• Journal of the Korean Wood Science and Technology
• /
• 제50권6호
• /
• pp.427-435
• /
• 2022

For effective applicability of reinforced cork, cork composites reinforced with metal, glass fiber, and carbon fiber were developed, and the effects of the reinforcing materials on the mechanical properties of cork composites were investigated. The bending moduli of elasticity (MOE) of cork composites were in the 32.7-35.9 MPa range, while the bending strength values were in the 1.62-1.73 MPa range. The strength performance decreased in the order cork-metal > cork-carbon fiber > cork-glass fiber. The bending MOEs were improved by 29%-41% compared with simple cork boards, while the bending strengths of reinforced cork were 35%-45% higher. The strength performance significantly improved following the incorporation of thin mesh materials into the middle layer of the studied cork composites. The bending strains of the cork composites were remarkably higher compared with oak wood, making them promising for applications that require bending processing, such as curved jointing. The internal bond strengths of the cork composites were 0.26-0.44 MPa, approximately 0.36-0.60 times lower compared with medium-density fiber boards.

• 생약학회지
• /
• 제42권2호
• /
• pp.169-174
• /
• 2011

In this study, we investigated on antioxidative activity, antibacterial activity and tyrosinase inhibitory activity in 75% ethanol extracts of bark and cork layer from Prunus sargentii. The total polyphenol content of cork and bark extract was found to be 217.4 mg/g and 184.3 mg/g. And flavonoid content was found to be 31.9 mg/g and 58.6 mg/g respectively. In DPPH radical scavenging ability, cork extract was exhibited stronger scavenging ability than bark extract. Moreover, cork extract was showed higher inhibitory activity than bark extract in tyrosinase inhibitory activity. In antibacterial activity, bark extract was showed higher growth inhibition effect than cork extract against tested bacterial strains. In measurement of cytotoxicity by MTT assay, bark and cork extract showed fine cell viabilities(95.7~120.9%) against RAW 264.7 cell.

• 한국작물학회지
• /
• 제41권3호
• /
• pp.362-369
• /
• 1996

3년생 의성작약품종(faeornia lacrifora Pall.)을 1994년 2월에 수확하여 유피 및 거피상태로 처리한 후 상온음건법, 화력건조법, 증건법 및 냉동건조법으로 건조방법을 각각 달리하여 주 약용성분인 paeoniflorin함량 및 일반 화학성분을 조사한 결과는 다음과 같다. 1. 건물비율 50%까지의 건조일수는 거피상태 3$0^{\circ}C$ 화력건조가 동일온도의 유피상태보다 5일이 짧으며, 거피상태에서는 5$0^{\circ}C$ 화력건조법이 1.5일로 가장 빨랐고, 121$^{\circ}C$ 증건법은 8일로 가장 늦었다. 2. 상온음건 및 화력건조법의 경우 paeoniflorin 함량은 거피상태가 더 높았고, 반대로 증건법은 유피상태가 더 높았다. 화력건조법의 경우 건조온도가 높아짐에 따라 paeoniflorin 함량은 감소하였다. 3. 건조방법 중 3$0^{\circ}C$화력건조가 Paeoniflorin함량이 4.0%로 가장 높고, 건조일수가 단축되며, 색택 이 양호한 가장 적절한 건조법 이었다. 4. 화력건조시 건조온도가 높아짐에 따라 총당의 함량은 감소하고 전분은 증가하는 경향을 보였으며, 또 전분함량은 121$^{\circ}C$의 증건법을 제외한 모든 건조방법에서 거피상태보다 유피상태가 더 높았다. 5. 조단백질, 조섬유 및 조회분의 함량은 유피, 거피 및 건조방법에 따라 큰 차이가 없었다. 6. Paeoniflorin과 총당의 관계는 유피상태에서 정의 유의상관이, 그리고 paeoniflorin과 전분의 관계는 거피상태에서 부의 유의상관이 있었다.

• 한국군사과학기술학회지
• /
• 제21권4호
• /
• pp.464-470
• /
• 2018

A development of one-dimensional thermal analysis tool is performed to estimate the thickness of cork insulation for flight vehicle. In the calculation of cork temperature, the cork density model, heat of ablation and pyrolysis gas enthalpy model were applied. The calculation for the two-layer model of cork and metal was performed by the tool and compared with the experimental data. The results for the two aerodynamic heating conditions were 17 % and -12 % different from the experimental data, respectively. The effect of mechanical ablation not included in the calculation can be expected as the cause of the difference. The temperature-density curve of cork which adjusted by experimental data was also presented.

