Low-intensity drying is widely believed to protect waterlogged archeological wood against the adverse effects of dimensional alteration and cracking. However, slow drying generates substantial costs for the conservation process. This study compares the effects on conservation of highly-degraded sapwood (SW) and slightly-degraded heartwood (HW) from waterlogged archeological Scots pine wood treated with polyethylene glycol either as a mixture of polyethylene glycol (PEG) 400/4000 or PEG 2000 solution and air-dried using different approaches. The reference air-drying approach, using gradually decreasing air relative humidity (RH), i.e., 96, 86, 75, 66, and finally 44% (multi-stage schedule), was compared to an alternative approach, using constant RH of 44% (single-stage schedule). The Fourier-transform infrared spectroscopy (FTIR) analysis confirmed the decomposition of hydrophilic chemical wood components and revealed differences in the degree of degradation of waterlogged SW and HW. The drying time of PEG-treated waterlogged wood air-dried using a one-stage schedule was shorter compared to the drying time using multi-stage drying. Multivariate analysis (ANOVA) revealed that the drying schedule used after impregnation of waterlogged wood with PEG can have a beneficial effect on wood hygroscopicity and dimensional stability. The drying schedule significantly affected the equilibrium moisture content (EMC) of SW and HW and reduced tangential (S_T) shrinkage of SW. These results show the positive effect of the single-stage alternative drying approach on the dimensional stability of highly-degraded Scots pine SW impregnated with PEG 2000. In the case of slightly-degraded HW, the drying approach did not affect wood preservation. These results can be useful for the conservation of highly-degraded waterlogged Scots pine wood.

中文翻译：

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PEG处理并用另一种方法干燥的浸水苏格兰松木的尺寸稳定性

人们普遍认为，低强度干燥可以保护浸水的考古木材免受尺寸变化和开裂的不利影响。但是，缓慢干燥会为保护过程带来大量成本。这项研究比较了用聚乙二醇（PEG）400/4000或PEG 2000混合溶液处理的浸水考古苏格兰松木对高度降解的边材（SW）和轻度降解的心材（HW）的保存效果然后用不同的方法风干 将使用逐渐降低的空气相对湿度（RH），即96、86、75、66，最后是44％（多阶段排程）的参考风干方法与使用恒定RH 44 ％（单阶段计划）。傅里叶变换红外光谱（FTIR）分析证实了亲水化学木材成分的分解，并揭示了浸水的SW和HW降解程度的差异。与使用多阶段干燥的干燥时间相比，使用一阶段时间表风干的PEG处理的浸水木材的干燥时间短。多变量分析（ANOVA）显示，用PEG浸渍浸水木材后使用的干燥时间表可能对木材的吸湿性和尺寸稳定性产生有利影响。干燥时间表明显影响了平衡水分含量（与使用多阶段干燥的干燥时间相比，使用一阶段时间表风干的PEG处理的浸水木材的干燥时间短。多变量分析（ANOVA）显示，用PEG浸渍浸水木材后使用的干燥时间表可能对木材的吸湿性和尺寸稳定性产生有利影响。干燥时间表明显影响了平衡水分含量（与使用多阶段干燥的干燥时间相比，使用一阶段时间表风干的PEG处理的浸水木材的干燥时间短。多变量分析（ANOVA）显示，用PEG浸渍浸水木材后使用的干燥时间表可能对木材的吸湿性和尺寸稳定性产生有利影响。干燥时间表明显影响了平衡水分含量（SW和HW的EMC（EMC），并减少SW的切向收缩（S _T）。这些结果表明，单阶段替代干燥方法对浸渍有PEG 2000的高度降解苏格兰松树SW的尺寸稳定性具有积极作用。在HW稍微降解的情况下，干燥方法不会影响木材的保存。这些结果可用于保护高度退化的浸水苏格兰松木。