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Tailoring optical constants of few-layer black phosphorus coatings: Spectroscopic ellipsometry approach supported by ab-initio simulation
Publikacja2D black phosphorus (BP) has attracted extensive attention as an anisotropic platform for novel optoelectronic and polarizing optics applications. Insight into the factors that tune the optical and polarizing properties of 2D BP reveals their essential influence on BP-based photonic and optoelectronic devices. In this work, studies of the optical constants of few-layer black phosphorus coatings are studied and discussed, with particular...
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Circular polarization diversity implementation for correlation reduction in wideband low-cost multiple-input-multiple-output antenna
PublikacjaIn this paper, a multiple-input-multiple-output (MIMO) antenna featuring circular polarization diversity, and designed on a common coplanar ground is presented. The proposed antenna design utilizes a coplanar waveguide (CPW) feeding technique with three parallel coplanar ground planes, and two feedlines in-between. For circular polarization (CP), quasi-loops are created by etching slots on the outermost ground planes. With this...
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Analysis of Modal Parameters Using a Statistical Approach for Condition Monitoring of the Wind Turbine Blade
PublikacjaThe primary objective of the presented paper is the numerical and experimental investigation related to developing a useful diagnostic method, which can be used for determining the site and size of damage in laminated shells of wind turbine blades. The described detection technique is based on the analysis of low frequencies bending vibrations mode shapes of rotor blades. The authors used the commonly applied statistics methods...
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The Use of Liquid Crystal Thermography in Selected Technical and Medical Applications—Recent Development
PublikacjaThermochromic liquid crystals (TLC) and true-colour digital image processing have been successfully used in non-intrusive technical, industrial and biomedical studies and applications. Thin coatings of TLC at surfaces are utilized to obtain detailed temperature distributions and heat transfer rates for steady or transient processes. Liquid crystals also can be used to make the temperature and velocity fields in liquids visible...
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Deposition and characterization of organic polymer thin films using a dielectric barrier discharge with different C2Hm/N2 (m = 2, 4, 6) gas mixtures
PublikacjaOrganic polymer thin films have been deposited on Si(100) and aluminum coated glass substrates by a dielectric barrier discharge (DBD) operated at medium pressure using different C2Hm/N2 (m = 2, 4, 6) gas mixtures. The deposited films were characterized by various spectroscopic techniques. Fourier transform infrared reflection absorption spectroscopy (FT-IRRAS) revealed the chemical functional groups present in the films. The surface...
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Recuperator with microjet technology as a proposal for heat recovery from low-temperature sources
PublikacjaA tendency to increase the importance of so called dispersed generation, based on the local energy sources and the working systems utilizing both the fossil fuels and the renewable energy resources is observed nowadays. Generation of electricity on industrial or domestic scale together with production of heat can be obtained for example through employment of the ORC systems. It is mentioned in the EU directive 2012/27/EU for cogenerative...
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Seismic probabilistic assessment of steel and reinforced concrete structures including earthquake-induced pounding
PublikacjaRecent earthquakes demonstrate that prioritizing the retrofitting of buildings should be of the utmost importance for enhancing the seismic resilience and structural integrity of urban structures. To have a realistic results of the pounding effects in modeling process of retrofitting buildings, the present research provides seismic Probability Factors (PFs), which can be used for estimating collision effects without engaging in...
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Comparative analysis of switched reluctance motor control algorithms
PublikacjaПредмет исследования. Развитие микропроцессорной техники и силовой электроники позволило создавать недорогие и эффективные системы управления различными электромеханическими объектами, которые ранее широко не использовались из-за сложности управления. К таким устройствам можно отнести вентильно-индукторные электрические машины. Данные машины широко применяются в различных практических разработках, например, в тяговом электроприводе,...
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Comparative analysis of switched reluctance motor control algorithms
PublikacjaПредмет исследования. Развитие микропроцессорной техники и силовой электроники позволило создавать недорогие и эффективные системы управления различными электромеханическими объектами, которые ранее широко не использовались из-за сложности управления. К таким устройствам можно отнести вентильно-индукторные электрические машины. Данные машины широко применяются в различных практических разработках, например, в тяговом электроприводе,...
