It is generally agreed that of all quadrature formulae, the trapezoidal rule, while being the simplest, is also the least accurate. There is, however, a rather general class of integrals for which the trapezoidal rule can be shown to be a highly accurate means of obtaining numerical values. Specifically, if the integrand is a periodic, even function with all derivatives continuous, then the int...

Recently, fuzzy linear programming problems have been considered by many. In the literature of fuzzy linear programming several models are offered and therefore some various methods have been suggested to solve these problems. One of the most important of these problems that recently has been considered; are Fully Fuzzy Linear Programming (FFLP), which all coefficients and variables of the prob...

It is generally agreed that of all quadrature formulae, the trapezoidal rule, while being the simplest, is also the least accurate. There is, however, a rather general class of integrals for which the trapezoidal rule can be shown to be a highly accurate means of obtaining numerical values. Specifically, if the integrand is a periodic, even function with all derivatives continuous, then the int...

Defuzzification is the process of converting a fuzzy quantity to precise quantity, just as fuzzification is the conversion of a precise quantity to a fuzzy quantity. Various types of defuzzification methods, are available for conversion of fuzzy to non-fuzzy. In this paper, defuzzification functions in intuitionistic fuzzy environment such as triangular, trapezoidal, L-trapezoidal, R-trapezoida...

trapezoidal channels are frequently used in irrigation networks and other free surface water conveyance systems. the computation of the critical flow depth is one of the primary importance in the design process. it is usually determined by using design charts of iteration techniques. however, researchers have recently proposed formulas that directly provide approximate solutions. this paper pre...

In this paper, convection heat transfer of Al2O3-water nanofluid turbulent flow through internally ribbed tubes with different rib shapes (rectangular, trapezoidal and semi-circular) is numerically investigated. For each rib shape, the optimum geometric ratio and volume fraction were calculated using entropy generation minimization technique. The governing equations in...

Tubular channel angular pressing (TCAP) is a recently invented novel severe plastic deformation technique for producing UFG tubes. Plastic deformation analysis using the finite element method (FEM) was carried out to investigate the effects of trapezoidal channel geometry on strain inhomogeneity index (SII), strain level and required load compared to previously used channel geometries. The resu...

A numerical study of the natural convection of the laminar heat transfers in the stationary state was developed in a horizontal ring and compared between a heated trapezoidal internal cylinder and a cold elliptical outer cylinder. This annular space is traversed by a Newtonian and incompressible fluid. The Prandtl number is set to 0.7 (air case) for different Rayleigh numbers. The system of equ...