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1

Anisotropy of mechanical parameters of weld for high-strength steel in tensile test for towing and coupling components in recovery vehicles

Szymczak Tadeusz, Herman Patryk

Zeszyty Naukowe. Transport / Politechnika Śląska

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2025

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z. 126

255--266

EN

The paper presents results for S700MC high-strength steel and its weld at longitudinal and transverse orientations of specimens. The determination of anisotropy features is proposed for the parent material and welding joint due to the often usage of this steel for manufacturing of towing and coupling components in recovery vehicles. This means that the most important mechanical parameters of the regions questioned should be determined for numerical and analytical analysis with the target to get their type approval and to keep the road safety. The mini-specimens were used to reflect the joint behaviour subjected to monotonic tension. The weld behaviour was assessed using the longitudinal specimen that was manufactured from the joint. The results enabled to indicate differences in the section tested depending on the loading orientations considered.

2

Eliminacja anizotropii w szkle hartowanym: przełom technologiczny dla płaskich i giętych tafli

Tarrus Joan, Hänig Julian

Świat Szkła

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2025

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R. 30, nr 11

23--29

3

Analysis of the impact of the method of manufacturing a rotor on the parameters of an AC IPM machine

Korkosz Mariusz, Młot Adrian, Sztajmec Elżbieta, Ryłło Karol

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2025

|

Vol. 73, nr 4, Special Section

art. no. e153433

EN

This article presents the technological problem related to the production of rotors with an internal permanent magnet. Most often, the magnetic circuits of such rotors used in alternating current synchronous motors (AC IPM) are made of isotropic magnetic sheets. At this point, it should be noted that it is often not taken into account that each isotropic magnetic sheet exhibits some anisotropy. This significantly affects the operational parameters of the brushless permanent magnet (PM) motor such as the cogging torque, electromagnetic torque ripples and an increase in induced voltage harmonics. To illustrate how important it is to properly design the rotor core, two rotors of the IPM motor were analyzed in this work. In the first rotor solution, minimization of the magnetic sheet anisotropy was not taken into account, and the skew of the magnets was not used. In the second case of the IPM motor, the problem of rotor magnetic circuit anisotropy was minimized and an additional skew of the PMs was used. The obtained measurements and calculations of selected useful parameters of both rotor designs were then compared with each other. Importantly, the conclusions drawn and the resulting comments will prove useful to designers, assemblers and manufacturers of electrical machine components.

4

Scale effects and spatial distribution characteristics of 3D roughness of natural rock fracture surfaces: statistical analysis

Huan Jiuyang, He Mingming, Wan Zhiwen, Li Meishu, Pan Hengfei, Hu Mengdie

Acta Geophysica

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2025

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Vol. 73, no. 1

83--103

EN

The roughness feature of a natural rock fracture surface is an important factor affecting the shear and poromechanical behavior of rock. The scale effect and spatial distribution characteristics of the fracture surface roughness are notable challenges at rock engineering sites. In this article, morphological data of a large-scale field rock fracture surface were collected using a 3D scanner. Then, the original surface was divided into several small fracture surfaces. With the use of a 2D roughness statistical index, the 2D roughness (JRC2D) of the fracture profile was evaluated. The 3D roughness (JRC3D) of the fracture surface along different directions was obtained via the weighted averaging method. Based on four oblique analysis schemes, the elevation statistical trend and roughness scale effect of fracture surfaces with different widths were examined. With increasing fracture size, the average elevation (^) and the standard deviation of elevation (a) showed different typical change patterns. The impact of size variation on the fracture surface roughness includes four types and exhibits significant anisotropy. Based on small fissure surfaces without mutual coverage, the spatial distribution characteristics of the fracture roughness were analyzed and were proven to exhibit high dispersion and anisotropy. With increasing width of the analyzed small fracture, the roughest position on the fracture surface basically remained the same, but there was a significant change in roughness anisotropy.

