PURPOSES : High temperatures induce excessive expansion in pavements, thus causing the closure of contraction joints between expansion joints. This results in the integration of slabs within the expansion joints into a unified slab. Compressive forces are generated owing to the friction that ensues between the unified slab and lower base layer. As the integrated slab expands and exceeds the allowable width of the expansion joint, the end restraint generates an additional compressive force. The escalating force, which reaches a critical threshold, induces buckling, thus compromising stability and causing blow-up incidents, which poses a significant hazard to road users. The unpredictable nature of blow-up incidents render their accurate prediction challenging because the compressive force within the slab must be predicted and the threshold for blow-up occurrence must be determined. METHODS : In this study, a GWNU blow-up model was developed to predict both the compressive force and period of blow-up incidents in jointed concrete pavements. The climate conditions, pavement structure, materials, and expansion joints were considered in this model. In the first stage of the model, the time at which the integrated slab expanded and surpassed the allowable width of the expansion joint was determined, and the compressive force was calculated. Subsequently, the compressive force within the integrated slab, considering both the end restraints and friction, was predicted. A large-scale blow-up test was performed to measure the blow-up force based on changes in the geometric imperfections. The measured blow-up force was adopted as the blow-up occurrence threshold, and the point at which the predicted compressive force within the slab exceeded the blow-up force was identified as the blow-up occurrence time. RESULTS : Using the GWNU blow-up model, the blow-up occurrence on the Seohean Expressway in Korea is predicted in the presence or absence of the alkali-silica reaction (ASR). Analysis is conducted using the expansion joint spacing and width as variables. As the expansion joint spacing increases, blow-up occurs sooner, and as the width increases, only the expansion joint life decreases. When applying an expansion joint spacing of 300 m and a width of 100 mm under an ASR with 99.9% TTPG reliability, the sum of the expansion joint life and blow-up occurrence time is 16 years. CONCLUSIONS : In the case of jointed concrete pavements where ASR occurred, installing an expansion joint spacing of 300 m and a width of 100 mm does not satisfy the design life of 20 years, and the expansion joint width minimally affect the blow-up occurrence time. To prevent blow-up incidents, a spacing of less than 300 m for the expansion joint is recommended. Based on the analysis results, the blow-up occurrence time and location can be predicted from the characteristics of the installed expansion joint, through which blow-up incidents can be prevented via preliminary maintenance.

Tomato leaves were inoculated with 1x104 spores · mL-1 and placed in an acryl box at 10, 15, 20, 25, and 30oC for 24 h. Ten days after inoculation, the incidence of late blight appeared as a typical symptom in 6 hrs treatment of leaf wet duration when the temperature is between 15 and 20oC at that time. The incidence of disease was 26% and 41% at 10oC and 25oC treatment although the disease did not occur even after treatment at 30oC for 16 h, respectively. The most important factors in the incidence of Late blight were leaf wet duration and temperature. Optimum growth temperature of tomato is from 15 to 25oC, thus the management of leaf wet duration is better than control by temperature to prevent the incidence of Late blight. After inoculation, the symptoms of Late blight occurred in 5 days, therefore the latency period was estimated to be 5 days. The incidence rate of Late blight was the highest at 15 and 20oC. At the time of chemicals application, when Fluopicolide 5%+Propamocarb hydrochloride 25% was applied at 12 h of leaf wet duration, the control effect was the highest as 95% at 36 h but decreased by 70% when treated after 48 h. On the other hand Cymoxanil 12% + Famoxadone 9% was applied at 18 h of leaf wet duration, the control effect was the highest as 95% at 36 h but decreased by 70% after 48 h as similar as Fluopicolide 5% +Propamocarb hydrochloride 50% treatments. In the application of Dimethomorph 15% +Dithianon 30%, the control effect was more or less low as 80% at 20 h of leaf wet duration and was decreased to 60% at 48 h.

최근 WMO는 온실가스 배출량 시나리오(SRES)를 대신하여 대표농도경로(RCP)를 바탕으로 새로운 기후변화 시나리오를 생산하였으며 기상연구소는 RCP 시나리오를 바탕으로 한반도의 새로운 기후변화 시나리오를 생산하였다. 본 연구에서는 과거 관측값을 바탕으로 평년(1981-2010)의 애멸구의 우화시기와 세대수를 추정하였으며, RCP 8.5 시나리오를 바탕으로 2020년대(2015-2024), 2050년대(2045-2054)와 2090년대(2085-2094) 애멸구의 우화시기와 세대수를 예측하였다. 평년 애멸구 월동 1세대수의 우화일인 176.0±0.97일과 비교하여 2050년대에서는 13.2±0.18일(162.8±0.91일), 2090년대에는 32.1±0.61일(143.9±1.08일) 앞당겨질 것을 예측되었다. 그리고 애멸구의 연간 세대수는 2050년대에서는 현재보다 2.0±0.02세대, 2090년대에는 5.2±0.06세대 증가할 것으로 예측되었다.

나무를 말라죽게 하기 때문에 경제적 피해가 크다. 화살깍지벌레는 난태생 하는 곤충으로 성충으로 월동하며 봄철 약충(알)을 생산하고, 실험실 조건에 서 최대 4-주기 산란 피크를 보인다. 최근 지구온난화가 진행되고 기후변화가 심하기 때문에 정확한 방제시기를 결정하기 위해서는 월동성충의 약충발생시 기 예찰모형이 절실히 요구된다. 월동성충의 일별 산란곡선 자료를 3-peak Gaussian 모형(9개 매개변수)에 적합시켜 약충발생기 예측모형을 개발하였다. 발육영점온도 13℃을 적용하여 매개변수 추정결과 첫 번째 산란 피크일 282DD, 두 번째 산란 피크일 500DD, 세 번째 산란 피크일 694DD 이었다. 추 정된 약충발생시기 예측모형의 포장적합 결과 첫 번째 산란시기의 경우 모형 과 실측치가 정확히 일치하였으며, 또한 두 번째 산란 피크일도 잘 예측되었 다(2005-2007년). 본 개발된 모형에 1961년부터 2008년까지 기상자료를 입력하 여 산란 피크일을 추정하고, 장기적인 약충발생시기 이동을 상황을 분석하였 다. 제주시 지역에서 첫 번째 약충발생 피크일의 경우 2001-2008년 평균 발생 일이 1961-1970년 평균 발생일 보다 8일 빨라졌으며, 두 번째 피크 발생일도 8일 빨라진 것으로 분석되었다. 서귀포 지역에서는 상기 동일변수들에 대하여 각각 14, 15일 빨라진 것으로 분석되어 온난화의 영향이 두드러졌다. 기타 온 도변화에 따른 화살깍지벌레 월동성충 산란시기 변동전망에 대하여 고찰하였 다.