http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
TOTANI, TOMONORI The Korean Astronomical Society 2015 天文學論叢 Vol.30 No.2
The FastSound project is a galaxy redshift survey using Subaru/FMOS to detect $H{\alpha}$ emitting galaxies at z ~ 1:3, for the purpose of probing the origin of the accelerated expansion of the universe. The survey has detected ~4,000 galaxy redshifts in a total area of $30deg^2$, and detected the redshift space distortion at this redshift range for the first time. The redshift space distortion (RSD) signal will be used to derive a measurement of the growth rate of large scale structure, which will provide a test for modified gravity as a possible origin of accelerated cosmic explansion. Here we present an overview and the current status of the project.
Makiya, R.,Totani, T.,Takeuchi, T.T.,Nagashima, M.,Kobayashi, M.A.R. The Korean Astronomical Society 2012 天文學論叢 Vol.27 No.4
We will report our recent study on the properties of more than 1,600 galaxies detected by the AKARI All-Sky Survey with physical quantities based on optical and 21-cm observations, to understand the physics determining the infrared spectral energy distribution (Totani et al., 2011). We discover a tight linear correlation for normal star-forming galaxies between the radiation field strength of dust heating (corresponding to dust temperature) and the galactic-scale infrared radiation field, $L_{TIR}/R^2$. This is the tightest correlation of dust temperature ever known, and the dispersion along the mean relation is 13% in dust temperature. This relation can be explained physically by a thin layer of heating sources embedded in a thicker, optically-thick dust screen. We also find that the number of galaxies sharply drops when galaxies become optically thin against dust-heating radiation, indicating that a feedback process to galaxy formation (e.g., by the photoelectric heating) is working when dust-heating radiation is not self-shielded on a galactic scale. We discuss implications from these findings for the $M_{H_I}$ -size relation, the Kennicutt-Schmidt relation, and galaxy formation in the cosmological context.
A CLUSTER SURVEY AROUND THE UNIDENTIFIED EGRET SOURCES
KAWASAKI WATARU,TOTANI TOMONORI The Korean Astronomical Society 2005 Journal of The Korean Astronomical Society Vol.38 No.2
Based on optical galaxy data, we executed a systematic search for galaxy clusters around the 15 steady unidentified EGRET GeV gamma-ray sources in high Galactic-latitude sky ([b] > $30^{\circ}$). We found a strong correlation with 3.7$\sigma$ level between close cluster pairs (merging cluster candidates) and the unidentified EGRET sources, though, in contrast, no correlation with single clusters. This result implies that merging clusters of galaxies are a possible candidate for the origin of high galactic-latitude, steady unidentified EGRET gamma-ray sources.
Cell Patterning on a Poly(2-hydroxyethyl methacrylate) Film Based on Interfacial Dynamics
Kento Kawabata,Masayasu Totani,Hisao Matsuno,Keiji Tanaka 한국고분자학회 2021 한국고분자학회 학술대회 연구논문 초록집 Vol.46 No.2
Thermal molecular motion in the outermost region of polymer films strongly impact on various material functions. Here we propose a novel concept for the two-dimensional (2D) regulation of chain dynamics at the water interface based on the introduction of silica nanoparticles (SiNP) into a polymer film, leading to the 2D-patterning of the fibroblast adhesion. A poly(2-hydroxyethyl methacrylate) (PHEMA) film was prepared on an SiNP line-patterned substrate. While X-ray photoelectron spectroscopic imaging confirmed that a whole outermost region of the film was fully covered with a single PHEMA component, atomic force microscopy-assisted force-distance curve measurements in water revealed that there were regions with different mechanical properties, that is, different interfacial dynamics, depending on the SiNP lines in the vicinity. On such a film, NIH3T3 cells showed heterogeneous adhesion and aggregates formation depending on the 2D-patterend interfacial dynamics.
