FEM Simulation of Waves Excited by Array Probe Propagating in Centrifugally Cast Stainless Steel With Hexagonal Column

Centrifugally cast stainless steel (CCSS) is widely used in PWR primary coolant systems. However, ultrasonic testing for such material is very challenging because its coarse grains and anisotropic property. The phased array ultrasonic technology (PAUT) is considered the most promising solution to the problem mentioned. To improve the accuracy of PAUT for CCSS with columnar grains, we used the voxel-based finite element method to perform simulation of wave propagation in CCSS, where waves were excited by a linear array. We modeled columnar grains in CCSS with hexagonal columns and introduced a side-drilled hole. It was easily to have different inclined columnar grains by rotating the crystal axes. All column crystals were considered cubic crystals while CCSS with columnar grains was macroscopically transversely isotropic. Wave propagations were computed for different focal laws and their results were compared. Waves exactly propagated toward and focused at the targeted SDH when focal laws were calculated according to the anisotropic property of CCSS, but deviated the target for focal laws based on isotropy.

Geomorphologic Analysis of Small River Basin within the Framework of Fractal Tree

This paper presents the modified framework of geomorphologic analysis based on the concept of fractal tree. Especially, it is intended to provide hydrologic practitioners with the information on the fractal property of small river basins. To this end, the complete drainage path network is applied to a growth process of a fractal tree for the basin of interest by connecting a channel network to overland drainage pathways. The growth process of a fractal tree would occur only within the limited region possessing channel flow properties in a natural river basin. The exponent of the intra basin type of Hack’s law could show a variable trend in small river basins mainly due to anisotropic property of the catchment planform. The bifurcation process of a drainage path network might be more sensitive to the growth step of the fractal tree than the meandering process of drainage path segment. The fractal dimension from the sinuosity of a channel segment is relatively stable compared to the one from the bifurcation process of the network, so that the geomorphologic features of a small river basin can be characterized by the anisotropic property of catchment planform as well as the bifurcation property of drainage path network with the growth of the fractal tree.

The World Beyond Black Holes

This book represents a New Theory about light which offers an easier way to understand the mathematical principles on which the theory for a Black Hole has been based. The fundamental difference with existing theories is the implementation of the anisotropic property of mass for light within the interaction with gravity. This "New Theory" has been based on the fundamental principle of a perfect Equlibrium in the entire universe in space and in time and unifies Newtonian Physics with Electrodynamics, Quantum Physics and General Relativity.

Joint Inversion of Magnetotelluric Impedance and Tipper Data in 3D Axial Anisotropic Media

Magnetotelluric (MT) impedance and tipper data can be utilized to reflect underground structural information. However, when the axial anisotropic property of an abnormal body is marked, it will seriously influence MT measuring data. This study divides the MT field into primary and secondary components and replaces the conductivity parameter in a three-dimensional (3D) governing equation with axial anisotropic conductivity. Analysis of the influence of axial anisotropy on MT tipper data is presented, and a limited-memory Broyden-Fletcher-Goldfarb-Shanno method is then utilized to realize a 3D MT axial anisotropic inversion with impedance and tipper data. The tests presented in this paper show that the resolution of the inverting axial anisotropic model with impedance and tipper data is better than that of only using impedance data.

Caracterización de un músculo artificial de nylon y su implementación en una articulación de un robot manipulador serial

In this paper we present the study and description of a nylon muscle, to validate its performance and define its properties, applying loads on it and subjecting it to thermal stimuli. The results of the implementation of the nylon muscle are reported in a joint of a rigid mechanism, of a serial manipulator, however, the difficult thermal control that the muscle possesses makes the thermal shock (the ambient temperature and the applied one) wear at a certain point to the muscle, exhausting its properties or a very slow response from it. Testing that the material can only be used in the suspension of the load in the application of rigid systems. It is observed that an important feature of nylon muscles is their incredible capacity to contract loads that are higher than the same weight of the muscle and that by means of a thermal stimulus can be contracted thanks to its anisotropic property, just as the material is extremely attractive for the application of soft robotics and intelligent materials