Article
Astronomy & Astrophysics
C. Zhang, Feng-Yao Zhu, Tie Liu, Z-Y Ren, H-L Liu, Ke Wang, J-W Wu, Y. Zhang, J-W Zhou, K. Tatematsu, Guido Garay, Anandmayee Tej, Shanghuo Li, W. F. Xu, Chang Won Lee, Leonardo Bronfman, Archana Soam, D. Li
Summary: Hydrogen radio recombination lines are used to study the properties of resolved UC H II regions. A large sample of these regions were investigated and it was found that their electron density, temperature, and abundance ratios are similar to the central star regions, while the helium abundance ratio is higher in the boundary region.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Jacob L. Ward, J. M. Diederik Kruijssen, Melanie Chevance, Jaeyeon Kim, Steven N. Longmore
Summary: This paper aims to study the lifecycle of molecular clouds in the Large Magellanic Cloud (LMC) and determines their lifetime to be around 11.8 million years. The study finds that molecular clouds in the LMC are decoupled from galactic dynamics and have short lifetimes regulated by internal processes, while atomic clouds are correlated with galactic dynamical timescales.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
G. Dominguez-Guzman, M. Rodriguez, J. Garcia-Rojas, C. Esteban, L. Toribio San Cipriano
Summary: Using deep spectra, we derived the physical conditions and chemical abundances of H ii regions in the Large Magellanic Cloud and Small Magellanic Cloud. The chemical elements are well mixed in both clouds, with slightly higher N/O ratio in the LMC and larger dispersion. Most of the iron atoms are deposited on dust grains in both clouds.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
C. Zhang, Neal J. Evans, T. Liu, J-W Wu, Ke Wang, H-L Liu, F-Y Zhu, Z-Y Ren, L. K. Dewangan, Chang Won Lee, Shanghuo Li, L. Bronfman, A. Tej, D. Li
Summary: This study reported the detection of H-40 alpha radio recombination line (RRL) towards 75 sources and calculated the ionized gas mass and star formation rate (SFR). The results showed that ionized gas is negligible in the star-forming clumps of the ATOMS sample. The SFR estimated with RRL H-40 alpha agrees well with the total bolometric luminosity (L-bol) when SFR ≥ 5 M-circle dot Myr(-1), indicating that millimetre RRLs are good tracers of SFR. Additionally, the correlations between CS J = 2-1, HC3N J = 11-10 molecular line luminosities (L-bo1) and L-bol were found to be approximately linear.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Hong-Li Liu, Anandmayee Tej, Tie Liu, Namitha Issac, Anindya Saha, Paul F. Goldsmith, Jun-Zhi Wang, Qizhou Zhang, Sheng-Li Qin, Ke Wang, Shanghuo Li, Archana Soam, Lokesh Dewangan, Chang Won Lee, Pak-Shing Li, Xun-Chuan Liu, Yong Zhang, Zhiyuan Ren, Mika Juvela, Leonardo Bronfman, Yue-Fang Wu, Ken'ichi Tatematsu, Xi Chen, Di Li, Amelia Stutz, Siju Zhang, L. Viktor Toth, Qiu-Yi Luo, Feng-Wei Xu, Jinzeng Li, Rong Liu, Jianwen Zhou, Chao Zhang, Mengyao Tang, Chao Zhang, Tapas Baug, E. Mannfors, Eswaraiah Chakali, Somnath Dutta
Summary: New observations of the massive protostellar clump MM1 in the infrared dark cloud G34 reveal a detailed picture of its seven cores. These cores are found to be gravitationally bound and show evidence of outflows, indicating a dynamic mass inflow/accretion process leading to star formation.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
S. Zamora, Angeles Diaz, Elena Terlevich, Vital Fernandez
Summary: This article presents a method to calculate extinction corrections based on weaker lines of He I and applies it to the study of the 30 Doradus nebula. The comparison between helium and hydrogen determinations of c(H beta) yields compatible results within the errors, and using both sets of lines simultaneously significantly reduces the error in the derivation.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
F. Meng, A. Sanchez-Monge, P. Schilke, A. Ginsburg, C. DePree, N. Budaiev, D. Jeff, A. Schmiedeke, A. Schwoerer, V. S. Veena, Th Moeller
Summary: This study aims to characterize the properties of HII regions in the molecular cloud Sagittarius B2, with a focus on identifying and analyzing various UCHIT regions in the complex to reveal different evolutionary stages of the cloud.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
E. M. Schneiter, J. Reyes-Iturbide, P. F. Velazquez, A. Esquivel
Summary: This study attempts to explain the discrepancy between the X-ray luminosity of the N70 superbubble and theoretical models by considering a core-collapse supernova explosion and photons emitted by the stars involved. The results show that the missing X-ray emission can be explained by a core-collapse supernova, and the radiation also affects the morphology and radius of the superbubble.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Hong-Li Liu, Anandmayee Tej, Tie Liu, Paul F. Goldsmith, Amelia Stutz, Mika Juvela, Sheng-Li Qin, Feng-Wei Xu, Leonardo Bronfman, Neal J. Evans, Anindya Saha, Namitha Issac, Ken'ichi Tatematsu, Ke Wang, Shanghuo Li, Siju Zhang, Tapas Baug, Lokesh Dewangan, Yue-Fang Wu, Yong Zhang, Chang Won Lee, Xun-Chuan Liu, Jianwen Zhou, Archana Soam
