Country：Japan

Country：Japan

Country：Japan

Authorship：Lead author,　Last author,　Corresponding author   Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s11663-022-02691-3

Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.ultsonch.2022.106209

Publishing type：Research paper (scientific journal)  

DOI： 10.3390/ma15217836

Publishing type：Research paper (scientific journal)  

DOI： 10.3390/catal12121491

Publishing type：Research paper (scientific journal)  

DOI： 10.1021/acsami.2c13189

Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.jallcom.2022.165128

Publishing type：Research paper (scientific journal)  

Authorship：Lead author,　Last author   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s11837-022-05440-8

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s11663-022-02553-y

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)  

Aiming at reducing energy consumptions in data writing, the development of new memory materials is highly required. To develop new phase change materials (PCMs) with extremely low operation energy used in non-volatile memory, such as storage-class memory, we performed Bayesian optimization for the physical properties of PCMs through numerical simulations. In this numerical simulation, the electrical potential and temperature distribution were solved simultaneously. It was found that a PCM with low thermal conductivity, low melting temperature, and low ratio of contact resistance to volumetric resistance results in a low operation energy of a PCM-based memory application. Finally, we developed a design strategy for PCMs. New PCMs should be developed by lowering the operation energy E, described as E = κ(1 + C)ΔT/Δz, where κ is the thermal conductivity of the PCM, ΔT is the melting temperature, C is the ratio of contact resistance to the volumetric resistance, and Δz is the thickness of the PCM. The present results clarify the relationship between thermal and electrical properties for lowering operation energy ever hidden in previous studies. According to the design strategy, an operation energy in phase change memory application can be decreased to less than 1/100 compared with conventional Ge-Sb-Te compounds.

DOI： 10.1016/j.matdes.2022.110560

Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.ultsonch.2022.105941

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s11837-021-04906-5

Other URL： https://link.springer.com/article/10.1007/s11837-021-04906-5/fulltext.html

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s11663-021-02320-5

Other URL： https://link.springer.com/article/10.1007/s11663-021-02320-5/fulltext.html

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)  

To evaluate the Thomson effect on the temperature increase in Ge2Sb2Te5 (GST)-based phase-change random access memory (PCRAM), we created new dimensionless numbers based on Buckingham's Pi theorem. The influence of the Thomson effect on the temperature increase depends on the dominant factor of electrical resistance in a PCRAM cell. When the effect is dominated by the volumetric resistance of the phase-change material (C = rho(c)/Delta(x)/sigma << O(1)), the dimensionless evaluation number is B = mu(T)sigma Delta phi/k, where rho(c) is the contact resistance, Delta x is the thickness of PCM, sigma and k are the electrical k and thermal conductivities, mu(T) is the Thomson coefficient, and Delta phi is the voltage. When the contact resistance cannot be ignored, the evaluation number is B/(1 + C). The characteristics of hexagonal-type crystalline GST in a PCRAM cell were numerically investigated using the defined dimensionless parameters. Although the contact resistance of GST exceeded the volumetric resistance across the temperature range, the ratio of contact resistance to the whole resistance reduced with increasing temperature. Moreover, increasing the temperature of GST enhanced the influence of the Thomson effect on the temperature distribution. At high temperatures, the Thomson effect suppressed the temperature increase by approximately 10%-20%.

DOI： 10.1088/2053-1591/ac3953

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.ultsonch.2021.105734

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s11663-021-02265-9

Other URL： https://link.springer.com/article/10.1007/s11663-021-02265-9/fulltext.html

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.jmatprotec.2021.117116

Publishing type：Research paper (scientific journal)  

The present study addresses the incorporation of fine particles into liquids via the creation of a large-scale swirling vortex on the liquid free surface using a rotary impeller positioned along the axis of a cylindrical vessel. Four types of particles are used in the experiments to investigate the incorporation efficiency of the particles into a water bath under different impeller rotation speeds. Additionally, the vortex characteristics are investigated numerically. The results reveal that two factors, namely the particle wettability and turbulent oscillations at the bottom part of vortex surface, play dominant roles in determining the particle incorporation behavior. Hydrophobic particles are incapable of being incorporated into the water bath under any of the conditions examined in the present study. Partly wettable particles are entrained into the water bath, with the efficiency increasing with the impeller rotation speed and particle size. This is because an increase in the impeller rotation speed causes vortex deformation, whereby its bottom part approaches the impeller blades where the turbulent surface oscillations reach maximum amplitudes. Another possible mechanism of particle incorporation is the effect of capillary increases of liquid into the spaces between particles, which accumulate on the bottom surface of the vortex.

