
	Where results make sense

Topic: Nucleosynthesis

Related Topics

Big Bang nucleosynthesis

Stellar nucleosynthesis

Neutron emission

Abundance of the chemical elements

Deuterium

Gamma radiation

Chemical element

Internal conversion

Alpha decay

Technetium

Beta decay

Radioactive decay

Itzhak Rabin

Don Imus

CBS

In the News (Mon 30 Nov 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	Nucleosynthesis - Wikipedia, the free encyclopedia
		The subsequent nucleosynthesis of the elements occurs primarily either by nuclear fusion or nuclear fission.
		Fred Hoyle's original work on nucleosynthesis of heavier elements in stars (including a detailed mechanistic analysis for the production of carbon) occurred just after World War II, but this work was in search of a way to produce heavier elements from hydrogen in stars, in the steady state model of cosmology.
		In explosive environments such as supernovae further nucleosynthesis processes can occur, such as the r process (in which elements heavier than iron and nickel are produced by rapid absorption of free neutrons) and the rp process (which involves the rapid absorption of free protons).
	en.wikipedia.org /wiki/Nucleosynthesis (931 words)

	Big Bang nucleosynthesis - Wikipedia, the free encyclopedia
		Another feature is that the process of nucleosynthesis is determined by conditions at the start of this phase of the life of the universe, making what happens before irrelevant.
		At the time at which nucleosynthesis occurs, the temperature is high enough for the mean energy per particle to be greater than the binding energy of deuterium; therefore any deuterium that is formed is immediately destroyed (a situation known as the deuterium bottleneck).
		During the 1970s, there was a major puzzle in that the density of baryons as calculated by Big Bang nucleosynthesis was much less than the observed mass of the universe based on calculations of the expansion rate.
	en.wikipedia.org /wiki/Big_Bang_nucleosynthesis (2022 words)

	Primordial Nucleosynthesis
		Translated literally, primordial refers to the early universe, while nucleosynthesis is the synthesizing, or forming, of nuclei.
		Primordial nucleosynthesis is a period in the early universe.
		On the later side of nucleosynthesis, the temperature was too low, so that there was simply not enough energy to form the nucleons.
	www.geocities.com /biggerleif/Nucleosynthesis.html (629 words)

	Nucleosynthesis (Site not responding. Last check: 2007-10-07)
		The principal modes of nucleosynthesis, along with isotopic abundances, for naturally-occurring isotopes have been tabulated (Anders and Grevesse 1989).
		Once s-process elements are formed, the AGB star conveniently convects these to the surface, where they may be released either in a stellar wind or in a subsequent supernova explosion.
		Perhaps the most dramatic nucleosynthesis is the formation of the iron-group elements.
	ultraman.ssl.berkeley.edu /nucleosynthesis.html (1277 words)

	Nucleosynthesis - (Site not responding. Last check: 2007-10-07)
		Big Bang nucleosynthesis occurred within the first three minutes of the universe and is responsible for most of the helium-4 and deuterium in the universe.
		Because of the very short period in which Big Bang nucleosynthesis occurred, no elements heavier than lithium could be formed.
		Supernova nucleosynthesis produces most of the elements heavier than oxygen, because the sequence of burning processes within stars occur more rapidly and reach heavier elements within supernova explosions.
	psychcentral.com /psypsych/Nucleosynthesis (617 words)

	Formation of the elements/Nucleosynthesis in the early universe
		At the time that nucleosynthesis began, the relative abundance of protons to neutrons was: 13% neutrons and 87% protons.
		So, when this first wave of nucleosynthesis was completed, the universe consisted of roughly 25% He and 75% H (by weight).
		Below is a graphical summation of nucleosynthesis in the early universe.
	aether.lbl.gov /www/tour/elements/early/early_a.html (1605 words)

