This study addresses a critical issue faced in harsh desert environments characterized by intense sunlight and dusty conditions, which pose significant challenges for applications ranging from solar panels and optical devices to architectural surfaces. In response, we have developed a silica coating that may offer a solution to these environmental challenges. The silica coating exhibits excellent anti-reflective properties, drastically reducing the amount of sunlight reflected from the coated surface and thereby enhancing photon absorption. This study examines the controlled tuning of optical and morphological properties in silica thin films, fabricated through reactive RF magnetron sputtering of an SiO2 target, using various oxygen-to-argon flow ratios [r(O2)=O2/Ar]. Empirical properties of the coatings were systematically examined and demonstrated to be finely tunable by adjusting r(O2). Additionally, surface morphology, as assessed by average roughness (Ra) measurements, was found to be strongly influenced by the oxygen concentration during deposition. Hydrophilicity of the silica coatings was assessed using contact angle measurements, demonstrating that the oxygen content in the films plays a significant role in influencing their hydrophilic properties. Furthermore, micromechanical properties of these silica coatings right after sputtering deposition and those exposed to outdoor conditions were systematically evaluated using Vickers indentation, showing, on one hand, that the hardness of the silica coatings can be regulated by adjusting the oxygen levels introduced during the deposition process, and on the other hand, a high mechanical stability of these silica even after 24 months of outdoor exposure in desert environments. Finally, this study also highlights that dust accumulation on the surface of these silica coatings is inversely proportional to the oxygen content into the films, demonstrating the coatings' self-cleaning properties. The hydrophobicity of the deposited silica thin films further contributes to their self-cleaning capabilities, making them particularly valuable in enhancing the performance of photovoltaic modules, especially in desert environments where dust accumulation can significantly impact efficiency. This multifaceted approach not only improves optical and mechanical properties but also offers a sustainable solution for maintaining the efficiency of solar panels and other devices in challenging environmental conditions.

For an offshore photovoltaic helical pile foundation, significant horizontal cyclic loading is imposed by wind and waves. To study a fixed offshore PV helical pile's horizontal cyclic bearing performance, a numerical model of the helical pile under horizontal cyclic loading was established using an elastic-plastic boundary interface constitutive model of the clay soil. This model was compared with a monopile of the same diameter under similar conditions. The study examined the effects of horizontal cyclic loading amplitude, period, and vertical loads on the horizontal cyclic bearing performance. The results show that under horizontal monotonic loading, the bearing capacities of a helical pile and monopile in a serviceability limit state are quite similar. However, as the amplitude of horizontal cyclic loading increases, soil stiffness deteriorates significantly, leading to greater horizontal displacement accumulation for both types of piles. The helical pile's bearing capacity under horizontal cyclic loadings is approximately 60% of that under monotonic loading. With shorter cyclic loading periods, horizontal displacement accumulates rapidly in the initial stage and stabilizes over a shorter duration. In contrast, longer cyclic loading periods lead to slower initial displacement accumulation, but the total accumulated displacement at stabilization is greater. When vertical loads are applied, the helical pile exhibits more stable horizontal cyclic bearing performance than the monopile.