OBJECTIVE To evaluate the power of prenatal 2-D ultrasound examination in the 2nd trimester as a method of choice for accurate diagnosis of annular pancreas. METHODS Co-incidence of the double bubble sign (often accompanying gastroduodenal dilatation) together with a hyperechogenic band around the duodenum (corresponding with the tissue of annular pancreas) was used as a diagnostic criterion....

in this study, the vibration behavior of functional graded (fg) circular and annular nanoplate embedded in a visco-pasternak foundation and coupled with temperature change is studied. the effect of in-plane pre-load and temperature change are investigated on the vibration frequencies of fg circular and annular nanoplate. to obtain the vibration frequencies of the fg circular and annular nanopla...

We show cyclic sieving phenomena on annular noncrossing permutations with given cycle types. We define annular q-Kreweras numbers, annular q-Narayana numbers, and annular q-Catalan numbers, and show that a sum of annular q-Kreweras numbers becomes an annular q-Narayana number and a sum of annular q-Narayana numbers becomes an annular q-Catalan number. We also show that these polynomials are clo...

In this study, the vibration behavior of functional graded (FG) circular and annular nanoplate embedded in a Visco-Pasternak foundation and coupled with temperature change is studied. The effect of in-plane pre-load and temperature change are investigated on the vibration frequencies of FG circular and annular nanoplate. To obtain the vibration frequencies of the FG circular and annular nanopla...

In this article, an exact levy solution is presented for bending analysis of a functionally graded (FG) annular sector plate. The governing equilibrium equations are obtained based on the classical plate theory. Introducing an analytical method for the first time, the three coupled governing equilibrium equations are replaced by an independent equation in term of transverse deflection. This equ...