저농도 에틸렌옥사이드에 폭로된 중앙공급십 근무자들의 건강형태 및 작업환경에 관한 연구

한문선,김재권,이동근 圓光大學校 醫科學硏究所 1999 圓光醫科學 Vol.15 No.2

Background: Hospital employees are exposed to various hazards, and turn out neglecting to health problems caused by these hazardous factors, so it is necessary to measuring hospital working environment. Methods: This study was performed to evaluate the possible effects on health following exposure to low levels of ethylene oxide in central supply sterilizing room workers. Questionnaires, measuring the volume of ethylene oxide exposure, hematologic and urinary examination were performed and the obtained results were as follows : Results: 1. Four(l7.4%) workers answered as "very serious" and 9(39.1%) answered as "serious" to the survey about the understanding the effect on the individual health when they use ethylene oxide, 9(39.1%) replied as "Yes" and 14(60.0%) replied as "No" about the question if they get the regular education, 19(82.6%) agreed to the necessity of measureing the working environment. It was found that 6(26.1%) wear the protector and 17(73.9%) do not wear the protector during their work. 2. The exposure concentration of ethylene oxide in the central supply sterilizing room was measured as follow : Average 0.076 ppm for the individual exposure, average 0.106 ppm for the main operating room, and average 0.088 ppm for the side operating room. 3. As the result of the hematologic examination, the average rate of each part except for the number of leucocytes was included in the normal category. There was a significant statistical difference in the number of leucocytes between the exposed group and the control group(p<(0.05). 4. The exposed group was divided 2 groups according to their working period as over 12 year group and under 12 year group. Although the average rate of each part was analyzed as normal, the number of leucocytes showed a significant statistical difference between the two groups(p<0.05). 5. There was no significant statistical difference between the exposed group and the control group in the urine protein test. Conclusions: Tlt is considered that they need the measuring equipment and the constant measuring management of the working environment. Furthermore, regular safety education for the preventive plans for the health troubles and keeping the rule of earing the protector during their work are recommended.

생물학적 영양염류 제거를 위한 돈사폐수의 반응특성

한동준,류재근,임연택,임재명 江原大學校 附設 環境硏究所 1998 環境硏究 Vol.15 No.-

본 연구는 생물학적 영양염류제거에 있어 돈사폐수의 반응특성을 고찰하기 위하여 수행되었다.반응특성으로는 돈사폐수 욘존 COD의 약 66.1%는 생물학적 분해가 빨리 일어나는 유기물이였으며, 생물학적 분해가 불가능한 용존COD는 약 11~12%였다. 호기성 고정생물막 반응조에서 질소는 탈기 ,질산화, autotrophic,과 heterotrophic미생물의 세포합성으로 제거되었는데, 제거율은 각각 12.1%,68,9%15,0% 그리고 4.0%였다. 돈사폐수 This study was performed to investigate the reaction characteristics of piggery wastewater for biological nutrient removal. The reaction characteristics discussed the fraction of organics the behavior of nitrogen, nitrification, denitrification and the behavior of phosohorus. The fraction of readily soluble COD was 11~12 percent. The ammonia nitrogen was removed via stripping nitrification autotrophic cell synthsis and heterotrophic cell synthesis. The removal percents by each step were 12.1%, 68.9%, 15.0% and 4.0% respectively. Nitrification inhibition of piggery wastewater was found to occur at an in fluent volumetric loading rate over 0.2 NH_(3)-Nkg/㎥/d. Denitrification rates were the highest in the raw wastewater and the lowest in the anaerobic effluent. The denitritation of piggery wastewater came out to be possibe, and the rate of organic carbon consumption deceased about 10 percent The phosphorus removed was released in the form ortho-p in the aerobic fixed biofilm reactor it was caused by autooxidation. The synthesis and release of phosphorus were related to the ORP and the boundary value for the phase change was about 170mV. In the synthesis phase, the phosphorus removal rate per COD removed was 0.023mgP_(ayn)/mgCOD_(rem) The phosphorus contents of the microorganism were 4.3~6.0% on a dry weight basis

