1,209 research outputs found
Gamma-ray Flares and VLBI Outbursts of Blazars
A model is developed for the time dependent electromagnetic - radio to
gamma-ray - emission of active galactic nuclei, specifically, the blazars,
based on the acceleration and creation of leptons at a propagating
discontinuity or {\it front} of a Poynting flux jet. The front corresponds to a
discrete relativistic jet component as observed with
very-long-baseline-interferometry (VLBI). Equations are derived for the number,
momentum, and energy of particles in the front taking into account synchrotron,
synchrotron-self-Compton (SSC), and inverse-Compton processes as well as
photon-photon pair production. The apparent synchrotron, SSC, and
inverse-Compton luminosities as functions of time are determined. Predictions
of the model are compared with observations in the gamma, optical and radio
bands. The delay between the high-energy gamma-ray flare and the onset of the
radio is explained by self-absorption and/or free-free absorption by external
plasma. Two types of gamma-ray flares are predicted depending on pair creation
in the front.Comment: 11 pages, submitted to ApJ. 10 figures can be obtained from R.
Lovelace by sending postal address to [email protected]
Variability Profiles of Millisecond X-Ray Pulsars: Results of Pseudo-Newtonian 3D MHD Simulations
We model the variability profiles of millisecond period X-ray pulsars. We
performed three-dimensional magnetohydrodynamic simulations of disk accretion
to millisecond period neutron stars with a misaligned magnetic dipole moment,
using the pseudo-Newtonian Paczynski-Wiita potential to model general
relativistic effects. We found that the shapes of the resulting funnel streams
of accreting matter and the hot spots on the surface of the star are quite
similar to those for more slowly rotating stars obtained from earlier
simulations using the Newtonian potential. The funnel streams and hot spots
rotate approximately with the same angular velocity as the star. The spots are
bow-shaped (bar-shaped) for small (large) misalignment angles. We found that
the matter falling on the star has a higher Mach number when we use the
Paczynski-Wiita potential than in the Newtonian case.
Having obtained the surface distribution of the emitted flux, we calculated
the variability curves of the star, taking into account general relativistic,
Doppler and light-travel-time effects. We found that general relativistic
effects decrease the pulse fraction (flatten the light curve), while Doppler
and light-travel-time effects increase it and distort the light curve. We also
found that the light curves from our hot spots are reproduced reasonably well
by spots with a gaussian flux distribution centered at the magnetic poles. We
also calculated the observed image of the star in a few cases, and saw that for
certain orientations, both the antipodal hot spots are simultaneously visible,
as noted by earlier authors.Comment: 9 pages, 10 figures, accepted for publication in ApJ; corrected some
typo
Досвід протидії ксенофобії
Романова, О. І. Досвід протидії ксенофобії / О. І. Романова // Вісник Кримінологічної асоціації України. - 2013. - № 4. - С. 170-179.В статті проаналізовані питання актуальної нормативної і правознавчої діяльності в державі, протидії різноманітним формам нетолерантного ставлення, у тому
числі й запобігання кримінально-правовими засобами.In this article author analyzes questions of urgent normative and law-founding activity in
the state concerning counteractions to different forms of not tolerant attitude and attitude
by criminal and law enforcement means too.В статье проанализированы вопросы актуальной нормативной и правоприменительной деятельности в государстве, противодействие разнообразным нетолерантного отношения, в том числе предупреждение уголовно-правовыми способами
Winter rye (Secale cereale L.) antioxidant capacity, total phenolic content and quality indices
Rye (Secale cereale L.) grain is an excellent raw material for healthy and tasty foods.
