Heat stress intensity

The primary limitation of a HAZOP study is the length of time required to perform it. Because the study is designed to provide a complete analysis, study sessions can be intensive and lii ing. HAZOP studies typically do not look at occupational hazards (e.g., electrical equipment, rotating equipment, hot surfaces) or chronic hazards (e.g., chronic chemical exposure, noise, heat stress). For experience with HAZOP see Swann (1995). 

A further estimation of the corrosion resistance of maraging steel can be obtained from data on the rate of crack propagation. Although the rate of crack propagation has been found to be a function of stress intensity in some alloys, for many alloys and heat treatments there is a range of stress... 

Fig. 8.24 Influence of heat-treatment conditions on the sub-critical stress corrosion growth rate of a nickel-bearing SS as a function of stress intensity. In the as-quenched condition, the steel shows much faster crack grown rates (after Spaehn )...

In both aqueous and organic environments the crack velocity is related to the instantaneous stress intensity factor, as shown in Fig. 8.53. Three regions may be observed I, II and III. Regions I and III are not always observed and the specific relationship observed depends upon the alloy composition and heat treatment, the environmental composition and the experimental conditions. ... 

This predictive degradation strategy was demonstrated for biomolecules as a tool to accelerate drug development (Kleintop et al., 1998). Biomolecule samples are exposed to various accelerated stressed environments such as acid, base, heat, high intensity light, and humidity. Molecular weight information obtained from... 

Intensity of heat stress = [(Atemperature) x (rate of heating) x (duration of exposure)]... 

Effect of heat stress on DF in WT and HsfA2 mutants. DF intensity declined more markedly in HsfA2 mutants than in WT plants after a 2 h heat stress at 40°C (Fig. 1). There was no significant difference in DF intensity in heat-stressed relative to unheated-stressed leaves for WT however, a significant difference in DF... 

Fig. 1. Effect of heat stress on DF intensity in WT and HsfA2 mutants.

Recovery dynamics of DF and Pn after heat stress. As shown in Fig. 2, after heat stress, DF intensity and Pn consistently recovered the level of control (at 25°C) after cooling the leaves from high temperature for 12 h in WT but not in KoHsfA2 mutants (Fig. 2A, B). This indicated that heat stress caused an irreversible damage to HsfA2 mutants but a reversibe to WT. 

Fig. 3. ROS production (A) and effect of antioxidant on DF intensity (B) after a 2-h heat stress. Data are the mean SE of seven replicates. Scale bars = 10 pm.

Resistance to hydrogen induced SCC (HISCC) of 9Cr-lMo steel, as evaluated by CERT method, indicated that the the HISCC resistance increases with increase in tempering time. Untempered steel is most susceptible to HISCC. Threshold stress intensity factors for HISCC and crack growth rates were established for this steel in various heat treated conditions in NaCl solution and aggressive acidic solution containing a recombination poison, As2 03. 

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