Integrated analysis of quench propagation in a system of magnetically coupled superconducting coils

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Since their advent in the early 20th century, lightning detection and location systems (LLSs) have become a substantial component of weather observation and undergone a remarkable evolution both in their capabilities and their performance. Nowadays, ground-based low-frequency lightning location systems are able to locate the strike point of cloud-to-ground lightning discharges with a median location error that is in the order of 100 - 150 m, and estimate the peak currents of lightning return strokes with re

Accurate and rapid simulation of the free boundary tokamak plasma equilibrium evolution is essential for modern plasma control, stability analysis, and scenario development. This paper presents the Free-Boundary Grad-Shafranov Evolutive (FGE) code, a highly flexible and control-oriented solver designed to address the challenges posed by advanced plasma configurations across a range of devices. FGE evolved from the FBT [Hofmann, 1988] and LIUQE [Moret et al., 2015] codes and is part of the MEQ suite, sharing

The SARS-CoV-2 outburst in March 2020 has led to the lockdown of several countries across the world. Mobility restrictions have been constantly put into action and reversed to find the trade-off between minimizing the number of infections and death and mitigating the inevitable damage to the economy and the societal systems. These emergency measures lead to collateral effects that prove the need for robust and dynamic models for policymakers to make efficient and targeted decisions in short amounts of time.

The power exhaust through the scrape-off layer (SOL) in fusion reactors is expected to be significantly higher than in ITER, thus questioning the extrapolation of the ITER exhaust solution to these devices. The snowflake (SF) magnetic configuration is one of the alternative exhaust configurations being considered to mitigate the heat vessel loads in fusion reactors. The SF configuration features a second-order null of the poloidal magnetic field, i.e. a point where the poloidal magnetic field and its spatia

Impedance analyzers are essential equipment's for any engineer working in the domain of electrical circuits. The impedance of a circuit is determined by exciting this later with a sine voltage over a frequency span and by observing the current consequently flowing through it (or vice versa). The excitation level is limited to low amplitudes and in some cases, is not sufficient to reach the saturation/non-linearity zone of the circuit while it does have to be used, and therefore charactefized, in that zone.

Extensive work on flow boiling in microchannels with the aim of cooling of electronics has been undertaken in the past 15 to 20 years. With this knowledge in hand, the next step is to develop detailed, accurate and validated simulation codes for steady-state and transient operations of (i) the entire thermal package (micro-channel evaporator, its inlet and outlet ports, the thermal interface material and the electronic chip), (ii) the flow distribution to multiple chips to be cooled in parallel, and (ii) th

Purpose – Since pulsed lasers are mainly used in selective laser sintering (SLS) – contrarily to selective laser melting (SLM) – only the exterior of the powder particles is molten while their core stays solid. The purpose of this paper is to investigate the binding mechanism between two particles of titanium powder. Design/methodology/approach – A dedicated experimental setup is used to isolate the particles. They are then irradiated by the laser. SEM micrographs are taken at each step and image analysis i

High demographic dynamics and greater poverty in developing countries carry the urgent need to provide low cost housing to the poorest in urban regions. In Colombia the development of social housing settlements is characterized by two deficits, a quantitative one (related to urban density) and a qualitative one (related to indoor building conditions). It is therefore imperative to identify solutions that may lead to the adequate development of social housing in Colombia. This paper studies the relation betw

The Advanced Single-stage Planar Actuator (ASPA) is a nanometer-accurate magnetically levitated planar actuator with moving magnets. It is designed at the Eindhoven University of Technology in collaboration with an industrial partner active in the semiconductor industry. The first version of the ASPA is already industrialized. In order to significantly improve both accuracy and acceleration, the design procedure of a new ASPA is started. The goal of this project is to generate a thermal model of the ASPA an

Bent-crystal channeling is a technique with a potential to increase beam-halo collimation efficiency in high-energy colliders. First measurements at the Tevatron in 2005 have shown that using a thin silicon crystal to deflect the 1-TeV proton beam halo onto a secondary collimator improves the system performance by reducing the machine impedance, beam losses in the collider detectors and irradiation of the superconducting magnets, all in agreement with simulations. Recent results, obtained with an improved g

The flow pattern based flow boiling heat transfer and two-phase pressure drop models for CO2, recently developed by Cheng et al. [L Cheng, G. Ribatski. J. Moreno Quiben, J.R. Thome, New prediction methods for CO2 evaporation inside tubes: Part I - A two-phase flow pattern map and a flow pattern based phenomenological model for two-phase flow frictional pressure drops, Int. J. Heat Mass transfer 51 (2008) 111-124; L Cheng, G. Ribatski, J.R. Thome, New prediction methods for CO2 evaporation inside tubes: Part

