DC Wave Questions

--- As John Popelish remarked, boiling is only possible if the medium in which the boiling is occurring is a liquid, so if the water has turned into ice at 0°C, sublimation is the mechanism which water molecules will use to evaporate from their parent structure.

Since this a technical forum and we _do_ have ground rules, I believe we generally agree that, unless otherwise specified, standard pressure is defined as 760 millimeters of mercury and standard temperature is defined as zero degrees celcius. While the boiling point of water is dependent on pressure, the freezing point, I believe, is not.

At least, not to a great extent. I don't have any data to support that position, but I'd love to see some, if it's out there.

-- John Fields Professional Circuit Designer

Handbook of Chemistry and Physics, Twenty Fifth Edition, Table p.1696.

All you have to do is go ice skating! You skate on a thin layer of water, produced by the pressure of the skates. Water is also one of the few liquids that expands when it freezes, which is fortunate for life on this earth! :-)

I believe that in this forum we assume temperature is a variable that must be accommodated in design, unless otherwise stated. I cannot imagine why any unstated temperature would be assumed to be 0 oC. I suppose sea-level atmospheric pressure is often assumed, but where it matters, it should not be assumed at all.

You might want to consider the "triple point" of water, below which pressure "melting point" is meaningless and the "freezing point" varies considerably with pressure.

See:

are? And

There seems to be a consensus that, since no signal is absolutely stable with time, then DC must not exist. That does simplify life.

John

Using the usual meaning of "freezing" which is the transition from liquid to solid, that graph shows "freezing" occurring at 273K over a million to one range in pressure. I would say that the statement "While the boiling point of water is dependent on pressure, the freezing point, I believe, is not" is essentially true- to all except a nitwit like you.

Atta boy, Kevin. Ratch

solid, that graph shows "freezing" occurring at 273K

It does not. The straight part of the liquid/solid phase boundary covers less than 5 orders of magnitude. "Over a million to one" would be more than 6 orders of magnitude.

on pressure, the freezing point, I believe, is not"

In a discussion that has involved sublimation, to exclude that part of the phase space would be essentially silly.

Off your meds again, Fred? I expect you to be more careful with your graph reading before breaking into your frothing-at-the-mouth modes.

...

What happened to the ground rules you mentioned? Being correct isn't one of them?

Tell us more about AC, so we can laugh again. Then come back to this, for more!

What's the matter John, are you bitter that several people, who do understand the theory and practice, have said you are wrong...

John Fields wrote: (snip)

If you are willing to consider extreme conditions, not only does the freezing point change, but there are many ice phases, each structurally distinct and with temperature and pressure boundaries.

Ladies and Gentlemen--jackbruce9 has left the building. ;-))

Tut

DIE THREAD!!!!!!!

Didn't see this response, so piggy-backing my reply.

There are literally hundreds of references on the web about DC, AC and Transient Analyses. Browse some of the simpler overviews, and you will see that the mathematical differences are clearly defined, and that's what it's all about. The math determines the signal type. It is my belief that the widespread disagreement is due to participants that just like to argue a lot.

Anyone who went to university studying a natural science will know the meaning of all of these terms and the others expose their ignorance by speculating and making up instead. You clearly belong to the last category.

solid, that graph shows "freezing" occurring at 273K

Bull- it goes from 10^3 to 10^9 Pa, idiot.

on pressure, the freezing point, I believe, is not"

There is no discussion- the statement was about water "freezing", pseudo-intellectual.

More of your parroting insults from other mediocre and pretentious garbage like yourself? Like I say- you are typical USENET garbage, all mouth and heap of worthless garbage in the physical world. My, how that keyboard empowers unskilled nobodies...

That is the pseudo-intellectuals for you, speculating about elementary definitions- and later on you find even a second order network is hopelessly beyond their abilities of computation. They are worthless zeroes of the highest order. The original weakling who started the thread with his ignorant question offered no discussion about direct responses to its question, preferring instead to pseudo-intellectualize about the fundamental principles of terminology, in a weak and ineffective way- OP=ZEROID.