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Search results for: symmetric extendibility
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Selective Harmonic Elimination PWM For a Cascaded Multi-level Inverter
PublicationThis paper deals with the selective harmonic elimination pulse width modulation (SHE-PWM) technique. This technique is used for the elimination of selected dominant low order harmonics in the multi-level inverter output voltage. The presence of these harmonics is the essential drawback of such kind of inverters; especially when it is used for the control of different AC drivers. The SHE-PWM is based...
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Schemes of transmission of classical information via quantum channels with many senders: Discrete- and continuous-variable cases
PublicationSuperadditivity effects in the classical capacity of discrete multiaccess channels and continuous variable (CV) Gaussian MACs are analyzed. Several examples of the manifestation of superadditivity in the discrete case are provided, including, in particular, a channel which is fully symmetric with respect to all senders. Furthermore, we consider a class of channels for which input entanglement across more than two copies of the...
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Algorytmy wyodrębniania składowych symetrycznych sygnału pomiarowego napięcia w przypadku asymetrii sieci trójfazowej
PublicationW artykule zaprezentowano działanie wybranych algorytmów wykorzystywanych do wyodrębniania składowych symetrycznych z sygnałów pomiarowych napięcia lub prądu w przypadku wystąpienia asymetrii trójfazowej sieci elektroenergetycznej. Weryfikacji działania algorytmów dokonano na podstawie badań symulacyjnych i laboratoryjnych w układzie w którym jako odbiornik zastosowano stojan maszyny asynchronicznej pierścieniowej. Określono wpływ...
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RADIATION OF HIGH INTENSITY SOUND BY CIRCULAR DISC BY MEANS OF THE NUMERICAL METHOD
PublicationThe main goal of this paper is to find sound pressure distribution radiated by the circular piezoelectric disc that vibrates with the finite amplitude. There has been presented the pressure distribution close to the radiating surface. Also it is shown the sound pressure distribution in the 3D form. The mathematic modeling was carried out on the base of the nonlinear acoustic equation with the proper boundary condition. The axial...
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Nośność kotew wklejanych w elementy wapienno-piaskowe drążone pionowo
PublicationW artykule przedstawiono wyniki pomiarów skuteczności montażu kotew wklejanych osadzonych w drążonych pionowo blokach wapienno - piaskowych. Badania wykonano dla przypadków montażu kotew w różnych fragmentach bloków: w części pełnościennej, w osi symetrii oraz na krawędzi otworu pionowego. Przebadano wpływ lokalizacji miejsc osadzenia kotew na sposób kształtowania się połączenia między żywicą a materiałem bloku. Główny nacisk...
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(7Z,7'Z)-7,7'-(1,2,4-trithiolane-3,5-diylidene)bis[2-methylquinolin-8(7H)-one] chloroform disolvate
PublicationTytułowy związek, C22H14N2O2S3*2CHCl3 został otrzymany jako produkt reakcji pomiędzy kwasem 8-hydroksy-2-metylochinolinokarboditionowym a trifluorooctanem magnezu (lub manganu). Procesy utlenienia oraz eliminacji siarki spowodowały kondensację dwóch cząsteczek kwasu z wytworzeniem pięcioczłonowego aromatycznego pierścienia heterocyklicznego S3C2 (tritiolanu). Cząsteczka wykazuje symetrię C2. Związek ko-krystalizuje z dwoma cząsteczkami...
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Characterizing the Performance of <span class="sc">xor</span> Games and the Shannon Capacity of Graphs
PublicationIn this Letter we give a set of necessary and sufficient conditions such that quantum players of a two-party xor game cannot perform any better than classical players. With any such game, we associate a graph and examine its zero-error communication capacity. This allows us to specify a broad new class of graphs for which the Shannon capacity can be calculated. The conditions also enable the parametrization of new families of games...
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Sensitivity analysis of critical loads of I-columns
PublicationThe first order variation of critical buckling load of thin-walled columns with bisymmetric open cross-section due to some variations of the design variables such as: cross-section dimensions, or material characteristics is derived. The influence of the residual welding stresses is taken into account. In the numerical examples dealing with I-column the functions describing the effect of the variation of the dimensions of the flange...
