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Search results for: THREE-PHASE GRID-CONNECTED INVERTERS
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Current trends in consumption of multimedia content using online streaming platforms: A user-centric survey
PublicationIn its early days, consumption of multimedia content was only possible at a stationary terminal device. The music player was located at home, and had to have a physical drive. Over the last decade, there has been an enormous increase in the number of online streaming platforms. These services enable users to consume rich multimedia content on various devices. Thanks to the widespread and availability of portable devices, any person...
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Groundwater Quality in the Gdansk Aquifer System
PublicationThe Gdańsk hydrogeological system consists of three main aquifers: Cretaceous, Paleogene-Neogene and Pleistocene. Chemical composition of groundwater varies between water-bearing beds, although water from Pleistocene and Paleogene-Neogene aquifers shows much similarities. The dominant hydrochemical groundwater types is HCO3-Ca. This type is characteristic for Pleistocene deposits in the Kashubian Lake District where natural chemical...
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Investigation and operation problems of metal tanks in Poland
PublicationThe paper consists of three parts concerned with steel cylindrical, vertical tank for liquid fuel. In the first part the present trends in tank design and building in Poland are described. The main are: · reduction of environment contamination danger caused by tank leakage and hydrocarbons evaporation, · increasing capacity of new tanks (100000 m3 and more) due to economic factor - reduction of steel amount per m3 of storage capacity....
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Removal of persistant organic pollutants from landfill leachates treated in three constructed wetland systems
PublicationThe objective of the study was assessment of occurrence and removal of two groups of persistent organic pollutants: polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in landfill leachate (LL) treated in three constructed wetland systems (CWs) of different construction and flow regime. Two subsurface flow systems (SSF) were analyzed: one with horizontal flow and the second one consisting of two vertical...
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A Comprehensive Analysis of Deep Neural-Based Cerebral Microbleeds Detection System
PublicationMachine learning-based systems are gaining interest in the field of medicine, mostly in medical imaging and diagnosis. In this paper, we address the problem of automatic cerebral microbleeds (CMB) detection in magnetic resonance images. It is challenging due to difficulty in distinguishing a true CMB from its mimics, however, if successfully solved it would streamline the radiologists work. To deal with this complex three-dimensional...
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A strategy for GPS data processing in a precise local network during high solar activity
PublicationThis paper presents the analyses connected with reduction of errors from ionospheric refraction using GPS data from local satellite networks. This is particularly essential during rising solar activity. The Bernese GPS Software v. 4.2 was used, as an analytical tool. The test data included measurements from a geodynamic network SUDETES situated in the Sudety Mountains across the border between the Czech Republic and Poland. A local...
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Ce site dilution effects in the antiferromagnetic heavy fermion CeIn3
PublicationLa-doped intermetallic single crystals of Ce1−xLaxIn3 were synthesized via an In self-flux method throughout the entire range (x = 0–1). The prototypical heavy-fermion compound CeIn3 shows an antiferromagnetic phase transition at 10.1 K and becomes superconducting near a critical pressure where TN is completely suppressed. As the La concentration increases, Ce moments are diluted, and the lattice constant increases linearly, satisfying Vegard’s...
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Effect of irradiation intensity and initial pollutant concentration on gas phase photocatalytic activity of TiO2 nanotube arrays
PublicationWell-organized TiO2 nanotube arrays were fabricated via one-step anodization process. The as-prepared TiO2 nanotubes were characterized by X-ray powder diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), diffuse reflectance spectroscopy (DRS) and scanning electron microscopy (SEM). Photocatalytic activity of obtained photocatalyst was studied in reaction of toluene degradation in the gas phase using low powered and low...
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Unequally-Spaced Slot Strategy for Radiation Null Reduction in Single SIW-Embedded Antenna Element
PublicationThe incorporation of higher-order modes (HOMs) can substantially augment the antenna gain and bandwidth, but this improvement is typically accompanied by compromised radiation performance including radiation nulls and higher side lobe levels. In this study, an inventive strategy is introduced to reduce the radiation nulls and the side lobe levels of a single antenna element by positioning multiple slots of the radiating element...
