From owner-freebsd-chat Fri Oct 12 14: 3:12 2001 Delivered-To: freebsd-chat@freebsd.org Received: from robin.mail.pas.earthlink.net (robin.mail.pas.earthlink.net [207.217.120.65]) by hub.freebsd.org (Postfix) with ESMTP id 33A9437B401 for ; Fri, 12 Oct 2001 14:03:06 -0700 (PDT) Received: from blossom.cjclark.org (dialup-209.245.143.238.Dial1.SanJose1.Level3.net [209.245.143.238]) by robin.mail.pas.earthlink.net (8.11.5/8.9.3) with ESMTP id f9CL34T18591; Fri, 12 Oct 2001 14:03:04 -0700 (PDT) Received: (from cjc@localhost) by blossom.cjclark.org (8.11.6/8.11.3) id f9CKNWD05596; Fri, 12 Oct 2001 13:23:32 -0700 (PDT) (envelope-from cjc) Date: Fri, 12 Oct 2001 13:23:32 -0700 From: "Crist J. Clark" To: "Gary W. Swearingen" Cc: freebsd-chat@FreeBSD.ORG Subject: Re: Use of the UNIX Trademark Message-ID: <20011012132331.K293@blossom.cjclark.org> Reply-To: cjclark@alum.mit.edu References: <007701c15216$867d47c0$1401a8c0@tedm.placo.com> <6xzo6xssir.o6x@localhost.localdomain> <20011011210426.D293@blossom.cjclark.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: ; from swear@blarg.net on Fri, Oct 12, 2001 at 08:11:12AM -0700 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 On Fri, Oct 12, 2001 at 08:11:12AM -0700, Gary W. Swearingen wrote: > "Crist J. Clark" writes: > > > On Thu, Oct 11, 2001 at 03:47:56PM -0700, Gary W. Swearingen wrote: > > > > > > Also, I'll bet a tank of compressed air is a lot cheaper than one of > > > either Oxygen or Nitrogen. > > > > I've never seen a commerial cylinder of air. I don't know if you can > > buy one. I would think that for the vast majority of applications it > > is cheaper to buy an air compressor than to buy cylinders of air. > > I'm sure that you can buy nearly any gas you want, but maybe its > uncommon need outside the SCUBA field would make it no cheaper than O & N. > I do remember seeing hugh tanks of liquified air that someone preferred > to an air compressor. Liquifying air is a whole separate matter from just having compressed gas in a cylinder. You need to refrigerate air in order to get it to liquify. Air at "normal" (any natural terrestrial temperature) is above the critical temperature and never liquifies. Purchasing and maintaining equipment for liquifying atmospheric gases is very different from doing the same for compressed air. Lots of _big_ chemical plants don't even do it for themselves, but have co-located liquified gas plants from people who specialize in it, like Air Products. -- Crist J. Clark | cjclark@alum.mit.edu | cjclark@jhu.edu http://people.freebsd.org/~cjc/ | cjc@freebsd.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-chat" in the body of the message