• 제목/요약/키워드: Korean white oak

검색결과 70건 처리시간 0.024초

난연처리된 목재의 연소속도에 관한 연구 (A Study on the Burning Rate of Fire Retardant Treated Wood)

  • 박형주
    • 한국안전학회지
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    • 제22권6호
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    • pp.46-54
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    • 2007
  • The purpose of this study was to examines the burning rate of fire retardant treated wood in the cone heater with a one-dimensional integral model. The wood samples used in this study were four species. The species of woods are Redwood, White oak, Douglas fir and Maple. Each sample was nominally 50mm thick and 100mm square. Samples were exposed to a range of incident heat fluxes 10 to $35kW/m^2$ using the cone heater. A one-dimension integral model has been used to predict burning rate, heat of gasification, flame heat fluxes, charring rate and char depth of samples. As a result measurement of mass loss rate, softwoods(Redwood and Douglas fir) has relatively low value than those for hardwoods(White oak and Maple). Average charring rate of woods in case of fire retardant treatment showed reduction effect of 41.29%, 50.00%, 48.18% and 60.82% for Redwood, Douglas fir, White fir and Maple, respectively. Almost all the predictions from integral model showed faster charring than those measured. Average difference between predictions and experimental data was 16%, 9.5% and 11.8% for N, F1 and F2 respectively. Water-soluble fire retardant used in this study find out more effect in hardwood than softwood from the result of measurement of mass loss rate and average charring rate.

일정한 복사열원에 노출된 목재의 탄화속도에 관한 연구 (A Study on Charring Rate of Wood Exposed to a Constant Incident Radiation Heat Flux)

  • 박형주;김홍
    • 한국화재소방학회논문지
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    • 제18권4호
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    • pp.86-92
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    • 2004
  • 일정한 외부 복사열원(10, 15, 20, 25, and 35 ㎾/㎡)에 노출된 목재의 탄화속도를 측정하기 위해 목재의 종류별로 5개의 시료를 사용하였으며, 목재에 복사열원을 노출시키기 위해 Cone heater를 사용하였다. 시료의 크기는 100㎜×100㎜×50㎜로 Redwood, White oak, Douglas fir, Maple의 4종류의 목재를 사용하였다. 연구결과, 일정한 외부 복사열원에 노출된 목재의 탄화는 시간의 선형함수로 간주 될 수 있다. 일정한 외부 복사열원에 따른 목재의 종류별 탄화속도를 계산할 결과 Redwood가 가장 빠르게 나타나고. Douglas fir가 가장 느리게 나타났으며. 복사열원이 35㎾/㎡일 때 탄화속도는 10㎾/㎡일 때 보다 약 2배정도 빠르게 진행됨을 알 수 있었다. 식 (2)의 α 값은 외부복사열이 10, 15, 20, 25, 35㎾/㎡일 때 각각 1.02, 1.16, 1.23, 1.32, 1.44임을 평가할 수 있었다.

Trametes versicolor에 의한 상수리나무의 분해형태 (Morphological aspects of white-rot degraded oak wood by Trametes versicolor)

  • 유태방;윤민호;최우영;이종신
    • 농업과학연구
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    • 제28권2호
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    • pp.125-131
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    • 2001
  • 백색부후균 Trametes versicolor(CV5) 균주에 의한 wood lignin의 분해능을 조사하였다. CV5는 활엽수와 침엽수에 속하는 여러 수종의 프로토 리그닌 분해 시 활엽수에 한해서 분해되는 특성을 보였으며, 특히 상수리나무에서 33.5%의 가장 높은 리그닌이 분해되었다. 리그닌 분해에 관련된 phenoloxidase 분비능을 Bavendamm 시험을 통해 검토한 결과 CV5는 지금까지 연구된 우수 백색 부후균과 같은 유사 반응 형태를 나타내고 있음을 확인하였다. 또한 상수리 목재 chip표면에 CV5의 균사가 생육하면서 목재조직이 부후된 상태를 주사전자 현미경으로 관찰한 결과 목섬유 및 도관에서 균사의 침투와 목재조직의 분해를 확인하고 리그닌에 대한 높은 선택적 분해력을 갖고 있음을 구명하였다.

