Boron is the chemical element with atomic number 5 and
... icosahedra which are, however, bonded randomly to each other without long‐range order. Crystalline boron is a very hard, black material with a high melting point of above 2000 °C. It exists in four major polymorphs: α, β, γ and T. Whereas α, β and T phases are based on B12 icosahedra, the γ‐phase ...
... icosahedra which are, however, bonded randomly to each other without long‐range order. Crystalline boron is a very hard, black material with a high melting point of above 2000 °C. It exists in four major polymorphs: α, β, γ and T. Whereas α, β and T phases are based on B12 icosahedra, the γ‐phase ...
Potassium abundances in nearby metal-poor stars
... agreement with the statistical equilibrium of sodium, magnesium and aluminium (Gehren et al. 2004, 2006). The reduction of surface gravity results in a decreased efficiency of collisions with electrons and hydrogen atoms, which again leads to stronger NLTE effects. We do not find dependencies of ∆[K/Fe ...
... agreement with the statistical equilibrium of sodium, magnesium and aluminium (Gehren et al. 2004, 2006). The reduction of surface gravity results in a decreased efficiency of collisions with electrons and hydrogen atoms, which again leads to stronger NLTE effects. We do not find dependencies of ∆[K/Fe ...
P1 09 Red Shift - Animated Science
... Some people think that Penzias and Wilson’s discovery of cosmic microwave background radiation was just lucky. Others disagree. What do you think? Give reasons for your answer. ...
... Some people think that Penzias and Wilson’s discovery of cosmic microwave background radiation was just lucky. Others disagree. What do you think? Give reasons for your answer. ...
The ISO–SWS Spectrum of Planetary Nebula NGC 7027
... and demonstrate that no flux is missing in the SWS observation. In present observations the Brα (measured with the smallest SWS aperture), [Mg V ] and [Ar III ] are stronger than those of Persi et al. (1999), indicating that no flux is being lost in the present observations. Strong differences in bo ...
... and demonstrate that no flux is missing in the SWS observation. In present observations the Brα (measured with the smallest SWS aperture), [Mg V ] and [Ar III ] are stronger than those of Persi et al. (1999), indicating that no flux is being lost in the present observations. Strong differences in bo ...
Mn, Cu, and Zn abundances in barium stars and their correlations
... In the present work we derived the abundances based on a spectrum synthesis for 14 stars that were previously analyzed by Smiljanic et al. (2007). Although the focus of this paper is on performing relations between abundances of some iron peak and heavy elements, other elements than those discussed ...
... In the present work we derived the abundances based on a spectrum synthesis for 14 stars that were previously analyzed by Smiljanic et al. (2007). Although the focus of this paper is on performing relations between abundances of some iron peak and heavy elements, other elements than those discussed ...
Extreme abundance ratios in the polluted atmosphere of the cool
... Polluted white dwarfs (typed with a suffix ‘Z’) provide an opportunity to investigate the ultimate fate of planetary systems. Although planets have not yet been detected around white dwarfs, the evidence for the presence of planetary debris around these objects lies in their polluted atmospheres. Ap ...
... Polluted white dwarfs (typed with a suffix ‘Z’) provide an opportunity to investigate the ultimate fate of planetary systems. Although planets have not yet been detected around white dwarfs, the evidence for the presence of planetary debris around these objects lies in their polluted atmospheres. Ap ...
Subatomic particle processes within neutron stars
... already back in 1970 by a number of researchers that neutrons, protons plus the heavier constitutes (∆, Σ, Λ, Ξ) can melt, creating the quark-gluon plasma state. Evidence of the creation of such matter in the framework of CERN’s Lead Beam Program has been claimed very recently (actually this very ye ...
... already back in 1970 by a number of researchers that neutrons, protons plus the heavier constitutes (∆, Σ, Λ, Ξ) can melt, creating the quark-gluon plasma state. Evidence of the creation of such matter in the framework of CERN’s Lead Beam Program has been claimed very recently (actually this very ye ...
The slow-neutron capture process at low metallicity
... Overview of talk 1. We present theoretical models for the slow neutron capture (s-process) in asymptotic giant branch (AGB) stars of metallicity Z = 0.0001 or [Fe/H] ...
... Overview of talk 1. We present theoretical models for the slow neutron capture (s-process) in asymptotic giant branch (AGB) stars of metallicity Z = 0.0001 or [Fe/H] ...
