Article
Optics
Naoki Kimura, Naoki Priti, Naoki Numadate, Ryunosuke Kodama, Nobuyuki Nakamura
Summary: This study investigates the ionization processes between barium ions in an electron-beam ion-trap plasma. Indirect ionization processes through metastable states lead to the production of higher-charge-state ions. The observed characteristic behavior is consistent with theoretical simulations.
Article
Astronomy & Astrophysics
A. Hui-Bon-Hoa
Summary: The study focuses on the effects of self-consistent Rosseland mean opacity calculations on stellar structure and evolution, compared with models using fixed metal mixtures. The developed strategy allows fast calculations of Rosseland opacities consistent with the chemical mix in the star. The self-consistent models show minimal structural differences compared to models with fixed metal mixtures.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Multidisciplinary Sciences
Mikhail Finko, Batikan Koroglu, Kate E. Rodriguez, Timothy P. Rose, Jonathan C. Crowhurst, Davide Curreli, Harry B. Radousky, Kim B. Knight
Summary: In this study, a coupled Monte Carlo Genetic Algorithm (MCGA) approach is used to optimize a gas phase uranium oxide reaction mechanism based on plasma flow reactor (PFR) measurements. The PFR produces a steady Ar plasma containing U, O, H, and N species with high temperature regions relevant to UO formation observation. A global kinetic treatment is used to model the chemical evolution in the PFR and produce synthetic emission signals for direct comparison with experiments. The parameter space of the uranium oxide reaction mechanism is explored via Monte Carlo sampling and refined using a genetic algorithm. The optimized reaction channels highlight the importance of the OH radical in oxidizing uranium in the PFR.
SCIENTIFIC REPORTS
(2023)
Article
Chemistry, Physical
M. Manrho, T. L. C. Jansen, J. Knoester
Summary: This paper investigates the effect of charge transfer (CT) states on the absorption spectrum of linear molecular aggregates using a scattering matrix technique. The research finds that the absorption spectrum exhibits a characteristic two-peak shape in both weak and strong coupling regimes, and suggests that the skewness of the high-frequency peak can be used to identify the strength of exciton-CT state coupling.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Astronomy & Astrophysics
A. Hui-Bon-Hoa, J-C Pain, O. Richard
Summary: This study investigates the impact of newly computed monochromatic cross sections on the Rosseland mean opacity of nickel and on the structure of main-sequence massive pulsators. The results show that the new data has similar Rosseland opacities to the Opacity Project or OPAL at high temperatures, but significant differences are observed at lower temperatures.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Physics, Fluids & Plasmas
Valentin V. Karasiev, S. X. Hu, Nathaniel R. Shaffer, Gennady Miloshevsky
Summary: This study applies a recently developed methodology based on free-energy density functional theory (DFT) to investigate the optical properties of iron and chromium in warm dense matter. The results demonstrate that the role of the exchange-correlation (XC) functional can be neglected at high temperatures, and good agreement is found with experimental measurements and other theoretical models.
Article
Chemistry, Physical
Rouzbeh Ramezani, Renzo Di Felice
Summary: The study investigated the characterization and kinetics of CO2 absorption in potassium carbonate (K2CO3) solution promoted by diethylenetriamine (DETA). It was found that the addition of small amounts of DETA resulted in a significant enhancement in CO2 absorption rate, with a reaction order of 1.6 and an activation energy of 35.6 kJ mol(-1). DETA showed better performance compared to other promoters.
GREEN ENERGY & ENVIRONMENT
(2021)
Article
Physics, Fluids & Plasmas
Menahem Krief
Summary: In this work, systematic methods for analyzing the number of relativistic electronic configurations in high-density plasmas of intermediate or high-Z elements are presented. Two useful methods for estimating the number of populated configurations are discussed, as well as the effects of temperature and density on the number of configurations are explained. Comprehensive average-atom finite-temperature density functional theory (DFT) calculations are performed to study the mechanisms leading to the huge number of populated configurations in different plasmas.
Article
Astronomy & Astrophysics
A. Perdomo Garcia, N. Vitas, E. Khomenko, M. Collados, C. Allende Prieto, I. Hubeny, Y. Osorio
Summary: The accuracy of the opacity binning method was evaluated by varying the choice of free parameters. The monochromatic opacities were used to construct ODFs, which were then compared with the results of the ATLAS code. It was found that the ODFs showed consistent results for F, G, and K-type stars, but significant differences were observed for M-type stars due to molecular line lists.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Thermodynamics
Bingjie Chen, Peng Liu, Zepeng Li, Nils Hansen, William L. Roberts, Heinz Pitsch
Summary: This study comprehensively explored the formation pathways of furan from different substrates, providing insights into the chemistry of furan formation in low temperature oxidation. The proposed new reaction pathways were found to contribute to both furan formation and fuel consumption, improving the prediction accuracy compared to the base model.
COMBUSTION AND FLAME
(2021)
Review
Physics, Nuclear
A. M. Laird, M. Lugaro, A. Kankainen, P. Adsley, D. W. Bardayan, H. E. Brinkman, B. Cote, C. M. Deibel, R. Diehl, F. Hammache, J. W. den Hartogh, J. Jose, D. Kurtulgil, C. Lederer-Woods, G. Lotay, G. Meynet, S. Palmerini, M. Pignatari, R. Reifarth, N. de Sereville, A. Sieverding, R. J. Stancliffe, T. C. L. Trueman, T. Lawson, J. S. Vink, C. Massimi, A. Mengoni
Summary: Understanding the production process of Al-26 is essential for interpreting astronomical and meteoritic data, and requires studying the nuclear reactions involved in the relevant stellar sites.
JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Julien de Wit, Iouli Gordon
Summary: The limits of our knowledge on light-matter interactions, specifically opacity models, will have an impact on the exploration of exoplanetary atmospheres. Taking these limits into account can help prevent biased claims. Guided improvements, standardization, and dissemination of opacity models will ensure maximum return on investment from next-generation observatories, including the JWST.
Article
Optics
Daiwei Zhang, N. Sedao, Nicolas Faure, Yannick Bleu, Razvan Stoian, Ciro D'amico
Summary: We use THz probe pulses to detect and analyze the dynamics of charge transport anisotropies generated by ultrafast laser two-photon absorption in Zinc Telluride (ZnTe) semi-insulating crystal. The detected anisotropy consists in a modulation of the THz transmission as a function of the orientation of the <001 > axis of ZnTe. The change in THz transmission after pump excitation is attributed to free carrier absorption of the THz field in the laser-induced electron-hole plasma.
Article
Astronomy & Astrophysics
V Witzke, A. Shapiro, M. Cernetic, R. Tagirov, N. M. Kostogryz, L. S. Anusha, Y. C. Unruh, S. K. Solanki, R. L. Kurucz
Summary: Researchers have developed an efficient code that combines opacity distribution functions, stellar atmospheres, and spectral synthesis, providing more numerical functionality and being substantially faster compared to other available codes. This all-in-one code has been validated against previous calculations and observations.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Xin Xu, Jun Chen, Xiaoxiao Lu, Wei Fang, Shu Liu, Dong H. Zhang
Summary: In the OH + HCl reaction, the presence of resonance states greatly induces quantum tunneling of hydrogen atoms, causing the reaction rates to deviate substantially from Arrhenius behavior at low temperature.