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파열된 반월상 연골판의 관절경적 봉합술 - 파열 위치와 동반 손상 여부에 따른 비교 - (Arthroscopic Repair of Meniscus Tears - Comparison of torn location and combined injury -)

  • 정영복;태석기;진휘재;정재원;박철경
    • 대한관절경학회지
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    • 제5권2호
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    • pp.85-91
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    • 2001
  • 목 적 : 반월상 연골판의 관절경적 봉합술후 파열 위치나 동반 손상 여부에 따라 어떠한 결과의 차이가 있었는지 알아보고자 하였다. 대상 및 방법 : 1994년부터 관절경적 봉합술을 시행 후 1년 이상 추시가 가능했던 73례를 대상으로 하였다. 위치에 따라서는 red-red zone이 29례, red-white zone이 36례 그리고 white-white zone이 8례이었다. 26례에서 동반 손상이 있었고 동측 전방 십자 인대 파열이 17례가 있어 동시에 치료하였다. 결과는 OAK system에 의한 기준을 사용하여 평가하였다. 결과 : 양호 이상의 결과를 나타낸 것은 연골판 단독 손상인 경우 $94\%$, 동반 손상이 있었던 경우 $88\%$이었는데, 특히 전방십자인대 파열후 재건술을 동시에 한 경우는 $94\%$로 좋았다. 연골판 파열의 위치에 따른 결과에서는 red-red zone은 $90\%$, red-white zone은 $91\%$, white-white zone은 모든례에서 양호 이상의 결과를 보였다. 결론 : 전방 십자 인대 파열이 동반된 경우는 동시에 치료하는 것이 좋고, white-white zone의 봉합도 가능한 것으로 사료되었다.

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폭쇄법(爆碎法)을 이용(利用)한 목질계(木質系) biomass의 종합적(綜合的) 이용(利用)(II) -폭쇄재(爆碎材)로부터 Carboxymethyl cellulose의 제조(製造)- (Total Utilization of Woody Biomass by Steam Explosion(II) -The Preparation of Carboxymethylcellulose from Exploded Wood-)

  • 한상열;장준복;이종윤
    • Journal of the Korean Wood Science and Technology
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    • 제22권2호
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    • pp.30-36
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    • 1994
  • Steam explosion process is one of the most efficient, pretreatment method for the utilization of lignocellulosic biomass. The carbxymethyl-cellulose(CMC) was prepared with steam exploded wood(EXW), pine(Pinus densiflora) and oak(Quercus mongolica), by standard method using isopropyl alcohol and monochloroacetic acid. The range of water solubility of carboxymethylated pine exploded wood was 45.2~66.8 % and those of oak was 60.7~84.7 %. The degree of substitution(D.S) of carboxymethylated pine exploded wood was 0.11~0.33 and oak exploded wood was 0.48~0.76. The color of carboxymethylated pine and oak exploded wood was brown-black. When carboxymethylated EXW was purified by sulfuric acid, the yield of carboxymethylated wood was lower than non-treated one. However, the color was still brown-black although after delignification. In carboxymethylated EXM prepared after delignification, the water solubility and degree of substitution(D.S) of pine were 81.4~95.9 % and 0.71~0.79, and those of oak were 76.2~89.5 % and 0.79~1.05. The values were higher than non-treated. The degree of substitution of purified carboxymethylated wood prepared with delignified EXM, pine and oak were 0.50~0.71 and 0.70~0.88. The color of carboxymethylated wood was white. In carboxymethylated wood preparde after delignification of EXM, swelling ratio and water retention value of pine were 95.9~96.5 and 580.0~751.2, those of oak were 76.2~89.5 and 124.3~307.6.

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LED 혼합광이 표고 '농진고' 자실체의 생육에 미치는 영향 (Effects of mixed LED light sources on the fruiting body growth of oak mushroom (Lentinula edodes) 'Nongjingo')

  • 박윤진;오태석;조용구;김창호;김태권;장명준
    • 한국버섯학회지
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    • 제15권4호
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    • pp.259-263
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    • 2017
  • 표고 '농진고'를 LED 혼합광에 따른 갓의 색차 및 경도차를 확인한 결과 갓의 명도값은 형광등 처리구 대비 LED혼합광 처리구 모두 낮아지는 결과를 나타내었다. 적색도는 형광등 처리구에 비해 처리구 모두 높아졌고, 황색도는 낮아지는 결과를 보였다. 광원별 자실체의 생육특성을 조사한 결과 형광등 대조구 대비 처리구 모두에서 갓직경이 컸으며, 자실체들에 대한 균일도는 형광등 처리구 대비 LED를 사용하였을 경우 낮은 값을 나타내어 형광등을 처리하는 것보다 균일도가 있는 것으로 나타났다. 대직경은 처리구간 큰 차이를 보이지는 않았으나 White Green LED에서 다른 처리구보다 높은 것으로 조사되었고, 대길이는 형광등 처리구보다 LED처리구 모두에서 다소 높게 조사되었다. 갓직경과 대길이의 비를 조사한 결과 White Green LED을 제외한 White LED와 White Blue LED에서 형광등 처리구 대비 높은 값을 나타내어 대길이에 비해 갓의 직경이 길어지는 것을 확인할 수 있었다. 자실체 물추출물의 항산화능을 확인한 결과 형광등 처리구에서 가장 높은 항산화능을 확인할 수 있었고 LED 처리는 White LED처리에서 가장 큰 항산화능을 확인하였고 White Green LED, White Blue LED간에는 유의한 차이를 보이지 않았으나 LED처리는 Vitamin C 보다 높은 항산화능을 나타내었다. 위의 결과를 통해 White LED와 White Blue 처리가 표고버섯 자실체의 생육 및 항산화능에 영향을 미치는 광원임을 확인할 수 있었다.

