Re: Quartz/Halogen incandescent bulbs

["Bernard G. Cleyet & Nancy Ann Seese" <georgeann@REDSHIFT.COM>]

Mea culpa -- I have confused breech and breach. It's breech that originally meant to
smell.

bc


"Bernard G. Cleyet & Nancy Ann Seese" wrote:

> I suspect that the tungsten fluoride bond requires a very high temp. to
> disassociate.  (The electronegativity is only 2.3, though.)  At what temp., for
> example, does the NaCl bond (much greater electroneg. diff.) break?
>
> My dict. ('49) reports both a transitive (to make a breach in) and in. ("thar she
> blows!").  Did C. B. just misspell?
>
> bc
>
> P.s. The original meaning was "smelly."
>
> Chuck Britton wrote:
>
> > At 3:21 PM -0800 2/11/00, Leigh Palmer wrote:
> > > There is a tendency (on a very long timescale) for viteous quartz to
> > > "devitrify", or return to a crystalline phase. This tendency is
> > > accelerated by the presence of some foreign materials on the surface
> > > of hot fused quartz, whence the warning that quartz light bulbs not
> > > be handled with the bare hand.
> >
> > My understanding of quartz-halogen bulbs is that the 'bulb' is quite
> > pure SiO2 (quartz) in order to withstand the extremely high T that
> > they reach. Yes the quartz is 'vitrious', more often referred to as
> > 'fused quartz' (In honor of it's having been melted from the
> > crystalline form).
> >
> > As for the 'do not touch' warning, I believe that it is to prevent
> > overheating of the bulb at the location of the contaminant (usually a
> > tin film of body oil). A bulb that HAS been touched will produce an
> > 'aneurysm' when the softened quartz is pushed out by the P > 1 atm of
> > chlorine. (Fluorine has some superior abilities in this mysterious
> > process of redepositing evaporated tungsten onto the HOTTEST,
> > thinnest length of the filament, but seems to be frowned upon in the
> > industry.)
> >
> > I don't think that the body oil on the surface acts to 'breech the
> > degeneracy' of the vitreous quartz.
> >
> >                 (but I, too, am enjoying this learned discussion of
> > entropy et al.)
> >
> >    -.     .-.     .-.     .-.     .-.     .-.     .-.     .-.     .-.     .-
> >      \   /   \   /   \ N /   \ C /   \ S /   \ S /   \ M /   \   /   \   /
> >       `-'     `-'     `-'     `-'     `-'     `-'     `-'     `-'     `-'
> > Chuck Britton                                   Education is what is left when
> > britton@academic.ncssm.edu                      you have forgotten everything
> > North Carolina School of Science & Math         you learned in school.
> > (919) 286-3366  x224                            Albert Einstein,        1936