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Search results for: SINGLE-PHASE TRANSFORMER
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A simple modular active power electronic transformer
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Topochemical, Single‐Crystal‐to‐Single‐Crystal [2+2] Photocycloadditions Driven by Chalcogen‐Bonding Interactions
PublicationThe face-to-face association of (E)-1,2-di(4-pyridyl)ethylene (bpen) molecules into rectangular motifs stabilized for the first time by chalcogen bonding (ChB) interactions is shown to provide photoreactive systems leading to cyclobutane formation through single-crystal-to-single-crystal [2+2] photodimerizations. The chelating chalcogen bond donors are based on original aromatic, ortho-substituted bis(selenocyanato)benzene derivatives...
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Jarosław Guziński prof. dr hab. inż.
PeopleJaroslaw Guzinski received M.Sc., Ph.D. and D.Sc. degrees from the Electrical Engineering Department at Technical University of Gdansk, Poland in 1994, 2000 and 2011 respectively. Since 2016 he is Associate Professor at Gdansk University of Technology. Currently he is the head of the Department of Electric Drives and Energy Conversion. From 2006 to 2009 he was involved in European Commission Project PREMAID Marie Curie, ‘Predictive...
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THERMION-C2S_0301 Phase transition in Cu1.96Se
Open Research DataInvestigation of a phase transition in Cu1.96Se was investigated. The data contains results of thermal analysis (DSC) and thermoelectric properties measurements. These measurements were performed with different heating and cooling rates. Structure and elemental composition were also analysed. The data shows the influence of the kinetics of the transition...
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A new approach to a fast and accurate design of microwave circuits with complex topologies
PublicationA robust simulation-driven design methodology of microwave circuits with complex topologies has been presented. The general method elaborated is suitable for a wide class of N-port unconventional microwave circuits constructed as a deviation from classic design solutions. The key idea of the approach proposed lies in an iterative redesign of a conventional circuit by a sequential modification and optimisation of its atomic building...
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PHASE OBJECT OBSERVATION SYSTEM BASED ON DIFFRACTION PHASE MICROSCOPY
PublicationIn 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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Ultrasonic spectroscopy of silicon single crystal
PublicationSpecimens of Si single crystals with different crystal orientation [100] and [110] were studied by the electro-ultrasonic spectroscopy (EUS) and Resonant Ultrasonic Spectroscopy (RUS). A silicon single crystal is an anisotropic crystal, so its properties are different in different directions in the material relative to the crystal orientation. EUS is based on interaction of two signals: electric AC signal and ultrasonic signal,...
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Internationalization and Europeanization of Businesses in the Single European Markets
PublicationThe aim of the article is to determine internationalization and Europeization of businesses in the Single European Market, especially the territorial scope of their international activities
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Principles and Developments of Solid-Phase Microextraction
PublicationSample 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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Design of a simple modular active power electronic transformer
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Some remarks on the design of microstrip to coplanar line transformer.
PublicationPrzedyskutowano technikę projektowania transformatora standardu umożliwiającego współpracę linii mikropaskowej i linii koplanarnej. Jako sekcję pośrednią wykorzystano uziemiony falowód koplanarny (conductor backed coplanar waveguide). Dokonano oceny różnych profili sekcji pośredniej w oparciu o szereg symulacji elektromagnetycznych, jak i pomiarów charakterystyk transmisji wykonanych modeli transformatorów.
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Demagnetization of the core and reduction of power transformer inrush current
PublicationW artykule przedstawiono metodę ograniczenia prądów włączania transformatora energetycznego za pomocą demagnetyzacji rdzenia magnetycznego. Jako źródło energii do demagnetyzacji w proponowanej metodzie zastosowano kondensator. Do wytworzenia pola rozmagnesowującego wykorzystano uzwojenia robocze transformatora. Przeprowadzono obliczenia magnetyzmu szczątkowego rdzenia po demagnetyzacji dla różnych wartości pojemności, napięcia...
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Digital structures for high-speed signal processing
PublicationThe work covers several issues of realization of digital structures for pipelined processing of real and complex signals with the use of binary arithmetic and residue arithmetic. Basic rules of performing operations in residue arithmetic are presented along with selected residue number systems for processing of complex signals and computation of convolution. Subsequently, methods of conversion of numbers from weighted systems to...
