The poultry red mite (PRM), Dermanyssus gallinae, is one of the most important external parasites in the poultry industry. PRM adheres to birds’ bodies, and its hematophagy causes anemia and itching, and reducing egg production (~20%). Fipronil is a toxic pesticide used to control PRM. Thus, an environmentally friendly alternative control agent is needed. In this study, the effectiveness of various environmentally friendly PRM control measures including an acaricide consisting of synthetic silica, clove extracts, garlic extracts, and a probiotic solution were evaluated, comparing them to a combined treatment using the chemical acaricides. Each agent was tested in vitro using two approaches, in which PRMs were either added to environments containing acaricide, or sprayed in situ. Within 10 hours of inoculation, all the environmentally friendly acaricides except for the probiotic solution killed or rendered immotile significantly more mites than the control, normal saline (p < 0.05). The performance of the environmentally friendly acaricides, except for synthetic silica, was significantly weaker than that of commercial chemical acaricides. (p < 0.05). Further tests to determine the optimal concentration of amorphous synthetic silica agent for complete PRM control found this to be 400 g/L. PRM motility following treatment showed the same pattern: the synthetic silica agent and chemical acaricide killed mites, while application of other environmentally friendly agents resulted in living, but immotile, insects, or those with reduced motility. As a result, these environmentally friendly acaricides, especially the synthetic silica agent, could be used as alternatives to chemical acaricides for PRM control.

도심지나 문화재가 인접한 지역 등의 소음, 진동 등 기존 발파해체 공법이 제한적인 조건에서 사용할 수 있는 구조물 해체 공법으로 무소음화학팽창제(soundless chemical demolition agent, SCDA)를 이용한 공법이 있다. 그러나 SCDA의 사용에 대한 기준이나 가이드라인에 참고될 만한 연구는 미미한 실정이다. 이 연구에서는 실내실험을 수행하여 강관의 길이, 외부수분차단, 수화열 발산 등의 다양한 조건에 따른 SCDA의 팽창압 발현 특성을 확인하였다. 또한 SCDA의 최소요구팽창압 예측을 위한 해석모델(자유단 1면, 고정단 3면의 직사각형 모델)을 개발하고 주요변수해석(홀 간 거리, 콘크리트 압축강도)을 수행하였다. 이 연구의 해석결과를 활용하여 자유단으로부터 콘크리트 구조물의 박락을 효과적으로 유도할 수 있을 것으로 판단된다.

In the present study, the impact of RO polyamide layer by long-term chemical exposure was evaluated. Basic cleaning chemicals such as NaOH increased the pure water flux and salt passage of RO membrane up to 1.6 times and 2 times, respectively. In contrast, membranes exposed to acidic chemicals such as HCl have experienced no discernible change of permeability, which indicated that basic chemicals caused the more serious damage to RO polymeric layers. However, XPS analysis showed that both membranes were experienced significant damages on cross-linking of polyamide structures. It can be concluded that basic cleaning chemicals induced the enlarged pore structure due to electrostatic repulsion between damaged polymers, while acidic chemicals caused less performance deterioration by shrinkage of the polyamide structure.

해양암반이나 구조물 해체를 위한 전통적인 방법은 다이나마이트를 이용한 발파공법, 잭해머(Jackhammer)를 이용한 공법이다. 이러한 방법은 소음이나 폭발의 위험등으로 인해 사용에 많은 제약이 따른다. 이런 제한된 상황에서 사용할 수 있는 무소음화학팽창제(SCDA)의 사용이 증가하고 있는 추세이다. 그러나 무소음화학팽창제의 사용에 관한 규격이나 설계 및 시공에 대한 제안서는 현재 전무한 상황이다. 따라서 본 연구에서는 다양한 조건(구조물의 구속, 천공홀의 크기, 천공홀의 수 등)에서 콘크리트 구조물에 균열이 생성, 진전될 수 있는 최소요구팽창압을 예측하였다.

