Airship Technology - Aluminium, Hydrogen, Helium, Propeller, Hot Air Balloon, Monocoque, Buoyancy, Truss, History of Ballooning, Umberto Nobile (Paperback)

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Pages: 82. Chapters: Aluminium, Hydrogen, Helium, Propeller, Hot air balloon, Monocoque, Buoyancy, Truss, History of ballooning, Umberto Nobile, Polyester, Mooring mast, Thrust vectoring, RAF Cardington, Aramid, Buoyancy compensator, Airship hangar, Spy basket, Laminate, Geodesic airframe, Goldbeater's skin, Lifting gas, Ballonet, Polyvinyl fluoride, Thermic welding, Hybrid moored balloon. Excerpt: Helium ( -lee- m) is the chemical element with atomic number 2 and an atomic weight of 4.002602, which is represented by the symbol He. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table. Its boiling and melting points are the lowest among the elements and it exists only as a gas except in extreme conditions. Next to hydrogen, it is the second most abundant element in the universe and accounts for 24% of the elemental mass of our galaxy. An unknown yellow spectral line signature in sunlight was first observed during a solar eclipse in 1868 by French astronomer Jules Janssen. Janssen is jointly credited with the discovery of the element with Norman Lockyer, who observed the same eclipse and was the first to propose that the line was due to a new element, which he named helium. In 1903, large reserves of helium were found in natural gas fields in parts of the United States, which is by far the largest supplier of the gas. Helium is used in cryogenics (its largest single use, absorbing about a quarter of production), particularly in the cooling of superconducting magnets, with the main commercial application being in MRI scanners. Helium's other industrial uses- as a pressurizing and purge gas, as a protective atmosphere for arc welding and in processes such as growing crystals to make silicon wafers- account for half of the gas produced. A well-known but minor use is as a...