Analyzing asphalt mixture images can provide crucial information not only for generating advanced geometry structure in several numerical computations (i.e. FEM and/or DEM) codes, but also for numerically evaluating the material microstructure. It is well known that 3D X-Ray Computer Tomography (CT) can provide accurate and realistic microstructure information of asphalt mixtures; however, this technology still presents two limitations: 1) the equipment is very expensive and, therefore, only few pavement agencies can afford it, and 2) the software required to generate realistic image of asphalt mixture with three-phase structure (aggregate, asphalt binder and air-voids) is based on a global thresholding algorithm which cannot be easily accessed and edited by users and practitioners. In this paper, accurate and realistic 2D three-phase asphalt mixture images were generated using an advanced DIP analysis code (implemented on MATLABTM) and a common flatbed scanner, which can be easily purchased at relatively low price. The threshold algorithm was developed based on the computed results of Gmm (maximum specific gravity), Gmb (bulk specific gravity), VMA (voids in mineral aggregates) of given asphalt mixtures which can be experimentally obtained in a laboratory environment. 2D three-phase images of asphalt mixtures were derived from grey scale images (color intensity from 0 to 255) obtained from original RGB (Red-Green-Blue) scale images with a dual-threshold computation techniques (i.e. one step for computing air voids phase, T1, and a second step for computing asphalt binder (and/or mastic) phase, T2). An example of DIP analysis results is shown in Figure 1. Based on the computation results, quite accurate and good visual agreement was observed between RGB scale image and DIP analyzed image. The findings indicate that this advanced DIP analysis technique can provide reliable geometry and microstructural information for several numerical simulations such as finite element method (FEM) and discrete element modeling (DEM). This research work represents a solid base for performing simple 2D microstructure analysis using 2- and 3-point correlation function and for developing the Moon Cannone Falchetto (MCF) model which will be introduced in the next annual KSRE conference.

As the fabrication technology used in FPDs(flat-panel displays) advances, the size of these panels is increasing and the pattern size is decreasing to the um range. Accordingly, a cleaning process during the FPD fabrication process is becoming more important to prevent yield reductions. The purpose of this study is to develop a FPD cleaning system and a cleaning process using a two-phase flow. The FPD cleaning system consists of two parts, one being a cleaning part which includes a two-phase flow nozzle, and the other being a drying part which includes an air-knife and a halogen lamp. To evaluate the particle removal efficiency by means of two-phase flow cleaning, silica particles 1.5μm in size were contaminated onto a six-inch silicon wafer and a four-inch glass wafer. We conducted cleaning processes under various conditions, i.e., DI water and nitrogen gas at different pressures, using a two-phase-flow nozzle with a gap distance between the nozzle and the substrate. The drying efficiency was also tested using the air-knife with a change in the gap distance between the air-knife and the substrate to remove the DI water which remained on the substrate after the two-phase-flow cleaning process. We obtained high efficiency in terms of particle removal as well as good drying efficiency through the optimized conditions of the two-phase-flow cleaning and air-knife processes.

(Fe0.98Mn0.02)xSi2(x≤1) 조성으로, 용융법으로 제조한 α-Fe2Si5상의 잉곳을 730~850˚C에서 4~20시간 열처리하거나, 기계적 합금화로 제조한 ε-FeSi과 Si상으로 구성된 분말을 760~850˚C에서 10분간 가압통전소결하므로써 β-FeSi2기지상에 Si이 분산된 미세조직을 얻을 수 있었다. 조성, 열처리 온도와 소결 온도에 따라 Si 분상의 크기와 간격이 각기 0.05~0.27μm와 0.2~0.6μm 범위에서 변화하였다. 이와 같은 Si 분산상에 의해 β-FeSi2의 격자 열전도도가 감소되어 성능지수가 향상될 수 있을 것으로 기대된다.