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Wyniki wyszukiwania dla: ENERGY CHARACTERISTICS OF THE FLOW SECTION
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The Possibility of Phase Change Materials (PCM) Usage to Increase Efficiency of the Photovoltaic Modules
PublikacjaSolar energy is widely available, free and inexhaustible. Furthermore this source of energy is the most friendly to the environment. For direct conversion of solar energy into useful forms like of electricity and thermal energy, respectively photovoltaic cells and solar collectors are being used. Forecast indicate that the first one solution will soon have a significant part in meeting the global energy demand. Therefore it is...
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Sound intensity distribution around organ pipe
PublikacjaThe aim of the paper was to compare acoustic field around the open and stopped organ pipes. The wooden organ pipe was located in the anechoic chamber and activated with a constant air flow, produced by an external air-compressor. Thus, long-term steady state response was possible to obtain. Multichannel acoustic vector sensor was used to measure the sound intensity distribution of radiated acoustic energy. Measurements have been...
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Comparative study of a bottoming SRC and ORC for Joule–Brayton cycle cooling modular HTR exergy losses, fluid-flow machinery main dimensions, and partial loads
PublikacjaEnergy conversion efficiency increase in power plants with high-temperature gas-cooled reactors via implementation of the bottoming cycle was investigated under nominal and minimal thermal load of a high-temperature reactor (HTR). Heat transfer surface area and turbine outlet volumetric flow rate in bottoming cycles was also investigated. Water and two low-boiling point working fluids (ammonia and ethanol) were analyzed. Analyzed...
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Measurements and visualization of sound field distribution around organ pipe
PublikacjaMeasurements and visualization of acoustic field around an organ pipe are presented. Sound intensity technique was applied for this purpose. Measurements were performed in free field. The organ pipe was activated with a constant air flow, produced by an external compressor, aimed at obtaining long-term steady state responses of generated acoustic signal. Sound energy distribution was measured in a defined fixed grid of points...
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Proces zmiany sprzedawcy energii elektrycznej w Polsce
PublikacjaOstatnie kilkanaście lat w polskiej energetyce to okres dynamicznych zmian. Jednym z istotnych przykładów tych przemian jest liberalizacja rynku energii. Wprowadzone, w krajowej energetyce, mechanizmy rynku konkurencyjnego umożliwiają odbiorcom energii m.in. swobodny wybór sprzedawcy energii elektrycznej w formule TPA. W artykule przedstawiony został proces zmiany sprzedawcy bazujący na generalnej umowie dystrybucji (GUD). W trakcie...
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Extended investigation of performance-energy trade-offs under power capping in HPC environments
Publikacja—In the paper we present investigation of performance-energy trade-offs under power capping using modern processors. The results are presented for systems targeted at both server and client markets and were collected from Intel Xeon E5 and Intel Xeon Phi server processors as well as from desktop and mobile Intel Core i7 processors. The results, when using power capping, show that we can find various interesting combinations of...
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Analysis of the possibility of increasing thermal-electric energy conversion ratio in CHP units based on micro gas turbine
PublikacjaThe aim of this paper is to analyze the possibility of increasing thermal energy to electricity conversion efficiency in combined heat and power (CHP) units based on micro gas turbine during low heat demand periods. At the beginning sustainable development postulates under power engineering are explained. Next micro CHP as part of distributed generation idea is presented. The main part of the article is based on results of thermodynamic...
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Selection of drive engines for dredge pumps
PublikacjaThis paper presents the principles of selecting drive engines for dredge pumps, formulated by this author. In order to formulate them influence of drive engines on dredge pump characteristics and dredger effectiveness, have been analyzed. Also, an analysis of results of the author's operational investigations concerning energy consumption and parameters of excavated soil transport on board dredgers has been performed.
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Plate heat exchanger with porous structure for potential use in ORC system
PublikacjaThe experimental analysis of passive heat transfer intensification in the case of plate heat exchanger has been carried out. The passive intensification was obtained by a modification of the heat transfer surface, which was covered by a metallic porous microlayer. The experiment was accomplished in two stages. In the first stage the commercial stainless steel gasketed plate heat exchanger was investigated, while in the second one...
