Magnet iron-core

Figure 20.1 Mutually coupling and leakage fluxes in coils that share a common magnetic iron core.

For the theory of neutralization of the magnetic effect on the conductor in a non-magnetic shielding, refer to the continuous enclosures for isolated phase bus systems discussed in Section 31.2.2. As a result of non-magnetic shielding there will be no saturation of the iron core and the V-I characteristic of the reactor will remain almost linear. 

Unlike an air core, the inductor coil now has an iron core that may be provided with air gaps or non-magnetic... 

Similarly, gapped iron core reactors as shown in Figure 27.4, in which the iron core content is reduced by providing an air gap or non-magnetic material between the core laminations, also raise the saturation level (the core remaining unsaturated. Figure 27.1 I) to help provide an... 

Coreless, gapped iron core or / with magnetic shielding ... 

American physicist Joseph Henry develops a coil magnet that grows stronger as more wire is wound around an iron core. He succeeds in lifting more than a ton of metal. Thermostat is invented. 

FIGURE 6.3 Sequence developing chamber by Buncak 1 — support with mobile phase source (reservoir), 2 — holding frame, 3 — magnet holder, 4 — magnet, 5 — cover plate, 6 — TLC plate, 7 — wick with iron core, 8 — solvent entry. (From Buncak, P., GIT Fachz. Lab. (Suppl., Chromatographie), G-I-T-Verlag, Darmstadt, 3-8, 1982. With permission.)... 

Magnetic (iron oxide core) microspheres have been imprinted with S-pro-pranolol. The magnetism allowed the facile separation of the imprinted beads from the liquid matrix. The particles exhibited the expected affinity towards the template molecule. This technique was also proposed as a putative tool for cell sorting [81]. 

Graft polymerization of monomers such as acrylic acid on core particles consisting of magnetic iron oxide embedded in cross-linked poly (vinyl alcohol) (PVA) has been described previously (2). 

There is a number of synthetic substitutes for natural ferritin and the properties of these have been compared with those of ferritin. The synthetic polysaccharide iron complex (PIC), has a magnetic blocking temperature of 48K (Mohie-Eldin et al. 1994). Iron-dextran complexes are used as a substitute for ferritin in the treatment of anaemia. The iron cores of these complexes consist not of ferrihydrite, but of very poorly crystalline akaganeite with magnetic blocking temperatures of between 150 and 290 K (Muller, 1967 Knight et al. 1999) which were lowered from 55K to 35 and 25K, if prepared in the presence of 0.250 and 0.284 Al/(A1 -i- Fe), respectively (Cheng et al.2001). 

A second form of storage iron is haemosiderin (Weir et al., 1984). This is deposited in humans as a response to the condition of iron overload. Haemosiderin forms as insoluble granules with electron dense cores surrounded by a protein shell. It exists in two forms primary haemosiderin is the result of iron overload due to excessive adsorption of iron in the gut, whereas the secondary form is caused by the numerous blood transfusions which are used to treat thallassaemia (a form of anaemia). Electron diffraction indicated that the iron core in primary haemosiderin is a 3-line ferrihydrite with magnetic hyperfine splitting only below 4 K and, in the secondary form, consists of poorly ordered goethite. As goethite is less soluble in ammonium oxalate buffer solution (pH 3) it has a lower intrinsic toxicity (Mann et al., 1988). 

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