Two-Dimensional Ray Mathematical Model of Mechanoelectric Transformations Method for Location of Macrodefects Identification in Solid Dielectric Structures

Method of mechanoelectric transformations can be applied to determine both horizontal position and the depth of a defect in solid nonconductor samples. The method is based on phenomenon of electromagnetic emission in sources of mechanoelectric transformations, such as cracks, voids and impurities of sample structure. It has been shown that method can be used to evaluate integrated stress-strain state of solid dielectric materials. The method is also capable of finding defects is the sample volume, but the robust methodology has to be developed. To develop a methodology of the proper scanning process the experimental setup was created. This work represents ray model of this setup. The model allows us to research pulse characteristics of the response signal considering a variety of excitation signal parameters, defect locations and depths. The model includes dimensions of real sample. Pulse characteristics for response signals of single-period excitation waves with 100 kHz, 300 kHz, and 600 kHz frequencies were obtained. It is shown that increasing the frequency of excitation increases the accuracy of estimating the depth of macrodefects. Time-response characteristics of the signal are most informative.

Oceanic tracer and proxy time scales revisited

Quantifying time-responses of the ocean to passive and active tracers is critical for the interpretation of paleodata from sediment cores because surface-injected tracers do not instantaneously spread throughout the ocean. To obtain insights into the time response, a computationally efficient state transition matrix method is demonstrated and used to compute successive states of passive tracer concentrations in the global ocean. Times to equilibrium exceed a thousand years for any one region of the global ocean outside of the injection and convective regions and concentration gradients give time-lags from hundreds to thousands of years between the Atlantic and Pacific abyss, depending on the injection region and the nature of the boundary conditions employed. Equilibrium times can be much longer than radiocarbon ages as the latter are strongly biased towards the youngest fraction of fluid captured in a sample. Pulse-like inputs can produce very different transient approaches to equilibrium in different parts of the ocean generating event identification problems.

Improvement of Deposition Uniformity in Laminated Templates Electro-Deposition

Laminated templates electro-deposition (LTE) is a small-sized metallic-structure fabrication technique based on template-patterned depositing. Avoiding locally excessive electroplating at the template edge area has been proved crucial to this method. To improve deposition uniformity, auxiliary cathode and modulated double-pulse current were tried individually and assessed on their effects and efficiencies. By applying assisting cathode the deposition uniformity in plannar pattern depositing was significantly improved with an increased thickness ratio of edge to center for the plating sample. Pulse application, especially double-pulse was studied mainly on the proportion between anodic duty circle and cathodic duty circle. Through a group of optimized parameters, including current density ranging 8-10A/dm2, anodic and cathodic duty circle of respectively 80% and 30%, frequency 300HZ, a bulk of copper parts, section size 20×20mm and 4-7mm thick were produced with a well depositing quality.