<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31347180</termId><termName>air filters</termName><termType>PT</termType><termNote><![CDATA[ Devices for removing undesirable gaseous or solid particles from ambient air. ]]></termNote><termCreatedDate>2026-03-30 20:33:40</termCreatedDate><relation><relationType>UF</relationType><termId>31347181</termId><termName>air cleaners</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31347182</termId><termName>air filter</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31347183</termId><termName>cleaners, air</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31347184</termId><termName>filters, air</termName><termType>ND</termType></relation><relation><relationType>BT</relationType><termId>31322112</termId><termName>ventilation system components</termName><termType>PT</termType></relation><relation><relationType>NT</relationType><termId>31377280</termId><termName>dry filters</termName><termType>PT</termType></relation><relation><relationType>NT</relationType><termId>31377287</termId><termName>viscous impingement filters</termName><termType>PT</termType></relation></term>  </Zthes>