• 한국농공학회논문집
• /
• 제50권4호
• /
• pp.17-24
• /
• 2008

Exposure risk assessment of pesticide molinate using the RICEWQ model in a rice paddy plot was performed to observe the effects of various water and pesticide management scenarios. Several scenarios were developed to represent the specific water and pesticide management practices of rice cultivation in Korea. The results of the scenario analysis using the RICEWQ model simulation from the previous studies were analysed. The molinate risk for aquatic organisms is evaluated by the ratio of the predicted environmental concentration(PEC) and the predicted no-effect concentration(PNEC). The results showed that the no-effect periods for aquatic organisms for the deep, shallow and very shallow irrigation conditions were 33.3, 28.9 and 25.6 DATs for the lable rate application and 36.4, 33.7 and 30.8 DATs for the double lable rate application, respectively. The higher application rate showed greater exposure risk to the aquatic organisms. Based on this study, the withholding period of molinate practiced in Korea, that is 3 to 4 DATs, must be much longer. The results of this study can be used for the non-point source pollution control and environmental policy making regarding pesticides.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
• /
• pp.42-44
• /
• 2005

Many cellular phone volunteer studies have been conducted since such a social issue is raised that the long time usage of cellular phone may increase health risk. While there were various volunteer studies using GSM cellular phone on heart rate and blood pressure at abroad, very few studies using CDMA phone were conducted in domestic and abroad. In this study, the volunteer groups of 21 adults were exposed at 300 mW for half an hour, and the physiological parameters such as blood pressure, heart rate, respiration rate, and skin impedance were measured. All the parameters' results did not reveal any differences between exposure and non-exposure conditions in adults.

• Asian-Australasian Journal of Animal Sciences
• /
• 제2권2호
• /
• pp.91-97
• /
• 1989

The present experiment was carried out to investigate the effects of heat exposure on water metabolism and the passage of indigestible particles in sheep. Water intake, respiratory rate, rectal temperature and pH of ruminal fluid and urine were significantly higher (P<0.05) in the hot environment ($32\;^{\circ}C$) than in the control environment ($20\;^{\circ}C$). Urine osmolality and blood volume were increased, while glomerular filtration rate was decreased, in the hot environment. The liquid flow rate from reticulo-rumen and the excretion of indigestible particles of specific gravity 0.99 (but not 1.27 or 1.38) were increased in the hot environment. From these findings, it is suggested that an increased water intake evoked by heat exposure might affect the flow rate of digesta in sheep.

• Asian-Australasian Journal of Animal Sciences
• /
• 제20권5호
• /
• pp.742-747
• /
• 2007

In order to investigate the mechanism of adaptation to long-term heat stress, six female buffalo calves of about 7 to 8 months age, were exposed to the cool-comfort environment (THI 65) for 21 days to obtain normal values of blood acid-base. An adaptive response of acid-base regulation was determined to long term (21 days) exposure of buffalo calves to hot-dry (THI 80) and hot-humid (THI 84) conditions. Higher rectal temperature and respiratory rate was recorded under hot-humid exposure compared to hot-dry. Significant reduction in the rectal temperature and respiratory rate on day 21 of hot-dry exposure indicated early thermal adaptation compared to hot-humid. Decreasing rectal temperature and respiratory rate from day 1 to 21 was associated with concurrent decrease in blood pH and pCO2. Increased plasma chloride concentration with low base excess in blood and in extracellular fluid suggested compensatory response to respiratory alkalosis. Reduced fractional excretion of sodium with increased fractional excretion of potassium and urine flow rate indicated renal adaptive response to heat stress.

