1,324 research outputs found
Bank for breast milk
The article presents the purpose and tasks of the human milk banks. A brief historical review of the establishment and the development of a network of human milk banks in Europe and Bulgaria has been made. The activities and the main challenges for the further expansion of the network of human milk banks in Bulgaria are examined
The different origins of magnetic fields and activity in the Hertzsprung gap stars, OU Andromedae and 31 Comae
Context: When crossing the Hertzsprung gap, intermediate-mass stars develop a
convective envelope. Fast rotators on the main sequence, or Ap star
descendants, are expected to become magnetic active subgiants during this
evolutionary phase. Aims: We compare the surface magnetic fields and activity
indicators of two active, fast rotating red giants with similar masses and
spectral class but diferent rotation rates - OU And (Prot=24.2 d) and 31 Com
(Prot=6.8 d) - to address the question of the origin of their magnetism and
high activity.
Methods: Observations were carried out with the Narval spectropolarimeter in
2008 and 2013.We used the least squares deconvolution technique to extract
Stokes V and I profiles to detect Zeeman signatures of the magnetic field of
the stars. We provide Zeeman-Doppler imaging, activity indicator monitoring,
and a precise estimation of stellar parameters. We use stellar evolutionary
models to infer the evolutionary status and the initial rotation velocity on
the main sequence.
Results: The detected magnetic field of OU And is a strong one. Its
longitudinal component Bl reaches 40 G and presents an about sinusoidal
variation with reversal of the polarity. The magnetic topology of OU And is
dominated by large scale elements and is mainly poloidal with an important
dipole component, and a significant toroidal component. The detected magnetic
field of 31 Com is weaker, with a magnetic map showing a more complex field
geometry, and poloidal and toroidal components of equal contributions. The
evolutionary models show that the progenitors of OU And and 31 Com must have
been rotat
Conclusions: OU And appears to be the probable descendant of a magnetic Ap
star, and 31 Com the descendant of a relatively fast rotator on the main
sequence.Comment: 16 pages, 12 figure
Signature of a silver phase percolation threshold in microscopically phase separated ternary Ge0.15Se0.85-xAgx (0 <= x <= 0.20) glasses
Temperature modulated Alternating Differential Scanning Calorimetric (ADSC)
studies show that Se rich Ge0.15Se0.85-xAgx (0 <= x <= 0.20) glasses are
microscopically phase separated, containing Ag2Se phases embedded in a
Ge0.15Se0.85 backbone. With increasing silver concentration, Ag2Se phase
percolates in the Ge-Se matrix, with a well-defined percolation threshold at x
= 0.10. A signature of this percolation transition is shown up in the thermal
behavior, as the appearance of two exothermic crystallization peaks. Density,
molar volume and micro-hardness measurements, undertaken in the present study,
also strongly support this view of percolation transition. The super-ionic
conduction observed earlier in these glasses at higher silver proportions, is
likely to be connected with the silver phase percolation.Comment: 4 pages, 7 figure
Effect of nitrogenous bases on the thermal stability of jet fuels
Fuels from naphthenic petroleums were evaluated, and it was found that they had more N bases than those paraffinic ones (0.00024 and 0.000009% N, respectively). The removal of the N bases improved significantly the thermal stability and reduced the residue formation during oxidation of the fuel. The improvement depended on both content and composition of the bases. Thus, fuels with similar content of N bases (0.00058% N) and thermal stability had oxidation residues of 17.5 and 5.6 and sol. gum of 13 and 1.5 mg/100 ml, before and after removing the N bases, respectively
Principles of Sakha Language Terminology Description in Linguistics of 1920-1940
The features of term studies formation in the works of researchers of the Sakha language in the 1920-1940-ies are considered. It is reported that at this time, a lot of work was done to develop the theoretical foundations and principles of creating the terms of the Sakha language, as well as a large number of terms in various fields of knowledge, especially in the socio-political sphere. It is emphasized that terminology complexes have been developed in all subjects in the volume of high school. It is shown that these goals were achieved relatively quickly because of the Yakut intelligentsia leaders of terms construction, who recognized the great importance of this work, enthusiastically took up the work and led others. Among leaders there were now well-known figures of language and - wider - cultural construction: A. E. Kulakovskiy, S. A. Novgorodov, A. A. Ivanov (Күндэ), G. V. Baishev (known by literary pseudonym Altan Saryn) and P. A. Oyunskiy. The article notes that each of these scientists went his own way, had his own priorities. Based on the results of the review, it is proved that the activity on the Yakut terminology system development was initially focused on two main ways of terminology fund formation: the use of internal language resources and borrowing of terms from other languages, in particular Russian. The article attempts to analyse dictionaries compiled by figures of linguistic construction of 1920-1940 from the point of view of the theory of modern thermography in order to optimize typical and composite parameters of terminological dictionaries
Influence of exogenous urea on photosynthetic pigments, 14CO2 uptake, and urease activity in Elodea densa-environmental implications
This paper analyzes the effect of exogenous urea in increased concentration gradient (0, 100, 500 and 1,000 mg L-1) on photosynthetic pigments (measured spectrophotometrically), uptake of 14CO2 (using radioisotope), and urease activity (by measuring ammonia with Nessler's reagent) in leaves of Elodea densa Planch. We have observed that low concentration of urea (100 mg L-1) stimulates the accumulation of photosynthetic pigments and intensifies photosynthesis in E. densa, whereas high concentration (1,000 mg L-1) suppresses these processes. Urease activity increased by approximately 2.7 and 8 fold when exogenous urea concentrations were 100 and 500 mg L-1, respectively. However, exogenous urea in high concentration (1,000 mg L-1) decreased urease activity by 1.5 fold compared to the control. The necessity of mitigating urea and other nitrogen-containing compounds (NH3 from urea) in water bodies has been discussed with emphasis on the potential for phytoremediation of urea using common water weed viz. E. densa. © 2013 Springer-Verlag Berlin Heidelberg
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