본 연구에서는 해상용 경유의 희석량에 따른 선박용 윤활유의 점도 및 전단응력의 변화 등 유변학적 거동에 대한 연구를 하였다. 연료희석에 의한 윤활유의 점도감소는 피스톤링 및 라이너의 마모로 인한 엔진내구성을 저하키는 중요한 요소이다. 연구에 사용된 윤활유는 고유황 경유(황함유량 0.05 %)를 3 %, 6 %, 10 %, 15 %, 20 %로 희석하여 magnetic stirrer를 이용, 혼합하여 제조하였다. 측정온도는 -10℃ ~ 80℃ 범위로 설정하고, 점도 및 전단응력 변화는 회전점도계인 Brookfield Viscometer를 이용하여 측정하였다. 윤활유에 해상용 경유의 희석량이 증가할수록 점도 및 전단응력이 감소하며, 이것은 상대적으로 낮은 점도의 해상용 경유가 윤활유에 희석됨에 따라 윤활유의 점도 및 전단응력이 낮아지기 때문이다. 특히, 저온(0 ~ -10℃)에서는 점도 및 전단응력이 급격이 낮아지다가, 40℃ 이상에서는 점도 및 전단응력 감소가 해상용 경유 희석량의 영향을 거의 받지 않는다. 온도가 높아짐에 따라, 윤활유의 점도 및 전단응력 감소는 윤활유의 뉴턴유체 거동을 보이는 것을 확인했다. 경유의 혼입에 의한 점도감소로 선박의 엔진마모를 촉진할 수 있으므로 엔진의 내구성 향상을 위해 윤활유의 주기적인 관리가 필요하다.

The emulsion and micro-encapsuled formulation from three essential oils, cassia, thyme white and lemon grass were tested for their insecticidal activities against Lycoriella ingenua (Dufour) adults at 0.3% concentration. As a result, the micro-encapsules than emulsion formulation was confirmed to show greater activity. Based on this result, insecticidal activities at several levels of concentration were examined, resulting in more than 80% insecticidal activity after 30 minutes at 0.6% level of cassia formulation. And also, insecticidal activity of three oil-based micro-encapsuled formulations lasted for up to 12 hours at 0.9% concentration. The main ingredients derived from three essential oils were evaluated on the insecticidal activity against Lycoriella ingenua. As a result, in case of thymol from thyme white, it showed more than 80% mortality after over 30 minutes at 0.25%, and in cinnamic aldehyde and citral, exhibited 88% and 82% mortality after 30 minutes at the 0.5% level, respectively. These three compounds were examined for whether the insecticidal activity was maintained depending on being over time. In case of thymol, it maintained good insecticidal activity against Lycoriella ingenua at 0.5% level until 120 hours, while cinnamic aldehyde and citral showed lower activity after 12 hours.

In the previous study, the plant essential oils such as clove bud , thyme white and garlic oils gave potent toxicity with the range of 1.5 to 4.5×10-3 ul cm-3 of LC50 values against Bemisia tabaci. Based on the bio-assay results, three plant essential oils(clove bud, thyme white and garlic) were applied to 30% emulsion type. The 100, 200 and 400 fold dilution of these emulsions was showed mild toxicity under port scale treatment against Q biotype. At each fold dilution, clove bud showed 44, 26 and 14%, and thyme white produced 44, 39 and 27%, respectively. Of garlic emulsion, its toxicity was evaluated with 27, 26 and 11%, respectively. But, in case of clove bud and thyme white mixture, their toxicity was more good under the mixture than under the single treatment. Mixture with clove bud 200 fold dilution adding to thyme white 200 fold dilution showed potent activity with 86% mortality. And also 200 adding to 400, and 400 to 400 exhibited 61%, 76%, respectively. These essential oil mixtures showed similar strong toxicity against B biotype under port scale test. In particular, the mixture with clove bud 200 fold dilution adding to thyme white 200 fold dilution showed the highest synergistic effect. Toxicity to plants, except the 100 fold dilution of these emulsions was not observed.

Five field-collected populations (TR-CP, UR-CP, JR-CP, GR-CP, and BR-CP colonies) of northern house mosquito, Culex pipiens pallens, identified by polymer chain reaction (PCR) were tested for susceptibility to 10 different insecticides by direct-contact mortality bioassay in comparison with an insecticide-susceptible KS-CP strain. Marked regional variations of insecticide susceptibility were observed. Extremely high to high levels of resistance were obtained: bifenthrin, resistance ratio (RR) = 1–520; β-cyfluthrin, RR = 16–397; α -cypermethrin, RR = 9–343; deltamethrin, RR = 1–40; etofenprox, RR = 2–42; permethrin, RR = 2–12; chlorpyrifos, RR = 2–675; fenitrothion, RR = 0.5–364; and fenthion, RR = 2–360. All of the colonies were susceptible to one or more of the insecticides examined. These results indicate that careful selection and rotational use of these insecticides should result in continued satisfactory control against field populations of northern house mosquito.

Through earlier breeding efforts, portions of the genome of the wild species Oryza grandiglumis (2n=48) have been introgressed into the rice cultivar, Hwaseongbyeo (Oryza sativa spp. japonica). Hwaseongbyeo was used as recurrent parent and O. grandiglumis