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Atomistic Surrogate-Based Optimization for Simulation-Driven Design of Computationally Expensive Microwave Circuits with Compact Footprints
PublicationA robust simulation-driven design methodology for computationally expensive microwave circuits with compact footprints has been presented. The general method introduced in this chapter is suitable for a wide class of N-port un-conventional microwave circuits constructed as a deviation from classic design solutions. Conventional electromagnetic (EM) simulation-driven design routines are generally prohibitive when applied to numerically...
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Laboratory Load Model Based on 150 kVA Power Frequency Converter and Simulink Real-Time – Concept, mplementation, Experiments
PublicationFirst section of the paper provides technical specification of laboratory load model basing on 150 kVA power frequency converter and Simulink Real-Time platform. Assumptions, as well as control algorithm structure is presented. Theoretical considerations based on criteria which load types may be simulated using discussed laboratory setup, are described. As described model contains transformer with thyristor-controlled tap changer,...
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High step-up continuous input current LCCT-Z-source inverters for fuel cells
PublicationFalowniki typu Z (ZSI) przeznaczone są do układów wymagających szerokiej zmiany wzmocnienia napięciowego, np. w energetyce odnawialnej. Ostatnio zaproponowano w literaturze zmienione struktury - falowniki typu Trans-Z (TZSI) oraz typu T (TSI) - w których dzięki zastosowaniu dławików sprzężonych uzyskano lepsze wzmocnienie niż w ZSI. W tym artykule przedstawiono ideę rozszerzonej struktury TZSI. Zaproponowano dwie nowe struktury...
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The Assessment of the Influence of Low-Frequency Electromagnetic Fields Originated from the Power Infrastructure on Humans’ Health
PublicationThe objective of this study is to assess the impact of low-frequency electromagnetic fields (LF EMFs) generated by power infrastructure on the nearby environment. Measurements of electric (E) and magnetic (H) field intensities were conducted around high-voltage power lines, transformer stations and facilities related to them. Numerical simulations were also performed to model the distribution of the field values around real buildings...
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Reliable data-driven modeling of high-frequency structures by means of nested kriging with enhanced design of experiments
PublicationData-driven (or approximation) surrogate models have been gaining popularity in many areas of engineering and science, including high-frequency electronics. They are attractive as a way of alleviating the difficulties pertinent to high computational cost of evaluating full-wave electromagnetic (EM) simulation models of microwave, antenna, and integrated photonic components and devices. Carrying out design tasks that involve massive...
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Separability in terms of a single entanglement witness
PublicationThe separability problem is formulated in terms of a characterization of a single entanglement witness. More specifically, we show that any (in general multipartite) state rho is separable if and only if a specially constructed entanglement witness W-rho is weakly optimal, i.e., its expectation value vanishes on at least one product vector. Interestingly, the witness can always be chosen to be decomposable. Our result changes the...
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Sensing Direction of Human Motion Using Single-Input-Single-Output (SISO) Channel Model and Neural Networks
PublicationObject detection Through-the-Walls enables localization and identification of hidden objects behind the walls. While numerous studies have exploited Channel State Information of Multiple Input Multiple Output (MIMO) WiFi and radar devices in association with Artificial Intelligence based algorithms (AI) to detect and localize objects behind walls, this study proposes a novel non-invasive Through-the-Walls human motion direction...
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Green aspects, developments and perspectives of liquid phase microextraction techniques
PublicationDetermination of analytes at trace levels in complex samples (e.g. biological or contaminated water or soils) are often required for the environmental assessment and monitoring as well as for scientific research in the field of environmental pollution. A limited number of analytical techniques are sensitive enough for the direct determination of trace components in samples and, because of that, a preliminary step of the analyte...
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Single-Family Treatment Wetlands Progress in Poland
PublicationLong distances from one farm to another as well as unfavourable terrain configuration in rural areas in Poland result in high investment and operation costs of sewerage systems. Treatment wetlands (TWs) can be an alternative solution to sewage treatment in rural communities, schools, at campsites and for single houses. In this paper the results of 4 years monitoring of single-family treatment plants (SFTWs) in Kaszuby Lake...