A nuclear, biological, chemical (NBC) canister was indigenously developed using active carbon impregnated with ammoniacal salts of copper (II), chromium (VI) and silver (I), and high efficiency particulate aerosol filter media. The NBC canister was evaluated against carbon tetra chloride (CCl4) vapours, which were used as a simulant for persistent chemical warfare agents under dynamic conditions for testing breakthrough times of canisters of gas masks in the National Approval Test of Respirators. The effects of CCl4 concentration, test flow rate, temperature, and relative humidity (RH) on the breakthrough time of the NBC canister against CCl4 vapour were also studied. The impregnated carbon that filled the NBC canister was characterized for surface area and pore volume by N2 adsorption-desorption isotherm at liquid nitrogen temperature. The study clearly indicated that the NBC canister provides adequate protection against CCl4 vapours. The breakthrough time decreased with the increase of the CCl4 concentration and flow rate. The variation in temperature and RH did not significantly affect the breakthrough behaviour of the NBC canister at high vapour concentration of CCl4, whereas the breakthrough time of the NBC canister was reduced by an increase of RH at low CCl4 vapour concentration.

Identifying effective chemical control agents of Bemisia tabaci biotype B and Q is an important step toward IPM strategy. Until 2008, only 10 chemical agents were registered for B. tabaci. From the laboratory screening of 60 insect- and acaricides, 18 chemicals for egg, 10 for nymph and 8 for adult stage were found effective (>90% mortality). Also ten chemicals were less toxic to B. tabaci. Among ten chemicals, some conventional insecticides need further careful resistance monitoring. Field trials with some of the selected chemicals open the possibility to chemical control of B. tabaci biotype Q. Further consideration of non-target effects and resistance development has to be exerted before registration process.

A field experiment was carried out to determine the effects of mechanical and chemical drying agents at mowing on the field drying rate and hay quality of orchardgrass dominant pasture plants. The mower conditioner /chemical drying agent ( 2% conditioning

A field experiment was carried out to determine the effects of chemical drying agents at mowing on the field drying rate of alfalfa (cv. Vernal) and rye (cv. Koolgrazer) for hastening hay manuf8cture. In alfalfa; chemicals ( 2% 3% 2% , 2% 2% + , 1% only

본 연구에서는 유황을 폴리머화하여 내화학성능이 요구되는 구조물의 콘크리트 표면보호재로 활용할 수 있도록 성능을 검토하였다.평가 결과, 유황폴리머 표면도포재의 중력식 스프레이가 적절한 것으로 나타났으며, 도포횟수는 왕복 3회 이상 도포했을 때 1MPa 이상의 부착강도 확보가 가능하였다. 표면보호재가 도포될 콘크리트 표면조건은 상온조건 (20~30℃) 이상에서 높은 부착강도를 나타내었으며,온도가 높을수록 부착강도가 증가하였다. 표면보호재의 채움재 혼입량에 따른 강도특성 평가결과, 20~40% 정도 혼입된 채움재는 유황폴리머의 수축을 저감시키는 효과를 나타내어 강도 향상에 기여하였다. 또한, 플라이애시 보다는 규사 혼입시 부착강도가 높았고, 동시 혼입시가장 우수한 부착강도 특성을 나타내었다. 화학저항성은 플라이애시 및 규사를 각각 20% 대체한 배합에서 부착강도 저하가 최소로 되어우수한 내화학성을 나타내었다. 염소이온 침투에 대한 성능평가를 수행한 결과, 표면보호재를 도포하지 않은 시험체에 비하여 유황폴리머표면보호재를 도포한 경우, 29~48% 정도 염소이온침투저항성이 증대되었다. 표면보호재의 도포조건, 압축강도, 부착강도, 화학저항성, 염해저항성 등을 모두 고려하여 볼 때, 본 연구범위에서는 유황폴리머에 채움재로서 규사와 플라이애시를 각각 20%씩 대체하는 것이 적절한수준인 것으로 판단된다.