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Search results for: directional coupler
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Obesity and hypertension—the issue is more complex than we thought
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Technological and tribological aspects of milling-burnishing process of complex surfaces
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On the use of instantaneous complex frequency for analysis and modification of simple sounds
PublicationW pracy przedstawiono możliwości wykorzystania zespolonej pulsacji chwilowej do analizy i modyfikacji prostych dźwięków. Opisywany algorytm składa się z dwóch kroków: bifaktoryzacji sygnału na obwiednię minimalnofazową i fazor dodatnipskrętny, a następnie estymacja i modyfikacja zespolonej pulsacji chwilowej obu czynników faktoryzacji.
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Numerical investigation on the performance of a small counter-rotating wind turbine
PublicationThe article presents the results of the investigation on the performance of a small counter-rotating wind turbine. The wind turbine has been simulated using Computational Fluid Dynamics methods. Actuator Line Model has been successfully used to represent rotors in the computational domain. A parametric study has been carried out, taking into account changes in the tip speed ratio of the rotors while maintaining a constant distance...
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Numerical analysis of the ostiomeatal complex aeration using the CFD method
PublicationWe aimed to analyse ostiomeatal complex (OMC) aeration using the computational fluid dynamics (CFD) method of simulation based on human craniofacial computed tomography (CT) scans. The analysis was based on CT images of 2 patients: one with normal nose anatomy and one with nasal septal deviation (NSD). The Reynolds-Average Simulation approach and turbulence model based on linear eddy viscosity supplemented with the two-equation...
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Relatively high-Seebeck thermoelectric cells containing ionic liquids supplemented by cobalt redox couple
PublicationMeanwhile no general and reliable equation determining the Seebeck coefficient (S e ) and involving electro-chemical reaction effects was derived for solutions. We reported the database of 15,000 ionic liquids supplemented by three different redox couple systems: 0.01 mol/l Co 3+/2+ (bpy) 3 , 0.01 mol/l I 3-/3I- and 0.2 mol/l 3- /3I- , and the corresponding estimated Seebeck coefficients. We also reported methods for estimating...
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Buckling Analysis of a Micro Composite Plate with Nano Coating Based on the Modified Couple Stress Theory
PublicationThe present study investigates the buckling of a thick sandwich plate under the biaxial non-uniform compression using the modified couple stress theory with various boundary conditions. For this purpose, the top and bottom faces are orthotropic graphene sheets and for the central core the isotropic soft materials are investigated. The simplified first order shear deformation theory (S-FSDT) is employed and the governing differential...
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Cloud-to-ground lightning dipole moment from simultaneous observations by ELF receiver and combined direction finding and time-of-arrival lightning detection system
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Chemical kinetic approach to the mechanism of coupled transport of Cu(II) Ions through bulk liquid membranes
PublicationW celu lepszego zrozumienia transportu jonów miedzi przez ciekłe membrany zaproponowano schemat kinetyczny na poziomie molekularnym oparty o dwie nastepujące po sobie reakcje odwracalne. Zasegurowano uzywając membrany ciekłej o wysokiej polarności i polaryzowalności oraz szybkiego mieszania mozna zwiekszyć wydajnośc transportu.
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Wave-induced stress and breaking of sea ice in a coupled hydrodynamic discrete-element wave–ice model
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Rapid assessment of the authenticity of limequat fruit using the electronic nose and gas chromatography coupled with mass spectrometry
PublicationCitrus fruits are very popular food products. There are many species and varieties of them. There are also documented cases of some citrus fruits causing a severe allergic reaction. Some species of the citrus fruits, especially hybrid ones show a reduced allergenic effect due to the lack of seeds. There is a need for rapid methods for evaluation of citrus’ botanical origin. During research, the headspace of three citrus fruits...
