scholarly journals Aperiodic and wave disturbances in the ionosphere: the results of vertical sounding»

2021 ◽  
Author(s):  
O.V. Bogomaz ◽  
L.F. Chernogor ◽  
V.V. Barabash ◽  
S.V. Katsko
Keyword(s):  
Experimental Data ◽  
Remote Sensing ◽  
Radio Source ◽  
Periodic Wave ◽  
Cosmic Body ◽  
Powerful Radio ◽  
Wave Disturbances ◽  
Study Results ◽  
Solar Eclipses

The monograph presents the study results of aperiodic and quasi-periodic wave perturbations in the ionosphere during unique phenomena in geospace: partial solar eclipses, the fall of the Chelyabinsk cosmic body and during the operation of a powerful radio source – the heating stand «Sura». Experimental data obtained by the method of remote sensing are analyzed. Designed for scientists in the field of ionosphere physics, radio physics, radar, as well as for lecturers, graduate and Ph.D. students.

Concentration Dependence of the Surface Tension of Three and Four-Component Systems with Peculiarities in the Surface Tension Isotherms of Lateral Binary Melts

2021 ◽  
Vol 1022 ◽  
pp. 194-202
Author(s):  
R.Kh. Dadashev ◽  
R.A. Kutuev
Keyword(s):  
Experimental Data ◽  
Surface Tension ◽  
Concentration Dependence ◽  
Experimental Error ◽  
Binary Systems ◽  
Experimental Studies ◽  
Study Results ◽  
Component Systems ◽  
Minimum Depth ◽  
Surface Tension Isotherms

The experimental study results of the melts concentration dependence of the surface tension of the four-component indium-tin-lead-bismuth system and its constituent binary systems of indium-tin, indium-lead, indium-bismuth, tin-lead, tin-bismuth, lead-bismuth are presented in the paper. It is shown that the concentration dependence of the melts surface tension of the In-Sn-Pb-Bi four-component system can be predicted from the data on ST (surface tension) values of lateral binary systems. Features in the ST isotherms in the form of a minimum are observed only in the indium-tin lateral system from all lateral binaries. A distinctive feature of the detected minimum is that the minimum depth slightly exceeds the experimental error. Therefore, in addition to the fact that the area of average compositions was studied more thoroughly, we carried out the surface tension measurements by two independent methods. The experimental data obtained by both methods coincide within the experimental error and indicate the extremum availability on ST isotherms. Thus, ST experimental studies by two independent methods confirmed the presence of a flat minimum on ST isotherms of the indium-tin binary system increasing the reliability of the obtained data. The obtained outcomes and their comparison with experimental data have shown that the considered models for predicting surface properties based on data due to similar properties of lateral binary systems adequately reflect the experimental dependences. However, the prediction model based on Kohler's method of excess values describes the experimental curves more accurately.

scholarly journals 5 GHz EVN Polarization of 3C286

1996 ◽  
Vol 175 ◽  
pp. 85-87 ◽  
Author(s):  
D. Dallacasa ◽  
R.T. Schilizzi ◽  
H.S. Sanghera ◽  
D.R. Jiang ◽  
E. Lüdke ◽  
...  
Keyword(s):  
Electric Field ◽  
Radio Source ◽  
Field Vector ◽  
Central Component ◽  
Electric Field Vector ◽  
Powerful Radio ◽  
Line System ◽  
Rotation Measure ◽  
Polarized Emission ◽  
5 Ghz

3C286 (1328+307) is a powerful radio source identified with a quasar at z=0.849. There is a foreground galaxy responsible for an H I absorption line system at z=0.6922 (Brown & Roberts 1973), centered approximately 2.″5 to the southeast of 3C286. The radio source has a steep spectrum (α = −0.61, Sv ∝ vα between 1.4 and 15 GHz) which turns over at about 100 MHz. Subarcsecond resolution radio images show a misaligned triple structure, dominated by the central component (Spencer et al. 1989) which accounts for at least 95% of the total flux density at all frequencies. 3C286 is one of the strongest extragalactic sources in polarized emission (0.84 Jy at 5 GHz and 1.41 Jy at 1.4 GHz) and with a rotation measure close to 0 rad m–2 (Rudnick and Jones 1983). Hence the observed orientation of the electric field vector is essentially independent of frequency.

