N(.beta.-chloro-propionyl or acryloyl)carbamyl or ureido piperaz
Negligible pressure drop absorber
Nested diffusional filter
Nitrogen-selective zeolitic adsorbent for use in air separation
Nitroso-dimer-containing compositions and photoimaging process
Noble gas purifier with single purifier vessel and recuperative
Non-particulating compact adsorbent filter
Nonparticulating adsorbent recirculating filter
Novel spiro-heterocyclic compounds, their preparation, and use t