Review
Chemistry, Physical
William B. Derdeyn, Sara Mastromarino, Ruchi Gakhar, Mark H. Anderson, Mikhail A. Kats, Raluca O. Scarlat
Summary: In order to predict the radiative heat transfer behavior of molten salts, we conducted a comprehensive review of optical spectroscopic measurements on molten fluoride salts. We discussed the experimental methods of transmittance, reflectance, and trans-reflectance, along with the corresponding data reduction techniques and limitations. Optical spectroscopy is a convenient method to indirectly observe changes in structural parameters with temperature and composition. We compiled absorption data for various solutes and solvents and discussed the corresponding structural interpretation, comparing it with other experimental and theoretical work. We found that vibrational absorption in the mid-infrared range is significant and affects radiative heat transfer. By extrapolating and averaging existing data, we estimated the gray absorption coefficient values for FLiBe at 700°C to be 546 m-1 and for FLiNaK to be 276 m-1, both within the engineering-relevant range of 1-6000 m-1.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Materials Science, Multidisciplinary
Gimin Park, Kyeongman Roh, Hoon Kim, Salman Khan, Minjae Lee, Byung-Wook Kim, Woochul Kim
Summary: The performance of a radiative cooling material is greatly influenced by environmental factors, which led to the development of a well-controlled setup to evaluate its performance universally. By fixing the total emissivity of the experimental setup, eliminating atmospheric radiation, and using a solar simulator to replicate solar flux, the proposed measurement setup can evaluate the material's performance independently of time, location, and environmental conditions.
ADVANCED MATERIALS TECHNOLOGIES
(2022)
Article
Astronomy & Astrophysics
Sandor Demes, Francois Lique, Alexandre Faure, Floris F. S. van der Tak, Claire Rist, Pierre Hily-Blant
Summary: In this study, the collisional excitation of the hydronium cation in interstellar environments was investigated, and new collisional rate coefficients were provided. Analysis of state-to-state collisional data for rotational de-excitation and radiative transfer calculations showed significant impacts on the brightness and excitation temperatures of H3O+. The calculated rate coefficients can help in recalculating the column density of hydronium in interstellar clouds, leading to a better understanding of interstellar water and oxygen chemistry.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
J. P. Terry, C. Hall, S. Abreau, S. Gleyzer
Summary: This study demonstrates that machine learning can quickly and accurately detect the presence of planets and constrain their location. This is crucial for studying planet formation.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
P. Pirlot Jankowiak, F. Lique, P. J. Dagdigian
Summary: In this study, hyperfine resolved rate coefficients for (CCH)-C-13 and (CCH)-C-13 isotopologues in collisions with para-H-2 were computed using a newly published C2H-H-2 potential energy surface. The cross sections and rate coefficients between the first 98 energy levels of the two isotopologues were determined using a recoupling technique for temperatures ranging from 5 to 100 K. Significant isotopic substitution effects were observed, emphasizing the importance of computing isotopologue specific collisional data. These rate coefficients were then used in a simple radiative transfer modeling for typical molecular cloud conditions.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
P. Pirlot Jankowiak, F. Lique, P. J. Dagdigian
Summary: This study provides important data for the determination of physical conditions in interstellar clouds, including fine-structure resolved and hyperfine structure resolved cross-sections and rate coefficients for C2H and C2D.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Environmental Sciences
Adrian Doicu, Alexandru Doicu, Dmitry S. Efremenko, Diego Loyola, Thomas Trautmann
Summary: This paper presents neural network methods for predicting uncertainty in atmospheric remote sensing, which include solutions for direct and inverse problems in a Bayesian framework. Methods involve simulating radiative transfer models and using Bayesian approaches, as well as neural networks for predicting uncertainties in noise distributions and input parameters. Testing is done using a neural network with assumed density filtering and interval arithmetic, with analysis focusing on the retrieval of cloud parameters from radiances measured by the Earth Polychromatic Imaging Camera (EPIC).
Article
Astronomy & Astrophysics
Tamaz Kereselidze, Irakli Noselidze, John F. Ogilvie
Summary: The study emphasizes the significance of the quasi-molecular mechanism in cosmological recombination and presents a calculation scheme for free-bound radiative transitions in H-2(+), which can be used for the design of a rapid and complete cosmological recombination code.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Tamaz Kereselidze, Irakli Noselidze, Shota Khetsuriani
Summary: This study investigates the population of 2B-level hydrogen formed in the early Universe, and examines this process within both standard and non-standard quasi-molecular mechanisms of recombination. The findings suggest that the probabilities of population differ significantly when attractive quasi-molecular channels are uninvolved.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Pei Ma, Hao Zhang, Yazhou Yang, Te Jiang, Daniel Britt, Menghua Zhu
Summary: Phase ratio imagery is a new remote sensing tool that calculates the ratio of images taken at different phase angles, suppressing albedo variations and enhancing texture features. This technique has been used to study the surface structure of airless bodies like the Moon and Mercury. Laboratory phase ratio measurements were conducted on eight planetary analog materials, providing insights into the effectiveness of this method.
