Size, apparent

In addition to chemical analysis a number of physical and mechanical properties are employed to determine cemented carbide quaUty. Standard test methods employed by the iadustry for abrasive wear resistance, apparent grain size, apparent porosity, coercive force, compressive strength, density, fracture toughness, hardness, linear thermal expansion, magnetic permeabiUty, microstmcture, Poisson s ratio, transverse mpture strength, and Young s modulus are set forth by ASTM/ANSI and the ISO. 

The structure of SSZ-35 (IZA structure code STF) as viewed in the [001] direction is shown in Fig. 17. The dimensions of the 10-MR structures are 5.5 x 6.1 A and the diameter of the 18-MR structures is 12.5 x 9 A. This pore structure is in contrast to the structure of SSZ-44 (IZA structure code SFF) shown in Fig. 18, where the 10-MR structures are nearly spherical (5.8 A) and the 18-MR structures are slightly larger (12.9 x 9 A). These small differences in pore size apparently translate into startling differences in reactivity. A study of m-xylene conversion shows a high degree of isomerization versus disproportionation, which is consistent with a 10-MR pore system (47). The interesting data is the para to ortho selectivity in the isomerization products, where SSZ-44 exhibited a higher para/ortho... 

According to Ref 122a, p 123, values from 1100 to 2700 m/sec were observed for AN, depending on whether the detonation was incomplete or complete. Because of the insensitivity of AN its rate of detonation is affected by its particle size, apparent density, degree of confinement, efficiency of booster charge and temperature of charge. Increase in rate is brought about by decrease... 

When a CO in air stream is introduced in the reaction cell, for the range of conditions we have examined in this study (CO in air 0.4-3%, temperatures between 25-250°C), the behavior of the system is a function of its prior history. If the catalyst had been previously treated in a CO in N2 mixture,then the band at 1800 cm- -gradually disappears, the band at 2060 cm-- - decreases in size (a broadening of the 2060 cm-l band is also observed) while the band at 2120 cm- - increases in size apparently in expense of the bands at 2060 cm- - and 1800 cm- -. However, if a fresh catalyst (or a catalyst treated in N2) was used, then only the bands at 2120 cm- -and 2060 cm- - appear. It is conceivable, however, that for lower O2 concentrations similar to the ones used by Cutlip and Kenney [12], the band at 1800 cm- - might be present. This is currently under investigation. 

As discussed in Section 7.3, the optimization in chromatography proceeds as follows. From the discovery experiments the mobile-phase composition, particle size (apparent or nominal), the thermodynamic parameters and the Knox parameters are known. From the mobile-phase composition, the feed composition (simplify to a binary mixture, one impurity and the product), the viscosity can be estimated from data in the literature. The void fraction can be measured from the retention of unretained component (Eq. (7.24)), or estimated based on vendor information. The packing density is typically known by... 

Many more stories can be told in this regard. The chaimel structure of natural mordenite was not foreseen on the basis of sorption experiments because a relatively small number of blockages or dislocations quite adequately blocked the large charmels. In an experiment in my laboratory, sodium LTA failed completely to sorb tetrachloroethylene (both fully anhydrous) because of its size (The crystal structure of a single crystal in an atmosphere of ca 100 torr of C2CI4 for more than a week was exactly that of fully dehydrated LTA.) we should have honored a simple mechanical calculation of size apparently no alternative mechanism existed. In contrast, statements that Cs ions should not be able to enter sodalite cavities in LTA or FAU, have repeatedly been shown crystallographically to be incorrect such entry of Cs" " appears to occur both in the presence and absence of water. 

This series of the pores with various sizes apparently provide various potential strengths, but their excess potential energy relative to the fluid s solid state is commonly zero for these methane walls. Thus the results would not suffer from the complication by the enhancing effect, and the geometrical effect only would prevail here, showing reasonable tendency of greater hindrance for smaller pores. The observed depressions will be utilized to model the hindrance effect, together with information on microstructure of the frozen state in cylindrical pores, which is hoped to be published soon. 

In Figure 18 we can see the TOR as a function of sample temperature for different cluster sizes. Apparently it increases when the particle size decreases. 

Under the microscope a crystal with desirable attributes (size, apparent crystallinity) is selected and cleaned. The crystal is then removed from the oil by lifting it out with a prepared mounting fiber (see below for description), and immediately transferred to the cold stream on the diffractometer. This step can often be simplified if the crystal is moved toward the surface of the oil before one attempts to pick it up. 

Despite these advances, it is generally accepted that the vast majority of die observed color in aged red wine remains to be characterized. The obvious factor that separates characterized compounds from uncharacterized compounds appears to be molecular weight, with much of the high molecular weight material being unknown in structure. What is apparent is that as wine ages, the observed red color increases in size, apparently due to interaction between anthocyanins and proanthocyanidins (tannin) (10). 

For a particular coal, there is an optimum temperature for solvent extraction that is usually recognized as the decomposition temperature of the coal. The effect of particle size apparently has little effect on solvent action, with or without accompanying hydrogenation, and has been interpreted in terms of an equilibrium condition rather than rate. 

Toshima [162, 164, 165] has studied a series of PVP protected colloidal bimetallic PtPd catalysts in olefin hydrogenation catalysis. The highest activity for the hydrogenation of 1,3-cyclooctadiene to cyclooctene was observed at a Pd Pt radio of 4 1. On the basis of EXAFS analysis [165] it was concluded that the distribution of the two metals in the particles is nonuniform, and that at the most active composition the colloid particles had a platinum core coated with palladium. A less active 1 1 Pd/Pt catalyst, with the same particle size, apparently had a more uniform distribution of metals, with both platinum and p ladium atoms at the surface. 

An AQL of 1 % defects in the population has been chosen in this example. The producer s risk is then extremely high, namely about 25 % for a sample size n = 30 and will increase even more for larger sample sizes. Apparently it is not possible to obtain the desired acceptance plan by manipulating the sample size. The following example shows how to improve the characteristic and get a better result by changing the acceptance criterion as well. 

On the other hands, the size of apparent crystallite can be estimated from the peak broadening. Hence, the size of crystallite can be estimated by the Scherrer equation (D=O.9A/(pcos0)), where D is the size of crystallite, X is the wave length of CuKa, P is the half width of the peak and 6 is the Bragg angle. From the half width of the peak of 20x= 21.1°, the size apparent of crystallite in the PC-LB film was about 15A. 

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