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Search results for: FAULT LOOP IMPEDANCE
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Phong B. Dao D.Sc., Ph.D.
PeoplePhong B. Dao received the Engineer degree in Cybernetics in 2001, the M.Sc. degree in Instrumentation and Control in 2004, both from Hanoi University of Science and Technology in Vietnam, and the Ph.D. degree in Control Engineering in 2011 from the University of Twente, the Netherlands. In May 2020, Dr. Dao received the degree of D.Sc. (Habilitation) in Mechanical Engineering from the AGH University of Science and Technology, Poland....
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Analysis and Detection of Faults at Insulated Conductors of Overhead Medium Voltage Lines
PublicationThe paper dealt with the issue of breakdowns detection of isolated hanging wires on the medium-voltage transmission. The main aim of article is to describe the function of created breakdowns detector and evaluation its. The breakdowns detector is created based in indicators of faults such as touch between tree limbs and insulated wire, touch tree limbs with several phases or fall insulated wire on the ground. Breakdowns detector...
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Two‐functional μBIST for Testing and Self‐Diagnosis of Analog Circuits in Electronic Embedded Systems
PublicationThe paper concerns the testing of analog circuits and blocks in mixed‐signal Electronic Embedded Systems (EESs), using the Built‐in Self‐Test (BIST) technique. An integrated, two‐functional, embedded microtester (μBIST) based on reuse of signal blocks already present in an EES, such as microprocessors, memories, ADCs, DACs, is presented. The novelty of the μBIST solution is its extended functionality. It can perform 2 testing functions:...
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Model-Free Controller Tuning Based on DFT Processing: Application to Induction Motor Drives
PublicationIn this paper, we present a new approach based on discrete Fourier transform (DFT) analysis for controller tuning of the closed-loop system with unknown plant. The DFT analysis is used to process the closed-loop measurements collected online to derive the frequency response of an initial closed-loop system that does not provide a good performance. Based on the closed-loop frequency response data, we propose two methods for tuning PID...
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Application of data driven methods in diagnostic of selected process faults of nuclear power plant steam turbine
PublicationArticle presents a comparison of process anomaly detection in nuclear power plant steam turbine using combination of data driven methods. Three types of faults are considered: water hammering, fouling and thermocouple fault. As a virtual plant a nonlinear, dynamic, mathe- matical steam turbine model is used. Two approaches for fault detection using one class and two class classiers are tested and compared.
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Comparative Evaluation of Multicoil Inductive Power Transfer Approaches Based on Z-source Network
PublicationThis paper describes comparative evaluation between wireless power transfer topologies with utilization of Z-source network. Paper describes components calculation method. List of open-loop, close-loop simulations were conducted to compare both topologies. Spectrum of signals is also researched.
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Aleksandra Karpus dr inż.
PeopleAleksandra Karpus jest absolwentką Matematyki Stosowanej na Wydziale Fizyki Technicznej i Matematyki Stosowanej oraz Informatyki na Wydziale Elektroniki, Telekomunikacji i Informatyki Politechniki Gdańskiej. W latach 2011-2014 pracowała z danymi w przemyśle, wykorzystując bazy danych Oracle. Od 2014 roku jest zawodowo związana z Politechniką Gdańską, obecnie jest zatrudniona na stanowisku adiunkta naukowo-dydaktycznego w Katedrze...
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OBSERVATION OF THE THERMOSIPHON EFFECT IN THE CIRCULATION OF ACETONE AS WORKING FLUID IN MODERN COOLING SYSTEM
Publicationplants or computer server rooms has led to the demand for new and reliable methods for electronic cooling. Because of bigger and bigger power levels and miniaturization of the electronic devices, lack of free space in such a high heat flux. The increasing integration of electronic logy that supposed to be designed for high thermal performance, low mass, and able to work in harsh environments. In this paper presented a prototype...
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A solution of the integrated µBIST for functional and diagnostic testing in mixed-signal electronic embedded systems
PublicationMain problem of the paper is testing of analog circuits and blocks in mixed-signal electronic embedded systems (EESs), using the built-in self-test (BIST) technique. The integrated mBIST based on reusing signal blocks already present in an EES, such as processors, memories, ADCs, is presented. The novelty of the solution is the extended functionality of the mBIST. It can perform 2 testing functions: functional testing and fault...
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Improving Control Dynamics of PMSM Drive by Estimating Zero-Delay Current Value
PublicationDynamic performance of current control loop still remains crucial for position-, speed-, and torque-controlled drives. In the study, a current loop solution has been designed for field oriented control of permanent magnet synchronous motors (PMSM). It enhances typical PI controller with an estimator of zero-delay current (ZDC) value. The ZDC estimation allows for selecting substantially higher controller gain. It reduces control...
