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Search results for: voltage source inverters
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Analysis of Organic Rankine Cycle efficiency and vapor generator heat transfer surface in function of the reduced pressure
PublicationIn the paper presented is analysis of the influence of reduced pressure on efficiency and heat transfer area of vapor generator of Organic Rankine Cycle (ORC) in case of subcritical and supercritical parameters of operation. Compared are two cases of subcritical and supercritical ORC featuring a similar arrangement of heat source supply and heat removal, that is featuring the same temperatures of working fluid before the turbine,...
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Compact Quasi-Elliptic-Type Inline Waveguide Bandpass Filters With Nonlinear Frequency-Variant Couplings
PublicationThis work presents the design techniques to synthesize a class of compact inline quasi-elliptic-type waveguide cavity bandpass filters based on novel nonlinear frequency-variant couplings (NFVCs). These highly dispersive frequency-variant couplings (FVCs) are realized by means of a pair of partial-height posts that are placed at the junctions between every two cavity resonators. Each NFVC produces a transmission pole in between...
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Compressive strength and density of cement pastes containing iron oxide (Fe3O4) nanoparticles (nanomagnetite)
Open Research Data*.ODS - open-data source spreadsheet - Dataset presenting:
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Luminescence properties of TeOx-Dy gels
Open Research DataThe DataSet contains the emission and excitation spectra of TeOx-Dy gel. The material was obtained by the sol-gel method. The starting solution was prepared by mixing telluric acid (precursor) with thetraetylene glycol, water, and ethanol. Next, the 5% mol of dysprosium ions were added, the nitrates were used as a source of rare-earth ions. The sol...
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Luminescence properties of TeOx-Tb gels
Open Research DataThe DataSet contains the emission and excitation spectra of TeOx-Tb gel. The material was obtained by the sol-gel method. The starting solution was prepared by mixing telluric acid (precursor) with thetraetylene glycol, water, and ethanol. Next, the 5% mol of terbium ions were added, the nitrates were used as a source of rare-earth ions. The sol was...
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Luminescence properties of TeOx-Eu gels
Open Research DataThe DataSet contains the emission and excitation spectra of TeOx-Eu gels. The material was obtained by the sol-gel method. The starting solution was prepared by mixing telluric acid (precursor) with thetraetylene glycol, water, and ethanol. Next, the 5% mol of europium ions were added, the nitrates were used as a source of rare-earth ions. The sol...
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Raman spectra for pyrolized natural compounds
Open Research DataThe presented data showcases the results of Raman spectroscopy analysis conducted on pyrolyzed natural compounds both with and without the inclusion of graphene. The study delved into four specific compounds: methylcellulose with lysine (ML), methylcellulose with lysine-graphene composite (MLG), algae (A), and algae-graphene composite (AG). Raman spectra...
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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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Nonlinear generation of non-acoustic modes by low-frequency sound in a vibrationally relaxing gas
PublicationTwo dynamic equations referring to a weakly nonlinear and weakly dispersive flow of a gas in which molecular vibrational relaxation takes place. are derived. The first one governs an excess temperature associated with the thermal mode, and the second one describes variations in vibrational energy. Both quantities refer to non-wave types of gas motion. These variations are caused by the nonlinear transfer of acoustic energy into...
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Purification and biochemical characteristic of a cold-active recombinant esterase from Pseudoalteromonas sp. 643A under denaturing conditions.
PublicationIn this paper production of a cold-active esterase EstA from the Antarctic bacterium Pseudoalteromonas sp. 643A in E. coli expression system was described. The purification and biochemical characteristic of EstA were performed in the presence of urea and then compared with results obtained for the esterase with no addition of urea and isolated from the native source. In both cases the cold-active enzyme displayed similar properties....
