A number of plating companies have been exposed to the risk of fire due to unexpected temperature increasing of water or other reasons in a plating bath. Since the companies are not able to forecast the unexpected temperature increasing of plating bath and most of raw materials in the bath have low ignition temperature, it is easy to be exposed to the risk of fire. Thus, in previous study, we tried to monitor and notice the dangerous change of temperature of water immediately to prevent the risk of fire from plating process. However, unfortunately previous studies were not able to shut out the fundamental cause of fire since bath temperature sensor can detect air temperature when the level sensor was malfunctioned. In this paper we developed the Teflon heater which contains a built in temperature sensor and improved plating equipment system. Teflon heater is improved using Pt 100Ω sensor which can detect until 600°C . When the bath temperature sensor detects over 60°C or the Teflon heater sensor detects over 240°C they temporarily shut down the heater to control temperature. Also relay completely shuts down main power when detects instant temperature is detected over 5% of 240°C by the heater sensor to prevent teflon melting down and fire spreads. Developed plating equipment system can monitor a real time temperature in the teflon tube and bath water. Therefore we think the proposed plating equipment can eliminate the possibility of fire in plating processes fundamentally.

In this paper we developed the Teflon heater which contains a built in temperature sensor and a relay for improved plating equipment system. Teflon heater is improved by using Pt 100Ω sensor which can detect until 600°C. When the bath temperature sensor detects over 60°C or the Teflon heater sensor detects over 240°C they temporarily shut down the heater to control temperature. Also relay completely shuts down main power when detects instant temperature is detected over 5% of 240°C by the heater sensor to prevent teflon melting down and fire spreads. Developed plating equipment system can monitor a real time temperature in the teflon tube and bath water. Therefore we think the proposed plating equipment can eliminate the possibility of fire in plating processes fundamentally.

본 연구에서는 기후변화에 따른 농업생산기반의 취약성 평가를 위해 홍수 및 가뭄에 대해 대리변수를 선정하고 취약성 평가 지표를 산정하였다. 기후변화의 취약성 정의는 기후변화에 대한 시스템의 노출, 민감도, 적응 능력의 세가지 구성요소로 나타난다. 국내외 문헌조사와 기존연구결과를 토대로 홍수 및 가뭄에 대한 노출, 민감도, 적응능력 등 3가지 카테고리에 대한 대리변수를 각각 선정하였으며, 기상자료, 농업생산기반통계연보 및 각 시·도별 통계자료를 이용하여 선정된 대리변수에 대한 데이터베이스를 구축하였다. 수집된 기초 통계자료의 표준화를 위해 z-스코어 방법을 이용하였고, 이를 통해 모든 변수의 평균은 0, 표준편차는 1의 정규분포로 정규화되었으며, 왜곡도 분석 결과도 절대치 0.151에서 1.947 사이로 나타나 모든 데이터를 자연로그 변환 과정을 거치지 않고 표준화한 값을 취약성 지수로 산정하였다. 표준화된 각 대리변수의 결과로부터 향후 각 시도별 취약성 평가를 수행하고, 결측된 자료의 보완과 자료기간이 상이한 자료의 처리에 대한 연구방법을 정립하는 것이 요구된다.

본 연구에서는 비점오염저감장치를 이용하여 밭 시험포장에서의 저감효과를 평가하기 위하여, 경남 사 천시 용현면에 시험포장을 설치하고 포장실험을 수행하였다. 시험포장은 6개의 시험구와 3개의 침사구로 구성되어 있으며, 각 시험구의 크기는 가로 5 m, 세로 22 m의 크기로 각 시험구의 말단에는 유출량을 측정하기 위한 수위계를 설치하였고, 포장에서의 강우량을 측정하기 위해 강우계를 설치하였다. 인공 강우 실험을 통해 유출수의 시간변화에 따른 수질을 측정한 결과 초기 유출시 SS, TOC, T-N, T-P, COD, NTU의 농도는 각각 15.00, 1.54, 5.27, 0.07, 4.72, 0.45 mg/L로 나타났으며, 4시간 후의 농도는 각각 1.00, 0.94, 4.06, 0.01, 0.60, 0.33 mg/L로 측정되었다. 대부분의 수질측정값이 초기 유출 시 높고 시간이 흐름에 따라 감소하는 경향을 보였다. 인공강우에 의한 유출실험 결과, 침사구에서의 부유물질은 시간이 흐름에 따라 눈으로 식별 가능할 정도로 줄었으나 각 수질측정값은 불규칙한 경향을 보였으며, 이는 샘플링 시료에 포함되는 부유물질의 양이 일정하지 않았기 때문으로 풀이된다. 향후 추가적인 연구를 통해 밭비점오염원 저감효과를 평가하고 제어대책을 개발하게 되면 밭에서의 비점오염 배출을 최소화시켜 수질개선에 기여할 것으로 사료된다.

