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Date submitted2020-05-19
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Date accepted2021-03-02
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Date published2021-04-26
Results of Comprehensive Geophysical Studies on the Search for Crypts on the Territory of Suburban Necropolis of Tauric Chersonese in the Karantinnaya Balka
The article presents the results of comprehensive studies carried out by the research team of Saint Petersburg Mining University in cooperation with the specialists from the State Museum-Preserve "Tauric Chersonese" in 2019. The purpose of the work was to discover and map antique and medieval crypts (ancient burial structures) on the territory of suburban necropolis of Tauric Chersonese in the Karantinnaya balka. The complex of geophysical methods included continuous ground penetrating radar sounding at two center frequencies of 350 and 500 MHz and contactless electrical tomography. To minimize spatial errors in the process of studies, topographic and geodetic works were carried out. For the first time wave electromagnetic effects were identified, which indicated the positions of hidden underground crypts. Geological factors were established that are favorable for cutting crypts in the layered thickness of Sarmatian limestones. The obtained results allowed to justify the feasibility of continuing geophysical works at the necropolis in order to study interior space of the discovered crypts and to determine the boundaries of archaeological heritage.
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Date submitted2017-12-29
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Date accepted2018-03-06
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Date published2018-06-22
Evaluation of signal properties when searching for cavities in soil under concrete slabs by radio detection stations of subsurface investigation
- Authors:
- G. V. Rudianov
- E. I. Krapivskii
- S. M. Danilev
A method of localization of concealed cavities on the basis of studying of the reflected electromagnetic impulses is considered in the paper. An issue of early detecting of concealed cavities in engineering facilities is a critical one due to a significant influence on further serviceability of a structure. Problems of localization of concealed cavities in the soil body under the concrete slabs of hydropower stations were studied; the results of ground radar detecting investigations of the cavities, physical simulation of a cavity as well as a mathematical modeling of a reflected signal are presented. Modern subsurface radar detection provides methods which allow to reliably detect concealed cavities in the soil. However, it is possible only in case of a clear boundary between the adjacent layers that conditions a jump of dielectric permeability. In the result of an abrupt change of dielectric permeability a reflected wave occurred; the existence of subsurface heterogeneity is conditioned by the properties of this wave. Moreover, the greater is the difference between the values of dielectric permeability in the adjacent layers, the larger amplitude the reflected wave will have. If the cavity is at the stage of forming, i.e. it is filled with the soil of reduced density, then there is no clear boundary at the border of the layers which will condition a gradual change of dielectric permeability with depth. In this case an amplitude of a reflected wave will be minimal and a formation signal will be masked out by jamming signals reflected from various heterogeneities. In such case to determine a cavity at the stage of forming seems to be impossible. To determine poor signals an analysis of a phase of a reflected signal may be used; phase alters in compliance with the reflection coefficient change pattern. The article contains information about signals reflected from the heterogeneities and a conclusion regarding a possibility of detecting cavities in the soil on the basis of a method of coherent processing of signals is made.
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Date submitted2018-01-02
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Date accepted2018-03-08
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Date published2018-06-22
Noncontact laser control of electric-physical parameters of semiconductor layers
- Authors:
- A. B. Fedortsov
- A. S. Ivanov
Non-contact non-destructive laser-interferometric methods for measuring several electrophysical parameters of semiconductor and dielectric layers are proposed. They are the lifetime of charge carriers for electrons and holes separately; parameters of recombination centers, namely their concentration and capture cross-sections; bulk volume lifetime and rate of surface recombination, as well as the diffusion length of charge carriers. The methods are based on the interference-absorption interaction in a semiconductor of two laser radiations with different wavelengths. Short-wave injection radiation generates additional charge carriers in the material, which leads to a change in its optical constants at the wavelength of the other – long-wavelength probing laser radiation – and to modulation of this radiation as it passes through the sample of the studied material. The means for implementing the proposed methods and methods for processing the modulation signal for determining the parameters of the investigated samples are developed. The methods have been successfully tested on samples of such materials as germanium, silicon, indium antimonide and cadmium-mercury-tellurium alloy. It is shown that the methods can be used both in scientific research and electronic industry.
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Date submitted2017-09-17
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Date accepted2017-11-06
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Date published2018-02-22
Collaborative interpretation of the data obtained by resistivity and ground penetrating radar methods for assessing the permeability of sandy clay soils
- Authors:
- D. A. Lalomov
- V. V. Glazunov
A method for estimating the filtration factor of sandy clay soils is considered on the basis of a joint interpretation of the data of a set of methods of engineering electrical exploration, including electrical resistivity tomography and ground penetrating radar studies. The solution of this problem is based on the use of known empirical connections between the imaginary and real parts of the complex dielectric permittivity, specific electrical resistance, and Q factor. An example of the effective joint use of the ground penetrating radar and non-contact electrical resistivity tomography shows how to obtain qualitative and quantitative estimates of a changing filtration factor in a draining road layer. It is necessary to use precise engineering geological information in order to provide the required estimates. The proposed approach makes it possible to describe continuous profiles of a pavement and underlying layers by ground penetrating radar and electrical resistivity tomography, as well as to assess soil properties when conducting an electrical survey from the surface of asphalt concrete pavement. Recommendations for the implementation of the developed methods of complex engineering and geophysical research are given for solving issues of repair work design, supervision, and quality control of road construction.
