Results 21 to 30 of about 1,234,720 (380)

Close Binaries and the Abundance Discrepancy Problem in Planetary Nebulae

open access: yesGalaxies, 2018
Motivated by the recent establishment of a connection between central star binarity and extreme abundance discrepancies in planetary nebulae, we have carried out a spectroscopic survey targeting planetary nebula with binary central stars and previously ...
R. Wesson   +4 more
doaj   +1 more source

The Record-Warm Barents Sea and 0-Group Fish Response to Abnormal Conditions

open access: yesFrontiers in Marine Science, 2020
The Barents Sea is a nursery area for many commercially and ecologically important fish stocks, and this whole region is presently subject to rapid climatic change from a cold period in the 1980s to a record warm period in the latest decade, with a peak ...
Elena Eriksen   +7 more
doaj   +1 more source

Magellanic Clouds Cepheids: Thorium Abundances [PDF]

open access: yesJournal of Astronomy and Space Sciences, 2018
The analysis of the high-resolution spectra of 31 Magellanic Clouds Cepheid variables enabled the identification of thorium lines. The abundances of thorium were found with spectrum synthesis method. The calculated thorium abundances exhibit correlations
Yeuncheol Jeong   +5 more
doaj   +1 more source

Light Elements in the Universe

open access: yesFrontiers in Astronomy and Space Sciences, 2021
Due to their production sites, as well as to how they are processed and destroyed in stars, the light elements are excellent tools to investigate a number of crucial issues in modern astrophysics: from stellar structure and non-standard processes at work
Sofia Randich, Laura Magrini
doaj   +1 more source

Solar oxygen abundance [PDF]

open access: yesMonthly Notices of the Royal Astronomical Society, 2021
ABSTRACT Motivated by the controversy over the surface metallicity of the Sun, we present a re-analysis of the solar photospheric oxygen (O) abundance. New atomic models of O and Ni are used to perform non-local thermodynamic equilibrium (NLTE) calculations with 1D hydrostatic (MARCS) and 3D hydrodynamical (Stagger and Bifrost) models ...
Monika Ellwarth   +13 more
openaire   +7 more sources

Indirect Measurements of n- and p-Induced Reactions of Astrophysical Interest on Oxygen Isotopes

open access: yesFrontiers in Astronomy and Space Sciences, 2020
Observations of abundances and isotopic ratio determinations in stars yield powerful constraints on stellar models. In particular, the oxygen isotopic ratios are of particular interest because they are affected not only by nucleosynthesis but also by ...
M. L. Sergi   +12 more
doaj   +1 more source

Fecal pollution can explain antibiotic resistance gene abundances in anthropogenically impacted environments

open access: yesNature Communications, 2019
Discharge of treated sewage leads to release of antibiotic resistant bacteria, resistance genes and antibiotic residues to the environment. However, it is unclear whether increased abundance of antibiotic resistance genes in sewage and sewage-impacted ...
Antti Karkman   +3 more
semanticscholar   +1 more source

ASPCAP: THE APOGEE STELLAR PARAMETER AND CHEMICAL ABUNDANCES PIPELINE [PDF]

open access: yes, 2015
The Apache Point Observatory Galactic Evolution Experiment (APOGEE) has built the largest moderately high-resolution (R ≈ 22,500) spectroscopic map of the stars across the Milky Way, and including dust-obscured areas.
A. G. García Pérez   +29 more
semanticscholar   +1 more source

Inequality in abundance

open access: yesFrontiers in Research Metrics and Analytics, 2022
With technological advance has come the possibility of a new era of abundance. Technologies like 3D printing and robotics promise to lower the costs of production and distribution of goods and services, presumably making these goods and services readily available to those across income and wealth spectrums. This undoubtedly is a good thing.
openaire   +3 more sources

Neon and Sulfur Abundances of Planetary Nebulae in the Magellanic Clouds [PDF]

open access: yes, 2007
The chemical abundances of neon and sulfur for 25 planetary nebulae (PNe) in the Magellanic Clouds are presented. These abundances have been derived using mainly infrared data from the Spitzer Space Telescope.
Aller L. H.   +12 more
core   +4 more sources

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