In this paper, a generalized expression for the flow field in axisymmetric extrusion process is suggested to be valid for any dies and the boundary shapes of the plastic deformation zone. The general power terms are derived and the extrusion force is calculated by applying upper bound technique for a streamlined die shape and exponential functions for shear boundaries. It is shown that assuming...

The assessment of the influence of the work-hardening of material on the optimum die profile and drawing force  in rod drawing process is the main objective of the present paper. The upper bound solution, based on the assumption of perfect plasticity, has been extended to consider the work-hardening of the material during the rod drawing process through curved dies. Analytical results of drawin...

in this work we deal with the coefficients of a (e it ) 2 , where a is in a class of polynomialshaving unimodular coefficients. we first present a technique that calculates lower bounds for particularautocorrelations and then in a more general case we present an upper bound for their maximal order.

In this paper, we obtain some upper and lower bounds for the general extended energy of a graph. As an application, we obtain few bounds for the (edge) Zagreb energy of a graph. Also, we deduce a relation between Zagreb energy and edge-Zagreb energy of a graph $G$ with minimum degree $delta ge2$. A lower and upper bound for the spectral radius of the edge-Zagreb matrix is obtained. Finally, we ...

In this paper, we consider upper bound graphs and double bound graphs of posets. We obtain a characterization of upper bound graphs whose complements are also upper bound graphs as follows: for a connected graph G, both G and G are upper bound graphs if and only if G is a split graph with V(G)= K + S, where K is a clique and S is an independent set, satisfying one of the following conditions: (...

Fuzzy integral equations have a major role in the mathematics and applications.In this paper, general fuzzy integral equations with nonlinear fuzzykernels are introduced. The existence and uniqueness of their solutions areapproved and an upper bound for them are determined. Finally an algorithmis drawn to show theorems better.