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Effect of Microplastics Pollution on Hydrogen Production from Biomass: A Comprehensive Review
PublicationHydrogen production from biomass and organic wastes is considered as a potential alternative energy source and is known as a clean and CO2-free fuel energy carrier. H2 is considered very promising among the other energy sources; therefore, the effective conversion of biomass and organic solid waste to this secondary energy source is urgently sought. As a result, it is of importance to assess the impact of the existence of microplastics...
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Guessing Intrinsic Forwarding Trustworthiness of Wireless Ad Hoc Network Nodes
PublicationA novel node misbehavior detection system called GIFTED is proposed for a multihop wireless ad hoc network (WAHN) whose nodes may selfishly refuse to forward transit packets. The system guesses the nodes’ intrinsic forwarding trustworthiness (IFT) by analyzing end-to-end path performance rather than utilizing unreliable and incentive incompatible low-layer mechanisms. It can work with occasional IFT jumps, directional antennae,...
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Jeffreys heat conduction in coupled semispaces subjected to interfacial heating
PublicationA Jeffreys heat conduction problem for coupled semispaces subjected to the action of an interfacial heat source was defined. An analytical solution of the problem was derived for a polynomial specific power of the heat source using the Laplace transform approach. The asymptotic and parametric analysis was performed for different ratios of thermal conductivities , thermal diffusivities , thermal relaxation times and coefficients...
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Modelling of MV and HV Cable Lines
PublicationOverhead and cable lines are fundamental elements of power systems. Participation of cable lines is smaller and their percentage decreases as voltage is increased. HV cable lines are often built with the use of cables which are composed of coaxial metallic sheaths. Such cables are also often used in MV networks. The sheath may operate in different confgurations. In the case of Polish MV network the sheaths are earthed at both ends....
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System of protection against electric shock for circuits with power electronics converters
PublicationModern low voltage circuits are very often equipped with power electronics converters, therefore in these circuits non-sinusoidal earth currents (touch currents) may occur. For non-sinusoidal currents safety criteria should be modified. This paper presents these modified criteria and a computer system of protection against electric shock which can be implemented in circuits with power electronics converters. The system is based...
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Intelligent turbogenerator controller based on artifical neural network
PublicationThe paper presents a desing of an intelligent controller based on neural network (ICNN). The ICNN ensures at the same time two fundamental functions : the maintaining of generator voltage at the desired value and the damping of the electromechanical oscillations. Its performance is evaluted on a single machine infinite bus power system through computer simulations. The dynamic and transient operation of the proposed controller...
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Study of Direct Methanol Fuel Cell Process Dynamics Using Dynamic Electrochemical Impedance Spectroscopy
PublicationA new technique, which was developed to characterize the direct methanol fuel cell under work conditions, has been presented in this paper. The impedance measurements were made using dynamic electrochemical impedance spectroscopy research technique in the galvanostatic mode, using multiple sinusoidal excitation. Obtained results show, that together with an increase of the temperature and working load, the global impedance...
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Elctrochemical oxidation and corrosion resistance of the Ti13Nb13Zr alloy
PublicationThis paper presents the results of oxidation and corrosion tests carried out on titanium alloy Ti13Nb13Zr. The oxide film was prepared by electrochemical environment 2M H3PO4 for 30 min and 1 h, at a constant voltage 40V. The tests of corrosion resistance were performed by potentiostatic method in Ringer's solution at different pH values: 7, 5 and 3. The change in an appearance of surface and the increase in corrosion resistance...
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A predictive estimation based control strategy for a quasi-resonant dc-link inverter
PublicationIn this paper the predictive estimation based control strategy for a quasi-resonant dc link inverter (PQRDCLI) is developed. Instead of direct measurement of dc link input inverter current – its estimation with one step prediction is applied. The PQRDCLI fed induction motor, controlled with a predictive current estimation stabilized inverter output voltage slopes independently of load. Moreover, reduction of overvoltage spikes...
