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Nadezhda Dvurechenskaya

Bio: Nadezhda Dvurechenskaya is an academic researcher from Wrocław University of Technology. The author has contributed to research in topics: Electromagnetic shielding & Image segmentation. The author has an hindex of 4, co-authored 7 publications receiving 46 citations. Previous affiliations of Nadezhda Dvurechenskaya include Novosibirsk State Technical University.

Papers
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Journal ArticleDOI
TL;DR: In this article, the results of shielding effectiveness measurement of textile materials containing metal by the free-space transmission technique (FSTT) in the 1-26.5 GHz frequency range are presented.
Abstract: The results of shielding effectiveness (SE) measurement s of textile materials containing metal by the free-space transmission technique (FSTT) in the 1-26.5 GHz frequency range are presented in the paper. It is shown that experimental data processing using time -domain gating (TDG) makes it possible to effective ly remove diffracted and reflected components from the desired signal. The comparison with the results obtained by other techniques, namely modified FSTT with TDG and coaxial line probe technique (ASTM D4935 -99) is given. The comparison shows that the prop osed technique gives more reasonable results while the measurement set-up is simpler in realization.

23 citations

Proceedings ArticleDOI
01 Dec 2010
TL;DR: In this paper, the authors present results of measurement S21 parameter for two special shielding materials in the 2,5-5 GHz frequency band, where the experimental set-up has been modified by adding an absorbing frame to reduce resonant and diffraction effects at specimen edges.
Abstract: In this paper, we present results of measurement S21 parameter for two special shielding materials in the 2,5–5 GHz frequency band Measurements were carried out using well-known free-space transmission technique Experimental set-up has been modified by adding an absorbing frame to reduce resonant and diffraction effects at specimen edges Shielding effectiveness (SE) of two test materials depending on electromagnetic (EM) wave polarization and distance between a material under test and an antenna are presented

7 citations

Journal ArticleDOI
TL;DR: In this paper, two types of newly manufactured shielding materials (nonwoven and fabric) were measured using improved free-space transmission technique at 25 GHz depending on electromagnetic wave (EM) polarization and antenna to specimen distance.
Abstract: In this paper we discuss state of the art in the field of shielding materials investigation. Two types of newly manufactured shielding materials (nonwoven and fabric) were measured using improved free-space transmission technique at 25 GHz depending on electromagnetic wave (EM) polarization and antenna to specimen distance. Results of shielding effectiveness (SE) evaluation based on measured complex transmission coefficients (S21) were presented and compared with SE measured using coaxial transmission line technique. Also results of surface resistance measurements with the four-probe technique for the test materials are shown. Keywords—Nonwoven, fabric, shielding effectiveness, freespace measurements, surface resistivity.

6 citations

Proceedings Article
15 Nov 2011
TL;DR: In this paper, the authors present detailed description, advantages and disadvantages of the well-known free-space measurement technique which uses illumination of a material under test (MUT) under different angles of incidence.
Abstract: In this paper, we present detailed description, advantages and disadvantages of the well-known free-space measurement technique which uses illumination of a material under test (MUT) under different angles of incidence This technique is considered with applying to shielding materials investigation at 1–10 GHz It has been shown how to extract own MUT's electrical and magnetic parameters (complex relative permittivity and complex relative permeability) from a set of reflection coefficients measured at different angles of incidence, frequencies and electromagnetic (EM) wave polarizations using numerical methods Shielding effectiveness (SE) than can be calculated easily using these parameters Also experimental results obtained for special metalized materials measured at 2–25 GHz have been presented and analyzed with the use of elaborated model

5 citations


Cited by
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Reference EntryDOI
31 Oct 2001
TL;DR: The American Society for Testing and Materials (ASTM) as mentioned in this paper is an independent organization devoted to the development of standards for testing and materials, and is a member of IEEE 802.11.
Abstract: The American Society for Testing and Materials (ASTM) is an independent organization devoted to the development of standards.

3,792 citations

Journal ArticleDOI
01 Nov 2019-Carbon
TL;DR: In this article, the synthesis and EMI shielding performances of carbon-based materials in X-band (8.2-12.4 GHz) have been reviewed and their shielding mechanisms are discussed.

306 citations

Journal ArticleDOI
Heguang Liu, Shaoqing Wu, Caiyin You, Na Tian, Yuan Li1, Nitin Chopra1 
01 Feb 2021-Carbon
TL;DR: In this paper, the authors mainly focus on the EMI shielding mechanism and the performance of various forms of carbon materials, and their future development is also prospected, together with the current research status.

98 citations

Journal ArticleDOI
TL;DR: In this paper, a resistive pattern printed on a dielectric spacer backed by a conducting surface is used to extend an absorption spectrum up to an octave and beyond, which is very competitive over alternative solutions.
Abstract: A novel type of a broadband flexible electromagnetic absorbing panel made of a resistive pattern printed on a dielectric spacer backed by a conducting surface is investigated in this paper. It is shown that an appropriate choice of the shape and sheet resistance of the pattern allows extending an absorption spectrum up to an octave and beyond, which is very competitive over alternative solutions. The pattern is made of ink with graphene nano-platelets, which allows achieving expected sheet resistance with decent repeatability, what is confirmed with measurements undertaken with the DC point probe and microwave dielectric resonator techniques. An exemplary sample of the proposed absorber is manufactured and characterized, indicating a very good agreement between theoretical study and experiments.

73 citations

Journal ArticleDOI
TL;DR: In this article, the microwave-shielding behavior of epoxy thermosetting plastic reinforced with silanized Cu and Fe3O4 compound particles were studied in frequency bands E, F, I, and J.
Abstract: In this work, microwave-shielding behavior of epoxy thermosetting plastic reinforced with silanized Cu and Cu–Fe3O4 compound particles were studied in frequency bands E, F, I, and J. The principal aim of this work is to evaluate the significant advantage of surface-modified magnetic and conductive fillers over as-received fillers in microwave shielding. The conductive and magnetic properties of epoxy resin were improved by additions of Cu and Fe3O4 particles. Compound particles of Cu–Fe3O4 were produced by mechanical alloying process (ball milling). The compound particles were surface treated by 3-Aminopropyltrimethoxysilane (APTMS) for better dispersion in epoxy resin matrix. Functional groups on particle’s surface after silane surface treatment were confirmed by FT-IR spectra analysis. The TEM images revealed that effective Cu–Fe3O4 particle compounding was formed at 1 h milling time. The maximum dielectric constant of 6.8 and magnetization of 675E−6 were observed for surface-modified compound particle-reinforced epoxy composite designation RCF2. Similarly, maximum microwave attenuation of 35% (44 dB) was observed for surface-modified compound particle-reinforced composite designation RCF2 in ‘J’-band frequency.

61 citations