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Wyniki wyszukiwania dla: sedimet flux
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Flux
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Sediment
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Toxicity Assessment by Microtox® in Sediments, Pore Waters and Sediment Saline Elutriates in the Gulf of Gdansk (Baltic Sea)
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The home-made in situ passive flux sampler for the measurement of monoterpene emission flux: preliminary studies
PublikacjaThe paper presents the construction and metrological characteristics of the home-made in situ passive flux sampler, an analytical tool representing small-scale emission chambers working in situ and passively sampling analytes from the gaseous phase. The sorption element was a cylindrical container made of stainless steel net, packed with a carbon sorbent bed-graphitized charcoal, Carbograph 4 (35/50mesh). The recommended working/exposure...
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Analysis of leakage flux in deenergized transformer
PublikacjaThe article presents the numerical analysis of the magnetic field that occurs around the transformer after it has been switched off. The purpose of this analysis was to determine if it is possible to define the residual fluxes in the legs of transformer based on the measurements of this field. These studies have allowed us to determine the quantity and location of the sensors. The influence of the Earth's magnetic field has also...
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The Influence of Permanent Magnet Length and Magnet Type on Flux-control of Axial Flux Hybrid Excited Electrical Machine
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Edge effects for heat flux in fibrous composites
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Modeling of Axial Flux Permanent Magnet Generators
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Research of IPM electrical machine with flux barriers
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The flux compression generator load parameters selection
PublikacjaComputer simulation results of the flux compression generator (FCG) loaded with an inductor has been presented in this paper. Simulation research has been performed in order to select the parameters of FCG load coil properly. The influence of the load inductance and resistance on the current gain factor and the magnetic field energy accumulated in a load coil has been investigated.
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Wetlands in flux: looking for the drivers in a central European case
PublikacjaPlanet Earth is undergoing significant changes which are driven by natural and anthropogenic factors. However, it is difficult to identify the drivers and their effect on the environment and ecosystems because there are many interdependencies. In this study we present a multi-parameter approach to assess the effect of changes in human-induced and natural drivers on a wetland ecosystem. The study area is one of the most prominent...
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Model of coreless axial flux permanent magnet generator
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Hybrid excited electric machine with axial flux bridges
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Reduction of the Velocity Impact on the Magnetic Flux Leakage Signal
PublikacjaThe velocity effect on the magnetic flux leakage (MFL) signal was investigated in this paper. Experiments were performed for velocity of the MFL tool within the range of 0–2 m/s. The velocity was not constant during each measurement to imitate real operational conditions of the MFL tool. Two components of the leakage were measured, i.e. the tangential to the motion direction (x) and the normal to the investigated surface (z). In...
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A device for measuring heat flux on a rocket skin surface
PublikacjaA novel method for measuring heat flux on a surface is presented. It is an extensive upgrade of currently known heat flux sensors used mostly in civil engineering. As the thermal environment of launchers, especially sounding rocket can have an enormous negative effect on payload, careful considerations have to be taken in the process of preparing insulation. Usually, thermal data provided by the launch vehicle manufacturer is limited...
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Dynamics of Field Line Mappings in Magnetic Flux Tubes
PublikacjaWe study the topological constraints on the dynamics of magnetic field lines in flux tubes. Our approach is based on the application of the topological invariant: fixed point index. We consider periodic flux tubes and find various restrictions on the field lines that come from the sequence of fixed point indices of iterations. We also analyze the case of a tube with a cylindrical obstacle, deducing some special dynamical properties...
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Modelling of the Heat Flux Density Distribution for Laser Beam Welding
PublikacjaGreat interest of the laser beam welding in industry is a new theoretical task, making planning the welding procedure specification and the quality control of welded joints easier. Estimating and calculating the dimensions of a weld pool and temperature distribution near weld mainly concern heat source modelling. In the presented work calculations of welding pool shape and thermal field for cylindrical-powered-normally model of...
