385 research outputs found
A Gamma Doradus Candidate In Eclipsing Binary BD And?
The BVR photometric light curves of the eclipsing binary BD And were obtained
in 2008 and 2009. We estimated the mass ratio of the system as 0.97 and the
photometric solutions were derived. The results show that BD And is a detached
binary system, whose components have a little temperature difference of about
40 K. By analyzing photometric available light minimum times, we also derived
an update ephemeris and found for the first time a possible periodic
oscillation with an amplitude of 0.011 days and a period of 9.6 years. The
results indicate that the periodic oscillation could be caused by a third
component physically attached to the eclipsing binary. After removing the light
variations due to the eclipses and proximity effects, the light-curve
distortions are further explained by the pulsation of the primary component
with a dominant period of 1 day. In accordance with the position of the primary
component on the Hertzsprung-Russell diagram and its pulsation period, the
primary component of BD And could be an excellent gamma Doradus candidate. It
is rarely phenomenon that a component of the eclipsing binary system is a gamma
Doradus variable.Comment: 34 pages, 8 figures. arXiv admin note: text overlap with
arXiv:1112.1916 by other authors without attributio
Absolute Properties of An Overcontact Binary HH Boo
We obtained multi-colour light curves of HH Boo. We analysed the orbital
period variation of the system. The analysis indicated that there is possible
mass transfer from the second component to the primary or mass loss with
-5.04x10-7 Msun per year. Re-analysing the available radial velocity curve, we
analysed the light curves. The inclination (i) of the system was found to be
69.71(0.16) deg, while the semi-major axis (a) was computed as 2.246(0.064)
Rsun. The mass of the primary component was found to be 0.92(0.08) Msun, while
it was obtained as 0.58(0.06) Msun for the secondary component. The radius of
the primary component was computed as 0.98(0.03) Rsun, while it was computed as
0.80(0.02) Rsun for the secondary component. We demonstrated that HH Boo should
be a member of the A-type subclass of W UMa binaries.Comment: 20 pages, 5 figures, 4 table
V1135 Herculis: a double-lined eclipsing binary with an Anomalous Cepheid
BVR light curves and radial velocities for the double-lined eclipsing binary
V1135\,Her were obtained. The brighter component of V1135\,Her is a Cepheid
variable with a pulsation period of 4.224330.00026 days. The orbital
period of the system is about 39.997820.00233 days, which is the shortest
value among the known Type\,II Cepheid binaries. The observed B, V, and R
magnitudes were cleaned for the intrinsic variations of the primary star. The
remaining light curves, consisting of eclipses and proximity effects, are
obtained. Our analyses of the multi-colour light curves and radial velocities
led to the determination of fundamental stellar properties of both components
of the interesting system V1135\,Her. The system consists of two evolved stars,
G1+K3 between giants and supergiants, with masses of M=1.4610.054
\Msun ~and M=0.5040.040 {\Msun} and radii of R=27.10.4
{\Rsun} and R=10.40.2 {\Rsun}. The pulsating star is almost filling
its corresponding Roche lobe which indicates the possibility of mass loss or
transfer having taken place. We find an average distance of d=7500450 pc
using the BVR magnitudes and also the V-band extinction. Location in the Galaxy
and the distance to the galactic plane with an amount of 1300 pc indicate that
it probably belongs to the thick-disk population. Most of the observed and
calculated parameters of the V1135\,Her and its location on the color-magnitude
and period-luminosity diagrams lead to a classification of an Anomalous
Cepheid.Comment: 25 pages, 9 Tables, 9 Figures, Accepted Revista Mexicana de
Astronom\'ia y Astrof\'isica. arXiv admin note: substantial text overlap with
arXiv:1211.120
Pooled Analysis of Resistance Patterns of Escherichia coli Strains Isolated From Urine Cultures in Turkey: Comparison of 1997–2001 and 2002–2007 Periods
WOS: 00026328780028
Systematic study of magnetic linear dichroism and birefringence in (Ga,Mn)As
Magnetic linear dichroism and birefringence in (Ga,Mn)As epitaxial layers is
investigated by measuring the polarization plane rotation of reflected linearly
polarized light when magnetization lies in the plane of the sample. We report
on the spectral dependence of the rotation and ellipticity angles in a broad
energy range of 0.12-2.7 eV for a series of optimized samples covering a wide
range on Mn-dopings and Curie temperatures and find a clear blue shift of the
dominant peak at energy exceeding the host material band gap. These results are
discussed in the general context of the GaAs host band structure and also
within the framework of the k.p and mean-field kinetic-exchange model of the
(Ga,Mn)As band structure. We find a semi-quantitative agreement between
experiment and theory and discuss the role of disorder-induced non-direct
transitions on magneto-optical properties of (Ga,Mn)As.Comment: 18 page
The CSU Accelerator and FEL Facility
The Colorado State University (CSU) Accelerator
Facility will include a 6-MeV L-Band electron linear
accelerator (linac) with a free-electron laser (FEL) system
capable of producing Terahertz (THz) radiation, a laser
laboratory, a microwave test stand, and a magnetic test
stand. The photocathode drive linac will be used in
conjunction with a hybrid undulator capable of producing
THz radiation. Details of the systems used in CSU
Accelerator Facility are discusse
Metastatic Serous Carcinoma Initially Presented As An Incarcerated And Strangulated Umbilical Hernia: A Rare Case Report
Introduction: We report a rare case of a metastatic serous ovarian carcinoma presented as an incarcerated and strangulated umbilical hernia.Presentation of case: A 54 year-old female was admitted to the hospital with a painful mass around the umblical region. It was elucidated during clinical history that the mass had been present for 3 to 4 years without pain. An incarcerated and strangulated umbilical hernia including a solid mass and mesenteric fat was detected on physical examination. She underwent an urgent operation for strangulated umbilical hernia. The pathological diagnosis of the hernia material was reported as carcinoma compatible with serous ovarian carcinoma metastasis. Concurrently, total abdominal histerectomy and bilateral salphingo-oopherectomy, pelvic and paraaortic lymph node dissection, omentectomy and sigmoid colon resection were performed. Histopathological evaluation confirmed the serous carcinoma originated from the left ovary.Conclusion: In the literature, some metastatic tumors have been reported to be presented as umbilical metastasis rarely. However, the present case is the first metastatic ovarian cancer that initially presented as an incarcerated and strangulated umbilical hernia in the literature, to the best of our knowledge.
Charge and spin distributions in GaMnAs/GaAs Ferromagnetic Multilayers
A self-consistent electronic structure calculation based on the
Luttinger-Kohn model is performed on GaMnAs/GaAs multilayers. The Diluted
Magnetic Semiconductor layers are assumed to be metallic and ferromagnetic. The
high Mn concentration (considered as 5% in our calculation) makes it possible
to assume the density of magnetic moments as a continuous distribution, when
treating the magnetic interaction between holes and the localized moment on the
Mn(++) sites. Our calculation shows the distribution of heavy holes and light
holes in the structure. A strong spin-polarization is observed, and the charge
is concentrated mostly on the GaMnAs layers, due to heavy and light holes with
their total angular momentum aligned anti-parallel to the average
magnetization. The charge and spin distributions are analyzed in terms of their
dependence on the number of multilayers, the widths of the GaMnAs and GaAs
layers, and the width of lateral GaAs layers at the borders of the structure.Comment: 12 pages,7 figure
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