scholarly journals Radio Source Environments at Redshifts > 0.5

1996 ◽  
Vol 175 ◽  
pp. 321-322
Author(s):  
M. Lacy ◽  
S. Rawlings ◽  
M. Wold ◽  
A. Bunker ◽  
K.M. Blundell ◽  
...  
Keyword(s):  
Radio Source ◽  
High Redshift ◽  
Elliptical Galaxies ◽  
Radio Sources ◽  
Powerful Radio ◽  
Host Galaxies ◽  
Local Universe ◽  
Wide Range ◽  
Age Of The Universe ◽  
The Universe

The most powerful radio sources in the local Universe are found in giant elliptical galaxies. Looking back to a redshift of 0.5 (≈ half the age of the Universe for ω = 1), we see that these host galaxies are increasingly found in moderately rich clusters. This fact gives us hope that radio sources can be used as tracers of high density environments at high redshift. By exploiting radio source samples selected over a wide range in luminosity (Blundell et al., these proceedings), we will also be able to test whether the luminosities of radio sources are correlated with their environments.

Hosts of Powerful Radio Galaxies in the Near‐Infrared: Implications for Radio Source Evolution

1998 ◽  
Vol 503 (1) ◽  
pp. 156-167 ◽  
Author(s):  
W. H. de Vries ◽  
C. P. O'Dea ◽  
S. A. Baum ◽  
E. Perlman ◽  
M. D. Lehnert ◽  
...  
Keyword(s):  
Radio Source ◽  
Near Infrared ◽  
Radio Galaxies ◽  
Powerful Radio

scholarly journals CARBON STOCK ESTIMATION OF MANGROVE VEGETATION USING REMOTE SENSING IN PERANCAK ESTUARY, JEMBRANA DISTRICT, BALI

2018 ◽  
Vol 14 (2) ◽  
pp. 137
Author(s):  
Amandangi Wahyuning Hastuti ◽  
Komang Iwan Suniada ◽  
Fikrul Islamy
Keyword(s):  
Remote Sensing ◽  
Carbon Stock ◽  
Remote Sensing Data ◽  
Total Carbon ◽  
Total Biomass ◽  
Sensing Data ◽  
Ground Biomass ◽  
Study Results ◽  
Mangrove Vegetation ◽  
Total Carbon Stock

Mangrove vegetation is one of the forest ecosystems that offers a potential of substantial greenhouse gases (GHG) emission mitigation, due to its ability to sink the amount of CO2 in the atmosphere through the photosynthesis process. Mangroves have been providing multiple benefits either as the source of food, the habitat of wildlife, the coastline protectors as well as the CO2 absorber, higher than other forest types. To explore the role of mangrove vegetation in sequestering the carbon stock, the study on the use of remotely sensed data in estimating carbon stock was applied. This paper describes an examination of the use of remote sensing data particularly Landsat-data with the main objective to estimate carbon stock of mangrove vegetation in Perancak Estuary, Jembrana, Bali. The carbon stock was estimated by analyzing the relationship between NDVI, Above Ground Biomass (AGB) and Below Ground Biomass (BGB). The total carbon stock was obtained by multiplying the total biomass with the carbon organic value of 0.47. The study results show that the total accumulated biomass obtained from remote sensing data in Perancak Estuary in 2015 is about 47.20±25.03 ton ha-1 with total carbon stock of about 22.18±11.76 tonC ha-1and CO2 sequestration 81.41±43.18 tonC ha-1.