효율적 질소제거를 위하 단일 혐기성 반응조의 개선

한동중,류재근,임연택,임재명 江原大學校 附設 環境硏究所 1998 環境硏究 Vol.15 No.-

This research aims to remove nitogen in the piggery wastewater by combined process with upflow anaerobic sludge blanket(UASB) and biofilm process. For the effective denitrification anaerobic and anoxic reactors were connected to a reactor. The effluent of aerobic reactor was recycled equally with influent in the upper filter of anaerobic reactor for denitrification and outlet of UBF reactor was connected to the settling tang with 1.5ℓ capacity and the settling sludge was repeatedly recycled to UASB zone. The organic loading rate of total reactor was operated from 0.4 to 3.1kgCOD/㎥/d and it was observed that the removal rate of TCOD was 80 to 95 percentage AMMonia nitrogen was removed over 90 percentage in the less volumetric loading rate than 0.1 kgN/㎥/d But because of non-limitation of organic materials, it was reduced to 70 perventage in the more volumetric loading rate than 0.6kgN/㎥/d But denitrification rate was observed 100 percentage in the all of loading rate. This is caused by the maintenance of optimum temperature, surfficient carbon source and competition of observed with the 71.7 percentage of influent COD. It was revealed that the most part of organic materials was removed in the aerobic and the anaerobic reactor because 38.4 percentage was conbersed into CH_(4) gas and 11 percentage was removed in the aerbic reactor with cell synthesis and metabolism. Besides, 5.7% organics was used to denitrification reaction and 3.7% organics related to sulgate reduction.

尿에 依한 完全混合 및 接觸安定 活性슬러지 工法의 比較 硏究

韓雄傳,朴東根,林哉明 釜山水産大學校 1982 釜山水産大學 硏究報告 Vol.22 No.1

Nightsoil as a major water pollution in Korea has been treated by the municipal nightsoil treatment plants. It necessary to segregate feces and urine from nightsoil collected in a privy for reducing the organic loading and making easy treatment of nightsoil in future. However, little studies have been provided for the evaluation of the kinetic coefficients when the only urine is treated. This study was, therefore, design to compare the complete mixing activated sludge (CMAS) process with the contact stabilization activated sludge (CSAS) process by the kinetic coefficients and the organics removal characteristics. Two processes were operated at continuous bench scale units by using urine as the substrate. In addition, aeration only CMAS process was operated to investigate the transition of nitrogen compounds in urine. The results obtained were as follows; 1. Kinetic coefficients of two processes CMAS CSAS Yield coefficient(Y) 0.53 0.44 Endogenous respiration coefficient(??), ???? 0.005 0.020 Saturation constant (Ks), ???? 86 86 Max. substrate utilization rate (R), ???? 1.22 1.22 2. ICOD to MLVSS were 1.48, 1.75 and 1.55 at aeration tank, contact tank and stabilization tank, respectively. 3. BOD and COD removal efficiencies were 90.5% and 45.6% at CMAS process and thoe were 87.5% and 54.4% at CSAS sprocess. 4. The amount of wasted sludge to removed BOD by two processes of CMAS and CSAS were 0.51 and 0.35. 5. Effluent water qualities of CMAS process were superior to those of CSAS process at the same influent BOD loadings. 6. MOST TKN in urine were released into the air and a little was transformed to microorganism, NO₂-N ,and NO₃-N. 7. When aeration time was 5 hours or more, the pH of the aeration tank was constant.

