scholarly journals Detailed chemical composition of the open cluster IC 4651: The iron peak, $\mathsf{\alpha}$ elements, and Li

2004 ◽  
Vol 424 (3) ◽  
pp. 951-963 ◽  
Author(s):  
L. Pasquini ◽  
S. Randich ◽  
M. Zoccali ◽  
V. Hill ◽  
C. Charbonnel ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Open Cluster ◽  
Detailed Chemical

scholarly journals The chemical composition of the oldest nearby open cluster Ruprecht 147

2018 ◽  
Vol 619 ◽  
pp. A176 ◽  
Author(s):  
Angela Bragaglia ◽  
Xiaoting Fu ◽  
Alessio Mucciarelli ◽  
Gloria Andreuzzi ◽  
Paolo Donati
Keyword(s):  
Chemical Composition ◽  
High Resolution ◽  
Motion Parallax ◽  
Open Cluster ◽  
Red Giants ◽  
Evolutionary Models ◽  
Chemical Abundance ◽  
Cluster Distance ◽  
Very High ◽  
Detailed Chemical

Context. Ruprecht 147 (NGC 6774) is the closest old open cluster, with a distance of less than 300 pc and an age of about 2.5 Gyr. It is therefore well suited for testing stellar evolution models and for obtaining precise and detailed chemical abundance information. Aims. We combined photometric and astrometric information coming from literature and the Gaia mission with very high-resolution optical spectra of stars in different evolutionary stages to derive the cluster distance, age, and detailed chemical composition. Methods. We obtained spectra of six red giants using HARPS-N at the Telescopio Nazionale Galileo (TNG). We also used European Southern Observatory (ESO) archive spectra of 22 main sequence (MS) stars, observed with HARPS at the 3.6 m telescope. The very high resolution (115 000) and the large wavelength coverage (about 380–680 nm) of the twin instruments permitted us to derive atmospheric parameters, metallicity, and detailed chemical abundances of 23 species from all nucleosynthetic channels. We employed both equivalent widths and spectrum synthesis. We also re-derived the cluster distance and age using Gaia parallaxes, proper motions, and photometry in conjunction with the PARSEC stellar evolutionary models. Results. We fully analysed those stars with radial velocity and proper motion/parallax in agreement with the cluster mean values. We also discarded one binary not previously recognised, and six stars near the MS turn-off because of their high rotation velocity. Our final sample consists of 21 stars (six giants and 15 MS stars). We measured metallicity (the cluster average [Fe/H] is +0.08, rms = 0.07) and abundances of light, α, Fe-peak, and neutron-capture elements. The Li abundance follows the expectations, showing a tight relation between temperature and abundance on the MS, at variance with M 67, and we did not detect any Li-rich giant. Conclusions. We confirm that Rup 147 is the oldest nearby open cluster. This makes it very valuable to test detailed features of stellar evolutionary models.

scholarly journals Chemical Composition and Antimicrobial Activities of the Essential Oil From the Leaves of Pterocephalus hookeri

2020 ◽  
Vol 15 (12) ◽  
pp. 1934578X2098123
Author(s):  
Peng-fei Yang ◽  
Hui Lu ◽  
Qiong-bo Wang ◽  
Zhi-wei Zhao ◽  
Qiang Liu ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Chemical Composition ◽  
Essential Oil ◽  
Chemical Constituents ◽  
Antimicrobial Activities ◽  
Gas Chromatography Mass Spectrometry ◽  
Flame Ionization ◽  
And Staphylococcus Aureus ◽  
Antimicrobial Assay ◽  
Detailed Chemical

Detailed chemical constituents of essential oil from the Pterocephalus hookeri leaves and its antimicrobial activities were investigated in this study. The essential oil, obtained by hydrodistillation, was characterized by gas chromatography-flame ionization detection and gas chromatography-mass spectrometry analyses. Among the 90 identified compounds, hexadecanoic acid (21.27%), phytol (8.03%), furfural (7.08%), oleic acid (5.25%), and phytone (4.56%) were the major components. In the antimicrobial assay, the essential oil showed strong inhibitory activities against Escherichia coli, Candida albicans, and Staphylococcus aureus with minimum inhibitory concentration values of 31.3, 62.5, and 125 µg/mL, respectively. To our knowledge, this is the first report concerning chemical composition and antimicrobial activities of the essential oil from Pterocephalus hookeri.

