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The distribution of stellar abundances along the Galactic disk is an important constraint for models of chemical evolution and Galaxy formation. In this study we derive radial gradients of C, N, O, Mg, Al, Si, as well as S, from abundance…

Astrophysics · Physics 2009-11-10 Simone Daflon , Katia Cunha

Very recently, we have introduced correlation consistent effective core potentials (ccECPs) derived from many-body approaches with the main target being its use in explicitly correlated methods but also in mainstream approaches. The ccECPs…

We have derived elemental abundances of three field red horizontal branch stars using high-resolution (R$\simeq$ 45,000), high signal-to-noise ratio (S/N $\gtrsim$ 200) $H$ and $K$ band spectra obtained with the Immersion Grating Infrared…

We present deep spectrophotometry of 18 HII regions in the nearby massive spiral galaxies M101 and M31. We have obtained direct determinations of electron temperature in all the nebulae. We detect the CII 4267 line in several HII regions,…

Astrophysics of Galaxies · Physics 2019-12-18 C. Esteban , F. Bresolin , J. García-Rojas , L. Toribio San Cipriano

We present the results of a comprehensive theoretical investigation on the Period-Radius (PR) relation of classical Cepheids based on new sequences of full amplitude, nonlinear convective models constructed by adopting a wide range of both…

Astrophysics · Physics 2007-05-23 Bono Giuseppe , Caputo Filippina , Marconi Marcella

In this paper we introduce the concept of a prime radical of an ideal of an L-ring L(mu,R) . Among various results pertaining to this concept, we prove here that prime radicals of an ideal eta, its radical , its semiprime radical S(eta) and…

Rings and Algebras · Mathematics 2025-08-22 Naseem Ajmal , Anand Swaroop Prajapati

We study the physical and chemical properties of a sample of HII regions located at RG >11 kpc and present the radial distribution of abundances towards the Galaxy anticentre. We carried out optical spectroscopic observations of nine HII…

Astrophysics of Galaxies · Physics 2017-01-18 Alba Fernández-Martín , Enrique Pérez-Montero , José Manuel Vílchez , Antonio Mampaso

We perform a new analysis of electron-proton scattering data to determine the proton electric and magnetic radii, enforcing model-independent constraints from form factor analyticity. A wide-ranging study of possible systematic effects is…

High Energy Physics - Phenomenology · Physics 2015-07-29 Gabriel Lee , John R. Arrington , Richard J. Hill

We report a new approach to simulate amorphous networks of covalently bonded materials that leads to excellent radial distribution functions and realistic atomic arrangements. We apply it to generate the first ab initio structures of…

Materials Science · Physics 2007-05-23 Fernando Alvarez , Ariel A. Valladares

Under the name prime decomposition (pd), a unique decomposition of an arbitrary $N$-dimensional density matrix $\rho$ into a sum of seperable density matrices with dimensions given by the coprime factors of $N$ is introduced. For a class of…

Quantum Physics · Physics 2011-07-19 D. Ellinas , E. G. Floratos

Density Functional Theory calculations have been performed to obtain lattice parameters, elastic constants, and electronic properties of ideal pyrochlores with the composition A$_2$B$_2$O$_7$ (where A=La,Y and B=Ti,Sn,Hf, Zr). Some thermal…

Materials Science · Physics 2009-11-11 J. M. Pruneda , Emilio Artacho

We demonstrate that recent advances in QED theory of Li-like ions [V. A. Yerokhin et al., Phys. Rev. A 112, 042801 (2025)] enable determinations of absolute nuclear charge radii for heavy elements. By incorporating constraints derived from…

Atomic Physics · Physics 2026-01-06 V. A. Yerokhin , B. Ohayon

We present the results of a detailed NLTE abundance study of nine beta Cephei stars, all of them being prime targets for theoretical modelling: gamma Peg, delta Cet, nu Eri, beta CMa, xi1 CMa, V836 Cen, V2052 Oph, beta Cep and DD (12) Lac.…

Astrophysics · Physics 2009-11-11 T. Morel , K. Butler , C. Aerts , C. Neiner , M. Briquet

Solar photospheric abundances and CI-chondrite compositions are reviewed and updated to obtain representative solar system abundances of the elements and their isotopes. The new photospheric abundances obtained here lead to higher solar…

Solar and Stellar Astrophysics · Physics 2025-02-18 Katharina Lodders , Maria Bergemann , Herbert Palme

We present new calculations and analytic fits to the rates of radiative recombination towards H-like, He-like, Li-like and Na-like ions of all elements from H through Zn (Z=30). The fits are valid over a wide range of temperature, from 3 K…

Astrophysics · Physics 2009-10-28 D. A. Verner , G. J. Ferland

We report valence and conduction band alignments and offsets for heterojunctions between CdCr2Se4, an n-type ferromagnetic semiconductor, and the non-magnetic materials Si and GaAs, evaluated using density functional theory. We explore…

Materials Science · Physics 2007-05-23 J. M. Sullivan , S. C. Erwin

This paper presents for the first time the exact structures at the atomic level of two important nanomaterials, boron nitride and coronene. Both these compounds are hexagonal layer structures similar to graphene in two dimensions and to…

General Physics · Physics 2011-12-20 Raji Heyrovska

We map the trends of elemental abundance ratios across the Galactic disk, spanning R = 3-15 kpc and midplane distance |Z|= 0-2 kpc, for 15 elements in a sample of 20,485 stars measured by the SDSS/APOGEE survey (O, Na, Mg, Al, Si, P, S, K,…

The traditional display of elements in the periodic table is convenient for the study of chemistry and physics. However, the atomic number alone is insufficient for training statistical machine learning models to describe and extract…

Materials Science · Physics 2023-08-25 Anthony Onwuli , Ashish V. Hegde , Kevin Nguyen , Keith T. Butler , Aron Walsh

Correlated ab-initio ground-state calculations, using relativistic energy-consistent pseudopotentials, are performed for six II-VI semiconductors. Valence ($ns,np$) correlations are evaluated using the coupled cluster approach with single…

Materials Science · Physics 2009-10-30 Martin Albrecht , Beate Paulus , Hermann Stoll