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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Dear RASMB’er,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Here are a few questions regarding our XL-I.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Question 1:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>On the laser tube it reads for the wavelength of the laser
675 nm. Since we have a new computer the reported wavelength for the recorded
scans is 655 nm (before it was 660 nm!?). Why are these different and how can
we change or set this back to 675 nm?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Question 2:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>If I set up the laser (delay and duration) and check the
magnitude versus pixels per fringe (see attachment) I often get a pretty smooth
curve but with a kink half way, just before the maximum. Is it very important
to obtain a completely smooth curve? Adjusting the laser delay, the kink can be
minimized but usually doesn’t disappear completely.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Question 3:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>The rotor is driven by three coils underneath the rotor
chamber that produce a (alternating?) magnetic field(s). Since I measured the
sedimentation velocity of magnetic particles I would like to raise the following
question: can somebody provide me information on how strong this magnetic field
is (or better: how strong is the magnetic field that the sample sector of a
standard d.s. centerpiece experiences?) and how the magnetic field lines in the
rotor chamber and in the sample sector of a standard d.s. centerpiece look like?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Thank you in advance for your answer(s) (and time),<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Kind regards, Karel Planken.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>K. L. Planken</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Van 't Hoff Laboratory for Physical and Colloid Chemistry</span></font><o:p></o:p></p>
<p class=MsoNormal><st1:place w:st="on"><st1:PlaceName w:st="on"><font size=2
face=Arial><span style='font-size:10.0pt;font-family:Arial'>Utrecht</span></font></st1:PlaceName><font
size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'> <st1:PlaceType
w:st="on">University</st1:PlaceType></span></font></st1:place><o:p></o:p></p>
<p class=MsoNormal><st1:PlaceType w:st="on"></st1:PlaceType><st1:place w:st="on"></st1:place><font
size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>H.R.
Kruytgebouw</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Padualaan 8</span></font><font size=2 face=Verdana><span
style='font-size:10.0pt;font-family:Verdana'><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>3584 CH <st1:City w:st="on">Utrecht</st1:City>, The <st1:place
w:st="on"><st1:country-region w:st="on">Netherlands</st1:country-region></st1:place></span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Phone: +31-30-253 2888</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Fax: +31-30-253 3870</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><a
href="http://www.chem.uu.nl/fcc/www/peopleindex/karel/karel.htm">Please visit
my webpage!</a></span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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