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The interaction parameters for solutions of n-butylurea in aqueous solutions of N-methylacetamide – The volumetric and compressibility studies between 288.15 K and 308.15 K
PublikacjaDensities and speed of sound were measured for solutions of n-butylurea in aqueous solution of Nmethylacetamide 2, 4, 6 and 8 (mol/kg) at T = (288.15, 298.15 and 308.15) K. From these data the apparent molar volumes, Vf, the apparent molar isentropic compressions, KSf, of the solute were determined. The concentration dependencies of the calculated quantities have been used to obtain the standard partial molar parameters. The latter...
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Quantumness in Diagnostics of Marine Internal Combustion Engines and Other Ship Power Plant Machines
PublikacjaThe article provides proof that the diagnostics of marine internal combustion engines and other ship power plant machines should take into account the randomness and unpredictability of certain events, such as wear, damage, the variations of mechanical and thermal loads, etc., which take place during machine operation. In the article, the energy E, like the other forms (methods) that it can be converted into (heat and work), is...
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Five-phase induction motor drive with sine-wave filter
PublikacjaThe paper presents closed loop ac drive with 5 phase induction motor operating with voltage source inverter and sine wave filter. The motor supply voltages and currents have sinusoidal shape. For well known adjustable electric drives the field oriented control method with flux and speed co ntrol can be applied. In the presence of output filter both control and estimation algorithms should be modified due to sine wave filter installation....
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Understanding the interactions between protein stabilizers and the peptide bond through the analysis of the volumetric and compressibility properties for the model systems
PublikacjaThis work confirms our earlier supposition, that volumetric and acoustic parameters for simple model proposed by us are directly related to stabilizing/destabilizing effect of osmolytes on proteins structure. The apparent molar volumes, V and the apparent molar isentropic compressions, KS,, of glycine and N,N,N –trimethylglycine (betaine) were determined from densities and speed of sound measurements in aqueous solution of N-methylacetamide...
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Influence of temperature and anion type on thermophysical properties of aqueous solutions of morpholine based amino acid ionic liquids
PublikacjaDensities and sound velocities of aqueous solutions of N-butyl-N-methylmorpholine based amino acid ionic liquids (AAILs), including N-acetyl-L-alanine, N-acetyl-Lvalinate, N-acetyl-L-leucinate, and N-acetyl-L-izoleucinate anions were measured at a temperature from 293.15 to 313.15 K at 5 K intervals and atmospheric pressure. These data were used to calculate the apparent molar volumes and the apparent molar compressibilities in...
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In-ADC, Rank-Order Filter for Digital Pixel Sensors
PublikacjaThis paper presents a new implementation of the rank-order filter, which is established on a parallel-operated array of single-slope (SS) analog-to-digital converters (ADCs). The SS ADCs use an “on-the-ramp processing” technique, i.e., filtration is performed along with analog-to-digital conversion, so the final states of the converters represent a filtered image. A proof-of-concept 64 × 64 array of SS ADCs, integrated with MOS...
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Low-frequency tripping characteristics of residual current devices
PublikacjaFast development of various types of converters makes their utilization in industry and in domestic installations very common. Due to converters, an earth fault current waveform in modern circuits can be distorted or its frequency can be different than 50/60 Hz. Frequency of earth fault (residual) current influences tripping of residual current devices which are widely used in low voltage systems. This paper presents the behaviour...
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Grid-Forming Operation of Energy-Router Based on Model Predictive Control with Improved Dynamic Performance
PublikacjaThe focus of this study is on the grid-forming operation of the Energy Router (ER) based on Model Predictive Control (MPC). ER is regarded as a key component of microgrids. It is a converter that interfaces the microgrid (s) with the utility grid. The ER has a multiport structure and bidirectional energy flow control. The ER concept can be implemented in Nearly Zero-Energy Buildings (NZEB) to provide flexible energy control. A...