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Plate heat exchanger with porous structure for potential use in ORC system
PublikacjaThe experimental analysis of passive heat transfer intensification in the case of plate heat exchanger has been carried out. The passive intensification was obtained by a modification of the heat transfer surface, which was covered by a metallic porous microlayer. The experiment was accomplished in two stages. In the first stage the commercial stainless steel gasketed plate heat exchanger was investigated, while in the second one...
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Influence of metallic porous microlayer on pressure drop and heat transfer of stainless steel plate heat exchanger
PublikacjaThe experimental analysis of passive heat transfer intensification in the case of plate heat exchanger has been carried out. On the heat transfer surface of heat exchanger the metallic porous layer was created. The experiment was accomplished in two stages. In the first stage the commercial stainless steel gasketed plate heat exchanger was investigated, while in the second one – the identical heat exchanger but with the modified...
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Study of Direct Methanol Fuel Cell Process Dynamics Using Dynamic Electrochemical Impedance Spectroscopy
PublikacjaA 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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Improvement of Thrust Bearing Calculation Considering the Convectional Heating within the Space between the Pads
PublikacjaA modern thrust bearing tool is used to estimate the behavior of tilting pad thrust bearings not only in the oil film between pad and rotating collar, but also in the space between the pads. The oil flow in the space significantly influences the oil film inlet temperature and the heating of pad and collar. For that reason, it is necessary to define an oil mixing model for the space between the pads. In the bearing tool, the solutions...
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Alternative Energy: Photovoltaic Solar Cells
PublikacjaSolar radiation is a fuel for photovoltaic cells and modules, which are a source of electric energy. Viable solar technologies that have been developed in the past are starting to be adopted on a broader and more meaningful global scale across different sectors with ever-increasing market penetration. In this entry, a brief overview of the material properties relevant to solar cell operation, the structure of the solar cell, and electrical...
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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
PublikacjaDue 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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Construction and investigation of SO2 amperometric sensor with a solid polymer electrolyte membrane
Publikacjan this paper a sensor for detection of the sulphur dioxide based on three electrode cell configuration with a liquid electrolyte, a mercury sulphate reference electrode and a solid polymer electrolyte working electrode is presented. Working elec- trode was obtained by using Takenaka-Torikai chemical deposi- tion method by precipitation of Au particles into the pores of the Nafion membrane. Sensors characteristics measurements were...
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ANALIZA PRZEPUSTOWOŚCI WYBRANEGO UKŁADU TOROWEGO W PRZESTRZENI CZĘŚCIOWO – UPORZĄDKOWANEJ
PublikacjaNa sieci kolejowej istotny wpływ na płynność ruchu mają odpowiednio usytuowane odcinki odstępowe. Z podobną sytuacją mamy do czynienia przy modernizacji stacji kolejowych i tworzeniu nowych rozwiązań, w których należy uwzględnić prognozy rozwoju ruchu na danym elemencie sieci kolejowej. Jednak w przypadku stacji sytuacja staje się dużo bardziej skomplikowana i kosztowna, gdyż poprawa przepustowości wymaga istotnych zmian organizacyjnych...
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Use of Modified Cuckoo Search algorithm in the design process of integrated power systems for modern and energy self-sufficient farms
PublikacjaIn the face of increasingly stringent pollutant emission regulations, designing an agricultural holding becomes a difficult challenge of connecting a large number of coefficients that describe an energy system of a farm in regard to its ecological and economic efficiency. One way to cope with this issue is to design an energy self-sufficient farm that integrates various technologies, including renewable energy. However, the selection...
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Magnetic semiconductor photocatalysts for the degradation of recalcitrant chemicals from flow back water
PublikacjaIn the present study treatability of persistent organic compounds from the flow back water after hydrauling fracturing was investigated. The combination of TiO2 photocatalyst and magnetic oxide nanoparticles enhance the separation and recoverable property of nanosized TiO2 photocatalyst. Fe3O4/ TiO2 and Fe3O4@SiO2/TiO2 nanocomposites were prepared by heteroagglomeration. The photocatalysts’ characteristics by X-ray diffractometry...
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Optimizing CO2 Purification in a Negative CO2 Emission Power Plant
PublikacjaIn the pursuit of mitigating CO2 emissions, this study investigates the optimisation of CO2 purification within a Negative CO2 Emission Power Plant using a spray ejector condenser (SEC) coupled with a separator. The approach involves direct-contact condensation of vapour, primarily composed of an inert gas (CO2), facilitated by a subcooled liquid spray. A comprehensive analysis is presented, employing a numerical model to simulate...
