From owner-freebsd-chat Thu Oct 11 2:30:23 2001 Delivered-To: freebsd-chat@freebsd.org Received: from riker.skynet.be (riker.skynet.be [195.238.3.132]) by hub.freebsd.org (Postfix) with ESMTP id DB6B037B409 for ; Thu, 11 Oct 2001 02:30:18 -0700 (PDT) Received: from [194.78.144.28] ([194.78.144.28]) by riker.skynet.be (8.11.6/8.11.6/Skynet-OUT-2.15) with ESMTP id f9B9Tai15058; Thu, 11 Oct 2001 11:29:36 +0200 (MET DST) (envelope-from ) Mime-Version: 1.0 X-Sender: bs663385@pop.skynet.be Message-Id: In-Reply-To: <007701c15216$867d47c0$1401a8c0@tedm.placo.com> References: <007701c15216$867d47c0$1401a8c0@tedm.placo.com> Date: Thu, 11 Oct 2001 11:21:53 +0200 To: "Ted Mittelstaedt" , , "Salvo Bartolotta" From: Brad Knowles Subject: RE: Use of the UNIX Trademark Cc: "P. U. (Uli) Kruppa" , Content-Type: text/plain; charset="us-ascii" ; format="flowed" Sender: owner-freebsd-chat@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org At 10:35 PM -0700 2001/10/10, Ted Mittelstaedt wrote: > So, in the head > scratching process of trying to figure out how to answer this, someone > happened to look up old actuator patents and ran across one that ran > off of compressed air. Indeed, that makes a lot of sense. > The patent had of course long since expired > but there was enough of a description of how it worked to give them > a general idea of what the inventor had been getting at, so they > built an actuator that used a cylinder of compressed oxygen (such > cylinders are commonly used in welding) that could supply the actuator > with mechanical power for a couple hundred cycles. I've used such cylinders in Oxyacetylene cutting torches, and brazing, but I don't recall them ever being able to generate enough heat to do proper welding. When I did welding, I used standard arc welding equipment, while my cousin (who is a professional race car builder) uses very expensive MIG (Metal-Inert-Gas) and TIG (Tungsten-Inert-Gas) welding equipment. MIG welding uses a spool of wire that is used as the "welding rod" and through which the current is passed, and then that wire is surrounded by a high-pressure curtain of inert gas (Nitrogen, I think). TIG welding uses a Tungsten tip on the welding rod, which doesn't itself actually melt. You have to supply a separate rod that is actually melted during the process (kind of like soldering or brazing, but at much, much higher temperatures and where the pieces you're working on are also brought to a liquid state), but otherwise is similar to MIG. However, all that said, by far the most dangerous of all gases that are used in welding and similar activities is compressed Oxygen. All other flammable gases will have a hard time finding enough oxygen to burn cleanly or completely, if they are released by accident (such as in an explosion). However, with enough oxygen present, just about anything can be burnt very, very easily. I would seriously hope that these people weren't actually using compressed oxygen, but perhaps instead compressed Nitrogen, or some relatively inert gas. -- Brad Knowles, H4sICIFgXzsCA2RtYS1zaWcAPVHLbsMwDDvXX0H0kkvbfxiwVw8FCmzAzqqj1F4dy7CdBfn7 Kc6wmyGRFEnvvxiWQoCvqI7RSWTcfGXQNqCUAnfIU+AT8OZ/GCNjRVlH0bKpguJkxiITZqes MxwpSucyDJzXxQEUe/ihgXqJXUXwD9ajB6NHonLmNrUSK9nacHQnH097szO74xFXqtlbT3il wMsBz5cnfCR5cEmci0Rj9u/jqBbPeES1I4PeFBXPUIT1XDSOuutFXylzrQvGyboWstCoQZyP dxX4dLx0eauFe1x9puhoi0Ao1omEJo+BZ6XLVNaVpWiKekxN0VK2VMpmAy+Bk7ZV4SO+p1L/ uErNRS/qH2iFU+iNOtbcmVt9N16lfF7tLv9FXNj8AiyNcOi1AQAA To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-chat" in the body of the message