• 한국축산시설환경학회지
• /
• 제3권1호
• /
• pp.1-12
• /
• 1997

This study was conducted to investigate the combined effects of VFA composition of rumen fluid and heat exposure (30${\pm}$2$^{\circ}C$) on the general clinical view and insulin secretory response to glucose in sheep. The total infusion of nutrients was examined in sheep via the technique of continuous alimentation. Four adult Suffolk sheep fitted with a permanent ruminal cannula and a simple T-shaped duodenal cannula were used. A peristaltic pump was used to infuse the solutions of volatile fatty acid triglycerides (VFA-TG) consisting of 70 triacetin : 20 tripropionin : 10 tributyrin (low propionin division: LP) and 50 triacetin : 40 tripropionin : 10 tributyrin (high propionin division: HP) on the basis of energy and minerals into the rumen, and casein solution into the duodenum. The effects of heat exposure and type of the levels of VFA-TG solutions on the insulin secretory response to glucose in sheep were investigated by using hyperglycemic clamp (HGC) technique. The results obtained are summarized as follows: 1. During the heat exposure (latter half of the infusion period), respiration rate, heart rate and rectal temperature increased (P＜0.01, P＜0.01, P＜0.05), but the levels of VFA-TG solutions (LP and HP division) did not affect the general clinical view except for the heart rate. 2. In the HGC technique, glucose infusion rate (GIR) and mean plasma insulin increments (MPII) tended to be ower in the heat exposure than in the thermoneutral environment, but no significant difference was found among the treatments. GIR and MPII remained unchanged between the levels of VFA-TG solutions. 3. In the HGC technique, ratio of MPII to GIR (MPII/GIR) which represents pancreatic ${\beta}$-cell response to glucose stimulation remained unchanged among the treatments.

• 한국산업보건학회지
• /
• 제28권2호
• /
• pp.144-150
• /
• 2018

Objectives: The purpose of this study is to analyze the trend for exceedance of the domestic permissible exposure limit of benzene based on a review of the previous literature. Materials and methods: From among 13 chemical substances regulated through a PEL (Permissible Exposure Limit) in the Occupational Safety and Health Act, the research object of this study is benzene. The information utilized is work environment measurement data from 2004 to 2013. The highest level among the concentration data measured at various workplaces was selected as a representative value through the data process. N.D. (Not Detected) data was considered as 1/2 of the LOD (limit of detection). Results: Among the work environment measurement data between 2004 and 2013, the highest number of exceeding workplaces and the excess rate (12 sites and 5.4%) was observed in the 2006 data when applying the current PEL for benzene. When compared with the action level, which means a level one-half of the PEL, 2005's data showed the highest number of exceeding workplaces and greatest excess rate (89 sites & 13.3%). The number of exceeding workplaces and excess rate relative to the PEL for benzene showed an increasing trend in 2004, but tended to decrease after 2007. Conclusions: Based on the results obtained from this study, the exposure level for benzene among domestic workers is not considered to be in a safe phase regardless of the year of work environment measurement. Thus, strict preventive management in workplaces should be provided for reducing exposure to benzene.

• 대한교통학회지
• /
• 제31권5호
• /
• pp.26-36
• /
• 2013

지역단위 도로교통안전도에 대한 거시적 평가는 인구, 자동차대수, 도로연장 등의 거시적 노출변수(Macroscopic Exposure Measures)에 기반한 사고율을 노출지표로 이용하는 것이 일반적이나, 노출지표를 이용한 도로교통안전도 평가에 노출지표들이 미치는 영향이 각기 다르기 때문에 결과적으로 각각의 개별노출지표별 평가시 평가결과가 서로 상이하게 되는 문제가 있으며, 이는 예산투자의 효율적 집행을 위한 교통안전정책의 결정과정에 방해요인으로 작용하게 된다. 따라서 본 연구에서는 최소제곱법 및 가중치를 일정단위로 변화시키는 시뮬레이션을 이용하여 노출지표별 최적의 가중치를 도출하였으며, 이를 종합적으로 반영할 수 있는 도로교통안전도 비교평가지수 산정방법을 개발하였다. 지수를 구성하는 노출지표별 가중치는 인구당사고율이 0.29, 자동차등록대수당사고율이 0.52, 도로연장당 사고율이 0.19로 도출되었으며, 개발된 방법을 적용하여 전국 기초지자체별로 도로교통안전도 비교평가지수를 산정하였다. 본 연구에서 제시한 방법을 통해 노출지표별로 평가결과가 상이해지는 문제를 해결할 수 있으며, 교통안전예산의 투자효율성을 높이기 위한 교통안전정책의 합리적인 결정방법으로 활용될 수 있을 것으로 판단된다.

