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Author Topic: Golden sun block. Coolent.  (Read 11837 times)

Offline Hadrian

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Golden sun block. Coolent.
« Reply #25 on: 12/02/2007 12:36:33 »
at least we can all start now today to make a difference



 

lyner

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Golden sun block. Coolent.
« Reply #26 on: 15/02/2007 10:44:59 »
Quote
The correct term is "malleability", which is the ability to be stretched in a big foil, while "ductility" means the ability to be stretched in a long thread.

Was this an "argumentum ad hominem"? (http://members.ozemail.com.au/~enigman/latin.html)

Whilst we're in a pedantic mood. The word malleability refers to hammering , rolling or beating (from the latin word '"malleo"  - "I hammer")  into shapes - like bowls, sheets or foils.  Ductile (from the latin word  "ducare" - "to lead")  refers to stretching - wires or sheet, for instance, if you spin a disc and make it stretch.

 

Offline lightarrow

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Golden sun block. Coolent.
« Reply #27 on: 15/02/2007 17:50:57 »
Quote
The correct term is "malleability", which is the ability to be stretched in a big foil, while "ductility" means the ability to be stretched in a long thread.
Was this an "argumentum ad hominem"? http://members.ozemail.com.au/~enigman/latin.html)
Whilst we're in a pedantic mood. The word malleability refers to hammering , rolling or beating (from the latin word '"malleo"  - "I hammer")  into shapes - like bowls, sheets or foils.  Ductile (from the latin word  "ducare" - "to lead")  refers to stretching - wires or sheet, for instance, if you spin a disc and make it stretch.

You are right! I made a mistake, sorry. Since centrifugal force applies a tensile stress to the disc, the rotating disc becomes thinner because of ductility!

What confused me is the fact that the term "ductility" is usually used in materials technology to the making of thin threads, while "malleability" is usually used in the making of thin foils.
 
Malleability
It can be defined as the property of a metal to be deformed by compression without cracking or rupturing. The load may be applied slowly or suddenly and will determine whether the material will be suitable for forging or rolling into thin sheet.

Ductility
The property of metal which permits it to be reduced in cross sectional area without fracture. In a tensile test, ductile metals show considerable elongation eventually failing by necking, with consequent rapid increase in local stresses.

Apologizes!
Alberto.
« Last Edit: 15/02/2007 18:08:04 by lightarrow »
 

lyner

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Golden sun block. Coolent.
« Reply #28 on: 16/02/2007 11:22:55 »
No worries. It is still a barmy idea. Worthy of George Bush or Ronald Reagan.
It reminds me of a definition of an Engineer, I once heard; Someone who can do, for 5, what an ordinary guy can do for 10.
Why is the 'space' solution so attractive for every problem? I even heard someone on Radio 4 claiming that the Carbon footprint for a space launch was negligible!
 

The Naked Scientists Forum

Golden sun block. Coolent.
« Reply #28 on: 16/02/2007 11:22:55 »

 

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