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Zastosowanie sygnałów o projektowanych kształtach do diagnostyki obiektów wysoko-impedancyjnych metodą spektroskopii impedancyjnej
PublicationW artykule przedstawiono metodę szybkiej spektroskopii impedancyjnej obiektów o wysokich impedancjach (|Zx| > 1 GOhm) z zastosowaniem sygnałów o projektowanych kształtach. Sygnał pobudzenia wytwarzany jest w module DAQ U2531A i doprowadzany na wejście badanego obiektu za pośrednictwem przetwornika cyfrowo-analogowego (CA). Sygnały odpowiedzi proporcjonalne do napięcia na mierzonej impedancji Zx oraz prądu płynącego przez Zx są...
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Iterative Global Sensitivity Analysis Algorithm with Neural Network Surrogate Modeling
PublicationGlobal sensitivity analysis (GSA) is a method to quantify the effect of the input parameters on outputs of physics-based systems. Performing GSA can be challenging due to the combined effect of the high computational cost of each individual physics-based model, a large number of input parameters, and the need to perform repetitive model evaluations. To reduce this cost, neural networks (NNs) are used to replace the expensive physics-based...
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Resonance problems in UHV transmission lines
PublicationThe paper presents resonance phenomena observed in 400 kV transmission lines in the Polish power system. Two events are analysed, when shunt reactors used for reactive power compensation, caused overvoltages and overcurrent protection tripping as a result of resonance. An oscillographic fault recordings from protection devices are compared to time domain simulation results. The obtained simulation results match fault recordings,...
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Service-based Resilience via Shared Protection in Mission-critical Embedded Networks
PublicationMission-critical networks, which for example can be found in autonomous cars and avionics, are complex systems with a multitude of interconnected embedded nodes and various service demands. Their resilience against failures and attacks is a crucial property and has to be already considered in their design phase. In this paper, we introduce a novel approach for optimal joint service allocation and routing, leveraging virtualized...
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Programmable dynamically changing RC model for evaluation of Dynamic EIS methods and instrumentation
PublicationThe paper concerns the RC equivalent circuit of electrochemical cell with the impedance changed during the experiment. The model was constructed using the digital potentiometers controlled by the microcontroller. This solution allows to control the model impedance by the software means. By creating adequate changes of the impedance spectrum as a time function, the different impedance measurement method can be tested to find out...
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Residual current devices in electric vehicles charging installations
PublicationThe main requirements of national regulations and international standards regarding protection against electric shock in electric vehicle charging installations are presented. The principles of using residual current devices (RCDs) in such installations are discussed. It is pointed out that RCDs are mandatory equipment for safe charging of electric vehicles. It is noted that the standards require the use of RCDs having an appropriate...
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Redundantly Actuated 3RRR Parallel Planar Manipulator - Numerical Analyses of its Dynamics Sensitivity on Modifications of its Platform’s Inertia Parameters
PublicationIn the paper, numerical analyses, as well as dynamics of a complex mechanism, are presented. Two objectives are crucial for the paper: inverse dynamic model is needed (dedicated to be use in the model predictive controller); an identification method is searched (some trajectory parameters are controlled, when specific trajectory is tracked under an open-loop model-based control), as selected parameters must be identified for the...
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Rurka ciepła z pętlą obiegową jako urządzenie do odzysku ciepła
PublicationW pracy przedstawiono możliwości odzysku ciepła za pomocą rurki ciepła z pętlą obiegową (ang. loop heat pipe)
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Multichannel self-optimizing narrowband interference canceller
PublicationThe problem of cancellation of a nonstationary sinusoidal interference, acting at the output of an unknown multivariable linear stable plant, is considered. No reference signal is assumed to be available. The proposed feedback controller is a nontrivial extension of the SONIC (self-optimizing narrowband interference canceller) algorithm, developed earlier for single-input, single-output plants. The algorithm consists of two loops:...
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Indirect adaptive controller based on a self-structuring fuzzy system for nonlinear modeling and control
PublicationIn this paper, a unified nonlinear modeling and control scheme is presented. A self-structuring Takagi-Sugeno (T-S) fuzzymodel is used to approximate the unknown nonlinear plant based on I/O data collected on-line. Both the structure and theparameters of the T-S fuzzy model are updated by an on-line clustering method and a recursive least squares estimation(RLSE) algorithm. The rules of the fuzzy model can be added, replaced or...
