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Wyniki wyszukiwania dla: linear phase filters
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Prediction of Peptide Retention at Different HPLC Conditions from Multiple Linear Regression Models
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Robustly feasible integral LQ-MPC controller for output tracking in constrained linear systems
PublikacjaW pracy rozważany jest regulator predykcyjny typu dual-mode MPC z liniowo kwadratowym wskaźnikiem jakości w aplikacji do krzepkiego śledzenia wyjść liniowego obiektu dyskretnego w obecności addytywnych zakłóceń. W celu zapewnienia dopuszczalności sterowań regulatora wykorzystano teorię zbiorów niezmienniczych. W celu polepszenia śledzenia wyjść i odrzucenia zakłóceń w regulatorze wykorzystano działanie całkujące (integral control)....
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Effective highly accurate time integrators for linear Klein-Gordon equations across the scales
PublikacjaWe propose an efficient approach for time integration of Klein-Gordon equations with highly oscillatory in time input terms. The new methods are highly accurate in the entire range, from slowly varying up to highly oscillatory regimes. Our approach is based on splitting methods tailored to the structure of the input term which allows us to resolve the oscillations in the system uniformly in all frequencies, while the error constant...
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Asymptotic numerical solver for the linear Klein–Gordon equation with space- and time-dependent mass
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Effective highly accurate time integrators for linear Klein-Gordon equations across the scales
PublikacjaWe propose an efficient approach for time integration of Klein-Gordon equations with highly oscillatory in time input terms. The new methods are highly accurate in the entire range, from slowly varying up to highly oscillatory regimes. Our approach is based on splitting methods tailored to the structure of the input term which allows us to resolve the oscillations in the system uniformly in all frequencies, while the error constant...
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Introducing Bentonite into the Environment in the Construction Stage of Linear Underground Investment Using the HDD Method
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Review of Linear Electric Motor Hammers—An Energy-Saving and Eco-Friendly Solution in Industry
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Non-linear strain rate analysis of earthquake-induced pounding between steel buildings
PublikacjaPast and recent earthquakes have shown that ground motions may cause severe structural damage to civil engineering structures. Earthquake-induced pounding between adjacent buildings has been identified as one of the reasons which intensifies damages. The aim of this paper is to show the results of the detailed nonlinear FEM analysis of earthquake-induced pounding between two steel buildings. The elastic – perfectly plastic material...
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Nickel phase deposition on V2CTx/V2AlC as catalyst precursors for a dry methane reforming: The effect of the deposition method on the morphology and catalytic activity
PublikacjaDry reforming of methane (DRM) is a promising alternative technology for the production of syngas with simultaneous utilization of two main greenhouse gases (CH4, CO2). However, DRM technology is still an industrially immature process due to the lack of stable and active catalyst. Therefore, the search for new catalytic materials is of great research interest. Recently, MAX and MXenes materials are increasingly being tested as...
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Diverse roles, advantages and importance of deep eutectic solvents application in solid and liquid-phase microextraction techniques – A review
PublikacjaDeep eutectic solvents (DESs) are an emerging class of promising green solvents used as an alternative to traditional organic solvents in various scientific fields. The high biodegradability, biocompatibility, eco-friendliness, tunable properties, and presence of active groups in DESs make them the preferred solvent in a variety of solid- and liquid-phase microextraction techniques. Aside from these benefits, the use of DESs in...
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Modified SPWM Technique with Zero-Sequence Voltage Injection for a Five-Phase, Three-Level NPC Inverter
PublikacjaThis article presents a modified sinusoidal pulse-width modulation (SPWM) scheme for a five-phase, three-level neutral-point-clamped inverter. The modulation scheme deploys a modified min–max function to inject the zero-sequence components into the reference modulating signals; hence enabling the effective utilization of the DC-link voltage. Balanced split-input DC-link voltages were achieved through further incorporation of adjustable...
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Novel Family of Single-Phase Modified Impedance-Source Buck-Boost Multilevel Inverters With Reduced Switch Count
Publikacjahis paper describes novel single-phase solutions with increased inverter voltage levels derived by means of a nonstandard inverter configuration and impedance source networks. Operation principles based on special modulation techniques are presented. Detailed component design guidelines along with simulation and experimental verification are also provided. Possible application fields are discussed, as well as advantages and disadvantages....
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Dot-com and AI bubbles: Can data from the past be helpful to match the price bubble euphoria phase using dynamic time warping?
PublikacjaThe article investigates the existence of a price bubble in the artificial intelligence market, employing the Generalised Supremum Augmented Dickey-Fuller test and dynamic time warping methodology. It proposes a method to detect the end of the price bubble euphoria phase, generating an average profit of close to 7% over 5 days and over 10.5% over 20 days, with almost 90% effectiveness. The study found that the AI market experienced...
