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The measurements of wind velocity and direction using an acoustic reflection against a wall are described. We aim to measure the spatial mean wind velocity and direction to be used for an air-conditioning system. The proposed anemometer consists of a single wall and two pairs of loudspeakers (SP) and microphones (MIC) that form a triangular shape. Two sound paths of direct and reflected waves are available. One is that of the direct wave and the other is that of the wave reflected on the wall. The times of flights (TOFs) of the direct and reflected waves can be measured using a single MIC because there is a difference in the TOF between direct and reflected waves. By using these TOFs, wind velocity and direction can be calculated. In the experiments, the wind velocities and directions were measured in a wind tunnel by changing the wind velocity. The wind direction was examined by changing the setup of the transducers. The measured values using the proposed and conventional anemometers agreed with each other. By using the wave reflected against a wall, wind velocities and directions can be measured using only two pairs of transducers, while four pairs are required in the case of conventional anemometers.

Xe-CT can provide substantial information on hepatic blood flow quantitatively and visually with separation of arterial and portal components.

Air movement caused by ventilation in greenhouses is an important factor that affects the uniformity of greenhouse environment and consequently the uniformity of plant growth and quality. Natural ventilation systems have been widely adopted. The studies of the air movement in naturally-ventilated greenhouses have been performed by means of field experiments, laboratory tests such as wind tunnel tests using scale models, and numerical simulations using computational fluid dynamics (CFD) approach. The primary characteristics of the air movement caused by wind and stack effects in a single-span greenhouse are described. Recent studies on the air movement and the uniformity of environment under natural ventilation are reviewed and discussed with respect to the multi-span greenhouses, the effect of plants, the vent configuration, and the effect of wind direction.

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Using the CFD model, a new ventilation system design will be found later taking into consideration the ventilation efficiency such as uniformity, stability, and suitability of environmental factors in a naturally ventilated broiler house. Because conducting a field experiment for the ventilation study presented so many difficulties, a reliable 3-dimentional computational fluid dynamics (CFD) model had to be developed to investigate the natural ventilation. Before investigating its accuracy, a wind tunnel and particle image velocimetry (PIV) test was initially conducted to find their best experimental conditions and improve the PIV accuracy 13,15 . A 1/20 scale model of a naturally ventilated broiler house was used to get qualitative and quantitative airflow distribution in the broiler house using the PIV and CFD. To improve the CFD accuracy, the PIV and CFD computed airflows in the broiler house were compared, particularly on the distribution, local air velocity, and turbulent intensity in the house. The quality of the mesh density and the design of the boundary condition, especially the wind velocity and turbulence profiles, were found to be very important for getting accurate results. Assuming the PIV results were accurate, the most accurate CFD results were obtained when using a RNG k-ε turbulence numerical model. The average error of the CFD computed air velocity when using the RNG k-ε models was -6.2%.

Our investigation showed that there is a close correlation between liver function and hepatic blood flow.