In this paper, a pulsed Nd:YAG laser with a maximum power of 700 W, was utilized to investigate the laser surface hardening of AISI 410 martensitic stainless steel. Focal point position, scanning speed and pulse width were considered as process variable parameters. Corrosion behavior of laser surface hardened samples were investigated by IVIUMSTAT apparatus in a 3.5wt% NaCl solution. Maximum microhardness, depth, and width of hardness and percentage of ferrite phase of metallographic and FESEM pictures were evaluated. Results show that surface hardness increased up to 762 HV. Results also reveal that the laser focal point position and pulse width are effective parameters in laser hardening process. In potentiodynamic polarization tests potential stated to increase at a rate of 1 mV/s from -0.4 V to 0.2 V. Results indicate that the corrosion resistance increased due to laser hardening process.

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In the present study, sand behavior on the transformation of sandy beaches is simulated by a Lagrangian approach using a solver based on smooth particle hydrodynamics (SPH) method. There are interpolation points that are assumed as fluid particles with arbitrary distribution. These particles carry mass, velocity, density, and other material properties depending on the given problem. The multi-phase flows can be modeled by SPH and each particle is assigned to a different phase. The WCSPH method is used to solve Newtonian and non-Newtonian fluid flow which causes smaller computation power in comparison with the fluid dynamics. The present method is validated by solving a dam break, submerged hatch and sedimentation problems. In addition, the computational results are evaluated with the experimental and numerical data. The formation of bed ripples in sandy beaches is investigated in details and an intended model is accomplished.

In this paper, growth and collapse of a cavitation bubble inside a rigid cylinder with a compliant coating (a model of humans vessels) is studied using Boundary Integral Equation and Finite Difference Methods. The fluid flow is treated as a potential flow and Boundary Integral Equation Method is used to solve Laplaces equation for velocity potential. The compliant coating is modeled as a membrane with a spring foundation. The effects of the parameters describing the flow and the parameters describing the compliant coating on the interaction between the fluid and the cylindrical compliant coating are shown throughout the numerical results. It is shown that by increasing the compliancy of the coating, the bubble life time is decreased and the mass per unit area has an important role in bubble behavior.