Fracture has always been a serious concern in the design and repair of steel structures such as ships. Because of these concerns, much research has been ongoing in the causes of fractures and in ways which they could be predicted and thus prevented. The objective of this study was to flnd, test and evaluate a method for measuring tht:: critical strain energy density with tensile specimens. Plas...

The strain, stress and strain energy density of a vanadium dioxide (VO2)-based microactuator were obtained from experimental curvature measurements as a function of temperature. The study revealed fully reversible strain and stress changes of up to −0.32% and −510 MPa, respectively, and a maximum strain energy density of approximately 8.1 × 105 J/m3 through a temperature window of only 15 ◦C. T...

Mn doped ZnO nanocrystals were prepared by co-precipitation route sintered at 450 °C temperature. XRD results indicate that the samples having hexagonal (wurtzite) structure. From X-ray data it is found that the lattice parameters increase with increasing Mn concentration. The X-ray density decreases with increasing Mn concentration of Zn 1-x Mnx O nanocrystals. It indicates that the Mn...

background: the consumption of low quality foods is common in low socioeconomic areas; and according to epidemiological studies, the density of nutrients often proves the quality of diet. this study aimed to compare the density of macronutrients and micronutrients in various parts of tehran.   methods: this was a cross-sectional study performed from september to december 2007 in all the 22 dist...