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1

Big-Bang Nucleosynthesis verifies classical Maxwell-Boltzmann distribution  

E-Print Network [OSTI]

We provide the most stringent constraint to date on possible deviations from the usually-assumed Maxwell-Boltzmann (MB) velocity distribution for nuclei in the Big-Bang plasma. The impact of non-extensive Tsallis statistics on thermonuclear reaction rates involved in standard models of Big-Bang Nucleosynthesis (BBN) has been investigated. We find that the non-extensive parameter $q$ may deviate by, at most, $|\\delta q|$=6$\\times$10$^{-4}$ from unity for BBN predictions to be consistent with observed primordial abundances; $q$=1 represents the classical Boltzmann-Gibbs statistics. This constraint arises primarily from the {\\em super}sensitivity of endothermic rates on the value of $q$, which is found for the first time. As such, the implications of non-extensive statistics in other astrophysical environments should be explored. This may offer new insight into the nucleosynthesis of heavy elements.

S. Q. Hou; J. J. He; A. Parikh; K. Daid; C. Bertulani

2014-08-15T23:59:59.000Z

2

Primordial Lithium Abundance in Catalyzed Big Bang Nucleosynthesis  

E-Print Network [OSTI]

There exists a well known problem with the Li7+Be7 abundance predicted by standard big bang nucleosynthesis being larger than the value observed in population II stars. The catalysis of big bang nucleosynthesis by metastable, \\tau_X \\ge 10^3 sec, charged particles X^- is capable of suppressing the primordial Li7+Be7, abundance and making it consistent with the observations. We show that to produce the correct abundance, this mechanism of suppression places a requirement on the initial abundance of X^- at temperatures of 4\\times 10^8 K to be on the order of or larger than 0.02 per baryon, which is within the natural range of abundances in models with metastable electroweak-scale particles. The suppression of Li7+Be7, is triggered by the formation of (Be7X^-), compound nuclei, with fast depletion of their abundances by catalyzed proton reactions, and in some models by direct capture of X^- on Be7. The combination of Li7+Be7 and Li6 constraints favours the window of lifetimes, 1000s \\la tau_X \\leq 2000 s.

Chris Bird; Kristen Koopmans; Maxim Pospelov

2008-05-19T23:59:59.000Z

3

Big Bang Nucleosynthesis with Independent Neutrino Distribution Functions  

E-Print Network [OSTI]

We have performed new Big Bang Nucleosynthesis calculations which employ arbitrarily-specified, time-dependent neutrino and antineutrino distribution functions for each of up to four neutrino flavors. We self-consistently couple these distributions to the thermodynamics, the expansion rate and scale factor-time/temperature relationship, as well as to all relevant weak, electromagnetic, and strong nuclear reaction processes in the early universe. With this approach, we can treat any scenario in which neutrino or antineutrino spectral distortion might arise. These scenarios might include, for example, decaying particles, active-sterile neutrino oscillations, and active-active neutrino oscillations in the presence of significant lepton numbers. Our calculations allow lepton numbers and sterile neutrinos to be constrained with observationally-determined primordial helium and deuterium abundances. We have modified a standard BBN code to perform these calculations and have made it available to the community.

Christel J. Smith; George M. Fuller; Michael S. Smith

2008-12-06T23:59:59.000Z

4

Modified big bang nucleosynthesis with non-standard neutron sources  

E-Print Network [OSTI]

During big bang nucleosynthesis, any injection of extra neutrons around the time of the $^7$Be formation, i.e. at a temperature of order $T \\simeq 50$~keV, can reduce the predicted freeze-out amount of $^7$Be + $^7$Li that otherwise remains in sharp contradiction with the Spite plateau value inferred from the observations of Pop II stars. However, the growing confidence in the primordial D/H determinations puts a strong constraint on any such scenario. We address this issue in detail, analyzing different temporal patterns of neutron injection, such as decay, annihilation, resonant annihilation, and oscillation between mirror and standard model world neutrons. For this latter case, we derive the realistic injection pattern taking into account thermal effects (damping and refraction) in the primordial plasma. If the extra neutron supply is the sole non-standard mechanism operating during the BBN, the suppression of lithium abundance below Li/H~$\\leq 1.9 \\times 10^{-10}$ always leads to the overproduction of deuterium, D/H~$\\geq 3.6 \\times 10^{-5}$, well outside the error bars suggested by recent observations.

Alain Coc; Maxim Pospelov; Jean-Philippe Uzan; Elisabeth Vangioni

2014-05-07T23:59:59.000Z

5

The NACRE Thermonuclear Reaction Compilation and Big Bang Nucleosynthesis  

E-Print Network [OSTI]

The theoretical predictions of big bang nucleosynthesis (BBN) are dominated by uncertainties in the input nuclear reaction cross sections. In this paper, we examine the impact on BBN of the recent compilation of nuclear data and thermonuclear reactions rates by the NACRE collaboration. We confirm that the adopted rates do not make large overall changes in central values of predictions, but do affect the magnitude of the uncertainties in these predictions. Therefore, we then examine in detail the uncertainties in the individual reaction rates considered by NACRE. When the error estimates by NACRE are treated as 1\\sigma limits, the resulting BBN error budget is similar to those of previous tabulations. We propose two new procedures for deriving reaction rate uncertainties from the nuclear data: one which sets lower limits to the error, and one which we believe is a reasonable description of the present error budget. We propagate these uncertainty estimates through the BBN code, and find that when the nuclear data errors are described most accurately, the resulting light element uncertainties are notably smaller than in some previous tabulations, but larger than others. Using these results, we derive limits on the cosmic baryon-to-photon ratio $\\eta$, and compare this to independent limits on $\\eta$ from recent balloon-borne measurements of the cosmic microwave background radiation (CMB). We discuss means to improve the BBN results via key nuclear reaction measurements and light element observations.

Richard H. Cyburt; Brian D. Fields; Keith A. Olive

2001-05-17T23:59:59.000Z

6

Lithium in cool stellar atmospheres: Big bang nucleosynthesis and extrasolar planets  

E-Print Network [OSTI]

Lithium in cool stellar atmospheres: Big bang nucleosynthesis and extrasolar planets Matthias Steffen and Elisabetta Caffau Sternphysik In metal-poor stellar atmospheres, the Lithium line at 6707 Ã?-NLTE, respectively. The accurate spectroscopic determination of the Lithium abundance and in particular the 6Li/7Li

7

Astrophysical S-factor for destructive reactions of lithium-7 in big bang nucleosynthesis  

SciTech Connect (OSTI)

One of the most prominent success with the Big Bang models is the precise reproduction of mass abundance ratio for {sup 4}He. In spite of the success, abundances of lithium isotopes are still inconsistent between observations and their calculated results, which is known as lithium abundance problem. Since the calculations were based on the experimental reaction data together with theoretical estimations, more precise experimental measurements may improve the knowledge of the Big Bang nucleosynthesis. As one of the destruction process of lithium-7, we have performed measurements for the reaction cross sections of the {sup 7}L({sup 3}He,p){sup 9}Be reaction.

Komatsubara, Tetsuro; Kwon, YoungKwan; Moon, JunYoung; Kim, Yong-Kyun [Rare Isotope Science Project, Institute for Basic Science, Daejeon (Korea, Republic of); Moon, Chang-Bum [Hoseo University, Asan, Chungnam (Korea, Republic of); Ozawa, Akira; Sasa, Kimikazu; Onishi, Takahiro; Yuasa, Toshiaki; Okada, Shunsuke; Saito, Yuta [Division of Physics, University of Tsukuba, Tsukuba, Ibaraki (Japan); Hayakawa, Takehito; Shizuma, Toshiyuki [Japan Atomic Energy Agency, Shirakata Shirane, Tokai, Ibaraki (Japan); Kubono, Shigeru [RIKEN, Hirosawa, Wako, Saitama (Japan); Kusakabe, Motohiko [School of Liberal Arts and Science, Korea Aerospace University (Korea, Republic of); Kajino, Toshitaka [National Astronomical Observatory, Osawa, Mitaka, Tokyo (Japan)

2014-05-02T23:59:59.000Z

8

Refined scenario of standard Big Bang nucleosynthesis allowing for nonthermal nuclear reactions in the primordial plasma  

SciTech Connect (OSTI)

The standard scenario of big bang nucleosynthesis (BBN) is generalized to take into account nonthermal nuclear reactions in the primordial plasma. These reactions are naturally triggered in the BBN epoch by fast particles generated in various exoergic processes. It is found that, although such particles can appreciably enhance the rates of some individual reactions, their influence on the whole process of element production is not significant. The nonthermal corrections to element abundances are obtained to be 0.1% ({sup 3}H), -0.03% ({sup 7}Li), and 0.34 %-0.63% (CNO group).

Voronchev, Victor T.; Nakao, Yasuyuki; Nakamura, Makoto; Tsukida, Kazuki [Institute of Nuclear Physics, Moscow State University, Moscow 119991 (Russian Federation); Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, Motooka, Fukuoka 819-0395 (Japan); Division of Advanced Plasma Research, Japan Atomic Energy Agency, 2-166 Oaza-Obuchi-Aza-Omotedate, Rokkasho, Kamikita, Aomori 039-3212 (Japan); Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, Motooka, Fukuoka 819-0395 (Japan)

2012-11-12T23:59:59.000Z

9

Deep Mixing of He-3: Reconciling Big Bang and Stellar Nucleosynthesis  

E-Print Network [OSTI]

Low-mass stars, ~1-2 solar masses, near the Main Sequence are efficient at producing He-3, which they mix into the convective envelope on the giant branch and should distribute into the Galaxy by way of envelope loss. This process is so efficient that it is difficult to reconcile the low observed cosmic abundance of He-3 with the predictions of both stellar and Big Bang nucleosynthesis. In this paper we find, by modeling a red giant with a fully three-dimensional hydrodynamic code and a full nucleosynthetic network, that mixing arises in the supposedly stable and radiative zone between the hydrogen-burning shell and the base of the convective envelope. This mixing is due to Rayleigh-Taylor instability within a zone just above the hydrogen-burning shell, where a nuclear reaction lowers the mean molecular weight slightly. Thus we are able to remove the threat that He-3 production in low-mass stars poses to the Big Bang nucleosynthesis of He-3.

Peter P Eggleton; David S P Dearborn; John C Lattanzio

2006-11-01T23:59:59.000Z

10

Using Big Bang Nucleosynthesis to Extend CMB Probes of Neutrino Physics  

E-Print Network [OSTI]

We present calculations showing that upcoming Cosmic Microwave Background (CMB) experiments will have the power to improve on current constraints on neutrino masses and provide new limits on neutrino degeneracy parameters. The latter could surpass those derived from Big Bang Nucleosynthesis (BBN) and the observationally-inferred primordial helium abundance. These conclusions derive from our Monte Carlo Markov Chain (MCMC) simulations which incorporate a full BBN nuclear reaction network. This provides a self-consistent treatment of the helium abundance, the baryon number, the three individual neutrino degeneracy parameters and other cosmological parameters. Our analysis focuses on the effects of gravitational lensing on CMB constraints on neutrino rest mass and degeneracy parameter. We find for the PLANCK experiment that total (summed) neutrino mass $M_{\

M. Shimon; N. J. Miller; C. T. Kishimoto; C. J. Smith; G. M. Fuller; B. G. Keating

2010-05-10T23:59:59.000Z

11

Using Big Bang Nucleosynthesis to Extend CMB Probes of Neutrino Physics  

E-Print Network [OSTI]

We present calculations showing that upcoming Cosmic Microwave Background (CMB) experiments will have the power to improve on current constraints on neutrino masses and provide new limits on neutrino degeneracy parameters. The latter could surpass those derived from Big Bang Nucleosynthesis (BBN) and the observationally-inferred primordial helium abundance. These conclusions derive from our Monte Carlo Markov Chain (MCMC) simulations which incorporate a full BBN nuclear reaction network. This provides a self-consistent treatment of the helium abundance, the baryon number, the three individual neutrino degeneracy parameters and other cosmological parameters. Our analysis focuses on the effects of gravitational lensing on CMB constraints on neutrino rest mass and degeneracy parameter. We find for the PLANCK experiment that total (summed) neutrino mass $M_{\

Shimon, M; Kishimoto, C T; Smith, C J; Fuller, G M; Keating, B G

2010-01-01T23:59:59.000Z

12

New effects of a long-lived negatively charged massive particle on big bang nucleosynthesis  

SciTech Connect (OSTI)

Primordial {sup 7}Li abundance inferred from observations of metal-poor stars is a factor of about 3 lower than the theoretical value of standard big bang nucleosynthesis (BBN) model. One of the solutions to the Li problem is {sup 7}Be destruction during the BBN epoch caused by a long-lived negatively charged massive particle, X{sup ?}. The particle can bind to nuclei, and X-bound nuclei (X-nuclei) can experience new reactions. The radiative X{sup ?} capture by {sup 7}Be nuclei followed by proton capture of the bound state of {sup 7}Be and X{sup ?} ({sup 7}Be{sub x}) is a possible {sup 7}Be destruction reaction. Since the primordial abundance of {sup 7}Li originates mainly from {sup 7}Li produced via the electron capture of {sup 7}Be after BBN, the {sup 7}Be destruction provides a solution to the {sup 7}Li problem. We suggest a new route of {sup 7}Be{sub x} formation, that is the {sup 7}Be charge exchange at the reaction of {sup 7}Be{sup 3+} ion and X{sup ?}. The formation rate depends on the ionization fraction of {sup 7}Be{sup 3+} ion, the charge exchange cross section of {sup 7}Be{sup 3+}, and the probability that excited states {sup 7}Be{sub x}* produced at the charge exchange are converted to the ground state. We find that this reaction can be equally important as or more important than ordinary radiative recombination of {sup 7}Be and X{sup ?}. The effect of this new route is shown in a nuclear reaction network calculation.

Kusakabe, Motohiko [School of Liberal Arts and Science, Korea Aerospace University, Goyang 412-791, Korea and Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of); Kim, K. S. [School of Liberal Arts and Science, Korea Aerospace University, Goyang 412-791 (Korea, Republic of); Cheoun, Myung-Ki [Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of); Kajino, Toshitaka [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan and Department of Astronomy, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Kino, Yasushi [Department of Chemistry, Tohoku University, Sendai 980-8578 (Japan); Mathews, Grant J. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan and Center for Astrophysics, Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States)

2014-05-02T23:59:59.000Z

13

Big-Bang Nucleosynthesis and Gamma-Ray Constraints on Cosmic Strings with a large Higgs condensate  

E-Print Network [OSTI]

We consider constraints on cosmic strings from their emission of Higgs particles, in the case that the strings have a Higgs condensate with amplitude of order the string mass scale, assuming that a fraction of the energy of condensate can be turned into radiation near cusps. The injection of energy by the decaying Higgs particles affects the light element abundances predicted by standard Big-Bang Nucleosynthesis (BBN), and also contributes to the Diffuse Gamma-Ray Background (DGRB) in the universe today. We examine the two main string scenarios (Nambu-Goto and field theory), and find that the primordial Helium abundance strongly constrains the string tension and the efficiency of the emission process in the NG scenario, while the strongest BBN constraint in the FT scenario comes from the Deuterium abundance. The Fermi-LAT measurement of the DGRB constrains the field theory scenario even more strongly than previously estimated from EGRET data, requiring that the product of the string tension {\\mu} and Newton's constant G is bounded by G{\\mu} < 2.7x10^{-11}{\\beta}_{ft}^{-2}, where {\\beta}_{ft}^2 is the fraction of the strings' energy going into Higgs particles.

H. F. Santana Mota; Mark Hindmarsh

2015-01-06T23:59:59.000Z

14

General limit on the relation between abundances of D and $^7$Li in big bang nucleosynthesis with nucleon injections  

E-Print Network [OSTI]

The injections of energetic hadrons could have occurred in the early universe by decays of hypothetical long-lived exotic particles. The injections induce the showers of nonthermal hadrons via nuclear scattering. Neutrons generated at these events can react with $^7$Be nuclei and reduce $^7$Be abundance solving a problem of the primordial $^7$Li abundance. We suggest that thermal neutron injection is a way to derive a model independent conservative limit on the relation between abundances of D and $^7$Li in a hadronic energy injection model. We emphasize that an uncertainty in cross sections of inelastic $n+p$ scattering affects the total number of induced neutrons, which determines final abundances of D and $^7$Li. In addition, the annihilations of antinucleons with $^4$He result in higher D abundance and trigger nonthermal $^6$Li production. It is concluded that a reduction of $^7$Li abundance from a value in the standard big bang nucleosynthesis (BBN) model down to an observational two $\\sigma$ upper limit is necessarily accompanied by an undesirable increase of D abundance up to at least an observational 12 $\\sigma$ upper limit from observations of quasi-stellar object absorption line systems. The effects of antinucleons and secondary particles produced in the hadronic showers always lead to a severer constraint. The BBN models involving any injections of extra neutrons are thus unlikely to reproduce a small $^7$Li abundance consistent with observations.

Motohiko Kusakabe; Myung-Ki Cheoun; K. S. Kim

2014-04-11T23:59:59.000Z

15

A revised thermonuclear rate of $^{7}$Be($n$,$\\alpha$)$^{4}$He relevant to Big-Bang nucleosynthesis  

E-Print Network [OSTI]

In the standard Big-Bang nucleosynthesis (BBN) model, the primordial $^7$Li abundance is overestimated by about a factor of 2--3 comparing to the astronomical observations, so called the pending cosmological lithium problem. The $^7$Be($n$,$\\alpha$)$^4$He reaction, which may affect the $^7$Li abundance, was regarded as the secondary important reaction in destructing the $^7$Be nucleus in BBN. However, the thermonuclear rate of $^7$Be($n$,$\\alpha$)$^4$He has not been well studied so far. This reaction rate was firstly estimated by Wagoner in 1969, which has been generally adopted in the current BBN simulations and the reaction rate library. This simple estimation involved only a direct-capture reaction mechanism, but the resonant contribution should be also considered according to the later experimental results. In this work, we have revised this rate based on the indirect cross-section data available for the $^4$He($\\alpha$,$n$)$^7$Be and $^4$He($\\alpha$,$p$)$^7$Li reactions, with the charge symmetry and deta...

Hou, S Q; Kubono, S; Chen, Y S

2015-01-01T23:59:59.000Z

16

A revised thermonuclear rate of $^{7}$Be($n$,$?$)$^{4}$He relevant to Big-Bang nucleosynthesis  

E-Print Network [OSTI]

In the standard Big-Bang nucleosynthesis (BBN) model, the primordial $^7$Li abundance is overestimated by about a factor of 2--3 comparing to the astronomical observations, so called the pending cosmological lithium problem. The $^7$Be($n$,$\\alpha$)$^4$He reaction, which may affect the $^7$Li abundance, was regarded as the secondary important reaction in destructing the $^7$Be nucleus in BBN. However, the thermonuclear rate of $^7$Be($n$,$\\alpha$)$^4$He has not been well studied so far. This reaction rate was firstly estimated by Wagoner in 1969, which has been generally adopted in the current BBN simulations and the reaction rate library. This simple estimation involved only a direct-capture reaction mechanism, but the resonant contribution should be also considered according to the later experimental results. In this work, we have revised this rate based on the indirect cross-section data available for the $^4$He($\\alpha$,$n$)$^7$Be and $^4$He($\\alpha$,$p$)$^7$Li reactions, with the charge symmetry and detailed-balance principle. Our new result shows that the previous rate (acting as an upper limit) is overestimated by about a factor of ten. The BBN simulation shows that the present rate leads to a 1.2\\% increase in the final $^7$Li abundance compared to the result using the Wagoner rate, and hence the present rate even worsens the $^7$Li problem. By the present estimation, the role of $^7$Be($n$,$\\alpha$)$^4$He in destroying $^7$Be is weakened from the secondary importance to the third, and the $^7$Be($d$,$p$)2$^4$He reaction becomes of secondary importance in destructing $^7$Be.

S. Q. Hou; J. J. He; S. Kubono; Y. S. Chen

2015-02-13T23:59:59.000Z

17

Before the Big Bang  

ScienceCinema (OSTI)

The second law of thermodynamics says, in effect, that things get more random as time progresses. Thus, we can deduce that the beginning of the universe - the Big Bang - must have been an extraordinarily precisely organized state. What was the nature of this state? How can such a special state have come about? In Penrose's talk, a novel explanation is suggested.

Roger Penrose

2010-09-01T23:59:59.000Z

18

Monte-Carlo Analysis of Big Bang Production of Beryllium and Boron  

E-Print Network [OSTI]

There is continued interest in the possibility that big bang nucleosynthesis may produce significant quantities of Be and B. In this paper we reevaluate the primordial abundances taking into account uncertainties in reactions rates. We discuss the implications for primordial nucleosynthesis, and for galactic cosmic ray spallation.

David Thomas

1994-12-11T23:59:59.000Z

19

Big Bang Synthesis of Nuclear Dark Matter  

E-Print Network [OSTI]

We investigate the physics of dark matter models featuring composite bound states carrying a large conserved dark "nucleon" number. The properties of sufficiently large dark nuclei may obey simple scaling laws, and we find that this scaling can determine the number distribution of nuclei resulting from Big Bang Dark Nucleosynthesis. For plausible models of asymmetric dark matter, dark nuclei of large nucleon number, e.g. > 10^8, may be synthesised, with the number distribution taking one of two characteristic forms. If small-nucleon-number fusions are sufficiently fast, the distribution of dark nuclei takes on a logarithmically-peaked, universal form, independent of many details of the initial conditions and small-number interactions. In the case of a substantial bottleneck to nucleosynthesis for small dark nuclei, we find the surprising result that even larger nuclei, with size >> 10^8, are often finally synthesised, again with a simple number distribution. We briefly discuss the constraints arising from the novel dark sector energetics, and the extended set of (often parametrically light) dark sector states that can occur in complete models of nuclear dark matter. The physics of the coherent enhancement of direct detection signals, the nature of the accompanying dark-sector form factors, and the possible modifications to astrophysical processes are discussed in detail in a companion paper.

Edward Hardy; Robert Lasenby; John March-Russell; Stephen M. West

2015-01-24T23:59:59.000Z

20

Compilation and R-matrix analysis of Big Bang nuclear reaction rates  

E-Print Network [OSTI]

We use the R-matrix theory to fit low-energy data on nuclear reactions involved in Big Bang nucleosynthesis. A special attention is paid to the rate uncertainties which are evaluated on statistical grounds. We provide S factors and reaction rates in tabular and graphical formats.

Pierre Descouvemont; Abderrahim Adahchour; Carmen Angulo; Alain Coc; Elisabeth Vangioni-Flam

2004-07-06T23:59:59.000Z

Note: This page contains sample records for the topic "oxford big-bang nucleosynthesis" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Effective dynamics of the matrix big bang  

SciTech Connect (OSTI)

We study the leading quantum effects in the recently introduced matrix big bang model. This amounts to a study of supersymmetric Yang-Mills theory compactified on the Milne orbifold. We find a one-loop potential that is attractive near the big bang. Surprisingly, the potential decays very rapidly at late times where it appears to be generated by D-brane effects. Usually, general covariance constrains the form of any effective action generated by renormalization group flow. However, the form of our one-loop potential seems to violate these constraints in a manner that suggests a connection between the cosmological singularity and long wavelength, late time physics.

Craps, Ben [Theoretische Natuurkunde, Vrije Universiteit Brussel and International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium); Instituut voor Theoretische Fysica, Universiteit van Amsterdam, Valckenierstraat 65, 1018 XE Amsterdam (Netherlands); Rajaraman, Arvind [Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Sethi, Savdeep [Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637 (United States)

2006-05-15T23:59:59.000Z

22

Space Time Quantization and the Big Bang  

E-Print Network [OSTI]

A recent cosmological model is recapitulated which deduces the correct mass, radius and age of the universe as also the Hubble constant and other well known apparently coincidental relations. It also predicts an ever expanding accelerating universe as is confirmed by latest supernovae observations. Finally the Big Bang model is recovered as a suitable limiting case.

B. G. Sidharth

1998-06-21T23:59:59.000Z

23

Looking back in time beyond the big bang  

E-Print Network [OSTI]

String theory can (in principle) describe gravity at all curvature scales, and can be applied to cosmology to look back in time beyond the Planck epoch. The duality symmetries of string theory suggest a cosmological picture in which the imprint of a primordial, pre-big bang phase could still be accessible to present observations. The predictive power of such a scenario relies, however, on our ability to connect in a smooth way the pre-big bang to the present cosmological regime. Classical radiation back reaction seems to play a key role to this purpose, by isotropizing and turning into a final expansion any state of anisotropic contraction possibly emerging from the pre-big bang at the string scale.

M. Gasperini

1999-05-18T23:59:59.000Z

24

Verification of Maxwell-Boltzmann distribution with Big-Bang Nucleosyntheis theory  

E-Print Network [OSTI]

The current Big-Bang Nucleosynthesis (BBN) model has been constructed based on a nuclear reaction network operating with thermal reactivities of Maxwell-Boltzmann (MB) distribution plasma. However, does the classical MB distribution still hold for the extremely high-temperature (in order of 10$^9$ K) plasma involved in the Big-Bang environment? In this work, we have investigated the impact of non-extensive Tsallis statistics (in $q$-Guassian distribution) on the thermonuclear reaction rates. We show for the first time that the reverse rates are extremely sensitive to the non-extensive $q$ parameter. Such sensitivity does not allow a large deviation of non-extensive distribution from the usual MB distribution. With a newly developed BBN code, the impact of primordial light-element abundances on $q$ values has been studied by utilizing the most recent BBN cosmological parameters and the available nuclear cross-section data. For the first time, we have accurately verified the microscopic MB distribution with the macroscopic BBN theory and bservation. By comparing the recent observed primordial abundances with our predictions, only a tiny deviation of $\\pm$6$\\times$10$^{-4}$ at most can be allowed for the MB distribution. However, validity of the classical statistics needs to be studied further for the self-gravitating stars and binaries of high-density environment, with the extreme sensitivity of reverse rate on $q$ found here.

S. Q. Hou; J. J. He; others

2014-06-18T23:59:59.000Z

25

Big Bang Day: 5 Particles - 3. The Anti-particle  

ScienceCinema (OSTI)

Simon Singh looks at the stories behind the discovery of 5 of the universe's most significant subatomic particles: the Electron, the Quark, the Anti-particle, the Neutrino and the "next particle". 3. The Anti-particle. It appears to be the stuff of science fiction. Associated with every elementary particle is an antiparticle which has the same mass and opposite charge. Should the two meet and combine, the result is annihilation - and a flash of light. Thanks to mysterious processes that occurred after the Big Bang there are a vastly greater number of particles than anti-particles. So how could their elusive existence be proved? At CERN particle physicists are crashing together subatomic particles at incredibly high speeds to create antimatter, which they hope will finally reveal what happened at the precise moment of the Big Bang to create the repertoire of elementary particles and antiparticles in existence today.

None

2011-04-25T23:59:59.000Z

26

Big Bang Day: 5 Particles - 3. The Anti-particle  

SciTech Connect (OSTI)

Simon Singh looks at the stories behind the discovery of 5 of the universe's most significant subatomic particles: the Electron, the Quark, the Anti-particle, the Neutrino and the "next particle". 3. The Anti-particle. It appears to be the stuff of science fiction. Associated with every elementary particle is an antiparticle which has the same mass and opposite charge. Should the two meet and combine, the result is annihilation - and a flash of light. Thanks to mysterious processes that occurred after the Big Bang there are a vastly greater number of particles than anti-particles. So how could their elusive existence be proved? At CERN particle physicists are crashing together subatomic particles at incredibly high speeds to create antimatter, which they hope will finally reveal what happened at the precise moment of the Big Bang to create the repertoire of elementary particles and antiparticles in existence today.

None

2009-10-07T23:59:59.000Z

27

Big Bang Day : The Great Big Particle Adventure - 3. Origins  

ScienceCinema (OSTI)

In this series, comedian and physicist Ben Miller asks the CERN scientists what they hope to find. If the LHC is successful, it will explain the nature of the Universe around us in terms of a few simple ingredients and a few simple rules. But the Universe now was forged in a Big Bang where conditions were very different, and the rules were very different, and those early moments were crucial to determining how things turned out later. At the LHC they can recreate conditions as they were billionths of a second after the Big Bang, before atoms and nuclei existed. They can find out why matter and antimatter didn't mutually annihilate each other to leave behind a Universe of pure, brilliant light. And they can look into the very structure of space and time - the fabric of the Universe

None

2011-04-25T23:59:59.000Z

28

Graceful exit via polymerization of pre-big bang cosmology  

E-Print Network [OSTI]

We consider a phenomenological modification of the Pre Big Bang scenario using ideas from the resolution of curvature singularities in Loop Quantum Cosmology. We show that non-perturbative Loop modifications to the dynamics, arising from the underlying polymer representation, can resolve the graceful exit problem. The curvature and the dilaton energy stay finite at all times, in both the string and Einstein frames. In the string frame, the dilaton tends to a constant value at late times after the bounce.

Giuseppe De Risi; Roy Maartens; Parampreet Singh

2007-09-25T23:59:59.000Z

29

Supernova bangs as a tool to study big bang  

SciTech Connect (OSTI)

Supernovae and gamma-ray bursts are the most powerful explosions in observed Universe. This educational review tells about supernovae and their applications in cosmology. It is explained how to understand the production of light in the most luminous events with minimum required energy of explosion. These most luminous phenomena can serve as primary cosmological distance indicators. Comparing the observed distance dependence on red shift with theoretical models one can extract information on evolution of the Universe from Big Bang until our epoch.

Blinnikov, S. I., E-mail: Sergei.Blinnikov@itep.ru [Institute for Theoretical and Experimental Physics (Russian Federation)

2012-09-15T23:59:59.000Z

30

The Decay of the Neutron or Beta Decay, the Big Bang, and the...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Decay of the Neutron or Beta Decay, the Big Bang, and the Left-Handed Universe Apr 03 2014 01:00 PM - 02:30 PM Geoffrey L. Greene Physics Division, ORNL Research Accelerator...

31

Big Bang Day : Afternoon Play - Torchwood: Lost Souls  

ScienceCinema (OSTI)

Martha Jones, ex-time traveller and now working as a doctor for a UN task force, has been called to CERN where they're about to activate the Large Hadron Collider. Once activated, the Collider will fire beams of protons together recreating conditions a billionth of a second after the Big Bang - and potentially allowing the human race a greater insight into what the Universe is made of. But so much could go wrong - it could open a gateway to a parallel dimension, or create a black hole - and now voices from the past are calling out to people and scientists have started to disappear... Where have the missing scientists gone? What is the secret of the glowing man? What is lurking in the underground tunnel? And do the dead ever really stay dead? Lost Souls is a spin-off from the award-winning BBC Wales TV production Torchwood. It stars John Barrowman, Freema Agyeman, Eve Myles, Gareth David-Lloyd, Lucy Montgomery (of Titty Bang Bang) and Stephen Critchlow.

None

2011-04-25T23:59:59.000Z

32

From the Big Bang to the Higgs Boson in Less Than an Hour  

E-Print Network [OSTI]

From the Big Bang to the Higgs Boson in Less Than an Hour Jeffrey D neutrino Z0 W + W -g gluon (8) photon Z boson W bosons Quarks Leptons H Higgs boson Gauge bosons (force field quanta) Higgs boson and vacuum expectation value Strong force EM force Weak force #12;Par7cles

Fygenson, Deborah Kuchnir

33

From the Big Bang to the Higgs Boson in Less Than an Hour  

E-Print Network [OSTI]

From the Big Bang to the Higgs Boson in Less Than an Hour Jeffrey D H Higgs boson Gauge bosons (force field quanta) Higgs boson and vacuum expectation value Strong) photon Z boson W bosons H Higgs boson Gauge bosons (force field quanta) Higgs boson and vacuum

Fygenson, Deborah Kuchnir

34

Birth of Supermassive Black holes and Star Formation after the Big Bang  

E-Print Network [OSTI]

Modern observations of star formation in different galaxies contradicts with the current star formation theories. There are few questions and observations where current star formation theories were not able to explain well. This paper proposes an alternative theory of Star formation and birth of Supermassive Black holes after the Big Bang, which can answer the contradictions without violating the physics laws and fit perfectly well with the modern observations.

A Paramashivam

2013-01-01T23:59:59.000Z

35

Big-bang nucleosynthesis with a long-lived CHAMP including He4 spallation process  

E-Print Network [OSTI]

We propose helium-4 spallation processes induced by long-lived stau in supersymmetric standard models, and investigate an impact of the processes on light elements abundances. We show that, as long as the phase space of helium-4 spallation processes is open, they are more important than stau-catalyzed fusion and hence constrain the stau property. This talk is based on works (Jittoh et al., 2011).

Toshifumi Jittoh; Kazunori Kohri; Masafumi Koike; Joe Sato; Kenichi Sugai; Masato Yamanaka; Koichi Yazaki

2012-09-10T23:59:59.000Z

36

R+S^2 theories of gravity without big-bang singularity  

E-Print Network [OSTI]

The R+S^2 theories of gravity, where S^2 denotes the quadratic torsion terms, are analyzed under three cases. In the first two cases, the matter fields are described by two different spin fluids which are not homogeneous and isotropic. In the third case, a homogeneous and isotropic torsion field is used. It is found that under all the three cases, the R+S^2 theories may avert the big-bang singularity of the Robertson--Walker universe, with three corresponding constraints on the parameters.

Jia-An Lu

2015-02-10T23:59:59.000Z

37

CMB B-modes, spinorial space-time and Pre-Big Bang (II)  

E-Print Network [OSTI]

The BICEP2 collaboration reported recently a B-mode polarization of the cosmic microwave background (CMB) radiation inconsistent with the null hypothesis at a significance of > 5 {\\sigma}. This result has been often interpreted as a signature of primordial gravitational waves from cosmic inflation, even if actually polarized dust emission may be at the origin of such a signal. Even assuming that part of this CMB B-mode polarization really corresponds to the early Universe dynamics, its interpretation in terms of inflation and primordial gravitational waves is not the only possible one. Alternative cosmologies such as pre-Big Bang patterns and the spinorial space-time (SST) we introduced in 1996-97 can naturally account for such CMB B-modes. In particular, the SST automatically generates a privileged space direction (PSD) whose existence may have been confirmed by Planck data. If such a PSD exists, it seems normal to infer that vector perturbations have been present in the early Universe leading to CMB B-modes in suitable cosmological patterns. Inflation would not be required to explain the BICEP2 result assuming it really contains a primordial signal. More generally, pre-Big Bang cosmologies can also generate gravitational waves in the early Universe without any need for cosmic inflation. We further discuss here possible alternatives to the inflationary interpretation of a primordial B-mode polarization of cosmic microwave background radiation.

Luis Gonzalez-Mestres

2014-08-02T23:59:59.000Z

38

The Big Bang, COBE, and the Relic Radiation of Creation (LBNL Science at the Theater)  

ScienceCinema (OSTI)

Berkeley Lab's George Smoot won the 2006 Physics Nobel Prize, together with John Mather of NASA Goddard Space Flight Center, for "the discovery of the blackbody form and anisotropy of the cosmic microwave background radiation." The anisotropy showed as small variations in the map of the early universe. This research looks back into the infant universe and provides a better understanding of the origin of galaxies and stars. The cosmic background radiation is a tool to understand the structure and history of the universe and the structure of space-time. These observations have provided increased support for the big bang theory of the universe's origin. The Cosmic Background Explorer (COBE) NASA satellite, launched in 1989, carries instruments that measured various aspects of cosmic microwave background radiation, and produced the data for these compelling scientific results, which opened up a field that continues very actively today.

Smoot, George

2011-04-28T23:59:59.000Z

39

Are Dark Matter and Dark Energy the Residue of the Expansion-Reaction to the Big Bang ?  

E-Print Network [OSTI]

We derive the phenomenological Milgrom square-law acceleration, describing the apparent behavior of dark matter, as the reaction to the Big Bang from a model based on the Lorentz-Dirac equation of motion traditionally describing radiation reaction in electromagnetism but proven applicable to expansion reaction in cosmology. The model is applied within the Robertson-Walker hypersphere, and suggests that the Hubble expansion exactly cancels the classical reaction imparted to matter following the Big Bang, leaving behind a residue proportional to the square of the acceleration. The model further suggests that the energy density associated with the reaction acceleration is precisely the critical density for flattening the universe thus providing a potential explanation of dark energy as well. A test of this model is proposed.

Harry I. Ringermacher; Lawrence R. Mead

2006-10-16T23:59:59.000Z

40

"Big Bang" as a first-order phase transition in the early Universe  

E-Print Network [OSTI]

It is argued that the "Big Bang" initiating the creation of our Universe may be a consequence of a first-order phase transition induced by interaction of a fundamental non-linear scalar field with gravitational field. The Lagrangian describing the scalar field f characterized by "imaginary mass" and nonlinearity of ${\\phi}^4$ type, existing in the space-time with non-zero scalar curvature $R$, is proposed to be augmented with an additional linear term $\\propto R{\\phi}$, along with the standard term $\\propto R|{\\phi}|^2$ quadratic in ${\\phi}$. The term linear in ${\\phi}$, playing the role of an "external field", leads to a cubic equation in ${\\phi}$ for the extrema of the potential energy of the scalar field and ensures the possibility of a first-order phase transition driven by the parameter proportional to $R$. It is assumed that the early Universe is filled with non-linear scalar field in the ground state and cold matter, neutral with respect to all charges, satisfying the equation of state $p={\

E. A. Pashitskii

2014-05-23T23:59:59.000Z

Note: This page contains sample records for the topic "oxford big-bang nucleosynthesis" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Dust production 680-850 million years after the Big Bang  

E-Print Network [OSTI]

Dust plays an important role in our understanding of the Universe, but it is not obvious yet how the dust in the distant universe was formed. I derived the dust yields per asymptotic giant branch (AGB) star and per supernova (SN) required to explain dust masses of galaxies at z = 6.3-7.5 (680-850 million years after the Big Bang) for which dust emission has been detected (HFLS3 at z = 6.34, ULAS J1120+0641 at z = 7.085, and A1689-zD1 at z = 7.5), or unsuccessfully searched for. I found very high required yields, implying that AGB stars could not contribute substantially to dust production at these redshifts, and that SNe could explain these dust masses, but only if they do not destroy majority of the dust they form (which is unlikely given the upper limits on the SN dust yields derived for dust non-detected galaxies). This suggests that the grain growth in the interstellar medium is likely required at these early epochs.

Micha?owski, Micha? J

2015-01-01T23:59:59.000Z

42

Testing a Dilaton Gravity Model using Nucleosynthesis  

E-Print Network [OSTI]

Big Bang Nucleosynthesis (BBN) offers one of the most strict evidences for the Lambda-CDM cosmology at present, as well as the Cosmic Microwave Background (CMB) radiation. In this work, our main aim is to present the outcomes of our calculations related to primordial abundances of light elements, in the context of higher dimensional steady-state universe model in the dilaton gravity. Our results show that abundances of light elements (primordial D, 3He, 4He, T, 7Li) are significantly different for some cases, and a comparison is given between a particular dilaton gravity model and Lambda-CDM in the light of the astrophysical observations.

Sibel Boran; Emre Onur Kahya

2014-09-05T23:59:59.000Z

43

Origin of matter and space-time in the big bang  

SciTech Connect (OSTI)

We review the case for and against a bulk cosmic motion resulting from the quantum entanglement of our universe with the multiverse beyond our horizon. Within the current theory for the selection of the initial state of the universe from the landscape multiverse there is a generic prediction that pre-inflation quantum entanglement with other universes should give rise to a cosmic bulk flow with a correlation length of order horizon size and a velocity field relative to the expansion frame of the universe. Indeed, the parameters of this motion are are tightly constrained. A robust prediction can be deduced indicating that there should be an overall motion of of about 800 km/s relative to the background space time as defined by the cosmic microwave background (CMB). This talk will summarize the underlying theoretical motivation for this hypothesis. Of course our motion relative to the background space time (CMB dipole) has been known for decades and is generally attributed to the gravitational pull of the local super cluster. However, this cosmic peculiar velocity field has been recently deduced out to very large distances well beyond that of the local super cluster by using X-ray galaxy clusters as tracers of matter motion. This is achieved via the kinematic component of the Sunyaev-Zeldovich (KSZ) effect produced by Compton scattering of cosmic microwave background photons from the local hot intracluster gas. As such, this method measures peculiar velocity directly in the frame of the cluster. Similar attempts by our group and others have attempted to independently assess this bulk flow via Type la supernova redshifts. In this talk we will review the observation case for and against the existence of this bulk flow based upon the observations and predictions of the theory. If this interpretation is correct it has profound implications in that we may be observing for the first time both the physics that occurred before the big bang and the existence of the multiverse beyond our horizon.

Mathews, G. J. [University of Notre Dame, Center for Astrophysics/JINA, Notre Dame, IN 46556, USA and Division of Theoretical Astronomy, National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Kajino, T. [Division of Theoretical Astronomy, National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588, Japan and Department of Astronomy, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Yamazaki, D. [Division of Theoretical Astronomy, National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Kusakabe, M. [School of Liberal Arts and Science, Korea Aerospace University, Goyang 412-791, Korea and Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of); Cheoun, M.-K. [Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of)

2014-05-02T23:59:59.000Z

44

Nuclear reaction rates and the primordial nucleosynthesis  

E-Print Network [OSTI]

The theoretical predictions of the primordial abundances of elements in the big-bang nucleosynthesis (BBN) are dominated by uncertainties in the input nuclear reaction rates. We investigate the effect of modifying these reaction rates on light element abundance yields in BBN by replacing the thirty-five reaction rates out of the existing eighty-eight. We have studied these yields as functions of evolution time or temperature. We find that using these new reaction rates results in only a little increase in helium mass fraction over that obtained previously in BBN calculations. This allows insights into the role of the nuclear reaction rates in the setting of the neutron-to-proton ratio during the BBN epoch. We observe that even with considerable nuclear physics uncertainties, most of these nuclear reactions have minimal effect on the standard BBN abundance yields of $^6$Li and $^7$Li.

Abhishek Mishra; D. N. Basu

2011-11-15T23:59:59.000Z

45

Neutron injection during primordial nucleosynthesis alleviates the primordial 7Li problem  

E-Print Network [OSTI]

We present a parametrized study of the effects of free thermal neutron injection on primordial nucleosynthesis, where both the rate and the time scale of injection are varied. This generic approach is found to yield a successful solution for reducing the 7Li abundance without causing significant problems to other elemental abundances. Our analysis demonstrates that hadronic injection, possibly due to decays or annihilations of dark matter particles with a mass of about 1 to 30 GeV, provides a possible solution to an outstanding problem in the standard Big Bang model.

Daniel Albornoz Vasquez; Alexander Belikov; Alain Coc; Joseph Silk; Elisabeth Vangioni

2012-08-02T23:59:59.000Z

46

Big Bang Day : Today  

ScienceCinema (OSTI)

Andrew Marr will be reporting live from the CERN control room for the Today programme, with correspondent Tom Feilden. (Wednesday 10th September, 6.00-9.00am )

None

2011-04-25T23:59:59.000Z

47

Cosmological solutions to the Lithium problem: Big-bang nucleosynthesis with photon cooling, $X$-particle decay and a primordial magnetic field  

E-Print Network [OSTI]

The $^7$Li abundance calculated in BBN with the baryon-to-photon ratio fixed from fits to the CMB power spectrum is inconsistent with the observed lithium abundances on the surface of metal-poor halo stars. Previous cosmological solutions proposed to resolve this $^7$Li problem include photon cooling (possibly via the Bose-Einstein condensation of a scalar particle) or the decay of a long-lived $X-$particle (possibly the next-to-lightest supersymmetric particle). In this paper we reanalyze these solutions, both separately and in concert. We also introduce the possibility of a primordial magnetic field (PMF) into these models. We constrain the $X-$particles and the PMF parameters by the observed light element abundances using a likelihood analysis to show that the inclusion of all three possibilities leads to an optimum solution to the lithium problem. We deduce allowed ranges for the $X-$particle parameters and energy density in the PMF that can solve $^7$Li problem.

