Search results for "Current distribution"
showing 7 items of 17 documents
A Simple Method for Evaluating Ground-Fault Current Transfer at the Transition Station of a Combined Overhead-Cable Line
2008
When a substation is fed by a combined overhead-cable transmission line, a significant part of the ground fault current flows through cable sheaths and is discharged into the soil at the transition station where cables are connected to the overhead line. Such a phenomenon, known as ldquofault application transfer,rdquo may result in high ground potentials at the transition station which may cause shocks and equipment damage. The scope of this paper is to present new analytic formulas which can be used for the direct calculation of the fault current transferred at the transition station and its ground potential rise as well as the substation earth current. The proposed formulas allow evaluat…
Current and Voltage Behaviour During a Fault in a HV/MV System: Methods and Measurements
2015
When a single line to ground fault happens on the MV side of a HV/MV system, only a small portion of the fault current is injected into the ground by the ground-grid of the faulty substation. In fact the fault current is distributed between grounding electrodes and MV cables sheaths. In systems with isolated neutral or with resonant earthing this may be sufficient to provide safety from electric shock. Experimental measurements were performed on a real MV distribution network: a real single line to ground fault was made and fault currents were measured in the faulty substation and in four neighbouring substations. In this paper the problem of fault current distribution is introduced, the te…
Quantum Transport and Current Distribution at Radio Frequency in Multiwall Carbon Nanotubes
2012
Multiwall carbon nanotubes represent a low-dimensional material that could serve as building blocks for future carbon-based nanoelectronics. The understanding of the electromagnetic performances at radio frequency of these materials for use in nanointerconnects is strictly related to the analysis of their transport properties as function of the working conditions. In this paper, we present an explicit expression of the conducting channels as function of diameter, temperature, doping, and supply voltage for both metallic and semiconducting carbon nanotubes. The proposed formula is based on the Dirac cone approximation of the conducting band energy of graphene nearby the Fermi points, combine…
Hydrophobicity of ionisable compounds studied by countercurrent chromatography
2011
Countercurrent chromatography (CCC) is a liquid chromatography technique in which the stationary phase is also a liquid. The main chemical process involved in solute separation is partitioning between the two immiscible liquid phases: the mobile phase and the support-free liquid stationary phase. The octanol-water partition coefficients (P(o/w)) is the accepted parameter measuring the hydrophobicity of molecules. It is considered to estimate active principle partitioning over a biomembrane. It was related to the substance biological activity. CCC is able to work with an octanol stationary phase and an aqueous mobile phase. In this configuration, CCC is a useful and easy alternative to measu…
Plenary talk - non coaxial force and inductance calculations for bitter coils and coils with uniform radial current distributions
2011
Recently the Bessel function approach to calculating the magnetic fields of coils has been used to calculate the mutual inductance and the force between two non coaxial thick cylindrical coils with parallel axes and uniform radial current distributions. This method can also be applied to calculate the force and inductance between an ordinary coil and a Bitter coil, or between two bitter coils, not necessarily coaxial. Bitter coils give a simpler case of the method, and it is possible to solve analytically for the magnetic field of a bitter disk.
Countercurrent chromatography: People and applications
2009
The scientific literature was scanned for the published research articles dealing with countercurrent chromatography (CCC) over the time period 1980-May 2008. The search returned 1638 articles that were analyzed focussing on people and applications. Concerning the people, it was found that the geographical location of the CCC authors was relatively well balanced between USA, Asia with mainly China and Japan and Europe. Yoichiro Ito, the inventor of the technique, is by far the most productive author in the field with 331 articles or more than one over five CCC articles published in the time period. Without surprise, English is the dominant language with more than 82% of the articles. A sign…
Limiting current phenomena in electro-membrane processes: local occurrence or stack-dependent one?
2021
Background Electro-membrane processes are gaining great interest in the field of desalination and brine valorisation. However, limiting current phenomena can be a bottleneck for their techno-economic performances. In the present work, the in-out distribution of current density is measured to elucidate the achievement of limiting conditions in real stacks. Materials and Methods A 10-cell pairs Electrodialysis stack (10×40 cm2 active area), equipped with four-segmented electrodes, was tested. NaCl solutions at an inlet concentration ranging from 0.5 to 60 g/l were fed at velocities of either 2 or 4 cm/s in parallel flow. Current density-voltage curves were built by applying equal increasing s…