B-series are a fundamental tool in practical and theoretical aspects of numerical integrators for ordinary differential equations. A composition law for B-series permits an elegant derivation of order conditions, and a substitution law gives much insight into modified differential equations of backward error analysis. These two laws give rise to algebraic structures (groups and Hopf algebras of...

In this article, we concerned with the development of a method for solving two point boundary value problems of ordinary differential equations. To develop method, we consider derivative of solution of a problem as an intermediate problem (IP). The analytical solution of the problem and IP were locally approximated by a nonlinear function with fixed step length. Some numerical experiments have ...

A jointed rock mass presents a more complex design problem than the other rock masses. The complexity arises from the number (greater than two) of joint sets which define the degree of discontinuity of medium.  The condition that arises in these types of rock masses is the generation of discrete rock blocks, of various geometries. They defined by the natural fracture surfaces and the excavation...

in the past, rock slope stability analysis were performed either graphically or using a hand-held calculator, but nowadays there are variety of slope stability analysis which can be used according to the field condition and potential failure mode. in 2-d analysis, effect of convex and concave walls are neglected, however concave slopes are believed to be more stable than straight walls due to t...

riverbank erosion, land loss and associated sedimentation are river engineering and water resources management problems of global significance. the ability to predict riverbank stability on eroding rivers is the prerequisite of developing a channel width adjustment model and is essential for estimating riverbank erosion and associated sedimentation. in this research, a detailed model for stabil...

in order to study adapatability and yield stability of irrigated bread wheat cultivars alvand, alamout, zarrin, navid, azar 2, sabalan, omid and bezostiya this experiment was conducted in rcbd during three cropping seasons (2007-2010) in six cities. simple anova and combined analysis of variance for three years in every location and also combined analysis of variance for three years and six loc...

the design of appropriate, cost-effective remedial measures requires a clear understanding of the processes that are causing the landslide. this understanding require a detailed site investigation, a reconnaissance of the landslide as soon as possible after it's occurrence can allow important observations of the processes involved. a key step in analyses of soil slope stability is measurin...

An explicit numerical method to solve a fractional cable equation which involves two temporal Riemann-Liouville derivatives is studied. The numerical difference scheme is obtained by approximating the first-order derivative by a forward difference formula, the Riemann-Liouville derivatives by the Grünwald-Letnikov formula, and the spatial derivative by a three-point centered formula. The accura...

Objective: Yield components and genetic contribution have the most important in final yield and breeding programs of crop plants. For this purpose, 20 varieties of grapevines with Russia origin were evaluated in Urmia and Takestan research station (under full irrigation and drought stress). Methods: Twenty grapevine genotypes were evaluated in Urmia and Takestan research station (under full irr...

Objective: Yield components and genetic contribution have the most important in final yield and breeding programs of crop plants. For this purpose, 20 varieties of grapevines with Russia origin were evaluated in Urmia and Takestan research station (under full irrigation and drought stress). Methods: Twenty grapevine genotypes were evaluated in Urmia and Takestan research station (under full irr...