Local adaptation, which has been detected for several wild pathosystems is influenced by gene flow and recombination. In this study, we investigate local adaptation and population structure at a fine scale in wild populations of a plant‐pathogen fungus. We sampled hierarchically strains of Colletotrichum lindemuthianum in a wild population of its host. The analysis of AFLP patterns obtained for 86 strains indicated that: (i) many different haplotypes can be discriminated, although occurrence of recombination could not be shown; (ii) migration between adjacent plants seemed rare during the season; and (iii) neutral diversity is structured according to groups of plants and individual host plants. Furthermore, we tested for the occurrence of local adaptation using a cross‐inoculation experiment. Our results showed local adaptation at the scale of the individual host plant. These results indicate that fine‐scale dynamics has evolutionary consequences in this pathosystem.

The following cases of hydrogen influence on pipeline metal were considered: gaseous hydrogen under internal pressure in notched pipes and electrochemically generated hydrogen on external pipe surface from soil aqueous environment. The burst tests of externally notched pipes under pressure of hydrogen and natural gas (methane) were carried out after the pipe has been exposed to a constant ''holding'' pressure. It has been shown that even for relatively ''soft'' test conditions (holding pressure p ¼ 20 bar and ambient temperature) the gaseous hydrogen is able to penetrate into near surface layers of metal and to change the mechanism of local fracture at notch. The sensitivity to hydrogenating of given steel in deoxygenated, near-neutral pH NS4 solution under soft cathodic polarisation was studied and the assessment local strength at notches in pipeline has been made for this conditions. Here, the relationship between hydrogen concentration and failure loading has been found. The existence of some critical hydrogen concentration, which causes the significant loss of local fracture resistance of material, was also shown.

A B S T R A C T In this review paper, only constraint and stress gradient approaches to transferability of fracture toughness are examined. The different constraint parameters are defined and discussed, and one example is given in each case. Factors that influence the constraint are studied. Special attention is given to the actual trends to use the plastic constraint in the material failure master curve and the material transition temperature master curve. The paper also deals on the influence of T stress on the crack path and out-of-plane constraint and on the influence of thickness on fracture toughness. The uses of plasticity with gradient and the relative stress gradient in local fracture approaches are also examined.A = constant A i = Williams' stress distribution parameterŝ A i = HRR stress distribution parameters A P = Constraint parameter A p,c = current plastic zone area A p,ssy = reference plastic zone area A εp,c = area surrounded by the equivalent plastic strain A εp,ref = reference area surrounded by the (ε p ) isolines B = thickness B 0 , B 1 , B 2 and B 3 = constants D = pipe diameter D 0 = length E = Young's modulus F = geometry correction factor G = shear modulus G c = fracture toughness I = complex function of eigenvalues I n = dimensionless integration constant J = path integral J c = fracture toughness J Ic = fracture toughness in plane strain conditions J ref = reference fracture toughness K Ic = fracture toughness for plane strain conditions K Jc = fracture toughness K Iz,c = three-dimensional fracture toughness in pure mode I K 0 = lower bound of the notch fracture toughness K ρ,c = notch fracture toughness K 0 ρ;c = fracture toughness corresponding to T ef,c = 0 L = plastic constraint factor N = strain hardening exponent

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Structural integrity assessment of defected high density poly-ethylene pipe: burst test and finite element analysis based on J-integral criterion, (2015),