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Search results for: NAPIĘCIE COMMON MODE
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Local basis function estimators for identification of nonstationary systems
PublicationThe problem of identification of a nonstationary stochastic system is considered and solved using local basis function approximation of system parameter trajectories. Unlike the classical basis function approach, which yields parameter estimates in the entire analysis interval, the proposed new identification procedure is operated in a sliding window mode and provides a sequence of point (rather than interval) estimates. It is...
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The influence of combination of binding agents on fatigue properties of deep cold in-place recycled mixtures in Indirect Tensile Fatigue Test (ITFT)
PublicationThe publication presents fatigue properties of cold recycled mixtures for eight combinations of binding agents (cement and bituminous emulsion). Cold recycled mixtures were evaluated in Indirect Tensile Fatigue Test (ITFT) at the temperature of 20 C in controlled stress mode. As a function of horizontal stress, fatigue life is strongly influenced by combination of the binding agents. When fatigue life is analyzed as a function...
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Jahn-Teller and related conical intersections in the benzene radical cation and the monofluoro derivate
PublicationThe multi-state multi-mode vibronic interactions in the benzene radical cation and its monofluoro derivative have been investigated theoretically, based on high-level electronic structure calculations for the system parameters and a quantum treatment of the nuclear motion. The available experimental data are well reproduced. The interplay of different vibronic coupling mechanisms is pointed out leading to multiple nonadiabatic...
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New concept and analysis of the multicell piezoelectric motor
PublicationThis work presents the design, modeling and tests of the prototype multicell piezoelectric motor (MPM). A new concept of the electromechanical structure of the considered prototype is based on three rotating-mode actuators. The electromechanical structure of each actuator has been considered as an independent one - referred to as a ”single cell” (single actuator). Combined three resonant actuators generate three traveling waves...
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Assessment of copper surface coverage with corrosion inhibitor using AFM-based local electrical measurements
PublicationThe paper presents a new method of assessment of metal surface coverage with corrosion inhibitor and thus of inhibitor protective performance. It is based on the atomic force microscopy measurement performed in a contact mode. Apart from topography images the proposed approach allows acquisition of local DC maps and local electrical impedance spectra via application of DC bias voltage or AC perturbation signal between the conductive...
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Impedance monitoring of corrosion degradation of plasma electrolytic oxidation coatings (PEO) on magnesium alloy
PublicationImpedance technique based on continuous multisinusoidal current perturbation was used to explain degradation process of plasma electrolytic oxidation coatings (PEO) on magnesium alloy. An obtained impedance spectrum was fitted by electrical equivalent circuit to describe properties of conversion layer on magnesium alloy. Additionally, galvanostatic mode maintained during experiment, with DC current equal to zero, allowed to achieve...
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Koncepcja, realizacja i analiza nowego typu silnika piezoelektrycznego o strukturze wielokomórkowej
PublicationDotychczasowe wyniki badań w obszarze aktuatorów piezoelektrycznych, wskazują ich potencjalnie duże możliwości w przyszłych zastosowaniach specjalnych. W artykule przedstawiono proces projektowania nowego typu silnika piezoelektrycznego. Opisane zostały wybrane topologie maszyn piezoelektrycznych. Przedstawiono wady i zalety silnika ultrasonicznego z falą biegnącą oraz silnika o ruchu obrotowym. W ramach realizacji projektu...
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Determination of leakage inductances of multi-winding and single-phase transformer
PublicationThis paper presents the method for determination of leakage inductances of single-phase and multi-winding transformer. The matrix of leakage inductances takes into account leakage self and also leakage mutual magnetic couplings. It is assumed that there is a flux common to all windings and several leakage fluxes referred to a particular winding. The flux linkages of each coil needed fo calculation of leakage inductances was computed...