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Novel 2-alkythio-4-chloro-N-[imino(heteroaryl)methyl]benzenesulfonamide Derivatives: Synthesis, Molecular Structure, Anticancer Activity and Metabolic Stability
PublicationA series of novel 2-alkythio-4-chloro-N-[imino-(heteroaryl)methyl]benzenesulfonamide derivatives, 8–24, were synthesized in the reaction of the N-(benzenesulfonyl)cyanamide potassium salts 1–7 with the appropriate mercaptoheterocycles. All the synthesized compounds were evaluated for their anticancer activity in HeLa, HCT-116 and MCF-7 cell lines. The most promising compounds, 11–13, molecular hybrids containing benzenesulfonamide...
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Subjective Quality Evaluation of Underground BPL-PLC Voice Communication System
PublicationDesigning a reliable voice transmission system is not a trivial task. Wired media, thanks to their resistance to mechanical damage, seem an ideal solution. The BPL-PLC (Broadband over Power Line – Power Line Communication) cable is resilient to electricity stoppage and partial damage of phase conductors. It maintains continuity of transmission in case of an emergency situation, including paramedic rescue operations. These features...
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Proton conductivity in multi-component ABO4-type oxides
PublicationThis work investigates how configurational entropy in oxides could affect proton conductivity. For this purpose, three samples of different elemental compositions are synthesized. Five, six and seven elements were introduced into the A-site of ANbO4, forming La1/5 Nd1/5 Sm1/5Gd1/5 Eu1/5NbO4, La1/6Nd1/6Sm1/6Gd1/6Eu1/6Ho1/6NbO4 and La1/7Nd1/7Sm1/7Gd1/7Eu1/7Ho1/7Er1/7NbO4, respectively. The high configuration disorder changes the...
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Effect of molar ratio [NCO]/[OH] groups during prepolymer chains extending step on the morphology and selected mechanical properties of final bio‐based thermoplastic poly(ether‐urethane) materials
PublicationThe main aim of this work was to investigate the effect of [NCO]/[OH] molar ratio used during the prepolymer chain extending step (with bio‐based diols) on the chemical structure, and thermomechanical and mechanical properties of thermoplastic poly(ether‐urethane)s. Thermoplastic poly(ether‐urethane)s were obtained from bio‐based polyol (polytrimethylene ether glycol), bio‐based glycol (1,4‐butanediol or 1,3‐propanediol), and 4,4'diphenylmethane...
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Mechanism of Binding of Antifungal Antibiotic Amphotericin B to Lipid Membranes: An Insight from Combined Single-Membrane Imaging, Microspectroscopy, and Molecular Dynamics
PublicationAmphotericin B is a lifesaving polyene antibiotic used in the treatment of systemic mycoses. Unfortunately, the pharmacological applicability of this drug is limited because of its severe toxic side effects. At the same time, the lack of a well-defined mechanism of selectivity hampers the efforts to rationally design safer derivatives. As the drug primarily targets the biomembranes of both fungi and humans, new insights into the...
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IDENTIFICATION OF THE INTERFECE OF LATERAL SLIDE BEARINGS
PublicationIn the paper, the model of slide bearings of motor engine, the metodology of research on this type of bearings and its results are presented measurement standpoint consisting of main elements of Briggs & Stratton 550 serie 10 T 802 model piston motor engine driven by three phase elektric engine is introduced . On the measurement standpoint are measurements were done, needed for specification...
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Simulation-Based Design of Microstrip Linear Antenna Arrays Using Fast Radiation Response Surrogates
PublicationFast yet accurate technique for simulation-based design of linear arrays of microstrip patch antennas is presented. Our technique includes: (i) optimization of the corrected array factor of the antenna array under design for a phase excitation taper resulting in reduced side lobes; (ii) simulation-driven optimization of the array element for element dimensions resulting in matching at and about operational frequency, and (iii)...