	Big bang nucleosynthesis Info - Encyclopedia WikiWhat.com (Site not responding. Last check: 2007-10-07)
		Big bang nucleosynthesis refers to the process of element production during the early phases of the universe, shortly after the Big Bang.
		So there was a bottleneck in the nucleosynthesis that stopped the process there.
		The relative abundances of the different elements produced are dependent on the number of photons per baryon.
	www.wikiwhat.com /encyclopedia/b/bi/big_bang_nucleosynthesis.html (375 words)

	Big Bang nucleosynthesis: Facts and details from Encyclopedia Topic (Site not responding. Last check: 2007-10-07)
		In the first half of the 20th century, the word universe was used to mean the whole spacetime continuum in which we exist, together with all the energy...
		Another feature is that the process of nucleosynthesis is determined by conditions at the start of this phase of the life of the universe, EHandler: no quick summary.
		Ralph asher alpher (born 1921) is a u.s.
	www.absoluteastronomy.com /encyclopedia/b/bi/big_bang_nucleosynthesis.htm (2867 words)

	2.4 Nucleosynthesis (Site not responding. Last check: 2007-10-07)
		However, it is interesting to investigate other more general models to assert the role of shear and curvature on the nucleosynthesis process.
		Their results have been used to place a limit on anisotropy at the epoch of nucleosynthesis.
		The numerical simulations also demonstrate that, because of the back diffusion, a cosmological model with a critical baryon density cannot be made consistent with helium and deuterium observations, even with substantial baryon inhomogeneities and the anticipated neutron diffusion effect.
	relativity.livingreviews.org /Articles/lrr-1998-2/node6.html (307 words)

	nucleosynthesis
		Helium and some lithium was produced by cosmic nucleosynthesis just after the Big Bang, but today most element-building nucleosynthesis takes place in stars.
		Stellar nucleosynthesis converts hydrogen into helium, either by the proton-proton chain or by the carbon-nitrogen-oxygen cycle.
		The heaviest elements of all are produced by explosive nucleosynthesis in supernova explosions, by mechanisms such as the p-process, r-process, and s-process.
	www.daviddarling.info /encyclopedia/N/nucleosynthesis.html (244 words)

	ASTROPHYSICS: ON STELLAR NUCLEOSYNTHESIS
		Thus there is an intricate relationship between the life cycles of stars and the nucleosynthesis of the elements.
		After a nucleus has captured a neutron to become a heavier nucleus, the time scale t(sub-n) for it to capture an additional neutron is either slow or rapid on the competing time scale t(sub-beta) for it to undergo beta decay.
		Such element generation or nucleosynthesis, through transmutation of one element into another, is a crucial by-product of stellar energy generation.
	scienceweek.com /2004/sa041126-2.htm (1796 words)

	Science and Reason: The Big Bang
		From calculations of the amount of deuterium that should be produced by nucleosynthesis, there must have been about one baryon per 1.8 billion photons in order to account for the amount of deuterium that is actually observed.
		General nucleosynthesis doesn't really get going until more like 300 seconds, when there are no longer enough energetic photons to destroy deuterium, and enough deuterium nuclei have formed to combine with additional neutrons to make helium-3, helium-4, and lithium-7.
		Although nuclei of a few lightweight elements were formed in the nucleosynthesis process, they were not yet atoms as we know them, since they were fully ionized – electrons still moved about freely instead of being bound to a nucleus.
	www.scienceandreason.net /oq/oq-co008.htm (20702 words)

	nucleosynthesis on Encyclopedia.com (Site not responding. Last check: 2007-10-07)
		The origin of matter: the question of how matter triumphed over antimatter in the formation of the u...
		NUCLEOSYNTHESIS [nucleosynthesis] or nucleogenesis, in astronomy, production of all the chemical elements from the simplest element, hydrogen, by thermonuclear reactions within stars, supernovas, and in the big bang at the beginning of the universe (see nucleus ; nuclear energy).
		However, during a supernova, an extremely intense flux of neutrons is generated and nuclear reactions proceed so rapidly that the radioactive elements do not have enough time to decay, resulting in the rapid creation of the radioactive elements up to and beyond uranium.
	encyclopedia.infonautics.com /html/n1/nucleosy.asp (684 words)

