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Search results for: BUCK CONVERTER
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Opto-Electrochemical Sensing Device Based on Long-Period Grating Coated with Boron-Doped Diamond Thin Film
PublicationThe fabrication process of thin boron-doped nanocrystalline diamond (B-NCD) microelectrodes on fused silica single mode optical fiber cladding has been investigated. The B-NCD films were deposited on the fibers using Microwave Plasma Assisted Chemical Vapor Deposition (MW PA CVD) at glass substrate temperature of 475 ºC. We have obtained homogenous, continuous and polycrystalline surface morphology with high sp3 content in B-NCD...
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Optical fiber aptasensor for label-free bacteria detection in small volumes
PublicationHighly sensitive devices for fast bacteria detection are sought to be developed with the task of quantifying the worldwide problem of pathogenic bacteria and thus helping to take control over spreading bacterial infections. This work concerns a sensing solution based on microcavity in-line Mach-Zehnder interferometer (μIMZI) induced in an optical fiber. Such a device exhibits ultrahigh sensitivity to refractive index changes...
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A Novel Synthesis Technique for Microwave Bandpass Filters with Frequency-Dependent Couplings
PublicationThis paper presents a novel synthesis technique for microwave bandpass filters with frequency-dependent couplings. The proposed method is based on the systematic extraction of a dispersive coupling coefficient using an optimization technique based on the zeros and poles of scattering parameters representing two coupled resonators.The application of this method of synthesis is illustrated using two examples involving four and five-pole...
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Control system for contactless electrical energy transfer with varying air gap
PublicationInductive power transfer (IPT) is a system by which electrical energy may be transmitted without electrical connection through a large air gap between coils. Systems usually considered in the literature are the ones with a constant air gap. The paper describes the analysis of IPT, which allows for supplying an electrical load in the conditions of slow, in relation to the dynamics of power supply, changes in the dimensions of the...
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NARAŻENIA NAPIĘCIOWE SILNIKÓW INDUKCYJNYCH ZASILANYCH Z FALOWNIKÓW NAPIĘCIA
PublicationW artykule przedstawiono zagadnienia związane z narażeniami izolacji silników pracujących w układach napędowych z falownikami napięcia. Znaczne stromości napięć oraz zjawiska falowe w przewodach zasilających powodują przyspieszoną degradacje izolacji maszyn. Rozwiązaniem jest stosowanie filtrów biernych na wyjściu falownika.
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Application of Headspace Solid-phase Microextraction with Poly(1-vinyl-3- Hexylimidazolium Chloride) Polymeric Ionic Liquid Coating using GC - MS to Determine Volatile Fatty Acids in Dairy Wastewater
PublicationVolatile fatty acids were determined in this study using headspace solid-phase microextraction (HS-SPME) with a poly(1-vinyl-3-hexylimidazolium chloride) polymeric ionic liquid coated fiber followed by gas chromatography - mass spectrometry. Experimental parameters such as extraction time and temperature, sample volume as well as desorption time and temperature were optimized. Detection limits of the method were in the range of...
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The field–dependent interface recombination velocity for organic–inorganic heterojunction
PublicationWe have derived an analytical formula which describes the field–dependent interface recombination velocity for the boundary of two materials characterized by different permittivities. The interface recombination of charge carriers has been considered in the presence of image force Schottky barrier. We suggest that this effect may play an important role in the loss of current for organic–inorganic hybrid heterojunctions. It has...
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Characterization of Bi6Fe2Ti3O18 Ceramics with Impedance Spectroscopy
PublicationIn the present research the tool of impedance spectroscopy was utilized to characterize dielectric behavior of Aurivillius-type ceramics of Bi6Fe2Ti3O18 composition fabricated by hot pressing method from the stoichiometric mixture of oxides Bi2O3, TiO2 and Fe2O3. Impedance spectroscopy was applied to characterize dielectric response of bulk, grain boundary, and material/electrode interfaces of the fabricated polycrystalline ceramic...
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Stability of cylindrical steel silos composed of corrugated sheets and columns based on FE analyses versus Eurocode 3 approach
PublicationComprehensive static and dynamic 3D stability finite element analyses of a cylindrical steel silo composed of corrugated sheets and open thin-walled vertical stiffener profiles were carried out by taking the geometric and material non-linearity into account. The silowas subjected to axisymmetric and non-axisymmetric loads imposed by a bulk solid following Eurocode 1. Theoretical and measured initial geometric imperfections were...
