• 한국지반환경공학회 논문집
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• 제25권5호
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• pp.5-13
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• 2024

본 논문에서는 유기오염물질인 benzyl butyl phthalate(BBP)에 오염된 퇴적토를 산/염기 개질활성탄을 이용한 퇴적토의 안정화 과정과 그 영향을 연구하였다. 실험을 통해 안정화제의 효율성을 평가하고, Lumbriculus variegatus를 이용한 생물학적 영향과 함께 개질활성탄의 혼합량 증가가 오염물질의 흡착에 미치는 영향을 분석하였다. 또한, low-density polyethylene를 사용한 공극수 내 유기오염물질 농도 측정을 통해 안정화제가 환경 내 오염물질의 이동을 어떻게 제한하는지에 대해 조사하였다. 연구 결과 Lumbriculus variegatus의 생존률이 90% 이상을 나타내었으며, 체내 BBP 축적 농도는 개질활성탄을 10% 혼합한 두 실험군보다 개질활성탄을 5% 혼합한 두 실험군이 약 2% 낮은 농도를 나타내었다. 수중으로의 용출량은 노출기간 7일 경과 후 모든 실험조건에서 대조군 대비 18% 이상 저감 되었으며, 노출기간 28일 후 모든 실험조건에서 25% 이상 저감된 효율을 확인하였다. 공극수의 농도를 측정하였다. 7일 노출 후의 결과는 기계혼합 실험군이 생물혼합 실험군 보다 높은 안정화율을 보였으며, 기계혼합 실험군에서, 개질활성탄을 10% 혼합한 실험군이 개질활성탄을 5% 혼합한 실험군 보다 1% 높은 안정화율을 보였다. 28일간 노출 후의 결과는 생물혼합 실험군이 기계혼합 실험군보다 높은 안정화율을 보였으며, 개질활성탄을 10% 혼합한 생물혼합 실험군이 개질활성탄을 5% 혼합한 실험군보다 약 0.1% 높은 안정화율을 보였다.

• 대한방사선기술학회지:방사선기술과학
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• 제26권1호
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• pp.39-44
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• 2003

Sodium Carboxy Methyl Cellulse(이하 SCMC)와 $BaSO_4$의 특성분석을 통하여, 소장조영 검사에 효과적인 조영제의 W/V% 농도와 점도를 알아보고자 하였으며 이를 통한 소장질환의 미세한 병변 진단에 대한 효율성을 높이고자 실험하였다. 그 결과 100 KVp 고압촬영 방식에서 살펴 볼 때, 높은 투과율로 검사의 효율성이 증대되었다. 압박 촬영과 이중조영 촬영을 시행함에 있어, High Density바륨 사용으로 인한 광학 농도의 차이를 극복함으로서 High Contrast 영상을 얻을 수 있다. CMC-Na의 평균농도 0.625 W/V%으로 선예한 이미지를 얻을 수 있었으며, 적정한 점막 코팅과 검사시간도 단축시킬 수 있다. 결론적으로, F그룹 방식의 CMC-Na을 혼합한 황산바륨 조영제를 조제하여 사용해본 결과, 경구소장조영 검사에 대한 모든 조건에 만족할 만한 것으로 나타났다.

• 한국재난정보학회 논문집
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• 제4권1호
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• pp.86-100
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• 2008

It is needed to classify the kinds of construction and demolition(c&d) debris to 6 catagories of waste concrete, waste asphalt concrete, waste wood, scraps, combustible waste and incombustible waste in order to properly do a separate discharge and to estimate unit generation rate in construction site. Also, in this case, the unit treating cost for mixed wastes should be applied with the unit treating cost for combustible waste. The construction standard materials estimation data is used for basic data for estimating unit generation rate. The mixed wastes in this data should be classified to waste wood, combustible waste and incombustible waste, and their ratio is obtained by using the unit generation rate of Asia Pacific Environment and Management Institute and Seoul Metropolitan Development Institute. The waste amounts generated from newly-built construction can be obtained from multiplying the loss rate by the amount of materials used from construction standard estimation data. Also, those from dismantling construction can be obtained by subtracting waste amount generated during newly-built construction from total input amount of materials in newly-built construction. Those in two cases can be used in construction site. It can be used for estimating the amount generated and establishing the treating plan in the case of setting up the policy of waste management and doing the environment impact assessment.

• Toxicological Research
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• 제17권1호
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• pp.7-9
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• 2001

The quantitative assessment of the penetration of organic solvents through skin is necessary for the evaluation of health hazards in occupational environments. We investigated the rate of dermal penetration when mixed or single forms of organic solvents were placed into a diffusion cell in vitro or into an experimental animal in vivo. The diffusion rates of methanol. toluene, and styrene were 6.07, 0.129, and 0.046 mg/$cm^2$/h, respectively. When skin was exposed to the mixed solvent of methanol and toluene, the penetration rate of toluene did not change significantly (0.110 mg/$cm^2$/h). However, the rate of methanol penetration increased to 43.90 mg/$\textrm{cm}^2$/h. The penetration rate of methanol also increased significantly to 54.69 mg/$cm^2$/h by mixing it with styrene. The concentration of methanol in the blood was monitored during the epicutaneous exposure in rats. The blood concentration of methanol was increased by mixing methanol with toluene as seen in the in vitro experiments. These results showed that the penetration rate of organic solvents would be enhanced by mixing them with other solvents.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 춘계 학술논문 발표대회
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• pp.180-181
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• 2017

This study aims to analyze the high strength mortar's fundamental properties and autogenous shrinkage properties by taking into consideration the result of the previous study in which it was found that ERBO(Biodiesel) exercises greatest effect on the expansion effect of mortar, and changing the time and rate of mixing the ERBO. A total of five levels were set as experimental variables: the three levels of the rate of ERBO, 0, 0.5, 1.0%, and the two levels of the time of mixing the ERBO: first, adding the ERBO with the mixing water and mixing it before, and second, mixing it after the mortar is completely mixed. It was found that the rate of length change decreased as the rate of ERBO increased, and the rate of length change was lower when the ERBO was mixed sooner.