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Asynchronous phase-location system
PublicationThis 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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Mechanical exfoliation and layer number identification of single crystal monoclinic CrCl3
PublicationAfter the recent finding that CrI3, displays ferromagnetic order down to its monolayer, extensive studies have followed to pursue new two-dimensional (2D) magnetic materials. In this article, we report on the growth of single crystal CrCl3 in the layered monoclinic phase. The system after mechanical exfoliation exhibits stability in ambient air (the degradation occurs on a time scale at least four orders of magnitude longer than...
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FLUID PHASE EQUILIBRIA
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Monitoring of single-side lap grinding with electroplated tools
PublicationThe results presented in the paper show that utilising microphones as audible sound sensors is a suitable approach for monitoring a single-side lap grinding process due to the low levels of noise generated by the drives of a machine tool. The results confirm that sound signal analysis is a feasible and relatively simple method to monitor a lap grinding process with the use of an audible sound sensor. Proposed method can be used...
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Nonlinear secondary arc model use for evaluation of single pole auto-reclosing effectiveness
PublicationPurpose – The purpose of this paper is to discuss two evaluation methods of single pole autoreclosing process effectiveness in HV transmission lines. Secondary arc current and recovery voltage results obtained by load flow calculation are compared to the results obtained by the time domain simulations. Moreover, a nonlinear secondary arc implementation is presented. Design/methodology/approach – A computer simulation studies were...
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Design and evaluation of a base module of active power electronic transformer
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Adaptacyjny regulator transformatora blokowego = Adaptive controller of generator transformer
PublicationW referacie przedstawiono koncepcję adaptacyjnego regulatora transformatora blokowego jako narzędzia do rozszerzenia ograniczeń generacji mocy biernej generatora synchronicznego.
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Management of MV/LV Transformer Replacement Based on AMI Platform
PublicationThe paper presents the extended possibilities of managing the selection and replacement of MV/LV transformers using the measurement data from the Advanced Metering Infrastructure (AMI) system. The analysis was conducted on samples of over 1900 transformers that operate in two different types of MV grids: rural and urban. The analysis has shown that there is a great potential in the field of optimizing the rated power of the transformers.
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Secondary arc modelling for single pole reclosing analyses
PublicationThe paper discusses two evaluation methods of single pole auto-reclosing process effectiveness in HV transmission lines. Secondary arc current and recovery voltage calculation results obtained by load flow calculation are compared to the results obtained by the time domain simulations. Moreover, a nonlinear secondary arc model implementation is presented. The paper presents the study results for the three types of EHV transmission...
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Single crystal growth and physical properties of MCo2Al9 (M= Sr, Ba)
PublicationSingle crystals of SrCo2Al and BaCo2Al9 were grown using a self-flux method. A LeBail analysis of the powder X-ray diffraction patterns show that both compounds crystallize in a hexagonal (P6/mmm) crystal structure with lattice parameters: a = 7.8995(1) Å, c = 3.9159(1) Å for SrCo2Al9, and a = 7.9162(2) Å, c = 3.9702(1) Å for BaCo2Al9 aluminide. The low temperature analysis of the heat capacity measurements give a Sommerfeld...
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Miniaturized solid-phase extraction techniques
PublicationMore 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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New Polymeric Materials for Solid Phase Extraction
PublicationSolid phase extraction (SPE) is a popular sample preparation technique, which can be applied directly in gas–solid phase and liquid–solid phase, or indirectly to solid samples by using, e.g., thermodesorption with subsequent chromatographic analysis. Although SPE can be described as a physical extraction process involving a liquid phase and a solid phase, the increased use of packed sorbent formats seems to have led to a bias toward...
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THE PHASE SHIFTERS INFLUENCE ON THE POWER SYSTEM STABILITY
PublicationThe 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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Modelowanie ciągów danych z użyciem sieci neuronowych
PublicationRozdział opisuje problematykę przetwarzania ciągów danych. Opisane zostały typy ciągów danych: dane sekwencyjne, sekwencje czasowe oraz przebiegi czasowe. Przedstawiona została architektura sieci rekurencyj
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Design-Oriented Two-Stage Surrogate Modeling of Miniaturized Microstrip Circuits with Dimensionality Reduction
PublicationContemporary microwave design heavily relies on full-wave electromagnetic (EM) simulation tools. This is especially the case for miniaturized devices where EM cross-coupling effects cannot be adequately accounted for using equivalent network models. Unfortunately, EM analysis incurs considerable computational expenses, which becomes a bottleneck whenever multiple evaluations are required. Common simulation-based design tasks include...
