Difference between revisions of "Talk:Electrical Conductors"

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:-- [[User:Mdelaney|Mdelaney]] 19:26, 11 May 2007 (UTC)
 
:-- [[User:Mdelaney|Mdelaney]] 19:26, 11 May 2007 (UTC)
 
The only problem I see is that sodium/potassium may not be suitable for buried wires, as described in the [[Sodium Scenario]], as they can be easily scooped with a spoon or cut with a knife.  Even if the wire is re-enforced with fibers and an iron core, malleability of the conductive layer could prove to be an issue in high use areas.  Excavations and geologic settling would need to be very closely monitored.  Long term studies of this kind of buried wire combo may have very interesting results.  Would Na and K slowly mix and produce NaK?  Would there be enough heat or tension to meld them together?  How would the wire deform under varying subterranean pressures?  I also cannot help my curiosity about the rate of loss experienced by bare cable buried in lunar regolith, as it will be interesting to see what effects the nano-phase surface iron may have on an uninsulated circuit.  How could all of the above effects be mitigated?  Oh, what I would give for a bag of mare simulant and a couple of vacuum chambers in a real lab right about now.
 
 
[[User:Jarogers2001|Jarogers2001]] 17:22, 12 May 2007 (UTC)
 
 
:I thought they got somewhat cold winters where you live. Have you never seen condensation on windows and walls in winter? (Not usually prevalent in modern homes, but was quite a problem in older stone, brick and block buildings in much of Europe)
 
 
:Luna's not very cold, but it's not very warm underground either, certainly not warm enough to eliminate the possibility of condensation. So I don't think sodium is suitable for indoors. Outdoors there's the problem of the daytime heat, more than enough to melt sodium.
 
 
:If you're going to go to the trouble of using an iron core, I don't think sodium offers enough of an advantage over just using iron on it's own. And remember, they only use conductive skins to mitigate skin effect, something that's not particularly bad over relatively short spans at high voltage and low frequency. Basically your common HT cable on Earth is steel, they just put an aluminum skin on it to reduce losses.
 
 
:Technically these two posts should be moved to [[Talk:Sodium_Scenario]]. If you move yours, I'll move mine. Using export - import isn't worth the headache for two posts. :)
 
 
:-- [[User:Mdelaney|Mdelaney]] 01:25, 13 May 2007 (UTC)
 
  
 
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It appears the table has been corrected. Likely lunar sodium is mostly compounds rather than free metal. Since sodium compounds are soluable in water, it is easily separated from even a high percentage of insoluable material. The water is easily recovered for reuse.  Neil
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*It seems that part of the edit by user 69.117.44.141 on the 15th of March was not an improvement.  Perhaps someone might say that it takes much energy to melt aluminum, but the big energy requirement in using lunar aluminum is smelting.  There is no significant reduced aluminum native to Luna.  On Earth aluminum occurs as sulfates, silicates, and oxides in various mixed mineral species with other metals.  Whatever the ore from which aluminum will be recovered on Luna, it will require considerable energy to reduce the metal.  Smelting will be the major concern with Aluminum.  Iron on the other hand occurs in reduced form.  Using iron requires separating and melting the reduced iron particles.  The conduction properties of iron could be significant if it is used as rails and a small amount of current is conducted along the path of the rails.  --[[User:Farred|Farred]] 23:00, 23 March 2009 (UTC)
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== The availability of metals on Luna ==
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Recent edits about where iron and silver are found on the moon introduced an important question.  However the availability on the moon is best addressed in the main article of each metal considered as a conductor.  There is a link to the main article in each case.  I have addressed the question somewhat and will see to proper organization later.

Latest revision as of 07:23, 9 August 2016

Element Resistivity @ 20°C Density (~ r.t.) Availability Highland Lowland
Silver 15.87 nΩ·m 10.490  g·cm−3 Unknown Unknown Unknown
Copper 16.78 nΩ·m 8.960 g·cm−3 Unknown Unknown Unknown
Gold 22.14 nΩ·m 19.300  g·cm−3 Unknown Unknown Unknown
Aluminum 26.50 nΩ·m 2.700 g·cm−3 Yes 133,000 69,700
Magnesium 43.90 nΩ·m 1.738 g·cm−3 Yes 45,500 57,600
Sodium 47.70 nΩ·m 0.968 g·cm−3 Yes 3,100 2,900
Potassium needs ref ~70.00 nΩ·m 0.890 g·cm−3 Yes 800 1,100
Iron 96.10 nΩ·m 7.150 g·cm−3 Yes 48,700 132,000
Chromium 125.00 nΩ·m 7.860 g·cm−3 Yes 850 2,600
Titanium 420.00 nΩ·m 4.506 g·cm−3 Yes 3,100 31,000
Manganese 1440.00 nΩ·m 7.210 g·cm−3 Yes 675 1,700
Lower # => better r.t. = room temperature ppm by weight ppm by weight

Thinking Moon

The Sodium entry is a good example of thinking Moon. That is, looking at ideas that are insignificant when used on Earth but could really save the day when used on the Moon. It does take a rather long scenario to show how Sodium could be used, but this is part of the process needed to compare complicated technical ideas.

--Jriley 13:25, 11 May 2007 (UTC)

Indeed ISRU is important.
I can't see sodium being much use as a conductor inside a habitat due to it's potential for interaction with condensation. Neither can I see much use for NaK in a hab, though that might have uses outdoors.
I've forked Sodium Scenario to it's own article, partly because it deserves an article and partly because this page is intended primarily as a fact resource for other articles.
-- Mdelaney 19:26, 11 May 2007 (UTC)

Sodium Abundance

Having looked around I'm only seeing Sodium in the 3k ppm range or listed in compounds that have % occurrences of ~0.5%. Could you cite your sources supporting said abundance of Sodium?

-- Mdelaney 19:27, 11 May 2007 (UTC)


It appears the table has been corrected. Likely lunar sodium is mostly compounds rather than free metal. Since sodium compounds are soluable in water, it is easily separated from even a high percentage of insoluable material. The water is easily recovered for reuse. Neil

  • It seems that part of the edit by user 69.117.44.141 on the 15th of March was not an improvement. Perhaps someone might say that it takes much energy to melt aluminum, but the big energy requirement in using lunar aluminum is smelting. There is no significant reduced aluminum native to Luna. On Earth aluminum occurs as sulfates, silicates, and oxides in various mixed mineral species with other metals. Whatever the ore from which aluminum will be recovered on Luna, it will require considerable energy to reduce the metal. Smelting will be the major concern with Aluminum. Iron on the other hand occurs in reduced form. Using iron requires separating and melting the reduced iron particles. The conduction properties of iron could be significant if it is used as rails and a small amount of current is conducted along the path of the rails. --Farred 23:00, 23 March 2009 (UTC)

The availability of metals on Luna

Recent edits about where iron and silver are found on the moon introduced an important question. However the availability on the moon is best addressed in the main article of each metal considered as a conductor. There is a link to the main article in each case. I have addressed the question somewhat and will see to proper organization later.