Investigation of Ion and Electron Conduction in the Mixed Ionic-Electronic Conductor- La-Sr-Co-Fe-Oxide (LSCF) Using Alternating Current (AC) and Direct Current (DC) Techniques

Among many mixed ionic electronic conductors (MIECs), lanthanum strontium cobalt iron oxide (LSCF) has been proven as a promising material for use as cathode in SOFCs. The ion and electron conduction in LSCF need to be studied separately. To measure the ionic conductivity of LSCF, YSZ disks were applied to block the electronic current, and multilayered samples were made with YSZ disks in series with an LSCF disk. Both AC and DC techniques were used for the measurements. An LSCF(porous)/LSCF(dense)/LSCF(porous) bar-shaped sample was made to measure the electronic conductivity of LSCF. DC technique was utilized for the measurement. Results show that the ionic conductivity of LSCF is much lower than its electronic conductivity. The ionic conductivity of LSCF increases with increasing temperature (600-900°C), and the electronic conductivity decreases with increasing temperature (600-900°C). Measurements were also made on a foil of silver to investigate oxygen transport through it. From this, oxygen ion conductivity through silver was estimated.

A comparative study of two-step anodization with one-step anodization at constant voltage

Two-step anodization has been widely used because it can produce highly self-organized anodic TiO2 nanotubes, but the differences in morphology and current-time curve of one-step anodization and two-step anodization are rarely reported. Here, one-step anodization and two-step anodization were conducted at different voltages. By comparing the FESEM image of anodic TiO2 nanotubes fabricated by one-step anodization and two-step anodization, it was found that the variation of morphology characteristics is same with voltage. The distinction of morphology and current-time curve between one-step anodization and two-step anodization at the same voltage were analyzed: the nanotube average growth rate and porosity of two-step anodization are greater than that of one-step anodization. In the current-time curve, the duration of stage I and stage II in two-step anodization are significantly shorter than one-step anodization. The traditional field-assisted dissolution theory cannot explain the three stages of the current-time curves and their physics meaning under different voltages in the same fluoride electrolyte. Here, for the first time, the distinction between one-step anodization and two-step anodization was clarified successfully by the theories of ionic current and electronic current and oxygen bubble mould.

Electronic Current Transformer Defects Statistical Analysis of Intelligent Substation

In order to master operation status of the electronic current transformer(ECT), application investigation and defects statistical analysis were conducted on ECT of 110(66)kV~1000kV applied in smart substation of the State Grid Corporation of China(SGCC). The defect location, defect cause and defect type of ECT with different principles are analyzed. The results indicate that the defects of ECT are mainly concentrated in the acquisition unit, the defect rate is closely related to the reliability of electronic components, the technical level, production process and quality control of the manufacturer. In view of the typical defect analysis, the corresponding solution measures are put forward to provide reference for the subsequent research and application of ECT.

Electronic Currents and Anapolar Response Induced in Molecules by Monochromatic Light

It is shown that the electric dipole- and electric quadrupole–anapole polarizabilities, denoted respectively by fαβ′ and gα,βγ′, and the anapole magnetizability aαβ, are intrinsic properties of the electron cloud of molecules responding to optical fields. fαβ′ is a nonvanishing property of chiral and achiral compounds, whereas aαβ is suitable for enantiomer discrimination of chiral species. They can conveniently be evaluated by numerical integration, employing a formulation complementary to that provided by perturbation theory and relying on the preliminary computation of electronic current density tensors all over the molecular domain. The origin dependence of the dynamic anapolar response is rationalized via related computational techniques employing numerical integration, as well as definitions of molecular property tensors, for example, electric dipole and electric quadrupole polarizabilties and magnetizability. A preliminary application of the theory is reported for the Ra enantiomer of the hydrogen peroxide molecule, evaluating tensor components of electric dipole-anapole polarizability and anapole magnetizability as functions of the dihedral angle ϕ≡∠ H-O-O-H in the range 0∘≤ϕ≤180∘.

Human Body–Electrode Interfaces for Wide-Frequency Sensing and Communication: A Review

Several on-body sensing and communication applications use electrodes in contact with the human body. Body–electrode interfaces in these cases act as a transducer, converting ionic current in the body to electronic current in the sensing and communication circuits and vice versa. An ideal body–electrode interface should have the characteristics of an electrical short, i.e., the transfer of ionic currents and electronic currents across the interface should happen without any hindrance. However, practical body–electrode interfaces often have definite impedances and potentials that hinder the free flow of currents, affecting the application’s performance. Minimizing the impact of body–electrode interfaces on the application’s performance requires one to understand the physics of such interfaces, how it distorts the signals passing through it, and how the interface-induced signal degradations affect the applications. Our work deals with reviewing these elements in the context of biopotential sensing and human body communication.

A Study to Resist Conduced Interference from GIS Bus-Charging Currents Switching for Electronic Current Transformer

In this paper, we study the conducted interference to an electronic current transformer introduced in the process of bus-charging currents which are caused by switching a gas insulated switchgear (GIS) disconnector. To cope with these issues, the EMTP-ATP and Matlab/Simulink software are used to carry out equivalent modeling simulations and experimental research, respectively. More specifically, the very fast transient current generated by disconnector switching (DS) is used as the input source of the equivalent simulation model of the Rogowski coil, and the characteristics of conducted interference waveforms of the Rogowski coil, the active integrator and filter outputs under single and multiple breakdowns are analyzed step by step. Moreover, several anti-interference methods are proposed to improve the resistance to the high-voltage and high-frequency conducted interference for the Rogowski coil, such as reducing the Rogowski cut-off frequency, increasing the transient voltage suppressor (TVS), active filter, and Cy capacitor. Besides, the study also reveals that the residual charge of the integral capacitor will discharge with a time constant τ = 1 s after arc quenching with the first-order discharge circuit, which is composed of the feedback resistance and the integral capacitor C. Lastly, the experimental results demonstrate the correctness of the modeling method proposed in this paper and the effectiveness of anti-interference measures.