5

Wyznaczanie zależności kątowej prądu krytycznego Ic w wysokotemperaturowych taśmach nadprzewodnikowych 1G

Habelok Krzysztof, Gruszczyk Kamil, Lasek Paweł, Stępień Mariusz

Przegląd Elektrotechniczny

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2024

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R. 100, nr 10

35--38

PL

W artykule przedstawiono analizę teoretyczną oraz pomiarową zależności kątowej prądu krytycznego w wysokotemperaturowych taśmach nadprzewodnikowych (HTS) pierwszej generacji. Badania skupiały się na analizie wpływiu wartości i kierunku pola magnetycznego na prądy krytyczne. W pracy opisano również budowę i działanie specjalnie zaprojektowanego stanowiska testowego, wykorzystującego magnesy neodymowe w konfiguracji Halbacha, które umożliwia dokładne pomiary i charakteryzację taśm HTS. Wyniki badań potwierdziły zgodność z modelem Kima i pozwoliły na rozwój modelu gęstości prądu krytycznego, który może być wykorzystany w dalszych symulacjach komputerowych.

EN

The article presents a theoretical and measurement analysis of the angular dependence of the critical current in high-temperature superconducting (HTS) tapes of the first generation. The research focused on the impact of the value and direction of the magnetic field on critical currents. The paper also describes the construction and operation of a specially designed test station using neodymium magnets in the Halbach configuration, which allows for precise measurements and characterization of HTS tapes. The results confirmed the consistency with the Kim model and contributed to the development of a critical current density model that can be used in further computer simulations.

6

Difficulties of hydrofracturing in sandstone - experimental study

Vikram S., Kumar Dheeraj, Subrahmanyam D. S.

Journal of Sustainable Mining

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2024

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Vol. 23, iss. 2

160--176

EN

Hydrofracturing in sandstone is not an easy task. Sandstone is porous; fluid dissipation is common hence unable to obtain breakdown pressures in certain flow rates (0.0000005-0.0001 m3/s). The higher flow rate (0.00025 m3/s) is ascertained to determine the fracturing pressures. Due to this, fracture propagation and delineation are observed (Satya Subrahmanyam, 2022) [1]. To enhance, an experimental method is adopted by carrying out 6 Hydrofracturing tests in a borehole comprising sandstone. A high flow rate of 0.00025 m3/s and viscosity 0.001 Pa s is applied. Later, the fracture simulation was run on 12 core samples collected from the same depths in a lab. The fluid flow rates of 0.0000005-0.0000015 m3/s, viscosity 0.27 Pa- second, pore pressure of 4 MPa, confining pressures in vertical-12 MPa and horizontal 6, 18, 24, 30 MPa is applied. The fracture traces and the stress results exhibit a difference of 80°-300° observed in both cases. The major principle stress orientation obtained in the borehole is 20° and 40°. In lab tests with confining horizontal pressures at 6 and 18 MPa, it is 120° and 130°, and at 24 and 30 MPa is 20°. This indicated that there is fracture delineation occurred. It is observed in the higher flow rate and confining pressures.

7

Cubic elasticity of porous materials produced by additive manufacturing: experimental analyses, numerical and mean‑field modelling

Kowalczyk-Gajewska Katarzyna, Maj Michał, Bieniek Kamil, Majewski Michał, Opiela Kamil C.

Archives of Civil and Mechanical Engineering

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2024

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Vol. 24, no. 1

art. no. e34, 2024

EN

Although the elastic properties of porous materials depend mainly on the volume fraction of pores, the details of pore distribution within the material representative volume are also important and may be the subject of optimisation. To study their effect, experimental analyses were performed on samples made of a polymer material with a predefined distribution of spherical voids, but with various porosities due to different pore sizes. Three types of pore distribution with cubic symmetry were considered and the results of experimental analyses were confronted with mean-field estimates and numerical calculations. The mean-field ‘cluster’ model is used in which the mutual interactions between each of the two pores in the predefined volume are considered. As a result, the geometry of pore distribution is reflected in the anisotropic effective properties. The samples were produced using a 3D printing technique and tested in the regime of small strain to assess the elastic stiffness. The digital image correlation method was used to measure material response under compression. As a reference, the solid samples were also 3D printed and tested to evaluate the polymer matrix stiffness. The anisotropy of the elastic response of porous samples related to the arrangement of voids was assessed. Young’s moduli measured for the additively manufactured samples complied satisfactorily with modelling predictions for low and moderate pore sizes, while only qualitatively for larger porosities. Thus, the low-cost additive manufacturing techniques may be considered rather as preliminary tools to prototype porous materials and test mean-field approaches, while for the quantitative and detailed model validation, more accurate additive printing techniques should be considered. Research paves the way for using these computationally efficient models in optimising the microstructure of heterogeneous materials and composites.

