Biology Reference
In-Depth Information
Table 1.
Results of Applying Magnetic Force in Addition to Magnetic Field
Position a
Experiment No.
Upper
Middle
Lower
Outside
1 H
6
10
6
0
H (grad H )
+400 c
0
−400
0
Resolution b
3.2
3.42
6.5
4.1
2 H
6
10
6
0
H (grad H )
+400
0
−400
0
Resolution
2.99
3.4
3.9
6
3 H
4.8
8
4.8
0
H (grad H )
+256
0
−256
0
Resolution
3.15
2.9
4.15
3.15
4 H
4.8
8
4.8
0
H (grad H )
+256
0
−256
0
Resolution
2.9
4.15
3.7
a Position means the three different positions (upper, middle, lower) where crystal growth took place
in a vertical bore of a superconducting magnet. At these places, a magnetic field H and a field, gra-
dient product H (grad H ) of the specified values are present. Outside means that the crystal growth
took place outside of the superconducting magnet, where H = 0.
b Resolution corresponds to the specific resolution values at which the S/N ratio = 2 using an oscilla-
tion photograph.
c The plus sign means that (grad H ) reduces on going upward; a diamagnetic substance receives an
upward magnetic force if the sign of H (grad H ) > 0. See the “Theoretical Background” section, p. 2, for
reasons and details.
thus obtained had a consistently better quality, as judged in this case
by the “modified or relative Wilson plot.” The reason was ascribed to con-
vection damping. The quality improvement was even considerably better
than in a case where crystals were grown in a homogeneous 15 T magnetic
field (Yin et al ., 2004), a situation where better crystals grew, as already
described, than without a magnetic field at all.
Yin and his colleagues (2008) recently grew the tetragonal form of
crystals of hen egg-white lysozyme in a completely floating droplet with-
out any support or container. Given the constant relative positions between
suspended crystals, it can be considered that no convection flow is
present in the levitated droplet. The quality of these crystals has not yet
been reported, as long as the present author is aware. Clearly, there is
 
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