Dai G. Yamazaki; Motohiko Kusakabe; Toshitaka Kajino; Grant. J. Mathews; Myung-Ki Cheoun

2014-06-30T23:59:59.000Z

48

Constraining spacetime noncommutativity with primordial nucleosynthesis  

SciTech Connect (OSTI)

We discuss a constraint on the scale {lambda}{sub NC} of noncommutative (NC) gauge field theory arising from consideration of the big bang nucleosynthesis of light elements. The propagation of neutrinos in the NC background described by an antisymmetric tensor {theta}{sup {mu}}{sup {nu}} does result in a tree-level vectorlike coupling to photons in a generation-independent manner, raising thus a possibility to have an appreciable contribution of three light right-handed (RH) fields to the energy density of the Universe at nucleosynthesis time. Considering elastic scattering processes of the RH neutrinos off charged plasma constituents at a given cosmological epoch, we obtain for a conservative limit on an effective number of additional doublet neutrinos {delta}N{sub {nu}}=1, a bound {lambda}{sub NC} > or approx. 3 TeV. With a more stringent requirement, {delta}N{sub {nu}} < or approx. 0.2, the bound is considerably improved, {lambda}{sub NC} > or approx. 10{sup 3} TeV. For our bounds the {theta} expansion of the NC action stays always meaningful, since the decoupling temperature of the RH species is perseveringly much less than the inferred bound for the scale of noncommutativity.

Horvat, Raul [Physics Division, Rudjer Boskovic Institute, Zagreb (Croatia); Trampetic, Josip [Theoretical Physics Division, Rudjer Boskovic Institute, Zagreb (Croatia)

2009-04-15T23:59:59.000Z

49

Probing neutrino physics with a self-consistent treatment of the weak decoupling, nucleosynthesis, and photon decoupling epochs  

E-Print Network [OSTI]

We show that a self-consistent and coupled treatment of the weak decoupling, big bang nucleosynthesis, and photon decoupling epochs can be used to provide new insights and constraints on neutrino sector physics from high-precision measurements of light element abundances and cosmic microwave background observables. Implications of beyond-standard-model physics in cosmology, especially within the neutrino sector, are assessed by comparing predictions against five observables: the baryon energy density, helium abundance, deuterium abundance, effective number of neutrinos, and sum of the light neutrino mass eigenstates. We give examples for constraints on dark radiation, neutrino rest mass, lepton numbers, and scenarios for light and heavy sterile neutrinos.

Grohs, E; Kishimoto, C T; Paris, M W

2015-01-01T23:59:59.000Z

50

Statistical Methods for Thermonuclear Reaction Rates and Nucleosynthesis Simulations  

E-Print Network [OSTI]

Rigorous statistical methods for estimating thermonuclear reaction rates and nucleosynthesis are becoming increasingly established in nuclear astrophysics. The main challenge being faced is that experimental reaction rates are highly complex quantities derived from a multitude of different measured nuclear parameters (e.g., astrophysical S-factors, resonance energies and strengths, particle and gamma-ray partial widths). We discuss the application of the Monte Carlo method to two distinct, but related, questions. First, given a set of measured nuclear parameters, how can one best estimate the resulting thermonuclear reaction rates and associated uncertainties? Second, given a set of appropriate reaction rates, how can one best estimate the abundances from nucleosynthesis (i.e., reaction network) calculations? The techniques described here provide probability density functions that can be used to derive statistically meaningful reaction rates and final abundances for any desired coverage probability. Examples are given for applications to s-process neutron sources, core-collapse supernovae, classical novae, and big bang nucleosynthesis.

Christian Iliadis; Richard Longland; Alain Coc; F. X. Timmes; Art E. Champagne

2014-09-19T23:59:59.000Z

51

Big Bang Day: Engineering Solutions  

ScienceCinema (OSTI)

CERN's Large Hadron Collider is the most complicated scientific apparatus ever built. Many of the technologies it uses hadn't even been invented when scientists started building it. Adam Hart-Davis discovers what it takes to build the world's most intricate discovery machine.

None

2011-04-25T23:59:59.000Z

52

Big Bang Day : Physics Rocks  

ScienceCinema (OSTI)

Is particle physics the new rock 'n' roll? The fundamental questions about the nature of the universe that particle physics hopes to answer have attracted the attention of some very high profile and unusual fans. Alan Alda, Ben Miller, Eddie Izzard, Dara O'Briain and John Barrowman all have interests in this branch of physics. Brian Cox - CERN physicist, and former member of 90's band D:Ream, tracks down some very well known celebrity enthusiasts and takes a light-hearted look at why this subject can appeal to all of us.

None

2011-04-25T23:59:59.000Z

53

CANWE COME? THE BIG BANG  

E-Print Network [OSTI]

for him to be there, he said, because "all the problems those guys don't solve wind up with us." #12;Today occurred about 13 Billion Years Ago ·We can describe the history of the universe, starting at t=3minutes energy? ·What is responsible for ``inflation"? ·What happened at t=0? #12;Physical Law and the Universe

California at Santa Cruz, University of

54

Big-Bang Cosmology Hitoshi Murayama  

E-Print Network [OSTI]

is no anti-gravity to stop it!) · Needs initial seed density fluctuation · Density fluctuation grows little

Murayama, Hitoshi

55

LHC, le Big Bang en éprouvette  

ScienceCinema (OSTI)

Notre compréhension de l?Univers est en train de changer? Bar des Sciences - Tout public Débat modéré par Marie-Odile Montchicourt, journaliste de France Info. Evenement en vidéoconférence entre le Globe de la science et de l?innovation, le bar le Baloard de Montpellier et la Maison des Métallos à Paris. Intervenants au CERN : Philippe Charpentier et Daniel Froideveaux, physiciens au CERN. Intervenants à Paris : Vincent Bontemps, philosophe et chercheur au CEA ; Jacques Arnould, philosophe, historien des sciences et théologien, Jean-Jacques Beineix, réalisateur, producteur, scénariste de cinéma. Intervenants à Montpellier (LPTA) : André Neveu, physicien théoricien et directeur de recherche au CNRS ; Gilbert Moultaka, physicien théoricien et chargé de recherche au CNRS. Partenariat : CERN, CEA, IN2P3, Université MPL2 (LPTA) Dans le cadre de la Fête de la science 2008

None

2011-10-06T23:59:59.000Z

56

A different Big Bang theory: Los Alamos  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered‰PNGExperience hands-onASTROPHYSICSHeResearchcharm that has been

57

oxford world's classics PHILOSOPHICAL CRUMBS  

E-Print Network [OSTI]

by publishing worldwide in Oxford New York Auckland Cape Town Dar es Salaam Hong Kong Karachi Kuala Lumpur

Kovalev, Leonid

58

Summer 2011 2 Oxford Philosophy Summer 2011 3Oxford Philosophy Summer 2011  

E-Print Network [OSTI]

Oxford Philosophy Summer 2011 #12;2 Oxford Philosophy Summer 2011 3Oxford Philosophy Summer 2011 Editors Design Photography Printing Contact us at: Oxford Philosophy Faculty of Philosophy University of Oxford 10 Merton Street Oxford OX1 4JJ UK email:news@philosophy.ox.ac.uk tel:+44 (0)1865 276928 fax:+44

Oxford, University of

59

OxfordRoadOxfordRoadOxfordRoad UpperBrookStreetUpperBrookStreet  

E-Print Network [OSTI]

West Whitworth Street Fairfield Street Charles Street Charles St Altrincham Street Mancunian Way St OXFORD RD STATION OXFORD RD STATION PICCADILLY TRAIN STATION AND METROLINK BBC CITY CENTRE, Platt Church of England 47. Platt Fields Park, open space with a lake. 48. Allen Hall 49. The Islah

60

Nucleosynthesis in Type II Supernovae  

E-Print Network [OSTI]

Presupernova evolution and explosive nucleosynthesis in massive stars for main-sequence masses from 13 $M_\\odot$ to 70 $M_\\odot$ are calculated. We examine the dependence of the supernova yields on the stellar mass, $^{12}C(\\alpha, \\gamma) ^{16}O}$ rate, and explosion energy. The supernova yields integrated over the initial mass function are compared with the solar abundances.

K. Nomoto; M. Hashimoto; T. Tsujimoto; F. -K. Thielemann; N. Kishimoto; Y. Kubo

1997-06-03T23:59:59.000Z

Note: This page contains sample records for the topic "oxford big-bang nucleosynthesis" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Technology Transfer from the University of Oxford  

E-Print Network [OSTI]

Technology Transfer from the University of Oxford www.isis-innovation.com #12;Isis Innovation Ltd Oxford Technology Transfer IP, Patents, Licences, Spin-outs, Material Sales, Seed Funds, Isis Angels Network Oxford Expertise Consulting, Services Isis Consulting Business Technology Transfer and Innovation

Paxton, Anthony T.

62

Big Bang Day : The Great Big Particle Adventure - 1. Atom  

ScienceCinema (OSTI)

In this series, comedian and physicist Ben Miller asks the CERN scientists what they hope to find. The notion of atoms dates back to Greek philosophers who sought a natural mechanical explanation of the Universe, as opposed to a divine one. The existence what we call chemical atoms, the constituents of all we see around us, wasn't proved until a hundred years ago, but almost simultaneously it was realised these weren't the indivisible constituents the Greeks envisaged. Much of the story of physics since then has been the ever-deeper probing of matter until, at the end of the 20th century, a complete list of fundamental ingredients had been identified, apart from one, the much discussed Higgs particle. In this programme, Ben finds out why this last particle is so pivotal, not just to atomic theory, but to our very existence - and how hopeful the scientists are of proving its existence.

None

2011-04-25T23:59:59.000Z

63

Big Bang Day: 5 Particles - 1. The Electron  

ScienceCinema (OSTI)

Simon Singh looks at the stories behind the discovery of 5 of the universe's most significant subatomic particles: the Electron, the Quark, the Anti-particle, the Neutrino and the "next particle". 1. The Electron Just over a century ago, British physicist J.J. Thompson experimenting with electric currents and charged particles inside empty glass tubes, showed that atoms are divisible into indivisible elementary particles. But how could atoms be built up of these so called "corpuscles"? An exciting 30 year race ensued, to grasp the planetary model of the atom with its orbiting electrons, and the view inside the atom was born. Whilst the number of electrons around the nucleus of an atom determines their the chemistry of all elements, the power of electrons themselves have been harnessed for everyday use: electron beams for welding,cathode ray tubes and radiation therapy.

None

2011-04-25T23:59:59.000Z

64

Echo of the Big Bang Anisotropies in the  

E-Print Network [OSTI]

: Some Facts 7) CMB highly (impressively) Isotropic: - in each direction on the sky the radiation has Microwave Radiometer Cosmic Microwave Background #12;7/1/2009 6 Spectrum Blackbody Radiation John Mather: - photon energy 4) Energy Density Radiation evolves: Cosmic Radiation 44 )1()( ztarad 3 )(tanrad 1 )(tarad

Weijgaert, Rien van de

65

PPPL, Princeton launch hunt for Big Bang particles offering clues...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Universe Massive Neutrino Yield." Ptolemy was an ancient Greek astronomer who lived in Egypt during the first century. Darkest, coldest conditions achievable The task calls for...

66

Big Bang Day: 5 Particles - 2. The Quark  

ScienceCinema (OSTI)

Simon Singh looks at the stories behind the discovery of 5 of the universe's most significant subatomic particles: the Electron, the Quark, the Anti-particle, the Neutrino and the "next particle". 2. The Quark "Three Quarks for Master Mark! Sure he hasn't got much of a bark." James Joyce's Finnegans Wake left its mark on modern physics when physicist Murray Gell Mann proposed this name for a group of hypothetical subatomic particles that were revealed in 1960 as the fundamental units of matter. Basic particles it seems are made up of even more basic units called quarks that make up 99.9% of visible material in the universe.. But why do we know so little about them? Quarks have never been seen as free particles but instead, inextricably bound together by the Strong Force that in turn holds the atomic nucleus together. This is the hardest of Nature's fundamental forces to crack, but recent theoretical advances, mean that the properties of the quark are at last being revealed.

None

2011-04-25T23:59:59.000Z

67

Big Bang Day: 5 Particles - 5. The Next Particle  

ScienceCinema (OSTI)

Simon Singh looks at the stories behind the discovery of 5 of the universe's most significant subatomic particles: the Electron, the Quark, the Anti-particle, the Neutrino and the "next particle". 5. The Next Particle The "sparticle" - a super symmetric partner to all the known particles could be the answer to uniting all the known particles and their interactions under one grand theoretical pattern of activity. But how do researchers know where to look for such phenomena and how do they know if they find them? Simon Singh reviews the next particle that physicists would like to find if the current particle theories are to ring true.

None

2011-04-25T23:59:59.000Z

68

Big Bang Day: The Making of CERN (Episode 1)  

SciTech Connect (OSTI)

A two-part history of the CERN project. Quentin Cooper explores the fifty-year history of CERN, the European particle physics laboratory in Switzerland. The institution was created to bring scientists together after WW2 .......

None

2009-10-06T23:59:59.000Z

69

Big Bang Day: 5 Particles - 4. The Neutrino  

ScienceCinema (OSTI)

Simon Singh looks at the stories behind the discovery of 5 of the universe's most significant subatomic particles: the Electron, the Quark, the Anti-particle, the Neutrino and the "next particle". It's the most populous particle in the universe. Millions of these subatomic particles are passing through each one of us. With no charge and virtually no mass they can penetrate vast thicknesses of matter without any interaction - indeed the sun emits huge numbers that pass through earth at the speed of light. Neutrinos are similar to the more familiar electron, with one crucial difference: neutrinos do not carry electric charge. As a result they're extremely difficult to detect . But like HG Wells' invisible man they can give themselves away by bumping into things at high energy and detectors hidden in mines are exploiting this to observe these rare interactions.

None

2011-04-25T23:59:59.000Z

70

Gravity waves generated by sounds from Big Bang phase transitions  

E-Print Network [OSTI]

Inhomogeneities associated with the cosmological QCD and electroweak phase transitions produce hydrodynamical perturbations, longitudinal sounds and rotations. It has been demonstrated numerically by Hindmarsh et al. that the sounds produce gravity waves (GW), and that this process does continue well after the phase transition is over. We further introduce a long period of the so-called inverse acoustic cascade, between the UV momentum scale at which the sound is originally produced and the IR scale at which GW is generated. It can be described by the Boltzmann equation, possessing stationary power and self-similar time-dependent solutions. If the sound dispersion law allows one-to-two sound decays, the exponent of the power solution is large and a strong amplification of the sound amplitude (limited only by the total energy) takes place. Alternative scenario dominated by sound scattering leads to smaller indices and much smaller IR sound amplitude. We also point out that two on shell phonons can produce a gr...

Kalaydzhyan, Tigran

2014-01-01T23:59:59.000Z

71

Gravity waves generated by sounds from Big Bang phase transitions  

E-Print Network [OSTI]

Inhomogeneities associated with the cosmological QCD and electroweak phase transitions produce hydrodynamical perturbations, longitudinal sounds and rotations. It has been demonstrated by Hindmarsh et al. that the sounds produce gravity waves (GW) well after the phase transition is over. We further argue, that, under certain conditions, an inverse acoustic cascade may occur and move sound perturbations from the (UV) momentum scale at which the sound is originally produced to much smaller (IR) momenta. Weak turbulence regime of this cascade is studied via Boltzmann equation, possessing stationary power and time-dependent self-similar solutions. We suggest certain indices for strong turbulence regime as well, into which the cascade eventually proceeds. Finally, we point out that two on shell sound waves can produce one on-shell gravity wave, and evaluate the rate of the process using standard sound loop diagram.

Tigran Kalaydzhyan; Edward Shuryak

2015-01-14T23:59:59.000Z

72

On the Electrodynamics of the Big Bang Universe  

E-Print Network [OSTI]

Applying the known physics of plasmas to the evolution of galaxies and quasars in the Early Universe, a unique "Strong" Magnetic Field Modsl (SMF) was created that explains the origin of a very large-scale primordial magnetic field in each Supercluster and the observed large-scale structure of galaxies. This physical model, involving both gravitation and cosmical magnetism, explains the existence of significant magnetic fields in galaxies. An intense highly relativistic gravitationally bound current loop (Storage Ring) is formed by gravitational collapse explaining the nature of the AGN/Quasar Central Engine, galactic structure and radio, optical and X-ray jets.

Howard D. Greyber

2005-09-08T23:59:59.000Z

73

Big Bang Day: The Making of CERN (Episode 2)  

ScienceCinema (OSTI)

A two-part history of the CERN project. Quentin Cooper explores the fifty-year history of CERN, the European particle physics laboratory in Switzerland.

None

2011-04-25T23:59:59.000Z

74

Big Bang Day: The Making of CERN (Episode 1)  

ScienceCinema (OSTI)

A two-part history of the CERN project. Quentin Cooper explores the fifty-year history of CERN, the European particle physics laboratory in Switzerland. The institution was created to bring scientists together after WW2 .......

None

2011-04-25T23:59:59.000Z

75

What Was There Before the Big Bang? | GE Global Research  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched FerromagnetismWaste and MaterialsWenjun DengWISP Sign InWhat Was There Before the Big

76

John C. Mather, the Big Bang, and the COBE  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-SeriesFlickrinformation forTechnologies |JenniferB. Storer (1983) March 05,

77

A different Big Bang theory: Los Alamos unveils explosives detection  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert SouthwestTechnologies |November 2011A FirstEMSL ShellACalmodulin

78

Big Bang or Big Bounce? | Princeton Plasma Physics Lab  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to someone6 M. Babzien, I.Program InformationBibliographicAnodeOctober 30,

79

BAS C. VAN FRAASSEN CLARENDON PRESS -OXFORD  

E-Print Network [OSTI]

THE SCIENTIFIC IMAGE BAS C. VAN FRAASSEN CLARENDON PRESS - OXFORD #12;18 ARGUMENTS CONCERNING adequate, ones whose models fit the observable phenomena. while recognizing that what counts

Fitelson, Branden

80

University of Oxford Environmental Sustainability Policy 2008  

E-Print Network [OSTI]

water) drains and sewers. SUSTAINABLE BUILDINGS ­ The University of Oxford Sustainable Buildings Policy is to build environmentally sustainable buildings, and embed sustainable building best practice

Melham, Tom

Note: This page contains sample records for the topic "oxford big-bang nucleosynthesis" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Harry Potter, Oxford and Nuclear Energy | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

Harry Potter, Oxford and Nuclear Energy Harry Potter, Oxford and Nuclear Energy July 16, 2012 - 1:30pm Addthis Assistant Secretary Dr. Peter Lyons meets with students on the Oxford...

82

Nucleosynthesis in Early Neutrino Driven Winds  

SciTech Connect (OSTI)

Two recent issues related to nucleosynthesis in early proton-rich neutrino winds are investigated. In the first part we investigate the effect of nuclear physics uncertainties on the synthesis of {sup 92}Mo and {sup 94}Mo. Based on recent experimental results, we find that the proton rich winds of the model investigated here can not be the only source of the solar abundance of {sup 92}Mo and {sup 94}Mo. In the second part we investigate the nucleosynthesis from neutron rich bubbles and show that they do not contribute to the nucleosynthesis integrated over both neutron and proton-rich bubbles and proton-rich winds.

Hoffman, R; Fisker, J; Pruet, J; Woosley, S; Janka, H; Buras, R

2008-01-09T23:59:59.000Z

83

Nucleosynthesis in O-Ne-Mg Supernovae  

SciTech Connect (OSTI)

We have studied detailed nucleosynthesis in the shocked surface layers of an oxygen-neon-magnesium core collapse supernova with an eye to determining whether the conditions are suitable for r-process nucleosynthesis. We find no such conditions in an unmodified model, but do find overproduction of N=50 nuclei (previously seen in early neutron-rich neutrino winds) in amounts that, if ejected, would pose serious problems for Galactic chemical evolution.

Hoffman, R D; Janka, H; Muller, B

2007-12-18T23:59:59.000Z

84

Outstanding problems in nuclear astrophysics: recent progress at TRIUMF  

SciTech Connect (OSTI)

Recent experimental and theoretical efforts at TRIUMF on nuclear reactions relevant to big bang nucleosynthesis, quiescent stellar fusion, classical novae, and Type I X-ray bursts are described.

Davids, B., E-mail: davids@triumf.ca [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC (Canada)

2014-04-15T23:59:59.000Z

85

Rep. Prog. Phys. 62 (1999) 395464. Printed in the UK PII: S0034-4885(99)74702-0 Nuclear astrophysics  

E-Print Network [OSTI]

decays via strong interaction 423 5. Thermonuclear reactions in non-explosive events 424 5.1. Energy and concomitant nucleosynthesis 425 6. Thermonuclear reactions in explosive events 427 6.1. Big Bang

Mojzsis, Stephen J.

86

Supernova neutrinos and explosive nucleosynthesis  

SciTech Connect (OSTI)

Core-collapse supernovae eject huge amount of flux of energetic neutrinos. We studied the explosive nucleosyn-thesis in supernovae and found that several isotopes {sup 7}Li, {sup 11}B, {sup 92}Nb, {sup 138}La and {sup 180}Ta as well as r-process nuclei are affected by the neutrino interactions. The abundance of these isotopes therefore depends strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. We discuss first how to determine the neutrino temperatures in order to explain the observed solar system abundances of these isotopes, combined with Galactic chemical evolution of the light nuclei and the heavy r-process elements. We then study the effects of neutrino oscillation on their abundances, and propose a novel method to determine the still unknown neutrino oscillation parameters, mass hierarchy and ?{sub 13}, simultaneously. There is recent evidence that SiC X grains from the Murchison meteorite may contain supernova-produced light elements {sup 11}B and {sup 7}Li encapsulated in the presolar grains. Combining the recent experimental constraints on ?{sub 13}, we show that our method sug-gests at a marginal preference for an inverted neutrino mass hierarchy. Finally, we discuss supernova relic neutrinos that may indicate the softness of the equation of state (EoS) of nuclear matter as well as adiabatic conditions of the neutrino oscillation.

Kajino, T. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan and Department of Astronomy, Graduate School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan); Aoki, W. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Cheoun, M.-K. [Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of); Hayakawa, T. [Japan Atomic Energy Agency, Shirakara-Shirane 2-4, Tokai-mura, Ibaraki 319-1195 (Japan); Hidaka, J.; Hirai, Y.; Shibagaki, S. [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Mathews, G. J. [Center for Astrophysics, Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Nakamura, K. [Faculty of Science and Engineering, Waseda University, Ohkubo 3-4-1, Shinjuku, Tokyo 169-8555 (Japan); Suzuki, T. [Department of Physics, College of Humanities and Sciences, Nihon University, Sakurajosui 3-25-40, Setagaya-ku, Tokyo 156-8550 (Japan)

2014-05-09T23:59:59.000Z

87

Department of Materials University of Oxford  

E-Print Network [OSTI]

Objective A report: A detailed design proposal which could be used by a manufacturer/company as the basis with your supervisor. #12;Department of Materials University of Oxford Log book Keep all info in a bound log

Paxton, Anthony T.

88

OXFORD UNIVERSITY JOINT COMMITTEE FOR MATHEMATICS AND  

E-Print Network [OSTI]

OXFORD UNIVERSITY JOINT COMMITTEE FOR MATHEMATICS AND PHILOSOPHY October 2014 Programme: for Mathematics, Statistics and Operational Research, and for Philosophy. http · to provide, within the supportive and stimulating environment of the collegiate university, a course

89

NUCLEAR ASPECTS OF STELLAR AND EXPLOSIVE NUCLEOSYNTHESIS  

E-Print Network [OSTI]

NUCLEAR ASPECTS OF STELLAR AND EXPLOSIVE NUCLEOSYNTHESIS Thomas Rauscher 1 , Friedrich. of Astron. and Astroph., Univ. of California, Santa Cruz, CA 95064 Abstract The majority of nuclear­Feshbach). The global parametrizations of the nuclear properties needed for predictions far off stability probe our

Rauscher, Thomas

90

Physics on a circle and geometry Balazs Szendroi, Oxford  

E-Print Network [OSTI]

Physics on a circle and geometry Balazs Szendroi, Oxford The 1st Strathmore University Mathematics Conference 18-20 August 2011 Physics on a circle and geometry Balazs Szendroi University of Oxford #12;Physics on a circle and geometry Balazs Szendroi, Oxford The 1st Strathmore University Mathematics

Szendröi, Balázs

91

The Oxford Programme on the Changing Character of War  

E-Print Network [OSTI]

The Oxford Programme on the Changing Character of War Seminars Michaelmas Term 2013 Lunchtime Discussions with Changing Character of War Seminars are at 1.00pm, Seminar Room G, Manor Road Building, Oxford Oliveira (Oxford) War and Peace in Angola Tuesday 22nd October Professor Christopher Coker (LSE) Men at War

Oxford, University of

92

UK Energy Research Centre Demand Reduction Theme, University of Oxford  

E-Print Network [OSTI]

UK Energy Research Centre Demand Reduction Theme, University of Oxford The Experience of Carbon Energy Research Centre ­ Demand Reduction Theme Environmental Change Institute Oxford University Centre for the Environment South Parks Road Oxford OX1 3QY www.eci.ox.ac.uk www.ukerc.ac.uk #12;UK Energy Research Centre 2 1

93

OXFORD BIBLIOGRAPHIES IN ECOLOGY "HEAVY METAL TOLERANCE"  

E-Print Network [OSTI]

cellular mechanisms affected by heavy metals is Bánfalvi 2011. Pollution by heavy metals is an important environmental problem, and sources that focus on heavy metal pollution often contain information about heavyOXFORD BIBLIOGRAPHIES IN ECOLOGY "HEAVY METAL TOLERANCE" By Nishanta Rajakaruna and Robert S. Boyd

Rajakaruna, Nishanta

94

Modeling The Nucleosynthesis Of Massive Stars  

E-Print Network [OSTI]

This overview discusses issues relevant to modeling nucleosynthesis in type II supernovae and implications of detailed studies of the ejecta. After a brief presentation of the most common approaches to stellar evolution and parameterized explosions, the relevance of a number of nuclei to obtain information on the evolution and explosion mechanisms is discussed. The paper is concluded by an outlook on multi-dimensional simulations.

T. Rauscher

2003-09-09T23:59:59.000Z

95

Effect of nuclear structure on Type Ia supernova nucleosynthesis  

E-Print Network [OSTI]

The relationship among nuclear structure, the weak processes in nuclei, and astrophysics becomes quite apparent in supernova explosion and nucleosynthesis studies. In this brief article, I report on progress made in the last few years on calculating electron capture and beta-decay rates in iron-group nuclei. I also report on applications of these rates to Type-Ia nucleosynthesis studies.

D. J. Dean

2000-12-08T23:59:59.000Z

96

Type Ia Supernovae: Simulations and Nucleosynthesis  

E-Print Network [OSTI]

We present our first nucleosynthesis results from a numerical simulation of the thermonuclear disruption of a static cold Chandrasekhar-mass C/O white dwarf. The two-dimensional simulation was performed with an adaptive-mesh Eulerian hydrodynamics code, FLASH, that uses as a flame capturing scheme the evolution of a passive scaler. To compute the isotopic yields and their velocity distribution, 10,000 massless tracer particles are embedded in the star. The particles are advected along streamlines and provide a Lagrangian description of the explosion. We briefly describe our verification tests and preliminary results from post-processing the particle trajectories with a modest (214 isotopes) reaction network.

E. F. Brown; A. C. Calder; T. Plewa; P. M. Ricker; K. Robinson; J. B. Gallagher

2005-05-19T23:59:59.000Z

97

Oxford Catalysts Group plc | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformation Earth'sOklahoma/GeothermalOrange County is aOrmesa IOvonic Battery CompanyOwlOxford

98

The Oxford Programme on the Changing Character of War  

E-Print Network [OSTI]

The Oxford Programme on the Changing Character of War Michaelmas Term 2014 Lunchtime Discussions with Changing Character of War Seminars are at 1.00pm, Seminar Room G, Manor Road Building, Oxford A light Slekys, University of Vilnius The Russian-Ukrainian War: Challenges for Military Policy in the Baltic

Oxford, University of

99

The Oxford Programme on the Changing Character of War  

E-Print Network [OSTI]

The Oxford Programme on the Changing Character of War Trinity Term 2013 Lunchtime Discussions with Changing Character of War Seminars are at 1.00pm, Seminar Room G, Manor Road Building, Oxford A light and Political Will Tuesday 21st May Dr Jessica Wolfendale (West Virginia) War Crimes, Character

Oxford, University of

100

The Oxford Programme on the Changing Character of War  

E-Print Network [OSTI]

The Oxford Programme on the Changing Character of War Michaelmas Term 2014 Lunchtime Discussions with Changing Character of War Seminars are at 1.00pm, Seminar Room G, Manor Road Building, Oxford A light, University of Vilnius The Russian-Ukrainian War: Challenges for Military Policy in the Baltic States Tuesday

Oxford, University of

Note: This page contains sample records for the topic "oxford big-bang nucleosynthesis" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Electron capture cross sections for stellar nucleosynthesis  

E-Print Network [OSTI]

In the first stage of this work, we perform detailed calculations for the cross sections of the electron capture on nuclei under laboratory conditions. Towards this aim we exploit the advantages of a refined version of the proton-neutron quasi-particle random-phase approximation (pn-QRPA) and carry out state-by-state evaluations of the rates of exclusive processes that lead to any of the accessible transitions within the chosen model space. In the second stage of our present study, we translate the above mentioned $e^-$-capture cross sections to the stellar environment ones by inserting the temperature dependence through a Maxwell-Boltzmann distribution describing the stellar electron gas. As a concrete nuclear target we use the $^{66}Zn$ isotope, which belongs to the iron group nuclei and plays prominent role in stellar nucleosynthesis at core collapse supernovae environment.

Giannaka, P G

2015-01-01T23:59:59.000Z

102

Challenges in explosive nucleosynthesis of heavy elements  

SciTech Connect (OSTI)

We show that a treatment of charged-current neutrino interactions in hot and dense matter that is consistent with the nuclear equation of state has a strong impact on the spectra of the neutrinos emitted during the deleptonization period of a protoneutron star formed in a core-collapse supernova. We compare results of simulations including and neglecting mean field effects on the neutrino opacities. Their inclusion reduces the luminosities of all neutrino flavors and enhances the spectral differences between electron neutrino and antineutrino. The magnitude of the difference depends on the equation of state and in particular on the symmetry energy at sub-nuclear densities. These modifications reduce the proton-to-nucleon ratio of the neutrino-driven outflow, increasing slightly their entropy. They are expected to have a substantial impact on the nucleosynthesis in neutrino-driven winds, even though they do not result in conditions that favor an r-process. Contrarily to previous findings, our simulations show that the spectra of electron neutrinos remain substantially different from those of other (anti)neutrino flavors during the entire deleptonization phase of the protoneutron star. The obtained luminosity and spectral changes are also expected to have important consequences for neutrino flavor oscillations and neutrino detection on Earth.

Pinedo, Gabriel Martinez; Fischer, T.; Lohs, A.; Huther, L. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, Schlossgartenstrasse 2, 64289 Darmstadt, Germany and GSI Helmholtzzentrum fuer Schwerioneneforschung, Planckstrasse 1, 64291 Darmstadt (Germany); GSI Helmholtzzentrum fuer Schwerioneneforschung, Planckstrasse 1, 64291 Darmstadt, Germany and Institut fuer Kernphysik, Technische Universitaet Darmstadt, Schlossgartenstrasse 2, 64289 Darmstadt (Germany); Institut fuer Kernphysik, Technische Universitaet Darmstadt, Schlossgartenstrasse 2, 64289 Darmstadt (Germany)

2012-10-20T23:59:59.000Z

103

Oxford Colleges On-line Reports for Tutorials  

E-Print Network [OSTI]

OxCORT Oxford Colleges On-line Reports for Tutorials Tutor Role Version 4.5 BSP Training TeamCORT..........................................................................5 Roles in OxCORT..................................................................................5 of Revision Class reports.......................................................8 Report states

Oxford, University of

104

Neutrinos and nucleosynthesis in core-collapse supernovae  

SciTech Connect (OSTI)

Massive stars (M > 8-10 M{sub ?}) undergo core collapse at the end of their life and explode as supernova with ? 10{sup 51} erg of kinetic energy. While the detailed supernova explosion mechanism is still under investigation, reliable nucleosynthesis calculations based on successful explosions are needed to explain the observed abundances in metal-poor stars and to predict supernova yields for galactic chemical evolution studies. To predict nucleosynthesis yields for a large number of progenitor stars, computationally efficient explosion models are required. We model the core collapse, bounce and subsequent explosion of massive stars assuming spherical symmetry and using detailed microphysics and neutrino physics combined with a novel method to artificially trigger the explosion (PUSH). We discuss the role of neutrinos, the conditions in the ejecta, and the resulting nucleosynthesis.

Fröhlich, C.; Casanova, J. [Department of Physics, North Carolina State University, Raleigh, NC, 27695 (United States); Hempel, M.; Liebendörfer, M. [Departement für Physik, Universität Basel, CH-4056 Basel (Switzerland); Melton, C. A. [Department of Physics, North Carolina State University, Raleigh, NC 27695 (United States); Perego, A. [Institut für Kernphysik, Technische Universität Darmstadt, D-64289 Darmstadt (Germany)

2014-06-24T23:59:59.000Z

105

Primordial Li abundance and massive particles  

SciTech Connect (OSTI)

The problem of the observed lithium abundance coming from the Big Bang Nucleosynthesis is as of yet unsolved. One of the proposed solutions is including relic massive particles into the Big Bang Nucleosynthesis. We investigated the effects of such particles on {sup 4}HeX{sup -}+{sup 2}H{yields}{sup 6}Li+X{sup -}, where the X{sup -} is the negatively charged massive particle. We demonstrate the dominance of long-range part of the potential on the cross-section.

Latin-Capital-Letter-Eth apo, H. [Department of Physics, Akdeniz University, TR-07058, Antalya (Turkey)

2012-10-20T23:59:59.000Z

106

space. Theories of how the Universe evolved in the first few moments after the Big Bang  

E-Print Network [OSTI]

both books are efforts to `explain' chemistry, they have different scopes and styles. Both succeed. Stimulating Concepts in Chemistry is exclusively focused on organic chemistry and its borders with the philosophy of its subjects--morewiththeirnutsandbolts. Organic chemistry is currently in a phase of change

Prentiss, Mara

107

Big Bang Day : The Great Big Particle Adventure - 2. Who Ordered That?  

ScienceCinema (OSTI)

In this series, comedian and physicist Ben Miller asks the CERN scientists what they hope to find. The atoms that make up our material world are important to us, but it turns out they aren't so significant on the cosmic stage. In fact early in the search for the stuff of atoms, researchers discovered particles that played no part in Earthly chemistry - for example particles in cosmic rays that resemble electrons (the stuff of electricity and the chemical glue in molecules) in almost all respects except that they weigh 140 times more. "Who ordered that?" one Nobel laureate demanded. They also discovered antimatter - the destructive mirror-image particles at obliterate all matter they come into contact with. In fact, the Universe is mostly made up of particles that could never make atoms, so that we are just the flotsam of the cosmos. But the main constituent of the Universe, what makes 80% of creation, has never been seen in the lab. Researchers at CERN believe they can create samples of it, down here on Earth.

None

2011-04-25T23:59:59.000Z

108

Matter, antimatter and surviving the big bang is topic of Lab...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of matter over antimatter developed, eventually leading to galaxies and stars and planets . . . and us." Talk begins at 7 p.m. and open to public LOS ALAMOS, N.M., Oct. 31,...

109

The Planck energy-mass source as an alternative to the Big Bang  

E-Print Network [OSTI]

The general theory of relativity is used to show that the total energy-mass of the visible Universe could be produced by an energy-mass source with the Planck power. The source was supposedly born at the phase of cosmic inflation and acts continuously throughout the lifetime of our Universe. The model allows one to treat dark energy as a real form of energy without using the hypothesis of anti-gravity.

Timashev, Serge F

2008-01-01T23:59:59.000Z

110

The Big Bang quantum cosmology: The matter-energy production epoch  

E-Print Network [OSTI]

The exactly solvable quantum model of the homogeneous, isotropic and closed universe in the matter-energy production epoch is considered. It is assumed that the universe is originally filled with a uniform scalar field and a perfect fluid which defines a reference frame. The stationary state spectrum and the wave functions of the quantum universe are calculated. In this model the matter-energy in the universe has a component in the form of a condensate of massive zero-momentum excitation quanta of oscillations of primordial scalar field. The mean value of the scale factor of the universe in a given state is connected with the mass of a condensate by a linear relation. The nucleation rate of the universe from the initial cosmological singularity point is calculated. It is demonstrated that the process of nucleation of the universe can have an exponential (explosive) nature. The evolution of the universe is described as transitions with non-zero probabilities between the states of the universe with different masses of a condensate.

V. E. Kuzmichev; V. V. Kuzmichev

2008-04-30T23:59:59.000Z

111

The Planck energy-mass source as an alternative to the Big Bang  

E-Print Network [OSTI]

The general theory of relativity is used to show that the total energy-mass of the visible Universe could be produced by an energy-mass source with the Planck power. The source was supposedly born at the phase of cosmic inflation and acts continuously throughout the lifetime of our Universe. The model allows one to treat dark energy as a real form of energy without using the hypothesis of anti-gravity.

Serge F. Timashev

2008-04-17T23:59:59.000Z

112

Supercomputing: A Toolbox to Simulate the Big Bang and Beyond | Department  

Energy Savers [EERE]

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion |Energy UsageAUDITVehicles »ExchangeDepartmentResolveFutureSupercomputers'of Energy

113

COLLOQUIUM: One Second After the Big Bang | Princeton Plasma Physics Lab  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to someone6Energy, science,Principles ofPhysics Lab January 8,

114

Neutrinos' Instant Identity Changes Could Mean Big Things for the Big Bang  

Office of Environmental Management (EM)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "of EnergyEnergyENERGY TAXBalanced Scorecard Federal2Energy Second QuarterRate principles mustDepartment|

115

SciTech Connect: Quark mass variation constraints from Big Bang  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administrationcontroller systemsBi (2) Sr (2) Ca (2)Framework Conference:andnucleosynthesis

116

PPPL, Princeton launch hunt for Big Bang particles offering clues to the  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006 TheSteven Ashby Dr. Steven Ashbystation |project |organizer |origin

117

DOE research makes big bang | OSTI, US Dept of Energy, Office of Scientific  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to UserProduct: CrudeOffice of ScientificSolar Residence by e2

118

Big Bang or Big Bounce? Professor Paul J. Steinhardt Princeton University  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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119

NERSC User Group 2013 Big Bang, Big Data, Big Iron Planck Satellite Data Analysis At NERSC  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Opticalhttp://www.fnal.gov/directorate/nalcal/nalcal02_07_05_files/nalcal.gif Directorate -News,AdvancedSeeksDay February

120

Matter, antimatter and surviving the big bang is topic of Lab's next  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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Note: This page contains sample records for the topic "oxford big-bang nucleosynthesis" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

The Decay of the Neutron or Beta Decay, the Big Bang, and the Left-Handed  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmittedStatus TomAboutManusScience andFebruary 28,Universe | ornl.gov

122

The Big-Bang quantum cosmology: The matter-energy production epoch  

E-Print Network [OSTI]

The exactly solvable quantum model of the homogeneous, isotropic and closed universe in the matter-energy production epoch is considered. It is assumed that the universe is originally filled with a uniform scalar field and a perfect fluid which defines a reference frame. The stationary state spectrum and the wave functions of the quantum universe are calculated. In this model the matter-energy in the universe has a component in the form of a condensate of massive zero-momentum excitation quanta of oscillations of primordial scalar field. The mean value of the scale factor of the universe in a given state is connected with the mass of a condensate by a linear relation. The nucleation rate of the universe from the initial cosmological singularity point is calculated. It is demonstrated that the process of nucleation of the universe can have an exponential (explosive) nature. The evolution of the universe is described as transitions with non-zero probabilities between the states of the universe with different ma...

Kuzmichev, V E

2007-01-01T23:59:59.000Z

123

University of oxford & CUlham sCienCe Centre  

E-Print Network [OSTI]

Ation entrepreneuriAl connections Aerospace expertise to fusion cooling technology that optimises the heat flow ireland's group (department of engineering) has considerable experience in the cooling technology used supplies, including the uK's 2020 energy targets. "The University of Oxford attracts world

124

Hamilton-Oxford METRO stops along the route are  

E-Print Network [OSTI]

Hamilton-Oxford Metro METRO stops along the route are marked with red and white Metro signs. For safety reasons, bus drivers may only pick-up and drop-off at designated bus stops. At Miami Hamilton of University Hall. OUTBOUND BUS STOPS Miami University Hamilton Campus Harry T. Wilks Conference Center

Dollar, Anna

125

Amsterdam Oxford Joint Rescue Forces Team Description Paper  

E-Print Network [OSTI]

Amsterdam Oxford Joint Rescue Forces Team Description Paper Virtual Robot competition Rescue van Weelden1 , Chaim Bastiaan1 , Niels Out1 , Olaf Zwennes1 , Sev´aztian Soffia Ot´arola1 , Julian de://www.jointrescueforces.eu Abstract. With the progress made in active exploration, the robots of the Joint Rescue Forces are capable

Visser, Arnoud

126

IT Policy, Procedures and Guidance University College, Oxford  

E-Print Network [OSTI]

IT Policy, Procedures and Guidance University College, Oxford Patrick Baird IT and Web Fellow Andy Hamilton IT Manager Helene Augar College Registrar #12;Summary This policy and guidance document. Transgressions (Junior Members) 14 14. Flexible Hours and Working at Home (Staff) 15 15. Revisions to this Policy

Henderson, Gideon

127

University of Oxford Transgender Policy Purpose of this policy  

E-Print Network [OSTI]

University of Oxford Transgender Policy Purpose of this policy 1. The purpose of this policy the process of gender reassignment. The policy and associated guidance give more detail on how the Universitys Equality Policy applies to transgender people. 2. This policy also supports members of the University

Henderson, Gideon

128

Oxford University Press 2005 1 Text Mining and Information Extraction  

E-Print Network [OSTI]

© Oxford University Press 2005 1 Text Mining and Information Extraction Novel Unsupervised Feature Filtering of Biological Data Roy Varshavsky1,* , Assaf Gottlieb2 , Michal Linial3 and David Horn2 1 School developed for selecting small informative feature subsets in large noisy data. However, unsuper- vised

Horn, David

129

Statistical Methods for Thermonuclear Reaction Rates and Nucleosynthesis Simulations  

E-Print Network [OSTI]

Rigorous statistical methods for estimating thermonuclear reaction rates and nucleosynthesis are becoming increasingly established in nuclear astrophysics. The main challenge being faced is that experimental reaction rates are highly complex quantities derived from a multitude of different measured nuclear parameters (e.g., astrophysical S-factors, resonance energies and strengths, particle and gamma-ray partial widths). We discuss the application of the Monte Carlo method to two distinct, but related, questions. First, given a set of measured nuclear parameters, how can one best estimate the resulting thermonuclear reaction rates and associated uncertainties? Second, given a set of appropriate reaction rates, how can one best estimate the abundances from nucleosynthesis (i.e., reaction network) calculations? The techniques described here provide probability density functions that can be used to derive statistically meaningful reaction rates and final abundances for any desired coverage probability. Examples ...

Iliadis, Christian; Coc, Alain; Timmes, F X; Champagne, Art E

2014-01-01T23:59:59.000Z

130

Oxford University Civil Engineering Novel Foundations for Offshore Wind FarmsNovel Foundations for Offshore Wind Farms  

E-Print Network [OSTI]

Oxford University Civil Engineering Novel Foundations for Offshore Wind FarmsNovel Foundations for Offshore Wind Farms Prof. Guy Houlsby, Dr Byron Byrne, Dr Chris Martin Oxford University #12;Oxford each turbine does not generate all the time, say 3000) #12;Oxford University Civil Engineering Wind

Houlsby, Guy T.

131

Non Thermal Features in the Cosmic Neutrino Background  

E-Print Network [OSTI]

I review some of the basic information on the Cosmic Neutrino Background momentum distribution. In particular, I discuss how present data from several cosmological observables such as Big Bang Nucleosynthesis, Cosmic Microwave Background and Large Scale Structure power spectrum constrain possible deviations from a standard Fermi-Dirac thermal distribution.

