Volume 60, Number 2, June 2015

S T U D I A

                UNIVERSITATIS BABEŞ-BOLYAI

                               MATHEMATICA

CONTENTS

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . 149

Heinz-Joachim Rack and Robert Vajda, Optimal cubic Lagrange

interpolation: Extremal node systems with minimal Lebesgue constant . .. . . . . . . . . . . . . . . 151

Sorinel Dumitrescu, Estimates for the ratio of gamma functions by

using higher order roots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173

Ana Maria Acu and Heiner Gonska, Weighted Ostrowski-Gruss type

inequalities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183

Ildiko Somogyi and Anna Soos, Spline and fractal spline interpolation . . . . . . . . . . . . . . . . . .193

Valentin Gabriel Cristea, A direct approach for proving Wallis ratio

estimates and an improvement of Zhang-Xu-Situ inequality . . . . . . . . . . . . . . . . . . . . . . . . . . 201

Gradimir V. Milovanovic, Construction and applications of Gaussian

quadratures with nonclassical and exotic weight functions . . . . . . . . . . . . . . . . . . . . . . . . . . . 211

Alexandru I. Mitrea, On the unbounded divergence of interpolatory

product quadrature rules on Jacobi nodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235

Cristina Sanda Cismasiu, The generalization of Mastroianni operators

using the Durrmeyer's method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241

Harun Karsli and Huseyin Erhan Altin, A Voronovskaya-type

theorem for a certain nonlinear Bernstein operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249

Harun Karsli and Esra Unal, On convergence of a kind of complex

nonlinear Bernstein operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259

Harun Karsli and Mehmet Vural, On convergence of nonlinear

singular integral operators with non-isotropic kernels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267

Gabor Fabian and Lajos Gergo, Adaptive algorithm for polyhedral

approximation of 3D solids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .277

Marius Birou, Discrete operators associated with the Durrmeyer operator . . . . . . . . . . . . . . . 295

Maria Talpau Dimitriu, On global smoothness preservation by

Bernstein-type operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303

Ioana Chiorean, Statistical aspects on the usage of some dermatological

creams with metallic nanoparticles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311

Maria Gabriela Trimbitas and Radu T. Trimbitas, Finding initial

solutions for a class of nonlinear BVP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319

Anca Farcas, A convergence result for a contact problem with adhesion . . . . . . . . . . . . . . . . . 329

Diana Andrada Filip, Radu T. Trimbitas and Ioan Pop, Fully developed mixed convection

through a vertical porous channel with an anisotropic permeability: case of heat flux . . . . . . . 341

Book reviews . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .351