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Magnesium alloys are attractive lightweight structural materials that have the potential to be used in aerospace, automotive and medical industries. However, fatigue is a major cause of failure in structural components. It is also known that notches, which are unavoidable, have a detrimental effect on fatigue resistance. Fatigue damage is associated with the formation of crack(s). Therefore, it is necessary to understand the fatigue crack growth behavior for better design analysis. In this research, a V-notched specimen machined from ZK60 magnesium extrusion is tested under cyclic axial loading. Fatigue experiment was performed under completely reserved force-controlled loading with an amplitude of 12 kN and under standard laboratory conditions. The fatigue test was interrupted 14 times in order to perform ex-situ x-ray tomographic analysis using the Nikon XTH 225 ST system. The sample failed after 184,005 cycles. A gray-level thresholding process was performed using MATLAB on the selected slices to convert each pixel to either white or black color. Then, these slices were stacked using imaging software to make 2D representations of the crack surface at different cycles. As a result, the areas of the crack surfaces were measured for all scans. The result suggests an exponential relationship between the crack surface area and the number of cycles.

Dust mitigation in photovoltaic panels has been a growing technological challenge as an increasing number of largescale solar cell installations are taking place in the desert environment and space to harness the abundant solar radiation effectively. The conventional methods of dust removal require a large quantity of water, complex mechanical instrumentation, enormous logistics, and manpower in the inhospitable and hostile desert environment. Many variants of electrodynamic dust shield (EDS) systems have been successfully tried for dust mitigation as this method involves low-cost installation and unmanned lowpower operation. In this work, we present the design and fabrication of a locally made three-phase electrodynamic dust repulsion system. The dust removal efficiency of the EDS system was optimized for the electrode geometry and the electrical parameters like AC source voltage and frequency. The dust removal efficiency as high as 92 ± 1% was observed for an optimum combination of geometrical and electrical parameters of the EDS. The operation and the optimization of the EDS system were elucidated by analyzing various electrostatic and mechanical forces and the generation of traveling waves involved in this process.The EDS system was applied on the solar cell under natural sunlight to study the efficacy of the system in improving the photovoltaic performance of the solar cell in the dusty environment. As the dust characteristics play an essential role in the dust removal efficiency, the morphological and elemental characterizations and dust particle size analysis of dust from a natural sandstorm were also conducted.

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