Summary: In this comprehensive study, we analyze the gas kinematics of density structures at different spatial scales in the filamentary infrared dark cloud G34. We find that the gas motions in these structures are supersonic, with leaves exhibiting lower dynamical supersonicity than branches. Larger-scale branch structures follow the Larson scaling exponent in the velocity-size relation, while smaller-scale leaf structures deviate from this trend. We propose that turbulence and gravity-driven ordered gas flows contribute to the observed kinematics of branch structures, while gravity-driven chaotic gas motion is likely responsible for leaf structures. Our findings suggest a scale-dependent combination of turbulence and gravity in the star-formation processes of G34.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Y. X. Wang, J. S. Zhang, Y. T. Yan, J. J. Qiu, J. L. Chen, J. Y. Zhao, Y. P. Zou, X. C. Wu, X. L. He, Y. B. Gong, J. H. Cai
Summary: This study aims to investigate the evolution of HC3N in high-mass star-forming regions (HMSFRs) at different evolutionary stages and detect the existence of HC5N and HC7N in HMSFRs. The results show that the detection rate, column density, and relative abundance of HC3N are higher in Maser-RRL sources and lower in RRL-only sources.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
F. Fontani, A. Schmiedeke, A. Sanchez-Monge, L. Colzi, D. Elia, V. M. Rivilla, M. T. Beltran, L. Bizzocchi, P. Caselli, L. Magrini, D. Romano
Summary: The study reveals that the chemical properties of the outer star-forming regions of the Galaxy are similar to those of the inner and local regions. Methanol (CH3OH) is detected in the observed targets, and its emission is associated with an extended envelope, indicating that it mainly comes from a cold and quiescent region. The relative abundance of CH3OH shows good correlations with that of H2CO, but not with HCO. These findings have significant implications for understanding the organic and possibly pre-biotic chemistry in the outermost star-forming regions of the Galaxy.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Ahmad A. Ali
Summary: Gas metallicity and dust-to-gas ratio can influence the growth of H II regions by affecting temperatures and sizes of the regions. Radiation pressure may dominate locally over gas pressure, while UV absorption by dust plays a more significant role in hindering growth compared to radiation pressure.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Ahmad A. Ali
Summary: Gas metallicity and the dust-to-gas ratio affect the growth of H ii regions through metal line cooling and UV absorption. Models show that radiation pressure can dominate over gas pressure locally and that UV absorption can hinder growth more than radiation pressure helps it, resulting in different ionized gas expansion velocities and affecting neutral gas expulsion.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
N. Castro, P. A. Crowther, C. J. Evans, J. S. Vink, J. Puls, A. Herrero, M. Garcia, F. J. Selman, M. M. Roth, S. Simon-Diaz
Summary: In this study, spectroscopic analysis of 333 OB-type stars in the central region of NGC 2070 in the Tarantula Nebula on the Large Magellanic Cloud was conducted, revealing two main sequence groups with estimated ages of 2.1 +/- 0.8 and 6.2 +/- 2 Myr. It was also observed that the stellar masses derived from the sHRD were systematically larger than those obtained from the conventional HRD, especially for the most massive stars.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Agata Karska, Maciej Koprowski, Aleksandra Solarz, Ryszard Szczerba, Marta Sewilo, Natasza Siodmiak, Davide Elia, Marcin Gawronski, Konrad Grzesiak, Bosco H. K. Yung, William J. Fischer, Lars E. Kristensen
Summary: This study aims to develop a methodology to identify and classify young stellar objects in the outer Galaxy and resolve the distance and evolutionary status of a specific star. By using machine learning algorithms and publicly available data, the researchers were able to identify and classify YSO candidates and determine their physical properties and distances.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Computer Science, Interdisciplinary Applications
H. Hassani, J. A. Tenreiro Machado, E. Naraghirad, Z. Avazzadeh
Summary: This paper introduces a general class of nonlinear system of fractional partial differential equations with initial and boundary conditions. A hybrid method based on the transcendental Bernstein series and the generalized shifted Chebyshev polynomials is proposed for finding the optimal solution of the nonlinear system of fractional partial differential equations. The solution of the nonlinear system of fractional partial differential equations is expanded in terms of the transcendental Bernstein series and the generalized shifted Chebyshev polynomials, as basis functions with unknown free coefficients and control parameters. The corresponding operational matrices of fractional derivatives are then derived for the basis functions. These basis functions, with their operational matrices of fractional order derivatives and the Lagrange multipliers, transform the problem into a nonlinear system of algebraic equations. By means of Darbo's fixed point theorem and Banach contraction principle, an existence result and a unique result for the solution of the nonlinear system of fractional partial differential equations are obtained, respectively. The convergence analysis is discussed and several illustrative experiments illustrate the efficiency and accuracy of the proposed method.