DOI： 10.3390/ma14112710

Publishing type：Research paper (scientific journal)  

InxGa1-xSe mixed crystals have been successfully grown from an indium flux by the traveling heater method at three growth temperatures. The thickness of the grown InxGa1-xSe mixed crystal perpendicular to (001) was more than 3 mm. The lattice constant, and optical and electrical properties of the InxGa1-xSe mixed crystals and undoped GaSe crystals were investigated and compared. The indium content of the InxGa1-xSe mixed crystals was observed to increase with decreasing growth temperature, while the lattice constant along the c-axis was observed to follow Vegard's law. It was confirmed that a bandgap of In0.020Ga0.980Se is narrower than that of undoped GaSe according to the photoluminescence (PL) spectra. Compared with undoped GaSe crystal, the carrier concentration p was decreased by the incorporation of indium (In0.020Ga0.980Se, p = 6.4 x 10(14) cm(-3) at 257 K; In0.037Ga0.963Se, p = 2.6 x 10(14) cm(-3) at 257 K). In addition, it was suggested that the dominant carrier scattering mechanism of high-indium-content crystals at low temperature is ionized impurity scattering.

DOI： 10.1007/s11664-020-08689-4

Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.jallcom.2020.158231

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.ultsonch.2020.105381

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.ultsonch.2020.105387

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)  

DOI： 10.1063/5.0017175

Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.ultsonch.2020.105236

Publishing type：Research paper (scientific journal)  

The growth rate of crystalline GaSe from solution was increased by using indium as a solvent. The solubility and concentration gradient of Se were measured using differential scanning calorimetry (DSC). The Se solubility and the temperature coefficient of the solubility were respectively 15 times and 2.2 times greater in crystals grown from an In flux with GaSe at saturation compared with the case of Se dissolved in a Ga flux. In this study, we succeeded in growing InxGa1-xSe ingots from an In flux without the need for a seed crystal, and in increasing the growth rate of GaSe from solution. In addition, we used difference frequency generation to generate THz waves (with a frequency of 9.7 THz) in an InxGa1-xSe mixed crystal and investigated the relationship between the output energy of the THz radiation and the interaction length of the excitation light. The conversion efficiency of THz wave (9.7 THz) from the InxGa1-xSe mixed crystal with thickness of 860 mu m was 26 times greater than that of GaSe crystal with thickness 100 mu m grown from Ga solvent.

DOI： 10.1088/2399-6528/ab983d

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s11663-020-01842-8

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.ultsonch.2019.104874

Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

We demonstrate the generation of THz waves (frequency 9.7 THz) using difference frequency generation in an InxGa1-xSe mixed crystal grown from In flux. The amount of indium and the lattice constant of the crystal were evaluated using electron micro probe analysis and X-ray diffraction, respectively. We believe that the Ga sites were substituted by In atoms in the InxGa1-xSe crystal because the In content, estimated according to the Vegard's law, was similar to that measured by EPMA. The maximum power of the generated THz wave was 39 pJ and the conversion efficiency was 1.7×10-5 J-1. This conversion efficiency was 28 times larger than that reported for undoped GaSe crystal.