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Controlling the europium oxidation state in diopside through flux concentration
PublikacjaThis paper explores the connection between the H3BO3 flux concentration and the co-existence of Eu2+ and Eu3+ dopants within CaMgSi2O6 crystals (diopside). The samples were synthesised using a solid-state synthesis method under varying atmospheric conditions, including oxidative (air), neutral (N2), and reductive (H2/N2 mixture) environments. Additionally, some materials underwent chemical modification by partially substituting...
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Effects of Storing Flux-Cored Wires under Various Conditions
PublikacjaWelding processes involving the use of flux-cored wires are becoming increasingly popular, particularly in shipbuilding as well as in off-shore and civil engineering. The article presents characteristics of the welding process, its areas of application as well as advantages and disadvantages (e.g. necessity of ensuring appropriate conditions for the storage of filler metal wires). The satisfaction of quality-related requirements...
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Diffusible Hydrogen Control in Flux Cored Arc Welding Process
PublikacjaOne of the types of hydrogen degradation of steel welded joints is cold cracking. The direct cause of the formation of cold cracks is simultaneous presence of hydrogen, residual stresses and brittle structure. The way of preventing the occurring of degradation is to eliminate at least one of these factors. Practice has shown that the best solution is to control the amount of hydrogen in deposited metal. In this paper an experimental...
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Inspection of Gas Pipelines Using Magnetic Flux Leakage Technology
PublikacjaMagnetic non-destructive testing methods can be classified into the earliest methods developed for assessment of steel constructions. One of them is the magnetic flux leakage technology. A measurement of the magnetic flux leakage is quite commonly used for examination of large objects such as tanks and pipelines. Construction of a magnetic flux leakage tool is relatively simple, but a quantitative analysis of recorded data is a...
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Performance Evaluation of an Axial Flux Machine with a Hybrid Excitation Design
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JOURNAL OF SOILS AND SEDIMENTS
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INVESTIGATION OF BOTTOM SEDIMENT STRATIFICATION
PublikacjaThe main goal of this paper is to find a method to assess remotely the type of sediments on the basis of the signal received using the parametric echosounder. The images of the sea bottom sediments taken by a parametric echosounder show the fine structure of the upper layer of the bottom sediments. The depth of penetration depends on the type of sediment, in fact on the attenuation of acoustic wave. In the paper the method of distinguishing...
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Determination of tributyltin in marine sediment.
PublikacjaPrzedstawiono wyniki badań międzynarodowego porównawczego, międzylaboratoryjnego oznaczania zawartości tributylocyny w osadzie morskim. Badania były organizowane przez Comite Consultatif pour la Quantite de Matiere (CCQM) pilot study P-18 international intercomparison i była to ich pierwsza część - badania pilotażowe. W badaniach uczestniczyło 11 laboratoriów. Uzyskano zadowalająco zgodne wyniki oznaczeń tributylocyny.
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Non-Destructive Testing for the In Situ Assessment of the Ionic Flux in Cementitious Materials
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Exploring the trends in flux-cored arc welding: scientometric analysis approach
PublikacjaFlux-cored arc welding (FCAW) is a universal group of welding methods in terms of the scope of application and automation possibilities, the share of which in various industries in many countries is still increasing. The paper presents the results of bibliographic analyses (scientometric analysis with the use of VOSviewer, Bibliometrix and CitNetExplorer tools) of a data set of 993 publications indexed in the Web of Science database...
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A fast algorithm for computing the flux around non-overlapping disks on the plane
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Rotor-Flux Vector based Observer of Interior Permanent Synchronous Machine
PublikacjaThe sensorless control system of the interior permanent magnet machine is considered in this paper. The control system is based on classical linear controllers. In the machine, there occurs non-sinusoidal distribution of rotor flux together with the slot harmonics, which are treated as the control system disturbances. In this case, the classical observer structure in the (d-q) is unstable for the low range of rotor speed resulting...
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Preliminary studies of seamless flux cored wires stored in extreme conditions
PublikacjaIn the paper preliminary experimental studies of flux cored wires moisturized under controlled conditions are described. Three seamless wires of different grades have been placed in environmental chamber and moisturized in extremely adverse conditions (temperature T = 60° C, relative humidity H = 90%) for 240 hours. During this time measurements of weight gain and observations of surface of wires have been carried out. Also diffusible...