G. Mangano

2006-03-22T23:59:59.000Z

132

Nuclear physics and cosmology  

SciTech Connect (OSTI)

There are important aspects of Cosmology, the scientific study of the large scale properties of the universe as a whole, for which nuclear physics can provide insights. Here, we will focus on Standard Big-Bang Nucleosynthesis and we refer to the previous edition of the School [1] for the aspects concerning the variations of constants in nuclear cosmo-physics.

Coc, Alain [Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), CNRS/IN2P3, Université Paris Sud 11, UMR 8609, Bâtiment 104, F-91405 Orsay Campus (France)

2014-05-09T23:59:59.000Z

133

Oxford Area Community School District (Michigan) Bonds Case Study  

Broader source: Energy.gov [DOE]

Michigan’s Oxford Area Community School District entered into an energy savings performance contract and issued limited tax general obligation bonds to fund the up-front costs of almost $3 million of energy-related improvements. Case study is excerpted from Financing Energy Upgrades for K-12 School Districts: A Guide to Tapping into Funding for Energy Efficiency and Renewable Energy Improvements. Author: Merrian Borgeson and Mark Zimring

134

City of Oxford, Georgia (Utility Company) | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Office of Inspector GeneralDepartmentAUDITOhioOglesby, Illinois (Utility Company) Jump to:Osborne,Oxford City of Place:

135

City of Oxford, Mississippi (Utility Company) | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Office of Inspector GeneralDepartmentAUDITOhioOglesby, Illinois (Utility Company) Jump to:Osborne,Oxford City of

136

Collaborative Research: Neutrinos & Nucleosynthesis in Hot Dense Matter  

SciTech Connect (OSTI)

It is now firmly established that neutrinos, which are copiously produced in the hot and dense core of the supernova, play a role in the supernova explosion mechanism and in the synthesis of heavy elements through a phenomena known as r-process nucleosynthesis. They are also detectable in terrestrial neutrino experiments, and serve as a probe of the extreme environment and complex dynamics encountered in the supernova. The major goal of the UW research activity relevant to this project was to calculate the neutrino interaction rates in hot and dense matter of relevance to core collapse supernova. These serve as key input physics in large scale computer simulations of the supernova dynamics and nucleosynthesis being pursued at national laboratories here in the United States and by other groups in Europe and Japan. Our calculations show that neutrino production and scattering rate are altered by the nuclear interactions and that these modifications have important implications for nucleosynthesis and terrestrial neutrino detection. The calculation of neutrino rates in dense matter are difficult because nucleons in the dense matter are strongly coupled. A neutrino interacts with several nucleons and the quantum interference between scattering off different nucleons depends on the nature of correlations between them in dense matter. To describe these correlations we used analytic methods based on mean field theory and hydrodynamics, and computational methods such as Quantum Monte Carlo. We found that due to nuclear effects neutrino production rates at relevant temperatures are enhanced, and that electron neutrinos are more easily absorbed than anti-electron neutrinos in dense matter. The latter, was shown to favor synthesis of heavy neutron-rich elements in the supernova.

Reddy, Sanjay

2013-09-06T23:59:59.000Z

137

Cosmology and the weak interaction  

SciTech Connect (OSTI)

The weak interaction plays a critical role in modern Big Bang cosmology. This review will emphasize two of its most publicized cosmological connections: Big Bang nucleosynthesis and Dark Matter. The first of these is connected to the cosmological prediction of Neutrino Flavours, N{sub {nu}} {approximately} 3 which is now being confirmed at SLC and LEP. The second is interrelated to the whole problem of galaxy and structure formation in the universe. This review will demonstrate the role of the weak interaction both for dark matter candidates and for the problem of generating seeds to form structure. 87 refs., 3 figs., 5 tabs.

Schramm, D.N. (Fermi National Accelerator Lab., Batavia, IL (USA)):(Chicago Univ., IL (USA))

1989-12-01T23:59:59.000Z

138

Nucleosynthesis in the Outflow from Gamma Ray Burst Accretion Disks  

E-Print Network [OSTI]

We examine the nucleosynthesis products that are produced in the outflow from rapidly accreting disks. We find that the type of element synthesis varies dramatically with the degree of neutrino trapping in the disk and therefore the accretion rate of the disk. Disks with relatively high accretion rates such as 10 M_solar/s can produce very neutron rich nuclei that are found in the r process. Disks with more moderate accretion rates can produce copious amounts of Nickel as well as the light elements such as Lithium and Boron. Disks with lower accretion rates such as 0.1 M_solar/s produce large amounts of Nickel as well as some unusual nuclei such as Ti-49, Sc-45, Zn-64, and Mo-92. This wide array of potential nucleosynthesis products is due to the varying influence of electron neutrinos and antineutrinos emitted from the disk on the neutron-to-proton ratio in the outflow. We use a parameterization for the outflow and discuss our results in terms of entropy and outflow acceleration.

R. Surman; G. C. McLaughlin; W. R. Hix

2005-09-13T23:59:59.000Z

139

Village of Oxford, Nebraska (Utility Company) | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia:FAQ < RAPID Jump to:Seadov PtyInformation UCOpenVerona,Hampton Place: NebraskaMayville,Oxford, Nebraska

140

Oxford Institute for Energy Studies | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformation Earth'sOklahoma/GeothermalOrange County is aOrmesa IOvonic Battery CompanyOwlOxford

Note: This page contains sample records for the topic "oxford big-bang nucleosynthesis" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

City of Oxford, Kansas (Utility Company) | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 NoPublic Utilities Address: 160Benin:Energy Nebraska (UtilityGeorgia (UtilityNewburgOrrville, OhioOxford, Kansas

142

Client Project Job No Exeter College Ruskin College, Oxford CG/8069  

E-Print Network [OSTI]

through underlying deep gravels causes drop in water level. West East Gravels ­ permeability typically 10eFIGURES #12;Client Project Job No Exeter College Ruskin College, Oxford CG/8069 Title Site location Observational Quarter #12;#12;Client Project Job No Exeter College Ruskin College, Oxford CG/8069 Title

Flynn, E. Victor

143

Department of Computer Science, University of Oxford Grade 06S Parttime Project Administrator  

E-Print Network [OSTI]

Department of Computer Science, University of Oxford Grade 06S Parttime Project Administrator Further Details This post is open to internal applicants only The Department of Computer Science, University of Oxford has a vacancy for a Parttime Project Administrator to support the work of Professor

Oxford, University of

144

Impartiality in Moral and Political Philosophy. By Susan Mendus. Oxford: Oxford University Press, 2002. 168 pages, ISBN 0-19-829781-5. Hardback $45.00  

E-Print Network [OSTI]

Impartiality in Moral and Political Philosophy. By Susan Mendus. Oxford: Oxford University Press, 2002. 168 pages, ISBN 0-19-829781-5. Hardback $45.00 RoksanaAlavi University of Kansas Susan Mendus's book, Impartiality in Moral and Political... Philosophy, is an attempt to reconcile the ongoing conflict between partial and impartial concerns both in everyday decision-making and in the context of political philosophy (p. 7). The thought is since we live in a pluralist society, along with people...

Alavi, Roksana

145

Nucleosynthesis of heavy elements in gamma ray bursts  

E-Print Network [OSTI]

The ultrarelativistic jets responsible for prompt and afterglow emission in gamma ray bursts are presumably driven by a central engine that consists of a dense accretion disk around a spinning black hole. We consider such engine, composed of free nucleons, electron-positron pairs, Helium nuclei, and cooled by neutrino emission. A significant number density of neutrons in the disk provide conditions for neutron rich plasma in the outflows and jets. Heavy nuclei are also formed in the accretion flow, at the distances 150-250 gravitational radii from the black hole. We study the process of nucleosynthesis in the GRB engine, depending on its physical properties. Our results may have important observational implications for the jet deceleration process and heavy elements observed in the spectra of GRB afterglows.

,

2015-01-01T23:59:59.000Z

146

Beta decay rates for nuclei with 115 < A < 140 for r-process nucleosynthesis  

E-Print Network [OSTI]

For r-process nucleosynthesis the beta decay rates for a number of neutron-rich intermediate heavy nuclei are calculated. The model for the beta strength function is able to reproduce the observed half~lives quite well.

Kamales Kar; Soumya Chakravarti; V. R. Manfredi

2006-03-19T23:59:59.000Z

147

Neutron-induced background by an alpha-beam incident on a deuterium gas target and its implications for the study of the 2H(alpha,gamma)6Li reaction at LUNA  

E-Print Network [OSTI]

The production of the stable isotope Li-6 in standard Big Bang nucleosynthesis has recently attracted much interest. Recent observations in metal-poor stars suggest that a cosmological Li-6 plateau may exist. If true, this plateau would come in addition to the well-known Spite plateau of Li-7 abundances and would point to a predominantly primordial origin of Li-6, contrary to the results of standard Big Bang nucleosynthesis calculations. Therefore, the nuclear physics underlying Big Bang Li-6 production must be revisited. The main production channel for Li-6 in the Big Bang is the 2H(alpha,gamma)6Li reaction. The present work reports on neutron-induced effects in a high-purity germanium detector that were encountered in a new study of this reaction. In the experiment, an {\\alpha}-beam from the underground accelerator LUNA in Gran Sasso, Italy, and a windowless deuterium gas target are used. A low neutron flux is induced by energetic deuterons from elastic scattering and, subsequently, the 2H(d,n)3He reaction. Due to the ultra-low laboratory neutron background at LUNA, the effect of this weak flux of 2-3 MeV neutrons on well-shielded high-purity germanium detectors has been studied in detail. Data have been taken at 280 and 400 keV alpha-beam energy and for comparison also using an americium-beryllium neutron source.

M. Anders; D. Trezzi; A. Bellini; M. Aliotta; D. Bemmerer; C. Broggini; A. Caciolli; H. Costantini; P. Corvisiero; T. Davinson; Z. Elekes; M. Erhard; A. Formicola; Zs. Fülöp; G. Gervino; A. Guglielmetti; C. Gustavino; Gy. Gyürky; M. Junker; A. Lemut; M. Marta; C. Mazzocchi; R. Menegazzo; P. Prati; C. Rossi Alvarez; D. Scott; E. Somorjai; O. Straniero; T. Szücs

2013-01-30T23:59:59.000Z

148

BIG BANG ACOUSTICS SOUND IN THE EARLY UNIVERSE Article for the Acoustical Society of America magazine: ECHOES  

E-Print Network [OSTI]

includes all the associated sounds, can be found on my website at http://www.astro.virginia.edu/dmw8f

Whittle, Mark

149

A constraint on a varying proton--electron mass ratio 1.5 billion years after the Big Bang  

E-Print Network [OSTI]

A molecular hydrogen absorber at a lookback time of 12.4 billion years, corresponding to 10$\\%$ of the age of the universe today, is analyzed to put a constraint on a varying proton--electron mass ratio, $\\mu$. A high resolution spectrum of the J1443$+$2724 quasar, which was observed with the Very Large Telescope, is used to create an accurate model of 89 Lyman and Werner band transitions whose relative frequencies are sensitive to $\\mu$, yielding a limit on the relative deviation from the current laboratory value of $\\Delta\\mu/\\mu=(-9.5\\pm5.4_{\\textrm{stat}} \\pm 5.3_{\\textrm{sys}})\\times 10^{-6}$.

Bagdonaite, J; Murphy, M T; Whitmore, J B

2015-01-01T23:59:59.000Z

150

The r-process nucleosynthesis: Nuclear physics challenges  

SciTech Connect (OSTI)

About half of the nuclei heavier than iron observed in nature are produced by the socalled rapid neutron capture process, or r-process, of nucleosynthesis. The identification of the astrophysics site and the specific conditions in which the r-process takes place remains, however, one of the still-unsolved mysteries of modern astrophysics. Another underlying difficulty associated with our understanding of the r-process concerns the uncertainties in the predictions of nuclear properties for the few thousands exotic neutron-rich nuclei involved and for which essentially no experimental data exist. The present contribution emphasizes some important future challenges faced by nuclear physics in this problem, particularly in the determination of the nuclear structure properties of exotic neutron-rich nuclei as well as their radiative neutron capture rates and their fission probabilities. These quantities are particularly relevant to determine the composition of the matter resulting from the r-process. Their impact on the r-abundance distribution resulting from the decompression of neutron star matter is discussed.

Goriely, S. [Institut d'Astronomie et d'Astrophysique, Universite Libre de Bruxelles Campus de la Plaine, CP 226, 1050 Brussels (Belgium)

2012-10-20T23:59:59.000Z

151

The Effects of Thermonuclear Reaction Rate Variations on Nova Nucleosynthesis: A Sensitivity Study  

E-Print Network [OSTI]

We investigate the effects of thermonuclear reaction rate uncertainties on nova nucleosynthesis. One-zone nucleosynthesis calculations have been performed by adopting temperature-density-time profiles of the hottest hydrogen-burning zone (i.e., the region in which most of the nucleosynthesis takes place). We obtain our profiles from 7 different, recently published, hydrodynamic nova simulations covering peak temperatures in the range from Tpeak=0.145-0.418 GK. For each of these profiles, we individually varied the rates of 175 reactions within their associated errors and analyzed the resulting abundance changes of 142 isotopes in the mass range below A=40. In total, we performed 7350 nuclear reaction network calculations. We use the most recent thermonuclear reaction rate evaluations for the mass ranges A=1-20 and A=20-40. For the theoretical astrophysicist, our results indicate the extent to which nova nucleosynthesis calculations depend on presently uncertain nuclear physics input, while for the experimental nuclear physicist our results represent at least a qualitative guide for future measurements at stable and radioactive ion beam facilities. We find that present reaction rate estimates are reliable for predictions of Li, Be, C and N abundances in nova nucleosynthesis. However, rate uncertainties of several reactions have to be reduced significantly in order to predict more reliable O, F, Ne, Na, Mg, Al, Si, S, Cl and Ar abundances. Results are presented in tabular form for each adopted nova simulation.

Christian Iliadis; Art Champagne; Jordi Jose; Sumner Starrfield; Paul Tupper

2002-06-03T23:59:59.000Z

152

Sensitivity study of explosive nucleosynthesis in Type Ia supernovae: I. Modification of individual thermonuclear reaction rates  

E-Print Network [OSTI]

We explore the sensitivity of the nucleosynthesis due to type Ia supernovae with respect to uncertainties in nuclear reaction rates. We have adopted a standard one-dimensional delayed detonation model of the explosion of a Chandrasekhar-mass white dwarf, and have post-processed the thermodynamic trajectories of every mass-shell with a nucleosynthetic code, with increases (decreases) by a factor of ten on the rates of 1196 nuclear reactions. We have computed as well hydrodynamic models for different rates of the fusion reactions of 12C and of 16O. For selected reactions, we have recomputed the nucleosynthesis with alternative prescriptions for their rates taken from the JINA REACLIB database, and have analyzed the temperature ranges where modifications of their rates have the strongest effect on nucleosynthesis. The nucleosynthesis resulting from the Type Ia supernova models is quite robust with respect to variations of nuclear reaction rates, with the exception of the reaction of fusion of 12C nuclei. The energy of the explosion changes by less than \\sim4%. The changes in the nucleosynthesis due to the modification of the rates of fusion reactions are as well quite modest, for instance no species with a mass fraction larger than 0.02 experiences a variation of its yield larger than a factor of two. We provide the sensitivity of the yields of the most abundant species with respect to the rates of the most intense reactions with protons, neutrons, and alphas. In general, the yields of Fe-group nuclei are more robust than the yields of intermediate-mass elements. Among the charged particle reactions, the most influential on supernova nucleosynthesis are 30Si + p \\rightleftarrows 31P + {\\gamma}, 20Ne + {\\alpha} \\rightleftarrows 24Mg + {\\gamma}, and 24Mg + {\\alpha} \\rightleftarrows 27Al + p. The temperatures at which a modification of their rate has a larger impact are in the range 2 < T < 4 GK. (abridged)

Eduardo Bravo; Gabriel Martínez-Pinedo

2012-04-09T23:59:59.000Z

153

Falk Herwig18 July 2007 Slide 1 Nucleosynthesis and mixing in  

E-Print Network [OSTI]

Falk Herwig18 July 2007 Slide 1 Nucleosynthesis and mixing in the first generations of low July 2007 Slide 2 We have seen yesterday: rotation is important at extremely low and zero metalicity Slide 3 The convective-reactive events occur favorably at Z=0 or extremely low metallicity: ·the entropy

Herwig, Falk

154

{beta}-delayed neutron decay in {sup 17}B and {sup 19}C  

SciTech Connect (OSTI)

The {beta}-delayed neutron decays of {sup 17}B and {sup 19}C were studied using radioactive ion beams. The neutron energies, measured via time-of-flight, give information on states above the neutron decay threshold in {sup 17}C and {sup 19}N, respectively. These low lying states are of possible interest for Big Bang nucleosynthesis. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

Raimann, G. [Department of Physics, The Ohio State University, Columbus, Ohio 43210 (United States); Ozawa, A. [The Institute of Physical and Chemical Research (RIKEN), Wako-shi, Saitama 351-01 (Japan); Boyd, R.N. [Department of Physics, The Ohio State University, Columbus, Ohio 43210 (United States)]|[Department of Astronomy, The Ohio State University, Columbus, Ohio 43210 (United States); Chloupek, F.R. [Department of Physics, The Ohio State University, Columbus, Ohio 43210 (United States); Fujimaki, M. [The Institute of Physical and Chemical Research (RIKEN), Wako-shi, Saitama 351-01 (Japan); Kimura, K. [Nagasaki Institute of Applied Science, Nagasaki, Nagasaki 851-01 (Japan); Kobayashi, T. [The Institute of Physical and Chemical Research (RIKEN), Wako-shi, Saitama 351-01 (Japan); Kolata, J.J. [Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Kubono, S. [Institute of Nuclear Study, University of Tokyo, Tanashi, Tokyo 188 (Japan); Tanihata, I.; Watanabe, Y.; Yoshida, K. [The Institute of Physical and Chemical Research (RIKEN), Wako-shi, Saitama 351-01 (Japan)

1995-02-05T23:59:59.000Z

155

Activation measurement of the 3He(alpha,gamma)7Be cross section at low energy  

E-Print Network [OSTI]

The nuclear physics input from the 3He(alpha,gamma)7Be cross section is a major uncertainty in the fluxes of 7Be and 8B neutrinos from the Sun predicted by solar models and in the 7Li abundance obtained in big-bang nucleosynthesis calculations. The present work reports on a new precision experiment using the activation technique at energies directly relevant to big-bang nucleosynthesis. Previously such low energies had been reached experimentally only by the prompt-gamma technique and with inferior precision. Using a windowless gas target, high beam intensity and low background gamma-counting facilities, the 3He(alpha,gamma)7Be cross section has been determined at 127, 148 and 169 keV center-of-mass energy with a total uncertainty of 4%. The sources of systematic uncertainty are discussed in detail. The present data can be used in big-bang nucleosynthesis calculations and to constrain the extrapolation of the 3He(alpha,gamma)7Be astrophysical S-factor to solar energies.

D. Bemmerer; F. Confortola; H. Costantini; A. Formicola; Gy. Gyurky; R. Bonetti; C. Broggini; P. Corvisiero; Z. Elekes; Zs. Fulop; G. Gervino; A. Guglielmetti; C. Gustavino; G. Imbriani; M. Junker; M. Laubenstein; A. Lemut; B. Limata; V. Lozza; M. Marta; R. Menegazzo; P. Prati; V. Roca; C. Rolfs; C. Rossi Alvarez; E. Somorjai; O. Straniero; F. Strieder; F. Terrasi; H. P. Trautvetter

2006-09-11T23:59:59.000Z

156

STORING ARB HYUNGSOK AHN, Credit Agricol Lazard Financial Products & U. of Oxford, UK  

E-Print Network [OSTI]

STORING ARB HYUNGSOK AHN, Credit Agricolé Lazard Financial Products & U. of Oxford, UK ALBINA with a liquid forward market. Of particular note is pump storage in power markets (this includes air compression hand, is a purely financial product with no limit on injection/withdrawal rate and zero delivery charge

157

BRASENOSE COLLEGE /UNIVERSITY OF OXFORD DATA PROTECTION ACT 1998: INFORMATION ON STUDENT PERSONAL  

E-Print Network [OSTI]

BRASENOSE COLLEGE /UNIVERSITY OF OXFORD DATA PROTECTION ACT 1998: INFORMATION ON STUDENT PERSONAL University') process (i.e. collect and use) your personal data and any disclosures that they may make of those data outside the College/University. It is important that you are aware of the personal data which

Oxford, University of

158

PRESS RELEASE: `Oxford Principles' provide a code of conduct for geoengineering research  

E-Print Network [OSTI]

PRESS RELEASE: `Oxford Principles' provide a code of conduct for geoengineering research and policy makers to begin to explore geoengineering ­ the deliberate, largescale intervention in the Earth a potential delivery mechanism for a geoengineering technique (SPICE Project http://gow.epsrc

Oxford, University of

159

Chapter 17 Eye-head Gaze shifts Oxford Handbook on Eye Movements  

E-Print Network [OSTI]

1 Chapter 17 Eye-head Gaze shifts Oxford Handbook on Eye Movements "The Neural Basis of Gaze Shifts" 1. Kinematics of eye-head gaze shifts a. Terminology for describing eye-head gaze shifts b. Variability in eye and head motion during gaze shifts c. Gaze shifts in complex environments d. Bottom

Corneil, Brian D.

160

Free Will and the Bounds of the Self1 [Forthcoming in Robert Kane, ed. Oxford Handbook  

E-Print Network [OSTI]

1 Free Will and the Bounds of the Self1 [Forthcoming in Robert Kane, ed. Oxford Handbook of Free responsible for anything we did. After all, we would never be free to choose any behavior other than the one cannot be fully free or responsible. Our aim here is to get at the sources of this discomfort and thereby

Knobe, Joshua

Note: This page contains sample records for the topic "oxford big-bang nucleosynthesis" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

University of Oxford Department of Computer Science Job description and selection criteria  

E-Print Network [OSTI]

University itself. Our annual income in 2009/10 was £879.8m. Oxford is one of Europe's most innovative, Mathematical Institute, the Department of Physics, Department of Plant Sciences, Department of Zoology and training staff in the application process. The role will include reviewing and evaluating existing

Martin, Ralph R.

162

University of Oxford Department of Computer Science Job description and selection criteria  

E-Print Network [OSTI]

University itself. Our annual income in 2009/10 was £879.8m. Oxford is one of Europe's most innovative, Mathematical Institute, the Department of Physics, Department of Plant Sciences, Department of Zoology programming (GP) is a technique that exploits the inherent structure that exists in data, where this structure

Martin, Ralph R.

163

NERC Research Experience Placement Scheme Summer 2012 Department of Earth Sciences, University of Oxford  

E-Print Network [OSTI]

; exploration of other sample types (soils etc.); and/or calculation of the production rates of other rare of Oxford 236 U production rates and concentrations in the natural and polluted environment Supervisor: Prof a potential tracer of natural processes such as ocean circulation (e.g. Christl et al. 2012). 236 U also

Henderson, Gideon

164

Bottom-up, social innovation for addressing climate change Noam Bergman, University of Oxford  

E-Print Network [OSTI]

1 Bottom-up, social innovation for addressing climate change Noam Bergman, University of Oxford and practice in the area of bottom-up, social innovation could yield benefits if integrated into wider employing new technical solutions, we identify these as warranting more research, policy and support. Bottom-up

165

Last updated 6 May 2011 Kenya: Balazs Szendroi, University of Oxford, UK, and the Department of  

E-Print Network [OSTI]

Last updated 6 May 2011 Kenya: Balazs Szendroi, University of Oxford, UK, and the Department of Mathematics and Applied Statistics, Maseno University, Kenya Contacts: Professor John Ogonji (Dean), Professor, Kenya, NETwork. The following sessions were held during the course of the visit. (i) Five talks

Burton, Geoffrey R.

166

Monte Carlo Methods for Uncertainty Quantification Mathematical Institute, University of Oxford  

E-Print Network [OSTI]

Lecture 1: Introduction and Monte Carlo basics some model applications random number generation Monte force being outside some specified range Note: if we turn this into a full finite element analysis on the boundary. Mike Giles (Oxford) Monte Carlo methods October 25, 2013 7 / 28 #12;Application 3 In modelling

Giles, Mike

167

The Karlsruhe Astrophysical Database of Nucleosynthesis in Stars Project - Status and Prospects  

E-Print Network [OSTI]

The KADoNiS (Karlsruhe Astrophysical Database of Nucleosynthesis in Stars) project is an astrophysical online database for cross sections relevant for nucleosynthesis in the $s$ process and the $\\gamma$ process. The $s$-process database (www.kadonis.org) was started in 2005 and is presently facing its 4th update (KADoNiS v1.0). The $\\gamma$-process database (KADoNiS-p, www.kadonis.org/pprocess) was recently revised and re-launched in March 2013. Both databases are compilations for experimental cross sections with relevance to heavy ion nucleosynthesis. For the $s$ process recommended Maxwellian averaged cross sections for $kT$= 5-100~keV are given for more than 360 isotopes between $^{1}$H and $^{210}$Bi. For the $\\gamma$-process database all available experimental data from $(p,\\gamma), (p,n), (p,\\alpha), (\\alpha,\\gamma), (\\alpha,n)$, and $(\\alpha,p)$ reactions between $^{70}$Ge and $^{209}$Bi in or close to the respective Gamow window were collected and can be compared to theoretical predictions. The aim of both databases is a quick and user-friendly access to the available data in the astrophysically relevant energy regions.

Iris Dillmann; Tamas Szücs; Zsolt Fülöp; Ralf Plag; Franz Käppeler; Thomas Rauscher

2014-08-16T23:59:59.000Z

168

Nucleosynthesis in Fast Expansions of High-Entropy, Proton Rich Matter  

E-Print Network [OSTI]

We demonstrate that nucleosynthesis in rapid, high-entropy expansions of proton-rich matter from high temperature and density can result in a wider variety of abundance patterns than heretofore appreciated. In particular, such expansions can produce iron-group nuclides, p-process nuclei, or even heavy, neutron-rich isotopes. Such diversity arises because the nucleosynthesis enters a little explored regime in which the free nucleons are not in equilibrium with the abundant alpha particles. This allows nuclei significantly heavier than iron to form in t he presence of abundant free nucleons early in the expansion. As the temperature drops, nucleons increasingly assemble into alpha particles and heavier nuclei. If the assembly is efficient, the resulting depletion of free neutrons allows disintegrat ion flows to drive nuclei back down to iron and nickel. If this assembly is inefficient, then the large abundance of free nucleons prevents the disintegration flows and leaves a distribution of heavy nuclei after reaction freezeout. For cases in between, an intermediate abundance distribution, enriched in p-process isotopes, is frozen out. These last expansions may contribute to the solar system's supply of the p-process nuclides if mildly proton-rich, high-entropy matter is ejected from proto-neutron stars winds or other astrophysical sites. Also sign ificant is the fact that, because the nucleosynthesis is primary, the signature of this nucleosyn thesis may be evident in metal poor stars.

G. C. Jordan IV; B. S. Meyer

2004-06-29T23:59:59.000Z

169

NUCLEOSYNTHESIS IN THE OUTFLOWS ASSOCIATED WITH ACCRETION DISKS OF TYPE II COLLAPSARS  

SciTech Connect (OSTI)

We investigate nucleosynthesis inside the outflows from gamma-ray burst (GRB) accretion disks formed by the Type II collapsars. In these collapsars, massive stars undergo core collapse to form a proto-neutron star initially, and a mild supernova (SN) explosion is driven. The SN ejecta lack momentum, and subsequently this newly formed neutron star gets transformed to a stellar mass black hole via massive fallback. The hydrodynamics and the nucleosynthesis in these accretion disks have been studied extensively in the past. Several heavy elements are synthesized in the disk, and much of these heavy elements are ejected from the disk via winds and outflows. We study nucleosynthesis in the outflows launched from these disks by using an adiabatic, spherically expanding outflow model, to understand which of these elements thus synthesized in the disk survive in the outflow. While studying this, we find that many new elements like isotopes of titanium, copper, zinc, etc., are present in the outflows. {sup 56}Ni is abundantly synthesized in most of the cases in the outflow, which implies that the outflows from these disks in a majority of cases will lead to an observable SN explosion. It is mainly present when outflow is considered from the He-rich, {sup 56}Ni/{sup 54}Fe-rich zones of the disks. However, outflow from the Si-rich zone of the disk remains rich in silicon. Although emission lines of many of these heavy elements have been observed in the X-ray afterglows of several GRBs by Chandra, BeppoSAX, XMM-Newton, etc., Swift seems to have not yet detected these lines.

Banerjee, Indrani; Mukhopadhyay, Banibrata, E-mail: indrani@physics.iisc.ernet.in, E-mail: bm@physics.iisc.ernet.in [Department of Physics, Indian Institute of Science, Bangalore 560 012 (India)

2013-11-20T23:59:59.000Z

170

Low-mass helium star models for type Ib supernovae - Light curves, mixing, and nucleosynthesis  

SciTech Connect (OSTI)

The applicability of theoretical models of He-star explosions to type Ib SN explosions is explored. Particular attention is given to light curves and mixing, Rayleigh-Taylor instabilities and mixing, and nucleosynthesis and the mass of Ni-56. Typical numerical results are presented in graphs, and it is concluded that the explosions of SN 1983N and SN 1983I can be accurately represented in terms of explosions of He stars with M(alpha) of 3-4 solar mass. A strong M(alpha) dependence of light-curve shape, photospheric velocity, and Ni-56 mass is found. 44 refs.

Shigeyama, Toshikazu; Nomoto, Kenichi; Tsujimoto, Takuji; Hashimoto, Masaki (Tokyo Univ. (Japan) Kyushu Univ., Fukuoka (Japan))

1990-09-01T23:59:59.000Z

171

On the introduction of {sup 17}O+p reaction rates evaluated through the THM in AGB nucleosynthesis calculations  

SciTech Connect (OSTI)

The rates for the {sup 17}O(p,??{sup 14}N, {sup 17}O(p,?){sup 18}F and {sup 18}O(p,?){sup 15}N reactions deduced trough the Trojan Horse Method (THM) have been introduced into a state-of-the-art asymptotic giant branch (AGB) models for proton-capture nucleosynthesis and cool bottom process. The predicted abundances have been compared with isotopic compositions provided by geochemical analysis of presolar grains. As a result, an improved agreement is found between the models and the isotopic mix of oxide grains of AGB origins, whose composition is the signature of low-temperature proton-capture nucleosynthesis.

Palmerini, S.; Sergi, M. L.; La Cognata, M.; Pizzone, R. G. [I.N.F.N. Laboratori Nazionali del Sud, via Santa Sofia 62, Catania (Italy); Lamia, L.; Spitaleri, C. [Dipartimento di Fisica e Astronomia, Universitá degli Studi di Catania (Italy)

2014-05-09T23:59:59.000Z

172

Determination of Dark Energy and Dark Matter from the values of Redshift for the present time, Planck and Trans-Planck epochs of the Big-Bang model  

E-Print Network [OSTI]

As an alternative to the Standard cosmology model we have developed a new modified Freundlich's (quantum relativity) redshift (MFRS) mechanisms, which provide a precise solutions of the Dark Energy and Dark Matter problems. We apply the joint solution of three MFRS equations for concordances quantize bounce Planck hierarchy steps. Simultaneous scaling solutions of MFRS equations in logarithmic scale appropriate to three cosmological epoch's, yields a currently testable predictions regarding the Dark Matter {\\Omega}_{DM} = 0.25, and Dark Energy {\\Omega}_{DE} = 0.75. These predictions coincides with the recent observational data from WMAP and other a key supernovae SNe Ia findings. Thus, the presence of Dark Matter and Dark Energy had already been not only detected observationally, but also confirmed theoretically with the very compelling accuracy. From the WMAP7 and our predicted ages we find a value of the Hubble constant H_0 = 65.6 km * s^{-1} Mpc^{-1} which is excellent agreement with the Planck 2013 results XVI. Compared with the "holographic scenario" results, we find an important coincidence between our new and "holographic" parameters. We discuss the connection hierarchy between the multiverse masses and examine the status of the cosmic acceleration. The product of the age of the Universe into the cosmic acceleration in each cosmological epochs --including present day are constant and precisely corresponds to an possible observable-geophysical parameter g_U = 9.50005264_{265} (exact) * (m/s^2). For the derived by WMAP7 age of the Universe t_{W7} = 13.75(13) * 10^9 yr, we find the relevant acceleration a_{W7} = 6.91(65) * 10^{-10} m/s^2. The predicted value of t_0 = 9.0264_9(51) * 10^2 Gyr is consistent with the background acceleration. a_0 = 1.05246_4(61) * 10^{-11} m/s^2.

Asger G. Gasanalizade; Ramin A. Hasanalizade

2015-02-20T23:59:59.000Z

173

Inverse Problems 15 (1999) 329341. Printed in the UK PII: S0266-5611(99)97635-9 Bigger uncertainties and the Big Bang  

E-Print Network [OSTI]

and energy in the Universe. Evidence of this heterogeneity is the non-zero quadrupole term in the CMB, or on modelling the effect of unestimated high-frequency terms, without accounting for model uncertainty Background Explorer (COBE), carrying the Differential Microwave Radiometer (DMR) instrument on 0266

Lineweaver, Charles H.

174

Beta-decay spectroscopy relevant to the r-process nucleosynthesis  

SciTech Connect (OSTI)

A scientific program of beta-decay spectroscopy relevant to r-process nucleosynthesis has been started using high intensity U-beam at the RIBF. The first results of {beta}-decay half-lives of very neutron-rich Kr to Tc nuclides, all of which lie close to the r-process path, suggest a systematic enhancement of the the {beta}-decay rates of the Zr and Nb isotopes around A110 with respect to the predictions of the deformed quasiparticle-random-phase-approximation model (FRDM + QRPA). An impact of the results on the astrophysical r-process is discussed together with the future perspective of the {beta}-decay spectroscopy with the EURICA.

Nishimura, Shunji [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Collaboration: RIBF Decay Collaboration

2012-11-12T23:59:59.000Z

175

The 40Ca(alpha,gamma)44Ti reaction in the energy regime of supernova nucleosynthesis  

E-Print Network [OSTI]

The 44Ti(t1/2 = 59 y) nuclide, an important signature of supernova nucleosynthesis, has recently been observed as live radioactivity by gamma-ray astronomy from the Cas A remnant. We investigate in the laboratory the major 44Ti production reaction, 40Ca(alpha,gamma)44Ti (E_cm = 0.6-1.2 MeV/u), by direct off- line counting of 44Ti nuclei. The yield, significantly higher than inferred from previous experiments, is analyzed in terms of a statistical model using microscopic nuclear inputs. The associated stellar rate has important astrophysical consequences, increasing the calculated supernova 44Ti yield by a factor ~2 over previous estimates and bringing it closer to Cas A observations.

H. Nassar; M. Paul; I. Ahmad; Y. Ben-Dov; J. Caggiano; S. Ghelberg; S. Goriely; J. P. Greene; M. Hass; A. Heger; A. Heinz; D. J. Henderson; R. V. F. Janssens; C. L. Jiang; Y. Kashiv; B. S. Nara Singh; A. Ofan; R. C. Pardo; T. Pennington; K. E. Rehm; G. Savard; R. Scott; R. Vondrasek

2006-01-11T23:59:59.000Z

176

Neutron capture cross section of unstable 63Ni: implications for stellar nucleosynthesis  

E-Print Network [OSTI]

The $^{63}$Ni($n, \\gamma$) cross section has been measured for the first time at the neutron time-of-flight facility n\\_TOF at CERN from thermal neutron energies up to 200 keV. In total, capture kernels of 12 (new) resonances were determined. Maxwellian Averaged Cross Sections were calculated for thermal energies from kT = 5 keV to 100 keV with uncertainties around 20%. Stellar model calculations for a 25 M$_\\odot$ star show that the new data have a significant effect on the $s$-process production of $^{63}$Cu, $^{64}$Ni, and $^{64}$Zn in massive stars, allowing stronger constraints on the Cu yields from explosive nucleosynthesis in the subsequent supernova.

C. Lederer; C. Massimi; S. Altstadt; J. Andrzejewski; L. Audouin; M. Barbagallo; V. Bécares; F. Bevá; F. Belloni; E. Berthoumieux; J. Billowes; V. Boccone; D. Bosnar; M. Brugger; M. Calviani; F. Calviño; D. Cano-Ott; C. Carrapiço; F. Cerutti; E. Chiaveri; M. Chin; N. Colonna; G. Cortés; M. A. Cortés-Giraldo; M. Diakaki; C. Domingo-Pardo; I. Duran; R. Dressler; N. Dzysiuk; C. Eleftheriadis; A. Ferrari; K. Fraval; S. Ganesan; A. R. García; G. Giubrone; M. B. Gómez-Hornillos; I. F. Gonçalves; E. González-Romero; E. Griesmayer; C. Guerrero; F. Gunsing; P. Gurusamy; D. G. Jenkins; E. Jericha; Y. Kadi; F. Käppeler; D. Karadimos; N. Kivel; P. Koehler; M. Kokkoris; G. Korschinek; M. Krtika; J. Kroll; C. Langer; H. Leeb; L. S. Leong; R. Losito; A. Manousos; J. Marganiec; T. Martínez; P. F. Mastinu; M. Mastromarco; M. Meaze; E. Mendoza; A. Mengoni; P. M. Milazzo; F. Mingrone; M. Mirea; W. Mondelaers; C. Paradela; A. Pavlik; J. Perkowski; M. Pignatari; A. Plompen; J. Praena; J. M. Quesada; T. Rauscher; R. Reifarth; A. Riego; F. Roman; C. Rubbia; R. Sarmento; P. Schillebeeckx; S. Schmidt; D. Schumann; G. Tagliente; J. L. Tain; D. Tarrío; L. Tassan-Got; A. Tsinganis; S. Valenta; G. Vannini; V. Variale; P. Vaz; A. Ventura; R. Versaci; M. J. Vermeulen; V. Vlachoudis; R. Vlastou; A. Wallner; T. Ware; M. Weigand; C. Weiß; T. J. Wright; P. Zugec

2013-04-11T23:59:59.000Z

177

THE IMPACT OF HELIUM-BURNING REACTION RATES ON MASSIVE STAR EVOLUTION AND NUCLEOSYNTHESIS  

SciTech Connect (OSTI)

We study the sensitivity of presupernova evolution and supernova nucleosynthesis yields of massive stars to variations of the helium-burning reaction rates within the range of their uncertainties. The current solar abundances from Lodders are used for the initial stellar composition. We compute a grid of 12 initial stellar masses and 176 models per stellar mass to explore the effects of independently varying the {sup 12}C({alpha}, {gamma}){sup 16}O and 3{alpha} reaction rates, denoted R{sub {alpha},12} and R{sub 3{alpha}}, respectively. The production factors of both the intermediate-mass elements (A = 16-40) and the s-only isotopes along the weak s-process path ({sup 70}Ge, {sup 76}Se, {sup 80}Kr, {sup 82}Kr, {sup 86}Sr, and {sup 87}Sr) were found to be in reasonable agreement with predictions for variations of R{sub 3{alpha}} and R{sub {alpha},12} of {+-}25%; the s-only isotopes, however, tend to favor higher values of R{sub 3{alpha}} than the intermediate-mass isotopes. The experimental uncertainty (one standard deviation) in R{sub 3{alpha}}(R{sub {alpha},12}) is approximately {+-}10%({+-}25%). The results show that a more accurate measurement of one of these rates would decrease the uncertainty in the other as inferred from the present calculations. We also observe sharp changes in production factors and standard deviations for small changes in the reaction rates, due to differences in the convection structure of the star. The compactness parameter was used to assess which models would likely explode as successful supernovae, and hence contribute explosive nucleosynthesis yields. We also provide the approximate remnant masses for each model and the carbon mass fractions at the end of core-helium burning as a key parameter for later evolution stages.

West, Christopher; Heger, Alexander [Minnesota Institute for Astrophysics, School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States); Austin, Sam M., E-mail: west0482@umn.edu, E-mail: alexander.heger@monash.edu, E-mail: austin@nscl.msu.edu [Joint Institute for Nuclear Astrophysics, Notre Dame, IN 46556 (United States)

2013-05-20T23:59:59.000Z

178

THE CENTRAL CONCEPTS OF INCLUSIVE FITNESS 3000 word article in the Oxford University Press Encyclopedia of Evolution, January  

E-Print Network [OSTI]

1 THE CENTRAL CONCEPTS OF INCLUSIVE FITNESS 3000 word article in the Oxford University Press with alternative traits have lower fitness than "normal" individuals who exhibit the established trait. For example is that the neighbours of the taller individual would have slightly less fitness and, because of limited dispersal

Taylor, Peter

179

UK Workshop on Grid Security Experiences, Oxford 8th and 9th July 2004 Multilayer Privilege Management for Dynamic Collaborative  

E-Print Network [OSTI]

UK Workshop on Grid Security Experiences, Oxford 8th and 9th July 2004 Multilayer Privilege will witness on-demand creation of dynamically-evolving, scalable Virtual Organisations (VO) spanning national satellite imagery). Being a large project, it would have several work packages involving different parts

Kent, University of

180

Kenya: Balazs Szendroi, University of Oxford, UK, and the Department of Mathematics and Applied Statistics, Maseno University, Kenya  

E-Print Network [OSTI]

Kenya: Balazs Szendroi, University of Oxford, UK, and the Department of Mathematics and Applied Statistics, Maseno University, Kenya Contacts: Professor John Ogonji (Dean), Professor Omolo Ongati (Head was supported by local funds from MACKNET, the Maths And Computer science, Kenya, NETwork. The following

Szendröi, Balázs

Note: This page contains sample records for the topic "oxford big-bang nucleosynthesis" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Nuclear Astrophysics  

E-Print Network [OSTI]

Nuclear physics has a long and productive history of application to astrophysics which continues today. Advances in the accuracy and breadth of astrophysical data and theory drive the need for better experimental and theoretical understanding of the underlying nuclear physics. This paper will review some of the scenarios where nuclear physics plays an important role, including Big Bang Nucleosynthesis, neutrino production by our sun, nucleosynthesis in novae, the creation of elements heavier than iron, and neutron stars. Big-bang nucleosynthesis is concerned with the formation of elements with A nuclear physics inputs required are few-nucleon reaction cross sections. The nucleosynthesis of heavier elements involves a variety of proton-, alpha-, neutron-, and photon-induced reactions, coupled with radioactive decay. The advent of radioactive ion beam facilities has opened an important new avenue for studying these processes, as many involve radioactive species. Nuclear physics also plays an important role in neutron stars: both the nuclear equation of state and cooling processes involving neutrino emission play a very important role. Recent developments and also the interplay between nuclear physics and astrophysics will be highlighted.

Carl R. Brune

2005-02-28T23:59:59.000Z

182

The Effects of Variations in Nuclear Interactions on Nucleosynthesis in Thermonuclear Supernovae  

E-Print Network [OSTI]

The impact of nuclear physics uncertainties on nucleosynthesis in thermonuclear supernovae has not been fully explored using comprehensive and systematic studies with multiple models. To better constrain predictions of yields from these phenomena, we have performed a sensitivity study by post-processing thermodynamic histories from two different hydrodynamic, Chandrasekhar-mass explosion models. We have individually varied all input reaction and, for the first time, weak interaction rates by a factor of ten and compared the yields in each case to yields using standard rates. Of the 2305 nuclear reactions in our network, we find that the rates of only 53 reactions affect the yield of any species with an abundance of at least 10^-8 M_sun by at least a factor of two, in either model. The rates of the 12C(a,g), 12C+12C, 20Ne(a,p), 20Ne(a,g) and 30Si(p,g) reactions are among those that modify the most yields when varied by a factor of ten. From the individual variation of 658 weak interaction rates in our network by a factor of ten, only the stellar 28Si(b+)28Al, 32S(b+)32P and 36Ar(b+)36Cl rates significantly affect the yields of species in a model. Additional tests reveal that reaction rate changes over temperatures T > 1.5 GK have the greatest impact, and that ratios of radionuclides that may be used as explosion diagnostics change by a factor of less than two from the variation of individual rates by a factor of 10. Nucleosynthesis in the two adopted models is relatively robust to variations in individual nuclear reaction and weak interaction rates. Laboratory measurements of a limited number of reactions would help to further constrain predictions. As well, we confirm the need for a consistent treatment for relevant stellar weak interaction rates since simultaneous variation of these rates (as opposed to individual variation) has a significant effect on yields in our models.

