatively than the aortic stenosis group. In the annuloaortic ectasia group, left ventricular enddiastolic pressure (LVEDP) might be the predictor to the prognosis. This group had the worst prognosis, of the three groups. Early operation should be considered for patients who have no, or only mild symptoms of, aortic valve disease.</p
Charge trapping characteristics of Al2O3/Al-rich Al2O3/SiO2 stacked films fabricated by radio-frequency magnetron co-sputtering
The ASTRO-H X-ray Observatory
The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly
successful X-ray missions initiated by the Institute of Space and Astronautical
Science (ISAS). ASTRO-H will investigate the physics of the high-energy
universe via a suite of four instruments, covering a very wide energy range,
from 0.3 keV to 600 keV. These instruments include a high-resolution,
high-throughput spectrometer sensitive over 0.3-2 keV with high spectral
resolution of Delta E < 7 eV, enabled by a micro-calorimeter array located in
the focal plane of thin-foil X-ray optics; hard X-ray imaging spectrometers
covering 5-80 keV, located in the focal plane of multilayer-coated, focusing
hard X-ray mirrors; a wide-field imaging spectrometer sensitive over 0.4-12
keV, with an X-ray CCD camera in the focal plane of a soft X-ray telescope; and
a non-focusing Compton-camera type soft gamma-ray detector, sensitive in the
40-600 keV band. The simultaneous broad bandpass, coupled with high spectral
resolution, will enable the pursuit of a wide variety of important science
themes.Comment: 22 pages, 17 figures, Proceedings of the SPIE Astronomical
Instrumentation "Space Telescopes and Instrumentation 2012: Ultraviolet to
Gamma Ray
The Quiescent Intracluster Medium in the Core of the Perseus Cluster
Clusters of galaxies are the most massive gravitationally-bound objects in
the Universe and are still forming. They are thus important probes of
cosmological parameters and a host of astrophysical processes. Knowledge of the
dynamics of the pervasive hot gas, which dominates in mass over stars in a
cluster, is a crucial missing ingredient. It can enable new insights into
mechanical energy injection by the central supermassive black hole and the use
of hydrostatic equilibrium for the determination of cluster masses. X-rays from
the core of the Perseus cluster are emitted by the 50 million K diffuse hot
plasma filling its gravitational potential well. The Active Galactic Nucleus of
the central galaxy NGC1275 is pumping jetted energy into the surrounding
intracluster medium, creating buoyant bubbles filled with relativistic plasma.
These likely induce motions in the intracluster medium and heat the inner gas
preventing runaway radiative cooling; a process known as Active Galactic
Nucleus Feedback. Here we report on Hitomi X-ray observations of the Perseus
cluster core, which reveal a remarkably quiescent atmosphere where the gas has
a line-of-sight velocity dispersion of 164+/-10 km/s in a region 30-60 kpc from
the central nucleus. A gradient in the line-of-sight velocity of 150+/-70 km/s
is found across the 60 kpc image of the cluster core. Turbulent pressure
support in the gas is 4% or less of the thermodynamic pressure, with large
scale shear at most doubling that estimate. We infer that total cluster masses
determined from hydrostatic equilibrium in the central regions need little
correction for turbulent pressure.Comment: 31 pages, 11 Figs, published in Nature July
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