• Journal of the KSME
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• v.29 no.3
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• pp.231-243
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• 1989

복합재료의 탄성 문제를 정리하면 다음과 같다. 복합재료와 등방성 재료의 탄성학적 차이는 재료의 탄성계수에 기인하며 이것은 각각 다른 형태의 응력-변형률관계를 갖게 한다. 한편 응 력-변형률 관계식을 제외한 탄성학의 지배방정식은 재료의 종류에 관계없이 성립한다. 복합적 층판의 Stiffness와 응력 등은 Lamination 이론을 사용하여 구할 수 있다. 판이론은 평형식을 z방향으로 적분한 식, 즉 합력(resultant force)와 모멘트로 나타낸 평형식을 사용하는데 이 때 처짐 방정식을 구하기 위해 합력. 모멘트-곡률. 변형률 관계식을 이용하는데 이 관계식이 복합 재료와 등방성재료가 상이하다. 결과로 복합재료는 커플링 효과를 갖게 되며, 복합적층판을 대 칭으로 쌓으면 이 효과를 상쇄시킬 수 있다. 복합적층 보의 이론은 유효 굽힘 계수를 도입하면 등방체 보 이론을 사용하여 보의 처짐을 해석할 수 있다. 복합적층 보의 경우 굽힘 응력의 최 대치는 등방체와는 달리 보의 표면에서만 일어나지 않고 내부에서도 일어날 수 있다.

• Journal of the Korean Magnetics Society
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• v.27 no.4
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• pp.135-139
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• 2017

The magneto-impedance effect (MI effect) has been investigated in metal core/soft magnetic shell composite wires fabricated by electrodeposition of $Ni_{80}Fe_{20}$ on Cu wire (diameter $190{\mu}m$). The diagonal impedances $Z_{zz}$ and $Z_{{\theta}{\theta}}$ in cylindrical coordinate showed strong MI effect for the magnetic field applied along z-axis, while the off-diagonal impedance $Z_{{\theta}z}$ showed very weak MI effect. We have tried to develop the Cu $core/Ni_{80}Fe_{20}$ shell composite wire having strong MI effect in off-diagonal impedance by electrodeposion under torsional strain. The core/shell composite wire electrodeposited under torsional angles above $270^{\circ}$ showed significantly enhanced MI effect in the off-diagonal impedance. The maximum MI effect was observed in the composite wire electrodeposited under torsional angle of $360^{\circ}$. The developed method to enhance off-diagonal MI effect is expected to increase the applicability of the core/shell composite wire to magnetic sensor material.

• Journal of Ginseng Research
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• v.12 no.2
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• pp.135-144
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• 1988

When ginseng saponin fractions were treated with secretion regulatory agents, it increased cAMP level at the case of thyrotropin (but the amounts were small). Total saponin increased cAMP level at DEcAMP and isoproterenol, and decreased the level at carbachol and propranolol, but at NaF it had little effect. When diol saponin or triol saponin were treated with secretion regulatory agents, biol saponin decreased cAMP level but triol saponin increased it except for isoproterenol. Also, in propra%olol, which inhibits the increase of CAMP level, diol and triol saponin showed crossing effect, too. From the above results, ginseng saponin fractions are believed that it has the, effects of promotion or inhibition on cAMP production in the thyroid , both diol saponin and triol saponin have crossing effect on thyroid hormone secretion regulatory agents. The normalizatin action of ginseng saponin fractions is notable at the case of NaF and carbachol.

• Korean Journal of Food Science and Technology
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• v.44 no.2
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• pp.257-262
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• 2012

Currently, various treatments available for alleviating hair loss and combination treatments are commonly used, which are frequently questionable and in effective. We aimed to investigate the synergistic effect regarding the combination of oral herbal composition and topical hair tonic on anagen induction and hair restoration in a shaving model of C57BL/6 mice. Seven-week old mice were trimmed by electric clippers and treated with oral herbal composition and topical hair tonic either alone or in combination. The combination treatment showed the highest hair growth promoting effect. Moreover, it significantly improved total blood antioxidant capacity and reduced lipid peroxidation and triglyceride level, which was not observed in the topical hair tonic treated group. These results suggest that the combination of oral herbal composition and topical hair tonic has a synergistic hair growth promoting effect and such synergism may be the result of the differing hair regrowth mechanisms concerning treatments.

