Publishing type：Research paper (scientific journal)  

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Language：Japanese   Publishing type：Research paper (scientific journal)  

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Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.3130/aijt.19.507

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SOC WOOD SCI TECHNOL  

The equilibrium moisture content (EMC) of Russian larch wood, Sugi wood, and Hinoki wood was measured under vacuum conditions at temperatures of 45, 50, and 60 degrees C and ambient pressures of 13.3, 53.3, and 101.3 kPa. The results show that the EMC of each species increased with a decrease in ambient pressure. The effect of temperature and RH on EMC under vacuum conditions showed a similar tendency. Wet-bulb temperature needed to be controlled to measure EMC, even under vacuum, because pressure was not maintained only by water vapor pressure because of the presence of air in the vessel. There were obvious differences between the EMC values obtained in this experiment and previous experimental EMC values in which the wet-bulb temperature was not controlled.

Web of Science

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER TOKYO  

To improve the accuracy of the new in-process moisture content (MC) monitoring concept under radiofrequency/vacuum (RF/V) drying, equilibrium moisture content (EMC) tests were carried out under various ambient pressures, and pressure curves in wood were analyzed during chamber evacuation and heating phases. The results showed that EMC increased with a decrease in ambient pressure regardless of temperature, relative humidity (RH), and species. The accuracy of MC estimation for Hinoki under RF/V drying was improved from 1.5% maximum absolute errors to 0.6% after EMC modification. The pressure curves for Hinoki and Sugi under RF/V drying showed similar tendencies to an idealized process. Russian larch showed different curves, indicating that the pressure in the wood did not reach the ambient pressure because of its low permeability. Therefore, MC could not be estimated using this monitoring concept because of the presence of much air in the wood of Russian larch.

DOI： 10.1007/s10086-009-1079-4

Web of Science

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：RESEARCH PUBLISHING SERVICES  

Collapse is considered one of the severest defects of eucalyptus wood resulting in degradation during drying. Liquid tension is one cause of the formation of collapse. Some transient-collapse cells can be recovered with the reduction of liquid tension when moisture content is reduced during the drying process. How to control the occurrence of collapse and help its recovery are key factors of drying technology. Based on this, a sequential drying technology should be considered in the drying process; therefore, intermittent drying procedures were used in this study. Shrinkage and collapse were measured in Eucalyptus urophylla under continuous drying and intermittent drying processes. The key factors of the intermittent drying schedule which affected collapse recovery were length of the drying period and the temperature in the intermittent period.

DOI： 10.3850/978-981-08-5716-5_T264

Web of Science

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Publishing type：Research paper (scientific journal)  

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DOI： 10.1166/jctn.2008.816

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER TOKYO  

To explore the influence of the basic density on collapse-type shrinkage properties and to quantify the relationships of the main anatomical features with shrinkage and collapse properties, all above-mentioned parameters were determined and analyzed for three species of collapse-susceptible eucalypts, Eucalyptus urophylla, Eucalyptus grandis, and E. urophylla x E. grandis, planted in South China. The correlation coefficients were also determined and the corresponding regression equations were established with the anatomical parameters measured by using multiple linear regression. The results indicated that: (1) basic density was strongly positively linearly related to both unit tangential shrinkage (r = 0.970) and unit radial shrinkage (r = 0.959), weakly positively related to total shrinkage (r = 0.656 and 0.640 for tangential and radial, respectively), and weakly negatively related to residual collapse (r = 0.632 and 0.616 for tangential and radial, respectively). (2) The main factors affecting unit shrinkage were cell wall proportion (WP), microfibril angle (MFA), and double fiber cell wall thickness (DWT); factors playing an important role in total shrinkage were WP, ray parenchyma proportion (RP), and MFA, while RP had the highest effect on residual collapse (r = 0.949 and 0.860 for tangential and radial, respectively). (3) All corresponding regression models obtained were very suitable for the evaluation of relationships between the anatomical parameters and unit shrinkage, total shrinkage, and residual collapse, as measured using a moisture content of 28% as the fiber saturation point for all specimens.

