Papers by Author: Na Ri Lee

Abstract: Recently, touch screen is one of the most popular pieces of electrical and electronic equipment in our society, such as laptops, cellular phones, and digital cameras. Indium tin oxide (ITO) is mainly used to make transparent conductive coatings for touch and flat screen. Therefore, there is an increasing demand accordingly. Although accounted for 1% of the touch screen, indium is rare metals. Consequently, it is important to Recycling ITO for National Strategies about Resource Conservation, and reduce Environmental burden. The case which disuses ITO like landfill or incineration, it cloud be harmful to the human health in the long-term. This study intended to identify the environmental aspects with the ITO recycling. The potential environmental impacts were evaluated by using Material Life Cycle assessment method (MLCA). As the result of this study, MLCA would provide more information for environmental issues of ITO. So that it is possible to improve the environmental issues by the monitoring that could be useful and effective for ITO. The study includes two scenarios, the basic scenario is recycling of ITO (10, 20 and 30%) and the other scenario is landfill of ITO.

Abstract: Nowadays, rapidly growing mobile machines such as tablet PC and smart phone equipped with touch screen panel using a sturdy material for products surface protection. Therefore, surge of chemical strengthening glass was increased. Through large areas of chemical strengthening glass, the surface scratch will cause a major failure. Most of these failures will be discarded because it is difficult to reuse. Thus, discarded chemical strengthening glass is expected to increase as with the demand. Accordingly, the importance of environmental pollution, waste landfill has been proposed. Recently, touch screen of chemical strengthened glass all-in-one type was commercialized. Therefore reuse is possible, due to surface of discarded chemical strengthening glass is washed and wipe off the electrode. In this study, we carried out the MLCA(Material Life Cycle Assessment; MLCA) on a chemical strengthening glass by landfill scenario, reuse scenario and identified the key issues.

Abstract: The most promising methods for high purity hydrogen production are membranes separation such as polymer, metal, ceramic and composites. It is well known that Pd and Pd-alloys membranes have excellent properties for hydrogen separation. However, it has hydrogen embrittlement and high cost for practical applications. Therefore, most scientists have studied new materials instead of Pd and Pd-alloys. On the other hand, ceramic materials are great in resistance to acids and chemically stable under high operating temperature. Recent research in cermet materials for membrane applications interests to permeability and selectivity of hydrogen. High purity hydrogen can be produced through simple process by membrane. Recently, research in ceramic composites for membrane applications attract to hydrogen separation. Porous ceramic membrane process which has high permeability and hydrogen flux is chemically and thermally stable. Therefore, they are attractive for applications in hydrogen production process. However, porous ceramic membrane had low selectivity, hard to produce high purity hydrogen. Many studies were carried out Pd and Pd alloys coating, they were fabricated dense cermet membrane. In this work, ACZ ceramic membrane was fabricated disk type membrane by cold isostatic press (CIP) and then coated Pd and Pd-alloys.. It was characterized by XRD, SEM, EDX and BET. Also, we estimated the hydrogen permeability by Sievert's type hydrogen permeation membrane equipment.