scholarly journals Non-equilibrium condensation process in a holographic superconductor

2010 ◽  
Vol 2010 (7) ◽  
Author(s):  
Keiju Murata ◽  
Shunichiro Kinoshita ◽  
Norihiro Tanahashi
Keyword(s):  
Condensation Process ◽  
Holographic Superconductor ◽  
Non Equilibrium

scholarly journals Non-equilibrium field dynamics of an honest holographic superconductor

2012 ◽  
Vol 2012 (11) ◽  
Author(s):  
Xin Gao ◽  
Matthias Kaminski ◽  
Hua-Bi Zeng ◽  
Hai-Qing Zhang
Keyword(s):  
Holographic Superconductor ◽  
Non Equilibrium

scholarly journals Неравновесная кинетика начальной стадии фазового перехода

2020 ◽  
Vol 62 (1) ◽  
pp. 40
Author(s):  
Г.И. Змиевская
Keyword(s):  
Phase Transition ◽  
Transition Probability ◽  
Kinetic Equations ◽  
Elastic Interaction ◽  
Distribution Functions ◽  
Condensation Process ◽  
Stochastic Dynamic ◽  
Transition Probability Density ◽  
Temporal Structures ◽  
Non Equilibrium

Kinetic partial differential equations of Kolmogorov-Feller and Einstein-Smoluchowski equation with nonlinear coefficients are solved by a new, stable numerical methods. The theory of stochastic dynamic variables establishes the connection of the solution of Ito stochastic equations in the sense of Stratonovich for the trajectories of Wiener random processes with the transition probability density of these processes, or distribution functions of kinetic equations. The classical theory of nucleation (formation of nuclei of the first order phase transition) describes a non-equilibrium stage of the condensation process by a diffusion random process in the space of the size of the nuclei of the phase transition, when fluctuations affect the clustering of the nuclei. The model of formation of vacancy-gas defects (pores, blisters) in the crystal lattice, arising as a result of its irradiation by inert gas ions xenon, is supplemented by the consideration of Brownian motion of non-point lattice defects, occurring under the action of superposition of paired long-range potentials of indirect elastic interaction of pores between themselves and with the boundaries of the layers. Pores coordinates are changing at times of the order of 10 − 100 ms, sustainable algorithms for calculating which provide a self-consistent defnition spatial - temporal structures of porosity in the sample. According to calculations of 106 trajectories, non-equilibrium kinetic functions were found. Pores distribution in size and coordinates in the layers of the irradiated materials, they characterize the fluctuation instability the initial stage of the phase transition, they are estimated local stresses and porosity in the model volume.

scholarly journals Non-equilibrium phase and entanglement entropy in 2D holographic superconductors via gauge–string duality

2016 ◽  
Vol 94 (10) ◽  
pp. 1102-1111
Author(s):  
Najmeh Al Sadat Mazhari ◽  
Davood Momeni ◽  
Ratbay Myrzakulov ◽  
Hosein Gholizade ◽  
Muhammad Raza
Keyword(s):  
Entanglement Entropy ◽  
Equilibrium Phase ◽  
Approximate Solutions ◽  
Dynamical Instability ◽  
Holographic Superconductor ◽  
Maxwell Fields ◽  
Normal Mass ◽  
Definition Of ◽  
Log Ratio ◽  
Non Equilibrium

An alternative method of developing the theory of non-equilibrium two-dimensional holographic superconductor is to start from the definition of a time-dependent AdS3 background. As originally proposed, many of these formulae were cast in exponential form, but the adoption of the numeric method of expression throughout the bulk serves to show more clearly the relationship between the various parameters. The time dependence behavior of the scalar condensation and Maxwell fields are fitted numerically. A usual value for Maxwell field on AdS horizon is exp(–bt), and the exponential log ratio is therefore 10−8 s−1. The coefficient b of the time in the exponential term exp(–bt) can be interpreted as a tool to measure the degree of dynamical instability; its reciprocal 1/b is the time in which the disturbance is multiplied in the ratio. A discussion of some of the exponential formulae is given by the scalar field ψ(z, t) near the AdS boundary. It may be possible that a long interval would elapse in the system, which tends to the equilibrium state, where the normal mass and conformal dimensions emerged. A somewhat curious calculation has been made to illustrate the holographic entanglement entropy for this system. The foundation of all this calculation is, of course, a knowledge of multiple (connected and disconnected) extremal surfaces. There are several cases in which exact and approximate solutions are jointly used; a variable numerical quantity is represented by a graph, and the principles of approximation are then applied to determine related numerical quantities. In the case of the disconnected phase with a finite extremal area, we find a discontinuity in the first derivative of the entanglement entropy as the conserved charge J is increased.

scholarly journals Effects of the Wet Steam Non-Equilibrium Condensation on the Dynamics of the Excitation-Relying Bearing-Rotor system

