• The Korean Journal of Pesticide Science
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• v.9 no.4
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• pp.354-358
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• 2005

The study was carried out to investigate dissipation pattern of pesticide residue in/on different varieties of lettuce applied with foliar spraying under greenhouse. The initial deposited amount of alpha-cypermethrin and imidacloprid in/on the crop was entirely corresponded with shape of the crop. Dissipation of deposited pesticide residue was supposed to be related with degradation by sunlight and wash off by watering rather than dilution effect by biomass increase. The crop grouping in leaf vegetables has to be carefully considered even in lettuce for dissipation pattern of pesticide residue; head type and leafy type.

• Korean Journal of Food Science and Technology
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• v.44 no.5
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• pp.628-633
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• 2012

This study investigated the washing efficiency of electrolyzed water for the removal of microorganisms and pesticide residues from Chinese cabbage. Initial total bacteria and coliform counts were 6.64 and 3.56 log cfu/g respectively. After washing, total bacteria count of tap water (TW) were 5.97 log cfu/g and low alkaline electrolyzed water (LAlEW) and strong acidic electrolyzed water (SAcEW) were 1.63-4.67 log cfu/g. Especially SAcEW-100 was found to the most effective method of washing the cabbages. After washing, the coliform count was dramatically reduced. The removal rate of pesticide residues by NaClO treatment (36.93-50.13%) was greater than that of TW treatment (32.28-38.46%). The removal rate of LAlEW-100 and SAcEW-100 was 63.79 and 78.30% respectively, and was higher than those of TW and NaClO treatments. The vitamin C content of the Chinese cabbages after all treatments did not differ significantly. Consequentially, the electrolyzed water was found to be effective to remove bacteria and pesticide residues from Chinese cabbage without affecting quality.

• Korean journal of applied entomology
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• v.41 no.4
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• pp.293-298
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• 2002

Cadusafos and fosthiazate were applied at the rate of 1.8 g a.i./6$\m^2$ as pre-plant or pre-plant＋post-plant treatments on winter-grown oriental melon in a greenhouse soil infested with Meloidogyne arenaria. Nematicides reduced root-knot nematode population from 35 to 90% compared with control； fosthiazate was better than cadusafos (P ＝ 0.003) and fosthiazate pre-plant＋post-plant application reduced nematode population densities as much as 90%. Nematicides increased yield in an average of 23% (11-38%) in May, 39% (2-65%) in June, and 31% (12-46%) for the total (P ＝ 0.085). The residue in the fruit of oriental melon by post-plant treatment of fosthiazate exceeded maximum residue limit of 0.2ppm, while the Cadusafos residue was below the limit. It is concluded that fosthiazate cannot be used as a post-plant treatment in winer-grown oriental melon with overall consideration, i. e., danger of residue, value of melon, costs of nematicide, consumer demand on safer agricultural products, and effects of fallow.

• Journal of Applied Biological Chemistry
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• v.63 no.3
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• pp.275-282
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• 2020

As pesticide safety was extended to agricultural environments and Positive List System was carried out, Pesticide safety management in soils has become even more important. To improve pesticide safety in soils needs the degradation technology of the residues in soils and reduce plant uptake of pesticides. In this study, biochars and quicklime as the degradation methods of pesticides (azoxystrboin, procymidone and tricyclazole) were used to identify the reduction effects. The experimental methods were putting biochars and quicklimes (0, 0.5, 1.0, 2.0% per 15 cm soil weight) in soils and analyzing the pesticide residues at 0, 10, 20, 35, 50 day. To identify the reduction effects of uptake from soil to korean cabbages (roots, leave, stems) by biochar treatment, the residues in samples were analyzed. As a results, azoxystrobin (36-96%), procymidone (40-117%) and tricyclazole (26-83%) were reduced in soils when treated with 2.0% quicklime (p<0.05). There were no reduction effect in soils when treated with 1.0% or less biochar. However, the amounts of residues translocated to roots (0.11-1.62 mg/kg), leave (0.05-0.29 mg/kg), stems (0.06-0.1 mg/kg) were reduced treated with 2.0% biochar treatments. The biochar and quicklime can be applicable to agricultural field to improve pesticide safety in soils.