ENGINEERING WITH COMPUTERS
(2023)
Article
Mathematics
M. T. Heydari
Summary: The focus of this paper is on the selfcommutator and the anti selfcommutator of an automorphic composition operator. The adjoint of a composition operator induced by a conformal automorphism is computed, providing a starting point for the analysis of the selfcommutator and the anti selfcommutator. Additionally, the spectrum and norm of these operators for involution automorphism phi are computed.
INDIAN JOURNAL OF PURE & APPLIED MATHEMATICS
(2023)
Article
Operations Research & Management Science
T. Dehghan Niri, M. Heydari, M. M. Hosseini
Summary: The current study introduces two modified adaptive cubic regularized (ARC) methods for solving unconstrained optimization problems. These methods combine ARC with the nonmonotone Armijo-type line search and calculate step lengths in different paths. The global convergence properties of the proposed methods are analyzed, and the results demonstrate their superior performance compared to other existing algorithms.
Article
Mathematics, Applied
Y. Cao, O. Nikan, Z. Avazzadeh
Summary: This paper presents an accurate localized meshless collocation approach for solving a two-dimensional nonlinear integro-differential equation with multi-term kernels. The proposed strategy discretizes the unknown solution in two phases using finite difference and convolution quadrature rules. The method shows unconditional stability and first-order convergence in L2-norm, which is supported by numerical results.
APPLIED NUMERICAL MATHEMATICS
(2023)
Article
Chemistry, Physical
Aisha kamal Mahmoud, M. Abdulfadhil Gatea, Taif Alawsi, A. K. Kareem, M. Heydari Vini, S. Daneshmand
Summary: In recent years, bimetallic strips have been increasingly used in manufacturing for various purposes. The rolling process is a popular method for producing bimetallic strips. This study proposes a new analytical model based on the slab method to predict the bond strength of two layer strips. Results show that increasing the thickness reduction during rolling improves the bond strength. Finite element simulation and experimental study further validate the results obtained from the new analytical model for producing AA1060/AA7075 bimetallic strips. Additionally, the proposed analytical model is suitable for modeling the roll bonding process of two-layer strips, and it contributes to our understanding and production of bimetal strips. Scanning electron microscopy (SEM) was used to investigate the peeled surface of the samples.
SURFACE REVIEW AND LETTERS
(2023)
Article
Chemistry, Physical
Waluyo Adi Siswanto, Andres Alexis Ramirez-Coronel, A. K. Kareem, Mohammad Heydari Vini, Saeed Daneshmand
Summary: In this study, hybrid aluminum metal matrix composites (AMMCs) were produced by adding steel slag and Gr particles to the matrix aluminum using a combination of powder metallurgy and press bonding process. The composites showed excellent distribution of particles and no reaction between Al and particles. The addition of Gr content up to 10vol.% resulted in a decrease in wear rate and density of the composites by 2.3% and 24% respectively, while the wear rate increased by 181% due to the increase in hardness value.
SURFACE REVIEW AND LETTERS
(2023)
Article
Mathematics, Interdisciplinary Applications
O. Bavi, M. Hosseininia, M. Hajishamsaei, M. H. Heydari
Summary: In this study, a time fractional reaction-diffusion equation based on the moving least squares method was used to predict the growth of the GBM tumor model in the mouse brain. The results showed that the Proliferation-Invasion model implemented in a time fractional form had a better agreement with experimental results, with a prediction error of less than 1%. The presented model also has the potential to consider the effects of therapeutic factors on tumor growth and can be applied in personalized medicine.
