A screening method has been developed for detecting sulfamethazine(SMZ) contamination of meat or feeds by using horseradish pero×idase (HRP) labeled protein A (Prot A-HRP)and an indirect competitive enzyme-linked immunosorbent assay(ELISA). The assay is based on competitive binding of guinea pig anti-SMZ with SMZ in sample and SMZ-gelatin con$lt;jugate(SMZ.GEL) followed by the uptake of prot A-HR,P onto polystyrene microwell plate coated with SMZ.GEL. Percent binding B/Bo × 100) was calculated from the absorbance in the absence (BO) and presence (B) of SMZ. By the sandard curve prepared by plotting log(SMZ) vs percent binding of each lmown reference solution, the detection limit was 1.0 ppb or leas. Cross reaction with sulfadimethoxine, sulfaguaniding, sulfamerazine, sulfamthoaypyridazine, sulfanilamide, aulfisomidine and aulfisoxazole were not observed. But sulfamerazine crosareacted in the test. The EC-50 value (concentration causing 50% inhibition of color development compared with blank) of sulfamerazine was 2.0 ppm. Further quality control will make the ELISA system ideal for the detection of SMZ in meat or feeds.

Visibility and Automatic Weather System(AWS) data near Nakdong river were analyzed to characterize fog formation during 2012-2013. The temperature was lower than its nearby city – Daegu, whereas the humidity was higher than the city. 157 fog events were observed in total during the 2 year period. About 65% of the events occurred in fall (September, October, and November) followed by winter, summer, and spring. 94 early morning fog events of longer than 30 minutes occurred when south westerly wind speed was lower than 2 m/s. During these events, the water temperature was highest followed by soil surface and air temperatures due to the advection of cold and humid air from nearby hill. The observed fog events were categorized using a fog-type classification algorithm, which used surface cooling, wind speed threshold, rate of change of air temperature and dew point temperature. As a result, frontal fog observed 6 times, radiation 4, advection 13, and evaporation 66. The evaporation fog in the study area lasted longer than other reports. It is due to the interactions of cold air drainage flow and warm surface in addition to the evaporation from the water surface. In particular, more than 60% of the evaporation fog events were accompanied with cold air flows over the wet and warm surface. Therefore, it is needed for the identification of the inland fog mechanism to evaluate the impacts of nearby topography and land cover as well as water body.

This study presents the characteristics of nocturnal inversion layer and their effect on the concentration variations of surface air pollutants using tethersonde and automatic weather station (AWS, 2 layer tower) system in Ulsan during 2003. The method for the distinction of inversion intensity was decided based on the sum of nocturnal temperature gradient. As the results, there was a close correlation (correlation coefficient of 0.76) between the maximum inversion height obtained from tethersonde and the sum of nocturnal temperature gradient. The air pollutant concentration was also directly proportional to the inversion intensity. When the inversion intensity was strong in the nighttime, ozone (O3) concentration was lower, while nitrogen dioxide (NO2) concentration was higher. The carbon monoxide (CO) concentration was gradually higher according to the nocturnal inversion intensity, whereas sulfur dioxide (SO2) concentration was relatively constant. In addition, we found that there was no correlation between the inversion intensity and TSP concentration.