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Non-uniqueness of fracture parameter choice in simulations of concrete cracking at mesoscale level
PublikacjaIn the paper a non-uniqueness of fracture parameter choice in simulations of cracking process in plain concrete specimens at mesoscale level under monotonic static loading is analysed. The Finite Element Method is used, where cracks are defined in a discrete way using interface cohesive elements with nonlinear material law including softening. The concrete mesostructure (such as: cement matrix, air voids, aggregates, and Interfacial...
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Ab initio chemical kinetics of Isopropyl acetate oxidation with OH radicals
PublikacjaGlobal reactivity descriptors of isopropyl acetate (IPA) and thermo-kinetic aspects of its oxidation via OH radicals have been studied. Transition state theory (TST) was utilized to estimate the bimolecular rate constants. Ten oxidation pathways have been investigated, and all of them are exothermic. The potential energy diagram has been sketched using different pre- and post-reactive complexes for all reaction pathways. Rate coefficient...
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Molecular hydrogen solvated in water – A computational study
PublikacjaThe aqueous hydrogen molecule is studied with molecular dynamics simulations at ambient temperature and pressure conditions, using a newly developed flexible and polarizable H2 molecule model. The design and implementation of this model, compatible with an existing flexible and polarizable force field for water, is presented in detail. The structure of the hydration layer suggests that first-shell water molecules accommodate the...
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COMPARISON OF HEAT TRANSFER CHARACTERISTICS IN SURFACE COOLING WITH BOILING MICROJETS OF WATER, ETHANOL AND HFE7100
PublikacjaThe basis of microjet technology is to produce laminar jets which when impinging the surface have a very high kinetic energy at the stagnation point. Boundary layer is not formed in those conditions, while the area of film cooling has a very high turbulence resulting from a very high heat transfer coefficient. Applied technology of jet production can result with the size of jets ranging from 20 to 500μm in breadth and 20 to 100μm...
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Determination of Selected Metals in Fruit Wines by Spectroscopic Techniques
PublikacjaThe determination of metals in different types of food and beverages samples has drawn significant attention due to several reasons with the most important one being the nutritional and toxic effects of these elements or their compounds. The knowledge of certain elements content in wines/fruit wines is of special interest due to their toxicity in case of excessive intake and also the effect they seem to have on the organoleptic...
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Experimental comparison of hydrodynamic thrust bearings with different pad surface materials
PublikacjaBabbitt is the material most frequently used as the pad surface material for hydrodynamic bearings operating at usual operating conditions. It shows many advantages important for safe bearing operation, as for example: low friction coefficient, corrosion resistance, fair mechanical properties and outstanding conformability. On the other hand, it is not free from disadvantages, such as limited fatigue strength or limited resistance...
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The Dilemmas of Choosing a Suitable Technology for Low Energy and Passive Houses in the Context of their Overheating Issues
PublikacjaIn compliance with European Union directives, numerous countries are introducing increasingly stricter legal limits on the estimated energy consumption of newly designed residential buildings. However, the fact, that regulations and designers' efforts are focused on decreasing energy consumption (and consequently carbon dioxide emissions) only at the post-occupancy stage, may lead to a significant increase in the carbon footprint...
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On Alternative Approaches to Design of Corporate Feeds for Low-Sidelobe Microstrip Linear Arrays
PublikacjaTwo design approaches, illustrated by simulations and measurements, aiming at a systematic computer-aided design of printed circuit feeds for low-sidelobe microstrip antenna arrays are described. The novelty of these approaches resides in identification of the optimal feed architectures with subsequent simulation-based optimization of the feed and array aperture dimensions. In this work, we consider microstrip corporate feeds realizing...
