SEMIRAMIS: an asymmetrical bounded wave EMP simulator with a good confinement inside the transmission line

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Combined high-fusion performance and long-pulse operation is one of the key integration challenges for fusion energy development in magnetic devices. Addressing these challenges requires an integrated vision of physics and engineering aspects with the purpose of simultaneously increasing time duration and fusion performance. Since the previous 2023 IAEA Fusion Energy Conference, significant progresses have been made in tokamaks and stellarators including very recent achievement in duration and/or performanc

Fifty years ago, transportation and logistics problems were primarily analyzed either from a supply-side or a demand-side perspective, with the fields of operations research and demand modeling evolving separately. Since then, there has been a growing interest in behavioral optimization models, aiming to integrate both supply and demand aspects. The purpose of this survey is to offer a historical perspective on the evolution of behavioral optimization models in transportation and logistics. It does so by de

The improvement of the efficiency of vehicle energy systems promotes an active search to find innovative solutions during the design process. Engineers can use computer-aided processes to find automatically the best design solutions. This kind of approach named “multi-objective optimization” is based on genetic algorithms. The idea is to obtain simultaneously a population of possible design solutions corresponding to the most efficient energy system definition for a vehicle. These solutions will be optimal

The material presented in this document is intended as a comprehensive, implementation-oriented supplement to the experimental optimization framework presented in [Bunin, G.A., Francois, G., Bonvin, D.: Feasible-side global convergence in experimental optimization. SIAM J. Optim. (submitted) (2014)]. The issues of physical degradation, unknown Lipschitz constants, measurement/estimation noise, gradient estimation, sufficient excitation, and the handling of soft constraints and/or a numerical cost function a

This work focuses on the design, simulation and optimization of a Rectisol®-based process tailored for the selective removal of H2S and CO2 from gasification derived synthesis gas. Such task is quite challenging due to the need of addressing simultaneously the process design, energy integration and utility design. The paper, starting from a Rectisol® configuration recently proposed by the authors, describes the models and the solution strategy used to carry out the multi-objective optimization with respect

We have realized an implantable and wearable system for the continuous monitoring of human metabolites, such as glucose, lactate, ATP, etc.. The implantable portion of the device consists of a cylinder of 2.2 mm in diameter and 15 mm in length to be inserted in the interstitial tissue. The implanted device houses five electrochemical biosensors for the simultaneous monitoring of metabolites, as well as temperature and pH sensors for calibration, and it transmits data to a wearable skin patch in close proxim

Efficient, real-time and unsupervised data analysis is one of the key elements for achieving scientific success in complex engineering and physical systems, of which three examples are the currently operating Joint European Torus (JET) and the soon-to-be-built International Thermonuclear Experimental Reactor (ITER) and the Square Kilometre Array (SKA) telescope. There is a wealth of signal processing techniques that are being applied to data analysis in such complex systems, and here we wish to present some

For the case of urban overhead lines, the presence of nearby buildings is expected to affect the overvoltages induced by nearby lightning return strokes. This effect until now has been seldom taken into account in the literature on the subject. The paper presents a 3D FEM model that calculates the lightning electromagnetic pulse (LEMP) taking into account the presence of building placed in proximity of the LEMP-coupled overhead line. As a first approximation, the building surfaces are assumed as perfect con

This paper presents a new approach for substrate parasitic current simulation in smart power integrated circuit. A new compact modeling approach developed in previous work has been used to create an equivalent substrate schematic. The latter is composed of new components having the peculiarity not to fully recombine minority carrier at their boundary. By the interconnection of these special components in the electrical design, the effect of substrate current is simulated. Having this information early in th

In this paper, we investigate the effect of periodically-grounded shielding wires and surge arresters on the attenuation of lightning-induced voltages. We discuss the adequacy of the commonly made simplification of assuming the shielding wire at ground potential, instead of being treated as one of the conductors of the multiconductor system. We also compare then the mitigation effect of shielding wires with that achievable by the insertion of surge arresters along the line. The computation results are first

Current profile tailoring by electron cyclotron heating (ECH) and current drive (ECCD) is used to improve central electron energy confinement in the TCV tokamak. Counter-ECCD on axis alone achieves this goal in a transient manner only. A stable scenario is obtained by a two-step sequence of err-axis ECH, which stabilizes magnetohydrodynamics modes, and on-axis counter-ECCD, which generates a flat or inverted current profile. This high-confinement regime, with central temperatures up to 9 keV (at a. normaliz

A model for the calculation of lightning-induced voltages is presented with the aim of assessing the effect of corona when power distribution lines are illuminated by lightning electromagnetic fields. Corona is taken into account by means of dynamic capacitance describing a charge-voltage diagram. Such an equivalent capacitance is then introduced in a model which describes a line illuminated by a lightning electromagnetic field. It is first concluded that the influence of corona on lightning induced overvol

Extensive simulations are performed to investigate effects of electron cyclotron instabilities on the gyrotron beam quality, using two-dimensional axisymmetric particle-in-cell (PIG) codes. Both electrostatic and electromagnetic models, as well as realistic geometries of the gyrotron, are considered. It is found that a large beam density can lead to an electrostatic-instability-induced energy spread which substantially degrades the gyrotron efficiency. (C) 1997 American institute of Physics.

A model for the calculation of lightning-induced voltages is presented allowing the assessment of the effect of corona when power distribution lines are illuminated by lightning electromagnetic fields. It is shown that, as far as corona can be described by means of an increase of capacitance after the voltage has reached a threshold value, corona can produce an increase in the peak amplitude of the induced voltage. An explanation of this result is given. The need for experimental results to test this theore

Dispersion supported transmission (DST) is a new technique which combines intensity modulation (IM) and optical frequency modulation (OFM) to allow transmission spans beyond the usual dispersion limit. Using computer simulation, DST limitations are evaluated and optimum values for the frequency deviation and receiver bandwidth are determined. Finally, the maximum transmission distance is estimated for a power penalty of 1 and 2 dB.

The paper presents a modelling procedure for evaluating the voltages and currents induced on transmission lines by nearby lightning. Models are needed in order to evaluate lightning effects where experimental results are not available. These models allow better design and coordination of the protection of power and telecommunication networks against lightning induced effects

SEMIRAMIS: an asymmetrical bounded wave EMP simulator with a good confinement inside the transmission line

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