scholarly journals Runaway dynamics in the DT phase of ITER operations in the presence of massive material injection

2020 ◽  
Vol 86 (4) ◽  
Author(s):  
O. Vallhagen ◽  
O. Embreus ◽  
I. Pusztai ◽  
L. Hesslow ◽  
T. Fülöp
Keyword(s):  
Electric Fields ◽  
Ohmic Heating ◽  
Noble Gas ◽  
Temperature Evolution ◽  
Plasma Current ◽  
High Current ◽  
Radiation Losses ◽  
Initial Plasma ◽  
Wide Range ◽  
Avalanche Generation

A runaway avalanche can result in a conversion of the initial plasma current into a relativistic electron beam in high-current tokamak disruptions. We investigate the effect of massive material injection of deuterium–noble gas mixtures on the coupled dynamics of runaway generation, resistive diffusion of the electric field and temperature evolution during disruptions in the deuterium–tritium phase of ITER operations. We explore the dynamics over a wide range of injected concentrations and find substantial runaway currents, unless the current quench time is intolerably long. The reason is that the cooling associated with the injected material leads to high induced electric fields that, in combination with a significant recombination of hydrogen isotopes, leads to a large avalanche generation. Balancing Ohmic heating and radiation losses provides qualitative insights into the dynamics; however, an accurate modelling of the temperature evolution based on energy balance appears crucial for quantitative predictions.

scholarly journals Измерение мощности радиационных потерь и эффективного заряда плазмы на токамаке Глобус-М2

2021 ◽  
Vol 47 (2) ◽  
pp. 9
Author(s):  
Е.А. Тюхменева ◽  
Н.Н. Бахарев ◽  
В.И. Варфоломеев ◽  
В.К. Гусев ◽  
Н.С. Жильцов ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electron Density ◽  
Central Region ◽  
Input Power ◽  
Toroidal Magnetic Field ◽  
Plasma Current ◽  
Radiation Losses ◽  
Radiated Power ◽  
Wide Range ◽  
Measurement Results

This paper presents the measurement results of the radiated power Prad and the effective ion charge Zeff in a toroidal magnetic field of up to 0.7 T and a plasma current of up to 300 kA for a wide range of electron density, which were first obtained on the Globus-M2 tokamak. An analysis of the results demonstrated that the content of radiation losses relative to the input power decreased in the Globus-M2 tokamak compared to the Globus-M tokamak, and the measured profiles of Prad had a strong dip in the central region. In addition, a decrease of the effective ion charge Zeff with increasing electron density was observed.

scholarly journals Technologies and Extraction Methods of Polyphenolic Compounds Derived from Pomegranate (Punica granatum) Peels. A Mini Review

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 236
Author(s):  
Dimitrios Lampakis ◽  
Prodromos Skenderidis ◽  
Stefanos Leontopoulos
Keyword(s):  
Electric Fields ◽  
Bioactive Compounds ◽  
New Technologies ◽  
Ohmic Heating ◽  
Punica Granatum ◽  
Extraction Methods ◽  
Added Value ◽  
Green Solvents ◽  
Ultrasound Assisted Extraction ◽  
Functional Product

The interest in using plant by-product extracts as functional ingredients is continuously rising due to environmental and financial prospects. The development of new technologies has led to the achievement of aqueous extracts with high bioactivity that is preferable due to organic solvents nonuse. Recently, widely applied and emerging technologies, such as Simple Stirring, Pressure-Applied Extraction, Enzymatic Extraction, Ultrasound-Assisted Extraction, Pulsed Electric Fields, High Hydrostatic Pressure, Ohmic Heating, Microwave Assistant Extraction and the use of “green” solvents such as the deep eutectic solvents, have been investigated in order to contribute to the minimization of disadvantages on the extraction of bioactive compounds. This review is focused on bioactive compounds derived from pomegranate (Punica granatum) peels and highlighted the most attractive extraction methods. It is believed that these findings could be a useful tool for the pomegranate juices industry to apply an effective and economically viable extraction process, transforming a by-product to a high added value functional product.

