Mediaspace scheduled maintenance: Aug 25, 2026 07:00 - 12:00 AM. During this time, videos will be temporarily unavailable. Check status updates.

Concept

Densité de puissance

Publications associées (29)

Electrochemical devices and computer science: water/thermal management of proton exchange membrane fuel cells and electrolyzers in different scales

Hossein Pourrahmani

The current restrictions on the registration of combustion engines in different countries and the harmful impacts of fossil fuels on the environment and human health have motivated decision-makers to use batteries and/or fuel cells as alternatives for comb ...

EPFL2023

Spatiotemporal energy‐density distribution of time‐reversed electromagnetic fields

Farhad Rachidi-Haeri, Marcos Rubinstein, Nicolas Mora Parra, Hamidreza Karami, Elias Per Joachim Le Boudec

Time reversal exploits the invariance of electromagnetic wave propagation in reciprocal and lossless media to localize radiating sources. Time-reversed measurements are back-propagated in a simulated domain and converge to the unknown source location. The ...

2024

Reversible photo-electrochemical device for solar hydrogen and power generation

Sophia Haussener, Saurabh Yuvraj Tembhurne, Alexandre Dominique M. Cattry, Matthieu Jonin, Mahendra Patel

A reversible photo-electrochemical device operating under concentrated irradiation could offer a stand-alone solution for producing solar fuel (in photo-driven electrolysis mode) and power (in fuel cell mode). This strategy would present the advantage of h ...

2024

Modeling and optimization of PCB coils for inductive power transfer systems

Xiaotong Du

The auxiliary power supply for medium voltage converters requires high insulation capability between the source and the load. Inductive power transfer technology, with an air gap between the primary and secondary coil, offers such high insulation capabilit ...

EPFL2024

Zinc carboxylate optimization strategy for extending Al-air battery system's lifetime

Andreas Züttel, Liping Zhong, Thi Ha My Pham, Manhui Wei

Although Al-air batteries are expected to be the candidates for energy conversion systems in renewable energy market due to the higher energy density, richer reserves, and lighter mass of Al metal, the anode self-discharge is seen as a notorious issue that ...

ELSEVIER SCI LTD2023

Cotton yarns decorated with hydrothermally reduced graphene oxide for flexible supercapacitors

Dou Du

Cotton fibers, a natural cellulose, have played a critical role in the development of wearable energy storage, owning to their wearability, integrability, eco-benignity, and cost effectiveness. Graphene, a two-dimensional carbon material, possesses excelle ...

Elsevier2023

Wind farm power density optimization according to the area size using a novel self-adaptive genetic algorithm

Fernando Porté Agel, Nicolas Otto Kirchner Bossi

This work studies the power density (PD) optimization in wind farms, and its sensitivity to the available area size. A novel genetic algorithm (PDGA) is introduced, which optimizes PD and the turbine layout, by self-adapting to the PD and to the solutions ...

Pergamon-Elsevier Science Ltd2023

Measurement of WBG-based power supplies

Elison de Nazareth Matioli, Armin Jafari, Hongkeng Zhu

This paper discusses different measurement methods to evaluate the efficiency of WBG-based power supply solutions, including electrical measurement methods and their verification with calorimetric methods, and compares the performance of Si-based and GaN-b ...

IEEE2023

Evaluation Criterion of Proton Exchange Membrane (ECPEM) fuel cells considering inserted porous media inside the gas flow channel

Jan Van Herle, Hossein Pourrahmani

The focus of this study is to evaluate the effects of porous media inside the gas flow channel of Proton Exchange Membrane Fuel Cells (PEMFC) on four different output parameters of voltage, power density, pressure drop, and Nusselt number (Nu) considering ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Wind farm layout and unconstrained hub height optimization using genetic algorithms applied to different power densities

Fernando Porté Agel, Nicolas Otto Kirchner Bossi

LES and wind tunnel studies have shown significant benefit when allowing turbines (T) in a wind farm to adopt different heights. This work presents two new genetic algorithms (GA) that perform wind farm layout optimization (WFLO) involving continuous and t ...

