On the application of a discharge with liquid electrodes for polishing metal surfaces

The work investigates the electrical parameters of the discharge plasma with a liquid cathode and a combined porous anode. The discharge is carried out in the vertical position of the plasma column, has a volumetric multichannel structure with a pronounced diffuse structure of the electrode spots. The influence of the porous element on the stabilization of the discharge characteristics is revealed. Discharges with a liquid electrolyte cathode continue to be of great interest from the point of view of practical application and are studied in a wide range of changes in physical and geometric characteristics [1 - 4]. Discharge plasma with a liquid cathode can be most effectively used for cleaning, polishing, with simultaneous removal of fractured and relief layers, hardening, gas saturation, surface activation, improvement of mechanical and other characteristics of agricultural machinery parts. In this work, for plasma polishing, parts of the bearing assemblies of disc harrows were selected.

Microfabrication of Anode Functional Layer in SOFC by 3D Printer

This work aims to increase the interface between anode and electrolyte in solid oxide fuel cells by controlling the 3D microstructure with a commercial ink-jet 3D printer. Anode and electrolyte inks suitable for use in a 3D printer were prepared by altering the viscosity and the droplet size. A porous anode structure that ensures a flow path for gases was achieved by addition of acrylic particles into the anode ink. A dense electrolyte structure that prevents leakage was created. The anode and electrolyte layers were produced as long, flat strips which were aligned in parallel to form sheets; these sheets were stacked orthogonally to complete the 3D microstructure called the ‘anode functional layer’. The anode functional layer was roughly 100 micrometers on a side with a thickness of 4 micrometers. The anode functional layer was inserted between the anode and electrolyte. The assembled solid oxide fuel cell showed high performance when tested at 600 °C with dry methane as the fuel source.

Modeling of Electronic Amplification Processes in Channels of Multipliers on Porous Structures of Aluminum Oxide

The secondary-emission multiplier of spatial-distributed flows of electrons – microchannel membrane – determines along with the photocathode, luminescent screen, electron-optical system determines the amplifying characteristics of the electron-optical transformers, photoelectronic multipliers. This, in its turn, determines the application areas and the operating range of the items. The actual task is an improvement of the microchannel membrane parameters and the search for new approaches to manufacture on alternative materials of the secondary-emission multipliers. In the paper the use of self-organizing high-ordered porous anode structures of aluminum oxide as the secondary-electronic emitters have been considered. The theoretical and practical approaches to development and the implementation of the computer models of processes of multiplying electrons in the channel of the based on aluminum oxide, have been offered. Based on the results of the calculations, performed using this model, the amplifying ability of such channels has been determined, their optimal caliber is 25, and the supply voltage is 300 V. A comparative analysis of these characteristics of secondary electron multipliers with corresponding parameters of microchannel plates based on lead silicate glass has been performed. It has been determined that that porous anodized alumina may be suitable for the manufacture of secondary electron multipliers. Its secondary emission ability is comparable to lead silicate glass.

Improved Electrochemical Properties of an Ni-Based YSZ Cermet Anode for the Direct Supply of Methane by Co Alloying with an Impregnation Method

To avoid the proneness to degradation due to coking in the operation of solid oxide fuel cells (SOFCs) directly running on methane (CH4) fuels, a modified porous anode of the Ni1−XCoX/YSZ (yttria-stabilized zirconia) cermet prepared by an impregnation method is presented. The influence of the Co alloying content on the cermet microstructure, SOFC characteristics, and prolonged cell performance stability has been studied. Co was incorporated into Ni and formed a solid solution of Ni1−XCoX alloy connected with the YSZ as the cermet anode. The porous microstructure of the Ni1−XCoX/YSZ cermet anode formed by sintering exhibited a grain growth with an increase in the Co alloying content. The electrochemical performance of the cells consisting of the Ni1−XCoX/YSZ cermet anode, the YSZ electrolyte, and the LSM (La0.8Sr0.2MnO3) cathode showed an enhancement by the Ni1−XCoX impregnation treatment for the respective supply of H2 and CH4 to the anode. The cell using the Ni0.75Co0.25/YSZ cermet anode (the Ni0.75Co0.25 cell) showed the highest cell performance among the cells tested. In particular, the performance enhancement of this cell was found to be more significant for CH4 than that for H2; a 45% increase in the maximum power density for CH4 and a 17% increase for H2 at 750 °C compared with the performance of the cell using the Ni/YSZ cermet anode. Furthermore, the prolonged cell performance stability with a continuous CH4 supply was found for the Ni0.85Co0.15 and Ni0.75Co0.25 cells at least for 60 h at 750 °C. These enhancement effects were caused by the optimum porous microstructure of the cermet anode with the low anodic polarization resistance.