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Application of magnetic nanoparticles for magnetic solid-phase extraction in preparing biological, environmental and food samples
PublikacjaThe need to obtain meaningful results as the basis for determining the content of trace amounts of analytes has become the driving force behind the development of modern analytical techniques, including sample-preparation techniques, such as solid-phase extraction (SPE). Recently, great interest was aroused in the use of magnetic nanoparticles (MNPs) in SPE. These materials exhibit high selectivity, and, in small amounts, can provide...
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Effectiveness of toluene separation from gas phase using supported ammonium ionic liquid membrane
PublikacjaAmmonium ionic liquids (ILs) are relatively cheap in synthesis and environmentally benign and despite that they have been very rarely used in gas separation. In this research we used several ammonium ILs as liquid membranes for removal of residual toluene from gas phase. Ionic liquids used in this study were composed of bis(trifluoromethylsulfonyl)imide anion [Tf2N] and trimethylbutylammonium [N1114], trietylbutylammonium [N2224],...
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A study about daylighting knowledge and education in Europe. Results from the first phase of the DAYKE project
PublikacjaThis paper presents selected results from the first stage of DAYKE (Daylight Knowledge in Europe), a 3- phase project that investigates the knowledge on daylighting in buildings among architecture students and practitioners across Europe. Subjective judgements from 561 students from 8 architecture universities in the EU, collected through two surveys in 2018. The key findings are: (i) the spatial distribution of comfort and mood...
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Sensorless Field Oriented Control of Five Phase Induction Motor with Third Harmonic Injection
PublikacjaIn this paper, a sensorless field oriented control system of five-phase induction machine with the 3rd harmonic rotor flux is presented. Two vector models, α1-β1 and α3-β3, were transformed into d1-q1, d3-q3 models oriented in rotating frames, which correspond to the 1st and 3rd harmonic plane respectively. The authors proposed the linearization of the model in d-q coordinate frames by introducing a new variable “x” which is proportional...
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A dipole-driven path for electron and positron attachments to gas-phase uracil and pyrimidine molecules: a quantum scattering analysis
PublikacjaElectron and positron scattering processes in the gas-phase are analysed for uracil and pyrimidine molecules using a multichannel quantum approach at energies close to threshold. The special effects on the scattering dynamics induced by the large dipole moments in both molecules on the spatial features of the continuum leptonic wavefunctions are here linked to the possible bound states of the Rydberg-like molecular anions or ‘positroned’...
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Supervisory Control System for Adaptive Phase and Work Cycle Management of Sequencing Wastewater Treatment Plant
PublikacjaThe paper presents the design of the integrated control system applied to Sequencing Batch Reactor (SBR) in a biological Wastewater Treatment Plant (WWTP) in Swarzewo, which operates under activated sludge technology. Based on the real data records, ASM2d biological processes model and aeration system model, hierarchical control system for dissolved oxygen tracking and cycle management is designed. Internal Model Controller (IMC)...
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Effect of isovalent substitution on microstructure and phase transition of LaNb1−xMxO4 (M=Sb, V or Ta; x=0.05–0.3)
PublikacjaLaNb1−xMxO4 oxides with pentavalent elements of different ionic sizes (M=Sb, Ta and V, x=0.05–0.3) were synthesized by the solid state reaction method. Special interest was devoted to the antimony substituted lanthanum niobate which is a new material in this group. Rietveld analysis of the X-ray diffraction patterns was used to determine the influence of the material composition on unit cell parameters. On the basis of dilatometric...
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Estimation of time-frequency complex phase-based speech attributes using narrow band filter banks
PublikacjaIn this paper, we present nonlinear estimators of nonstationary and multicomponent signal attributes (parameters, properties) which are instantaneous frequency, spectral (or group) delay, and chirp-rate (also known as instantaneous frequency slope). We estimate all of these distributions in the time-frequency domain using both finite and infinite impulse response (FIR and IIR) narrow band filers for speech analysis. Then, we present...
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Zdzisław Kowalczuk prof. dr hab. inż.
OsobyW 1978 ukończył studia w zakresie automatyki i informatyki na Wydziale Elektroniki Politechniki Gdańskiej, następnie rozpoczął pracę na macierzystej uczelni. W 1986 obronił pracę doktorską, w 1993 habilitował się na Politechnice Śląskiej na podstawie pracy Dyskretne modele w projektowaniu układów sterowania. W 1996 mianowany profesorem nadzwyczajnym, w 2003 otrzymał tytuł profesora nauk technicznych. W 2006 założył i od tego czasu...
