The special form of pipe-like structure provides the helical route for ultrasonic guided wave. Considering pipe as a flattened plate but with periodical replications, wave becomes intuitional and corresponding imaging algorithm can be constructed. This work proposes multihelical Lamb method by utilizing multiple arrival wavepackets which are denoted different orders. signal model is presented c...

In this paper, efficient managing particle swarm optimization (EMPSO) for high dimension problem is proposed to estimate defect profile from magnetic flux leakage (MFL) signal. In the proposed EMPSO, in order to strengthen exchange of information among particles, particle pair model was built. For more efficient searching when facing different landscapes of problems, velocity updating scheme in...

When aluminum alloy tube have defects, they may be damaged by lateral impact in practical applications. Based on the general finite element analysis software, dynamic and performance research of with without defects different diameter to thickness ratios velocities were conducted this paper. The results show that weak resistance are prone local damage. Reducing ratio can improve structure; when...

the objective of analyzing the localization of deformation infO narrow bands of inDe-Shin Liu tense straining. Two different loadings, namely, the top and bOllom surfaces :.'ubjected to a prescribed tangential velocity, and these two surfaces subjected {O a Department of Mechanical and Aerospace preassigned normal velocity, are considered. In each case a material defect, flaw, or Engineering an...

We show that backflow, the coupling between the order parameter and the velocity fields, has a significant effect on the motion of defects in nematic liquid crystals. In particular, the defect speed can depend strongly on the topological strength in two dimensions and on the sense of rotation of the director about the core in three dimensions.

Electro-oculographic recordings were obtained from 11 patients with Huntington's disease. Significant reduction of saccadic velocity was constantly found. In all the patients vertical saccades were much more impaired than horizontal. When present, vertical saccades showed long latency, low amplitude, low velocity, and disturbances related to blinking. Following movements were jerky, and ability...

We report on measurements of delay time corresponding to evanescent coupled-cavity modes in threedimensional photonic crystals. By creating a defect inside the crystal, photons are confined within a boxlike cavity of volume ;(l/2). It is observed that photon lifetime increases drastically and group velocity of photons tends towards zero at the waveguiding band edges of the periodic coupled cavi...

Studies in experimental diabetic rat attribute the acute reversible nerve conduction defect as well as the early structural abnormalities of the node of Ranvier and myelinated axons to changes in nerve metabolism secondary to hyperglycaemia and activation of the pol yo1 pathway.’-8 The early readily reversible slowing of nerve conduction velocity in the diabetic rats correlates with a decrease ...

It is well known that the correlation between the Smagorinsky model and the subgrid scale stress is low, while the model based on the scale similarity assumption has considerably higher correlation. However, the scale similarity model by itself does not work well in a shear ow simulation because it seems passive on the mean velocity. Therefore the model is usually used together with the Smagori...

We report the simulation results for impact of nonlinear Kerr effect on band structures of a ‎two dimensional photonic crystal (2D-PhC) with no defect, a PhC based W1-waveguide ‎‎(W1W), and also Coupled-Cavity Waveguides (CCWs). All PhC structres are assumed to a ‎square lattice of constant a made of GaAs rods of radius r=0.2a, in an air background. The ‎numerical simulation was performed using...