The vibration of electrified water drops

1971 ◽  
Vol 322 (1551) ◽  
pp. 523-534 ◽  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Axial Ratio ◽  
Uniform Electric Field ◽  
Interferometric Technique ◽  
Photographic Analysis ◽  
Wide Range ◽  
Water Drops ◽  
Strength And Deformation ◽  
A Charge

Pressure has been used as the principal parameter in calculations of the fundamental vibrational frequencies of spherical drops of radius R , density ρ, and surface tension T carrying a charge Q or uncharged spheroidal drops of axial ratio a / b situated in a uniform electric field of strength E . Freely vibrating charged drops have a frequency f = f 0 ( 1 - Q 2 /16π R 3 T ) ½ , as shown previously by Rayleigh (1882) using energy considerations; f 0 is the vibrational frequency of non-electrified drops (Rayleigh 1879). The fundamental frequency of an uncharged drop in an electric field will decrease with increasing field strength and deformation a / b and will equal zero when E ( R )/ T ) ½ = 1.625 and a / b = 1.86; these critical values correspond to the disintegration conditions derived by Taylor (1964). An interferometric technique involving a laser confirmed the accuracy of the calculations concerned with charged drops. The vibration of water drops of radius around 2 mm was studied over a wide range of temperatures as they fell through electric fields either by suspending them in a vertical wind tunnel or allowing them to fall between a pair of vertical electrodes. Photographic analysis of the vibrations revealed good agreement between theory and experiment over the entire range of conditions studied even though the larger drops were not accurately spheroidal and the amplitude of the vibrations was large.

High-Current Plasma Current Opening Switch Powered from Magneto-Cumulative Generator

2007 ◽  
Author(s):  
A.S. Boriskin ◽  
P.N. Burenkov ◽  
V.A. Demidov ◽  
P.I. Golyakov ◽  
S.A. Kazakov ◽  
...  
Keyword(s):  
Plasma Current ◽  
High Current ◽  
Opening Switch

scholarly journals Improving of electrical channels for magnetotelluric sounding instrumentation

2015 ◽  
Vol 4 (2) ◽  
pp. 149-154 ◽  
Author(s):  
A. M. Prystai ◽  
V. O. Pronenko
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Deep Structure ◽  
Experimental Tests ◽  
Magnetotelluric Sounding ◽  
Earth’S Crust ◽  
Geomagnetic Variations ◽  
The Earth ◽  
Wide Range ◽  
Earth's Crust

Abstract. The study of the deep structure of the Earth's crust is of great interest for both applied (e.g. mineral exploration) and scientific research. For this the electromagnetic (EM) studies which enable one to construct the distribution of electrical conductivity in the Earth's crust are of great use. The most common method of EM exploration is magnetotelluric sounding (MT). This passive method of research uses a wide range of natural geomagnetic variations as a powerful source of electromagnetic induction in the Earth, producing telluric current variations there. It includes the measurements of variations of natural electric and magnetic fields in orthogonal directions at the surface of the Earth. By this, the measurements of electric fields are much more complicated metrological processes, and, namely, they limit the precision of MT prospecting. This is especially complicated at deep sounding when measurements of long periods are of interest. The increase in the accuracy of the electric field measurement can significantly improve the quality of MT data. Because of this, the development of a new version of an instrument for the measurements of electric fields at MT – both electric field sensors and the electrometer – with higher levels relative to the known instrument parameter level – was initiated. The paper deals with the peculiarities of this development and the results of experimental tests of the new sensors and electrometers included as a unit in the long-period magnetotelluric station LEMI-420 are given.

scholarly journals Orientation of Temporal Interference for Non-Invasive Deep Brain Stimulation in Epilepsy

2020 ◽  
Author(s):  
Florian Missey ◽  
Evgeniia Rusina ◽  
Emma Acerbo ◽  
Boris Botzanowski ◽  
Romain Carron ◽  
...  
Keyword(s):  
Electric Fields ◽  
Brain Regions ◽  
Intracranial Stimulation ◽  
Epileptogenic Zone ◽  
Implanted Electrodes ◽  
Non Invasive ◽  
Gamma Range ◽  
Wide Range ◽  
Drug Resistant Epilepsy ◽  
Intracranial Electrodes

