<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31304537</termId><termName>impact-echo</termName><termType>PT</termType><termNote><![CDATA[ Impact-echo is a nondestructive evaluation technique for masonry construction which detects flaws by monitoring impact-generated sound waves that are disseminated through a structure and are reflected by internal flaws and external surfaces. ]]></termNote><termCreatedDate>2026-03-30 20:21:54</termCreatedDate><relation><relationType>BT</relationType><termId>31298665</termId><termName>analysis and testing techniques</termName><termType>PT</termType></relation></term>  </Zthes>