Significance hardness

Low—medium alloy steels contain elements such as Mo and Cr for hardenabiHty, and W and Mo for wear resistance (Table 4) (7,16,17) (see Steel). These alloy steels, however, lose their hardness rapidly when heated above 150—340°C (see Fig. 3). Furthermore, because of the low volume fraction of hard, refractory carbide phase present in these alloys, their abrasion resistance is limited. Hence, low—medium alloy steels are used in relatively inexpensive tools for certain low speed cutting appHcations where the heat generated is not high enough to reduce their hardness significantly. 

Air temperature variations are reasonably well-reflected in the soil surface but disappear rapidly in depth at 50 cm depth daily variations are hardly significant, and only seasonal temperature fluctuations are registered. Almost similar situations occur in hard consolidated rocks. Those, although having a somewhat higher thermal conductivity than loose materials, do not... 

The bulk polymerisation of 4-methoxystyrene (Deffieux et al., 1980) also gave a kp of the same order of magnitude, but to calculate it from their less detailed measurements the authors had to assume values for the rates of initiation and termination in order to obtain [P+n] , and they chose to use those for styrene. It seems to us that it would have been more logical to take the rates of initiation and termination for another ether, e.g., IBVE, but in fact according to our calculations the resulting p+ is only ca. 50% greater, a difference which is hardly significant in the present context. 

A commercial iron-promoted catalyst (Sn/Sb/Fe = 1/4/0.25) was studied by Germain et al. [92,93,135,137]. Iron is reported to improve the ammoxidation qualities of the catalyst although it has no effect on the oxidation [93], The kinetics, determined in a flow reactor at 445°C and with a feed ratio C3H6/NH3/air = 1/1.2/10, are essentially similar for this catalyst and bismuth molybdate. The initial selectivity is 80% and the maximum yield is 65% (at 445°C). The initial selectivity markedly depends on the temperature (e.g. 91% at 415°C and 72% at 507°C). The effect of water is hardly significant for this catalyst the acrylonitrile formation is slightly inhibited, while some more acrolein is formed. Presumably, water and ammonia compete in the interaction with the catalyst, which is much less reactive with respect to ammonia than bismuth molybdate. The acrolein ammoxidation is very rapid (about six times the propene ammoxidation rate) and selective (86%). A comparison of the Sn—Sb—Fe—O catalyst with bismuth molybdate is presented in Table 14. 

Table 12.3 compares the estimated analyte concentrations for DIED, PARAFAC, and PARAFAC x 3 noise (PARAFAC with the addition of a factor of three greater random errors) applied to the same calibration problem. Table 12.4 is analogous to Table 12.3, except that it also presents the squared correlation coefficients between the true and estimated X-way and Y-way profiles for all three species present in the six samples. It is first evident that PARAFAC slightly outperforms DTLD when applied to the same calibration problem. However, the improvement often lies in the third or fourth decimal place and is hardly significant when compared with the overall precision of the data. This near equivalence of DTLD and PARAFAC is rooted in the fact that DTLD performs admirably, and there is little room for... 

The range of sterilization specifications calculable by these various approaches is summarized in Table 2. It is apparent that very brief sterilization specifications (on the order of 2-3 min holding time at 121°C) are obtainable when the microbiological contamination is completely characterized in terms of numbers and thermal resistances. In practice, such limits on hold times could be difficult to control precisely, are probably insignificant in terms of thermal lethality compared with heat-up and cool-down times, and could prove difficult to sell to regulators. Without complete thermal characterization of thermal resistances, specifications calculable by the bioburden approach are hardly significantly shorter than overkill specifications. Thus, it probably makes practical sense in most cases to choose only between overkill cycles for thermally resistant products and aseptic manufacture for heat-sensitive products. 

Flexural strength varies primarily with thickness. It also varies with the tensile strength of the paper on the side tested, but the paper used on any one product is reasonably uniform. The correlation coefficients on individual products show slight increases indicating that there may be some correlation with the variations in paper strength, but the changes are hardly significant. 

The A log Ka for similar substitutions in saturated acids are hardly significant, being +.01 and +.06 respectively. The slopes of the cinnamic and /3-phenyl propionic acid lines in Figure 36 also illustrate this point. 

Glycerol (Figure 3.2). This aqueous system was dealt with in detail (Marcus 2000) and the system is close to ideal, but 8x(yw > 0 and 8x(vs < 0, contrary to aqueous ethylene glycol, though both parameters are very small Sx(vw(niax) = 0.014 and 5x(vs(niin) = -0.005 (hardly significant) at 298 K. 

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