If process modelling is a well known approach to compute the performances of fuel cell systems, the optimal design of systems where the process configuration is not fixed a priori remains an issue. The goal of the presented methodology for integrating and optimising fuel cell systems is to help in this preliminary design step. The thermo-economic model developed includes three parts : 1) the energy flow model that represent the thermodynamic performances of the chemical and energy conversions in the physica

The control of the current, position and shape of an elongated cross-section tokamak plasma is complicated by the instability of the plasma vertical position. In this case the control becomes a significant problem when saturation of the power supplies is considered. Current saturation is relatively benign due to the integrating nature of the tokamak, resulting in a reasonable time horizon for strategically handling this problem. On the other hand, voltage saturation is produced by the feedback controller it

For describing the E-J relation of high-Tc superconductors (HTS) in power applications, where the applied current I is generally limited by Ic, the critical state model, a piecewise linear generalization, or a simple power-law of the type E=Ec(J/Jc)^n are most often used. The power-law cannot be used for modelling the E-J relation with I>>I_c due to the unbound exponential increase of the electric field for currents above Ic, while in reality the non-linear HTS resistivity is limited by its normal state val

Within the EFDA technology program, CRPP designed and prepared a short length of full size Nb3Sn developmental conductor to be tested in the SULTAN test facility. Nb3Sn strand with a higher specification and low Cu:non-Cu ratio was supplied by Outokumpu. Half of the produced wire length has been Cr-plated half was left bare. Subsequently, two Ti-jacketed cable-in-conduit conductors based on a braid as the first stage, have been manufactured by VNIIKP. After reaction heat treatment, the annular space of the

We report direct absorption spectroscopic detection of ozone at ambient pressure with a pulsed, DFB quantum-cascade laser (QCL) tuned within 1044-1050 cm(-1) by temperature scanning. Wavelength calibration curves were derived from FTIR and CO2 spectra and interpreted with respect to the heat transfer from the heterostructure to the sink. The laser linewidth (similar to0.13 cm(-1) FWHM) was found to decrease with temperature, probably as a result of operation at constant current. Spurious spectral features d

For many years, calorimetry has been recognized as a powerful and universal tool for monitoring chem. and biol. processes. A lab.-scale reaction calorimeter (RC1, Mettler-Toledo), initially developed for chem. reaction studies with a sensitivity of 100-150 mW/l, has been improved to enable the monitoring of very low heat prodn. rates (

The high-pressure freezing (HPF) technique was applied to the cryo-immobilization of alginate gels and the quality of the freezing analyzed on a TEM by comparison of the segregation pattern of samples of decreasing thickness. Dynamic simulations of heat transfer within an idealized slab of pure water surrounded by two walls of aluminum were performed to illustrate the effect of the heat-transfer coeff. by convection on the cooling rate of the sample. Heat-transfer coeffs. in liq. nitrogen and liq. propane a

The nonlinear behavior of High Temperature Superconductors (HTS) is often modeled by an E-J power law in order to describe their electromagnetic properties. This paper presents AC loss calculations in HTS tapes, performed by means of FEM commercial software using the A-V method. The implemented nonlinear model of the HTS tapes takes into account the B-dependence of the critical current density Jc and the power index n. The expressions for Jc(B) and n(B) are obtained from electrical measurements of a Bi-2223

We used a pump-probe technique to measure the transient change of optical reflectivity of both La2-xSrxCuO4, of various dopings, and slightly underdoped YBa2Cu3O7-x and NdBa2Cu3O7-x thin films. For the La2-xSrxCuO4 films, our data demonstrate the coexistence, in the superconducting state, of two coupled subsystems with different relaxation times and different contributions to the optical reflectivity. One subsystem is associated with the superconducting phase. By contrast. the data from YBa2Cu3O7-x, and NdB

Integrated analysis of quench propagation in a system of magnetically coupled superconducting coils

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Urban Energy Simulation of a Social Housing Neighbourhood in Bogota, Colombia

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Low-temperature electron microscopy for the study of polysaccharide ultrastructures in hydrogels. I. Theoretical and technical considerations

Finite element method simulation of ac loss in HTS tapes with B-dependent E-J power law

Evidence for two coupled subsystems in the superconducting state of La2-xSrxCuO4