scholarly journals ANALYSIS OF THE GEOECOLOGICAL SITUATION IN KALUSH: CURRENT SITUATION AND WAYS OF SOLVING THE PROBLEM

2021 ◽  
Vol 47 (4) ◽  
pp. 170-180
Author(s):  
Pavlo Zhyrnov ◽  
Olha Tomchenko ◽  
Iryna Pidlisetska ◽  
Olena Mykolaienko
Keyword(s):  
Remote Sensing ◽  
Surface Water ◽  
Economic Activity ◽  
Remote Sensing Data ◽  
Potassium Salts ◽  
Geological Processes ◽  
Study Results ◽  
State Enterprises ◽  
The City ◽  
Negative Phenomena

Careless economic activity of chemical and mining enterprises of the Kalush-Holyn potassium salts deposit has caused ecological disbalance in a subsurface rock layers. This caused a technogenic disaster in Kalush such as the intensification of dangerous geological processes: flooding and waterlogging of lands, intensification of karst and suffusion processes, deterioration of groundwater and surface water. The study results of the geoecological situation in Kalush using research reports’ materials of the specialized state enterprises and relevant thematic maps; and interpretation of remote sensing data are higlighted in the article. Comprehensive map of the geoecological situation of Kalush was developed in order to visualize the processes associated with the deformation of the earth’s surface in the area of Kalush and other negative phenomena that must be taken into account when planning the development of the city.

scholarly journals Estimation of Forest Stand Parameters Using SPOT-5 Satellite Images and Topographic Information

2017 ◽  
Author(s):  
Shiqin Xie ◽  
Wei Wang ◽  
Qian liu ◽  
Jinghui Meng ◽  
Tianzhong Zhao ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Satellite Images ◽  
Satellite Image ◽  
Forest Stand ◽  
Textural Features ◽  
Spectral Features ◽  
Topographic Information ◽  
Study Results ◽  
Stand Parameters ◽  
Spot 5

In recent years, remote sensing technology has been widely used to predict forest stand parameters. In order to compare the effects of different features of remote sensing images and topographic information on the prediction of forest stand parameters, multivariate stepwise regression analysis method was used to build estimation models for important forest stand parameters by using textural and spectral features as well as topographic information of SPOT-5 satellite images in northeastern Heilongjiang Province in China as independent variables. The study results show that the optimal window to predict forest stand parameters using textural features of SPOT-5 satellite image is 9×9; the ability of textural features was better than that of spectral features in terms of predicting forest stand parameters; with the inclusion of topographic information, the accuracy of prediction of all models was improved, of which elevation has the most significant effect. The highest accuracy was achieved when predicting the stand volume (SV) (R2adj=0.820), followed by basal area (BA) (R2adj =0.778), accuracy of both above models exceeded 75%. The results show that models combined use of textural, spectral features and topographic information of SPOT-5 images have a good application prospect in predicting forest stand parameters.

scholarly journals The Emission Line Properties of the 3CR Radio Galaxies at Redshift One: Shocks, Evolution, and the Alignment Effect

1999 ◽  
Vol 194 ◽  
pp. 241-245
Author(s):  
Philip Best ◽  
Huub Röttgering ◽  
Malcolm Longair
Keyword(s):  
Emission Line ◽  
Radio Source ◽  
Velocity Structure ◽  
Radio Galaxies ◽  
Linear Size ◽  
Continuum Emission ◽  
Radio Sources ◽  
Powerful Radio ◽  
Alignment Effect ◽  
Optical Continuum

The results of a deep spectroscopic campaign on powerful radio galaxies with redshifts z ˜ 1, to investigate in detail their emission line gas properties, are presented. Both the 2-dimensional velocity structure of the [OII] 3727 emission line and the ionisation state of the gas are found to be strongly dependent upon the linear size (age) of the radio source in a manner indicative of the emission line properties of small (young) radio sources being dominated by the passage of the radio source shocks. The consequences of this evolution throughout the few x107 year lifetime of the radio source are discussed, particularly with relation to the alignment of the UV–optical continuum emission of these objects along their radio axis, the nature of which shows similar evolution.

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