12,060 research outputs found

    Observations and light curve solutions of ultrashort-period eclipsing binaries

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    Photometric observations in V and I bands and low-dispersion spectra of ten ultrashort-period binaries (NSVS 2175434, NSVS 2607629, NSVS 5038135, NSVS 8040227, NSVS 9747584, NSVS 4876238, ASAS 071829-0336.7, SWASP 074658.62+224448.5, NSVS 2729229, NSVS 10632802) are presented. One of them, NSVS 2729229, is newly discovered target. The results from modeling and analysis of our observations revealed that: (i) Eight targets have overcontact configurations with considerable fillout factor (up to 0.5) while NSVS 4876238 and ASAS 0718-03 have almost contact configurations; (ii) NSVS 4876238 is rare ultrashort-period binary of detached type; (iii) all stellar components are late dwarfs; (iv) the temperature difference of the components of each target does not exceed 400 K; (v) NSVS 2175434 and SWASP 074658.62+224448.5 exhibit total eclipses and their parameters could be assumed as well-determined; (v) NSVS 2729229 shows emission in the H_{alpha} line. Masses, radii and luminosities of the stellar components were estimated by the empirical relation "period, orbital axis" for short- and ultrashort-period binaries. We found linear relations mass-luminosity and mass-radius for the stellar components of our targets.Comment: Accepted for publication in PAS

    Buffalo Child Care Means Business: Full Study Report

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    [Excerpt] Buffalo Child Care Means Business presents the economic and business case for making Buffalo\u27s children the focus of economic development. The 2006 survey of 117 businesses located in downtown Buffalo, New York, documents the business sector\u27s present and projected reliance upon high quality child care services as a necessary component to optimum workplace recruitment, productivity and stability. This promising study highlights research specific to the Buffalo region measuring the cost the community bears as a result of low quality child care and early education. It draws upon nationally recognized economic development strategies to offer recommendations for a strategic child care plan integral to the City of Buffalo\u27s overall strategic initiatives to strengthen downtown\u27s attractiveness to successful enterprises. The early development needs of Buffalo\u27s children must be front and center if the potential economic power of broadly successful education is to be realized. With business, government, education and child care leaders at the table, Buffalo\u27s economic renaissance can be built on individual and social foundations that last a lifetime

    Elaboration and characterization of Fe1–xO thin films sputter deposited from magnetite target

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    Majority of the authors report elaboration of iron oxide thin films by reactive magnetron sputtering from an iron target with Ar–O2 gas mixture. Instead of using the reactive sputtering of a metallic target we report here the preparation of Fe1–xOthin films, directly sputtered froma magnetite target in a pure argon gas flow with a bias power applied. This oxide is generally obtained at very low partial oxygen pressure and high temperature.We showed that bias sputtering which can be controlled very easily can lead to reducing conditions during deposition of oxide thin film on simple glass substrates. The proportion of wustite was directly adjusted bymodifying the power of the substrate polarization. Atomic force microscopy was used to observe these nanostructured layers. Mössbauer measurements and electrical properties versus bias polarization and annealing temperature are also reported

    Selective recovery of tropane alkaloids applying liquid membrane technique

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    A tropine recovery from its solutions applying a liquid membrane technique was studied. Among several studied organic solvents, chloroform showed best extraction ability towards atropine. Pertraction studies were carried out in a laboratory bulk liquid membrane contactor with agitation of all three phases. Both, aqueous solutions of pure atropine and extract of Atropa Belladonna L. roots were used as feed solutions, as well as chloroform and diluted sulphuric acid as a liquid membrane and a stripping liquor, respectively. The effect of phase agitation on alkaloid pertraction was studied for the cases when pure atropine solutions were used as feed phase. A pertraction process carried out with native liquid extracts from A. Belladonna provided selective alkaloid recovery and its concentration in the acceptor solutio

    Peak positions and shapes in neutron pair correlation functions from powders of highly anisotropic crystals

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    The effect of the powder average on the peak shapes and positions in neutron pair distribution functions of polycrystalline materials is examined. It is shown that for highly anisotropic crystals, the powder average leads to shifts in peak positions and to non-Gaussian peak shapes. The peak shifts can be as large as several percent of the lattice spacing

    Mode identification in the high-amplitude {\delta} Scuti star V2367 Cyg

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    We report on a multi-site photometric campaign on the high-amplitude δ\delta Scuti star V2367 Cyg in order to determine the pulsation modes. We also used high-dispersion spectroscopy to estimate the stellar parameters and projected rotational velocity. Time series multicolour photometry was obtained during a 98-d interval from five different sites. These data were used together with model atmospheres and non-adiabatic pulsation models to identify the spherical harmonic degree of the three independent frequencies of highest amplitude as well as the first two harmonics of the dominant mode. This was accomplished by matching the observed relative light amplitudes and phases in different wavebands with those computed by the models. In general, our results support the assumed mode identifications in a previous analysis of Kepler data.Comment: 9 pages, 5 figures, 4 tables. Accepted for publication in MNRA
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