In this paper, the stress concentration around a hole in the single layer composite materials with long fibers is examined. The single layer has an infinite length, limited with and instant thickness and is loaded by a constant tension force p at infinity. The width of the lamina is considered to be finite and bears a hole as a defect. Due to presence of excessive shear stress in the matrix bay...

the effect of different fertilizing systems and drought stress during grain development on grain minerals of barley (hordeum vulgare l.) was studied in field experiments on a clay-loamy soil during 2007 and 2008 growing seasons. the treatments consisted of three irrigation regimes (main plots) of: non-stressed (ns, normal irrigation continued until the end of plant physiological maturity), ...

in this work, the effects of silicon (si) supplementation were studied in pistachio (pistacia veral. cv ahmadaghaii) plants exposed to high salinity stress. plants were grown in pots undercontrol and salt (ec=15 ds m-1) conditions without or with si treatment (0.35 g na2sio3 kg-1soil) under field conditions. salt stress reduced the plants’ growth significantly in both –si and+si plants; however...

cadmium (cd), known as a non-essential heavy metal, can cause oxidative stress in plants. in this study, an attempt was carried out to find out whether cd-induced oxidative and microscopic changes could be observed in the early stage of seedling growth. seeds of brassica napus (cvs. zheda 619 and zs 758) were germinated in vitro at 0, 100, 200, 300, and 500 μm cd concentrations in dark for 48 h...

controversy exists regarding cavity preparation for restoration of interproximal caries in posterior teeth in terms of preserving the tooth structure and suitable stress distribution. this study aimed to assess the effect of extension and type of class ii cavities and the remaining tooth structure in maxillary premolars restored with composite resin on the biomechanical properties of teeth usin...

It has been reported that mental stress causes abnormality of spermiogram parameters. We investigated the effect of psychological stress on the L-arginine-nitric oxide (NO) pathway. Semen samples were collected from 29 healthy fourth semester medical students just before (stress) and 3 months after (non-stress) the final examinations. Psychological stress was measured by the State Anxiety Inven...