DOI： 10.1364/OE.28.000472

PubMed

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)  

DOI： 10.1080/13640461.2019.1690417

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s11663-019-01681-2

Publishing type：Research paper (scientific journal)  

DOI： 10.3390/ma12213532

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)  

DOI： 10.2320/matertrans.M2019055

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.ultsonch.2019.104684

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.ces.2019.07.019

Publishing type：Research paper (scientific journal)  

DOI： 10.1002/crat.201900014

Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.ultsonch.2018.12.003

Publishing type：Research paper (scientific journal)  

In order to determine the optimum heating rate for the planned microgravity experiments on the International Space Station (ISS), axisymmetric 2D numerical simulations were performed under the zero-gravity condition to investigate the effect of heating rate on the dissolution process of the seed and feed crystals in a sandwich system of InGaSb. The simulation results showed that the dissolution lengths of the seed and feed crystals are strongly affected by heating rate. A higher heating rate leads to larger feed and seed dissolutions. Simulation results suggest that the microgravity experiments on the ISS should not adopt a heating rate higher than 3.6 K/h in order to avoid a complete dissolution of the feed and/or seed crystals in this sandwich system.

DOI： 10.1007/s12217-019-9698-x

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.cej.2019.02.130

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.ces.2018.12.007

Publishing type：Research paper (scientific journal)  

Aiming at improving the efficiency of cavitation treatment, this work investigates characteristics of acoustic streaming and cavitation generated in water by dumbbell-shaped sonotrodes with plane, truncated and conical tips. The main emphasis was placed on elucidating the effects of tip shape and vibration amplitude ranged from 40 to 60 μm. The PIV technique and Weissler reaction were used to measure flow pattern and velocity of acoustic streaming, and cavitation efficiency, respectively. To provide a theoretical explanation to the experimental results, a self-developed mathematical model was used to simulate the acoustic streaming and predict the size of cavitation zone numerically. Both the experimental and numerical results revealed that the sonotrode tip shape affects the acoustic streaming significantly, altering the flow magnitude and direction from fast and downward under the plane and truncated tips to relatively slow and upward near the conical tip. Besides, the conical tip provides a more efficient cavitation treatment in comparison with the plane and truncated tips. The simulation results showed that widening of cavitation zone and altering of acoustic streaming velocity and direction near the sonotrode tip are responsible for the enhancement of cavitation treatment efficiency.

DOI： 10.1016/j.ultsonch.2018.05.011

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)  

This study investigated the flow characteristics of aluminum melt agitated by differently shaped impellers. A typical impeller used in the aluminum industry has twisted blades. The present study examined the effect of twisting angle on the flow pattern through PIV experiments and numerical simulation using water model. The results revealed that the twisting angle affects the strength and direction of discharge flow. The strength of discharge flow became weaker with increasing the twisting angle while the flow direction was influenced by both the front blade surface of impeller and space interval between the adjacent blades. The structure of trailing vortices was found to be also varied depending on the impeller twisting angle.

DOI： 10.1016/j.jmatprotec.2018.06.012

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)  

In the present study, an optimized low-cost numerical model has been developed to simulate melt stirring and mass transfer in aluminum melting furnace. To validate the numerical model, scaled-down water model experiments were also conducted. The present numerical results revealed good agreement with the experimental observations. Faster speeds of impeller rotation could improve the stirring efficiency
however, a strong surface vortex was formed at the free surface under these conditions. The perfect mixing time was the longest at middle immersion depth of impeller and the strong surface vortex was generated at the largest immersion depth. The mechanism of surface vortex generation was explained in terms of pressure distribution around the blades, which is created by the impeller rotation.

DOI： 10.1016/j.jmatprotec.2018.04.025

Publishing type：Research paper (international conference proceedings)  

Ultrasonic technology has been widely investigated in the past as one of the advance oxidation processes to treat wastewater, in this process acoustic cavitation causes generation of OH radical, which play a vital role in improving the treatment efficiency. In this study, OH radical formation rate was measured in batch and circulatory reactor by using Weissler reaction at various ultrasound output power. It is found that the generation rate in batch reactor is higher than that in circulatory reactor at the same output power. The generation rate tended to be slower when output power exceeds 137W. The optimum condition for circulatory reactor was found to be 137W output and 4L/min flow rate. Results of aluminum foil erosion test revealed a strong dependence of cavitation zone length on the ultrasound output power. This is assumed to be one of the reasons why the generation rate of HO radicals becomes slower at higher output power in circulatory reactor.

