• Defense and Technology
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• no.1 s.179
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• pp.52-61
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• 1994

곡사포탄은 적의 종심공격, 대포병사격, 적 전투차량 제압, 보병부대의 일반지원 등의 임무를 효율적으로 수행하기 위해 사거리 연장, 정확도 증대 및 위력증대의 3가지 목표를 극대화하는 방향으로 발전되어 왔다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.170-178
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• 2019

Recently, as the interest in energy savings has increased, there has been increasing use of LED lighting, which is an eco-friendly device that replaces high energy consuming fluorescent lamps and incandescent lamps. In the case of a high output LED, however, the life time is shortened due to deterioration caused by heat generation. As a solution to this problem, this paper evaluated the LED life extension effect by increasing the convective heat transfer coefficient of the heat sink surface for LED packaging. A roughing process was carried out using sandpaper and sand blasting. The changes in surface roughness and surface area after each surface treatment process were evaluated quantitatively and the convective heat transfer coefficient was measured. When sandblasting and sandpaper were used to roughen the aluminum surface, a higher convection heat transfer coefficient was obtained compared to the untreated case, and a high heat dissipation efficiency of 82.76% was obtained in the sandblast treatment. Therefore, it is expected that the application of heat dissipation to the heat sink will extend the lifetime of the LED significantly and economically by increasing the heat efficiency.

• The Korean Ginseng Research and Industry
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• v.2 no.2
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• pp.13-21
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• 2008

• Korean journal of applied entomology
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• v.40 no.1
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• pp.89-95
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• 2001

Effects of application method of eight nematicides on reproduction of iweloidogyne arenaria were tested in pot. In pre-treatment, cadusafos , dazomet, fosthiazate reduced over 90% in number of egg masses of M. arenaria at recommended rate . Carbofuran showed similar reduction only at three times of recommended rate. Benfuracarb was the least effective. Post-treatments, in general, were less effective than pre-treatment except fostiazate which reduced root egg mass of iW. arenaria as much as pre-treatment at recommended rate . Systematic nematicide, fosthiazate has potential as post-treatment nematicide.

• Journal of Applied Biological Chemistry
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• v.64 no.3
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• pp.197-203
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• 2021

Saponarin is a crucial component of barley sprout, and the production and quantitative analysis are issued to date. In this study, the optimal saponarin extraction conditions were presented on the subject of acetonitrile, ethanol, methanol, and water for the quantitative analysis in barley sprout through the extraction efficiency compared with the solvent concentration and extraction time using the reaction surface methodology. The optimal extraction time and solvent condition for saponarin were 3.9 h and 53.7% of aqueous methanol, respectively. In addition, the effect of LED artificial light on the saponarin production in barley sprouts was evaluated by the light cycle, light quantity, and light quality. The optimal cultivation conditions under artificial light for the growth of barley sprout and saponarin production were most effectively achieved on 220-320 μmol m^-2 s^-1 of the light quantity with 8 h day^-1 of a daylight cycle under 6500K LED combined with red light. Furthermore, blue light was evaluated as the main factor in the biosynthesis of saponarin.

• 프린팅코리아
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• s.20
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• pp.110-115
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• 2004

최초의 국내 껌 생산은 해태제과에서, 오늘날의 추잉 껌과 같은 제품은 1880년 경 미국인 토마스 아담스에 의해 상품화되었다. 그가 멕시코에서 자라나는 사포릴라 나무의 라텍스인 치클을 뜨거운 물 속에 넣어 부드럽게 한 다음, 손으로 둥글게 빚어서 약국에서 판매한 것이 껌의 원조가 되었다. 본격적으로 껌이 생산된것은 1890년대 초반, 월리엄 위그리가 회사를 설립하여 미국 전역에 판매하면서부터 확장되기 시작했다. 이 회사는 오늘날까지 전 세계 껌 시장의 최강자 위치를 굳히고 있다. 1928년에는 회계사인 월터 다이머가 풍선껌을 개발하여 껌의 대중화에 지대한 공헌을 세웠다.

• 한국약용작물학회:학술대회논문집
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• 2012.05a
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• pp.249-250
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• 2012

• Proceedings of the Ginseng society Conference
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• 1993.09a
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• pp.132-137
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• 1993

Several Prosapogenins and sapogenins obtained by acid hydrolysis or alkaline cleavage of Korean red ginseng saponins were separated and identified by spectral and physical methods. Some of these degradation products showed the cytotoxic activities against various cancer cell lines, that is, A549, SK - OV - 3, L121O, P388 and K562. The significant difference of activity between stereoisooers was not approved and the activity was inversely proportional to the number of sugars binding to sapogenins. It was clear that diol type prosapogenins and sapogenins were more cytotoxic than triol type ones.

• Polymer(Korea)
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• v.37 no.5
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• pp.579-586
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• 2013

Poly(vinyl alcohol)(PVA) nanocomposite films containing various saponite (SPT) clay contents were synthesized using a solution intercalation method. The thermal property, morphology, optical transparency, and gas permeability of the PVA nanocomposite films with various SPT contents in the range of 0 to 10 wt% were examined. PVA nanocomposite film containing 5 wt% SPT showed excellent thermal and gas barrier property. The hybrid films containing 5 wt% SPT were equibiaxially stretched with stretching ratios ranging from 150 to 250%. The clay dispersion, optical transparency, and gas permeability were also examined as a function of equibiaxial stretching ratio. The PVA nanocomposite films with various equibiaxial stretching ratios showed excellent optical transparency and barrier to oxygen permeability.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.499-505
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• 2021

The purpose of this study is to investigate experimentally the physical/chemical properties of concrete surface according to types of formworks. Plywood formwork and coated plywood formwork were prepared. In addition, plywood formwork with sand paper was prepared to simulate deterioration of concrete or rough surface of concrete. Normal concrete was used in this study. The properties of concrete surface were investigated by visual inspection, scanning electron microscopy and energy-dispersive X-ray spectroscopy techniques, elemental mapping, 2D and 3D surface profile measurement, and zeta potential measurement. Test results showed that concrete in a coated formwork had smooth surface and concrete in the formwork with sand paper had rough surface. It was observed that properties of concrete surface depended on types of formworks. Furthermore, differences in surface roughness were significantly higher than those in chemical compositions and zeta potential.