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Delivery of Ancillary Services in Distribution Power Systems
PublicationOne of the technical and organizational challenges the power system faces in deregulated market conditions is to organize an ancillary services market. The growing share of distributed generation of variable (intermittent) energy sources and a change in the market position of consumers, causes the demand for distributed delivery of ancillary services. For this purpose, it is sought to use the ability of the regulatory measures:...
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Simulation of the Dynamics of Renewable Energy Sources with Energy Storage Systems
PublicationThe intermittency of renewable energy sources (RES) constitutes a challenge for effective power system control. Fossil-fuel-based units offering ancillary power services to meet the short-term power imbalance are a financial and environmental burden for the society. Energy storage systems (ESS) can be the solution in view of the electricity market development and growing environmental concern. The major questions are, in what circumstances...
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The luminescence study of Ga1.98–xAlxO3:0.02Cr3+ coumpounds.
Open Research DataA chemical and mechanical pressure-induced photoluminescence tuning method was developed through structural evolution and hydrostatic pressure involving phase transition. A series of Ga1.98−xAlxO3:0.02Cr3+ phosphors were synthesized by collaborators from National Taiwan University. Structural evolution reveals a crystal phase change with the incorporation...
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The luminescence study of Ga2–x(Al0.68In0.32)xO3:Cr3+ coumpounds.
Open Research DataNear-infrared (NIR) phosphor-converted light-emitting diodes (pc-LEDs) are a highly efficient perspective NIR light source, with application hindered by a narrow emission band. In this work, we broaden the emission of a new series of NIR phosphors by controlling crystal structure disorder through cation cosubstitution. By substituting Ga3+ with (Al0.68In0.32)3+,...
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Modeling of the Two-Dimensional Flow Caused by Sea Conditions and Wind Stresses on the Example of Dead Vistula
PublicationThe article presents the results of two-dimensional modeling of flows caused by the sea conditions and wind stresses on the example of Dead Vistula. Based on the available bathymetric data, a numerical model of the river section was created, which was supplemented with data on the position of the water table depending on hydrometeorological conditions. To describe the flow field in steady conditions, a simplified model of two-dimensional...
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Speech Analytics Based on Machine Learning
PublicationIn this chapter, the process of speech data preparation for machine learning is discussed in detail. Examples of speech analytics methods applied to phonemes and allophones are shown. Further, an approach to automatic phoneme recognition involving optimized parametrization and a classifier belonging to machine learning algorithms is discussed. Feature vectors are built on the basis of descriptors coming from the music information...
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A framework for risk matrix design: A case of MASS navigation risk
PublicationRisk matrix, a tool for visualizing risk assessment results, is essential to facilitate the risk communication and risk management in risk-based decision-making processes related to new and unexplored socio-technical systems. The use of an appropriate risk matrix is discussed in the literature, but it is overlooked for emerging technologies such as Maritime Autonomous Surface Ships (MASS). In this study, a comprehensive framework...
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The use of thermal imaging camera to estimate velocity profiles based on temperature distribution in a free convection boundary layer
PublicationThis work describes an attempt to assess whether the temperature field from a thermal imaging camera can be converted into a velocity field with an accuracy sufficient for qualitative conducting or describing the phenomenon, i.e. when the Navier-Stokes, Fourier-Kirchhoff and continuity equations are mutually coupled. The consequence of this link between temperature fields and velocity is the possibility to formulate the hypothesis...
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Automatic labeling of traffic sound recordings using autoencoder-derived features
PublicationAn approach to detection of events occurring in road traffic using autoencoders is presented. Extensions of existing algorithms of acoustic road events detection employing Mel Frequency Cepstral Coefficients combined with classifiers based on k nearest neighbors, Support Vector Machines, and random forests are used. In our research, the acoustic signal gathered from the microphone placed near the road is split into frames and converted...
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Melanoma, metastatic - Male, 79 - Tissue image [9140730014159911]
Open Research DataThis is the histopathological image of LIVER AND INTRAHEPATIC BILE DUCTS tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format.
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Melanoma, metastatic - Male, 79 - Tissue image [9140730014157851]
Open Research DataThis is the histopathological image of LIVER AND INTRAHEPATIC BILE DUCTS tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format.
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Melanoma, metastatic - Male, 79 - Tissue image [9140730014156841]
Open Research DataThis is the histopathological image of LIVER AND INTRAHEPATIC BILE DUCTS tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format.
