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최명재 ( Myung Jae Choi ),박혜경 ( Hae Kyung Park ),윤석환 ( Seuk Hwan Yun ),이장호 ( Jang Ho Lee ) 한국물환경학회 2012 한국물환경학회지 Vol.28 No.2
The fish community within the lake and 5 tributaries of Lake Chungju in spring and autumn, 2009 was surveyed. In this study, the total 128,506 individuals were collected belonging to 11 families 29 genera 34 species. The most dominant species was Squalidus japonicus coreanus that account for 91.6% of population and 49% of biomass of fish community. In the point of population, dominant species were small-sized species, which became the prey of big-sized predatory species. In the point of biomass, dominant species were predatory species which were large-sized. The most dominant species in lacustrine area was S. japonicus coreanus which accounted for 92.2% of total population and 49.1% of total biomass. The most dominant species of tributary streams was Tridentiger brevispinis which accounted for 66.4% of total population and 55.1% of total biomass. The site of C3 in lacustrine area and Dongdal-cheon in tributary streams collected the most number of species. Through ecological health evaluation of five tributary streams using 8 metric index of biological integrity (IBI) model, two streams (Dongdal-cheon, Kwang-cheon were evaluated as, B, good condition, and Jangsung-cheon obtained grade C indicating Fair condition, Jecheon-cheon obtained grade D indicating Poor condition based on IBI model. Lepomis macrochirus which was designated as a domestic ecosystem-disturbing alien species with wide food niche have shown tendency to increase the number of individuals since 1991 indicating the adverse effect on not only fish community but also aquatic ecosystem food web of Lake Chungju.
MoO3 / bismuth molybdate 혼합 2상 촉매의 구조에 따른 프로필렌 선택산화반응 특성
차태병,최명재,박대원,정종식 ( T . B . Cha,M . J . Choi,D . W . Park,J . S . Chung ) 한국공업화학회 1992 공업화학 Vol.3 No.1
프로필렌을 선택산화시켜 아크로레인을 제조하는 반응을 Bi-molybdate 촉매상에서 고정층 반응기를 사용하여 연구하였다. α-Bi_2Mo_3O_12 위에 MoO_3를 담지시킨 M/BM-series 촉매는 함침법으로 제조되었고, 역으로 BM/M-series 촉매는 MoO_3 위에 α-Bi_2Mo_3O_12을 침전시켜 제조하였다. 또한 촉매의 특성분석을 위하여 질소흡착과 XRD, SEM을 이용하였다. M/BM-series 촉매에서는 MoO_3가 작은 입자로 분산되고 α-Bi_2Mo_3O_12의 결정구조는 MoO_3상이 추가되어도 그 형상이 변하지 않는 채로 유지되었으나, BM/M-series 촉매의 표면형상 및 전체 구조는 촉매제조 중에 생기는 침전물인 Bi(OH)_3가 소성 도중 MoO_3와 반응하여 α-Bi_2Mo_3O_12을 형성하는 관계로 그 조성에 따라 매우 불규칙적으로 변화하였다. 반응실험 결과, 두 종류의 촉매 모두에서 excess MoO_3가 포함되었을 때 활성이 크게 증가하였는데, 이는 선별산화반응이 주로 α-Bi_2Mo_3O_12에서 일어나고 MoO_3는 α-Bi_2Mo_3O_12에 산소 공급을 원활히 하여 활성을 증가시키기 때문으로 판명되었다. 또한 이러한 활성 증가는 α-Bi_2Mo_3O_12와 기계적 혼합물 (mechanical mixture)에서도 관찰되었다. M/BM-series catalysts, MoO_3 supported on α-Bi_2Mo_3O_12 were prepared by impregnation method. BM/M-series catalysts, α-Bi_2Mo_3O_12 supported on MoO_3 were also prepared by coprecipitation. Structure and catalytic properties of the two phase catalysts were studied by means of using nitrogen adsorption, X-ray diffraction, and scanning electron microscopy. The reaction test for the selective oxidation of propylene to acrolein over Bi-molybdate catalysts was studied using a fixed-bed reactor system. In M/BM -series catalysts, MoO_3 was dispersed on α-Bi_2Mo_3O_12, and the crystal structure of α-Bi_2Mo_3O_12 remains unchanged by the presence of excess MoO_3. However the surface morphology and bulk structure of BM/M-series catalysts were altered probably because the precipitated Bi(OH)_3 reacted with MoO_3 during the calcination to form α-Bi_2Mo_3O_12 phase. The results of propylene oxidation on both series catalysts showed that the reaction took place over the surface of α-Bi_2Mo_3O_12 particle and the role of excess MoO_3 was to supply oxygen to α-Bi_2Mo_3O_12. These increasing effects on activity were also observed in the mechanical mixtures of α-Bi_2Mo_3O_12 and MoO_3.