Amorphous cores

When pea seed apoferritin is reconstituted in vitro in the absence of phosphate, the reconstituted mineral core consists of crystalline ferrihydrite (Rohrer et ah,1990 Wade et ah, 1993 Waldo et ah, 1995). Conversely, horse spleen ferritin reconstituted in the presence of phosphate produces an amorphous core (Rohrer et ah,1990 St. Pierre et ah, 1996)... 

There are a variety of types of ferritin nonheme iron core, ranging from the highly ordered cores of horse spleen ferritin to the amorphous cores of bacterioferritins. As noted... 

Reconstitution experiments with apoferritins from animal and bacterial sources, whose native iron-loaded ferritins had crystalline and amorphous cores respectively, have been informative in showing that the core morphology is not determined by the protein shell. For example, Baaghil et al and Mann etalP were able to form crystalline cores in bacterioferritins, and Rohrer formed cores of iron-... 

These are experimentally determined values for polydisperse preparations of the holoferritins. a, Amorphous core c, crystalline core Ic, core of limited crystallinity. 

We can consider spending some more money and avail ourselves of magnetic materials like amorphous cores or Kool Mu if we want to achieve higher inductance (with higher saturation flux densities), in a smaller size. 

The acid sensitive photoinitiator Lucirin TPO could effectively be shielded from an acidic environment by encapsulating it into PMMA or PBA-co-PMMA particles [173]. The hybrid particles show a core-shell morphology (Fig. 16c) which is generated by phase separation during the polymerization process. While the photoinitiator is readily soluble in the monomer(s), it becomes insoluble in the polymer. Therefore, Lucirin TPO precipitates during the polymerization and forms an amorphous core surrounded by a polymeric shell. The encapsulation efficiency was determined as about 90%. 

Cui U, Ruffo R. Chan CK. Peng HL. Cui Y (2009) Crystalline-amorphous core-shell silicon nanowires for high capacity and high current battery electrodes. Nano Lett 9 491-495. doi 10.1021/ nl8036323... 

Fig. 7. Example of contrast matching between different domains of a diblock copolymer two-dimensional micelle (crystalline-amorphous core-brush morphology) and solvent by modification of the solvent scattering length density the full contrast, core contrast and brush contrast (from left to right) can be adjusted.

As shown in Figure 9.12, an increase in the packing pressure produces a considerable enlargement of the amorphous core layer. Equivalently, a reduction in the molding temperature produces a thickening of all the amorphous layers, with particular effect on the skin layer. The situation is further influenced by the stress-induced crystallization. 

Figure 3. Scanning electron micrograph of the core of a deposit produced in a Kratschmer generator. The outer shell, consisting of tropostratic graphite, has been removed. The amorphous core material contains up to 50% multiple-wall CNT.

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