• Journal of the Korean Wood Science and Technology
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• 제45권4호
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• pp.399-408
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• 2017

Research on the rapid and accurate prediction of physical properties of wood using near-infrared (NIR) spectroscopy has attracted recent attention. In this study, partial least squares analysis was performed between NIR spectra and air-dried specific gravity of five domestic conifer species including larch (Larix kaempferi), Korean pine (Pinus koraiensis), red pine (Pinus densiflora), cedar (Cryptomeria japonica), and cypress (Chamaecyparis obtusa). Fifty different lumbers per species were purchased from the five National Forestry Cooperative Federations of Korea. The air-dried specific gravity of 100 knot- and defect-free specimens of each species was determined by NIR spectroscopy in the range of 680-2500 nm. Spectral data preprocessing including standard normal variate, detrend and forward first derivative (gap size = 8, smoothing = 8) were applied to all the NIR spectra of the specimens. Partial least squares analysis including cross-validation (five groups) was performed with the air-dried specific gravity and NIR spectra. When the performance of the regression model was expressed as $R^2$ (coefficient of determination) and root mean square error of calibration (RMSEC), $R^2$ and RMSEC were 0.63 and 0.027 for larch, 0.68 and 0.033 for Korean pine, 0.62 and 0.033 for red pine, 0.76 and 0.022 for cedar, and 0.79 and 0.027 for cypress, respectively. For the calibration model, which contained all species in this study, the $R^2$ was 0.75 and the RMSEC was 0.37.

• 한국식품영양과학회지
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• 제33권4호
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• pp.716-722
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• 2004

국내산 새송이 버섯을 스폰지 케이크 제조에 이용하고자 열풍건조와 동결건조로 각각 가공된 두 가지 새송이 버섯 분말을 케이크 배합비에 3%, 5% 및 7%의 비율로 첨가하여 케이크의 품질에 어떤 영향을 미치는지 알아보았다. 반죽의 비중과 점도 및 그에 따른 최종 케이크 품질 물리적 및 관능적 특성을 조사하였다. 이들의 결과에서 건조방법이 다른 두 종류의 버섯 분말의 첨가 비율이 증가함에 따라 케이크 반죽 비중 및 점도는 증가하였고, 케이크의 부피와 높이는 오히려 감소하는 경향을 나타내었다. 색상은 새송이 버섯 분말의 첨가에 따라 표면과 내부의 색깔을 모두 어둡게 하였으며, 조직감은 새송이 버섯 분말의 첨가 증가에 따라 경도가 증가하였다. 새송이 버섯 건조방법이 스폰지 케이크의 관능검사에 미치는 영향에서는 버섯 분말 3%와 5% 첨가구가 버섯 분말을 첨가하지 않은 대조구에 비하여 높은 기호도를 나타내었다.

• 한국가구학회지
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• 제16권2호
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• pp.77-83
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• 2005

The specific gravity of wood treated with the essential oil penetration was higher than that of untreated wood. However, in case of oven-dried wood the difference of treated and untreated products decreased, compared with air-dried wood. The shrinkage of treated wood showed no consistent trend and the difference was trivial. In addition, similar trend was shown in each direction. Compression strength parallel to grain of treated wood was somewhat higher than that of untreated wood and the difference was trivial. The difference in static bending strength was slight and showed no consistent trend. The stage of check for Pinus koraiensis and Populus tomentiglandulosa and Alnus hirsuta was 2 stage and 3 stage, respectively. Deformation stage with no relation to the essential oil treatment was 1 stage for Pinus koraiensis, 2 stage Populus tomentiglandulosa and 3 stage for Ainus hirsuta, respectively, and there was no difference in essential oil penetration.