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Removal and speciation of heavy metals in the constructed wetland treating landfill leachate
PublicationThe results of heavy metals removal and speciation of metals at two treatment wetlands receiving landfill are discussed. The first TW is a surface flow facility consisting of 10 ponds. The next TW is a newly constructed pilot-scale facility consisting of three beds with alternately vertical and horizontal sub-surface flow. The metals concentrations were analysed in leachate(both TWs) and bottom sediments (surface flow TW). Seasonal...
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A study on microcrack monitoring in concrete: discrete element method simulations of acoustic emission for non-destructive diagnostics
PublicationThe research is focused on the monitoring of fracture evolution in concrete beams under three-point bending using the acoustic emission technique and the discrete element method. The main objective of the study was to numerically and experimentally investigate the mechanism behind the generation of elastic waves during acoustic emission events and their interaction with micro- and macro-cracking in concrete beams under monotonic...
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Modification of structured bio‑carbon derived from spongin-based scaffolds with nickel compounds to produce a functional catalyst for reduction and oxidation reactions: Potential for use in environmental protection
PublicationThree different 3D fibrous-like NiO/Ni(OH)2/Ni‑carbonized spongin-based materials were prepared via a simple sorption–reduction method. Depending on the support used, the catalysts were composed of carbon, nickel oxide, nickel hydroxide and zero-valent nickel, with the surface content of the nickel-containing phase in the range 15.2–26.0 wt%. Catalytic studies showed promising activity in the oxidation of phenolic compounds in water...
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Two-dimensional simulations of concrete fracture at aggregate level with cohesive elements based on X-ray lCT images
PublicationThe paper presents results of two-dimensional meso-scale simulations of fracture in notched concrete beams subjected to three-point bending test. Concrete was assumed as a 4-phase material composed of aggregate grains placed in the cement matrix, interfacial transitional zones (ITZs) and macro-voids. The particle distribution was taken from real concrete beams on the basis of X-ray lCT images. Comprehensive numerical analyses were carried...
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Mono- and bimetallic nanoparticles decorated KTaO 3 photocatalysts with improved Vis and UV–Vis light activity
PublicationNew mono- and bimetallic nanoparticle-decorated perovskite-type KTaO3 photocatalysts were successfully synthesized by hydrothermal reaction followed by photodeposition of MNPs/BNPs. The effect of noble metal type, amount of metal precursor as well as photoreduction method on the physicochemical and photocatalytic properties of MNPs- and BNPs-KTaO3 have been investigated. Photocatalytic activity under Vis light irradiation was estimated...
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The shallow sea experiment with usage of linear hydrophone array
PublicationPurpose of this article is to present designed and made linear hydrophone array and the results obtained during in situ trails on Gulf of Gdańsk. The measuring system allowed to localize hydrophones in the selected points and perform measurements in both the horizontal antenna positioning and vertical. Made in this way recordings allow creating accurate 3D imaging of sound intensity/propagation. During research three floating objects...
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Framework of an Evolutionary Multi-Objective Optimisation Method for Planning a Safe Trajectory for a Marine Autonomous Surface Ship
PublicationThis paper represents the first stage of research into a multi-objective method of planning safe trajectories for marine autonomous surface ships (MASSs) involved in encounter situations. Our method applies an evolutionary multi-objective optimisation (EMO) approach to pursue three objectives: minimisation of the risk of collision, minimisation of fuel consumption due to collision avoidance manoeuvres, and minimisation of the extra...
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EVALUATION OF LIQUID-GAS FLOW IN PIPELINE USING GAMMA-RAY ABSORPTION TECHNIQUE AND ADVANCED SIGNAL PROCESSING
PublicationLiquid-gas flows in pipelines appear in many industrial processes, e.g. in the nuclear, mining, and oil industry. The gamma-absorption technique is one of the methods that can be successfully applied to study such flows. This paper presents the use of thegamma-absorption method to determine the water-air flow parameters in a horizontal pipeline. Three flow types were studied in this work: plug, transitional plug-bubble,...