8

Behaviour of the aeolian sands under true-triaxial conditions

Ma Zhigang, Li Xuefeng

Archives of Civil and Mechanical Engineering

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2024

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Vol. 24, no. 3

art. no. e151, 2024

EN

To clarify the stress–strain behaviour, strength on the deviatoric plane, shear band formation, and dilatancy characteristics of aeolian sand under three-dimensional loading conditions, a series of true-triaxial tests with various intermediate principal stress coefficients b ∈ [0.0, 1.0] at constant effective mean principal stress p' were conducted under drained and undrained conditions. The results presented that the variations of the stress–strain, strength, and effective internal friction angle show its significant dependence on the relative magnitude of the intermediate principal stress expressed in terms of the b value. Because a clear penetrating shear band was produced in the prismatic specimen at b = 0.2 and b = 0.4, the stress–strain response exhibits softening, and its peak shear stress and effective internal friction angle are reduced. Besides, shear bands often appear in the hardening regime. Moreover, the dilatancy was the weakest at b = 0.0 and the strongest at b = 0.4, which depended on the stress path in terms of the b value. The peak shear stress on the deviatoric plane decreased in a transverse “S” shape with the b value varying from 0.0 to 1.0, correspondingly, the effective internal friction angle increased first and then decreased. But in the case of increasing p' value, aeolian sand has a unified critical state line and phase transformation line at constant b value.

9

Modelling hysteresis loops of non-oriented electrical steel

Chwastek Krzysztof, Koprivica Branko, Rosić Marko, Gozdur Roman, Gębara Piotr

Przegląd Elektrotechniczny

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2023

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R. 99, nr 11

221--223

EN

Non-oriented electrical steels constitute the most important segment of the market of soft magnetic materials. In the paper the usefulness of the model based on hyperbolic tangent nonlinear transformation for the description of quasi-static hysteresis loops for this type of material is verified.

PL

Blachy elektrotechniczne o ziarnach niezorientowanych stanowią najważniejszy segment rynku materiałów magnetycznie miękkich. W pracy zweryfikowano użyteczność modelu opartego na nieliniowej transformacji tangens hiperboliczny do opisu quasi-statycznych pętli histerezy dla tego typu materiału.

10

Influence of soil anisotropic stiffness on the deformation induced by an open pit excavation

Lisewska Katarzyna, Cudny Marcin

Archives of Civil Engineering

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2023

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Vol. 69, nr 4

141--156

EN

In this paper, the problem of deformation induced by an open pit excavation in anisotropic stiff soils is analysed by FE modelling. The presented research is focused on the influence of material model with anisotropic stiffness on the accuracy of deformation predictions as compared with the field measurements. A new hyperelastic-plastic model is applied to simulate anisotropic mechanical behaviour of stiff soils. It is capable to reproduce mixed variable stress-induced anisotropy and constant inherent cross-anisotropy of the small strain stiffness. The degradation of stiffness depending on strain is modelled with the Brick-type model. The model formulation and parameters are briefly presented. General deformation pattern obtained in the exemplary 2D boundary value problem of an open pit excavation is investigated considering different values of inherent cross-anisotropy coefficient of small strain stiffness. The numerical simulations are performed as a coupled deformation-flow analysis which allows to properly model the drainage conditions. The excavation phases are simulated by removal of soil layers according to the realistic time schedule. Finally, the monitored case of the trial open pit excavation in heavily overconsolidated Oxford Clay at Elstow, UK is simulated with proposed material model both in 2D and 3D conditions. The obtained calculation results are compared with displacement measurements and discussed.