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Tax Policy Tools of Selected European Countries as a Mechanism for Counteracting the Effects of the Crisis Caused by the COVID-19 Disease Pandemic
PublicationCrises play an important role in a economics life. They are common and it is impossible to omit them. This following study investigates the concept of ‘crisis’ in the context of economic situation. This text describes the most important financial crises that took place in the past. After that authors passes on a detailed analysis of the actual corona-crisis and the way that it affects the economy globally. The main goal of this...
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High-Resolution, Broad-Range Detection Setup for Polarimetric Optical Fiber Sensors
PublicationA common-path polarization interferometer using a Wollaston prism and an area detector for the measurement of retardation or optical path difference is presented. Employing a moderate-resolution 1280 by 1024 pixel monochrome camera, it offers a measurement range of approximately 780 radians at 830 nm and 1350 radians at 515 nm while maintaining a high measurement resolution. Retardation introduced by a zero-order waveplate or a...
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Stakeholders Satisfaction Index as an Important Factor of Improving Quality Management Systems of Universities in Poland
PublicationThe following article analyses the role of stakeholders in selected methods of assessing the quality of educational services of universities and discusses quality management systems according to Common Assessment Framework for education. Furthermore, it presents the example of method of stakeholder satisfaction measurement called Stakeholders Satisfaction Index (SSI) which is an original proposal of an aggregate measure of satisfaction...
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Multiple jets impingement – numerical analysis by the ζ-f and hybrid VLES turbulence models
PublicationPresented paper summarizes the Authors findings referring to the numerical analyses of the jet impinging phenomena in the case of complex jets configurations in various applications e.g. in the heat exchangers. Multiple jets interference resulting in the cross-flow and the surface curvature are the factors which impose the need of advanced turbulence models utilization. The outcome of the research based on the ζ-f turbulence model...
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PCR detection of Scopulariopsis brevicaulis
PublicationScopulariopsis brevicaulis is known as a most common etiological factor of the mould toenail infections. There are also reports indicating that S. brevicaulis could cause organ and disseminated infections. Nowadays microscopic observations from the direct sample and culture are crucial for the appropriate recognition of the infection. In this paper is presented a PCR-based method for S. brevicaulis detection. The specificity of...
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Entrepreneurship after the Age of Sixty–Five? Reflections of Third Age University students
PublicationThe common synonyms for entrepreneurship usually include such concepts as creativity, innovation, and activity. These, in turn, are more often associated with youth rather than people of older age (Górniak, 2013). On the basis of literature research and interviews conducted with students from the Sopot School of Social Psychology of the University of the Third Age, the authors determined that among individuals...
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Motor bearing diagnostics performed by means of laser vibrometer
PublicationDamage of bearings is the most common cause of failures in squirrel-cage induction motors. That is why the issues connected with diagnostics of bearings are so important. The equipment employed for bearing diagnostics usually makes use of vibrations as the criterion for technical condition of the bearings. This paper presents exemplary results of the research conducted on bearings with artificially introduced damage. A scanning...
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Investigation of abdomen surface deformation due to life excitation: implications for implant selection and orientation in laparoscopic ventral hernia repair
PublicationVentral hernia is a common medical problem. Statistically there are around 10% recurrences of the sickness. The authors' former investigation proved edges of the hernia orifice displacements to be one of the factors causing recurrence. Thus, experimental investigation of the abdomen surface deformation due to some normal activities of people is studied.The extreme strains, their localization and directions are identified. The acquired...
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Numerical modal analysis of a vertical rising steel water gate
PublicationVertical rising steel water gates are very common not only in Poland and Germany but also in other countries of the world. Their popularity is mainly attributed to their simplicity of construction, which makes their production process cheaper and faster when compared to other solutions. The aim of this paper is to conduct a numerical modal analysis to examine the eigenvalues and eigenmodes of a vertical rising steel gate. Two cases...
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Numerical Studies on Propellers in Open Water and behind Hulls aiming to support the Evaluation of Propulsion Tests
PublicationA RANS based numerical analysis of propellers can contribute considerably to our understanding of propeller/hull interaction. It may also allow for a review of scaling procedures on results from experimental fluid dynamics (EFD). Using various RANS codes (Fluent, CFX, STAR-CCM+ and FreSCo+) on common test cases the authors first focused on propeller open water (POW) calculations. Next we simulated the propeller hull interaction...