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Characteristics of Cucumis metuliferus, Actinidia deliciosa and Musa paradisica fragrance profiles using a comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometric detection (GC×GC-TOF MS)
PublicationComprehensive two-dimensional gas chromatography with time-of-flight mass spectrometric detection (GC×GC-TOF-MS) is a modern analytical technique used in many fields. This technique enables an effective separation of volatile chemical compounds [1]. In recent years, the topic of healthy food and healthy living has become very popular. For this reason, more and more scientific publications related to the analysis of food products...
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CO2 capture through direct-contact condensation in a spray ejector condenser and T- junction separator
PublicationThe design principle underlying the steam condensation and CO2 purification in a gas power plant with a focus on reducing CO2 emissions encompasses the deployment of a spray ejector condenser (SEC) and separator. This innovative system facilitates direct-contact condensation of steam with non-condensable gas (CO2) by inter acting with a spray of subcooled water, seamlessly integrated with a T-junction separator mechanism aimed...
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Dynamics of fault arc traveling along busbars in high voltage switchboards = Dynamika łuku zwarciowego przemieszczającego się wzdłuż szyn rozdziel-nic wysokiego napięcia
PublicationThe paper presents the results of magnetic induction and electrodynamic force calculations acting on arc column during short-circuit in medium voltage air-insulated bus-bars. The gap between the bars was 120 mm and the prospective short-circuit currents ranged from 4 kA to 8 kA. The paper also shows the measurement results of average velocity fault arc depending on currents arc diameter and arc current was established and described....
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A Self-Equalized Waveguide Filter With Frequency-Dependent (Resonant) Couplings
PublicationThis letter presents a design of a fifth-order linear phase filter with frequency-dependent couplings. The filter is composed of a triplet that is directly coupled to two resonators at the input and output. To provide group delay flattening a cross-coupling in the trisection has a strongly dispersive character with a negative slope parameter. To achieve this, an E-plane stub with a septum was used. To further improve the filter...
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Pulse-Width Modulation Template for Five-Level Switch-Clamped H-Bridge-Based Cascaded Multilevel Inverter
PublicationThis article presents a carrier-based pulse-width modulation (PWM) template for a 5-level, H bridge-based cascaded multilevel inverter (MLI). The developed control concept generates adequate modulation template for this inverter topology wherein a sinusoidal modulating waveform is modified to fit in a single triangular carrier signal range. With this modulation approach, classical multiplicity and synchronization of the triangular...
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Profitability criteria of partial cogeneration in nuclear power plant.
PublicationIn this paper, profitability criteria and calculation methodology of profitability conditions for partial cogeneration in nuclear power plant (NPP) was presented. Considered NPP supplies electricity to consumers through public power system, whereas heat is expected to be supplied to consumption regions via long-distance heat transport line. First proposed profitability criterion was total annual costs of electricity and heat delivered...
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Analytical ‘Steady-State’-Based Derivation and Clarification of the Courant-Friedrichs-Lewy Condition for Pipe Flow
PublicationThis article addresses the problem of choosing the optimal discretization grid for emulating fluid flow through a pipeline. The aggregated basic flow model is linearized near the operating point obtained from the steady state analytic solution of the differential equations under consideration. Based on this model, the relationship between the Courant number (μ) and the stability margin is examined. The numerically set coefficient...
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Investigations on fracture in reinforced concrete beams in 3-point bending using continuous micro-CT scanning
PublicationThis study explores a fracture process in rectangular reinforced concrete (RC) beams subjected to quasi-static three-point bending. RC beams were short and long with included longitudinal reinforcement in the form of a steel or basalt bar. The ratio of the shear span to the effective depth was 1.5 and 0.75. The focus was on the load–deflection diagram and crack formation. Three-dimensional (3D) analyses of the size and distribution...
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The Use of Ultra-Fast Gas Chromatography for Fingerprinting-Based Classification of Zweigelt and Rondo Wines with Regard to Grape Variety and Type of Malolactic Fermentation Combined with Greenness and Practicality Assessment
PublicationIn food authentication, it is important to compare different analytical procedures and select the best method. The aim of this study was to determine the fingerprints of Zweigelt and Rondo wines through headspace analysis using ultra-fast gas chromatography (ultra-fast GC) and to compare the effectiveness of this approach at classifying wines based on grape variety and type of malolactic fermentation (MLF) as well as its greenness...