Anuj Parikh; Jordi Jose; Ivo R. Seitenzahl; Friedrich K. Roepke

2013-06-25T23:59:59.000Z

183

SYSTEMATICS OF DYNAMICAL MASS EJECTION, NUCLEOSYNTHESIS, AND RADIOACTIVELY POWERED ELECTROMAGNETIC SIGNALS FROM NEUTRON-STAR MERGERS  

SciTech Connect (OSTI)

We investigate systematically the dynamical mass ejection, r-process nucleosynthesis, and properties of electromagnetic counterparts of neutron-star (NS) mergers in dependence on the uncertain properties of the nuclear equation of state (EOS) by employing 40 representative, microphysical high-density EOSs in relativistic, hydrodynamical simulations. The crucial parameter determining the ejecta mass is the radius R{sub 1.35} of a 1.35 M{sub Sun} NS. NSs with smaller R{sub 1.35} (''soft'' EOS) eject systematically higher masses. These range from {approx}10{sup -3} M{sub Sun} to {approx}10{sup -2} M{sub Sun} for 1.35-1.35 M{sub Sun} binaries and from {approx}5 Multiplication-Sign 10{sup -3} M{sub Sun} to {approx}2 Multiplication-Sign 10{sup -2} M{sub Sun} for 1.2-1.5 M{sub Sun} systems (with kinetic energies between {approx}5 Multiplication-Sign 10{sup 49} erg and 10{sup 51} erg). Correspondingly, the bolometric peak luminosities of the optical transients of symmetric (asymmetric) mergers vary between 3 Multiplication-Sign 10{sup 41} erg s{sup -1} and 14 Multiplication-Sign 10{sup 41} erg s{sup -1} (9 Multiplication-Sign 10{sup 41} erg s{sup -1} and 14.5 Multiplication-Sign 10{sup 41} erg s{sup -1}) on timescales between {approx}2 hr and {approx}12 hr. If these signals with absolute bolometric magnitudes from -15.0 to -16.7 are measured, the tight correlation of their properties with those of the merging NSs might provide valuable constraints on the high-density EOS. The r-process nucleosynthesis exhibits a remarkable robustness independent of the EOS, producing a nearly solar abundance pattern above mass number 130. By the r-process content of the Galaxy and the average production per event the Galactic merger rate is limited to 4 Multiplication-Sign 10{sup -5} yr{sup -1} (4 Multiplication-Sign 10{sup -4} yr{sup -1}) for a soft (stiff) NS EOS, if NS mergers are the main source of heavy r-nuclei. The production ratio of radioactive {sup 232}Th to {sup 238}U attains a stable value of 1.64-1.67, which does not exclude NS mergers as potential sources of heavy r-material in the most metal-poor stars.

Bauswein, A.; Janka, H.-T. [Max Planck Institute for Astrophysics, Karl-Schwarzschild-Str. 1, D-85748 Garching (Germany); Goriely, S. [Institut d'Astronomie et d'Astrophysique, Universite Libre de Bruxelles, C.P. 226, B-1050 Brussels (Belgium)

2013-08-10T23:59:59.000Z

184

The r-process nucleosynthesis during the decompression of neutron star crust material  

SciTech Connect (OSTI)

About half of the nuclei heavier than iron observed in nature are produced by the so-called rapid neutron capture process, or r-process, of nucleosynthesis. The identification of the astrophysics site and the specific conditions in which the r-process takes place remains, however, one of the still-unsolved mysteries of modern astrophysics. Another underlying difficulty associated with our understanding of the r-process concerns the uncertainties in the predictions of nuclear properties for the few thousands exotic neutron-rich nuclei involved, for which essentially no experimental data exist. The present paper emphasizes some important future challenges faced by nuclear physics in this problem, particularly in the determination of the nuclear structure properties of exotic neutron-rich nuclei as well as their radiative neutron capture rates and their fission probabilities. These quantities are particularly relevant to determine the composition of the matter resulting from the r-process. Both the astrophysics and the nuclear physics difficulties are critically reviewed with special attention paid to the r-process taking place during the decompression of neutron star matter following the merging of two neutron stars.

Goriely, S. [Institut d'Astronomie et d'Astrophysique, CP-226, Université Libre de Bruxelles, 1050 Brussels (Belgium); Bauswein, A. [Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece and Max-Planck-Institut für Astrophysik, Postfach 1317, 85741 Garching (Germany); Janka, H.-T. [Max-Planck-Institut für Astrophysik, Postfach 1317, 85741 Garching (Germany); Sida, J.-L.; Lemaître, J.-F.; Panebianco, S. [C.E.A. Saclay, Irfu/Service de Physique Nucléaire, 91191 Gif-sur-Yvette (France); Dubray, N.; Hilaire, S. [CEA, DAM, DIF, F-91297 Arpajon (France)

2014-05-02T23:59:59.000Z

185

"Minds, Brains and Tools" (with a response by Daniel Dennett,) in Hugh Clapin (ed) PHILOSOPHY OF MENTAL REPRESENTATION (Clarendon Press, Oxford, 2002)  

E-Print Network [OSTI]

OF MENTAL REPRESENTATION (Clarendon Press, Oxford, 2002) Minds, Brains and Tools (Comments on Dennett small texts seemed to fit together and, collectively, to greatly illuminate the shape of Dennett's whole

Clark, Andy

186

1996 Oxford University Press 47094718Nucleic Acids Research, 1996, Vol. 24, No. 23 Logitlinear models for the prediction of splice sites in  

E-Print Network [OSTI]

© 1996 Oxford University Press 4709­4718Nucleic Acids Research, 1996, Vol. 24, No. 23 Logitlinear the degree of fit to some average signal pattern around known splice sites in a learning set (e.g., 3

Brendel, Volker

187

Can mirror matter solve the the cosmological lithium problem?  

SciTech Connect (OSTI)

The abundance of lithium-7 confronts cosmology with a long lasting inconsistency between the predictions of standard Big Bang Nucleosynthesis with the baryonic density determined from the Cosmic Microwave Background observations on the one hand, and the spectroscopic determination of the lithium-7 abundance on the other hand. We investigated the influence of the existence of a mirror world, focusing on models in which mirror neutrons can oscillate into ordinary neutrons. Such a mechanism allows for an effective late time neutron injection, which induces an increase of the destruction of beryllium-7and thus a lower final lithium-7 abundance.

Coc, Alain [Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), CNRS/IN2P3, Université Paris Sud 11, UMR 8609, Bâtiment 104, 91405 Orsay Campus (France); Uzan, Jean-Philippe; Vangioni, Elisabeth [Institut d'Astrophysique de Paris, UMR-7095 du CNRS, Université Pierre et Marie Curie, 98 bis bd Arago, 75014 Paris, France and Sorbonne Universités, Institut Lagrange de Paris, 98 bis bd Arago, 75014 Paris (France)

2014-05-02T23:59:59.000Z

188

Standard and non-standard primordial neutrinos  

E-Print Network [OSTI]

The standard cosmological model predicts the existence of a cosmic neutrino background with a present density of about 110 cm^{-3} per flavour, which affects big-bang nucleosynthesis, cosmic microwave background anisotropies, and the evolution of large scale structures. We report on a precision calculation of the cosmic neutrino background properties including the modification introduced by neutrino oscillations. The role of a possible neutrino-antineutrino asymmetry and the impact of non-standard neutrino-electron interactions on the relic neutrinos are also briefly discussed.

P. D. Serpico

2006-08-14T23:59:59.000Z

189

Radiological characterization survey results for Gaskill Hall, Miami University, Oxford, Ohio (OXO015)  

SciTech Connect (OSTI)

Between October 1952 and February 1957, National Lead of Ohio (NLO), a primary contractor for the Atomic Energy Commission (AEC), subcontracted certain uranium machining operations to Alba Craft Laboratory, Incorporated, located at 10-14 West Rose Avenue, Oxford, Ohio. In 1992, personnel from Oak Ridge National Laboratory (ORNL) confirmed the presence of residual radioactive materials from the AEC-related operations in and around the facility in amounts exceeding the applicable Department of Energy (DOE) guidelines. Although the amount of uranium found on the property posed little health hazard if left undisturbed, the levels were sufficient to require remediation to bring radiological conditions into compliance with current guidelines, thus ensuring that the public and the environment are protected. Because it was suspected that uranium may have been used in the past in the immediate vicinity of Alba Craft in a Miami University building a team from ORNL, performed a radiological characterization survey of that structure in January 1994. The survey was conducted at the request of DOE as a precautionary measure to ensure that no radioactive residuals were present at levels exceeding guidelines. The survey included the determination of directly measured radiation levels and the collection of smear samples to detect possible removable alpha and beta-gamma activity levels, and comparison of these data to the guidelines. Results of the survey showed that all measurements were below the applicable guideline limits set by DOE.

Kleinhans, K.R.; Murray, M.E.; Carrier, R.F.

1996-04-01T23:59:59.000Z

190

New Nuclear Reaction Flow during r-Process Nucleosynthesis in Supernovae: Critical Role of Light Neutron-Rich Nuclei  

E-Print Network [OSTI]

We study the role of light neutron-rich nuclei during r-process nucleosynthesis in supernovae. Most previous studies of the r-process have concentrated on the reaction flow of heavy unstable nuclei. Although the nuclear reaction network includes a few thousand heavy nuclei, only limited reaction flow through light-mass nuclei near the stability line has been used in those studies. However, in a viable scenario of the r-process in neutrino-driven winds, the initial condition is a high-entropy hot plasma consisting of neutrons, protons, and electron-positron pairs experiencing an intense flux of neutrinos. In such environments light-mass nuclei as well as heavy nuclei are expected to play important roles in the production of seed nuclei and r-process elements. Thus, we have extended our fully implicit nuclear reaction network so that it includes all nuclei up to the neutron drip line for Z $ \\leq 10$, in addition to a larger network for Z $ \\geq 10$. In the present nucleosynthesis study, we utilize a wind model of massive SNeII explosions to study the effects of this extended network. We find that a new nuclear-reaction flow path opens in the very light neutron-rich region. This new nuclear reaction flow can change the final heavy-element abundances by as much as an order of magnitude.

M. Terasawa; K. Sumiyoshi; T. Kajino; G. J. Mathews; I. Tanihata

2001-07-19T23:59:59.000Z

191

A review of "The Oxford Handbook of John Milton" edited by Nicholas McDowell and Nigel Smith  

E-Print Network [OSTI]

? essay attempts to o#12;er an original thesis as if the larger collection assumes an audience of both general readers and academic specialists. Indeed, the claim to o#12;er ?original scholarship? becomes a selling point, as in the case of #31;e Oxford... intensi#14;ed the crack-down on perceived copyright infringements, thereby making it more di#11;cult for instructors to include critical readings in their classes. To meet the demand for ready access to scholarship, academic publishers appear to have...

McDowell, Sean H.

2011-01-01T23:59:59.000Z

192

Non-Extensive Statistics, New Solution to the Cosmological Lithium Problem  

E-Print Network [OSTI]

In the primordial Big Bang nucleosynthesis (BBN), only the lightest nuclides (D, $^3$He, $^4$He, and $^7$Li) were synthesized in appreciable quantities, and these relics provide us a unique window on the early universe. Currently, BBN simulations give acceptable agreement between theoretical and observed abundances of D and $^4$He, but it is still difficult to reconcile the predicted $^7$Li abundance with the observation for the Galactic halo stars. The BBN model overestimates the primordial $^7$Li abundance by about a factor of three, so called the cosmological lithium problem, a long-lasting pending issue in BBN. Great efforts have been paid in the past decades, however, the conventional nuclear physics seems unable to resolve such problem. It is well-known that the classical Maxwell-Boltzmann (MB) velocity distribution has been usually assumed for nuclei in the Big-Bang plasma. In this work, we have thoroughly investigated the impact of non-extensive Tsallis statistics (deviating from the MB) on thermonuclear reaction rates involved in standard models of BBN. It shows that the predicted primordial abundances of D, $^4$He, and $^7$Li agree very well with those observed ones by introducing a non-extensive parameter $q$. It is discovered that the velocities of nuclei in a hot Big-Bang plasma indeed violate the classical Maxwell-Boltzmann (MB) distribution in a very small deviation of about 6.3--8.2%. Thus, we have for the first time found a new solution to the cosmological lithium problem without introducing any mysterious theories. Furthermore, the implications of non-extensive statistics in other exotic high-temperature and density astrophysical environments should be explored, which might offer new insight into the nucleosynthesis of heavy elements.

J. J. He; S. Q. Hou; A. Parikh; D. Kahl; C. A. Bertulani; other collaborators

2014-12-22T23:59:59.000Z

193

10/05/2013 10:34Cherwell.org -Oxford / News / Academic / The Hole Truth Page 1 of 2http://www.cherwell.org/news/academic/2013/05/09/the-hole-truth  

E-Print Network [OSTI]

Walsh has published 6 articles Photograph: WikiImages The Hole Truth New research by Oxford academics10/05/2013 10:34Cherwell.org - Oxford / News / Academic / The Hole Truth Page 1 of 2http://www.cherwell.org/news/academic Colleges Academic Town Worcester Provost battles with Exeter building plan Teddy Hall Earth Sciences dinner

Gardner, Andy

194

New neutron capture and total cross section measurements on {sup 88}Sr and their impact on s-process nucleosynthesis  

SciTech Connect (OSTI)

The authors have made new and improved measurements of the neutron capture and total cross sections of {sup 88}Sr at the Oak Ridge Electron Linear Accelerator (ORELA). Improvements over previous measurements include a wider incident neutron energy range, the use of metallic rather than carbonate samples, better background subtraction, reduced sensitivity to sample-dependent backgrounds, and better pulse-height weighting functions. Because of its small cross section, the {sup 88}Sr(n,{gamma}) reaction is an important bottleneck during the s-process nucleosynthesis. Hence, an accurate determination of this rate is needed to better constrain the neutron exposure in s-process models and to more fully exploit the recently discovered isotopic anomalies in certain meteorites. They describe the experimental procedures, compare the results to previous data, and discuss their astrophysical impact.

Koehler, P.E.; Spencer, R.R.; Guber, K.H. [and others

1998-11-01T23:59:59.000Z

195

The Sensitivity of Nucleosynthesis in Type I X-ray Bursts to Thermonuclear Reaction-Rate Variations  

E-Print Network [OSTI]

We examine the sensitivity of nucleosynthesis in Type I X-ray bursts to variations in nuclear rates. As a large number of nuclear processes are involved in these phenomena -with the vast majority of reaction rates only determined theoretically due to the lack of any experimental information- our results can provide a means for determining which rates play significant roles in the thermonuclear runaway. These results may then motivate new experiments. For our studies, we have performed a comprehensive series of one-zone post-processing calculations in conjunction with various representative X-ray burst thermodynamic histories. We present those reactions whose rate variations have the largest effects on yields in our studies.

Anuj Parikh; Jordi Jose; Fermin Moreno; Christian Iliadis

2008-06-18T23:59:59.000Z

196

Impact of neutrino flavor oscillations on the neutrino-driven wind nucleosynthesis of an electron-capture supernova  

E-Print Network [OSTI]

Neutrino oscillations, especially to light sterile states, can affect the nucleosynthesis yields because of their possible feedback effect on the electron fraction (Ye). For the first time, we perform nucleosynthesis calculations for neutrino-driven wind trajectories from the neutrino-cooling phase of an 8.8 Msun electron-capture supernova, whose hydrodynamic evolution was computed in spherical symmetry with sophisticated neutrino transport and whose Ye evolution was post-processed by including neutrino oscillations both between active and active-sterile flavors. We also take into account the alpha-effect as well as weak magnetism and recoil corrections in the neutrino absorption and emission processes. We observe effects on the Ye evolution which depend in a subtle way on the relative radial positions of the sterile MSW resonances, of collective flavor transformations, and on the formation of alpha-particles. For the adopted supernova progenitor, we find that neutrino oscillations, also to a sterile state with eV-mass, do not significantly affect the element formation and in particular cannot make the post-explosion wind outflow neutron rich enough to activate a strong r-process. Our conclusions become even more robust when, in order to mimic equation-of-state dependent corrections due to nucleon potential effects in the dense-medium neutrino opacities, four cases with reduced Ye in the wind are considered. In these cases, despite the conversion of neutrinos to sterile neutrinos, Ye increases compared to the values obtained without oscillations and active flavor transformations. This is a consequence of a complicated interplay between sterile-neutrino production, neutrino-neutrino interactions, alpha-effect.

Else Pllumbi; Irene Tamborra; Shinya Wanajo; H. -Thomas Janka; Lorenz Huedepohl

2014-06-11T23:59:59.000Z

197

A resolution of the cosmic Lithium problem  

E-Print Network [OSTI]

In 1982, Monique and Francois Spite discovered that the 7Li abundance in the atmosphere of old metal-poor dwarf stars in the galactic halo was independent of metallicity and temperature. Since then, 7Li abundance in the Universe has become a subject of intrigue, because there is less of it in Population II dwarf stars (by a factor of 3) than standard big bang nucleosynthesis predicts. Here we show how quark-novae (QNe) occurring in the wake of Pop. III stars, can elegantly produce an A(Li) ~ 2.2 Lithium plateau in Pop. II (low-mass) stars formed in the pristine cloud swept up by the mixed SN+QN ejecta. We also find an increase in the scatter as well as an eventual drop in A(Li) below the Spite plateau values for very low metallicity ([Fe/H] < -3) in excellent agreement with observations. We propose a solution to the discrepancy between the Big Bang Nucleosynthesis 7Li abundance and the Spite plateau and list some implications and predictions of our model.

Rachid Ouyed

2014-02-20T23:59:59.000Z

198

The Author 2012. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com Tree Physiology 32, 401413  

E-Print Network [OSTI]

© The Author 2012. Published by Oxford University Press. All rights reserved. For Permissions Research paper Xylem hydraulic adjustment and growth response of Quercus canariensis Willd. to climatic to more xeric conditions at low elevations by reducing radial growth and hydraulic diameter (DH

199

C-3/Oxford/Fish Locomotion/Fish Loco Chap 7/Fish Loco Settings/II/ Chap 7/11-04-09/200 Ecology and Evolution of  

E-Print Network [OSTI]

C-3/Oxford/Fish Locomotion/Fish Loco Chap 7/Fish Loco Settings/II/ Chap 7/11-04-09/200 Ecology and Evolution of Swimming Performance in Fishes: Predicting Evolution with Biomechanics R. Brian Langerhans1, * and David N. Reznick2 NT NINTRODUCTIONTN NINTRODUCTION Residing within the immense diversity of fishes

Langerhans, Brian

200

Near-UV Observations of CS29497-030: New Constraints on Neutron-Capture Nucleosynthesis Processes  

E-Print Network [OSTI]

Employing spectra obtained with the new Keck I HIRES near-UV sensitive detector, we have performed a comprehensive chemical composition analysis of the binary blue metal-poor star CS29497-030. Abundances for 29 elements and upper limits for an additional seven have been derived, concentrating on elements largely produced via neutron-capture nucleosynthesis. Included in our analysis are the two elements that define the termination point of the slow neutron-capture process, lead and bismuth. We determine an extremely high value of [Pb/Fe] = +3.65 +/- 0.07 (sigma = 0.13) from three features, supporting the single-feature result obtained in previous studies. We also detect Bi for the first time in a metal-poor star. Our derived Bi/Pb ratio is in accord with those predicted from the most recent FRANEC calculations of the slow neutron-capture process in low-mass AGB stars. We find that the neutron-capture elemental abundances of CS29497-030 are best explained by an AGB model that also includes very significant amounts of pre-enrichment of rapid neutron-capture process material in the protostellar cloud out of which the CS29497-030 binary system formed. Thus, CS29497-030 is both an ``r+s'' and ``extrinsic AGB'' star. Furthermore, we find that the mass of the AGB model can be further constrained by the abundance of the light odd-element [Na/Fe] which is sensitive to the neutron excess.

Inese I. Ivans; Christopher Sneden; Roberto Gallino; John J. Cowan; George W. Preston

2005-04-29T23:59:59.000Z

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201

Results of the radiological survey at the former Alba Craft Laboratory site properties, Oxford, Ohio (OXO001)  

SciTech Connect (OSTI)

At the request of the US Department of Energy (DOE), a team from Oak Ridge National Laboratory conducted a radiological survey at the former Alba Craft Laboratory Site Properties, Oxford, Ohio. The survey was performed in July and September of 1992. The purpose of the survey was to determine whether the property was contaminated with radioactive residues, primarily [sup 238]U, from uranium machining operations conducted for National Lead of Ohio, a prime Atomic Energy Commission contractor. The survey included scan measurement of direct radiation levels inside and outside the former laboratory, outdoors on eight properties adjoining the former laboratory, and the city right-of-way adjacent to the surveyed properties. Radionuclide concentrations were determined in outdoor surface and subsurface soil samples taken from each property and the exterior of the laboratory. Fixed surface residual radioactivity was measured inside the laboratory and outside the building. Air samples were collected, direct exposure was measured, and samples were collected to measure transferable radioactivity inside the building. Results of the survey indicate areas where surface and soil contamination level s are above the DOE guidelines for uncontrolled areas.

Murray, M.E.; Brown, K.S.; Mathis, R.A.

1993-03-01T23:59:59.000Z

202

Volume 5 Number 2 February 14, 2004 THE UNIVERSITY OF HONG KONG  

E-Print Network [OSTI]

), the big bang (the first moments of the universe), gamma ray bursts (the biggest explosions in the universe

Tam, Vincent W. L.

203

The Search for a Primordial Magnetic Field  

E-Print Network [OSTI]

Magnetic fields appear wherever plasma and currents can be found. As such, they thread through all scales in Nature. It is natural, therefore, to suppose that magnetic fields might have been formed within the high temperature environments of the big bang. Such a primordial magnetic field (PMF) would be expected to arise from and/or influence a variety of cosmological phenomena such as inflation, cosmic phase transitions, big bang nucleosynthesis, the cosmic microwave background (CMB) temperature and polarization anisotropies, the cosmic gravity wave background, and the formation of large-scale structure. In this review, we summarize the development of theoretical models for analyzing the observational consequences of a PMF. We also summarize the current state of the art in the search for observational evidence of a PMF. In particular we review the framework needed to calculate the effects of a PMF power spectrum on the CMB and the development of large scale structure. We summarize the current constraints on the PMF amplitude $B_\\lambda$ and the power spectral index $n_B$ and discuss prospects for better determining these quantities in the near future.

Dai G. Yamazaki; Toshitaka Kajino; Grant J. Mathew; Kiyotomo Ichiki

2012-04-16T23:59:59.000Z

204

Cosmological Deuterium Abundance and the Baryon Density of the Universe  

E-Print Network [OSTI]

Standard big bang nucleosynthesis (BBNS) promises accurate predictions of the primordial abundances of deuterium, helium-3, helium-4 and lithium-7 as a function of a single parameter. Previous measurements have nearly always been interpreted as confirmation of the model (Copi, Schramm & Turner 1995). Here we present a measurement of the deuterium to hydrogen ratio (D/H) in a newly discovered high redshift metal-poor gas cloud at redshift $z=2.504$. This confirms our earlier measurement of D/H (Tytler, Fan & Burles 1996), and together they give the first accurate measurement of the primordial D abundance, and a ten fold improvement in the accuracy of the cosmological density of ordinary matter.This is a high density, with most ordinary matter unaccounted or dark, which is too high to agree with measurements of the primordial abundances of helium-4 and lithium-7. Since the D/H measurement is apparently simple, direct, accurate and highly sensitive, we propose that helium requires a systematic correction, and that population II stars have less than the primordial abundance of $^7$Li. Alternatively, there is no concordance between the light element abundances, and the simple model of the big bang must be incomplete and lacking physics, or wrong.

Scott Burles; David Tytler

1996-03-19T23:59:59.000Z

205

Carbon-enhanced metal-poor stars: a window on AGB nucleosynthesis and binary evolution. I. Detailed analysis of 15 binary stars with known orbital periods  

E-Print Network [OSTI]

AGB stars are responsible for producing a variety of elements, including carbon, nitrogen, and the heavy elements produced in the slow neutron-capture process ($s$-elements). There are many uncertainties involved in modelling the evolution and nucleosynthesis of AGB stars, and this is especially the case at low metallicity, where most of the stars with high enough masses to enter the AGB have evolved to become white dwarfs and can no longer be observed. The stellar population in the Galactic halo is of low mass ($\\lesssim 0.85M_{\\odot}$) and only a few observed stars have evolved beyond the first giant branch. However, we have evidence that low-metallicity AGB stars in binary systems have interacted with their low-mass secondary companions in the past. The aim of this work is to investigate AGB nucleosynthesis at low metallicity by studying the surface abundances of chemically peculiar very metal-poor stars of the halo observed in binary systems. To this end we select a sample of 15 carbon- and $s$-element-en...

Abate, C; Karakas, A I; Izzard, R G

2015-01-01T23:59:59.000Z

206

The Oxford-Dartmouth Thirty Degree Survey I: Observations and Calibration of a Wide-Field Multi-Band Survey  

E-Print Network [OSTI]

The Oxford Dartmouth Thirty Degree Survey (ODTS) is a deep, wide, multi-band imaging survey designed to cover a total of 30 square degrees in BVRi'Z, with a subset of U and K band data, in four separate fields of 5-10 deg^2 centred at 00:18:24 +34:52, 09:09:45 +40:50, 13:40:00 +02:30 and 16:39:30 +45:24. Observations have been made using the Wide Field Camera on the 2.5-m Isaac Newton Telescope in La Palma to average limiting depths (5 sigma Vega, aperture magnitudes) of U=24.8, B=25.6, V=25.0, R=24.6, and i'=23.5, with observations taken in ideal conditions reaching the target depths of U=25.3, B=26.2, V=25.7, R=25.4, and i'=24.6. The INT Z band data was found to be severely effected by fringing and, consequently, is now being obtained at the MDM observatory in Arizona. A complementary K-band survey has also been carried out at MDM, reaching an average depth of K_{5\\sigma}~18.5. At present, approximately 23 deg^2 of the ODTS have been observed, with 3.5 deg^2 of the K band survey completed. This paper details the survey goals, field selection, observation strategy and data reduction procedure, focusing on the photometric calibration and catalogue construction. Preliminary photometric redshifts have been obtained for a subsample of the objects with R <= 23. These results are presented alongside a brief description of the photometric redshift determination technique used. The median redshift of the survey is estimated to be z~0.7 from a combination of the ODTS photometric redshifts and comparison with the redshift distributions of other surveys. Finally, galaxy number counts for the ODTS are presented which are found to be in excellent agreement with previous studies.

Emily C. MacDonald; Paul Allen; Gavin Dalton; Leonidas A. Moustakas; Catherine Heymans; Edward Edmondson; Chris Blake; Lee Clewley; Molly C. Hammell; Ed Olding; Lance Miller; Steve Rawlings; Jasper Wall; Gary Wegner; Christian Wolf; .

2004-05-11T23:59:59.000Z

207

Oxford System 400  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006 The 2002Optics GroupPlanning Workshop Overview ofOverview

208

Ecology to evolution, marine biology to molecular biology: Oxford's prestigious Life Science journals uncover the extraordinary scope of life on our planet. Our diverse range of titles includes Annals of Botany, the Journal of  

E-Print Network [OSTI]

service including offsite access (46 titles) 1. Forest & Conservation History and Environmental History Review merged in 1996 to become Environmental History 2. Previously named Journal of Electron Microscopy library. The Oxford Journals Life Sciences Collection 2014 Impact Factors taken from the 2012 Journal

Kaski, Samuel

209

Blackwell Publishing, Ltd.Oxford, UKAPELAsian-Pacific Economic Literature0818-9935 2005 Asia Pacific School of Economics and Government, The Australian National University and Blackwell Publishing Asia Pty LtdNovember 2005192ORIGINAL ARTICLEROLAND-HOLST a  

E-Print Network [OSTI]

18 Blackwell Publishing, Ltd.Oxford, UKAPELAsian-Pacific Economic Literature0818-9935© 2005 Asia Pacific School of Economics and Government, The Australian National University and Blackwell Publishing and ITS NEIGHBOURSASIAN-PACIFIC ECONOMIC LITERATURE People's Republic of China and its Neighbours

Kammen, Daniel M.

210

A loophole to the universal photon spectrum in electromagnetic cascades: application to the "cosmological lithium problem"  

E-Print Network [OSTI]

The standard theory of electromagnetic cascades onto a photon background predicts a quasi-universal shape for the resulting non-thermal photon spectrum. This has been applied to very disparate fields, including non-thermal big bang nucleosynthesis (BBN). However, once the energy of the injected photons falls below the pair-production threshold the spectral shape is very different, a fact that has been overlooked in past literature. This loophole may have important phenomenological consequences, since it generically alters the BBN bounds on non-thermal relics: for instance it allows to re-open the possibility of purely electromagnetic solutions to the so-called "cosmological lithium problem", which were thought to be excluded by other cosmological constraints. We show this with a proof-of-principle example and a simple particle physics model, compared with previous literature.

Poulin, Vivian

2015-01-01T23:59:59.000Z

211

A loophole to the universal photon spectrum in electromagnetic cascades: application to the "cosmological lithium problem"  

E-Print Network [OSTI]

The standard theory of electromagnetic cascades onto a photon background predicts a quasi-universal shape for the resulting non-thermal photon spectrum. This has been applied to very disparate fields, including non-thermal big bang nucleosynthesis (BBN). However, once the energy of the injected photons falls below the pair-production threshold the spectral shape is very different, a fact that has been overlooked in past literature. This loophole may have important phenomenological consequences, since it generically alters the BBN bounds on non-thermal relics: for instance it allows to re-open the possibility of purely electromagnetic solutions to the so-called "cosmological lithium problem", which were thought to be excluded by other cosmological constraints. We show this with a proof-of-principle example and a simple particle physics model, compared with previous literature.

Vivian Poulin; Pasquale D. Serpico

2015-03-04T23:59:59.000Z

212

Bose and Fermi gases in the early Universe with self-gravitational effect  

SciTech Connect (OSTI)

We study the self-gravitational effect on the equation of state (EoS) of Bose and Fermi gases in thermal equilibrium at the end of reheating, the period after quark-hadron transition and before big bang nucleosynthesis (BBN). After introducing new grand canonical partition functions based on the work of Uhlenbeck and Gropper, we notice some interesting features of the newly developed EoSs with distinct behaviors of relativistic and nonrelativistic gases under self-gravity. The usual negligence of the self-gravitational effect when solving the background expansion of the early Universe is justified with numerical results, showing the magnitude of the self-gravitational modification of the state constant to be less than O(10{sup -78}). This helps us to clarify the background thermal evolution of the primordial patch. Such clarification is crucial in testing gravity theories, evaluating inflation models and determining element abundances in BBN.

Niu Yuezhen; Huang Junwu; Ma Boqiang [School of Physics and State Keye Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China) and Center for High Energy Physics, Peking University, Beijing 100871 (China) and Center for History and Philosophy of Science, Peking University, Beijing 100871 (China)

2011-03-15T23:59:59.000Z

213

WIMP Dark Matter Limit-Direct Detection Data and Sensitivity Plots from the Cryogenic Dark Matter Search II and the University of California at Santa Barbara  

DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

Expectations for non-baryonic dark matter are founded principally in Big Bang nucleosynthesis calculations, which indicate that the missing mass of the universe is not likely to be baryonic. The supersymmetric standard model (SUSY) offers a promising framework for expectations of particle species which could satisfy the observed properties of dark matter. WIMPs are the most likely SUSY candidate for a dark matter particle. The High Energy Physics Group at University of California, Santa Barbara, is part of the CDMSII Collaboration and have provided the Interactive Plotter for WIMP Dark Matter Limit-Direct Detection Data on their website. They invite other collaborations working on dark matter research to submit datasets and, as a result, have more than 150 data sets now available for use with the plotting tool. The published source of the data is provided with each data set.

214

Spherically symmetric cosmological spacetimes with dust and radiation — numerical implementation  

SciTech Connect (OSTI)

We present new numerical cosmological solutions of the Einstein Field Equations. The spacetime is spherically symmetric with a source of dust and radiation approximated as a perfect fluid. The dust and radiation are necessarily non-comoving due to the inhomogeneity of the spacetime. Such a model can be used to investigate non-linear general relativistic effects present during decoupling or big-bang nucleosynthesis, as well as for investigating void models of dark energy with isocurvature degrees of freedom. We describe the full evolution of the spacetime as well as the redshift and luminosity distance for a central observer. After demonstrating accuracy of the code, we consider a few example models, and demonstrate the sensitivity of the late time model to the degree of inhomogeneity of the initial radiation contrast.

Lim, Woei Chet [Department of Mathematics, University of Waikato, Private Bag 3105, Hamilton 3240 (New Zealand); Regis, Marco [Dipartimento di Fisica, Università di Torino and INFN, Torino (Italy); Clarkson, Chris, E-mail: wclim@waikato.ac.nz, E-mail: regis@to.infn.it, E-mail: chris.clarkson@gmail.com [Astrophysics, Cosmology and Gravity Centre, and Department of Mathematics and Applied Mathematics, University of Cape Town, Rondebosch 7701, Cape Town (South Africa)

2013-10-01T23:59:59.000Z

215

A loophole to the universal photon spectrum in electromagnetic cascades: application to the "cosmological lithium problem"  

E-Print Network [OSTI]

The standard theory of electromagnetic cascades onto a photon background predicts a quasi-universal shape for the resulting non-thermal photon spectrum. This has been applied to very disparate fields, including non-thermal big bang nucleosynthesis (BBN). However, once the energy of the injected photons falls below the pair-production threshold the spectral shape is very different, a fact that has been overlooked in past literature. This loophole may have important phenomenological consequences, since it generically alters the BBN bounds on non-thermal relics: for instance it allows to re-open the possibility of purely electromagnetic solutions to the so-called "cosmological lithium problem", which were thought to be excluded by other cosmological constraints. We show this with a proof-of-principle example and a simple particle physics model, compared with previous literature.

Vivian Poulin; Pasquale D. Serpico

2015-02-04T23:59:59.000Z

216

WMAPping out Neutrino Masses  

E-Print Network [OSTI]

Recent data from from the Wilkinson Microwave Anisotropy Probe (WMAP) place important bounds on the neutrino sector. The precise determination of the baryon number in the universe puts a strong constraint on the number of relativistic species during Big-Bang Nucleosynthesis. WMAP data, when combined with the 2dF Galaxy Redshift Survey (2dFGRS), also directly constrain the absolute mass scale of neutrinos. These results impinge upon a neutrino oscillation interpretation of the result from the Liquid Scintillator Neutrino Detector (LSND). We also note that the Heidelberg--Moscow evidence for neutrinoless double beta decay is only consistent with the WMAP+2dFGRS data for the largest values of the nuclear matrix element.

Aaron Pierce; Hitoshi Murayama

2003-10-28T23:59:59.000Z

217

Bimetric gravity is cosmologically viable  

E-Print Network [OSTI]

Bimetric theory describes gravitational interactions in the presence of an extra spin-2 field. Previous work has suggested that its cosmological solutions are generically plagued by instabilities. We show that by taking the Planck mass for the second metric, $M_f$, to be small, these instabilities can be pushed back to unobservably early times. In this limit, the theory approaches general relativity with an effective cosmological constant which is, remarkably, determined by the spin-2 interaction scale. This provides a late-time expansion history which is extremely close to $\\Lambda$CDM, but with a technically-natural value for the cosmological constant. We find $M_f$ should be no larger than the electroweak scale in order for cosmological perturbations to be stable by big-bang nucleosynthesis.

Akrami, Yashar; Könnig, Frank; Schmidt-May, Angnis; Solomon, Adam R

2015-01-01T23:59:59.000Z

218

The 3He(alpha,gamma)7Be S-factor at solar energies: the prompt gamma experiment at LUNA  

E-Print Network [OSTI]

The 3He(alpha,gamma)7Be process is a key reaction in both Big-Bang nucleosynthesis and p-p chain of Hydrogen Burning in Stars. A new measurement of the 3He(alpha,gamma)7Be cross section has been performed at the INFN Gran Sasso underground laboratory by both the activation and the prompt gamma detection methods. The present work reports full details of the prompt gamma detection experiment, focusing on the determination of the systematic uncertainty. The final data, including activation measurements at LUNA, are compared with the results of the last generation experiments and two different theoretical models are used to obtain the S-factor at solar energies.

H. Costantini; D. Bemmerer; F. Confortola; A. Formicola; Gy. Gyürky; P. Bezzon; R. Bonetti; C. Broggini; P. Corvisiero; Z. Elekes; Zs. Fülöp; G. Gervino; A. Guglielmetti; C. Gustavino; G. Imbriani; M. Junker; M. Laubenstein; A. Lemut; B. Limata; V. Lozza; M. Marta; R. Menegazzo; P. Prati; V. Roca; C. Rolfs; C. Rossi Alvarez; E. Somorjai; O. Straniero; F. Strieder; F. Terrasi; H. P. Trautvetter

2008-09-30T23:59:59.000Z

219

Blue-tilted Tensor Spectrum and Thermal History of the Universe  

E-Print Network [OSTI]

We investigate constraints on the spectral index of primordial gravitational waves (GWs), paying particular attention to a blue-tilted spectrum. Such constraints can be used to test a certain class of models of the early Universe. We investigate observational bounds from LIGO+Virgo, pulsar timing and big bang nucleosynthesis, taking into account the suppression of the amplitude at high frequencies due to reheating after inflation and also late-time entropy production. Constraints on the spectral index are presented by changing values of parameters such as reheating temperatures and the amount of entropy produced at late time. We also consider constraints under the general modeling approach which can approximately describe various scenarios of the early Universe. We show that the constraints on the blue spectral tilt strongly depend on the underlying assumption and, in some cases, a highly blue-tilted spectrum can still be allowed.

Sachiko Kuroyanagi; Tomo Takahashi; Shuichiro Yokoyama

2014-07-17T23:59:59.000Z

220

Archeops: an instrument for present and future cosmology  

E-Print Network [OSTI]

Archeops is a balloon-borne instrument dedicated to measure the cosmic microwave background (CMB) temperature anisotropies. It has, in the millimetre domain (from 143 to 545 GHz), a high angular resolution (about 10 arcminutes) in order to constrain high l multipoles, as well as a large sky coverage fraction (30%) in order to minimize the cosmic variance. It has linked, before WMAP, Cobe large angular scales to the first acoustic peak region. From its results, inflation motivated cosmologies are reinforced with a flat Universe (Omega_tot=1 within 3%). The dark energy density and the baryonic density are in very good agreement with other independent estimations based on supernovae measurements and big bang nucleosynthesis. Important results on galactic dust emission polarization and their implications for Planck are also addressed.

M. Tristram

2003-09-12T23:59:59.000Z

Note: This page contains sample records for the topic "oxford big-bang nucleosynthesis" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Results of the independent radiological verification survey of the remedial action performed at 525 S. Main Street, Oxford, Ohio, (OXO002)  

SciTech Connect (OSTI)

Between October 1952 and February 1957, National Lead of Ohio (NLO), a primary contractor for the Atomic Energy Commission (AEC), subcontracted certain uranium machining operations to Alba Craft Laboratory, Incorporated, located at 10-14 West Rose Avenue, Oxford, Ohio. In 1992, personnel from Oak Ridge National Laboratory (ORNL) confirmed the presence of residual radioactive materials from the AEC-related operations in and around the facility in amounts exceeding the applicable Department of Energy (DOE) guidelines. Above-guideline radiation levels were also found both indoors and outdoors at 525 S. Main Street, a private residential property in the immediate vicinity of the Alba Craft site. This document reports the findings at this private residence. Although the amount of uranium found on the properties posed little health hazard if left undisturbed, the levels were sufficient to require remediation to bring radiological conditions into compliance with current guidelines, thus ensuring that the public and the environment are protected. A team from ORNL conducted a radiological verification survey of the property at 525 S. Main Street, between November 1993 and December 1994. The survey was conducted at the request of DOE and included directly measured radiation levels, the collection and analysis of soil samples to determine concentrations of uranium and certain other radionuclides, and comparison of these data to the guidelines.

Kleinhans, K.R.; Rice, D.E.; Murray, M.E.; Carrier, R.F.

1996-04-01T23:59:59.000Z

222

The Oxford-Dartmouth Thirty Degree Survey II: Clustering of Bright Lyman Break Galaxies - Strong Luminosity Dependent Bias at z=4  

E-Print Network [OSTI]

We present measurements of the clustering properties of bright ($L>L_{*}$) z$\\sim$4 Lyman Break Galaxies (LBGs) selected from the Oxford-Dartmouth Thirty Degree Survey (ODT). We describe techniques used to select and evaluate our candidates and calculate the angular correlation function which we find best fitted by a power law, $\\omega(\\theta)=A_{w}\\theta^{-\\beta}$ with $A_{w}=15.4$ (with $\\theta$ in arcseconds), using a constrained slope of $\\beta=0.8$. Using a redshift distribution consistent with photometric models, we deproject this correlation function and find a comoving $r_{0}=11.4_{-1.9}^{+1.7}$ h$_{100}^{-1}$ Mpc in a $\\Omega_m=0.3$ flat $\\Lambda$ cosmology for $i_{AB}\\leq24.5$. This corresponds to a linear bias value of $b=8.1_{-2.6}^{+2.0}$ (assuming $\\sigma_{8}=0.9$). These data show a significantly larger $r_{0}$ and $b$ than previous studies at $z\\sim4$. We interpret this as evidence that the brightest LBGs have a larger bias than fainter ones, indicating a strong luminosity dependence for the measured bias of an LBG sample. Comparing this against recent results in the literature at fainter (sub-$L_{*}$) limiting magnitudes, and with simple models describing the relationship between LBGs and dark matter haloes, we discuss the implications on the implied environments and nature of LBGs. It seems that the brightest LBGs (in contrast with the majority sub-$L_{*}$ population), have clustering properties, and host dark matter halo masses, that are consistent with them being progenitors of the most massive galaxies today.

Paul D. Allen; Leonidas A. Moustakas; Gavin Dalton; Emily MacDonald; Chris Blake; Lee Clewley; Catherine Heymans; Gary Wegner

2005-05-02T23:59:59.000Z

223

New Blog Seeks Out the "Next Big Thing" | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

Money This image shows the barred spiral galaxy NGC 1398. | Image courtesy of the Dark Energy Survey. Supercomputing: A Toolbox to Simulate the Big Bang and Beyond...

224

Secretary Chu Announces New Institute to Help Scientists Improve...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Articles This image shows the barred spiral galaxy NGC 1398. | Image courtesy of the Dark Energy Survey. Supercomputing: A Toolbox to Simulate the Big Bang and Beyond New...

225

E-Print Network 3.0 - astrophysically relevant energies Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

environments ranging from the Big Bang to the inner workings... to determine thermonuclear reaction rates and Q-values to determine ... Source: Controlled Fusion Atomic Data...

226

Can We Observe Galaxies that Recede Faster than Light ? -- A More Clear-Cut Answer  

E-Print Network [OSTI]

A more clear-cut answer to the title question is, ``Yes'' if the universal expansion started with a big bang; ``No'' if it started infinitely slowly.