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Experimental study of the post tensioned prestressed concrete corbels
PublicationThe results of experimental investigation of 6 symmetrical double prestressed corbels of variable shear span to depth ratio and variable location of prestressing bars are presented in the paper. The post ten- sioned corbels were prestressed with Macalloy 1030 bars of 25 mm in diameter. The results of the tests were compared with the cracking and load carrying capacity of corbels reinforced with passive reinforce- ment. As a result...
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A NOTE ON ON-LINE RAMSEY NUMBERS FOR QUADRILATERALS
PublicationWe consider on-line Ramsey numbers defined by a game played between two players, Builder and Painter. In each round Builder draws an the edge and Painter colors it either red or blue, as it appears. Builder’s goal is to force Painter to create a monochromatic copy of a fixed graph H in as few rounds as possible. The minimum number of rounds (assuming both players play perfectly) is the on-line Ramsey number \widetilde{r}(H) of...
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Design and optimization of a novel miniaturized low-profile circularly polarized wide-slot antenna
PublicationThis paper presents a novel structure of a compact circularly polarized (CP) antenna. CP is obtained using a parasitic quasi-rectangular strip placed coplanar to the feedline. A ground plane perturbation combined with the asymmetric geometry of the coplanar waveguide ground planes is utilized to excite additional CP modes. All antenna dimensions are rigorously optimized to achieve the best possible performance in terms of the impedance...
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2-D constitutive equations for orthotropic Cosserat type laminated shells in finite element analysis
PublicationWe propose 2-D Cosserat type orthotropic constitutive equations for laminated shells for the purpose of initial failure estimation in a laminate layer. We use nonlinear 6-parameter shell theory with asymmetric membrane strain measures and Cosserat kinematics as the framework. This theory is specially dedicated to the analysis of irregular shells, inter alia, with orthogonal intersections, since it takes into account the drilling...
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Synergic Effect of Naphthylated Carbon Nanotubes and Gold Nanoparticles on Catalytic Performance of Hybrid Films Containing Bilirubin Oxidase for the Dioxygen Reduction
PublicationTo improve the direct electron transfer from a multicopper oxidase MvBOd to the glassy carbon electrode surface the naphthylated multiwall carbon nanotubes (Napht-MWCNTs) are ombined with gold nanoparticles (AuNPs) to form a conductive network at the electrode and to increase its working surface. Such approach allowed to eliminate the necessity of employing mediators to reach elevated current values. The enzyme stability was improved...
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The modyfication of the dynamic characteristics of vibratory conveyor
PublicationThe vibratory conveyors are used in the industry for continuous transportation of loose substances on distance up to 20meters. These conveyors are often suspended on expensive and massive frames, which are softly vibroisolated from the ground. As a result, they transfer significant dynamic forces on the ground. In case of 5 - 20 meter-long devices, the biggest construction problems are proper vibrations of the panel caused by bilateral...
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Action-reaction based synthesis of acoustic wavefield equations
PublicationThe analysis of acoustic fields is usually based on the well-known mathematics of second order partial differential equations called wave equations. The author explores the duality and symmetry of linear fluid mechanics and develops two distinct equations of acoustics on the basis of a causal approach to local small-scale phenomena. Wavefields that are solutions of these equations have different composition, the spherical pressure...
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Development of the sound field 3D intensity probe based on miniature microphones
PublicationThe engineered measuring probe uses three pairs of miniature microphones coupled. The signals from the microphones after an initial amplification are fed to differential circuits. Due to the required symmetry of the circuit it was necessary to select electronic components very carefully. Moreover, additional digital signal processing techniques were applied to avoid amplitude and phase mismatch. The view of the engineered probe...
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NANOCRYSTALLINE CATHODES FOR SOLID OXIDE FUEL CELLS MADE OF NOBLE METALS
PublicationCathodes for solid oxide fuel cells prepared by the infiltration method at 600 °C are presented. The infiltration method allows to produce stable, nanostructured electrodes. Cathodes were prepared using gold, platinum, La2NiO4+δ (L2N) and La0.6Sr0.4Co0.2Fe0.8O3 δ (LSCF). Symmetrical cathode/electrolyte/cathode samples were prepared and examined with SEM microscopy and electrochemical impedance spectroscopy. Despite successful deposition...
