<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31304639</termId><termName>vitrification</termName><termType>PT</termType><termNote><![CDATA[ To change into glass or a glassy substance by heat and fusion; especially to produce, as in ceramics, close crystallization by high firing to make the substance nonporous. ]]></termNote><termCreatedDate>2026-03-30 20:21:56</termCreatedDate><relation><relationType>UF</relationType><termId>31304640</termId><termName>vitrified</termName><termType>ND</termType></relation><relation><relationType>BT</relationType><termId>31298688</termId><termName>physicochemical processes</termName><termType>PT</termType></relation></term>  </Zthes>