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Local properties of organic coatings close to glass transition temperature
PublicationAcrylic coating applied on copper substrate has been investigated at different temperatures starting from the ambient one up to the level above the glass transition temperature. Its local topographic and electric properties have been examined with the atomic force microscopy (AFM) based approach including dc current mapping and local impedance spectroscopy. The local findings have been compared with the information from global...
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Improvement of time difference of arrival measurements resolution by using fractional delay filters in a direct sequence-code division multiple access radionavigation system
PublicationThis study presents a method of improving time measurements resolution in a direct sequence-code division multiple access receiver by using a fine code tracking loop based on fractional delay filtering of a despreading sequence. It briefly describes the structure of a generic digital code tracking loop and the proposed modification which allows to measure time difference of arrival values with the subsample resolution, together...
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Optimising approach to designing kernel PCA model for diagnosis purposes with and without a priori known data reflecting faulty states
PublicationFault detection plays an important role in advanced control of complex dynamic systems since precise information about system condition enables efficient control. Data driven methods of fault detection give the chance to monitor the plant state purely based on gathered measurements. However, they especially nonlinear, still suffer from a lack of efficient and effective learning methods. In this paper we propose the two stages learning...
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A method of measuring RLC components for microcontroller systems
PublicationA new method of measuring RLC components for microcontroller systems dedicated to compact smart impedance sensors based on a direct sensor-microcontroller interface is presented. In the method this direct interface composed of a reference resistor connected in series with the tested sensor impedance is stimulated by a square wave generated by the microcontroller, and then its voltage response is sampled by an internal ADC of the...
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LabVIEW-based intelligent system of protection against electric shock for photovoltaic installations
PublicationEvaluation of shock hazard in installations with photovoltaic sources of energy is more complicated than in a conventional low voltage system. In case of earth fault in photovoltaic generators, that are connected to the AC power public grid, a composite waveform of earth fault current in the installation may occur. For composite waveforms, the safety criteria should be modified. The paper considers the effect of the composite waveforms...
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Low-frequency tripping characteristics of residual current devices
PublicationFast development of various types of converters makes their utilization in industry and in domestic installations very common. Due to converters, an earth fault current waveform in modern circuits can be distorted or its frequency can be different than 50/60 Hz. Frequency of earth fault (residual) current influences tripping of residual current devices which are widely used in low voltage systems. This paper presents the behaviour...
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Electrical Propterties of Solution Mixtures for Bath Supervision in Ambient Assisted Living
PublicationImpedance properties of bath solution are compared. Any ingredient such as soap, shampoo or bathing salt changes bath-solution’s electrical properties eg. impedance. We have measured and analysed influence of typical bathing ingredients on electrical properties of the solution. We investigate impedance changes over frequency range from 100Hz tu 100kHz as it is most applicable for person detection. Electrical properties of bath...
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Photocatalytic ethylene decomposition with the use of fluidized bed photoreactor
Open Research DataData contain exported raw data recorded during decomposition of ethylene during utilization of fluidized bed photoreactor equipped with either UV-LEDs or fluorescent UV lamps as well as in either humid or dry conditions. In separate folder, the photographs of the photocatalytic system were included. As photocatalytic material, polystyrene spheres coated...
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Ethylene decomposition on TiO2 under UV
Open Research DataData contain chromatograms recorded during decomposition of ethylene over TiO2 in a flow reactor under UV irradiation. Semilac UV lamp with total power of 72 W was used as a source of UV light. Chromatograms were recorded in Trace GC Ultra chromatograph equipped in FID detector. Sampling was realised via the dosing sample loop. TiO2 was coated on the...
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Szybkie uziemniki do ograniczania skutków zwarć łukowych w okrętowych rozdzielnicach SN
PublicationW artykule scharakteryzowano moc i napięcie łuku, jak również przedstawiono model termodynamiczny służący do obliczania ciśnienia i temperatury gazów w otoczeniu łuku zwarciowego. Przedstawiono przykładowy układ elektrowni okrętowej i zasilania najważniejszych odbiorników na statku do przewozu gazu ziemnego w stanie ciekłym. Na podstawie parametrów prądnic i silników odbiorników zasilanych z rozdzielnicy głównej obliczono prądy...
