514 research outputs found
Mean Long-Term Seasonal Variability of the Coastal Current at the Crimea Southern Coast in 2002β2020
Purpose. The study is aimed at systematizing new scientific knowledge on the regime, regularities and features of seasonal water circulation in the Black Sea coastal zone, i.e. in the dynamically active area near the of the Southern coast of Crimea. The data for the past decade were obtained in course of a long-term in situ experiment.
Methods and Results. The presented results were obtained by means of complex processing and analyzing the data on the currents monitored at the Black Sea hydrophysical sub-satellite test site of Marine Hydrophysical Institute of RAS in 2002β2020. Instrumental measurements were performed by a cluster of the autonomous Euler current meters using a verified monitoring information technology from a stationary oceanographic platform in the deep sea at a distance 0.5 km from the coast. The information of the generated long-term currents monitoring database has been confirmed by the metrological control of measurements quality and has got state registration. In the coastal zone, parameters of the along-coastal current directed to the west-south-west were studied at the average (for 19 years) flow velocity 8.1 cm/s which was maximal in the near-surface layer. When the eddy-wave oscillations propagate near the coast, the elliptical orbital circulation is transformed into a system of the along-coastal reciprocal water oscillations of the corresponding scales which are collinear to the existing coastal current. The existence of a bimodal distribution of occurrence frequency of the along-coastal current direction depends on intensity of contribution of the eddy-wave oscillations to water circulation. The bimodal structure of a current is arises at such modulus values of the perturbation orbital velocities that exceed the one of the velocity of the monomodal along-coastal current vector.
Conclusions. Based on the results of spectral analysis, the energy contribution of the coastal water different-scale fluctuations to variability of the stationary along-coastal current near the Cape Kikineiz was systematized. Analysis of the long-term average frequency spectra of distribution of the kinetic energy density of water oscillations in the coastal ecotone permitted to identify statistically reliably the intense seasonal current fluctuations for an annual period, as well as the fluctuations near the second and third annual harmonics. It is shown that large-scale variability of the quasi-stationary coastal current is controlled by water dynamics in the shelf-slope zone of the Black Sea, whereas on smaller scales it is affected by influence of the local wind conditions
Hybrid Active and Passive Cable Contour Shielding of Magnetic Fields of Double-Circuit Overhead Power Lines
The purpose of the work is to design a hybrid screen designed to reduce the level of the magnetic field generated by double-circuit overhead power lines, to increase the efficiency of shielding the original magnetic field in residential buildings, to the level of sanitary standards and to reduce the sensitivity of the system to changes in system parameters. To achieve this goal, the structure of a hybrid screen was determined, consisting of a double contour active and a cable contour passive part. The developed hybrid screen is characterized by increased efficiency in reducing the magnetic field of industrial frequency. Designing a hybrid screen comes down to solving a minimax vector optimization problem, in which the vector objective function is calculated based on solution to Maxwell's equations in a quasi-stationary approximation using the COMSOL Multiphysics software package. The solution to the minimax vector optimization problem is calculated based on multi-particle swarm optimization algorithms from Pareto-optimal solutions taking into account binary preference relations. During the design of the hybrid screen, the coordinates of the spatial location of the two compensation windings, as well as the magnitude of the currents and its phases in the windings of the active screen, were calculated. The important results are theoretical and experimental studies on the effectiveness of the designed hybrid magnetic field shield generated by double-circuit overhead power lines. The significance of the results obtained lies in the fact that practical recommendations are given for a reasonable choice of the spatial arrangement of two shielding windings of a robust system of hybrid shielding of the magnetic field generated by double-circuit overhead power lines
Magnetic information sensing based on magneto-optic plasmonic nanostructure
Magnetized garnet layer is used to detect thin ferromagnetic layers. Incident light
changes its polarization when passing through garnet layer due to Faraday effect. External
sources of magnetic field impacts this process. We can detect these changes and so understandnature of external sources
MxTiSe2 (M = Cr, Mn, Cu) electronic structure study by methods of resonant X-ray photoemission spectroscopy and X-Ray absorption spectroscopy
Electronic structure and chemical bonding in TiX2 (X=S, Se, Te), TMxTiSe2
(TM=Cr, Mn, Cu) and CrxTi1-xSe2 were studied by x-ray resonance photoemission
and absorption spectroscopy. These methods are detected to be strong sensitive