T. Kiang

2003-05-27T23:59:59.000Z

227

OXFORD CITY COUNCIL Emily Green  

E-Print Network [OSTI]

and ConservationEnvironmental Sustainability Officer Environmental Development Subject Former Ruskin College Site application for the former Ruskin College Site on Walton Street. The desk study did not reveal any significant. Emily Green Environmental Sustainability Officer #12;

Flynn, E. Victor

228

Oxford, Ohio, Site Fact Sheet  

Office of Legacy Management (LM)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarlyEnergyDepartment ofDepartment ofof EnergyYou$0.C. 20545*.MSE Cores" _August

229

Oxford Innovation | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy ResourcesLoading map...(UtilityCounty,Orleans County, Vermont:OttawaCounty, IndianaOwlsInnovation Place:

230

Oxford Solar | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy ResourcesLoading map...(UtilityCounty,Orleans County, Vermont:OttawaCounty, IndianaOwlsInnovation

231

www.newphytologist.org 1 Blackwell Publishing LtdOxford, UKNPHNew Phytologist0028-646X The Authors (2007). Journal compilation New Phytologist (2007)232010.1111/j.1469-8137.2007.02320.xNovember 2007001???14???MethodsMethods Methods  

E-Print Network [OSTI]

www.newphytologist.org 1 Research Blackwell Publishing LtdOxford, UKNPHNew Phytologist0028-646X© The Authors (2007). Journal compilation © New Phytologist (2007)232010.1111/j.1469-8137.2007.02320.x phylogenetic analyses reveal some inconsistencies in species concepts in these taxonomically challenging

Taylor, Lee

232

Cosmic Data Fusion  

E-Print Network [OSTI]

We compare and combine likelihood functions of the cosmological parameters Omega_m, h and sigma_8 from the CMB, type Ia supernovae and from probes of large scale structure. We include the recent results from the CMB experiments BOOMERANG and MAXIMA-1. Our analysis assumes a flat LambdaCDM cosmology with a scale-invariant adiabatic initial power spectrum. First we consider three data sets that directly probe the mass in the Universe, without the need to relate the galaxy distribution to the underlying mass via a `biasing' relation: peculiar velocities, CMB and supernovae. We assume a baryonic fraction as inferred from Big-Bang Nucleosynthesis and find that all three data sets agree well, overlapping significantly at the 2-sigma level. This therefore justifies a joint analysis, in which we find a joint best fit point and 95% confidence limits of Omega_m=0.28 (0.17,0.39), h=0.74 (0.64,0.86), and sigma_8=1.17 (0.98,1.37). Secondly we extend our earlier work on combining CMB, supernovae, cluster number counts, IRAS galaxy redshift survey data to include BOOMERANG and MAXIMA-1 data and to allow a free Omega_b h^2. We find that, given our assumption of a scale invariant initial power spectrum (n=1), we obtain the robust result of Omega_b h^2= 0.031 +/- 0.03, which is dominated by the CMB constraint.

S. L. Bridle

2000-12-22T23:59:59.000Z

233

Using BBN in cosmological parameter extraction from CMB: a forecast for Planck  

E-Print Network [OSTI]

Data from future high-precision Cosmic Microwave Background (CMB) measurements will be sensitive to the primordial Helium abundance $Y_p$. At the same time, this parameter can be predicted from Big Bang Nucleosynthesis (BBN) as a function of the baryon and radiation densities, as well as a neutrino chemical potential. We suggest to use this information to impose a self-consistent BBN prior on $Y_p$ and determine its impact on parameter inference from simulated Planck data. We find that this approach can significantly improve bounds on cosmological parameters compared to an analysis which treats $Y_p$ as a free parameter, if the neutrino chemical potential is taken to vanish. We demonstrate that fixing the Helium fraction to an arbitrary value can seriously bias parameter estimates. Under the assumption of degenerate BBN (i.e., letting the neutrino chemical potential $\\xi$ vary), the BBN prior's constraining power is somewhat weakened, but nevertheless allows us to constrain $\\xi$ with an accuracy that rivals bounds inferred from present data on light element abundances.

Jan Hamann; Julien Lesgourgues; Gianpiero Mangano

2008-03-05T23:59:59.000Z

234

Measuring the Neutron Lifetime Using Magnetically Trapped Neutrons  

E-Print Network [OSTI]

The neutron beta-decay lifetime plays an important role both in understanding weak interactions within the framework of the Standard Model and in theoretical predictions of the primordial abundance of 4He in Big Bang Nucleosynthesis. In previous work, we successfully demonstrated the trapping of ultracold neutrons (UCN) in a conservative potential magnetic trap. A major upgrade of the apparatus is nearing completion at the National Institute of Standards and Technology Center for Neutron Research (NCNR). In our approach, a beam of 0.89 nm neutrons is incident on a superfluid 4He target within the minimum field region of an Ioffe-type magnetic trap. A fraction of the neutrons is downscattered in the helium to energies <200 neV, and those in the appropriate spin state become trapped. The inverse process is suppressed by the low phonon density of helium at temperatures less than 200 mK, allowing the neutron to travel undisturbed. When the neutron decays the energetic electron ionizes the helium, producing scintillation light that is detected using photomultiplier tubes. Statistical limitations of the previous apparatus will be alleviated by significant increases in field strength and trap volume resulting in twenty times more trapped neutrons.

C. M. O'Shaughnessy; R. Golub; K. W. Schelhammer; C. M. Swank; P. -N. Seo; P. R. Huffman; S. N. Dzhosyuk; C. E. H. Mattoni; L. Yang; J. M. Doyle; K. J. Coakley; A. K. Thompson; H. P. Mumm; S. K. Lamoreaux; G. Yang

2009-03-31T23:59:59.000Z

235

Measuring the Neutron Lifetime Using Magnetically Trapped Neutrons  

E-Print Network [OSTI]

The neutron beta-decay lifetime plays an important role both in understanding weak interactions within the framework of the Standard Model and in theoretical predictions of the primordial abundance of 4He in Big Bang Nucleosynthesis. In previous work, we successfully demonstrated the trapping of ultracold neutrons (UCN) in a conservative potential magnetic trap. A major upgrade of the apparatus is nearing completion at the National Institute of Standards and Technology Center for Neutron Research (NCNR). In our approach, a beam of 0.89 nm neutrons is incident on a superfluid 4He target within the minimum field region of an Ioffe-type magnetic trap. A fraction of the neutrons is downscattered in the helium to energies <200 neV, and those in the appropriate spin state become trapped. The inverse process is suppressed by the low phonon density of helium at temperatures less than 200 mK, allowing the neutron to travel undisturbed. When the neutron decays the energetic electron ionizes the helium, producing sci...

O'Shaughnessy, C M; Schelhammer, K W; Swank, C M; Seo, P -N; Huffman, P R; Dzhosyuk, S N; Mattoni, C E H; Yang, L; Doyle, J M; Coakley, K J; Thompson, A K; Mumm, H P; Lamoreaux, S K; Yang, G

2009-01-01T23:59:59.000Z

236

On the lithium dip in the metal poor open cluster NGC 2243  

SciTech Connect (OSTI)

Lithium is a key element for studying the mixing mechanisms operating in stellar interiors. It can also be used to probe the chemical evolution of the Galaxy and the Big Bang nucleosynthesis. Measuring the abundance of Lithium in stars belonging to Open Clusters (hereafter OC) allows a detailed comparison with stellar evolutionary models. NGC 2243 is particularly interesting thanks to its relative low metallicity ([Fe/H]=?0.54 ± 0.10 dex). We performed a detailed analysis of high-resolution spectra obtained with the multi-object facility FLAMES at the VLT 8.2m telescope. Lithium abundance has been measured in 27 stars. We found a Li dip center of 1.06 M{sub ?}, which is significantly smaller than that observed in solar metallicity and metal-rich clusters. This finding confirms and strengthens the conclusion that the mass of the stars in the Li dip strongly depends on stellar metallicity. The mean Li abundance of the cluster is log n(Li) = 2.70 dex, which is substantially higher than that observed in 47 Tue. We derived an iron abundance of [Fe/H]=?0.54±0.10 dex for NGC 2243, in agreement (within the errors) with previous findings.

François, P. [GEPI, Paris-Meudon Observatory, 61 Avenue de l'Observatoire, F-75014 Paris (France); Pasquini, L.; Palsa, R. [ESO, European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching bei München (Germany); Biazzo, K. [INAF, Capodimonte Astronomical Observatory, via Moiariello 16, 80131 Naples (Italy); Bonifacio, P. [GEPI, Paris-Meudon Observatory, Place Jules Janssen 92190, Meudon (France)

2014-05-02T23:59:59.000Z

237

The Primordial Lithium Problem  

E-Print Network [OSTI]

Big-bang nucleosynthesis (BBN) theory, together with the precise WMAP cosmic baryon density, makes tight predictions for the abundances of the lightest elements. Deuterium and 4He measurements agree well with expectations, but 7Li observations lie a factor 3-4 below the BBN+WMAP prediction. This 4-5\\sigma\\ mismatch constitutes the cosmic "lithium problem," with disparate solutions possible. (1) Astrophysical systematics in the observations could exist but are increasingly constrained. (2) Nuclear physics experiments provide a wealth of well-measured cross-section data, but 7Be destruction could be enhanced by unknown or poorly-measured resonances, such as 7Be + 3He -> 10C^* -> p + 9B. (3) Physics beyond the Standard Model can alter the 7Li abundance, though D and 4He must remain unperturbed; we discuss such scenarios, highlighting decaying Supersymmetric particles and time-varying fundamental constants. Present and planned experiments could reveal which (if any) of these is the solution to the problem.

Brian D. Fields

2012-03-15T23:59:59.000Z

238

Explosive lithium production in the classical nova V339 Del (Nova Delphini 2013)  

E-Print Network [OSTI]

The origin of lithium (Li) and its production process have long been an unsettled question in cosmology and astrophysics. Candidates environments of Li production events or sites suggested by previous studies include big bang nucleosynthesis, interactions of energetic cosmic rays with interstellar matter, evolved low mass stars, novae, and supernova explosions. Chemical evolution models and observed stellar Li abundances suggest that at least half of the present Li abundance may have been produced in red giants, asymptotic giant branch (AGB) stars, and novae. However, no direct evidence for the supply of Li from stellar objects to the Galactic medium has yet been found. Here we report on the detection of highly blue-shifted resonance lines of the singly ionized radioactive isotope of beryllium, $^{7}$Be, in the near ultraviolet (UV) spectra of the classical nova V339 Del (Nova Delphini 2013). Spectra were obtained 38 to 48 days after the explosion. $^{7}$Be decays to form $^{7}$Li within a short time (half-li...

Tajitsu, Akito; Naito, Hiroyuki; Arai, Akir; Aoki, Wako

2015-01-01T23:59:59.000Z

239

An Improved Reaction Rate Formulation for Charged-Particle Induced Thermonuclear Reaction of {sup 2}H(d,{gamma}){sup 4}He  

SciTech Connect (OSTI)

The reaction rate formula utilized in compilations such as the Nuclear Astrophysics Compilation of Reaction Rates (NACRE) uses low energy approximation due to temperatures in stars are in the region of a few keVs. Most nuclear reaction experiments were done in MeV range and the interior temperatures of massive stars are {approx}10{sup 9} K. Hence an improved formulation for calculating the nuclear reaction rate that is applicable to high temperatures is discussed in this work. The exact tunneling probability that is applicable for all energies is obtained by solving the Schroedinger equation. This yields an enhanced expression for the astrophysical S-factor for calculating the thermonuclear reaction rate at high temperature. The thermonuclear reaction rate from this work is applied to the {sup 2}H(d,{gamma}){sup 4}He reaction and is compared with the NACRE compilation. This improved reaction rate can be included in the nuclear reaction network in a Big Bang nucleosynthesis (BBN) code or a stellar nuclear network code.

Aziz, Azni Abdul; Yusof, Norhasliza; Idris, Mahirah; Kassim, Hasan Abu [Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia)

2011-03-30T23:59:59.000Z

240

Radiative neutron capture on 9be, 14c, 14n, 15n and 16o at thermal and astrophysical energies  

E-Print Network [OSTI]

The total cross sections of the radiative neutron capture processes on 9Be, 14C, 14N, 15N, and 16O are described in the framework of the modified potential cluster model with the classification of orbital states according to Young tableaux. The continued interest in the study of these reactions is due, on the one hand, to the important role played by this process in the analysis of many fundamental properties of nuclei and nuclear reactions, and, on the other hand, to the wide use of the capture cross section data in the various applications of nuclear physics and nuclear astrophysics, and, also, to the importance of the analysis of primordial nucleosynthesis in the Universe. This article is devoted to the description of results for the processes of the radiative neutron capture on certain light atomic nuclei at thermal and astrophysical energies. The considered capture reactions are not part of stellar thermonuclear cycles, but involve in the reaction chains of inhomogeneous Big Bang models.

Sergey Dubovichenko; Albert Dzhazairov-Kakhramanov; Nadezhda Afanasyeva

2014-01-28T23:59:59.000Z

Note: This page contains sample records for the topic "oxford big-bang nucleosynthesis" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

New Bounds for Axions and Axion-Like Particles with keV-GeV Masses  

E-Print Network [OSTI]

We give updated constraints on hypothetical light bosons with a two-photon coupling such as axions or axion-like particles (ALPs). We focus on masses and lifetimes where decays happen near big bang nucleosynthesis (BBN), thus altering the baryon-to-photon ratio and number of relativistic degrees of freedom between the BBN epoch and the cosmic microwave background (CMB) last scattering epoch, in particular such that $N_{\\rm eff}^{\\rm CMB} 3\\sigma$ by the combination of CMB+D/H measurements if only ALPs and three thermalized neutrino species contribute to $N_{\\rm eff}$. The bound relaxes if there are additional light degrees of freedom present which, in this scenario, have their contribution limited to $\\Delta N_{\\rm eff}=1.1\\pm0.3$. We give forecasts showing that a number of experiments are expected to reach the sensitivity needed to further test this region, such as Stage-IV CMB and SUPER-KEKB, the latter a direct test insensitive to any extra degrees of freedom.

Millea, Marius; Fields, Brian

2015-01-01T23:59:59.000Z

242

Neutrinoless double-beta decay with three or four neutrino mixing  

E-Print Network [OSTI]

Considering the scheme with mixing of three neutrinos and a mass hierarchy that can accommodate the results of solar and atmospheric neutrino experiments, it is shown that the results of solar neutrino experiments imply a lower bound for the effective Majorana mass in neutrinoless double-beta decay, under the natural assumptions that massive neutrinos are Majorana particles and there are no unlikely fine-tuned cancellations among the contributions of the different neutrino masses. Considering the four-neutrino schemes that can accommodate also the results of the LSND experiment, it is shown that only one of them is compatible with the results of neutrinoless double-beta decay experiments and with the measurement of the abundances of primordial elements produced in Big-Bang Nucleosynthesis. It is shown that in this scheme, under the assumptions that massive neutrinos are Majorana particles and there are no cancellations among the contributions of the different neutrino masses, the results of the LSND experiment imply a lower bound for the effective Majorana mass in neutrinoless double-beta decay.

C. Giunti

1999-08-27T23:59:59.000Z

243

Spatial Variability in the Ratio of Interstellar Atomic Deuterium to Hydrogen. I. Observations toward delta Orionis by the Interstellar Medium Absorption Profile Spectrograph  

E-Print Network [OSTI]

Studies of the abundances of deuterium in different astrophysical sites are of fundamental importance to answering the question about how much deuterium was produced during big bang nucleosynthesis and what fraction of it was destroyed later. With this in mind, we used the Interstellar Medium Absorption Profile Spectrograph (IMAPS) on the ORFEUS-SPAS II mission to observe at a wavelength resolution of 4 km/s (FWHM) the L-delta and L-epsilon absorption features produced by interstellar atomic deuterium in the spectrum of delta Ori A. A chi-square analysis indicated that 0.96 atomic ratio of D to H, we measured the L-alpha absorption features in 57 spectra of delta Ori in the IUE archive. From our measurement of N(H I)= 1.56e20 cm^{-2}, we found that N(D I)/N(H I)= 7.4(+1.9,-1.3)e-6 (90% confidence). Our result for D/H contrasts with the more general finding along other lines of sight that D/H is approximately 1.5e-5. The underabundance of D toward delta Ori A is not accompanied by an overabundance of N or O relative to H, as one might expect if the gas were subjected to more stellar processing than usual.

Edward B. Jenkins; Todd M. Tripp; Przemyslaw R. Wozniak; Ulysses J. Sofia; G. Sonneborn

1999-01-28T23:59:59.000Z

244

Heavy sterile neutrinos, entropy and relativistic energy production, and the relic neutrino background  

E-Print Network [OSTI]

We explore the implications of the existence of heavy neutral fermions (i.e., sterile neutrinos) for the thermal history of the early universe. In particular, we consider sterile neutrinos with rest masses in the 100 MeV to 500 MeV range, with couplings to ordinary active neutrinos large enough to guarantee thermal and chemical equilibrium at epochs in the early universe with temperatures T > 1 GeV, but in a range to give decay lifetimes from seconds to minutes. Such neutrinos would decouple early, with relic densities comparable to those of photons, but decay out of equilibrium, with consequent prodigious entropy generation prior to, or during, Big Bang Nucleosynthesis (BBN). Most of the ranges of sterile neutrino rest mass and lifetime considered are at odds with Cosmic Microwave Background (CMB) limits on the relativistic particle contribution to energy density (e.g., as parameterized by N_eff). However, some sterile neutrino parameters can lead to an acceptable N_eff. These parameter ranges are accompanie...

Fuller, George M; Kusenko, Alexander

2011-01-01T23:59:59.000Z

245

Primordial black holes from temporally enhanced curvature perturbation  

E-Print Network [OSTI]

Scalar field with generalized kinetic interactions metamorphoses depending on its field value, ranging from cosmological constant to stiff matter. We show that such a scalar field can give rise to temporal enhancement of the curvature perturbation in the primordial Universe, leading to efficient production of primordial black holes while the enhancement persists. If the inflation energy scale is high, those mini-black holes evaporate by the Hawking radiation much before Big Bang nucleosynthesis and the effective reheating of the Universe is achieved by the black hole evaporation. Dominance of PBHs and the reheating by their evaporation modify the expansion history of the primordial Universe. This results in a characteristic feature of the spectrum of primordial tensor modes in the DECIGO frequency band, opening an interesting possibility of testing PBH reheating scenario by measuring the primordial tensor modes. If the inflation energy scale is low, the PBH mass can be much larger than the solar mass. In this case, PBH is an interesting candidate for seeds for supermassive black holes residing in present galaxies.

Teruaki Suyama; Yi-Peng Wu; Jun'ichi Yokoyama

2014-06-02T23:59:59.000Z

246

Direct Search for Right-handed Neutrinos and Neutrinoless Double Beta Decay  

E-Print Network [OSTI]

We consider an extension of the Standard Model by two right-handed neutrinos, especially with masses lighter than charged $K$ meson. This simple model can realize the seesaw mechanism for neutrino masses and also the baryogenesis by flavor oscillations of right-handed neutrinos. We summarize the constraints on right-handed neutrinos from direct searches as well as the big bang nucleosynthesis. It is then found that the possible range for the quasi-degenerate mass of right-handed neutrinos is $M_N \\geq 163 \\MeV$ for normal hierarchy of neutrino masses, while $M_N = 188 \\text{--} 269 \\MeV$ and $M_N \\geq 285 \\MeV$ for inverted hierarchy case. Furthermore, we find in the latter case that the possible value of the Majorana phase is restricted for $M_N = 188 \\text{--} 350 \\MeV$, which leads to the fact that the rate of neutrinoless double beta decay is also limited.

Takehiko Asaka; Shintaro Eijima

2013-08-16T23:59:59.000Z

247

Nuclear Reactions from Lattice QCD  

E-Print Network [OSTI]

One of the overarching goals of nuclear physics is to rigorously compute properties of hadronic systems directly from the fundamental theory of strong interactions, Quantum Chromodynamics (QCD). In particular, the hope is to perform reliable calculations of nuclear reactions which will impact our understanding of environments that occur during big bang nucleosynthesis, the evolution of stars and supernovae, and within nuclear reactors and high energy/density facilities. Such calculations, being truly ab initio, would include all two-nucleon and three- nucleon (and higher) interactions in a consistent manner. Currently, lattice QCD provides the only reliable option for performing calculations of some of the low- energy hadronic observables. With the aim of bridging the gap between lattice QCD and nuclear many-body physics, the Institute for Nuclear Theory held a workshop on Nuclear Reactions from Lattice QCD on March 2013. In this review article, we report on the topics discussed in this workshop and the path planned to move forward in the upcoming years.

Raúl A. Briceño; Zohreh Davoudi; Thomas C. Luu

2014-11-25T23:59:59.000Z

248

K-mouflage Cosmology: the Background Evolution  

E-Print Network [OSTI]

We study the cosmology of K-mouflage theories at the background level. We show that the effects of the scalar field are suppressed at high matter density in the early Universe and only play a role in the late time Universe where the deviations of the Hubble rate from its $\\Lambda$-CDM counterpart can be of the order five percent for redshifts $1 \\lesssim z \\lesssim 5$. Similarly, we find that the equation of state can cross the phantom divide in the recent past and even diverge when the effective scalar energy density goes negative and subdominant compared to matter, preserving the positivity of the squared Hubble rate. These features are present in models for which Big Bang Nucleosynthesis is not affected. We analyze the fate of K-mouflage when the nonlinear kinetic terms give rise to ghosts, particle excitations with negative energy. In this case, we find that the K-mouflage theories can only be considered as an effective description of the Universe at low energy below $1$ keV. In the safe ghost-free models, we find that the equation of state always diverges in the past and changes significantly by a few percent since $z\\lesssim 1$.

Philippe Brax; Patrick Valageas

2014-11-30T23:59:59.000Z

249

Nuclear reactions from lattice QCD  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

One of the overarching goals of nuclear physics is to rigorously compute properties of hadronic systems directly from the fundamental theory of strong interactions, Quantum Chromodynamics (QCD). In particular, the hope is to perform reliable calculations of nuclear reactions which will impact our understanding of environments that occur during big bang nucleosynthesis, the evolution of stars and supernovae, and within nuclear reactors and high energy/density facilities. Such calculations, being truly ab initio, would include all two-nucleon and three- nucleon (and higher) interactions in a consistent manner. Currently, lattice QCD provides the only reliable option for performing calculations of some of the low- energy hadronic observables. With the aim of bridging the gap between lattice QCD and nuclear many-body physics, the Institute for Nuclear Theory held a workshop on Nuclear Reactions from Lattice QCD on March 2013. In this review article, we report on the topics discussed in this workshop and the path planned to move forward in the upcoming years.

Briceno, Raul A. [JLAB; Davoudi, Zohreh; Luu, Thomas C.

2015-02-01T23:59:59.000Z

250

Asymmetric condensed dark matter  

E-Print Network [OSTI]

We explore the viability of a boson dark matter candidate with an asymmetry between the number densities of particles and antiparticles. A simple thermal field theory analysis confirms that, under certain general conditions, this component would develop a Bose-Einstein condensate in the early universe that, for appropriate model parameters, could survive the ensuing cosmological evolution until now. The condensation of a dark matter component in equilibrium with the thermal plasma is a relativistic process, hence the amount of matter dictated by the charge asymmetry is complemented by a hot relic density frozen out at the time of decoupling. Contrary to the case of ordinary WIMPs, dark matter particles in a condensate can be very light, $10^{-22}\\,{\\rm eV} \\lesssim m \\lesssim 10^2\\,{\\rm eV}$; the lower limit arises from constraints on small-scale structure formation, while the upper bound ensures that the density from thermal relics is not too large. Big-Bang nucleosynthesis constrains the temperature of deco...

Aguirre, Anthony

2015-01-01T23:59:59.000Z

251

Cosmic Minivoids in the Intergalactic Medium  

E-Print Network [OSTI]

The Gunn-Peterson effect, absorption of Lya photons by a homogeneous component of the intergalactic medium (IGM), potentially provides a test of Big Bang Nucleosynthesis (BBN). With a lower limit on the UV radiation field estimated from the contribution due to QSOs, a measurement of the Lya opacity of the intergalactic medium would permit the derivation of a lower bound to the baryonic density of the universe. The effect, however, has continually eluded a convincing detection, both in HI and HeII, despite extensive searches. Recent cosmological hydrodynamical simulations of structure formation in the intergalactic medium suggest an explanation for its absence. In a Cold Dark Matter dominated cosmology, the fragmentation of the baryons is nearly complete, leaving a negligible remnant to comprise a smoothly distributed component. The fragmentation extends even into regions that are underdense, where it gives rise to most of the optically thin HI systems and nearly all of the HeII systems, both thin and saturated. The result is a Lya opacity from a smooth IGM that is suppressed by over two orders of magnitude from the BBN value.

Avery Meiksin

1996-11-01T23:59:59.000Z

252

Cosmological and supernova neutrinos  

SciTech Connect (OSTI)

The Big Bang nucleosynthesis (BBN) and the cosmic microwave background (CMB) anisotropies are the pillars of modern cosmology. It has recently been suggested that axion which is a dark matter candidate in the framework of the standard model could condensate in the early universe and induce photon cooling before the epoch of the photon last scattering. Although this may render a solution to the overproduction problem of primordial {sup 7}Li abundance, there arises another serious difficulty of overproducing D abundance. We propose a hybrid dark matter model with both axions and relic supersymmetric (SUSY) particles to solve both overproduction problems of the primordial D and {sup 7}Li abundances simultaneously. The BBN also serves to constrain the nature of neutrinos. Considering non-thermal photons produced in the decay of the heavy sterile neutrinos due to the magnetic moment, we explore the cosmological constraint on the strength of neutrino magnetic moment consistent with the observed light element abundances. Core-collapse supernovae eject huge flux of energetic neutrinos which affect explosive nucleosynthesis of rare isotopes like {sup 7}Li, {sup 11}B, {sup 92}Nb, {sup 138}La and {sup 180}Ta and r-process elements. Several isotopes depend strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. Combining the recent experimental constraints on ?{sub 13} with predicted and observed supernova-produced abundance ratio {sup 11}B/{sup 7}Li encapsulated in the presolar grains from the Murchison meteorite, we show a marginal preference for an inverted neutrino mass hierarchy. We also discuss supernova relic neutrinos (SRN) that may indicate the softness of the equation of state (EoS) of nuclear matter and adiabatic conditions of the neutrino oscillation.

Kajino, T. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan Department of Astronomy, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan); Aoki, W. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Balantekin, A. B. [Department of Physics, University of Wisconsin - Madison, Wisconsin 53706 (United States); Cheoun, M.-K. [Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of); Hayakawa, T. [Japan Atomic Energy Agency, Shirakara-Shirane 2-4, Tokai-mura, Ibaraki 319-1195 (Japan); Hidaka, J. [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Hirai, Y.; Shibagaki, S. [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan and Department of Astronomy, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan); Kusakabe, M. [School of Liberal Arts and Science, Korea Aerospace University, Goyang 412-791 (Korea, Republic of); Mathews, G. J. [Department of Physics, University of Notre Dame, IN 46556 (United States); Nakamura, K. [Waseda University, Ohkubo 3-4-1, Shinjuku, Tokyo 169-8555 (Japan); Pehlivan, Y. [Mimar Sinan GSÜ, Department of Physics, ?i?li, ?stanbul 34380 (Turkey); Suzuki, T. [Nihon University, Sakurajosui 3-25-40, Setagaya-ku, Tokyo 156-8550 (Japan)

2014-06-24T23:59:59.000Z

253

Effects of Long-lived 10 MeV Scale Sterile Neutrino on Primordial Elemental Abundances and Effective Neutrino Number  

E-Print Network [OSTI]

The primordial lithium abundance inferred from observations of metal-poor stars is ~3 times smaller than the theoretical value in standard big bang nucleosynthesis (BBN) model. We assume a simple model including a sterile neutrino nu_H with mass of O(10) MeV which decays long after BBN. We then investigate cosmological effects of a sterile neutrino decay. We formulate the injection spectrum of nonthermal photons induced by electrons and positrons generated at the nu_H decay, as a function of the nu_H mass and the photon temperature. We then consistently solve (1) the cosmic thermal history, (2) nonthermal nucleosynthesis induced by the nonthermal photons, (3) the baryon-to-photon ratio eta, and (4) the effective neutrino number N_eff. Amounts of energy injection at the nu_H decay are constrained from limits on primordial D and 7Li abundances, the N_eff value, and the cosmic microwave background energy spectrum. We find that 7Be is photodisintegrated and the Li problem is partially solved for the lifetime 10^4-10^5 s and the mass >~ 14 MeV. 7Be destruction by more than a factor of 3 is not possible because of an associated D over-destruction. In the parameter region, the eta value is decreased slightly, while the N_eff value is increased by a factor of <~ 1. In this study, errors in photodisintegration cross sections of 7Be(g, a)3He and 7Li(g, a)3H that have propagated through literatures are corrected. It is then found that the new photodisintegration rates are 2.3 to 2.5 times smaller than the old rates, so that efficiencies of 7Be and 7Li photodisintegration are significantly smaller.

Hiroyuki Ishida; Motohiko Kusakabe; Hiroshi Okada

2014-08-11T23:59:59.000Z

254

Type Ia supernova rate at a redshift of ~;0.1  

E-Print Network [OSTI]

since the Big Bang: Supernovae and Gamma-Ray Bursts, held 3-rst the EROS search for supernovae is reviewed in Sect. 2.2. The EROS search for supernovae The EROS experiment used a

2004-01-01T23:59:59.000Z

255

BOSS Measures the Universe to One-Percent Accuracy  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

part of the mix. By 380,000 years after the big bang, however, the temperature of the expanding mixture had cooled enough for light to escape, suffusing the newly transparent...

256

Freshman Seminar on New Cosmology MAE 87 8-10 am in EBUII 479  

E-Print Network [OSTI]

the standard NASA-and (dark energy) CDM (cold dark matter) HC (hierarchical clustering) cosmological model-gravitational-dynamics HGD emerges. According to HGD cosmology, life begins soon after the big bang in hot water oceans

Wang, Deli

257

Energy Blog | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

19, 2013 This image shows the barred spiral galaxy NGC 1398. | Image courtesy of the Dark Energy Survey. Supercomputing: A Toolbox to Simulate the Big Bang and Beyond Learn...

258

Power Suppression in D-Brane Inflation  

E-Print Network [OSTI]

Cosmological inflation is the period of rapid, accelerated expansion that occurred in the fraction of a second between the creation of spacetime and the Big Bang. Its proposal 35 years ago singlehandedly solved the three greatest issues of the Big...

Akers, Christopher Nelson

2013-10-01T23:59:59.000Z

259

Fermilab | Science | Inquiring Minds | Questions About Physics  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Hello, At least some contemporary big bang theories begin with the entire universe packed into a very small, atom sized volume. Since black hole densities can be achieved by...

260

amide deuterium isotope: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

in this system, which implies Omega(Baryon) < 0.016 for a Hubble constant of 100 kmsecMpc. This new upper limit on Omega(Baryon) relieves the conflict with standard Big Bang...

Note: This page contains sample records for the topic "oxford big-bang nucleosynthesis" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

1  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

hundred million years after the Big Bang and began to transform the universe from a cold, dark, featureless void into the vast cosmic web of galaxies observed today. A few of these...

262

Supercomputers Model 3D Map of Adolescent Universe  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

slice of the adolescent universe-just 3 billion years after the Big Bang. The map shows a web of hydrogen gas that varies from low to high density at a time when the universe was...

263

LIFE ON EARTH -- AN ACCIDENT? Chiral Symmetry and the Anthropic Principle  

E-Print Network [OSTI]

I discuss the fine-tuning of the nuclear forces and in the formation of nuclei in the production of the elements in the Big Bang and in stars.

Ulf-G. Meißner

2013-12-29T23:59:59.000Z

264

8.286 The Early Universe, Spring 2004  

E-Print Network [OSTI]

The Early Universe provides an introduction to modern cosmology. The first half deals with the development of the big-bang theory from 1915 to 1980, and latter half with recent impact of particle theory.

Guth, Alan

265

Science and Technology Review, January-February 1997  

SciTech Connect (OSTI)

Table of contents: accelerators at Livermore; the B-Factory and the Big Bang; assessing exposure to radiation; next generation of computer storage; and a powerful new tool to detect clandestine nuclear tests.

NONE

1997-01-01T23:59:59.000Z

266

LIFE ON EARTH -- AN ACCIDENT? Chiral Symmetry and the Anthropic Principle  

E-Print Network [OSTI]

I discuss the fine-tuning of the nuclear forces and in the formation of nuclei in the production of the elements in the Big Bang and in stars.

,

2013-01-01T23:59:59.000Z

267

WADHAM COLLEGE OXFORD Conference Charges for 2013  

E-Print Network [OSTI]

, Lunch, 3 Course Dinner) (all bedrooms have Fridge, Tea/Coffee making facilities, Telephone, Towels Refreshments (Coffee/Tea and Biscuits)... ... ... ... ... ... £ 2.60 + VAT Morning Pastries with Coffee/Tea Half Day Holywell Music Room inc Green Room (194 capacity) Concert venue ... £385.00 N/A + PRS fee (use

Wallace, Mark

268

UNIVERSITY COLLEGE OXFORD DATA PROTECTION POLICY  

E-Print Network [OSTI]

and employees understand what personal data is, how its use is regulated and how the College complies with the rules for protecting personal data and the importance of doing so. This policy is relevant to all of the College Community who process personal data on behalf of the College must ensure that they comply

Henderson, Gideon

269

Delivered by Ingenta to: University of Oxford  

E-Print Network [OSTI]

(ICL), Dan F. Smith Department of Chemical Engineering, Lamar University, Beaumont, Texas 77710, USA 5

Guo, John Zhanhu

270

Report - Academic Practice Conference in Oxford, 2009  

E-Print Network [OSTI]

-formal discussion sessions, addressing subjects of particular shared interest; a private reception for early career academics (doctoral students, postdoctoral researchers, research staff and new lecturers); and hopefully a third strand – narrative histories...

Arnold, Richard

2009-01-01T23:59:59.000Z

271

UNIVERSITY OF OXFORD Department of Materials  

E-Print Network [OSTI]

as the preparation of permanent magnets, magnetic recording in hard drive disks, magnetic resonance imaging or even with electrical circuits In cavity quantum electrodynamics (QED), strong coupling of atoms and light is studied.m. Thursday, 9th February Dr Vincent Dupuis , Université Pierre et Marie Curie, Paris Magnetic nanoparticles

Paxton, Anthony T.

272

Oxford, Massachusetts: Energy Resources | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy ResourcesLoading map...(UtilityCounty,Orleans County, Vermont:OttawaCounty,

273

Oxford, Michigan: Energy Resources | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy ResourcesLoading map...(UtilityCounty,Orleans County, Vermont:OttawaCounty,2.8247524°, -83.2646624°

274

Oxford, Mississippi: Energy Resources | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy ResourcesLoading map...(UtilityCounty,Orleans County, Vermont:OttawaCounty,2.8247524°,

275

Oxford, Ohio: Energy Resources | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy ResourcesLoading map...(UtilityCounty,Orleans County, Vermont:OttawaCounty,2.8247524°,is a city in

276

Cosmology for high energy physicists  

SciTech Connect (OSTI)

The standard big bang model of cosmology is presented. Although not perfect, its many successes make it a good starting point for most discussions of cosmology. Places are indicated where well understood laboratory physics is incorporated into the big bang, leading to successful predictions. Much less established aspects of high energy physics and some of the new ideas they have introduced into the field of cosmology are discussed, such as string theory, inflation and monopoles. 49 refs., 5 figs.

Albrecht, A.

1987-11-01T23:59:59.000Z

277

6. D. Sutton, A Revision of the Tribe Antirrhineae (Oxford Univ. Press, Oxford, 1988).  

E-Print Network [OSTI]

, R. Carpenter, C. Martin, Cell 47, 285 (1986). 22. W. S. Moore, J. T. Price, in Hybrid Zones sequence before publication; M. Burrus, L. Copsey, J. Bowers, C. Cazettes-Vicedo, and Z.-L. Liu

Upchurch, Gary - Department of Biology, Texas State University

278

Undergraduate Handbook 2013-14 Welcome to Oxford, or welcome back to Oxford!  

E-Print Network [OSTI]

will need to enter search parameters as follows: select "By year group" on the left hand side of the screen dates (of teaching terms, course-work submission deadlines, field trips and so on), that you will need

279

Stable quarks of the 4th family?  

E-Print Network [OSTI]

Existence of metastable quarks of new generation can be embedded into phenomenology of heterotic string together with new long range interaction, which only this new generation possesses. We discuss primordial quark production in the early Universe, their successive cosmological evolution and astrophysical effects, as well as possible production in present or future accelerators. In case of a charge symmetry of 4th generation quarks in Universe, they can be stored in neutral mesons, doubly positively charged baryons, while all the doubly negatively charged "baryons" are combined with He-4 into neutral nucleus-size atom-like states. The existence of all these anomalous stable particles may escape present experimental limits, being close to present and future experimental test. Due to the nuclear binding with He-4 primordial lightest baryons of the 4th generation with charge +1 can also escape the experimental upper limits on anomalous isotopes of hydrogen, being compatible with upper limits on anomalous lithium. While 4th quark hadrons are rare, their presence may be nearly detectable in cosmic rays, muon and neutrino fluxes and cosmic electromagnetic spectra. In case of charge asymmetry, a nontrivial solution for the problem of dark matter (DM) can be provided by excessive (meta)stable anti-up quarks of 4th generation, bound with He-4 in specific nuclear-interacting form of dark matter. Such candidate to DM is surprisingly close to Warm Dark Matter by its role in large scale structure formation. It catalyzes primordial heavy element production in Big Bang Nucleosynthesis and new types of nuclear transformations around us.

K. Belotsky; M. Khlopov; K. Shibaev

2008-06-05T23:59:59.000Z

280

Heavy sterile neutrinos, entropy and relativistic energy production, and the relic neutrino background  

E-Print Network [OSTI]

We explore the implications of the existence of heavy neutral fermions (i.e., sterile neutrinos) for the thermal history of the early universe. In particular, we consider sterile neutrinos with rest masses in the 100 MeV to 500 MeV range, with couplings to ordinary active neutrinos large enough to guarantee thermal and chemical equilibrium at epochs in the early universe with temperatures T > 1 GeV, but in a range to give decay lifetimes from seconds to minutes. Such neutrinos would decouple early, with relic densities comparable to those of photons, but decay out of equilibrium, with consequent prodigious entropy generation prior to, or during, Big Bang Nucleosynthesis (BBN). Most of the ranges of sterile neutrino rest mass and lifetime considered are at odds with Cosmic Microwave Background (CMB) limits on the relativistic particle contribution to energy density (e.g., as parameterized by N_eff). However, some sterile neutrino parameters can lead to an acceptable N_eff. These parameter ranges are accompanied by considerable dilution of the ordinary background relic neutrinos, possibly an adverse effect on BBN, but sometimes fall in a range which can explain measured neutrino masses in some particle physics models. A robust signature of these sterile neutrinos would be a measured N_eff not equal to 3 coupled with no cosmological signal for neutrino rest mass when the detection thresholds for these probes are below laboratory-established neutrino mass values, either as established by the atmospheric neutrino oscillation scale or direct measurements with, e.g., KATRIN or neutrino-less double beta decay experiments.

George M. Fuller; Chad T. Kishimoto; Alexander Kusenko

2011-10-28T23:59:59.000Z

Note: This page contains sample records for the topic "oxford big-bang nucleosynthesis" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Cosmological Cosmic Rays: Sharpening the Primordial Lithium Problem  

E-Print Network [OSTI]

Cosmic structure formation leads to large-scale shocked baryonic flows which are expected to produce a cosmological population of structure-formation cosmic rays (SFCRs). Interactions between SFCRs and ambient baryons will produce lithium isotopes via \\alpha+\\alpha \\to ^{6,7}Li. This pre-Galactic (but non-primordial) lithium should contribute to the primordial 7Li measured in halo stars and must be subtracted in order to arrive to the true observed primordial lithium abundance. In this paper we point out that the recent halo star 6Li measurements can be used to place a strong constraint to the level of such contamination, because the exclusive astrophysical production of 6Li is from cosmic-ray interactions. We find that the putative 6Li plateau, if due to pre-Galactic cosmic-ray interactions, implies that SFCR-produced lithium represents Li_{SFCR}/Li_{plateau}\\approx 15% of the observed elemental Li plateau. Taking the remaining plateau Li to be cosmological 7Li, we find a revised (and slightly worsened) discrepancy between the Li observations and Big Bang Nucleosynthesis predictions by a factor of ^7Li_{BBN}/^7Li_{plateau} \\approx 3.7. Moreover, SFCRs would also contribute to the extragalactic gamma-ray background (EGRB) through neutral pion production. This gamma-ray production is tightly related to the amount of lithium produced by the same cosmic rays; the 6Li plateau limits the pre-Galactic (high-redshift) SFCR contribution to be at the level of I_{\\pi_{\\gamma}SFCR}/I_{EGRB} < 5% of the currently observed EGRB.

Tijana Prodanovic; Brian D. Fields

2007-09-20T23:59:59.000Z

282

CMB constraints on mass and coupling constant of light pseudoscalar particles  

E-Print Network [OSTI]

Transformation of CMB photons into light pseudoscalar particles at post big bang nucleosynthesis epoch is considered. Using the present day value of a large scale magnetic field to estimate it at earlier cosmological epochs, the oscillation probability of photons into light pseudoscalar particles with an account of coherence breaking in cosmological plasma is calculated. Demanding that the photon transformation does not lead to an exceedingly large CMB spectral distortion and temperature anisotropy, the constraints on the coupling constant of axion like particles to photons, $ g_{\\phi\\gamma} B \\lesssim (10^{-15} - 10^{-12}) \\textrm{nG}\\times \\textrm{GeV}^{-1}$, are found for the axion like particle mass in the interval $10^{-25}$ eV $\\lesssim m_{\\phi}\\lesssim 10^{-5}$ eV, where $B$ is the strength of the large scale magnetic field at the present time. Our results update the previously obtained ones since we use the density matrix formalism which is more accurate than the wave function approximation for the description of oscillations with an essential coherence breaking. In the axion like particle mass range $10^{-25}$ eV $\\lesssim m_{\\phi}\\lesssim 10^{-14}$ eV, weaker limits, by at least 2 orders of magnitude $g_{\\phi\\gamma} B \\lesssim 10^{-11}\\textrm{nG}\\times \\textrm{GeV}^{-1}$, are obtained in comparison with the wave function approximation. In the mass range $10^{-14}$ eV $\\lesssim m_{\\phi}\\lesssim 10^{-5}$ eV, on the other hand, limits that are stronger, by more than an order of magnitude are obtained. Our results are derived by using upper limits on spectral distortion parameter $\\mu$ and temperature anisotropy $\\Delta T/T$ found by COBE and expected sensitivities by PIXIE/PRISM.

Damian Ejlli; Alexander D. Dolgov

2014-09-15T23:59:59.000Z

283

Incompatibility of a comoving Ly-alpha forest with supernova-Ia luminosity distances  

E-Print Network [OSTI]

Recently Perlmutter et al. suggested a positive value of Einstein's cosmological constant Lambda on the basis of luminosity distances from type-Ia supernovae. However, Lambda world models had earlier been proposed by Hoell & Priester and Liebscher et al. on the basis of quasar absorption-line data. Employing more general repulsive fluids ("dark energy") encompassing the Lambda component we quantitatively compare both approaches with each other. Fitting the SN-data by a minimum-component model consisting of dark energy + dust yields a closed universe with a large amount of dust exceeding the baryonic content constrained by big-bang nucleosynthesis. The nature of the dark energy is hardly constrained. Only when enforcing a flat universe there is a clear tendency to a dark-energy Lambda fluid and the `canonical' value Omega_M = 0.3 for dust. Conversely, fitting the quasar-data by a minimum-component model yields a sharply defined, slightly closed model with a low dust density ruling out significant pressureless dark matter. The dark-energy component obtains an equation-of-state P = -0.96 epsilon close to that of a Lambda-fluid. Omega_M = 0.3 or a precisely flat spatial geometry are inconsistent with minimum-component models. It is found that quasar and supernova data sets cannot be reconciled with each other via (repulsive ideal fluid+dust+radiation)-world models. Compatibility could be reached by drastic expansion of the parameter space with at least two exotic fluids added to dust and radiation as world constituents. If considering such solutions as far-fetched one has to conclude that the quasar absorption line and the SN-Ia constraints are incompatible.

Jens Thomas; Hartmut Schulz

2001-03-18T23:59:59.000Z

284

QCD landscape?  