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Magnetic field microsensor based on GaAs MESFET
PublicationA novel concept of the drain separation design in a horizontally-split-drain GaAs MAGFET sensor, based on epitaxial layer growth, was developed. Proper choice of GaAs/AlAs/GaAs epitaxial layer sequence provided good electrical isolation between the drain regions. The measured leakage current between the drain regions was in the range of nA for up to 2V drain voltage bias difference. Performed analytical and numerical calculations...
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MOŻLIWOŚĆ WYKORZYSTANIA ELEKTROWNI JĄDROWEJ JAKO ŹRÓDŁA ENERGII ELEKTRYCZNEJ I CIEPLNEJ
PublicationW niniejszym artykule przedstawiono zagadnienia związane z możliwością pracy elektrowni jądrowej (EJ) również w charakterze źródła ciepła, a więc w warunkach skojarzonego wytwarzania energii elektrycznej oraz ciepła. Rozpatrzono dwa poziomy mocy cieplnych oddawanych do systemów ciepłowniczych. Przeprowadzone wstępnie badania techniczne i ekonomiczne dla lokalizacji elektrowni jądrowej nad Jeziorem Żarnowieckim potwierdziły potencjalną...
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Algorytmy wykrywania krawędzi w obrazie
PublicationWykrywanie krawędzi jest pierwszym etapem w cyfrowym przetwarzaniu obrazów. Operacja ta polega na usunięciu informacji takich jak kolor czy też jasność, a pozostawieniu jedynie krawędzi. Efektem tej operacji jest znaczna redukcja ilości danych do dalszej analizy. Pozwala to na zastosowanie w następnych etapach bardziej złożonych algorytmów rozpoznawania obiektów na podstawie kształtu. W artykule zaprezentowano zastosowanie algorytmów...
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Low frequency nois of supecapacitor
Open Research DataDataset contains noise measurement results on prototype electrochemical double layer capacitor. The measurement procedure is described in https://dx.doi.org/10.1515/mms-2017-0059.
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Rate performance of mixture (NH4)2V6O16 and (NH4)2V10O25·8H2O as cathode material in Li-ion batteries
Open Research DataThe DataSet contains the galvanostatic charge/discharge curves of the ammonium vanadate nanostructures obtained by the hydrothermal method without initial pressure (mixture (NH4)2V6O16 and (NH4)2V10O25·8H2O). The battery tests of the samples were performed using the ATLAS 0961 MBI multichannel battery testing system with different current densities...
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One-Step Synthesis of b-Lactams with Retro-Amide Side Chain
PublicationAbstract: A one pot synthesis for preparation of 1,4-disubstituted-2-oxo-azetidine-3-carboxylic acid amides was developed. 5-(α-N-substituted-amino-α'-hydroxy)methylene Meldrum's acids act as a source of ketenes that react with aldimines in boiling toluene to give b-lactams with retro-amid side chain.
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Heat Dissipation from the Power Cable in the Casing Pipe
PublicationThe current carrying capacity of a power cable determines its ability to carry a specific current and is related to the efficiency of dissipation of heat generated in the cable laid in a specific environment. The studies were conducted in order to determine how the characteristics of the medium around the cable affected its temperature, and thus the ability of the cable to transmit electricity. The experimentation in the lab and...
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PARAMETERS OF THE ELECTROPHORETIC DEPOSITION PROCESS AND ITS INFLUENCE ON THE MORPHOLOGY OF HYDROXYAPATITE COATINGS. REVIEW
PublicationMetallic materials intended for bone implants should exhibit not only appropriate mechanical properties, but also high biocompatibility. The surface treatment modifications, for example acidic treatment, laser treatment, ion implantation and deposition of highly biocompatible coatings, are practiced. One of the most popular methods of surface modification is to deposit hydroxyapatite (HAp) coatings. HAp naturally occurs in human...
