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1

Scattering of electromagnetic waves by plasma layer sandwiched between two layers of thin glass

Lavrushev Vladimir Niriforovich, Dautov Osman Shakirovich, Al-Abadi Mohammad Sadon, Almakki Ali Nadhim Jbarah

Przegląd Elektrotechniczny

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2023

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R. 99, nr 4

102--106

EN

A technique for monitoring plasma parameters for antenna measurements using a model of low-pressure fluorescent lamps is studied. The physical parameters of the plasma in the layout were obtained using microwave interferometry measurements. Using an accurate analytical model, it is shown that, this layer absorbs almost half the incident power. The noticeable dissipation of electromagnetic waves in the frequency band makes it possible to consider a thin layer of plasma as a plasma absorber.

PL

Badana jest technika monitorowania parametrów plazmy do pomiarów antenowych przy użyciu modelu niskociśnieniowych lamp fluorescencyjnych. Parametry fizyczne plazmy w układzie uzyskano za pomocą pomiarów interferometrii mikrofalowej. Korzystając z dokładnego modelu analitycznego, wykazano,że warstwa ta pochłania prawie połowę mocy padającej. Zauważalne rozpraszanie fal elektromagnetycznych w paśmie częstotliwości pozwala uznać cienką warstwę plazmy za absorber plazmy.

2

Badania transmisyjności szkła okiennego o różnej grubości

Orzechowski Tadeusz, Lesiak Paweł

Ciepłownictwo, Ogrzewnictwo, Wentylacja

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2020

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T. 51, nr 1

6--10

PL

Obecne budownictwo charakteryzuje się dużym zużyciem energii na cele ogrzewania i chłodzenia. Jednym z najważniejszych czynników mających wpływ na bilans cieplny budynku jest jego oszklenie, którego jakość określa się współczynnikiem transmisji. Wykorzystanie możliwie dokładnych parametrów fizycznych szkła jest niezbędne do sporządzenia prawidłowego bilansu energetycznego budynku. Szkło okienne jest produkowane przez różnych producentów i w różnej technologii, z różnymi dodatkami, które wpływają na właściwości transmisyjne produktu. W pracy dla jednakowego gatunku i od tego samego producenta szkła wyznaczono współczynniki przepuszczalności szyb o różnej grubości od 2 mm do 12 mm. Pokazano również, że nie jest możliwe ich wykorzystanie do układów wieloszybowych. Z tego względu dokładne obliczenia bilansowe należy prowadzić z uwzględnieniem nie tylko rodzaju szkła, ale też i liczby szyb w oknach.

EN

Currently, the building sector is characterized by high energy consumption for heating and cooling. One of the most important factors affecting the building’s heat balance is its glazing, whose quality is determined by the transmission factor. The use of the most accurate physical parameters of glass is necessary to prepare a proper energy balance of the building. Window glass is produced by various manufacturers and in different technologies, with various additives that affect the transmission properties of the product. The permeability coefficients for glass of different thickness from 2 to 12 mm were investigated in the paper for the same grade and from the same glass manufacturer. It was also shown that it is not possible to use them for multi-pane systems. Therefore, accurate balance calculations should be carried out taking into account not only the type of glass, but also the number of glazing in the window.

3

Scattering of oblique water waves by an infinite step

Dolai P., Dolai D. P.

International Journal of Applied Mechanics and Engineering

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2018

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Vol. 23, no. 2

327--338

EN

The present paper is concerned with the problem of scattering of obliquely incident surface water wave train passing over a step bottom between the regions of finite and infinite depth. Havelock expansions of water wave potentials are used in the mathematical analysis to obtain the physical parameters reflection and transmission coefficients in terms of integrals. Appropriate multi-term Galerkin approximations involving ultra spherical Gegenbauer polynomials are utilized to obtain very accurate numerical estimates for reflection and transmission coefficients. The numerical results are illustrated in tables.

4

Response of corrugated interface on incident qSV-wave in monoclinic elastic half-spaces

Singh S. S., Lalvohbika J.

International Journal of Applied Mechanics and Engineering

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2018

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Vol. 23, no. 3

727--750

EN

This paper is concerned with the problem of reflection and transmission of elastic waves due to an incident plane qSV-wave at a corrugated interface between two dissimilar monoclinic elastic half-spaces. Due to the corrugated nature of the interface, there exist regularly and irregularly reflected and transmitted elastic waves. Using Rayleigh’s method of approximation, the reflection and transmission coefficients of regular and irregular waves are obtained for the first order of approximation. We have found that these coefficients are functions of the angle of incidence, elastic constants, corrugation and the frequency parameter. These coefficients are obtained for a special type of interface, z =dcos py. We have computed these coefficients for a particular model and discussed the effects of corrugation and frequency parameter.

5

Analytical study of the reflection and transmission coefficient of the submarine interface

Zhang G., Hao C., Yao C.

