Somewhat OT: Long term design

They'll pretty well stay put. Diffusion is an exponential thing, so where it's happening at say 800K, it's down by exp(800K/300K) = 14.4 times at room temperature. Wait, that's not so impressive.

References.... ah, diffusion follows the Arrhenius equation, which puts it in terms of exp(Eo/k_B*T), so the ratio between temperatures is exp(-(Eo/k_B*T) * (1/T1 - 1/T2)). That requires knowing what the activation energy is, though. Can't find it.

Tim

-- Deep Friar: a very philos>> >>

Didn't you mean "Variac"

;-)

There are some recorded instances of "tin plague" in organ pipes in unusually cold weather.

planets

How small of a dose, and is it contagious? ;-)

I think they predated even 'lint' by quite a bit. ::))

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WangoTango

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sitting?

They will stay put pretty well. Solid solubility at normal terrestrial=20 surface temperatures is mighty low. Micron per hour diffusion requires=20 about 2000K. And the mobility does follow the e^kt Arrhenious=20 relationship.

You could ask Jim to settle it. ;-)

Lets say that I found too many defective tantalums in broken equipment. When it comes to capacitors: electrolytics come first, tantalums next. Besides that, a lot of rain forrest is cut to get the tantalum.

John Larkin schrieb:

Hello,

you forgot the bad effect of temperature cycles at low temperatures between -60 and -10 °C. Low and constant temperatures would be better.

Bye

Michael A. Terrell schrieb:

Hello,

there is another problem with tin at low temperatures, it may transform into another modification, the solid metal will be a powder then. In german we call it Zinnpest or tin-plague. It has destroyed some organ pipes in churches during a very cold winter. It may be avoided by using a proper alloy of tin.

Bye

Jim Thompson schrieb:

Hello,

not only the pipes and bellows, but also the keyboards and the valves cotrolling the air to the pipes.

Bye

John Larkin schrieb:

Hello,

rubber often does not stand for many decades, it loses flexiblity and goes hard and brittle developing cracks.

Bye

I have also heard of it being a problem with the buttons of early 1900s=20 Russian military uniforms in very cold climates.

and the organist....