Recently brain imaging techniques have relied on the close coupling between neural activities, local changes in blood flow and a change of oxygen environment. Because of the importance and widespread use of these techniques, we need to clarify their relationship. In auditory cortex, primary auditory cortex (AI) is an unique region in which acoustic frequency are topographically mapped In this study, to clarify the precise relationship between neural activity and local cerebral blood flow (CBF) in guinea pig AI, we measured CBF change and neural activity with Laser Doppler Flowmetry (LDF) and optical recording with voltage sensitive dye (RH795) during and after applying the acoustic stimulus of various frequencies (1,4,7,12 kHz). And to see how tissue pO2 respond to stimulus, we also measured tissue pO2 with an oxgen microelectrode (tip diameter<10μm).Then we visualized micro-vessels in guinea pig which effect the results of above measurements and brain imaging techniques

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The direct numerical simulation (hereafter, DNS) of turbulent heat transfer in a plane Couette flow has been performed with respect to a large-scale turbulence structure (LSS). Two kinds of boundary temperature conditions are employed ; these are the uniform heat flux heating (UHF) and the constant temperature difference between both walls (CTD). A series of present DNS has been carried out for several large computational box-sizes than those of existing DNS to examine their effect upon the large-scale structures and the statistical quantities such as temperature variance. The differences caused by the box-size and the boundary conditions of temperature field are discussed with respect to LSS.

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Flow and mixing characteristics for turbulent flow in a counter-type T-junction channel have been examined experimentally. The T-junction was modeled by a mixing tee with square cross sections, in which the mixing channel was connected with the main and counter channels at right angles. Detail distributions of velocity and concentration after the mixing have been measured using PFV and LIF, respectively. Two-point correlations of velocity fluctuation were compared with those of concentration fluctuation. These results show that the spatial pattern of concentration fluctuation connected with turbulent mixing is conveyed downstream with extension growth.

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An experimental study was conducted on turbulent thermal mixing in rectangular channels with a T-junction, which simulate the HVAC unit used for an automobile air-conditioning system. Experiments were conducted keeping Reynolds number and temperature of the main-channel flow at 2.5×10^4 and 10℃, respectively, and the velocity of the branching-channel flow (65℃) was set at the same value as that of the main channel. The simultaneous measurement of the fluctuating velocity and temperature was conducted using LDV and cold-wire thermometry. The temperature fluctuation and turbulent heat flux in the transverse direction show similar distributions and they become the maximums in the middle of the thermal mixing layer, while the peaks of velocity fluctuations appear in the shear layer around the separation bubble that is located below the mixing layer.

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This paper presents experimental results of turbulent heat transfer in a separated and reattached flow in a sudden expansion rectangler channel. The step height H is 26mm, its spanwise length 200mm, and the channel expansion ratio 2.86, respectivety. The Reynolds number Re based on the uniform flow velocity at step and H was varied from 5000 to 35000. The flow in the channel becomes asymmetric due to the Coanda effect. It is found that the local Nusselt number profile is quite different on the upper and lower walls, and the location of maximum Nusselt number is very close to the flow reattachment point.

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Experimental study with the conditionally sampling method was made on the turbulent heat transfer in the separated, reattached and redeveloping regions of an air flow over a blunt flat plate. It is clarified that the large scale vortices have three-dimensional structure, and that the heat transfer in the reattached and redeveloping regions is strongly characterized by the large scale vortices shed from the reattachment region. These large scale votices exhibit the stucture of hairpin-like vorex.

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Numerical simulation of thermo-fluid dynamics and electrochemical reaction in planar-type solid oxide fuel cell (SOFC) was carried out in order to obtain a clue for better cell design. The simulation reveals that the internal resistance of interconnector should be a primary contributor to the deterioration of cell voltage. Based on the result, an improved cell design is suggested, and it is demonstrated that the cell output voltage increases about 7 to 9 % compared to the conventional design. However, the decrease in the maximum cell temperature is difficult to achieve only by changing its design or material.

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In order to make PEFC be used by the general public, it is important that PEFC have not only high efficiency but also high durability. The operation parameters of PEFC have to be controlled in order to achieve that. In this study, we discuss the impact of operation parameters on MEAs, which have important role of power generation. In this experiment, by using a single cell, reduction in ECSA was observed at cathode after 1000 times start-and-stop tests. The decrease in voltage was also observed in an IV curve. Subsequently, the environment in which MEAs are exposed to was then simulated by using our theoretical model that considered multi-dimensional transport phenomena as well as electrochemical reactions that took place in the cell.

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In this study, we have studied the performance of PEFC by using metallic gas diffusion layer. We fabricated it by using micromachining technology. It has a lot of micro holes. At first, we compared metallic diffusion layer with carbon diffusion layer. And the change of water and gas dynamics on the surface of MEA and in gas diffusion layer was investigated with changing the hole dimensions and the hole area. These results provide useful information for advanced PEFC designs.

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Based on cold-hot-medium type three-fluid heat exchanger, the characteristics of the three-fluid plate heat exchangers composed of 6 channels and 9 channels have been investigated theoretically. The heat transfer effectiveness of the three-fluid plate heat exchangers was defined by considering the maximum heat transfer rate. It was found that the performance of the three-fluid plate heat exchangers depended on the arrangements of three-fluid heat exchanger and the initial temperature ratio.

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Currently, we focus on a micro tubular SOFC (μSOFC) to develop the small-scale power supply devices for portable applications. The investigation of the appropriate cell assembly with use of μSOFCs is a significant issue for practical use of μSOFC. In this paper, the power generation test results of a single μSOFC, of which inner diameter is 2mm and length is 55mm, are examined. Operating on hydrogen at 800℃, the maximum power of 8mW/cm^2 was obtained at the current of 16mA/cm^2. In the case of butane, the maximum power reached to 50mW/cm^2 at 800℃, and it was confirmed that the present experimental results substantially correspond to the data in the previous work. Operating on butane, the voltage drop over time was observed, because carbon was deposited on the anode surface at the fuel inlet side.

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