Repairing denier woven polypropylene involves cleaning the area thoroughly first with soapy water and allowing it to dry. For small tears, use waterproof polypropylene tape as a simple solution by applying it on both sides of the tear. For larger tears or areas, sewing with a polypropylene thread is advisable, using a zigzag stitch for added strength. If the damage is significant, applying a patch of similar material, secured with strong polypropylene glue or stitched in place, is effective. Always test repair materials on a small, inconspicuous area first to ensure compatibility. It’s also crucial to maintain tension in the material during the repair to avoid puckering.

The number of amino acids in the APQ2 protein can vary depending on the species in question as well as the specific isoform of the protein. Generally, proteins named "APQ2" might not be universally recognized across scientific databases without more context. The designation "APQ2" seems atypical or could be a typographical error, possibly intending to reference a member of the aquaporin family (often abbreviated as AQP followed by a number) or another protein family entirely. Aquaporins, for instance, are a family of water channel proteins that play crucial roles in the transport of water across cell membranes, and their length can vary between 200 to 300 amino acids, depending on the specific family member and organism. To provide an accurate count of amino acids in the APQ2 protein, one would need the correct protein name or the species of origin for a precise lookup in a protein or genomic database such as UniProt or NCBI's Protein database.

PVC (Polyvinyl Chloride) hoses are commonly used for a variety of applications, including air transport. However, when it comes to air quality, there are a few considerations. PVC can release harmful chemicals at high temperatures or when cut or burned. For air transfer applications, it is generally safe under normal conditions. Yet, for indoor air quality or in applications with high temperature or direct food contact, alternatives like polyurethane or silicone hoses might be recommended due to their lower toxicity levels and higher temperature resistance. Always ensure the specific PVC hose is designed for your intended use and complies with any relevant safety standards.