이온화방사선에 의한 느타리버섯(Rleurotus ostreatus)의 ITS2 염기서열 변화

이영근,장화형,한갑진,고동규,이기성 한국환경생물학회 1998 환경생물 : 환경생물학회지 Vol.16 No.4

rDNA의 ITS2(internal transcribed spacer 2)부위에 대한 이온화방사선(gamma-ray)의 영향을 알아보기 위해서 감마선을 조사한 느타리버섯(Pleurotus ostreatus)의 5종의 변이중에서 ITS2의 염기서열을 결정하였다. ITS2의 염기서열은 1 kGy 조사군(PO-5, PO-6, PO-15와 PO-16)에서 변화되지 않았으나, 2kGy 조사군(PO-14)에서는 1개의 염기가 치환되었다. RAPD(ramdomly amplified polymorphic DNA) 양상에 의한 유전유사도의 변화가 다양하였고 섬유소성 고체검정 배지에서도 다양한 생장특성을 나타내었다. 본 연구결과는 ITS염기서열이 이온화 방사선에 의해 선량의존적으로 변화될 수 있음을 시사해 주었다.

초지연제의 응결시간차를 이용하여 수평분할 타설한 매스 콘크리트의 온도이력 특성

전충근,윤치환,신동안,오선교,한천구 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2

In this paper, field application test of super retarding agent is discussed to reduce hydration heat of mass concrete considering setting time difference of super retarding agent by using horizontal placing layer in Megatrium building construction field at Yongsan in Seoul. Properties of fresh and hardened concrete and hydration heat are investigated, According to test results, both base concrete and flowing concrete meet the requirement of designed slump and air content, although some variances exist. As for compressive strength, it also satisfies the specified strength the consumer need in base concrete and hardened concrete. As for hydration heat, highest temperature of middle section in top placing layer is 65v at 28hours, and in bottom placing layer is 73℃ at 68hours.

PMMA와 SAN混合物의 劣化速度에 관한 硏究

薛秀德,韓丞完,金東建,文德柱 동아대학교 공과대학 부설 한국자원개발연구소 1988 硏究報告 Vol.12 No.2

The thermal degradation behavior of the homopolymer poly(methyl methacrylate) (PMMA) and styrene-co-acrylonitril (SAN) as well as their mixture were carried out using the thermogravimetric and infrared spectroscopy method in the stream of various gases. The activation energies evaluated by the reported various kinetics equations except PMMA80%-SAN20% Mixture agreed with each other very well. The thermal degradation of PMMA and SAN mixture were considered to be carried out by the main chain scission.

급성 심근 경색에서 시행한 관상 동맥 우회술의 조기 결과

지현근,이원용,김응중,두영철,한규록,오동진,임종윤 대한순환기학회 1998 Korean Circulation Journal Vol.28 No.8

표준 용매 벤젠의 Rayleigh 비의 온도 의존성

박일현,이종근,윤관한,조동환,민병길,방대석 金烏工科大學校 2000 論文集 Vol.21 No.-

The Rayleigh ratio of benzene is a very important physical constant with which the integrated scattered intensity of laser light scattering can be converted into the absolute value. In this study temperature dependence of Rayleigh ratio of this solvent has been investigated with two different methods in the temperature range of 25-75℃. It was found that in the direct measurement the non-linear behavior of its Rayleigh ratio were observed as increasing temperature even if the scattering volume correction was applied to the scattered intensity of benzene. However the result of indirect measurement based upon the invariance of molecular weight of standard polystyrene polymer for any polymer solution temperature showed us that its temperature dependence up to 75℃ could be expressed with the Benoit's linear equation rather than the non-linear one. It seems that the scattered intensity in direct method has more complicate contributions at the elevated temperature. Further research works are necessary in order to solve such discrepancy clearly.

2상2중쵸퍼를 이용한 축전지 충전제어

이정준,함년근,조정민,김동운,한경희 明知大學校 産業技術硏究所 2000 産業技術硏究所論文集 Vol.19 No.-

Recently, increasing of portable, importance of battery has identified. And battery is used for non-utility generation and emergency power for communication power, it has researched for power of electric vehicle. But it is disadvantage that life cycle of battery is decreased by overcharging and overdischarging. In this paper, using two phase with combined step-down chopper, we controlled charging and discharging of battery. It is dereased ripple of current and charging time with continuous current by using two phase with combined step-down chopper. Detecting the full charging voltage and cut-off voltage, it is prohibit overcharging and overdischarging with microprocessor.