• 한국의학물리학회지:의학물리
• /
• 제9권1호
• /
• pp.55-64
• /
• 1998

고선량률 원격 강내조사 선원은 전량 외국에서 수입되어 왔으며, 최근 Co-60 소선원의 공급부진으로 초기 도입시의 치료시간에 비해 4내지 5배의 시간을 조사하게 되어 대체용 선원의 개발이 크게 요구되고 있다. 이 연구는 국내 하나로 원자로의 중성자를 이용하여 $^{191}$ Ir(n,Υ)$^{192}$ Ir 핵반응을 일으켜 Ir-192 선원 2.87 Ci (밀봉 1.012 Ci)를 생산하고, 고선량률 원격 강내조사선원의 선량특성을 조사하였다. 제작선원에 대한 조사선량률은 아크릴 지지체의 중앙에 아크릴 아프리케이터를 고정하고 선원의 중심으로부터 각각 5, 10, 20 cm 거리에 전리함을 설치하여 일정시간 선원을 노출시켜 측정한 결과 6.36 $\pm$ 0.147 Rm$^2$/GBq-hr (2.350 $\pm$ 0.054 R$cm^2$/mCi-hr)을 결정하였으며, 측정오차는 1$\sigma$ 는 2.2% 였다. 계산선량은 조사선량률 상수 4.69 R$cm^2$/h-mCi 와 Ir-192 에너지 스펙트럼을 이용한 선원자체 및 철에 대한 질량흡수계수를 통해 구했으며, 실제 측정선량과 평균 3.8 % 오차범위에서 일치하였다. 선량 등방성은 선원의 측방향과 축 및 대각선방향으로 전리함을 이용하여 측정한 결과 3 % 이내 균등한 선량을 나타내었으며, 필름선량에서도 균등선량분포를 확인할 수 있었으며, Co-60 선원과 유사한 선량분포를 얻었을 수 있었다. 특히 본 연구의 선량특성조사는 강내조사선량선원 대체용의 선원개발과 선량계획 전산화의 근거가 될 것으로 믿는다.

• 한국산학기술학회논문지
• /
• 제16권4호
• /
• pp.2933-2939
• /
• 2015

보험요율은 기본적으로 보험목적물이 자연재해위험에 노출된 정도에 따라 합리적으로 차등되어 적용되어야 한다. 하지만 현행 보험요율은 예상되는 자연재해로 인한 위험정도에 따른 구분이 없이 시 군 구별로 동일한 기본요율을 적용하고 있다. 본 연구에서는 이를 개선하기 위해 하도버퍼링을 이용한 홍수위험도 분석 방법을 이용하여 홍수위험에 노출된 정도를 분석하고, 이를 반영하여 보험요율을 차등화 할 방안을 제시하였다. 본 연구는 향후 위험도가 반영된 풍수해보험 기본요율 산정과 홍수범람 모의 여건이 부족한 지방하천의 홍수위험도 평가에 기여할 수 있을 것으로 판단된다.

• Corrosion Science and Technology
• /
• 제21권3호
• /
• pp.184-199
• /
• 2022

Steel was exposed in an atmospheric environment, and atmospheric environmental factors that include chloride, humidity, SO₂, NO₂ etc. induced the corrosion of steel. Corrosivity categories classified by SO₂ and chloride deposition rate were low, but those classified by TOW were high in the Korean Peninsula, and on these environmental categories, the corrosivity of atmospheres classified by corrosion rate in carbon steel was low medium, C2-C3, and medium, C3 for zinc, copper, and aluminum. This work performed the outdoor exposure test for 10 years at 14 areas in Korea and calculated the atmospheric corrosion rate of carbon steel. The atmospheric corrosion behavior of carbon steel is discussed based on the various corrosion factors. When the corrosion product forms on carbon steel by atmospheric corrosion, cracks may also be formed, and through these cracks, the environmental factors can penetrate into the interior of the product, detach some of the corrosion products and finally corrode locally. Thus, the maximum corrosion rate was about 7.3 times greater than the average corrosion rate. The color difference and glossiness of carbon steel by the 10 year-outdoor exposure tests are discussed based on the corrosion rate and the environmental factors.