PL

Modelowanie numeryczne zagadnień geotechnicznych związanych z odciążeniem podłoża (np. tunelowanie, wykopy) wymaga odpowiedniego opisu materiałowego gruntu, który pozwala na prawidłową symulację charakterystyki mechanicznej w zakresie małych odkształceń. Najważniejszymi elementami są tutaj nieliniowość sztywności związana z barotropią oraz degradacją stycznego modułu ścinania z odkształceniem oraz inherentna anizotropia sztywności. Modele konstytutywne dostępne w popularnych systemach obliczeniowych rzadko pozwalają na uwzględnienie anizotropii sztywności w zakresie małych odkształceń. Najczęściej przyczyną jest bardziej skomplikowana procedura implementacji niż w przypadku modeli z izotropową sztywnością, jak również ograniczona dostępność parametrów materiałowych związanych z anizotropią. Rozwój technik pomiarowych w eksperymentalnej mechanice gruntów, obserwowany w ostatnich latach na całym świecie, pozwala jednak na zaprojektowanie i przeprowadzenie badań anizotropii sztywności w warunkach ważnych inwestycji lub projektów badawczych. Najczęściej jest to pomiar współczynnika anizotropii αG w aparacie trójosiowym wyposażonym w elementy sejsmiczne bender zorientowane zarówno w pionie jak i w poziomie. System taki pozwala na bezpośrednie wyznaczenie modułów ścinania w płaszczyźnie pionowej Gvh oraz poziomej Ghh (αG= Ghh/Gvh). W artykule przedstawiono własny hipersprężysto-plastyczny model konstytutywny uwzględniający zarówno nieliniowość jak i anizotropię sztywności w zakresie małych odkształceń. W modelu tym wykorzystano anizotropową hipersprężystość do opisu sztywności początkowej, system zagnieżdżonych powierzchni plastyczności w przestrzeni odkształcenia do opisu degradacji sztywności (tzw. model Brick) oraz konwencjonalne kryterium wytrzymałości na ścinanie do ograniczenia dewiatorowych stanów naprężenia. Model został zaimplementowany w programie metody elementów skończonych Plaxis w ramach opcji User Defined Soil Model (UDSM). Analizowanym zagadnieniem brzegowo początkowym jest próbny otwarty wykop wykonany w ile oxfordzkim w Elstow, Wielka Brytania. Szeroka baza danych dotyczących niestandardowych badań laboratoryjnych iłu oksfordzkiego zorientowanych, oprócz wyznaczenia parametrów standardowych, na charakterystykę anizotropii sztywności dostępna jest w literaturze. Dokładny opis realizacji wykonanego próbnego wykopu z danymi pozwalającymi na przeprowadzenie własnych analiz wraz z wynikami monitoringu przemieszczeń dostępne są w publikacji Hird&Pierpoint (Geotechnique 47(3), 1997). Umożliwiło to, kalibrację parametrów anizotropowego modelu hipersprężysto-plastycznego i przeprowadzenie analizy wstecz będącej cenną weryfikacją przydatności opracowanego modelu konstytutywnego. Przed wykonaniem symulacji numerycznych próbnego wykopu w Elstow przeprowadzono również serię obliczeń na uproszczonym przykładowym modelu wykopu otwartego w płaskim stanie odkształcenia w celu rozpoznania wpływu czystej anizotropii inherentnej na deformację powstającą podczas odciążenia podłoża gruntowego takim wykopem. Symulację numeryczną wykopu próbnego w Elstow przeprowadzono zarówno w płaskim stanie odkształcenia jak i na modelu przestrzennym. Metoda symulacji odpowiadała podejściu sprzężonemu konsolidacji z równoczesnym uwzględnieniem przepływu wody w gruncie (coupled deformation flow analysis). Warunki czasowe wykonania wykopu próbnego, jak również parametry filtracyjne oraz mechaniczne zalegających gruntów powodują jednak, że przedmiotowe zagadnienie brzegowo-początkowe zachodzi ostatecznie w warunkach bliskich warunkom braku drenażu. Wyniki przeprowadzonych symulacji numerycznych porównano z wynikami monitoringu przemieszczenia. Uzyskano zadowalającą zgodność obliczonego i pomierzonego pola przemieszczenia. Dokładność wyników obliczeń jest jednak zmienna w zależności od obszaru analizowanego zagadnienia. Odpowiednie porównania przedstawiono na rysunkach w artykule.