본 연구에서는 낙동강 유역 오염총량관리대상지역의 수질오염물질간의 상관관계를 분석을 통해 하나의 오염 자료를 이용하여 다른 외부 오염자료의 평가에 대한 적용성을 검토하였다. 이를 위해 낙동강 유역의 수질관측 자료를 수집 정리하고 이를 이용하여 지점별 분석을 거쳐 관측지점을 군집화와 수질오염물질간 의 상관관계를 분석하였다. 낙동강유역환경청에서 제공하는 수질관측지점별 pH, DO, BOD, COD, SS, TN, TP의 1989년부터 2009년까지의 월별 자료를 수집하여 정리하였으며 안동1, 안동2, 예천, 상주 등 12개 지점의 월별 BOD 측정 자료를 이용하여 오염측정지점 간에 상관분석을 실시하였고 군집분석을 수 행한 결과 1군은 안동1, 안동2, 예천, 2군은 상주, 상주2, 상주3, 고령, 현풍, 합천, 남지, 3군은 구미와 달성으로 분류되었다. 수질오염물질간 상관분석에서는 오염총량관리대상지역으로 지정되는 구미 지점과 남지 지점에 대해 수질항목별 비강우시와 초기강우시 그리고 이틀간 10 mm이상의 강우시로 구분하여 상 관관계를 분석하였다. 그 결과 비강우시와 초기강우시에 두 지점에서 일관성 있는 상관관계를 나타낸 항 목은 없었으나 이틀간 강우량이 10 mm이상의 강우시에 구미 지점에서 COD-SS와 COD-TP에서 각각 0.735, 0.563로 높은 상관관계가 있었으며 남지 지점에서도 COD-SS와 COD-TP에서 0.888, 0.788로 높 은 상관관계를 나타내 낙동강 유역에서의 수질항목별 상관관계에서 앞서 연구된 새만금 하구 담수호로 유 입되는 하천수의 수질항목별 상관관계 분석과 유사한 경향을 보였다.

The objective of this study was to assess the statistics and associated criteria for field-scale model used to simulate nutrient concentrations in paddy field. CREAMS-PADDY, a modified version of the field-scale CREAMS model, simulates the hydrologic, sediment, and nutrient cycles in paddy fields was applied in this study. The model was calibrated and validated using data from study rice paddy fields in Republic of Korea. The calibration statistics include mean and the minimum-maximum range associated with a “temporal window” that spans a period of several days. Because nutrient concentrations in paddy filed are typically sampled infrequently (on a weekly basis, at best) and represent only an instant in time, it is not reasonable to expect any model to simulate a daily average concentration equal to an observed value on a particular day. The 5-day window and related calibration statistics were applied in this study and the applicability of this concept was tested for field-scale water quality model. As a result of calibration and validation, the ponded water nutrient concentration values showed only small changes except the fertilization period. Because of the small changes in ponded water concentration, the size of 5-day window was too small to capture the observed values. Further study is required to establish the 5-day window calibration method for field-scale water quality modeling.

