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1

The analysis of the different modeling in CST for predicting designs of a monostatic and bistatic RCS

Bekimetov Alisher Farxodovich, Yangibaeva Madina

Diagnostyka

|

2023

|

Vol. 24, No. 3

art. no. 2023308

EN

In this, research paper, we analyzed different radar cross-sections and models in Computer Simulation Technology (CST) software and tell in advance the RCS of the layer. In this variation exploration and representation of antenna layout in CST, we make a decision on various polarized plane wave angles. The research results may influence aircraft and any vehicle building, connecting with the incorporation of magnetic and electrical part power going return, therefore the polarization of plane waves, the use of different materials, aircraft, and any vehicle size. For this article, a microstrip antenna design with a reduced monostatic (RCS) with changing angle is described. Radar recognizes a reflected signal from this target due to microwave sensors' capacity to adequately light it with energy. The research used several both basic and sophisticated targets at an unaccompanied median rate of occurrence. Two categories of target forms, basic and complicated, made of iron material, give an appearance for assessing RCS in two distinct systems, Monostatic and Bistatic, with a range of angles.

2

Reflection and transmission in non-local couple stress micropolar thermoelastic media

Gupta Deepa, Malik Sangeeta, Kumar Krishan, Sharma Raj Kumar

International Journal of Applied Mechanics and Engineering

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2022

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Vol. 27, no. 2

53--76

EN

We have studied the problem of homogenous, isotropic non-local couple stress micropolar thermoelastic solid in the absence of body forces, couple density and heat resources. The reflection and transmission of waves at the interface of two distinct media have been investigated. It is observed that amplitude ratios of various reflected and transmitted waves are functions of wave number of incident waves and are affected by the non-local parameter of thermoelastic solid.

3

Experimental study of hydraulic response of smooth submerged breakwaters to irregular waves

Mahmoudof Seyed Masoud, Hajivalie Fatemeh

Oceanologia

|

2021

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No. 63 (4)

448--462

EN

This paper presents the results of a laboratory experiment on transmission, reflection, and dissipation of irregular waves over smooth impermeable submerged breakwaters. Experiments included 75 JONSWAP-based irregular waves with five different wave characteristics generated at three water depths in a 2D wave flume. The investigated breakwater sections were three rectangular breakwaters with different widths, a toothed rectangular breakwater, and a trapezoidal breakwater with a slope of 1:2. A new comprehensive dimensionless parameter (β) was proposed representing both wave hydrodynamic and breakwater geometry characteristics. This parameter could be employed as a suitable descriptive option to make an accurate estimate of the hydraulic performances of submerged breakwaters. The β parameter is composed of four conventional simple dimensionless variables. However, the results revealed that the relative submergence depth significantly affects the hydraulic responses of submerged breakwaters. The transmission, reflection and dissipation of waves show a logarithmic growth, a logarithmic reduction, and a quadratic decreasing trend against the increasing of β parameter, respectively. The verifications of results revealed the high efficiency of β parameter for data reported by Carevic et al. (2013) with R2 = 0.88 and high agreement with predictions made by Van der Meer et al. (2005) formulation with R2 = 0.93.

4

Influence of Walls in a Container on the Growth of the Chlorella Vulgaris Algae

Kondzior Paweł, Butarewicz Andrzej

Journal of Ecological Engineering

|

2021

|

Vol. 22, nr 10

98--108

EN

Most of the algae are eukaryotic organisms commonly found in the aquatic environment. They are characterized by a great variety of species and the possibility of growing under various conditions. They photosynthesize, mainly needing light, water and carbon dioxide to grow. Algae can be used in various branches of the economy for the production of food, animal feed, bio-fertilizers, pigments, they can be used for sewage treatment or carbon dioxide sequestration. The aim of the work was to investigate the effect of the material from which the walls of containers are made on the bioreactors for algae cultivation. Two wall materials were used in the research: shiny aluminium foil and matte black light-absorbing paper. The content of photosynthetic pigments in algae cells, optical density, temperature and pH were examined. The tests were performed in triplicate and the standard error was calculated with the 95% confidence interval. It was observed that the glossy aluminium foil wall significantly improved the growth of the Chlorella vulgaris algae at the lowest light intensities by more than 4 times chlorophyll a compared to the sample placed in a container with walls of matte black paper. This means that the use of walls in shiny aluminium foil containers can reduce the lighting costs and contribute to an increase in the produced biomass.