Article
Engineering, Multidisciplinary
M. R. A. Abdelmalik, Z. Cai, T. Pichard
Summary: The paper proposes a closure method based on phi-divergence for the radiative transfer equation, which remains computationally tractable even at high order and does not trigger ray effects.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2023)
Article
Mathematics, Applied
Juergen Doelz, Olena Palii, Matthias Schlottbom
Summary: This paper studies the iterative solution of linear systems arising from the discretization of the anisotropic radiative transfer equation with discontinuous elements on the sphere. Preconditioned Richardson iterations in Hilbert spaces are developed to achieve robust convergence behavior in the discretization and physical parameters. The proposed method proves convergence of the resulting scheme and constructs a preconditioner in two steps, borrowing ideas from matrix splittings and using a subspace correction technique.
JOURNAL OF SCIENTIFIC COMPUTING
(2022)
Article
Environmental Sciences
Anil Kumar, Panagiotis Kosmopoulos, Yashwant Kashyap, Rupam Gautam
Summary: In this study, the possibility of estimating GHI in parallel to PV power production in India was investigated using the RTM model called libRadtran. Satellite information on cloud and aerosol conditions, along with ground-based measurements of GHI and COT, were used as input parameters. The simulation results were compared with actual data from four solar power plants in Rajasthan, India. The study found significant attenuation due to clouds and aerosols, with a maximum energy loss observed at one location.
Article
Astronomy & Astrophysics
M. A. Amor, K. Hammami, L. Wiesenfeld
Summary: The potential energy surface (PES) for the collision between HMgNC and He was evaluated using the high-accuracy CCSD(T)-F12 ab initio method, leading to quantum dynamical scattering calculations. Radiative transfer computations were performed to assess the impact on the brightness and excitation temperatures of selected observed j = 8 - 7 transition.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
F. Khadri, L. Hachani, H. Elabidi, K. Hammami
Summary: In this study, we report a new calculation of rate coefficients for C2O colliding with helium, based on a new potential energy surface. The derived physical conditions of interstellar clouds can be more accurate with these rate coefficients.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
J. Cernicharo, C. Cabezas, J. R. Pardo, M. Agundez, O. Roncero, B. Tercero, N. Marcelino, M. Guelin, Y. Endo, P. de Vicente
Summary: We discovered four series of harmonically related lines in IRC +10216, each corresponding to different molecules with specific rotational and distortion constants. Through ab initio calculations, we determined that metal-bearing cations, specifically MgC4H+, MgC3N+, MgC6H+, and MgC5N+, are responsible for these lines. These findings provide new insights into the reactivity of ionized metals in astrophysical environments.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
M. Agundez, O. Roncero, N. Marcelino, C. Cabezas, B. Tercero, J. Cernicharo
Summary: This study conducted an observational search for the molecules H2NC and H2CN in different types of interstellar regions, aiming to understand their abundance and formation mechanism. H2NC was detected in all but one of the cold dense clouds targeted, while H2CN was only detected in five out of the eight clouds. The column densities of H2NC and H2CN ranged from 10(11) to 10(12) cm(-2), and the abundance ratio H2NC/H2CN varied between 0.51 and >2.7. The chemical link between NH3 and H2NC was supported by the correlation between their column densities. The reaction C + NH3 was found to be the main source of H2NC in interstellar clouds according to both astronomical observations and theoretical calculations.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Eleonora Bianchi, Anthony Remijan, Claudio Codella, Cecilia Ceccarelli, Francois Lique, Silvia Spezzano, Nadia Balucani, Paola Caselli, Eric Herbst, Linda Podio, Charlotte Vastel, Brett McGuire
Summary: In this study, a comprehensive investigation of the cyanopolyyne chemistry in the prototypical prestellar core L1544 is conducted. HC9N is detected for the first time towards the source. The high spectral resolution reveals double-peak spectral line profiles, with the redshifted peak being 3-5 times brighter. The emission of cyanopolyyne is likely associated with the southern region of the core where free carbon atoms are available for the formation of long chains.