	A Dictionary of Physics: nucleosynthesis @ HighBeam Research (Site not responding. Last check: 2007-10-07)
		Primordial nucleosynthesis took place very soon after the big bang, when the universe was extremely hot.
		This process was responsible for the cosmic abundances observed for light elements, such as helium.
		Explosive nucleosynthesis can also occur during the explosion of a supernova.
	highbeam.com /doc/1O83:nucleosynthesis/nucleosynthesis+...?refid=ip_hf (146 words)

	Nucleosynthesis
		In nuclear chemistry terms, deuterium nuclei are very reactive and able to efficiently react with each other – by a variety of nuclear reactions – to give a mixture of: 3_He, 4_He, 7_Li, along with the 1_H and 2_H.
		Due to the thermochemistry of the various nuclear processes, each shell of nucleosynthesis proceeds on an accelerating time scale and Si burns to Fe in hours.
		All these nucleosynthesis reactions can be found in The Chemical Thesaurus.
	www.meta-synthesis.com /webbook/32_n-synth/nucleosynthesis.html (1156 words)

	Baryon Density Constraint (Site not responding. Last check: 2007-10-07)
		The rate at which the early Universe expands is independent of the density of more massive particles such as protons and neutrons (baryons) (the baryons are simply along for the ride).
		The yield of Big Bang nucleosynthesis, however, depends strongly upon the density of protons and neutrons in the early Universe.
		The reaction rates for the protons and neutrons (and therefore the yields of Big Bang nucleosynthesis) can be changed by making different assumptions about the baryon density in the Universe.
	zebu.uoregon.edu /~imamura/123/lecture-8/limits.html (286 words)

	Fusion Brief (Site not responding. Last check: 2007-10-07)
		In all of the stars throughout the universe fusion is the process which creates the tremendous amounts of energy that is released.
		As difficult as it may be to believe, the majority of the elements around us were created at some time in the distant past by this process.
		On the Sun and other medium and smaller size stars the fuel for this nucleosynthesis is hydrogen.
	edmall.gsfc.nasa.gov /99invest.Site/science-briefs/ace/ed-fusion.html (946 words)

	ESF - P-Process Nucleosynthesis
		European teams working in the scientific domain of heavy element nucleosynthesis are recognized by the international Nuclear Astrophysics community to have - currently - the leading role in this field.
		A considerable contribution to this European scientific status has been made by a few theoreticians from the discipline of astrophysics and of course by a number of small nuclear physics laboratories with very low national European funding.
		As in the case of NACRE, the results of the proposed workshop are expected to have - at an international level - a long lasting impact on studies related to heavy element nucleosynthesis.
	www.esf.org /esf_article.php?language=0&activity=4&domain=1&article=230&page=733 (181 words)

	3.4 Nucleosynthesis (Site not responding. Last check: 2007-10-07)
		He increases with increasing shear; this is due to time scale effects and the competition between dissipation and enhanced reaction rates from photon heating and neutrino blue shifts.
		Li increase with anisotropy in accord with [48].
		However, plane symmetric, general relativistic simulations with neutron diffusion [39] show that the neutrons diffuse back into the high density regions once nucleosynthesis begins there - thereby wiping out the effect.
	relativity.livingreviews.org /Articles/lrr-1998-9/node9.html (321 words)

	nucleosynthesis concept from the Astronomy knowledge base (Site not responding. Last check: 2007-10-07)
		primordial nucleosynthesis (6 facts) (big-bang nucleosynthesis) - The production of heavy nuclei from the fusion of lighter ones during the Big Bang.
		All other elements would have to be formed later, in nucleosynthesis processes.
		It is believed that most of the helium, the next lightest element after hydrogen, was formed when the universe was a few minutes old, The creation of elements that occurred just minutes after the Big Bang.
	www.site.uottawa.ca:4321 /astronomy/nucleosynthesis.html (180 words)

	sliabh.net » Nucleosynthesis (Site not responding. Last check: 2007-10-07)
		It manages to neatly bring together the infinitesimally small worlds of sub atomic physics with the gargantuan scale of stars and galaxies.
		If you are not familiar with nucleosynthesis it is the process for how new atoms are formed from simpler elements.
		For pretty much anything more complex than helium, nucleosynthesis describes how the stars are the forges of creation.
	www.sliabh.net /?p=527 (715 words)