• 한국약용작물학회지
• /
• 제10권5호
• /
• pp.392-398
• /
• 2002

4년생 의성작약을 재료로 하여 작약의 주 이용부위인 약근 외에 뇌두, 줄기, 잎과 같은 작약 식물체 각 부위로 시료를 구분하고, 또한 작약근의 경우 관행적 법제시 박피를 통해 제거되는 코르크층과 코르크층의 유 무에 따라 유피근 및 거피근으로 구분하여 각 시료에 함유된 작약 주요 생리활성 성분의 함량 분포를 검토한 결과 작약 식물체 부위별 paeoniflorin, albiflorin 및 phenolic compounds의 각 함량은 뇌두가 뿌리보다 높은 양상을 나타내었다. 또한 기능성 물질로 평가되는 gallic acld 및 benzoic acid는 작약의 잎과 줄기에도 상당히 많은 양이 존재하였고, 특히 잎에는 paeoniflorln도 약 2.3%가 존재하는 것을 확인할 수 있었다. 따라서 현재까지 번식용으로만 이용되어온 작약의 뇌두도 약재로서의 이용 가능성을 체계적으로 검토할 필요가 있을 것이며, 작약의 잎 및 줄기도 gallic acid 및 그 유도체들의 source가 될 수 있으므로 이들 부위의 이용성도 체계적으로 검토되어야 할 것이다. 한편 작약근에 함유된 유용 생리활성 성분들은 목부와 껍질부위의 코르크층에 함께 존재하였다 특히 albiflorin, gallic acid, benzoic acid 및 (-)-epicatechin 성분은 코르크층에 많이 존재하였고, 목부에 더 많은 양이 존재하는 성분은 paeoniflorin, (+)-taxifolin $3-O-{\beta}-D-glucopyranoside$ 및 (+)-catechin이었다. 결국 작약근 이용시 코르크층을 벗기면 albiflorin을 포함한 유용성분의 손실이 발생되고, phenol 성 물질의 분비로 외면의 갈변이 유도되므로 상품의 질을 떨어뜨리는 원인이 된다. 그러므로 작약근의 이용 시 거피를 하지 않는 것이 유용성분의 활용 면에서도 유리하고, 수치작업에 대한 노력이 감소되므로 경제적 측면에서도 유리한 것으로 평가된다.

• 한국약용작물학회지
• /
• 제11권3호
• /
• pp.201-206
• /
• 2003

한국산 재배작약의 품질평가 기준 확립을 위한 연구의 일환으로 국내 재매작약의 생육년수, 품종, 건조방법에 따른 작약의 성분적 품질평가의 한 요인이 되는 엑스 함량을 검토하고 아울러 작약의 활성효과 중 항염증 작용 및 위액분비 억제 작용에 관여하는 것으로 보고된 엑스의 pH 변화 양상을 검토한 결과를 요약하면 다음과 같다. 1. 생육년수의 차이에 따른 엑스 함량 및 pH변화를 검토한 결과 유피근, 거피근 모두 생육년수에 따른 통계적 차이를 나타내지 않았다. 한편 $2{\sim}4$년생 작약의 유피근 함유엑스 함량이 거피근보다 $3.7%{\sim}9.2%$ 높은 양상을 나타내므로 작약근 껍질부위에도 엑스 추출 시 용출되는 물질이 다량 존재함을 알 수 있다. 2. 4년생 의성작약, 영천작약 및 좀작약을 각각 유피근과 거피근으로 가공하고 상온에서 음건한 후 각 품종별 엑스함량 및 엑스의 pH변화를 조사한 결과 엑스 함량의 경우 유피근, 거피근 모두 품종 간 차이를 나타내었고, 영천작약이 유피근, 거피근 각각 36%, 30% 수준으로 의성 작약 및 좀작약 보다 높은 엑스 함량을 나타내었으며, 엑스의 pH는 품종 간 차이가 인정 되지 않았다. 3. 4년생 의성작약을 대상으로 건조방법에 따른 엑스 함량 및 엑스의 pH 변화를 검토한 결과 유피근, 거피근 모두 건조방법 간에 뚜렷한 차이를 나타내었다. 엑스 함량은 유피근의 경우 상온 음건이, 거피근은 $80^{\circ}C$ 수증건법 이 가장 높았고, 동결건조법은 유피근, 거피근 모두 가장 낮은 함량을 나타내었다. 엑스의 pH변화는 유피근, 거피근 모두 냉동건조법이 pH 5.1 수준으로 가장 높았고, $80^{\circ}C$ 수증건법이 유피근, 거피근 모두 pH 3.7 수준으로 가장 낮은 양상을 나타내었다.