• Proceedings of the Korean Society For Composite Materials Conference
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• 1999.11a
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• pp.118-123
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• 1999

저밀도 폐놀계 탄소/탄소 복합재의 층간전단강도를 개선하기 위해 흑연분말, 카본블랙, 카본매트, 단섬유 등의 첨가제를 사용하였다. 카본매트와 단섬유를 첨가한 경우, 수지의 부족에 의한 층간접착력의 약화를 가져왔으며, 카본블랙을 첨가한 경우에도 큰 효과를 나타내지 못했다. 흑연을 첨가했을 때 약 30%의 층간강도 개선을 가져왔으며 특히 9 vol.%의 첨가량에 대해서 가장 큰 효과를 보였다.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2001.11a
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• pp.118-123
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• 2001

항공기 운항 중에 손상된 부품의 교환이나 수리는 항공기 운항 시 안전 유지와 고가의 항공기 수명연장을 위하여 필수적이다. 여러 가지 손상이나 고장 중에서 균열은 기계적 체결요소(리벳, 볼트 등)나 패칭에 의하여 효과적으로 보수될 수 있다. 항공기 동체 보수 시 접착제 접합을 사용한 복합재료 패칭은 하부구조에 손상이 없이 균열진전을 줄일 수 있고 구멍의 생성으로 인한 응력 집중을 제거할 수 있으며 접합된 면을 외부로부터 차단시켜 부식을 방지하는 효과가 있어 많이 사용된다 특히 고강도 복합재료와 접착제의 개발로 인하여 손상된 구조의 보수를 위한 복합재료 패칭의 사용은 더욱 증가되고 있다.(중략)

• Tuberculosis and Respiratory Diseases
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• v.44 no.3
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• pp.525-533
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• 1997

Background : No ideal combination chemotherapy for lung cancer has been established even though lots of combination anticancer chemotherapies have been tried. For the combination of anticancer drugs, the interaction of anticancer drugs is very important but unpredictable factor. In this experiment, we designed and tested new experiment to measure the interaction of two anticancer drugs using MIT assay in an attempt to predict clinical response of the combination regimen. Methods : With human lung adenocarcinoma cell line (PC-14), the cytotoxic effect of cisplatin, adriamycin, mitomycin C and etoposide were measured by in vitro chemosensitivity test (MIT assay). The combined cytotoxic effects of combination of two drugs were also measured in every combination of the drug concentrations and analyzed the interaction by Anava analysis of two way factorial design. Results : Four individual drugs showed cytotoxic effects on PC-14 by dose dependent fashion. Comparison of two drug combinations revealed that mitomycin C + cisplatin and adriamycin + cisplatin combinations showed stronger synergistic cytotoxic effects. Conclusion : From this experiment, we suggest two combinations of mitomycin C + cisplatin and adriamycin + cisplatin as chemotherapeutic regimens for unresectable non-small cell lung cancer. Furthermore, this experimental design could be applied to other types of cancer requiring combination anticancer chemotherapy.

• Proceedings of the Korean Society For Composite Materials Conference
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• 1999.04a
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• pp.135-138
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• 1999

• Proceedings of the Korean Society For Composite Materials Conference
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• 1999.04a
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• pp.85-90
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• 1999

• Composites Research
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• v.27 no.6
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• pp.219-224
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• 2014

Nancomposites manufacture has been developed rapidly, because of reinforcing effects of CNT in terms of mechanical, electrical and thermal properties. In this study, 10 wt% CNT paste was fabricated with good dispersion state and easy processability. Damage sensing and reinforcing effect of CNT paste were investigated in nanocomposites. 10 wt% CNT paste exhibited better tensile and flexural properties than those of general 1 wt% CNT nanocomposites. To observe the healing effect of CNT paste, a crack was made artificially with 30wt% CF30wt%/PP composites, and the CNT paste was filled inside the crack. The damage sensing of CNT paste in CF30wt%/PP composites was investigated by electrical resistance measurement and mechanical tests. CNT paste exhibited good reinforcing effect in mechanical properties of CF30wt%/PP composites, and this reinforcing effect was getting better with larger cracks. The reason was because CNT paste had good interfacial adhesion with CF30wt%/PP composites to resist crack propagation. In electrical resistance measurement, there was a jump in electrical resistance signal at the adhesion interface. The jumping signal could be used to predict fracture of CF/PP composites. CNT nanocomposites for damage sensing had crack reducing effect and damage detection using electrical resistance method.