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Heat transfer intensification by enlarged surface roughness in the plate heat exchanger
PublikacjaIn the paper an experimental analysis of passive heat transfer intensification technique employed in the case of the plate heat exchanger is presented. The passive intensification was obtained by a modification of the heat transfer surface. The roughness of surface was increased by a use of glass micro-beads. Single-phase convective heat transfer in the water-water system was studied. The experiment was accomplished in two stages....
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Study of pH and temperature effect on lipophilicity of catechol-containing antioxidants by reversed phase liquid chromatography
PublikacjaLipophilicity of selected antioxidant phytochemicals, including flavonoids, phenolic acids and xanthonoids, was determined by reversed phase high performance liquid chromatography with UV detection (RP-HPLC-UV). The analyses run at different temperature and pH conditions in isocratic mode suggested that lipophilicity as distribution coefficient (logD) between aqueous and organic phase decreases with increasing temperature. For...
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Prediction of fracture toughness in fibre-reinforced concrete, mortar, and rocks using various Machine learning techniques
PublikacjaMachine Learning (ML) method is widely used in engineering applications such as fracture mechanics. In this study, twenty different ML algorithms were employed and compared for the prediction of the fracture toughness and fracture load in modes I, II, and mixed-mode (I-II) of various materials, including fibre-reinforced concrete, cement mortar, sandstone, white travertine, marble, and granite. A set of 401 specimens of “Brazilian...
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Correlation between Compressive Strength and Heat of Hydration of Cement Mortars with Siliceous Fly Ash
PublikacjaThis paper presents the results of calorimetric and strength tests of mortars with ordinary Portland cement and two substitution rates (10 and 20%) of cement by siliceous fly ash. The prepared samples were cured under isothermal conditions at four different temperatures: 23, 33, 43 and 53 °C. Heat of hydration was measured using an isothermal calorimeter dedicated to monitor the hydration process of cementitious composites such...
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Ground Tire Rubber Filled Flexible Polyurethane Foam—Effect of Waste Rubber Treatment on Composite Performance
PublikacjaThe application range of flexible polyurethane (PU) foams is comprehensive because of their versatility and flexibility in adjusting structure and performance. In addition to the investigations associated with further broadening of their potential properties, researchers are looking for new raw materials, beneficially originated from renewable resources or recycling. A great example of such a material is ground tire rubber (GTR)—the...
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Numerically Efficient Miniaturization-Oriented Optimization of an Ultra-Wideband Spline-Parameterized Antenna
PublikacjaDesign of ultra-wideband radiators for modern handheld applications is a challenging task that involves not only selection of an appropriate topology, but also its tuning oriented towards balancing the electrical performance and size. In this work, a low-cost design of a compact, broadband, spline-parameterized monopole antenna has been considered. The framework used for the structure design implements trust-region-based methods,...
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Current Trends in Wick Structure Construction in Loop Heat Pipes Applications: A Review
PublikacjaThermal control systems have been introduced as an important part of electronic devices, enabling thermal management of their electronic components. Loop heat pipe (LHP) is a passive two-phase heat transfer device with significant potential for numerous applications, such as aerospace applications, high-power LEDs, and solar central receivers. Its advantages are high heat transfer capability, low thermal resistance, long-distance...
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Seismic damage diagnosis in adjacent steel and RC MRFs considering pounding effects through improved wavelet-based damage-sensitive feature
PublikacjaThis paper aims to propose complex Morlet (cmorfb-fc) wavelet-based refined damage-sensitive feature (rDSF) as a new and more precise damage indicator to diagnose seismic damages in adjacent steel and Reinforced Concrete (RC) Moment Resisting Frames (MRFs) assuming pounding conditions using acceleration responses. The considered structures include 6- and 9-story steel and 4- and 8-story RC benchmark MRFs that are assumed to have...
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Comparative Analysis of Developed Rainfall Intensity–Duration–Frequency Curves for Erbil with Other Iraqi Urban Areas
PublikacjaRainfall Intensity–Duration–Frequency (IDF) relationships are widely used in water infrastructure design and construction. IDF curves represent the relationship between rainfall intensity, duration, and frequency, and are obtained by analyzing observed data. These relationships are critical for the safe design of flood protection structures, storm sewers, culverts, bridges, etc. In this study, the IDF curves and empirical IDF formulas...