ASTROPHYSICAL JOURNAL
(2023)
Article
Chemistry, Physical
Pablo del Mazo-Sevillano, Alfredo Aguado, Alexandre Zanchet, Octavio Roncero
Summary: The reaction dynamics of $(H_{2}CO)_{2}+OH$ and $H_{2}CO-OH+H_{2}CO$ at temperatures below 300 K are theoratically studied. It is found that there is a submerged reaction barrier, which serves as a catalytic effect induced by the presence of the third molecule. However, the dominant reaction channel is the dimer-exchange mechanism below 200 K, and the reactive rate constant tends to stabilize at low temperatures due to the reduction of effective dipole of the dimers. The reactivity of the dimers cannot explain the large rate constants measured at temperatures below 100 K.
Article
Food Science & Technology
Gokben Ozbey, Mustafa Necati Muz, Elif Seren Tanriverdi, Sultan Erkan, Niyazi Bulut, Baris Otlu, Frantisek Zigo
Summary: The study investigated the antimicrobial effect of propolis ethanol extract from different regions of Turkey on Escherichia coli, Helicobacter pylori, Pseudomonas aeruginosa, and Staphylococcus aureus. The chemical constituents were detected and the propolis compounds were analyzed using molecular docking. The propolis samples had a high concentration of phenolic compounds, with 3-4 dimethoxycinnamic acid, caffeic acid, and genistein being the predominant compounds. The propolis extract showed strong antibacterial activity, especially against Staphylococcus aureus.
CZECH JOURNAL OF FOOD SCIENCES
(2023)
Article
Chemistry, Physical
Fabien Dumouchel, Ernesto Quintas-Sanchez, Christian Balanca, Richard Dawes, Francois Lique, Nicole Feautrier
Summary: Interstellar anions are important indicators of physical and chemical conditions in cold molecular clouds and circumstellar gas. Non-LTE models are needed to understand the observed lines of anions, and collision data is crucial for these models. In this study, the 4D potential energy surface of the C2H--H-2 complex was computed to derive collision cross sections and rate coefficients of C2H- induced by collisions with para- and ortho-H-2.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Vikram Plomp, Jolijn Onvlee, Francois Lique, Sebastiaan Y. T. van de Meerakker
Summary: We conducted an experimental study on state-to-state inelastic scattering of NH radicals with He atoms using a crossed molecular beam apparatus. By developing new REMPI schemes, we were able to selectively detect NH radicals and compare the results with quantum scattering calculations based on an ab initio NH-He potential energy surface.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Biochemistry & Molecular Biology
Cahit Orek, Massimiliano Bartolomei, Cecilia Coletti, Niyazi Bulut
Summary: Gold(I) metal complexes have potential applications as therapeutic agents, and graphene and its derivatives show promise as drug nanocarriers. In this study, the adsorption of a gold(I) N-heterocyclic monocarbene on graphene was computationally investigated. The study found that the drug adsorption on graphene was very favorable, mainly driven by dispersion and electrostatic attraction.
Article
Chemistry, Multidisciplinary
K. Dahmani, Mouhsine Galai, M. Ouakki, Z. Benzekri, A. El Magri, R. Iachhab, S. Kaya, N. Bulut, N. Arrousse, S. Boukhris, M. Cherkaoui
Summary: In this study, two newly synthesized inhibitors, ZM-3 and ZM-4, were found to be promising corrosion inhibitors for mild steel in 1 M HCl solution. Electrochemical experiments, theoretical chemistry calculations, and molecular dynamic simulations were performed to investigate their properties and mechanism of action. The inhibitory efficiency of ZM-3 and ZM-4 reached 90.8% and 91.3% at 10(-3) M inhibitor concentrations, respectively. The corrosion behavior of mild steel at the optimal inhibitor concentration was studied at temperatures ranging from 298 to 328 K. The inhibitors exhibited a mixed type inhibition behavior and followed the Langmuir adsorption mechanism. The corroded surface was analyzed using various techniques such as SEM/EDX, AFM, contact angle, and XRD.
