Article
Mathematics
Lorenzo Campoli, Elena Kustova, Polina Maltseva
Summary: This study explores the usage of machine learning algorithms to reduce the computational cost of state-to-state numerical simulations of high-speed reacting flows. By comparing different machine learning regression models, accurate predictions of relaxation source terms are possible in significantly shorter times. Strategies to speed up the solver were also investigated by coupling it with pre-trained machine learning algorithms. The results show that the performance depends on the interfaced codes and the set of variables used for coupling. Additionally, a deep neural network was used to infer the solution of the state-to-state Euler system of equations solely based on data.
Article
Chemistry, Physical
Zhaoxi Sun, Qiaole He
Summary: The combination of free energy simulations in the alchemical and configurational spaces provides a feasible route to access the thermodynamic profiles under a computationally demanding target Hamiltonian. In this work, the possibility of further accelerating the nonequilibrium free energy simulation is explored by employing unidirectional pulling and using a selection criterion. Numerical tests are performed to provide insights and guidelines for using this selection-criterion-based scheme.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Thermodynamics
Ahmed G. Abo-Khalil, Maaza Abdalla, Ramesh C. Bansal, Nsilulu T. Mbungu
Summary: This study explores islanding detection methods for distributed generators to ensure the safety and reliability of electrical networks. By evaluating various methods, including passive, active, and remote techniques, the study detects islanding phenomena in distributed generation networks, studying their merits, demerits, and overall efficacy.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Chemistry, Physical
Michael Bley, Joachim Dzubiella
Summary: The study focused on the non-equilibrium behavior during fast diffusion-influenced polymerization, examining the impact of excess free energy on the system properties through computer simulations and statistical mechanics concepts.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Physics, Nuclear
A. Dehghan Niri, H. R. Moshfegh
Summary: This study calculates the number spectrum of nonequilibrium neutrinos resulting from the deviation of neutron star matter from beta equilibrium. Realistic descriptions of nuclear matter and the presence of free hyperons in the neutron star core are taken into account. The study finds that the addition of a three-body force interaction can significantly change the trend of the symmetry energy and thus the dominant flavor of the nonequilibrium neutrinos. The presence of hyperons also affects the value of the chemical potential gap noticeably.
Article
Materials Science, Multidisciplinary
Alexander Fabian, Michael Czerner, Christian Heiliger, Hugo Rossignol, Ming-Hung Wu, Martin Gradhand
Summary: This study focuses on the calculation of spin accumulation at the surface of a thin metallic layer and makes quantitative predictions for different materials. By comparing semiclassical and fully quantum mechanical methods, it is found that the two methods agree well in the limit of the relaxation time approximation, with deviations attributed to the complexity of Fermi surfaces. Results are compared with experimental values, showing good agreement in the trend across the considered elements.
Article
Green & Sustainable Science & Technology
H. Ishaq, I. Dincer
Summary: The paper investigates three renewable energy based configurations for hydrogen production: solar PV, geothermal power generation, and biomass gasification. It suggests that biomass gasification technique provides higher hydrogen production efficiency compared to geothermal power generation and solar PV systems.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2021)
Article
Thermodynamics
Muhammed Iberia Aydin, Ibrahim Dincer
Summary: This study evaluates the feasibility of renewable and nuclear-based hydrogen production methods through a life cycle impact analysis and investigates the environmental effects of using hydrogen to power fuel cell electric buses. The results show that the Cu-Cl cycle is the most environmentally friendly method of hydrogen production, and electrolysis methods also outperform conventional hydrogen production. Fuel cell electric buses utilizing hydrogen from clean energy sources have lower emissions compared to diesel buses.
Article
Chemistry, Physical
Tatsuya Ishiyama
Summary: NE-AIMD simulations were used to study the vibrational energy relaxation path of excited non-hydrogen-bonded OH at an air/water interface. The simulations reproduced experimentally observed features, showing that relaxation time scales of free OH at the surface of pure water and isotopically diluted water are similar. It was found that both stretching vibrational coupling and bend-stretching combination band contribute to the relaxation path of free OH at the surface.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Physics, Fluids & Plasmas
Geng Li, Z. C. Tu
Summary: This paper proposes a method based on a linear nonequilibrium equality to estimate the equilibrium free-energy difference more efficiently, showcasing its accuracy and effectiveness through simulations of a Brownian particle in a double-well potential.
Article
Physics, Multidisciplinary
Zhiyuan Lin, Tong Fu, Juying Xiao, Shanhe Su, Jincan Chen, Yanchao Zhang
Summary: In this study, a double quantum-dot system with Coulomb coupling was built to investigate the connections among entropy production, free energy, and information flow. By utilizing concepts in stochastic thermodynamics and graph theory analysis, researchers were able to interpret the local second law of thermodynamics for subsystems and identify energy-related and information-related contributions to thermodynamic irreversibility. Additionally, a global cycle associated with feedback-induced information flow was found to pump electrons against the bias voltage, implementing a Maxwell demon.
Article
Physics, Multidisciplinary
Kazuyuki Kuroyama, Sadashige Matsuo, Jo Muramoto, Shunsuke Yabunaka, Sascha R. Valentin, Arne Ludwig, Andreas D. Wieck, Yasuhiro Tokura, Seigo Tarucha
Summary: We report experimental observations of charge-spin cooperative dynamics of two-electron states in a GaAs double quantum dot located in a nonequilibrium phonon environment. The spin-flip rate of a single electron is significantly enhanced when the phonon energy exceeds the lowest excitation energy in the quantum dot. In addition, the spatial gradient of phonon density between the dots leads to a higher probability of parallel spin states than antiparallel ones.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
R. A. Dumer, M. Godoy
Summary: The nonequilibrium Ising model on a restricted scale-free network has been studied using Monte Carlo simulations. The dynamics of the system are defined by the probability of one- and two-spin flip processes, simulating contact with a heat bath or an external flux of energy. The study found finite critical points and calculated thermodynamic quantities and critical exponents for the system.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2023)
Article
Physics, Fluids & Plasmas
Lee Jinwoo
Summary: When a system is in equilibrium, external perturbations result in nonequilibrium distributions. Recent experiments have shown that these nonequilibrium data can contain critical information. Jinwoo and Tanaka mathematically prove that the nonequilibrium free energy profile of a process is connected to Jarzynski's work, which dissipates while molecules perform their tasks. We verify this fact numerically and provide an example of RNA translocation analysis using a computer simulation, confirming the efficiency of the process.
Article
Agronomy
Cheng Ning Loong, Wai Yi Chau, Yu-Hsing Wang, Siu-Wai Chiu
Summary: This study proposes two methods for reconstructing tree dynamics using the mechanical energy derived from dynamic properties and motion measurements. The first method reconstructs the mechanical energy using stochastic subspace identification, while the second method optimizes a finite-element model using a particle swarm optimization algorithm. The methods are applied to analyze the vibration of a Ficus microcarpa tree under pull-and-release tests.
AGRICULTURAL AND FOREST METEOROLOGY
(2023)