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Search results for: LIMIT OF POWER CONVERSION EFFICIENCY, ENERGY BAND GAP, INDOOR PHOTOVOLTAICS, PHOSPHOR-BASED LED BULB
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Theory of valence-band and core-level photoemission from plutonium dioxide
PublicationThe correlated-band theory implemented as a combination of the local-density approximation with the dynamical mean-field theory is applied to PuO2. An insulating electronic structure, consistent with the experimental valence-band photoemission spectra, is obtained. The calculations yield a nonmagnetic ground state that is characterized by a noninteger filling of the plutonium 5f shell. The noninteger filling as well as the satellites...
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Efficiency Evaluation of High Performance Computing Systems Using Data Envelopment Analysis
PublicationThe paper presents an evaluation method of high performance computing (HPC) systems using multicriteria efficiency analysis. The Data Envelopment Analysis approach was applied and adapted to the specifics of HPC, which enabled us to compare relative efficiency of systems considering simultaneously multiple parameters. The analysis is based on the TOP500 list of world largest supercomputers and their parameters such as: the number...
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On the use of a charge balancing method for low energy measurements
PublicationThe 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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A Compact Self-Hexaplexing Antenna Implemented on Substrate-Integrated Rectangular Cavity for Hexa-Band Applications
PublicationThis brief introduces a novel architecture of a compact self-hexaplexing antenna (SHA) implemented on a substrate-integrated rectangular cavity (SIRC) for hexa-band applications. The proposed SHA is configured by using an SIRC resonator, two Pi-shaped slots (PSSs), and six 50Ω microstrip feedlines. The PSSs are connected back-to-back and loaded on top of the SIRC resonator to produce six patch radiators (PRs). The PRs are excited...
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Limit Analysis of a Strip Footing on Stochastic Subsoil.
PublicationW pracy analizowana jest ława fundamentowa posadowiona na losowym podłożu.Poszukiwane są oszacowania nośności podłoża na podstawie twierdzeń o dolnej i górnej ocenie obciążenia granicznego. Dla różnych statycznie dopuszczalnych pól naprężenia i kinematycznie dopuszczalnych pól prędkości, wyznaczono wartości oczekiwane i wariancje obciążenia granicznego. Pozwoliło to na określenie odpowiednich dystrybuant, rozumianych...
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A simplified energy dissipation based model of heat transfer for post-dryout flow boiling
Publicationmodel for post dryout mist flow heat transfer is presented based on considerations of energy dissipation in the flow. The model is an extension of authors own model developed earlier for saturated and subcooled flow boiling. In the former version of the model the heat transfer coefficient for the liquid singlephase convection as a reference was used, due to the lack of the appropriate model for heat transfer coefficient for the...
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Wideband Channel Measurements for Polarised Indoor Off-Body Communications
PublicationThis paper presents the initial results of wideband channel measurements for polarised off-body communication at 5.8 GHz, in an indoor environment. Channel Impulse Response measurements were performed simultaneously for two orthogonal polarisations of the wearable antenna, and repeated for vertical and horizontal orientations of the off-body one. Four types of measurement scenarios were considered in order to investigate the influence...
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Efficiency of acoustic heating in the Maxwell fluid
PublicationThe nonlinear effects of sound in a fluid describing by the Maxwell model of the viscous stress tensor is the subject of investigation. Among other, viscoelastic biological media belong to this non-newtonian type of fluids. Generation of heating of the medium caused by nonlinear transfer of acoustic energy, is discussed in details. The governing equation of acoustic heating is derived by means of the special linear combination...
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Efficiency of acoustic heating in the Maxwell fluid
PublicationThe nonlinear effects of sound in a fluid describing by the Maxwell model of the viscous stress tensor is the subject of investigation. Among other, viscoelastic biological media belong to this non-newtonian type of fluids. Generation of heating of the medium caused by nonlinear transfer of acoustic energy, is discussed in details. The governing equation of acoustic heating is derived by means of the special linear combination...