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BPL-PLC Voice Communication System for the Oil and Mining Industry
PublicationApplication of a high-efficiency voice communication systems based on broadband over power line-power line communication (BPL-PLC) technology in medium voltage networks, including hazardous areas (like the oil and mining industry), as a redundant mean of wired communication (apart from traditional fiber optics and electrical wires) can be beneficial. Due to the possibility of utilizing existing electrical infrastructure, it can...
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TiO 2 Co x O y composite nanotube arrays via one step electrochemical anodization for visible light–induced photocatalytic reaction
PublicationTiO2CoxOy (x = 1, y = 1 or x = 3, y = 4) composite photocatalysts have been synthesized via one step anodic anodization of TiCo alloys. The effects of the cobalt content in the alloy (5, 10 and 15 wt%), water content (2, 5 and 10%) in the electrolyte solution, and applied voltage (30, 40 and 50 V) during the anodization process on the morphology and surface properties. Additionally, the dependence of cobalt content in the nanotubes...
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Determiantion of optimal conditions for the isolation of oil from the fishing industry offal
PublicationFish processing generates significant amounts of offal, which usually is converted into fodder meal or is stored into landfills. However, some part of this offal could serve as a source of valuable products, such as fish oil, collagen or gelatin. the aim of the study was to determine the conditions of oil isolation from salmon skins ensuring high yield and quality of the product.
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Generowanie modeli symulacyjnych na potrzeby systemu ekspertowego wspomagającego projektowanie układów automatyki statku
PublicationOmówiono automatyczne generowanie modeli symulacyjnych na potrzeby systemu ekspertowego wspomagającego projektowanie układów automatyki statków. Na podstawie przyjętych założeń projektowych system ekspertowy zleca badania wybranych struktur podsystemów elektroenergetycznych statków. Aplikacja symulacyjna pobiera z biblioteki modele matematyczne elementów składowych struktur, a następnie zestawia modele symulacyjne, wykonuje badania...
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Framework for extracting rails and setting-out railway line axis based on UAV photogrammetric measurements
Open Research DataTechnical diagnostics enables assessing the current technical condition of a railway line and adjacent infrastructure, and to forecast its changes over a specific time horizon. One of its elements is the periodic monitoring of rail position and their geometry. The data set presents a new framework for the setting-out of a railway track axis. The process...
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The OpenMolcas Web: A Community-Driven Approach to Advancing Computational Chemistry
Open Research DataThe developments of the open-source OpenMolcas chemistry software environment since spring 2020 are described, with a focus on novel functionalities accessible in the stable branch of the package or via interfaces with other packages. These developments span a wide range of topics in computational chemistry and are presented in thematic sections: electronic...
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Nonlinear impedance of 50Bi2VO5.5-50SrB4O7 glass measured with impedance spectroscopy method at low temperature region
Open Research DataThe nonlinear electrcial properties of 50(Bi2VO5.5)-50SrB4O7 glass was measured by impedance spectroscopy method.
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Nonlinear impedance of Bi2VO5.5 ceramic prepared by traditional melt quenching technique was measured with impedance spectroscopy method at low temperature region
Open Research DataThe nonlinear electrical properties of Bi2VO5.5 ceramic prepared by traditional melt quenching technique was measured by impedance spectroscopy method.
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Nonlinear impedance of 50Bi2VO5.5-50SrB4O7 annealed glass at 593 K measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties of 50Bi2VO5.5-50SrB4O7 annealed glass was measured by impedance spectroscopy method.
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Nonlinear impedance of 35Bi2VO5.5-65SrB4O7 glass measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties of 35Bi2VO5.5-65SrB4O7 glass was measured by impedance spectroscopy method.
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Nonlinear impedance of as-quenched 40Bi2VO5.5-60SrB4O7 glass measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrical properties of as-quenched 40Bi2VO5.5-60SrB4O7 glass was measured by impedance spectroscopy method.
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Nonlinear impedance of 30Bi2VO5.5-70SrB4O7 glass measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties of 30Bi2VO5.5-70SrB4O7 glass was measured by impedance spectroscopy method.
