Self-supporting filaments

The concentrated polyelectrolyte inks rapidly coagulate to yield self-supporting filaments (or rods) upon deposition into an alcohol/water reservoir (Figure 6.3a and b). The exact coagulation mechanism, driven by electrostatics in water-rich or solvent quality effects in alcohol-rich reservoirs, as well as the magnitude of ink elasticity depends strongly on reservoir composition [15]. As shown in Figure 6.4b, the PAA/PEI ink ([COONa]/[NHJ = 5.7) exhibits a dramatic rise in ink elasticity from... 

The surface area of the red cell is approximately 140 p,m, which is greater than the surface of a sphere needed to enclose the contents of the red cell (98 p,m ). The presence of this extra membrane and the cytoskeleton that supports it allows the red cell to be stretched and deformed by mechanical stresses as the cell passes through narrow vascular beds. On the cytoplasmic side of the membrane, proteins form a two-dimensional lattice that gives the red cell its flexibility (Fig. 44.10). The major proteins are spectrin, actin, band 4.1, band 4.2, and ankyrin. Spectrin, the major protein, is a heterodimer composed of a and (3 subunits wound around each other. The dimers self-associate at the heads. At the opposite end of the spectrin dimers, actin and band 4.1 bind near to each other. Multiple spectrins can bind to each actin filament, resulting in a branched membrane cytoskeleton. 

The method described here for the manufacture of an aluminum-stabilized multifilamentary superconductor is essentially a two-step process, as illustrated in Fig. 1. First, a composite of multifilamentary NbTi embedded in an aluminum alloy (1100 Al or 6061 Al) matrix is prepared in the usual manner. The extruded NbTi-Al alloy composite is then inserted into a high-purity Al tube, and the whole composite is drawn in a Cu jacket. In this way, the high-strength NbTi filaments are supported in a stronger and work-hardenable Al matrix. As far as the softer, self-annealing pure Al is concerned, the center core, i.e., the NbTi-Al composite, can be considered as a unit, such as a NbTi monofilament. The whole composite can be reduced without localized nonhomogeneous deformation. 

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