In simple words, an Oxygen Concentrator works on electricity; takes in room air, removes Nitrogen from it and provides upto 95% pure Oxygen. The composition of air (78% Nitrogen, 21% Oxygen and 1% other gases like Carbon Dioxide, Argon, etc.) clearly shows that air is mainly comprised of two gases: Nitrogen and Oxygen [together 99%].
Word Origin and History for savoir-faire Expand. n. instinctive knowledge of the right course of action in any circumstance, 1815, from French, literally to know (how) to do, from savoir to know (from Latin sapere; see sapient) + faire (from Latin facere; see factitious).
In the United States, it now generally refers to the process by which prospective jurors are questioned about their backgrounds and potential biases before being chosen to sit on a jury. Voir Dire is the process by which attorneys select, or perhaps more appropriately reject, certain jurors to hear a case..