Depth hysteresis

Neither frictional anisotropy nor depth hysteresis was observed for sliding perpendicular to the column tilt axis. However, sliding with and against the column tilt axis results in a measurable friction anisotropy as well as depth hysteresis. In contrast, planar films do not show either frictional anisotropy or depth hysteresis [115]. 

Sorbed pesticides are not available for transport, but if water having lower pesticide concentration moves through the soil layer, pesticide is desorbed from the soil surface until a new equiUbrium is reached. Thus, the kinetics of sorption and desorption relative to the water conductivity rates determine the actual rate of pesticide transport. At high rates of water flow, chances are greater that sorption and desorption reactions may not reach equihbrium (64). NonequiUbrium models may describe sorption and desorption better under these circumstances. The prediction of herbicide concentration in the soil solution is further compHcated by hysteresis in the sorption—desorption isotherms. Both sorption and dispersion contribute to the substantial retention of herbicide found behind the initial front in typical breakthrough curves and to the depth distribution of residues. 

Because these analysers do not employ magnets, peak switching for selected ion monitoring can be done more quickly without hysteresis effects, which makes this system ideal for depth profiling, where it is necessary constantly to switch among masses. These instruments do have the disadvantage of loss of transmission and mass... 

FIG. 6.10 Contact angle hysteresis (a) weighing a meniscus in a Wilhelmy plate experiment versus the depth of immersion of the plate (b) both the advancing and receding contact angles are equal (c) 6a > dr. 

Figure 9.12 contains sketches for several different models of pores that will be useful in our discussion of capillary condensation. Figure 9.12a is the simplest, attributing the entire effect just described to variations in pore radius with the depth of the pore. That is, when liquid first begins to condense in the pore, the larger radius Ra determines the pressure at which the adsorption-condensation occurs. Once the pore has been filled and the desorption-evaporation branch is being studied, the smaller radius Rd determines the equilibrium pressure. Although bottlenecked pores of this sort may exist in some cases, this model seems far too specialized to account for the widespread occurrence of hysteresis. 

Intrinsic hysteresis is a direct result of surface configuration change, which occurs as a result of wetting the surface with water. The plates were purposely immersed to a deeper immersion depth in the second cycle to observe the extent of intrinsic hysteresis. Significant surface configuration change affects the calculated contact angles on immersion and emersion, which violates the assumption of... 

The plot of Fig. 7 is made against the maximum depth reached by the seal. For cases C-G this is the present depth for cases A, B, M, and N this was the depth at 85 myrbp. The maximum depth of the seal has been chosen as the control on the permeabilities because a body of rock salt once exposed to a pres-sure/temperature regime largely keeps the petrophysical properties acquired at that time even if subsequently discharged and cooled due to tectonic uplift (permeability hysteresis see Borgmeier and Weber,... 

FKi. 22. Hysteresis loop in the cyelie n tnoindcmution of Si (maximum loud 70 niNj in the average eoniact pressure vxeoniiiei depth eoordinuies. 

Transparent ferroelectric single crystals are traditionally used for electro-optic applications. Since the optical transparency was first discovered in lead-lanthanum-zirconate-titanate (PLZT), ferroelectric ceramics have been investigated in great depth such that, today, their characteristics allow them to compete with single crystals for certain electro-optic applications. The electro-optic properties of PLZT compositions are intimately related to their ferroelectric properties. Variations in ferroelectric polarization with an electric field, such as in a hysteresis loop, also affect the optical properties of the material. 

Fig. 11.10. Relationship between depth of immersion and force (a) no hysteresis (b) hysteresis present.

Sakai and co-workers have investigated the GCs produced by different densifi-cation processes using a Vickers indenter. The indentation hysteresis behavior was found on curves of indentation load versus indentation depth for all indentation loads from 10 to 500 N. For GCs, it was also observed that ring/cone cracks were induced by Vickers indentation instead of the median/radial crack systems more usually observed in brittle materials under a sharp indenter. A superior feature of GCs compared to ordinary brittle ceramics is their resistance to strength degradation by contact with hard particles as demonstrated by anomalous ring/cone crack formation. 

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