E-Print Network [OSTI]

Just comparing with the scenario that the (3+1)-dimensional "real world" of the Calabi-Yau compactification has a tremendous landscape, we conjecture that a (4+1)-dimensional holographic theory may also hold a landscape of its vacua. Unlike the traditional studies of the AdS/CFT phenomenology where the vacua are always constructive, we discuss the proper holographic vacua and their flux compactification, starting from some general compact Einstein manifolds. The proper vacua should be restricted by (i) a consistent worldsheet theory that possesses the superconformal symmetry, (ii) some definite symmetries to keep/break the corresponding symmetries of the dual field theory, (iii) certain brane/flux configurations to cancel anomalies, and (iv) stabilities. We consider diverse fundamental parameters of the dual field theory, fixed by some special vacuum moduli. In an opposite way, if some field theory such as QCD holds an AdS dual, it may also possesses various fundamental parameters by an "landscape" of its vacuum. Different vacua may be adjacent with each other, and divided by domain walls. If the size of a single vacuum region is smaller than the visible universe, it may be testable. We discuss the consequences of this conjecture in the astrophysical environments, include but not limit to: (i) consistency with the critical energy density of the universe, (ii) the behaviors of cosmic rays, (iii) the stability and abundance of deuterons and other nuclei in the big-bang nucleosynthesis and the star burning scenarios, and (iv) the existence of strange/charm stars.

Cong-Xin Qiu

2009-11-23T23:59:59.000Z

285

The 3.5 keV X-ray line signature from annihilating and decaying dark matter in Weinberg model  

E-Print Network [OSTI]

Recently two groups independently observed unidentified X-ray line signal at the energy 3.55 keV from the galaxy clusters and Andromeda galaxy. We show that this anomalous signal can be explained in annihilating dark matter model, for example, fermionic dark matter model in hidden sector with global $U(1)_X$ symmetry proposed by Weinberg. There are two scenarios for the production of the annihilating dark matters. In the first scenario the dark matters with mass 3.55 keV decouple from the interaction with Goldstone bosons and go out of thermal equilibrium at high temperature ($>$ 1 TeV) when they are still relativistic, their number density per comoving volume being essentially fixed to be the current value. The correct relic abundance of this warm dark matter is obtained by assuming that about ${\\cal O}(10^3)$ relativistic degrees of freedom were present at the decoupling temperature or alternatively large entropy production occurred at high temperature. In the other scenario, the dark matters were absent at high temperature, and as the universe cools down, the SM particles annihilate or decay to produce the dark matters non-thermally as in `freeze-in' scenario. It turns out that the DM production from Higgs decay is the dominant one. In the model we considered, only the first scenario can explain both X-ray signal and relic abundance. The X-ray signal arises through $p$-wave annihilation of dark matter pair into two photons through the scalar resonance without violating the constraints from big bang nucleosynthesis, cosmic microwave background, and astrophysical objects such as red giants or white dwarfs. We also discuss the possibility that the signal may result from a decaying dark matter in a simple extension of Weinberg model.

Seungwon Baek; P. Ko; Wan-Il Park

2014-05-28T23:59:59.000Z

286

Unified description of $^6$Li structure and deuterium-$^4$He dynamics with chiral two- and three-nucleon forces  

E-Print Network [OSTI]

Prototype for the study of weakly bound projectiles colliding on stable targets, the scattering of deuterium ($d$) on $^4$He ($\\alpha$) is an important milestone in the search for a fundamental understanding of low-energy reactions. At the same time, it is also important for its role in the Big-bang nucleosynthesis of $^6$Li and applications in the characterization of deuterium impurities in materials. We present the first unified {\\em ab initio} study of the $^6$Li ground state and $d$-$^4$He elastic scattering using two- and three-nucleon forces derived within the framework of chiral effective field theory. The six-nucleon bound-state and scattering observables are calculated by means of the no-core shell model with continuum. %and are compared to available experimental data. We analyze the influence of the dynamic polarization of the deuterium and of the chiral three-nucleon force, and examine the role of the continuum degrees of freedom in shaping the low-lying spectrum of $^6$Li. We find that the adopted Hamiltonian correctly predicts the binding energy of $^6$Li, yielding an asymptotic $D$- to $S$-state ratio of the $^6$Li wave function in $d+\\alpha$ configuration of $-0.027$ in agreement with the value determined from a phase shift analysis of $^6$Li+$^4$He elastic scattering, but overestimates the excitation energy of the first $3^+$ state by $350$ keV. The bulk of the computed differential cross section is in good agreement with data.

Guillaume Hupin; Sofia Quaglioni; Petr Navrátil

2014-12-12T23:59:59.000Z

287

Measuring the Density Fluctuation From the Cluster Gas Mass Function  

E-Print Network [OSTI]

We investigate the gas mass function of clusters of galaxies to measure the density fluctuation spectrum on cluster scales. The baryon abundance confined in rich clusters is computed from the gas mass function and compared with the mean baryon density in the universe which is predicted by the Big Bang Nucleosynthesis. This baryon fraction and the slope of the gas mass function put constraints on $\\sigma_8$, the rms linear fluctuation on scales of $8h^{-1}\\Mpc$, and the slope of the fluctuation spectrum, where $h$ is the Hubble constant in units of 100 $\\kms \\oMpc$. We find $\\sigma_8 = 0.80 \\pm 0.15$ and $n \\sim -1.5$ for $0.5 \\le h \\le 0.8$, where we assume that the density spectrum is approximated by a power law on cluster scales: $\\sigma(r) \\propto r^{-{3+n\\over{2}}}$. Our value of $\\sigma_8$ is independent of the density parameter, $\\Omega_0$, and thus we can estimate $\\Omega_0$ by combining $\\sigma_8$ obtained in this study with those from $\\Omega_0$-dependent analyses to date. We find that $\\sigma_8(\\Omega_0)$ derived from the cluster abundance such as the temperature function gives $\\Omega_0 \\sim 0.5$ while $\\sigma_8(\\Omega_0)$ measured from the peculiar velocity field of galaxies gives $\\Omega_0 \\sim 0.2-1$, depending on the technique used to analyze peculiar velocity data. Constraints are also derived for open, spatially flat, and tilted Cold Dark Matter models and for Cold + Hot Dark Matter models.

Kazuhiro Shimasaku

1997-01-27T23:59:59.000Z

288

Surface brightness in plasma-redshift cosmology  

E-Print Network [OSTI]

In 2001 Lori M. Lubin and Allan Sandage, using big-bang cosmology for interpreting the data, found the surface brightness of galaxies to be inversely proportional to about the third power of (1+z), while the contemporary big-bang cosmology predicts that the surface brightness is inversely proportional to the fourth power of (1+z). In contrast, these surface brightness observations are in agreement with the predictions of the plasma-redshift cosmology. Lubin and Sandage (2001) and Barden et al. (2005), who surmised the big-bang expansion, interpreted the observations to indicate that the diameters of galaxies are inversely proportional to (1+z). In contrast, when assuming plasma-redshift cosmology, the diameters of galaxies are observed to be constant independent of redshift and any expansion. Lubin and Sandage (2001) and Barden et al. (2005), when using big-bang cosmology, observed the average absolute magnitude of galaxies to decrease with redshift; while in plasma redshift cosmology it is a constant. Lubin and Sandage and Barden et al. suggested that a coherent evolution could explain the discrepancy between the observed relations and those predicted in the big-bang cosmology. We have failed to find support for this explanation. We consider the observed relations between the redshift and the surface-brightness, the galaxy diameter, and the absolute magnitude to be robust confirmations of plasma-redshift cosmology.

Ari Brynjolfsson

2006-05-31T23:59:59.000Z

289

Turbulence and turbulent mixing in natural fluids  

E-Print Network [OSTI]

Turbulence and turbulent mixing in natural fluids begins with big bang turbulence powered by spinning combustible combinations of Planck particles and Planck antiparticles. Particle prograde accretion on a spinning pair releases 42% of the particle rest mass energy to produce more fuel for turbulent combustion. Negative viscosity and negative turbulence stresses work against gravity, creating mass-energy and space-time from the vacuum. Turbulence mixes cooling temperatures until a quark-gluon strong-force SF freeze-out. Gluon-viscosity anti-gravity ({\\Lambda}SF) exponentially inflates the fireball to preserve big bang turbulence information at scales larger than ct as the first fossil turbulence. Cosmic microwave background CMB temperature anisotropies show big bang turbulence fossils along with fossils of weak plasma turbulence triggered (10^12 s) as plasma viscous forces permit gravitational fragmentation on supercluster to galaxy mass scales (10^13 s). Turbulent morphologies and viscous-turbulent lengths a...

Gibson, Carl H

2010-01-01T23:59:59.000Z

290

Synchronicity: Nature and Psyche in an Interconnected Universe  

E-Print Network [OSTI]

, calling it the ?biggest blunder? of his life. I will give a few details of the controversies in cosmology from 1922 through the 1950s (for a detailed study see Big Bang by Simon Singh, 2004), which would include the time frame for Jung?s formula- tions... In sketching out details as he understood them, Lema?tre gave the first scientific description ( 1??) Chapter 1 of what would become the Big Bang model in 1927 at the Solvay con- ference. According to Singh, Einstein informed him of Friedmann?s work while...

Cambray, Joseph

2009-09-11T23:59:59.000Z

291

Propagation of gravitational waves in a universe with slowly-changing equation of state  

E-Print Network [OSTI]

An exact solution for the expansion of a flat universe with dark energy evolving according to a simple model is explored. The equation for weak primordial gravitational waves propagating in this universe is solved and explored; gravitational waves in a flat cosmology possessing both a "big bang" singularity and a "big rip" singularity can be described with confluent Heun functions. We develop approximation methods for confluent Heun equations in regimes of interest to gravitational wave astronomers and predict the diminution in gravitational wave amplitude in a universe with both a Big Bang and a Big Rip.

Edmund Schluessel

2014-06-17T23:59:59.000Z

292

Formation of super-heavy elements in astrophysical nucleosynthesis  

SciTech Connect (OSTI)

The unexplored area of heavy neutron-rich nuclides is extremely important for the understanding of the r process of astrophysical nucleogenesis. For elements with Z>100 only neutron deficient isotopes (located to the left of the stability line) have been synthesized so far. The 'north-east' area of the nuclear map can be reached neither in fusion reactions nor in fragmentation processes. Low energy multi-nucleon transfer reactions are quite promising for the production and study of neutron-rich heavy nuclei including those located at the superheavy (SH) island of stability [1]. The neutron capture process is considered here as an alternative method for the production of SH nuclei. Requirements for the pulsed reactors of the next generation that could be used for the synthesis of long-living neutron rich SH nuclei are formulated. Formation of SH nuclei in supernova explosions is also discussed and the abundance of SH elements in nature is estimated.

Zagrebaev, V. I.; Karpov, A. V.; Mishustin, I. N.; Greiner, Walter [Flerov Laboratory of Nuclear Reactions, JINR, Dubna, Moscow Region (Russian Federation); Frankfurt Institute for Advanced Studies, J.W. Goethe-Universitaet, Frankfurt (Germany)

2012-10-20T23:59:59.000Z

293

Neutrinos and Nucleosynthesis in Gamma-Ray Burst Accretion Disks  

E-Print Network [OSTI]

We calculate the nuclear composition of matter in accretion disks surrounding stellar mass black holes as are thought to accompany gamma-ray bursts (GRBs). We follow a mass element in the accretion disk starting at the point of nuclear dissociation and calculate the evolution of the electron fraction due to electron, positron, electron neutrino and electron antineutrino captures. We find that the neutronization of the disk material by electron capture can be reversed by neutrino interactions in the inner regions of disks with accretion rates of 1 M_solar/s and higher. For these cases the inner disk regions are optically thick to neutrinos, and so to estimate the emitted neutrino fluxes we find the surface of last scattering for the neutrinos (the equivalent of the proto-neutron star neutrinosphere) for each optically thick disk model. We also estimate the influence of neutrino interactions on the neutron-to-proton ratio in outflows from GRB accretion disks, and find it can be significant even when the disk is optically thin to neutrinos.

R. Surman; G. C. McLaughlin

2003-11-24T23:59:59.000Z

294

THE QUEEN'S COLLEGE, OXFORD STATEMENT OF SAFETY POLICY  

E-Print Network [OSTI]

and Safety at Work etc. Act 1974 which came into force on 1 April 1975 lay a duty on all employers to ensure, as far as is reasonably practicable, the safety of their employees at work by maintaining safe plant statement of his general policy with respect to the health and safety at work of his employees

Capdeboscq, Yves

295

Vol. 0 no. 0 2007 Oxford University Press 2007 1  

E-Print Network [OSTI]

suffer from large number of false predictions. They mostly use sequence in- formation in a position be further improved by taking into account locational preference of binding events. By testing on expe a recent review, see Tompa et al., 2005), were designed to this end. The other task is motif search, i

296

OxfordMusicOnline (GroveMusicOnline)  

E-Print Network [OSTI]

and links on the left-hand side: Search terms are highlighted in yellow. A "Search within this article under the call number ML102.J3 N48 2001. Enter keyword(s) in either open field and click the box or choose Advanced Search links for more options, such as combining keywords. From the opening screen

297

FAS CENTER FOR NANOSCALE SYSTEMS 11 OXFORD STREET  

E-Print Network [OSTI]

_Research_Proposal.doc 1 7/29/2009 Proposal for Minor to Conduct Research or Work in a Laboratory (To be completed by CNS Faculty or Staff Sponsor) Persons under 18 years of age (minors) wishing to work or conduct research hazards in the laboratory. · Hazardous operations are defined and safe practices and protective equipment

298

Oxford Institute for Energy Studies Natural Gas Research Programme  

E-Print Network [OSTI]

demand and price dynamics than by crude oil or oil product prices. The author, Dr Michelle Michot Foss, this means that as long as crude oil prices remain significantly in excess of $35/bbl, European gas markets ­ where prices are indexed to those of oil products ­ should be able to attract LNG supplies away from

Texas at Austin, University of

299

IARU GSP @ University of Oxford 2013/12/18 120132  

E-Print Network [OSTI]

)Literature Exeter college 20132 2013/12/18 6 Home university Major UC Berkeley, 4 Copenha gen, 3 ANU (Autraria security · Economic models · Energy Oil · International development · Poverty · Aid & trade? Essay International development Technology Resources Behavior Poverty Internet power EU politics Food security general

Miyashita, Yasushi

300

University of Oxford Energy Toolkit2011/12  

E-Print Network [OSTI]

to reduce its energy consumption, due to: The rising cost of electricity, gas and oil Increasing legislative and cut your energy bills. The toolkit will help you to reduce electricity, gas and oil consumption dioxide we emit under the Government's Carbon Reduction Commitment (CRC) Energy Efficiency Scheme The need

Melham, Tom

Note: This page contains sample records for the topic "oxford big-bang nucleosynthesis" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Oxford Colleges On-line Reports for Tutorials  

E-Print Network [OSTI]

of term procedures for Tutorial Office..........................................15 End of term procedures To enter College bank details..............................................................23 7. Enter Or Maintain Teaching Hours Weighting Data ................................25 To enter weighting data

Oxford, University of

302

Oxford Colleges On-line Reports for Tutorials  

E-Print Network [OSTI]

of term procedures for Tutorial Office..........................................15 End of term procedures To enter College bank details..............................................................25 7. Enter Or Maintain Teaching Hours Weighting Data ................................27 To enter weighting data

Oxford, University of

303

DMAC 36 SHORTENED MINUTES Oxford University Department of Materials  

E-Print Network [OSTI]

comprising CMB (Chair), AJW, JMS, SCB, and JaMS will report to DMAC by MT06. If at their initial meeting

Paxton, Anthony T.

304

DMAC 34 SHORTENED MINUTES Oxford University Department of Materials  

E-Print Network [OSTI]

comprising CMB (Chair), AJW, JMS, SCB, and JaMS will report to DMAC by MT06. If at their initial meeting

Paxton, Anthony T.

305

UNIVERSITY O F OXFORD Ttltphunc 53281 DEPARTMENT OF THEORETICAL PHYSICS  

E-Print Network [OSTI]

with Matrix-Elements and Energies given by Jones. Your last: letter t o r Sl l E , SOlA and W3n, as well as the energy values. 6 e previous letter gave us explicit expressions in Ni for D15N, D15C, D05A and D15 on your algebra. Reassuring, at least. #12;Next we tried an internal check. Consider the energy matrix

Browder, Tom

306

Exeter College. Oxford 02.03.12 Max Fordham LLP  

E-Print Network [OSTI]

.0 Introduction 4 2.0 Sustainable Design 5 2.1 Legislative Context 5 2.2 National Policy: Building Regulations 5 2 and sustainability; external lighting and noise control for the proposed new accommodation building for Exeter College. The Sustainability and Energy Strategy sections set out the requirements for sustainable building

Flynn, E. Victor

307

Earl Oxford Hall: A Brief Biography and Wartime History  

E-Print Network [OSTI]

engines, and the guns overhauled. Descriptions of the airstrips speak of narrow dusty strips hacked out of the palms, with little clearance for takeoff and landing. In Haugland’s The AAF Against Japan, he notes: “Development of airfields was a major.... It shows the distinctive tail profile and wing congiguration. Several gun positions are visible. (Combat photographs in this section courtesy the USAF Museum Photo Archives. B-17E - Three plane flight over water. This is probably typical of a...

Hall, Hal W.

2008-07-17T23:59:59.000Z

308

Earl Oxford Hall: A Brief Biography and Wartime History  

E-Print Network [OSTI]

in Japanese hands up to August 1942. On August 7, 1942, U. S. troops landed on Guadalcanal. Resistance was fierce, with the island not completely secured until February 9, 1943. Henderson Field was secured and made operational for air defense by August... 17th . Throughout the fall, Henderson was under constant attack. On October 14th, the Japanese all but destroyed the field in massive bombing and naval bombardment attacks, but by late November or early December, Henderson Field was secure...

Hall, Hal W.

2010-08-12T23:59:59.000Z

309

New Oxford, Pennsylvania: Energy Resources | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy ResourcesLoading map...(Utility Company) Jump to: navigation,0558143° Loading map...

310

Chapman of XSD Wins Oxford Cryosystems Poster Prize  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed New Substation SitesStanding FriedelIron-Sulfur ProteinChallengeforMorgan

311

DOE - Office of Legacy Management -- Oxford_FUSRAP  

Office of Legacy Management (LM)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarlyEnergyDepartment ofDepartment ofof EnergyYou are herePAOsborne Co - OH 34 FUSRAP Considered

312

Oxford, North Carolina: Energy Resources | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformation Earth'sOklahoma/GeothermalOrange County is aOrmesa IOvonic Battery

313

DOE - Office of Legacy Management -- Oxford OH Site - OH 22  

Office of Legacy Management (LM)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarlyEnergyDepartment ofDepartment ofof EnergyYou areDowntown SiteOhioMissouriMaywoodNY 17

314

Oxford County, Maine: Energy Resources | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy ResourcesLoading map...(UtilityCounty,Orleans County, Vermont:OttawaCounty, IndianaOwls

315

Oxford, United Kingdom: Energy Resources | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy ResourcesLoading map...(UtilityCounty,Orleans County, Vermont:OttawaCounty,2.8247524°,is a city in

316

UNIVERSITY PRBSS Oxford University Press, Inc., publishes works that further  

E-Print Network [OSTI]

Shanghai Taipei Toronto With offices in Argentina Austria Brazil Chile Czech Republic France Greece ifwe agree that congestion wastes time, is minimizing congestion the most appropriate public policy goal (Taylor 2003)? Do measures of congestion provide the basis for policy prescriptions? We argue

Levinson, David M.

317

Modeling Environmental Justice: A Normative Conception for Healthier Communities  

E-Print Network [OSTI]

by Martha Nussbaum and Amartya Sen. Oxford: Clarendon Press,Peter Sudhir Anand, Amartya Sen. Oxford: Oxford UniversityFabienne Peter and Amartya Sen. Oxford: Oxford University

Gendreau, Megan Smith

2011-01-01T23:59:59.000Z

318

Copper vs. Copper at the Relativistic Heavy Ion Collider (2005)  

ScienceCinema (OSTI)

To investigate a new form of matter not seen since the Big Bang, scientists are using a new experimental probe: collisions between two beams of copper ions. The use of intermediate size nuclei is expected to result in intermediate energy density - not as

Brookhaven Lab - Fulvia Pilat

2010-01-08T23:59:59.000Z

319

Supersymmetry and Inflation  

E-Print Network [OSTI]

Inflation is a promising solution to many problems of the standard Big-Bang cosmology. Nevertheless, inflationary models have proved less compelling. In this chapter, we discuss why supersymmetry has led to more natural models of inflation. We pay particular attention to multifield models, both with a high and a low Hubble parameter.

Lisa Randall

1997-11-25T23:59:59.000Z

320

7 de janeiro de 2009 EXPERIMENTO A BORDO DE BALO ESTRATOSFRICO DA NASA, QUE  

E-Print Network [OSTI]

medidas do céu em micro-ondas à procura da energia emitida pelas primeiras estrelas que se formaram qual o nosso Sistema Solar pertence. O Universo é permeado por um sinal residual do Big Bang, observado causados pelo decaimento de partículas primordiais ou pela injeção de energia no Universo produzida pela

Domingues, Margarete Oliveira

Note: This page contains sample records for the topic "oxford big-bang nucleosynthesis" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Name ___KEY_______________ Due Date: __________________  

E-Print Network [OSTI]

solar system formed. Following the Big Bang, some first generation stars became supernovae, spreading an atmosphere with about 20% oxygen, compared to no free oxygen early in the Earth's history? Write down. Photosynthesis by algae eventually produced free oxygen in the atmosphere, which allowed for development of air

Kirby, Carl S.

322

The Royal Observatory Edinburgh comprises the UK Astronomy Technology Centre of the Science and Technology Facilities Council, the Institute for Astronomy of the University of Edinburgh and the ROE Visitor Centre.  

E-Print Network [OSTI]

for designing and building the spectrometer pre-optics sub-system, which includes a set of four image slicers a hexagonal primary mirror with a collecting area of 25 square metres, passively cooled to 40K and placed, ranging from the first luminous glows after the Big Bang, to the formation of solar systems capable

Tittley, Eric

323

Feynman Clocks, Causal Networks, and The Origin of Hierarchical 'Arrows of Time' in Complex Systems. Part 1: 'Conjectures'  

E-Print Network [OSTI]

A theory of time as 'information' is outlined using new tools such as Feynman Clocks (FCs), Collective Excitation Networks (CENs), Sequential Excitation Networks (SENs), and Plateaus of Complexity (POCs). Applications of this approach range from the Big Bang to the emergence of 'consciousness'.

Scott Hitchcock

2001-02-06T23:59:59.000Z

324

Nerds of Colors Assemble: The Role of Race and Ethnicity in Fandom  

E-Print Network [OSTI]

With shows such as Big Bang Theory and the increased mainstreaming of San Diego Comic-con, now more than ever before, it is acceptable to be a “nerd”. The question now becomes what efforts are being made to appeal to fans of color in traditional...

Williams, Simon 1984-

2012-12-10T23:59:59.000Z

325

[The Story of the Solar System] The Solar System -II  

E-Print Network [OSTI]

-TauriPhase SolarNebula #12;Giant Molecular Cloud o About 50-100 light years across o more than a million times[The Story of the Solar System] The Solar System - II Alexei Gilchrist #12;Some resources o Section of the Solar System, M Garlick, (Cambridge Uni. Press, 2002) #12;Timeline Today Big Bang Earliest Fossils Birth

Wardle, Mark

326

Can The Natario Warp Drive Explain The OPERA Superluminal Neutrino At CERN??  

E-Print Network [OSTI]

Can The Natario Warp Drive Explain The OPERA Superluminal Neutrino At CERN?? Fernando Loup of the micro Warp Drive:Microscopical particle-sized Warp Bubbles carrying inside sub-atomic particles Universe after the Big Bang and they used the Alcubierre Warp Drive geometry in their mathematical model

Paris-Sud XI, Université de

327

How The 17 GeV OPERA Superluminal Neutrino From CERN Arrived At Gran Sasso Without Desintegration??:It Was Carried Out By A  

E-Print Network [OSTI]

??:It Was Carried Out By A Natario Warp Drive.Explanation for the results obtained by Glashow-Cohen and Gonzalez introduced the idea of the micro Warp Drive:Microscopical particle-sized Warp Bubbles carrying inside sub in the Early Universe after the Big Bang and they used the Alcubierre Warp Drive geometry in their mathematical

Paris-Sud XI, Université de

328

Waves in Nature, Lasers to Tsumanis and Beyond  

ScienceCinema (OSTI)

Waves are everywhere. Microwaves, laser beams, music, tsunamis. Electromagnetic waves emanating from the Big Bang fill the universe. Learn about the similarities and difference in all of these wavy phenomena with Ed Moses and Rick Sawicki, Lawrence Livermore National Laboratory scientists Series: Science on Saturday [10/2006] [Science] [Show ID: 11541

LLNL - University of California Television

2009-09-01T23:59:59.000Z

329

The idea of the neutrino was put forward in 1930 by Wolfgang Pauli in a desperate attempt to preserve energy  

E-Print Network [OSTI]

are neutrinos expected from cosmological point sources such as gamma-ray bursts and active galactic nuclei microwave en- ergies (10­4 eV) up to the highest cosmic-ray energies (1020 eV). The lowest-energy neutrinos Supernova 1987A Atmospheric GZK BigBang Gamma-raybursts Active galactic nuclei NEUTRINO ENERGY (e

Knowles, David William

330

Edgy Science III: From NSF Physics Frontier  

E-Print Network [OSTI]

Edgy Science III: From NSF Physics Frontier Centers NSTA 2010 Philadelphia, PA From brains to the Big Bang, take a crash course in forefront science with the NSF Physics Frontier Centers, including - National Science Foundation (NSF) Physics Frontier Centers (PFCs) · Each Center - Science News - Resources

Collar, Juan I.

331

2005 Pearson Education Inc., publishing as Addison-Wesley  

E-Print Network [OSTI]

value over time. ·More distant supernovae are dimmer than expected ·Something ("Dark Energy") is causing the expansion to accelerate. We don't know what Dark Energy is ­ only that it appears breath you take: the big bang is all around us. It is a theory, but a theory with a web of evidence

Shirley, Yancy

332

National Aeronautics and Space Administration Science Program  

E-Print Network [OSTI]

that powered the Big Bang, and the dark energy propelling the cosmic expansion today. Forward, will measure them in exquisite detail. The weak ripples in gas and dark matter later create the first stars, quasars powered by supermassive black holes, and finally the great cosmic web of galaxies like our own

333

Columbia University http://www.columbia.edu/~mem4/  

E-Print Network [OSTI]

Mike Mauel Columbia University http://www.columbia.edu/~mem4/ National Undergraduate Fusion plant · Columbia University's plasma physics experiments 6Friday, June 5, 2009 #12;Forces of Nature, 2009 100-300 s after the "Big-Bang": The Age of Fusion · At 100 sec, the universe cools to 1

Mauel, Michael E.

334

A search for particle dark matter using cryogenic germanium and silicon detectors in the one- and two- tower runs of CDMS-II at Soudan  

SciTech Connect (OSTI)

Images of the Bullet Cluster of galaxies in visible light, X-rays, and through gravitational lensing confirm that most of the matter in the universe is not composed of any known form of matter. The combined evidence from the dynamics of galaxies and clusters of galaxies, the cosmic microwave background, big bang nucleosynthesis, and other observations indicates that 80% of the universe's matter is dark, nearly collisionless, and cold. The identify of the dar, matter remains unknown, but weakly interacting massive particles (WIMPs) are a very good candidate. They are a natural part of many supersymmetric extensions to the standard model, and could be produced as a nonrelativistic, thermal relic in the early universe with about the right density to account for the missing mass. The dark matter of a galaxy should exist as a spherical or ellipsoidal cloud, called a 'halo' because it extends well past the edge of the visible galaxy. The Cryogenic Dark Matter Search (CDMS) seeks to directly detect interactions between WIMPs in the Milky Way's galactic dark matter halo using crystals of germanium and silicon. Our Z-sensitive ionization and phonon ('ZIP') detectors simultaneously measure both phonons and ionization produced by particle interactions. In order to find very rare, low-energy WIMP interactions, they must identify and reject background events caused by environmental radioactivity, radioactive contaminants on the detector,s and cosmic rays. In particular, sophisticated analysis of the timing of phonon signals is needed to eliminate signals caused by beta decays at the detector surfaces. This thesis presents the firs two dark matter data sets from the deep underground experimental site at the Soudan Underground Laboratory in Minnesota. These are known as 'Run 118', with six detectors (1 kg Ge, 65.2 live days before cuts) and 'Run 119', with twelve detectors (1.5 kg Ge, 74.5 live days before cuts). They have analyzed all data from the two runs together in a single, combined analysis, with sensitivity to lower-energy interactions, careful control of data quality and stability, and further development of techniques for reconstructing event location and rejecting near-surface interactions from beta decays. They also present a revision to the previously published Run 119 analysis, a demonstration of the feasibility of a low-threshold (1 or 2 keV) analysis of Soudan data, and a review of the literature on charge generation and quenching relevant to the ionization signal.

Ogburn, Reuben Walter, IV; /Stanford U., Phys. Dept.

2008-04-01T23:59:59.000Z

335

NINE-YEAR WILKINSON MICROWAVE ANISOTROPY PROBE (WMAP) OBSERVATIONS: FINAL MAPS AND RESULTS  

SciTech Connect (OSTI)

We present the final nine-year maps and basic results from the Wilkinson Microwave Anisotropy Probe (WMAP) mission. The full nine-year analysis of the time-ordered data provides updated characterizations and calibrations of the experiment. We also provide new nine-year full sky temperature maps that were processed to reduce the asymmetry of the effective beams. Temperature and polarization sky maps are examined to separate cosmic microwave background (CMB) anisotropy from foreground emission, and both types of signals are analyzed in detail. We provide new point source catalogs as well as new diffuse and point source foreground masks. An updated template-removal process is used for cosmological analysis; new foreground fits are performed, and new foreground-reduced CMB maps are presented. We now implement an optimal C {sup –1} weighting to compute the temperature angular power spectrum. The WMAP mission has resulted in a highly constrained ?CDM cosmological model with precise and accurate parameters in agreement with a host of other cosmological measurements. When WMAP data are combined with finer scale CMB, baryon acoustic oscillation, and Hubble constant measurements, we find that big bang nucleosynthesis is well supported and there is no compelling evidence for a non-standard number of neutrino species (N {sub eff} = 3.84 ± 0.40). The model fit also implies that the age of the universe is t {sub 0} = 13.772 ± 0.059 Gyr, and the fit Hubble constant is H {sub 0} = 69.32 ± 0.80 km s{sup –1} Mpc{sup –1}. Inflation is also supported: the fluctuations are adiabatic, with Gaussian random phases; the detection of a deviation of the scalar spectral index from unity, reported earlier by the WMAP team, now has high statistical significance (n{sub s} = 0.9608 ± 0.0080); and the universe is close to flat/Euclidean (?{sub k} = -0.0027{sup +0.0039}{sub -0.0038}). Overall, the WMAP mission has resulted in a reduction of the cosmological parameter volume by a factor of 68,000 for the standard six-parameter ?CDM model, based on CMB data alone. For a model including tensors, the allowed seven-parameter volume has been reduced by a factor 117,000. Other cosmological observations are in accord with the CMB predictions, and the combined data reduces the cosmological parameter volume even further. With no significant anomalies and an adequate goodness of fit, the inflationary flat ?CDM model and its precise and accurate parameters rooted in WMAP data stands as the standard model of cosmology.

Bennett, C. L.; Larson, D.; Weiland, J. L. [Department of Physics and Astronomy, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218-2686 (United States); Jarosik, N.; Page, L. [Department of Physics, Jadwin Hall, Princeton University, Princeton, NJ 08544-0708 (United States); Hinshaw, G.; Halpern, M. [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1 (Canada); Odegard, N.; Hill, R. S. [ADNET Systems, Inc., 7515 Mission Drive, Suite A100, Lanham, MD 20706 (United States); Smith, K. M. [Perimeter Institute for Theoretical Physics, Waterloo, ON N2L 2Y5 (Canada); Gold, B. [School of Physics and Astronomy, University of Minnesota, 116 Church Street S.E., Minneapolis, MN 55455 (United States); Komatsu, E. [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild Str. 1, D-85741 Garching (Germany); Nolta, M. R. [Canadian Institute for Theoretical Astrophysics, 60 St. George Street, University of Toronto, Toronto, ON M5S 3H8 (Canada); Spergel, D. N. [Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08544-1001 (United States); Wollack, E.; Kogut, A. [Code 665, NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Dunkley, J. [Oxford Astrophysics, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Limon, M. [Columbia Astrophysics Laboratory, 550 West 120th Street, Mail Code 5247, New York, NY 10027-6902 (United States); Meyer, S. S. [Departments of Astrophysics and Physics, KICP and EFI, University of Chicago, Chicago, IL 60637 (United States); Tucker, G. S., E-mail: cbennett@jhu.edu [Department of Physics, Brown University, 182 Hope Street, Providence, RI 02912-1843 (United States); and others

2013-10-01T23:59:59.000Z

336

REGROWTH BEHAVIOR OF THREE DIFFERENT DAMAGE STRUCTURES IN P+ IMPLANTED AND SUBSEQUENTLY LASER ANNEALED Si  

E-Print Network [OSTI]

94720 +Department of Metallurgy University of Oxford OxfordUK) through Department of Metallurgy, Oxford. REFERENCES G.

Sadana, D.K.

2012-01-01T23:59:59.000Z

337

Higher Dimensional Szekeres' Space-time in Brans-Dicke Scalar Tensor Theory  

E-Print Network [OSTI]

The generalized Szekeres family of solution for quasi-spherical space-time of higher dimensions are obtained in the scalar tensor theory of gravitation. Brans-Dicke field equations expressed in Dicke's revised units are exhaustively solved for all the subfamilies of the said family. A particular group of solutions may also be interpreted as due to the presence of the so-called C-field of Hoyle and Narlikar and for a chosen sign of the coupling parameter. The models show either expansion from a big bang type of singularity or a collapse with the turning point at a lower bound. There is one particular case which starts from the big bang, reaches a maximum and collapses with the in course of time to a crunch.

Asit Banerjee; Ujjal Debnath; Subenoy Chakraborty

2004-04-21T23:59:59.000Z

338

Stable bounce and inflation in non-local higher derivative cosmology  

SciTech Connect (OSTI)

One of the greatest problems of primordial inflation is that the inflationary space-time is past-incomplete. This is mainly because Einstein's GR suffers from a space-like Big Bang singularity. It has recently been shown that ghost-free, non-local higher-derivative ultra-violet modifications of Einstein's gravity may be able to resolve the cosmological Big Bang singularity via a non-singular bounce. Within the framework of such non-local cosmological models, we are going to study both sub- and super-Hubble perturbations around an inflationary trajectory which is preceded by the Big Bounce in the past, and demonstrate that the inflationary trajectory has an ultra-violet completion and that perturbations do not suffer from any pathologies.

Biswas, Tirthabir [Department of Physics, Loyola University, 6363 St. Charles Avenue, Campus Box 92, New Orleans (United States); Koshelev, Alexey S. [Theoretische Natuurkunde, Vrije Universiteit Brussel and The International Solvay Institutes, Pleinlaan 2, B-1050, Brussels (Belgium); Mazumdar, Anupam [Consortium for Fundamental Physics, Physics Department, Lancaster University, Lancaster, LA1 4YB (United Kingdom); Vernov, Sergey Yu., E-mail: tbiswas@loyno.edu, E-mail: alexey.koshelev@vub.ac.be, E-mail: a.mazumdar@lancaster.ac.uk, E-mail: svernov@theory.sinp.msu.ru [Instituto de Ciencias del Espacio, Institut d'Estudis Espacials de Catalunya, Campus UAB, Facultat de Ciències, Torre C5-Parell-2a planta, E-08193, Bellaterra (Barcelona) (Spain)

2012-08-01T23:59:59.000Z

339

Does the universe obey the energy conservation law by a constant mass or an increasing mass with radius during its evolution?  

E-Print Network [OSTI]

How the energy conservation law is obeyed by the universe during its evolution is an important but not yet unanimously resolved question. Does the universe have a constant mass during its evolution or has its mass been increasing with its radius? Here, we evaluate the two contending propositions within the context of the Friedmann equations and the standard big bang theory. We find that though both propositions appeal to the Friedmann equations for validity, an increasing mass with increasing radius is more in harmony with the thermal history of the big bang model. In addition, temperature and flatness problems that plague the constant mass proposal are mitigated by the increasing mass with radius proposal. We conclude that the universe has been increasing in mass and radius in obedience to the energy conservation law.

Akinbo Ojo

2008-10-09T23:59:59.000Z

340

The Origin of the Elements  

ScienceCinema (OSTI)

The world around us is made of atoms. Did you ever wonder where these atoms came from? How was the gold in our jewelry, the carbon in our bodies, and the iron in our cars made? In this lecture, we will trace the origin of a gold atom from the Big Bang to the present day, and beyond. You will learn how the elements were forged in the nuclear furnaces inside stars, and how, when they die, these massive stars spread the elements into space. You will learn about the origin of the building blocks of matter in the Big Bang, and we will speculate on the future of the atoms around us today.

Murphy, Edward

2014-08-06T23:59:59.000Z

Note: This page contains sample records for the topic "oxford big-bang nucleosynthesis" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Gravity-anti-Gravity Symmetric Mini-Superspace: Quantum Entanglement and Cosmological Scale Factor Grid  

E-Print Network [OSTI]

A gravity-anti-gravity (GaG) odd linear dilaton action offers an eternal inflation evolution governed by the unified (cosmological constant plus radiation) equation of state $\\rho-3P=4\\Lambda$. At the mini superspace level, a 'two-particle' variant of the no-boundary proposal, notably 'one-particle' energy dependent, is encountered. While a GaG-odd wave function can only host a weak Big Bang boundary condition, albeit for any $k$, a strong Big Bang boundary condition requires a GaG-even entangled wave function, and singles out $k=0$ flat space. The locally most probable values for the cosmological scale factor and the dilaton field form a grid $\\{a^2,a\\phi\\}\\sim\\sqrt{4n_1+1}\\pm\\sqrt{4n_2+1}$.

Aharon Davidson; Tomer Ygael

2014-10-22T23:59:59.000Z

342

Centre for the Study of African Economies Department of Economics . University of Oxford . Manor Road Building . Oxford OX1 3UQ  

E-Print Network [OSTI]

, Olivia D'Aoust , Olivier Sterck§ May 2014 Abstract We aim at understanding the triggers of electoral, Electoral violence, Polarization, Demobilization, Burundi JEL Classification: D74, O11, O17, O55 We thank, Antonio Estache, James Fenske, Anke Hoeffler, Davy Paindaveine, Cyrus Samii and Philip Verwimp

Oxford, University of

343

Centre for the Study of African Economies Department of Economics . University of Oxford . Manor Road Building . Oxford OX1 3UQ  

E-Print Network [OSTI]

Kenzie and Woodruff (2008) (DMW henceforth). The authors find large returns to capital drops both in the form of cash

Oxford, University of

344

Centre for the Study of African Economies Department of Economics . University of Oxford . Manor Road Building . Oxford OX1 3UQ  

E-Print Network [OSTI]

the adoption of com- munal palm harvesting (imachi nkwu) in response to commercialization of palm oil among result is that, if the price of palm oil rises above a certain threshold, commu- nal property in Nigeria, however, curtailed private rights over palm trees in response to the palm produce trade

Oxford, University of

345

Centre for the Study of African Economies Department of Economics . University of Oxford . Manor Road Building . Oxford OX1 3UQ  

E-Print Network [OSTI]

.enquiries@economics.ox.ac.uk . W: www.csae.ox.ac.uk 1 Climate Change, Green Growth and Aid Allocation to Poor Countries Stefan Dercon1 Abstract With serious impacts of climate change looming in a few decades, but current poverty to climate change, and remain focused on fighting current poverty reduction, including via economic growth

Oxford, University of

346

Centre for the Study of African Economies Department of Economics . University of Oxford . Manor Road Building . Oxford OX1 3UQ  

E-Print Network [OSTI]

international tests, based on cross-sectional data on children in middle or secondary school, raise two, prior to school enrolment, with children in Vietnam at the upper end, children in Ethiopia at the lower, and with Peru and India in between. Differences between country samples grow in magnitude at later ages

Oxford, University of

347

Centre for the Study of African Economies Department of Economics . University of Oxford . Manor Road Building . Oxford OX1 3UQ  

E-Print Network [OSTI]

commodities. A sustained increase in the price of renewables (wool) reduces inequality whreas the same for non-renewable that one of the key empirical foundations of the Engerman and Sokoloff argument is that inequality in Latin America was higher than North America. Perhaps, but what about Europe? Williamson (2010) and Milanovic et

Oxford, University of

348

Inflation and the Higgs Scalar  

E-Print Network [OSTI]

This note makes a self-contained exposition of the basic facts of big bang cosmology as they relate to inflation. The fundamental problems with that model are then explored. A quartic scalar potential model of inflation is evaluated which provides the solution of those problems and makes predictions which will soon be definitively tested. The possibility that the recently discovered fundamental Higgs scalar field drives inflation is explored.

Dan Green

2014-12-05T23:59:59.000Z

349

Cosmology, Thermodynamics and Matter Creation  

E-Print Network [OSTI]

Several approaches to the matter creation problem in the context of cosmological models are summarily reviewed. A covariant formulation of the general relativistic imperfect simple fluid endowed with a process of matter creation is presented. By considering the standard big bang model, it is shown how the recent results of Prigogine et alii \\cite{1} can be recovered and, at the same time their limits of validity are explicited.

J. A. S. Lima; M. O. Calvao; I. Waga

2007-08-24T23:59:59.000Z

350

Instantaneous Power Radiated from Magnetic Dipole Moments  

E-Print Network [OSTI]

We compute the power radiated per unit solid angle of a moving magnetic dipole moment, and its instantaneous radiated power, both non-relativistically and relativistically. This is then applied to various interesting situations: solar neutrons, electron synchrotrons and cosmological Dirac neutrinos. Concerning the latter, we show that hypothesized early-universe Big Bang conditions allow for neutrino radiation cooling and provide an energy loss-mechanism for subsequent neutrino condensation.

Peter D. Morley; Douglas J. Buettner

2014-07-04T23:59:59.000Z

351

Gravitational Entropy and the Second Law of Thermodynamics  

E-Print Network [OSTI]

The spontaneous violation of Lorentz and diffeomorphism invariance in a phase near the big bang lowers the entropy, allowing for an arrow of time and the second law of thermodynamics. The spontaneous symmetry breaking leads to $O(3,1)\\rightarrow O(3)\\times R$, where $O(3)$ is the rotational symmetry of the Friedmann-Lema\\^{i}tre-Robertson-Walker spacetime. The Weyl curvature tensor $C_{\\mu\

Moffat, J W

2014-01-01T23:59:59.000Z

352

Quark Nuggets as Baryonic Dark Matter  

E-Print Network [OSTI]

The cosmic first order phase transition from quarks to hadrons, occurring a few microseconds after the Big Bang, would lead to the formation of quark nuggets which would be stable on a cosmological time scale, if the associated baryon number is larger than a critical value. We examine the possibility that these surviving quark nuggets may not only be viable candidates for cold dark matter but even close the universe.

Jan-e Alam; Sibaji Raha; Bikash Sinha

1997-04-23T23:59:59.000Z

353

Columbia University http://www.columbia.edu/~mem4/  

E-Print Network [OSTI]

Mike Mauel Columbia University http://www.columbia.edu/~mem4/ and Jefferson Science Fellow EEB slow! #12;100-300 s after the "Big-Bang": The Age of Fusion · At 100 sec, the universe cools to 1,000,000,000° · Protons and neutrons fuse to Deuterium (heavy hydrogen).The whole universe is a "burning plasma"! · D + D

Mauel, Michael E.

354

On the Weyl curvature hypothesis  

SciTech Connect (OSTI)

The Weyl curvature hypothesis of Penrose attempts to explain the high homogeneity and isotropy, and the very low entropy of the early universe, by conjecturing the vanishing of the Weyl tensor at the Big-Bang singularity. In previous papers it has been proposed an equivalent form of Einstein’s equation, which extends it and remains valid at an important class of singularities (including in particular the Schwarzschild, FLRW, and isotropic singularities). Here it is shown that if the Big-Bang singularity is from this class, it also satisfies the Weyl curvature hypothesis. As an application, we study a very general example of cosmological models, which generalizes the FLRW model by dropping the isotropy and homogeneity constraints. This model also generalizes isotropic singularities, and a class of singularities occurring in Bianchi cosmologies. We show that the Big-Bang singularity of this model is of the type under consideration, and satisfies therefore the Weyl curvature hypothesis. -- Highlights: •The singularities we introduce are described by finite geometric/physical objects. •Our singularities have smooth Riemann and Weyl curvatures. •We show they satisfy Penrose’s Weyl curvature hypothesis (Weyl=0 at singularities). •Examples: FLRW, isotropic singularities, an extension of Schwarzschild’s metric. •Example: a large class of singularities which may be anisotropic and inhomogeneous.