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RANS-based design optimization of dual-rotor wind turbines
PublikacjaPurpose An improvement in the energy efficiency of wind turbines can be achieved using dual rotors. Because of complex flow physics, the design of dual-rotor wind turbines (DRWTs) requires repetitive evaluations of computationally expensive partial differential equation (PDE) simulation models. Approaches for solving design optimization of DRWTs constrained by PDE simulations are investigated. The purpose of this study is to determine...
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The resistance of S235JR steel to cavitation erosion
PublikacjaThe erosion resistance of S235JR steel to flow cavitation was investigated. In order to understand an influence of steel properties and cavitation intensities on the degradation mechanisms, low-carbon S235JR steel was tested in the as-received state and after thermal treatment (annealing) under four different flow velocities. Annealing decreased steel hardness, which made S235JR steel less resistant to cavitation erosion. The performed...
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Thermal visualization of Ostwald-de Waele liquid in wavy trapezoidal cavity: Effect of undulation and amplitude
PublikacjaThe present study is concerned with the numerical simulations of Ostwald-de Waele fluid flow in a wavy trapezoidal cavity in the presence of a heated cylinder situated at the center of the cavity. The work consists in characterizing the mixed convection as a function of the intensity of heat flow. The flow behaviour and temperature distribution in a cavity are the main focus of this study. The lower wall of the cavity is fixed...
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Low energy elastic electron scattering from benzonitrile (C6H5CN)
PublikacjaWe present experimental differential elastic scattering cross sections (DCSs) for low energy electron scattering from benzonitrile along with integral and momentum-transfer cross sections that are determined from these DCSs. The measurements of DCSs are obtained using the relative flow method with helium as the standard gas, in a crossed electron-molecular gas beam arrangement. Our measurements are made at incident electron energies...
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Window frame integrable air recuperation minichannel/minigap heat exchanger
PublikacjaThis article describes an evaluation of mini heat exchangers operation as a decentralized mechanical ventilation system with recuperative heat recovery that can be integrated into the window frame. The relatively small yet efficient air recuperation system allows for retrofitting existing buildings by reducing the overall energy consumption and thus the CO2 emissions. The proposed design, unlike existing systems, is easy to scale...
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Review and Indication of Key Activities for Energy Management Improvement in DC Microgrids
PublikacjaDC MicroGrids (MG) must have Energy Management Systems (EMS) to guarantee efficient, dependable, and environmentally friendly electricity. The application of Model Predictive Control (MPC), proved to be helpful due to its adaptability and capacity to use non-linear models. This paper, based on an extensive literature review, identifies and discusses the three key activities to improve the characteristics of DC microgrids, i.e.:...
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Updating the Coupling Algorithm between HYDRUS and MODFLOW in the HYDRUS Package for MODFLOW
PublikacjaThe HYDRUS-based flow package for MODFLOW (the HPM or the HYDRUS package) is an existing unsaturated zone flow package for MODFLOW. In MODFLOW with the HPM, the groundwater modeling domain is discretized into regular grids that can be combined into multiple zones based on similarities in soil hydrology, topographical characteristics, and the depth to the groundwater. Each of these zones is assigned one unsaturated soil profile...
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Simulation of influence of the air gap asymmetryon voltage waveforms of a synchronous machine
PublikacjaResults of simulation of a synchronous generator with the air gap asymmetry characterised by eccentricity are presented in the paper. The Lagrange's energy method has been used in derivation of the model equations. Analysis of influence of the air gap asymmetry on characteristics of self and mutual inductances of windings, as well as analysis of induced voltage waveforms as a function of the air gap asymmetry have been performed....
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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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The use of liquid crystal thermography TLC and particle image velocimetry PIV in selected technical applications
PublikacjaNowadays, the energy cost is very high and this problem is carried out to seek techniques for improvement of the aerothermal and thermal (heat flow) systems performances in different technical applications. The transient and steady-state techniques with liquid crystals for the surface temperature and heat transfer coefficient or Nusselt number distribution measurements have been developed. The flow pattern produced by transverse...
