Results 11 to 20 of about 676,534 (379)
Review of Membranes for Helium Separation and Purification
Membranes, 2017 Membrane gas separation has potential for the recovery and purification of helium, because the majority of membranes have selectivity for helium. This review reports on the current state of the research and patent literature for membranes undertaking ...
Colin A. Scholes, Ujjal K. Ghosh
doaj +2 more sources
The principles of helium exploration
Petroleum Geoscience, 2022 Commercial helium systems have been found to date as a serendipitous by-product of petroleum exploration. There are nevertheless significant differences in the source and migration properties of helium compared with petroleum.
D. Danabalan +6 more
semanticscholar +1 more source
Unimpeded Permeation of Water Through Helium-Leak–Tight Graphene-Based Membranes [PDF]
Science, 2011 Porous Membranes Thin semi-permeable membranes are commonly used as chemical barriers or for filtration purposes. While the size of the pores will influence which molecules are able to pass, other factors—including the surface chemistry of the pore walls,
R. Nair +4 more
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Confirmation of WASP-107b’s Extended Helium Atmosphere with Keck II/NIRSPEC [PDF]
Astronomical Journal, 2020 We present the detection of helium in the extended atmosphere of the sub-Saturn WASP-107b using high-resolution (R ≈ 25,000) near-infrared spectra from Keck II/Near Infrared Echelle Spectrograph (NIRSPEC). We find peak excess absorption of 7.26% ± 0.24% (
J. Kirk +3 more
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The PHLEK Survey: A New Determination of the Primordial Helium Abundance [PDF]
Astrophysical Journal, 2020 We present Keck NIRSPEC and Keck NIRES spectroscopy of sixteen metal-poor galaxies that have pre-existing optical observations. The near-infrared (NIR) spectroscopy specifically targets the He i λ10830 Å emission line, due to its sensitivity to the ...
Tiffany Hsyu +3 more
semanticscholar +1 more source
The Evolution of Massive Helium Stars, Including Mass Loss [PDF]
Astrophysical Journal, 2019 The evolution of helium stars with initial masses in the range 1.6–120 is studied, including the effects of mass loss by winds. These stars are assumed to form in binary systems when their expanding hydrogenic envelopes are promptly lost just after ...
S. Woosley
semanticscholar +1 more source
Improving helium abundance determinations with Leo P as a case study [PDF]
Journal of Cosmology and Astroparticle Physics, 2020 Currently, the primordial helium abundance is best estimated through spectroscopic observations of H II regions in metal-poor galaxies. However these determinations are limited by several systematic uncertainties which ultimately limit our ability to ...
E. Aver +5 more
semanticscholar +1 more source
Collisional Plasma Models with APEC/APED: Emission-Line Diagnostics of Hydrogen-like and Helium-like Ions [PDF]
, 2001 New X-ray observatories (Chandra and XMM-Newton) are providing a wealth of high-resolution X-ray spectra in which hydrogen- and helium-like ions are usually strong features.
Randall K. Smith +3 more
semanticscholar +1 more source
Astrophysical detection of the helium hydride ion HeH+ [PDF]
Nature, 2019 During the dawn of chemistry1,2, when the temperature of the young Universe had fallen below some 4,000 kelvin, the ions of the light elements produced in Big Bang nucleosynthesis recombined in reverse order of their ionization potential.
R. Güsten +9 more
semanticscholar +1 more source
Ground-based detection of an extended helium atmosphere in the Saturn-mass exoplanet WASP-69b [PDF]
Science, 2018 Helium escaping from hot gas giants Many gas giant exoplanets orbit so close to their host star that they are heated to high temperatures, causing atmospheric gases to escape.
L. Nortmann +27 more
semanticscholar +1 more source