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Wyniki wyszukiwania dla: PHASE SHIFTERS
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THE PHASE SHIFTERS INFLUENCE ON THE POWER SYSTEM STABILITY
PublikacjaThe paper presents the effect of phase shifters as FACTS devices on the possibility of improving the angle stability. Presented results obtained by the dynamic simulation performed on the mathematical model of the three machine system cooperating with the 400 kV network. The generative blocks models include turbine models with their controllers and models of synchronous generators with their excitation systems and voltage regulation....
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THE INFLUENCE OF PHASE SHIFTERS ON THE VOLTAGE STABILITY OF CONNECTED POWER SYSTEMS
PublikacjaThe paper presents the results of simulation tests of connected power systems in which phase shifters were installed on cross-border links. The analysis was carried out in terms of assessing the impact of shifters on node voltage stability. Individual systems were characterized by different balance of active power: deficit or excess. The evaluation of voltage stability was based on the dU/dQ and dU/dP criteria.
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Measurement method for capacitive sensors for microcontrollers based on a phase shifter
PublikacjaA complete measurement method dedicated to capacitive sensors has been developed. It includes the development of hardware (an analogue interface circuit for microcontrollers with built-in times/counters and analogue comparators) and software (a measurement procedure and a systematic error calibration (correction) algorithm which is based on a calibration dictionary). The interface circuit consists of a low-pass filter and a phase...
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Low-Loss Mechanically Tunable Resonator and Phase Shifters in Groove Gap Waveguide Technology
PublikacjaThis research is focused on the design and realization of high-performance high-power variable phase shifters in groove gap waveguide technology. Specifically, it is shown that the unique characteristic of groove gap waveguides, which is its proper operation without the need for electrical connection between the top and bottom sections of the waveguide, can be used to design mechanically tunable devices. Using the proposed method,...
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Simulation and Experiment of a Compact Wideband 90^{circ} Differential Phase Shifter
PublikacjaArtykuł przedstawia projekt i analizę kompaktowego różnicowego przesuwnika fazy, który jest rozwinięciem konfiguracji zaproponowanej Abbosha poprzez modyfikację obciążenia wrót. Zaproponowana konfiguracja zawiera 3dB sprzęgacz kierunkowy z wrotami transmisyjnymi i sprzężonymi zakończonymi obciążeniami reaktancyjnymi. W artykule przedstawiono model teoretyczny prezentujący zasadę działania układu i jego projekt. Uzyskane wyniki...
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A gap waveguide-based mechanically reconfigurable phase shifter for high-power Ku-band applications
PublikacjaThis paper presents a novel design of a low-loss, reconfgurable broadband phase shifter based on groove gap waveguide (GGW) technology. The proposed phase shifter consists of a folded GGW and three bends with a few pins forming the GGW and one bend attached to a movable plate. This movable plate allows for adjustments to the folded waveguide length, consequently altering the phase of electromagnetic waves. The advantage of GGW...
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Quantitative structure—retention relationships of some steroid and phenanthrene derivatives on cyano-, reversed-phase, and normal-phase thin-layer chromatography stationary phases
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The New LM-PCR/Shifter Method for the Genotyping of Microorganism
PublikacjaTechniques relies on the ligation of appropriates adapters (LM-PCR) as AFLP, PCR MP and ADSRRS are successfully used for epidemiological studies for prokaryotic and eukaryotic microorganisms. In this study we propose a new method, called the LM-PCR/Shifter, based on the use of a Class IIS restriction enzyme giving restriction fragments with different 4 base 5' overhangs (Shifter) and the ligation of appropriate oligonucleotide...