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Reversed-phase and normal-phase thin-layer chromatography and their application to the lipophilicity prediction of synthetic pyrethroids based on quantitative structure–retention relationships
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Chromatographic lipophilicity determination using large volume injections of the solvents non-miscible with the mobile phase
PublikacjaA new perspective in the lipophilicity evaluation through RP-HPLC is permitted by analysis of the retentionfactor (k) obtained by injecting large volumes of test samples prepared in solvents immiscible withmobile phase. The experiment is carried out on representative groups of compounds with increasedtoxicity (mycotoxins and alkaloids) and amines with important biological activity (naturally occurringmonoamine compounds and related...
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THERMION-C2S_10 Ionic thermoelectri effect in the phase transition in Cu2Se
Dane BadawczeThe dataset contains results of measurements of the ionic thermoelectric effect in copper selenide with Cu1.99Se and Cu1.8Se compositions. X-Ray diffraction data, SEM images and EDX spectra of the samples are also in the dataset.
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On iterates of strong Feller operators on ordered phase spaces.
PublikacjaPraca dotyczy asymptotycznych własności iteracji operatorów Markowa. Udowodniono, że operatory Lasoty i ich wielowymiarowe uogólnienia są asymptotycznie stabilne. Wyniki mają zastosowanie w modelowaniu rozwoju komórki.
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U-Turn Compression to a New Isostructural Ferrocene Phase
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Phase-decoupled refraction–diffraction for spectral wave models
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Effective dielectric constant of two phase dielectric systems
PublikacjaW tym artykule model brick-layer ścianie został rozszerzony na dwufazowe systemy perkolacyjne. Porównano wyniki obliczeń z danymi eksperymentalnymi. Stałe dielektryczne obu faz oraz próg perkolacji pozwala na wyznaczenie efektywnej stałej dielektrycznej systemu dwufazowego.
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Interaction of imidazolium type ionic liquids with the solid phase
PublikacjaNiektóre ciecze jonowe, w szczególności te posiadające kation organiczny podstawiony długim łańcuchem alkilowym, wykazują strukturalne podobieństwo do surfaktantów. Samoczynne formowanie się agregatów cieczy jonowych może wpływać na procesy przenoszenia masy w wielu operacjach jednostkowych jak: ekstrakcja, nanofiltracja lub kataliza oraz transport i rozmieszczenie tych związków w środowisku naturalnym. W niniejszej publikacji...
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Determination of pKa by pH Gradient Reversed-Phase HPLC
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Two-phase thermosiphon heat exchanger for heat recovery
PublikacjaW pracy przedstawiono wyniki badań eksperymentalnych dotyczących wpływu geometrii pęku rur, rodzaju powierzni przejmowania ciepła parownika oraz płynu pośredniego na całkowitą wydajność dwufazowego termosyfonowego wymiennika ciepła (DTWC). Badaniu poddano sześć prototypowych DTWC z dwiema podziałkami rur w parowniku, dla trzech rodzajów powierzchni rur parownika oraz z zastosowaniem trzech rodzajów płynów pośrednich. Lepszą wydajność...
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Enantioselective Gel Phase Synthesis of Metal–Organic Materials
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Solid phase synthesis of two muramyl pentapeptide derivatives
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Superconductivity phase diagram of Na x CoO2·1.3H2O
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Rich magnetic phase diagram of the kagome-staircase compoundMn3V2O8
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The first order phase transition and superconductivity in BaNi2As2single crystals
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An ultrasonic obstacle detector based on phase beamforming principles
PublikacjaW artykule przedstawiono rezultaty prac nad ultradźwiękowym wykrywaczem przeszkód dla niewidomych. Opisano metodę lokalizacji przeszkód w oparciu o algorytm beamformingu fazowego. Zaprezentowano rezultaty badań przeprowadzonych nad prototypem urządzenia.
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Solid phase extraction technique - trends, opportunities and applications
PublikacjaW pracy opisano wykorzystanie ekstrakcji do fazy stałej w chemii analitycznej. Ekstrakcja do fazy stałej może być przydatna nie tylko do izolacji i wzbogacania analitów z fazy wodnej, ale również do wymiany matrycy oraz oczyszczania ekstraktu. Stosowane sorbenty są analogiczne do stosowanych w chromatografii cieczowej. Omówione zostały: mechanizmy ekstrakcji, sposoby przeprowadzania ekstrakcji (kolumienki, krążki, pipety), rodzaje...
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Three phase transient model of wet coal pyrolysis
PublikacjaA one-dimensional transient mathematical model was developed to describe the thermal and flow phenomena during coal pyrolysis in a coke oven. The model was solved numerically using partly implicit methods for gas flow and heat transfer problems. It was successfully validated with industrial-scale measurements of temperature change in the middle-plane of the coke oven chamber. The evolution of temperature and pressure, distributions...
