scholarly journals CCI. Contributions to the chemical history of gun-cotton and xyloidine

1845 ◽  
Vol 3 ◽  
pp. 412
Author(s):  
John Hall Gladstone
Keyword(s):  
History Of ◽  
Chemical History

The Chemical History of Morphine: An 8000-year Journey, from Resin to de-novo Synthesis

2017 ◽  
Vol 3 (2) ◽  
pp. 50-55 ◽  
Author(s):  
Karolina Brook ◽  
Jessica Bennett ◽  
Sukumar P. Desai
Keyword(s):  
De Novo ◽  
De Novo Synthesis ◽  
History Of ◽  
Chemical History

scholarly journals Convective Overshooting: New Integrated Colours vs Age Relations for Star Clusters

1986 ◽  
Vol 116 ◽  
pp. 511-512
Author(s):  
G. Bertelli ◽  
A.G. Bressan ◽  
C. Chiosi ◽  
E. Nasi ◽  
L. Pigatto
Keyword(s):  
Stellar Evolution ◽  
Preliminary Investigation ◽  
Observational Evidence ◽  
Star Cluster ◽  
Standard Theory ◽  
Chemical Compositions ◽  
History Of ◽  
Chemical History ◽  
Nearby Galaxies ◽  
Age Relations

If the integrated colours of a star cluster mainly depend on chemical composition and age, then theoretical calibrations of colours as function of age for different chemical compositions are very useful to obtain quantitative determinations of the age and composition of individual clusters, and thus to trace the chemical history of nearby galaxies. Several calibration curves exist in the literature which rest on the standard theory of stellar evolution. However, a growing amount of observational evidence seems to indicate that overshooting from convective cores may be an important phenomenon in stellar evolution. In fact models computed with overshooting are significantly different from the standard ones. The aim of this preliminary investigation is to study the effects of convective overshooting on the integrated colours of clusters whose turnoff mass is in that range in which convective overshooting is effective.

The Chemical History of the Atmosphere: Self-Organizing Processes and Biological Consequences

2000 ◽  
pp. 59-90
Author(s):  
G. Beckmann ◽  
B. Klopries ◽  
H. Hämmerle ◽  
O. Inacker ◽  
P. Smolka
Keyword(s):  
History Of ◽  
Chemical History ◽  
Self Organizing

scholarly journals Iron abundance distribution in the hot gas of merging galaxy clusters

2019 ◽  
Vol 629 ◽  
pp. A31 ◽  
Author(s):  
I. Urdampilleta ◽  
F. Mernier ◽  
J. S. Kaastra ◽  
A. Simionescu ◽  
J. de Plaa ◽  
...  
Keyword(s):  
Galaxy Clusters ◽  
Clear Correlation ◽  
Iron Abundance ◽  
History Of ◽  
Chemical History ◽  
Lower Entropy ◽  
Abundance Profile ◽  
Low Entropy ◽  
First Time ◽  
Good Agreement

We present XMM-Newton/EPIC observations of six merging galaxy clusters and study the distributions of their temperature, iron (Fe) abundance and pseudo-entropy along the merging axis. For the first time, we focused simultaneously, and in a comprehensive way, on the chemical and thermodynamic properties of the newly collided intra cluster medium (ICM). The Fe distribution of these clusters along the merging axis is found to be in good agreement with the azimuthally-averaged Fe abundance profile in typical non-cool-core clusters out to r500. In addition to showing a moderate central abundance peak, though less pronounced than in relaxed systems, the Fe abundance flattens at large radii towards ∼0.2−0.3 Z⊙. Although this shallow metal distribution is in line with the idea that disturbed, non-cool-core clusters originate from the merging of relaxed, cool-core clusters, we find that in some cases, remnants of metal-rich and low entropy cool cores can persist after major mergers. While we obtain a mild anti-correlation between the Fe abundance and the pseudo-entropy in the (lower entropy, K = 200−500 keV cm2) inner regions, no clear correlation is found at (higher entropy, K = 500−2300 keV cm2) outer radii. The apparent spatial abundance uniformity that we find at large radii is difficult to explain through an efficient mixing of freshly injected metals, particularly in systems for which the time since the merger is short. Instead, our results provide important additional evidence in favour of the early enrichment scenario in which the bulk of the metals are released outside galaxies at z >  2−3, and extend it from cool-core and (moderate) non-cool-core clusters to a few of the most disturbed merging clusters as well. These results constitute a first step toward a deeper understanding of the chemical history of merging clusters.

The chemical history of color

2013 ◽  
Vol 50 (09) ◽  
pp. 50-5006-50-5006
Keyword(s):  
History Of ◽  
Chemical History

A re-evaluation of the blueschist facies

1979 ◽  
Vol 116 (3) ◽  
pp. 191-201 ◽  
Author(s):  
R. M. Wood
Keyword(s):  
Chemical Interaction ◽  
Chemical Exchange ◽  
Mineral Species ◽  
New Mineral ◽  
Competitive Reaction ◽  
New Mineral Species ◽  
Gradual Process ◽  
History Of ◽  
Chemical History ◽  
Growth Adaptation

SummaryWithin blueschist facies rocks it is common to find that mineral assemblages represent a series of attempts to arrive at changing states of equilibrium. To interpret such rocks it is necessary to study how the mineral constrains and determines chemical interaction. The gradual process of chemical exchange between minerals, during changes in conditions, is interrupted by the nucleation of a new mineral species. Mineral reactions are instigated by the nucleation of one new mineral species, though when a reaction is seen at an equilibrated completion the reaction path cannot be traced. In low temperature metamorphism the preservation of partial mineral reactions is very widespread. The growth, adaptation and resorption of a mineral are considered in order to demonstrate: (1) how and why a mineral should zone during growth: (2) the competitive reaction paths that may allow a mineral to change composition, even across and internal solvus; and, (3) through the consideration of a few simple parameters, the prediction of a variety of resorption textures. It is proposed that through an understanding of the way in which the mineral can store information on the chemical history of the rock it is possible to obtain a metamorphic analysis without recourse to the conventional phase equilibrium metamorphic model - a frequent misapplication in the blueschist facies.

scholarly journals The nature of the Galactic bulge: A view from bulge planetary nebulae and globular clusters

2011 ◽  
Vol 7 (S283) ◽  
pp. 408-409
Author(s):  
Alexander F. Kholtygin ◽  
Yulia V. Milanova ◽  
Igor' I. Nikiforov ◽  
Olga V. Vasyakina
Keyword(s):  
Globular Clusters ◽  
Milky Way ◽  
Planetary Nebulae ◽  
Thin Disk ◽  
Type Ii ◽  
Galactic Bulge ◽  
Abundance Pattern ◽  
History Of ◽  
Disk Subsystem ◽  
Chemical History

AbstractModern data concerning the planetary nebulae (PNe) in the bulge, bar and disk of the Milky Way are used to study the chemical history of bulge. We show that the abundance pattern is similar for PNe in the bulge and Peimbert's type II PNe. We also found that the globular clusters (GCs), especially their metal-rich disk subsystem, form on metallicity maps a bar-like structure which parameters are very close to those for the Galactic bar. These results evidence an old age of the Galactic bulge and bar. We propose a scenario of the successive star formation in the bulge, bar and thin disk.

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