DOI： 10.1088/1755-1315/120/1/012019

Authorship：Lead author   Publishing type：Research paper (scientific journal)  

A numerical simulation study was carried out to investigate the suspension of cell colonies in bioreactors of stirring and orbiting shaking tanks. The cell colonies in a culture liquid were modeled as rigid spherical solid particles. The shear stresses acting on these particles were analyzed. The simulation results have shown that the maximum shear stress acting on the particles in the stirring tank is higher than that on the particles in the orbital shaking tank. However, the average values of the shear stress on the particles in both tanks are comparable. The simulation results also show that more particles accumulate at the bottom of the orbital shaking tank in which the particle aggregation obeys the Einstein's tea leaf paradox. The simulation results are evaluated based on the predicted shear stress profiles and tank configuration.

DOI： 10.1252/jcej.17we112

Publishing type：Research paper (scientific journal)  

Marangoni convection driven by surface tension gradient plays an important role in nano-scale processes and also the processes under microgravity in space, where the effect of surface tension may become significant compared with that of the gravitational body force. For a better understanding of Marangoni convection occurring in a nano-scale process, Molecular Dynamics (MD) and Computational Fluid Dynamics (CFD) simulations were carried out for a thin liquid film with concentration gradient. The computed flow structures by these methods were compared. The results show quantitative differences in the magnitudes of the flow velocity and the deformation of the liquid film. It was also found that a stronger driving force would be needed to generate nano-scale flows compared with that required for macro-scale flows. This is due to the fact that a stronger surface force may be needed to overcome the random movements of molecules.

DOI： 10.1016/j.jtice.2018.05.015

Authorship：Lead author   Publishing type：Research paper (scientific journal)  

A numerical simulation study was carried out to examine the transport phenomena occurring during the Top-Seeded Solution Growth (TSSG) process of SiC. The simulation model includes the contributions of radiative and conductive heat transfer in the furnace, mass transfer and fluid flow in the melt, and the induced electric and magnetic fields. Results show that the induced Lorentz force is dominant in the melt compared with that of buoyancy. At the relatively low coil frequencies, the effect of the Lorentz force on the melt flow is significant, and the corresponding flow patterns loose their axisymmetry and become almost fully disturbed. However, at the relatively higher frequency values, the flow is steady and the flow patterns remain axisymmetric.

DOI： 10.1016/j.jcrysgro.2016.12.086

Authorship：Lead author   Publishing type：Research paper (scientific journal)  

A global numerical simulation was performed for the induction heating Top-Seeded Solution Growth (TSSG) process of SiC. Analysis included the furnace and growth melt. The effects of interfacial force due to free surface tension gradient, the RF coil-induced electromagnetic body force, buoyancy, melt free surface deformation, and seed rotation were examined. The simulation results showed that the contributions of free surface tension gradient and the electromagnetic body force to the melt flow are significant. Marangoni convection affects the growth process adversely by making the melt flow downward in the region under the seed crystal. This downward flow reduces carbon flux into the seed and consequently lowers growth rate. The effects of free surface deformation and seed rotation, although positive, are not so significant compared with those of free surface tension gradient and the electromagnetic body force. Due to the small size of the melt the contribution of buoyancy is also small. (C) 2017 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jcrysgro.2017.04.016

Publishing type：Research paper (scientific journal)  

InxGa1-xSb bulk crystals have been grown on the International Space Station using a GaSb (feed) / InSb / GaSb (seed) sandwich -structured sample. In order to gain a deeper insight into the transport phenomenon and the relevant fundamental mechanisms during the dissolution process of InGaSb in this system, four numerical simulations with different temperature conditions and under the assumption of zero gravity were performed by the volume -averaging continuum model. Simulation results showed the heat loss through the bottom wall did not affect the final feed/seed dissolution lengths and the grown crystal interface shape. The final dissolution lengths of the feed and seed crystals were determined by the temperature calculated along the seed interface. The results also indicate that the actual temperature of the growth ampoule should be around 3K lower than that measured on the outside the protective cartridge.