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Comprehensive thermodynamic analysis of steam storage in a steam cycle in a different regime of work: A zero-dimensional and three-dimensional approach
PublicationDue to the current trends aiming to reduce carbon dioxide emissions by increasing the use of renewable energy sources, changes are required in the operation of coal-fired steam units. The unstable nature of renewable energy sources, depending on weather conditions, means that the amount of energy produced varies and is not always in line with peak demand. To ensure the security and stability of energy supplies in the energy system,...
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Visible light photocatalysis employing TiO2/SrTiO3-BiOI composites: Surface properties and photoexcitation mechanism
PublicationA series of binary TiO2/SrTiO3 and ternary TiO2/SrTiO3_BiOI composites have been synthesized using multistep preparation method. Characterization of the obtained photocatalysts covered complex analysis including morphology + y (SEM), BET specific surface area, porosity, optical properties (DRS), chemical composition of surface (XPS), crystal structure and crystal size (XRD). UV–vis and Vis ligh induced photocatalytic activity was...
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The role of time perspectives and impulsivity dimensions in coping styles
PublicationBoth time perspectives and impulsivity dimensions are groups of traits that are connected to self-control abilities and might be important for coping styles. However, to date, no study has systematically investigated their utility in predicting coping styles with regard to their multidimensional nature. The current study was correlational and exploratory, aiming to discover what amount of variance in each of the three coping...
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Diagnostic system of wheeled tractors detecting four defect's categories
PublicationIn a classical approach to damage diagnosis, the technical condition of an analyzed machine is identified based on the measured symptoms, such as performance, thermal state or vibration parameters. In wheeled tractor the fundamental importance has monitoring and diagnostics during exploitation concerning technical inspection and fault element localizations. The main functions of a diagnostic system are: monitoring tractor components...
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Protection and renovation of public areas in a modernist city: the case of three streets in the historic City Centre of Gdynia
PublicationThis article concerns issues related to the preservation and restoration of public space in Gdynia’s city centre, which was designed and built mainly in the 1920s and 1930s. In 2007, a major part of the city centre was entered into the register of monuments asa historic complex of urban architecture. Moreover, in 2015, the area was declared a Monument of History. Protection of a complex of urban architecture covers not only the...
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Data-driven, probabilistic model for attainable speed for ships approaching Gdańsk harbour
PublicationThe growing demand for maritime transportation leads to increased traffic in ports. From this arises the need to observe the consequences of the specific speed ships reach when approaching seaports. However, usually the analyzed cases refer only to the statistical evaluation of the studied phenomenon or to the empirical modelling, ignoring the mutual influence of variables such as ship type, length or weather conditions. In this...
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Effect of annealing temperature on slurry erosion resistance of ferritic X10CrAlSi18 steel
PublicationIn the present work, the slurry erosion tests were carried out to investigate the influence of heat treatment on slurry erosion process of ferritic X10CrAlSi18 stainless steel using a slurry pot test rig. X10CrAlSi18 stainless steel was tested in as-received condition and after annealing at three different temperatures: 600°C, 800°C and 1000°C. Degradation of materials due to slurry erosion depends on many factors connected with...
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Analytical design method for widening the intertrack space
PublicationThe paper involved the issue of arching of the railway turnouts. This is an issue which is given relatively less attention to scientific and research activities. Reference has been made to the book by Wladyslaw Rzepka, under the title „Curved turnouts in plan and profile”, which has been used in Poland for more than 50 years as the main source of information relating to the turnouts on the curve. The book is a compilation of elaborations...
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Satellite Image Classification Using a Hierarchical Ensemble Learning and Correlation Coefficient-Based Gravitational Search Algorithm
PublicationSatellite image classification is widely used in various real-time applications, such as the military, geospatial surveys, surveillance and environmental monitoring. Therefore, the effective classification of satellite images is required to improve classification accuracy. In this paper, the combination of Hierarchical Framework and Ensemble Learning (HFEL) and optimal feature selection is proposed for the precise identification...