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Magnetoacoustic Heating in Nonisentropic Plasma Caused by Different Kinds of Heating-Cooling Function
PublikacjaThe nonlinear phenomena which associate with magnetoacoustic waves in a plasma are analytically studied. A plasma is an open system with external inflow of energy and radiation losses. A plasma’s flow may be isentropically stable or unstable. The nonlinear phenomena occur differently in dependence on stability or instability of a plasma’s flow. The nonlinear instantaneous equation which describes dynamics of nonwave entropy mode...
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Instantaneous Heating and Cooling Caused by Periodic or Aperiodic Sound of Any Characteristic Duration in a Gas with Vibrational Relaxation
PublikacjaThermodynamic relaxation of internal degrees of a molecule's freedom in a gas occurs with some characteristic time. This makes wave processes in a gas behave differently depending on the ratio of characteristic duration of perturbations and the relaxation time. In particular, generation of the secondary non-wave modes by intense sound in a nonlinear flow dependens on frequency. These kinds of interaction are considered in this...
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The description of non-linear interactions of wave and non-wave modes in a non-adiabatic plasma flow
PublikacjaThe method of derivation of non-linear equations for interacting modes is explained and applied to a plasma's flow affected by a magnetic field. It is based on the linear projecting of the total perturbation field into specific variations of variables in individual modes of a flow. The method may be applied in many examples of fluid flows with different mechanisms of non-adiabaticity. It is of special importance in complex flows...
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Hybrid geothermal-fossil power cycle analysis in a Polish setting with a focus on off-design performance and CO2 emissions reductions
PublikacjaGrowing demand for electricity due to economic development contributes to increased greenhouse gas production, especially CO2. However, emissions can be limited by enhancing the efficiency of primary energy conversion, such as integrating geothermal energy into coal-fired power plants. Therefore, this paper proposes replacing conventional feed-water heaters with geothermal preheaters to create a hybridized system. This study was...
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Composite as a Material of the Future in the Era of Green Deal Implementation Strategies
PublikacjaComposite materials have become synonymous with modernity, desired in nearly every aspect of our daily lives, from simple everyday objects to sanitary facilities, pipelines, the construction of modern sewer networks, their renovation, water supply, and storage reservoirs, to complex structures—automotive, planes, and space science. Composites have seen a considerable rise in attention owing to their characteristics, durability,...
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Models of using the Internet by young Poles and their social capital.
PublikacjaHighlights • Study examining Polish youth on internet usage styles. • Online communication is the most common form of spending time on the Internet. •...
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Estimation of the Regenerative Braking Process Efficiency in Electric Vehicles
PublikacjaIn electric and hybrid vehicles, it is possible to recover energy from the braking process and reuse it to drive the vehicle using the batteries installed on-board. In the conditions of city traffic, the energy dissipated in the braking process constitutes a very large share of the total resistance to vehicle motion. Efficient use of the energy from the braking process enables a significant reduction of fuel and electricity consumption...
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Analysis of inductive power transfer systems for variable air gap and voltage supply frequency
PublikacjaThe paper describes an IPT system, by which electrical energy may be transmitted through a large air gap between coils without electrical connection. It presents theoretical and simulation analysis of IPT, which allows for supplying a receiver in the conditions of slow, in relation to the dynamics of power supply, changes in dimension of the air gap. The influence of frequency characteristics of the system on the possible selection...
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Particle Image Velocimetry Measurements of Airflow in Electrohydrodynamic Device for Dust Particle Collection
PublikacjaIn this paper the pumping effect of air in the electrohydrodynamic (EHD) device for dust particle collection is presented. To induce an airflow in this EHD device corona discharge was used. The discharge was generated between the one-sided spike electrodes and the plate electrodes. The asymmetric electric field and generated discharge resulted in a unidirectional airflow through the EHD device. The current-voltage characteristics...
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A Set of Experience-Based Smart Synergy Security Mechanism in Internet of Vehicles
PublikacjaIn this article, we introduce a novel security mechanism, the Smart Synergy Security (3S). The mechanism uses the Set of Experience Knowledge Structure (SOEKS) and the synergy of security methods in different domains to provide the global optimal security strategy. The proposed strategy is taking into account the characteristics of information security (i.e. confidentiality, integrity, availability, controllability, and reviewability)...