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Tereny polarne - interesującym obszarem do badań Cz. II - Analityka próbek abiotycznych w Arktyce
PublikacjaW pracy ujęto problematykę zanieczyszczeń obszarów polarnych. Zwrócono szczególną uwagę na trwałe związki organiczne obecne w rejonie Arktyki w elementach przyrody nieożywionej. TZO pochodzenia antropogenicznego mogą pojawiać się na terenach polarnych za sprawą transportu na duże odległości z obszarów Euroazji i Ameryki Północnej. Badania poziomów zanieczyszczeń obecnych w próbkach abiotycznych na obszarze Arktyki stanowią fundament...
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The hydration properties of protein stabilizer, trimethylamine-N-oxide in aqueous solutions of N-methylacetamide – The volumetric and compressibility studies between 288.15 and 308.15 K
PublikacjaApparent molar volumes and apparent molar isentropic compressions of the protein stabilizer, trimethylamine-N-oxide (TMAO) were determined from the densities and speed of sound measured at T = (288.15, 298.15 and 308.15) K in aqueous solutions of N-methylacetamide (NMA) at four different concentrations (2, 4, 6 and 8 mol/kg). The concentration dependencies of the calculated quantities extrapolated to the infinite dilution lead...
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Volumes of N,N-dimethylacetamide solvated metal cations. Variation within the manganese(II) to zinc(II) series
PublikacjaDensities and apparent molar volumes for Mn(ClO4)2,Co(ClO4)2 , Ni(ClO4)2,Cu(ClO4)2 , and Zn(ClO4)2 in N, N -dimethylacetamide (DMA) solutions at T = 298.15 K are reported. Densities and apparent molar volumes of tetrabutylammonium tetraphenylborate...
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Budowa i sterowanie układu równoważenia napięć w obwodziepośredniczącym czteropoziomowego przekształtnika 4l-DCC
PublikacjaW artykule opisano budowę nowego układu równoważenia napięć w obwodzie pośredniczącym czteropoziomowego przekształtnika4L-DCC (ang. Four Level Diode Clamped Converter) oraz zaproponowano dwa alternatywne algorytmy modulacji szerokości impulsów - modulacjęPD-PWM (ang. Phase Disposition PWM) oraz PO-PWM (ang. Phase Opposition PWM). Zawarto rozważania dotyczące realizacji układu regulacjinapięć kondensatorów obwodu pośredniczącego.
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Voltage Source Power Line Conditioner for Applications in Local Supply Systems
PublikacjaThe paper presents the basic principles of operation of voltage source power line conditioners (VSPLC) as well as their energy and filtration properties. A 4-level cascade based Voltage Source Converter (VSC) is used as a voltage source. The advantages of this topology is relatively simple construction and simple way of balancing DC link voltages. Results of the theoretical and experimental investigations confirm good energetic...
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Przekształtnik prądu jako sterownik w układach napędowych z silnikami indukcyjnymi
PublikacjaThe circuits used for power conversion applied in drives with electric machines are classified into two groups: voltage source inverters (VSI) and current source inverters (CSI). Application of the current source inverter results in better properties of drive than application of voltage source inverter because there is no output filter. The development of power electronics and especially the IGBTs, in which on/off-times are very...
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Prądy łożyskowe w układach napędowych z silnikami indukcyjnymi
PublikacjaW pracy przedstawiono problemy występujące w układach napędowych z silnikami indukcyjnymi zasilanymi z falownika napięcia. Zwrócono uwagę na rosnącą liczbę uszkodzeń silników w napędach przekształtnikowych. Wskazano przyczyny wynikające z charakteru zasilania przekształtnikowego silnika. Główną uwagę poświęcono prądowi łożyskowemu, który odpowiada za większość awarii maszyn. Przedstawiono rodzaje prądów łożyskowych, wyjaśniając...