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Effect of adhesive compliance in the assessment of soft adhesives with the wedge test
PublicationWedge tests are usually analysed assuming that the free, unbonded members may be treated as encastré cantilever beams. However, if the adhesive layer is sufficiently flexible (e.g., due to low elastic modulus), then significant strain in the bonded region may occur and lead to modification of the behaviour outside this region. Using in conjunction a sensitive strain gauge method on asymmetric wedge tests and a mathematical analysis...
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<i>catena</i>-Poly[[[bis(thiourea-κS)cadmium]-di-μ-thiocyanato-κ<sup>2</sup>N:S;κ<sup>2</sup>S:N] dihydrate]
PublicationTytułowy związek tworzy jednowymiarowy łańcuch na skutek występowania mostkujących grup SCN pomiędzy atomami kadmu. Atomy kadmu obsadzają krystalograficzne środki symetrii i są koordynowane oktaedrycznie (zdeformowany oktaedr) przez 2 atomy S i 2 atomy N z mostkujących ligandow SCN oraz przez 2 atomy S z dwóch cząsteczek tiomocznika. Upakowanie jest wspomagane przez dodatkowe wiązania międzycząsteczkowe OH...S, NH...O i NH...N....
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Farrow structure for complex digital Hilbert filter of low complexity
PublicationW pracy przeanalizowano złożoność numeryczną filtru Hilberta (filtr zespolony), złożonego z pary filtrów cyfrowych o zmiennym opóźnieniu ułamkowym, o strukturze Farrowa. Struktura ta pozwala na zmianę opóźnienia ułamkowego na bieżąco, bez potrzeby każdorazowego przeprojektowywania filtru. Zaproponowano algorytmy/struktury wykorzystujące nie tylko symetrię oryginalnej struktury Farrowa, ale również wspólne elementy opóźniające podfiltrów...
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Testowanie i diagnostyka układów w pełni różnicowych
PublicationZaproponowano tester wbudowany realizujący nowe podejście do testowania układów w pełni różnicowych, polegające na pobudzaniu układu sygnałem wspólnym i pomiarze wyjściowego napięcia różnicowego. Tester wykrywa uszkodzenia parametryczne i strukturalne, które powodują zaburzenie symetrii układu i w rezultacie wzrost wartości napięcia różnicowego. Przeprowadzono analizę właściwości diagnostycznych funkcji układowej, na której bazuje...
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Microwave Alignment and Displacement Sensors in Groove Gap Waveguide Technology
PublicationThis paper is aimed at presenting highly sensitive microwave displacement and alignment sensors. With this goal, the method of realizing mechanically tunable cavity resonators in groove gap waveguides technology is presented. The resonance frequency of the cavity is then used for displacement sensing. It is also demonstrated that the symmetry properties of a pair of groove gap waveguide cavities can be used to improve the robustness...
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Application of polarisation-maintaining side-hole fibres do direct force measurement
PublicationW pracy przedstawiono zastosowanie utrzymujących polaryzację światłowodów typu Side Hole do bezpośredniego pomiaru siły. Dla wybranych struktur tych światłowodów wyznaczono, przy pomocy Metody Elementów Skończonych i metody modów sprzężonych, czułość na siłę działającą prostopadle do osi symetrii światłowodu. Określono zależność tej czułości od poszczególnych wymiarów struktur tych światłowodów. Następnie, biorąc pod...
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Spatially variant PSF modeling in confocal macroscopy
PublicationThe point spread function (PSF) of imaging systems plays an essential role in image reconstruction. In the context of confocal microscopy, optical performance degrades towards the edge of the field of view. In confocal macroscopy, the related artifacts are even stronger, as the field of view is much larger. Because the related PSFs are strongly spatially variant, it is essential to be able to model them with few parameters. The...
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An asymmetrical λ-foot of condensing steam flow in the IMP PAN nozzle
PublicationIn the present paper we have focused on the precise prediction of the spontaneous condensation phenomena in wet steam flow. Novelty of our approach lies on modelling both the moment of initiation of a phase transition, as well as the moment of its reverse progress - called here re-vaporization of the condensate phase. The practical issue is to elaborate of a model of spontaneous condensation/vaporization of water steam flow...