This study was conducted to investigate the survival rate of frozen-thawed spermatozoa in equine by glycerol concentration and freezing speed. Two stallions (1 Thoroughbred-13 year old and 1 Arab-7 year old) bred in Korea Racing authority was examined for 1 times in a couple of weeks. Semen was collected by condom method standing heated mare and were centrifuged 650 g for 15 min. and isolated the seminal plasma. Thick fraction of semen was diluted EDTA-Lactose-egg yolk diluents to 1:1 and contained in 0.5 ml straw as 6～14×107cells/ml. Final concentrations of glycerol were 3, 5 and 7% in cryopreseved diluents and added 4 times for 2 hours equilibration. For the freezing, equilibrated straws were located 3 or 5 cm above LN2 gas for 5 or 10 min. Survival rates of pre-frozen sperm were 65.0±13.2%, 68.3±10.4%, 66.7±11.5% and post-frozen were 53.3±23.1%, 45.0±15.0%, 50.0±18.0% in 3, 5, 7% glycerol concentration, respectively. There was no difference between glycerol concentrations. Survival rates of frozen-thawed sperm on freezing speed were 36.7±10.4%, 40.0±7.1%, 30.0±13.2% at 3 cm－5 min and 33.3±11.5%, 31.7± 2.9%, 21.7±10.4% at 3 cm－10 min in 3, 5, 7% glycerol concentration, respectively. Survival rates of frozen-thawed sperm on freezing speed were 43.3±15.3%, 32.0±17.9%, 22.3±15.7% at 5cm－5 min and were 47.5±15.0%, 43.3±12.6%, 48.3±15.3% at 5cm－10 min in 3, 5, 7% glycerol concentration, respectively. There were significantly different between groups (p<0.05). These results suggest that glycerol concentration did not affect cryopreservation of stallion semen within 3～7% but freezing speed affects. In our experiment, the best cryopreservation condition was at 5 cm above LN2 gas for 10 min for pre-freezing and 7% of glycerol concentration. These results lead to commercial AI with frozen-thawed stallion semen.

This study was performed to investigate the characteristics within ages and freezing tolerance of spermatozoa in Jindo Dog. Experimental animals were selected 12 herds within 1～8 year’s old and collected semen for 2 times in a week. Collected semen was evaluated whole volume and sperm number with CASA system (SIAS, Medical Supply, Korea). Then seminal plasma were separated and diluted with modified Tris-egg yolk extender and added 4, 6 and 8% glycerol for 4 times to final concentration and equilibrated for 1.5 hrs. Before and after freezing, equilibrated semen were evaluated the survival rates. Total volume of sperm at 1～2 year old group is as 5.2×108 cells/ ml largest and there were no significance among groups. The motility of 1～2 year old group is highest as 90.9% and there were significance among groups. Abnormal sperm showed similar among groups. The survival rate in terms of pre-freezing and post-freezing were decreased all levels of glycerol and reveled 87.0% to 64.5% in 4%, 87.5% to 51.9% in 6% and 73.4% to 29.7% in 8%, there were significant difference among the groups (p<0.05). These results suggest that the optimal sperm-freezing methods in Jindo Dog are utilized with modified Tris egg-yolk extender with 4% glycerol and were improve the reproductive activity by these methods.

The objective of this study was investigate the superovulation treatment and to relate concentrations of blood urea nitrogen(BUN) in Hanwoo donors. Thirty six, at random stages of the estrous cycle, received a CIDR. Four days later, the animals were superovulated with a total of 28AU FSH (Antorin, 2AU=1 ml) administered twice daily in constant doses over 4 days. On the 3th administration of FSH, CIDR was withdrawn and 25 mg PGF2α was administered. Cows were artificially inseminated twice after estrous detection at 12 hr intervals. The cows received 100 μg GnRH at the time of 1st insemination. Embryos were recovered 7 or 8 days after the 1st insemination. Cows with BUN ＜10, 11～18 and ≥19 mg/dl had return of estrus of 34.6, 30.5 and 30.4 days respectively. Return of estrus after superovulation treatment was not significantly lower for cows with blood urea nitrogen (BUN) above 10 mg/dl than for cows with BUN below 10 mg/dl. Cows with BUN ＜10, 11～18 and ≥19 mg/dl had number of transferable embryos of 3.2±1.2, 5.4±1.9 and 4.1±2.1 respectively.