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A Comparative Quantitative Structure-Retention Relationships Study for Lipophilicity Determination of Compounds with a Phenanthrene Skeleton on Cyano-, Reversed Phase-, and Normal Phase-Thin Layer Chromatography Stationary Phases
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Chemically Bonded Silica Stationary Phases: Synthesis, Physicochemical Characterization, and Molecular Mechanism of Reversed-Phase HPLC Retention
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Pitch shifter with complex instantaneous frequency rescaling and direct digital synthesis
PublikacjaW 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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Pertussis outbreak in Polish shooters with adverse event analysis
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PHASE OBJECT OBSERVATION SYSTEM BASED ON DIFFRACTION PHASE MICROSCOPY
PublikacjaIn the paper authors present a special measurement system for observing phase objects. The diffraction phas microscopy makes it possible to measure the dimensions of a tested object with a nanometre resolution. To meet this requirement, it is proposed to apply a spatial transform. The proposed setup can be based either on a two lenses system (called 4 f ) or a Wollaston prism. Both solutions with all construction aspects are described...
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On continuity conditions at the phase interface of two-phase elastic shells
PublikacjaW pracy rozwinięto ogólną nieliniową teorię powłok sprężystych podlegających przejściom fazowym typu martenzytowego. Przedstawione sformułowanie oparte jest na statycznie i kinematycznie ścisłym modelu powłokowym. Uwzględniono gęstośc energii odkształcenia, jak również siły i momenty zadane wzdłuż krzywoliniowego przejścia fazowego. W szczególności otrzymano statyczne warunki ciągłości wzdłuż koherentnego połączenia oraz połączenia...
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Isotope shifts in the spectrum of Pb I
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Sputtered silicon solid phase microextraction fibers with a polydimethylsiloxane stationary phase with negligible carry-over and phase bleed
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A new pitch shifter based on complex instantaneous frequency rescaling and direct digital synthesis
PublikacjaZaproponowano nową metodę zmiany wysokości dźwięku za pośrednictwem skalowania zespolonej częstotliwości chwilowej i na podstawie cyfrowej syntezy bezpośredniej. Zaprezentowano schematy blokowe opracowanych algorytmów. Pracę zilustrowano przykładem syntezy sygnału wywoławczego (''dzwonka'' telefonicznego), gdzie dźwięki poszczególnych nut generowanej melodii uzyskano na podstawie naturalnego sygnału - pojedynczego świergotu o widmie...
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Shifts in Female Facial Attractiveness during Pregnancy
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Five-phase Induction Motor Drive Operation During Stator Phase Fault
PublikacjaThe article presents the most important advantages of multi-phase electric drives. The construction of a five-phase squirrel cage induction motor together with possible stator winding distribution cases is presented, which affect the properties of such motor. Increased reliability of five-phase drives was indicated. The drive operation properties were confirmed by experimental results.
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Two-phase flow in heterogeneous porous media with non-wetting phase trapping
PublikacjaThis article presents amathematical model describing flowof two fluid phases in a heterogeneous porous medium. Zaproponowano model matematyczny przepływu dwufazowego w drobnoziarnistym ośrodku porowatym zawierającym inkluzje gruboziarniste. Inkluzje charakteryzują się niższą wartością ciśnienia wejścia dla płynu niezwilżającego (np. powietrze, ropa naftowa) niż materiał podstawowy. Podczas nawadniania takiego ośrodka dochodzi do...
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Measurements of Dispersed Phase Velocity in Two-Phase Flows in Pipelines Using Gamma-Absorption Technique and Phase of the Cross-Spectral Density Function
PublikacjaThis paper concerns the application of the gamma radiation absorption method in the measurements of dispersed phase velocity in two-phase flows: liquid–gas flow in a horizontal pipe- line and liquid–solid particles in a vertical pipe. Radiometric sets containing two linear 241Am gamma radiation sources and two NaI(Tl) scintillation detectors were used in the research. Due to the stochastic nature of the signals obtained from the...
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Molecular mechanism of retention in reversed-phase high-performance liquid chromatography and classification of modern stationary phases by using quantitative structure–retention relationships
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Polyfunctional chemically bonded stationary phase for reversed phase high-performance liquid chromatography
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Imidazole Hidden Polar Phase
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Mechanism of the phase transitions in MnAs
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Miniaturized solid phase extraction
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Miniaturized solid phase microextratcion
PublikacjaWithout any doubt analytical laboratories have an essential role in environmental protection due to the fact that they takes an active part in the monitoring pollutants present in air, water or soil. From the other side, the analytical activity is involved in the generation of toxic waste what is associated with the use of not eco-friendly reagents and solvents. For these reasons, green analytical chemistry (GAC) was introduced...
