Results 61 to 70 of about 22,641 (242)

Exploring the Effects of Reduced Gravitational Field Impacts on Convective Heat Transfer: A Comprehensive Review

Heat Transfer, Volume 55, Issue 1, Page 764-774, January 2026.
ABSTRACT This review explores the impact of gravitational instability on convective heat transfer, integrating existing research results and theoretical models. Gravitational instability is vital in promoting or hindering convective actions in different systems, such as atmospheric events, ocean currents, and industrial processes.
Hossam A. Nabwey, Muhammad Ashraf, A. M. Rashad, Ali J. Chamkha   +3 more
wiley   +1 more source

Heteroatom-doped hydrogenated amorphous carbons, a-C:H:X 'Volatile' silicon, sulphur and nitrogen depletion, blue photoluminescence, diffuse interstellar bands and ferro-magnetic carbon grain connections (Research Note)

, 2013
Context. Hydrogenated amorphous carbons, a-C:H, can incorporate a variety of heteroatoms, which can lead to interesting effects. Aims. To investigate the doping of interstellar a-C:H grains with, principally, Si, O, N and S atoms within the astrophysical
Jones, A. P.
core   +1 more source

Data-driven Discovery of Diffuse Interstellar Bands with APOGEE Spectra

The Astrophysical Journal
Data-driven models of stellar spectra are useful tools to study nonstellar information, such as the diffuse interstellar bands (DIBs) caused by intervening interstellar material.
Kevin A. McKinnon, Melissa K. Ness, Constance M. Rockosi, Puragra Guhathakurta   +3 more
doaj   +1 more source

Strength Ratios of Diffuse Interstellar Bands in Slightly Reddened Objects

Universe
The disk of the Milky Way fills the interstellar medium in the form of discrete clouds, many (∼30) light-years across. The average density of this medium is 1 hydrogen atom per cm3 (Oort limit), in the clouds—several dozen atoms, and between the clouds ...
Jacek Krełowski, Arkadii Bondar
doaj   +1 more source

Optical Spectroscopy of a post-AGB star HD 187885

Open Astronomy, 2013
The physical parameters of the atmosphere and its chemical composition for a post-AGB star HD 187885 are determined from high resolution spectra. The effective temperature Teff = 8000 ± 200 K and the surface gravity log g = 1.0 ± 0.3 were derived.
Kipper Tõnu
doaj   +1 more source

Nachtsicht ins All mit dem bloßen Auge: Sag mir, wie weit die Sterne steh'n

Physik in unserer Zeit, Volume 57, Issue 1, Page 32-40, January 2026.
Beim Blick in den Nachthimmel sehen wir ohne optische Hilfsmittel und abhängig von der lokalen Lichtverschmutzung viele Hundert bis maximal einige Tausend Sterne und auch einige Galaxien. Aber wie weit sind diese von uns entfernt? Und bis zu welchen maximalen Entfernungen können wir Objekte im Weltall mit dem bloßen Auge wahrnehmen?
Michael Vollmer
wiley   +1 more source

Diffuse Interstellar Bands in z < 0.6 CaII Absorbers

, 2007
The diffuse interstellar bands (DIBs) probably arise from complex organic molecules whose strength in local galaxies correlates with neutral hydrogen column density, N(HI), and dust reddening, E(B-V).
Ellison, Sara L., Murphy, Michael T., Sarre, Peter J., Smith, Arfon M., York, Brian A., Zych, Berkeley J.   +5 more
core   +1 more source

A Tale of Two Sightlines: Comparison of Hydrocarbon Dust Absorption Bands toward Cygnus OB2-12 and the Galactic Center

The Astrophysical Journal
Infrared spectra of hydrocarbon dust absorption bands toward the bright hypergiant Cygnus OB2-12 are compared to published spectra of the Quintuplet Cluster, a sightline to the Galactic center. The Cyg OB2-12 data include a new ground-based 2.86−3.70 μ m
Yvonne J. Pendleton, T. R. Geballe, Laurie E. U. Chu, Marjorie Decleir, Karl D. Gordon, A. G. G. M. Tielens, Louis J. Allamandola, Jeroen Bouwman, J. E. Chiar, Curtis Dewitt, Burcu Gunay, Thomas Henning, Vito Mennella, M. E. Palumbo, Alexey Potapov, Maisie Rashman, Sascha Zeegers   +16 more
doaj   +1 more source

Adsorption of Helium on Cationic or Anionic Tetracene and Pentacene

Small Structures, Volume 7, Issue 1, January 2026.
How does the arrangement of helium atoms that are adsorbed on tetracene or pentacene ions change with increasing coverage? When does the adsorption layer change from 1D to 2D, and to 3D? Is the transition abrupt? Are the helium atoms localized? Is the arrangement the same for cations and anions? What changes as the acene grows in length?
Miriam Kappe, Florent Calvo, Rasif William, Bilal Rasul, Masoomeh Mahmoodi‐Darian, Paul Scheier, Olof Echt   +6 more
wiley   +1 more source

The Optical -- Mid-infrared Extinction Law of the l=165 Sightline in the Galactic Plane: Diversity of Extinction Law in the Diffuse Interstellar Medium

, 2017
Understanding the effects of dust extinction is important to properly interpret observations. The optical total-to-selective extinction ratio, Rv = Av/E(B-V), is widely used to describe extinction variations in ultraviolet and optical bands. Since the Rv=
Chen, Xiaodian, de Grijs, Richard, Jiang, Biwei, Wang, Shu, Zhao, He   +4 more
core   +2 more sources