Suzaku observations of subhalos in the Coma cluster

We observed three massive subhalos in the Coma cluster with {\it Suzaku}. These subhalos, labeled "ID 1", "ID 2", and "ID 32", were detected with a weak-lensing survey using the Subaru/Suprime-Cam (Okabe et al. 2014a), and are located at the projected distances of 1.4 $r_{500}$, 1.2 $r_{500}$, and 1.6 $r_{500}$ from the center of the Coma cluster, respectively. The subhalo "ID 1" has a compact X-ray excess emission close to the center of the weak-lensing mass contour, and the gas mass to weak-lensing mass ratio is about 0.001. The temperature of the emission is about 3 keV, which is slightly lower than that of the surrounding intracluster medium (ICM) and that expected for the temperature vs. mass relation of clusters of galaxies. The subhalo "ID 32" shows an excess emission whose peak is shifted toward the opposite direction from the center of the Coma cluster. The gas mass to weak-lensing mass ratio is also about 0.001, which is significantly smaller than regular galaxy groups. The temperature of the excess is about 0.5 keV and significantly lower than that of the surrounding ICM and far from the temperature vs. mass relation of clusters. However, there is no significant excess X-ray emission in the "ID 2" subhalo. Assuming an infall velocity of about 2000 $\rm km~s^{-1}$, at the border of the excess X-ray emission, the ram pressures for "ID 1" and "ID 32" are comparable to the gravitational restoring force per area. We also studied the effect of the Kelvin-Helmholtz instability to strip the gas. Although we found X-ray clumps associated with the weak-lensing subhalos, their X-ray luminosities are much lower than the total ICM luminosity in the cluster outskirts.Comment: 19 pages, 8 figures, ApJ in pres

The Use of Titanium in Dentistry

The aerospace, energy, and chemical industries have benefitted from favorable applications of titanium and titanium alloys since the 1950\u27s. Only about 15 years ago, researchers began investigating titanium as a material with the potential for various uses in the dental field, mainly because of its proven biocompatibility and other attractive properties. The present review examines updated information on the use of titanium in a major area of dentistry. Titanium-based alloys used for casting, casting equipment and procedures, casting investment materials, and porcelain veneering are discussed. Information about advances made in techniques other than casting, which could widen the applications of this metal to dentistry, is also included

グリッドコンピューティングを用いたボリュームレンダリング手法の開発

平成18年度電気・情報関連学会中国支部第57回連合大会資料 岡山理科大学, 岡山 (2006 10

Visualization Technique based on Grid Computing for Large-scale Volume-data

情報処理学会研究報告 グラフィクスとCAD研究会 2007.0

Visualization Technique based on Grid Computing for Large-scale Volume-data

近年, 高解像度化の進むCTやMRIから出力されるボリュームデータを,高精度にかつ高速に可視化するため,本研究ではグリッドコンピューティングを用いてボリュームレンダリングを行う手法を提案する.医療施設や研究機関に多数導入されている計算機を計算資源とするグリッドコンピューティングを用いる.計算能力の不均一な環境下において,可視性に基づき動的にタスクの投入を行うための手法を提案し,シミュレーションによりその有用性を確認した.提案手法をインプリメントし,グリッドコンピューティングを用いて大規模ボリュームデータのレンダリングを行った.To visualize high-resolution volumedata acquired from a recent CT or MRI, we propose a method for rendering the large-scale volume data using a grid computing. We use existing computers with non-homogeneous computing tasks to agent machines based on the visibility of divided volume data in a grid computing environment. Simulation results demonstrate the usefulness of the propose method. A large scale volumedata is rendered using our grid computing system

Volume rendering using grid computing for large-scale volume data

In this paper, we propose a volume rendering method using grid computing for large-scale volume data. Grid computing is attractive because medical institutions and research facilities often have a large number of idle computers. A large-scale volume data is divided into sub-volumes and the sub-volumes are rendered using grid computing. When using grid computing, different computers rarely have the same processor speeds. Thus the return order of results rarely matches the sending order. However order is vital when combining results to create a final image. Job-Scheduling is important in grid computing for volume rendering, so we use an obstacle-flag which changes priorities dynamically to manage sub-volume results. Obstacle-Flags manage visibility of each sub-volume when line of sight from the view point is obscured by other sub-volumes. The proposed Dynamic Job-Scheduling based on visibility substantially increases efficiency. Our Dynamic Job-Scheduling method was implemented on our university's campus grid and we conducted comparative experiments, which showed that the proposed method provides significant improvements in efficiency for large-scale volume rendering

