This study was carried out to estimate the usefulness of metal oxide semiconductor(MOS) sensor as an odor measuring instrument. In this study, sensor output for 12 legal malodorous compounds was measured by two kinds of the marketed MOS sensor and was investigated the correlation coefficient between sensor output and odor indicators as like odor concentration, air dilution ratio. As a results, it was estimated that MOS sensor has a high use possibility as odor measuring device for the single compound analysis, as the correlation coefficient between sensor outputs and odor concentration, R2 appeared to 0.9 or more high.

As a pa rt 0 1' the effort to develop a suitable scaffold for tissue-engineered bone regene ration, we modified calcium metaphosphate(CMP) ce ramic with 5 mol% Na20 or K20 to improve t he biodegradability and evaluated their effi ciency as a biodegr adable scaffold for ti ssue-engineered bone regeneration. The macroporous αiIP ceramic blocks incor porated with 5 mol% Na20 or K20 were prepa recl to have average pore size of 250 um in an inte rconnectecl framework structure The influ e nce of inco r pora tecl 5 mol% Na20 or K20 on cytotoxicity‘ cellular attachmont and t heir clifferentiation was evaluated by in vit ro analyzing sys tern. res pectively. The bioclegradability, histocompatibility, and osteogenic effect by cell-scaffolcl co nstruc ts were evalua ted by im plantation of them into subcutaneous pouches of SD-rats 0 1' SCID ITllce The incorporation of 5 mol% Na20 or K20 causecl clecrease of compressive strength without improving of biodegr adabili ty . The moclifi ed scaffolcls revea led no cy totoxic and excell ent biocompatability but osteogneic effect was recluced compa red to pure CMP ce ramic porous blocks . These res ul Ls s ugge::;t tha t the incorporation of 5 mol% Na20 0 1' K20 into pure CMP is not effective for improv ing effï ciency 0 1' scaffolcls fo1' tissue-engineered bone regeneration in terms of bioclegradabi li ty‘ physical s trength . a ncl osteogenic rege ne ra tive effect

본 연구에서는 고온의 LiCl-LlO 용융염계에서 우라늄 산화물의 금속전환과 LiO의 전해반응이 동시에 진행되는 통합 반응 메카니즘을 기초로 한 전기화학적 금속전환기술을 제안하였다. 본 실험에서는 전기화학적 환원반응에 의해 생성된 Li 금속이온이 음극에 전착과 동시에 우라늄 산화물과 반응하여 금속전환율 99 % 이상의 우라늄 감속을 생성하는 통합 반응 메카니즘을 확인할 수 있었다. 또한 전기화학적 금속전환기술의 공정 적용성 평가 일환으로 우라늄 산화물의 금속전환성, 반응 메카니즘 규명, LiO의 closed recycle rate 및 물질전달 특성 등의 기초 데이터를 확보하였다 향후 전기화학적 금속전환기술은 LiCl-Li 용융염계의 금속전환공정의 반응조건 제한성 해소, 금속전환율 향상 및 공정의 단순화 등의 기술성과 경제성 향상 측면에서 획기적인 방안으로 고려될 수 있을 것으로 판단된다.

In this study, we evaluated the photocatalytic oxidation efficiency of aromatic volatile hydrocarbons by using WO3–doped TiO2 nanotubes (WTNTs) under visible-light irradiation. One-dimensional WTNTs were synthesized by ultrasonic-assisted hydrothermal method and impregnation. XRD analysis revealed successful incorporation of WO3 into TiO2 nanotube (TNT) structures. UV-Vis spectra exhibited that the synthesized WTNT samples can be activated under visible light irradiation. FE-SEM and TEM images showed the one-dimensional structure of the prepared TNTs and WTNTs. The photocatalytic oxidation efficiencies of toluene, ethylbenzene, and o-xylene were higher using WTNT samples than undoped TNT. These results were explained based on the charge separation ability, adsorption capability, and light absorption of the sample photocatalysts. Among the different light sources, light-emitting-diodes (LEDs) are more highly energy-efficient than 8-W daylight used for the photocatalytic oxidation of toluene, ethylbenzene, and o-xylene, though the photocatalytic oxidation efficiency is higher for 8-W daylight.

The effect of the metal oxide catalyst in the dimerization of waste vegetable oil was investigated. The high efficiency and recyclability has allowed different metal oxides to be used as catalysts in numerous synthetic reactions. Herein, clay, aluminum, titanium, calcium, magnesium and silicon oxide micro/nanoparticles are used in a Diels-Alder reaction to catalyze the production of the dimer acids. The metal oxides assist the electron transfers during cyclization to produce the desired product. Liquid chromatography mass spectroscopy (LC-MS) and gel permeation chromatography (GPC) were used to verify the production of dimer acids. For the confirmation of cyclization, compounds were analyzed using the nuclear magnetic resonance (NMR) spectroscopy. From the analysis, silylated or pristine clay showed its effectiveness as a catalyst in dimerization. Furthermore, alumina and alumina/silica composite showed successful performance in the reaction to yield cyclic dimer acids. These result suggested that metal oxides and montmorillonite might be used in synthesis of dimer acids for the recycle of waste vegetable oils.

Oxidative TCE decomposition over TiO2-supported single and complex metal oxide catalysts has been conducted using a continuous flow type fixed-bed reactor system. Different types of commercial TiO2 were used for obtaining the supported catalysts via an incipient wetness technique. Among a variety of titanias and metal oxides used, a DT51D TiO2 and CrOx would be the respective promising support and active ingredient for the oxidative TCE decomposition. The TiO2-based CrOx catalyst gave a significant dependence of the catalytic activity in TCE oxidation reaction on the metal loadings. The use of high CrOx contents for preparing CrOx/TiO2 catalysts might produce Cr2O3 crystallites on the surface of TiO2, thereby decreasing catalytic performance in the oxidative decomposition at low reaction temperatures. Supported CrOx-based bimetallic oxide systems offered a very useful approach to lower the CrOx amounts without any loss in their catalytic activity for the catalytic TCE oxidation and to minimize the formation of Cl-containing organic products in the course of the catalytic reaction.