Results 51 to 60 of about 54,813 (368)

Catalytic Activity of a Composition Based on Strontium Bismuthate and Bismuth Carbonate at the Exposure to the Light of the Visible Range

open access: yesInternational Journal of Chemical Engineering, 2018
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]

open access: yesMon.Not.Roy.Astron.Soc.378:563-568,2007, 2007
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]

open access: yes, 2015
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]

open access: yes, 2007
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]

open access: yes, 2013
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

Comprehensive Groundwater Quality Analysis in Chronic Kidney Disease of Unknown Etiology (CKDu) Prevalence Areas of Sri Lanka to Investigate the Responsible Culprit

open access: yesJournal of Chemistry, 2022
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

Assessing Sedimentary Boundary Layer Calcium Carbonate Precipitation and Dissolution Using the Calcium Isotopic Composition of Pore Fluids

open access: yesFrontiers in Earth Science, 2021
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]

open access: yesApJ, 2014, 787, 162, 2014
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]

open access: yes, 2007
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]

open access: yesMaterials Research
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

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