The cracked Brazilian disc (CBD) specimen is widely used in order to determine mode-I/II and mixed-mode fracture toughness of a rock medium. In this study, the stress intensity factor (SIF) on the crack-tip in this specimen is calculated for various geometrical crack conditions using the extended-finite element method (X-FEM). This method is based upon the finite element method (FEM). In this m...

Knowledge of acoustic arrival angle can be useful for studying penetration mechanisms and for estimating sediment sound speed dispersion. The arrival angle of the acoustic field penetrating the water-sediment interface, however, is difficult to measure using sparsely distributed pressure sensors. The arrival angle, as well as amplitude information, can be unambiguously obtained by measuring par...

As the core component of flexible nozzle on solid rocket motors, joint relies shear deformation its silicone rubber elastomers to achieve a large vector angle, and is prone fatigue failure when working under high pressure. Aiming resolve elastomers, cracking energy density (CED) method was introduced into analysis joints. A convenient integral formula for calculating CED derived from Ogden seco...

We discuss the interplay of particle-particle and particle-hole spin-triplet channels in high-Tc superconductors using a quasiparticle dispersion motivated by angle-resolved photoemission. Within a generalized randomphase approximation, we find a well-defined antibound state of two holes, the p resonance of Demler and Zhang, as well as a bound state of a particle and a hole, the spin exciton. W...

A temporally and spatially nonscanning imaging spectrometer is described in terms of computedtomography concepts, specifically the central-slice theorem. A sequence of three transmission sinusoidalphase gratings rotated in 60° increments achieves dispersion in multiple directions and into multiple orders. The dispersed images of the system's field stop are interpreted as two-dimensional project...

Chirality-dependent van Hove singularities ~vHs! of the one-dimensional electronic density of states ~DOS! are discussed in connection with resonant Raman spectroscopy. The effect of trigonal warping on the energy dispersion relations near the Fermi energy splits the peaks of the density of states for metallic nanotubes, and the magnitude of this effect depends on the chiral angle of the carbon...

BACKGROUND P wave dispersion is an independent predictor of atrial fibrillation. P wave dispersion is associated with inhomogeneous and discontinuous propagation of sinus impulses. The purpose of this study was to investigate P wave dispersion and transthoracic echocardiographic findings in elite women basketball players. METHODS We recruited 27 well-trained woman athletes with a training his...

understanding the spatial distribution of weeds would provide good results for the commercial applications of future research programs, development forecast desirable of yield loss and understanding the processes that cause changes in spatial and temporal distribution weeds. in this order an experiment was conducted in 1388 to find the effects of biological interactions, climate and agricultura...

The Maximum Minsum Dispersion Problem (Max-Minsum DP) is a strongly NP-Hard problem that belongs to the family of equitable dispersion problems. When dealing with dispersion, the operations research literature has focused on optimizing efficiency-based objectives while neglecting, for the most part, measures of equity. The most common efficiency-based functions are the sum of the inter-element ...

Abstract Biocomposites of poly(lactic acid) (PLA) and pectin, which are low-cost organic materials, were prepared using an internal mixing machine in various pectin contents, i.e., 2, 4, 6 8% w/w. When was added as a nucleating agent, the mechanical properties biocomposites, such tensile impact testing, considerably improved, particularly following annealing process. In addition, PLA–pectin ann...