Well, I guess we can keep on using the thorium, but I understand the cerium and yttrium are rare earth minerals and will soon be export restricted by the Chinese government. Since 90% of the world supply of rare earths come from China and "domestic demand is so great there will not be any for export". What will we do when we can't get gas mantles - camp in the dark? And, we can't stay home and work on disk drive computers that use neodymium magnets in the motors. Or use fiber optics that are erbium doped. Darn!! -----Original Message----- From: David D. Hillman <[log in to unmask]> To: TechNet <[log in to unmask]> Sent: Fri, Aug 20, 2010 3:59 pm Subject: [TN] NTC Friday Element Quiz: The Answer Hi folks - here is the Friday Element Quiz Question and Answer: he Question: I am an element that was first produced in 1828 but was identified enturies earlier. Peak demand for this element was in the 1960s. This lement has been extensively studied for possible use in reactor fuel reeding but only one master alloy is commercially available. The dominant isotope of this element has a half life of 1.41 x 1010 years. This lement's compounds were part of an invention in 1891 and have been a ignificant part of people's camping experience. This element comprises .1 ppm of the earth's crust. What element am I? The Answer: The element is Thorium (Th). Thorium oxide (ThO2)was part of the ncandescent gas light mantle patent (which I didn't know myself until oday). Gas camping lanterns have woven cotton mantles that are soaked in ThO2 and Ce(NO3)3 solution. The cotton burns away when first lit leaving delicate web of sintered nitrate residues. The ThO2 has low thermal onductivity and supports/insulates the CeO2 particles which catalyze gas ombustion. Today, U.S manufacturers have substituted Yttrium to avoid he regulatory costs associated with Th. he winner of the quiz is Bev Christian, RIM, will get the services of lumpy, the 8th dwarf, for one task. Bev - you will need to let us know hat Clumpy accomplished for you. veryone have a good weekend. Dave Hillman ockwell Collins [log in to unmask] ______________________________________________________________________ his email has been scanned by the MessageLabs Email Security System. or more information please contact helpdesk at x2960 or [log in to unmask] _____________________________________________________________________ --------------------------------------------------- echnet Mail List provided as a service by IPC using LISTSERV 15.0 o unsubscribe, send a message to [log in to unmask] with following text in he BODY (NOT the subject field): SIGNOFF Technet o temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) o receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest earch the archives of previous posts at: http://listserv.ipc.org/archives lease visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for dditional information, or contact Keach Sasamori at [log in to unmask] or 47-615-7100 ext.2815 ---------------------------------------------------- ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------