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Preferences of the Facade Composition in the Context of Its Regularity and Irregularity
PublicationAbstract: The aim of this study is to determine the preferences of Polish society towards building facades depending on the degree of the composition regularity of the facade elements. The subject matter is inspired by the authors’ observations in relation to the current architectural trends. The purposefulness of the conducted research results from several issues. Firstly, the reports of psychology and neurosciences clearly indicate...
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Arithmetic Loophole in Bell's Theorem: Overlooked Threat to Entangled-State Quantum Cryptography
PublicationBell’s theorem is supposed to exclude all local hidden-variable models of quantum correlations. However,an explicit counterexample shows that a new class of local realistic models, based on generalized arith-metic and calculus, can exactly reconstruct rotationally symmetric quantum probabilities typical oftwo-electron singlet states. Observable probabilities are consistent with the usual arithmetic employedby macroscopic observers...
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Torsional earthquake-induced pounding between adjacent buildings founded on different soil types
PublicationThis paper investigates the effect of the soil type on the torsional response of build- ings experiencing torsional pounding due to earthquake excitations. Six buildings (one 4-storey building and five 6-storey buildings) with different configurations have been considered. First, pounding between different structures has been analysed for a specified soil type and the effect of the torsional pounding and the contact asymmetry on...
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Budowa 3-osiowej maszyny frezującej CNC, wraz z doborem parametrów regulatorów w torach sterowania serwomechanizmów
PublicationW pracy przedstawiono proces tworzenia stanowiska laboratoryjnego - maszyny frezującej CNC, której osie poziome napędzane są poprzez serwomechanizmy, zaś oś pionowa napędzana jest przez silnik skokowy. Budowę stanowiska kończy proces programowania maszyny, wraz z doborem parametrów regulatorów w torach sterowania serwomechanizmów. W tym celu zostały wykorzystane kryteria: Hurwitza oraz optimum symetrii. Rezultaty strojenia regulatorów...
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Face detection in image sequences using a portable thermal camera
PublicationFace detection is often a first step in quantitative analysis of face images. It is an important research area for visible images and recently also for thermography. Due to technological developments thermal cameras may be embedded into wearable devices to provide remote healthcare. In this paper, we compared three algorithms for face detection in thermal images by testing execution time, accuracy, symmetry ratio and false-positives....
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A Compact and Lightweight Microwave Tilt Sensor Based on an SRR-Loaded Microstrip Line
PublicationIn this paper, the symmetry property of split ring resonators (SRRs) is exploited to develop a tilt sensor. The sensor is composed of an SRR-loaded microstrip line operating at microwave frequencies. It is shown that the depth of notch in the reflection characteristic of the microstrip is a function of the tilt angle of the SRR. Thus, it can be used for sensing inclination. The sensor benefits from very compact size and light weight....
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Sensitivity analysis of flexural and torsional buckling loads of laminated columns
PublicationThe paper concerns first order sensitivity analysis of flexural and torsional bucklin g loads of axiallycompressed thin-walled columns with bisymmetric or axisymmetric cross-section made of unidirectional fibre-reinforcedlaminate. The first variation of critical loads versus some variations of the column material properties and cross-sectionaldimensions is derived. Numerical examples dealing with simply supported I-columns are...
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An in situ technique for the assessment of adhesive properties of a joint under load
PublicationSlow crack propagation in adhesive bonded joints has been characterised using an asymmetric wedge test. Crack position was evaluated from strain gauge measurements, both in the debonded partof the joint and in the bonded zone. Test temperature was changed during loading, giving insight into bond evolution. The technique allows accurate, and virtually continuous, determination of crack position to be made, and therefore the evaluation...
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Recent Achievements in Constitutive Equations of Laminates and Functionally Graded Structures Formulated in the Resultant Nonlinear Shell Theory
PublicationThe development of constitutive equations formulated in the resultant nonlinear shell theory is presented. The specific features of the present shell theory are drilling rotation naturally included in the formulation and asymmetric measures of strains and stress resultants. The special attention in the chapter is given to recent achievements: progressive failure analysis of laminated shells and elastoplastic constitutive relation...
