The subject of this study is the modeling of the evolution of the swelling pressure of granulates with cohesive-frictional, rough and elasto-plastic “microscopic” contact properties. The spherical particles are randomly arranged in a periodic cubic space with a fixed volume so that an increase of the particle size – i.e. swelling that can be caused by intake of some fluid – is accompanied by a ...

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...

Surfaces can be slippery or sticky depending on surface chemistry and roughness. We demonstrate in atomistic simulations that regular and random slip patterns on a surface lead to pressure excursions within a lubricated contact that increase quadratically with decreasing contact separation. This is captured well by a simple hydrodynamic model including wall slip. We predict with this model that...

This contribution presents a generalized approach to friction induced vibrations in systems of moving continua. To this end, Hamilton’s Principle is used to state a weak formulation of the system dynamics without using specific structural models, like beams or plates for instance. The normal contact is enforced by a penalty formulation, which motivates the use of a constitutive contact model ba...

We revisit the problem of the stress distribution in a frictional sandpile with both normal and tangential (frictional) inter-granular forces, under gravity, equipped with a new numerical method of generating such assemblies. Numerical simulations allow a determination of the spatial dependence of all the components of the stress field, principle stress axis, angle of repose, as a function of s...

inclined retaining walls with slopes less than perpendicular are appropriate candidates in several engineering problems. yet, to the knowledge of authors, only a few analytical solution for calculation of active earth pressure on such walls, which will be usually smaller than the same pressure on vertical ones, has been presented neither in research papers nor in design codes. considering limit...

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...

Improving the accuracy of slurry flow predictions in different operating regimes remains a major focus for multiphase research, and it is especially targeted at industrial applications such as oil gas. In this paper we develop robust integrated method consisting an artificial neural network (ANN) support vector regression (SVR) to estimate critical velocity, regime change, ultimately, frictiona...