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Analiza symulacyjna wybranych algorytmów dostarczania paczek wiadomości w sieci DTN na Bałtyku
PublicationJedną z dróg zwiększania bezpieczeństwa żeglugi morskiej jest zapewnienie powszechnej dostępności usług e-nawigacji na obszarach morskich pozbawionych dostępu do Internetu. W artykule opisano wyniki symulacji wybranych algorytmów przekazywania wiadomości usług niewrażliwych na opóźnienia w znacznej odległości od lądu, w sieci o nieciągłej i sporadycznej łączności.
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Exploring the Solubility Limits of Edaravone in Neat Solvents and Binary Mixtures: Experimental and Machine Learning Study
PublicationThis study explores the edaravone solubility space encompassing both neat and binary dissolution media. Efforts were made to reveal the inherent concentration limits of common pure and mixed solvents. For this purpose, the published solubility data of the title drug were scrupulously inspected and cured, which made the dataset consistent and coherent. However, the lack of some important types of solvents in the collection called...
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Peptidoglycan hydrolases - potential weapons against Staphylococcus aureus
PublicationBacteria of the genus Staphylococcus are common pathogens responsible for a broad spectrum of human and animal infections and belong to most important etiological factors causing food poisoning. Because of rapid increase in prevalence of isolation of staphylococci resistant to many antibiotics, there is an urgent need for development of new alternative chemotherapeutics. A number of studies have recently demonstrated the strong...
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The influence of electromagnetic pollution on living organisms – historical trends and forecasting changes
PublicationCurrent technologies have become a source of omnipresent electromagnetic pollution from generated electromagnetic fields and resulting electromagnetic radiation. In many cases this pollution is much stronger than any natural sources of electromagnetic fields or radiation. Wireless and radio communication, electric power transmission or devices in daily use such as smartphones, tablets and portable computers every day expose people...
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Authenticity of Architectural Heritage in a Rebuilt City. Comments to Vaclav Havel’s Impression after His Visit in Gdansk in 2005
PublicationThere is no doubt that authenticity is a cardinal feature of architectural heritage and should be protected in the same way as historical and cultural value of monuments or their integrity. Sometimes, one decides to reconstruct a destroyed historical building due to important emotional, scientific, artistic or political reasons (e.g. the Zwinger Palace in Dresden or the Royal Castle in Warsaw). However, the solution which should...
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approximation of photonic crystal fibres with large air holes by the step index fibre model
PublicationAn equivalent step index fibre with a silica core and air cladding is used to model photonic crystal fibres with large air holes. We model this fibre for linear polarisation (we focus on the lowest few transverse modes of the electromagnetic field). The equivalent step index radius is obtained by equating the lowest two eigenvalues of the model to those calculated numerically for the photonic crystal fibres. The step index parameters...
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The Reactivity of the Imine Bond within Polynuclear Nickel(II) Complexes
PublicationThree novel Ni complexes with the Schiff base ligand 2-methoxy-6-(E-2-pyridyliminomethyl)-phenol (L1) are described. In comparison with the similar 2-(pyridine-2-ylimino-methyl)phenol (pymp), the mode of coordination of L1 is altered due to the presence of methoxy substituent introducing the sterical hindrance. During the synthesis of the complexes, partial hydrolysis of the ligand was observed. Since such immediate hydrolysis...
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Hybrid Method Analysis of Unshielded Guiding Structures
PublicationA combination of mode matching, finite element methods and generalized impedance matrix is presented in a context of propagation problems for open guiding structures. The computational domain is divided into two regions: the first one is a circular cylinder containing whole guiding structure and the second one surrounds this artificial cylinder. The impedance matrix is calculated with the use of finite element method in the first...
