皮膚科 外來 癩患者의 動態

宋浚榮,朴義守,徐舜鳳,徐基錫,河龍馬,孫在卿,金基洪,金蘭姬 大韓癩學會 1981 癩學 會誌 Vol.14 No.1

고상추출카트리지를 이용한 잔류농약 다중분석과정에서 정제용매에 따른 회수율 비교

두옥주,정보경,김경식,정의근,김진곤,김명희 한국환경농학회 2002 한국환경농학회지 Vol.21 No.2

채소류 중 비교적 matrix효과가 적고, 수분 함량이 적절하여 회수율이 양호한 오이를 대상으로 하여 총 16종의 농약 성분을 A, B 두 group으로 나누어, 농약의 동시 다성분 분석의 전처리 과정 중 정제에 사용하는 용출용매로서 5%~20%의 acetone/hexane과 5%~20%의 ethyl acetate/hexane을 사용하여 각각의 회수율을 분석하여 얻은 결과는 다음과 같다. Acetone/hexane을 사용한 경우 5% acetone에서 총 16종의 농약 성분 중 ethalfluralin, trifluralin, chlorothalonil 등 11종의 농약은 높은 회수율을 보였으나, alachlor와 iprodione, endosulfan sulfate, bifenthrin, fenarimol은 매우 낮은 회수율을 나타내었고, 10% 이상의 acetone/hexane에서는 bifenthrin과 fenarimol 제외한 14종의 농약에서 높은 회수율을 얻을수 있었다. 그러나 bifenthrin은 20%의 acetone/hexane을 사용한 경우는 용출되지 않았고, fenarimol은 10% 이하의 acetone/hexane을 사용하였을 때는 낮은 회수율을 나타냈었다. Ethyl acetone/hexane을 사용하여 총 16 종의 농약 성분의 회수율 분석을 한 결과, 5% ethyl acetone에서 ethalfluralin, α-endosulfan, β-endosulfan (A group), vinclozolin, tetradifon, cyprethrin, fenvalerate (B group)에서만 70% 이상의 회수율을 얻었다. 10%의ethyl acetone/hexane을 사용하여 분석한 경우는 trifuralin, chlorothalonil, α-endosulfan, β-endosulfan, endosulfan sulfate(A group), vinclozolin, procymidone, tetradifon, cypermethrin, 그리고 fenvalerate(B group) 에서는 70% 이상의 회수율을 얻었고, 20%의 cthyl acetone/hexane 을 사용하여 분석한 경우는 5%나 10%의 ethyl acetone/hexan 을 사용하여 분석했을 때보다 좋은 결과를 나타내어 전체 16종의 농약 중 14종에서 75% 이상의 회수율을 얻었으나, alachlor와 bifenthrin은 매우 낮은 회수율을 보여서 ethyl acetate 와 hexane의 혼합용매가 이들 두 농약성분의 분석에는 적합하지 않은 용출 용매임을 알 수 있었다. A study was carried out to optimize the cleanup step using a solid-phase extraction (SPE) cartridge, SupelClean^(TM) Florisil, for multiresidue analysis of 16 pesticides in cucumber matrix. Eluting efficiencies of two solvent systems including acetone/n-hexane and ethyl acetate/n-hexane mixtures were critically evaluated by recoveries of target anaytes from the SPE Florisil column. Based on the recovery as a measure of eluting efficiency, an acetone/n-hexane (20/80,v/v) mixture provided more than 80% recovery for 15 pesticides except bifenthrin. In case of ethyl acetate/n-hexane, 14 pesticides showed recoveries higher than 75%, while those for alachior and bifenthrin were less than 30%.

Effects of heat-treatment temperature on carbon-based composites with added illite

Eui-Gyung Jeong,Jin-Hoon Kim,Young-Seak Lee 한국탄소학회 2011 Carbon Letters Vol.12 No.2

