EFFECT OF CONDUCTIVITY IN CORROSION PROBLEM USING BOUNDARY ELEMENT METHOD AND GENETIC ALGORITHM

Boundary element method applications with inverse solution are used to apply the indirect analysis for modeling of corrosion problem. Laplace equation has been used to model the electrical potential in the electrolyte surface. In this paper a computer modeling has been developed to visualize the effect of conductivity value in corrosion problem. Genetic algorithm is used to create the conductivity value based on the mechanics of natural selection and genetics. The boundary element method is then calculating the potential value of the whole domain. FORTRAN and MATLAB program have been developed to calculate and visualize the potential distribution in the domain. Two-dimensional example problems are analyzed to demonstrate the application of the proposed boundary element modeling procedure.

Characteristics of Bipolar Nanosecond Discharges in Air Formed in the Electrode System “BLADE-SURFACE of Nonmetallic Liquid -BLADE”

Curcumin The design of the device for producing a high-current, bipolar nanosecond discharge over the surface of a non-metallic liquid (water, electrolytes, alcohols, etc.) in air is given. Air pressure is ranged from 5 to 101 kPa. The distance between the tip of the blade and the surface of water or liquid (5% solution of copper sulfate in distilled water) was 4 mm, and the distance between parallel metal blades was 40 mm. The conditions for uniform plasma overlapping of the electrolyte surface between the metal blades are established. The spatial, electrical, and optical characteristics of the discharge are investigated. It is shown that the discharge under study allows obtaining colloidal solutions of copper nanoparticles in distilled water in a macroscopic amount (1 liter or more). The developed reactor is of interest for use in poisonous chemical solution disinfection systems, solutions based on dangerous bacteria and viruses for which the use of traditional systems with a point spark discharge or a barrier discharge becomes ineffective. The rector is also promising for the synthesis of colloidal solutions of transition metal oxide nanoparticles from solutions of the corresponding salts. These solutions can be used in micro-nanotechnology and for antibacterial treatment of plants in greenhouses, processing of medical instruments and materials.

Robust Micro Arc Oxidation Coatings on 6061 Aluminum Alloys via Surface Thickening and Microvoid Reducing Approach

The hardness and wear resistance of micro arc oxidation (MAO) ceramic coatings were influenced by phase compositions, surface thickness, porosity and microcracks. In this work, ceramic coatings with enhanced microhardness and friction resistance were fabricated on 6061 Al-alloy by increasing thickness and decreasing porosity through adding sodium hexametaphosphate ((NaPO3)6) as additive in silicate-based electrolyte. Surface morphologies and microhardness of the as-fabricated MAO coatings were evaluated using scanning electron microscope (SEM) and thickness meter. As a binary additive, the addition of (NaPO3)6 in electrolytes can obviously change the surface morphologies, thickness and microhardness of the resultant MAO coatings.

Spontaneous formation of nanoparticles on electrospun fibers for fuel cell electrodes

Nanofibers spontaneously decorated with nanoparticles were synthesized by nozzle-free electrospinning, showcasing the latter as a novel, inexpensive and scalable method for depositing high-surface area composites. Layers of nanofibers of the intermediate-temperature proton conducting electrolyte cesium dihydrogen phosphate, (CsH2PO4, CDP), were deposited from homogeneous undersaturated solutions of CDP and polyvinylpyrrolidone (PVP), uniformly over large area substrates. Under certain conditions, the nanofibers develop CDP nanoparticles on their surface, which increases the exposed electrolyte surface area and ultimately enhances electrocatalytic performance. Indeed, fuel cell tests on cathodes made of processed nanoparticle-decorated CDP nanofibers produced higher cell voltage, as compared to state-of-the-art electrodes.