We have derived elemental abundances of a remarkable star, HD 179821, with unusual composition (e.g. Na/Fe = 1.0 ± 0.2 dex) and extra-ordinary spectral characteristics. Its metallicity at Fe/H = 0.4 ...dex places it among the most metal-rich stars yet analysed. The abundance analysis of this luminous star is based on high-resolution and high-quality (S/N ≈ 120–420) optical echelle spectra from McDonald Observatory and Special Astronomy Observatory. The data includes five years of observations over 21 epochs. Standard 1D local thermodynamic equilibrium analysis provides a fresh determination of the atmospheric parameters over all epochs:
T
eff
= 7350 ± 200 K, log g= +0.6 ± 0.3, and a microturbulent velocity ξ = 6.6 ± 1.6 km s−1 and Fe/H = 0.4 ± 0.2, and a carbon abundance C/Fe = −0.19 ± 0.30. We find oxygen abundance O/Fe = −0.25 ± 0.28 and an enhancement of 0.9 dex in N. A supersonic macroturbulent velocity of 22.0 ± 2.0 km s−1 is determined from both strong and weak Fe i and Fe ii
lines. Elemental abundances are obtained for 22 elements. HD 179821 is not enriched in s-process products. Eu is overabundant relative to the anticipated X/Fe ≈ 0.0. Some peculiarities of its optical spectrum (e.g. variability in the spectral line shapes) is noticed. This includes the line profile variations for H α line. Based on its estimated luminosity, effective temperature and surface gravity, HD 179821 is a massive star evolving to become a red supergiant and finally a Type II supernova.
The aim of this study was to investigate the removal of 3-monochloropropane-1,2-diol (3-MCPD) and glycidyl esters (GEs) from edible oils by using Metal Organic Frameworks (MOF) and natural clays. ...First, the model oil was treated with adsorbents and titanium (IV) butoxide-terephthalate MOF (Ti-MOF) and kaolin were selected as the best performing MOF along with natural clay, respectively, for the removal of 3-MCPD and GEs. The effects of treatment conditions were also investigated, 6.0% adsorbent level, 120 min treatment time and 95 ºC temperature were determined to be the best treatment parameters. Finally, palm oil samples were treated with Ti-MOF and kaolin under the selected conditions and removal of 3-MCPD and GEs was obtained at up to 27% and 58%, respectively. In conclusion, MOFs and natural clays showed good potential for the removal of 3-MCPD and GEs, and the efficiency of the treatment can be improved by modifying the adsorbents.
We have derived elemental abundances of eight RV Tauri-type post-asymptotic giant branch stars: AR Sgr, CE Vir, DY Aql, HP Lyr, SS Gem, SZ Mon, TT Oph, and UZ Oph. The abundance analysis of these ...luminous stars is based on the high-resolution (R approximately equal to 55 000) optical echelle spectra obtained with the 2.1 m Struve reflector telescope and the CCD-equipped Sandiford Cassegrain echelle spectrograph at the McDonald Observatory. Standard 1D local thermodynamic equilibrium analysis provides a fresh determination of the atmospheric parameters and elemental abundances for 17 species including C, Na, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Y, and Nd. Then, the computed up-to- date abundances are used to investigate FIP in the program stars, as seen in the Sun and sun-like stars. Also, we scrutinize their behavior for dust-gas separation as an alternative mechanism to the FIP. For the first time, we provide atomic line lists with up-to-date atomic data employed in the analysis for AR Sgr, HP Lyr, SZ Mon, TT Oph, and UZ Oph.
Despite advances in the diagnosis and treatment of ankylosing spondylitis (AS), the risk of cardiovascular complications in AS patients is still higher than in the general population. Macrophages are ...at the intersection of the basic pathogenetic processes of AS and atherosclerosis. Although syndecan-4 (SDC4) mediates a variety of biological processes, the role of SDC4 in macrophage-mediated atherogenesis in AS patients remains unclear. Herein, we aimed to investigate the role of SDC4 in subclinical atherosclerosis in AS patients.
Subjects were selected from eligible AS patients and control subjects without a prior history of AS who were referred to the rheumatology outpatient clinics. All participants' past medical records and clinical, and demographic characteristics were scanned. In addition, carotid intima-media thickness (CIMT) measurement and disease activity index measurement were applied to all patients.
According to our data, serum SDC4 level was significantly higher among AS patients compared with the control group (6.7 1.5-35.0 ng/mL vs 5.1 0.1-12.5 ng/mL, P < .001). The calculated CIMT was also significantly higher in AS patients than in the control group (0.6 0.3-0.9 mm vs 0.4 (0.2-0.7), P < .001. Additionally, serum C-reactive protein level and SDC4 level were independent predictors of AS and strongly associated with CIMT. Linear regression analysis showed that serum SDC4 level was the best predictor of CIMT (P = .004).
Our data indicate that serum SDC4 levels provide comprehensive information about the clinical activity of the disease and subclinical atherosclerosis in AS patients.
