[en] The possible changes of pH following anodic oxidation of niobium and aluminium volume-porous anodes are experimentally determined and theoretically calculated. The increase in acidity affects the structure and properties of the formed oxide film. The process of electrochemical formation of anode oxide films in porous bodies from niobium and aluminium is limitted by the diffusion processes. The usage of variable asymmetric current for Nb and Al oxidation acelerates diffusion processes, which constitutes to obtain anode oxide films with high dielectric properties

No abstract available

[en] Nanotubular and nanoporous structures of ZrO₂ were synthesized by potentiostatic anodization with varying the temperatures of anode in the range of T_A = 0 – 90 °C and electrolyte in the range of T_El = 20 – 50 °C. It was shown that difference between T_A and T_El had significant influence on growth rate and morphology type of zirconia nanostructures. Optimal parameters of thermal modes for nanotubular ZrO₂ synthesis were discussed. (paper)

[en] Highlights: • A model of TiO₂ nanotube arrays growing on Ti mesh was proposed. • The TiO₂/Ti mesh was used for the anode without current collector or binder required. • The capacity of the TiO₂/Ti-600 min mesh electrode is 1745.5 μAh cm⁻² over 100 cycles. • The TiO₂/Ti mesh electrode still maintains its 3D nanostructure after 100 cycles. - Abstract: Three-dimensional (3D) TiO₂ nanotube arrays grown on Ti mesh were prepared via the anodization process. The diameters of the Ti and TiO₂/Ti wires and the length of the TiO₂ nanotubes have linear relationships with the anodization processing time. When the anodization processing time is 600 min, the TiO₂/Ti mesh anode materials showed good capacity retention and high specific area capacity, without the need for a current collector or binder, due to their high surface area, high substrate utilization, and large active material loading rate per unit area. At the current density of 50 μA cm⁻², TiO₂/Ti mesh with 600 min anodization processing time has a stable discharge platform at 1.78 V, and the specific area capacity is 1745.5 μAh cm⁻² over 100 cycles. By tuning the geometric parameters of the TiO₂/Ti mesh and the anodization processing time, we can pave the way to finding TiO₂/Ti mesh electrodes for lithium-ion batteries with high capacity per unit area and outstanding mechanical behaviour

[en] The spectrum of visible and near-UV luminescence due to a microdischarge on an AMg-6 aluminum alloy was studied under conditions of valve anodization in solutions of sodium carbonate and other electrolytes. It was shown that emission spectra exhibit lines that characterize anodic (aluminum and magnesium) and electrolytic (sodium) components. The dependence of the temperature of the microdischarge on the electrolyte concentration and composition is discussed

[en] Highlights: •Developed communities at 0 mV and −400 mV vs. Ag/AgCl for converting biomass-derived liquids. •Electroactive community at −400 mV achieved a maximum current density of 12 A/m². •Lower set anode potential resulted in a 1.5-fold higher electrical efficiency. •A maximum hydrogen productivity of 10.9 L-H₂/L-anode-day was obtained. -- Abstract: A unique aspect of microbial electrolysis cells is the use of an applied voltage for H₂ production. A variation on this parameter is the use of a controlled anode potential rather than controlled cell voltage, which can result in a more stable redox environment for the anode microbes. In this study, long-term exposure of anode consortia at −400 mV and 0 mV vs. Ag/AgCl resulted in a gradual divergence of the resulting bioanode midpoint potentials by >100 mV over a 6-month period. Cyclic voltammetry revealed a shift in peak current production to more negative potentials for the reactor poised at −400 mV. Furthermore, chronopotentiometry indicated very different profiles, showing a difference of 500 mV in the potential required to achieve a current of 15 mA (equivalent to 12 A/m²). A 3-fold higher current was observed at a poised potential of −400 mV for the anode enriched at a poised potential of −400 mV, compared to that enriched at 0 mV. The substrate used was a bio-oil aqueous phase (BOAP) derived from switchgrass, making this study unique with potential for biorefinery application in producing hydrogen, fuels or chemicals. Operation at −400 mV resulted in a 1.5-fold higher electrical efficiency reaching 164.9%, while marginally reducing hydrogen recovery by 1.0%. The results provide evidence for adaptation of complex communities to optimize applied potential, while reducing energy input for electrolysis. The community developed here has potential to be explored further to understand complex community-function relationships.

No abstract available

[en] The mechanism and chemical reaction kinetics of anodic electrolysis of certain radionuclides including ¹⁴⁴Ce, ⁵⁴Mn, ²⁴²Cm, ¹⁴³Pr, ¹⁶⁶Ho, ¹⁴⁷Nd were studied. The effect of the electrode potential, the pH of the solution, the chemical concentration of the carrier on the reaction rate and the distribution coefficient were determined. Results of the electrolytic studies could be utilized in the separation of ¹⁴⁴Ce from ¹⁴⁰La, fission products as ¹⁴⁴Ce from UO₂²⁺ ions. (V.N.) 35 refs.; 12 figs

[en] A physically based equation for predicting required p-emitter length of a snapback-free reverse-conducting insulated gate bipolar transistor (RC-IGBT) with field-stop structure is proposed. The n-buffer resistances above the p-emitter region with anode geometries of linear strip, circular and annular type are calculated, and based on this, the minimum p-emitter lengths of those three geometries are given and verified by simulation. It is found that good agreement was achieved between the numerical calculation and simulation results. Moreover, the calculation results show that the annular case needs the shortest p-emitter length for RC-IGBT to be snapback-free. (semiconductor devices)

No abstract available