This study is a study on the cracking of the main piston surface which is generated in the injection molding machine to generate mold force. The main piston machining process consists of high frequency heat treatment, grinding and super finishing after lathe turning. Scale, defect size, and fracture texture were observed for four cracks on the surface of the piston during the tempering process after high frequency heat treatment using a metallurgical microscope. In this study, it was confirmed that the cracked structure of the piston structure was ferrite and pearlite structure. It was confirmed that cracks progressed to 480 ㎛ and scale layer of 3 ㎛ or less. Surface hardening layer and hardness were min 2.0mm/HRc 58±2 spec 1.6 mm/HRc 56.5~57.5 In addition, cracks on the surface of the piston appear perpendicular to the rolling process. Therefore, it can be assumed that the crack occurred in the low temperature tempering process at 200°C or less after the high frequency heat treatment, not the material defect. Therefore, the temperature should be maintained at 200°C or higher during tempering after high-frequency heat treatment, and the cracking defect on the surface of the piston can be prevented by setting the feed rate to 1.3 mm/s or less during heat treatment.

An injection unit is the important part which guide the melted resine into the mold. Once injection molding is performed, there will be a pressure of 33 MPa built up inside of injection cylinder body. It was confirmed that the crack occurs by internal stress on the 9 mm material when the machine is used for long time. Because the cylinder rod has material thickness of 9~12 mm during manufacturing process on the cylinder body, there would be 3 mm thickness differences. In this experiment, IDEAS, a computer aided structure analysis software, is used to present the optimized design condition. Insert rod with inner diameter of 9 mm was set as a normal and vary 3 mm in x, y axis direction. When the internal pressure of 33 MPa occurs at the injection unit, fix the x and y direction and find out the stress acting only in z axis. It was confirmed that the stress of 45~82 N/mm 2 was built up when the left of cylinder body had been set 9 mm by using a structure analysis. Also, it has been verified the thickness of the material on the left need to be greater and equal than 12 mm to prevent a material crack by an internal stress.

Understanding how researchers are tackling globally important issues, such as climate change, is crucial to identify whether current research is comprehensive enough to make substantive predictions about general responses to climate change. We assessed the type of studies being conducted by researchers to understand the impacts of climate change on insects, published. Most published research is generated from Europe and North America and being dedicated to core data analysis, with reviews being highly produced. Temperature – only is the main climate change factor being analysed, with most researchers are assessing changes in abundance or distribution/range shifts. Of most concern is the number of studies which do not specifically identify a climate change factor (ie just arm wave), the lack of studies on Hemimetabolous insects and the need for more studies to assess specific mechanistic responses to climate change.