DOI： 10.15011//jasma.34.340206

Publishing type：Research paper (scientific journal)  

© 2018, Gadjah Mada University. All rights reserved. In a suspension culture of iPS cells, the shear stress generated during mixing is expected to promote differentiation of induced pluripotent stem (iPS) cells. The stress on the cells can be controlled by rotational rate and shape of impeller. However, it is difficult to optimize these operative parameters by experiments. Therefore, we have developed a numerical model to obtain the average and the maximum shear stress in two kinds of stirred tanks and an orbital shaking cylindrical container. The present results showed that the shear stress strongly depended on the type of mixing and lesser extent on the shape of the impeller. The average shear stress is larger in the shaking mode than that in the stirring mode. In contrast, the maximum shear stress is much smaller in the shaking than the stirring. These results suggest that stirring and shaking should be selectively used depending on the application.

Authorship：Lead author   Publishing type：Research paper (scientific journal)  

Three numerical methods, namely, volume of fluid (VOF), simple coupled volume of fluid with level set (S-CLSVOF), and S-CLSVOF with the density-scaled balanced continuum surface force (CSF) model, have been incorporated into OpenFOAM source code and were validated for their accuracy for three cases: (i) an isothermal static case, (ii) isothermal dynamic cases, and (iii) non-isothermal dynamic cases with thermocapillary flow including dynamic interface deformation. Results have shown that the S-CLSVOF method gives accurate results in the test cases with mild computation conditions, and the S-CLSVOF technique with the density-scaled balanced CSF model leads to accurate results in the cases of large interface deformations and large density and viscosity ratios. These show that these high accuracy methods would be appropriate to obtain accurate predictions in multiphase flow systems with thermocapillary flows. Copyright (c) 2016 John Wiley & Sons, Ltd.

DOI： 10.1002/fld.4267

Publishing type：Research paper (scientific journal)  

© 2018, Gadjah Mada University. All rights reserved. Non-equilibrium molecular dynamics simulations for the 2- and 3-phase systems were performed to investigate the flow with two free surfaces in a nanoscale, where solute, water, and argon were assigned as each phase. We observed that the behaviors of some 3-phase systems significantly differ from those of 2-phase systems. In all 2-phase systems, the solutes just diffused into the water phase. On the other hand, the solutes were transferred along the liquid-gas interfaces in the case of 3-phase systems with a large surface tension gradient. These results indicated that solutal Marangoni convection existed even in the nano-scale and it affected mass transfer greatly.

<p>InGaSb crystals have been grown on the International Space Station using a GaSb (feed) / InSb / GaSb (seed) sandwich-structured sample. To shed light on the experimental results, numerical simulations were carried out to investigate the transport phenomena and mechanisms during the dissolution process of InGaSb crystal under zero-gravity. Simulation results showed that the dissolution lengths of feed and seed crystals were determined by the temperature along the seed interface. The results also indicate a 3 K temperature difference between the inside growth ampoule and the outside cartridge.</p>

DOI： 10.11345/japannctam.64.0_OS7-05

CiNii Article

Authorship：Lead author   Publishing type：Research paper (scientific journal)  

NASA astronaut Pettit has conducted thermocapillary flow experiments in water films suspended in a solid ring onboard the International Space Station (ISS) in 2003 and 2011. In one of these experiments, an oscillatory thermocapillary flow was observed. The developed flow broke its symmetry along the centerline of the film. To the best of our knowledge, there are no studies on such oscillatory thermocapillary flows in thin films, and the flow-mechanism giving rise to such oscillatory flows is also not well understood. In order to shed light on the subject, we have carried out a numerical simulation study. The simulation results have shown that the water film geometry (film surface shape; being concave) is an important parameter and give rise to three oscillatory flow structures in the film, namely, a hydrothermal wave developing near the heated section, a symmetric oscillatory flow due to temperature variations, and a symmetry breaking flow due to the hydrodynamic instability along the free boundary layer (mixing layer) and the development of the hydrothermal waves. Simulation results show that the symmetry-breaking phenomenon observed in the thin film experiment on the ISS can be explained by the hydrodynamic instability and the development of hydrothermal waves. (C) 2016 AIP Publishing LLC.