5

Acoustic Panels Inspired by Nature

Borkowski Bartłomiej, Suder-Dębska Katarzyna, Wiciak Jerzy, Szlachta Anna Maria

Archives of Acoustics

|

2021

|

Vol. 46, No. 1

135--146

EN

The article presents the approach to the design process of acoustic panels based on the scientific research. This approach is based on combining the technical and the design competences to develop the innovative product value for the concept of acoustic panels. The article presents the concepts of two new acoustic panels – an absorbing and scattering panel and a panel reflecting sound waves. The first part of the article presents the starting point for the presented project – the acoustic research and the inspiration for both types of presented solutions. Next, the materials possible to use were discussed, which could reproduce the natural acoustic properties of the lava and glacier caves. The next part presents consecutive stages of the product development in a modern form, ensuring the expected acoustic properties. The last part of the article presents a fully functional solution and proposes further research and development directions.

6

Supervision as a tool for preventing emotional burnout of social workers

Ivzhenko Inna

Zeszyty Naukowe Wyższej Szkoły Technicznej w Katowicach

|

2020

|

nr 12

91--98

EN

The article provides a theoretical analysis of the concept of supervision as a means of preventing emotional burnout of social workers and an element of assistance, as it aims to ensure quality standards and support social workers in their daily activities. The analysis of the last researches and publications of domestic and foreign scientists is carried out, the purpose and urgency of work is defined. Emphasis is placed on the high level of empathy of social workers, which can lead to emotional burnout. Emotional burnout syndrome is characterized, special attention was paid to its prevention and means of recovery at the physiological, mental and professional levels. The features, purpose, subject and goals of supervision, competencies that supervisors should have, the main forms of focus of supervision (on the employee’s system, on the practice system, on the team system, on the system of the institution) are determined. It is concluded that the content of supervision depends on the content of social services. The main forms are named: supervision as an analysis of the work and practice of the supervisor directly, supervision as an analysis by the supervisor of the employee’s work directly, supervision as an element of the curriculum and methodological work. The concept of reflection as an important component of determining the attitude of the specialist to himself as a subject of activity and vision of himself in a specific work situation is analyzed. Types of supervision are identified, such as: one-on-one, group supervision, informal supervision, unscheduled consultation, crisis supervision, unscheduled discussion of a case that is of great concern to the employee and occupies most of his thoughts. The phases of supervision (inductive, communication and integration) are defined and analyzed. Conclusions are made on the importance of supervision in the organization of domestic social work.

PL

Artykuł stanowi teoretyczną analizę koncepcji nadzoru jako środka zapobiegającego wypaleniu emocjonalnemu pracowników socjalnych oraz elementu pomocy, gdyż ma na celu zapewnienie standardów jakości i wsparcie pracowników socjalnych w ich codziennych działaniach. Przeprowadzana jest analiza ostatnich badań i publikacji naukowców krajowych i zagranicznych, określany jest cel i ważność pracy. Podkreśla się wysoki poziom empatii pracowników socjalnych, który może prowadzić do wypalenia emocjonalnego. Scharakteryzowano zespół wypalenia emocjonalnego, zwrócono szczególną uwagę na jego profilaktykę i sposoby powrotu do zdrowia na poziomie fizjologicznym, psychicznym i zawodowym. Określono cechy, przeznaczenie, przedmiot i cele nadzoru, kompetencje, jakie powinni posiadać przełożeni, główne formy ukierunkowania nadzoru (na system pracownika, na system praktyki, na system zespołu, na system instytucji). Wynika z tego, że treść nadzoru zależy od treści usług społecznych. Główne formy noszą nazwy: nadzór jako analiza pracy i praktyki przełożonego bezpośrednio, nadzór jako analiza przez superwizora pracy pracownika bezpośrednio, nadzór jako element pracy programowo-metodycznej. Analizowana jest koncepcja refleksji jako ważnego elementu określającego stosunek specjalisty do siebie jako podmiotu działania i wizji siebie w konkretnej sytuacji zawodowej. Wyróżnia się takie rodzaje nadzoru, jak: nadzór indywidualny, grupowy, nieformalny, niezaplanowane konsultacje, nadzór kryzysowy, niezaplanowane omówienie sprawy, która bardzo niepokoi pracownika i zajmuje mu większość myśli. Definiuje się i analizuje fazy nadzoru (indukcyjną, komunikacyjną i integracyjną). Wyciągnięto wnioski na temat znaczenia nadzoru w organizacji domowej pracy socjalnej.