Acta Geophysica

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2018

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Vol. 66, no. 4

449--460

EN

The analytical study of the reflection and transmission coefficient of the seafloor interface is essential for the characterization of the ocean bottom in marine seismic exploration. Based on the boundary conditions of the seafloor interface, the analytical expression of the reflection and transmission coefficient at the submarine interface is derived in this study by using the steady-state wave solution of the elastic wave in a homogeneous, isotropic medium. With this analytical expression, the characteristics of the reflection and transmission coefficient at the submarine interface are analysed and discussed using critical angles. The results show that the change in the reflection and transmission coefficient with the incidence angle presents a ‘‘segmented’’ characteristic, in which the critical angle is the dividing point. The amplitude value and phase angle of the coefficient at the submarine interface change dramatically at the critical angle, which is related to the P- and S-wave velocities in the seabed layer. Compared with the stiff seabed, the soft seabed has a larger P-wave critical angle and an absence of the converted S-wave critical angle, owing to the low P- and S-wave velocities in the solid seabed layer. By analysing and discussing the special changes that occur in the coefficient values at the critical angle, the reflection and transmission characteristics of the different incident angles are obtained. Synthetic models of both stiff and soft seafloors are provided in this study to verify the analytical results. Finally, we compared our synthetic results with real data from the Gulf of Mexico, which enabled the validation of our conclusions.

6

Simulation of neutron irradiation influence on p-n-p bipolar transistor characteristics

Miskiewicz S., Komarov F., Komarov A., Żukowski P., Michailov V.

Przegląd Elektrotechniczny

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2016

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R. 92, nr 11

236--238

EN

We have developed numerical model and software to simulate the ionizing radiation influence on the bipolar transistor parameters. The software allows to calculate the input and output characteristics, the current transmission coefficient and other parameters under the irradiation for various temperatures, base and collector voltages.

PL

Opracowaliśmy model numeryczny i oprogramowanie do symulacji wpływu promieniowania jonizującego na parametry tranzystorów bipolarnych. Oprogramowanie pozwala obliczyć parametry wejściowe i wyjściowe, aktualny współczynnik transmisji i inne parametry na podstawie napromieniowania dla różnych temperatur, napięć bazy i kolektora.

7

New Textiles Designed for Anti-Radar Camouflage

Redlich G., Obersztyn E., Olejnik M, Fortuniak K, Bartczak A, Szugajew L, Jarzemski J.

Fibres & Textiles in Eastern Europe

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2014

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Vol. 22, no. 1 (103)

34--42

EN

This paper presents newly designed textiles (woven and knitted fabrics) for camouflage against radar, with a particular emphasis on the conductive yarns applied and their distribution throughout the structure of the goods. The levels obtained for the coefficients of re- flection and the transmission of electromagnetic waves have been discussed for woven and knitted fabrics, both raw and those subjected to finishing treatment. These parameters were determined using two methods: waveguide applicators and in the space in a semi-anechoic chamber within the time domain. The issues this publication covers are an integral part of research on developing textile products featuring a broad spectrum of masking, i.e. within the visible (VIS), near infrared (IR), and that of the subject - the anti-radar band. The first two types of camouflage were discussed in an earlier publication entitled “Assessment and Verification of the Functionality of New, Multi-component, Camouflage Materials” (Fibres & Textiles in Eastern Europe 2013; 21, 5(101): 73-79).

PL

W artykule przedstawiono nowoopracowane konstrukcje włókiennicze (tkaniny, dzianiny) maskujące przeciwradiolokacyjnie, ze szczególnym uwzględnieniem zastosowanych przędz konduktywnych oraz ich rozkładu w strukturze wyrobów. Omówiono poziomy uzyskanych wartości współczynników odbicia i transmisji fal elektromagnetycznych, zarówno dla tkanin i dzianin surowych, jak i poddanych obróbce wykańczalniczej. Parametry te były wyznaczane z zastosowaniem dwóch metod tj. z wykorzystaniem aplikatorów falowodowych oraz w przestrzeni w komorze bezechowej w domenie czasu. Zagadnienia ujęte w niniejszej publikacji stanowią integralną część badań nad opracowaniem wyrobów włókienniczych o szerokim spektrum maskowania, tj. w zakresie widzialnym (VIS), bliskiej podczerwieni (IR) oraz przedmiotowym czyli przeciwradiolokacyjnym. Dwa pierwsze rodzaje maskowania zostały przedstawione we wcześniejszej publikacji pt. „Assessment and verification of functionality of new, multi-component, masking materials ”(Fibres & Textiles in Eastern Europe 2013; 21, 5(101): 73-79).

8

Conductivity and transmission coefficients of ultra-thin disordered metallic films

Spisak B.J., Paja A.

Materials Science Poland

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2006

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Vol. 24, No. 3

605--609

EN

The diffusive motion of quasi-two-dimensional electron gas through an ultra-thin system of disordered potentials is considered. In such system the Fermi sphere splits into a set of independent sheets due to the small thickness of the system. Each sheet can be seen as an electron sub-band. The electron transport goes through these sub-bands independently. The sum of electrical conductivities over these sub-bands determines the total current which is calculated for ultra-thin films of cesium. We also present the relation between our approach and Landauer formalism based on the notation of the transmission coefficient.