DC Wave Questions

Jun 10, 2005 365 Replies

So, you miserable, troublemaking piece of shit, you've decided to take on John Larkin? Big mistake. There's no way you can even begin to think about getting close to his track record, let alone even get into the stadium, so why don't you just quit before you embarrass yourself by not even being able to leave the starting blocks?

The boiling and freezing points are pressure dependent. Not only that, a certain amount of heat must be lost or gained (latent heat, I believe, is the term) before the change of state occurs. I am simply going by memory of my old Physics classes, and I have no idea what pressure would be required to allow water to boil at 0 C. I think other substances have boiled at lower temperatures than that at STP though.

Tom

"Tom MacIntyre" wrote in message news: snipped-for-privacy@4ax.com...

Strictly speaking, the change of state occurs as the latent heat is transferred, not after.

If you peruse the phase space of water at

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you will see that there is no liquid/vapor boundary at 0 oC. At a range of pressure well below standard atmospheric, it could happen near 0.01 oC.

John's challenge is a bit of a trick and appears to show he knows how to read that graph and accompanying table.

--Larry Brasfield email: donotspam_larry_brasfield@hotmail.com Above views may belong only to me.

Good one, John!

Best regards, Spehro Pefhany

"it's the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com

At one atmosphere of pressure, the "latent heat of vaporization" of water is 540 calories per gram and is the amount of heat required to change liquid water at 100°C into steam at 100°C. That's used to great advantage, in reverse, in steam heating systems where steam which has been generated in a boiler is forced to condense into liquid water in a remotely located radiator and release that heat into the environment surrounding the radiator when it (the steam) changes state.

Why should he or I? The error wasn't ours and I for one don't need to prove it to anyone. You are out of line for asking for it.

In other words, go research it yourself.

Don (B)

Are you saying that it could happen at 0.01C but not at 0.00C, because you see something in that chart which says water is liquid at 0.01C and not at 0.00C?

I don't see that in the chart at all. The chart does not have sufficient resolution. It doesn't discuss that in the text either.

Did you mean something else?

Floyd L. Davidson Ukpeagvik (Barrow, Alaska) floyd@barrow.com

The answer of course is: not much.

Floyd L. Davidson Ukpeagvik (Barrow, Alaska) floyd@barrow.com

Up the paddle without a creek? ;-}

Ed

Well, it takes one calorie per gram to raise liquid water one degree centigrade - I wonder if, at an ambient pressure of, say, 10^3 Pa, it still takes 540 calories per gram to transform a gram of liquid water at

0degC to a gram of gaseous steam at 0degC.

According to the graph at

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, approx. 10^3 Pa, whatever the hell that means. Obviously, an atmosphere is up there near the "annoying point", ;-) , between 10^8 and 10^9 Pa.

Hope This Helps! :-) Rich

Lame.

Approx. 10^3 Pa.

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;^j

The Pig Bladder from Uranus, still waiting for that hot babe to ask what my favorite planet is! ;-J

From "Channeling Class": "...You will know how to interpret the information in my energy because it will show up as a pattern in your imagination.

"Channeling, like all other inner phenomena happens in the imagination. This is the faculty humans use to access the inner planes, spiritual worlds, divine reality or whatever you wish to call what is beyond the external, material world. We'll make use of the imagination to establish contact with each other, and to carry out the channeling process. You can think of the imagination as a permeable membrane located right at the water line in the metaphor of the iceberg in the introduction to this class. Being between the two major parts of the mind, it is shared by both.

"New ideas, insights, creative inspiration and intuition all begin in the unconscious mind. As these kinds of impressions, including the energy you will be interpreting, rise to awareness, they pass through the imagination. The conscious, aware mind perceives these impressions as representations in the imagination. Sometimes the impressions are represented visually as images or pictures, sometimes auditorily as sounds or words, and sometimes sensorially as feelings or energy." --

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So, don't knock the imagination. ;-D

Love, Rich for further information, please visit http://www.godchannel.com

Do you happen to know what the triple-point of water is?

Best regards, Spehro Pefhany

"it's the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com

Was the topic "Olympic-Grade Trollfeeding?"

John Fields, you won that one by a landslide some time ago.

Flap! The Pig Bladder from Uranus, still waiting for that hot babe to ask what my favorite planet is. ;-j

In any case, what you have to do in analysis is to treat each frequency separately, including the 0 frequency term. What's the big deal.??

Don Kelly dhky@peeshaw.ca remove the urine to answer

Anybody who doesn't like it, feel free to bang out the de's.

j

Not true, unless 0.01+ oC counts as "0C" or "boil" has some novel meaning other than a liquid to vapor phase transition occuring within the liquid due to applied heat.

[Stuff on latent heat zapped.]

I said "near 0.01 oC", not "at". At temperatures above the triple point (at 0.01 oC), a liquid/vapor phase change exists. Below that, there is no such phase change, so there is no possibility of boiling, which requires a liquid. Precisely at the triple point, I'm not sure it is meaningful to speak of boiling because the triple point exists under equilibrium conditions and boiling is not an equilibrium. (Boiling is a catastrophic process.)

The table of triple points shows, in its first row, that triple point often referred to as "the triple point". (That is the one now used to define 0.01 oC on the Centrigrade temperature scale.) This triple point, between the liquid, Ih (hexagonal ice-one) and vapor phases, represents the lowest pressure at which an Ih/liquid phase transition exists, as can be seen from the graph. It is clear from the graph that the vapor phase boundary slope is continuous as it passes thru that triple point, and has positive slope. So, clearly, where it passes thru 0 oC has to be below that triple point.

Nope.

--Larry Brasfield email: donotspam_larry_brasfield@hotmail.com Above views may belong only to me.

Not in my donut - there was no hole till the donut was made - I was there and I saw it enter the mixture.

Ken

Hmmm... Same as the answer to: "What does Floyd L. Davidson know about anything?".

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