• Journal of the Korean Wood Science and Technology
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• 제46권5호
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• pp.437-448
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• 2018

본 연구는 태백산맥을 기준으로 영동(고성군), 영서(홍천군), 영남(봉화군) 세 지역 간 소나무의 재질차이의 유무를 알기위해 물리적 특성을 조사하였다. 기건함수율 및 생재함수율(인위적)의 산지 간 차이를 보이지 않았다. 비중은 심재부와 변재부에서 봉화군 소나무가 두 산지보다 높았으며, 고성군과 홍천군 소나무 사이에는 심재부에서는 고성군 소나무가 높고 변재부에서는 홍천군 소나무가 고성군 소나무 보다 높게 나타났다. 심재부의 비중이 높게 나타난 고성군 소나무가 강도적으로 홍천군 소나무보다 클 것으로 판단된다. 수축율은 방사방향의 경우 산지 간 차이가 없고, 접선방향의 경우는 가도관장이 긴 봉화군 소나무가 높게 나타났다. 흡습율은 산지 간 차이가 거의 없는 것으로 나타났다. 이 결과로 소나무를 효율적으로 사용할 수 있고, 육종적으로 좋은 재질의 품종생산에도 도움이 될 것으로 생각한다.

• Journal of the Korean Wood Science and Technology
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• 제14권1호
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• pp.45-54
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• 1986

A study was conducted to determine the physical properties related to drying characteristics, the seasonal air drying curves and the kiln drying schedule for taun lumber imported and utilized. This kiln drying schedule was found by oven drying and developed by pilot testing of green lumber and partially air dried lumber. The results of this study were as follows; 1. Average green specific gravity and standard deviation of heartwood lumber were 0.60${\pm}$0.03 and those of sapwood lumber were 0.64${\pm}$0.02. 2. Radial shrinkage from green to air dry and from green to oven dry were 3.05 percent and 5.96 percent respectively, and tangential shrinkage from green to air dry and to oven dry were 5.49 percent and 8.74 percent respectively. 3. Drying time for 25mm thick green lumber (50 percent moisture content) air dried to 30 percent moisture content were 14 days in springtime. 6 days in summertime, and 12 days in autumntime, whereas for 50mm thick lumber in 36 days in springtime, 18 days in summertime, 38 days in autumntime. 4. Kiln drying schedules developed by oven drying were T8-B3 for 25mm thick lumber and T5-B2 for 50mm thick lumber. 5. Kiln drying curves of green 25mm and 50mm thick lumber were similar to those of partially air dried lumber from the level of 30 percent average moisture content. Green 25mm thick lumber (55.7 percent moisture content) was dried to 9.3 percent moisture content in 101.5 hours and green 50mm thick lumber (65.6 percent moisture content) was dried to 11.5 percent moisture content in 526 hours. 6. End checking for green 25mm thick lumber occured in 49.6 percent moisture content and reached maximum amount in 27.6 percent moisture content and closed in 15.8 percent moisture content. 7. End checking for green 50mm thick lumber and partially air dried lumber developed and reached maximum amount earlier then for 25mm thick lumber. 8. Final moisture content of surface layer for 50mm thick lumber was one half of that of core, and moisture content equalized in the lumber after nine days of room conditioning. 9. Casehardening for 50mm thick lumber was slight and was conditioned after nine days of room stroage. 10. Drying defects, such as end checking and surface checking, were not observed and the quality of dry lumber was first.

• 한국산림과학회지
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• 제37권1호
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• pp.17-30
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• 1978