CHAOS SOLITONS & FRACTALS
(2023)
Article
Mathematics, Interdisciplinary Applications
M. H. Heydari, M. Razzaghi
Summary: In this paper, the authors investigate two important subjects. Firstly, they generate a fruitful family of functions called the orthonormal piecewise fractional Chebyshev cardinal functions, which have the interpolation property, and provide a formulation for their fractional derivative matrix. Secondly, they use these functions and their expressed matrix to construct a numerical method for the fractional Ginzburg-Landau equation with a non-smooth solution. The proposed method approximates the problem solution using the expressed fractional functions in the temporal direction and classical Chebyshev cardinal polynomials in the space direction, and it is able to obtain highly accurate solutions for problems with piecewise form, fractional powers, or both. The ability and validity of the method are demonstrated through the solution of numerical examples.
CHAOS SOLITONS & FRACTALS
(2023)
Article
Mathematics, Applied
Mohammad Hossein Heydari, Mahmoud Shaabani, Zahra Rasti
Summary: This paper introduces a fractional version of reaction-diffusion equations with non-local boundary conditions using the non-singular fractional derivative defined by Atangana and Baleanu. The orthonormal discrete Legendre polynomials are introduced as a suitable family of basis functions for finding the solution of these equations. An operational matrix is derived for the fractional derivative of these polynomials. A collocation method based on the expressed polynomials and their operational matrices is developed for solving such problems. The established method transforms the original problem into solving a system of algebraic equations. Numerical examples are used to validate the presented method.
MATHEMATICAL METHODS IN THE APPLIED SCIENCES
(2023)
Review
Food Science & Technology
Ali Ardekani, Reza Tabrizi, Elham Maleki, Kamran Bagheri Lankarani, Seyed Taghi Heydari, Mehdi Moradinazar, Maryam Akbari
Summary: In this meta-analysis, the effects of CoQ10 supplementation on lipid profiles and liver enzymes of NAFLD patients were evaluated. The overall findings showed a non-significant decrease in lipid profiles and liver enzymes, but sensitivity and subgroup analyses revealed significant effects in certain conditions. Further randomized controlled trials are needed to confirm these results.
FOOD SCIENCE & NUTRITION
(2023)
Article
Engineering, Multidisciplinary
Saeed Daneshmand, S. Mohammad Sajadi, Mohammad Heydari Vini
Summary: The mechanical, corrosion, and wear features of AA1050/TiC composites were studied through molecular dynamics simulation. Powder metallurgy and accumulative roll bonding were used to fabricate the composites. It was found that increasing the Nano TiC Wt.% enhanced wear and corrosion resistance, density, hardness, and strength while reducing elongation, bonding strength, and electrical conductivity.
ENGINEERING ANALYSIS WITH BOUNDARY ELEMENTS
(2023)
Article
Mathematics, Applied
O. Bavi, M. Hosseininia, M. H. Heydari
Summary: In this research, a fractional diffusion equation with variable-order (VO) was used to predict the diffusion of the SARS-CoV-2 virus. The use of VO form resulted in more accurate predictions of viral behavior compared to constant-order fractional derivatives. The method also has the advantage of accurately predicting the propagation behavior of microorganisms over large time and dimensional scales. Additionally, it can be applied to investigate the diffusion patterns of other environmental pollutants at the nanoscale/microscale.
MATHEMATICAL METHODS IN THE APPLIED SCIENCES
(2023)
Article
Mathematics, Applied
M. Hosseininia, M. H. Heydari, M. Razzaghi
Summary: In this study, the Caputo fractional derivative is used to define the time fractional 3D Sobolev equation, and a hybrid technique based on the 2D shifted second kind Chebyshev cardinal polynomials and second kind Chebyshev polynomials is proposed. The problem solution is approximated by simultaneously utilizing these basis functions in two dimensions. Operational matrices of these polynomials are derived and combined with the collocation approach to solve the expressed fractional 3D problem as an equivalent system of algebraic equations. Numerical examples demonstrate the accuracy of the proposed algorithm.
MATHEMATICAL METHODS IN THE APPLIED SCIENCES
(2023)
Article
Mathematics, Applied
M. H. Heydari, M. Hosseininia, D. Baleanu
Summary: In this paper, a numerical method based on orthonormal shifted discrete Chebyshev polynomials is proposed to solve the complex solution of the Helmholtz equation. This method transforms the equation into an algebraic system of equations that can be easily solved. Four practical examples are provided to demonstrate the accuracy of the proposed technique.
Letter
Public, Environmental & Occupational Health
Mohammad Heidari, Hamid Jafari, Seyede Irandokht Nohi
DISASTER MEDICINE AND PUBLIC HEALTH PREPAREDNESS
(2023)