Results 51 to 60 of about 54,813 (368)
This paper presents the results pertaining to studying the properties of the photocatalytically active composition of strontium bismuthate SrBi2.70O5.05, SrBi2.90O5.35, and SrBi3.25O5.88 and bismuth carbonate (BiO)2CO3 in molar ratios 1/0.67, 1/0.56, and
K. S. Makarevich+4 more
doaj +1 more source
Carbon Rich Extremely Metal Poor Stars: Signatures of Population-III AGB stars in Binary Systems [PDF]
We use the Cambridge stellar evolution code STARS to model the evolution and nucleosynthesis of zero-metallicity intermediate-mass stars. We investigate the effect of duplicity on the nucleosynthesis output of these systems and the potential abundances of the secondaries.
arxiv +1 more source
Oxygen Isotope Analysis of Human Bone Phosphate Evidences Weaning Age in Archaeological Populations [PDF]
Acknowledgements With special thanks to Jean-Jacques Hublin and the MPI-EVA; to Annabell Reiner (MPI-EVA) and Bernd Steinhilber (Universitat Tubingen) for technical support;and to the Deutscher Akademischer Austausch Dienst for financial support to KB ...
Alvarez+129 more
core +1 more source
Abundances on the Main Sequence of Omega Centauri [PDF]
Abundance ratios of carbon, nitrogen and strontium relative to iron, calculated using spectrum synthesis techniques, are given for a sample of main sequence and turnoff stars that belong to the globular cluster omega Centauri. The variations of carbon, nitrogen and/or strontium show several different abundance patterns as a function of [Fe/H].
arxiv +1 more source
The laurentian record of neoproterozoic glaciation, tectonism, and eukaryotic evolution in Death Vally, California [PDF]
Neoproterozoic strata in Death Valley, California contain eukaryotic microfossils and glacial deposits that have been used to assess the severity of putative Snowball Earth events and the biological response to extreme environmental change.
A. E. Fallick+62 more
core +1 more source
Chronic kidney disease of unknown etiology (CKDu) is a serious health problem in Sri Lanka especially among agricultural communities in dry zone since 19th century. In the present study, several water quality parameters were studied in well water samples
T. D. Fernando+3 more
doaj +1 more source
We present pore fluid geochemistry, including major ion and trace metal concentrations and the isotopic composition of pore fluid calcium and sulfate, from the uppermost meter of sediments from the Gulf of Aqaba (Northeast Red Sea) and the Iberian Margin
Daniel H. James+10 more
doaj +1 more source
Exploring the Origin of Lithium, Carbon, Strontium and Barium with four new Ultra Metal-Poor Stars [PDF]
We present an elemental abundance analysis for four newly discovered ultra metal-poor stars from the Hamburg/ESO survey, with $\mathrm{[Fe/H]}\leq-4$. Based on high-resolution, high signal-to-noise spectra, we derive abundances for 17 elements in the range from Li to Ba.
arxiv +1 more source
Metals in the shell of Bathymodiolus azoricus from a hydrothermal vent site on the Mid-Atlantic Ridge [PDF]
Specimens of the mussel Bathymodiolus azoricus were collected from Menez Gwen, a relatively shallow (850 m) hydrothermal vent field on the Mid-Atlantic Ridge. Each bivalve shell (n = 21) was individually cleaned by selective chemical.
Bebianno, Maria João+5 more
core +1 more source
Magnetic Materials Enriched with Strontium: a Study of the use as Catalysts in the Transesterification Reaction of Babassu Oil [PDF]
This work described a new magnetic material enriched with strontium as catalyst to produce babassu biodiesel. The use of magnetic materials has attracted attention due to easy and fast separation from reaction medium.
Wiury Chaves de Abreu+6 more
doaj +2 more sources