• Journal of Ocean Engineering and Technology
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• v.9 no.2
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• pp.133-140
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• 1995

This paper deals with the residual strength characteristics of composite materials under the environment of high temperature and humidity. Two types of GFRP, one with unidirection and randomly oriented, are used to investigate the features of moisture absorption and the residual strength. The results show that, when exposed longterms in high temperature and humidity, the randomly oriented composites is more stable than the unidirection one.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2007.06a
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• pp.76-80
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• 2007

반도체 제조공정에서 매엽식 습식 식각 공정은 기판을 회전하면서 상하 면에 약액을 분사하는 형태로 박막을 식각한다. 이 때 기판은 척을 이용하여 고정되는 데 기판과 척이 접촉하는 가장자리 부분에서 약액의 흐름이 정체되거나 일정하지 못해 잔류막질이 남게 되고, 후속 공정에서 기판 오염의 문제를 야기하게 된다. 본 논문에서는 이러한 문제를 해결하기 위해 기판을 파지하는 여러 개의 척을 2개조로 나누어 교대로 파지하도록 하는 기능을 제시하였다. 2개 조의 척들은 자성체를 사용하여 고속 회전 중에 비접촉 방식으로 구동하였고 실제 약액 처리론 수행하여 효과를 관찰하였다. 결과적으로 기존 고정형 파지 방식에 비해 교차형이 기판 베벨면이나 에지면에서의 잔류 막질 제거에 탁월한 효과가 있음을 확인하였다.

• Journal of Ocean Engineering and Technology
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• v.9 no.1
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• pp.57-62
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• 1995

The hygrothermal effect on three different types of Glass/Polypropylene was investigated under the environment of 4$0^{\circ}C$ distilled water. The residual strength of Glass/Polypropylene with randomly oriented and fiber content of 4-wt%(R40) was found stable under the moisture content of 0.2%. In this case, the maximum moisture content was 0.53%. On the other hand, Glass/Polypropylene with unidirection and 42wt%(U42) and 50st%(U50) fiber content, respectively, showed the residual strength less stable than R40. However, the maximam moisture contents were 0.52% and 0.45% respectively.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.10
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• pp.27-33
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• 2003

A method for the retardation of fatigue crack growth using ring indentation at the vicinity of a crack is examined. Residual stresses near crack tip are evaluated using fracture mechanics approach using the Bueckner weight function. The motivation is to develop a simple and effective method for obtaining an increase in fatigue lives to total failure of materials with crack. Fatigue testing of aluminum specimen showed that the retardation effects are observed after the application of the method.

• The Journal of Korean Academy of Prosthodontics
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• v.52 no.2
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• pp.136-142
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• 2014

Nowadays, dental zirconia is widely used as a framework material for a fixed dental prosthesis as well as a single restoration. However, clinical studies have reported high incidence of veneer chipping of zirconia-ceramic restorations compared to that of metal-ceramics. Several factors were raised as the possible causes of veneer ceramic chipping, however, it is still in debate. Recently, residual stresses in the veneer ceramics after cooling process gathers attention as one possible cause of chipping and many studies reported that the rate of cooling significantly influenced the types and the amount of residual stress. The purpose of current review was to briefly describe the effect of cooling rate on the residual stress in zirconia-ceramics. It was also described that the different behavior of residual stress between zirconia-ceramics and metal-ceramics following different cooling rate.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.3
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• pp.333-338
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• 2013

The compressive residual stress and fatigue behavior of shot peened alloy 600 under a high-temperature environment is investigated in this study. Alloy 600 is used in the main parts of nuclear power plants, and the compressive residual stress induced by the shot peening process is considered to prevent SCC (stress corrosion cracking). To obtain practical results, the fatigue characteristics and compressive residual stress are evaluated under the actual operating temperature of a domestic nuclear power plant, as well as a high-temperature environment. The experimental results show that the peening effects are valid at a high temperature lower than approximately $538^{\circ}C$, which is the threshold temperature. The fatigue life was maintained at temperatures lower than $538^{\circ}C$, and the compressive residual stress at $538^{\circ}C$ was 68.2% of that at room temperature. The present results are expected to be used to obtain basic safety and reliability data.