한국형 후각검사 KVSS Test의 개발

홍석찬,유영석,김은서,김석천,박수홍,김진국,강성호 대한이비인후과학회 1999 대한이비인후과학회지 두경부외과학 Vol.42 No.7

통계분석법을 이용한 영산강 유역의 수질평가

정희정 ( Hee Jeong Jeong ),허유정 ( Yu Jeong Huh ),이영재 ( Yeong Jae Lee ),김갑순 ( Kap Soon Kim ),유창석 ( Chang Seok Yoo ),임병진 ( Byung Jin Lim ) 한국물환경학회 ( 구 한국수질보전학회 ) 2010 공동 추계학술발표회 Vol.2010 No.-

Synthesis of Zeolite Added Clay and Sewage Sludge

Yoo, Yeong Seok,Cheon, Kyeong Ho,Lee, Jae Ik,Ban, Hyo Jin,Seo, Gyu Tae Trans Tech Publications, Ltd. 2009 Materials science forum Vol.620 No.-

<P>Zeolite has been used as catalyzer, absorbent, ion-exchange matter and dehydrating agent due to its excellent catalytic property and ion-exchange. In recent years, many studies have been conducted to apply zeolite as new materials such as zeolite membranes and zeolite sensor films. To introduce properties of zeolite, it should be examined how zeolite could be reacted other materials. In this study, it is investigated whether zeolite is successfully synthesized or not when clay and/or sewage sludge coexist with zeolite precursor. Zeolite precursor was made of liquid sodium silicate and sodium aluminate. Mixing ratio of caly and/or sewage sludge is 0-10%(wt.). To compare two processes, the mixture was synthsized by hydrothermal method and high temperature sintering process. It is synthesized by hydrothermal with sintering at high temperature process. The resulting materials were characterized by XRD and SEM. As a result, various type of zeolite such as zeolite X, zeolite A and zeolite P1 was successfully synthesized by hydrothermal method when clay and/or sewage coexist with zeolite precursor. However, zeolite was rarely synthesized by high temperature sintering process. Therefore, when preperation of zeolite material mixed with other material such as clay and sewage sludge, hydrothermal method is more effective than sintering at high temperature process.</P>

MODELING AND SIMULATION OF ENERGY DISTRIBUTION SYSTEMS IN A PETROCHEMICAL PLANT

Yoo, Yeong Ho,Yi, Heui Seok,Yeo, Yeong Koo,Kim, Myung Kil,Yang, Hong Suk,Chung, Kwang Pil 한국화학공학회 1996 Korean Journal of Chemical Engineering Vol.13 No.4

A systematic method for analysis and design of plant-wide energy distribution systems is proposed to minimize the net cost of providing energy to the plant. The method is based on the steady-state modeling and simulation of steam generation process and steam distribution network. Modeling of steam generation process and steam distribution network were performed based on actual plant operation data. Heuristic operational knowledges are incorporated in the modeling of steam distribution network. Newton's iteration method and a simple linear programming algorithm were employed in the simulation. The letdown amount from superheated high-pressure steam (SS) header and the amount of SS produced at the boiler showed good agreement with those of actual operational data.

Development of Artificial Soil Using Sewage Sludge

Yoo, Yeong Seok,Shin, Hyun Chul,So, Hyung Suk,Kim, Beom Suk,Kim, Jong Bo Trans Tech Publications, Ltd. 2007 Materials science forum Vol.544 No.-

<P>We made artificial soil using sewage sludge, the organic wastes. The optimum composition is 50% of sewage sludge cake, 45% of illite low-quality clay, 3% of glassfrit, and 2% of other components. The surface was coated with γ-alumina. For an optimum manufacturing condition, we sintered and bubbled the plastic material with dry surface by flowing N2 gas at 800°C for 20 minutes. The developed artificial soil shows excellent characteristics; more than 60% of porosity, of 0.8 of density g/cm3, 80ton/m2 of compression, pH 7.4, cation exchange capacity (CEC) 10 meq/100g and about 2000 of hydraulic conductivity. The developed product performs 1.5 ~ 10 times better than the existing perlite in open porosity, nutrient holding capacity, proof compression and CEC. However, the bulk density is 1.5 times higher and heavier than perlite, it is not so problematic to green roof. The developed artificial soil shows positive effect on the development of ecotype leaf or the growth speed by period comparative to the common fertile soil. The number of pollens and lipid shows excellent growth on the artificial soil. The product can be applied to various kinds of plants such as flowering plants, foliage plants, trees and ground cover plant. It can also be applicable to other large amounts of plants grown on the other artificial grounds (slope, road, etc.)</P>

Characteristics of Pollutants Removal by Carbonized Porous Media Made from Sewage Sludge 

Yoo, Yeong Seok,Jo, Jun Ho,Seo, Gyu Tae Trans Tech Publications, Ltd. 2015 Materials science forum Vol.804 No.-

<P>In this study, carbonized porous media was manufactured using sewage sludge and analyzed for pollutants removal characteristics. Sewage sludge produced by activated sludge sewage treatment contained much organics to be carbonized, so it was mixed with other mixtures, extruded and formed in ∅ 5~10 mm ball shape, and sintered at 900°C and 1 hour in furnace for carbonization under N2 purge. The characteristics of the porous media was BET 35 m<SUP>2</SUP>/g and average pore size 39.3Å, pore volume 0.0092 cm<SUP>3</SUP>/g, Iodine number 45.9 and bulk density 0.91 cm<SUP>3</SUP>/g. Experiments were performed for SS, phosphate, nitrate and heavy metals (Cu, Zn). Its removal characteristics of SS and fertilizer components were compared with gravel’s used in filtration and its heavy metals removal was characterized by derivation of its adsorption equilibrium equations. In result, the carbonized porous media could be utilized as massive adsorption media for pollutant removal or fertilizer adsorption in fields of roof planting or non-point source pollutants control.</P>