AbstractIn patients with focal drug-resistant epilepsy, electrical stimulation from intracranial electrodes is frequently used for the localization of seizure onset zones and related pathological networks. The ability of electrically stimulated tissue to generate beta and gamma range oscillations, called rapid-discharges, is a frequent indication of an epileptogenic zone. However, a limit of intracranial stimulation is the fixed physical location and number of implanted electrodes, leaving numerous clinically and functionally relevant brain regions unexplored. Here, we demonstrate an alternative technique relying exclusively on nonpenetrating surface electrodes, namely an orientation-tunable form of temporally-interfering (TI) electric fields to target the CA3 of the mouse hippocampus which focally evokes seizure-like events (SLEs) having the characteristic frequencies of rapid-discharges, but without the necessity of the implanted electrodes. The orientation of the topical electrodes with respect to the orientation of the hippocampus is demonstrated to strongly control the threshold for evoking SLEs. Additionally, we demonstrate the use of square waves as an alternative to sine waves for TI stimulation. An orientation-dependent analysis of classic implanted electrodes to evoke SLEs in the hippocampus is subsequently utilized to support the results of the minimally-invasive temporally-interfering fields. The principles of orientation-tunable TI stimulation seen here can be generally applicable in a wide range of other excitable tissues and brain regions, overcoming several limitations of fixed electrodes which penetrate tissue.

scholarly journals Mechanisms Responsible for Arc Cooling in Different Gases in Turbulent Nozzle Flow

2017 ◽  
Vol 4 (3) ◽  
pp. 234-240 ◽  
Author(s):  
Y. Guo ◽  
H. Zhang ◽  
Y. Yao ◽  
Q. Zhang ◽  
J. D. Yan
Keyword(s):  
Material Properties ◽  
High Speed ◽  
Gas Flow ◽  
Ohmic Heating ◽  
Circuit Breaker ◽  
Fault Current ◽  
High Current ◽  
Physical Mechanisms ◽  
Current Zero ◽  
Different Gases

A high voltage gas blast circuit breaker relies on the high speed gas flow in a nozzle to remove the energy due to Ohmic heating at high current and to provide strong arc cooling during the current zero period to interrupt a fault current. The physical mechanisms that are responsible for the hugely different arc cooling capabilities of two gases (SF<sub>6</sub> and air) are studied in the present work and important gas material properties controlling the cooling strength identified.

scholarly journals A III B VI PHOTOVOLTAIC RECEPTORS FOR EXPERIMENTAL DETERMINATION OF CARBON COMPOUNDS IN ATMOSPHERE

2016 ◽  
Vol 19 (3) ◽  
Author(s):  
IULIANA CARAMAN ◽  
IGOR EVTODIEV ◽  
OXANA RACOVEŢ ◽  
MARIUS STAMATE
Keyword(s):  
Electric Fields ◽  
Full Range ◽  
Absorption Bands ◽  
Gaseous State ◽  
Wide Range ◽  
Carbon Compounds ◽  
Strong Electric Fields ◽  
Qualitative Measurements ◽  
Semiconductor Type

<p><span lang="EN-US">This paper examines the prospects of using semiconductor layered A<span class="apple-converted-space"> </span><sup>III</sup><span class="apple-converted-space"> </span>B<span class="apple-converted-space"> </span><sup>VI</sup><span class="apple-converted-space"> type -</span> photovoltaic cells<span class="apple-converted-space"> </span>and the photoresis<span class="apple-converted-space">tors</span> as receptors<span class="apple-converted-space"> </span>for quantitative and qualitative measurements of carbon oxides. Carbon compounds in gaseous state form absorption bands of<span class="apple-converted-space"> </span>electromagnetic<span class="apple-converted-space"> </span>radiation in a wide range of spectrum (200 ÷ 100 000) cm<sup>-1</sup>.<span class="apple-converted-space"> </span>The light absorbed<span class="apple-converted-space"> </span>or emitted<span class="apple-converted-space"> </span>in these bands <span class="apple-converted-space">at the</span> excitations with ionizing radiation (X, γ) or strong electric fields contain direct information about the<span class="apple-converted-space"> </span>concentration of these molecules.  The frequencies that<span class="apple-converted-space"> </span>correspond to maxima of these bands are characteristic parameters of absorbing molecules. Fundamental absorption bands of CO, CO<span class="apple-converted-space"> </span><sub>2</sub> and NC have the edge of band at the border of ultraviolet-vacuum, while the emission bands <em>d</em> cover their full range of wave numbers from 45000 cm<sup>-1 </sup>to 10000 cm<sup>-1</sup>. Two types of radiation receptors from lamellar semiconductor type A<sup>III</sup>B<sup>VI</sup><span class="apple-converted-space"> </span>photosensitive in this spectral range are studied.</span></p>

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