No abstract available

No abstract available

[en] An experimental and theoretical study is presented of the stability of the critical state in composite superconductors with a transport current

[en] The process of the normal zone propagation in ac and dc composite conductors near and over the superconductor critical current is studied

No abstract available

[en] The process of quench development in two- and six-strand cables was investigated in detail. Different types of quenches were found. The increase of the starting current level led to a change of nature of the quench, from current redistribution, to a quench in all strands, to multi-quench with acceleration of the process from step to step, and to fast quench. Strand currents never achieved the critical current value under DC circumstances. This paper concludes that the reason of fast quench in AC-cables is a specific mechanism of electromagnetic development of quench

[en] A measurement of the neutral (NC) to charged current (CC) cross section ratios has been performed using the CDHS detector in the CERN 200 GeV narrow band neutrino beam. The final analysis of data which have been taken in the years 1978/79 is presented. Preliminary results from a partial sample have been reported previously. The analysis follows very closely the method used in the first neutral current experiment of this collaboration, and only its main features are recalled here. (author)

[en] The finite difference time domain (FDTD) method in combination with a well established frequency scaling method was used to calculate the internal fields and current densities induced in a simple model of a pregnant woman and her foetus, when exposed to hand-held metal detectors. The pregnant woman and foetus were modelled using a simple semi-heterogeneous model in 10 mm resolution, consisting of three different types of tissue. The model is based on the scanned shape of a pregnant woman in the 34th gestational week. Nine different representative models of hand-held metal detectors operating in the frequency range from 8 kHz to 2 MHz were evaluated. The metal detectors were placed directly on the abdomen of the computational model with a spacing of 1 cm. Both the induced current density and the specific absorption rate (SAR) are well below the recommended limits for exposure of the general public published in the ICNIRP Guidelines and the IEEE C95.1 Standard. The highest current density is 8.3 mA m^-2 and the highest SAR is 26.5 μW kg^-1. Compared to the limits for the induced current density recommended in the ICNIRP Guidelines, a minimum safety factor of 3 exists. Compared to the IEEE C95.1 Standard, a safety factor of 60,000 for the specific absorption rate was found. Based on the very low specific absorption rate and an induced current density below the recommended exposure limits, significant temperature rise or nerve stimulation in the pregnant woman or in the foetus can be excluded

[en] One of the main research issues in the thermonuclear fusion area is the identification of plasma contour starting from external magnetic measurements. Possible approaches to this inverse problem make use of equivalent currents to represent the plasma internal current density, regularizing in this way the magnetic field reconstruction. Of course, the choice of the representation basis for such equivalent currents is critical. The paper aims at analyzing the effect of the number and position of base currents on the performance of the identification algorithm. (orig.)

[en] Highlights: • The differences between charge and discharge was explored using dynamic EIS;. • At the same SOC, R_ct during charge was usually smaller than that during discharge due to surface concentration change;. • The charge transfer resistance decreased with the charging/discharging current. - Abstract: The electrochemical impedance spectroscopy (EIS) of a lithium-ion battery is usually measured at open-circuit state under a constant state-of-charge (SOC). In this way, the differences between charge and discharge cannot be distinguished, because they both occur in one cycle of the alternating current. To explore the differences, in this study, we propose a new implementation method measuring the dynamic EIS (DEIS) of a LiMn₂O₄/Li half-cell (0.8 mAh) in the galvanostatic mode while the cell is under charging or discharging at a series of direct currents (DC). The results show the charge transfer resistance, R_ct, decreases with the increased DC. Also, R_ct during charging is usually smaller than that during discharging. The dependency of R_ct on the DC can be explained according to the Butler-Volmer equation. The difference in R_ct between charge and discharge, ΔR_ct, is ascribed to a significant surface concentration variation caused by the DC