Results 71 to 80 of about 48,373 (195)

Absence of a Lower Limit on Omega_b in Inhomogeneous Primordial Nucleosynthesis

open access: yes, 1994
We show that a class of inhomogeneous big bang nucleosynthesis models exist which yield light-element abundances in agreement with observational constraints for baryon-to-photon ratios significantly smaller than those inferred from standard homogeneous ...
Fuller, G. M.   +2 more
core   +1 more source

An Analytical Method for Quantification of Sn Isotope Variations in Geological Materials Using MC‐ICP‐MS

open access: yesGeostandards and Geoanalytical Research, Volume 48, Issue 4, Page 863-885, December 2024.
Key Points A method is described to obtain high precision Sn isotope ratios using the double spike technique in geological reference materials containing 0.03 to 7 μg g−1 of Sn. δ122/118Sn values are reported for sixteen geological RMs. Improved precision was achieved compared with previous studies by using low concentration Sn analyte.
Dipankar Pathak, Klaus Mezger
wiley   +1 more source

Mixing and Magnetic Fields in Asymptotic Giant Branch Stars in the Framework of FRUITY Models

open access: yesUniverse, 2021
In the last few years, the modeling of asymptotic giant branch (AGB) stars has been much investigated, both focusing on nucleosynthesis and stellar evolution aspects. Recent advances in the input physics required for stellar computations made it possible
Diego Vescovi
doaj   +1 more source

Detection of Inconsistencies in Isotope Ratios Certified in the Isotopic Primary Standards for Copper, Zinc and Nickel

open access: yesGeostandards and Geoanalytical Research, Volume 48, Issue 4, Page 795-805, December 2024.
Key Points Isotopic reference materials are rarely cross‐examined. An optimised regression model and MC‐ICP‐MS offer a cost‐effective way to assess the reliability of values assigned to multi‐isotope reference materials. A significant lack of consistency has been observed in the long‐standing isotopic reference materials for nickel and zinc. Calibrated
Juris Meija   +4 more
wiley   +1 more source

Effects of a torsion field on Big Bang nucleosynthesis

open access: yes, 1999
In this paper it is investigated whether torsion, which arises naturally in most theories of quantum gravity, has observable implications for the Big Bang nucleosynthesis.
C. N. Yang   +18 more
core   +1 more source

SNR-calibrated Type Ia supernova models [PDF]

open access: yes, 2019
Current Type Ia supernova (SN Ia) models can reproduce most visible+IR + UV observations. In the X-ray band, the determination of elemental abundance ratios in supernova remnants (SNRs) through their spectra has reached enough precision to constrain SN ...
Badenes Montoliu, Carles   +2 more
core   +2 more sources

The evolution and history of Vinca alkaloids: From the Big Bang to the treatment of pediatric acute leukemia

open access: yesPediatric Blood &Cancer, Volume 71, Issue 11, November 2024.
Abstract An attractive flower from the island of Madagascar has in part saved the lives of thousands of children with acute lymphoblastic leukemia (ALL). Random mutations and alterations to the genome led to the evolution of genes encoding enzymes, which would provide the periwinkle flower an arsenal of secondary metabolites to survive within the ...
Jeffrey W. Taub   +5 more
wiley   +1 more source

The Nuclear Astrophysics program at n_TOF (CERN)

open access: yesEPJ Web of Conferences, 2017
An important experimental program on Nuclear Astrophysics is being carried out at the n_TOF since several years, in order to address the still open issues in stellar and primordial nucleosynthesis.
Colonna N.   +129 more
doaj   +1 more source

Upper limit to $\Omega_B$ in scalar-tensor gravity theories

open access: yes, 1997
In a previous paper (Serna & Alimi 1996), we have pointed out the existence of some particular scalar-tensor gravity theories able to relax the nucleosynthesis constraint on the cosmic baryonic density.
Arai K.   +5 more
core   +2 more sources

Big-Bang Nucleosynthesis

open access: yes, 2014
15 pages, 1 (new) figure; mini-review in the Review of Particle Physics 2014 by the Particle Data Group (http://pdg.lbl.gov/)
Fields, B, Molaro, P, Sarkar, S
openaire   +3 more sources

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