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Assessment of absorbability of seamless flux cored wires stored in extreme conditions
PublikacjaWater absorption tests by gravimetric method of three specimens of seamless rutile flux cored wires for flux cored arc welding were carried out. Examined wires are characterized by varied absorbability (Wg is ranged from 0.03 to 0.11% after 200 h of moisturizing).
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A Wind Energy Conversion System Based on a Generator with Modulated Magnetic Flux
PublikacjaIn this work, the concept of an energy conversion system for wind turbines based on the modified permanent magnet synchronous generator (PMSG) is presented. In the generator, a pair of three-phase windings is used, one of which is connected in a “star” and the second in a “delta” configuration. At the outputs of both windings, two six-pulse uncontrolled (diode) rectifiers are included. These rectifiers are mutually coupled by a...
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SEDIMENT DEPOSITION IN RESERVOIRS IN URBAN BASIN
PublikacjaIn recent years Gdańsk had sustained economic and social losses due to severe flash floods coming down from moraine hills. The first flood occurred in July 2001 and the second in July 2016. Both events were caused by intense and long rainfall characterized by different from each other rain intensity in time. Among other Gdansk’s streams the Oliwski Stream has the most extended flood protection system consist of 15 small retention...
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Trends and variability of the atmosphere–ocean turbulent heat flux in the extratropical Southern Hemisphere
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Influence of circuit breaker operation upon transformeros residual flux and inrush current
PublikacjaPrzedstawiono model i wyniki obliczeń prądu i strumienia magnetycznego w układzie zawierającym transformator trójfazowy i wyłącznik. Opracowano obwodowy model łącznika z łukiem elektrycznym. Model łuku zbudowano w oparciu o jego statyczną charakterystykę prądowo-napięciową z uwzględnieniem uproszczonej charakterystyki dynamicznej. Przeprowadzone symulacje wykazały, że wartość maksymalna prądu włączania transformatora zależy zarówno...
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Nonlinear control of induction motor in field weakning region with consideration of stator flux
PublikacjaMetody nieliniowgo sterowania mogą poprawić właściwości silnika indukcyjnego w stanach przejściowych wektora strumienia. Badano sterowanie oparte na modelu multiskalarnym silnika indukcyjnego w zakresie osłabiania pola. Dwie nowe zmienne wejściowe pojawiające się w modelu multiskalarnym są równe czynnej i biernej mocy silnika. Pokazano, że te wielkości mogą byc kompensowane, jeżeli rozważane są jako mierzone zakłócenia. Maksymalny...
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Stability of a proportional observer with additional integrators on the example of the flux observer of induction motor
PublikacjaArtykuł opisuje zagadnienia związane ze stabilnością proporcjonalnego obserwatora Luenbergera z dodatkowymi integratorami
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Storage of High-Strength Steel Flux-Cored Welding Wires in Urbanized Areas
PublikacjaThe condition of the consumables is a key factor determining the waste reduction in the welding processes and the quality of the welded joint. The paper presents the results of tests of four types of fux-cored wires dedicated for welding high-strength steels, stored for 1 month and 6 months in Poland in two urbanized areas: in a large seaside city (Gdańsk) and in Warsaw, located in the center of the country. The wires were subjected...
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Multiscalar Control Based Airgap Flux Optimization of Induction Motor for Loss Minimization
PublikacjaBased on the induction motor model, considering the core loss resistance that accounts for magnetic characteristic saturation, a speed control approach is devised with an adaptive full-order (AFO) speed observer. The induction motor model analysis is done sincerely in a stationary reference frame. The control approach incorporates a flux reference generator designed to meet optimal operational circumstances and a nonlinear speed...
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Effect of Storage Conditions of Rutile Flux Cored Welding Wires on Properties of Welds
PublikacjaThe influence of storage locations of two grades of rutile flux cored welding wires on their surface condition and the strength of the welds made with them were studied. Wires were stored in real urban conditions (Gdańsk and Katowice) for 1 month, simultaneously recording changes in conditions: temperature and relative humidity of the environment. Visual tests of wires in the delivered and stored condition as well as visual and...