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Energy Modeling of Single-Family Houses in the Conceptual Phase
PublikacjaThe aim of the article is to identify the potential impact of the latest commercial digital tools for building energy analysis on the everyday architectural practice in Poland in the context of typology and energy optimization of single –family houses. The reason for this survey is that “architect friendly” interfaces simulation results’ visualization and energy analysis tools are not given deserved attention in the architectural...
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Frequency and phase analysis of daily reprocessed solutions from selected EPN stations relating to geological phenomena,
PublikacjaThe main assumption of this research was to check and verify the behaviour of a few EPN (European Permanent Network) stations on both sides of the Teisseyre-Tornquist zone (T-T zone), which is located on Polish territory and crosses Poland almost in half. The selected EPN stations’ time series were a subject of frequency and phase analysis. The main purpose of the research was to verify if there is any correspondence between stations...
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Optimized Space Vector Modulation strategy for five phase voltage source inverter with third harmonic injection
PublikacjaThis paper presents a simple and an effective SVM algorithm for five-phase Voltage-Source Inverters with the possibility to control independently the voltage vectors for fundamental and auxiliary orthogonal subspaces. The essential benefit is that output voltage is generated using only four active voltage vectors with limited numbers of switching. In the proposed solution, four active vectors are arbitrary chosen, independent of...
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Optimized Space-Vector Modulation Schemes for Five-Phase Precision Low-Speed Drives with Minimizing the Stator Current Ripple
PublikacjaOne of the main ways to improve the quality of a precision electric drive is minimization of the stator current pulsations generated by the voltage inverter. The solution of this problem can be achieved by using of multiphase inverters, as well as improving control algorithms. This paper considers the influence of the space-vector modulation algorithm with different switching sequences of basic vectors on the stator current pulsations...
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Investigations on mixture preparation for two phase adiabatic pressure drop of R134a flowing in 5 mm diameter channel
PublikacjaThe article presents detailed two-phase adiabatic pressure drops data for refrigerant R134a. Study cases have been set for a mass flux varying from 200 to 400 kg/m2 s, at the saturation temperature of 19.4 ◦C. Obtained experimental data was compared with the available correlations from the literature for the frictional pressure drop during adiabatic flow. Influence of mixture preparation on pressure drop was investigated, for...
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Thermal properties of a cement composite containing phase change materials (PCMs) with post-pyrolytic char obtained from spent tyres as a carrier
PublikacjaThis work examines the possible use of post-pyrolysis char made from spent vehicle tyres as a carrier for phase change materials (PCM), which could be used as an additive to cement mortar. Because of the ability of PCM to accumulate heat, the cement composite obtained from it, apart from its structural and strength properties, will acquire an additional energy storage function, which can be very important for energy-saving construction. In...
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Recent advances of selected passive heat transfer intensification methods for phase change material-based latent heat energy storage units: A review
PublikacjaThe following article overviews recent studies regarding heat transfer enhancement methods, explicitly focusing on fins and coils utilization, in phase change material-based latent heat thermal energy storage systems. It discusses the influence of various geometrical and material parameters on the melting and solidification processes, as well as the orientation of the heat transfer surface within the storage tank. Additionally,...
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First deep eutectic solvent-based (DES) stationary phase for gas chromatography and future perspectives for DES application in separation techniques
PublikacjaThe paper presents the first application of deep eutectic solvents (DES) as stationary phases for gas chromatography. DES obtained by mixing tetrabutylammonium chloride (TBAC) as a hydrogen bond acceptor (HBA) with heptadecanoic acid being a hydrogen bond donor (HBD) in a mole ratio of HBA:HBD equal to 1:2 was characterized by its ability to separate volatile organic compounds (VOCs). The Rohrschneider – McReynolds constants determined...
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Electrical and mechanical characterization of two-phase alloys by means of scanning probe microscopy in dynamic impedance spectroscopy mode
PublikacjaDynamic impedance spectroscopy, evaluated for measuring non-stationary systems, was used in combination with scanning probe microscope. Using this approach, localized impedance measurements in the AFM contact mode could be carried out. Additionally, impedance–force curves were made at each phase of investigated materials to illustrate the relation between impedance and the force applied to a probe. Therefore, correlation of electrical...
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Analytical and experimental determination of parameters for the non-linear viscoelastic model of earthquake-induced structural pounding
PublikacjaNieliniowy model lepko-sprężysty umożliwia dokładną symulację siły zderzenia w czasie oraz symulację odpowiedzi konstrukcji podatnej na zderzanie podczas trzęsień ziemi. Jednym z celów niniejszego artykułu jest wyprowadzenie wzoru na zależność pomiędzy liczbą tłumienia zderzenia (parametr wspomnianego modelu), a współczynnikiem odbicia. Kolejnym celem jest wyznaczenie zakresu wartości współczynników odbicia oraz współczynników...