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Influence of soil anisotropic stiffness on the deformation induced by an open pit excavation.
PublikacjaIn 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...
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Investigation of use of hydrophilic/hydrophobic NADESs for selective extraction of As(III) and Sb(III) ions in vegetable samples: Air assisted liquid phase microextraction and chemometric optimization
PublikacjaIn this paper, a green, cost-effective sample preparation method based on air assisted liquid phase microextraction (AA-LPME) was developed for the simultaneous extraction of As(III) and Sb(III) ions from vegetable samples using hydrophilic/hydrophobic natural deep eutectic solvents (NADESs). Central composite design was used for the optimization of extraction factors including NADES volume, extraction cycle, pH, and curcumin concentration....
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Structural and physical characterization of NpPt2In7
PublikacjaA new neptunium intermetallic compound, NpPt2In7, has been synthesized in polycrystalline form and characterized by several macroscopic techniques. A Rietveld analysis of its powder x-ray diffraction pattern shows that NpPt2In7 crystallizes in a tetragonal lattice with I4/mmm symmetry and lattice parameters a = 4.58471(3) Å, c = 21.5065(3) Å. Magnetic susceptibility, electrical resistivity, Hall effect, and heat capacity measurements indicate...
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Density, sound velocity, viscosity, and refractive index of new morpholinium ionic liquids with amino acid-based anions: Effect of temperature, alkyl chain length, and anion
PublikacjaIn this work, room temperature synthesis of twenty new ionic liquids (ILs) based on the N-alkyl-N-methylmorpholinium ([Mor1,R], R = 2, 3, 4, 6, 8) cation and N-acetyl-L-amino acid anions (L-alaninate, L-valinate, L-leucinate, L-isoleucinate) was described. The synthesized ILs were characterized by various spectroscopic techniques and high-resolution mass spectrometry. Furthermore, density (ρ), sound velocity (v), viscosity (η)...
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ECHOES REDUCTION DURING DIGITAL DATA TRANSMISSION IN HYDROACOUSTIC CHANNEL – LABORATORY EXPERIMENT
PublikacjaThe possibility of using a hydroacoustic channel for digital data transmission is very limited. This is due to the effect of multipath propagation of the emitted acoustic wave and the damping of the mechanical wave in this medium, which increase with frequency. The first of these phenomena results in inter-symbol interference disturbances in data transmission systems, including even hundreds of symbols. Due to the number of reflections...
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Performance analyses of helical coil heat exchangers. The effect of external coil surface modification on heat exchanger effectiveness
PublikacjaThe shell and coil heat exchangers are commonly used in heating, ventilation, nuclear industry, process plant, heat recovery and air conditioning systems. This type of recuperators benefits from simple construction, the low value of pressure drops and high heat transfer. In helical coil,centrifugal force is acting on the moving fluid due to the curvature of thetube results in the development. It has been long recognized that the...
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Pressure effects on the superconductivity of the HfPd2Al Heusler compound: Experimental and theoretical study
PublikacjaPolycrystalline HfPd2Al has been synthesized using the arc-melting method and studied under ambient-pressure conditions by x-ray diffraction from room temperature up to 450 °C. High-pressure x-ray diffraction up to 23 GPa was also performed using Diacell-type membrane diamond anvil cells. The estimated linear thermal expansion coefficient was found to be α=1.40(3)×10−5K−1, and the bulk modulus derived from the fit to the third-order...
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Development of an orbital shaker-assisted fatty acid-based switchable solvent microextraction procedure for rapid and green extraction of amoxicillin from complex matrices: Central composite design
PublikacjaIn this study, a cheap, fast and simple orbital shaker-assisted fatty acid-based switchable solvent microextraction (OS-FASS-ME) procedure was developed for the extraction of amoxicillin (AMOX) in dairy products, pharmaceutical samples and wastewater prior to its spectrophotometric analysis. Fatty acid-based switchable solvents were investigated for extracting AMOX. The key factors of the OS-FASS-ME procedure were optimized using...