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The influence of the size of a one-faced metallic head in Janus nanoparticles as a co-catalyst on the photocatalytic efficiency of hydrogen evolution under vis light irradiation
PublicationJanus nanoparticles (NPs) consisting of MoOxSy nanospheres and silver (Ag) head, successfully developed by a simple, controlled method were in the first time they were applied as a co-catalysts in photocatalytic hydrogen generation reaction under vis light irradiation (λ > 420 nm). The MoOxSy-Ag as a co-catalysts were deposited on the obtained ZnIn2S4 microspheres (ZIS) using physical absorption method. The influence of the size...
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Entangled rendezvous: a possible application of Bell non-locality for mobile agents on networks
PublicationRendezvous is an old problem of assuring that two or more parties, initially separated, not knowing the position of each other, and not allowed to communicate, are striving to meet without pre-agreement on the meeting point. This problem has been extensively studied in classical computer science and has vivid importance to modern and future applications. Quantum non-locality, like Bell inequality violation, has shown that in many...
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Miniaturized dual‐band branch‐line coupler with enhanced bandwidth
PublicationIn this letter, a miniaturized hybrid dual-band branch-line coupler (BLC) with enhanced fractional bandwidths is proposed. Compact size and bandwidth enhancement are obtained using meandered transmission line sections with broken symmetry between cross-coupling branches. The circuit is designed at a low numerical cost using surrogate-assisted techniques. The optimized design features small size of only 0.25λg×0.19λg(28% miniaturization...
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Influence of dopants on structure of polycrystalline bismuth niobate
PublicationBismuth niobate (BiNbO4) has attracted attention as a low-fired ceramics with promising microwave application potential. BiNbO4 ceramics was fabricated by mixed oxide method and sintered at temperature T<1000˚C. As the sintering aids a small amount of CuO oxide was used. The crystalline structure of the ceramic samples was examined by X-ray diffraction method at room temperature. The Rietveld refinement method was used for analysis...
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Formänderungsgrössenverfahren mittig gedrückter dünnwandiger Stäbe mit einfach- und doppeltsymmetrischen offenen Querschnitten
PublicationW nawiązaniu do klasycznej metody przemieszczeń dla skręcania mieszanego prętów cienkościennych, rozwinięto ją dla problematyki wyboczeń prętów. W pracy ukazano ogólne rozwiązanie podstawowego układu równań różniczkowych dla przekrojów monosymetrycznych i jego szczególne postacie dla trzech głównych sposobów podparcia pręta. Wyznaczono wzory dla bimomentów brzegowych. Związki te następnie uproszczono dla podwójnej symetrii przekroju....
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Three electrode configuration measurements of electrolyte-diffusion barrier-cathode interface
PublicationMeasurements of a system consisting of cathode/doped ceria diffusion barrier/doped zirconia electrolyte were made using two- and three-electrode configuration. Results obtained on a three-electrode measurement configuration were compared with and reflect the results obtained in two-electrode configuration. Three-electrode measurements allowed separating the impact of the symmetrical interface in the investigated system. They also...
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Formulation of Time-Fractional Electrodynamics Based on Riemann-Silberstein Vector
PublicationIn this paper, the formulation of time-fractional (TF) electrodynamics is derived based on the Riemann-Silberstein (RS) vector. With the use of this vector and fractional-order derivatives, one can write TF Maxwell’s equations in a compact form, which allows for modelling of energy dissipation and dynamics of electromagnetic systems with memory. Therefore, we formulate TF Maxwell’s equations using the RS vector and analyse their...
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On Earth as in Universe
PublicationOn Earth as in Universe Ślady zostawione na podobraziu przygotowanym własnoręcznie przez Kazimierza Ostrowskiego. Kilka pociągnięć pędzlem ciemną farbą na odwrocie płótna, tu i ówdzie przyklejone włosy do powierzchni gruntu, kurz nagromadzony przez lata - słowem każdy element artefaktu, który trafił do mnie, był kapsułą czasu sprzed około pięćdziesięciu lat. Jedyne co mogłem zrobić, to wpisać drobiny obecności Kazimierza Ostrowskiego...