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Impact of radio wave polarisation on off-body communications in indoor environments
PublicationThis paper describes the measurements and the analysis of the impact of radio wave polarisation on off-body communications in Body Area Networks in indoor environments. Measurements on polarisation impact are briefly described. Five investigated scenarios with different body postures and different antenna placements are characterised. The difference between the vertical and horizontal components of the received radio signal are...
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Power Hardware-in-the-Loop Approach In Power System Development
PublicationThe 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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Capacity of Surface Production of Band Sawing in Manufacture of Oak Floor Upper Layers
PublicationThin lamellae, corresponding to the layer components of structural glued members, i.e., 2-ply or 3-ply glued flooring, can be manufactured in re-sawing operations of kiln-dried wood blocks or in wet technologies, which currently seem to be more common because of the shorter drying time. The re-sawing process in wet technology is conducted on dedicated thin-cutting band sawing machines with stellite-tipped band saws. The goal of...
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Investigation on air quality of specific indoor environments—spa salons located in Gdynia, Poland
PublicationDue to excessive application of essential oils and scented products in spa salons during aromatherapy and massage sessions, the elevated concentration of total volatile organic compounds (TVOCs), particularly terpenes, which are known as secondary organic aerosol (SOA) precursors, is expected there. This study was aimed at determination of VOCs with a particular regard to terpenes in air samples collected in selected spa salons...
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The operating field of a hydrostatic drive system. Parameters of the energy efficiency investigations of pump and hydraulic motors
PublicationPrzedstawiono pole pracy układu napędu hydrostatycznego. Uzasadniono podział parametrów pracy silnika hydraulicznego i pompy na parametry niezależne i zależne od pracy tych maszyn wyporowych i układu z nich utworzonego. Zaproponowano podjęcie tematu badawczego mającego na celu opracowanie metod wyznaczania charakterystyk energetycznych pomp i silników hydraulicznych obrotowych oraz zmodyfikowanych metod wyznaczania charakterystyk...
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Energy losses in the hydraulic rotational motor - definitions and relations for evaluation of the efficiency of motor and hydrostatic drive
PublicationStosowane dotychczas w badaniach naukowych i w praktyce przemysłowej metody oceny strat i sprawności energetycznej obrotowych silników hydraulicznych stosowanych w napędach hydrostatycznych dają błędne rezultaty, ponieważ obarczone są wpływem samych strat na parametry, w funkcji których straty i sprawności są oceniane.Celem pracy było zdefiniowanie w silniku parametrów pracy, rozwijanych mocy, występujących strat i sprawności energetycznej...
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Effective Gap Size Index for Determination of Optimum Separation Distance Preventing Pounding between Buildings during Earthquakes
PublicationSeismic excitations may lead to collisions between adjacent civil engineering structures causing major damage. In this paper, an effective equation for calculating the gap size index is proposed so as to provide the optimum separation distance preventing structural pounding during different earthquakes. Evaluation of the best prediction of the required separation distance between two adjacent buildings was carried out by using...
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Person Tracking in a Ferry Environment Using Ultra-Wide Band Radio Interface
PublicationThis article presents research and analysis of effectiveness of tracking moving people in an environment of passenger ferry, using measurements of propagation time of ultra-wide band radio signal (UWB - Ultra-Wide Band). Constructed measurement stand and results of measurements carried out in a real propagation conditions were shortly discussed.
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The concept of a new two-stage fuse for high power pulse forming
PublicationThis manuscript introduces the concept, physical operating principle and studies on a new and unique two stage forming fuse (TSFF) with interstage spark gap commutation and presents its application for forming high power pulses of extreme parameters. The paper classifies TSFF performance and compares it with conventional single-stage forming fuses. The conclusions are supported by analytical and experimental studies in laboratory...
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Activity coordination of capacitor banks and power transformer controllers in order to reduce power losses in the MV grid
PublicationOne of the main issues related to the optimization of the MV (middle voltage) network is to reduce losses of active and reactive power. Lower losses of active and reactive power give not only economic advantage, but also improvement of energy quality. The object of regulation that can be used for these purposes are transformer with On-Load Tap Changer and capacitor's banks. This paper presents results of analysis of the possibility...