To investigate new applications for illite as an additive for carbon-based composites, the composites were prepared with and without illite at different heat-treatment temperatures. The effects of the heat-treatment temperature on the chemical structure, microstructure, and thermal oxidation properties of the resulting composites were studied. As the heat-treatment temperature was increased, silicon carbide SiC formation via carbothermal reduction increased until all the added illite was consumed in the case of the samples heat-treated at 2,300℃. This is attributed to the intimate contact between the SiO2 in the illite and the phenol carbon precursor or the carbon fibers of the preform. Among composites prepared at all temperatures, those with illite addition exhibited fewer pores, voids, and interfacial cracks, resulting in larger bulk densities and lower porosities. A delay of oxidation was not observed in the illite-containing composites prepared at 2,300℃, suggesting that the illite itself absorbed energy for exfoliation or other physical changes. Therefore, if the illite-containing C/C composites can reach a density generally comparable to that of other C/C composites, illite may find application as a filler for C/C composites. However, in this study, the illite-containing C/C composites exhibited low density, even when prepared at a high heat-treatment temperature of 2300℃, although the thermal oxidation of the resulting composites was improved.

New Application of Clay Filler for Carbon/Carbon Composites and Improvement of Filler Effect by Clay Size Reduction

Eui-Gyung Jeong,Jin-Hoon Kim,Young-Seak Lee 한국탄소학회 2010 Carbon Letters Vol.11 No.4

To investigate new potential application of a clay material for C/C composites, illite added C/C composites were prepared with various illite contents. The improvement of filler effect by illite size reduction was also investigated using wet ballmilling by evaluating illite/phenolic resin infiltration using bulk density and porosity measurements, chemical structural changes of the composites using XRD, and thermal oxidation stability in air of the composites using TGA. The size reduction of illite resulted in narrower particle size distribution and improved illite infiltration into carbon preform. And the resultant C/C composites prepared with illite had even more improved thermal oxidation stability in air, showing more increased IDTs up to 100℃, compared to those of the C/C composites with pristine illite, due to the SiC formation through carbothermal reduction between illite and carbon materials. The illite induced delay in oxidation of the illite-C/C composites was also observed and the delayed oxidation behavior was attributed to the layered structure of illite, which improved illite/phenol resin infiltration. Therefore, the potential use of illite as filler to improve oxidation stability of C/C composite can be promising. And the size reduction of illite can improve its effect on the desired properties of illite-C/C composites even more.

불소화 일라이트/폴리프로필렌 복합섬유 형성 및 열 및 기계적 특성

정의경 ( Eui Gyung Jeong ),이영석 ( Young Seak Lee ) 한국공업화학회 2011 공업화학 Vol.22 No.5

본 연구에서는 천연물을 이용한 기능성 섬유를 제조하기 위하여 미처리 및 불소화 일라이트를 첨가하여 일라이트/PP 복합섬유를 용융방사로 제조하고 그 물리적 특성을 고찰하였다. 복합필라멘트 형성 시 층상구조를 가지는 일라이트의 윤활특성으로 순수 PP 필라멘트에 비해 복합필라멘트의 직경이 감소하는 현상이 나타났으며, 불소화의 효과로 인한 계면 친화성 향상 및 분산성 향상으로 불소화 일라이트/PP 복합필라멘트의 직경이 순수 PP 필라멘트의 2/3 정도로 감소하였다. 미처리 및 불소화 일라이트 모두 일라이트/PP 복합필라멘트의 열안정성을 향상시키는 효과가 있는 것으로 확인되었다. 또한, 미처리 일라이트/PP 복합필라멘트는 연신 공정을 거칠 때 절사가 발생하여, 복합섬유로서 활용 될 수 없었으나, 불소화 일라이트/PP 복합필라멘트는 연신 후 순수 PP 필라멘트와 비슷한 인장강도를 가지고, 50%정도 증가한 탄성률을 가지는 것으로 보아 복합섬유로서 사용될 수 있음을 확인할 수 있었다. 일라이트/PP 복합필라 멘트를 형성 시, 불소화를 통하여 일라이트/PP간의 계면 친화성이 향상되고 고분자 내 분산성은 향상이 되었으나, 층간 결합력이 강한 비팽윤성 일라이트 고유의 성질로 인하여 일라이트의 박리나 PP의 일라이트 내 층간삽입이 충분히 발생하지 않은 것으로 보아 나노복합체가 아닌 마이크로 복합체를 형성하는 것으로 여겨진다. This study investigated illite/polypropylene (PP) composite filament formation via melt-spinning and evaluated their physical properties to prepare functional fibers using natural materials. When composite filaments were formed, the composite filaments exhibited smaller fiber diameters compared to that of neat PP filament because of the lubricant effect of illite induced by its layered structure. Moreover, fluorination effect increased interfacial affinity and dispersion in the polymer, resulting in smaller diameter of fluorinated illite/PP composite filament, which was 2/3 of the neat PP filament diameter. Addition of raw and fluorinated illite improved thermal stability of illite/PP composite filament. Raw illite/PP composite filament cannot be used for a practical application, because it broke during drawing process, whereas the fluorinated illite/PP composite filament can be used for a practical application, because it exhibited similar tensile strength of the neat PP filament and 50% increased modulus. Even with improved illite/PP interfacial affinity and illite dispersion in the polymer, illite/PP composite filament formed microcomposite, because non-expandable illite had strongly bound layers, resulting in only a little illite exfoliation and PP intercalation into illite.