Accuracy and applicable range of a reconstruction technique for hybrid rockets
Nagata, Harunori,Nakayama, Hisahiro,Watanabe, Mikio,Wakita, Masashi,Totani, Tsuyoshi Techno-Press 2014 Advances in aircraft and spacecraft science Vol.1 No.3
Accuracy of a reconstruction technique assuming a constant characteristic exhaust velocity ($c^*$) efficiency for reducing hybrid rocket firing test data was examined experimentally. To avoid the difficulty arising from a number of complex chemical equilibrium calculations, a simple approximate expression of theoretical $c^*$ as a function of the oxidizer to fuel ratio (${\xi}$) and the chamber pressure was developed. A series of static firing tests with the same test conditions except burning duration revealed that the error in the calculated fuel consumption decreases with increasing firing duration, showing that the error mainly comes from the ignition and shutdown transients. The present reconstruction technique obtains ${\xi}$ by solving an equation between theoretical and experimental $c^*$ values. A difficulty arises when multiple solutions of ${\xi}$ exists. In the PMMA-LOX combination, a ${\xi}$ range of 0.6 to 1.0 corresponds to this case. The definition of $c^*$ efficiency necessary to be used in this reconstruction technique is different from a $c^*$ efficiency obtained by a general method. Because the $c^*$ efficiency obtained by average chamber pressure and ${\xi}$ includes the $c^*$ loss due to the ${\xi}$ shift, it can be below unity even when the combustion gas keeps complete mixing and chemical equilibrium during the entire period of a firing. Therefore, the $c^*$ efficiency obtained in the present reconstruction technique is superior to the $c^*$ efficiency obtained by the general method to evaluate the degree of completion of the mixing and chemical reaction in the combustion chamber.
Hanako Tauchi,Chikahiro Imashiro,Taiki Kuribara,Genichiro Fujii,Yuta Kurashina,Kiichiro Totani,KenjiroTakemura 한국생물공학회 2019 Biotechnology and Bioprocess Engineering Vol.24 No.3
Bioengineering research and applications are supported by cell culture technologies that produce a large number of homogeneous cells. However, trypsin used in the general culture procedure for cell detachment decreases cell activity and culture efficiency. Furthermore, manually conducted culture procedures, especially pipetting after trypsin treatment, can induce inhomogeneous mechanical stress in cells, which may influence cellular functions. Alternate detachment methods using specialized culture devices without trypsin and/or manual pipetting have been reported. However, conventional trypsinization is still widely used. Diluted trypsin increases culture efficiency. Therefore, we developed a cell-detaching method using diluted trypsin and ultrasonic vibration for cell detachment from ubiquitous culture vessels. To demonstrate our concept, we used a T25 flask. Vibration of the culture surface was excited by ultrasonic waves propagated from an ultrasonic transducer placed under the flask. Using the proposed method, cells were completely detached by diluted trypsin, whereas 8.6% of cells remained on the flask with manual pipetting. The viability and proliferation of cells detached by the proposed method were higher than those of cells detached by the conventional method, owing to the low concentration of trypsin. Furthermore, glucose consumption after detachment showed no abnormality, eliminating possible oncogenesis. Two membrane proteins were quantified immediately after detachment and at 24 h of culture, and there were no differences between the detachment methods. Thus, we conclude that our proposed method improves culture efficiency without any adverse effects and ensures homogeneous mechanical stress on cells.
Investigation of axial-injection end-burning hybrid rocket motor regression
Saito, Yuji,Yokoi, Toshiki,Neumann, Lukas,Yasukochi, Hiroyuki,Soeda, Kentaro,Totani, Tsuyoshi,Wakita, Masashi,Nagata, Harunori Techno-Press 2017 Advances in aircraft and spacecraft science Vol.4 No.3
The axial-injection end-burning hybrid rocket proposed twenty years ago by the authors recently recaptured the attention of researchers for its virtues such as no ${\zeta}$ (oxidizer to fuel mass ratio) shift during firing and good throttling characteristics. This paper is the first report verifying these virtues using a laboratory scale motor. There are several requirements for realizing this type of hybrid rocket: 1) high fuel filling rate for obtaining an optimal ${\zeta}$; 2) small port intervals for increasing port merging rate; 3) ports arrayed across the entire fuel section. Because these requirements could not be satisfied by common manufacturing methods, no previous researchers have conducted experiments with this kind of hybrid rocket. Recent advances in high accuracy 3D printing now allow for fuel to be produced that meets these three requirements. The fuel grains used in this study were produced by a high precision light polymerized 3D printer. Each grain consisted of an array of 0.3 mm diameter ports for a fuel filling rate of 98% .The authors conducted several firing tests with various oxidizer mass flow rates and chamber pressures, and analysed the results, including ${\zeta}$ history, using a new reconstruction technique. The results show that ${\zeta}$ remains almost constant throughout tests of varying oxidizer mass flow rates, and that regression rate in the axial direction is a nearly linear function of chamber pressure with a pressure exponent of 0.996.