Stoica, Ovidiu Cristinel, E-mail: holotronix@gmail.com

2013-11-15T23:59:59.000Z

355

Hubble constant from lensing in plasma-redshift cosmology, and intrinsic redshift of quasars  

E-Print Network [OSTI]

In a series of articles, we have shown that the newly discovered plasma-redshift cosmology gives a simpler, more accurate and consistent explanation of many cosmological phenomena than the big-bang cosmology. The SNe Ia observations are in better agreement with the magnitude-redshift relation predicted by the plasma redshift than that predicted by the multi-parameter big-bang cosmology. No deceleration or expansion parameters are needed. The plasma-redshift cosmology is flat and quasi-static on a large scale. The Hubble constant is no longer an expansion parameter, but is instead a measure of the average electron density along the line of sight towards an object. Perusal of the SNe Ia data and quasar data has shown that there is no time dilation. The conventional estimates of the Hubble constant from gravitational lensing observations use the big-bang cosmology for interpreting the observations. This has lead to a large spread and discordant estimates of the Hubble constant. The purpose of the present article is to show that the gravitational lensing observations are in agreement with the plasma-redshift cosmology, and to show how to evaluate the lensing observations based on the new plasma-redshift cosmology. The lensing observations also indicate that the quasars have large intrinsic redshifts.

Ari Brynjolfsson

2004-12-02T23:59:59.000Z

356

Cross-section measurement of the $^{130}$Ba(p,$?$)$^{131}$La reaction for $?$-process nucleosynthesis  

E-Print Network [OSTI]

A measurement of total cross-section values of the $^{130}$Ba(p,$\\gamma$)$^{131}$La reaction at low proton energies allows a stringent test of statistical model predictions with different proton+nucleus optical model potentials. Since no experimental data are available for proton-capture reactions in this mass region around A~$\\approx$~130, this measurement can be an important input to test the global applicability of proton+nucleus optical model potentials. The total reaction cross-section values were measured by means of the activation method. After the irradiation with protons, the reaction yield was determined by use of $\\gamma$-ray spectroscopy using two clover-type high-purity germanium detectors. In total, cross-section values for eight different proton energies could be determined in the energy range between 3.6 MeV $\\leq E_p \\leq$ 5.0 MeV, thus, inside the astrophysically relevant energy region. The measured cross-section values were compared to Hauser-Feshbach calculations using the statistical model codes TALYS and SMARAGD with different proton+nucleus optical model potentials. With the semi-microscopic JLM proton+nucleus optical model potential used in the SMARAGD code, the absolute cross-section values are reproduced well, but the energy dependence is too steep at the lowest energies. The best description is given by a TALYS calculation using the semi-microscopic Bauge proton+nucleus optical model potential using a constant renormalization factor.

L. Netterdon; A. Endres; G. G. Kiss; J. Mayer; T. Rauscher; P. Scholz; K. Sonnabend; Zs. Török; A. Zilges

2014-09-27T23:59:59.000Z

357

The effect of 12C + 12C rate uncertainties on the evolution and nucleosynthesis of  

E-Print Network [OSTI]

Contact: M. E. Bennett, Keele University, meb@astro.keele.ac.uk Published: Bennet et al., Monthly Notices

Herwig, Falk

358

Experimental study of beta-delayed proton decay of (23)Al for nucleosynthesis in novae  

E-Print Network [OSTI]

. Roeder,2 E. Simmons,2 G. Tabacaru,2,? R. E. Tribble,2 P. J. Woods,4 and J. ?Aysto?1 1Department of Physics, University of Jyva?skyla?, P.O. Box 35 (YFL), FI-40014 Finland 2Cyclotron Institute, Texas A&M University, College Station, Texas 77843-3366, USA...?ja?rvi for their valuable comments. This work has been supported by the Academy of Finland under the Finnish Centre of Excellence Programme 2006-2011 (Project No. 213503, Nuclear and Accelerator Based Physics Programme at JYFL) and by the US Department of Energy under...

Saastamoinen, A.; Trache, L.; Banu, A.; Bentley, M. A.; Davinson, T.; Hardy, John C.; Iacob, V. E.; McCleskey, M.; Roeder, B. T.; Simmons, E.; Tabacaru, G.; Tribble, Robert E.; Woods, P. J.; Aysto, J.

2011-01-01T23:59:59.000Z

359

Nucleosynthesis at the proton drip line a challenge for nuclear physics  

E-Print Network [OSTI]

are thermonuclear flashes on the surface of accreting neutron stars [1--3] (see also the review article [4 in a thermonuclear runaway. Helium is burned via the 3ff­reaction and the ffp­process (a sequence of (ff,p) and (p fuel to power the second burst and can therefore not be explained by the simple #12; thermonuclear

Rauscher, Thomas

360

Neutrino-nucleus reactions and their role for supernova dynamics and nucleosynthesis  

E-Print Network [OSTI]

The description of nuclear reactions induced by supernova neutrinos has witnessed significant progress during the recent years. At the energies and momentum transfers relevant for supernova neutrinos neutrino-nucleus cross sections are dominated by allowed transitions, however, often with non-negligible contributions from (first) forbidden transitions. For several nuclei allowed Gamow-Teller strength distributions could be derived from charge-exchange reactions and from inelastic electron scattering data. Importantly the diagonalization shell model has been proven to accurately describe these data and hence became the appropriate tool to calculate the allowed contributions to neutrino-nucleus cross sections for supernova neutrinos. Higher multipole contributions are usually calculated within the framework of the Quasiparticle Random Phase Approximation, which describes the total strength and the position of the giant resonances quite well. This manuscript reviews the recent progress achieved in calculating su...

Balasi, K G; Martínez-Pinedo, G

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "oxford big-bang nucleosynthesis" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Study of {sup 24}Mg resonances relevant for carbon burning nucleosynthesis  

SciTech Connect (OSTI)

We have studied decays of resonances in {sup 24}Mg at excitation energies above the {sup 12}C+{sup 12}C decay threshold, using {sup 12}C({sup 16}O,?){sup 24}Mg* reaction. This experiment has been performed at INFNLNS, using Tandem accelerator beam of 16O at E = 94 MeV. Some preliminary results are presented.

Toki?, V.; Soi?, N.; Blagus, S.; Fazini?, S.; Jelavi?-Malenica, D.; Miljani?, D.; Prepolec, L.; Skukan, N.; Szilner, S.; Uroi?, M. [Ru?er Boškovi? Institute, Bijeni?ka cesta 54, 10000 Zagreb (Croatia); Milin, M. [Faculty of Science, University of Zagreb, Bijeni?ka cesta 32, 10000 Zagreb (Croatia); Di Pietro, A.; Figuera, P.; Fisichella, M.; Lattuada, M.; Scuderi, V.; Strano, E.; Torresi, D. [INFN-Laboratori Nazionali del Sud, via S.Sofia 62, 95125 Catania (Italy); Freer, M.; Ziman, V. [School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT (United Kingdom); and others

2014-05-09T23:59:59.000Z

362

Nucleosynthesis of Nickel-56 from Gamma-Ray Burst Accretion Disks  

E-Print Network [OSTI]

We examine the prospects for producing Nickel-56 from black hole accretion disks, by examining a range of steady state disk models. We focus on relatively slowly accreting disks in the range of 0.05 - 1 solar masses per second, as are thought to be appropriate for the central engines of long-duration gamma-ray bursts. We find that significant amounts of Nickel-56 are produced over a wide range of parameter space. We discuss the influence of entropy, outflow timescale and initial disk position on mass fraction of Nickel-56 which is produced. We keep careful track of the weak interactions to ensure reliable calculations of the electron fraction, and discuss the role of the neutrinos.

R. Surman; G. C. McLaughlin; N. Sabbatino

2011-12-12T23:59:59.000Z

363

Nucleosynthesis of Elements in Low to Intermediate Mass Stars through the  

E-Print Network [OSTI]

evolution (which is discussed in detail in section IV). c fl 1995 American Institute of Physics 1 #12; 2 A Basic Evolution at 1 Solar Mass We make the usual assumption that a star reaches the zero­age main se. Core H­burning occurs radiatively, and the central temperature and density grow in response

Lattanzio, John

364

nu-Process Nucleosynthesis in Population III Core-Collapse Supernovae  

E-Print Network [OSTI]

We investigate the effects of neutrino-nucleus interactions (the nu-process) on the production of iron-peak elements in Population III core-collapse supernovae. The nu-process and the following proton and neutron capture reactions produce odd-Z iron-peak elements in complete and incomplete Si burning region. This reaction sequence enhances the abundances of Sc, Mn, and Co in the supernova ejecta. The supernova explosion models of 15 M_sol and 25 M_sol stars with the nu-process well reproduce the averaged Mn/Fe ratio observed in extremely metal-poor halo stars. In order to reproduce the observed Mn/Fe ratio, the total neutrino energy in the supernovae should be 3 - 9 x 10^{53} ergs. Stronger neutrino irradiation and other production sites are necessary to reproduce the observed Sc/Fe and Co/Fe ratios, although these ratios increase by the nu-process.

Takashi Yoshida; Hideyuki Umeda; Ken'ichi Nomoto

2007-10-01T23:59:59.000Z

365

1IFM'07, Oxford, UK, July 3-5, 2007 Translating FSP into LOTOS and  

E-Print Network [OSTI]

-to-use notation ­ basic verification means (LTSA) animation and LTL property checking · LOTOS is an ISO standard: ­ FSP is a simple yet expressive notation ­ CADP is a rich toolbox to be used jointly with LTSA

Joseph Fourier Grenoble-I, Université

366

Status of T2K Target 2nd Oxford-Princeton High-Power Target Workshop  

E-Print Network [OSTI]

Graphite (ToyoTanso IG-43) Current Target Design Helium cooling Graphite to titanium diffusion bond 47.0 46-Power Target Workshop Mike Fitton IG43 Graphite diffusion bonded into Ti-6Al-4V titanium, Special Techniques Group at UKAEA Culham Diffusion Bond + Graphite-Graphite bonding test Aluminium intermediate layer

McDonald, Kirk

367

OxfordCentreforTectonicandMetallogenicStudies For details concerning OCTAMS initiatives, or undergraduate/postgraduate  

E-Print Network [OSTI]

the relationships between the pattern of global tectonics and the nature and distribution of the Earth's mineral elsewhere in the world. · OCTAMS hopes to interact closely with industrial partners from both the minerals. The nature and distribution of both metal and petroleum resources will be examined in the context

Henderson, Gideon

368

The Oxford Handbook of american eLecTiOnS  

E-Print Network [OSTI]

. Kenney, Laura Langer, meghan Leonard, Jan e. Leighley, Suzanna Linn, arthur Lupia, Jon a. Krosnick, Karen mossberger, Jonathan nagler, Barbara norrander, Josh Pasek, andrea Polk, Lynda W. Powell, David W

369

Teaching natural philosophy and mathematics at Oxford and Cambridge 1500-1570  

E-Print Network [OSTI]

of the subject; Pole was a noted theologian who used the Greek fathers; and Cecil’s personal library contained many Greek works. 21 Diarmaid MacCulloch, The Later Reformation in England 1547 - 1603 (London, 1990). p. 67. 22 It is clear that even Pole took... of natural philosophy. This is a trade off between instances where an individual bought the collected works without much interest in the section on natural philosophy, and those who were interested in the Physica and De anima to the exclusion of all...

Hannam, James

2008-04-22T23:59:59.000Z

370

The origins .... of life A sermon delivered in The Queen's College, Oxford  

E-Print Network [OSTI]

on with, you know, this origin of life business. More scuffling, more coughs. But why? Simply because

Capdeboscq, Yves

371

The Queen's College Guide to Driving and Parking in and around Oxford  

E-Print Network [OSTI]

Street (182 spaces) ­ City Centre · Abbey Place (80 spaces) - Opposite the ice-rink · Gloucester green (100 spaces) - Underground close to the centre · Oxpens (56 spaces) - Next to the ice-rink · St

Capdeboscq, Yves

372

PLEASE SCROLL DOWN FOR ARTICLE This article was downloaded by: [University of Oxford  

E-Print Network [OSTI]

://www.informaworld.com/smpp/title~content=t713439457 Understanding Carbon Offset Technologies Heather Lovella ; Diana Livermanb a Centre for the Study(2010) 'Understanding Carbon Offset Technologies', New Political Economy, 15: 2, 255 -- 273 To link Carbon Offset Technologies HEATHER LOVELL & DIANA LIVERMAN In this article we unpack the `black box

373

E-Print Network 3.0 - annual meeting oxford Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of East Anglia Collection: Environmental Sciences and Ecology ; Geosciences 5 CURRICULUM VITAE Andrew Hollingworth Summary: eye movements told us so far, and what is next?...

374

Compact Manifolds with Holonomy Spin(7) Christine Taylor, Balliol College, Oxford  

E-Print Network [OSTI]

with Holon- omy Spin(7) 8 2.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2

Joyce, Dominic

375

This article was downloaded by: [the Bodleian Libraries of the University of Oxford], [Yadvinder Malhi  

E-Print Network [OSTI]

to monitor aboveground biomass in forest and oil palm in Sabah, Malaysia, for 2000­2008 with Landsat ETM to monitor aboveground biomass in forest and oil palm in Sabah, Malaysia, for 2000­2008 with Landsat ETM the potential to monitor aboveground biomass in forest and oil palm in Sabah, Malaysia, for 2000

Malhi, Yadvinder

376

P. MCK Cryst. Res. Technol. 35 (2000) 529-540 Department of Materials, University of Oxford  

E-Print Network [OSTI]

Comparison of Experiments and Theories for Plastic Deformation in thermally processed GaAs Wafers Different single crystal X-ray transmission topography, scanning infrared polariscopy, visible light interferometry that reduces the yield of electronic devices in manufacturing processes on an industrial scale [KIYAMA et al

Moeck, Peter

377

CopyrightOxfordUniversityPress2006v1.0 Statistical Mechanics  

E-Print Network [OSTI]

in physics. Indeed, many physicists in their later careers are now taking excursions into these other finds Maxwell relations for the stock market, or Clausius­Clapeyron equations appli- cable applications of statistical mechanics: random matrix theory, stock-market volatility, the KAM theorem, Shannon

Sethna, James P.

378

DEPARTMENT OF EARTH SCIENCES, UNIVERSITY OF OXFORD SECOND YEAR FIELD COURSE -SE FRANCE  

E-Print Network [OSTI]

that grip well. Safety helmets will be used when working beneath cliffs and road-cuts or in quarries. Safety

Niocaill, Conall Mac

379

Yanxu Zhang 193 Pierce Hall, 29 Oxford Street, Harvard University, Cambridge MA 02138 USA  

E-Print Network [OSTI]

, Seattle WA l Doctor of Philosophy, Department of Atmospheric Sciences, 2013 Peking University, Beijing China l Doctor of Philosophy, College of Urban and Environmental Sciences, 2010 l Bachelor of Science China, 2005-2009 Dissertation: The Emission, Transport and Risk of Atmospheric Polycyclic Aromatic

Jacob, Daniel J.

380

Microsoft PowerPoint - Oxford_MiniBooNE_and_SterileNus.ppt  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces andMapping Richland OperationsU.S.Online CA: EnablingJuly 30,Actions

Note: This page contains sample records for the topic "oxford big-bang nucleosynthesis" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Chapter 7.42 Oxford Plasmalab 100 ICP (Compound III-V)  

E-Print Network [OSTI]

purging steps in the load lock vent. Do not breathe in vapor from the loadlock on vent. Never abort a vent degree 7.2.5 Known possible problems: 7.2.5.1 Overpassivation: The CH3+Cl2+H2 chemistry is a very use the "stop" button. This is equivalent to aborting your process and will leave the wafer

Healy, Kevin Edward

382

Monte Carlo Methods for Uncertainty Quantification Mathematical Institute, University of Oxford  

E-Print Network [OSTI]

methods October 25, 2013 7 / 28 Application 3 In modelling groundwater flow in nuclear waste repositories: Introduction and Monte Carlo basics some model applications random number generation Monte Carlo estimation specified range Note: if we turn this into a full finite element analysis, then the computational cost

Giles, Mike

383

Opening a bank account in Oxford A guide for European and International Students  

E-Print Network [OSTI]

of the facilities offered by the five main UK banks; Santander, LloydsTSB, HSBC, Nat West, and Barclays is included and International students: LloydsTSB Santander HSBC (Nat West 29 September only) Do take advantage and go along

Oxford, University of

384

Information correct as of September 2012 Opening a bank account in Oxford  

E-Print Network [OSTI]

TSB, HSBC, Nat West, and Barclays is included at the end of this document. This information is provided

Oxford, University of

385

The Formation of Primordial Luminous Objects  

SciTech Connect (OSTI)

The scientific belief that the universe evolves in time is one of the legacies of the theory of the Big Bang. The concept that the universe has an history started to attract the interest of cosmologists soon after the first formulation of the theory: already Gamow (1948; 1949) investigated how and when galaxies could have been formed in the context of the expanding Universe. However, the specific topic of the formation (and of the fate) of the first objects dates to two decades later, when no objects with metallicities as low as those predicted by primordial nucleosynthesis (Z {approx}< 10{sup -10} {approx} 10{sup -8}Z{sub {circle_dot}}) were found. Such concerns were addressed in two seminal papers by Peebles & Dicke (1968; hereafter PD68) and by Doroshkevich, Zel'Dovich & Novikov (1967; hereafter DZN67), introducing the idea that some objects could have formed before the stars we presently observe. (1) Both PD68 and DZN67 suggest a mass of {approx} 10{sup 5} M{sub {circle_dot}} for the first generation of bound systems, based on the considerations on the cosmological Jeans length (Gamow 1948; Peebles 1965) and the possible shape of the power spectrum. (2) They point out the role of thermal instabilities in the formation of the proto-galactic bound object, and of the cooling of the gas inside it; in particular, PD68 introduces H{sub 2} cooling and chemistry in the calculations about the contraction of the gas. (3) Even if they do not specifically address the occurrence of fragmentation, these papers make two very different assumptions: PD68 assumes that the gas will fragment into ''normal'' stars to form globular clusters, while DZN67 assumes that fragmentation does not occur, and that a single ''super-star'' forms. (4) Finally, some feedback effects as considered (e.g. Peebles & Dicke considered the effects of supernovae). Today most of the research focuses on the issues when fragmentation may occur, what objects are formed and how they influence subsequent structure formation. In these notes we will leave the discussion of feedback to lecture notes by Ferrara & Salvaterra and by Madau & Haardt in this same book and focus only on the aspects of the formation of the first objects. The advent of cosmological numerical hydrodynamics in particular allow a fresh new look at these questions. Hence, these notes will touch on aspects of theoretical cosmology to chemistry, computer science, hydrodynamics and atomic physics. For further reading and more references on the subject we refer the reader to other relevant reviews such as Barkana & Loeb 2001, and more recently Ciardi & Ferrara 2004, Glover 2004 and Bromm & Larson 2004. In these notes, we try to give a brief introduction to only the most relevant aspects. We will start with a brief overview of the relevant cosmological concepts in section 2, followed by a discussion of the properties of primordial material (with particular emphasis to its cooling and its chemistry) in section 3. We will then review the technique and the results of numerical simulations in sections 4 and 5: the former will deal with detailed 3D simulations of the formation of gaseous clouds which are likely to transform into luminous objects, while the latter will examine results (mostly from 1D codes) about the modalities of such transformation. Finally, in section 6 we will critically discuss the results of the previous sections, examining their consequences and comparing them to our present knowledge of the universe.

Ripamonti, Emanuele; /Kapteyn Astron. Inst., Groningen; Abel, Tom; /KIPAC, Menlo Park

2005-08-04T23:59:59.000Z

386

Study Protocol: The Back pain Outcomes using Longitudinal Data (BOLD) Registry  

E-Print Network [OSTI]

modeling for health economic evaluation. Oxford: OxfordSonnad SS, Polsky D: Economic evaluation in clinical trials.

2012-01-01T23:59:59.000Z

387

Equine Grazing in Managed Subalpine Wetlands: Effects on Arthropods and Plant Structure as a Function of Habitat  

E-Print Network [OSTI]

Environmental impacts of ecotourism. CABI, Oxford, pp 41-60Environmental impacts of ecotourism. CABI, Oxford, pp Oliver

Holmquist, Jeffrey G; Schmidt-Gengenbach, Jutta; Haultain, Sylvia A

2013-01-01T23:59:59.000Z

388

Gamma-Ray Bursts from Primordial Quark Objects in Space  

E-Print Network [OSTI]

We investigate the possibility that gamma-ray bursts originate in a concentric spherical shell with a given average redshift and find that this is indeed compatible with the data from the third BATSE (3B) catalog. It is also shown that there is enough freedom in the choice of unknown burst properties to allow even for extremely large distances to the majority of bursts. Therefore, we speculate about an early, and very energetic, origin of bursts, and suggest that they come from phase transitions in massive objects of pure quark matter, left over from the Big Bang.

B. Anoushirvani; D. Enström; S. Fredriksson; J. Hansson; P. Ökvist; A. Nicolaidis; S. Ekelin

1997-11-28T23:59:59.000Z

389

No excess of bright galaxies around the redshift 7.1 quasar ULAS J1120+0641  

E-Print Network [OSTI]

to facilitate studies of the Universe in the first billion years after the big bang in two ways. First, since they are the most luminous non-transient objects, it is possible to measure the opacity of the intergalactic medium (IGM) along the line of sight due... whether this was due to flat-fielding errors by constructing a corrective flat-field from our pipelined images. All 25 ACS images were scaled to the same sky level, and this stack was median filtered before the small-scale structure was removed...

Simpson, Chris; Mortlock, Daniel; Warren, Stephen; Cantalupo, Sebastiano; Hewett, Paul; McLure, Ross; McMahon, Richard; Venemans, Bram

2014-07-02T23:59:59.000Z

390

"Millikan oil drops" as quantum transducers between electromagnetic and gravitational radiation  

E-Print Network [OSTI]

Pairs of Planck-mass-scale drops of superfluid helium coated by electrons (i.e., "Millikan oil drops"), when levitated in the presence of strong magnetic fields and at low temperatures, can be efficient quantum transducers between electromagnetic (EM) and gravitational (GR) radiation. A Hertz-like experiment, in which EM waves are converted at the source into GR waves, and then back-converted at the receiver from GR waves back into EM waves, should be practical to perform. This would open up observations of the gravity-wave analog of the Cosmic Microwave Background from the extremely early Big Bang, and also communications directly through the interior of the Earth.

Raymond Y. Chiao

2007-02-25T23:59:59.000Z

391

Planck Surveyor On Its Way to Orbit  

ScienceCinema (OSTI)

An Ariane 5 rocket carried the Planck Surveyor and a companion satellite into space May 14, 2009 from the European Space Agency (ESA) base on the northwest coast of South America. Once in orbit beyond the moon, Planck will produce the most accurate measurements ever made of the relic radiation from the big bang, plus the largest set of CMB data ever recorded. Berkeley Labs long and continuing involvement with Planck began when George Smoot of the Physics Division proposed Plancks progenitor to ESA and continues with preparations for ongoing data analysis for the U.S. Planck team at NERSC, led by Julian Borrill, co-leader of the Computational Cosmology Center

None

2010-01-08T23:59:59.000Z

392

Defects in Four-Dimensional Continua: A Paradigm for the Expansion of the Universe?  

E-Print Network [OSTI]

The presence of defects in material continua is known to produce internal permanent strained states. Extending the theory of defects to four dimensions and allowing for the appropriate signature, it is possible to apply these concepts to space-time. In this case a defect would induce a non-trivial metric tensor, which can be interpreted as a gravitational field. The image of a defect in space-time can be applied to the description of the Big Bang. A review of the four-dimensional generalisation of defects and an application to the expansion of the universe will be presented.

A. Tartaglia

2008-08-24T23:59:59.000Z

393

From the Dark Matter Universe to the Dark Energy Universe  

E-Print Network [OSTI]

Till the late nineties the accepted cosmological model was that of a Universe that had originated in the Big Bang and was now decelerating under the influence of as yet undetected dark matter, so that it would come to a halt and eventually collapse. In 1997 however, the author had put forward a contra model wherein the Universe was driven by dark energy, essentially the quantum zero point field, and was accelerating with a small cosmological constant. There were other deductions too, all in total agreement with observation. All this got confirmation in 1998 and subsequent observations have reconfirmed the findings.

Burra G. Sidharth

2008-03-30T23:59:59.000Z

394

Metamaterial-based model of the Alcubierre warp drive  

E-Print Network [OSTI]

Electromagnetic metamaterials are capable of emulating many exotic space-time geometries, such as black holes, rotating cosmic strings, and the big bang singularity. Here we present a metamaterial-based model of the Alcubierre warp drive, and study its limitations due to available range of material parameters. It appears that the material parameter range introduces strong limitations on the achievable "warp speed", so that ordinary magnetoelectric materials cannot be used. On the other hand, newly developed "perfect" bi-anisotropic non-reciprocal magnetoelectric metamaterials should be capable of emulating the physics of warp drive gradually accelerating up to 1/4c.

Igor I. Smolyaninov

2011-08-11T23:59:59.000Z

395

Russian Military and Security Forces: A Postulated Reaction to a Nuclear Detonation  

SciTech Connect (OSTI)

In this paper, we will examine how Russia's military and security forces might react to the detonation of a 10-kiloton nuclear weapon placed next to the walls surrounding the Kremlin. At the time of this 'big bang,' Putin is situated outside Moscow and survives the explosion. No one claims responsibility for the detonation. No other information is known. Numerous variables will determine how events ultimately unfold and how the military and security forces will respond. Prior to examining these variables in greater detail, it is imperative to elucidate first what we mean by Russia's military and security forces.

Ball, D

2005-04-29T23:59:59.000Z

396

Inquiring Minds - Questions About Physics  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFunInfrared Land Surface Emissivity inFermilab Paving theIsBig Bang & Bosons

397

Inquiring Minds - Questions About Physics  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFunInfrared Land Surface Emissivity inFermilab Paving theIsBig Bang &

398

Inquiring Minds - Questions About Physics  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFunInfrared Land Surface Emissivity inFermilab Paving theIsBig Bang

399

Inquiring Minds - Questions About Physics  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFunInfrared Land Surface Emissivity inFermilab Paving theIsBig BangHello, At

400

Inquiring Minds - Questions About Physics  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFunInfrared Land Surface Emissivity inFermilab Paving theIsBig BangHello,

Note: This page contains sample records for the topic "oxford big-bang nucleosynthesis" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Inquiring Minds - Questions About Physics  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFunInfrared Land Surface Emissivity inFermilab Paving theIsBig BangHello,Why is a

402

Inquiring Minds - Questions About Physics  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFunInfrared Land Surface Emissivity inFermilab Paving theIsBig BangHello,Why is

403

Inquiring Minds - Questions About Physics  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFunInfrared Land Surface Emissivity inFermilab Paving theIsBig BangHello,Why isDo

404

Inquiring Minds - Questions About Physics  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFunInfrared Land Surface Emissivity inFermilab Paving theIsBig BangHello,Why

405

NUCLEOSYNTHESIS IN INTERMEDIATE MASS AGB STARS JOHN LATTANZIO 1;2 , MANUEL FORESTINI 2 , CORINNE CHARBONNEL 3  

E-Print Network [OSTI]

periodic thermal excursions, and the hydrogen shell overlaps the bottom of the convective envelope (in some of partial mixing of the convective envelope with carbon-enriched matter, during the dredge-up phase (Iben; the bottom of the convective envelope dips into the top of the hydrogen burning shell. This then brings

Lattanzio, John

406

SN 2006aj Associated with XRF 060218 At Late Phases: Nucleosynthesis-Signature of A Neutron Star-Driven Explosion  

E-Print Network [OSTI]

Optical spectroscopy and photometry of SN 2006aj have been performed with the Subaru telescope at t > 200 days after GRB060218, the X-ray Flash with which it was associated. Strong nebular emission-lines with an expansion velocity of v ~ 7,300 km/s were detected. The peaked but relatively broad [OI]6300,6363 suggests the existence of ~ 2 Msun of materials in which ~1.3 Msun is oxygen. The core might be produced by a mildly asymmetric explosion. The spectra are unique among SNe Ic in (1) the absence of [CaII]7291,7324 emission, and (2) a strong emission feature at ~ 7400A, which requires ~ 0.05 Msun of newly-synthesized 58Ni. Such a large amount of stable neutron-rich Ni strongly indicates the formation of a neutron star. The progenitor and the explosion energy are constrained to 18 Msun < Mms < 22 Msun and E ~ (1 - 3) 10^{51} erg, respectively.

Maeda, K; Tanaka, M; Nomoto, K; Tominaga, N; Hattori, T; Minezaki, T; Kuroda, T; Suzuki, T; Deng, J; Mazzali, P A; Pian, E; Maeda, Keiichi; Kawabata, Koji; Tanaka, Masaomi; Nomoto, Ken'ichi; Tominaga, Nozomu; Hattori, Takashi; Minezaki, Takeo; Kuroda, Takami; Suzuki, Tomoharu; Deng, Jinsong; Mazzali, Paolo A.; Pian, Elena

2007-01-01T23:59:59.000Z

407

Neutron-capture elements in the s- and r-process-rich stars: Constraints on neutron-capture nucleosynthesis processes  

E-Print Network [OSTI]

The chemical abundances of the very metal-poor double-enhanced stars are excellent information for setting new constraints on models of neutron-capture processes at low metallicity. These stars are known as s+r stars, since they show enhancements of both s-process and r-process elements. The observed abundance ratios for the double-enhanced stars can be explained by those of stars that were polluted by an AGB star and subsequently accreted very significant amounts of r-process material out of an AIC (accretion-induced collapse) or Type 1.5 supernova. In this paper we present for the first time an attempt to fit the elemental abundances observed in the s- and r-rich, very metal-poor stars using a parametric model and suggest a new concept of component coefficients to describe the contributions of the individual neutron-capture processes to double-enhanced stars. We find that the abundance ratios of these stars are best fitted by enrichments of s- and r-process material. The overlap factor in the AGB stars where the observed s-process elements were produced lies between 0.1 and 0.81. Taking into account the dependence of the initial-final mass relations on metallicity, this wide range of values could possibly be explained by a wide range of core-mass values of AGB stars at low metallicity. The component coefficient of the r-process is strongly correlated with the component coefficient of the s-process for the double-enhanced stars. This is significant evidence that the r-process material in double-enhanced stars comes from an AIC or Type 1.5 supernova.

Bo Zhang; Kun Ma; Guide Zhou

2006-05-14T23:59:59.000Z

408

Unified Theory of Bivacuum, Particles Duality, Fields & Time. New Bivacuum Mediated Interaction, Overunity Devices, Cold Fusion & Nucleosynthesis  

E-Print Network [OSTI]

New concept of Bivacuum is introduced, as a dynamic matrix of the Universe, composed from sub-quantum particles and antiparticles, forming vortical structures. These structures are presented by continuum of dipoles, each dipole containing a pair of correlated torus and antitorus: V(+) and V(-) of the opposite energy/mass, spin, charge and magnetic moments, compensating each other. The rest mass and charge of sub-elementary fermions or antifermions is a result of Bivacuum dipoles opposite symmetry shifts. Their fusion to triplets follows by elementary particles and antiparticles origination. The [corpuscle (C) - wave (W)] duality is a result of correlated beats between the 'actual' and 'complementary' states of sub-elementary fermions of triplets. It is shown, that Principle of least action, the 2d and 3d laws of thermodynamics can be a consequences of forced combinational resonance between positive and negative virtual pressure waves (VPW+/-) of Bivacuum and [C-W] pulsation of elementary particles. The quantum entanglement, mediated by virtual microtubules, composed from Bivacuum dipoles, connecting remote particles, is a result of such Bivacuum-matter interaction. The pace of time for any closed system is determined by pace of kinetic energy change of this system. The proposed mechanism of overunity devices can be provided by the electrons acceleration, induced by their resonant interaction with high frequency positive and negative VPW+/- in pull-in range conditions. The latter can be excited by pulsing currents and fields. The mechanism of overheating and cold fusion in electrolytic cells without violation of energy conservation is proposed also.

Alex Kaivarainen

2006-07-14T23:59:59.000Z

409

PUBLICATIONS ROBERT EVERETT CRISS 1999 Criss, R.E., Principles of Stable Isotope Distribution, Oxford University Press,  

E-Print Network [OSTI]

of a rainfall-driven theoretical hydrograph compared to common models and observed data. Water Resources and the global power. Int. J. of Earth Science (Bykov Special Issue), 97, p. 241-244 Criss, R. E., (2008) Terrestrial oxygen isotope variations and their implications for planetary lithospheres. Rev. Mineral., 68, ch

410

PUBLICATIONS ROBERT EVERETT CRISS 1999 Criss, R.E., Principles of Stable Isotope Distribution, Oxford University Press,  

E-Print Network [OSTI]

Sciences (accepted; JES-05-2014-0170). Criss, R.E. (2015) Use of Geochemical and Geophysical Techniques to Characterize and Prospect for Geothermal Resources and Hydrothermal Ore Deposits Journal of Earth Sciences Environment (STOTEN), 447, p. 235-247. Hasenmueller, E. A. and Criss, R. E. (2013) Geochemical techniques

411

Proceedings of: ''Formal Methods Europe'', March 1996, Oxford, UK, LNCS 1051, Springer Automatic Verification of a Hydroelectric Power  

E-Print Network [OSTI]

Verification of a Hydroelectric Power Plant 1 Rosario Pugliese Enrico Tronci Dip. di Scienze dell@univaq.it Abstract. We analyze the specification of a hydroelectric power plant by ENEL (the Italian Electric Company we report on the analysis of a hydroelectric power plant by ENEL (the Italian Electric Company). Our

Tronci, Enrico

412

In Press. To appear in A. Kramer, D. Wiegmann, & A. Kirlik (Eds.) Attention: From Theory to Practice. New York: Oxford.  

E-Print Network [OSTI]

In Press. To appear in A. Kramer, D. Wiegmann, & A. Kirlik (Eds.) Attention: From Theory forgot to set the hydraulic pumps to the high position, which was part of the normal procedure of these accidents, but a central aspect of each accident was the failure of the crew #12;In Press. To appear in A

413

Ann. Occup. Hyg., Vol. 53, No. 6, pp. 551560, 2009 The Author 2009. Published by Oxford University Press  

E-Print Network [OSTI]

not elevated among millers). Results from linear mixed-effects models of levels of U-Nap, U-Phe, OH-Phe, and OH; exposure; PAH; urine INTRODUCTION Asphalt (also referred to as bitumen) is a by-product of petroleum refining that is widely used to pave roads. Road-paving workers are exposed to emis- sions from hot asphalt

California at Berkeley, University of

414

2001 Oxford University Press Nucleic Acids Research, 2001, Vol. 29, No. 22 46634673 Importance of the conserved nucleotides around the  

E-Print Network [OSTI]

of the conserved nucleotides around the tRNA-like structure of Escherichia coli transfer- messenger RNA for protein nucleotide stretches 16­20 and 333­335 seriously impair protein tagging with only minor changes nucleotides next to the tRNA-like portion is proposed. Overall, the highly conserved nucleotides around the t

Paris-Sud XI, Université de

415

1997 Oxford University Press49945002 Nucleic Acids Research, 1997, Vol. 25, No. 24 Information analysis of Fis binding sites  

E-Print Network [OSTI]

analysis of Fis binding sites Paul N. Hengen1, Stacy L. Bartram1,2,+, Lisa E. Stewart1 and Thomas D 30, 1997 ABSTRACT Originally discovered in the bacteriophage Mu DNA inversion system gin, Fis (Factor for Fis to locate its binding sites, we collected a set of 60 experimentally defined wild-type Fis DNA

Schneider, Thomas D.

416

1997 Oxford University Press 13391346Nucleic Acids Research, 1997, Vol. 25, No. 7 Mechanisms of triplex-caused polymerization arrest  

E-Print Network [OSTI]

of triplex-caused polymerization arrest Andrey S. Krasilnikov1,2, Igor G. Panyutin3, George M. Samadashwily1/purine/purine triplexes are known to inhibit DNA polymerization. Here we have studied the mech- anisms of this inhibition temperatures and ambient conditions make them a barrier to polymerization. INTRODUCTION During the last decade

Mirkin, Sergei

417

The Twisted Matrix: Dream, Simulation or Hybrid? to appear in C. Grau (ed) Philosophical Essays on the Matrix (Oxford University  

E-Print Network [OSTI]

³The Twisted Matrix: Dream, Simulation or Hybrid?² to appear in C. Grau (ed) Philosophical Essays://whatisthematrix.warnerbros.com/rl_cmp/phi.html The Twisted Matrix: Dream, Simulation or Hybrid1? 1. Ambivalence "The Matrix is a computer in a world of persisting, external, independent people, cities, cars and objects, and you yourself

Clark, Andy

418

1996 Oxford University Press 713720Nucleic Acids Research, 1996, Vol. 24, No. 4 Atomic force microscopy of long and short  

E-Print Network [OSTI]

of DNA can be reliably imaged and identified and also what substrates and methods of sample preparation technique for observing DNA. The AFM can image conformations of DNA molecules (3­5), nucleosome Corporation; Wood Dale, IL) and cleaved with tape immediately before use. Silicon. Oxidized silicon substrates

Hansma, Helen

419

1998 Oxford University Press 7379Nucleic Acids Research, 1998, Vol. 26, No. 1 SGD: Saccharomyces Genome Database  

E-Print Network [OSTI]

, Erich T. Hester, Yankai Jia, Gail Juvik, TaiYun Roe, Mark Schroeder, Shuai Weng and David Botstein

Botstein, David

420

178 VI. CLASSICAL PROBABILITY AND ITS RENAISSANCE 11. M. Tribus, Rational Descriptions, Decisions and Designs, p. 130. Oxford: Pergamon,  

E-Print Network [OSTI]

. However, the classical theory lacked guidelines for the identifica- tion of a balance of evidence gives us few guidelines for the actual determination of logical probability. Finally, we consider Carnap, quantitative logical relation, called degree of confirmation (d.c.), to measure the support one statement lends

Fitelson, Branden

Note: This page contains sample records for the topic "oxford big-bang nucleosynthesis" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Subtraction-noise projection in gravitational-wave detector networks  

SciTech Connect (OSTI)

In this paper, we present a successful implementation of a subtraction-noise projection method into a simple, simulated data analysis pipeline of a gravitational-wave search. We investigate the problem to reveal a weak stochastic background signal which is covered by a strong foreground of compact-binary coalescences. The foreground, which is estimated by matched filters, has to be subtracted from the data. Even an optimal analysis of foreground signals will leave subtraction noise due to estimation errors of template parameters which may corrupt the measurement of the background signal. The subtraction noise can be removed by a noise projection. We apply our analysis pipeline to the proposed future-generation space-borne Big Bang Observer mission which seeks for a stochastic background of primordial gravitational waves in the frequency range {approx}0.1 Hz--1 Hz covered by a foreground of black-hole and neutron-star binaries. Our analysis is based on a simulation code which provides a dynamical model of a time-delay interferometer network. It generates the data as time series and incorporates the analysis pipeline together with the noise projection. Our results confirm previous ad hoc predictions which say that the Big Bang Observer will be sensitive to backgrounds with fractional energy densities below {omega}=10{sup -16}.

Harms, Jan; Mahrdt, Christoph; Otto, Markus; Priess, Malte [Institut fuer Gravitationsphysik, Universitaet Hannover and Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut), Callinstrasse 38, 30167 Hannover (Germany)

2008-06-15T23:59:59.000Z

422

Loop quantum cosmology of k=1 FRW models  

E-Print Network [OSTI]

The closed, k=1, FRW model coupled to a massless scalar field is investigated in the framework of loop quantum cosmology using analytical and numerical methods. As in the k=0 case, the scalar field can be again used as emergent time to construct the physical Hilbert space and introduce Dirac observables. The resulting framework is then used to address a major challenge of quantum cosmology: resolving the big-bang singularity while retaining agreement with general relativity at large scales. It is shown that the framework fulfills this task. In particular, for states which are semi-classical at some late time, the big-bang is replaced by a quantum bounce and a recollapse occurs at the value of the scale factor predicted by classical general relativity. Thus, the `difficulties' pointed out by Green and Unruh in the k=1 case do not arise in a more systematic treatment. As in k=0 models, quantum dynamics is deterministic across the deep Planck regime. However, because it also retains the classical recollapse, in contrast to the k=0 case one is now led to a cyclic model. Finally, we clarify some issues raised by Laguna's recent work addressed to computational physicists.

Abhay Ashtekar; Tomasz Pawlowski; Parampreet Singh; Kevin Vandersloot

2007-01-23T23:59:59.000Z

423

Magnitude-Redshift Relation for SNe Ia, Time Dilation, and Plasma Redshift  

E-Print Network [OSTI]

We have previously shown that the type Ia supernovae data by Riess et al. match the prediction of the magnitude-redshift relation in the plasma-redshift cosmology. In this article, we also show that the recent SNLS data, which have a slightly narrower distribution as reported by Astier et al. in 2005, match the predictions of the plasma-redshift cosmology. The standard deviation of the SNLS-magnitude from the predicted curve is only about 0.14. The data indicate that there is no cosmic time dilation. The big-bang cosmology therefore appears false. The plasma redshift, which follows from exact evaluation of photons interaction with hot sparse electron plasma, leads to a quasi-static, infinite, and everlasting universe. It does not need big bang, dark energy, or dark matter for describing the observations. It predicts intrinsic redshifts of galaxies consistent with what is observed. The Hubble constant that best fits the SNLS data is about 63 km per sec per Mpc. This corresponds to an average electron density of about 0.0002 per cubic centimeter in intergalactic space. This density together with the plasma redshift heating to an average plasma temperature in intergalactic space of about 3 million K explains the observed isotropic cosmic microwave background (CMB) and the cosmic X-ray background.

Ari Brynjolfsson

2006-02-22T23:59:59.000Z

424

Plasma Redshift, Time Dilation, and Supernovas Ia  

E-Print Network [OSTI]

The measurements of the absolute magnitudes and redshifts of supernovas Ia show that conventional physics, which includes plasma redshift, fully explains the observed magnitude-redshift relation of the supernovas. The only parameter that is required is the Hubble constant, which in principle can be measured independently. The contemporary theory of the expansion of the universe (Big Bang) requires in addition to the Hubble constant several adjustable parameters, such as an initial explosion, the dark matter parameter, and a time adjustable dark energy parameter for explaining the supernova Ia data. The contemporary Big Bang theory also requires time dilation of distant events as an inherent premise. The contention is usually that the light curves of distant supernovas show or even prove the time dilation. In the present article, we challenge this assertion. We document and show that the previously reported data in fact indicate that there is no time dilation. The data reported by Riess et al. in the Astrophysical Journal in June 2004 confirm the plasma redshift, the absence of time dilation, dark matter, and dark energy.

Ari Brynjolfsson

2004-07-20T23:59:59.000Z

425

Fluid Mechanics Explains Cosmology, Dark Matter, Dark Energy, and Life  

E-Print Network [OSTI]

Observations of the interstellar medium by the Herschel, Planck etc. infrared satellites throw doubt on standard {\\Lambda}CDMHC cosmological processes to form gravitational structures. According to the Hydro-Gravitational-Dynamics (HGD) cosmology of Gibson (1996), and the quasar microlensing observations of Schild (1996), the dark matter of galaxies consists of Proto-Globular-star-Cluster (PGC) clumps of Earth-mass primordial gas planets in metastable equilibrium since PGCs began star production at 0.3 Myr by planet mergers. Dark energy and the accelerating expansion of the universe inferred from SuperNovae Ia are systematic dimming errors produced as frozen gas dark matter planets evaporate to form stars. Collisionless cold dark matter that clumps and hierarchically clusters does not exist. Clumps of PGCs began diffusion from the Milky Way Proto-Galaxy upon freezing at 14 Myr to give the Magellanic Clouds and the faint dwarf galaxies of the 10^22 m diameter baryonic dark matter Galaxy halo. The first stars persist as old globular star clusters (OGCs). Water oceans and the biological big bang occurred at 2-8 Myr. Life inevitably formed and evolved in the cosmological primordial organic soup provided by 10^80 big bang planets and their hot oceans as they gently merged to form larger binary planets and small binary stars.