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Comparative Evaluation of Multicoil Inductive Power Transfer Approaches Based on Z-source Network
PublicationThis paper describes comparative evaluation between wireless power transfer topologies with utilization of Z-source network. Paper describes components calculation method. List of open-loop, close-loop simulations were conducted to compare both topologies. Spectrum of signals is also researched.
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Starter for Voltage Boost Converter to Harvest Thermoelectric Energy for Body-Worn Sensors
PublicationThis paper examines the suitability of selected configurations of ultra-low voltage (ULV) oscilla-tors as starters for a voltage boost converter to harvest energy from a thermoelectric generator (TEG). Important properties of particularly promising configurations, suitable for on-chip imple-mentation are compared. On this basis, an improved oscillator with a low startup voltage and a high output voltage swing is proposed. The applicability...
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RF Indoor Positioning System Supported by Wireless Computer Vision Sensors
PublicationIn this paper the possibility of increase the accuracy of RF fingerprinting indoor tracking system by the use of additional information from simple vision system is examined. As the distances in signal space differs from ones in real environment the ambiguity in decision process of fingerprinting algorithm can occur when set of closest distances between tag and map points in signal space corresponds to big distances differences...
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Enhancement of SrSi2O2N2:Eu2+ phosphor by means of oxygen to nitrogen control
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Utilization of a Non-Linear Error Function in a Positioning Algorithm for Distance Measurement Systems Designed for Indoor Environments
PublicationA new positioning algorithm for distance measurement systems is outlined herein. This algorithm utilizes a non-linear error function which allows us to improve the positioning accuracy in highly difficult indoor environments. The non-linear error function also allows us to adjust the performance of the algorithm to the particular environmental conditions. The well-known positioning algorithms have limitations, mentioned by their...
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Optimizing the parameters of a small standalone hybrid power system
PublicationA hybrid power plant consists of renewable energy resources, an energy storage, a discharge load and an emergency power supply. Power plant parameters are tailored to meet the requirements of continuity of supply, cost minimization, return on investment period and system capacity utilization. The papaer presents the methodology for selecting power plant parameters with a larger number of decision criteria. The task is solved...
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Engineering TADF, Mechanochromism, and Second Harmonic Up- conversion Properties in Regioisomeric Substitution Space
PublicationThis research article explores the distinct TADF efficiency of three donor-acceptor based regio-isomers: DPAOCN (ortho- isomer), DPAMCN (meta-isomer), and DPAPCN (para-isomer). DPAPCN exhibits maximum TADF efficiency in both solution and solid-state with an impressive reverse inter-system crossing (RISC) rate of ~ 106 s-1; the underlying cause being the minimum singlet-triplet splitting energy or ∆EST and maximum SOC (spin-orbit...
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Partial Admission Stages of High Efficiency for a Microturbine
PublicationThe paper presents the results of a design analysis of a micro-turbine for a co-generation micro-power plant working in accordance with organic Rankine cycle. The heat power of the plant is assumed equal to 20kW and the corresponding available electric output is estimated to be about 3kW. After the design analysis, the axial turbine with partial admission in all stages was built and tested experimentally. Special attention was...
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Partial Admission Stages of High Efficiency for a Microturbine
PublicationThe paper presents the results of a design analysis of a microturbine for a cogeneration micro-power plant working in accordance with organic Rankine cycle. The heat power of the plant is assumed equal to 20kW and the corresponding available electric output is estimated to be about 3 kW. After the design analysis, the axial turbine with partial admission in all stages was built and tested experimentally. Special attentionwas paid...
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Do the New Requirements for the Use of Energy Efficient Lighting Design Mean the End of Creativity?,
PublicationThis paper addresses issues strongly connected to recent environmental discussions which are currently taking place in Europe, Asia, America, Australia and other parts of the world about global warming, the Greenhouse Effect, light pollution and other negative impacts artificial lighting has on our planet and what can be done about it. The author also attempts to answer indirectly two of the most important questions for lighting...