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Parametry uziemień przy przebiegach udarowych i wysokoczęstotliwościowych
PublicationW artykule skupiono się na porównaniu dwóch metod badania impedancji uziemienia odgromowego: udarowej z wysoką częstotliwościową. Zestawiono wyniki pomiarów istniejących uziemień z wynikami komputerowych obliczeń symulacyjnych przeprowadzonych w środowisku programu PSIM. Uzyskane wyniki wskazują na poprawność przyjętego toku modelowania, a uzyskane w ten sposób dane mogą być przydatne w fazie projektowania do szacowania...
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Price convergence in the European Union and in the new member states
PublicationThis paper examines price dispersion in the European Union (EU15) and in three New Member States (Poland, Hungary and the Czech Republic) between 1995 and 2006. The analysis utilizes both disaggregate and aggregate price data, including the prices of 157 products and two indices constructed using two different weighting procedures. For each category of goods the price dispersion is lower in EU15 than EU15 plus 3 NMS. Sigma convergence...
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Electrochemical impedance spectroscopy measurements - conductivity vs. temperature and conductivity vs. oxygen partial pressure - BaCe0.6Zr0.2Y0.1Tb0.1O3-δ
Open Research DataThe dataset consists of two main catalogs consisting of measurement data: of the electrical conductivity of the BaCe0.6Zr0.2Y0.1Tb0.1O3-δ (BCZYTb) sample as a function of temperature and of the electrical conductivity as a function of oxygen partial pressure (pO2). Measurements as a function of temperature were carried out in dry and wet air (pH2O ~...
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Demonstrator testera wbudowanego BIST dla układów w pełni różnicowych
PublicationPrzedstawiono demonstrator testera wbudowanego, przeznaczony do pracy na stanowisku dydaktycznym w laboratorium z przedmiotu Zaawansowane Metody Pomiarowe i Diagnostyczne. Na stanowisku studenci zapoznają się z technologią BIST (ang. Built-In Self-Test), która jest przykładem wdrożenia strategii projektowania dla testowania.
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Evaluation of organic coatings condition with AFM-based method
PublicationThe paper presents an atomic force microscopy (AFM)-based approach to evaluation of local protective properties of organic coatings. Apart from topography, it provides local ac and dc characteristics of examined coating. The method consists in application of ac voltage perturbation signal between conductive AFM tip and coated metal substrate. The resulting current is used to determine local impedance characteristics. Both impedance...
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Ethylene decomposition on TiO2 - UV and Fluorescence lamp
Open Research DataData contain chromatograms recorded during decomposition of ethylene flowing over TiO2 through the quartz tubular shape reactor. TiO2 was coated onto glass plates with dimension of 2cmx2cm, in total 3 plates were used and placed inside reactor. Reactor was irradiated by UV (Special 'TL'E, Philips) or fluorescent (Lumilux, OSRAM) 3 ring-shaped lamps,...
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Influence of vacuum sublimation deposited metal layer thickness on metrological parameters of the amperometric gas sensor with Nafion membrane
PublicationThe paper presents the results of investigation on an influence of vacuum sublimation deposited platinum layer thickness on the signal, sensitivity and response time of a prototype of sulphur dioxide sensor with Nafion membrane. The working electrode was made by vacuum sublimation deposition of platinum on a surface of Nafion membrane. Pt layers deposited changed an initial structure of Nafion membrane and that phenomenon was utilized...
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Application of RCD and AFDD in low-voltage electrical installations for protection against fire
PublicationThe paper presents the principles of application of residual current devices (RCDs) in protection against fire. The permissible rated residual operating current of RCDs is discussed. Limitations in the operation of RCDs in this type of protection are indicated. A new type of a protective device against fire – arc fault detection device (AFDD) – is described.
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Adaptive estimation of the transformer stray capacitances for DC–DC converter modelling
PublicationNew low cost and accurate estimation method of transformer stray capacitances for wide band DC–DC converter modelling and design is proposed. The Wiener filter (WF) method is applied to estimate the transformer impedance – referred to the selected transformer winding configurations. Laboratory tests are used to adapt the filter, that is to find optimal impedance which minimises mean square error between measured, noise perturbed...
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Use of Neural Networks in Diagnostics of Rolling-Element Bearing of the Induction Motor
PublicationBearing defect is statistically the most frequent cause of an induction motor fault. The research described in the paper utilized the phenomenon of the current change in the induction motor with bearing defect. Methods based on the analysis of the supplying current are particularly useful when it is impossible to install diagnostic devices directly on the motor. The presented method of rolling-element bearing diagnostics used indirect...