7

Lustrzana architektura : studia przypadków

Kuzia Wiktoria

Architecturae et Artibus

|

2019

|

Vol. 11, no. 2

5--12

PL

Celem artykułu jest analiza zagadnienia związanego z wykorzystaniem efektu lustrzanego odbicia w architekturze. Omówione są tu przykłady projektów i realizacji o wysokich walorach estetycznych i funkcjonalnych, uzyskanych dzięki użyciu luster. Autorka koncentruje się na motywach determinujących powstawanie lustrzanych obiektów, a także bada ich wpływ na otoczenie, kontekst miejsca i odbiorców. Prezentuje również szereg zalet estetycznych, jak i praktycznych, dzięki którym architektura ta staje się integralną częścią środowiska i intensyfikuje relacje z odbiorcą. Na podstawie przykładów można zauważyć wyraźny wzrost tendencji tworzenia budynków o lustrzanych elewacjach, co stanowi wyraz poszukiwania nowych aspektów postrzegania architektury.

EN

The aim of the article is to analyze architectural objects using the mirror reflection effect. The given examples of projects and world-wide implementations present high aesthetic and functional values obtained through the use of reflection. The author focuses on the motives that cause that mirrored buildings are created, and also examine their impact on the surroundings and people. In addition, the article presents a number of aesthetic and practical advantages of mirrored architecture which is becoming more and more popular. For these reason using mirrors may indicate the search for new aspects of the perception of architecture.

8

Rotation, initial stress, gravity and electromagnetic field effect on P wave reflection from stress-free surface elastic half-space with voids under three thermoelastic models

Abo-Dahab S. M., Rida S. Z., Mohamed R. A., Kilany A. A.

Mechanics and Mechanical Engineering

|

2018

|

Vol. 22, nr 1

313--328

EN

The present paper is devoted to investigate the influence of the rotation, thermal field, initial stress, gravity field, electromagnetic and voids on the reflection of P wave under three models of generalized thermoelasticity: Classical and Dynamical coupled model (CD), Lord-Shulman model (LS), Green-Lindsay model (GL), The boundary conditions at stress-free thermally insulated surface are satisfied to obtain Algebraic system of four equations in the reflection coefficients of various reflected waves. It is shown that there exist four plane waves; P1, P2, P3 and P4. In addition, the reflection coefficients from insulated and isothermal stress-free surface for the incident P wave are obtained. Finally, numerical values of the complex modulus of the reflection coefficients are visualized graphically to display the effects of the rotation, initial stress, gravity field magnetic field, thermal relaxation times and voids parameters.

9

Reflection of plane waves from surface of a generalized thermo-viscoelastic porous solid half-space with impedance boundary conditions

Singh B.