Chemical composition of globular clusters in dwarf galaxies

2019 ◽  
Vol 14 (S351) ◽  
pp. 317-320
Author(s):  
Søren S. Larsen
Keyword(s):  
Chemical Composition ◽  
Globular Clusters ◽  
Milky Way ◽  
Local Group ◽  
Dwarf Galaxies ◽  
Chemical Abundances ◽  
Preliminary Results ◽  
Detailed Chemical

AbstractThis contribution gives an update on on-going efforts to characterise the detailed chemical abundances of Local Group globular clusters (GCs) from integrated-light spectroscopy. Observations of a sample of 20 GCs so far, located primarily within dwarf galaxies, show that at low metallicities the [α/Fe] ratios are generally indistinguishable from those in Milky Way GCs. However, the “knee” above which [α/Fe] decreases towards Solar-scaled values occurs at lower metallicities in the dwarfs, implying that GCs follow the same trends seen in field stars. Efforts are underway to establish NLTE corrections for integrated-light abundance measurements, and preliminary results for Mn are discussed.

scholarly journals Chemical composition of A and F dwarfs members of the Hyades open cluster

2010 ◽  
Vol 523 ◽  
pp. A71 ◽  
Author(s):  
M. Gebran ◽  
M. Vick ◽  
R. Monier ◽  
L. Fossati
Keyword(s):  
Chemical Composition ◽  
Open Cluster

Emission factors and detailed chemical composition of smoke particles from the 2010 wildfire season

2013 ◽  
Vol 71 ◽  
pp. 295-303 ◽  
Author(s):  
Ana Vicente ◽  
Célia Alves ◽  
Ana I. Calvo ◽  
Ana P. Fernandes ◽  
Teresa Nunes ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Emission Factors ◽  
Smoke Particles ◽  
Wildfire Season ◽  
Detailed Chemical

scholarly journals Evaluation of Physical-Chemical Indexes, Sugars, Pigments and Phenolic Compounds of Fruits from Three Apple Varieties at the End of Storage Period

2014 ◽  
Vol 71 (1) ◽  
pp. 45
Author(s):  
Andruta Elena Muresan ◽  
Sevastita Muste ◽  
Andrei Borsa ◽  
Romina Alina Vlaic ◽  
Vlad Muresan
Keyword(s):  
Chemical Composition ◽  
Starch Content ◽  
Storage Period ◽  
Soluble Solids ◽  
Total Soluble Solids ◽  
Industrial Processing ◽  
Apple Varieties ◽  
The Individual ◽  
High Level ◽  
Detailed Chemical

Apples are the most cultivated and consumed fruits in the world. They not only taste great, but there are also rich sources of monosaccharides, pigments, fibers, functional compounds such as polyphenols which are well-known for their antioxidant action. Due to the high level of apples consumption, it is important to monitor and know the detailed chemical composition of this fruits on the market shelf. The aim of this paper was to study the detailed chemical composition of apples from three varieties. Samples from three varieties (Ionathan, Golden Delicious and Starkrimson) were taken from the Romanian market. Individual sugars composition was performed by HPLC, total polyphenols content by Folin Ciocalteu method, antioxidant capacity by using the DPPH test, while pigments were analysed by spectrophotometric specific methods and the total starch content measured by a polarimetric method. Water content, acidity, total soluble solids and pH were also monitored through specific methods. There were found differences between varieties particularly in relation to the polyphenols content, carotenoids and chlorophyll. Regarding the individual sugars composition, fructose and glucose were predominant followed by sucrose for all samples. Values of starch, moisture, acidity, total soluble solids and the pH were according to other apple varieties found in literature. These results provide important information regarding the chemical composition of apple varieties from Romanian market, for both human direct consumption and industrial processing. 

