Word: tantalum
(lookup in dictionary)
(lookup stats)
Dates: all
Sort By: most recent first
(reverse)
...produced element emits "soft" alpha particles, which have so little energy that they will not penetrate a sheet of heavy notepaper; thus they will not harm a patient. The French put 150 mg. (about one two-hundredth of an ounce) of Pu-238 into a capsule of platinum and tantalum. The Americans put 500 mg. (one-sixtieth of an ounce) in their capsule. In both devices, the patient is sufficiently shielded from the heat of the radioactive source by its plastic container. That heat is directed to a thermocouple that generates 200 milliwatts of electricity. This powers a tiny generator...
...their nuclear capability. One of the countries sure to be pinpointed on Chinese plotting maps is Japan, which, ironically, continues to supply Chinese buyers with the sophisticated technology that Peking needs for missilery, as in the recent sale of a vacuum furnace and rolling mill for titanium and tantalum rocket metals. Though Japan nominally subscribes to the Western list of goods forbidden for sale to the Communists, the lure of profits with the mainland has proved too great. Japan, in fact, has no investigative and inspection staff for checking on sales to China...
...that electronic engineers believe will soon replace most of the tangled guts of familiar apparatus. Least radical of the miniature gadgets are the "thin-film circuits." In the Philco version they are glass or ceramic sheets a few hundredths of an inch thick, covered with foil-thin layers of tantalum, chromium and gold. On top of the gold is a photosensitive material that becomes insoluble when exposed to light. The diagram of a desired circuit is printed by strong light on the photosensitive surface. Then the unexposed parts are dissolved, and the bare gold and chromium...
Where all the films are removed, the remaining glass is a nonconductor. When a section of tantalum remains, it acts as a resistor. A strip of gold and chromium is a good conductor, and serves as a thin wire. Capacitors can be made by covering tantalum with an oxide that acts as an insulator and then laying on a fresh film of gold. To make a complete circuit, tiny silicon transistors are electrically bonded to the proper sites. Complicated as it is, the process is wholly automatic, and up to one hundred microcircuits can be manufactured on a piece...
...create bigger National Distillers, with assets of $625 million. As unlikely at first glance as marriage of a parson and a show girl, merger would actually make good sense because National, second biggest U.S. maker of polyethylene (first: Union Carbide), also owns 60% of Reactive Metals, Inc. (zirconium, titanium, tantalum, columbium), managed by Bridgeport...