In this paper, the characteristics of blood cell motion are analysed by solving a coupled electromagnetic, fluid and particle dynamics problem. The forces acting on blood cells are obtained from magnetic field and fluid field distributions, both of which are numerically calculated by the finite element method. These force consist of the magnetophoretic force, drag force, buoyancy and gravity, these are driving terms in Newton's equation for the particle motion. We propose a numerical analysis procedure to solve the coupled problem, and a micro cell separation device without a micro fabricated structure is designed. The dynamic characteristics of the cell motion are simulated. The simulation results show the proposed numerical scheme to analyse the micro particle dynamics and also show the usefulness of the designed device.

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This paper proposes a nonlinear magnetic method to estimate wall thinning of carbon steel pipe used in the secondary steam cycle of nuclear power plants. The principle of the proposed method is based on utilizing the nonlinear property of magnetic saturation in the carbon steel. A magnetic sensor system for the nonlinear magnetic method is designed by the magnetic circuit concept, and is modeled and analyzed with the finite element method and an equivalent electric circuit. The experimental setup of the sensor system is built and tested for its performance of estimation. The data measured from the sensor system, that is used to estimate the wall thinning, are compared with the analysis results to demonstrate feasibility and validity of the proposed nonlinear magnetic method.

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Ultra-high-strength steel (UHSS) structures are exposed to corrosive environments during service, and hydrogen-assisted cracking (HAC) may occur owing to stress corrosion cracking and hydrogen embrittlement. In this study, the HAC threshold stress intensity factor and fatigue life of UHSS steel were evaluated by applying stress in a corrosive environment to prevent structural fracture. For specimen with semicircular slits by electric discharge machining, fatigue limit was obtained by static fatigue test under corrosive environment. The fatigue limit of the crack specimen was evaluated by the fatigue limit of the experiment and HAC threshold stress intensity factor, and comparative evaluation was performed. On the surface of cracks, grain boundaries were embrittled by corrosion, and grains were clearly observed. Meanwhile, cracks in the surface direction propagated slightly, unlike cracks in the depth direction. The static fatigue limit of UHSS (SKD11:HV670) was determined to be 400 MPa, and the fatigue limit of the crack specimen could be evaluated. The experimental results agreed well with the evaluation results.