11

Wpływ strumieni chłodzących na rozkład naprężeń i anizotropię w szkle hartowanym

Karvinen Reijo, Aronen Antti

Świat Szkła

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2022

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R. 27, nr 3

34--37

12

Pomiar anizotropii w szkle architektonicznym

Moreau Louis

Świat Szkła

|

2022

|

R. 27, nr 4

42--44

13

Ocena efektów zamglenia, anizotropii, zmian przejrzystości i interferencji (HACI)

Moreau Louis

Świat Szkła

|

2022

|

R. 27, nr 4

38--40

14

Nieniszcząca kontrola oraz ocena jakości (poziomu anizotropii) przy użyciu metod fotoelastycznych

Schaaf Benjamin, Di Biase Pietro, Feldmann Markus, Schuler Christian, Dix Steffen

Świat Szkła

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2022

|

R. 27, nr 1-2

36--40

15

Frequency behavior of specific total loss model taking into account anisotropy of electrical steel

Pluta Wojciech A.

Przegląd Elektrotechniczny

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2022

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R. 98, nr 12

129--132

EN

Due to Goss texture electrical steel displays strong anisotropy of magnetic properties. This phenomenon shoud be taken into account by designers of magnetic circuits as it has undesirable effect e.g. vibrations and noise. Several approaches for anisotropy of magnetic properties can be found in the literature. In this paper are presented frequency behavior of parameters of anisotropy PS loss model based on three components specific total loss model.

PL

Ze względu na fakturę Gossa stal elektryczna wykazuje silną anizotropię właściwości magnetycznych. Zjawisko to powinno być brane pod uwagę przez projektantów obwodów magnetycznych, ponieważ ma ono niepożądany efekt m.in. wibracje i hałas. W literaturze można znaleźć kilka podejść do anizotropii właściwości magnetycznych. W artykule przedstawiono charakterystykę częstotliwościową parametrów anizotropii modelu strat PS w oparciu o trzyskładnikowy model strat całkowitych.

16

Anisotropy of structural and mechanical properties in CuCrZr alloy following hydrostatic extrusion process

Przybysz Sylwia, Kulczyk Mariusz, Skiba Jacek, Skorupska Monika

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2022

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Vol. 70, nr 4

art. no. e141725

EN

The methods of severe plastic deformation (SPD) of metals and metal alloys are very attractive due to the possibility of refinement of the grains to nanometric sizes, which facilitates obtaining high mechanical properties. This study investigated the influence of SPD in the process of hydrostatic extrusion (HE) on the anisotropy of the mechanical properties of the CuCrZr copper alloy. The method of HE leads to the formation of a characteristic microstructure in deformed materials, which can determine their potential applications. On the longitudinal sections of the extruded bars, a strong morphological texture is observed, manifested by elongated grains in the direction of extrusion. In the transverse direction, these grains are visible as equiaxed. The anisotropy of properties was mainly determined based on the analysis of the static mini-sample static tensile test and the dynamic impact test. The obtained results were correlated with microstructural observations. In the study, three different degrees of deformation were applied at the level necessary to refine the grain size to the ultrafine-grained level. Regardless of the applied degree of deformation, the effect of the formation of a strong morphological texture was demonstrated, as a result of which there is a clear difference between the mechanical properties depending on the test direction, both by the static and dynamic method. The obtained results allow for the identification of the characteristic structure formed during the HE process and the more effective use of the CuCrZr copper alloy in applications.