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Constrained multi-objective optimization of compact microwave circuits by design triangulation and pareto front interpolation
PublicationDevelopment of microwave components is an inherently multi-objective task. This is especially pertinent to the design closure stage, i.e., final adjustment of geometry and/or material parameters carried out to improve the electrical performance of the system. The design goals are often conflicting so that the improvement of one normally leads to a degradation of others. Compact microwave passives constitute a representative case:...
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Dynamic Response of the Suspended on a Single Cable Footbridge
PublicationThe article presents numerical simulations, dynamic in situ load tests and a structural health monitoring (SHM) system installed in a suspended on a single cable footbridge. Numerical simulations performed prior to construction indicated the possibility of structural dynamics problems, finally confirmed in the course of dynamic test loading. In the dynamic load course the bridge deck developed vibrations displaying accelerations...
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Critical behaviour of the smectic A*–C* phase transition and electroclinic effect of ferroelectric liquid crystals with terphenyl rigid core
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Unequally-Spaced Slot Strategy for Radiation Null Reduction in Single SIW-Embedded Antenna Element
PublicationThe incorporation of higher-order modes (HOMs) can substantially augment the antenna gain and bandwidth, but this improvement is typically accompanied by compromised radiation performance including radiation nulls and higher side lobe levels. In this study, an inventive strategy is introduced to reduce the radiation nulls and the side lobe levels of a single antenna element by positioning multiple slots of the radiating element...
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Phase transition of a dimorphic fungus Penicillium marneffei
PublicationPenicillium marneffei is a pathogenic fungus that afflicts immunocompromised individuals who live or travel in Southeast Asia. This species is unique, because it is the only dimorphic member of the genus Penicillium. Dimorphism results from a process, termed phase transition, which is regulated by temperature of incubation. At room temperature, the fungus grows filamentously (mould phase), but at body temperature (37°C), a uninucleate...
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Automated Design of Linear Phase Filters
PublicationThis 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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Growth and characterization of PrBa2Cu3O7-δ single crystals
PublicationWe report on the growth of PrBa2Cu3O7-δ single crystals in the Al2O3 and ZrO2 crucibles by flux method. The high influence of the reaction between crucible and liquid on the initial melt composition has been established. We found that the precipitation of the chemically stable compound BaZrO3 and BaAl2O4 occurs by direct chemical reaction between BaCuO2 and ZrO2 or Al2O3 crucibles materials. Free separated crystals with maximum...
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On phase equilibrium of an elastic liquid shell with wedge disclination
PublicationBased on the six-parameter shell theory we consider the phase equilibrium of a two-phase liquid membrane containing a wedge disclination. The considered problems are related to modelling of phase transitions in biological or lipid membranes. In order to capture the membrane behaviour we consider a special case of elastic shells which energy is invariant under major transformations of a reference configuration and can be treated...
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Flow Boiling in Minigap in the Reversed Two-Phase Thermosiphon Loop
PublicationThe paper presents the results of experimental investigations of a model of a heat exchanger featuring a minigap, which is perceived as an evaporator for an inverted thermosiphon. The system works with a single component test fluid. The tested evaporator generates pumping power in the test loop in a way similar to the mammoth pump. The tests regarded a module of the heat exchanger, consisting of a hot leg and a cold leg with the...
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Liquid–phase microextraction: A review of reviews
PublicationSample 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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Stability and phase transition investigation of olanzapine polymorphs
PublicationWe use electrical embedded-fragment QM method with both DFT/ωB97XD/6-31G* and MP2/6-31G* to investigate the phase transformations of olanzapine. Gibbs free energy calculations predict that form I is always the most stable structure and form II is the least stable one, while form IV is more stable than form III below about 200 K but less stable above this temperature, implying a polymorphic phase transformation. This may account...
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Estimation of a single balun parameters on the base of back-to-back measurements
PublicationA method of estimation of a single balun S parameters based on the measured parameters of back-to-back configuration is presented in the paper. Proposed approach is to measure two back-to-back circuits: i) direct connection of baluns and ii) connection with additional transmission line segment between the baluns. Coupling effects in both circuits are calculated from full-wave simulations. Next they are applied to estimate the parameters...
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Phase-difference positioning in asynchronous system
PublicationThis 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.