Mechanics and Mechanical Engineering

|

2018

|

Vol. 22, nr 4

1483--1496

EN

A phenomenon of reflction of plane waves from a thermally insulated surface of a solid half-space is studied in context of Lord-Shulman theory of generalized thermo-viscoelasticity with voids. The governing equations of generalized thermo-viscoelastic medium with voids are specialized in x-z plane. The plane wave solution of these equations shows the existence of three coupled longitudinal waves and a shear vertical wave in a generalized thermo-viscoelastic medium with voids. For incident plane wave (longitudinal or shear), three coupled longitudinal waves and a shear vertical wave reflect back in the medium. The mechanical boundary conditions at free surface of solid half-space are considered as impedance boundary conditions, in which the shear force tractions are assumed to vary linearly with the tangential displacement components multiplied by the frequency. The impedance corresponds to the constant of proportionality. The appropriate potentials of incident and reflected waves in the half-space will satisfy the required impedance boundary conditions. A non-homogeneous system of four equations in the amplitude ratios of reflected waves is obtained. These amplitude ratios are functions of material parameters, impedance parameter, angle of incidence, thermal relaxation and speeds of plane waves. Using relevant material parameters for medium, the amplitude ratios are computed numerically and plotted against certain ranges of impedance parameter and the angle of incidence.

10

Propagation and reflection of plane waves in a rotating magneto-elastic fibre-reinforced semi space with surface stress

Roy I., Acharya D. P., Acharya S.

Mechanics and Mechanical Engineering

|

2018

|

Vol. 22, nr 4

939--957

EN

The present paper investigates the propagation of quasi longitudinal (qLD) and quasi transverse (qTD) waves in a magneto elastic fibre-reinforced rotating semi-infinite medium. Reflections of waves from the flat boundary with surface stress have been studied in details. The governing equations have been used to obtain the polynomial characteristic equation from which qLD and qTD wave velocities are found. It is observed that both the wave velocities depend upon the incident angle. After imposing the appropriate boundary conditions including surface stress the resultant amplitude ratios for the total displacements have been obtained. Numerically simulated results have been depicted graphically by displaying two and three dimensional graphs to highlight the influence of magnetic field, rotation, surface stress and fibre-reinforcing nature of the material medium on the propagation and reflection of plane waves.

11

Reflection of Plane Waves from Surface of a Generalized Thermo-viscoelastic Porous Solid Half-space with Impedance Boundary Conditions

Singh B.

Computational Methods in Science and Technology

|

2018

|

Vol. 24, No. 4

273--283

EN

A phenomenon of reflection of plane waves from a thermally insulated surface of a solid half-space is studied in the context of Lord-Shulman theory of generalized thermo-viscoelasticity with voids. The governing equations of generalized thermo-viscoelastic medium with voids are specialized in x-z plane. The plane wave solution of these equations shows the existence of three coupled longitudinal waves and a shear vertical wave in a generalized thermo-viscoelastic medium with voids. For incident plane wave (longitudinal or shear), three coupled longitudinal waves and a shear vertical wave reflect back in the medium. The mechanical boundary conditions on the free surface of solid half-space are considered as impedance boundary conditions, in which the shear force tractions are assumed to vary linearly with the tangential displacement components multiplied by the frequency. The impedance corresponds to the constant of proportionality. The appropriate potentials of incident and reflected waves in the half-space will satisfy the required impedance boundary conditions. A non-homogeneous system of four equations in the amplitude ratios of reflected waves is obtained. These amplitude ratios are functions of material parameters, impedance parameter, angle of incidence, thermal relaxation and speeds of plane waves. Using relevant material parameters for medium, the amplitude ratios are computed numerically and plotted against certain ranges of the impedance parameter and the angle of incidence.

12

Colorimeter based on color sensor

Snizhko D. V., Sushko O. A., Reshetnyak E. A., Shtofel D. H., Zyska T., Smolarz A., Mussabekov N., Kalizhanova A.

Przegląd Elektrotechniczny

|

2017

|

R. 93, nr 5

96--101

EN

In this paper colorimeter based on color sensor is considered. The developed colorimeter experimental utilization is shown on example of detection Cu2+, Co2+ ions and Neutral Red indicator. Realized measurement optical system in the colorimeter supports operation with different types of sorbents, as possibility is shown an operation with silica, polyurethane foam and the indicator paper. Dynamic range of device at 12 bit per channel and well stability of characteristic are enough to work with fine reliability that is no more 0.7% for analyzed test systems.