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Estimates for minimal number of periodic points for smooth self-maps of simply-connected manifolds
Dane BadawczeWe consider a closed smooth connected and simply-connected manifold of dimension at least 4 and its self-map f. The topological invariant Dr[f] is equal to the minimal number of r-periodic points in the smooth homotopy class of f. We assume that r is odd and all coefficients b(k) of so-called periodic expansion of Lefschetz numbers of iterations are...
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The Chow Ring of flag manifolds
Dane BadawczeSchubert calculus is the intersection theory of 19th century. Justifying this calculus is the content of the 15th problem of Hilbert. In the course to establish the foundation of algebraic geometry, Van der Vaerden and A. Weil attributed the problem to the determination of the chow ring of flag manifolds G/P, where G is a compact Lie group and P is...
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Description of symmetrical prolate ellipsoid magnetic signature parameters-Be = 50 mT, I = 70 deg, z = 50 m, q = 80 deg, j = 45 deg, a =4 m, e = 8, mr = 100
Dane BadawczeThe Earth magnetic field (Fig.1): BE – total magnetic flux density, BEx – x component of the Earth magnetic flux density, BEy = 0 y component of the Earth magnetic flux density, BEz – z component of the Earth magnetic flux density, I – the inclination of the Earth magnetic field.
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Description of symmetrical prolate ellipsoid magnetic signature parameters-Be = 50 mT, I = 70 deg, z = 100 m, q = 90 deg, j = 135 deg, a =4 m, e = 1, mr = 100
Dane BadawczeThe Earth magnetic field (Fig.1): BE – total magnetic flux density, BEx – x component of the Earth magnetic flux density, BEy = 0 y component of the Earth magnetic flux density, BEz – z component of the Earth magnetic flux density, I – the inclination of the Earth magnetic field.
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Description of symmetrical prolate ellipsoid magnetic signature parameters-Be = 50 mT, I = 70 deg, z = 10 m, q = 100 deg, j = 45 deg, a =4 m, e = 4, mr = 100
Dane BadawczeThe Earth magnetic field (Fig.1): BE – total magnetic flux density, BEx – x component of the Earth magnetic flux density, BEy = 0 y component of the Earth magnetic flux density, BEz – z component of the Earth magnetic flux density, I – the inclination of the Earth magnetic field.
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Description of symmetrical prolate ellipsoid magnetic signature parameters-Be = 50 mT, I = 70 deg, z = 20 m, q = 100 deg, j = 45 deg, a =4 m, e = 8, mr = 100
Dane BadawczeThe Earth magnetic field (Fig.1): BE – total magnetic flux density, BEx – x component of the Earth magnetic flux density, BEy = 0 y component of the Earth magnetic flux density, BEz – z component of the Earth magnetic flux density, I – the inclination of the Earth magnetic field.
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Description of symmetrical prolate ellipsoid magnetic signature parameters-Be = 50 mT, I = 70 deg, z = 200 m, q = 90 deg, j = 45 deg, a =4 m, e = 1, mr = 100
Dane BadawczeThe Earth magnetic field (Fig.1): BE – total magnetic flux density, BEx – x component of the Earth magnetic flux density, BEy = 0 y component of the Earth magnetic flux density, BEz – z component of the Earth magnetic flux density, I – the inclination of the Earth magnetic field.
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Description of symmetrical prolate ellipsoid magnetic signature parameters-Be = 50 mT, I = 70 deg, z = 50 m, q = 100 deg, j = 45 deg, a =4 m, e = 8, mr = 100
Dane BadawczeThe Earth magnetic field (Fig.1): BE – total magnetic flux density, BEx – x component of the Earth magnetic flux density, BEy = 0 y component of the Earth magnetic flux density, BEz – z component of the Earth magnetic flux density, I – the inclination of the Earth magnetic field.