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Zmodyfikowana metoda prognozowania rezultatów nadzorowania drgań narzędzie--przedmiot obrabiany. W: Projektowanie mechatroniczne. Zagadnienia wybrane. Praca zbiorowa pod red. T. Uhla. Kraków: Kated. Robotyki i Dynam. Masz.AGH**2003 s. 125-134, 3 rys. 1 tab. bibliogr. 6 poz.
PublicationW pracy przedstawiono zmodyfikowaną metodę prognozowania rezultatów nadzoro-wania drgań narzędzie-przedmiot obrabiany za pomocą sterowanej programowo prędkości obrotowej wrzeciona. Istotą modyfikacji jest uwzględnienie w mode-lu złożoności geometrycznej narzędzia oraz efektu rozproszenia energii pro-cesu skrawania. Podano opis dynamiki skrawania niestacjonarnego modelu obli-czeniowego, oraz sposobu nadzorowania. Zamieszczono...
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Design and modeling of the piezoelectric motor based on three resonance actuators
PublicationThis paper describes a piezoelectric motor which combines advantages from two existing piezoelectric motors topologies. The research work presents the design, simulations and measurements of the piezoelectric motor with three rotation-mode actuators. The aim of the project was to obtain the high speed piezoelectric motor. Other advantages of this conception are blocking torque, short response times, the ability to work in a hostile...
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Shielded coupled strip and slot guides with a thin omega pseudochiral medium layer
PublicationA method of moments combined with mode matching technique is applied to analyze the shielded coupled strip and slot line structures containing a thin plate of Omega pseudochiral medium. The boundary problems are simplified by introducing for omega medium the approximate continuity conditions. Such mathematical model allows to examine the field displacement effect appearing in the considered guide resulting from the coupling between...
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Acoustic Heating Produced in the Thermoviscous Flow of a Shear-Thinning Fluid
PublicationThis study is devoted to the instantaneous acoustic heating of a shear-thinningfluid. Apparent viscosity of a shear-thinning fluid depends on the shear rate. Thatfeature distinguishes it from a viscous Newtonian fluid. The special linear combi-nation of conservation equations in the differential form makes it possible to derivedynamic equations governing both the sound and non-wave entropy mode inducedin the field of sound. These...
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Determination of Failure Causes of a Steam Turbine Casing
PublicationThe paper presents results of research and failure analysis undertaken to determine failure causes of a steam turbine casing. After 130,000 hours of service the crack in a outer shell of the turbine casing was found. The inner shell of the casing was made of cast steel grade G21CrMoV5-7, and the outer shell of grade G20CrMo4-5. Following research were performed in order to determine causes of the casing failure: chemical analysis;...
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Fiber optic microsphere with a ZnO thin film for potential application in a refractive index sensor – theoretical study
PublicationOptical fiber sensors of refractive index play an important role in analysis of biological and chemical samples. This work presents a theoretical investigation of spectral response of a fiber optic microsphere with a zinc oxide (ZnO) thin film deposited on the surface and evaluates the prospect of using such a structure for refractive index sensing. A microsphere is fabricated by an optical fiber tapering method on the base of...
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Drgania i hałaśliwość silników asynchronicznych - weryfikacja nowych hipotez
PublicationArtykuł zawiera nowe spojrzenie na postaci drgań kadłuba i tarcz silników asynchronicznych wymuszanych siłami elektromagnetycznymi. Omówiono badania postaci drgań własnych i eksploatacyjnych kadłuba i tarcz łożyskowych. Poddano analizie związki przyczynowo-skutkowe postaci drgań tarcz łożyskowych z łożyskami tocznymi i ślizgowymi. Wykazano, że wibracyjne eksploatacyjne odkształcenia tarcz silników klatkowych małej i średniej mocy,...
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Representation of magnetic hysteresis in a circuit model of a single-phase transformer
PublicationThe paper presents a mathematical model for the hysteresis phenomenon in a multi-winding single-phase core type transformer. The set of loop differential equations was developed for K-th winding transformer model where the flux linkages of each winding includes a flux common Φ to all windings as function of magneto motive force Θ of all windings. The first purpose of this paper is to determine a hysteresis nonlinearity involved...