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Melanoma, metastatic - Male, 79 - Tissue image [914073001415661]
Open Research DataThis is the histopathological image of LIVER AND INTRAHEPATIC BILE DUCTS tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format.
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Phytoplankton in the Gulf of Gdańsk– microscope photos archive
Open Research DataHarmful blooms of cyanobacteria an dinoflagellates are recorded every year in various areas of the Baltic Sea. The data set contains photos of potentially toxic phytoplankton species found in the Gulf of Gdańsk and Puck Bay. These photos show potentialy toxic cyanobacteria and dinoflagellates observed in the surface water samples collected between 2010-2020....
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The influence of microstructure on the corrosion resistance for some titanium-based alloys
Open Research DataThis dataset contains scanning electron microscopy (SEM) micrographs revealing the microstructure of some Ti-based alloys, namely: Ti-6Al-4V (file name: TiV), Ti-6Al-7Nb (file name: TiNb) and TC21 (file name: TiAlSnZrMoCrNbSi) alloys and their localized corrosion as a result of passive layer breakdown in a corrosive environment, ie. 0.9% NaCl solution...
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4-(Cyclic-amidino)phenols. Preparation and Use in a Diamidine Synthesis
PublicationThe Pinner synthesis was applied to the prepn. of phenols 4-substituted with cyclic amidines in high yields from readily available 4-HOC6H4C(OMe):NH.HCl and aliph. diamines. An alternative attempt was made to convert 4-HOC6H4CSNH2 to 4-(1,4,5,6-tetrahydro-5-hydroxy-2-pyrimidinyl)phenol. A procedure for the prepn. of 3,6-bis(4-hydroxyphenyl)-1,2,4,5-tetrazine is reported. The syntheses of 2,4-bis[4-(4,5-dihydro-1H-imidazol-2-yl)phenoxy]pyrimidine...
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Cyanides in the environment—analysis—problems and challenges
PublicationCyanide toxicity and their environmental impact are well known. Nevertheless, they are still used in the mining, galvanic and chemical industries. As a result of industrial activities, cyanides are released in various forms to all elements of the environment. In a natural environment, cyanide exists as cyanogenic glycosides in plants seeds. Too much consumption can cause unpleasant side effects. However, environmental tobacco smoke...
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New Architecture of Solid-State High-Voltage Pulse Generators
PublicationThe application of the nanosecond pulsed electric field (nsPEF) for biomedical treatments has gained more interest in recent decades due to the development of pulsed power technologies which provides the ability to control the electric field dose applied during tests. In this context, the proposed paper describes a new architecture of solid-state high-voltage pulse generators (SSHVPG) designed to generate fully customised sequences...
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Analysis of different tillage implements with respect to reduced fuel consumption, tractor operating speed and its wheel slippage
PublicationNowadays the prices of agricultural farm produced products are increasing with ant-speed and the prices of input for raising crops are increasing with rocket-speed. Therefore, there is a dire need to conduct some important studies to innovate the techniques which can lower the costs of crop production. In this context, this study was conducted to evaluate the consumption of fuel at different tillage implements, tractor operating...
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Big Beautiful Buildings: Eine Schönheit, viele Maßstäbe - urbane Landschaften der Nachkriegsmoderne in Europa / Big Beautiful Buildings: one beauty, many scales - urban landscapes of the post-war modernism across Europe
PublicationMassive urbanization in Europe is not a phenomenon that began only in the 20th century. The roots of this process can be traced back two centuries. With the end of the Second World War the specific conjunction of powerful forces together changed the landscape of European cities. Urbanization was undoubtedly one of them. Among other factors, Musterd and van Kempen (2005) correctly itemized not only objective processes that can be...
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Powikłania po rekonstrukcji piersi: problem zakażeń i strategii prewencyjnej - przegląd literaturowy
PublicationW niniejszej pracy przedstawiono dane dotyczące powikłań po rekonstrukcji piersi. Manuskrypt ma na celu usystematyzowanie wyników badań z ostatnich lat wraz z aspektami, takimi jak: częstotliwość występowania powikłań oraz ich rodzaj, czynniki predysponujące, a także możliwości profilaktyki. Przeanalizowano dane literaturowe z ogólnie dostępnych artykułów z okresu ostatnich pięciu lat, ze szczególnym uwzględnieniem zakażeń. Do...