	Amazon.com: Principles of Stellar Evolution and Nucleosynthesis: Books: Donald D. Clayton (Site not responding. Last check: 2007-10-07)
		Nucleosynthesis and Chemical Evolution of Galaxies by Bernard E. Pagel
		Donald D. Clayton's Principles of Stellar Evolution and Nucleosynthesis remains the standard work on the subject, a popular textbook for students in astronomy and astrophysics and a rich sourcebook for researchers.
		The basic principles of physics as they apply to the origin and evolution of stars and physical processes of the stellar interior are thoroughly and systematically set out.
	www.amazon.com /exec/obidos/tg/detail/-/0226109534?v=glance (843 words)

	Amazon.com: Supernovae and Nucleosynthesis: Books: David Arnett (Site not responding. Last check: 2007-10-07)
		It concludes with a synthesis of these ideas for galactic evolution, with implications for nucleosynthesis in the first generation of stars and for the solar system abundance pattern.
		Emphasis is given to questions that remain open, and to active research areas that bridge the disciplines of astronomy, cosmochemistry, physics, and planetary and space science.
		"Supernovae and Nucleosynthesis" is not a textbook, but it is extremely useful for astronomy students, especially in stellar and chemical evolution.
	www.amazon.com /exec/obidos/tg/detail/-/0691011478?v=glance (882 words)

	Learn more about Stellar nucleosynthesis in the online encyclopedia. (Site not responding. Last check: 2007-10-07)
		Learn more about Stellar nucleosynthesis in the online encyclopedia.
		Stellar nucleosynthesis is the collective term for the nuclear reactions taking place in stars to build the nuclei of the heavier elements.
		The processes involved were elucidated over a number of years from early in the 20th century, when it was first realised that the energy released from nuclear reactions accounted for the longevity of the Sun as a source of heat and light.
	www.onlineencyclopedia.org /s/st/stellar_nucleosynthesis.html (401 words)

	Nucleosynthesis
		K) and the rate of nucleosynthesis had slowed down significantly.
		By the time the universe was three minutes old the process had basically stopped and the relative abundances of the elements was fixed at ratios that didn't change for very long time: 75% hydrogen, 25% helium, with trace amounts of deuterium (hydrogen-2), helium-3, and lithium-7.
		Discovered by Perrier and Segre in a sample of Molybdenum that had been irradiated by deuterons at the UC Berkeley cyclotron by E.O. Lawrence and then sent to Italy.
	www.hypertextbook.com /physics/modern/nucleosynthesis (693 words)

	Big Bang Nucleosynthesis (Site not responding. Last check: 2007-10-07)
		Big bang nucleosynthesis and physics beyond the standard model (1996)
		Nucleosynthesis bounds on a time-varying cosmological `constant' (1996)
		Primordial nucleosynthesis, additional neutrinos and neutral currents from the superstring (1986)
	www-thphys.physics.ox.ac.uk /users/SubirSarkar/bbn.html (137 words)

	ASTRONOMY: ON NUCLEOSYNTHESIS IN BINARY STARS
		Recently, a more complete accounting was given at the Lorentz Workshop on Nucleosynthesis in Binary Stars, held in April 2005 [2].
		This international gathering of experts in the field and others interested in stellar evolution and nucleosynthesis featured presentations of data, models, and lengthy discussions on what problems should be tackled and how.
		Lorentz Workshop on Nucleosynthesis in Binary Stars, Lorentz Center, Leiden, Netherlands, 4 to 15 April 2005.
	scienceweek.com /2006/sw060210-1.htm (1670 words)

Try your search on: Qwika (all wikis)