Segregation phase

Director, Corporate Engineering Division A. E. Staley Manufacturing Company Decatur, Illinois 

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HT motors must be provided with phase-segregated terminal boxes as illustrated in Figure 7.17. 

For large motors, 1000 kW and above, if they are provided with star windings the three neutral end leads must be connected to a separate terminal box to enable mounting of CTs for differential protection. The neutral terminal box need not be phase segregated. 

The two generic terms found in the blend literature are compatibility and miscibility. Components that resist gross phase segregation and/or give desirable blend properties are frequently said to have a degree of compatibility even though in a thermodynamic sense they are not miscible. In the case of immiscible systems, the overall physicomechanical behavior depends critically... 

The aim of the present communication is to apply the ASR-orbital peeling method for the study of phase ordering in PdV alloys and phase segregation in PdRh alloys. 

Some films containing deposited nickel together with copper were annealed at 500°C in order to ensure the homogenization of the alloys. After their cooling down to room temperature the X-ray diffraction patterns demonstrated phase segregation of the alloys similar to that described by Sachtler et al. (45). 

In the particular case of nickel-copper alloys their hydrogen pretreatment may result in phase segregation (48), at least at the surface. The desegregated rich in nickel alloy can display its relatively high catalytic quality and even keep it down to a certain temperature (lower than in the case of nickel itself), which would be the critical temperature of a given Ni-Cu-H system. 

Unlike the heterostructures whose periodic structure must be accurately controlled, the formation of nanocomposite structure is self-organized based upon thermodynamically driven spinodal phase segregation [118-121]. For the CVD... 

Tailoring block copolymers with three or more distinct type of blocks creates more exciting possibilities of exquisite self-assembly. The possible combination of block sequence, composition, and block molecular weight provides an enormous space for the creation of new morphologies. In multiblock copolymer with selective solvents, the dramatic expansion of parameter space poses both experimental and theoretical challenges. However, there has been very limited systematic research on the phase behavior of triblock copolymers and triblock copolymer-containing selective solvents. In the future an important aspect in the fabrication of nanomaterials by bottom-up approach would be to understand, control, and manipulate the self-assembly of phase-segregated system and to know how the selective solvent present affects the phase behavior and structure offered by amphiphilic block copolymers. 

The new phases were discovered by the combination of exploratory synthesis and a phase compatibility study. As commonly practised, the new studies were initially made through the chemical modification of a known phase. Inclusion of salt in some cases is incidental, and the formation of mixed-framework structures can be considered a result of phase segregation (for the lack of a better term) between chemically dissimilar covalent oxide lattices and space-filling, charge-compensating salts. Limited-phase compatibility studies were performed around the region where thermodynamically stable phases were discovered. Thus far, we have enjoyed much success in isolating new salt-inclusion solids via exploratory synthesis. 

Deposition of adamantane from petroleum streams is associated with phase transitions resulting from changes in temperature, pressure, and/or composition of reservoir fluid. Generally, these phase transitions result in a solid phase from a gas or a liquid petroleum fluid. Deposition problems are particularly cumbersome when the fluid stream is dry (i.e., low LPG content in the stream). Phase segregation of solids takes place when the fluid is cooled and/or depressurized. In a wet reservoir fluid (i.e., high LPG content in the stream) the diamondoids partition into the LPG-rich phase and the gas phase. Deposition of diamondoids from a wet reservoir fluid is not as problematic as in the case of dry streams [74, 75]. 

Other defects should be considered, such as uniform strain, which causes isotropic contraction/expan-sion of the cell giving rise to diffraction line shifts (but not broadening), chemical and/or phase segregation and... 

Since nanoscale metal nanoparticles are applicable to a number of areas of technological importance, the nano-structured materials chemistry will occupy much attention of scientists. It is certain that controlling the primary structures of metal nanoparticles, that is, size, shape, crystal structure, composition, and phase-segregation manner is still most important, because these structures dominate the physical and chemical properties of metal nanoparticles. Now the liquid phase synthesis facilitates the precise control of the primary structures. 

Triblock copolymers, as shown in Fig. 5.8 d), comprise a central homopolymer block of one type, the ends of which are attached to homopolymer chains of another type. As with other block copolymers, the components of triblocks may be compatible or incompatible, which will strongly influence their properties. Of particular interest are triblocks with incompatible sequences, the middle block of which is rubbery, and the end blocks of which are glassy and form the minor phase. When such polymers phase-segregate, it is possible for the end blocks of a single molecule to be incorporated into separate domains. Thus, a number of rubbery mid-block chains connect the glassy phases to one another. These materials display rubber-like properties, with the glassy domains acting as physical crosslinks. Examples of such materials are polystyrene/isoprene/polystyrene and polystyrene/polybutadiene/polystyrene triblock copolymers. 

In this chapter we have discussed the thermodynamic formation of blends and their behavior. Both miscible and immiscible blends can be created to provide a balance of physical properties based on the individual polymers. The appropriate choice of the blend components can create polymeric materials with excellent properties. On the down side, their manufacture can be rather tricky due to rheological and thermodynamic considerations. In addition, they can experience issues with stability after manufacture due to phase segregation and phase growth. Despite these complications, they offer polymer engineers and material scientists a broad array of materials to meet many demanding application needs. 

These results show that, even in an alloy system where no phase segregation is expected, a variation in preferred orientation in alloy films of... 

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