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Asynchronous phase-location system
PublikacjaThis paper presents concept and implementation of digital phase-location system, designed as a navigational aid for marine applications. The main feature of the proposed system is the ability to work in both synchronous mode, with one master station and set of slave stations synchronised with master, and in asynchronous mode with independent clocking of all stations.
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The Workshop on Multi-Phase Flows
PublikacjaPrzedstawiono ideę warsztatów ''Modelowanie przepływów wielofazowych w układach termochemicznych'' - organizowanych corocznie - od 2000 roku, przez Podsekcję Przepływów Wielofazowych Komitetu Mechaniki PAN. Omówiono tematykę VI Warsztatów, które były poświęcone głównie metodom eksperymentalnym.
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Automatic system for measuring shifts and deformation of dental prostheses
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Symulacja pracy przesuwnika fazowego w sieci elektroenergetycznej przy połączeniu transformatora szeregowego w gwiazdę
PublikacjaPoniższy artykuł prezentuje sposób regulacji mocy czynnej i biernej za pomocą przesuwnika fazowego, którego uzwojenie transformatora dodawczego (szeregowego) jest połączone w gwiazdę. W artykule pokazano regulację mocy czynnej i biernej na przykładzie wybranego systemu elektroenergetycznego. Omawiany przesuwnik fazowy reguluje jednocześnie przepływem mocy czynnej i biernej w danym systemie elektroenergetycznym.
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Liquid–phase microextraction: A review of reviews
PublikacjaSample preparation is an important step in chemical analysis. It is generally done to deal with problems associated with the nature of the matrix, low analyte concentrations in real samples or analyte features incompatible with the instrumentation. Classical methods of extraction consume large volumes of hazardous solvents and other reagents and are not in line with the recent emergence of green analytical chemistry. Liquid-phase...
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The σ-phase superconductors Nb20.4Rh5.7Ge3.9 and Nb20.4Rh5.7Si3.9
PublikacjaWe show that the previously unreported ternary σ phases Nb20.4Rh5.7Ge3.9 and Nb20.4Rh5.7Si3.9 are both superconductors with Tc values of approximately 1.9 K. The superconducting transitions were characterized through temperature-dependent magnetic susceptibility, electrical resistance, and specific heat measurements. The Sommerfeld constants, γ, for Nb20.4Rh5.7Ge3.9 and Nb20.4Rh5.7Si3.9 are 89(1) mJ mol-f.u.−1K−2 and 86(1) mJ mol-f.u.−1K−2...
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Phase-difference positioning in asynchronous system
PublikacjaThis paper presents concept and implementation of digital positioning system based on phase difference measurements, designed as a navigational aid for marine applications. Main feature of proposed system is the ability to work in both synchronous mode, with one master station and set of slave stations synchronized with master, and in asynchronous mode with independent clocking of all stations.
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Photochemical degradation of pollutants in aqueous phase
PublikacjaTlenek tytanu (IV) wykorzystywany jest jako fotokatalizator służący oczyszczaniu wody i powietrza z wykorzystaniem tzw. powierzchni samoczyszczających się. Zastosowanie fotodegradacji w obecności TiO2 uzasadnione jest przede wszystkim do usuwania substancji toksycznych i/lub trwałych i jednocześnie występujących w małych stężeniach oraz jeżeli w procesie fotodegradacji można wykorzystać promieniowanie słoneczne. Wyniki badań wskazują,...
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pH Gradient Reversed-Phase HPLC
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Control of five-phase induction motor
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Phase Transition in a Sequence-Structure Channel
PublikacjaWe study an interesting channel which maps binary sequences to self-avoiding walks in the two-dimensional grid, inspired by a model of protein folding from statistical physics. The channel is characterized by a Boltzmann/Gibbs distribution with a free parameter corresponding to temperature. We estimate the conditional entropy between the input sequence and the output fold, giving an upper bound which exhibits an unusual phase transition...