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A new analyzer based on pellistor sensor with neural network data postprocessing for measurement of hydrocarbons in lower explosive limit range
PublicationW pracy przedstawiono rezultaty pierwszego etapu badań nad nowym typem analizatora do oznaczania stężenia wodoru i lotnych węglowodorów w zakresie dolnej granicy wybuchowości. Analizator ten zbudowano w oparciu o pojedynczy czujnik pelistorowy z układem przetwarzania danych wykorzystującym sztuczną sieć neuronową.
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A Wideband Channel Model for Body Area Networks in Circular Metallic Indoor Environments
PublicationIn this paper, the wideband characterization of the propagation channel in circular metallic indoor environments is addressed, regarding Body Area Networks and 5G small cells, an analytical model for the dependence of the mean delay and the average delay spread on the circle radius, the working frequency and the distance between the transmitter and the receiver being proposed. The derivation of the model is initially done analytically,...
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Fast Fading Characterization for Body Area Networks in Circular Metallic Indoor Environments
PublicationWith the increasing development of 5G and Body Area Network based systems being implemented in unusual environments, propagation inside metallic structures is a key aspect to characterize propagation effects inside ships and other similar environments, mostly composed of metallic walls. In this paper, indoor propagation inside circular metallic structures is addressed and fast fading statistical distributions parameters are obtained...
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5G Millimeter Wave Network Optimization: Dual Connectivity and Power Allocation Strategy
PublicationThe fifth generation (5G) of mobile networks utilizing millimeter Wave (mmWave) bands can be considered the leading player in meeting the continuously increasing hunger of the end user demands in the near future. However, 5G networks are characterized by high power consumption, which poses a significant challenge to the efficient management of base stations (BSs) and user association. Implementing new power consumption and user...
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Possibilities of Increasing the Overall Efficiency of Gas-steam CHP Microplant
PublicationThe paper presents ways to increase the efficiency of a gas-steam micro power plant by modifying the cycle combination. The modification consists in partial release of the fluid downstream of the gas turbine and using it for ORC fluid overheating and evaporation. Advantages of this solution over the simplest gas and steam cycles’ combination are demonstrated.
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BODIPY‐Perylene Charge Transfer Compounds; Sensitizers for Triplet‐Triplet Annihilation Up‐conversion
PublicationBODIPY heterochromophores, asymmetrically substituted with perylene and/or iodine at the 2 and 6 positions were prepared and investigated as sensitizers for triplet-triplet annihilation up conversion (TTA-UC). Single-crystal X-ray crystallographic analyses show that the torsion angle between BODIPY and perylene units lie between 73.54 and 74.51, though they are not orthogonal. Both compounds show intense, charge transfer absorption...
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A method for preliminary estimation of the length of midship body block to be inserted during ship’s conversion
PublicationThe paper presents a method for preliminary estimation of the length of the midship body block, which inserted in the original hull, increases the deadweight of the ship in line with a required quantity. The method may be useful for establishing the scope of conversion to better adjust the ship for transportation tasks. The problem is formulated by using a mathematical model so selected that its solution, under set of assumptions,...
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The Efficiency and Productivity Evaluation of National Innovation Systems in Europe
PublicationPurpose: An efficient innovation system currently plays a crucial role in creating competitive prevalence, contributing to the economic growth of individual states. The innovation system is influenced by many socioeconomic factors, including in international rankings of innovativeness of economies. These classifications have some limitations. Primarily, they do not examine the efficiency, which means they do not analyze the...
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Analysis of the Impact of Charging Electric Cars on the Power System Load
PublicationThe paper presents ways of integrating electric cars with the power system. In connection with this, daily load curves in the average working day have been developed in the G2V (Grid-to-Vehicle) and V2G (Vehicle-to-Grid) variants. The G2V solution consists in unidirectional energy flow from the power system to a vehicle’s battery. The V2G solution consists in bi-directional energy exchange between the power system and electric...
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Frequency response spectra applied to assess efficiency of the training techniques
PublicationThe purpose of the research is to assess the increase of the muscle strength and power. Movement of the human body when the moving one impacts a stationary or moving body is taken under consideration. The waveform produced by an impact is transformed into frequency domain. The acceleration record is transformed as a complex spectrum, by the use of a Discrete Fourier Transformation. In this paper the applications of the discrete...