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Optimal retrofit strategy using viscous dampers between adjacent RC and SMRFs prone to earthquake‑induced pounding
PublicationNowadays, retrofitting-damaged buildings is an important challenge for engineers. Finding the optimal placement of Viscous Dampers (VDs) between adjacent structures prone to earthquake-induced pounding can help designers to implement VDs with optimizing the cost of construction and achieving higher performance levels for both structures. In this research, the optimal placement of linear and nonlinear VDs between the 3-story, 5-story,...
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An idea of an approach to self-testing of mixed signal systems based on a quadratic function stimulation
PublicationA new approach to self-testing of the analog parts of mixed-signal electronic systems controlled by microcontrollers equipped with an ADC and a DAC is presented. It is based on a BIST and a new fault diagnosis method. A novelty is the use of the DAC as a component of the BIST, allowing to generate a stimulating signal with a quadratic function shape. It contributes to a better extraction of information about the state of the circuit...
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Wybrane metody przydatne w analizie niezawodności i bezpieczeństwa funkcjonalnego systemów technicznych.
PublicationPrzedstawiono wybrane metody przydatne w analizie niezawodności i bezpieczeństwa funkcjonalnego systemów technicznych takie jak: metoda FMECA (failure mode, effect and criticality analysis, FTA (fault tree analysis, RBD (reliability block diagram) RCM (reliability centered maintenance, LCC (life cycle cost) i PMO (preventive maintenance optimising.
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Computer-Aided Greenery Design—Prototype Green Structure Improving Human Health in Urban Ecosystem
PublicationIncreasing population and urbanization, with climate change consequences, such as rising temperatures, influence public health and well-being. The search to improve the quality of life in cities becomes one of the priority objectives. A solution can be found in the role of greenery in an urban environment and its impact on human health. This opens a path toward experimentation on microclimate green structures that can be inserted...
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Trustworthiness and Subversion in Large Service- Oriented Multi-Agent Systems under Virtual Anonymity and Blind Provider Selection
PublicationTo promote honest service provision in multi-agent systems, a Computational Trustworthiness and Rating scheme collects service ratings and computes agents' trustworthiness levels (TLs). Studies of existing schemes fail to reflect closed-loop dynamics of TLs arising from the mutual influence of agents' behavior and TLs, and to capture relevant properties. Recent simulative and analytical models produce results tied to a particular...
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Active vibration reduction with a use of enegry performance index at acceleration feedback
PublicationW pracy przedstawiono wyniki badań eksperymentalnych i symulacji w trybie Hardware-in-the-loop nowego algorytmu aktywnej redukcji drgań. Algorytm ten bazuje na energetycznym wskaźniku jakości zmodyfikowanym w ten sposób, że wykorzystuje bezpośrednio sygnał sprzężenia zwrotnego przyspieszeń.
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Optimal configuration of an electrode array for measuring ventricles' contraction
PublicationAn influence of an electrode-array configuration on an impedance signal composition for a fixed spatial distribution of its sources is examined in the paper. The Finite Element Method and Geselowitz relationship were used for examining three different electrode-arrays. A sensitivity approach was used to evaluate each configuration assuming that localization of the signal source is known. A conductivity change, thus the source of...
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Nowa metoda optymalizacji pracy ogniw paliwowych.
PublicationPrzedstawiono dynamiczną technikę impedancją jako doskonałe narzędzie służące do określenia optymalnych warunków pracy ogniw paliwowych. Możliwości tej techniki zostały przedstawione na przykładzie ustalenia optymalnej temperatury pracy. Otrzymane wyniki zostały skonfrontowane z charakterystykami prądowo napięciowymi ogniwa.
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A comprehensive evaluation of mimosa extract as a corrosion inhibitor on AA6060 alloy in acid rain solution: part I. Electrochemical AC methods
PublicationThe inhibition effect of mimosa extract on the corrosion of AA6060 aluminum alloy in acid rain solution was investigated by electrochemical impedance spectroscopy and dynamic electrochemical impedance spectroscopy (DEIS). All the studied electrochemical parameters showed good corrosion inhibitive characteristics with respect to the aluminum alloy in the tested solution. Inhibitor efficiency increased with the concentration and...
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Modeling and control of a redundantly actuated variable mass 3RRR planar manipulator controlled by a model-based feedforward and a model-based-proportional-derivative feedforward–feedback controller
PublicationIn the paper, dynamics of a complex mechatronics system is considered. A redundantly actuated planar manipulator is the base of the mechanical part of it. It is a 3RRR 1 platform based parallel manipulator. To control its trajectory, a model-based feedforward controller is employed. Three aspects are fundamental in the presented investigations. The first focus is on development of an accurate numerical model used to solve the inverse...