Typical impurity content

Table HI. Typical Impurity Content of KTi0P04 and KTi0As04 Crystals Grown by the Flux and Hydrothermal Techniques (Parts Per Million by Weight)...

Because of the effects of impurity content and processing history, the mechanical properties of vanadium and vanadium alloys vary widely. The typical RT properties for pure vanadium and some of its alloys are hsted in Table 4. The effects of ahoy additions on the mechanical properties of vanadium have been studied and some ahoys that exhibit room-temperature tensile strengths of 1.2 GPa (175,000 psi) have strengths of up to ca 1000 MPa (145,000 psi) at 600°C. Beyond this temperature, most ahoys lose tensile strength rapidly. 

Fig. 2. Typical binary phase diagram for host and impurity, showing a constant distribution coefficient if impurity content is low. L = liquid composition after some solidification, a = B and small amount of A, /5 = A and small amount of B, = liquidus, and = solidus.

Neutral emission of species other than atomic Mg from MgO is a strong function of impurity content or microstructure (4). Samples with a cloudy appearance due to the presence of brucite (Mg(OH)2) precipitates, displayed especially high NE intensities of O2, CO, H2O, and CH4. The cloudy MgO is nominally as pure as the clear with respect to metallic impurities. Single crystals of MgO are often grown in an arc furnace, with water and carbon as minor impurities. Small amounts of brucite can precipitate in portions of the crystal mass. The precipitate/MgO interface can serve as a sink for many species which are then emitted as these interfaces are exposed in fracture. The cloudy MgO is more typical of geologic materials than clear MgO, implying that NE from geologic materials can be quite intense and rich. 

Careful attention has to be given to the purity of the precursors to avoid detrimental effects on conductivity. In a polycrystalline ceramic the conductivities of grain boundaries and bulk contribute to overall conductivity. In the case of polycrystalline YSZ, because of its unusually high intrinsic (bulk) conductivity the grain boundaries are far less conductive than the crystal, typically by a factor of 100. The effect the grain boundaries have on overall conductivity will depend on grain size and, of course, on impurity content (e.g. silica), since impurities tend to concentrate there. It is the effort to understand more of the various contributors to overall conductivity which has led to the application of impedance spectroscopy (see Section 2.7.5). 

Clinker belites typically contain 4-6% of impurity oxides, of which the chief ones are usually AI2O3 and Fe203. Correlations have been reported to exist between the MgO contents of belite and clinker (Kl), the Fe20, contents of belite and clinker (Kl), and the total impurity content of the belite and the MgO content of the clinker (B4). Early reports mention a compound KC23S,2, but the K2O content of 3.5% corresponding to this formula is well above those found in clinker belites, and recent electron optical work indicates that the limit of K2O substitution is about 1.2% (C1). 

As discussed in Section 9.1.2, reverse addition has been a time-honored method of producing small crystals. It typically suffers from broad size distribution and high impurity content (if present in the mother liquors) because of the excessive supersamration gradients encountered by the inlet solution. In the present example, the final product contained too much of an undesired impurity. This product will also be compared to that from the impinging jet operation in the discussion below. 

The impurity content of a WC powder is the result of three main factors (1) the purity content of the starting W powder (2) the impurity content of the carbon black or gaphite, and (3) the carburization temperature (the higher the temperature, the more die trace impurities are evaporated during carburization). A typical analysis is shown in Table 9.1. 

Color." The most obvious effect produced in silica gel by radiation is a grayish-purple color (64), which can be almost surely attributed to the same type of center as that responsible for the similar color in irradiated quartz, namely, a positive hole trapped at an oxygen ion adjacent to a substitutional Al + impurity ion (65-67). The attribution rests on the similarity in optical absorption between irradiated gel and irradiated quartz (66), on the dependence of the intensity of the color on the aluminum content (69), and on the observation of a hyperfine interaction characteristic of the spin of the 2 a1 nucleus (I = 5/2) in the ESR spectrum of the irradiated gel (70). Furthermore, the ESR sextet and the color are annealed at comparable rates above 200° (70) and are both destroyed by adsorption of H2 at room temperature (64, 70). Their intensities increase in parallel as the aluminum content, the severity of preirradiation heat treatment, or the length of irradiation is increased (70). The concentration of the center does not increase indefinitely. After some lO i ev/gm, it approaches a limiting value which depends on the impurity content, for typical gels around lO H2/gm (69). 

Typical test parameters for solutions and suspensions would include appearance, drug content, impurity levels, and pH. Although formal specifications are not usually applied, an analytical certificate will be provided that accurately describes the quality of the product administered. For animal feedstuffs, in addition to drug and impurity content, an important test parameter is uniformity of content throughout the mix. As for drug substance, in the absence of formal specifications, an evaluation of the suitability of the dosing product for its intended use is made by a similar team of relevant experts. 

Fig. 107. Schematic repiesentation of the electronic density of states in CeNiSn around the Fermi energy. Typical values (in K) are /) = 58, A = 23, W = 2 (Izawa et al. 1998). The height is strongjy dependent on impurity content.

More particular physical properties of nitric acid are given in handbooks [4,5]. Typical impurities in HNO3 originate frexn ammonia or the process. The standard bmite are the content of CI2- less than 5 ppmw, and HNO2 - less than 5 ppmw. 

The overall recovery efficiency, from vanadium trichloride to metal sponge, is 96 to 98 per cent. Typical vanadium and impurity contents are as follows ... 

Figure 14.7 Decrease in impurity content of 1.5 filter cake volumes suffice to remove the filter cake with the amount of washing liquid impurities stemming from adhering mother used for a displacement washing. The amount phase, is referenced to the filter cake volume. Typically,...

Aluminum oxide, also known as alumina, is the main component of bauxite, the principal ore of aluminum. The bauxite ore is made up of impure AI2O3, Fe203, and Si02. Typically, the content of AI2O3 in bauxite is about 40wt%. In the Bayer process, AI2O3 is dissolved in sodium hydroxide, then precipitates as Al(OH)3. 

Molecular ions are observed in spectra from rare earth metals with ion intensities similar to non-rare earth samples. Table 37C.2 lists typical intensity relationships observed in rare earth metal spectra for oxygen, fluorine, and carbon impurities and their associated matrix cluster ion intensities. Although the source of these ions relative to the solid sample has been studied by Muheim (1972, 1973), certain facets of their character remain clouded. Their intensities tend to be erratic and depend upon many parameters such as non-metallic impurity content, residual gas level in the spectrometer ion source chamber, contaminants on the surface of the metal sample, chemical environment, etc. The analytical usefulness of these cluster ion signals has not been established. 

In a typical air-supplied respirator, the quality of the air, impurity content and filter may not provide sufficient removal of material. One reason for this is the air temperature. When air is compressed it gets hot. and moisture or water vapor levels are raised, These problems can be eliminated for the most pan by passing the air tlirough air dryers, refrigerated air dryers or air purifiers. 

TABLE 10.6 Impurity Content of Typical Battery-Grade Zinc Powder... 

Table 1.2 Typical Interstitial Impurity Contents of Several Grades of Titanium...

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