positive-negative pressure breathing n.
Abbr. PNPB Inflation of the lungs with positive pressure and deflation with negative pressure as through the action of an automatic ventilator.
noun, Optics. 1. . noun, Optics. 1. a lens that converts parallel rays of light to convergent rays and produces a real image.
[poz-i-tiv-lee or especially for 3, poz-i-tiv-lee] /ˈpɒz ɪ tɪv li or especially for 3, ˌpɒz ɪˈtɪv li/ adverb 1. with certainty; absolutely: The statement is positively true. 2. decidedly; unquestionably; definitely: His conduct is positively shocking. interjection 3. (used to express strong affirmation) yes: Do you plan to go to the party? Positively! /ˈpɒzɪtɪvlɪ/ adverb […]
noun 1. customary law or law enacted by governmental authority (as distinguished from natural law).
noun, Physics, Chemistry. 1. See under (def 1). [ahy-uh n, ahy-on] /ˈaɪ ən, ˈaɪ ɒn/ noun, Physics, Chemistry. 1. an electrically charged atom or group of atoms formed by the loss or gain of one or more electrons, as a cation (positive ion) which is created by electron loss and is attracted to the cathode […]