Hysteresis area

In Figure 10, the ir-A curves, both experimental and theoretical, of the initial compression are plotted. We found good agreement with monolayer 30-16-1-13 (curves (a) and (a )) where the absolute value of q is small and the hysteresis areas of the... 

The effect of pore impregnation with nonpolar material was studied by treating samples with dichlorodimethylsilane (DCDMS). In each case a decrease in hysteresis area, compared to the untreated material, was observed after coating samples with DCDMS. The increases in the extrusion contact angle, with DCDMS compared to untreated sample, resulted in decreases in W q. In some cases impregnation with DCDMS led to greater mercury retention or an increase in IF, over the untreated material. However, this was always accompanied by a larger decrease in and thus a decrease in the pore potential. 

Another surface parameter of interest is the hysteresis area (AG), which is indicative of energy trapped in a monolayer. The hysteresis area is the difference between the free energy of compression and free energy of expansion which is calculated from the area under corresponding surface pressure - area isotherms. 

Figure 19.32. Hysteresis area depending on UHT temperature and cooling step temperature (Sedlmeyer and Kulozik 2006).

Carstensen JT, Marty JP, Puisieux F, Fessi H. Bonding mechanisms and hysteresis areas in compression cycle plots. J Pharm Sci 1981 70 222-223. 

It should be noted that the range of relative equilibrium pressure in the hysteresis area is the same for both isotherms, whereas the amounts adsorbed are significantly different. 

Furthermore, the mechanism of adsorption of the nonpolar hydrocarbon (benzene) and polar adsorbate (water) on active carbon differs greatly. This difference is well represented in Fig. 6.3. In particular, the curves in Fig. 6.3 show that the hysteresis area of benzene corresponds to the adsorption in mesopores, and results from capillary condensation, whereas the hysteresis area of water corresponds to the adsorption in micropores, and thus cannot result from capillary condensation. Dispersion interaction, plays a dominant role in the case of benzene, but is not significant for water. The main mechanism of water adsorption by carbonaceous adsorbents includes the formation of hydrogen bounds... 

These hysteresis areas are found at die limit of die normal and abnormal regions, and exhibit a typical wedge shape that vanishes as SAD = 0. From the practical point of view of emulsion making these features are quite useful. For instance, by starting in a normal A region and increas-... 

FIGURE 4.10 Suifece area A, versus surface tension lung surfactant. There is a hysteresis area and mean slope or compliance to the curve compare to Fig. 4.7. 

Figure 2b shows the normal force (i.e., applied load) versus tip—sample distance curves for pH values of 4 and 8.5. The change in adhesion hysteresis (area enclosed by... 

The Mullins effect, which can be considered as a hysteretic mechanism related to energy dissipated by the material during deformation, corresponds to a decrease in the number of elastically effective network chains. It results from chains that reach their limit of extensibility by strain amplification effects caused by the inclusion of undeformable filler particles [24,25]. Stress-softening in filled rubbers has been associated with the rupture properties and a quantitative relationship between total hysteresis (area between the first extension and the first release curves in the first extension cycle) and the enei-gy required for rupture has been derived [26,27]. 

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