We present LTE analysis of high resolution optical spectra for B-type hot PAGB stars LS IV-04 1 and LB3116 (LSE 237). The spectra of these high Galactic latitude stars were obtained with the 3.9-m ...Anglo-Australian Telescope (AAT) and the UCLES spectrograph. The standard 1D LTE analysis with line-blanketed LTE model atmospheres and spectral synthesis provided fundamental atmospheric parameters of
T
eff
= 15 000±1000 K, log
g
= 2.5±0.2, ξ = 5.0±1.0 km s
−1
, M/H = −1.81 dex, and
v
sin
i
= 5 km s
−1
for LSIV-04 1 and
T
eff
= 16 000±1000 K, log
g
= 2.5±0.1,
v
sin
i
= 25 km s
−1
, and Fe/H = −0.93 dex for LB 3116. Chemical abundances of ten different elements were obtained. For LS IV-04 1, its derived model temperature contradicts with previous analysis results. The upper limits for its nitrogen and oxygen abundances were reported for the first time. The magnesium, silicon and calcium were overabundant (i.e. Mg/Fe = 0.8 dex, Si/Fe = 0.5 dex, Ca/Fe = 0.9 dex). With its metal-poor photosphere and V
LSR
≈ 96 km s
−1
, LSIV-04 1 is likely a population II star and most probably a PAGB star. LTE abundances of LB 3116 were reported for the first time. The spectrum of this helium rich star shows 0.9 dex enhancement in the nitrogen. The photosphere of the star is slightly deficient in Mg, Si, and S. (i.e. Mg/Fe = −0.2 dex, Si/Fe = −0.4 dex, S/Fe = −0.2 dex). The Al is slightly enhanced. The phosphorus is overabundant, i.e. P/Fe ≈ 1.7 ± 0.47 dex, hence LB3116 may be the first example of a PAGB star which is rich in phosphorus. With its high radial velocity (i.e.
V
LSR
= 73 km s
−1
), and the deficiencies observed in C, Mg, Si, and S indicate that LB 3116 is likely a hot PAGB star at high galactic latitude.
Aims.
Both components of the bright eclipsing binary
α
Dra have been resolved using long baseline interferometry and the secondary component has been shown to contribute approximately 15% of the ...total flux; however, a spectroscopic detection of the companion star has so far been unsuccessful. We aim for a firm spectroscopic detection of the secondary component of
α
Dra using state-of-the-art spectroscopic analysis methods for very high-quality spectroscopic observations. This will allow the determination of fundamental and atmospheric properties of the components in the system with high precision and accuracy.
Methods.
To achieve our goals, we use a combined data set from interferometry with the Navy Precision Optical Interferometer (NPOI), photometry with the TESS space observatory, and high-resolution spectroscopy with the H
ERMES
fibre-fed spectrograph at the La Palma observatory. We use the method of spectral disentangling to search for the contribution of a companion star in the observed composite H
ERMES
spectra, to separate the spectral contributions of both components, and to determine orbital elements of the
α
Dra system. TESS light curves are analysed in an iterative fashion with spectroscopic inference of stellar atmospheric parameters to determine fundamental stellar properties and their uncertainties. Finally, NPOI interferometric measurements are used for determination of the orbital parameters of the system and angular diameters of both binary components.
Results.
We report the first firm spectroscopic detection of the secondary component in
α
Dra and deliver disentangled spectra of both binary components. The components’ masses and radii are inferred with high precision and accuracy, and are
M
A
= 3.186 ± 0.044
M
⊙
,
R
A
= 4.932 ± 0.036
R
⊙
, and
M
B
= 2.431 ± 0.019
M
⊙
,
R
B
= 2.326 ± 0.052
R
⊙
for the primary and secondary components, respectively. Combined astrometric and spectroscopic analysis yields the semi-major axis of the system, which is ultimately used to derive the dynamical parallax of
π
= 11.48 ± 0.13 mas, and the distance
d
= 87.07 ± 1.03 pc to the
α
Dra system. Evolutionary analysis of both binary components with M
ESA
stellar structure and evolution models suggests the primary is an evolved post-TAMS A-type star, while the companion is a main-sequence A-type star with a convective core mass of
M
cc
= 0.337 ± 0.011
M
⊙
. Positions of both binary components in the Kiel- and HR-diagrams suggest a value of the convective core overshooting parameter
f
ov
well below 0.010
H
p
, and we infer the age of the system to be 310 ± 25 Myr.
Conclusions.
The inferred near-core mixing properties of both components do not support a dependence of the convective core overshooting on the stellar mass. At the same time, the
α
Dra system provides extra support to hypothesise that the mass discrepancy in eclipsing spectroscopic double-lined binaries is associated with inferior atmospheric modelling of intermediate- and high-mass stars, and less so with the predictive powerof stellar structure and evolution models as to the amount of near-core mixing and mass of the convective core.
