Tag Archives: shielding

2445–2454 Y. Usherenko, V. Mironovs, V. Lapkovskis, S. Usherenko and V. Gluschenkov
Powder particle flow acceleration methods for simulation of interaction with materials used in spacecrafts
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Powder particle flow acceleration methods for simulation of interaction with materials used in spacecrafts

Y. Usherenko¹*, V. Mironovs¹, V. Lapkovskis¹, S. Usherenko² and V. Gluschenkov³

¹Riga Technical University, Civil Engineering Department, Scientific Laboratory of Powder Materials, Kipsalas str 6A-110, LV-1048 Riga, Latvia
²Belarusian National Technical University, Mechanical Engineering Faculty, Department of Powder Metallurgy, Welding and Material Production Technology, Nezavisimosty Ave., 65, BL220013 Minsk, Belarus
³Samara University, Moskovskoye shosse, 34, NIL-41, RU443086 Samara, Russia
*Correspondence: osher_yu@mail.ru

Abstract:

In recent decades, the role of satellites for monitoring the condition of agricultural land and forests, as well as in the study of natural resources, has especially increased. The amount of debris in near-Earth space is constantly increasing, which creates a real danger to the operation of satellites and other flying objects. The failures of satellites and spacecrafts increase the cost of their production and inhibit the development of the industry, lead to pollution of near-earth space by space debris. The U.S.-based Space Surveillance Network is currently tracking about 40,000 space objects- the vast majority of which are defunct satellites and fragments from collisions. It was estimated that there are more than 8,378 tons of junk around the Earth at speeds of up to 70 km h-1, threatening functioning spacecrafts. Development of a new method for ground-based testing of protective materials, microchips and control systems will enable to avoid further pollution of near-Earth space.
This paper discusses methods for accelerating fine particles using explosive devices and an electromagnetic field and the possibility of using them to develop and research protective materials.

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1053–1062 V. Mironovs, I. Boiko, T. Koppel and M. Lisicins
Cellular tubular structures from perforated metallic tape and its application
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Cellular tubular structures from perforated metallic tape and its application

V. Mironovs¹, I. Boiko²*, T. Koppel³ and M. Lisicins¹

¹Riga Technical university, Faculty of Civil Engineering, Institute of Building Production, Azenes street 16/20–331, LV-1048 Riga, Latvia
²Riga Technical University, Faculty of Mechanical Engineering, Transport and Aeronautics, Institute of Mechanical Engineering, Ezermalas street 6k, LV-1006 Riga, Latvia
³Tallinn University of Technology, Department of Labor Environment and Safety, SOC351, Ehitajate tee 5, EE19086 Tallinn, Estonia
*Correspondence: irina.boiko@rtu.lv

Abstract:

 The objectives of performed research were the following: 1) check out the possibility of effective formation of the tubular and planar structures from the perforated steel tapes, which were obtained as a waste during stamping of fine-sized details, by cutting and bending; 2) testing of achieved tubular and annular structures for fixing up of the electrical cables and as electromagnetic shielding solutions; 3) analysis of achieved results and elaboration of the recommendations for using of lightweight tubular shields for the electrical cables. The actuality of research is connected with the re-using of metallic wastes and shielding solutions against electromagnetic fields. All objectives were reached successfully using bending for formation of the tubular structures. The bending strength of achieved structures and the shielding efficiency in a controlled environment was examined. The measurement results have shown that perforated steel will exhibit noticeable shielding properties against both the electric and magnetic field. Such results open up wide possible application of the planar and cellular tubular structures from perforated metallic tapes.

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1015–1022 T. Koppel, A. Shiskin, I. Hussainova, H. Haldre and P. Tint
Electromagnetic shielding properties of ceramic spheres coated with paramagnetic metal
Abstract |
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Electromagnetic shielding properties of ceramic spheres coated with paramagnetic metal

T. Koppel¹*, A. Shiskin², I. Hussainova¹, H. Haldre³ and P. Tint¹

¹Tallinn University of Technology, Ehitajate 5, EE 12616 Tallinn, Estonia
²Faculty of Material Science and Applied Chemistry, Riga Technical University, 3 Paula Valdena str, LV-1048 Riga, Latvia
³Institute of Environmental Health and Safety, Jaam 14, EE 11615 Tallinn, Estonia
*Correspondence: tarmo.koppel@ttu.ee

Abstract:

 This study utilized a setup of radiofrequency generating and metering instruments to measure the reflective and pass-through properties of the innovative material of paramagnetic metal coated ceramic hollow spheres (MCS). The dimensions of the spherical articles reside around 50–250 μm, the thickness of metal (Cu) coating is 0.5–1.3 μm. The radiofrequency field was of 2.4 GigaHertz (GHz) frequency and radiated towards the material via a waveguide-horn antenna at 100 mWt power output. Two additional waveguide-horn antennas connected to a radiofrequency analyzer measured the reflection and pass-through characteristics of the material. Reflection and pass-through coefficients (from 0 to 1) were calculated to each tested sample. The material was tested at different thicknesses: from single – to multi (up to 5) mono-layers and 5 mm layer in bulk condition of MCS.
The measurement results show insignificant shielding characteristics for 1 to 5 layer thickness samples: pass-through coefficient from 0.96 to 0.92. Noteworthy shielding characteristics were starting to show in case of MCS mixed with graphite emulsion: transmission coefficient dropped to 0.16.
The latter sample demonstrates the prospective shielding characteristics of the material, since most of the radiofrequency radiation was not allowed to pass through the material neither to be reflected, but absorbed within the structure of the material.

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