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Inverse modeling for fast design optimization of small-size rat-race couplers incorporating compact cells
PublicationIn the paper, a framework for computationally-efficient design optimization of compact rat-race couplers (RRCs) is discussed. A class of hybrid RRCs with variable operating conditions is investigated, whose size reduction is obtained by replacing ordinary transmission lines with compact microstrip resonant cells (CMRCs). Our approach employs a bottom-up design strategy leading to the development of compact RRCs through rapid design...
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Rapid Design Tuning of Miniaturized Rat-Race Couplers Using Regression-Based Equivalent Network Surrogates
PublicationA simple technique for fast design tuning of compact rat-race couplers is presented. Our approach involves equivalent circuit representation, corrected by nonlinear functions of frequency with coefficients extracted through nonlinear regression. At the same time, the tuning process connects two levels of coupler representation: EM simulation of the entire circuit and re-optimization of the coupler building blocks (slow-wave cells...
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Thermal analysis of macro-encapsulated phase change material coupled with domestic gas heater for building heating
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New bulk liquid membrane oscillator composed of two coupled oscillators with diffusion-mediated physical coupling
PublicationA new type of bulk liquid membrane system, which represents the first example of a bulk liquid membrane oscillator characterised by the presence of two coupled oscillators, is described. When the benzyldimethyltetradecylammonium chloride surfactant undergoes an oscillatory mass transfer through a nitromethane liquid membrane, a new liquid layer (phase X) appears between the membrane and the acceptor phase. Kinetic analysis provides...
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HPLC-coupled post-column derivatization aims at characterization and monitoring of plant phytocomplexes, not at assessing their biological properties
PublicationTwo recent decades of research identified a number of environmental factors as well as mechanisms leading to pathogenic processes in the human organism. A common factor in pathogenesis of many diseases is oxidative stress, a condition in which the production of damaging reactive oxygen species (ROS), present in the body as an inevitable consequence of respiration and exacerbated by the inflammatory response and by exogenous factors...
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Rapid simulation-driven design of miniaturised dual-band microwave couplers by means of adaptive response scaling
PublicationOne of the major challenges in the design of compact microwave structures is the necessity of simultaneous handling of several objectives and the fact that expensive electromagnetic (EM) analysis is required for their reliable evaluation. Design of multi-band circuits where performance requirements are to be satisfied for several frequencies at the same time is even more difficult. In this work, a computationally efficient design...
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Thermal degradation assessment of canola and olive oil using ultra-fast gas chromatography coupled with chemometrics
PublicationOil blending is often used to enhance the properties of vegetable oils. The admixture of a more thermally stable oil makes the resulting blend more suitable for use in frying. A new method of quality assessment of vegetable oils used in frying is presented in this paper. In this method, ultra-fast gas chromatography coupled with flame ionization detector and chemometrics is employed. Principal component analysis was used for data...
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Coupled-Resonator Waveguide Filter in Quadruplet Topology With Frequency-Dependent Coupling - A Design Based on Coupling Matrix
PublicationThis letter presents an application of a recently developed coupling matrix synthesis technique to design of coupled-resonator filters with dispersive inter-resonator couplings. This technique is used to design a novel coupled-cavity bandpass filter. Measurements validate the design and confirm effectiveness of the synthesis method. The filter is a four-pole generalized Chebyshev filter with three transmission zeros. Resonators...
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DISPERSIVE LIQUID-LIQUID MICROEXTRACTION COUPLED WITH MICRO-VOLUME SPECTROPHOTOMETRY FOR DETERMINATION OF TOTAL IODINE IN URINE SAMPLES
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Ecology In Tribology: Selected Problems of Eliminating Natural Oil-Based Lubricants from Machine Friction Couples
PublicationThe elimination of mineral oil-based lubricants from machines has multiple beneficial effects on the natural environment. Firstly – these lubricants are a direct threat to the environment in the event of leaks; secondly – their elimination reduces the demand for crude oil from which they are obtained. In addition, in many cases, e.g. when replacing traditional lubricants with water, friction losses in the bearings can also be reduced...
