Abstract This paper presents experimental results and finite element analysis of hot upsetting titanium alloys Ti64 Ti407 using a dilatometer in loading mode. All samples showed barrelling, as consequence an inhomogeneous temperature distribution friction. The FE is full thermomechanical model the test calibrated multiple thermocouples. At each nominal strain rate, true flow stress–strain respo...

The influence of a localized inhomogeneity (oscillatory or stationary) on spatiotemporal chaotic state in an excitable reaction-diffusion system is investigated. We find that various coherent wave patterns, such as spiral waves (including multiarmed) and target wave patterns are able to be created by the inhomogeneity from the chaotic state. Due to the growth of these coherent wave patterns, th...

We employ three dimensional x-ray coherent diffraction imaging to map the lattice strain distribution, and to probe the elastic properties of a single crystalline Ni (001) nanowire grown vertically on an amorphous SiO2 k Si substrate. The reconstructed density maps show that with increasing wire width, the equilibrium compressive stress in the core region decreases sharply while the surface ten...

Spiral waves in active media react to small perturbations as particlelike objects. Here we apply asymptotic theory to the interaction of spiral waves with a localized inhomogeneity, which leads to a novel prediction: drift of the spiral rotation center along circular orbits around the inhomogeneity. The stationary orbits have fixed radii and alternating stability, determined by the properties o...

We perform the analytic investigation of stress-strain state a functionally graded cylindrical shell finite length heated by two-dimensional temperature field. The properties material are regarded as functions thickness coordinate. In our investigations, we use equations refined theory shells that takes into account deformation transverse shear and normal deformation. heat-conduction equation i...

FIELD INHOMOGENEITY COMPENSATION IN HIGH FIELD MAGNETIC RESONANCE IMAGING (MRI) Zhenghui Zhang, PhD University of Pittsburgh, 2006 This thesis concentrates on the reduction of field (both main field B0 and RF field B1) inhomogeneity in MRI, especially at high B0 field. B0 and B1 field inhomogeneity are major hindrances in high B0 field MRI applications. B1 inhomogeneity will lead to spatially v...

We consider an inhomogeneity of ‘arbitrary’ shape embedded within an infinite isotropic elastic medium (matrix) subjected to antiplane shear deformations under the assumption of uniform remote loading. The inhomogeneity–matrix interface is assumed to be imperfect, characterized by a single interface function. Under these assumptions, we present a novel method leading to the solution of the prob...

there are three main ideas about relation between creatures and god. one of them is the theory of separation, according to this theory there's not any homogeneity between creatures and god it means the essence and existence of creatures are completely inhomogeneity with god's essence and existence. the second is the theory of oneness, according to this theory creatures and god are uni...