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<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=224473614-03042007>Hi Kurt,</SPAN></FONT></DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=224473614-03042007></SPAN></FONT> </DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=224473614-03042007>yes indeed the short waves of cellphones and similar
stuff does need a much finer mesh. in fact you can see the mesh in the door of a
microwave to get a good indication of the size needed for such frequencies. i
think cellphones operate on quite similar wavelenths as microwaves. i guess the
normal rebar mesh does give a nice shielding for the 50hz
noise.</SPAN></FONT></DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=224473614-03042007>About the magnetism yes the sources you mention are
right. I'm curious 2 hear more of what the effects of it would be. Roughly my
gutfeeling tells me that its an order less of a problem then all the EM waves
we're dealing with on a daily basis. But of course its never wrong to minimise
the amount of steel. if for the energy that was needed for the production.
</SPAN></FONT></DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=224473614-03042007></SPAN></FONT> </DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=224473614-03042007>Bye</SPAN></FONT></DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=224473614-03042007></SPAN></FONT> </DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=224473614-03042007>Joost</SPAN></FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2></FONT><BR> </DIV>
<DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left>
<HR tabIndex=-1>
<FONT face=Tahoma size=2><B>From:</B> strawbale-bounces@amper....muni.cz
[mailto:strawbale-bounces@amper....muni.cz] <B>On Behalf Of </B>Kurt
Splittdorf<BR><B>Sent:</B> dinsdag 3 april 2007 15:47<BR><B>To:</B> European
strawbale building discussions<BR><B>Subject:</B> Re: [Strawbale] Concrete Base
- foundations question??<BR></FONT><BR></DIV>
<DIV></DIV>
<P>Hi Joost, </P>
<P>it is part of my job, so i know some about the "E-smog", that is the way we
call it in germany. </P>
<P>you can demagnetise iron, but it is complicatet and expensiv! </P>
<P>The iron is like a permant magnet, the magnetismen will be there for a very
long time. it gets usaly magnetised during the production process or when you
weld the iron. </P>
<P>It does shield off electro magnetic radiation, but this effect depends on the
mesh width. And the way we use the steel in concrete it has no efect at all!!!
It only keeps the very long waves out of the house. I just want to name the
Schumann-Frequenz, it is about 8 Hz. If we talk about mobiles than it is totaly
worthless! the waves are to small. the higher the frequence is that you want to
shield off, the smaller the mesh width need to be. </P>
<P>The good results in reduction of EMF is because of the mass of the concrete.
</P>
<P>But you dont need a lot of iron for a strawbale house, only in the
foundations we use a lot of it. </P>
<P>i suppose: </P>
<P>minimize the iron </P>
<P>if you habe a problem.... demagnetise or keep distance </P>
<P>kurt </P><BR><BR><BR>
<P><FONT face=Arial color=#000ff0 size=2>Hi Kurt,</FONT> </P>
<P> </P>
<P><FONT face=Arial color=#000ff0 size=2>what i know is that if a steel ship is
moored for a long time (a year or so) in the same direction it gets
magnetised in the same direction as the earth magnetic field. To let the
compasses work well the ships then need to be demagnetised. So parallel i guess
that the steel in concrete will also adapt to the local magnetic fields and over
time, like a cameleon, have the same properties as the land beneath.</FONT> </P>
<P><FONT face=Arial color=#000ff0 size=2>The good thing of steel is that it does
shield off lots of electro magnetic radiation. so for that reason i might rather
use some steel in my straw walls rather then to be afraid of magnetic
disturbances. However i'm not very experienced with devining and i'm sure a
sourcer can tell you more about this</FONT> </P>
<P> </P>
<P><FONT face=Arial color=#000ff0 size=2>bye</FONT> </P>
<P> </P>
<P><FONT face=Arial color=#000ff0 size=2>Joost Brand </FONT></P></BODY></HTML>