CHEMISTRY AFRICA-A JOURNAL OF THE TUNISIAN CHEMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
C. Hernandez-Vera, V. V. Guzman, J. R. Goicoechea, V. Maillard, J. Pety, F. Le Petit, M. Gerin, E. Bron, E. Roueff, A. Abergel, T. Schirmer, J. Carpenter, P. Gratier, K. Gordon, K. Misselt
Summary: Massive stars affect the evolution of molecular clouds through strong UV radiation and determine the thermal gas pressure. Observations of the Horsehead nebula using ALMA reveal the presence of a thin layer of neutral atomic gas and CO-dark gas at the edge of the cloud. The observations also show a web of molecular gas filaments with a density gradient, suggesting the influence of both stationary and dynamic effects.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Carlos M. R. Rocha, Octavio Roncero, Niyazi Bulut, Piotr Zuchowski, David Navarro-Almaida, Asuncion Fuente, Valentine Wakelam, Jean-Christophe Loison, Evelyne Roueff, Javier R. Goicoechea, Gisela Esplugues, Leire Beitia-Antero, Paola Caselli, Valerio Lattanzi, Jaime Pineda, Romane Le Gal, Marina Rodriguez-Baras, Pablo Riviere-Marichalar
Summary: This study revises the rates of major formation and destruction mechanisms of carbon monosulphide (CS). By performing ab initio calculations and detailed modeling, the authors find significant differences in some reaction rates compared to the classical capture model. The updated rates provide a better explanation for observations and have important implications for the study of interstellar matter.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
M. G. Santa-Maria, J. R. Goicoechea, J. Pety, M. Gerin, J. H. Orkisz, F. Le Petit, L. Einig, P. Palud, V. de Souza Magalhaes, I. Beslic, L. Segal, S. Bardeau, E. Bron, P. Chainais, J. Chanussot, P. Gratier, V. V. Guzman, A. Hughes, D. Languignon, F. Levrier, D. C. Lis, H. S. Liszt, J. Le Bourlot, Y. Oya, K. Oberg, N. Peretto, E. Roueff, A. Roueff, A. Sievers, P. -A. Thouvenin, S. Yamamoto
Summary: Studies have found that the radiation of HCN J = 1-0 in giant molecular clouds mainly comes from extended gas, contradicting previous views; the formation and excitation of HCN are promoted on a large scale due to the influence of FUV radiation; high HCN/CO J = 1-0 line intensity ratios do not always indicate the presence of dense gas, and HNC may be a better tracer of dense gas.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Chemistry, Inorganic & Nuclear
Lana Omar Ahmed, Niyazi Bulut, Luis Banares, Omer Kaygili, Hanifi Kebiroglu, Tankut Ates, Suleyman Koytepe, Burhan Ates
Summary: This work investigates Ce3+ and Er3+ co-doped hydroxyapatite (HAp) structures theoretically and experimentally for the first time. The Ce3+ content was varied incrementally from 0.13 at. % to 0.78 at. %, while the Er3+ content remained constant at 0.39 at. % for all samples. Various analyses were performed, and the results showed that the thermal behavior, morphology, and crystal structure-related parameters were significantly influenced by the concentration of Ce3+. The formation of HAp structures was confirmed through FTIR and Raman spectroscopy, and theoretical calculations revealed changes in density and bandgap with the addition of Ce3+.
INORGANIC CHEMISTRY COMMUNICATIONS
(2023)
Article
Biochemistry & Molecular Biology
Cahit Orek, Serhat Keser, Omer Kaygili, Piotr Zuchowski, Niyazi Bulut
Summary: In this study, the electrical, optical, and structural properties of a wurtzite-like zinc oxide (ZnO) nanostructure were analyzed theoretically and experimentally. The optical characteristics were investigated in relation to quantum confinement by studying two different ZnO clusters in nanowire structures. It was found that the band gap decreases with increasing number of atoms in the cluster due to quantum confinement. The CAM-B3LYP functional successfully reproduced the experimental data in this study and previously reported data.
JOURNAL OF MOLECULAR MODELING
(2023)
Article
Chemistry, Physical
Hulya Gunes Ates, Omer Kaygili, Niyazi Bulut, Fatih Osmanlioglu, Serhat Keser, Beyhan Tatar, Bahroz Kareem Mahmood, Tankut Ates, Filiz Ercan, Ismail Ercan, Burhan Ates, Imren Ozcan
Summary: The present study aims to provide a detailed report on the properties of hydroxyapatites (HAps) co-doped with Sr and Ce at different amounts, including structural, thermal, magnetic, and in vitro cell viability properties. The study includes experimental analyses as well as theoretical calculation results. All the samples exhibited diamagnetic behavior and high cell compatibility, and showed thermally stable behavior. The amount of co-dopants affected the mass change mechanism, specific heat capacity, bandgap value, and linear absorption coefficient.
JOURNAL OF MOLECULAR STRUCTURE
(2023)