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A nitrogen generator Bottle of 4Å molecular sieves. Pressure swing adsorption provides separation of oxygen or nitrogen from air without liquefaction. The process operates around ambient temperature; a zeolite (molecular sponge) is exposed to high pressure air, then the air is released and an adsorbed film of the desired gas is released.
A sample of 229 nearby "thick" disk stars has been used to investigate the existence of an age-metallicity relation in the Galactic thick disk and indicates that there is an age-metallicity relation present in the thick disk. [13] [14] Stellar ages from asteroseismology confirm the lack of any strong age-metallicity relation in the Galactic ...
A cosmological phase transition is an overall change in the state of matter across the whole universe. The success of the Big Bang model led researchers to conjecture possible cosmological phase transitions taking place in the very early universe, at a time when it was much hotter and denser than today.
Without major changes to the Big Bang theory itself, BBN will result in mass abundances of about 75% of hydrogen-1, about 25% helium-4, about 0.01% of deuterium and helium-3, trace amounts (on the order of 10 −10) of lithium, and negligible heavier elements. That the observed abundances in the universe are generally consistent with these ...
Observational cosmology – Study of the origin of the universe (structure and evolution) Observation history of galaxies – Large gravitationally bound system of stars and interstellar matter; Physical cosmology – Branch of cosmology which studies mathematical models of the universe; Timeline of cosmological theories
In modern physical cosmology, the cosmological principle is the notion that the spatial distribution of matter in the universe is uniformly isotropic and homogeneous when viewed on a large enough scale, since the forces are expected to act equally throughout the universe on a large scale, and should, therefore, produce no observable inequalities in the large-scale structuring over the course ...
Meteorites are often studied as part of cosmochemistry. Cosmochemistry (from Ancient Greek κόσμος (kósmos) 'universe' and χημεία (khēmeía) 'chemistry') or chemical cosmology is the study of the chemical composition of matter in the universe and the processes that led to those compositions. [1]
Sara Imari Walker is an American theoretical physicist and astrobiologist with research interests in the origins of life, astrobiology, physics of life, emergence, complex and dynamical systems, and artificial life.