Green state, mechanical properties

The concept of the fibre saturation point cannot be over emphasized. Its importance lies in the fact that the manner in which water is held is different in the adsorbed and absorbed states. The fact that the absorbed water can be removed before stripping off the adsorbed water indicates that a distinction can be made between these two states of sorption. For example, when green wood is dried there is no appreciable change in its mechanical properties until the fibre saturation point is reached. Below this moisture content they increase almost linearly with any further decrease in moisture content. Furthermore, wood only shrinks when the adsorbed water is removed from the cell walls. 

MECHANICAL PROPERTIES OF FILLED RUBBERS 8.5.1 Mechanical Properties in Green State... 

Solid-state lasers are based on a wide variety of materials. All of these materials are conceptually similar, however, in that a laser-active impurity ion is incorporated into the solid material, referred to as the host. In nearly all cases of interest to us, the host is an ionic solid (e.g., MgO), and the impurity carries a positive charge (e.g., NP+). As a simple illustration of this situation, a two-dimensional view of the MgO Ni system is pictured in Fig. 2. Here, a small fraction of the Mg + sites are substituted by ions. While the pure MgO crystal is clear, the NiO doping leads to green coloration. It is the impurity ions that are responsible for the laser action. The host medium nevertheless profoundly affects the electronic structure of the impurity and is, of course, responsible for the bulk optical, thermal, and mechanical properties of the laser medium. 

Davies, G.R. and Ward, I.M. (1988) Structure and properties of oriented thermotropic liquid crystal polymers in the solid state, in High Modulus Polymers (eds A.E. Zachariades and R.S. Porter), Marcel Dekker, New York, Chap. 2 Troughton, M.J., Davies, G.R. and Ward, I.M. (1989) Dynamic mechanical properties of random copolyesters of 4-hydroxybenzoic acid and 2-hydroxy 6-naphthoic acid. Polymer, 30, 58 Green, D.I., Unwin, A.P., Davies, G.R. and Ward, I.M. (1990) An aggregate model for random liquid crystalline copolyesters. Polymer, 31, 579. 

Fig. 10 Mechanical properties of polymeric hydrogels based on catechol-functiomalized PEG at different pH and comparison of a chemical and a physictil hydrogel, assessed by their elastic (GO and viscous (G O shear moduli, a Frequency-dependent loss (G") and storage (GO moduli of gels at pH 5 (green), pH 8 (blue), and pH 12 (red) (C circles-, G" triangles), b Comparison of physically (red) and chemically (black) crosslinked hydrogels, c Recovery of stiffness and cohesiveness after tearing by shear stress (same color code as in b). Modified from Waite et al. [121]. Copyright 2011 National Academy of Sciences of the United States...

In sintering, the green compact is placed on a wide-mesh belt and slowly moves through a controlled atmosphere furnace (Fig. 3). The parts are heated to below the melting point of the base metal, held at the sintering temperature, and cooled. Basically a solid-state process, sintering transforms mechanical bonds, ie, contact points, between the powder particles in the compact into metallurgical bonds which provide the primary functional properties of the part. 

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