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Nonlinear impedance of 50Bi2VO5.5-50SrB4O7 glass measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties of 50(Bi2VO5.5)-50SrB4O7 glass was measured by impedance spectroscopy method.
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Nonlinear impedance of 45Bi2VO5.5-55SrB4O7 glass measured with impedance spectroscopy method at high temperature region
Open Research DataThe nonlinear electrcial properties of 45Bi2VO5.5-55SrB4O7 glass was measured by impedance spectroscopy method.
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Experimental test results of the 150kVA 18-pulse diode rectifier with series active power filter
PublicationThe paper presents the control system and selected results of experimental tests of the ac/dc power converter consisting of 18-pulse diode rectifier on the basis of coupled reactors and a serial active power filter. Three configurations of the 150kVA converter were tested experimentally and compared: 18-pulse diode rectifier with and without additional grid reactor and the rectifier integrated with the active power filter. The...
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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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Preparation of nano-tubular oxide layers on titanium alloy Ti13Nb13Zr
PublicationThe article presents results of oxidation tests and corrosion investigations of titanium alloy Ti13Nb13Zr preformed at different conditions. The oxide layers have been formed using electrochemical method in 2M H3PO4 + 0,3% HF solution for 30 min. and 1h at 20V constant voltage. The corrosion tests heve been made with poteniodynamic method in Ringer's solution at pH ranged 3 and 7. It has been shown that the nano-oxide films, which...
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Modification of the operating point of residual current transformers for high frequency earth fault currents detection
PublicationFor protection against electric shock in low voltage systems residual current devices are commonly used. However, their proper operation can be interfered when earth fault current with high frequency components occurs. Serious hazard of electrocution exists then. One of the most important element of residual current devices is a residual current transformer with iron core. Tripping characteristic of residual current devices strictly...
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Average Redundancy of the Shannon Code for Markov Sources
PublicationIt is known that for memoryless sources, the average and maximal redundancy of fixed–to–variable length codes, such as the Shannon and Huffman codes, exhibit two modes of behavior for long blocks. It either converges to a limit or it has an oscillatory pattern, depending on the irrationality or rationality, respectively, of certain parameters that depend on the source. In this paper, we extend these findings, concerning the Shannon...
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Clean energy in the European Union: Transition or evolution?
PublicationIn this paper, we analyse two phenomena. First, the relationship between greenhouse gases emission and effectiveness of the European Union energy policies and second the transition from the fossil fuels to renewable energy sources. We run two-step data analysis concerning 25 European Union member states in the period from 1990 to 2018. We use information on greenhouse gases emission, introduction of new energy policies, source...
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Morphology, surface properties and photocatalytic activity of the bismuth oxyhalides semiconductors prepared by ionic liquid assisted solvothermal method
PublicationThis is the first report of the effect of the ILs cation type (imidazolium, pyridinium and pyrrolidinium) on the morphology, surface properties and photoactivity of BiOX semiconductors type obtained by solvothermal method in glycerol. The various ionic liquids (IL) cation type as a halogen source and templating agent for the synthesis of the bismuth oxyhalides nanoparticles has been systematically investigated. The role of ILs...
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IT Business Standards as an Ontology Domain
PublicationThe aim of this paper is to report a selection of Semantic Web aspects pertaining to ontology development activities in the domain of the IT business standard (TOGAF 9) such as formulating competency questions, conceptualization of the domain, resolution of the source knowledge deficiency and applying common design patterns in the OWL formalization. Authors also try to determine target groups that may benefit from such ontology...
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Modern Methods of Software Development
PublicationSoftware development methods consist of such activities like analysis, planning, development, testing, deployment, maintenance and retirement. All of them can be divided into two main categories - traditional and agile. The objective of this paper is to review some of the most popular traditional, agile and open source development methods. Special attention was paid to the common stages of all methods - testing and maintenance.