Da-Chuan Yin, Nobuko I. Wakayama, Hui-Meng Lu, Ya-Jing Ye, Hai-Sheng Li, Hui-Min Luo, Yuko Inatomi
CRYSTAL RESEARCH AND TECHNOLOGY 43(4) 447-454 2008年4月 査読有り
The reproducibility of biomacromolecular crystallization (tetragonal and orthorhombic lysozyme crystals) was studied by monitoring the evolution of protein concentration during the crystallization process using Mach-Zehnder interferometer. It was found that formation of both tetragonal and orthorhombic crystals exhibited poor reproducibility. When the crystallization occurred under isothermal conditions, the protein concentration in the solution varied differently in different experiments under identical conditions (for both types of crystals). Moreover, in the case of orthorhombic lysozyme crystallization (under either isothermal or thermal gradient conditions), it is clear that the crystals could not be always readily formed. When formation of tetragonal lysozyme crystals was conducted at a temperature gradient condition, however, the evolution of concentration was reproducible. The phenomena found in this study revealed that biomacromolecular crystallization can be uncertain, which is probably caused by the process of nucleation. Such uncertainties will be harmful for the efforts of screening crystallization conditions for biomacromolecules. (C) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Y. Inatomi, K. Iwamoto, T. Maki, Y. Takagi, K. Kuribayashi
Journal of the Japan Society of Microgravity Application 25 579-582 2008年 査読有り
In situ observation experiments of faceted cellular growth will be carried out in transparent organic alloy, salolt-butyl alcohol in microgravity conditions using a sounding rocket and the International Space Station. The growth rate and the profiles of temperature and solute concentration in the vicinity of the solid-liquid interface will be simultaneously measured by microscopic interferometers in order to evaluate the morphological instability taking account of released latent heat in faceting material.
MULTISCALE AND FUNCTIONALLY GRADED MATERIALS 973 482-487 2008年 査読有り
It has been shown by numerical simulations and by analysis of crystals that buoyancy convection in liquid might be suppressed at a particular rotation rate on a centrifuge. In the present study a damping effect that the Coriolis force has on buoyancy convection in low Prandtl number on a centrifuge was numerically analyzed under the condition of a free-swinging configuration. It is shown that the nondimensional angular velocity characterizes the minimum value of the flow velocity.
International Astronautical Federation - 58th International Astronautical Congress 2007 1 495-500 2007年 査読有り
This paper proposes a new micro gravity experimental system called BOV (Balloon-based Operation Vehicle). BOV uses a free-fall capsule with double-shell structure to prevent influence of aerodynamic disturbance. Additionally, BOV is raised to 40km by a high altitude balloon to extend micro gravity duration to 30(or possibly 60) seconds. Thus we realize a medium duration micro gravity system with good micro gravity environment. In this system, the most characteristic point is double-shell structure. The inner shell can fall freely since the outer shell measures the relative position with laser displacement sensors and is controlled by gas-jet thrusters not to collide the inner shell. Therefore the inner shell can be uninfluenced of the dynamic pressure and other aerodynamic disturbances ideally. The BOVs project has run since 2004. The first flight to check the whole system was accomplished in 2006. The aim of this flight was test of a high altitude balloon, communication and data handling system, control system, onboard electronics and operation. The second flight expected to achieve 30 seconds micro gravity was also accomplished on May in 2007. This paper presents the development of BOV's control system and shows the experimental results of micro gravity and consideration for effectiveness of the proposed system. Copyright 2007 by the IAF or the IAA. All rights reserved.
JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS 45(6A) 5274-5276 2006年6月 査読有り
The analysis of isotope ratio in a material consisting of a single element was developed as a fundamental technique to determine a self-diffusion coefficient in a melt based on time-of-flight secondary mass spectrometry (TOF-SIMS). The self-diffusion coefficient for a pure Ge melt was measured using the stable isotope 73 Ge as a tracer under a homogeneous static magnetic field in order to evaluate the influence of thermal convection upon isotope distribution. The results obtained showed that the magnetohydrodynamic effect in the melt obviously damped the convection, but it was not strong enough for the self-diffusion measurement.
MICROGRAVITY SCIENCE AND TECHNOLOGY 16(1-4) 104-106 2005年3月 査読有り
We carried out several analytical studies in order to determine the butanol distribution on a salol-butanol crystal. This work is required for a research using microgravity condition focused upon the in-situ observation with an interferometer of the temperature and concentration field for the organic transparent crystal (salol-butanol). In order to evaluate the concentration field for the liquid phase with an interferometer in case of crystal growth from solution in space, it is significant to determine the distribution of solute (butanol) on starting crystal before sample launching using a non-destructive analytical method. The Micro Raman Spectroscopy (MRS) was choice as the most appropriate analytical method among several analytical methods. We prepared a salol-butanol crystal enclosed into the 1mm thick quartz glass ampoule in order to verify the propriety for MRS. Obtained Raman spectrums for salol, butanol and salol-butanol crystal show that the butanol 2D-distribution on salol-butanol crystal can be determined by MRS. These results also demonstrate that there are no influences of thick glass cell upon measurements and that 3D-measurement is possible. In conclusion, we argue that MRS is the most appropriate method for determination of the 2D- and/or 3D-distribution of solute on the crystal among several non-destructive analytical methods.