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Solvation of ionic liquids based on N-methyl-N-alkyl morpholinium cations in dimethylsulfoxide – volumetric and compressibility studies
PublikacjaThe density and sound velocity of the solutions of ionic liquids based on N-alkyl-N-methyl-morpholinium cations, N-ethyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide, N-butyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide, N-methyl-N-octyl-morpholinium bis(trifluoromethanesulfonyl)imide and N-decyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide in dimethylsulfoxide were measured at T = (298.15 to 318.15)...
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A new index for statistical analyses and prediction of travelling ionospheric disturbances
PublikacjaTravelling Ionospheric Disturbances (TIDs) are signatures of atmospheric gravity waves (AGWs) observed in changes in the electron density. The analysis of TIDs is relevant for studying coupling processes in the thermosphere–ionosphere system. A new TID index is introduced, which is based on an easy extension of the commonly used approach for TID detection. This TID activity index, which can be applied for individual Global Navigation...
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Solvation of ionic liquids based on N -methyl- N -alkylmorpholinium cations in N,N -dimethylformamide and N,N -dimethylacetamide – Volumetric and compressibility studies
PublikacjaDensity and sound velocity of the solutions of ionic liquids based on N-alkyl-N-methyl- morpholinium cations: N-ethyl- -methylmorpholinium bis(trifluoromethanesulfonyl)imide, N-butyl-Nmethylmorpholinium bis(trifluoromethanesulfonyl)imide, N-octyl-N-methyl -morpholinium bis(trifluor omethanesulfonyl)imide and N-decyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide in N, N-dimethylformamide and N,N-dimethylacetamide were...
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On Algorithm Details in Multibeam Seafloor Classification
PublikacjaRemote sensing of the seafloor constitutes an important topic in exploration, management, protection and other investigations of the marine environment. In the paper, a combined approach to seafloor characterisation is presented. It relies on calculation of several descriptors related to seabed type using three different types of multibeam sonar data obtained during seafloor sensing, viz.: 1) the grey-level sonar images (echograms)...
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Acoustical images of the Gulf of Gdansk
PublikacjaAcoustic images of seabed are of interest to specialists in the field of marine engineering, marine navigation, marine archeology, hydrogeology, etc. New technolo gies based on use of elastic waves, predominantly acoustic waves that allow detecting complexity of geometric forms of seabed, ensure progress in studying the bathymetric structure of seafloor. Use of parametric sources of waves generated...
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RCDs Tripping in the Range from DC to AC 50 kHz for Slowly Rising Residual Current
PublikacjaThe wide use of power electronic converters means that in many low-voltage systems earth fault currents containing components from DC to AC of various frequencies have to be taken into account. Due to the tendency to increase the modulation frequency in converters, components of higher frequencies may be in the order of several tens of kilohertz. Therefore, it is very important to verify the behavior of devices for protection against...
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Optimized Space-Vector Modulation Schemes for Five-Phase Precision Low-Speed Drives with Minimizing the Stator Current Ripple
PublikacjaOne of the main ways to improve the quality of a precision electric drive is minimization of the stator current pulsations generated by the voltage inverter. The solution of this problem can be achieved by using of multiphase inverters, as well as improving control algorithms. This paper considers the influence of the space-vector modulation algorithm with different switching sequences of basic vectors on the stator current pulsations...
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Simulation of the switched reluctance drive system
PublikacjaSwitched reluctance motors (SRM), unlike other types of motors, for their application require a control system and the supply from a power electronic converter. A method of modelling and mathematical model of an SRM in a switched reluctance drive (SRD) system is presented in the paper. Modelling is based on Lagrange's energy method. Coefficients of the Lagrange's equation have been calculated using the finite element method (FEM)....
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Novel Family of Single-Phase Modified Impedance-Source Buck-Boost Multilevel Inverters With Reduced Switch Count
Publikacjahis paper describes novel single-phase solutions with increased inverter voltage levels derived by means of a nonstandard inverter configuration and impedance source networks. Operation principles based on special modulation techniques are presented. Detailed component design guidelines along with simulation and experimental verification are also provided. Possible application fields are discussed, as well as advantages and disadvantages....