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Novel composite of Zn/Ti-layered double hydroxide coupled with MXene for the efficient photocatalytic degradation of pharmaceuticals
PublicationIn the present study, a hybrid photocatalyst of Zn/Ti layered double hydroxide (LDH) coupled with MXene – Ti3C2 was synthesized for the first time and applied in photocatalytic degradation of acetaminophen and ibuprofen, two commonly present in the natural environment and prone to accumulate in the aquatic ecosystem pharmaceuticals. The effect of MXene content (0.5 wt%, 2.5 wt%, and 5 wt%) on the photocatalytic activity of LDH/MXene...
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Modelling of Capillary Pressure-driven Water Flow in Unsaturated Concrete Using Coupled DEM/CFD Approach.
PublicationSformułowano nowatorskie, połączone podejście do modelowania dwufazowego przepływu wody napędzanego kapilarami w nienasyconym betonie. Dzięki połączeniu metody elementów dyskretnych (DEM) z obliczeniową dynamiką płynów (CFD) w warunkach izotermicznych proces został zbadany numerycznie w mezoskali w warunkach dwuwymiarowych. Niewielkie próbki betonu o uproszczonej mezostrukturze cząstek poddano w pełni sprzężonym hydromechanicznym...
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FE analysis of a coupled energetic-statistical size effect in plain concrete beams with varying material properties.
PublicationThe numerical FE investigations of a coupled energetic-statistical size effect in unnotched concrete beams of similar geometry under quasi-static three point bending were performed within elasto-plasticity with non-local softening. The stochastic FE analyses were carried out with three different beam sizes. Deterministic calculations were performed with the uniform distribution of a uniaxial tensile strength. In statistical calculations...
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Simulations of hydro-fracking in rock mass at meso-scale using fully coupled DEM/CFD approach
PublicationThe paper deals with two-dimensional (2D) numerical modelling of hydro-fracking (hydraulic fracturing) in rocks at the meso-scale. A numerical model was developed to characterize the properties of fluid-driven fractures in rocks by combining the discrete element method (DEM) with computational fluid dynamics (CFD). The mechanical behaviour of the rock matrix was simulated with DEM and the behaviour of the fracturing fluid flow...
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Effect of gas content in macropores on hydraulic fracturing in rocks using a fully coupled DEM/CFD approach
PublicationW pracy skupiono się na wpływie zawartości gazu w makroporach skał na proces szczelinowania hydraulicznego. Proces został zasymulowany przez połączenie metody elementów dyskretnych (DEM) z obliczeniową dynamiką płynów (CFD) w ramach dwuwymiarowych (2D) warunków izotermicznych. Mechaniczne zachowanie skały zostało zasymulowane za pomocą DEM, a CFD została wykorzystana do opisu zachowanie przepływu laminarnego, dwufazowego płynu...
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FE-analysis of the beaviour of concrete elements with coupled elasto-plastic-damage models with non-local softening
PublicationArtykuł omawia wyniki symulacji zachowania sie elementów betonowych poddanych cyklicznemu obciążeniu. Do symulacji zastosowano połączone modele sprężysto-plastyczne z degradacją sztywności i z nielokalnym osłabieniem. Wyniki symulacji porównano z doswiadczeniami.
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Analysis of concrete behaviour under cycling within coupled elasto-plastic-damage with non-local softening
PublicationArtykuł omawia wyniki symulacji zachowania sie elementów betonowych poddanych cyklicznemu obciążeniu. Do symulacji zastosowano 3 połączone modele sprężysto-plastyczne z degradacją sztywności i z nielokalnym osłabieniem. Wyniki symulacji porównano z doświadczeniami laboratoryjnymi..
