| 1. |
- Awoyemi, Lawrence
(författare)
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Effect of borate pre-treatment on the hygroscopic and swelling properties of heat-treated wood
- 2005
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Ingår i: International Wood Products Journal. - : Informa UK Limited. - 0020-3203. ; 17:2, s. 94-98
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Tidskriftsartikel (refereegranskat)abstract
- Based on the strong correlation between acidity and some properties of heat treated wood reported in previous studies, the effect of borate impregnation as an alkali buffering medium was investigated on the hygroscopic and swelling properties of heat-treated wood. Wood samples were impregnated with 0.1M Sodium borate solution (pH = 9.4) before they were subjected to heat treatment at 200°C for durations of 2 and 4 hours. The pre-treatment impregnation with borate salt, increased the hydrophobic and antiswelling effects of the heat treatment on wood. This suggests that the bulking effect of the borate salt is more significant than its mitigating effect on the degree of cellulose degradation during heat treatment.
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| 2. |
- Awoyemi, Lawrence
(författare)
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Estimation of fibre saturation point from sorption behaviour of wood in water
- 2005
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Ingår i: International Wood Products Journal. - : Informa UK Limited. - 0020-3203. ; 17:2, s. 110-113
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Tidskriftsartikel (refereegranskat)abstract
- The fibre saturation point of wood is of tremendous importance both to the processing and properties of the material and as a result research on the various possible ways of estimating it can hardly be overemphasized. The rates of adsorption and desorption of water by wood were measured at various moisture contents. Fibre saturation point was estimated from the adsorption terminal and the intercept of the adsorption and desorption curves. The values obtained were compared with those obtained using the Walker's method. The use of the adsorptibn-desorption intercept method gave a mean accuracy of 96.1%.
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| 3. |
- Awoyemi, Lawrence
(författare)
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Influence of prefreezing on the fibre saturation point, sorption and swelling properties of birch (Betula pubescens) wood
- 2006
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Ingår i: International Wood Products Journal. - : Informa UK Limited. - 0020-3203. ; 17:4, s. 225-227
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Tidskriftsartikel (refereegranskat)abstract
- Matched samples were obtained from green birch (Betula pubescens) wood. Prefreezing was done at -20°C for 72hours. Both the prefrozen and unfrozen samples were dried and soaked in water for the determination of sorption behavior, swelling properties and fibre saturation point. Prefreezing resulted in 6.7 to 666.7% increase in rate of adsorption, 0 to 13.3% decrease in the rate of desorption, 2.2% decrease in volumetric swelling coefficient and 0.8% decrease in fibre saturation point. However only the change in the rate of water adsorption is statistically significant at 95% confidence level. Since these results were obtained from samples taken from a typical board, more results are required in order to characterise the effects of prefreezing on available stock of Birch wood
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| 4. |
- Awoyemi, Lawrence
(författare)
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Mechanical behaviour of birch (Betula Pubescens) wood under high temperature drying
- 2009
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Ingår i: International Wood Products Journal. - 0020-3203. ; 19:1, s. 27-30
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Tidskriftsartikel (refereegranskat)abstract
- High temperature drying is employed to reduce the drying time of sawn wood. However the deterioration in mechanical properties associated with it seems to be a major limitation of its use in the seasoning of some wood species. As in conventional drying, both the modulus of elasticity and modulus of rupture increase with decreasing moisture content. High temperature drying does not seem to constitute a meaningful threat to the mechanical properties of this species and hence its use is strongly recommended. The low effect of high temperature drying on this species strongly reinforces the results of the previous studies on other species that the effect of this technique is both species and property dependent.
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| 5. |
- Elustondo, Diego, et al.
(författare)
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Rfv drying schedule development for thick western red cedar timbers
- 2008
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Ingår i: International Wood Products Journal. - : Informa UK Limited. - 0020-3203. ; 18:2, s. 68-74
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Tidskriftsartikel (refereegranskat)abstract
- Radio frequency vacuum drying of timbers could result in internal checking (honeycombing) due to elevated internal temperatures and pressures that is believed to be associated to the level of applied power density, but it might be also related to the way electric power is applied during the drying process. In this exploratory study the relationship between power density and wood damage for thick western red cedar dried in a laboratory RFV dryer was evaluated. Two different types of drying strategies were assessed and the results were used to identify apparent trends and thus recommend the drying schedule that appears to minimize internal and surface checking.
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| 6. |
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