DOI： 10.1063/1.4943246

Publishing type：Research paper (international conference proceedings)   International / domestic magazine：International journal  

InxGa1−xSb bulk crystal was grown using a GaSb (seed)/InSb/GaSb (feed) sandwich-structured system onboard the International Space Station (ISS). In order to investigate the transport phenomena especially in terms of interface shapes and dissolution heights, the dissolution process was simulated under a micro-gravity level of the ISS. Simulation results showed that the seed/melt interface was concave towards the seed due to the temperature distribution of the system. This prediction is in good agreement with the results of our previous experimental study.

DOI： 10.7567/JJAPCP.4.011107

Publishing type：Research paper (scientific journal)  

DOI： 10.15011/jasma.33.330309

Authorship：Lead author   Publishing type：Research paper (scientific journal)  

The volume-averaging continuum technique has been utilized to obtain numerical predictions for the transport phenomena occurring during the dissolution process of GaSb into InSb melt in a sandwich system. Dissolution and subsequent growth in this system are achieved by the application of a temperature gradient. The developed model was first verified for two test cases [(i) fluid/solid conjugate heat transfer and (ii) the solidification process of the binary system]. The code was then utilized to simulate the dissolution process of GaSb into InSb in the GaSb/InSb/GaSb sandwich system. The present results show that the developed volume-averaging model provides accurate predictions.

DOI： 10.1080/10407790.2016.1230397

Authorship：Lead author   Publishing type：Research paper (scientific journal)  

Marangoni convection is induced in liquids by surface tension gradient along a free surface. Such flows also develop in nano- and micro-scale systems and play important roles. To have a better understanding for the phenomena occurring in processing of such micro-scale systems, generally two kinds of numerical simulation approaches have been considered: continuum and discrete (molecular dynamics). While the continuum-based techniques cannot capture the intermolecular effects, the molecular dynamics approach requires huge computational cost. To address the adverse futures of these techniques, a new numerical method has been developed by combining the computational fluid dynamics (CFD) from the continuum side and Langevin dynamics from the discrete approach. The present simulation results have shown that this new numerical technique can successfully study and predict the phenomena occurring in macro-scale process applications.

DOI： 10.1299/jtst.2016jtst0036

Publishing type：Research paper (scientific journal)  

InxGa1-xSb bulk crystals are to be grown using a GaSb(seed)/InSb/GaSb(feed) sandwich-structured sample onboard the International Space Station (ISS). The InGaSb crystals will be grown on top of GaSb seed single crystals with different orientations viz., (111)A, (111)B, (110), (100) in order to examine and understand the growth kinetics of the crystals. In the present work, a numerical model of the crystal growth system has been developed to investigate the interface kinetics effects on the growth process by taking kinetics coefficient into account. The proposed numerical model was applied to evaluate the effect of crystal orientation on growth rate. Simulation results showed that the kinetics coefficient, whose value depends on crystal orientation, affected the growth rate of InGaSb crystal and the dissolution rate of GaSb feed crystal in the sandwich system.

DOI： 10.1007/s12217-015-9417-1

Authorship：Lead author   Publishing type：Research paper (scientific journal)  

A numerical study of a thermocapillary flow in a thin circular pool under zero and normal gravity conditions was carried out to investigate the effect of free surface shape on flow direction. We have previously reported that the direction of a thermocapillary flow in a circular water film under zero gravity was dependent on the shape of the film. In the present study, we also found that the direction of the thermocapillary flow in a water pool is dependent on free surface shape even under normal gravity. This finding shows that we can control the direction of the flow in the pool by changing its free surface shape by varying the volume ratio of the pool.

DOI： 10.1252/jcej.14we141

Authorship：Lead author   Publishing type：Research paper (scientific journal)  

DOI： 10.2322/tastj.12.Pe_19

InGaSb is a promising material for electronic devices. However, it is difficult to grow high quality homogeneous InGaSb crystals on Earth due to gravitational segregation. This adverse effect is minimized in the microgravity environment due to the suppression of convection. We have conducted experiment on board the ISS to understand the underlying physics that play role in the growth of high-quality semiconductor crystals. In the present study, we investigated the influence of interface kinetics during the growth process by using numerical simulation. Numerical results showed that the kinetic coefficient affected the growth rate of InGaSb crystal and the dissolution rate of GaSb crystal.

