<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31377074</termId><termName>active solar heating</termName><termType>PT</termType><termNote><![CDATA[ Solar heating systems that include mechanical equipment and hardware to collect and transport heat; for solar heating systems without mechanical assistance, use "passive solar heating." ]]></termNote><termCreatedDate>2026-03-30 20:41:42</termCreatedDate><relation><relationType>UF</relationType><termId>31377075</termId><termName>active solar heating systems</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31377076</termId><termName>active solar systems</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31377077</termId><termName>active systems</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31377078</termId><termName>heating systems, active solar</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31377079</termId><termName>solar heating systems, active</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31377080</termId><termName>solar heating, active</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31377081</termId><termName>solar systems, active</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31377082</termId><termName>systems, active solar</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31377083</termId><termName>systems, active solar heating</termName><termType>ND</termType></relation><relation><relationType>BT</relationType><termId>31346564</termId><termName>solar heating</termName><termType>PT</termType></relation></term>  </Zthes>