We discuss the formation of a vortex polycrystal in type II superconductors from the competition between pinning and elastic forces. We compute the elastic energy of a deformed grain boundary, which is strongly nonlocal, and obtain the depinning stress for weak and strong pinning. Our estimates for the grain size dependence on the magnetic field strength are in good agreement with previous expe...

this experiment was laid out in order to evaluate the effects  of different biofertilizers on yield components of barley. the experiment was a factorial design with three replications. treatments were three nitrogen biofrtilizers (nitroksin, nitrokara and supernitroplass) and three phosphate  biofrtilizers (phosphate barvar2, biozarr and superplass) with control for them and yield components we...

We present preliminary results of a theoretical investigation of the thermal conductivity of polycrystalline GaN films. It is assumed that grain boundaries play a major role in limiting the thermal conductivity, which is calculated using the phononhopping transport approach. The effect of the grain size, size dispersion, and inter-grain interface structure on the thermal conductivity values is ...

Four principal factors contribute to grain-boundary strengthening: (a) the grain boundaries act as barriers to plastic flow; (b) the grain boundaries act as dislocation sources; (c) elastic anisotropy causes additional stresses in grain-boundary surroundings; (d) multislip is activated in the grain-boundary regions, whereas grain interiors are initially dominated by single slip, if properly ori...

This article systematically overviews the grain size effect on deformation twinning and detwinning in face-centered cubic (fcc) metals. With decreasing grain size, coarse-grained fcc metals become more difficult to deform by twinning, whereas nanocrystalline (nc) fcc metals first become easier to deform by twinning and then become more difficult, exhibiting an optimum grain size for twinning. T...

Austenite grain growth in microalloyed steels is governed by the coarsening of fine precipitates present at grain boundaries below the grain coarsening temperature. Zener model is widely used in metals to describe the pinning effect of second phase particles precipitated in the matrix. In this work it has been discussed whether grain boundary or volume diffusion is the rate controlling process ...

Since many of the quantitative plant characters of economic values are highly influenced by environmental condition, the progress in breeding in such a population is primarily conditioned by the magnitude, nature and inter-relations of genotypic and non-genotypic variations in plant characters. Therefore we estimated phenotypic, genotypic and environmental correlation coefficients and path coef...

In order to evaluate the relationship between morphological characters in rice lines two populations at F3 generation were grown in research field of Agricultural Sciences and Natural Resource University, Sari, Iran, during 2012. Statistical analysis on important agronomic traits showed that maximum standard deviation belonged to total grain number followed by filled grains per panicle and grai...

The effect of various impurities and micro-alloying additions (B, N, C, 0, AI, Si, S and P) on the intrinsic resistance of the ~3 (111) grain boundary in tungsten has been investigated using the molecular dynamics simulation. The atomic interactions have been accounted for through the use of Finnis-Sinclair interatomic potentials. The fracture resistance of the grain boundary has been character...

Understanding of various charging processes of dust grains is important in many different industrial applications as well as in the space research and theoretical studies of charging. An impact of energetic ions onto a dust grain leads to transfer of charge to the grain. This effect increases the charge of the dust grain until an equilibrium value is reached. After charging, the ion beam is swi...