도암만은 전남 장흥군, 강진군, 해남군, 완도군 등 4개 군으로 둘러싸인 전형적인 하구형 만으로, 남북방 향 길이 약 19km, 최대너비 약 7km의 네 방향으로 갈라진 십자형의 형태로, 만내에는 크고 작은 8개의 유 인도 및 무인도가 있으며, 남부에는 완도, 고금도 등이 위치하여 이들 사이의 수로를 통해 해수가 제한적으 로 유출입하는 반폐쇄성 만으로 파랑에 의한 영향이 적다. 만내로 전란남도의 3대강 중의 하나인 탐진강 하천수와 강진천, 칠량천, 대구천의 하천수가 유역으로 유입되면서 담수와 해수의 교환이 이루어지고 담수 유입량에 의해 조류가 영향을 받고 있다. 효율적인 내만의 수질관리를 위해서는 우선 부하발생원에 따른 오염배출량이 어느 정도 인지 확인하고 해역의 환경용량과 환경기준을 만족하기 위해서 부하삭감량을 산정하는 사전대책이 요구된다. 연안해역의 수질에 영향을 끼치는 부하발생원은 크게 점오염원과 비점오염원으로 구분되는데, 비점오염원은 강우시 도 시지역이나 농경지 및 산림지역의 유출수로 파악될 수 있지만, 유입지점을 명확하게 찾기 어렵고, 일간 계 절간 배출량 변화가 크며 예측과 정량화가 어려워서 관리가 힘든 특징이 있다. 이에 반해 점오염원은 가정 하수, 공장폐수 등으로 구성되며 일정한 지점에서 일정량이 지속적으로 발생하여서 배출구와 배출단위가 파 악가능하기 때문에 수질관리를 위한 부하삭감량 산정의 주 대상이 되고 있다. 따라서 본 연구에서는 해역으로 유입하는 외부부하량을 실측하고 분석하여 득량만의 효과적인 연안해역 의 수질관리의 기초자료로 활용하고자 한다. 하천 부하량 조사는 도암만 유역에 포함되는 하천 24개 지점을 대상으로 하였으며, 조사 시기는 3월부터 12월까지 매월 1회 실시 하였고, 각각의 유입하천은 직독식 전자 유속계(ACM-200PC) 및 부표를 이용하여 유속을 측정한 다음, 단면적을 계산하여 각 유입원의 유량을 산정 하였다. 각 시점에서 채수한 하천수의 pH, 수온, 염분, 전기전도도, 화학적 산소요구량(CODMn) ), 총질소(T-N), 총인(T-P), 용존산소(DO), 부유물 질(SS), 용존무기질소(DIN), 용존무기인(DIP) 등을 분석하였고, 환경부 수질오염공정시험방법(환경부, 2008), 해양환경공정시험기준(국토해양부, 2008), 준하여 분석하여 유량과 곱해서 그 부하량을 산정하였다. 하천 유량의 월별 총합은 821590∼5971583 m3/day 이고, 부유물질(SS)과 화학적 산소요구량(COD), 용존 무기질소(DIN), 용존 무기인(DIP), 총질소(TN), 총인(TP), 월별 부하량은 각각 6070.3∼47781.3(평균 20999.4)kg/day, 3570.5∼21471.5(평균 9455.2)kg/day, 843∼5042.4(평균 2015.1)kg/day, 14.2∼163.7(평균 66.7)kg/day, 1249.2∼10166.9(평균 4151.3)kg/day, 47.3∼390.8(평균 165.9)kg/day 이다.

The green peach aphid(Myzus persicae) and sweet-potato whitefly(Bemisia tabaci) biotype Q are serious pests in hot pepper and cucumber. To optimize the formulation type of Clothianidin 1.8% granule, coated and extruded granule formulation types were tested against green peach aphid in hot pepper and sweetpotato whitefly in cucumber. Clothianidin 1.8% granules were incorporated in soil before transplant of hot pepper and cucumber. At recommend dose(540g ai/ha), the efficacy of Clothianidin 1.8% coated and extruded granules were 83.3% and 94.4% and continued until 50 days and 70 days against green peach aphid, respectively. Against sweet-potato whitefly, the efficacy of Clothianidin 1.8% coated and extruded granules were 65.7% and 96.3% at 32 days in cucumber, respectively. Clothianidin 1.8% extruded granule was safe on crops (hot pepper, cucumber, melon, cabbage etc.) at 540g ai/ha (recommend dose) and 1080g ai/ha. The results suggested that Clothianidin 1.8% extruded granule is promising as a best insecticide against green peach aphid and sweet-potato whitefly, because of the high efficacy and low phytotoxicity.

Molecular genetic markers were genotyped used to detect chromosomal regions which contain economically important traits such as growth traits in pigs. Three generation resource population was constructed from a cross between the Korean native boars and Landrace sows. A total of 193 F2 animals from intercross of F1 were produced. Phenotypic data on 7 traits, birth weight, body weight at 3, 5, 12, 30 weeks of age, live empty weight were collected for F2 animals. Animals including grandparents (F0), parents (F1), offspring (F2) were genotyped for 194 microsatellite markers covering from chromosome 1 to 18. Quantitative trait locus analyses were performed using interval mapping by regression under line-cross model. To characterize presence of imprinting, genetic full model in which dominance, additive and imprinting effect were included was fitted in this analysis. Significance thresholds were determined by permutation test. Using imprinting full model, four QTL with expression of imprinted effect were detected at 5% chromosome-wide significance level for growth traits on chromosome 1, 5, 7, 13, 14, and 16.