Virgin states

To obtain the dynamic hysteresis loop of a ferroelectric capacitor the polarization is measured versus the applied voltage. Since the hysteresis is neither a linear nor a time invariant property, the hysteresis loop is dependent on the sample history and on the measurement method. To have a standardized and comparable hysteresis loop, certain parameters are commonly fixed. One is the absolute position of the loop on the polarization axis, since the initial (virgin) state of the polarization is unknown in almost all cases, the hysteresis loop is balanced to a reference value. Most commonly the positive and negative saturation polarization are set to... 

Figure 10. Composite differential distillation profiles for the 2% Cloisite filled system a virgin state and after 504 hours of aging. Solid, dashed and lines with circle symbols correspond to virgin, N2 aged and air aged samples respectively.

The silica-magnesia catalysts, DA-5 and Nalco, in the virgin state, along with Davison silica gel have practically their entire area and pore volume contributed by the very smallest of pores that are encountered in catalyst structures that is, pores in the 10 to 15 A. radius range. It is apparent in Fig. 2 that for these materials there is no appreciable adsorption at the high relative pressures. This indicates the absence of large pores. One and one-half monolayers according to the BET theory effectively fill the pore volume of the DA-5 and the Davison silica gel, and only two monolayers are required for Nalco. Very little hysteresis is observed for any of these three materials. 

Fig. 30. Potential energy wells for activated and interstate conversion in adsorbed layers, (a) Shows that the stable state is reached via an intermediate virgin state but passage to it is non-activated. (b) Shows the case where passage from one well to the next is activated.

Based on the yam volume description, the fibrous stmcture of the yarn, or, more generally, the fibrous stmcture of the unit cell, is described as follows. Consider a point P and the fibres in the vicinity of this point. The fibrous assembly can be characterised by physical and mechanical parameters of the fibres near the point (which are not necessarily the same in all points of the fabric), fibre volume fraction Vf and direction /of them. If the point does not lie inside a yam, then Ff = 0 and/is not defined. For a point inside a yam, fibrous properties are easily calculated, providing that the fibrous stmcture of the yam/ply in the virgin state is known and its dependency of local compression of the yarn/ply, bending and twisting of the yam are given. Searching the cross-sections of the yams, cross-sections S, = S(si) and S,+i =5 (s,+i) (s is a... 

With regard to the recyclability and reuse potential of PTFE in comparison to glass, every second interviewee perceived it to be much the same. Manufacturers have noted the ease of recyclability of all these materials that can all equally be returned back to their virgin state and recycled into new products. 

For certain chain polymers (e.g., cellulose), crystallised regions (so-called crystallites) are already present in the undeformed virgin state (see p. 619), but in other cases (e.g., rubber) they are formed during the stretching process. The molecules then become more and more oriented and are gradually forced into a crystalline lattice over certain parts of their length, which can be detected by means of X-rays (Fig. 14). 

Fig. 15. G c versus weight for polystyrene in the virgin state. Data of Robertson [76] M less than 40,000, ) and Wool and O Connor [13] ).

The dynamic flocculation model of stress softening and filler induced hysteresis assumes that the breakdown of filler clusters during the first deformation of the virgin samples is totally reversible, though the initial virgin state of filler-... 

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