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Bridging the gap between architectural and environmental engineering education in the context of climate change
PublicationIndicated in this article is the urgent need to adjust architectural education to the challenges triggered by climate change. Although reports on the future scenarios for cities are alarming, documents that set criteria for architectural education do not indicate competencies related to climate change adaptation and mitigation, mainly by avoiding environmental engineering considerations. An immediate answer to this problem could...
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Enhanced switched parasitic antenna with switched active monopoles for indoor positioning systems
PublicationThis paper presents the concept of enhanced reduced-size steerable antenna array with two rows of switched active and passive elements. Designed array is similar to ESPAR antenna but it has a set of switched monopoles instead of central one. It is intended for 2.4 GHz ISM applications with emphasis on indoor positioning systems (IPS). Proposed antenna provides improved radiation parameters and reduced dimensions in comparison to...
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Expedited Yield Optimization of Narrow- and Multi-Band Antennas Using Performance-Driven Surrogates
PublicationUncertainty quantification is an important aspect of engineering design, also pertaining to the development and performance evaluation of antenna systems. Manufacturing tolerances as well as other types of uncertainties, related to material parameters (e.g., substrate permittivity) or operating conditions (e.g., bending) may affect the antenna characteristics. In the case of narrow- or multi-band antennas, this usually leads to...
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Path Loss Analysis in Off-Body Channels in Indoor Environment
PublicationThis temporary document describes an analysis of path loss in off-body channels in an indoor environment. The influence of body orientation and on-body antenna placement on path loss in off-body communications as well as of different bodies has been investigated. Five static scenarios, six distances between body and antenna and eight body orientations were analysed; moreover, two dynamic scenarios were investigated. The smallest...
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Composites in energy storing prosthetic feet
PublicationComposites reinforced with carbon and glass fibers have become the commonly used material in the production of energy storing prosthetic feet (ESPF/elastic feet prostheses). Their properties ensure a stable and light structure that allows for accumulation, storage and release of energy during walking, thus ensuring an increase in gait efficiency. Depending on the modification of the composite in terms of fiber selection, their...
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Power System Dynamics. Stability and Control. 3rd edition
PublicationComprehensive, state-of-the-art review of information on the electric power system dynamics and stability. It places the emphasis first on understanding the underlying physical principles before proceeding to more complex models and algorithms. The book explores the influence of classical sources of energy, wind farms and virtual power plants, power plants inertia and control strategy on power system stability. The book cover...
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A Microwave Sensor with Operating Band Selection to Detect Rotation and Proximity in the Rapid Prototyping Industry
PublicationThis paper presents a novel sensor for detecting and measuring angular rotation and proximity, intended for rapid prototyping machines. The sensor is based on a complementary split-ring resonator (CSRR) driven by a conductor-backed coplanar waveguide. The sensor has a planar topology, which makes it simple and cost-effective to produce and accurate in measuring both physical quantities. The sensor has two components, a rotor, and...
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Energy Losses Due to Imperfect Payment Infrastructure and Payment Instruments
PublicationOne of the strategic objectives of the European Union is a reduction in greenhouse gas emissions and improvement of energy efficiency by at least 32.5% in different areas of the economy by 2030. However, little is known about the impact of payment in retail on energy consumption. The purpose of this paper is to assess the chain of losses of time and energy, and therefore financial losses, that occur due to the imperfection of payment...
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Energy Consumption Modeling in SPMD and DAC Applications
PublicationIn this chapter, we show a study of energy consumption during execution of SPMD and DAC application – the same applications which time of execution we modeled in the previous two chapters. We measured an average power usage at a single node of the GALERA+ cluster during application execution and then we modeled the total energy consumption by the application. Next we simulated the applications using MERPSYS and we compared the...
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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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Reliable renewable energy – application of electrochemical capacitors for electrical energy storage
PublicationThis paper presents electrical energy storage devices such as electrochemical capacitors, their principle of operation and electrode materials most commonly used in their manufacturing technology. Moreover, our research on development of new nanocomposite materials based on multi-walled carbon nanotubes and conducting polymer is shown. Additionally, the possibility and advantages of application of supercapacitors for accumulation...