The Formation of Primordial Luminous Objects - SLAC
... This kind of spectrum, in which fluctuations are typically larger on small scales, leads naturally to hierarchical structure formation, since smallscale fluctuations are the first to become non-linear (i.e. to reach δ ∼ 1), collapse and form some kind of astronomical object. It is also worth remarki ...
... This kind of spectrum, in which fluctuations are typically larger on small scales, leads naturally to hierarchical structure formation, since smallscale fluctuations are the first to become non-linear (i.e. to reach δ ∼ 1), collapse and form some kind of astronomical object. It is also worth remarki ...
chemical abundances for a-and f-type supergiant stars
... stay in the blue supergiant phase. Under these conditions CNO abundances remain unchanged (Stothers & Chin 1976; 1991). However, another scenario is possible for objects with intermediate masses (3 < M < 9 M⊙ ) and it is called the blue loop. In this stage the star has eventually developed a convect ...
... stay in the blue supergiant phase. Under these conditions CNO abundances remain unchanged (Stothers & Chin 1976; 1991). However, another scenario is possible for objects with intermediate masses (3 < M < 9 M⊙ ) and it is called the blue loop. In this stage the star has eventually developed a convect ...
the book - The Well Balanced Universe
... gravity, the starting point is the law of energy flow, which is arguably even more fundamental, and is understood on the level of particles. The article explains this simple law with the aid of everyday examples, and it goes on to look at the energy flow in the Earth's environment. The case is then ...
... gravity, the starting point is the law of energy flow, which is arguably even more fundamental, and is understood on the level of particles. The article explains this simple law with the aid of everyday examples, and it goes on to look at the energy flow in the Earth's environment. The case is then ...
22. Dark Matter and the Fate of the Universe
... © 2004 Pearson Education Inc., publishing as Addison-Wesley ...
... © 2004 Pearson Education Inc., publishing as Addison-Wesley ...
DSSU, the Non-Expanding Universe: Structure, Redshift, Distance
... portion of the universe with luminous ‘sawdust’ of galaxies. Recall the lab example, a dynamic mechanism prevented the sawdust on the surface of the liquid from migrating to the perimeter of the pan. Similarly, a dynamic action prevents galaxies from drifting (the proper term is comoving) into the d ...
... portion of the universe with luminous ‘sawdust’ of galaxies. Recall the lab example, a dynamic mechanism prevented the sawdust on the surface of the liquid from migrating to the perimeter of the pan. Similarly, a dynamic action prevents galaxies from drifting (the proper term is comoving) into the d ...
Chemical Composition of Planetary Nebulae: The Galaxy and the
... A well defined N/O v. N/H correlation is shown in Fig. 1 for Galactic (crosses), LMC (empty circles) and SMC (filled circles) nebulae. Average error bars are provided at the lower right corner. The dashed line shows the theoretical predictions of the final model for the LMC by Groenewegen and de Jong [ ...
... A well defined N/O v. N/H correlation is shown in Fig. 1 for Galactic (crosses), LMC (empty circles) and SMC (filled circles) nebulae. Average error bars are provided at the lower right corner. The dashed line shows the theoretical predictions of the final model for the LMC by Groenewegen and de Jong [ ...
New challenges in Nuclear Structure
... First excited states in nuclei close to the drip lines Neutron rich nuclei at (very) high spins Structure of the heaviest nuclei close to the “line of stability” ...
... First excited states in nuclei close to the drip lines Neutron rich nuclei at (very) high spins Structure of the heaviest nuclei close to the “line of stability” ...
Observations and three-dimensional photoionization modelling of
... 2012 with the 2.3-m ANU Telescope using the Wide Field Spectrograph (WiFeS; Dopita et al. 2007, 2010). The observations were done with a spectral resolution of R ∼ 7000 in the 441.5– 707.0 nm range in 2010 and R ∼ 3000 in the 329.5–932.6 nm range in 2012. The WiFeS has a field-of-view of 25 arcsec × ...
... 2012 with the 2.3-m ANU Telescope using the Wide Field Spectrograph (WiFeS; Dopita et al. 2007, 2010). The observations were done with a spectral resolution of R ∼ 7000 in the 441.5– 707.0 nm range in 2010 and R ∼ 3000 in the 329.5–932.6 nm range in 2012. The WiFeS has a field-of-view of 25 arcsec × ...