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Właściwości termoizolacyjne kompozytu wapienno-cementowego z udziałem paździerzy konopnych=Thermal insulation properties of the lime-cement composite with hemp shives
PublicationPrzedstawiono wyniki badań kompozytów wykonanych na bazie wapna budowlanego, cementu i dolomitu - spoiwa wiążącego z udziałem paździerzy konopi. Określono ich podstawowe właściwości, tj.: gęstość objętościową, współczynnik przewodzenia ciepła oraz wytrzymałości na ściskanie. Otrzymane wyniki dowodzą, że wytworzone kompozyty wapienno-cementowe z udziałem paździerzy konopnych są lekkie i charakteryzują się niskim współczynnikiem...
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The Influence of Titania Electrode Modification with Lanthanide Ions Containing Thin Layer on the Performance of Dye-Sensitized Solar Cells
PublicationThe lanthanide and scandium groups ions (except Pm and Ac) have been used as dopants of TiO2 film in dye-sensitized solar cells. The X-ray diffraction spectra show that the modification has no influence on the structure of the electrode; however, the diffuse reflectance UV-Vis measurements exhibit significant changes in the electronic properties of modified electrodes. The appearance of energy barrier preventing photoexcited electron...
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Anion binding by p-aminoazobenzene-derived aromatic amides: spectroscopic and electrochemical studies
PublicationThe synthesis and complexing properties of p-aminoazobenzene-derived mono-, bis-, and trisamides were described. Ligands 3 and 4 bind anions, including fluorides, chlorides, bromides, acetates, benzoates, dihydrogen phosphates, hydrogen sulfates, and p-toluenesulfonates, in chloroform forming 1 : 1 complexes. The highest value of stability constant was evaluated for the 4-F− complex (log K = 5.63 ± 0.21). On the basis of 1H NMR,...
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Experimental evaluation of estimator mean square error curve for cognitive tracking radar
PublicationTo make decisions, cognitive radar must rely on predictions of its own performance. In the literature, these predictions are usually based on some form of Cram\'er-Rao lower bound. This approach is scientifically sound, but it also brings a possibility of the cognitive controller overestimating radar performance. It therefore makes sense to back theoretical predictions with careful experiments which will verify their applicability....
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Small Scale Gasification of Biomass and Municipal Wastes for Heat and Electricity Production using HTAG Technology
PublicationCombustion and gasification technology utilizing high-cycle regenerative air/steam preheater has drawn increased attention in many application areas. The process is to be realized at temperature level above ash melting point using highly preheated agent. The use of highly preheated media above 900degC provides additional energy to conversion processes and results in considerable...
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An inclination in Thermal Energy Using Nanoparticles with Casson Liquid Past an Expanding Porous Surface
PublicationPhysical aspects of inclined MHD nanofluid towards a stretching sheet embedded in a porous medium are visualized. Two types of nanoparticles are used named as copper and alumna dioxide with water as base fluid. Similarity transformations are used to convert the partial differential equations into the set of ordinary differential equation. Closed solutions are found to examine the velocity and the temperature profiles. It is examined...
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Physics Comes to the Aid of Medicine—Clinically-Relevant Microorganisms through the Eyes of Atomic Force Microscope
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Accurate design of pseudoelliptic inline SIW filters with frequency-dependent couplings
PublicationThis paper presents an accurate synthesis method for inline SIW (Substrate Integrated Waveguide) generalized Chebyshev bandpass filters with frequency-dependent couplings. The technique is based on the synthesis of a coupling matrix that takes into account the impedance of the frequency-dependent stub. Thus, a loading effect compensation in adjacent resonators (via resonant frequency adjustment) and coupling elements (via coupling-value...
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Indirect Measurement of Motor Current Derivatives in PMSM Sensorless Drives
PublicationMotor current derivatives contain useful information for control algorithms, especially in sensorless electric drives. The measurement of motor current derivatives in electric motors supplied by voltage source inverter can be performed using di/dt transducers. However, in such a solution additional sensors have to be installed, e.g. Rogowski coils. Another approach is to measure current derivatives indirectly – by oversampling...
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Preliminary designing method of external pressure vessels for sea subsurface aplications
PublicationThis paper describes a unique engineering method intended for the preliminary designing of marine subsurface buoy mooring systems. The solved designing problem consists in determining geometrical parameters and selecting structural materials for a vessel of a buoyancy necessary to contain measuring instruments of a given mass, as well as its maximum dimensions and operational submersion depth. The assumed variability range of...
