A flexible eddy current probe can detect the defects in components with a complex structure due to its bendability and adaptation surface of tested specimen for nondestructive testing. However, traditional, circular rectangular coils may neglect small cracks along certain special orientations. In this paper, authors introduce theory fractal geometry guide design probes. An annular curve is first proposed, system iterative functions geometric characteristics are then studied. Following this,...

Abstract A flexible or planar eddy current probe with a differential structure can suppress the lift-off noise during inspection of defects. However, extent effect on probes, including different coil structures, varies. In this study, two probes pickup structures and same size, Koch circular were used to compare effects. The distributions perturbed by 0° 90° cracks obtained finite element analysis. analysis results show that crack impede induced even further at relatively low distance....

We numerically study the propagation of Gaussian beams in four different types transverse separation modulated photonic lattices. find modulation obeying hyperbolic secant or rectangular functions can act as optical potentials, and light waves be localized recur regions between such two positive respectively. While decay negative potentials since these structures could not support modes. Our results provide new ways for controlling manipulation

We investigate, both theoretically and numerically, the asymmetric light propagation in transverse separation modulated photonic lattices. The theoretical results show that transmission contrast η of structure is determined only by coupling strengths between chirped lattice two boundary uniform portions. numerical studies demonstrate independent modulation function lattice, which good agreement with theory.

A new rotational field planar eddy current probe is proposed. The combined with two orthogonal driver traces and a pickup coil that includes two-circular sector windings series connection. Rotational currents are induced by of the same amplitude frequency, but fed 90° phase different alternating exciting currents. An experimental demonstration using prototypes probes artificial defects showed more sensitive for detecting short than circular coil.

Flexible planar eddy current probes are widely used to detect conductive components with complex surface. In this study, topological transformation is applied design a differential Koch coil exciting probe. Two kinds of coils, A and B , were obtained by from three‐dimensional Finite element model simulation conducted visualize the differences distributions induced get defect signal. detailed comparison made among two circular probe experiments. The experiments demonstrate that sensitivity...

Koch curve exciting coil of an eddy current probe can adjust the distributing in more directions at a small domain to enhance sensitivity for short defect detection. In this study, relative entropy and cross tangential intersection angle spectrum are proposed evaluate distributions different when is positioned lift-off distances excited by frequency alternative currents. The induced circular fractal coils analyzed two indices. With increasing distance or decreasing frequency, close those coil.

We numerically study the formation of modulated waveguide generated Airy-like beams and their subsequent evolution in homogeneous medium. The results show that could be from narrow Gaussian propagating one-dimensional transverse separation unbent, cosine bent, or logarithm bent arrays, respectively. waveguide-generated maintain characteristics when without nonlinearity under self-defocusing medium, while are distorted self-focusing nonlinearity. deformation depends on bending outgoing angles...

In order to solve the problems of fixed model parameters and low efficiency in traditional numerical method software simulation for transformer excitation inrush current. this paper, response surface fitting is applied calculation current, which realizes efficient analysis peak value current with change closing Angle under condition different remanence main column. Firstly, generation mechanism was theoretically analyzed, key influencing factors were extracted. Secondly, parameter modeling...

This thesis explores the historical progression and theoretical constructs of financial mathematics, with an in-depth exploration Stochastic Calculus as showcased in Binomial Asset Pricing Model Continuous-Time Models. A comprehensive survey stochastic calculus principles applied to option pricing is offered, highlighting insights from Peter Carr Lorenzo Torricelli's ``Convex Duality Continuous Option Models". manuscript adopts techniques such Monte-Carlo Simulation machine learning...

We numerically study the propagations of Gaussian beams in four types separation modulated photonic lattices. The results shows that potential wells between double positive hyperbolic secant and rectangular barriers forms negative functions can both support localized linear modes. Moreover, coupling effects two modes be used to realize all-optical switch. Furthermore, nonlinear localization also observed high power. Our supply new ideas for all optical switch, light controlling manipulation

We consider four types of modulated photonic lattices and numerically study the optical Bloch oscillations Airy beams in these periodic structures. Our results demonstrate that transversely lattices, oscillation period increases amplitude reduces as separation variation index increases. However, increasing width could lead to a consistent reduction amplitude. On other hand, three kinds longitudinally bent trajectories follow waveguide shape perfectly within whole propagation length. For...

Gene silencing by P-element-induced wimpy testis-interacting RNAs is a mechanism to maintain genome integrity in germ cells. Here, we present protocol for knockin or knockout editing of male germline mediated CRISPR-Cas9 technology Caenorhabditis elegans. We describe steps constructing edited plasmids, microinjecting worms with these and screening worms. then detail procedures dissecting released sperm their observation fluorescence microscopy. Engineered provide model studying...

Based on the analysis of producing principles ethanol fuels for vehicles and their development in world,in article is compared with conventional eight indicators covering economic, environment technology by AHP model. The main objective this research work to study difficulties arising obstacles promoting fuel Chinese market based calculation results, finally propose appropriate solutions new ideas ease energy crisis traffic pollutions China.

Summary form only given. Since the first observation of Airy beam in 2007, its propagation properties, such as self-acceleration, self-healing and reflection/refraction, have been studied widely [1, 2]. Based on these achievements, with development photonic lattices, studies spread from homogeneous medium to periodic structures. In researchers demonstrate that accelerating is realizable controllable [3, 4]. Distinguished previous methods, using modulated lattices for generation an absolutely...

<title>Abstract</title> Flexible or planar eddy current probe with differential structure can suppress the lift-off noise during inspection of defects. However, influence extent effect on probes including different coil structures is various. This work proposed a Koch and circular pickup same size. The [[EQUATION]] signals output from two are compared under distances via finite analysis experimental methods. In addition, frequencies studied by experiment. result shows that signal for crack...