Rye products are characterized by their unique composition and properties such as antioxidant
capacity and total phenolic. The aim of the study was to assess radical scavenging capacity, total
phenolic content, protein, starch content and falling number in rye varieties wholemeal. The trial
included population winter rye varieties ‘Kaupo’, ‘Amilo’, ‘Dankowskie Amber’, ‘Dankowskie
Rubin’, ‘Inspector’ and hybrid rye varieties ‘SU Drive’, ‘SU Mephisto’, ‘SU Bendix’, ‘Brasetto’,
‘Palazzo’ grown in Latvia. The antioxidant activity was determined using the DPPH
(2.2-diphenyl-1-1-picrylhydrazyl radical) assay and total phenolic content was determined
spectrophotometrically according to the Folin-Ciocalteou method. The rye grain antioxidant
capacity was estimated as Trolox equivalent, while the total phenolic content was expressed as
gallic equivalents (GAE). ‘Su Drive’ rye variety contained the largest amount of total
phenolic (average 208 mg GAE 100 g
-1 DW), but the lowest – ‘Inspector’ rye variety
176 mg GAE 100 g
-1 DW. In general, all rye samples tested in this study demonstrated similar
level of antioxidant capacity (from 38.5 to 46.2 mmol Trolox eq. 100 g
-1
). Statistically higher
(P < 0.05) total phenols content and falling number had hybrid rye grains, compared to the
population rye grains. In the present trial, the differences between hybrid varieties grains protein
and starch content comparing to population varieties were not observed
Conductivity, weak ferromagnetism and charge instability in single crystal
The temperature dependence of resistivity, magnetization and electron-spin
resonance of the single crystal were measured in temperature
range of . Magnetization hysteresis in applied magnetic field
up to 0.7 T at , irreversible temperature behavior of
magnetization and resistivity were found . The obtained data were explained in
terms of degenerate tight binding model using random phase approximation. The
contribution of holes in and bands of manganese ions to the
conductivity, optical absorbtion spectra and charge instability in were studied. Charge susceptibility maxima resulted from the competition of
the on-site Coulomb interaction between the holes in different orbitals and
small hybridization of sub-bands were calculated at .Comment: 6 pages, 12 figure
Social and economic space compression in border areas: the case of the Northwestern Federal District
The so-called "compression" of social and economic space has been the subject of quite a few studies in the past decades. There are two principle types of compression: communicative, that is, associated with the development of transport and information systems, and physical, manifested in the rapid decrease of the number of new territories to explore. While physical and communicative compression are interrelated, they have different spatial expressions depending on geographical conditions, economic, environmental, historical, and political characteristics of the region. The authors identify the patterns of communicative and physical space compression using comparative mapping, statistical and historical research methods, and a model showing the spatial differentiation of regional socioeconomic characteristics in the Northwestern Federal District. The study focuses on border areas, where the following key manifestations of compression have been identified: transport connectivity, level of agriculture development, and depopulation. All these indicators of space compression process are studied at the municipal level. The authors identify the key features of socioeconomic space compression for the border areas of the Russian Northwest
Characterization of red raspberry (Rubus idaeus L.) for their physicochemical and morphological properties
Received: January 30th, 2021 ; Accepted: May 9th, 2021 ; Published: May 13th, 2021 ; Correspondence: [email protected] raspberry cultivars are grown in Latvia suitable both for fresh market and for
processing. Fresh local red raspberry is available for consumers from July to October. Information
about the physical, chemical, and morphology properties of raspberry fruit is essential for
understanding the behavior of the product during the postharvest operations such as harvesting,
transporting, sorting, grading, packaging and storage. Knowledge of the physicochemical
properties of red raspberries is essential because variations in the levels of these properties may
exist between cultivars. New varieties of plants were used to describe and compare the fruit
quality of red raspberry cultivars: ‘Daiga’, ‘Shahrazada’, ‘Norna’ and ‘Polana’ grown in Zemgales
region of Latvia. The samples were collected from farm ‘Pluģi’ the full stage of ripening. The
current research aimed to investigate and determine the chemical composition (total phenolic
content (TPC), total flavonoid content (TFC), titratable acidity (TAc), total soluble solids content
of raspberry fruits, the physical parameter pH, and color. Presented morphological parameters of
fruit included their weight, receptacle length (Rl), receptacle width (Rw), fruit length (Fl), fruit
width (Fw), weight of fruit (M), number of seeds. Research results showed significant differences
in all chemical and physical characteristics as well as in morphology properties (P < 0.05)
between cultivars
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