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일부 농촌지역의 오염원 현황과 먹는 물 수질에 관한 조사연구
김탁수,이용미,김문선,김성연,신해철,최경호,정문호 한국환경보건학회 2004 한국환경보건학회지 Vol.30 No.2
To evaluate the quality of drinking water and contamination sources in a rural community, this study was carried out on the summer of 2003 at Shin-Dong Myun, Chun-Cheon, Gang-Won province. Seventy three drinking water samples were collected from three different types of water supply systems. Sources of contamination were identified and the public perception of water quality area were evaluated. The findings of this study are as follows; Drinking water was mainly obtained from Local Water and Simple Piped Water Supply Systems, and pollution sources varied over the study area. Most of residents (>63%) were satisfied with the quality of drinking water and could not identify any contamination sources. Corresponding to this perception, measured water quality parameters generally met the Drinking Water Quality Standards (>64%). However, approximately 35.6% of samples exceeded the regulation for Nㅒ$_3$$^{-}$$_{-}$N, coliform, and general bacteria. The water quality was significantly different among the three water supply systems, and between the potentially contaminated areas and the rest of the areas (p<0.05). In the potentially contaminated areas, the levels of coliform and general bacteria contamination were significantly higher than the rest of the areas (p<0.05). The coliform and general bacteria values of Simple Piped Water were significantly higher than Own Piped Water's, and the NO$_3$$^{-}$$_{-}$N values of Own Piped Water were significantly higher than those of water's (p<0.05). Based on this study, NO$_3$$^{-}$$_{-}$N, coliform, and general bacteria were identified as a major problem of drinking water. To regularly manage drinking water supply systems, to identify contamination sources, and to add drainage systems are required in the study area.
TiO₂ 광촉매를 이용한 Methyl parathion 농약의 분해기전과 독성저감에 관한 연구
김탁수,김정곤,최경호,조경덕 대한환경공학회 2005 대한환경공학회 학술발표논문집 Vol.2005 No.12
본 연구에서는 대표적인 유기인계 농약인 methyl parathion을 대상으로 태양광의 조사 하에 TiO₂ 광촉매반응과 광반응을 이용하여 처리하고 제거기전을 구명하는 연구를 수행하였다. 반응시간에 따른 methyl parathion의 저감과 중간생성물의 발생 그리고 이온성부산물의 생성 등의 반응양상을 관찰하였다. TiO₂ 광촉매반응이 광반응과 TiO₂ 흡착에 비해서 가장 효과적으로 methyl parathion을 제거시켰다. 38 μM의 methyl parathion은 90분 이내에 광촉매반응으로 완전히 제거되었으며 최종 반응시간 150분후에 TOC는 약 60% 감소되었다. 광촉매반응에 의한 Methyl parathion의 제거에 따라 생성된 질소는 NO₂(-), NO₃(-), 그리고 NH₄(+)로 거의 100%, 황은 SO₄<sup>2-</sup>로 약 80%, 그리고 인은 PO₄(3-)로 5% 이하로 회수되었다. 중간 생성물은 methyl paraoxon과 4-nitrophenol을 측정 하였으며, 광촉매반응 시 30분 이내에 각각 최고농도인 약 2.6 μM과 7.8 μM까지 생성되었으며 150분 이후에 거의 제거되었다. Methyl parathion을 처리함과 동시에 광촉매공정의 효율을 평가하기 위해서 두 가지 생물종 Vibrio fischeri와 Daphnia magna를 이용하여 처리수의 급성 독성실험을 수행하였다. 급성 독성실험의 결과로 광촉매반응 시 처리수의 상대독성이 초기에 비해 150분후에 거의 100% 감소되었고, 이에 반해서 광반응에서는 Vibrio fischeri와 Daphnia magna 각각에 대해서 약 80%와 40%의 상대독성 감소가 관찰되었다. methyl parathion과 TOC의 감소와 급성독성의 저감양상은 유사한 경향을 보였다.
