Insect-Infested Wood Remediation by Microwave Heating and Its Effects on Wood Dehydration: A Case Study of Hylotrupes bajulus Larva

Wood artefacts are subject to damage by biologic infestations due to bacteria, insects, and fungal species. One of the worst feared attacks is due to the xylophagous insects whose larvae feed on wood by boring galleries, at the expense of building timbers and worked woods. These beetles are responsible for daily destruction of the world’s wooden cultural heritage, and their elimination has been always a big problem for conservation of wood. The need to avoid the use of chemical methods in conservation for pest control has led to the development of various non-chemical, non-toxic treatments. Among these, heating with microwaves (MW) seems to be one of the most promising, since it has already shown its high efficacy in destroying pests. Insect-infested wood remediation by MW heating in conservation is based on the larger thermal increment induced in larvae than in wood, due to their different dielectric permittivity in the GHz frequency range. However, the side effects that may occur due to MW heating of wood, such as dehydration, have never been discussed so far. Here we study the possible application of microwave heating as a remediation method for wood samples infested by the larvae of the insect Hylotrupes bajulus. We show that it is possible to set up exposure conditions able to achieve 100% of larvae death and that are sufficiently mild not to induce significant dehydration of the exposed wood from which shrinkage effects may derive. Indeed, under these conditions, MW-induced wood dehydration on cubic and parallelepiped sweetgum samples can be kept under control and to percentages as low as 0.4% (w/w).     

“五维一体”的大学经典阅读体系构建与实践——以常熟理工学院为例

[目的/意义] 大学经典阅读承载着大学通识教育功能。高校应为大学生设计一个多角度全方位的经典阅读体系,以引导大学生阅读经典并能体现良好的阅读效果。[方法/过程] 以文献研究和实践相结合的方法,总结多年阅读推广的实践经验,启动并强力推行一种新型的大学经典阅读体系。该体系展现了"五维一体"的经典阅读体验,包含经典阅读推广实体空间、经典阅读推广平台、常规化经典阅读推广项目、经典测试系统和经典阅读效果评价。[结果/结论] 该体系以合理性、客观性和科学性弥补以往经典阅读体系考核过程和效果评价等方面的不足,有很重要的推广意义。