scholarly journals Dissipative cooling induced by pulse perturbations

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
ANDREA NAVA ◽  
Michele Fabrizio
Keyword(s):  
Steady State ◽  
Excitation Energy ◽  
Ising Models ◽  
High Energy ◽  
Energy Sector ◽  
Low Energy ◽  
Quasi Steady State ◽  
Pulse Perturbation ◽  
Long Time ◽  
Infinite Range

We investigate the dynamics brought on by an impulse perturbation in two infinite-range quantum Ising models coupled to each other and to a dissipative bath. We show that, if dissipation is faster the higher the excitation energy, the pulse perturbation cools down the low-energy sector of the system, at the expense of the high-energy one, eventually stabilising a transient symmetry-broken state at temperatures higher than the equilibrium critical one. Such non-thermal quasi-steady state may survive for quite a long time after the pulse, if the latter is properly tailored.

Fluorescence analysis during steady-state photosynthesis

1989 ◽  
Vol 323 (1216) ◽  
pp. 253-268 ◽  
Keyword(s):  
Steady State ◽  
Excitation Energy ◽  
Fluorescence Analysis ◽  
High Energy ◽  
Photosynthetic Gas Exchange ◽  
Acceptor Side ◽  
Thioredoxin System ◽  
Psii Photochemistry ◽  
Photosynthetic Control ◽  
Absorbance Changes

Photosynthetic gas exchange of attached leaves has been measured under steady-state conditions at different light intensities and correlated with simultaneous measurements of chlorophyll fluorescence and oxidized P 700 (by absorbance changes at 820 nm). The data suggest that during light-saturated assimilation, photosystem II (PSII) photochemistry is mainly controlled by non-photochemical and non-radiative dissipation of excitation energy, rather than by accumulation of reduced acceptor, Q A , and this could be related to ‘high-energy quenching’ of fluorescence. The occurrence of oxidized P 700 at saturating light and low concentration of CO 2 suggests that in the steady state PSI photochemistry is controlled by a shortage of electron donation from the plastoquinone pool (photosynthetic control), rather than by excess electrons at the acceptor side. The significance of the oxidized form of P 700 as a ‘quencher’ of excitation energy is discussed. This control of photosystems I and II, both related to the proton gradient across the thylakoid membrane, may serve to match the potential rate of net photochemistry to the demand by the biochemical reactions. However, when light-saturated assimilation is not limited by CO 2 , PSI activity is controlled by accumulation of reduced electron acceptors, rather than by photosynthetic mechanisms. Photosynthetic control has been found to determine the redox state of the ferredoxin-thioredoxin system.

scholarly journals UV/IR MIXING AND BLACK HOLE THERMODYNAMICS

2008 ◽  
Vol 17 (01) ◽  
pp. 55-69 ◽  
Author(s):  
KOUROSH NOZARI ◽  
BEHNAZ FAZLPOUR
Keyword(s):  
Field Theory ◽  
Black Hole ◽  
Final Stage ◽  
High Energy ◽  
Energy Sector ◽  
Black Hole Thermodynamics ◽  
Low Energy ◽  
Evaporation Process ◽  
Schwarzschild Black Hole ◽  
Black Hole Evaporation

The goal of this paper is to investigate the final stage of the black-hole-evaporation process in the framework of Lorentz-violating modified dispersion relations (MDRs). As a consequence of MDRs, the high energy sector of the underlying field theory does not decouple from the low energy sector — a phenomenon known as UV/IR mixing. In the absence of exact supersymmetry, we derive an MDR which shows UV/IR mixing by a novel energy dependence. Then we investigate the effects of this type of MDRs on the thermodynamics of a radiating noncommutative Schwarzschild black hole. The final stage of black hole evaporation obtained in this framework is compared with existing pictures.

