Grain width

Fig. 4.70 a Critical bridging stress decreases with grain width b Variation of bridging zone length with average grain width [34]. With kind permission of John Wiley and Sons... 

Fig. 8.19 Relationship between the toughness ratio of a blunt crack to a sharp crack and the ratio of the blunt crack-tip radius to the effective grain width, where the hatched region represents the results for different characteristic zone size. The dashed lines in the insets are the crack front of different grain arrangement [15]. With kind permission of Elsevier...

Defects intervening in pieces are listed by official norms. For segmentation needs, we have divided the set of defects in two categories, volumetric and linear defects. A defect is considered as linear if its width is twice inferior to the size of the grain, all the rest are considered as volumetric defects. 

On short length scales the coarse-grained description breaks down, because the fluctuations which build up the (smooth) intrinsic profile and the fluctuations of the local interface position are strongly coupled and camiot be distinguished. The effective interface Flamiltonian can describe the properties only on length scales large compared with the width w of the intrinsic profile. The absolute value of the cut-off is difficult... 

Fig. 5. The immediate effect of temperature on strength properties of clear wood, expressed as percentage of value at 20°C. Trends illustrated are composites from studies on three strength properties modulus of mpture in bending, tensile strength perpendicular to grain, and compressive strength parallel to grain. VariabiUty in reported results is illustrated by the width of the bands. MC = moisture content.

A formal derivation of diffusion in a restricted, high diffusivity path which uses no atomic model of the grain boundary is that due to Fisher, who made a flux balance in unit width of a grain boundary having a drickness of <5. There is flux accumulation in the element according to Pick s second law given by... 

Fig. 7.37 Diffusion coefficients for some impurities in NiO grain boundaries compared with the corresponding lattice diffusivities (the grain boundary width is assumed to be I nm) (after...

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