191 research outputs found
Laboratory assessment of the thyroid system in women working at concentrating factory
The purpose of the article is to examine the state of thyroid system in workers of mining and processing plant, working in harmful conditions. Materials and Methods: The working conditions of 407 workers of concentrator (study group) and 128 women workers of energy department (control group). The level of thyroid stimulating hormone and free thyroxine, anti-thyroid peroxidase and thyroglobulin has been determined in 88 women-workers of the main group and 82 women workers of control group. 80 women-workers of main group have been examined on the iodine content in the hair. Results: It has been found that the conditions of workers at enrichment of copper-zinc ore are characterized by the influence of these chemical factors, dust, industrial noise, adverse climate. In the study of blood serum and hair decreased levels of iodine in their hair and deviations due to decrease of thyroid function, and strengthening of the body»s autoimmune processes have been revealed. Conclusion: Harmful working conditions in concentrating factory cause the risk of pathology of the thyroid gland
Time delays for 11 gravitationally lensed quasars revisited
We test the robustness of published time delays for 11 lensed quasars by
using two techniques to measure time shifts in their light curves.
We chose to use two fundamentally different techniques to determine time
delays in gravitationally lensed quasars: a method based on fitting a numerical
model and another one derived from the minimum dispersion method introduced by
Pelt and collaborators. To analyse our sample in a homogeneous way and avoid
bias caused by the choice of the method used, we apply both methods to 11
different lensed systems for which delays have been published: JVAS B0218+357,
SBS 0909+523, RX J0911+0551, FBQS J0951+2635, HE 1104-1805, PG 1115+080, JVAS
B1422+231, SBS 1520+530, CLASS B1600+434, CLASS B1608+656, and HE 2149-2745
Time delays for three double lenses, JVAS B0218+357, HE 1104-1805, and CLASS
B1600+434, as well as the quadruply lensed quasar CLASS B1608+656 are confirmed
within the error bars. We correct the delay for SBS 1520+530. For PG 1115+080
and RX J0911+0551, the existence of a second solution on top of the published
delay is revealed. The time delays in four systems, SBS 0909+523, FBQS
J0951+2635, JVAS B1422+231, and HE 2149-2745 prove to be less reliable than
previously claimed.
If we wish to derive an estimate of H_0 based on time delays in
gravitationally lensed quasars, we need to obtain more robust light curves for
most of these systems in order to achieve a higher accuracy and robustness on
the time delays
Microlensing in the double quasar SBS1520+530
We present the results of a monitoring campaign of the double quasar
SBS1520+530 at Maidanak observatory from April 2003 to August 2004. We obtained
light curves in V and R filters that show small-amplitude \Delta m~0.1 mag
intrinsic variations of the quasar on time scales of about 100 days. The data
set is consistent with the previously determined time delay of \Delta
t=(130+-3) days by Burud et al. (2002). We find that the time delay corrected
magnitude difference between the quasar images is now larger by (0.14+-0.03)
mag than during the observations by Burud et al. (2002). This confirms the
presence of gravitational microlensing variations in this system.Comment: 6 pages, 7 figures. Accepted for publication in A&
Resolving the Inner Structure of QSO Discs by Fold Caustic Crossing Events
Though the bulk of the observed optical flux from the discs of
intermediate-redshift lensed quasars is formed well outside the region of
strong relativistic boosting and light-bending, relativistic effects have
important influence on microlensing curves. The reason is in the divergent
nature of amplification factors near fold caustics increasingly sensitive to
small spatial size details. Higher-order disc images produced by strong light
bending around the black hole may affect the amplification curves, making a
contribution of up to several percent near maximum amplification. In accordance
with theoretical predictions, some of the observed high-amplification events
possess fine structure. Here we consider three putative caustic crossing
events, one by SBS1520+530 and two events for individual images of the
Einstein's cross (QSO J2237+0305). Using relativistic disc models allows to
improve the fits, but the required inclinations are high, about 70deg or
larger. Such high inclinations apparently contradict the absence of any strong
absorption that is likely to arise if a disc is observed edge-on through a dust
torus. Still, the high inclinations are required only for the central parts of
the disc, that allows the disc itself to be initially tilted by 60-90deg with
respect to the black hole and aligned toward the black hole equatorial plane
near the last stable orbit radius. For SBS1520+530, an alternative explanation