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Arching of railway turnouts by analytical design method
PublicationThe paper involved the issue of arching of the railway turnouts. This is an issue which is given relatively less attention to scientific and research activities. Reference has been made to the book by Wladyslaw Rzepka, under the title „Curved turnouts in plan and profile”, which has been used in Poland for more than 50 years as the main source of information relating to the turnouts on the curve. The book is a compilation of elaborations...
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Effects of Ni-NCAL and Ni–Ag electrodes on the cell performances of low-temperature solid oxide fuel cells with Sm0.2Ce0·8O2-δ electrolyte at various temperatures
PublicationThree low-temperature solid oxide fuel cells are built using Sm0.2Ce0·8O2-δ (SDC) as the electrolyte. Cell A is symmetrical and features Ni–LiNi0.8Co0·15Al0·05O2 (Ni–NCAL) electrodes, Cell B comprises a Ni–NCAL anode and a Ni–Ag cathode, and Cell C is fabricated using a Ni–NCAL cathode and a Ni–Ag anode. The ohmic resistance and polarization resistance (Rp) of Cells B and C are significantly higher than those of Cell A. The reduction...
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Subjective Quality Evaluation of Speech Signals Transmitted via BPL-PLC Wired System
PublicationThe broadband over power line – power line communication (BPL-PLC) cable is resistant to electricity stoppage and partial damage of phase conductors. It maintains continuity of transmission in case of an emergency. These features make it an ideal solution for delivering data, e.g. in an underground mine environment, especially clear and easily understandable voice messages. This paper describes a subjective quality evaluation of...
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MPPT and GMPPT Implementation for Buck-Boost Mode Control of quasi-Z-Source Inverter
PublicationThe focus is on the maximum power point tracking implementation for the buck-boost voltage mode control of a single-phase multilevel inverter based on a three-level neutral point clamped quasi-Z-source topology. To utilize shoot-through states only when boost function is needed and avoid it in the buck mode, two different control approaches are required. This work proposes merged control system which provides switching between...
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Evaluation of the potential of Microwave Plasma–Atomic Emission Spectrometry for trace elements leaching assessment from the concrete matrix with sewage sludge ash additives
PublicationThe management of ash generated during the thermal utilization of sewage sludge is a significant environmental problem requiring an effective technological solution. One alternative way to dispose of sewage sludge is to bind it in concrete as a substitute for part of the aggregate. The properties of the C-S-H phase enable effective immobilization of harmful substances that sewage sludge contains. The amount of individual compounds...
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EXPERIMENTAL AND NUMERICAL INVESTIGATIONS OF CONCRETE BEHAVIOUR AT MESO-LEVEL DURING QUASI-STATIC SPLITTING TENSION
PublicationThe paper describes experimental and numerical results of quasi-static splitting tensile tests on concrete specimens at meso-scale level. The loading strip was made of plywood or steel. Fracture in concrete was detected at the aggregate level by means of three non-destructive methods: 3D x-ray micro-computed tomography, 2D scanning electron microscope and manual 2D digital microscope. The discrete element method was used to directly...
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The reliability of any-hop star networks with respect to failures of communication nodes.
PublicationThis paper investigated the reliability of any-hop star networks. The any-hop star topology is used in centralized computer networks. We will assume that the all nodes fail independently, links are failure-free. Following measures of network reliability are assumed: the expected number of nodes, which can communicate with the central node; the expected number of node pairs, which are connected by a path through the central node;...
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TMSCl Promoted Acylation of Amines with 5-(α-amino- α'-hydroxy)methylene Meldrum's Acids - Elucidation of Mechanism.
PublicationRecently we have observed accelerating influence of trimethyl silyl chloride addition on the rate of the reactions of 5-(α-amino- α'-hydroxy)methylene Meldrum's Acids with amines, particularly in the case of highly basic amines. However the nature of the aforementioned process remain unexplained. In proposed communication we wish to report insightful elucidation of this mechanism. The reaction under investigation involves simply...