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Description of symmetrical prolate ellipsoid magnetic signature parameters-Be = 50 mT, I = 70 deg, z = 200 m, q = 80 deg, j = 45 deg, a =4 m, e = 8, mr = 100
Dane BadawczeThe Earth magnetic field (Fig.1): BE – total magnetic flux density, BEx – x component of the Earth magnetic flux density, BEy = 0 y component of the Earth magnetic flux density, BEz – z component of the Earth magnetic flux density, I – the inclination of the Earth magnetic field.
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Description of symmetrical prolate ellipsoid magnetic signature parameters-Be = 50 mT, I = 70 deg, z = 100 m, q = 90 deg, j = 45 deg, a =4 m, e = 4, mr = 100
Dane BadawczeThe Earth magnetic field (Fig.1): BE – total magnetic flux density, BEx – x component of the Earth magnetic flux density, BEy = 0 y component of the Earth magnetic flux density, BEz – z component of the Earth magnetic flux density, I – the inclination of the Earth magnetic field.
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Description of symmetrical prolate ellipsoid magnetic signature parameters -Be = 50 mT, I = 70 deg, z = 10 m, q = 80 deg, j = 45 deg, a =4 m, e = 8, mr = 100
Dane BadawczeThe Earth magnetic field (Fig.1): BE – total magnetic flux density, BEx – x component of the Earth magnetic flux density, BEy = 0 y component of the Earth magnetic flux density, BEz – z component of the Earth magnetic flux density, I – the inclination of the Earth magnetic field.
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Description of symmetrical prolate ellipsoid magnetic signature parameters-Be = 50 mT, I = 70 deg, z = 100 m, q = 100 deg, j = 45 deg, a =4 m, e = 8, mr = 100
Dane BadawczeThe Earth magnetic field (Fig.1): BE – total magnetic flux density, BEx – x component of the Earth magnetic flux density, BEy = 0 y component of the Earth magnetic flux density, BEz – z component of the Earth magnetic flux density, I – the inclination of the Earth magnetic field.
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Description of symmetrical prolate ellipsoid magnetic signature parameters-Be = 50 mT, I = 70 deg, z = 20 m, q = 100 deg, j = 90 deg, a =4 m, e = 4, mr = 100
Dane BadawczeThe Earth magnetic field (Fig.1): BE – total magnetic flux density, BEx – x component of the Earth magnetic flux density, BEy = 0 y component of the Earth magnetic flux density, BEz – z component of the Earth magnetic flux density, I – the inclination of the Earth magnetic field.
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Description of symmetrical prolate ellipsoid magnetic signature parameters-Be = 50 mT, I = 70 deg, z = 10 m, q = 90 deg, j = 45 deg, a =4 m, e = 4, mr = 100
Dane BadawczeThe Earth magnetic field (Fig.1): BE – total magnetic flux density, BEx – x component of the Earth magnetic flux density, BEy = 0 y component of the Earth magnetic flux density, BEz – z component of the Earth magnetic flux density, I – the inclination of the Earth magnetic field.
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Description of symmetrical prolate ellipsoid magnetic signature parameters-Be = 50 mT, I = 70 deg, z = 200 m, q = 80 deg, j = 45 deg, a =4 m, e = 4, mr = 100
Dane BadawczeThe Earth magnetic field (Fig.1): BE – total magnetic flux density, BEx – x component of the Earth magnetic flux density, BEy = 0 y component of the Earth magnetic flux density, BEz – z component of the Earth magnetic flux density, I – the inclination of the Earth magnetic field.
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Description of symmetrical prolate ellipsoid magnetic signature parameters-Be = 50 mT, I = 70 deg, z = 10 m, q = 90 deg, j = 45 deg, a =4 m, e = 8, mr = 100
Dane BadawczeThe Earth magnetic field (Fig.1): BE – total magnetic flux density, BEx – x component of the Earth magnetic flux density, BEy = 0 y component of the Earth magnetic flux density, BEz – z component of the Earth magnetic flux density, I – the inclination of the Earth magnetic field.