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Sensorless IPMSM drive with rotor position estimator based on analysis of phase current derivatives
PublicationThis paper describes a sensorless Interior Permanent Magnet Synchronous Motor (IPMSM) drive designed for traction applications. Wide-speed sensorless operation is provided with the use of three methods of rotor position estimation designed for: a standstill, low- and high-speed range. The paper focuses on the high-speed estimation algorithm. The estimator uses the derivatives of motor phase currentsresulting from PWM modulation...
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Application of Barycentric Coordinates in Space Vector PWM Computations
PublicationThis paper proposes the use of barycentric coordinates in the development and implementationof space-vector pulse-width modulation (SVPWM) methods, especially for inverters with deformed space-vector diagrams. The proposed approach is capable of explicit calculation of vector duty cycles, independentof whether they assume ideal positions or are displaced due to the DC-link voltage imbalance. The use ofbarycentric coordinates also...
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A convergence result for mountain pass periodic solutions of perturbed Hamiltonian systems
PublicationIn this work, we study second-order Hamiltonian systems under small perturbations. We assume that the main term of the system has a mountain pass structure, but do not suppose any condition on the perturbation. We prove the existence of a periodic solution. Moreover, we show that periodic solutions of perturbed systems converge to periodic solutions of the unperturbed systems if the perturbation tends to zero. The assumption on...
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Application of regularized Savitzky–Golay filters to identification of time-varying systems
PublicationSavitzky–Golay (SG) filtering is a classical signal smoothing technique based on the local least squares approximation of the analyzed signal by a linear combination of known functions of time (originally — powers of time, which corresponds to polynomial approximation). It is shown that the regularized version of the SG algorithm can be successfully applied to identification of time-varying finite impulse response (FIR) systems....
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Analiza systemu zabezpieczeń dla internetowego portalu typu Online Judge
PublicationPrzedmiotem rozważań jest powszechnie dostępny portal internetowy pozwalający na organizację zawodów programistycznych. System taki, określany popularnie jako online judge lub online contester, udostępnia użytkownikom do rozwiązania zestaw zadań o charakterze algorytmicznym. Reguły konkursów oraz treści i zasady oceny poszczególnych zadań ustalane są przez uprzywilejowanych użytkowników zarządzających swoimi konkursami poprzez...
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The Importance of Demand and Environment for Defining and Establishing the Role of Data Stewards
PublicationData stewardship is now a central part of FAIR research data management. Although various types of positions called data stewards have been created at academic institutions over the last years, no demand-oriented, formal model of data stewardship and the associated roles exist so far. This workshop report presents the outcomes of the panel discussion “The Importance of Demand and Environment for Defining Data Stewardship” held...
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Multi-Channel Virtual Instrument for Measuring Temperature—A Case Study
PublicationThe article presents the hardware and software configuration of the developed multi-channel temperature measurement system as well as calibration procedures and measurement results verifying the properties of measurement channels. The system has been developed and dedicated primarily for measuring the temperature distribution in a laboratory model simulating underground power lines. With the adopted configuration of the analog...
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Methylmercury and total mercury content in soft tissues of two bird species wintering in the Baltic Sea near Gdansk, Poland
PublicationOf the various forms of Hg occurring in nature, (mono) methylmercury (MeHg) is an especially toxic form and practically all forms of Hg can be converted into MeHg as a result of natural processes. Total mercury (THg) and MeHg were determined in tissues of two piscivorous birds: razorbill Alca torda and black-throated loon Gavia arctica to provide baseline data on current mercury concentrations for liver, kidneys and pectoral muscle...
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Behavior of residual current devices at frequencies up to 50 kHz
PublicationThe use of residual current devices (RCDs) is obligatory in many types of low-voltage circuits. They are devices that ensure protection against electric shock in the case of indirect contact and may ensure additional protection in the case of direct contact. For the latter purpose of protection, only RCDs of a rated residual operating current not exceeding 30 mA are suitable. Unfortunately, modem current-using equipment supplied...
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Thermal buckling of functionally graded piezomagnetic micro- and nanobeams presenting the flexomagnetic effect
PublicationGalerkin weighted residual method (GWRM) is applied and implemented to address the axial stability and bifurcation point of a functionally graded piezomagnetic structure containing flexomagneticity in a thermal environment. The continuum specimen involves an exponential mass distributed in a heterogeneous media with a constant square cross section. The physical neutral plane is investigated to postulate functionally graded material...