to chemical bonding. Charge transfer from the intercalated atoms to Ti 3d band
is detected. Narrow Ti 3d and Cu 3d bands are observed under Fermi level in
CuxTiSe2.Comment: 7 pages, 4 figeres, ISIC 16 conferenc
Magnetite-polymer Nanoparticles: Structure and Properties
The paper describes synthesis of magnetite-alginate composites. The main feature of such biomaterials is the simultaneous formation of magnetite nanoparticles inside the alginate matrix. Obtained samples were characterized by X-ray diffraction and transmission electron microscopy. In several samples the secondary phase of ammonium chloride was observed. The average crystallite sizes of magnetite phase are about 13 nm. The addition of alginate leads to the decrease of microstrains in [h k 0] direction
Detection of thin ferromagnetic layers based on Faraday effect
Optical head with magnetized garnet layer is used to detect presence of thin ferromagnetic layers such as printed text. Mathematical model of the system presented further was created. By varying opaque material, layer thicknesses and air gap between optical head and scanned object optimal configuration of the system was calculated. Incident P-polarized light affected by garnet layer changes its polarization due to Faraday effect. We can detect presence or absence of ferromagnetic after studying changes in polarization of the reflected light. Comparing results with and without influence of the ferromagnetic layers recognition of printed pattern under opaque material is achieved
The Study of the Influence of Static Magnetic Field on Brushite Crystallization in the Presence of Magnesium
The paper describes the influence of the imposition of static magnetic field on brushite crystallization.
Two different configurations of the magnetic field were used. The flasks with the precipitates were placed
near the different poles. It was shown that changing the magnetic field configuration and positioning the
samples in proximity to north or south poles can greatly affect their crystallinity and texture with most of
them having the preferred orientation along the b-axis according to the X-Ray diffraction data. The imposition
of the magnetic field also influences the microstrain ratio decreasing it significantly. It was also verified
[1] that the Mg substrate availability decreases the crystallinity of DCPD. The micrographs of the nanoparticles
with the different magnifications were obtained by the transmission electron microscopy
(TEM). The comparative analysis of the electron microscopy data correlates with the XRD data.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3546
Structural Properties of the Nanocrystallized Magnetite of Different Syntheses
Transmission electron microscopy (TEM) with electronic diffraction and X-ray diffraction (XRD) was
used to study structural features of nanosized magnetite Fe3O4, which was synthesized using polymeric
matrices (polysaccharide chitosan, at alias). From the received data it was revealed that growth inhibition
and size stabilization of Fe3O4 nanoparticles were strongly affected by polysaccharide matrix. It was also
observed that directional size decrease of Fe3O4 nanoparticles was accompanied by the increasing defectiveness
of crystal lattice and decreasing unit cell size. The effectiveness of complementary use of both
TEM with electronic diffraction and XRD techniques for structural and substructural parameters determination
while studying magnetite nanosized particles synthesized in polysaccharide matrices is shown in
this paper.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3545
Measurement of and Structure Functions in Low Region with the IHEP-JINR Neutrino Detector
The isoscalar structure functions and are measured as functions
of averaged over all permissible for the range of 6 to 28 GeV of
incident neutrino (anti-neutrino) energy at the IHEP-JINR Neutrino Detector.
The QCD analysis of structure function provides
MeV under the assumption of QCD
validity in the region of low . The corresponding value of the strong
interaction constant agrees with the
recent result of the CCFR collaboration and with the combined LEP/SLC result.Comment: 11 pages, 1 Postscript figure, LaTeX. Talk given at the 7th
International Workshop on Deep Inelastic Scattering and QCD (DIS 99),
Zeuthen, Germany, 19-23 Apr 199
Structural Properties of the Nanocrystallized Magnetite of Different Syntheses
Transmission electron microscopy (TEM) with electronic diffraction and X-ray diffraction (XRD) was
used to study structural features of nanosized magnetite Fe3O4, which was synthesized using polymeric
matrices (polysaccharide chitosan, at alias). From the received data it was revealed that growth inhibition
and size stabilization of Fe3O4 nanoparticles were strongly affected by polysaccharide matrix. It was also
observed that directional size decrease of Fe3O4 nanoparticles was accompanied by the increasing defectiveness
of crystal lattice and decreasing unit cell size. The effectiveness of complementary use of both
TEM with electronic diffraction and XRD techniques for structural and substructural parameters determination
while studying magnetite nanosized particles synthesized in polysaccharide matrices is shown in
this paper.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3545
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