Abstract Shipworms (Bivalvia: Teredinidae) are considered one of the main agents of wood bioerosion in the marine environment. They dig tunnels inside the wood they feed on, causing its progressive weakening. X-rays are a widely used non-destructive technique to assess wood biodeterioration (e.g. EN 275). However, an X-ray is a two-dimensional projection, with the possibility that some of the objects overlap and obfuscate each other. The higher the density of the shipworms, the more difficult is to count and measure the single tunnel. The aim of this work was to find a straight-forward method for calculating the volume of shipworm tunnels based on the size of shipworm shells, which are always clearly identifiable on the X-rays. Some wood test panels attacked by shipworms were analysed, with two distinct geometric methods being applied to estimate the tunnels volume based on radiographs. An allometric model was then introduced linking the volume to the shell diameter, which allows an easy estimation of the actual bioeroded volume from conventional two-dimensional radiographs. This technique allows to evaluate the bioerosion after the first growing season, shortening the exposure time and reducing costs. The model can be applied even when the tunnels are difficult to distinguish from each other, i.e. overlapped, folded or covering the whole surface of the radiograph.

中文翻译：

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从射线照片计算船虫隧道体积的简单方法

摘要 船虫（Bivalvia：Teredinidae）被认为是海洋环境中木材生物侵蚀的主要病原体之一。他们在以它们为食的木材内挖掘隧道，导致其逐渐减弱。X 射线是一种广泛使用的非破坏性技术，用于评估木材生物退化（例如 EN 275）。然而，X 射线是一种二维投影​​，其中一些物体可能会重叠并相互混淆。船虫的密度越高，单个隧道的计数和测量就越困难。这项工作的目的是找到一种直接的方法，根据船虫壳的大小计算船虫隧道的体积，船壳在 X 射线上总是清晰可辨的。分析了一些受船虫攻击的木材测试板，使用两种不同的几何方法根据射线照片估计隧道体积。然后引入异速生长模型，将体积与壳直径联系起来，这样可以从传统的二维射线照片中轻松估计实际的生物侵蚀体积。该技术允许评估第一个生长季节后的生物侵蚀，缩短暴露时间并降低成本。即使隧道难以相互区分，即重叠、折叠或覆盖射线照片的整个表面时，也可以应用该模型。该技术允许评估第一个生长季节后的生物侵蚀，缩短暴露时间并降低成本。即使隧道难以相互区分，即重叠、折叠或覆盖射线照片的整个表面时，也可以应用该模型。该技术允许评估第一个生长季节后的生物侵蚀，缩短暴露时间并降低成本。即使隧道难以相互区分，即重叠、折叠或覆盖射线照片的整个表面时，也可以应用该模型。