DOI： 10.11345/japannctam.63.0_33

CiNii Article

Authorship：Lead author   Publishing type：Research paper (scientific journal)  

NASA Astronaut Dr. Pettit carried out a thermocapillary flow experiment onboard the International Space Station in 2003. In this experiment a thin water film containing milk powder was formed in a stainless-steel wire ring. Heating a section of the ring by a soldering iron induced in the water film a thermocapillary flow towards the heated section of the ring (outward flow: cold to hot). This flow was in the opposite direction of the usually observed thermocapillary flows (inward flow: hot to cold). To shed light on this interesting phenomenon observed in the space experiment, we have conducted a three-dimensional numerical simulation study. Simulation results showed that the film geometry of the water film is a key factor determining flow direction and flow strength. When the liquid film free surfaces are convex, i.e., the water film volume is larger than that when the free surfaces are flat, an outward flow develops in the film as observed in the space experiment. However, when the free surfaces are concave, the simulation predicts an inward flow. (C) 2013 AIP Publishing LLC.

DOI： 10.1063/1.4818160

Authorship：Lead author,　Corresponding author   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

Publishing type：Rapid communication, short report, research note, etc. (scientific journal)  

Authorship：Lead author,　Corresponding author   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

DOI： 10.2320/materia.60.347

Authorship：Lead author   Publishing type：Article, review, commentary, editorial, etc. (other)  

Authorship：Lead author   Publishing type：Article, review, commentary, editorial, etc. (other)  

Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

Authorship：Lead author,　Corresponding author   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

Authorship：Lead author,　Corresponding author   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

Authorship：Lead author   Publishing type：Article, review, commentary, editorial, etc. (other)  

Authorship：Lead author   Publishing type：Article, review, commentary, editorial, etc. (other)  

J-GLOBAL

Authorship：Lead author,　Corresponding author   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

Authorship：Lead author   Publishing type：Article, review, commentary, editorial, etc. (other)  

Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

DOI： 10.2464/jilm.68.677

Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

Recent results on a numerical simulation of fluid dynamics, heat and mass transfer during SiC crystal growth by TSSG method are introduced as an example of chemical engineering process. It was found that Marangoni convection is dominant in the liquid phase and the three-dimentional numerical simulation result well explains the fluid flow in a water film suspended in a ring wire under the microgravity condition.

DOI： 10.4164/sptj.55.132

J-GLOBAL

J-GLOBAL

Marangoni convection becomes dominant under microgravity and micro-scale environments. In the micro-scale environment, the theory of macro-scale transport phenomena including fluid flow, heat and mass transfer can not be maintained. In addition, Marangoni convection with concentration gradient of surfactant is very difficult problem to analyze. To analyze mass transfer of some surfactants, we have to consider adhesion of surfactant to the interface, interaction between surfactants and macro-scale mass transfer. In this study, a numerical model for calculating the micro-scale phenomena has been developed. Multiphase simulation model including heat and mass transfer was developed and coupled with Discrete Element Method to analyze micro-scale mass transfer.

CiNii Article

Presentation type：Oral presentation (general)  

Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (invited, special)  

Presentation type：Oral presentation (general)  

Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Presentation type：Oral presentation (invited, special)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (invited, special)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (invited, special)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Symposium, workshop panel (nominated)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (invited, special)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Presentation type：Poster presentation  

Presentation type：Oral presentation (general)  

Presentation type：Symposium, workshop panel (nominated)  

Presentation type：Symposium, workshop panel (nominated)  

Presentation type：Symposium, workshop panel (nominated)  

Presentation type：Oral presentation (invited, special)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (invited, special)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (invited, special)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (invited, special)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (invited, special)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (invited, special)  

Presentation type：Poster presentation  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)