이태리포푸라재(材)의 건조(乾燥)의 한 방안(方案)으로서 열판건조(熱板乾燥)를 실시(實施)하여 건조중(乾燥中) 판재(板材)의 내부온도(內部溫度), 판재(板材)의 내부온도별(內部溫度別)에 따른 판재(板材)두께, 초기함수율(初期含水率), 말기함수율(末期含水率)과 건조시간(乾燥時間)의 관계(關係), 건조중(乾燥中) 함수율(含水率)과 건조속도(乾燥速度), 수축율(收縮率)과 복원율(復元率), 그리고 열판건조재(熱板乾燥材)의 생재비중(生材比重), 평형함수율(平衡含水率), 경단방향(徑斷方向) 전수축율(全收縮率) 등(等)을 조사(調査)하고 그 결과(結果)를 요약(要約)하면 다음과 같다. 1. 판재(板材)의 내부온도(內部溫度)는 건조초기(乾燥初期)에 급격히 상승(上昇)해서 15분(分) 동안 거의 일정(一定)하게 유지된 다음 서서히 상승(上昇)하였다. plateau temperature는 $114{\sim}119^{\circ}C$이었다. 2. 판재(板材)의 내부온도별(內部溫度別)에 있어서 판재(板材)의 건조시간(乾燥時間)(y)와 판재(板材)두께($x_1$), 초기함수율(初期含水率)($x_2$), 말기함수율(末期含水率)($x_3$) 사이에 관계식(關係式)은 다음과 같다. 3. 열판건조(熱板乾燥)의 건조시간(乾燥時間)(t)에 대(對)한 건조중(乾燥中) 함수율(含水率)(u)의 관계(關係)는 log u=4.658-0.060t(R=-0.990)이고, 건조속도(乾燥速度)(r)의 관계(關係)는 log r= -2.797-0.049t(R= -0.992)의 곡선(曲線)으로 각각(各各) 나타났다. 그리고 천연건조중(天然乾燥中) 함수율(含水率)과 건조속도(乾燥速度)는 그림 2 와 같다. 4. 열판건조중(熱板乾燥中) 건조시간(乾燥時間)(t) 에 대(對)한 판재(板材)두께 (y) 수축율(收縮率)의 관계(關係)는 log y= l.933+038t(R=0.927)이고, 판재복(板材福) 팽창율(膨脹率)(y)의 관계(關係)는 $y=-0.692+0.043t-0.001t^2(R=0.984)$의 곡선(曲綠)으로 각각(各各) 나타났다. 5. 말기함수율(末期含水率) 2%까지 건조시(乾燥時)에 열판(熱板)의 압력별(壓力別) 따른 두께 수축율(收縮率)은 압력(壓力) 높아질 수록 커졌으나 폭수축율(幅收縮率)과 두께 복원율(復元率)은 35psi에서 가장 컸다. 6. 열판건조재(熱板乾燥材)의 생재비중(生材比重)은 천연건조재(天然乾燥材)의 것보다 25% 증가하였으며, 평형함수율(平衡含水率)은 24% 감소하였고, 열판건조재(熱板乾燥材)의 항수축율(抗收縮率)은 27.7%이었다.

• Journal of the Korean Wood Science and Technology
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• 제30권4호
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• pp.87-95
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• 2002

3종류의 국내산 대나무의 생재 및 기건재를 3종류의 탄화로에서 탄화시키고 얻어진 죽초액에 대하여 그 특성을 검토하였다. 기계식 전용탄화로의 경우, 대부분 1단 회수 죽초액의 비중, 유기산 및 용해 타르 함량이 높았으나 2단 이상에서 감소하여 3단 이후에 일정해지는 경향을 나타내었으며 전체적으로는 기건재가 생재에 비해 이들 물성이 높게 나타났다. pH의 경우 맹종죽 기건재를 제외하고 생재가 기건재보다 높게 나타났다. 3성분합계는 비중, 유기산, 용해타르 함량과 유사한 경향을 나타내었다. 개량탄화로의 경우, 수종에 따라 전체 물성이 다양하게 나타났다. 간이탄화로에서 탄화시켜 연통온도 80℃로 얻어진 기건 죽초액의 경우 그 이상의 온도에서 얻어진 죽초액보다 비중, 용해타르 함량 및 3성분 합계가 높게 나타났다. 간이, 개량 및 기계식 전용탄화로에서 얻어진 죽초액의 비중은 온도, 수분함유 상태에 상관없이 유기산과 용해타르 함량의 합계와 0.90 정도의 높은 상관관계를 나타내어 앞으로 죽초액 품질 결정에 중요한 지표로 사용될 가능성이 시사되었다. 죽초액의 구성 유기성분의 경우 초산이 주성분이었으며, 리그닌의 열분해에 의하여 생성되는 guaiacyl 및 syringyl골격의 페놀류가 다량 검출되었다.

