scholarly journals Heat Transport in a Spin-Boson Model at Low Temperatures: A Multilayer Multiconfiguration Time-Dependent Hartree Study

Entropy ◽  
2020 ◽  
Vol 22 (10) ◽  
pp. 1099
Author(s):  
Chou-Hsun Yang ◽  
Haobin Wang
Keyword(s):  
Heat Transport ◽  
Thermal Flux ◽  
Quantum Dynamic ◽  
Time Dependent ◽  
Physical Parameters ◽  
Theory Approach ◽  
Dynamic Simulations ◽  
Redfield Theory ◽  
Temperature Heat ◽  
Boson Model

Extending our previous work, quantum dynamic simulations are performed to study low temperature heat transport in a spin-boson model where a two-level subsystem is coupled to two independent harmonic baths. Multilayer multiconfiguration time-dependent Hartree theory is used to numerically evaluate the thermal flux, for which the bath is represented by hundreds to thousands of modes. The simulation results are compared with the approximate Redfield theory approach, and the physics is analyzed versus different physical parameters.

Characteristics of melting heat transport of blood with time-dependent cross-nanofluid model using Keller–Box and BVP4C method

2021 ◽  
Author(s):  
Assad Ayub ◽  
Zulqurnain Sabir ◽  
Gilder Cieza Altamirano ◽  
R. Sadat ◽  
Mohamed R. Ali
Keyword(s):  
Heat Transport ◽  
Time Dependent ◽  
Melting Heat

scholarly journals Effect of Variable Viscosity and Gravity Modulation on Linear and Non-Linear Rayleigh-Benard Convection in Viscoelastic Ferromagnetic Liquids

2020 ◽  
Vol 9 (3) ◽  
pp. 3482-3488
Keyword(s):  
Stability Analysis ◽  
Heat Transport ◽  
Linear Stability ◽  
Linear Stability Analysis ◽  
Variable Viscosity ◽  
Low Frequency ◽  
Physical Parameters ◽  
Gravity Modulation ◽  
Non Linear ◽  
The Individual

The combined effect of various parameters of gravity modulation on the onset of ferroconvection is studied for both linear and non-linear stability. The effect of various parameters of ferroconvection is studied for linear stability analysis. The resulting seven-mode generalized Lorenz model obtained in non-linear stability analysis is solved using Runge -Kutta-Felberg 45 method to analyze the heat transfer. Consequently the individual effect of gravity modulation on heat transport has been investigated. Further, the effect of physical parameters on heat transport has been analyzed and depicted graphically. The low-frequency gravity modulation is observed to get an effective influence on the stability of the system. Therefore ferro convection can be advanced or delayed by controlling different governing parameters. It shows that the influence of gravity modulation stabilizes system.

scholarly journals Low-temperature heat transport in the geometrically frustrated antiferromagnetsR2Ti2O7(R = Gd and Er)

2014 ◽  
Vol 89 (9) ◽  
Author(s):  
F. B. Zhang ◽  
Q. J. Li ◽  
Z. Y. Zhao ◽  
C. Fan ◽  
S. J. Li ◽  
...  
Keyword(s):  
Low Temperature ◽  
Heat Transport ◽  
Geometrically Frustrated ◽  
Temperature Heat

Zero Mass Flux Effects on Time Dependent Flow of an Eyring Powell with Activation Energy

2020 ◽  
Vol 9 (3) ◽  
pp. 216-229
Author(s):  
Hussan Zeb ◽  
Hafiz Abdul Wahab ◽  
Umar Khan
Keyword(s):  
Activation Energy ◽  
Mass Flux ◽  
Slip Boundary Condition ◽  
Time Dependent ◽  
Physical Parameters ◽  
Detailed Result ◽  
Discussion Section ◽  
Nonlinear Odes ◽  
Zero Mass ◽  
The Impact

In this work we demonstrated the impacts of zero mass flux in Powell-Eyring fluid over time dependent stretching sheet. We analyzed the Arrhenius activation energy in heat transfer with momentum and thermal slip boundary condition. The governing model is very complex to solve it directly therefore we transform these governed model into a coupled nonlinear ODEs via similarity transformation. After that, we solve these ODEs by using numerica method so calledshooting technique with RK-technique. The characteristics of different beneficial physical parameters on momentum, energy and concentration fields are represented through graphs. We concluded in this work the arising or reducing in the velocity, temperature and concentration fields for the existence of physical parameters. The impact of physical quantities namely skin fraction (Cf), Nusselt (Nux) and Sherwood (Shx) numbers are calculated numerically via tables. In this paper we concluded that the decreases occurring in velocity field for higher values of (M) (H) and (β). Moreover the characteristics of concentration Φ(ζ), temperature θ(ζ) and velocity f′(ζ) gradients are presented for important physical parameters see in detailed Result and discussion section.

scholarly journals 1D Quantum Simulations of Electron Rescattering with Metallic Nanoblades

Instruments ◽  
2019 ◽  
Vol 3 (4) ◽  
pp. 59
Author(s):  
Joshua Mann ◽  
Gerard Lawler ◽  
James Rosenzweig
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Strong Field ◽  
Field Enhancement ◽  
Time Dependent ◽  
High Yield ◽  
Theory Approach ◽  
Full Time ◽  
Metallic Surfaces ◽  
Functional Theory

Electron rescattering has been well studied and simulated for cases with ponderomotive energies of the quasi-free electrons, derived from laser–gas and laser–surface interactions, lower than 50 eV. However, with advents in longer wavelengths and laser field enhancement metallic surfaces, previous simulations no longer suffice to describe more recent strong field and high yield experiments. We present a brief introduction to and some of the theoretical and empirical background of electron rescattering emissions from a metal. We set upon using the Jellium potential with a shielded atomic surface potential to model the metal. We then explore how the electron energy spectra are obtained in the quantum simulation, which is performed using a custom computationally intensive time-dependent Schrödinger equation solver via the Crank–Nicolson method. Finally, we discuss the results of the simulation and examine the effects of the incident laser’s wavelength, peak electric field strength, and field penetration on electron spectra and yields. Future simulations will investigate a more accurate density functional theory metallic model with a system of several non-interacting electrons. Eventually, we will move to a full time-dependent density functional theory approach.

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