Search results for " Heating"
showing 10 items of 150 documents
Sustainable and cost-efficient energy supply and utilisation through innovative concepts and technologies at regional, urban and single-user scales
2019
Abstract The environmental impact of the energy sector and the security and economics of energy supply and utilisation have been raising increasing concerns, stimulating the search for innovative solutions for a sustainable use of resources. This article provides an overview of published research in this area, with a focus on papers contributed in special issues of leading journals dedicated to the series of Conferences on Sustainable Development of Energy, Water and Environment Systems (SDEWES), including the articles in the current special issue. Based on this review, research trends are identified and achievements supporting the energy transition are highlighted. The studies that focused…
Overview of first Wendelstein 7-X high-performance operation
2019
Abstract The optimized superconducting stellarator device Wendelstein 7-X (with major radius , minor radius , and plasma volume) restarted operation after the assembly of a graphite heat shield and 10 inertially cooled island divertor modules. This paper reports on the results from the first high-performance plasma operation. Glow discharge conditioning and ECRH conditioning discharges in helium turned out to be important for density and edge radiation control. Plasma densities of with central electron temperatures were routinely achieved with hydrogen gas fueling, frequently terminated by a radiative collapse. In a first stage, plasma densities up to were reached with hydrogen pellet injec…
Characterization and reactivity of charcoal from high temperature pyrolysis (800-1600°C)
2019
This study presents the effect of wood origin and heat treatment temperature on the CO2 reactivity, nanostructure and carbon chemistry of chars prepared at 800, 1200, and 1600 °C in slow pyrolysis reactors. The structure of charcoal was characterized by transmission electron microscopy, Raman spectroscopy, mercury intrusion porosimetry and N2 adsorption. The CO2 reactivity of char was investigated by thermogravimetric analysis. Results showed that spruce and oak chars have similar reactivity at all heat treatment temperatures. The oak char prepared at 1600 °C contained long and flat graphene layers and interplanar distance that is similar to graphite and thus, was more ordered t…
Modelling of combined ICRF and NBI heating in JET hybrid plasmas
2017
During the 2015-2016 JET campaigns many efforts have been devoted to the exploration of high performance plasma scenarios envisaged for ITER operation. In this paper we model the combined ICRF+NBI heating in selected key hybrid discharges using PION. The antenna frequency was tuned to match the cyclotron frequency of minority hydrogen (H) at the center of the tokamak coinciding with the second harmonic cyclotron resonance of deuterium. The modelling takes into account the synergy between ICRF and NBI heating through the second harmonic cyclotron resonance of deuterium beam ions which allows us to assess its impact on the neutron rate RNT. We evaluate the influence of H concentration which w…
The Role of Combined ICRF and NBI Heating in JET Hybrid Plasmas in Quest for High D-T Fusion Yield
2017
Combined ICRF and NBI heating played a key role in achieving the world-record fusion yield in the first deuterium-tritium campaign at the JET tokamak in 1997. The current plans for JET include new experiments with deuterium-tritium (D-T) plasmas with more ITER-like conditions given the recently installed ITER-like wall (ILW). In the 2015-2016 campaigns, significant efforts have been devoted to the development of high-performance plasma scenarios compatible with ILW in preparation of the forthcoming D-T campaign. Good progress was made in both the inductive (baseline) and the hybrid scenario: a new record JET ILW fusion yield with a significantly extended duration of the high-performance pha…
Study of thermomagnetic energy conversion driven by renewable energy
2017
Magnetic heating, refrigeration and energy conversion have been defined very important challenges for promising environmentally future choices. Recent studies are focused attention on new thermomagnetic systems, devices working through thermomagnetic effect, driven by renewable energies. The aim of this work is a case study presentation of new thermomagnetic energy prototype coupled with renewable technologies or industrial waste heat. The paper is divided into four sections: the first gives a general state of art about magneto-caloric energy conversion systems, the second describes all general thermodynamics and magnetic laws governing the process, the third and fourth sections study in mo…
Flash microwave synthesis and sintering of nanosized La0.75Sr0.25Cr0.93Ru0.07o3–δ for fuel cell application.
2009
International audience; Perovskite-oxide nanocrystals of La0.75Sr0.25Cr0.93Ru0.07O3–δ with a mean size around 10 nm were prepared by microwave flash synthesis. This reaction was performed in alcoholic solution using metallic salts, sodium ethoxide and microwave autoclave. The obtained powder was characterised after purification by energy dispersive X-ray analysis (EDX), X-ray powder diffraction (XRD), BET adsorption technique, photon correlation spectroscopy (PCS) and transmission electron microscopy (TEM). The results show that integrated perovskite-type phase and uniform particle size were obtained in the microwave treated samples. At last the synthesised powder was directly used in a sin…
Plasma diagnostic tools for ECR ion sources : What can we learn from these experiments for the next generation sources
2019
International audience; The order-of-magnitude performance leaps of ECR ion sources over the past decades result from improvements to the magnetic plasma confinement, increases in the microwave heating frequency, and techniques to stabilize the plasma at high densities. Parallel to the technical development of the ion sources themselves, significant effort has been directed into the development of their plasma diagnostic tools. We review the recent results of Electron Cyclotron Resonance Ion Source (ECRIS) plasma diagnostics highlighting a number of selected examples of plasma density, electron energy distribution, and ion confinement time measurements, obtained mostly with the second-gener…
High-Temperature Short-Time Inactivation of Peroxidase by Direct Heating with a Five-Channel Computer-Controlled Thermoresistometer
1997
The thermal inactivation kinetics of horseradish and asparagus peroxidase in high-temperature short-time conditions was studied by heating in a five-channel computer-controlled thermoresistometer. Horseradish peroxidase was heated between 111.5 and 145°C and the reaction was analyzed assuming that two isoenzymes with EaL = 44.1 and Eas = 22.0 kcal/mol were present. Asparagus peroxidase heated from 110 to l20°C reacted with first-order kinetics, with Ea = 20 kcal/mol. The five-channel computer-controlled thermoresistometer enabled us to study the inactivation kinetics of the more labile fraction of horseradish peroxidase at temperatures above 100°C; this equipment was suitable for studying t…
Fast Response Heating Module for Temperature Programmed GC Analysis in Microreaction Systems
2000
For monitoring the reactant and product concentrations of a gas phase microreactor for ethylene oxide synthesis the development of a miniaturised device for fast GC analysis suitable for operation in conjunction with the microreactor is advantageous. Therefore, a method employing short (0.2 – 0.4 m) packed capillary columns was developed. Highly crosslinked polystyrene microspheres proved to be the most suitable adsorbent enabling a high separation efficiency. For fast temperature programming design concepts for an efficient heating module capable to be used with short capillary columns were developed. In principle, planar as well as cylindrical designs are suitable for integration of a res…