Development of Electrical Shielding system for auto dust removal for solar PV modules
Currently, Large-scale solar PV systems installations are taking place in the desert environment and space to harness abundant solar energy effectively. Dust accumulation on the surface of photovoltaic panels (PV) is the most stignant problem for photovoltaic panels, as dust deposition reduces PV problem energy generation efficiency significantly. Thus, the removal of dust from the PV panels has become very important to increase the rate of energy efficiency by the PV panels. The dust particles could be reduced using traditional dust cleaning techniques. But, in the harsh and hostile desert environment, these approaches which requires a lot of water, complicated mechanical instruments, enormous logistics, and personnel. Electrodynamic dust shielding (EDS) system has been developed at our laboratory to remove dust particles from the surface of the PV panels. The EDS system has been successfully tested for dust mitigation. The unique features of our EDS System is that it is cost effective, easy to install and no manpower required as it is an unmanned system. The design and construction of a single-phase electrodynamic dust repulsion device built locally in KSA is demonstrated in this study. This work showed that the optimized electrode design and electrical parameters, such as AC source voltage and frequency, maximized the EDS system's dust mitigation effectiveness. A perfect balance was achieved between the geometrical and electrical parameters of the EDS system, resulting in a dust removal efficiency of up to 92±1 ℅.
探討「互相牽制」中整除問題的整數解
在這篇作品中,探討科學研習月刊中森棚教官的數學題-「互相牽制」的整除問題,此問題是指「你可以找到多少組正整數對(x, y),讓x的平方減5為y的倍數且y的平方減5為x的倍數?」。我們除了探討原問題之外,也探討將5改為任意整數 l 的情況,我們要刻畫滿足 y | x2- l 且 x | y2- l 的所有整數解(x, y)。 首先建構生成另一組整數解的方法且推導出在 (x2+y2-l) / xy 為整數的條件下生成另一組整數解的方法。在 (x2+y2-l) /xy 為整數的條件下,可利用二階齊次線性遞迴數列及二次曲線刻畫滿足 y | x2 - l 且 x | y2- l 的所有整數解(x, y)。當上述條件不成立時,利用二次曲線試圖刻畫滿足 y | x2 且 x | y2 的所有整數解(x, y),進一步推導出在特定條件下,可利用二次曲線刻畫滿足 y | x2且 x | y2的所有整數解(x, y)。