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Date submitted2015-08-20
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Date accepted2015-10-17
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Date published2016-04-22
Increasing the accuracy of the fast laser measurments transparent solid and liquid films thicknesses
- Authors:
- A. B. Fedortsov
Nondestructive optical methods for measuring of the «thick» films thickness of the order of 0,001-1,00 mm are analyzed. It is shown that using the laser beam radiation and modern optical and electronic schemes possible to decrease the time of single measurement to 1ms and less at the measuring frequency of 10-50 Hz. The possibility of measuring thickness and spreading coefficient and evaporation kinetics of liquid films is demonstrated. A new computer method of the data processing aimed to determine the film thickness from the angle dependence of the laser beam reflection coefficient by the film is offered. The offered procedure and the experimental technique realizing it permits to decrease the thickness determination uncertainty to the order of ten.
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Date submitted2015-08-24
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Date accepted2015-10-16
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Date published2016-04-22
Ways to ensure reliability, safety and efficiency of the costruction and installation works when buildings and structures erecting by stabilizing process of the rocking cargo suspension
- Authors:
- L. A. Goldobina
- P. S. Orlov
Nondestructive optical methods for measuring of the «thick» films thickness of the order of 0,001-1,00 mm are analyzed. It is shown that using the laser beam radiation and modern optical and electronic schemes possible to decrease the time of single measurement to 1ms and less at the measuring frequency of 10-50 hz. The possibility of measuring thickness and spreading coefficient and evaporation kinetics of liquid films is demonstrated. A new computer method of the data processing aimed to determine the film thickness from the angle dependence of the laser beam reflection coefficient by the film is offered. The offered procedure and the experimental technique realizing it permits to decrease the thickness determination uncertainty to the order of ten.
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Date submitted2010-07-09
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Date accepted2010-09-13
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Date published2011-03-21
Application of the gpr method for investigetion of barring condition and outbarring spaces «Оctyabr’skiy» mine
- Authors:
- V. V. Glazunov
- S. M. Danilev
Results of the first application of GPR surveys of a mine cage for the purpose of an estimation of a technical condition barring and outbarring spaces on an example of a ventilating trunk «VC-1», mine «Octyabr’skiy» are considered.
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Date submitted2009-10-20
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Date accepted2009-12-11
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Date published2010-09-22
Monitoring of deformation processes of the earth surface with methods of differential interferometric treatment of radar data
- Authors:
- A. A. Krivenko
- Yu. A. Kashnikov
The Differential Interferometry SAR (DInSAR) has recently become one of the most popular methods to reveal and analyze the subsidence of the ground. This method is considered by researchers to be well suited to solve a problem of small relative ground shifts survey applying the short (centimeter) radio waves.
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Date submitted2009-07-11
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Date accepted2009-09-25
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Date published2010-04-22
Control of deformations of buildings and constructions at the built-up territories within mining diversions of oil and gas fields under conditions of Far North
Results of monitoring of buildings’ deformations in Noviy Urengoi town (situated inside the lease of giant oil and gas Urengoi field) are presented. Monitoring consists of multi-pass satellite radar imaging, GPS-measurements and repeated geometric leveling.
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Date submitted2008-10-05
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Date accepted2008-12-07
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Date published2009-12-11
Application of georadiolocation in hydrology
Georadiolocation is an effective tool to explore fresh water basins. When georadar is transported along the water surface by a small boat the bottom profile and the thickness of bottom sediments can be determined as well as sunk objects can be discovered. Investigation of a boundary between fresh and saline water in the estuaries of the rivers flown into the sea is a new field of georadars application. There is a possibility to determine damping factor, water electrical conductivity and, hence, water mineralization with the use of reflected signal amplitude.
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Date submitted2008-10-08
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Date accepted2008-12-08
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Date published2009-12-11
Georadar investigations of shallow depth оf geological section and engineering constructions
- Authors:
- V. V. Glazunov
- N. N. Efimova
The GPR-method showing high resolution, great performance and sensitivity to minor variations in the composition and conditions of soils and material has assumed a role of the leading geophysical method for looking at the upper part of the geological section. This paper presents the advanced directions of GPR application for engineering problems solution.