scholarly journals Investigation of the Double-mode Cepheid TU Cas: Atmospheric Parameters and Chemical Composition

1993 ◽  
Vol 139 ◽  
pp. 382-382
Author(s):  
S. M. Andrievsky ◽  
V. V. Kovtyukh ◽  
E. N. Makarenko ◽  
I. A. Usenko
Keyword(s):  
Chemical Composition ◽  
Southern Hemisphere ◽  
Open Cluster ◽  
Atmospheric Parameters

AbstractAtmospheric parameters and abundances of 25 elements were determined from two spectrograms of TU Cas (with dispersion 9 Å/mm) obtained in 1977 and 1990. We find Teff= 5860 - 6000K; logg = 1.0 - 1.5; and vt = 2.9 - 5.3 km/s.The value of [Fe/H] ∼ -0.5 testifies to the fact that TU Cas is deficient in metals compared with other double-mode Cepheids. More exact values of [Fe/H] for 9 double-mode Cepheids in the Southern Hemisphere (Barrell 1982), V367 Set (a member of the open cluster NGC 6649) and our value for TU Cas all show a good correlation with P1/P0. As the atmospheric Fe abundance increases, the ratio P1/P0 decreases.Our measured values for abundances (in brackets) of various elements in the atmosphere of TU Cas are: C (8.26), Na (6.32), Mg (7.07), Si (6.85), S (6.96), Ca (5.88), Sc (2.71), Ti (4.34), V (3.35), Cr (5.29), Mn (4.92), Fe (6.94), Co (4.47), Ni (5.70), Zn (3.63), Sr (2.00), Y (2.17), Zr (2.21), Ba (1.41), La (1.08), Ce (0.96), Nd (0.82), Sm (0.42), Eu (1.04), and Gd (0.92).

INFLUENCE DES CULTIVARS ET DES STADES DE CROISSANCE SUR LE RENDEMENT EN MATIERE SECHE ET LA COMPOSITION CHIMIQUE DE FOURRAGES D’AVOINE IMMATURE

1984 ◽  
Vol 64 (4) ◽  
pp. 935-943 ◽  
Author(s):  
PAUL GERVAIS
Keyword(s):  
Chemical Composition ◽  
Dry Matter ◽  
Mineral Elements ◽  
Vegetative Stage ◽  
Composition Chimique ◽  
Stages Of Growth ◽  
Nitrogen Free Extract ◽  
Significant Difference ◽  
Dough Stage ◽  
Detailed Chemical

The forage yields and the detailed chemical composition of six cultivars of oats harvested at the vegetative stage (three cuttings during the growing season to simulate grazing) and at the heading and dough stages (one cutting for silage) were established over a period of 3 yr. No significant difference in the dry matter yields of the cultivars was found within any of the three stages of growth. Highly significant increases in the yields, however, were recorded with advance in maturity from 4210 kg/ha at the vegetative stage to 6754 kg at heading and 9219 kg at dough stage. Likewise, the percent dry matter increased progressively from 12% to 19% to 33% for the same stages. In general, the organic and mineral compositions of the cultivars did not vary significantly within any stage of growth, but were influenced by the age of the tissues. The total digestible nutrient, the crude protein, the cell contents and the mineral elements Ca, P, K, Mg, Na, Zn and Fe decreased while the nitrogen-free extract, the cell walls, the lignin and the hemicellulose increased from the vegetative to the dough stage. The other constituents exhibited a less defined pattern or remained relatively stable from one stage to another.Key words: Yields, chemical composition, stages of growth, cultivars, forage oats

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