Enhanced Heat Transfer Structure Design for Ion Dump of EAST-NBI System Based on Hypervapotron

2017 ◽  
Author(s):  
Ling Tao ◽  
Chundong Hu ◽  
Yuanlai Xie
Keyword(s):  
Heat Transfer ◽  
Steady State ◽  
Energy Deposition ◽  
High Energy ◽  
Operating Conditions ◽  
Quasi Steady State ◽  
Enhanced Heat Transfer ◽  
Steady State Operation ◽  
The Future ◽  
Transfer Structure

Ion dump is an important functional component of the Neutral Beam Injection (NBI) system of Experimental Advanced Superconducting Tokamak (EAST) for absorbing un-neutralized particles deflected by deflection magnets during neutralization, and by means of the corresponding measurement and analyzing method on it, the total energy deposition value and instantaneous energy deposition distribution of the deflected ion beam can be obtained. According to the operation mechanism of the NBI system, ion dump is directly subjected to high-energy particle bombardment for long time, the corresponding heat-loaded on its plates is high, so the temperature rise control is demanding. In order to realize the running power of 2–4MW and running pulse length of more than 100s or even 1000s in the future NBI system, the structure of the ion dump must be designed in accordance with the quasi-steady state operation requirements to provide the guarantee for the steady state operation of EAST system. The Hypervapotron structure based on the subcooled boiling principle is used as an alternative structure to enhance the heat transfer of this high-heat-flux component. According to the operating requirements, space requirements, measurement requirements and beam power distribution characteristics, the engineering design and implementation of ion dump based on the enhanced heat transfer structure is realized for the future long pulse quasi-steady NBI system. The computational results of the heat-fluid-solid coupling simulation based on the two-phase heat transfer are also confirmed the feasibility of the proposed ion dump structure under quasi-steady-state operating conditions. This study is of great significance to explore the optimal heat transfer structure for quasi-steady ion dump to realize the high current, quasi-steady state and high power operation of EAST-NBI system.

scholarly journals Nature of Isoscalar Dipole Resonances in Heavy Nuclei

2018 ◽  
Vol 63 (12) ◽  
pp. 1043 ◽  
Author(s):  
V. I. Abrosimov ◽  
O. I. Davydovska
Keyword(s):  
Velocity Field ◽  
Excitation Energy ◽  
Collective Excitation ◽  
High Energy ◽  
Low Energy ◽  
Resonance Width ◽  
Heavy Nuclei ◽  
Translation Invariant ◽  
Dipole Resonance ◽  
Spherical Nuclei

The isoscalar dipole nuclear response reveals low- and high-energy resonances. The nature of isoscalar dipole resonances in heavy spherical nuclei is studied, by using a translation-invariant kinetic model of small oscillations of finite Fermi systems. Calculations of the velocity field at the centroid energy show a pure vortex character of the low-energy isoscalar dipole resonance in spherical nuclei and confirm the anisotropic compression character of the high-energy one. The evolution of the velocity field as a function of the excitation energy of the nucleus within the resonance width is studied. It is found that the low-energy isoscalar dipole resonance retains a vortex character, while with this collective excitation also involves a compression, as the energy increases. The high-energy resonance keeps the compression character with a change in the excitation energy within the resonance width, but the compression-expansion region of the velocity field related to this resonance shifts inside the nucleus.

A Stationary Solution of High-Energy Electron Reflection (HEER) for An Arbitrary Surface

1990 ◽  
Vol 48 (2) ◽  
pp. 374-375
Author(s):  
YIQUN MA
Keyword(s):  
Stationary Solution ◽  
High Energy ◽  
Bloch Wave ◽  
Dynamical Theory ◽  
High Energy Electron ◽  
Bulk Materials ◽  
Periodic Surface ◽  
Electron Transmission ◽  
Electron Reflection ◽  
Long Time

For a long time, the development of dynamical theory for HEER has been stagnated for several reasons. Although the Bloch wave method is powerful for the understanding of physical insights of electron diffraction, particularly electron transmission diffraction, it is not readily available for the simulation of various surface imperfection in electron reflection diffraction since it is basically a method for bulk materials and perfect surface. When the multislice method due to Cowley & Moodie is used for electron reflection, the “edge effects” stand firmly in the way of reaching a stationary solution for HEER. The multislice method due to Maksym & Beeby is valid only for an 2-D periodic surface.Now, a method for solving stationary solution of HEER for an arbitrary surface is available, which is called the Edge Patching method in Multislice-Only mode (the EPMO method). The analytical basis for this method can be attributed to two important characters of HEER: 1) 2-D dependence of the wave fields and 2) the Picard iteractionlike character of multislice calculation due to Cowley and Moodie in the Bragg case.

