~clap clap clap...~ Bravo...


----- Original Message -----
From: Severson, Scott M. <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, March 16, 2000 9:16 AM
Subject: Re: [TN] VOC legislation - evolved to dark


> All,
>
> This question took an interesting turn, so I went for an expert opinion
from
> my Physics professor.  See the following:
>
> Scott
>
> >Good Morning Dr. Otto,
> >
> >I have been involved in a philosophical discussion concerning Infrared
> >radiation spectrums.  Some of the questions that have come up that nobody
> >can seem to answer are as follows:
> >
> >    1)    At what point does a substance quit emitting an infrared
> >radiation? Absolute zero?
> >
> >    2)    Do most substances emit IR radiation?
> >                I think that it is a relative thing based on the
> surrounding
> >of the object.  In order to achieve equilibrium the object will either
> >absorb or give of IR radiation (heat) based on the temperature
differential
> >between it and its surroundings.
> >
> >Any comments.
> >
> >Scott
>
> Hi, Scott:
>
> In answer to question 1):  All matter emits blackbody radiation due to
> thermal motion, at any temperature above absolute zero.  However, the peak
> wavelength is inversely proportional to temperature, given by (peak
> wavelength in meters) x (temperature in Kelvin) = 2.898 x 10^3 m-K.  So,
> as the temperature gets smaller, the peak wavelength gets longer.  At body
> temperature, this peak is around 10 microns, in the Far Infrared.  At
> higher temperatures, the peak wavelength decreases until an appreciable
> amount of light is in the visible region ("red-hot").  At lower
> temperatures, the wavelength increases, into the microwave region (1 mm
> waves at about 3 Kelvin), and eventually to radio wavelengths, in the
> milli-Kelvin region.  However, the amount of power emitted is proportional
> to T^4, so as the temperature drops, the amount of power drops
drastically.
>
> Question 2):  Every substance emits IR, although substances which are
> "black" (good absorbers) are the best emitters.  The "emissivity" is a
> measure of how good an emitter a particular substance is.  A perfect black
> body has an emissivity of 1.0,  whereas polished copper has an emissivity
> of about 0.02, meaning that it emits only 2% as well as a black body.
>
> You are correct in thinking that it is a relative thing, since the
> surroundings are also emitting IR continuously.  This is one of the heat
> transfer mechanisms that help establish temperature equilibrium.  To check
> this, all you have to do is stand near a window (out of direct sunlight)
on
> a cold winter day.  You can feel cold "radiating in" at you on the side
> nearest the window, because your blackbody radiation is radiating away to
> the outside world, and less radiation is radiating back at you from the
> colder outside environment.
>
> So, in a nutshell, the rate of heat transfer due to radiation is
> approximately proportional to the temperature differential between the
> object and its surroundings.  This is known as "Newton's Law of Cooling".
>
> Have Fun!
>
> -- Dr. Otto
>
>
>
> -----Original Message-----
> From: Richard Tilbrook [mailto:[log in to unmask]]
> Sent: Thursday, March 16, 2000 9:22 AM
> To: [log in to unmask]
> Subject: Re: [TN] VOC legislation - evolved to dark
>
>
> I am not in any way en expert, but I would have thought that the sea emits
> IR at a
> low level, especially when compared to a human body. I would also have
> thought that
> a block of dry ice would emit a tiny amount of IR, possibly not detectable
> with
> current equipment. I would have thought that something like a low
> temperature
> superconductor, when in superconductive state, would emit no IR. Is this
so?
> Or
> would something have to be at absolute zero to emit no IR?
>
> Richard
>
>
>
>
>
> [log in to unmask] on 16/03/2000 13:05:35
> Please respond to [log in to unmask]@INTERNET@wtgw
> To:     [log in to unmask]@INTERNET@wtgw
> cc:
> Subject:        Re: [TN] VOC legislation - evolved to dark
>
>                    *** WARNING ***
>
> This mail has originated outside your organization,
> either from an external partner or the Global Internet.
>      Keep this in mind if you answer this message.
>
>
> Nope... they wouldn't be dead.. The sea, even if very cold still has an IR
> Signature itself... Proof, add an ice cube, do IR detection magnification,
> you can sea the cube as colder... Even colder dry ice will give you better
> differentiation.
>
> Alain Savard
>
> -----Original Message-----
> From: Smith Russell MSM LAPO US [mailto:[log in to unmask]]
> Sent: March 16, 2000 8:13 AM
> To: [log in to unmask]
> Subject: Re: [TN] VOC legislation - evolved to dark
>
>
> Ah , to throw the proverbial Monkey Wrench into the works
>          Have you considered submergence in Water, Either Sea of Fresh?
>         Since IR transmission in Water is minimal , Aquatic plants and
> animals exist in the ambient temperature. ( trying to raise body
temperature
> in such a heat sink would be a tremendous energy cost )
>         Since there is no discernible infrared signature from the aquatic
> life,
>           then by the logic would they not be considered dead?
>
> Russell Smith
> Ciba Specialty Chemicals
>
> ##############################################################
> TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
> ##############################################################
> To subscribe/unsubscribe, send a message to [log in to unmask] with
following
> text in
> the body:
> To subscribe:   SUBSCRIBE TECHNET <your full name>
> To unsubscribe:   SIGNOFF TECHNET
> ##############################################################
> Please visit IPC web site (http://www.ipc.org/html/forum.htm) for
additional
> information.
> If you need assistance - contact Keach Sasamori at [log in to unmask] or
> 847-509-9700 ext.5315
> ##############################################################
>
> ##############################################################
> TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
> ##############################################################
> To subscribe/unsubscribe, send a message to [log in to unmask] with
following
> text in
> the body:
> To subscribe:   SUBSCRIBE TECHNET <your full name>
> To unsubscribe:   SIGNOFF TECHNET
> ##############################################################
> Please visit IPC web site (http://www.ipc.org/html/forum.htm) for
additional
> information.
> If you need assistance - contact Keach Sasamori at [log in to unmask] or
> 847-509-9700 ext.5315
> ##############################################################
>
> ##############################################################
> TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
> ##############################################################
> To subscribe/unsubscribe, send a message to [log in to unmask] with
following text in
> the body:
> To subscribe:   SUBSCRIBE TECHNET <your full name>
> To unsubscribe:   SIGNOFF TECHNET
> ##############################################################
> Please visit IPC web site (http://www.ipc.org/html/forum.htm) for
additional
> information.
> If you need assistance - contact Keach Sasamori at [log in to unmask] or
> 847-509-9700 ext.5315
> ##############################################################
>

##############################################################
TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
##############################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in
the body:
To subscribe:   SUBSCRIBE TECHNET <your full name>
To unsubscribe:   SIGNOFF TECHNET
##############################################################
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - contact Keach Sasamori at [log in to unmask] or
847-509-9700 ext.5315
##############################################################