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Modeling protein structures with the coarse-grained UNRES force field in the CASP14 experiment
PublicationThe UNited RESidue (UNRES) force field was tested in the 14th Community Wide Experiment on the Critical Assessment of Techniques for Protein Structure Prediction (CASP14), in which larger oligomeric and multimeric targets were present compared to previous editions. Three prediction modes were tested (i) ab initio (the UNRES group), (ii) contact-assisted (the UNRES- contact group), and (iii) template-assisted (the UNRES-template...
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A spline-based FE approach to modelling of high frequency dynamics of 1-D structures
PublicationIn this paper a computational methodology leading to the development of a new class of FEs, based on the application of continuous and smooth approximation polynomials, being splines, has been presented. Application of the splines as appropriately defined piecewise elemental shape functions led the authors to the formulation of a new approach for FEM, named as spFEM, where contrary to the well-known NURBS approach, the boundaries...
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Microfluidically Frequency-Reconfigurable Compact Self-Quadruplexing Tunable Antenna with High Isolation Based on Substrate Integrated Waveguide
PublicationThis communication presents a novel concept of microfluidically frequency-reconfigurable self-quadruplexing tunable antenna for quad-band applications. At the initial design stage, a substrate-integrated square cavity is divided into four unequal quarter-mode cavity resonators by inserting an X-shaped slot on the top surface of the cavity. Applying four 50-ohm microstrip feed-lines to these four quarter-mode cavity resonators enables...
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Application of dynamic headspace and gas chromatography coupled to mass spectrometry (DHS-GC-MS) for the determination of oxygenated volatile organic compounds in refinery effluents
PublicationThe paper presents a new procedure for the determination of oxygenated volatile organic compounds (O-VOCs) in postoxidative effluents from the production of petroleum asphalt using dynamic headspace coupled to gas chromatography-mass spectrometry in the selected ion monitoring (SIM) mode (DHSGC-MS). Among the GC capillary columns tested, a polar SLB-IL111 column with the ionic liquid stationary phase was found to be superior due...
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Wykorzystanie sztucznych sieci neuronowych do szacowania wpływu drgań na budynki jednorodzinne
PublicationW artykule przedstawiono metodę prognozowania wpływu drgań na budynki mieszkalne z wykorzystaniem sztucznych sieci neuronowych. Drgania komunikacyjne mogą doprowadzić do uszkodzenia elementów konstrukcyjnych, a nawet do awarii budynku. Najczęstszym efektem są jednak rysy, pękanie tynku i wypraw. Metody oparte na sztucznej inteligencji są przybliżone, ale stanowią wystarczająco dokładną i ekonomiczną alternatywę dla tradycyjnych...
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Podejście nauczycieli akademickich do rozwoju narzędzi e-learningowych na wyższych uczelniach technicznych
PublicationPlatforma edukacyjna na uczelni wyższej stała się już standardem. Jest wyznacznikiem nowoczesno- ści danej uczelni. Wpływa na jej konkurencyjność. Mimo to, istnieje przekonanie że środowisko nauczycieli akademickich nie jest gotowe do akceptacji nowych środków nauczania. Postanowiono zbadać ten problem. Artykuł zawiera odpowiedź na pytanie jaki stosunek do metod e-nauczania panuje wśród nauczycieli akademickich, nie posiadających...
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Cough influence on fascia-mesh system built for a hernia repair - an experimental research
PublicationAn experimental approach to identify stronger and weaker fixation schemes in laparoscopic ventral hernia repair is presented in the paper. Two types of implants, whose mechanical properties are significantly different and five kinds of connectors are considered. Physical models of operated hernia have been built using those materials and porcine abdominal tissue. The models have been subjected to dynamic impulse load, similar to...