• 유기물자원화
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• 제27권3호
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• pp.41-48
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• 2019

유기질 비료 중 혼합유박은 작물생산성과 토양의 비옥도를 높일수 있는 농자재중 하나이다. 그러나 배추 재배시 혼합유박의 적정시용량에 대한 연구는 미비한 실정이다. 이에 본 연구는 혼합유박의 밑거름 시용량에 따른 배추의 생육, 수량 및 토양특성 변화를 확인하고 이를 통해 혼합유박의 밑거름 적정 시용량을 제시하고자 하였다. 본 시험은 무처리, NPK처리구($N-P_2O_5-K_2O$ : $320-78-198kg\;ha^{-1}$), 혼합유박 처리구는 밑거름을 질소기준 $210kg\;ha^{-1}$을 50, 100 및 150% 수준으로 기비하고 추비는 시기에 맞게 시비하는 것으로 설정하였다. 배추의 생육은 무처리구를 제외하고는 통계적 유의성은 없었으나, 수량의 경우 NPK 처리구 > MEC 150% 처리구 > MEC 100% 처리구 > MEC 50% 처리구 > 무처리구 순이었다. 처리구에 따른 질소 이용 효율은 혼합유박 처리량이 증가할수록 증가하는 경향이었다. 토양 특성의 경우 pH, OM, $Av.P_2O_5$, $NH_4-N$ 및 Ex.K의 경우 유의적인 차이는 없었으나 EC 및 $NO_3-N$은 혼합유박의 밑거름 시용량이 증가할수록 약간 증가하는 추세였다. 이를 통해 수량을 위한 혼합유박 밑거름 적정시용량은 밑거름 150% 처리인 것으로 판단된다.

• Journal of Chest Surgery
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• 제17권4호
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• pp.565-573
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• 1984

The increasing use of cardioplegic solution for the reduction of ischemic tissue injury requires that all cardioplegic solution be carefully assessed for any protective or damaging properties. This study describes functional assessment of the efficiency of steroid in cardioplegic solution by using a Langendorffs perfusion model. Isolated rat heart were subject to a 2 minute period of coronary infusion with the steroid mixed cold cardioplegic solution immediately before and also at the midpoint of a 60 minutes period of hypothermic [10\ulcorner\ulcorner] ischemic arrest. The result of this study were as follows: 1.Spontaneous heart beat after ischemic arrest occurred 14 second later Langendorffs reperfusion in the steroid mixed Young & GIK group and 16 second later in the control group. [Young & GIK without steroid] A good recovery state of spontaneous heart beat was shown in both groups. 2.The percentage of recoveries of heart rate during the 30 minute after postischemic Langendorffs reperfusion was; at first 5 minute 106.3\ulcorner.7% [P<0.05] in the steroid mixed Young & GIK group. This percentage of recovery of steroid mixed Young & GIK group was significantly greater than the control group during the first 5 minute course. 3.The percentage of recovery of coronary flow during the 30 minute after postischemic Langendorffs reperfusion was; at first 5 minute 101\ulcorner.2% in the steroid mixed Young & GI K group. This percentage of recovery of the steroid mixed Young & GIK group was not significantly than the control group during the first 5 minute.

• 대한기계학회논문집
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• 제15권6호
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• pp.2125-2131
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• 1991

본 연구에서는 고온고압의 기류중에 투입된 미소연료액적의 증발에 관한 정보 를 구하여 분무연소기구의 해명을 위한 기초테이터를 제공하려 시도한다.

• 한국농공학회지
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• 제39권2호
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• pp.32-43
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• 1997

Abstract A series of permeability tests was performed on the mixtures with specific mixing rates of sand and bentonite using modified rigid-wall permeameter. Sand-bentonite mixtures were permeated by organics, ethanol and TCE. Permeability of bentonite with several mixing rates had a tendency to decrease up to initial one pore volume and permeability was thereafter converged to a constant value. When sand-bentonite mixtures was permeated by water, permeability was decreased at the beginning but it was thereafter converged to a constant. Among several mixing rates, permeability was greatly decreased at 15% of mixing rate. When sand-bentonite mixtures with 15% mixing rate was permeated by ethanol, permeability was about 10 times larger value than permeability of water. Peameability was shown greater values when permeated by TCE (TrichloroEthylene) followed by ethanol. Suitable mixing rate of sand-bentonite for a liner of waste landfills was detected.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2003년도 추계학술대회 및 정기총회
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• pp.263-266
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• 2003

This paper is intended to compare between the Bayesian estimates of hazard rate and the hazard rates of mixed distributions. In estimating hazard rates, especially when the MLE method is used, such difficulties as a lack of data and the existence of censored data make it difficult to estimate the rates. For this reason, the estimates of hazard rate based on the Bayesian approach are introduced. For the simplicity, the exponential and gamma distributions are adopted as a sampling distribution and its natural conjugate prior distribution, respectively.