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Computer vision techniques applied for reconstruction of seafloor 3D images from side scan and synthetic aperture sonars data
PublikacjaThe Side Scan Sonar and Synthetic Aperture Sonar are well known echo signal processing technologies that produce 2D images of the seafloor. Both systems combines a number of acoustic pings to form a high resolution image of seafloor. It was shown in numerous papers that 2D images acquired by such systems can be transformed into 3D models of seafloor surface by algorithmic approach using intensity information, contained in a grayscaled...
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Estymacja napięcia niezrównoważenia w obwodzie pośredniczącym trójpoziomowego falownika NPC z wykorzystaniem obserwatora EKF
PublikacjaW artykule przedstawiono nowy algorytm estymacji napięcia niezrównoważenia w obwodzie pośredniczącym falownika 3L-NPC (ang. Three Level Neutral Diode-Clamped Converter) wykorzystujący rozszerzony filtr Kalmana. Algorytm może być wykorzystany do sterowania falownikiem bez czujnika napięcia w punkcie środkowym jak również może służyć do celów diagnostycznych czujnika polegających na porównaniu mierzonej wartości z estymowaną. W artykule...
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Determination of equivalent circuit parameters of an induction motor using field calculation software
PublikacjaSimulation of the drive system comprising a power electronic converter and an induction motor requires that the equivalent circuit parameters of the motor are known. These parameters can be either measured or calculated. A method of calculation of self and mutual inductances that are parameters of a polyphase model of the motor is presented in the paper. All self-inductances and mutual inductances have been calculated using the...
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Sensorless Rotor Position Estimation of Doubly-Fed Induction Generator Based on Backstepping Technique
PublikacjaThis paper proposes a speed observer algorithm for the sensorless control of a doubly-fed induction generator based on classical adaptive backstepping technique. The sensorless control is shown using classic stator field oriented control which is used to active and reactive power control. Performance of the proposed algorithm of a speed observer is validated by simulation and experimental results obtained using a small-rating generator...
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Modular high precision high current source for special applications — Simulation and verification
PublikacjaThis paper presents selected issues concerning realization of high precision high current source for special applications, where high demands of output parameters of such device are required. A new 80 kW prototype of modular high precision high current source is presented, where output current accuracy reaches 5x10-5. This paper presents also results of operation of the simulation model and of the prototype converter. In order...
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Hysteresis modelling of a medium frequency single-phase transformer
PublikacjaThe article describes a feedback Preisach hysteresis model equivalent circuit implementation of a medium frequency single-phase transformer being a part of a high power and high efficiency DC-DC converter. The macroscopic models of magnetic hysteresis are introduced and the feedback Preisach model is selected for further analysis. The hysteresis model is developed for a prototype transformer and the hysteresis loops are compared...
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Aggregated conducted interferences generated by group of asynchronous drives with deterministic and random modulation
PublikacjaThis paper addresses problems linked with electromagnetic interferences generated by group of three adjustable speed drives fed by frequency converters with deterministic and random modulation. Based on the experimental results it has been shown that decreasing of the conducted interferences in a case of random modulation is measuring phenomenon linked with selectivity of the EMI receiver.
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Thermodynamic interpretation and prediction of CO2 solubility in imidazolium ionic liquids based on regular solution theory
PublikacjaRegular solution theory (RST) is the most popular model for the interpretation of the interaction between CO2 and ionic liquids. In the present work, the parameters of this model were determined for the CO2 absorption in eleven imidazolium ionic liquids. The y-intercept (A) of the RST model for the investigated imidazolium liquids increases with increasing temperature whereas the slope (B) remains constant. The values of RST parameters...
