Theoretical modeling of propagation of magneto-acoustic waves in magnetic regions below sunspots

We use 2D numerical simulations and eikonal approximation, to study properties of MHD waves traveling below the solar surface through the magnetic structure of sunspots. We consider a series of magnetostatic models of sunspots of different magnetic field strengths, from 10 Mm below the photosphere to the low chromosphere. The purpose of these studies is to quantify the effect of the magnetic field on local helioseismology measurements by modeling waves excited by sub-photospheric sources. Time-distance propagation diagrams and wave travel times are calculated for models of various field strength and compared to the non-magnetic case. The results clearly indicate that the observed time-distance helioseismology signals in sunspot regions correspond to fast MHD waves. The slow MHD waves form a distinctly different pattern in the time-distance diagram, which has not been detected in observations. The numerical results are in good agreement with the solution in the short-wavelength (eikonal) approximation, providing its validation. The frequency dependence of the travel times is in a good qualitative agreement with observations.Comment: accepted by Ap

Influence of phase-diversity image reconstruction techniques on circular polarization asymmetries

Full Stokes filter-polarimeters are key instruments for investigating the rapid evolution of magnetic structures on the solar surface. To this end, the image quality is routinely improved using a-posteriori image reconstruction methods. We analyze the robustness of circular polarization asymmetries to phase-diversity image reconstruction techniques. We use snapshots of magneto-hydrodynamical simulations carried out with different initial conditions to synthesize spectra of the magnetically sensitive Fe I line at 5250.2 A. We degrade the synthetic profiles spatially and spectrally to simulate observations with the IMaX full Stokes filter-polarimeter. We also simulate the focused/defocused pairs of images used by the phase-diversity algorithm for reconstruction and the polarimetric modulation scheme. We assume that standard optimization methods are able to infer the projection of the wavefront on the Zernike polynomials with 10% precision. We also consider the less favorable case of 25% precision. We obtain reconstructed monochromatic modulated images that are later demodulated and compared with the original maps. Although asymmetries are often difficult to define in the quiet Sun due to the complexity of the Stokes V profiles, we show how asymmetries are degraded with spatial and spectral smearing. The results indicate that, although image reconstruction techniques reduce the spatial smearing, they can modify the asymmetries of the profiles, mainly caused by the appearance of spatially-correlated noise.Comment: 10 pages, accepted for publication in A&

Multifractal analysis of stress time series during ultrathin lubricant film melting

Melting of an ultrathin lubricant film confined between two atomically flat surfaces is we studied using the rheological model for viscoelastic matter approximation. Phase diagram with domains, corresponding to sliding, dry, and two types of $stick-slip$ friction regimes has been built taking into account additive noises of stress, strain, and temperature of the lubricant. The stress time series have been obtained for all regimes of friction using the Stratonovich interpretation. It has been shown that self-similar regime of lubricant melting is observed when intensity of temperature noise is much larger than intensities of strain and stress noises. This regime is defined by homogenous distribution, at which characteristic stress scale is absent. We study stress time series obtained for all friction regimes using multifractal detrended fluctuation analysis. It has been shown that multifractality of these series is caused by different correlations that are present in the system and also by a power-law distribution. Since the power-law distribution is related to small stresses, this case corresponds to self-similar solid-like lubricant.Comment: 22 pages, 10 figures, 41 reference

NEW 3-(2-PYRIDYL)-1,2,4-TRIAZOLE DERIVATIVES AND THEIR PALLADIUM (II) COMPLEXES

The article is devoted to investigation of coordination compounds of palladium (II) with 3-(2-pyridyl)-1,2,4-triazole derivatives containing amino groups. We syntesized 4 ligands and 4 new coordination compounds. An interesting after removing of BOC-protection, NH2-group is still uncoordinated. In 1H NMR spectra of complexes was a significant shift of the ortho-pyridine proton in a low-field area, which prove proposed structure. This may be due to its closeness to the lone electron pair of the nitrogen cycle of the second triazole ligand

New coordination compounds of uranyl ion with 3-(2-hydroxyphenyl)-1,2,4-triazole and its derivatives: synthesis and investigation of spectral properties

New methods of 3-(2-hydroxyphenyl)-1,2,4-triazoles synthesis were developed. Obtained ligands was used for synthesis of three new complex compounds of uranyl-ion with general composition [UO2(HL)2(Solv)]. These compounds were characterized by NMR and IR spectroscopy

Evaluation of health status of adult population in the observation area of Zaporizhia Nuclear Power Plant

Introduction. Exploitation of nuclear power plants (NPP) is accompanied by a specific radiation and non-radiation influence on the environment. That is why the detection of their influence on the health of adjacent areas residents is of great importance.Objective. To estimate health status of the population of observation area of nuclear power facilities ofUkraineon the example of Zaporizhia NPP.Materials and methods. System review, bibliographic, analytical and statistical methods are used in the research.Results. An increase in the disease incidences of the digestive system of the adult population was found in certain regions of Zaporizhia NPP observation area.Conclusions. In connection with further development of nuclear power engineering and extension of nuclear power plants inUkraineafter the end of their operation lifetime and possible influence of adverse environmental factors during their exploitation for health of population dwelling on the observation area, the morbidity of population requires more detailed study and estimation

Improving the system of radiation and hygienic monitoring of environmental objects in the areas of observation of Ukrainian nuclear power plants as a fundamental of radiation safety.

The relevance of the work is determined by the absence of documents on the problems of observation zones of nuclear power plants, including the organization and monitoring of environmental objects in Ukraine. The purpose of the study was to assess the state of radioactive contamination of the environmental objects of the observation zone of the Zaporizhzhia nuclear power plant. To accomplish the tasks, we analyzed the data of the laboratory control performed by the external radiation monitoring laboratory of the Zaporizhzhia nuclear power plant and the data of the State Institution «Zaporizhzhia Regional Laboratory Center of the Ministry of Health of Ukraine». The obtained results allow us to draw the conclusions that in the environmental objects (water of the Kakhovsky reservoir, atmospheric air, soil, drinking water) of the observation zone of the Zaporizhzhia nuclear power plant, the main dose-forming radionuclides were identified. It is established that their levels are not uniform, and the identified instability indicates the need for continuous laboratory monitoring of the content of cesium and strontium and the need to monitor the impact on health of the residents of the observation area. It is necessary to improve radiation monitoring through the development and implementation of new methodological documents and regulations on the organization of laboratory control, justification of its frequency and the required amount of laboratory research, which will allow to establish the true impact on public health in these areas