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Exploring ontological approach for user requirements elicitation in design of online virtual agents
PublicationEffective user requirements elicitation is a key factor for the success of software development projects. There are many qualitative and quantitative research studies that promulgate particular methods and show the application of user requirements elicitation in particular domains. However, few try to eliminate the burden of ambiguity in gathered data, naturally occurring in different groups of stakeholders. This paper deals with...
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Selected Features of Dynamic Voting
PublicationIn multi-agent systems composed of autonomous agents with local knowledge, it is often desirable to aggregate their knowledge in order to make an educated decision. One of the methods of agreeing to a common decision is voting. A new history-based dynamic weight protocol allows for identification of the agents which contribute to the correct system decision. The main advantage of this approach, compared to static weighted system...
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Critical Case Stochastic Phylogenetic Tree Model via the Laplace Transform
PublicationBirth–and–death models are now a common mathematical tool to describe branching patterns observed in real–world phylogenetic trees. Liggett and Schinazi (2009) is one such example. The authors propose a simple birth–and–death model that is compatible with phylogenetic trees of both influenza and HIV, depending on the birth rate parameter. An interesting special case of this model is the critical case where the birth rate equals the...
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Problems and Solutions of Software Design in Scrum Projects
PublicationThe aim of the paper is to identify the problems and solutions of the software design in Scrum project as well as to analyze the effectiveness of the solutions. Through a series of workshops with 4 experts from IT industry and academia we have identified 52 problems and 99 unique solutions. In this paper we present a list of 10 common problems and 5 solutions for each problem selected by the number of sources. The effectiveness...
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The Urbanity Phenomenon – Tradition and New Cultural Iterations
PublicationCities that have managed to survive and rebuild lost urbanity do not close themselves towards new forms that are largely generated by culture. People are increasingly organized around common, local goals. They want to live in cities that open themselves up to differences, with culture as a tool for the revitalization of urbanity. Flexible management methods, tailored to the context and new needs, are therefore emphasized. Nowadays,...
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XXX Europejskie Dni Dziedzictwa. Zaspa Nova, wystawa projektów studenckich
PublicationWystawa stanowi element projektu 30. obchodów Europejskich Dni Dziedzictwa, z podtytułem tegorocznej edycji: „Połączeni Dziedzictwem”. Nowe spojrzenie i włączenie elementów własnej kultury reprezentowane studentów z Niemiec, Hiszpanii, Turcji, Szkocji, Kraju Basków, Włoch, Grecji i Portugalii pozwala nam, gdańszczanom spojrzeć na znane dobrze osiedle z innej perspektywy. Projekty pokazują nieoczekiwane interpretacje odkrywające...
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Дослідження проблем зайнятості випускників навчальних закладів
PublicationУ зв'язку зі зниженням загального рівня зайнятості та з огляду на кризові явища в українській економіці актуальною залишається проблема працевлаштування молоді. Спільність проблеми зайнятості випускників вишів як в Україні, так і в Європі дала змогу провести міжнародне дослідження, щоб виявити основні причини її виникнення. Результати досліджень підтвердили гіпотезу авторів. В її основі лежить комплекс причин, що пов’язані як зі...
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Transient States during Short-circuit in a Line Powered by UPS and its Impact on Earth Fault Loop Impedance Measurement and Power Quality
PublicationThe short-circuit in a line powered by Uninterruptible Power Supply (UPS) during different UPS operation modes is presented in the article. The transient state condition related to the short-circuit in a line fed from double conversion On-line UPS is discussed in detail. The results of the measurements of earth fault loop impedance (FLI) in circuits powered by UPS with the instruments of various manufacturers are presented. The...
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Asymmetrical Modes in Polyphase Motors and Drives
PublicationThe effect of power supply and/or motor asymmetry on the phase-load distribution and the ripple of electromagnetic torque in a polyphase drive is studied by the method of symmetrical components. It is shown that the presence of asymmetry causes the mapping of all harmonics in the supply voltage into all planes of symmetrical components and eliminates the possibility of independent control of harmonics. The dynamic model of a five-phase...