내설악 전(젓)나무 고목림 구조 기초 조사

정의경 ( Eui Gyung Chung ),윤영일 ( Young Il Youn ) 한국환경생물학회 2005 환경생물 : 환경생물학회지 Vol.23 No.2

본 연구는 전나무림 생태계 이해를 위하여 전나무 임분구조에 관한 기초자료를 수집하는 조사의 일부이다. Leibundgut(1981)의 임분구조 분류에 따르면 A, B 임분은 쇠퇴기로 추정되며 C는 갱신기, D는 안정기와 쇠퇴기 복합형, E는 불안정한 시기인 택벌상으로 추정된다. Forest stand structure was surveyed to understand the Korean fir (Abies holophylla) dominant forest ecosystem in Nae-Sorak mountain. Despite limited surveyed area, a diverse forest structure, a characteristic in natural forests, is well presented in the area. According to Leibundgut`s (1984) classification of forest structure, stand A, B represents declining stage, stand C regeneration stage, stand D combination of stabilizing and declining stage, and stand E unstable stage of selection.

Investigation of β-Lactamase-producing Multidrug-resistant Pseudomonas aeruginosa Isolated from Non-Tertiary Care Hospitals in Korea

( Eui Suk Sohn ),( Jeong Sik Yoo ),( Jeom Kyu Lee ),( Kyeong Min Lee ),( Gyung Tae Chung ),( Eun Shim Shin ),( Sun Young Han ),( Sang Hee Lee ),( Joon Kim ),( Yeong Seon Lee ) 한국미생물생명공학회 2007 Journal of microbiology and biotechnology Vol.17 No.10

CaO 촉매에서 N2O 분해반응

김의식,권학선,이경우 한국공업화학회 2001 응용화학 Vol.5 No.2

Recently, N₂O emission from fossil fuel combustion has become a focus of attention since N₂O is not only a greenhouse gas but also an agent of ozone destruction in the stratosphere. The calcium oxide(CaO) is known to be a catalyst of N₂O decomposition. This study was carried out N₂O decomposition over calcium oxide by use of a fixed bed reactor. It was found that N₂O decomposition increased with increasing temperature. The result of kinetic study gained the heterogeneous reaction rate on N₂O decomposition. Reaction rate is 서식

하수처리시설의 슬러지 수거 일정계획 수립 및 수거차량 경로결정

최경현(Gyung-Hyun Choi),조중무(Joong-Mou Cho),노의수(Eui-Soo Noh),김민제(Min-Je Kim),허은정(Eun-Jung Heo) 한국산업경영시스템학회 2007 한국산업경영시스템학회지 Vol.30 No.1

  In this paper, we propose sludge collection strategies which allocate each sewage store of village to sewage treatment plants and decide the schedule of sludge collection in order to collect sludge efficiently. The strategies aim to decrease transportation cost with deciding proposed vehicle routing and scheduling the sludge collection. When we decide route of vehicles, we consider the collection time in sewage store of village, distance between sewage store of villages and vehicle information as average velocity of vehicle, operation time of vehicle driver. We also develop the SCMS (Sludge Collection Management System) based on windows system with real data which is used in certain circumstance. And we experiment to figure out vehicle route and transportation cost throughout changing input data.

플라즈마 CVD 의 특성과 그 적용

임경대,윤의박 ( Gyung Dae Lim,Yoon Eui Park ) 대한금속재료학회 1997 大韓金屬學會會報 Vol.10 No.1