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1. Despite the array of sophisticated imaging techniques available for biological applications, none of the standard biomedical techniques adequately provides the capability to measure motion and flow. Those techniques currently in use are particularly lacking in spatial and temporal resolution. 2. Herein, we introduce the technique of particle image velocimetry. This technique is a well-established tool in engineering research and industry. Particle image velocimetry is continuing to develop and has an increasing number of variants. 3. Three case studies are presented: (i) the use of microparticle image velocimetry to study flow generated by high-frequency oscillatory ventilation in a human airway model; (ii) the use of stereoparticle image velocimetry to study stirred cell and tissue culture devices; and (iii) a three-dimensional X-ray particle image velocimetry technique used to measure flow in an in vitro vascular flow model. 4. The case studies highlight the vast potential of applying the engineering technique of particle image velocimetry and its many variants to current research problems in physiology. [ABSTRACT FROM AUTHOR]

Abstract: A very small wind turbine system for multi-purposes was developed and its performance was reported in this paper. The rotor diameter of the turbine is 500mm. The tests of the energy output, turbine speed, power coefficient, and torque of turbine were carried out for a wide rage of free stream velocity. The flow around the wind turbine and the influence of the turbulence were investigated with a particle image velocimetry. Experimentally obtained power coefficient was 0.4 in maximum and 0.36 in the rated running condition, respectively. The tip speed ratio corresponding to the optimum driving condition was 2.7. Comparing with the other commercial turbines, the performance was excellent at a slow turbine speed. By the flow visualization and PIV measurement around the wind turbine, the approaching flow velocity and the accelerated flow field passing the blade tip was obtained. It was confirmed that the actual flow passed through the blades was about 20% slower than the ideal flow. Tip vortex shed from the blade tip was also visualized clearly. [Copyright &y& Elsevier]