In this paper, size-dependent effects on the vibration behavior of Timoshenko microbeams under pre-stress loading embedded in an elastic foundation, using modified strain gradient theory (MSGT) and surface stress effects, were studied. To consider the surface stress effects, the Gurtin–Murdoch continuum mechanical approach was employed. Using Hamilton’s principle, the governing equations of mot...

to investigate the effects of different salinity levels of nacl on germination of safflower (cv. esfahan 24) seeds under three different incubation methods, a factorial experiment was carried out based on a complete randomize design with three replications. salinity levels were 0, 5, 10, 15 and 20 dsm-1 (nacl) and incubation methods were sandwich method, and using petri dishes with open or clos...

introduction drought stress as the most important abiotic stress plays an important role in yield reduction of crops worldwide. considering the extends and problems caused by the moisture stress, agronomic and breeding strategies in reducing yield loss are essential. in this regard, the identification and selection of effective characteristics of wheat under drought stress in increasing yield, ...

in order to determine the best index for evaluating maize genotypes, 15 maize inbred lines were evaluated in two planting dates, 6 july to coincide heat stress with pollination time and 27 july as normal planting to avoid high temperature during pollination and grain filling period, using a randomized complete block design with three replications, in shushtar city, in 2007. result showed that i...

continuous desertification of arable lands mandates use of low quality/ saline water for irrigation, especially in regions experiencing water shortage. using low quality/ saline water for irrigation imposes more stress on plants that are already under stress in these regions. thus, a logical solution will be to find a salt/ drought-tolerant plant species that will survive/sustain under such str...

in order to study and determine the most effective traits, drought tolerance indices and identify tolerant genotypes in terminal drought stress on the cowpea, an experiment was carried out based on an augment design in two separate conditions in the karaj farm, faculty of agriculture, tehran university in 2009. drought stress was imposed by cutting irrigation after flowering against normal irri...

  Abstract Two experiments with factorial arrangements on the basis of randomized complete block design in three replications were conducted in 2007 and 2008, to evaluate chlorophyll content index (CCI), fluorescence of chlorophyll, proline content and grain yield of three soybean cultivars (Williams, Zan and L17) under a non-saline (control) and three saline (3, 6 and 9 ds/m NaCl) conditions...

Abstract: In order to evaluate the capacity of RC members, the main codes allow the use of stress-strain laws that can reproduce closely the real behaviour of concrete, as opposed to parabola-rectangular or equivalent rectangular diagrams. Both sectional strength and ductility depend on the law of concrete, therefore they are influenced by the confinement of members, as evidenced in the literat...