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Behavior of residual current devices at earth fault currents with DC component
PublikacjaLow-voltage electrical installations are increasingly saturated with power electronic converters. Due to very high popularity of photovoltaic (PV) installations and the spread of electric vehicles (EV) as well as their charging installations, DC–AC and AC–DC converters are often found in power systems. The transformerless coupling of AC and DC systems via power electronic converters means that an electrical installation containing...
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Applications of Alkanethiols in Organic Synthesis
PublikacjaThis manuscript is an update to the earlier Science of Synthesis contribution describing methods for the synthesis of alkanethiols. Thiols can be converted into sulfonic, sulfinic, sulfenic acid and their derivatives, sulfides, disulfides, polysulfides, sulfonium salts, and thiiranes, etc. These transformations are accomplished by nucleophilic displacement or addition, oxidation, condensation, or coupling reactions involving thiol...
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Phase change thermal energy storage – the experience of the materials preparation for the specific applications.
PublikacjaThermal energy storage and temperature stabilization is very important in many engineering applications. There are three kinds of thermal energy storage: sensible heat, latent heat and reversible chemical reaction heat. Phase change materials (PCM) absorb, store and release large amounts of energy in the form of latent heat, at constant temperature, called the transition temperature. Many innovative applications could be found...
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Shading, Dusting and Incorrect Positioning of Photovoltaic Modules as Important Factors in Performance Reduction
PublikacjaThe amount of solar radiation reaching the front cover of a photovoltaic module is crucial for its performance. A number of factors must be taken into account at the design stage of the solar installation, which will ensure maximum utilization of the potential arising from the location. During the operation of a photovoltaic installation, it is necessary to limit the shading of the modules caused by both dust and shadowing by trees...
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Wireless intelligent audio-video surveillance prototyping system
PublikacjaThe presented system is based on the Virtex6 FPGA and several supporting devices like a fast DDR3 memory, small HD camera, microphone with A/D converter, WiFi radio communication module, etc. The system is controlled by the Linux operating system. The Linux drivers for devices implemented in the system have been prepared. The system has been successfully verified in a H.264 compression accelerator prototype in which the most demanding...
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Effect of temperature and ionic strength on volumetric and acoustic properties of solutions of urea alkil derivatives in aqueous NaCl
PublikacjaThe present work was undertaken to study volumetric and acoustic properties for diluted solutions of tetramethylurea in pure water and for urea, n-propylurea, n-butylurea and tetramethylurea in 0.5 or 1 moldm3 aqueous solutions of sodium chloride. This paper presents measured values of densities and sound velocities at T = (288.15, 298.15 and 308.15) K. From these data the apparent molar volumes, , adiabatic compressibilities,...
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Luminescent properties of Ln3+ doped tellurite glasses containing AlF3
PublikacjaThe low-phonon energy tellurite glasses TeO2-BaO-Bi2O3 and TeO2-BaO-Bi2O3-AlF3 triply doped with Eu3+, Tb3+, Tm3+ ions in two different molar ratios were synthesized using melt-quenching technique. Their structure and luminescence properties were widely investigated by X-ray Diffraction (XRD), Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR) and Photoluminescence Spectroscopy (PL). The luminescence...
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Determiantion of optimal conditions for the isolation of oil from the fishing industry offal
PublikacjaFish 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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On the use of a charge balancing method for low energy measurements
PublikacjaThe paper presents the method for the estimation of the energy consumption of the low-power microcontroller-based devices. Due to high dynamics of the changes of the supply current of the tested devices during the operational cycle, the consumed energy estimation is not easy. In order to avoid disadvantages of known methods, the charge balancing method was employed similarly like in some types of A/D converters.