for the observed amplification curve is a superposition of two subsequent fold
caustic crossings. While relativistic disc models favour black hole masses
~10^10 solar (several times higher than the virial estimates) or small
Eddington ratios, this model is consistent with the observed distribution of
galaxies over peculiar velocities only if the black hole mass is about 3 10^8
solar.Comment: 19 pages, 16 figures, 3 tables; accepted to MNRAS; small proof
corrections mad
Gravitationally lensed QSOs in the ISSIS/WSO-UV era
Gravitationally lensed QSOs (GLQs) at redshift z = 1-2 play a key role in
understanding the cosmic evolution of the innermost parts of active galaxies
(black holes, accretion disks, coronas and internal jets), as well as the
structure of galaxies at intermediate redshifts. With respect to studies of
normal QSOs, GLQ programmes have several advantages. For example, a monitoring
of GLQs may lead to unambiguous detections of intrinsic and extrinsic
variations. Both kinds of variations can be used to discuss central engines in
distant QSOs, and mass distributions and compositions of lensing galaxies. In
this context, UV data are of particular interest, since they correspond to
emissions from the immediate surroundings of the supermassive black hole. We
describe some observation strategies to analyse optically bright GLQs at z of
about 1.5, using ISSIS (CfS) on board World Space Observatory-Ultraviolet.Comment: 7 pages, 4 figures, Accepted for publication in Astrophysics & Space
Scienc
Work of art in the space of network culture: Creativity as bricolage
The development of modern informational-communication technologies has led to the occurrence of the new unique sociocultural phenomenon – a network culture, with irony as the dominating rhetoric. In the space of network culture, under digital technologies, the forms, types, and functions of art, and creativity in general, change. The paper states that communication becomes the main function of art, while a work of art more and more becomes an object of communication. The authors propose to broaden the volume of creativity conception, going beyond the classical interpretation towards a broader understanding of this phenomenon, namely, creativity as bricolage. The methodological basis of the bricolage model of creativity, relevant for the new media art, is the concept of “bricolage” developed by Claude Lévi-Strauss. © 2020 The Author(s). Published by VGTU Press.The film distribution confirms this point of view. By the 2019 data, the film Matilda became the most unprofitable film supported by the Cinema Foundation of Russia: “Matilda’s losses became a sort of a record – 550 million rubles” (Zhitkova, 2018)
Disk-Jet Connection in the Radio Galaxy 3C 120
We present the results of extensive multi-frequency monitoring of the radio
galaxy 3C 120 between 2002 and 2007 at X-ray, optical, and radio wave bands, as
well as imaging with the Very Long Baseline Array (VLBA). Over the 5 yr of
observation, significant dips in the X-ray light curve are followed by
ejections of bright superluminal knots in the VLBA images. Consistent with
this, the X-ray flux and 37 GHz flux are anti-correlated with X-ray leading the
radio variations. This implies that, in this radio galaxy, the radiative state
of accretion disk plus corona system, where the X-rays are produced, has a
direct effect on the events in the jet, where the radio emission originates.
The X-ray power spectral density of 3C 120 shows a break, with steeper slope at
shorter timescale and the break timescale is commensurate with the mass of the
central black hole based on observations of Seyfert galaxies and black hole
X-ray binaries. These findings provide support for the paradigm that black hole
X-ray binaries and active galactic nuclei are fundamentally similar systems,
with characteristic time and size scales linearly proportional to the mass of
the central black hole. The X-ray and optical variations are strongly
correlated in 3C 120, which implies that the optical emission in this object
arises from the same general region as the X-rays, i.e., in the accretion
disk-corona system. We numerically model multi-wavelength light curves of 3C
120 from such a system with the optical-UV emission produced in the disk and
the X-rays generated by scattering of thermal photons by hot electrons in the
corona. From the comparison of the temporal properties of the model light
curves to that of the observed variability, we constrain the physical size of
the corona and the distances of the emitting regions from the central BH.Comment: Accepted for publication in the Astrophysical Journal. 28 pages, 21
figures, 2 table
On one class of commutative operads
© 2017 World Scientific Publishing CompanyIn this paper, we study one class of commutative operads, namely, the operads of multidimensional (hollow) cubes in Euclidean spaces and their generalization. We describe the varieties of universal algebras rational equivalent to the varieties of algebras over commutative operads
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