• The Korean Journal of Ecology
• /
• 제14권2호
• /
• pp.159-169
• /
• 1991

Floristic cmposition and soil properties were analyzed in chines cork oak(quercus variabilis)cmmunities in the limestone area, tanyang, ch'ungbuk province in korea. The tree layer was composed of quercus dentata, platycarya strobilacea, fraxinus rhynchophylla and others as wel as quercus variabilis. the shrub layer was dominated by ulmus davidiana for. suberosa,shrubby q. variabilis. euonymus alatus and rhus chinensis. among these, u. davidiana for. suberosa was known to have a restricted distribution to calcareous area, and 9 species in the shrub layer including e. alatus, indigofera kirilowii and rhamnus davurica belonged to the calcicole. The herb layer was dominated by carex lanceolata and spodiopogen cotulifer. ten specirs including g. lanceolata, clematis mandshurica, isachne globosa, lithospermum arvense and scabiosa mansenensis belonged to the calcicode. soil texture was classified to clay loam in both top and subsoil. Water cotent and organic matter were consistentl higher in top soil than in subsoil. soil ph rangd 7.8~8.4. Total n concentration in top soil ranged from 0.2 to 0.4mg/g, which was higher than that in subsoil. Available p and exchangeable k concentretion were also significantly higher in op soil than in subsoil. However, exchangeable ca concentration was similar betweenthe top and the subsoil. Unlike the other nutrients, exchangeable mg concentration in top soil was lower than that in subsoil. orangic matter, n, p and k content in this chinese cork oak stand showed as much as the other noncalcareous sites. Soil properties in this study area seemed to have been influenced by casts forming activities of earthworms.

• 생약학회지
• /
• 제42권3호
• /
• pp.213-217
• /
• 2011

Platycodon grandiflorum (Campanulaceae) is listed in Shin-Nong-Bon-Cho-Kyung (神農本草經) as the remedy for ventilation the lung, resolving phlegm, promoting pus discharge and subduing carbuncles. The prescriptions of Gil-Gyung-Tang (桔梗湯) are also recorded in many other Chinese medicinal books. The identification of the cultivation year of P. grandiflorum is very important in commercial market as well as in research field. However, any reports about it have not been clearly established yet. To clarify the criterion, the morphological and anatomical characteristics of the roots of P. grandiflorum cultivated in Korea for various years were studied. The characteristics of the cork layer, latex tube, and vessels were shown to be useful keys to confirm the cultivation year of P. grandiflorm. As a result, it was clarified that Kilkyung from Korea was the two years root of Platycodon grandiflorm.

• 생약학회지
• /
• 제35권1호통권136호
• /
• pp.45-51
• /
• 2004

Panax ginseng C. A. Meyer (Araliaceae) is listed in Shen Nung Pentsao Ching(神農本草經) as the remedy for replenishing the primodial qi(氣), restoring pulse, treating collapse, tonifing the spleen and lag, promoting the production of body fluid to quench thirst, tranquilizing the mind, and improving the function of brain. The prescriptions of In Sam Tang(人參揚) are also recorded in many other Chinese medical books. The identification of the age of Panax ginseng is very important in commercial market as well as in research field. However, any reports about it have not been clearly established yet. To clarify the criterion, the morphological and anatomical characteristics of the roots of various age Panax ginseng cultivated in Korea were studied. The characteristics of cork layer, secretory canal, and vessel were shown to bε useful keys to confirm the age of Panax ginseng.

• 한국약용작물학회지
• /
• 제20권3호
• /
• pp.159-164
• /
• 2012

In this study, we investigated the antibacterial activity, antioxidative activity and whitening effect of 75% ethanol extracts from different parts of Prunus sargentii. The total phenolic compound content of the branch extract was 277.92 mg/g as the highest level. In the measurement of DPPH radical scavenging ability, $SC_{50}$ values of the cork layer and branch extract were 26.79 ${\mu}g/m{\ell}$ and 30.13 ${\mu}g/m{\ell}$. In nitric oxide (NO) scavenging ability, $SC_{50}$ values of the branch and leaf extract were 49.19 ${\mu}g/m{\ell}$ and 55.55 ${\mu}g/m{\ell}$. All extracts exhibited higher NO scavenging ability than ascorbic acid used as positive control. On the other hand, in antibacterial activity against Staphylococcus epidermidis and Staphylococcus aureus by disc diffusion assay, the pure bark extract showed the highest activity. Moreover, tyrosinase inhibitory activity of cork layer, pure bark and branch extracts showed higher activity than arbutin used as positive control. In the cytotoxicity measurement by MTT assay, leaf extract was exhibited Raw 264.7 cell viabilities of 44.68~61.83% as cytotoxic result in tested concentration. In conclusion, the branch extract of Prunus sargentii will be a functional materials without damage compared to other parts such as pure bark or cork layer in the plant.