Carl H. Gibson

2012-11-02T23:59:59.000Z

426

On the Electrodynamics of Cosmic repulsion  

E-Print Network [OSTI]

Applying the known physics of plasmas, the 40 plus year old "Strong" Magnetic Field (SMF) model has been extended from explaining the nature of the AGN/quasar central engine, the evolution of galaxies, quasars and jets, the origin of large-scale magnetic fields and large-scale structure of galaxies in our Big Bang Universe, to explaining cosmic repulsion and why it overcame the influence of Gravity only about five billion years ago. Well-known facts about Einstein's general relativity equations, together with the SMF model, are used to explain the astronomical observations that forced us to deduce a present acceleration of the expansion of the Universe. Two groups of astronomical observers, one headed by Saul Perlmutter and the other by Robert Kirshner, recently found an amazing transition, from the expected slowing of the expansion of the Universe due to Gravity, to the expansion of the Universe beginning to be accelerated, at about an age of the Universe of nine billion years in our Big Bang Universe. Profound questions that arise are: what is this "dark energy" causing this result, and why has it started to overcome attractive gravity only in the last five billion years of our 14 billion year old Universe.

Howard D. Greyber

2005-09-08T23:59:59.000Z

427

E-Print Network 3.0 - applied nuclear physics Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

simulations (2003) Nucleosynthesis Nucleosynthesis in massive pop... of neutrinoless double beta decay nuclear matric elements (2003,2006) Low energy precision electroweak...

428

Reciprocity at the Elizabethan Court: The Earl of Leicester and Private Gifts in a Political Arena  

E-Print Network [OSTI]

of Tudor Literature: 1485-1603. Oxford; New York: Oxfordof Tudor Literature: 1485-1603. Oxford; New York: OxfordTudors. A wave of surveys in 1603-4 followed his accession

Xie, Jolene

2013-01-01T23:59:59.000Z

429

E-Print Network 3.0 - analisis terhadap tata Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

state of ... Source: Berry, Richard - Department of Physics, University of Oxford; Leake, Mark C. - Department of Physics, University of Oxford; Palmer, Tracy - Division of...

430

E-Print Network 3.0 - atom molecular mechanics Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of Tokyo Collection: Materials Science 42 List of useful books in the Physical Chemistry Library Mark Brouard, Reaction Dynamics, (Oxford Science Publications, Oxford, 1998)...

431

Predynastic Art  

E-Print Network [OSTI]

and ornamental forms attested in Egypt and Lower Nubia fromThe cultures of prehistoric Egypt. London: Oxford Universitycultures of prehistoric Egypt II. London: Oxford University

Wengrow, David

2009-01-01T23:59:59.000Z

432

WRITTEN TESTIMONY OF DR. ROBERT J. WOOD  

E-Print Network [OSTI]

WRITTEN TESTIMONY OF DR. ROBERT J. WOOD DIRECTOR OF THE COOPERATIVE OXFORD LABORATORY NATIONAL Robert Wood, Director of the Cooperative Oxford Laboratory, a cooperative scientific research laboratory

433

The 1964 Festival of Music of the Americas and Spain: A Critical Examination of Ibero-American Musical Relations in the Context of Cold War Politics  

E-Print Network [OSTI]

of the President's Music": Cold War composers and the Unitedduring the Depression and War. Oxford: Oxford Universityin The Spanish Civil War, 1936-39: American Hemispheric

Payne, Alyson

2012-01-01T23:59:59.000Z

434

Maximum Fuel Utilization in Advanced Fast Reactors without Actinides Separation  

E-Print Network [OSTI]

Oxford ; New York ; Oxford University Press. Fuel- Trac,Spent Fuel / Reprocessing, in Nuclear Industry Statusto Burn Non-Fissile Fuels. 2008. GA. Energy Multiplier

Heidet, Florent

2010-01-01T23:59:59.000Z

435

A life of worry : the cultural politics and phenomenology of anxiety in Ho Chi Minh City, Vietnam  

E-Print Network [OSTI]

self: A cultural phenomenology of charismatic healing.In A companion to phenomenology and existentialism. Oxford:In A companion to phenomenology and existentialism. Oxford:

Tran, Allen L.; Tran, Allen L.

2012-01-01T23:59:59.000Z

436

Representation of Oppositional Political Actors in Post-Apartheid South Africa: The Implications of PAGAD, TAC, and COPE for Democratic Government  

E-Print Network [OSTI]

Writing Radical Democracy in South Africa. Durham, NC: DukeThe Politics of the New South Africa: Apartheid and After.Twentieth-Century South Africa. Oxford: Oxford University

Tourek, Gabriel Z.

2009-01-01T23:59:59.000Z

437

Herman Rubin: Publications  

E-Print Network [OSTI]

Robustness in generalized ridge regression and related topics. In Bayesian statistics, 3 (Valencia, 1987), Oxford Sci. Publ., pages 403-410. Oxford Univ. Press ...

438

METAL-POOR STARS OBSERVED WITH THE MAGELLAN TELESCOPE. I. CONSTRAINTS ON PROGENITOR MASS AND METALLICITY OF AGB STARS UNDERGOING s-PROCESS NUCLEOSYNTHESIS  

E-Print Network [OSTI]

We present a comprehensive abundance analysis of two newly discovered carbon-enhanced metal-poor (CEMP) stars. HE 2138?3336 is a s-process-rich star with [Fe/H] = -2.79, and has the highest [Pb/Fe] abundance ratio measured ...

Placco, Vinicius M.

439

Observation of an Antimatter Hypernucleus  

SciTech Connect (OSTI)

Nuclear collisions recreate conditions in the universe microseconds after the Big Bang. Only a very small fraction of the emitted fragments are light nuclei, but these states are of fundamental interest. We report the observation of antihypertritons - composed of an antiproton, antineutron, and antilambda hyperon - produced by colliding gold nuclei at high energy. Our analysis yields 70 {+-} 17 antihypertritons ({sub {bar {Lambda}}}{sup 3}{bar H}) and 157 {+-} 30 hypertritons ({sub {Lambda}}{sup 3}H). The measured yields of {sub {Lambda}}{sup 3}H ({sub {bar {Lambda}}}{sup 3}{bar H}) and {sup 3}He ({sup 3}{ovr He}) are similar, suggesting an equilibrium in coordinate and momentum space populations of up, down, and strange quarks and antiquarks, unlike the pattern observed at lower collision energies. The production and properties of antinuclei, and nuclei containing strange quarks, have implications spanning nuclear/particle physics, astrophysics, and cosmology.

STAR Collaboration; Abelev, Betty

2010-07-05T23:59:59.000Z

440

Forecast Constraints on Inflation from Combined CMB and Gravitational Wave Direct Detection Experiments  

E-Print Network [OSTI]

We study how direct detection of the inflationary gravitational wave background constrains inflationary parameters and complements CMB polarization measurements. The error ellipsoids calculated using the Fisher information matrix approach with Planck and the direct detection experiment, BBO (Big Bang Observer), show different directions of parameter degeneracy, and the degeneracy is broken when they are combined. For a slow-roll parameterization, we show that BBO could significantly improve the constraints on the tensor-to-scalar ratio compared with Planck alone. We also look at a quadratic and a natural inflation model. In both cases, if the temperature of reheating is also treated as a free parameter, then the addition of BBO can significantly improve the error bars. In the case of natural inflation, we find that the addition of BBO could even partially improve the error bars of a cosmic variance-limited CMB experiment.

Sachiko Kuroyanagi; Christopher Gordon; Joseph Silk; Naoshi Sugiyama

2010-08-02T23:59:59.000Z

Note: This page contains sample records for the topic "oxford big-bang nucleosynthesis" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Supermassive Black Holes  

E-Print Network [OSTI]

Supermassive black holes have generally been recognized as the most destructive force in nature. But in recent years, they have undergone a dramatic shift in paradigm. These objects may have been critical to the formation of structure in the early universe, spawning bursts of star formation and nucleating proto-galactic condensations. Possibly half of all the radiation produced after the Big Bang may be attributed to them, whose number is now known to exceed 300 million. The most accessible among them is situated at the Center of Our Galaxy. In the following pages, we will examine the evidence that has brought us to this point, and we will understand why many expect to actually image the event horizon of the Galaxy's central black hole within this decade.

Fulvio Melia

2007-05-10T23:59:59.000Z

442

{Beta}-delayed neutron decay of {sup 17}C and {sup 18}C  

SciTech Connect (OSTI)

The {Beta}-delayed neutron decay of {sup 17}C and {sup 18}C has bear measured to investigate neutron-unbound levels in {sup 17}N and {sup 19}N. Levels of interest in {sup 17}N and {sup 18}N are those near the neutron threshold which may play a role in a astrophysical reprocess during an inhomogeneous Big Bang. Radioactive ion beaming of {sup 17}C and {sup 18}C were produced by beam fragmentation at the NSCL MSU. Ions were implanted in a plastic scintillator which served as a start detector for a time-of-flight measurement. Neutrons were detected in the MSU neutron detector array. Several neutron groups have been observed and the results will be discussed.

Scheller, K.W.; Goerres, J.; Vouzoukas, S.; Wiescher, M. [Univ. of Notre Dame, South Bend, IN (United States)] [and others

1993-10-01T23:59:59.000Z

443

Correspondence Between $5D$ Ricci-Flat Cosmological Models and Quintessence Dark Energy Models  

E-Print Network [OSTI]

We study the accelerating expansion and the induced dark energy of the $5D$ Ricci-flat universe which is characterized by having a big bounce as opposed to a big bang. We show that the arbitrary function $\\mu(t)$ contained in the $5D$ solutions can be rewritten in terms of the redshift $z$ as a new arbitrary function $f(z)$, and we find that there is a correspondence between this $f(z)$ and the potential $V(\\phi)$ of the 4D quintessence models. Using this correspondence, the arbitrary function $f(z)$ and the $5D$ solution could be specified for a given form of the potential $V(\\phi)$.

Lixin Xu; Hongya Liu; Baorong Chang

2005-12-26T23:59:59.000Z

444

Protein folding and cosmology  

E-Print Network [OSTI]

Protein denaturing induced by supercooling is interpreted as a process where some or all internal symmetries of the native protein are spontaneously broken. Hence, the free-energy potential corresponding to a folding-funnel landscape becomes temperature-dependent and describes a phase transition. The idea that deformed vortices could be produced in the transition induced by temperature quenching, from native proteins to unfolded conformations is discussed in terms of the Zurek mechanism that implements the analogy between vortices, created in the laboratory at low energy, and the cosmic strings which are thought to have been left after symmetry breaking phase transitions in the early universe. An experiment is proposed to test the above idea which generalizes the cosmological analogy to also encompass biological systems and push a step ahead the view that protein folding is a biological equivalent of the big bang.

González-Diáz, P F

1997-01-01T23:59:59.000Z

445

Generally covariant model of a scalar field with high frequency dispersion and the cosmological horizon problem  

E-Print Network [OSTI]

Short distance structure of spacetime may show up in the form of high freqency dispersion. Although such dispersion is not locally Lorentz invariant, we show in a scalar field model how it can nevertheless be incorporated into a generally covariant metric theory of gravity provided the locally preferred frame is dynamical. We evaluate the resulting energy-momentum tensor and compute its expectation value for a quantum field in a thermal state. The equation of state differs at high temperatures from the usual one, but not by enough to impact the problems of a hot big bang cosmology. We show that a superluminal dispersion relation can solve the horizon problem via superluminal equilibration, however it cannot do so while remaining outside the Planck regime unless the dispersion relation is artificially chosen to have a rather steep dependence on wavevector.

Ted Jacobson; David Mattingly

2000-09-11T23:59:59.000Z

446

G-Bounce Inflation: Towards Nonsingular Inflation Cosmology with Galileon Field  

E-Print Network [OSTI]

We study a nonsingular bounce inflation model, which can drive the early universe from a contracting phase, bounce into an ordinary inflationary phase, followed by the reheating process. Besides the bounce that avoided the Big-Bang singularity which appears in the standard cosmological scenario, we make use of the Horndesky theory and design the kinetic and potential forms of the lagrangian, so that neither of the two big problems in bouncing cosmology, namely the ghost and the anisotropy problems, will appear. The cosmological perturbations can be generated either in the contracting phase or in the inflationary phase, where in the latter the power spectrum will be scale-invariant and fit the observational data, while in the former the perturbations will have nontrivial features that will be tested by the large scale structure experiments. We also fit our model to the CMB TT power spectrum.

Qiu, Taotao

2015-01-01T23:59:59.000Z

447

Energy density fluctuations in early universe  

SciTech Connect (OSTI)

The primordial nucleosinthesys of the element can be influenced by the transitions of phase that take place after the Big Bang, such as the QCD transition. In order to study the effect of this phase transition, in this work we compute the time evolution of thermodynamical quantities of the early universe, focusing on temperature and energy density fluctuations, by solving the relevant equations of motion using as input the lattice QCD equation of state to describe the strongly interacting matter in the early universe plasma. We also study the effect of a primordial strong magnetic field by means of a phenomenological equation of state. Our results show that small inhomogeneities of strongly interacting matter in the early Universe are moderately damped during the crossover.

Guardo, G. L.; Ruggieri, M. [Department of Physics and Astronomy, University of Catania, Catania (Italy); Greco, V. [Department of Physics and Astronomy, University of Catania, Catania, Italy and INFN - Laboratori Nazionali del Sud, Catania (Italy)

2014-05-09T23:59:59.000Z

448

Recombinant Science: The Birth of the Relativistic Heavy Ion Collider (431st Brookhaven Lecture)  

SciTech Connect (OSTI)

As part of the celebration of Brookhaven Lab's 60th anniversary, Robert P. Crease, the Chair of the Philosophy Department at Stony Brook University and BNL's historian, will present the second of two talks on the Lab's history. In "Recombinant Science: The Birth of the Relativistic Heavy Ion Collider," Dr. Crease will focus on the creation of the world's most powerful colliding accelerator for nuclear physics. Known as RHIC, the collider, as Dr. Crease will recount, was formally proposed in 1984, received initial construction funding from the U.S. Department of Energy in 1991, and started operating in 2000. In 2005, the discovery at RHIC of the world's most perfect liquid, a state of matter that last existed just moments after the Big Bang, was announced, and, since then, this perfect liquid of quarks and gluons has been the subject of intense study.

Crease, Robert P. (Ph.D, Department of Philosophy, Stony Brook University) [Ph.D, Department of Philosophy, Stony Brook University

2007-12-12T23:59:59.000Z

449

Review of Particle Physics, 2010-2011  

E-Print Network [OSTI]

This biennial Review summarizes much of particle physics. Using data from previous editions, plus 2158 new measurements from 551 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We also summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors, probability, and statistics. Among the 108 reviews are many that are new or heavily revised including those on neutrino mass, mixing, and oscillations, QCD, top quark, CKM quark-mixing matrix, Vud & Vus, Vcb & Vub, fragmentation functions, particle detectors for accelerator and non-accelerator physics, magnetic monopoles, cosmological parameters, and big bang cosmology.

Nakamura, K; Hikasa, K; Murayama, H; Tanabashi, M; Watari, T; Amsler, C; Antonelli, M; Asner, D M; Baer, H; Band, H R; Barnett, R M; Basaglia, T; Bergren, E; Beringer, J; Bernardi, G; Bertl, W; Bichsel, H; Biebel, O; Blucher, E; Blusk, S; Cahn, R N; Carena, M; Ceccucci, A; Chakraborty, D; Chen, M-C; Chivukula, R S; Cowan, G; Dahl, O; D’Ambrosio, G; Damour, T; de Florian, D; de Gouvêa, A; DeGrand, T; Dissertori, G; Dobrescu, B; Doser, M; Drees, M; Edwards, D A; Eidelman, S; Erler, J; Ezhela, V V; Fetscher, W; Fields, B D; Foster, B; Gaisser, T K; Garren, L; Gerber, H-J; Gerbier, G; Gherghetta, T; Giudice, G F; Golwala, S; Goodman, M; Grab, C; Gritsan, A V; Grivaz, J-F; Groom, D E; Grünewald, M; Gurtu, A; Gutsche, T; Haber, H E; Hagmann, C; Hayes, K G; Heffner, M; Heltsley, B; Hernández-Rey, J J; Höcker, A; Holder, J; Huston, J; Jackson, J D; Johnson, K F; Junk, T; Karle, A; Karlen, D; Kayser, B; Kirkby, D; Klein, S R; Kolda, C; Kowalewski, R V; Krusche, B; Kuyanov, Yu V; Kwon, Y; Lahav, O; Langacker, P; Liddle, A; Ligeti, Z; Lin, C-J; Liss, T M; Littenberg, L; Lugovsky, K S; Lugovsky, S B; Lys, J; Mahlke, H; Mannel, T; Manohar, A V; Marciano, W J; Martin, A D; Masoni, A; Milstead, D; Miquel, R; Mönig, K; Narain, M; Nason, P; Navas, S; Nevski, P; Nir, Y; Olive, K A; Pape, L; Patrignani, C; Peacock, J A; Petcov, S T; Piepke, A; Punzi, G; Quadt, A; Raby, S; Raffelt, G; Ratcliff, B N; Richardson, P; Roesler, S; Rolli, S; Romaniouk, A; Rosenberg, L J; Rosner, J L; Sachrajda, C T; Sakai, Y; Salam, G P; Sarkar, S; Sauli, F; Schneider, O; Scholberg, K; Scott, D; Seligman, W G; Shaevitz, M H; Silari, M; Sjöstrand, T; Smith, J G; Smoot, G F; Spanier, S; Spieler, H; Stahl, A; Stanev, T; Stone, S L; Sumiyoshi, T; Syphers, M J; Terning, J; Titov, M; Tkachenko, N P; Törnqvist, N A; Tovey, D; Trippe, T G; Valencia, G; van Bibber, K; Venanzoni, G; Vincter, M G; Vogel, P; Vogt, A; Walkowiak, W; Walter, C W; Ward, D R; Webber, B R; Weiglein, G; Weinberg, E J; Wells, J D; Wheeler, A; Wiencke, L R; Wohl, C G; Wolfenstein, L; Womersley, J; Woody, C L; Workman, R L; Yamamoto, A; Yao, W-M; Zenin, O V; Zhang, J; Zhu, R-Y; Zyla, P A; Harper, G; Lugovsky, V S; Schaffner, P

2010-01-01T23:59:59.000Z

450

Falsification of dark energy by fluid mechanics  

E-Print Network [OSTI]

The 2011 Nobel Prize in Physics was awarded for the discovery of accelerating supernovae dimness, suggesting a remarkable change in the expansion rate of the Universe from a decrease since the big bang to an increase, driven by anti-gravity forces of a mysterious dark energy material comprising 70% of the Universe mass-energy. Fluid mechanical considerations falsify both the accelerating expansion and dark energy concepts. Kinematic viscosity is neglected in current standard models of self-gravitational structure formation, which rely on cold dark matter CDM condensations and clusterings that are also falsified by fluid mechanics. Weakly collisional CDM particles do not condense but diffuse away. Photon viscosity predicts superclustervoid fragmentation early in the plasma epoch and protogalaxies at the end. At the plasma-gas transition, the plasma fragments into Earth-mass gas planets in trillion planet clumps (proto-globular-star-cluster PGCs). The hydrogen planets freeze to form the dark matter of galaxies ...

Gibson, Carl H

2012-01-01T23:59:59.000Z

451

Quintessence and (anti-)Chaplygin gas in loop quantum cosmology  

SciTech Connect (OSTI)

The concordance model of cosmology contains several unknown components such as dark matter and dark energy. Many proposals have been made to describe them by choosing an appropriate potential for a scalar field. We study four models in the realm of loop quantum cosmology: the Chaplygin gas, an inflationary and radiationlike potential, quintessence and an anti-Chaplygin gas. For the latter we show that all trajectories start and end with a type II singularity and, depending on the initial value, may go through a bounce. On the other hand the evolution under the influence of the first three scalar fields behaves classically at times far away from the big bang singularity and bounces as the energy density approaches the critical density.

Lamon, Raphael; Woehr, Andreas J. [Institut fuer Theoretische Physik, Universitaet Ulm, Albert-Einstein-Allee 11, 89069 Ulm (Germany)

2010-01-15T23:59:59.000Z

452

Detecting dark energy with wavelets on the sphere  

E-Print Network [OSTI]

Dark energy dominates the energy density of our Universe, yet we know very little about its nature and origin. Although strong evidence in support of dark energy is provided by the cosmic microwave background, the relic radiation of the Big Bang, in conjunction with either observations of supernovae or of the large scale structure of the Universe, the verification of dark energy by independent physical phenomena is of considerable interest. We review works that, through a wavelet analysis on the sphere, independently verify the existence of dark energy by detecting the integrated Sachs-Wolfe effect. The effectiveness of a wavelet analysis on the sphere is demonstrated by the highly statistically significant detections of dark energy that are made. Moreover, the detection is used to constrain properties of dark energy. A coherent picture of dark energy is obtained, adding further support to the now well established cosmological concordance model that describes our Universe.

J. D. McEwen

2007-08-29T23:59:59.000Z

453

Exotic solutions in General Relativity: Traversable wormholes and 'warp drive' spacetimes  

E-Print Network [OSTI]

The General Theory of Relativity has been an extremely successful theory, with a well established experimental footing, at least for weak gravitational fields. Its predictions range from the existence of black holes, gravitational radiation to the cosmological models, predicting a primordial beginning, namely the big-bang. All these solutions have been obtained by first considering a plausible distribution of matter, and through the Einstein field equation, the spacetime metric of the geometry is determined. However, one may solve the Einstein field equation in the reverse direction, namely, one first considers an interesting and exotic spacetime metric, then finds the matter source responsible for the respective geometry. In this manner, it was found that some of these solutions possess a peculiar property, namely 'exotic matter,' involving a stress-energy tensor that violates the null energy condition. These geometries also allow closed timelike curves, with the respective causality violations. These soluti...

Lobo, Francisco S N

2007-01-01T23:59:59.000Z

454

Island Cosmology in the Landscape  

E-Print Network [OSTI]

In the eternally inflationary background driven by the metastable vacua of the landscape, it is possible that some local quantum fluctuations with the null energy condition violation can be large enough to stride over the barriers among different vacua, so that create some islands full of radiation in new vacua, and then these emergently thermalized islands will enter into the evolution of standard big bang cosmology. In this paper, we calculate the spectrum of curvature perturbation generated during the emergence of island. We find that generally the spectrum obtained is nearly scale invariant, which can be well related to that of slow roll inflation by a simple duality. This in some sense suggests a degeneracy between their scalar spectra. In addition, we also simply estimate the non-Gaussianity of perturbation, which is naturally large, yet, can lie well in the observational bound. The results shown here indicate that the island emergently thermalized in the landscape can be consistent with our observable universe.

Yun-Song Piao

2008-06-11T23:59:59.000Z

455

SciDAC Visualization and Analytics Center for EnablingTechnologies  

SciTech Connect (OSTI)

The Visualization and Analytics Center for EnablingTechnologies (VACET) focuses on leveraging scientific visualization andanalytics software technology as an enabling technology for increasingscientific productivity and insight. Advances in computational technologyhave resulted in an 'information big bang,' which in turn has created asignificant data understanding challenge. This challenge is widelyacknowledged to be one of the primary bottlenecks in contemporaryscience. The vision of VACET is to adapt, extend, create when necessary,and deploy visual data analysis solutions that are responsive to theneeds of DOE'scomputational and experimental scientists. Our center isengineered to be directly responsive to those needs and to deliversolutions for use in DOE's large open computing facilities. The researchand development directly target data understanding problems provided byour scientific application stakeholders. VACET draws from a diverse setof visualization technology ranging from production quality applicationsand application frameworks to state-of-the-art algorithms forvisualization, analysis, analytics, data manipulation, and datamanagement.

Bethel, E. Wes; Johnson, Chris; Joy, Ken; Ahern, Sean; Pascucci,Valerio; Childs, Hank; Cohen, Jonathan; Duchaineau, Mark; Hamann, Bernd; Hansen, Charles; Laney, Dan; Lindstrom, Peter; Meredith, Jermey; Ostrouchov, George; Parker, Steven; Silva, Claudio; Sanderson, Allen; Tricoche, Xavier.

2007-06-30T23:59:59.000Z

456

Protein folding and cosmology  

E-Print Network [OSTI]

Protein denaturing induced by supercooling is interpreted as a process where some or all internal symmetries of the native protein are spontaneously broken. Hence, the free-energy potential corresponding to a folding-funnel landscape becomes temperature-dependent and describes a phase transition. The idea that deformed vortices could be produced in the transition induced by temperature quenching, from native proteins to unfolded conformations is discussed in terms of the Zurek mechanism that implements the analogy between vortices, created in the laboratory at low energy, and the cosmic strings which are thought to have been left after symmetry breaking phase transitions in the early universe. An experiment is proposed to test the above idea which generalizes the cosmological analogy to also encompass biological systems and push a step ahead the view that protein folding is a biological equivalent of the big bang.

P. F. Gonzalez-Diaz; C. L. Siguenza

1997-06-04T23:59:59.000Z

457

The ATLAS Experiment: Mapping the Secrets of the Universe (LBNL Summer Lecture Series)  

ScienceCinema (OSTI)

Summer Lecture Series 2007: Michael Barnett of Berkeley Lab's Physics Division discusses the ATLAS Experiment at the European Laboratory for Particle Physics' (CERN) Large Hadron Collider. The collider will explore the aftermath of collisions at the highest energy ever produced in the lab, and will recreate the conditions of the universe a billionth of a second after the Big Bang. The ATLAS detector is half the size of the Notre Dame Cathedral and required 2000 physicists and engineers from 35 countries for its construction. Its goals are to examine mini-black holes, identify dark matter, understand antimatter, search for extra dimensions of space, and learn about the fundamental forces that have shaped the universe since the beginning of time and will determine its fate.

Barnett, Michael

2011-04-28T23:59:59.000Z

458

Developmental Science 9:3 (2006), pp 237269 2006 The Authors. Journal compilation 2006 Blackwell Publishing Ltd., 9600 Garsington Road, Oxford OX4 2DQ, UK and  

E-Print Network [OSTI]

impairments in dyslexia: a multiple case study of dyslexic children Sarah White,1 Elizabeth Milne,2,3 Stuart that characterizes dyslexia. Twenty-three children with dyslexia were compared to 22 control children, matched impairments. Introduction A classical account of the phonological theory of dyslexia assumes

Hansen, Peter

459

This article was downloaded by: [the Bodleian Libraries of the University of Oxford] On: 24 September 2013, At: 05:47  

E-Print Network [OSTI]

Center for Energy, Environment, and Sustainability, Wake Forest University, North Carolina,, USA f School Sciences, Umeå, Sweden d College of Life and Environmental Sciences, University of Exeter, Exeter, UK e

Malhi, Yadvinder

460

The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com Tree Physiology 34, 931943  

E-Print Network [OSTI]

as a potential source of biofuels (Hinchee et al. 2011). The use of woody biomass as a biofuel feedstock and potentially have a higher biomass production capacity than seasonal biofuel crops. Eucalyptus species

Note: This page contains sample records for the topic "oxford big-bang nucleosynthesis" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

The Author 2014. Published by Oxford University Press on behalf of the International Society for Behavioral Ecology. All rights reserved. For permissions,  

E-Print Network [OSTI]

for Behavioral Ecology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com The official journal of the ISBEInternational Society for Behavioral Ecology Behavioral Ecology Invited that our senses should provide us with an accu- rate perception of the world around us. But this is seldom

Ryan, Michael J.

462

This is a pre-print of a manuscript that will appear in: Nucleic Acids Research, 2005, Vol 33, Oxford University Press.  

E-Print Network [OSTI]

Function Prediction Brett Poulin*, Duane Szafron, Russell Greiner, Roman Eisner and Paul Lu *poulin@cs.ualberta.ca BIOINFORMATICS I We use Markov chains as a pre-processing filter for HMM software (HMMER)[2], removing the most

Alberta, University of

463

The Author 2014. Published by Oxford University Press on behalf of the UK Environmental Mutagen Society. doi:10.1093/mutage/geu025  

E-Print Network [OSTI]

) was ~10 times higher following temazcal use (P spent in temazcal with genetic damage, temazcal use may therefore be expected to contribute to an increased risk of DNA damage the combustion of biomass fuel (primarily wood) has been classified by the International Agency for Research

Silver, Whendee

464

McLennan, Eds. (Oxford Univ. Press, New York, 1985), pp. 160-186. 24. J. Schumpeter, The Theory ofEcoomic Development (Harvard Univ. Press, Cam-  

E-Print Network [OSTI]

that high energy prices discouraged investment and has also suggested that the energy crisis shiftedEcoomic Development (Harvard Univ. Press, Cam- bridge, MA, 1934). 25. D. W. Jorgensen [in The Positive Sum Strategy, R improved productivity in manufacturing since 1979, largely as a result of shake-outs induced by Prime

465

Overfishing in a nutshell Overfishing What Everyone Needs to Know by Ray Hilborn, with Ulrike Hilborn, Oxford University Press, 2012. US$16.95/10.99,  

E-Print Network [OSTI]

the oceans and from land. How significant those costs are for capture fisheries, how they are viewed of industri- al, artisanal, and recreational fisheries and the challenges associated with those. I disclose my own inter- ests: I have worked extensively on the effects of overfishing on ecosystems and have

Myers, Ransom A.

466

Molecular Gas, AGN Feedback and the Unusual Case of K. A. Alatalo (UC, Berkeley), T. A. Davis (Oxford University, United King-  

E-Print Network [OSTI]

Molecular Gas, AGN Feedback and the Unusual Case of NGC1266 K. A. Alatalo (UC, Berkeley), T. A effort. It remarkably hosts about 109 M of molecular gas and has a spectrum that exhibits extended wings and revealed that the bulk of the gas is concentrated within 100 pc of the nucleus. Combined with the presence

Bureau, Martin

467

The Author 2009. Published by Oxford University Press on behalf of The British Computer Society. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org  

E-Print Network [OSTI]

School of Electrical Engineering and Computer Science, University of Central Florida, Orlando FL 32816 approaches for automated role analysis: (1) a model-based system for combining evidence from observed events for such environments is a very challenging problem, due to shortening decision cycles, the changing nature of threats

Sukthankar, Gita Reese

468

Laurel Phillipson, Using Stone Tools: the Evidence from Aksum, Ethiopia: Cambridge Monographs in African Archaeology 77, Archaeopress, Oxford, 2009, 149 pp, ISBN 978 1 4073 0408 3  

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the Evidence from Aksum, Ethiopia Cambridge Monographs inarea in Tigray, northern Ethiopia. The study reported in theinvestigated region in Ethiopia, relatively little attention

Curtis, Matthew C.

2010-01-01T23:59:59.000Z

469

The Handbook of Applied Bayesian Analysis, Eds: Tony O'Hagan & Mike West, Oxford University Bayesian analysis and decisions in nuclear power plant  

E-Print Network [OSTI]

Bayesian analysis and decisions in nuclear power plant maintenance Elmira Popova, David Morton, Paul Damien are then applied to solving an important problem in a nuclear power plant system at the South Texas Project (STP) Electric Generation Station. STP is one of the newest and largest nuclear power plants in the US

Morton, David

470

I Reproducedwith pennissionfrom Elsevier Preparedfor Proceedingsof the4thBiomassConferenceof theAmericas,ElsevierScience,Ltd.,Oxford,UK, 1999.  

E-Print Network [OSTI]

with solid biomass. It is also far more efficient (Fig. 1), even considering biomass-to-fuels conversion. We present a preliminary assessment of the cost for producing these fuels from com stalks today to meet household cooking needs. 2. ENERGY BALANCES FOR F-T COOKING FUELS FROM BIOMASS Two clean

471

This article was downloaded by: [the Bodleian Libraries of the University of Oxford] On: 24 September 2013, At: 05:45  

E-Print Network [OSTI]

. Chung Gutierrez b , Gilberto E. Navarro-Aguilar a , Carlos A. Quesada f , Carlos G. Hidalgo a , Jose M Gutierrez, Gilberto E. Navarro-Aguilar, Carlos A. Quesada, Carlos G. Hidalgo, Jose M. Reyna Huaymacari, Kate.J. Girardinc , Jack A. Chung Gutierrezb , Gilberto E. Navarro-Aguilara , Carlos A. Quesadaf , Carlos G

Malhi, Yadvinder

472

This article was downloaded by: [the Bodleian Libraries of the University of Oxford] On: 08 October 2012, At: 10:58  

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, Chapel Hill, NC 27599, USA f FX Research and Trading Group, HSBC Bank, 8 Canada Square, London E14 5HQ and Technology, University of North Carolina, Chapel Hill, NC 27599, USA ?FX Research and Trading Group, HSBC

Porter, Mason A.

473

Guide prepared by Student Information email: student.information@admin.ox.ac.uk Information correct as of August 2013 Opening a bank account in Oxford  

E-Print Network [OSTI]

. A summary of the facilities offered by the five main UK banks; Santander, LloydsTSB, HSBC, Nat West

Oxford, University of

474

A classification of spherically symmetric self-similar dust models  

E-Print Network [OSTI]

We classify all spherically symmetric dust solutions of Einstein's equations which are self-similar in the sense that all dimensionless variables depend only upon $z\\equiv r/t$. We show that the equations can be reduced to a special case of the general perfect fluid models with equation of state $p=\\alpha \\mu$. The most general dust solution can be written down explicitly and is described by two parameters. The first one (E) corresponds to the asymptotic energy at large $|z|$, while the second one (D) specifies the value of z at the singularity which characterizes such models. The E=D=0 solution is just the flat Friedmann model. The 1-parameter family of solutions with z>0 and D=0 are inhomogeneous cosmological models which expand from a Big Bang singularity at t=0 and are asymptotically Friedmann at large z; models with E>0 are everywhere underdense relative to Friedmann and expand forever, while those with E0 ones. The 2-parameter solutions with D>0 again represent inhomogeneous cosmological models but the Big Bang singularity is at $z=-1/D$, the Big Crunch singularity is at $z=+1/D$, and any particular solution necessarily spans both z0. While there is no static model in the dust case, all these solutions are asymptotically ``quasi-static'' at large $|z|$. As in the D=0 case, the ones with $E \\ge 0$ expand or contract monotonically but the latter may now contain a naked singularity. The ones with E<0 expand from or recollapse to a second singularity, the latter containing a black hole.

B. J. Carr

2000-03-02T23:59:59.000Z

475

ACCESS Magazine Fall 2011  

E-Print Network [OSTI]

Sustainability Oxford University Press, 2009 Cer vero, Robert The Transit Metropolis Island Press, 1998; China Architecture

2011-01-01T23:59:59.000Z

476

Aiming for Unique and Outstanding Collections: Retrospective and Prospective Analysis of East Asian Collection Development at the University of California, San Diego  

E-Print Network [OSTI]

University of Arts, University of Michigan, University ofUniversity, the University of Michigan, Oxford University,

Cheng, Jim

2007-01-01T23:59:59.000Z

477

Active Visual Navigation using NonMetric Structure \\Lambda Paul A Beardsley, Ian D Reid, Andrew Zisserman and David W Murray  

E-Print Network [OSTI]

of Oxford Glasstone Fellowship to IDR. sue first highlighted by Koenderink [10]. If cameras are uncalibrated

Zisserman, Andrew

478

James N. Arnold, Mark R.Wormald, David M.Suter, Catherine M. Radcliffe, David J. Harvey, Raymond A. Dwek, Pauline M. Rudd and Robert B. Sim MRC Immunochemistry Unit and Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South  

E-Print Network [OSTI]

IgM was judged by SDS PAGE analysis to be > 95% pure. Small-Scale IgM Purification from Human Serum be implicated in the serum clearance of aggregated IgM. 00 Large-Scale IgM Purification from Human Serum Ig collected and pooled. The IgM still contained small amounts of IgG and. The IgG was removed using a 5ml Hi

479

From SupernovaeFrom Supernovae to Inflationto Inflation  

E-Print Network [OSTI]

From SupernovaeFrom Supernovae to Inflationto Inflation Katsuhiko SatoKatsuhiko Sato 1)Department.4. NucleosynthesisNucleosynthesis in supernovaein supernovae II.II. ParticleParticle cosmologycosmology andand Early

Yamamoto, Hirosuke

480

CRD Report  

E-Print Network [OSTI]

of supernovae, gamma ray bursts and nucleosynthesis. “HighBlack Holes to Gamma Ray Bursts. ” A book launch party is

Wang, Ucilia

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "oxford big-bang nucleosynthesis" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

MASS POLITICAL MOBILIZATION  

E-Print Network [OSTI]

................................................................................................................................................... MASS POLITICAL MOBILIZATION ................................................................................................................................................... Boix & Stokes: The Oxford Handbook of Comparative Politics Boixandstokes-chap21 Revise Proof page 497 20.4.2007 12:41pm #12;Boix & Stokes: The Oxford Handbook of Comparative Politics Boixandstokes-chap21

482

Thallium isotopes in early diagenetic pyrite A paleoredox proxy? Sune G. Nielsen a,b,  

E-Print Network [OSTI]

Thallium isotopes in early diagenetic pyrite ­ A paleoredox proxy? Sune G. Nielsen a,b, , Matt Goff of Oxford, South Parks Road, Oxford OX1 3AN, UK. Tel.: +44 1865272027. E-mail address: sune

Lee, Cin-Ty Aeolus

483

E-Print Network 3.0 - annual cross sectional Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

in the "Why am I here" section of Blueprint. - Proposing an article in Oxford Today on past and present famous Source: Herz, Laura M. - Department of Physics, University of Oxford...

484

Living and Dying Abroad: Aspects of Egyptian Cultural Identity in Late Bronze Age and Early Iron Age Canaan  

E-Print Network [OSTI]

Encyclopedia of Ancient Egypt. Volume I. Oxford. 161-162.1994 Amulets of Ancient Egypt. London. Anzaldúa, G. 1987Encyclopedia of Ancient Egypt. Volume III. Oxford. 179-181.

Pierce, Krystal Victoria Lords

2013-01-01T23:59:59.000Z

485

A review of "The Politics of Trade: The Overseas Merchant in State and Society, 1660-1720." by Perry Gauci  

E-Print Network [OSTI]

REVIEWS 305 Perry Gauci. The Politics of Trade: The Overseas Merchant in State and Society, 1660-1720. Oxford: Oxford University Press, 2001. xvi + 302 pp. $65.00. Review by JOSEPH P. WARD, UNIVERSITY OF MISSISSIPPI. This book explores...

Joseph P. Ward

2002-01-01T23:59:59.000Z

486

Tentative Futures: Ethics and Sexuality in the Nineteenth-Century Novel  

E-Print Network [OSTI]

James. Life of Samuel Johnson. Oxford: Oxford UniversityWoman: Jane Austen and Samuel Johnson. New York: AMS Press,most frequently turn to Samuel Johnson. 22 Austen was, to be

Jamgochian, Amy Hope

2010-01-01T23:59:59.000Z

487

Worlds on view : visual art exhibitions and state identity in the late Cold War  

E-Print Network [OSTI]

Acheson: A Life in the Cold War. Oxford: Oxford UniversityBarbara. Artists of World War II. Westport CT: GreenwoodExchange and the Cold War, Raising the Iron Curtain.

Holland, Nicole Murphy

2010-01-01T23:59:59.000Z

488

The Making of the Entrepreneur in Tanzania: experimenting with neo-liberal power through discourses of partnership, entrepreneurship, and participatory education  

E-Print Network [OSTI]

on Socialism (pp. 1-12). Dar es Salaam: Oxford UniversityEssays on Socialism. Dar es Salaam: Oxford University Press.Tangu (. ) tulitoka Dar es Salaam tulipokuja (. ) tulipopata

Boner, Elizabeth Helene

2011-01-01T23:59:59.000Z

489

The Rationalization of Space and Time: Dodoma and Socialist Modernity  

E-Print Network [OSTI]

1975. A portrait of Dodoma. Dar es Salaam: National Printingand speeches 1965- 1976. Dar es Salaam: Oxford UP. ---.1966.and speeches 1952-1965. Dar es Salaam: Oxford UP. Polanyi,

Yoon, Duncan

2011-01-01T23:59:59.000Z

490

Volume 11, Number 12 11 December 2010  

E-Print Network [OSTI]

@earth.ox.ac.uk) J. Biggs COMET+, Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3 December 2010. Ebmeier, S. K., J. Biggs, T. A. Mather, G. Wadge, and F. Amelung (2010), Steady downslope

Biggs, Juliet

491

Jill Lepore, "Long Division: Measuring the Polarization of American Politics," The New Yorker, December 2, 2013.  

E-Print Network [OSTI]

Productivity and Gridlock." In The Oxford Handbook of the American Congress, ed. Eric Schickler and Frances E. "Historical Approaches to the Study of Congress." In The Oxford Handbook of the American Congress. Kirkpatrick of Steam? Fro

492

A Review of "Archipelagic English: Literature, History and Politics, 1603-1707" by John Kerrigan  

E-Print Network [OSTI]

of Green is a moving, useful, pleasurable read. John Kerrigan. Archipelagic English: Literature, History and Politics 1603- 1707. Oxford: Oxford University Press, 2008. xiv + 599 pp. $49.95. Review by Eugene D. Hill, mount holyoke college. As the title...

Hill, Eugene D.

2009-01-01T23:59:59.000Z

493

A Review of "The Key of Green: Pasion and Perception in Renaissance Culture" by Bruce R. Smith  

E-Print Network [OSTI]

Kerrigan. Archipelagic English: Literature, History and Politics 1603- 1707. Oxford: Oxford University Press, 2008. xiv + 599 pp. $49.95. Review by Eugene D. Hill, mount holyoke college. As the title suggests, John Kerrigan?s is an uncommon...

Clark, Ira

2009-01-01T23:59:59.000Z

494

10.1098/rsta.2003.1269 T&T Proof 03TA2005 5 September 2003  

E-Print Network [OSTI]

Science, University of Oxford, Oxford OX1 3PJ, UK Programming robots and other autonomous systems in the area of cinema post- production (Pollefeys et al. 2000), where analysis of a stored film sequence

Oxford, University of

495

A review of "The Poetics of Melancholy in Early Modern England." by Douglas Trevor  

E-Print Network [OSTI]

as the social forces that regulate identity, the book represents an important contribution to theories of Renaissance subjec- tivity and identity. Allan Greer. Mohawk Saint: Catherine Tekakwitha and the Jesuits. Oxford: Oxford University Press, 2005. xiv...

Thomas P. Anderson

2005-01-01T23:59:59.000Z

496

The Threat from Within: American Jews, the State of Israel, and Intermarriage  

E-Print Network [OSTI]

Oxford University Press.   Heng, Geraldine and Janadasunlike both states (see Heng and Devan 1992, Yuval-Davis

Minkin, Sarah Anne

2011-01-01T23:59:59.000Z

497

MICHAEL MCGILLEN Dartmouth College  

E-Print Network [OSTI]

/Possibilities of a Hermeneutics of Religious Experience, University of Oxford, April 3­6, 2014. "Shipwreck of Language: Metaphor

Bucci, David J.

498

Previous Up Next Article From References: 1  

E-Print Network [OSTI]

, Oxford, 2003 MR2282631 (2007m:74003) 8. Birkhoff, G.: Tres observaciones sobre el algebra lineal. Univ

Chenchiah, Isaac Vikram

499

Rural electrification, climate change, and local economies: Facilitating communication in development policy and practice on Nicaragua's Atlantic Coast  

E-Print Network [OSTI]

Oxford University Press.   Illindala, M. , Siddiqui, A. , Aeck, 2005; Illindala, Siddiqui,  Venkataramanan, & Marnay, 

Casillas, Christian E.

2012-01-01T23:59:59.000Z

500

Marine Biology 00-Levinton-FM.indd 100-Levinton-FM.indd 1 26/04/13 10:24 PM26/04/13 10:24 PM  

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by publishing worldwide. Oxford New York Auckland Cape Town Dar es Salaam Hong Kong Karachi Kuala Lumpur Madrid