Uniform composition, line

For the disordered (A2) phases, rjeq = 0, Eq. 17.19 is satisfied automatically, and equilibrium tie-lines are present if W < 0 and T < Tcrit = W/k, as illustrated in Fig. 17.5. In the nearest-neighbor model, ordered B2 solutions can appear at any uniform composition Xb Nonzero equilibrium structural order parameters appear only if W > 0 at temperatures T satisfying... 

We are now in a position to study the series of states of uniform composition which are obtained when T,p and a 2 all vary simultaneously. These three variables are always related by the two equatoms (28.17) it follows therefore that only one of them can be varied independently, so that the states of uniform composition fall on a line called the azeotropic line. The differential relations which this line must satisfy are examined below. ... 

We recall that an equilibrium displacement of a two-phase binary system must satisfy equations (18.44) however, at all points along the line of uniform composition... 

We note that in a non-reacting two-phase system, the indifferent line is simply the line of uniform composition. 

The lines of coexistence AaEcB and AbEdB correspond to the curves rViPwiW, qq otupi and the point of uniform composition E corresponds to the indifferent system aej8. 

Viscosity and the Power-Law Index of Wood-Plastic Composite Materials Let us consider in more detail how fillers tend to make the system more shear thinning, that is, to decrease the power-law index. At lower shear rates or frequencies, neat plastics often exhibit a Newtonian plateau, that is, a higher apparent power-law index, and in the presence of fillers, the plateau often turns upward or even disappears. In other words, the addition of filler often makes the power-law plot more steep, that is, shifts it to a more uniform straight line dependence of viscosity verses shear rate (or frequency). 

To attain uniform composition and improved formability, the blended raw materials are fuUy kneaded. The forming of the mixture is carried out using a roll-molding machine at normal temperatures and under approximately 1000 kg/cm (300-500 kg/cm ) of line pressure. 

It is assumed here that solidification is being carried out as a series of equilibrium states in which the solid continually adjusts through solid-state diffusion to the value corresponding to the intersection of the tie-line with the solidus. Eventually as the temperature falls to T3, the final solid will have a uniform composition equal to the starting value. 

Some special requirements of continuous systems are (1) Metering the feed. A continuous system must be fed at a precise, uniform rate. (See Sec. 21.) (2) Dust collection. This is a necessary part of most diy-processing systems. Filters are available that can effectively remove dust down to 10 mg/m or less, and operate automatically. (Dust collection is covered in Sec. 17.) (3) Ondine analysis. For more precise operation, on-line analysis of product particle size and composition may be desirable. (4) Computer control. SiiTuilation can aid in optimizing system design and computer control. 

The test gas must be of uniform and known composition. This generally requires on-line gas analysis if flammable mixtures are not supplied from a suitable reservoir. If concentration gradients are created in the surrounding air, errors can be introduced by releasing the test gas stream from a perforated probe doubling as an electrode. The maximum effective energy of a... 

The foregoing are volume integrals evaluated over the entire volume of the rigid body and dw is an infinitesimal element of weight. If the body is of uniform density, then the center of gravity is also called the centroid. Centroids of common lines, areas, and volumes are shown in Tables 2-1, 2-2, and 2-3. For a composite body made up of elementary shapes with known centroids and known weights the center of gravity can be found from... 

The effect of these small cracks is to concentrate the stress at localised points within the specimen. Figure 7.4 illustrates how this happens, using lines to indicate the stress distribution in the sample. For the unnotched specimen, (a), the stress is uniformly distributed throughout the material. However, for the notched specimen, (b), the lines of stress can be seen to converge at the notch tip, this giving a local stress greater than the apparent applied stress. When this happens, the breaking stress, will occur in the material at an actual stress somewhat less than this. As a result, the material as a whole is weaker than predicted on the basis of is chemical composition. 

The diffraction lines due to the crystalline phases in the samples are modeled using the unit cell symmetry and size, in order to determine the Bragg peak positions 0q. Peak intensities (peak areas) are calculated according to the structure factors Fo (which depend on the unit cell composition, the atomic positions and the thermal factors). Peak shapes are described by some profile functions 0(2fi—2fio) (usually pseudo-Voigt and Pearson VII). Effects due to instrumental aberrations, uniform strain and preferred orientations and anisotropic broadening can be taken into account. 

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