Physical Relativism as an Interpretation of Existence
... configurations allowed by M-theory were manifested in some kind of multiverse, one could still just as easily ask why the basic axioms of M-theory had been miraculously selected in order to give rise to a multiverse containing a universe capable of supporting life. As noted by Greene, “Even if a cos ...
... configurations allowed by M-theory were manifested in some kind of multiverse, one could still just as easily ask why the basic axioms of M-theory had been miraculously selected in order to give rise to a multiverse containing a universe capable of supporting life. As noted by Greene, “Even if a cos ...
Abundance Anomalies In Tidal Disruption Events
... and nitrogen abundances. During the MS evolution, the average oxygen abundance slowly drops, but only by ∼ 10% of the carbon depletion. As the star begins hydrogen shell burning, the anomalies outside the helium core begin to drop again. However, first dredge up also mixes them into the outer parts ...
... and nitrogen abundances. During the MS evolution, the average oxygen abundance slowly drops, but only by ∼ 10% of the carbon depletion. As the star begins hydrogen shell burning, the anomalies outside the helium core begin to drop again. However, first dredge up also mixes them into the outer parts ...
Einstein static universe in braneworld scenario
... in which gravity is a truly higher-dimensional theory and becomes effectively 4-dimensional at lower energies. In these models, the standard gauge interactions are confined to the four-dimensional space time (the braneworld generated by a 3-brane) embedded in higher-dimensional bulk, while the gravit ...
... in which gravity is a truly higher-dimensional theory and becomes effectively 4-dimensional at lower energies. In these models, the standard gauge interactions are confined to the four-dimensional space time (the braneworld generated by a 3-brane) embedded in higher-dimensional bulk, while the gravit ...
All About Elements
... in the universe. Only Hydrogen is more abundant! These two elements were copiously formed during the creation of the universe. In the early stages of the universe, helium and hydrogen nuclei were actually formed. No atoms were formed until about 300,000 years after the Big Bang took place, when the ...
... in the universe. Only Hydrogen is more abundant! These two elements were copiously formed during the creation of the universe. In the early stages of the universe, helium and hydrogen nuclei were actually formed. No atoms were formed until about 300,000 years after the Big Bang took place, when the ...
Helium - Boreal Science
... in the universe. Only Hydrogen is more abundant! These two elements were copiously formed during the creation of the universe. In the early stages of the universe, helium and hydrogen nuclei were actually formed. No atoms were formed until about 300,000 years after the Big Bang took place, when the ...
... in the universe. Only Hydrogen is more abundant! These two elements were copiously formed during the creation of the universe. In the early stages of the universe, helium and hydrogen nuclei were actually formed. No atoms were formed until about 300,000 years after the Big Bang took place, when the ...
The Inflation Debate - Physics Department, Princeton University
... The inflaton’s potential energy can cause the universe to expand at an accelerated rate. In the process, it can smooth and flatten the universe, provided the field remains on the plateau long enough (about 10–30 second) to stretch the universe by a factor of 1025 or more along each direction. Inflat ...
... The inflaton’s potential energy can cause the universe to expand at an accelerated rate. In the process, it can smooth and flatten the universe, provided the field remains on the plateau long enough (about 10–30 second) to stretch the universe by a factor of 1025 or more along each direction. Inflat ...
G. Fiorentini a
... We perform a likelihood analysis of the recently released BOOMERanG and MAXIMA data, allowing for the possibility of a time-varying fine-structure constant. We find that in general these data prefer a value of a that was smaller in the past (which is in agreement with measurements of a from quasar o ...
... We perform a likelihood analysis of the recently released BOOMERanG and MAXIMA data, allowing for the possibility of a time-varying fine-structure constant. We find that in general these data prefer a value of a that was smaller in the past (which is in agreement with measurements of a from quasar o ...
103-122
... An assumption that the intrinsic scatter in [α /Fe] for halo stars is small is not necessarily compatible with the theories of Galactic chemical evolution. If the αelements and the iron-group are synthesized in different stars, and gas clouds in the early Galaxy were poorly mixed, one may expect, as ...
... An assumption that the intrinsic scatter in [α /Fe] for halo stars is small is not necessarily compatible with the theories of Galactic chemical evolution. If the αelements and the iron-group are synthesized in different stars, and gas clouds in the early Galaxy were poorly mixed, one may expect, as ...