• Korean Journal of Environmental Agriculture
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• v.39 no.4
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• pp.297-304
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• 2020

BACKGROUND: Emission of nitrous oxide (N2O) from the soil is expected to depend on the types of nitrogen fertilizer used. Biochar has recently been proposed as a potential mitigation of climate change by reducing the N2O emission. Although laboratory studies reported that biochar applications could reduce N2O emission, the number of field-based studies is still limited. Therefore, a field experiment was conducted to investigate the effect of biochar on N2O emission when different nitrogen fertilizers were applied in corn cultivated field. METHODS AND RESULTS: The field experiment consisted of six treatments: urea fertilizer without biochar (U), ammonium sulfate fertilizer without biochar (A), oil cake fertilizer without biochar (O), urea fertilizer with biochar (U+B), ammonium sulfate fertilizer with biochar (A+B), and oil cake fertilizer with biochar (O+B). Biochar was applied at a rate of 10 t/ha. Greenhouse gas fluxes were measured during growing seasons using static vented chambers. The cumulative N2O emissions were 0.99 kg/ha in the U, 1.23 kg/ha in the A, 3.25 kg/ha in the O, 1.19 kg/ha in the U+B, 0.86 kg/ha in the A+B, and 1.55 kg/ha in the O+B. CONCLUSION: It was found that N2O emission was related to application of both nitrogen fertilizer type and biochar. In particular, the N2O reduction effect was the highest in the corn field incorporated with biochar when oil cake was applied to the soil.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.4
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• pp.359-366
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• 2016

Exosome, a small vesicle secreted from cells, has diverse functions depending on cell origins and tissue types and plays a important role in cell viability and intercellular communication. Recently, many researchers have demonstrated the use of exosomes for the treatment of cancers and immune diseases, and the development of diagnostic biomarker. However, the secretion mechanism of exosome from skin cell and its physiological functions in skin remain unclear. Thus, this study aimed to explore whether keratinocyte-derived exosome affects proliferation and migration in HaCaTs. Exosomes were isolated from HaCaTs by ExoQuick-TC and then boiled or unbolied. Boiled and unboiled exosome induced proliferation in HaCaTs in a dose-dependant manner ($0.1{\sim}20{\mu}g/mL$), respectively. Boiled and unboiled exosome at concentration of $20{\mu}g/mL$ increased proliferation level in HaCaTs by $186.96{\pm}3.87%$ and $193.48{\pm}10.48%$ compared with control group. Unboiled exosome stimulated migration in HaCaTs in a dose-dependent manner ($0.1{\sim}20{\mu}g/mL$), which reached a maxium at concentration of $20{\mu}g/mL$ ($179.39{\pm}4.89%$ of control), but boiled exosome did not affect HaCaT migration. In addition, unboiled exosome ($0.1{\sim}20{\mu}g/mL$) dose-dependently stimulated sprout outgrowth in HaCats. These results demonstrate that in exosome from HaCaTs, heat-stable components such as lipid may induce HaCaT proliferation and heat-unstable components such as protein may stimulate migration and sprout outgrowth in HaCaTs, thereby leading to reepithelialization and skin-wound healing activities. It is concluded that exosomes from HaCaTs may be used as cosmetic materials.

• Tribology and Lubricants
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• v.29 no.1
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• pp.39-45
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• 2013

Magnetorheological (MR) fluid belongs to the group of smart materials. In MR fluid, iron particles in base oil form chains in the direction of the applied magnetic field, thus resulting in a variation in the stiffness and damping characteristics of the fluid. Research is being carried out on controlling the stiffness and damping characteristics as well as the tribological characteristics of the MR fluid. In this study, the friction characteristics of MR fluid have been evaluated using three types of materials and magnetic fields of different strengths. The coefficients of friction of the three types of MR fluid are measured, and the relationship between the coefficient of friction and the strength of the applied magnetic field is obtained.

• The Magazine of the IEIE
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• v.39 no.4
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• pp.32-38
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• 2012

• Proceedings of the Korean Society of Crop Science Conference
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• 1991.05a
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• pp.38-39
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• 1991

• 대한치주과학회:학술대회논문집
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• 2002.11a
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• pp.39-40
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• 2002

• 대한예방의학회:학술대회논문집
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• 2004.10a
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• pp.38.3-39
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• 2004

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2010.10a
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• pp.39-40
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• 2010

• 주택과사람들
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• s.205
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• pp.36-39
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• 2007

한국초고층건축포럼은 논현동 건설회관에서 '초고층 건축과 도시경쟁력' 이라는 주제로 국제 심포지엄을 개최했다. 이번 심포지엄에서는 초고층 건축의 건립을 통해 도시들이 경쟁력을 확보하기 위한 해외 초고층 개발사례와 국내.외 초고층 전문가들의 심층적인 분석이 발표됐다. 또 국내.외 지방자치단체의 초고층 건축에 의한 도시개발전략과 도시경쟁력 향상을 위한 방안이 논의됐다.

• the MEAT Journal
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• s.1 fall
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• pp.34-39
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• 1987

국내 무역정책이 수입 개방화로 전환되면서 외국의 거의 모든 상품이 국내에 수입될 형편에 이르러 식육 가공제품도 예외가 될 수 없게 되었다. 현재 미국의 시장개방 압력이 가장 거세어 미국의 상품이 우선 수입될 가능성이 크므로 미국의 적육 및 가금육, 가공업계 현황을 살펴보는 것도 국내 업계에 도움이 될 것으로 생각된다.