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Parametric FE studies on a coupled energetic-statistical size effect in plain concrete beams under bending
PublicationW artykule omówiono wyniki połączonego deterministyczno-statystycznego efektu skali w betonowych belkach podczas zginania. Obliczenia wykonano stosując MES w zakresie sprężysto-plastyczności z nielokalnym osłabieniem. Obliczenia wykonano dla różnych długości korelacji i współczynnika zmienności.
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Coupled DEM/CFD analysis of impact of free water on the static and dynamic response of concrete in tension regime
PublicationW tym artykule zbadano numerycznie quasi-statyczne i dynamiczne zachowanie częściowo nasyconego płynem betonu w warunkach dwuwymiarowego (2D) jednoosiowego rozciągania w mezoskali. Obliczono, jaki wpływ ma zawartość wolnego płynu porowego (gazu i wody) na proces pękania i wytrzymałość betonu w rozciąganiu. Do symulacji zachowania betonu całkowicie i częściowo nasyconego płynem w warunkach quasi-statycznych i dynamicznych wykorzystano...
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Hard anodization of copper in potassium carbonate aqueous solution
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Copper(I) iodide ribbons coordinated with thiourea derivatives
PublicationTwo products of the reactions of CuI with 1-benzoyl-3-(4-bromophenyl)thiourea and with 1-benzoyl-3-(2-iodophenyl)thiourea have been obtained and characterized, namely poly[[[1-benzoyl-3-(4-bromophenyl)thiourea-κS]-µ3-iodidocopper(I)] acetone hemisolvate], {[CuI(C₁₄H₁₁BrN₂OS)]‧0.5C₃H₆O}ₙ, and poly-[µ₄-iodido-µ₃-iodido-[N-(benzo[d]thiazol-2-yl)benzamide-κN]dicopper(I)], [Cu₂I₂(C₁₄H₁₀N₂OS)]ₙ. Their structures, determined by single-crystal...
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Copper containing protein sites - structure, properties and models
PublicationEnzymy organizmów żywych katalizują wiele reakcji stosowanych w przemyśle chemicznym. Przykładem potencjalnego zastosowania enzymu w produkcji jest synteza L-Dopy przy udziale tyrozynazy. Ze względu na możliwe praktyczne zastosowanie w katalizie, otrzymano i opisano wiele prostych modeli miejsc aktywnych enzymów. W artykule opisano niektóre modele białek zawierających miedź.
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Diffusion length of singlet excitons in copper phthalocyanine films
PublicationPraca przedstawia metodę określania długości drogi dyfuzji ekscytonów w oparciu o widmo fotoprądu. W pracy podana jest szacunkowa wartość drogi dyfuzji ekscytonów singletowych w próżniowo naparowanej warstwie ftalocyjaniny miedzi.
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Studies of the aromatic β-diketones as extractant of copper ions
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The Teutonic crusade in Prussia: reconstruction of a medieval fortified settlement complex at Unisław
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Pitch shifter with complex instantaneous frequency rescaling and direct digital synthesis
PublicationW artykule zaprezentowano nowy przesuwnik wysokości dźwięku ze skalowaniem częstotliwości chwilowej i z syntezą bezpośrednią. Jest on przeznaczony do komponowania melodii np. w telefonie komórkowym. Implementacja przesuwnika jest oparta na twierdzeniu Bedrosiana, zastosowanego do zespolonego odpowiednika hilbertowskiego przetwarzanego sygnału rzeczywistego. Filtr Hilberta pełni tu też dodatkową rolę. Jest nią filtracja antyaliasingowa....
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Thermally stimulated currents in amorphous solids due to complex heating regimes
PublicationPodano opis teoretyczny prądów termicznie stymulowanych w ciałach amorficznych. Dokonano rozszerzenia istniejących wzorów przybliżonych na przypadki opóźnionego i krokowego ogrzewania próbki. Otrzymane wyrażenia zweryfikowano za pomocą obliczeń numerycznych dla przypadku wykładniczego rozkładu pułapek.
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Simulation modelling for managing complex systems: case study for maintenance services.
