Dear folks,
I have a question related to possible temperature changes
of materials. The question is what kind of materials
which certain amount of solid object, may be thick or thin,
made by such materials allow maximum temperature changes, let say
temperature distribution, in other words, what is maximum temperature
derivatives on each point of the object one can impose temperature control
on the object to
achive such temperature distribution?
In particular, I interested in metals, such as platinum, rhodium,
palladium,
or ceramic.

If you reply to my question, please cc to my email at
.
I would appreciate all your helps.
Many thanks in advance,
H. Minh
--
Using M2, Opera's revolutionary e-mail client: http://www.opera.com/m2/

On Tue, 29 Jun 2004 09:10:39 +0200, Hoang Duc Minh
wrote:


Dear folks,
I have a question related to possible temperature changes
of materials. The question is what kind of materials
which certain amount of solid object, may be thick or thin,
made by such materials allow maximum temperature changes, let say
temperature distribution, in other words, what is maximum temperature
derivatives on each point of the object one can impose temperature control
on the object to
achive such temperature distribution?
In particular, I interested in metals, such as platinum, rhodium,
palladium,
or ceramic.

Upper limit is melting point, lower limit is absolute zero.

Next question, please.

w.

On Tue, 29 Jun 2004 09:10:39 +0200, Hoang Duc Minh
wrote:


Dear folks,
I have a question related to possible temperature changes
of materials. The question is what kind of materials
which certain amount of solid object, may be thick or thin,
made by such materials allow maximum temperature changes, let say
temperature distribution, in other words, what is maximum temperature
derivatives on each point of the object one can impose temperature control
on the object to
achive such temperature distribution?
In particular, I interested in metals, such as platinum, rhodium,
palladium,
or ceramic.

Upper limit is melting point, lower limit is absolute zero.

Next question, please.

w.

Hi,
I think you misunderstand my question.
What I concern is temperature derivative or something
like that. For example, I have a line of 1 meter of copper, I want
to have a distribution of temperature along the line from
500[K] at the one end to 1000 [K] at the other end.
The question is that is this kind of distribution is possible, what is the
limit?
In this example, roughly speaking, the derivative is 500 [K/m].
H. Minh

On Tue, 29 Jun 2004 09:59:22 +0200, Helmut Wabnig
wrote:

On Tue, 29 Jun 2004 09:10:39 +0200, Hoang Duc Minh
wrote:


Dear folks,
I have a question related to possible temperature changes
of materials. The question is what kind of materials
which certain amount of solid object, may be thick or thin,
made by such materials allow maximum temperature changes, let say
temperature distribution, in other words, what is maximum temperature
derivatives on each point of the object one can impose temperature
control
on the object to
achive such temperature distribution?
In particular, I interested in metals, such as platinum, rhodium,
palladium,
or ceramic.

Upper limit is melting point, lower limit is absolute zero.

Next question, please.

w.



--
Using M2, Opera's revolutionary e-mail client: http://www.opera.com/m2/

Do you mean paper cups full of water can be used to boil water over a
flame ?
Are you biulding a radiator or a heat sink ?
The best method can not be chosen without discribing the task.

Hoang Duc Minh wrote in message ...
Dear folks,
I have a question related to possible temperature changes
of materials. The question is what kind of materials
which certain amount of solid object, may be thick or thin,
made by such materials allow maximum temperature changes, let say
temperature distribution, in other words, what is maximum temperature
derivatives on each point of the object one can impose temperature control
on the object to
achive such temperature distribution?
In particular, I interested in metals, such as platinum, rhodium,
palladium,
or ceramic.

Hey, in case anybody gets upset with you over your English. Your
English is much much better than my German.

Anyway. A temperature difference means a heat flow. Sustaining a
temperature difference means you need a low thermal conductivity.
In conditions that change over time, you also need to know about
heat capacity, though in steady state conditions the heat capacity
is not important.

It's also a question of what sources of heat you have. If you have
a heat flow and want to sustain it, you need a heat source. If you
want colder and hotter areas, you also need a place to get rid of
heat, a heat sink.

So, what you need is a good reference manual that shows the thermal
conductivity and maybe the heat capacity of the materials you are
most interested in. You should also be checking out other materials
that will work for the temperature range you are interested in, and
possiby for any other conditions like pressure, mechanical load,
or whatever else is going on in your application. For standard or
common materials, like elements, you can look in the CRC handbook.
Especially for common engineering temperatures. For more rare or
more specialized materials, you may need more specialized texts.
For example, I work in the nuclear industry, and often consult
various NUREG documents for such things as the thermal conductivity
of Uranium oxide.

If you reply to my question, please cc to my email at

Sorry. Post here, read here.
Socks

Hoang Duc Minh wrote:

Dear folks,
I have a question related to possible temperature changes
of materials. The question is what kind of materials
which certain amount of solid object, may be thick or thin,
made by such materials allow maximum temperature changes, let say
temperature distribution, in other words, what is maximum temperature
derivatives on each point of the object one can impose temperature control
on the object to
achive such temperature distribution?
In particular, I interested in metals, such as platinum, rhodium,
palladium,
or ceramic.

If you reply to my question, please cc to my email at
.
I would appreciate all your helps.
Many thanks in advance,

Charity does not make house calls.

If you want maximum "stable" temperature gradients you want the
highest possible specific heat and the lowest possible thermal
conductivity. You will then have very high thermal inertia and
minimal spillover.

Cement Peltier hear/cooler elements on the other side of the thin slab
and let it wail. Or sandwich islated channels for circulating heating
and cooling fluids. Or add fluid cooling channels and electrical
heaters. Warmth is easy, coolth is not.

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
"Quis custodiet ipsos custodes?" The Net!