ショウエネルギー ニジュウ ハンテンケイ コガタ ジクリュウ ファン ノ ナイブ ナガレ ト コウセイノウ セッケイ ニ カンスル ケンキュウ

Small-sized axial fans are used as air cooler for electric equipments. But there is a strong demand for higher power of fan according to the increase of quantity of heat from electric devices. Therefore, higher rotational speed design is conducted although, it causes the deterioration of efficiency and the increase of noise. Then the adoption of contra-rotating rotors for small-sized fan was proposed for the improvement of performance. In the present paper, the performance and internal flow condition of a small-sized axial fan with 100mm diameter are shown as a first step of the research for the contra-rotating small-sized axial fan and the similarity law of this small-sized axial fan is discussed. Furthermore, the numerical flow simulation was conducted to investigate the performance of the contra-rotating small-sized axial fan and internal flow field and pressure distributions were clarified and the effect of contra-rotating rotors would be considered

Suzaku observations of the Hydra A cluster out to the virial radius

We report Suzaku observations of the northern half of the Hydra A cluster out to ~1.4 Mpc, reaching the virial radius. This is the first Suzaku observations of a medium-size (kT ~3 keV) cluster out to the virial radius. Two observations were conducted, north-west and north-east offsets, which continue in a filament direction and a void direction of the large-scale structure of the Universe, respectively. The X-ray emission and distribution of galaxies elongate in the filament direction. The temperature profiles in the two directions are mostly consistent with each other within the error bars and drop to 1.5 keV at 1.5 r_500. As observed by Suzaku in hot clusters, the entropy profile becomes flatter beyond r_500, in disagreement with the r^1.1 relationship that is expected from accretion shock heating models. When scaled with the average intracluster medium (ICM) temperature, the entropy profiles of clusters observed with Suzaku are universal and do not depend on system mass. The hydrostatic mass values in the void and filament directions are in good agreement, and the Navarro, Frenk, and White universal mass profile represents the hydrostatic mass distribution up to ~ 2 r_500. Beyond r_500, the ratio of gas mass to hydrostatic mass exceeds the result of the Wilkinson microwave anisotropy probe, and at r_100, these ratios in the filament and void directions reach 0.4 and 0.3, respectively. We discuss possible deviations from hydrostatic equilibrium at cluster outskirts. We derived radial profiles of the gasmass- to-light ratio and iron-mass-to-light ratio out to the virial radius. Within r_500, the iron-mass-to-light ratio of the Hydra A cluster was compared with those in other clusters observed with Suzaku.Comment: 16 pages, 15 figures; Accepted for publication in PAS

Correlation of cytotoxicity with elemental release from mercury- and gallium-based dental alloys in vitro

Objectives. An in vitro screening test was used to compare the cytotoxicity and elemental release from mercury- and gallium-based dental restorative materials. Methods. The test employed three sequential extractions of the samples into cell-culture medium which were then used to evaluate the cytotoxicity of the samples and the release of elements from the samples. Cytotoxicity was measured by placing the extract in contact with Balb/c mouse fibroblasts for 24 h and measuring the succinic dehydrogenase activity of the cells. The release of elements was measured by means of atomic absorption spectrophotometry. Results. Samples of Tytin (Kerr) showed no cytotoxicity compared to Teflon controls. Dispersalloy (Johnson and Johnson) was severely cytotoxic initially when Zn release was greatest, but was less toxic between 48 and 72 h as Zn release decreased. Gallium Alloy GF (Tokuriki Honten) was moderately cytotoxic after 8 h, and increased in cytotoxicity thereafter, which correlated with a substantial and persistent release of Ga from this material. Significance. The results of the current study concurred with in vivo assessments of these materials, and the use of sequential extractions was useful in determining trends in the cytotoxicity and elemental release from these materials.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31360/1/0000272.pd