• 한국군사과학기술학회지
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• 제20권3호
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• pp.384-392
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• 2017

A linear explosively formed penetrator(LEFP) is a modification of the explosively formed penetrator(EFP). An EFP is axisymmetric and has a dish-shaped liner while LEFP has a rectangular-shaped liner with curved cross section. Upon detonating LEFP forms laterally wide projectile like blade, leaving a long penetration hole on the target. On the other hand, a long-rod tungsten heavy alloy(WHA) penetrator is one of the major threats against most of the ground armored vehicles. In this paper, the feasibility of using an LEFP in protecting against a long-rod WHA penetrator by colliding LEFP into the threat was investigated through a set of numerical simulations. In this study, a scale-down WHA penetrator with length to diameter ratio(L/D) of 10.7 and 7.0 mm diameter was used to represent a long-rod WHA penetrator. LS-DYNA and Multi-Material ALE technique were employed for the simulation. For estimation of the protection effect by LEFP, residual penetration depths into RHA by the threat were compared according to various impact locations against the threat.

• 대한치과보철학회지
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• 제45권3호
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• pp.310-320
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• 2007

Statement of the problem. The fracture of acrylic resin dentures remains an unsolved problem. Therefore, many investigations have been performed and various approaches to strengthening acrylic resin, for example, the reinforcement of heat-cured acrylic resin using glass fibers, have been suggested over the years. But problems such as poor workability, rough surface, poor adhesion of glass fiber resin complex are not solved yet. Purpose. The aim of the present study was to investigate the effect of short glass fibers on the transverse strength of heat-polymerized denture base acrylic resin and roughness of resin complex after abrasion test. Material and methods. To avoid fiber bunching and achieve even fiber distribution, glass fiber bundles were mixed with acrylic resin powder in conventional mixer with a non-cutting blade, to produce the glass fiber($10{\mu}m$ diameter, 3mm length, silane treated) resin composite. Glass fibers were incorporated at 0%, 3%, 6% and 9% by weight. Transverse strength were measured. After abrasion test, surface roughness was evaluated and scanning electron microscope view was taken for clinical application. Results. 1. 6% and 9% incorporation of 3mm glass fibers in the acrylic resin enhanced the transverse strength of the test specimens(p<0.05). 2. Before abrasion test, incorporation of 0%, 3%, 9% glass fiber in the resin showed no dirrerence in roughness statisticaly(p>0.05). 3. After abrasion test, incorporation of 0%, 3%, 6% glass fiber in the resin showed same surface roughness value statistically(p>0.05). 4. In SEM, surface roughness increased as the percentage of the fibers increased. 5. In the areas where glass fiber bunchings are formated, a remarkably high roughness was noticed. Conclusion. 6% and 9% addition of silane-treated short glass fibers into denture base acrylic resin increased transverse strength significantly. Before and after abrasion test, incorporation of 0%, 3%, 6% glass fiber in the resin showed same surface roughness value statistically.

• KSBB Journal
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• 제5권2호
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• pp.175-182
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• 1990

N. tabacum $NR^-/SR^+$과 N. glutinosa의 엽육세포로부터 원형질체를 분리하여 전기적으로 융합 및 배양하였으며 AAPI 9M 배지에서 이 원형질체의 plating effici-ency는 30~35%였다. 분열 중인 소형 세포괴는 1.2mg / ml의 streptomycin이 포함된 $MSNO_3$배지에 치상하여 계속 분열을 유지하는 녹색 칼루스 계통을 선발하였다. 이 녹색 칼루스 계통에서 유래된 4계통의 식물들은 꽃의 형태, 화관의 길이와 염신의 모양에서 양쪽 모식물체의 중간형을 보였고, 엽조직의 peroxidase와 esterase의 isozyme분석에서도 양쪽 모식물체의 특성을 부분적으로 함께 나타냈으며 또한 결실되거나 새로운 isozyme band도 보였다. 이 융합체 추정계통들의 염색체 분석에서 L22계통에서 2n=66, L44계통에서 2n=54개가 조사되어 N.tabacum(2n=48)과 N.glutinosa(2n=24)의 융합체는 염색체의 부분적 감소현상을 보였다.