IOP Publishing2022

Multi-Scale Study of High-Temperature Latent Heat Storage With Metallic Phase Change Materials

Nithin Mallya

Energy storage is a central issue in the green economy with half the global end energy usage being heat. Latent heat thermal energy storage (LHTES) provides an energy dense heat storage solution with a well-defined discharge temperature. Utilizing low-cost ...

EPFL2022

Experimental Electromechanical Characterization of Slotted and Slotless Miniature Bearingless Drives

Yves Perriard, Juan Patricio Tomás Peralta Fierro, Guzmán Borque Gallego

Magnetically-levitated drives are interesting in applications which demand a combination of reliable operation and high speeds. In the latter domain, slotless stators are recognized as the most suitable, as they deliver higher power density and lower speed ...

IEEE2021

Carbon-Decorated Na3V2(PO4)(3) as Ultralong Lifespan Cathodes for High-Energy-Density Symmetric Sodium-Ion Batteries

Kangning Zhao

In this work, several carbon-decorated Na3V2(PO4)(3) materials (NVP@C-750/800/850) are successfully fabricated using a solgel approach and subsequent heat treatment. When NVP@C-800 is used as a cathode, it shows an ultralong cycle life (2000 cycles) at a h ...

AMER CHEMICAL SOC2021

Redefining Energy Density for an uniaxial Dielectric Elastomer Actuator

Yves Perriard, Yoan René Cyrille Civet, Jonathan André Jean-Marie Chavanne

The dielectric elastomer actuator (DEA) is a technology known to potentially provide high energy density (0.3 - 0.4 J.cm(-3)). However, in the literature, few demonstrations have been done to evaluate this figure. To well understand the ability of this tec ...

IEEE2021

Reinforced polypyrrole with 2D graphene flakes decorated with interconnected nickel-tungsten metal oxide complex toward superiorly stable supercapacitor

Ulf Anders Hagfeldt

Prompt development of electronic devices and sensors raised the requirement for design/fabrication of advanced energy sources capable of providing considerable amount of energy for consuming platforms through practical nanotechnological approaches. For thi ...

ELSEVIER SCIENCE SA2021

Enhanced-DAB Converter: Comprehensive Design Evaluation

Elison de Nazareth Matioli, Armin Jafari, Mohammad Samizadeh Nikooytabalvandani

Soft switching in dual-active-bridge (DAB) converters enables their efficient operation at high frequencies, where the reduction in the size of magnetic components could result in ultra-high power densities. Nonetheless, losing soft-switching at high frequ ...

IEEE2021

Steady-state neutronic measurements and comprehensive numerical analysis for the BME training reactor

Mathieu Hursin

This paper describes steady-state reactor physics measurements and calculations that were performed for the Training Reactor of Budapest University of Technology and Economics (BME TR) with the purpose of benchmarking. Based on the available geometry speci ...

2021

Pushing the Limits of Efficiency and Power Density in High-Frequency Power Conversion Based on Wide-Band-Gap Technologies

Armin Jafari

The emergence of wide-band-gap (WBG) power transistors with low conduction losses and high-speed switching speeds has paved the way for more-than-ever efficient power electronics systems and huge energy saving potentials. Likewise, power density- the ratio ...

EPFL2021

Towards reproducible lithium-ion battery cycling using liquid-phase transmission electron microscopy

Jing Hou

Electric vehicles (EVs) have gained widespread attention in recent years as the dominant strategy for curbing CO2 emissions through transport electrification. Lithium-ion batteries (LIBs) are currently the most suitable and almost exclusively employed ener ...

EPFL2021

Influence of Uncertainty of Body Permittivity on Achievable Radiation Efficiency of Implantable Antennas-Stochastic Analysis

Anja Skrivervik

Design of medical sensor implants is very challenging due to numerous restrictions in terms of size and biological acceptability. In addition, large absorption and reflection of electromagnetic waves in body tissues significantly degrades the communication ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2021