Features of the microstructural and mechanical degradation of long term operated mild steel

Purpose The purpose of this paper is to assess the technical state of old and repair steels of Shukhov’s tower elements after operation during ~ 110 and 70 years of the water tower in Nikolaev, basing on their mechanical tests, metallography and fractography investigations. Design/methodology/approach For their certification, the fractographic and structural features and mechanical properties (hardness, strength, plasticity and impact toughness) were analyzed. Both the steels under consideration were characterized by low values of hardness and brittle fracture resistance. The mechanical characteristics of the old steel are lower compared with the repair one. It cannot be only explained by the quality of metal rolling. Moreover, the plasticity characteristics of both steels, defined in synthetic acid rain environment, are lower than in the air. Using fractography investigation, the operational damages in the bulk metal in the form of the elements of cleavage fracture in the central part of the fracture surfaces of specimens tested at the hydrogenation condition by synthetic acid rain environment were revealed. Findings The results of this study suggested a degradation of steels’ characteristics caused by the development of scattering damages during their operation. Higher relative elongation of the old steel at lower hardness and impact toughness were also evidenced in that. The metallography and fractography investigations also supported this finding. Originality/value This original study aimed at characterizing the microstructural and mechanical degradation of mild steels that was collected from Shukhov’s tower structural elements.

Hydrogen-free defects in hydrogenated black TiO2

A hydrogen-free defect in the bulk TiO2 is newly proposed that can exist in hydrogenation condition and can account for most of unique properties of black TiO2 such as high electric conductivity and light absorption spectra.

Total synthesis of anisomycin

Two synthetic approaches to anisomycin had been studied. One approach used 2R 3R tartaric acid as starting material and was successfully converted to the hydrochlorides of (+)-anisomycin (22) in an overall yield of about 5% and (−)-anisomycin (1) in about 1% yield. Liberation of the free bases gave (+)-anisomycin and (−)-anisomycin. The other approach started with α-anisyl pyrrole and was converted to (±)-deacetyl anisomycin 2. The conversion of 2 to anisomycin was done by treating natural deacetyl anisomycin with benzyl bromide to give 9. Conversion of 8 and 9 to (+)-anisomycin and (−)-anisomycin was done by selective acetylation with acetic anhydride and debenzylation under hydrogenation condition.