• Journal of Ginseng Research
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• 제27권4호
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• pp.188-194
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• 2003

Rust-spot on North American ginseng roots (Panax quinquefolius L.) is considered a physiological, not a pathological disorder. Ginseng rust-spot starts as an orange spot on the surface of the root and may spread forming a sunken, round to irregular lesion. 5 mm in diameter. Pieces of root, 7 mm in length and containing a rust-spotted lesion, were embedded in agar and sectioned using a vibratome. These sections and hand sections, cut with a two-sided razor blade, were examined using fluorescence microscopy. The 4-5 cell layers of the periderm were destroyed in the area of the lesion and orange substance:, were deposited in and around the lesion. Sections stained with vanillin-HCI and viewed using bright field microscopy confirmed that the orange substances were phenolic compounds. Scanning electron micros-copy showed that the periderm had pulled away from the root, or was completely destroyed, in the area of the lesion. The smooth surface of the lesion indicates the deposition of phenolic compounds in surrounding cells as a wound response. Roots sprayed or dipped in ethephon (1500 mgㆍL$^{-1}$ ) developed rust-spots, more so at 21$\pm$2$^{\circ}C$ than at 3$\pm$0.2$^{\circ}C$. Roots held at 21$\pm$2$^{\circ}C$ were yellowish and developed white cell proliferations. Comparable control roots also developed rust-spots likely due to the high undecomposed organic matter content of the incubation soilless mix.

• Weed & Turfgrass Science
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• 제2권2호
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• pp.198-201
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• 2013

본 실험은 한국잔디 신품종 '세밀'(등록번호: 품종심사과-1749)의 개발에 관한 것이다. 한국에서 수집한 유전자원 중 금잔디(NM1) 와 수집계통 ASm간에 인공교배를 수행해서 F1계통을 얻었다. 작성한 F1 30개 계통 중에서 포장 상태에서 우수계통으로 선발된 (NM1 ${\times}$ ASM)-1이 '세밀'이다. '세밀'은 낮게 자라는 특성이 있고, 세엽으로 품질이 우수하다. 엽폭이 $2.7{\pm}0.12mm$로 중세엽 형이며, 초장은 $10.3{\pm}3.7cm$로 낮고, 지면으로부터 최하위 엽의 잎몸 기부까지의 길이가 $1.8{\pm}0.15cm$로 낮은 형태적 특성을 갖고 있어 낮은 잔디깎기에도 적응할 수 있는 영양번식형 잔디이다.

• 한국육종학회지
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• 제42권6호
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• pp.664-667
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• 2010

'Clara' 품종은 국립원예특작과학원에서 2005년도에 육성한 포인세티아 품종이다. 이 품종은 2002년에 진한 녹색 잎에 엽절이 있으며 선명한 적색인 'Red Velvet'을 모본으로, 단일반응이 빠르고 밝은 적색인 'Freedom Bright Red'를 부본으로 인공교배하여 양성된 실생계통 중 선발되었다. 2003년, 2004년 2차에 거쳐 특성검정을 하여 '원교 D5-12'를 육성하였고 2005년에 3차 특성검정과 품평회를 실시하여 최종선발 하였으며, 농작물 직무육성 신품종선정위원회를 거쳐 'Clara'로 명명하였다. 포엽의 형태는 난형이며 포엽의 엽맥 사이에 약한 주름이 있고 포엽의 색상은 적색이다. 잎몸은 난형이며 중간 녹색이고 엽절이 거의 없으며 엽병이 짧다. 줄기 색은 적색계이며 적심을 하지 않은 상태에서도 분지가 발생하고 줄기의 수는 중간이다. 초장은 작고 컴팩트한 수형을 이루며 단일처리 후 약 9주일이 경과하면 완전히 착색되어 출하가 가능하다.

• 한국육종학회지
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• 제42권6호
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• pp.611-614
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• 2010

'Heidi' 품종은 국립원예특작과학원에서 2004년도에 육성한 포인세티아 품종이다. 이 품종은 2001년에 생육이 왕성하고 진분홍색인 'Freedom Rose'를 모본으로, 진한 녹색 잎에 결각이 있으며 적색인 'Red Velvet'을 부본으로 교배를 실시하여 양성된 실생계통 중 선발되었다. 2002년과 2003년 2차에 거쳐 특성검정을 하여 '원교 D5-9'를 육성하였고, 2004년에 3차 특성검정과 품평회를 실시하여 최종선발, 'Heidi'로 명명하였다. 포엽의 형태는 타원형이며 포엽에 접힘이 있고 포엽엽맥사이에 중간 정도의 주름이 있으며 포엽의 색상은 벨벳질감의 적색이다. 잎몸은 난형이며 진한 녹색이고 결각이 거의 없으며 엽병이 짧다. 줄기 색은 적색계이며 적심을 하지않은 상태에서도 분지가 발생하나 줄기의 수는 적다. 초장은 작으며 단일처리 후 약 7.5주일이 경과하면 완전히 착색되어 출하가 가능하다.