DOI： 10.1007/s10086-005-0751-6

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：FOREST PRODUCTS SOC  

Sugi (Cryptomeri. japonica D. Don) is one of the main species used for structural lumber for Japanese wood housing. The initial moisture content (MC) of Sugi is relatively high and varies from board to board. This makes Sugi lumber difficult to dry. It has been said that sorting Sugi lumber based on the initial MC estimated from the green weight is useful for efficient drying. On the other hand, the MC and drying properties of the heartwood in Sugi is extremely different from those of the sapwood. So we assume that the heartwood-sapwood proportions affect the drying process. In this Study, the heartwood ratio was determined from the cross sections at both ends of sugi green boards using digital image analysis. Furthermore, heartwood color is quite different from board to board in sugi lumber, and there seems to be a relationship between heartwood color and drying characteristics. So, green sugi lumber was kiln-dried to examine the effect of initial MC, green weight, heartwood ratio, and heartwood color as sorting parameters for drying, and Cluster analysis was applied to separate those parameters. The results Of this study show the relationship between initial MC, heartwood color, green weight, and heartwood ratio to final MC. Sugi green lumber Should be sorted by initial MC; in this study, the threshold value of initial MC was 113 percent. Instead of sorting by initial MC, first, green lumber Must be sorted by heartwood color: red and non-red. Next, non-red heartwood lumber may be segregated by heartwood ratio, which in this study comprised approximately 60 percent.

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Language：Japanese  

CiNii Books

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Other Link： http://agriknowledge.affrc.go.jp/RN/2010683167

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In this study, we measured the temperature at many points using a fiber-optic and a platinum sensor in boxed heart, square timber of Sugi under various drying conditions that could affect temperature distribution. We then constructed a three-dimensional distribution chart of the average temperature during drying. During RF/Vacuum drying, the temperature near the midpoint between two opposing electrode plates should be higher than the boiling point corresponding to the ambient pressure, but the temperature near the plates and the evaporating surfaces should be less. The moisture content distribution after drying along the thickness direction (direction of the electric field) was affected by the drying temperature distribution. The region where the temperature was lower than the boiling point still had very high moisture content. In the other directions the temperature distribution had no effect on moisture content distribution. This difference was caused by two modes in heat transfer to reduce the surface temperature.

Scopus

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Language：Japanese   Publisher：日本木材学会  

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DOI： 10.1007/BF01177735

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Language：Japanese  

CiNii Books

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Language：Japanese  

CiNii Books

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Language：Japanese   Publisher：日本木材加工技術協会  

CiNii Books

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Language：Japanese   Publisher：愛媛県林業技術センター  

スギ板材を効率的に乾燥するためには、乾燥前に心材色を赤心と黒心に選別し、その後黒心の心材率を約60％で選別する方法が有効であると考えられている。しかし、選別因子である心材色と心材率の判定は乾燥技術者の目視で実施されているため、選別を自動化するためには心材色と心材率を効果的に測定する方法が求められる。本研究では、心材色を色彩色差計によりL＊a＊b＊表色系で測色し、赤心と黒心を判別する方法と、心材率を木口面の画像情報から算出する方法について検討した。その結果、心材色は判別分析を用いることにより、約95％が目視と同じ心材色に選別できることがわかった。また、この方法による心材色と目視の心材率からスギ板材を2グループに選別し、それぞれ異なる乾燥スケジュールで乾燥した結果、約95％の高い乾燥歩留まりが得られた。心材率については画像情報から得られた心材率で目視の心材率を推定できることがわかった。これらのことから、スギ板材の乾燥前選別における心材色および心材率の測定は自動化できると考えられた。

CiNii Books

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Language：Japanese   Publisher：愛媛大学農学部附属演習林  

CiNii Books

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Language：Japanese   Publisher：The Japan Institute of Energy  

DOI： 10.20550/jietaikaiyoushi.80Anniv.0_198

CiNii Books

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Language：English   Publishing type：Article, review, commentary, editorial, etc. (international conference proceedings)  

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Language：Japanese   Publisher：日本環境教育学会  

CiNii Books

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Language：Japanese   Publisher：Gifu University  

CiNii Books

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