Positive temperature coefficient of resistivity (PTCR) characteristics of (1-x)BaTiO3-x(Bi0.5K0.5)TiO3ceramics doped with Nb2O5 were investigated in order to develop the Pb-free PTC thermistor available at hightemperatures of >120oC. The PTCR characteristics appearing in the (Bi0.5Ki0.5)TiO3 (<5mol%) incorporatedBaTiO3 ceramics, which might be mainly due to Bi+3 ions substituting for Ba+2 sites. The 0.99BaTiO3-0.01(Bi0.5K0.5)TiO3 ceramics showed good PTCR characteristics of a low resistivity at room temperature (ρr) of31 Ω·cm, a high ρmax/ρmin ratio of 5.38×103, and a high resistivity temperature factor (α) of 17.8%/oC. Theaddition of Nb2O5 to 0.99BaTiO3-0.01(Bi0.5K0.5)TiO3 ceramics further improved the PTCR characteristics.Especially, 0.025mol% Nb2O5 doped 0.99BaTiO3-0.01(Bi0.5K0.5)TiO3 ceramics exhibited a significantly increasedρmax/ρmin ratio of 8.7×103 and a high α of 18.6%/oC, along with a high Tc of 148oC despite a slightly increasedρr of 39 Ω·cm.

The structural and electrical properties of amorphous BaSm2Ti4O12 (BSmT) films on a TiN/SiO2/Si substrate deposited using a RF magnetron sputtering method were investigated. The deposition of BSmT films was carried out at 300˚C in a mixed oxygen and argon (O2 : Ar = 1 : 4) atmosphere with a total pressure of 8.0 mTorr. In particular, a 45 nm-thick amorphous BSmT film exhibited a high capacitance density and low dissipation factor of 7.60 fF/μm2 and 1.3%, respectively, with a dielectric constant of 38 at 100 kHz. Its capacitance showed very little change, even in GHz ranges from 1.0 GHz to 6.0 GHz. The quality factor of the BSmT film was as high as 67 at 6 GHz. The leakage current density of the BSmT film was also very low, at approximately 5.11 nA/cm2 at 2 V; its conduction mechanism was explained by the the Poole-Frenkel emission. The quadratic voltage coefficient of capacitance of the BSmT film was approximately 698 ppm/V2, which is higher than the required value (<100 ppm/V2) for RF application. This could be reduced by improving the process condition. The temperature coefficient of capacitance of the film was low at nearly 296 ppm/˚C at 100 kHz. Therefore, amorphous BSmT grown on a TiN substrate is a viable candidate material for a metal-insulator-metal capacitor.

This research and development analysis provides numerical analysis techniques that can be used conveniently to determining the safety of the current state and to predict the stability in the future. It also seeks to present algorithms of back analysis to develop unified management system for control, prediction, coordination, and information modeling that can reasonably handle appropriate responses to structural behavior at project sites and design changes.

In this study, the development of gravity type collecting device for nuclear dismantling through CFD simulation is shown as follows. As a result of investigating the dust removal efficiency according to the treatment air velocity of 5 m/s (low speed) ～ 30 m/s (high speed), large dusts (80 ～ 100 ㎛) As the wind speed increases, the damping efficiency decreases and the particle size of the dust behavior increases with the increase of the wind speed. As a result, the wind speed (wind speed) 5 m/s is considered to be suitable for improving the vibration damping efficiency.

This study discusses regeneration of mercury-contaminated, activated carbon from adsorption in the mercuryrecovery process. Mercury in activated carbon was desorbed by thermal treatment, and the regeneration efficiency was confirmed by mercury content and iodine adsorption comparing new and spent activated carbon. Up to 95% of mercury desorbed and up to 86% adsorption performance regenerated at 673 K. Therefore, it is expected that activated carbon can be reused many times by regenerating it through thermal treatment without disposing of mercury-containing activated carbon.

A metal halide lamp was developed to improve the performance of high pressure mercury lamps. In South Korea, these are used in street lamps, fishing lamps, and automobile headlights; however, these are not specified in Annex A part 1 of the MINAMATA convention. In this study, valuable materials were investigated in automobile headlights and street lights and were minimized to contaminate mercury via staged crushing. The staged crushing prevents mercury emissions in the crushing process. Thus, the mercury concentration in glass-type byproducts from waste HID lamps was increased from 260.29 mg-Hg/kg to 2,907.16 mg-Hg/kg. In addition, glass from waste street lamps was increased from 1,083.71 mg-Hg/kg to 14,101.95 mg-Hg/kg. In the case of street light crushing, mercury-containing glass waste decreased by 67%. The specific wastes from staged crushing were mainly glass type. In this material, mercury species vaporize at over 800°C. The elemental mercury was estimated to oxidize during its use and crushing. Therefore, to ensure the harmless treatment of specific wastes from staged crushing, treatment at over 800°C is recommended.

This study investigates leaching and thermal treatment characteristics of mercury in waste phosphor powder from UV lamp for industrial use. Waste phosphor powder contaminated with mercury compounds requires proper treatment for final disposal. A sequential extraction procedure was conducted in order to estimate the stability of mercury compounds in waste phosphor powder. The fraction of mercury compounds leached in initial steps by ion-exchangeable and low acidic solutions was 62%, which would be unstable. Finally 36% of mercury compounds was left as a strongly stable form before last step of acid digestion by aqua regia. Mercury was decomposed rapidly during initial period in thermal treatment. However, the decomposition rate reached in steady later. Correlation of mercury content in residues with concentration of leaching extract was attempted in order to set a thermal treatment condition. When mercury content in residue of phosphor powder could be lowed up to about 13 mg-Hg/kg by thermally with satisfying the Korean leaching standard limit of 0.005 mg-Hg/L.

초고압 쇼트 아크램프는 빛에 반응하는 물질(Photo-resist: PR, 감광액)이 코팅된 시료에 원하는 패턴이 형성된 마스크를 올려놓고 자외선을 쏘여 감광막에 원하는 패턴을 전사시키는 장치를 말하며 국내에서는 삼성, 엘지, SK하이닉스 등 디스플레이, 반도체 사업장에서 연간 약 2~3만개가 사용되며 시장은 연간 약 2천억원으로 추산된다. 이 공정은 FPD 제조 공정 중 비용 및 시간적 측면에서 30~40% 이상을 차지하는 최고 핵심 공정이지만, 국내 기술 미흡으로 그동안 일본등 선진국에서 장비 및 제품을 전량 수입하였으며, 초고압 쇼트 아크램프의 기술 수준이 매우 높고, 선진 기업의 엄격한 기술 통제로 인하여 기술적 접근이 어려워 디스플레이 5대 핵심 장비 중 유일하게 국산화에 성공하지 못하였다. 재활용 기술 역시 전무한 상태로 국내에서 발생되는 연간 약 2~3만개의 폐 초고압 쇼트 아크램프는 낮은 가격에 전량 일본으로 유출되고 있는 상황이다. 초고압 쇼트 아크램프는 금, 은, 동, 텅스텐, 몰리브덴, 탄탈륨등 고가의 유가금속으로 구성되어 있으며, 이를 회수하고 적절한 방법으로 재활용한다면 고부가가치 창출을 실현할 수 있을 것으로 판단되어진다. 본 연구에서는 물리적인 방법으로 폐 쇼트 아크 램프를 해체・분리하여 고가의 유가자원을 회수하고 회수된 전극 표면에 다시 정밀 코팅을 실시하여 전극을 재사용하는 전극 재제조 공정기술을 확립하고자 하였다.