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FPGA implementation of reverse residue conversion based on the new Chinese Remainder Theorem II- Part II,- Experimantal results
PublikacjaW pracy opisano realizację sprzętową konwertera z systemu resztowego do systemu binarnego. Konwerter jest oparty na nowej formie chińskiego twierdzenia o resztach CRT II. Teoretyczne aspekty takiej konwersji przedstawiono w części I. Implementację konwertera wykonano w środowisku Xilinx FPGA. Zaprezentowano ogólną architekturę konwertera, a także opisano realizację wybranych bloków. Podano ilość koniecznych zasobów sprzętowych...
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Current trends in solid-phase microextraction (SPME) fibre catings
PublikacjaThis critical review presents information on known and innovative approaches to the manufacture of fibre coatings used in solid-phase microextraction (SPME). The properties, advantages and drawbacks of the different types of commercially available SPME fibre coatings are discussed in detail, as are those of novel types of coatings and the methodologies of their preparation. The applications of fibre coatings in the solid-phase...
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Photovoltaic-Installation Performance in Central Europe on the Example of Poland
PublikacjaThe amount of the electric energy obtained from a photovoltaic (PV) installation depends on the energy of the radiation. Weather conditions differ strongly between various years even in the same season. Depending on the climatic conditions of a given location, fixed PV solar plants as well as one-axis and dual-axis tracking PV solar plants are being installed worldwide. The aim of this work is to analyse the sunlight intensity...
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Heat Transfer of the Multicolor-Laser-Sources-Irradiated Nanoparticles in Reference to Thermal Processes
PublikacjaUnlike the standard materials, metallic nanoparticles offer enhancing the heat convertion rate which implies the maximum and average temperature boost significantly in the considered system. The work’s purpose is to examine heat transfer in the metallic nanoparticles which have been deposited on a glassy substrate, enabling the nanostructures thermoablation. Furthermore, the functionalized substrate is irradiated with multicolor-laser-sources,...
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Analysis of Investments in RES Based on the Example of Photovoltaic Panels in Conditions of Uncertainty and Risk—A Case Study
PublikacjaThe aim of this study is to examine the profitability of investment in a photovoltaic microinstallation, to analyze the impact of legal changes on its profitability, and to perform a sensitivity analysis of the investment profitability to energy price changes. The novelty of the research applies to the financial analysis of two legal systems of discount called net-metering and net-billing. The two systems and the change in energy...
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The Issue of Shading Photovoltaic Installation Caused by Dust Accumulation on the Glass Surface
PublikacjaThe issue of accumulation of dust and other pollutants on the surface of photovoltaic modules was thoroughly analysed over the years. One of the first surveys in this field of knowledge linked pollutant accumulation on the module surface with transmittance loss of its glass covering, which leads to lessened amount of solar radiation reaching solar cells. First stage of this accumulation process is linear transparency loss, and second...
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Power Hardware-in-the-Loop Approach In Power System Development
PublikacjaThe main objective of the research is the verification of the Power Hardware-In-The-Loop (PHIL) approach in power system analysis and design. The premise of the article is that using PHIL approach the performance of the power system in steady and transient state conditions can be analysed in real power system conditions. Models of induction machine were developed and real time simulations were performed. Simulation variables were...
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A Single-Carrier-Based Pulse-Width Modulation Template for Cascaded H-Bridge Multilevel Inverters
PublikacjaMultiplicity of the triangular carrier signals is a criterion for the extension of sinusoidal pulsewidth modulation, SPWM, to a number of output voltage levels per phase-leg in cascaded H-bridge (CHB) multilevel inverter (MLI). Considering medium and high voltage applications where appreciable number of output voltage levels from CHB MLI is needed, commensurate high number of carrier signals in either classical level- or phase-shifted...
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Equivalence of equicontinuity concepts for Markov operators derived from a Schur-like property for spaces of measures
PublikacjaVarious equicontinuity properties for families of Markov operators have been – and still are – used in the study of existence and uniqueness of invariant probability for these operators, and of asymptotic stability. We prove a general result on equivalence of equicontinuity concepts. It allows comparing results in the literature and switching from one view on equicontinuity to another, which is technically convenient in proofs....