Network reconstruction based on steady-state data

2008 ◽  
Vol 45 ◽  
pp. 161-176 ◽  
Author(s):  
Eduardo D. Sontag
Keyword(s):  
Steady State ◽  
Reverse Engineering ◽  
Theoretical Method ◽  
Network Reconstruction ◽  
Quasi Steady State ◽  
State Data

This paper discusses a theoretical method for the “reverse engineering” of networks based solely on steady-state (and quasi-steady-state) data.

PROSPECTS OF OBTAINING ALTERNATIVE FUEL FROM VARIOUS BIOMASS AND WASTE SPECIES IN AZERBAIJAN

2019 ◽  
pp. 25-41
Author(s):  
O. M. Salamov ◽  
F. F. Aliyev
Keyword(s):  
Power Plants ◽  
Energy Intensity ◽  
Oil And Gas ◽  
Renewable Energy Sources ◽  
Calorific Value ◽  
High Energy ◽  
Energy Sector ◽  
Energy Sources ◽  
Mineral Fertilizers ◽  
Gaseous Fuels

The paper discusses the possibility of obtaining liquid and gaseous fuels from different types of biomass (BM) and combustible solid waste (CSW) of various origins. The available world reserves of traditional types of fuel are analyzed and a number of environmental shortcomings that created during their use are indicated. The tables present the data on the conditional calorific value (CCV) of the main traditional and alternative types of solid, liquid and gaseous fuels which compared with CCV of various types of BM and CSW. Possible methods for utilization of BM and CSW are analyzed, as well as the methods for converting them into alternative types of fuel, especially into combustible gases.Reliable information is given on the available oil and gas reserves in Azerbaijan. As a result of the research, it was revealed that the currently available oil reserves of Azerbaijan can completely dry out after 33.5 years, and gas reserves–after 117 years, without taking into account the growth rates of the exported part of these fuels to European countries. In order to fix this situation, first of all it is necessary to use as much as possible alternative and renewable energy sources, especially wind power plants (WPP) and solar photovoltaic energy sources (SFES) in the energy sector of the republic. Azerbaijan has large reserves of solar and wind energy. In addition, all regions of the country have large reserves of BM, and in the big cities, especially in industrial ones, there are CSW from which through pyrolysis and gasification is possible to obtain a high-quality combustible gas mixture, comprising: H2 + CO + CH4, with the least amount of harmful waste. The remains of the reaction of thermochemical decomposition of BM and CSW to combustible gases can also be used as mineral fertilizers in agriculture. The available and projected resources of Azerbaijan for the BM and the CSW are given, as well as their assumed energy intensity in the energy sector of the republic.Given the high energy intensity of the pyrolysis and gasification of the BM and CSW, at the present time for carrying out these reactions, the high-temperature solar installations with limited power are used as energy sources, and further preference is given to the use of WPP and SFES on industrial scale.

Electrical Damage Due to Low Energy Plasma Processing of GaAs Structures

1991 ◽  
Vol 223 ◽  
Author(s):  
Hans P. Zappe ◽  
Gudrun Kaufel
Keyword(s):  
Chemical Processes ◽  
Low Energy ◽  
Electrical Behavior ◽  
Rapid Thermal Anneal ◽  
High Temperature Anneal ◽  
Significant Damage ◽  
Low Energies ◽  
Long Time ◽  
Physical Plasma

ABSTRACTThe effect of numerous plasma reative ion etch and physical milling processes on the electrical behavior of GaAs bulk substrates has been investigated by means of electric microwave absorption. It was seen that plasma treatments at quite low energies may significantly affect the electrical quality of the etched semiconductor. Predominantly physical plasma etchants (Ar) were seen to create significant damage at very low energies. Chemical processes (involving Cl or F), while somewhat less pernicious, also gave rise to electrical substrate damage, the effect greater for hydrogenic ambients. Whereas rapid thermal anneal treatments tend to worsen the electrical integrity, some substrates respond positively to long-time high temperature anneal steps.

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