Characteristics of MSWI Ash and its Application to Zeolite Synthesis

Yoo, Yeong Seok,Jo, Jun Ho Trans Tech Publications, Ltd. 2015 Materials science forum Vol.804 No.-

<P>In this study, composition for bottom ash and fly ash of MSWI was analyzed and zeolite was synthesized in order to expand its recycling on high quality and mass consumption. Analysis of ash its characteristics was performed by XRF, XRD, SEM, EDX, TG/DTA. Bottom/fly ash was fired for elimination of unburned carbon at 750°C/12 hr, crushed and synthesized to zeolite in 1, 2, 3, 4, 5 M NaOH solutions under 105°C/24hr by hydrothermal method. Calcite and calcium-silicate compound was mainly contained in bottom ash and CaCl2∙4H2O, Ca (OH)2, NaCl, and calcite and KCl in fly ash. Especially amount of Cl was much contained in fly ash due to Korean food waste characteristics. Bottom ash could synthesize Zeolites in form of sodalite under 3~4 M NaOH and fly ash could synthesize Zeolite A under 1~2 M NaOH. In addition, zeolite synthesized with bottom ash had higher specific surface area and zeolite from fly ash had higher CEC value. Accordingly, ash from MSWI could be recycled for further valuable uses such as non-point pollutant control and/or soil amendment.</P>

The Effect of Aging on Synthesis of Zeolite at High Temperature

Yoo, Yeong Seok,Ban, Hyo Jin,Cheon, Kyeong Ho,Lee, Jae Ik Trans Tech Publications, Ltd. 2009 Materials science forum Vol.620 No.-

<P>Zeolite are used as adsorbent, catalyst and ionexchang material. But it limited to extend the usage of the zeolite since almost zeolite synthesized by hydrothermal method. The purpose of this study was to synthesis zeolite by calcination at high temperature due to extend the application of zeolite, as ceramics process. The effect of aging temperature and time, crystallization temperature on the synthesis of zeolite has been studied. Aging was performed at room temperature~70°C during 0~3days. After aging, zeolite precursor sinter for 1 hours at 300, 400, 500°C in furnace. The resulting materials were characterized by XRD, TG, SEM When the aging time is less than 1 day zeolite was not synthesized. But zeolite A obtained from precursor of aging time is more than 1 day at all firing temperature. As a result the aging time and aging temperature is increased, the zeolite synthesis time is decreased. Therefore aging is benefit process on synthesis of zeolite at high temperature. </P>

신라ㆍ발해 시대의 정부 조직에 관한 연구

유석영(Yoo Seok-yeong) 서울행정학회 1999 한국사회와 행정연구 Vol.10 No.1

모델링에 의한 퇴비화 시설의 운전성에 관한 연구

유영석(Yeong Seok Yoo),김이태(I Tae Kim),지재성(Chai Sung Gee) 유기성자원학회 1995 유기물자원화 Vol.3 No.2

퇴비화 시설은 공기량과 수분 조절만으로 운전되기 때문에 2 개의 운전인자의 영향을 분석하기 위하여 수분을 첨가하는 경우와 첨가하지 않는 경우에 대하여 공기량을 변화시켜 모델링하였다. 또한 최적의 퇴비화 환경이 조성될지라도 발열량 및 분해속도에 따라 퇴비화 시설의 운전온도를 달리하여야하므로,고속분해 단계와 완속분해 단계의 운전온도를 변화시켜 모델링함으로써 퇴비화 공정에 대한 영향을 분석하였다. 한면 모텔은 미국 Roger T. Haug Inc 에서 개발한 “The Library of Compost Engineering Software" 를 사용하였다. 결과적으로 적정 함수율의 퇴비화 시설 운전이 공기량 변화에 대하여 운전온도의 변화가 민감하며, 수분이 부족한 경우에 비하여 오히려 적은 공기량으로 높은 반응율을 달성하게 된다. 완속분해 단계의 효과적인 운전이 전 공정의 분해율을 높일 수 있으므로 완속분해 물질의 분해에 춧점을 맞추어 단계별운전온도를 설정하여야 함을 알 수 있었다. Composting facilities are operated with air and moisture control. Composting effects on two operating factors was analysed changing aeration rate with and without water addition to maintain the optimun moisture level. Though the composting facilties are provided with appropriate surroundings for compositing, operating temperature is set for decomposition rate. Accordingly control of decomposition phases was analysed by modeling the process of high and low decomposition phases with various operating temperature. A composting model of ‘The Library of Compost Engineering Software" developed by Roger T. Haug Inc. in U.S.A. was applied in modeling. As result of this study, operation with optimum moisture has more sensitive temperature to aeration fluctuation and lead to higher reaction rate with lower aeration than operation with poor moisture. Decomposition rate in composting facilities depend on slow decomposition phase because high rate decomposing substances already have been decomposed before entire process is not completed. In order to enhance decomposition rate of organics, eHective decomposition in slow decomposition phase needs to be focused.