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Wpływ rodzaju kwasu jako dodatku do eluentu na parametry rozdzielania polifenoli techniką chromatografii cieczowej w odwróconych układach faz (RP-HPLC)
PublicationChromatografia cieczowa jest jedną z technik wykorzystywanych w badaniach składu mieszanin, a także do wydzielania czystych składników z mieszanin w postaci frakcji eluatu. Z punktu widzenia współczesnej chemii, farmakologii, a także medycyny, czy biotechnologii, chromatografia pełni ważną rolę, w zakresie analityki jakościowej i ilościowej. Dzięki możliwości otrzymywania naturalnych składników biologicznie czynnych w czystej...
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Helicity discrimination in N,N'-dibenzoyl-1,2,3,4,7,8,9,10-octahydro-1,10-phenanthrolines and their thiono- and selenocarbonyl analogues by inclusion complexation with chiral diols
PublicationX-ray crystallographic analysis of the title compounds revealed that they assume a folded helical con- formation of an approximate C2 symmetry in the solid state. Dithioamide, diselenoamide and monoselenoamide were resolved to enantiomers by inclusion crystallization with optically active diols (TADDOLs). The absolute configuration of the guest molecules in the complexes was assigned as P. The optical activity of the resolved compounds...
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Analiza działania rozszerzonego obserwatora prędkości w szerokim zakresie zmian prędkości maszyny indukcyjnej
PublicationW artykule przedstawiono zagadnienia związane z odtwarzaniem zmiennych stanu maszyny indukcyjnej. Wykorzystano obserwator oparty na modelu matematycznym maszyny z dodatkowymi zmiennymi. Przedstawiono macierz stanu zlinearyzowanych równań błędu odtwarzania. Opisano sposób definiowania wyznacznika jakości na podstawie rozkładu biegunów obserwatora. Zaproponowano metodę korekcji wzmocnień wraz ze zmianą warunków pracy maszyny. Wykazano...
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adaptive finite-element multigrid method in 3d magnetostatic analysis.
PublicationPrzedstawiono procedurę analizy magnetostatycznej obwodów mikrofalowych zawierających przewodniki o dowolnym kształcie. Zakłada się pobudzenie pola magnetostatycznego zadane w postaci wartości całkowitego prądu płynącego w przewodniku sygnałowym. Warunki brzegowe w strukturze od dowolnym kształcie, bez płaszczyzn symetrii wprowadza się za pomocą powierzchni rozdzielających. Takie sformułowanie problemu prowadzi jednak do szeregu...
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Commitment Ladder in the Relationship between Service Providers and Customers as Added Value in Sustainable Services Development
PublicationThe socioeconomic sphere and the relationships in which commitment occurs are important elements in the development of sustainable services. The study reported in this article identifies the elements that influence the development of the relationship between service providers and their customers and proposes a model that describes the state of the relationship between service providers and customers in terms of symmetrical commitment...
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Selected Stability Problems of Thin-Walled Columns and Beams
PublicationThe article reviews a number of papers in the light of buckling analy- sis of thin-walled columns and beams. Stability of thin-walled columns and beams are considered a vital engineering science issue in both historical and present-day approaches. The paper refers to the recent authors’ works of the 2012–2019 period, published in leading journals. Similar review of stability problems of thin-walled structures developed at Gdansk...
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LaNi1-xCoxO3-δ(x=0.4 to 0.7) cathodes for solid oxide fuel cells by infiltration
PublicationPerformance of LaNi 1-x Co x O 3−δ (LNC) (x=0.4 to 0.7) as a cathode in solid oxide fuel cell (SOFC) is evaluated. Symmetrical cathode/electrolyte/cathode cells for electrochemical testing are prepared by infiltration of yttria stabilized zirconia (YSZ) backbone with LNC solutions. It is showed that the cathode infiltrated with LaNi 0.5 Co 0.5 O 3−δ (LNC155) has the lowest polarization resistance and activation energy, 197 mΩ cm...
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A novel microstrip dual-layer rat-race coupler with compact size and enhanced bandwidth
PublicationMicrowave hybrid couplers are crucial components of mixers, phase shifters, amplifiers and other high-frequency systems. Conventional couplers are characterized by large size which limits their usefulness in modern applications. In this work, a novel compact rat-race coupler with enhanced bandwidth has been proposed. The structure consists of six compact microstrip resonant cells. It is implemented on two separate layers which permits...