Yue Wang, Katsuaki Kudo, Yuko Inatomi, Rongbin Ji, Tetsuichi Motegi
JOURNAL OF CRYSTAL GROWTH 275(1-2) E1551-E1556 2005年2月 査読有り
CdZnTe single crystal has been grown on CdTe substrate from Te solution with a traveling heater method under uniform static magnetic induction of 3 T. The growth experiments were carried out with growth rate of 4-10 mm/day and with temperature of 700-800 degrees C: The experimental results indicated that applying 3 T obviously improved the morphology of the growth interface in the crystal because of damping effect of the Lorentz force in Te solution, and that improvement of growth interface was beneficial to improve crystal micro-structure of CdZnTe. (C) 2004 Elsevier B. V. All rights reserved.
Crystal Research and Technology 38(7-8) 535-541 2003年 査読有り
Morphological stability of solid/liquid interface in semiconductor crystal growth from solution has been investigated using a near-infrared microscopic interferometer under a reduced convection condition by authors and Prof. Benz's group. In the result, step kinetic coefficient of the interface of GaP/GaP(111)B in liquid phase epitaxy growth was obtained and the estimated value of macrostep wavelength agreed well with the measured one.
D. C. Yin, Y. Inatomi, N. I. Wakayama, W. D. Huang
Crystal Research and Technology 38(9) 785-792 2003年 査読有り
This paper reports the measurement of temperature and concentration dependences of the refractive index of hen-egg-white lysozyme (HEWL) solution, and the temperature dependence of refractive index of the quartz container, which are indispensable for the efforts to measure HEWL concentration of the solution during the processes like crystal growth and dissolution using interferometer. As all of these dependences might be different under different observation wavelengths, temperatures and solution compositions, it is necessary to measure them for specific conditions. In this paper, the desired dependences were measured without knowing the actual value of the refractive index. The measurement method was introduced and the measurement experiments were undertaken at wavelength 780nm. The dependences obtained will be also useful for those studies employing the same wavelength and solution conditions.
The diffusivity of lysozyme molecules was deduced to decrease under a magnetic field, based on the discovery of magnetic damping of the dissolution process using a Mach-Zehnder interferometer. In the same experiment, a redistribution of the concentration before crystal growth was also found.
Japanese Journal of Applied Physics, Part 2: Letters 41(7 A) L811-L813 2002年7月1日 査読有り
Temperature dependence of interdiffusion coefficient of In-Sn was measured by a capillary method under a static magnetic field. The obtained diffusion coefficient data agreed well with data measured in microgravity environment at a lower temperature range. The application of static magnetic field could be a good substitute method for accurate measurement of diffusion coefficients in substitution for utilization of the microgravity environment.
Yuko Inatomi, Ayako Kato, Kengo Horiuchi, Aki Takada, Kazuhiko Kuribayashi
Materials Transactions, JIM 41(8) 1026-1033 2000年8月 査読有り
A formulation of the relation between static magnetic induction and Reynolds number in liquid, for vertical Bridgman and LPE growth processes of semiconductors in axial static magnetic field was derived based on a scaling analysis, and the validity of the estimation was experimentally investigated. The calculated values of the effective segregation coefficients for Ga-doped Ge and Pb1-xSnx Te crystals grown by the Bridgman method agreed well with the experimentally measured ones from 0 to 6 T of the magnetic induction. In the case of LPE growth on GaP(111)B, nearly diffusion-controlled condition in the liquid was achieved at 6 T. It was shown by in situ observation using a near-infrared (NIR) microscopic interferometer that the static magnetic reduced the LPE growth rate, and as a result, suppressed appearance of macro-steps and hillocks.
M. Arivanandhan, Y. Inatomi, Y. Hayakawa (担当:共著, 範囲:Compositionally homogeneous Si1-xGex and Mg2Si1-xGex bulk crystals for thermoelectric applications)
The 3rd Japan-France International Symposium on Space Nutrition/Medicine 2023年11月13日 Space Nutrition Course at Institute of Medical Nutrition, Tokushima University Graduate School 招待有り
Two conductive solid materials with their respective different compositions are joined in parallel with a gravity direction thereof, and then, heated and melted under static magnetic field orthogonal to the gravity direction to form two conductive melts with their respective different compositions. Then, the conductive melts are maintained for a predetermined period of time under the static magnetic field, and cooled and solidified.