컬러 컴퓨터시각에 의거한 건표고 등급 선별시스템 개발 (Development of Grading and Sorting System of Dried Oak Mushrooms via Color Computer Vision System)

  • 김시찬;최동엽;최선;황헌
    • Journal of Biosystems Engineering
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    • 제32권2호
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    • pp.130-135
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    • 2007
  • An on-line real time grading and sorting system for dried oak mushrooms was developed for on-site application. Quality grades of the mushrooms were determined according to an industrial specification. Three dimensional visual quality features were used for the grading. A progressive color computer vision system with white LED illumination was implemented to develop an algorithm to extract external quality patterns of the dried oak mushrooms. Cap (top) and gil (stem) surface images were acquired sequentially and side image was obtained using mirror. Algorithms for extracting size, roundness, pattern and color of the cap, thickness, color of the gil and amount of rolled edge of the dried mushroom were developed. Utilizing those quality factors normal and abnormal ones were classified and normal mushrooms were further classified into 30 different grades. The sorting device was developed using microprocessor controlled electro-pneumatic system with stainless buckets. Grading accuracy was around 97% and processing time was 0.4 s in average.

국가산림자원조사를 이용한 주요수종별 직경생장량 분석 - 강원도 산림을 대상으로 - (Diameter Growth Analysis for Major Species using National Forest Resource Inventory - In the Gangwon-do Forests -)

  • 이원아;신주원;최정기;이우균;이영진;김성호;정동준
    • Journal of Forest and Environmental Science
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    • 제27권2호
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    • pp.113-118
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    • 2011
  • This study was carried out to analyze annual diameter growth characteristics for major 11 tree species using the data for Gangwon province of the National Forest Resources Inventory in 2007. The annual diameter growth of coniferous species was 5.02 mm, 4.70 mm, and 3.90 mm in Korean white pine, Japanese larch, and Korean red pine, respectively. In growths of the deciduous trees, dogwood, basswood, and cork oak had 3.55 mm, 3.48 mm and 3.01 mm, respectively. Average of the annual diameter growths for all species was 3.38 mm. The relationship between diameter growth and age class showed that the growth rate decreased for all species as age increased. The age class II had the highest annual diameter rate. In relation of the stand density(trees per hectare) and diameter growth, the diameter growth tended to decrease as the stand density increased for most species, especially Korean white pine, cork oak, and basswood. Finally age had the highest value in the correlation coefficients between measurement factor and growth rate regardless of species.

The People of White Clothes(白衣民族) from Modern Perspectives

  • Soh, Hwang-Oak
    • International Journal of Costume and Fashion
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    • 제11권2호
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    • pp.25-36
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    • 2011
  • There seems to have arisen a preference for wearing white clothes amongst Koreans from the long past, even tracing back to the ancient times in tradition of Shamanism worshipping the sun. This "preference" persevered throughout the passage of time, even with the numerous internal and external pressures to forbid or interrupt this tradition. The wearing of White Clothes by Koreans can also be often found in the various records made by foreign visitors recognized as a noticeable phenomenon, and representative of Korea which seems to have influences even until now in the impressions of the country. Despite of this tradition that seems to have lasted over the last 5000 years, all of a sudden it disappeared within the last 50years. In the contemporary modern fashion of Korea, it seems hard to say, Koreans enjoyably sporting White clothes, is a stand out trait anymore, thus the equation of Koreans equivalent to the people of white not a valid stamen anymore. it could not be said that this tradition is representative of the Korean cultural Identity. Why would this be the case? What happened to the long lasted pattern? In what form or shape has this tradition trasnsformed and reappears before us today? This paper seeks to find the answers to these questions.