• Advances in environmental research
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• 제1권4호
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• pp.305-321
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• 2012

This study entails establishing reference standard sand in Nigeria for engineering and geoenvironmental research work. Sands from four geographical locations in southwestern Nigeria were examined for baseline geotechnical and mineralogical properties. A total of sixteen sand samples were collected. The samples were air dried and subjected to tests in accordance with standard specifications. The tests carried out were: specific gravity, grain size analysis, moisture content, bulk density, porosity, void ratio, chemical analysis, X-ray diffraction and Differential Thermal Analysis. The properties of the samples were compared with a standard (Ottawa sand in Illinois of the United States) in order to find out which of the four samples selected from southwestern Nigeria could serve as standard baseline sand. The results show that Igbokoda sand has geotechnical and mineralogical characteristics closest to Ottawa sand. It was therefore concluded that Igbokoda sand could be used as a standard baseline sand for research work in southwestern Nigeria and other parts of Nigeria since it needs little processing to bring it to the same level as standard baseline sand, like the Ottawa sand.

• Journal of the Korean Wood Science and Technology
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• 제20권2호
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• pp.51-60
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• 1992

This study was performed to investigate the effect of green sorting before drying on the high-temperature drying characteristics of southern yellow pine dimension lumber(2"${\times}$6"${\times}$12'). To test the advantages of weight sorting, green lumber was seperated into heavy(above 55 1b), medium(50-55 1b), and light(below 50 1b)weight classes. Pieces in each weight class were subgrouped into high(above 35%) and low(below 30%) latewood groups. Groups were dried and seperated by a standard commercial high-temperature schedule; dry bulb temperature $245^{\circ}$ F, wet bulb temperature $180^{\circ}$ F, and air velocity 1200fpm. The results obtained were as follows; 1. There was a highly significant correlation between annual rings per inch(X) and percent-latewood(Y). The regression equation was Y=24, 5047+1.3272X. 2. There were highly significant correlations between either annual rings per inch($X_1$) or percent-latewood($X_2$) a.d specific gravity in green wood(Y). Their regression equations were Y=0.4260+0.0081$X_1$ and Y=0.3749+0.0029$X_2$, respectively. 3. Heavier weight charges dried more slowly than lighter weight charges. 4. Board-to-board variation in green or dry moisture content was less for all seperate weight classes than for unseperated control charges. 5. Lower latewood pieces had higher initial moisture content than higher latewood pieces, and then drying time for lower late wood pieces was longer than higher latewood pieces.

• 한국가구학회지
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• 제18권1호
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• pp.39-46
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• 2007

This study was carried out to investigate the wood properties for efficient utilization of warm temperate tree species of Quercus acuta Thunb. grown in Korea. Fundamental wood properties in the anatomical, physical, mechanical and chemical characteristics were examined. Quercus acuta Thunb. is a radial-porous, straight grained and fine textured wood. The heartwood is not clearly distinguished from the sapwood. In physical properties, it has a high oven-dry specific gravity of $0.85{\pm}0.02$, and high shrinkage from green to air-dried condition of $7.05{\pm}0.52%$ in radial and $11.13{\pm}0.48%$ in tangential direction. Mechanical properties determined are strong with the MOR of $1,065{\pm}90kgf/cm^2$, and tensile strength parallel to grain of $1,490{\pm}258kgf/cm^2$ and shear strength of $175{\pm}13kgf/cm^2$. Also, this wood has high extractive contents: 11.11% for cold and 13.51% for hot water.