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Electrochemical Production of Sodium Hypochlorite from Salty Wastewater Using a Flow-by Porous Graphite Electrode
PublikacjaThe production of sodium hypochlorite (NaOCl) from salty wastewater using an electrochemical cell has several advantages over other methods that often require hazardous chemicals and generate toxic waste, being more sustainable and environmentally friendly. However, the process of producing sodium hypochlorite using an electrochemical cell requires careful control of the operating conditions, such as the current density, flow rate,...
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Strain energy density and entire fracture surface parameters relationship for LCF life prediction of additively manufactured 18Ni300 steel
PublikacjaIn this study, the connection between total strain energy density and fracture surface topography is investigated in additively manufactured maraging steel exposed to low-cycle fatigue loading. The specimens were fabricated using laser beam powder bed fusion (LB-PBF) and examined under fully-reversed strain-controlled setup at strain amplitudes scale from 0.3% to 1.0%. The post-mortem fracture surfaces were explored using a non-contact...
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INTENSYFIKACJA WYMIANY CIEPŁA W WYMIENNIKU WĘŻOWNICOWYM Z WYKORZYSTANIEM PRZEGRÓD O RÓŻNEJ GEOMETRII
PublikacjaW pracy zaprezentowano możliwości wykorzystania pasywnej intensyfikacji wymiany ciepła w postaci przegród dla podniesienia efektywności energetycznej wymiennika wężownicowego. Badania zostały przeprowadzone z wykorzystaniem modułowego wymiennika z wężownicą w postaci grzałki elektrycznej. Medium odbierającym ciepło była woda o stałych parametrach cieplnoprzepływowych na wlocie do modułu. Pomiary przeprowadzono dla szerokiego zakresu...
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Design and experimental investigations of a cylindrical microjet heat exchanger for waste heat recovery systems
PublikacjaCompact heat exchangers have more and more applications in many areas, including the HVAC, food and petrochemical industry. This paper describes the development of heat exchanger technology for waste heat recovery (WHR) from a range of processes. Case-study testing shows that the proposed heat exchanger can successfully enhance heat transfer and recover waste heat in a range of applications making them economically, environmentally and...
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An Experimental Investigation of Pressure Wave Celerity During the Transient Slurry Flow
PublikacjaTransportation of slurries in pressure pipelines is an example of a complex flow due to specific parameters of transported medium. For practitioners, the economy of designing and maintenance is usually the most important factor. For this reason, most of hydrotransport installations are fairly simple; however, they become more vulnerable to negative effects of the transient flow which can occur in pressure pipelines. As the consequence,...
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Example of Using Particle Swarm Optimization Algorithm with Nelder–Mead Method for Flow Improvement in Axial Last Stage of Gas–Steam Turbine
PublikacjaThis article focuses principally on the comparison baseline and the optimized flow efficiency of the final stage of an axial turbine operating on a gas–steam mixture by applying a hybrid Nelder– Mead and the particle swarm optimization method. Optimization algorithms are combined with CFD calculations to determine the flowpaths and thermodynamic parameters. The working fluid in this study is a mixture of steam and gas produced...
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Performance Evaluation of Selected Parallel Object Detection and Tracking Algorithms on an Embedded GPU Platform
PublikacjaPerformance evaluation of selected complex video processing algorithms, implemented on a parallel, embedded GPU platform Tegra X1, is presented. Three algorithms were chosen for evaluation: a GMM-based object detection algorithm, a particle filter tracking algorithm and an optical flow based algorithm devoted to people counting in a crowd flow. The choice of these algorithms was based on their computational complexity and parallel...
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Hydrogen production from ethanol In nitrogen microwave plasma At atmospheric pressure
PublikacjaHydrogen seems to be one of the most promising alternative energy sources. It is a renewable fuel as it could be produced from e.g. waste or bio-ethanol. Furthermore hydrogen is compatible with fuel cells and is environmentally clean. In contrast to conventional methods of hydrogen production such as water electrolysis or coal gasification we propose a method based on atmospheric pressure microwave plasma. In this paper we present...
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Analysis of the Impact of Charging Electric Cars on the Power System Load
PublikacjaThe 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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Architects and urban planners in the face of energy transition - smart cities energy aspects in shaping building structures and cities
PublikacjaContemporary architects and urban planners are facing steadily increasing challenges. The growing problems around environmental issues, shrinking natural resources and climate action are just some of them. Currently, planning should also include balancing with all the aspects of sustainable development such as not only the environmental issues, but also social and economic ones. How to meet them in the era of energy transition...