12,060 research outputs found
Observations and light curve solutions of ultrashort-period eclipsing binaries
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
[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
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
Recommended from our members
Some new categorical invariants
In this paper we introduce new categorical notions and give many examples. In an earlier paper we proved that the Bridgeland stability space on the derived category of representations of K(l), the l-Kronecker quiver, is biholomorphic to CxH for l >= 3. In the present paper we define a new notion of norm, which distinguishes {Db(K(l))}l >= 2. More precisely, to a triangulated category T which has property of a phase gap we attach a non-negative real number epsilon. Natural assumptions on a SOD T=T1,T2 imply epsilon}. Using the norm we define a topology on the set of equivalence classes of proper triangulated categories with a phase gap, such that the set of discrete derived categories is a discrete subset, whereas the rationality of a smooth surface S ensures that [Db(point)]is an element of Cl([Db(S)]). Categories in a neighborhood of Db(K(l)) have the property that Db(K(l)) is embedded in each of them. We view such embeddings as non-commutative curves in the ambient category and introduce categorical invariants based on counting them. Examples show that the idea of non-commutative curve-counting opens directions to new categorical structures and connections to number theory and classical geometry. We give a definition, which specializes to the non-commutative curve-counting invariants. In an example arising on the A side we specialize our definition to non-commutative Calabi-Yau curve-counting, where the entities we count are a Calabi-Yau modification of Db(K(l)). In the end we speculate that one might consider a holomorphic family of categories, introduced by Kontsevich, as a non-commutative extension with the norm, introduced here, playing a role similar to the classical notion of degree of an extension in Galois theory
Selective recovery of tropane alkaloids applying liquid membrane technique
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
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
We report on a multi-site photometric campaign on the high-amplitude
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
- …
