As a surface treatment method of concrete pavement in Korea, transverse tinning has initially been applied to improve drainage and friction at first. Since 2003, in order to reduce the noise of concrete pavement, longitudinal tinning have been studied and proved its superiority. Therefore, Korea Expressway Corporation (KEC) has applied this as surface texturing method in concrete pavement from 2008 to the present. However, the lateral vibration during vehicle running has been continuously raised in the longitudinal tinning section, and lots of efforts have been made to solve this problem. Nonetheless, complaints still occur intermittently in some sections. In this research, three sections in which complaints occur and three test sections were chosen to evaluate characteristics of lateral vibration between tire and longitudinal texturing. Based on the literature survey on the correlation between longitudinal texturing and tire, evaluation of the site and FEM analysis of each road surface were carried out. As a result of the analysis, the lateral vibration occurred most frequently in the random tinning section compared to other sections, and it was relatively few at the other improved tinning of the test section. Further studies on various tire types and timing intervals in the future will provide a standard of longitudinal texturing, which will reduce lateral vibration.

In this paper, double texturization of multi crystalline silicon solar cells was studied with laser and reactive ion etching (RIE). In the case of multi crystalline silicon wafers, chemical etching has problems in producing a uniform surface texture. Thus various etching methods such as laser and dry texturization have been studied for multi crystalline silicon wafers. In this study, laser texturization with an Nd:YVO4 green laser was performed first to get the proper hole spacing and 300μm was found to be the most proper value. Laser texturization on crystalline silicon wafers was followed by damage removal in acid solution and RIE to achieve double texturization. This study showed that double texturization on multi crystalline silicon wafers with laser firing and RIE resulted in lower reflectance, higher quantum yield and better efficiency than that process without RIE. However, RIE formed sharp structures on the silicon wafer surfaces, which resulted in 0.8% decrease of fill factor at solar cell characterization. While chemical etching makes it difficult to obtain a uniform surface texture for multi crystalline silicon solar cells, the process of double texturization with laser and RIE yields a uniform surface structure, diminished reflectance, and improved efficiency. This finding lays the foundation for the study of low-cost, high efficiency multi crystalline silicon solar cells.