PL

W artykule przedstawiono kolorymetr zbudowany z wykorzystaniem czujnika barwy. Przedstawiono wykorzystanie przedstawionego kolorymetry na przykładzie detekcji jonów Cu2+, Co2+ i neutralnego wskaźnika barwy czerwonej. Zrealizowany system optyczny kolorymetru umożliwia pracę z różnymi rodzajami sorbentów. Możliwości te pokazano z wykorzystaniem krzemionki, pianki poliuretanowej i papierka wskaźnikowego.

13

Reaction of plane waves from a rotating magneto-thermoelastic medium with two-temperature and initial stress under three theories

Othman M. I. A., Abo-Dahab S. M., Alsebaey O. N. S.

Mechanics and Mechanical Engineering

|

2017

|

Vol. 21, nr 2

217--232

EN

The model of the equations of generalized magneto-thermoelasticity in an isotropic elastic medium with two-temperature under the effect initial stress is established. The entire elastic medium is rotated with a uniform angular velocity. The formulation is applied under three theories of generalized thermoelasticity: Lord-Shulman, Green-Lindsay, as well as the coupled theory. The Harmonic function is used to obtain the exact expressions for the considered variables. Some particular cases are also discussed in the context of the problem. We introduce the equations of the velocity of p-wave, T-wave and SV-wave. The boundary conditions for mechanical and Maxwell’s stresses and thermal insulated or isothermal are applied to determine the reflection coefficients for p-wave, T-wave and SV-wave. Some new aspects are obtained of the reflection coefficients and displayed graphically and the new conclusions are presented. Comparisons are also made with the results predicted by different theories (CT, L-S, G-L) in the presence of rotation, initial stress, magnetic field, as well as, the two-temperature parameter on the reflection of generalized thermos-elastic waves.

14

Propagation and reflection of plane waves in a rotating magneto elastic fibre-reinforced semi space with surface stress

Roy I., Acharya D. P., Acharya S.

Mechanics and Mechanical Engineering

|

2017

|

Vol. 21, nr 4

1043--1061

EN

The present paper investigates the propagation of quasi longitudinal (qLD) and quasi transverse (qTD) waves in a magneto elastic fibre-reinforced rotating semi-in finite medium. Reflections of waves from the flat boundary with surface stress have been studied in details. The governing equations have been used to obtain the polynomial characteristic equation from which qLD and qTD wave velocities are found. It is observed that both the wave velocities depend upon the incident angle. After imposing the appropriate boundary conditions including surface stress the resultant amplitude ratios for the total displacements have been obtained. Numerically simulated results have been depicted graphically by displaying two and three dimensional graphs to highlight the in uence of magnetic field, rotation, surface stress and fibre-reinforcing nature of the material medium on the propagation and reflection of plane waves.

15

On generalized magneto-thermoelastic P-, T- and SV-waves propagation at the interface between two magnetized solid-liquid media with initial stress

Abo-Dahab S. M.

Mechanics and Mechanical Engineering

|

2017

|

Vol. 21, nr 4

897--917

EN

In this paper, we study the effects of magnetic field and initial stress on plane waves propagation. We have investigated the problem of reflection and refraction of thermoelastic waves at a magnetized solid-liquid interface in the presence of initial stress, in the context of CT (Classical theory) of thermoelasticity, the problem has been solved. The boundary conditions applied at the interface are: (i) continuity of the displacement, (ii) vanishing of the tangential displacement, (iii) continuity of normal force per unit initial area, (iv) vanishing of the tangential stress and (v) continuity of temperature. The amplitudes ratios for the incident P-, T-, and SV- waves have been obtained. The reflection and transmission coefficients for the incident waves are computed numerically, considering the initial stress and magnetic field effects and the results are represented graphically.

16

Appointing of surface topography parameters to describe the diffuse reflective properties of selected dielectrics

Majchrowski R., Rozanski L., Grochalski K.

Measurement Automation Monitoring

|

2017

|

Vol. 63, No. 3

78--81

EN

The investigations have been performed in order to choose the specific roughness parameters, which would inform the customer about the diffuse emissive and reflective characteristics of the adhesive tapes used in the thermographic measurements. To achieve that, a series of the surface topography parameters of various adhesive tapes (i.e. objects with diffusive reflective characteristics) and various glass plates (i.e. objects with directional reflective characteristics) has been examined. For the analysis of surface topography the following parameters were selected: Sdr (the Developed Interfacial Area Ratio) and Sdq (the Root Mean Square Surface Slope). These selected parameters seem to be most suitable to describe the properties of the surface in the discussed aspect.