17

Hydrodynamics and turbulence anisotropy for complex flow in a sinuous channel

Taye Jyotismita, Kumar Bimlesh

Acta Geophysica

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2022

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Vol. 70, no 5

2269--2282

EN

Sinuous channel flows are the most natural form of alluvial streams. The complex flow in the channel bends has been the main focus of the study. This paper examines the flow velocity and the three-dimensional velocity fluctuations in a pure sinuous channel. The main focus of the study is on the characterization of turbulence anisotropy along the sinuous bend. Experiments were conducted in a sinuous channel of a rectangular cross-section to identify the turbulence present in the flow. Secondary flow, Reynolds shear stress, turbulent kinetic energy, and anisotropy turbulence were evaluated in the sinuous bend. The bend apex is composed of a large circulation cell at the center of the bend section. The maximum Reynolds shear stress (RSS) is located at the bend apex with the streamwise-transverse and transverse-vertical components of RSS showing high peaks of positive and negative values. This fact is in support of the secondary flow observed in this study. Anisotropic stress tensors were estimated at different bend sections and are shown to have greater contribution toward streamwise and transverse direction. Anisotropic invariant map (AIM) identified the turbulence at bend sections and varying flow depth. Two dimensional, cigar-shaped, and pancake-shaped turbulence was observed at the bend upstream and downstream. Isotropic turbulence was observed at the bend apex. Near the bed (z∕h ≤ 0.2) and away from the bed (z∕h ≥ 0.4), pancake-shaped and cigar-shaped turbulence was observed.

18

Elastic full waveform inversion in VTI media using logging data constraints and gradient precondition

Xu Yipeng, Zhang Kai, Li Zhenchun, He Zilin, Gao Jinfeng, Zhao Xianyang

Acta Geophysica

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2022

|

Vol. 70, no 4

1665--1676

EN

Elastic full waveform inversion (EFWI) in VTI media using velocity model-based parameterization (PARM-VTIEFWI) can improve the sensitivity of anisotropic parameters, but there are still the problems of gradient’s interference and Nonunique. Research has shown that logging data can constrain the Non-unique of FWI. Therefore, in this paper, we use the logging data as a constraint to limit the Non-unique of the PARM-VTIEFWI. We derive the objective function and gradient equation for the PARM-VTIEFWI based on the constraint of logging information. In addition, to reduce the interference between the gradients of parameters in VTI media, we incorporate a pseudo-Hessian matrix to precondition the gradients and derive a gradient preconditioning formula based on the pseudo-Hessian matrix in this paper. In summary, we propose a new PARM-VTIEFWI method based on logging information constraint and gradient precondition, which reduces the interference between the parameter gradients and constrains the Non-unique of the inversion. The correctness and validity of the method were demonstrated by examples.

19

Nowe metody charakteryzacji materiałów dielektrycznych w zakresie mikrofalowym oraz fal milimetrowych

Karpisz Tomasz

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

|

2021

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nr 4

101--105

PL

Artykuł jest poświęcony rozwojowi jednowymiarowego, skalarnego, wielowarstwowego, elektromagnetycznego modelu otwartego rezonatora Fabry-Perot, wykorzystanego do pomiarów własności elektromagnetycznych elektrycznie cienkich warstw dielektryków na częstotliwości od 20 do 110 GHz. Pokrótce omówiono podstawy teoretyczne metody opisującej zachowanie fali elektromagnetycznej w otwartym rezonatorze Fabry-Perot oraz proces projektowania takiego układu pomiarowego. Następnie przedstawiono układ pomiarowy, kolejno zaprezentowano niektóre z wyników pomiarów wykonanych podczas prac związanych z doktoratem autora publikacji. Pod koniec omówiono ograniczenia omawianej metody oraz możliwe ścieżki rozwoju.

EN

This paper is focused on the introduction of a one-dimensional scalar multi-layer electromagnetic model of a Fabry-Perot open resonator and its use in the measurement of electromagnetic properties of electrically thin dielectric sheet materials in frequencies from 20 to 110 GHz. Short theoretical description of an electromagnetic wave inside resonator have been described. Furthermore, results of measurement for frequencies exceeding 50 GHz have been shown as well as unique capability of measurement of the samples with in-plane anisotropy. In the end measurement system limitation have been discussed with possibilities for further system development.

20

The onset of Soret driven ferrothermoconvective instability in the presence of darcy porous medium with anisotropy effect and MFD viscosity

Murugan D., Sekar R.

International Journal of Applied Mechanics and Engineering

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2021

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Vol. 26, no. 1

156--177

EN

The effect of magnetic dependent (MFD) viscosity on Soret driven ferrothermohaline convection in a densely packed anisotropic porous medium has been studied. The Soret effect is focused on the system. A linear stability analysis is carried out using a normal mode technique and a perturbation method is applied. It is found that a stationary mode is favorable for the Darcy model. Vertical anisotropy tends to destabilize the system and the magnetization effect is found to stabilize the system. It is also found that the MFD viscosity delays the onset of convection. Numerical computations are made and illustrated graphically.