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In this paper, in order to avoid the problems induced by cutting liquids like higher cost, environmental pollution and dangerous for operator health in milling process and also using the benefits of them such as increasing tool life and machined surface quality, machining by minimum quantity of lubrication (MQL) or near dry lubrication was introduced and that’s effects on main outputs (consumed power and surface roughness) was compared with other lubrication methods such as lubrication by cutting fluids and by air. In order to perform a series of experiments and investigate the effects of different process parameters such as tools rotational speed, feed rate, gas pressure and liquid flow rate on main outputs, the Taguchi method of design of experiments was employed and then the analysis of variance (ANOVA) was used to find the most important factors effecting main outputs. The results obtained by experiments showed that employing near dry lubrication leads to lower electrical power and comparable surface roughness as compared with other lubrication methods. The analysis of variance showed that feed rate is the most important factor affecting consumed power and liquid flow rate is the most important factor influencing surface roughness.

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The energy harvesting of a piezoelectric cantilever beam is obtained from the excitation of vibration modes. Vibration modes have strain nodes where the strain distribution changes in the direction of the beam length. Covering the strain nodes of the vibration modes with continuous electrodes effects a cancellation of the voltages outputs. The use of segmented electrodes avoids cancellations of the voltage for multi-mode vibration. The theory of Gauss law is presented for the voltage response due to the electro mechanic coupling. The effective parameter in the voltage response is the modal coupling term. This parameter depends on geometry, material, piezoelectric coefficients and the Eigen function of bending slope. If the slopes of the electrodes boundaries are close together, the electric response of vibration mode is very small. The resistive load affects the voltage and generated power. The optimum resistive load is considered for segmented and continuous electrodes, and then the power output is verified. One of the effective parameters on energy harvesting performance is the existence of concentrated mass. This topic is studied in this paper. Resonance and off-resonance cases are considered for the harvester. In this paper, both theoretical and experimental methods are used for satisfactory results.