17

Effect of geometry and impedance variation on the acoustic performance of a porous material lined duct

Masmoudi A., Makni A., Taktak M., Haddar M.

Journal of Theoretical and Applied Mechanics

|

2017

|

Vol. 55 nr 2

679--694

EN

In this paper, the effect of geometry and impedance on the acoustic behavior of wall and lined cylindrical ducts is investigated using a numerical model which enables one to compute the reflection and the transmission coefficients of such ducts using the multimodal scattering matrix. From this matrix, the acoustic power attenuation is deduced. By using these tools, the effect of duct diameter increase and duct diameter decrease of the wall or lined duct section is studied. The numerical results are obtained for two configurations of wall and lined ducts. Numerical coefficients of transmission and reflection as well as the acoustic power attenuation show the relative influence of each type of variation.

18

Reflection and Refraction of Plane HarmonicWaves at an Interface Between Elastic Solid and Magneto-thermoelastic Diffusion Solid with Voids

Kumar R., Kansal T.

Computational Methods in Science and Technology

|

2017

|

Vol. 23, No. 1

43--56

EN

The problem of the reflection and refraction phenomenon due to longitudinal and transverse waves incident obliquely at a plane interface between uniform elastic solid half-space and magneto-thermoelastic diffusive solid half-space with voids has been studied. It is found that the amplitude ratios of various reflected and refracted waves are functions of the angle of incidence and frequency of the incident wave. The amplitude ratios and energy ratios have been computed numerically for a particular model. The variations of energy ratios with angle of incidence are shown graphically.

19

Influences of a visco-elastically supported boundary on reflected waves in a couple-stress elastic half-space

Wang C. D., Wei P. J., Zhang P., Li Y. Q.

Archives of Mechanics

|

2017

|

Vol. 69, nr 2

131--156

EN

The reflection of elastic waves at the surface of a couple-stress elastic half-space with a viscoelastic support is studied in this paper. Different from the classical elastic solid, there are: a non-dispersive dilatational propagating wave, a dispersive transverse propagating wave and a dispersive evanescent wave in a couple-stress elastic solid. The boundary conditions at the visco-elastically supported surface of a couple-stress elastic half-space include the couple-stress vector and the rotation vector, which disappear in the classical elastic solid. They are used to obtain a set of linear algebraic equation, from which the amplitude ratios of reflection waves with respect to the incident wave can be determined. Then, the reflection coefficients in terms of energy flux ratios are calculated numerically, and the normal energy flux conservation is used to validate the numerical results. At last, the influence of the boundary parameters that reflect the mechanical behavior of a viscoelastic support on the amplitude ratio, the phase shift and the energy partition of reflection waves are discussed based on the numerical results. Both the incident longitudinal displacement wave (the P-wave) and incident transverse displacement wave (the SV-wave) are considered. It is found that the instantaneous elasticity and the delayed viscosity of a viscoelastic support have different influences on the reflection waves.

20

On reflection and refraction of plane electromagnetic waves at a conducting matter surface

Leble S., Vereshchagina S.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

|

2016

|

Vol. 20, No 2

207--217

EN

A general problem of monochrome plane electromagnetic wave reflection and refraction at the interface between the conducting medium and the dielectric is formulated and solved by symbolic computation for given incident wave polarization. The conductivity account via the Ohm law directly in the Maxwell equation leads to a complex wavenumber and hence complex amplitudes of the reflected and refracted waves. Atomic absorption is taken into account via the imaginary part of permittivity. The general formula for the time-averaged Pointing vector in the conducting media as a function of the medium parameters and the incident angle is derived and used for the refraction angle definition. The result is compared with textbooks and recent publications. The dependence of intensity as a function of the angle to the interface is determined also via the Pointing vector as a function of the incident wave and medium parameters.