PublicationModelowanie symulacyjne zyskuje sobie pozycje najważniejszego narzędzia w obszarze zarządzania wiedzą i informacją. W pracy przedstawiono zastosowanie modelowania symulacyjnego w zarządzaniu przepływem informacji w systemach złożonych. Posłużono się przykładem serwisu eksploatacji i przeglądów remontowych dla pięciu geograficznie rozproszonych przedsiębiorstw.
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Thermodynamic and electrostatic properties of ternary Oxytricha nova TEBP-DNA complex
PublicationZa pomocą metod chemi obliczeniowej badano właściwości molekularne kompleksu telomerowego białka TEBP z Oxytricha nova w kompleksie trójskkładnikowym z DNA o sekwencji telomerowej. Wyliczone wartości energii kompleksowania wskazują specyficznie na jedną z dróg tworzenia kompleksu, gdzie wpierw podjednostka alfa łaczy się z DNA a następnie podjednostka beta dołącza się do takiego dwuskładnikowego kompleksu. Policzone rozkłady molekularnego...
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Selected mitochondrial genes as species markers of the Arctic Contracaecum osculatum complex
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Ontology Oriented Approach to Service Selection and Invocation in Complex Context Analysis
PublicationContext-aware applications running in the intelligent space are taken into account and their execution in the service oriented environment is considered. It has been presented where and how SOA services can be utilized during their execution: to analyze current context of the application and to support execution of strictly determined actions suitable for that context. The proposed mechanism of context-aware service selection and...
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Magnetic properties of charge ordered complex TCNQ salts with lattice distortions
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FPGA computation of magnitude of complex numbers using modified CORDIC algorithm
PublicationIn this work we present computation of the magnitude of complex numbers using a modified version of the CORDIC algorithm that uses only five iterations. The relationship between the computation error and the number of CORDIC iterations are presented for floating-point and integer arithmetics. The proposed modification of CORDIC for integer arithmetic relies upon the introduction of correction once basic computations are performed...
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Efficient Complex Root Finding Algorithm for Microwave and Optical Propagation Problems
PublicationArticle relates to the use of innovative root finding algorithm (on a complex plane) to study propagation properties of microwave and optical waveguides. Problems of this type occur not only in the analysis of lossy structures, but also in the study of complex and leaky modes (radiation phenomena). The proposed algorithm is simple to implement and can be applied for functions with singularities and branch cuts in the complex plane...
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Measurement of complex refractive index of human blood by low-coherence interferometry
PublicationIn this article, the usefulness of the optical technique for measurements of blood complex refractive index has been examined. Measurement of optical properties of human blood is difficult to perform because of its nonuniform nature. However, results of my investigation have shown the usefulness of low-coherencei nterferometry for measurement complex refractive index of human blood. Furthermore, mathematical analysis of spectrum...
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Complex Monitoring of the Coastal Cliffs on the Example of Cliff in Jastrzebia Gora, Poland
PublicationThe cliff coasts, which are in total about 100 km long, are especially vulnerable to abrasion. The mean regression of the studied object which is the seacliff in Jastrzebia Gora depends on time. For example, from 1875 to 1937 the cliff regress 90 m in mean pace of 1.4 meter a year. Besides of natural factors causing the degradation, there is also an anthropogenic activity, which speeds up the abrasion process. Based on these informations,...
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A Stabilized Complex LOBPCG Eigensolver for the Analysis of Moderately Lossy EM Structures
PublicationThis letter proposes a stabilized locally optimal block preconditioned conjugate gradient method for computing selected eigenvalues for complex symmetric generalized non-Hermitian eigenproblems. Effectiveness of the presented approach is demonstrated for a moderately lossy dual-mode dielectric resonator, modeled using finite-element method with higher order elements
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Tracts of high or low sequence divergence in the mouse major histocompatibility complex.
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Counter-ion effect on antistaphylococcal activity and cytotoxicity of selected antimicrobial peptides
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