급속응고 Al-20Si-5Fe-2x(x=Ni, Cr or Zr) 합금의 미세조직 및 기계적 특성
김탁수,千炳善 대한금속재료학회 2002 대한금속·재료학회지 Vol.40 No.8
The microstructure and mechanical properties of the gas atomized and extruded Al-20Si-5Fe-2x (x=Cr, Zr or Ni) alloys were evaluated. The alloy powder was degassed under different vacuum levels in advance of the extrusion. It was shown that the addition of a quaternary element resulted in the formation of very fine particles that contributed to the improved mechanical properties of the alloys, especially at elevated temperatures. Of these additions, nickel was found to be the most effective in increasing the UTS of the alloy both at room and elevated temperatures. Degassing the rapidly solidified powders under better vacuum improved the properties further.
무균성 뇌막염에서 증상발현부터 진단까지 걸린 시간에 따른 시기별 유병기간의 검토
김탁수,허지연,박영희,정민구,김성원,Kim, Tag Soo,Hur, Ji Yeon,Park, Young Hee,Jung, Min Goo,Kim, Sung Won 대한소아감염학회 1996 Pediatric Infection and Vaccine Vol.3 No.2
Purpose : Aseptic meningitis is relatively frequent in children and caused mostly by enterovirus. The aim of the present study was to determine the effect of early diagnosis (spinal tapping) on symptom duration of childhood aseptic meningitis. Methods : One hundred fifty-three children who were hospitalized due to aseptic menigitis in the Department of Pediatrics St. Benedict Hospital from July 1996 through October 1996 were included in this study. Patients were divided to two groups according to the duration from first symptom onset to diagnosis. Early diagnosis group is diagnosed within 3 days from first symptom onset. Later diagnosis group is diagnosed after 4 days from first symptom onset. Results : 1) The average age of these patients was 4.3 years old in early diagnosis group and 4.1 years old in later diagnosis group. The sex ratio(male: female) was 2.04:1 in early diagnosis group and 2.5:1 in later diagnosis group. 2) The mean duration of diagnosis of this study was 2.04 day in early diagnosis group and 5.12 day in later diagnosis group. 3) The percentage of symptom and sign of the early diagnosis group were fever(100%), headache(88.4%), vomiting(86.9%), abdominal pain(39%), neck stiffness(36.2%), skin rash(18.8%), diarrhea(16.9%) and that of later diagosis group were fever(100%), headache(83.3), vomiting(80.9%), abdominal pain(47.6%), neck stiffness(41.6%), skin rash(29.7%), diarrhea(16.6%). 4) Initial CSF findings revealed leukocyte $146.8{\pm}386.3/mm^3$ with PMNL 38%, protein 32.47mg/dl, sugar 66.23mg/dl in early diagnosis group and leukocyte $458.1{\pm}663.2/mm^3$, protein 31.22mg/dl, sugar 64.21 mg/dl in later diagnosis group. 5) There was no statistically significant differance in the peripheral blood findings between early diagnosis group and later diagnosis group. 6) The duration of disappearance of symptom after spinal tap were 2.3 days in early diagnosis group and 2.24 days in later diagnosis group. Total symptom duration was 4.34 days in early diagnosis group and 7.36 days in later diagnosis group. Conclusions : Our results demonstrate that early diagnosis(early spinal tap) shortened duration of clinical symptoms.
정탁수 ( Tak-su Jeong ),왕우경 ( Woo-gyeong Wang ),김상암 ( Sang-am Kim ) 한국어업기술학회 2017 수산해양기술연구 Vol.53 No.1
Butanol has an ability to improve the ignition quality due to its lower latent heat of vaporization; it has an advantage to reduce a volume of a fuel tank because its energy density is higher than that of ethanol. Also, butanol-diesel oil blending quality is good because butanol has an effect to prevent the phase-separation between two fuels. Even if the blended oil contains water, it can reduce the corrosion of the fuel line. Thus, it is possible to use butanol-diesel oil blended fuel in diesel engine without modification, and it may reduce the environment pollution due to NOx and particulate and the consumption of diesel oil. Therefore, some studies are being advanced whether butanol is adequate as an alternative fuel for diesel engines, and the results of the combustion and exhaust gas emission characteristics are being presented. Though the injection and spray characteristics of butanol are more important in diesel combustion, the has not yet dealt with the matter. In this study, the influence in which differences of physical properties between butanol and diesel oil may affect the injection and spray characteristics such as injection rate, penetration, spray cone angle, spray velocity and process of spray development were examined by using CRDI system, injection rate measuring device and spray visualization system. The results exhibited that the injection and macroscopic spray characteristics of two fuels were nearly the same.