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Miniaturized solid-phase extraction techniques
PublikacjaMore than 80% of analysis time is spent on sample collection and sample preparation, so sample preparation is a critical part of the analytical process. Traditionally, liquid-liquid extraction was developed and employed to screen for general unknowns. However, solid-phase extraction (SPE) is becoming highly popular as an alternative, due to its simplicity and economy in terms of time and solvent. This review summarizes the current...
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Automated Design of Linear Phase Filters
PublikacjaThis paper presents a fast technique for an automated design of microwave filters with linear phase. The proposed method exploits the cost function defined using the location of complex zeros and poles of the filter’s transfer and reflection function. The effectiveness of the proposed technique is presented with two illustrative examples.
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Stability of Superhalogen Anions in the Aqueous Phase
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Principles and Developments of Solid-Phase Microextraction
PublikacjaSample preparation has been commonly considered a critical step of the analytical process. In this sense, remarkable efforts have been made to develop efficient sample preparation techniques which could overcome the limitations of conventional approaches. Since its inception in the early 1990’s, solid-phase microextraction (SPME) has become a widespread miniaturized sample preparation technique for extraction and preconcentration...
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Superconductivity phase diagram of NaxCoO2*1.3H2O.
PublikacjaW pracy przedstawiono wpływ ilości sodu w nowo odkrytym nadprzewodniku NaxCoO2*1.3H2O na właściwości nadprzewodzące. Istnienie obszarów ''underdoped'' i''overdoped'' wskazuje na podobieństwo nowego systemu NaxCoO2 yH2O do wysoko-temperaturowych nadprzewodników tlenkowo - miedziowych.
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Experimental investigation of a two-phase thermosiphon.
PublikacjaPrzedstawiono wyniki badań dwufazowego, termosyfonowego wymiennika ciepła. W szczególności uwzględniono wpływ podziałki rur oraz wartość ciśnienia w płaszczu na gęstość przenoszonego strumienia ciepła.
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The phenylnitrene rearrangment in the inner phase of a hemicarcerand
PublikacjaOpisano przegrupowanie fenylonitrenu wewnątrz kompleksu hemikarceratowego.
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Underwater Navigation System Based on Doppler Shifts of a Continuous Wave
PublikacjaThe paper describes a concept of an underwater navigation system designed to determine the location and speed of its ROVs or divers. Conducted by the Department of Marine Electronic Systems at the Gdansk University of Technology for several years, research has focused on navigation systems which determine positions on the basis of Doppler shifts of echo signals reflected from a moving object. This article presents a different version...
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Isotope shifts of multipole lines of Pb I and Pb II
PublikacjaStudies of isotope shifts of three multipole lines between levels of the ground configuration 6s26p2 of Pb I, i.e.: 461.9 nm(1S0→3P1), 531.5 nm(1S0→3P2) and 733.2 nm(1D2→3P1), as well as 710.2 nm line (6s26p2P3∕2→6s26p2P1∕2) of Pb II are presented. We determined the isotope shifts between four stable isotopes: 204, 206, 207, 208. By the use of King plot analysis we were able to separate the mass and the field shifts. We found that...
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Improving css-KNN Classification Performance by Shifts in Training Data
PublikacjaThis paper presents a new approach to improve the performance of a css-k-NN classifier for categorization of text documents. The css-k-NN classifier (i.e., a threshold-based variation of a standard k-NN classifier we proposed in [1]) is a lazy-learning instance-based classifier. It does not have parameters associated with features and/or classes of objects, that would be optimized during off-line learning. In this paper we propose...
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Conservation aspects of cast-iron platform shelters on the example of Vistula Pomerania railway stations
PublikacjaCast-iron shelters were used in the 19th century as cheaper alternatives to large platform halls. Nevertheless, they were aesthetically distinguishable from later riveted solutions. Because of their durability and continuous utility, they were not the subject of disassembly, as numerous transport infrastructure objects have been in recent decades. This article aims to indicate proper conservation practices during construction works...
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Graffiti saves birds: A year-round pattern of bird collisions with glass bus shelters
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