• 한국육종학회지
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• 제43권6호
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• pp.568-571
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• 2011

'Green Dream' 품종은 국립원예특작과학원에서 2009년도에 육성한 포인세티아 품종이다. 이 품종은 2006년에 진한 녹색잎에 초장이 짧고 아담한 연황색의 'Lemon Snow'를 모본으로, 생육이 왕성하고 진한 분홍색인 'Freedom Rose'를 부본으로 인공 교배하여 양성된 실생계통이다. 2007년과 2008년 2차에 거쳐 특성검정을 하여 '원교 D5-64'를 육성하였고 2009년에 3차 특성검정과 품평회를 실시하여 최종선발 하였으며, 농작물 직무육성 신품종선정위원회를 거쳐 '그린드림 (Green Dream)'으로 명명하였다. 포엽의 형태는 난형이며 포엽의 엽맥 사이에 중간 정도의 주름이 있고 포엽의 색상은 밝고 연한 황록색이다. 잎몸은 난형이며 진한 녹색이고 엽절이 적으며 엽병이 길다. 줄기 색은 녹색계이며 적심을 하지 않은 상태에서도 분지가 발생하고 줄기의 수는 중간이다. 초장은 크며 단일처리 후 약 7주일이 경과하면 완전히 착색되어 출하가 가능하다.

• 대한두개안면성형외과학회지
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• 제20권1호
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• pp.10-16
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• 2019

Background: Physicians tend to overcorrect when applying the acellular dermal matrix for reconstructive option because of volume decrement problem after absorption comparing with initial volume. However, there are no studies on the exact volume decrement and absorption rate with commercial products in South Korea. To figure out absorption rate of acellular dermal matrix product in South Korea (Megaderm), authors designed this experiment. Methods: Nine mice were used and randomly divided into three groups by the time with sacrificing. The implant (Megaderm) was tailored to fit a cuboid form ($1.0cm{\times}1.0cm$ in length and width and 2.0 mm in thickness). A skin incision was made at anterior chest with blade #15 scalpel with exposing the pectoralis major muscle. As hydrated Megaderm was located upon the pectoralis major muscle, the skin was sutured with Ethilon #5-0. After the surgical procedure, each animal group was sacrificed at 4, 8, and 12 weeks, respectively, for biopsies and histological analysis of the implants. All samples were stained with routine hematoxylin and eosin staining and Masson's trichrome staining and the thickness were measured. A measurements were analyzed using Friedman test. Statistically, the correlation between thicknesses of Megaderm before and after implantation was analyzed. Results: After sacrificing the animal groups at postoperative 4, 8, 12 weeks, the mean tissue thickness values were $2.10{\pm}1.03mm$, $2.17{\pm}0.21mm$, and $2.40{\pm}0.20mm$ (p= 0.368), respectively. The remaining ratios after absorption comparing with after initial hydrated Megaderm were 82.7%, 85.4%, and 94.5%, respectively. In histopathological findings, neovascularization and density of collagenous fiber was increased with time. Conclusion: Author's hypothesis was absorption rate of implant would be increased over time. But in this experiment, there is no statistical significance between mean absorption thickness of implant and the time (p= 0.368). Also it can be affected by graft site, blood supply, and animals that were used in the experiment.

• ALGAE
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• 제36권4호
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• pp.231-240
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• 2021

Saccharina sculpera is highly valued for human consumption and value-added products. However, natural resources of this kelp have decreased sharply and it is in danger of extinction. Resources recovery through cultivation is being trialed to enable the sustainable use of this species. In this study, the temperature range for survival and optimal growth of juvenile S. sculpera was identified and applied to field cultivation. This study investigated the survival and growth of juvenile S. sculpera under six temperatures (i.e., 5, 10, 15, 16, 18, and 20℃) and two light intensities (i.e., 20 and 40 µmol photons m^-2 s^-1) in an indoor culture experiment. In these experiments, the blade length decreased at 16℃ under the both light intensities. The thalli died at 20℃ and 20 µmol photons m^-2 s^-1, and at 18-20℃ and 40 µmol photons m^-2 s^-1. During the field cultivation, early growth of S. sculpera was highest at the 5 m depth and growth decreased as the water depth increased. When the initial rearing depth was maintained without adjustment throughout the cultivation period (from December to October), all the cultivated S. sculpera plants died during August and September. However, S. sculpera plants lowered from 5 to 15 m and grew to 90.8 ± 13.1 cm in July. The seawater temperature at 15 m depth was similar to the upper level of thermal tolerance demonstrated by juvenile S. sculpera in the indoor culture experiments (16℃ or lower). The plants were subsequently lowered to 25 m depth in August, which eventually led to their maturation in October. The present study confirmed that improved growth rates and a delay in biomass loss can be achieved by adjusting the depth at which the seaweeds are grown during the cultivation period. These results will contribute to the establishment of sustainable cultivation systems for S. sculpera.