Results 51 to 60 of about 319,875 (285)

Carbonaceous dust grains in luminous infrared galaxies [PDF]

open access: yesAstronomy & Astrophysics, 2007
[Conclusions] These observations further demonstrate the ubiquitousness of a-C:H in the diffuse interstellar medium (DISM) of galaxies, for a long time almost only observed in the Milky-Way ISM lines-of-sights. Whereas PAH emission lines trace the re-processing of energetic young stellar radiation, the observed a-C:H features underline the existence of
Dartois, Emmanuel   +1 more
openaire   +2 more sources

Distinct Microstructural Characteristic Lengths Defining Notch Fatigue Crack Initiation and Propagation, and Defect Tolerance in Advanced Steels

open access: yesAdvanced Engineering Materials, EarlyView.
Schematic representation of modes of microcrack nucleation, growth and temporary arrestment at different boundaries, with the criteria for crack propagation in three scenarios: (1) large notch, (2) defect/small sharp notch, and (3) long crack. This work revisits and integrates results on the fatigue behavior of advanced bainitic steels (in particular ...
Lucia Morales‐Rivas
wiley   +1 more source

Investigating Silicate, Carbon, and Water in the Diffuse Interstellar Medium: The First Shots from WISCI

open access: yesThe Astrophysical Journal
The dusty interstellar medium (ISM) of the Milky Way is distributed in a complex, cloudy structure. It is fundamental to the radiation balance within the Milky Way, provides a reaction surface to form complex molecules, and is the feedstock for future ...
S. T. Zeegers   +35 more
doaj   +1 more source

Cometary micrometeorites and input of prebiotic compounds

open access: yesBIO Web of Conferences, 2014
The apparition of life on the early Earth was probably favored by inputs of extraterrestrial matter brought by carbonaceous chondrite-like objects or cometary material. Interplanetary dust collected nowadays on Earth is related to carbonaceous chondrites
Engrand C.
doaj   +1 more source

13C-depleted moissanites in subduction-related rocks: tracers of slab fluids in the Earth’s mantle and a new diamond exploration tool [PDF]

open access: yesE3S Web of Conferences, 2019
A magnesian low-Ti shoshonite dike intruding Archean Norwegian Terrane includes numerous grains of black, blue and gray moissanite (SiC). Moissanite contains inclusions of native Si, Fe and Al, Fe-Cr carbides, Fe-Cr-Mn alloys and diamond.
Kepezhinskas Pavel, Kepezhinskas Nikita
doaj   +1 more source

THE APPLICATION OF SCANNING ELECTRON MICROSCOPY USING ENERGY- AND WAVELENGTH DISPERSIVE SPECTROMETERS FOR CHEMICAL DATING OF URANIUM MINERALIZATION ON THE EXAMPLE OF CARBONACEOUS SHALES OF THE DABANZHALGA SUITE (EAST SAYAN)

open access: yesГеодинамика и тектонофизика, 2022
On the one hand, the widespread use of electron microprobe analysis in the version of a scanning electron microscope (SEM) equipped with an energy dispersive spectrometer (EDS) and, on the other hand, the comparability of the metrological characteristics
D. K. Belyanin   +3 more
doaj   +1 more source

Microstructure Modification of Additively Manufactured Mo–9Si–8B by Annealing and Its Effects on High‐Temperature Mechanical Properties

open access: yesAdvanced Engineering Materials, EarlyView.
Postbuild annealing systematically modifies the phase fractions and morphology of EB‐PBF processed Mo–9Si–8B. Quantitative microstructure–property correlations reveal how controlled phase evolution enhances high‐temperature compressive strength and creep resistance.
Christopher Schmidt   +5 more
wiley   +1 more source

In Situ Isotopic Analysis of Presolar Graphite Challenges Stellar Models

open access: yesThe Astrophysical Journal
We have analyzed zirconium, molybdenum, and barium isotopes for the first time in situ in two presolar graphite grains found in polished thin sections from the CM2 meteorites Maribo and Murchison.
Thomas Stephan   +6 more
doaj   +1 more source

Investigating the Effect of Inclination Angle and the Influence of Scan Parameters on the Appearance and Thermal and Mechanical Properties of Filigree Tension Rods of LPBF‐Manufactured NiTi Shape‐Memory Alloys

open access: yesAdvanced Engineering Materials, EarlyView.
This article investigates the dependence of the properties on the manufacturing orientation in the form of the inclination angle to the build plate of LPBF‐fabricated NiTi rods with a diameter of 150–220 µm. Metallographic, chemical, thermal, and mechanical characterization show behavior under identical manufacturing conditions that ranges from ...
Sandra Herzig   +2 more
wiley   +1 more source

The Presolar Grain Database. I. Silicon Carbide

open access: yesThe Astrophysical Journal Supplement Series
The Presolar Grain Database (PGD) contains the vast majority of isotope data (published and unpublished) on presolar grains and was first released as a collection of spreadsheets in 2009.
Thomas Stephan   +10 more
doaj   +1 more source

Home - About - Disclaimer - Privacy