stand establishment in crusting soil is one of the main concerns in the production of crops with delicate seedlings such as cotton, onions and rape seed. crust breaking, maintaining soil moisture and adding chemical and organic amendments to soil are different methods to weaken soil strength and allow the shoots to emerge. these methods are not always successful because they depend on factors s...

While one might assume that the force to break a chemical bond gives a measure of the bond strength, this intuition is misleading. If the force is loaded slowly, thermal fluctuations may break the bond before it is maximally stretched, and the breaking force will be less than the bond can sustain. Conversely, if the force is loaded rapidly it is more likely that the maximum breaking force is me...

since bone marrow has been shown to contain osteoprogenitor cells, an experiment was devised to test its effects when injected percutaneously into osteotomies sites in rabbit radii. in this experimental study, the osteogenicity and its effect on early bone repair of bone marrow grafts were investigated. the purpose of this study was to determine whether bone marrow grafted percutaneously led to...

Background: Old laying hens are more prone to dietary calcium (Ca) and phosphorus (P) deficiencies as  they absorb Ca and P less efficiently than younger hens. OBJECTIVES: In a 2×2 factorial design, the influence of diets with two levels of available phosphorus (AP) and phytase enzyme on the laying performance, egg quality and tibia bone characteristics of laying hens at their late 2nd producti...

to investigate the characteristics of skin and leather of hairy goats according to their sex and age, 120 goat skins were selected from the western part of iran. results indicated that sex and age had significant effects on weight and area of skin and leather. moreover, sex and age had significant effects on thickness in different parts of skin except the belly. in this regard, the overall mean...

skin and leather characteristics of hair-type goats were studied in relation to their sex and age, using 100 randomly-selected skin from goats reared in east west iran. mean weights of skin and leather were 859.2±35.2 and 357.4±16.2 g, and the length and width of leather ranged from 60 to 121 and 41 to 87 cm, respectively. age had a significant effect on the weight and area of skin and leather....

Daily gain, daily feed intake, feed per unit of gain, serum Ca, serum P, serum Mg, structural soundness scores, foot pad scores, metacarpal breaking force and metacarpal ash values from five Ca P trials with barrows, gilts or boars were subjected by sex in each trial to multivariate analysis of variance. Correlation coefficients were obtained from the residual sums of squares and sum of product...

We measured the elastic properties and intrinsic breaking strength of free-standing monolayer graphene membranes by nanoindentation in an atomic force microscope. The force-displacement behavior is interpreted within a framework of nonlinear elastic stress-strain response, and yields second- and third-order elastic stiffnesses of 340 newtons per meter (N m(-1)) and -690 Nm(-1), respectively. Th...

We study one dimensional supersymmetric (SUSY) quantum mechanics of a spin 12 particle moving in a rotating magnetic field and scalar potential. We also discuss SUSY breaking and it is shown that SUSY breaking essentially depends on the strength and period of the magnetic field. For a purely rotating magnetic field the eigenvalue problem is solved exactly and two band energy spectrum is found.

Abrading decreases the strength of glass at these low temperatures in the same wayas at higher temperatures. Lowering the test temperature increases the strength, up to a point, of both abraded and unabraded specimens. The breaking stress at 194°K and 296 K is dependent on the rate of loading but appears to be independent of the rate at 20 0 K and 76°K. Contact with liquid nitrogen and hydrogen...