2018 ◽  
Vol 179 ◽  
pp. 01005
Author(s):  
Bing Guo ◽  
Weixiao Tang ◽  
Tianhui Zhen
Keyword(s):  
Coupled Model ◽  
Coupled System ◽  
Rotor System ◽  
Rotor Blades ◽  
Condensation Process ◽  
Wet Steam ◽  
Bearing Stiffness ◽  
Stiffness And Damping ◽  
Intense Vibration ◽  
Non Equilibrium

This paper investigated the effects of the wet steam non-equilibrium condensation on the dynamic characteristics of the bearing as well as the bearing-rotor system by constructing and analyzing a non-linear coupled model of the bearing-rotor system. An excitation-relying dynamic model of bearing is established based on the finite difference method, in which the excitation is converted from the pressure pulsation on the surface of rotor blades generated from the non-equilibrium condensation process. The Raccia transfer matrix method is implemented to analyse the dynamic behavior of this coupled system. Results show that the wet steam non-equilibrium condensation process would greatly reduce the bearing stiffness and damping and result in more intense vibration of the system, besides, its induced pulsed displacement would drive the excitation-relying bearing-rotor system more unstable.

Improved Non-Equilibrium Film Method for the Design of High-Temperature-Glide, Mini- and Microchannel Condensers

2014 ◽  
Author(s):  
Brian M. Fronk ◽  
Srinivas Garimella
Keyword(s):  
Mass Transfer ◽  
High Temperature ◽  
Heat And Mass Transfer ◽  
Design Method ◽  
Film Theory ◽  
High Heat ◽  
Condensation Process ◽  
Ammonia Water ◽  
Small Channels ◽  
Non Equilibrium

High-temperature-glide (i.e., large difference in dew and bubble point temperature) zeotropic mixtures such as ammonia/water have the potential to improve efficiency as new working fluids in advanced energy cycles for heating, cooling and power. Furthermore, the high heat capacity of ammonia/water mixtures makes them particularly attractive for use in compact mini- and microchannel devices. The non-isothermal condensation process of zeotropic mixtures leads to coupled heat and mass transfer resistances in each phase, which are not accounted for by single-component in-tube condensation modeling and correlation techniques. Previous attempts to design zeotropic condensers have relied on use of non-equilibrium film theory or mixture resistance correction factors. The film theory models have been developed with many simplifying assumptions including annular flow, negligible condensate and vapor sensible heat loads, and/or laminar condensate film, while the correction factor approaches do not directly consider mass transfer resistances. In the present study of high-temperature-glide mixtures in small channels, these assumptions are relaxed, and a new design method for mini- and microchannel zeotropic condensers is introduced. The approach is validated with experiments conducted for a range of tube diameters (0.98 < D < 2.16 mm), mass fluxes (50 < G < 200 kg m−2 s−1) and mass fractions of ammonia (0.80 < xbulk < 0.96). The results can be used in the development of compact, highly efficient heat and mass transfer devices.

A Study of Spontaneous Condensation in an LP Test Turbine

2015 ◽  
Author(s):  
Kane Chandler ◽  
Mauro Melas ◽  
Teresa Jorge
Keyword(s):  
Operating Conditions ◽  
Experimental Results ◽  
Light Extinction ◽  
Condensation Process ◽  
Inlet Temperature ◽  
Specific Work ◽  
Equilibrium Flow ◽  
Scaled Model ◽  
Local Flow ◽  
Non Equilibrium

Recent advances in computational fluid dynamics (CFD) offer the possibility to predict condensing flows in 3D LP steam turbine geometries. Correct analysis of wetness losses, droplet deposition and other two-phase effects in LP steam turbines requires accurate prediction of the non-equilibrium flow field and droplet sizes. The paper compares numerical results from a 3D, polydispersed, condensing flow CFD code to experimental data measured in a scaled model LP turbine for a range of operating conditions. In order to compare the computed efficiencies with the measured values, a method for averaging non-equilibrium flow fields has been developed. Comparisons are made between computational and experimental results for a series of inlet temperature variation tests where the inlet and exit pressures were kept constant. The steady calculations accurately predict the temperature that the primary nucleation zone moves to an upstream row. Furthermore, the mechanism of condensation as nucleation changes rows is explored and it is shown that initially a significant degree of subcooling is maintained in the inter-blade section and, as a result, nucleation occurs at a relatively low rate in a zone that extends far downstream of the blade’s trailing edge. This produces relatively large droplets compared to when nucleation occurs predominantly within the blade passage and is clearly visible in the measured module efficiencies and local flow angles, static pressures and light extinction. The measured variation of efficiency and specific work with inlet temperature is predicted accurately by the computations. It is concluded that steady condensing flow wet-steam calculations are able to predict the location of nucleation and the variation of flow dynamics and performance with inlet temperature accurately. A description of the condensation process as nucleation moves between rows has been given and is consistent with the numerical and experimental results.

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