Abstract In this study, spectral, age, kinematic, and orbital dynamical analyses were conducted on metal‐poor and high proper‐motion (HPM) stars, HD 8724 and HD 195633, selected from the Solar ...neighborhood. This analysis combines detailed abundance measurements, kinematics, and orbital dynamics to determine their origin. Standard 1D local thermodynamic equilibrium analysis provides a fresh determination of the atmospheric parameters: T eff = 4700 ± 115 K, log g = 1.65 ± 0.32 cgs, Fe/H = −1.59 ± 0.04 dex, and a microturbulent velocity 1.58 ± 0.50 km s −1 for HD 8724 and T eff = 6100 ± 205 K, log g = 3.95 ± 0.35 cgs, Fe/H = −0.52 ± 0.05 dex, and 1.26 ± 0.50 km s −1 for HD 195633. The ages were estimated using a Bayesian approach (12.25 Gyr for HD 8724 and 8.15 Gyr for HD 195633). The escape scenarios of these stars from 170 candidate globular clusters (GCs) in the Galaxy were also investigated because of their chemical and physical differences (HPM and metal‐poor nature). Accordingly, the calculated probability of encounter (59%) for HD 8724 at a distance of five tidal radius suggests that star HD 8724 may have escaped from NGC 5139 ( Cen), supported by its highly flattened orbit and may belong to a subpopulation of this GC. Conversely, HD 195633's kinematics, age, and metal abundances point toward an escape from the bulge GC NGC 6356.
We present an LTE analysis of high resolution echelle optical spectra obtained with the 3.9-m Anglo-Australian Telescope (AAT) and the UCLES spectrograph for a B1Ib high galactic latitude supergiant ...HD119608. A fresh determination of the atmospheric parameters using line-blanketed LTE model atmospheres and spectral synthesis provided
T
eff
= 23 300 ± 1000 K, log
g
= 3.0 ± 0.3, and the microturbulent velocity
ξ
= 6.0 ± 1.0 kms
−1
and Fe/H = 0.16. The rotational velocity of the star was derived fromC, O, N, Al, and Fe lines as
v
sin
i
= 55.8 ± 1.3 kms
−1
. Elemental abundances were obtained for 10 different species. He, Al, and P abundances of the star were determined for the first time. In the spectra, hot post-AGB status as well as the Pop I characteristics of the star were examined. The approximately solar carbon and oxygen abundances, along with mild excess in helium and nitrogen abundances do not stipulate a CNO processed surface composition, hence a hot post-AGB status. The LTE abundances analysis also indicates solar sulphur and moderately enriched magnesium abundances. The average abundances of B dwarfs of well studied OB associations and Population I stars show a striking resemblance to abundances obtained for HD119608 in this study. This may imply a runaway status for the star.
This study aimed to investigate the effects of boron compounds on cellulose fibers during recycling. Three recycling stages were conducted, applying boric acid and borax to bleached papers. Physical, ...mechanical, and optical properties were measured after each process. The highest water absorption (218 g/m
2
) was observed in test papers from the second recycling stage using 10% borax-treated pulps (10Bx2). Boric acid treatment notably improved burst strength, with the highest value (3.94 kPa m
2
/g) in the first recycling stage with 5.0% boric acid treatment (5Ba1). The highest tensile strength (49.48 Nm/g) occurred in the first recycling stage with 5.0% boric acid treatment, while the lowest (17.41 Nm/g) was in the second recycling stage (5Bx2) with 5.0% borax treatment. Tear strength exhibited different trends from burst and tensile strength, with notable improvements using 5.0% and 10% boric acid and 10% borax treatments on recovered cellulose fibers. The highest tear strength (9.20 Nm
2
/g) was achieved with 5.0% boric acid treatment (5Ba2) in the second recycling stage, followed by 8.21 Nm
2
/g with 10% boric acid treatment (10Ba1) in the first recycling stage. Tear strength trends differed from burst and tensile strength properties, regardless of treatment conditions.
Reactive oxygen species are believed to be involved in the development of sepsis. Plant-derived phenolic compounds are thought to be possible therapeutic agents against sepsis because of their ...antioxidant properties. Rosmarinic acid (RA) is a phenolic compound commonly found in various plants, which has many biological activities including antioxidant activity. The aim of this study was to investigate the effects of RA on sepsis-induced DNA damage in the lymphocytes and liver and kidney cells of Wistar albino rats by alkaline comet assay with and without formamidopyrimidine DNA glycosylase protein. The oxidative stress parameters such as superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities and total glutathione (GSH) and malondialdehyde (MDA) levels in the liver and kidney tissues and an inflammatory cytokine, tumor necrosis factor α (TNF-α) level in plasma were also evaluated. It is found that DNA damage in the lymphocytes, livers, and kidneys of the RA-treated rats was significantly lower than that in the sepsis-induced rats. RA treatment also decreased the MDA levels and increased the GSH levels and SOD and GSH-Px activities in the livers and kidneys of the sepsis-induced rats. Plasma TNF-α level was found to be decreased in the RA-treated rats. It seems that RA might have a role in the attenuation of sepsis-induced oxidative damage not only by decreasing the DNA damage but also by increasing the antioxidant status and DNA repair capacity of the animals.
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