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Numerical calculation of three-phase transformer's residual flux in ATP and PSpice programs.
PublikacjaW artykule przedstawiono analizę przebiegów prądu i strumienia magnetycznego podczas wyłączania transformatora energetycznego, wykonaną w celu określenia strumieni szczątkowych. Wykorzystano do tego celu modele obwodowe zbudowane w oparciu o programy symulacyjne ATP (Alternative Transients Program) i PSpice. Wyniki obliczeń okazały się bardzo zbliżone dla obu modeli. Przy ich wykorzystaniu obliczono strumienie szczątkowe w kolumnach...
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Sediment-quality assessment by intelligent data analysis
PublikacjaCoraz powszechniej do oceny jakości próbek środowiskowych osadów wykorzystuje się analizy chemometryczne. Ich głównym zadaniem jest znalezienie zależności pomiędzy wynikami analiz chemicznych oraz oszacowanymi parametrami toksyczności.Zastosowanie chemometrii w ocenie jakości próbek środowiskowych umożliwiłoby zredukowanie kosztów biomonitoringu prowadzonego na badanym obszarze poprzez optymalizację procedury badawczej.
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Historical records of organic pollutants in sediment cores
PublikacjaAnalyses of sediment core samples are primary sources of historical pollution trends in aquatic systems. Determining organic compounds, such as POPs, in the dated sediments enables the estimation of their temporal concentration changes and the identification of the contaminant origin in local regions. Wars, large-scale fires, economical transitions, and bans on certain chemicals are reflected in the sediment organic compound concentrations....
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Robust flux observer system with sliding mode and fuzzy logic control of Induction Motors
PublikacjaW pracy przedstawiono implementację nowego obserwatora strumienia wirnika silnika indukcyjnego zastosowanego w układzie sterowania polowo zorientowanego ze sterowaniem ślizgowym. Proponowany system jest niewrażliwy na zmiany rezystancji stojana silnika w wyniku zastosowania korekcyjnego sprzężenia zwrotnego. Przedstawiono porównanie układów z oraz bez zastosowania sterowania ślizgowego. Zamieszczono wyniki badań symulacyjnych...
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Technology of laser deposition of narrow bead overlays using solid and flux-cored wires
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Novel adaptive flux observer for wide speed range sensorless control of induction motor
PublikacjaA new adaptive flux observer of induction motor is presented in the paper. The Lyapunov theory is utilized for derivation of the adaptation law of rotor flux angular speed, which acts as unknown parameter in an augmented induction motor model. In the field weakening region, where stray fluxes are comparable with rotor flux magnitude, the air-gap flux stabilization is proposed. An air-gap flux multiscalar model is derived for stator...
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Obliczanie indukcyjnych układów grzejnych z wykorzystaniem interfejsu API komercyjnego pakietu Flux
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Kinetic flux vector splitting scheme for solving non-reactive multi-component flows
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Nonlinear control of five phase induction motor with synchronized third harmonic flux injection
PublikacjaThe paper deals with the novel control system for five phase induction motor (IM) that enables the injection of the rotor flux 3rd harmonic component. Two multiscalar models are transformed from the 1-1 and 2-2 vector models developed in the 1st and 3rd harmonic planes. Based on the obtained multiscalar models the synthesis of dual multiscalar control is established. The obtained two multiscalar control systems can independently...
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AUGMENTATION OF THE CRITICAL HEAT FLUX IN WATER-Al2O3, WATER-TiO2 AND WATER-Cu NANOFLUIDS
PublikacjaThe main aim of the proposed study is therefore recognition of the phenomena accompanying nucleate boiling crisis of selected nanofluids during boiling on horizontal tubes of various outside diameters. Of particular interest is impact of contact angle and tube diameter on the value of critical heat flux. The results obtained should give more light on the nature of nucleate boiling crisis and will serve as a basis for future theoretical...