Phase change effects

The temperature distribution has a characteristic maximum within the liquid domain, which is located in the vicinity of the evaporation front. Such a maximum results from two opposite factors (1) heat transfer from the hot wall to the liquid, and (2) heat removal due to the liquid evaporation at the evaporation front. The pressure drops monotonically in both domains and there is a pressure jump at the evaporation front due to the surface tension and phase change effect on the liquid-vapor interface. 

Cholesteric-Nematic Phase Change Effect (CNPC)... 

Figure 3.3 Schematic representation of a cholesteric-nematic phase-change effect (CNPC) LCD. ...

The first prototype GH-LCDs based on the chiral nematic phase change effect investigated initially by White and Taylor also used indophenol dyes. 

Analysis of the electro-optical characteristics of GH-LCDs showed that for all types of guest-host chiral nematic phase change effects the contrast is greatest when... 

In a detersive system containing a dilute surfactant solution and a substrate bearing a solid polar soil, the first effect is adsorption of surfactant at the soil-bath interface. This adsorption is equivalent to the formation of a thin layer of relatively concentrated surfactant solution at the interface, which is continuously renewable and can penetrate the soil phase. Osmotic flow of water and the extrusion of myelin forms follows the penetration, with ultimate formation of an equilibrium phase. This equilibrium phase may be microemulsion rather than liquid crystalline, but in any event it is fluid and flushable from the substrate surface. This phase change effect explains the detersive behavior of sucrose fatty esters in admixture with alkylarenesulfonates (117). 

Display devices can also be constructed using the field effect, the cholesteric memory effect and the cholesteric-nematic phase change effect [259, 262]. The recognition of the useful electro-optical properties of liquid crystals has stimulated efforts in synthesis of new mesomorphic materials. Today, more than 6000 compounds are available but an ideal liquid crystal is still elusive. 

E.P. Raynes, Cholesteric texture and phase change effects, in A.R. Kmetz and... 

Emphasis has been placed on nematic materials because of the predominance of the twisted nematic effect in display devices. However, its disadvantages have caused considerable interest in the cholesteric-nematic phase change effect and the dye-phase change device in particular.61>62... 

Results with and without phase change for the cell operates at nominal current density of 1.4 A/cm are discussed in this section. The selection of relatively high current density is due to illustrate the phase change effects, where it becomes clearly apparent between single and multi-phase model in the mass transport limited region. 

It is desirable from many aspects to examine those coatings in coated and laminated structures which are able to contribute to properties other than strength and barrier. The polymeric components in these structures could be provided with smart functions such as shape-memory and phase-change effects. During the past few years, some interesting developments have taken place with regard to smart... 

Vafai, K., and Tien, H.C., Numerical investigation of phase change effects in porous materials, Int. J. Heat Mass Transfer, 32(7), 1261 -1278 (1989). 

Other dichroic display types to improve the viewing angle of standard TN-cells can be found in the literature. The most popular are dichroic phase change effect displays or White-Taylor mode displays [21 ] and Heil-meier type dichroic LCDs [20, 22, 23]. 

Some polymer electrolytes show conductivity temperature dependence that falls outside the three types described above, with neither the Arrhenius law nor the VTF (or WLF) law being followed in the temperature ranges studied." Here, if there are no phase changes, effects associated with ionic aggregate equilibria are likely, superimposed on the simple variation in ionic mobility. In all cases, it is important to consider not only this parameter, but also the number and types of charge carriers, which are influenced by the ionic association that probably exists in ionic transport. ... 

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