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Mathematical analysis of transformer insulation state by means of composite indicator
PublicationThe paper is presenting mathematical model – composite indicator (CI), which was utilized on insulating state of distribution transformer to analyze and sensibility of individual measurements methods mutual comparison. We can uniquely determine importance of these measurements methods with this mathematical apparatus in these measurements methods in insulating state of transformers.
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A Combined TOPSIS and FA Based Strategic Analysis of Technical Condition of High Power Transformers
PublicationThe paper presents mathematical model { TOPSIS method, which was utilized on insulating state of distribution transformer to analyze and sensibility of individual measurements methods mutual comparison. We can uniquely determine the importance of these measurements methods with this mathematical appara- tus in these measurements methods in insulating state of transformers.
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Application of Fracture Mechanics for Energetic Effects Predictions While Wood Sawing
PublicationIn the classical approach, energetic effects (cutting forces and cutting power) of wood sawing process are generally calculated on the basis of the specific cutting resistance, which is in the case of wood cutting the function of more or less important factors. On the other hand, cutting forces (or power - more interesting from energetic point of view) could be considered from a point of view of modern fracture mechanics. Cutting...
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Badania eksperymentalne i symulacyjne dynamiki modelowego odcinka sieci trakcyjnej
PublicationW pracy przedstawiono główne założenia i strukturę opracowanego modelu matematycznego odcinka kolejowej górnej sieci trakcyjnej, opartego na metodzie energetycznej Lagrange’a. W celu wyznaczenia wybranych parametrów modelu, jak również dla oceny stopnia zgodności odwzorowania przez utworzony program symulacyjny stanów statycznych i dynamicznych sieci zbudowano laboratoryjny model odcinka sieci jezdnej z użyciem rzeczywistych jej...
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Renewable Energy in the Pomerania Voivodeship—Institutional, Economic, Environmental and Physical Aspects in Light of EU Energy Transformation
PublicationIn the era of globalization and rapid economic growth, affecting most world economies, increased production and consumption are leading to higher levels of energy production and consumption. The growing demand for energy means that energy resources from conventional sources are not sufficient; moreover, its production generates high costs and contributes to the emission of greenhouse gases and waste. In view of the above, many...
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Bicycle Traffic Model for Sustainable Urban Mobility Planning
PublicationModelling tools and transport models are required to assess the impact of measures for the effective planning of cycling routes in cities. This paper presents the methodology for developing a four-stage macroscopic model of bicycle traffic for the city of Gdynia, and its use in planning new bicycle routes, considering a modal shift. The model presented in this paper allows for the evaluation of the influence of the characteristics...
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Optimal state feedback controller for balancing cube
PublicationIn this paper, a nonlinear balancing cube system is considered, the concept for which is based on an inverted pendulum. The main purpose of this work was the modelling and construction of a balancing cube with the synthesis of the control system. The control objectives included swing-up and stabilization of the cube on its vertex at an unstable equilibrium. Execution of the intended purpose required, first, deriving a cognitive...
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Experimental and theoretical study of a vertical tube in shell storage unit with biodegradable PCM for low temperature thermal energy storage applications
PublicationThis article presents the experimental investigations of the coconut oil-based TES module for HVAC applications in the ambient and-sub ambient temperature range. To properly study this problem modular experimental module and test loop were developed. Special attention has been paid to study the physical mechanism of the melting/solidification process for natural substance (coconut oil) which has perspectives to be used in thermal...
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Typology, current state and non-destructive testing of timber roof trusses of historic churches in the West Vistula Delta, Poland
PublicationThis paper presents the current state of conservation of historic roof churches located in the Żuławy of Gdańsk (Poland). It also describes the architecture of these temples, the region itself and old carpentry techniques for constructing roof trusses. Interdisciplinary tests were carried out in six churches. The geometry of the load bearing structures, the moisture content and the carpentry technique were specified. The field...
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Composite GFRP U-shaped footbridge
PublicationThe paper presents proposals for the use of glass fiber reinforced polymer composites for the construction of engineering objects, known and commonly used in the shipbuilding industry. An example of a pedestrian footbridge was used in this case, which, despite the considerable thickness of the structural material, was made using infusion technology in one production cycle. The designed and produced footbridge span is durable, dynamically...
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Recycling of Photovoltaic Solar Cells and Modules - Te State - Of - Art
PublicationIn comparison to other energy producing techniques, photovoltaics (PV) is one of the most promising options: no emission of any matter into the environment during operation; extremely long operation period (estimated average: 25 years), minimum maintenance, robust technique, aesthetic aspects. The use of photovoltaics is rapidly increasing, and the respective market is developing accordingly. Although PV manufacturing equipment...
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CURRENT TRENDS IN RECYCLING OF PHOTOVOLTAIC SOLAR CELLS AND MODULES WASTE
PublicationIn comparison to other energy producing techniques, photovoltaics (PV) is one of the most promising options: no emission of any matter into the environment during operation; extremely long operation period (estimated average: 25 years), minimum maintenance, robust technique, aesthetic aspects. The use of photovoltaics is rapidly increasing, and the respective market is developing accordingly. Although PV manufacturing equipment...
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Design and Performance Evaluation of the Energy Subsystem of a Hybrid Light andWave Energy Harvester
PublicationThe paper presents the design and performance of an energy subsystem (ES) dedicated to hybrid energy harvesters (HEHs): wave energy converters (WECs) combined with photovoltaic panels (PVPs). The considered ES is intended for compact HEHs powering autonomous end-node devices in distributed IoT networks. The designed ES was tested experimentally and evaluated in relation to the mobile and wireless distributed communication use case....
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A continual model of a damaged medium used for analyzing fatigue life of polycrystalline structural alloys under thermal–mechanical loading
PublicationThe main physical laws of thermal–plastic deformation and fatigue damage accumulation processes in polycrystalline structural alloys under various regimes of cyclic thermal–mechanical loading are considered. Within the framework of mechanics of damaged media, a mathematical model is developed that describes thermal–plastic deformation and fatigue damage accumulation processes under low-cycle loading. The model consists of three...
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Dynamic GPU power capping with online performance tracing for energy efficient GPU computing using DEPO tool
PublicationGPU accelerators have become essential to the recent advance in computational power of high- performance computing (HPC) systems. Current HPC systems’ reaching an approximately 20–30 mega-watt power demand has resulted in increasing CO2 emissions, energy costs and necessitate increasingly complex cooling systems. This is a very real challenge. To address this, new mechanisms of software power control could be employed. In this...
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Remote current measurement with FPGA digital processing
PublicationThe work presents an implementation of a modular measurement and control systemthat controls variants of mains supply of 230V electrical equipment. The system allowsto supervise power consumption in the office electronic equipment. The system detectsthe instant of the reduced power consumption by a device and makes possible itsswitch-off in order to reduce energy cost. The current is measured with integratedcurrent/voltage converters....
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Cooperative Data Transmission in Wireless Vehicular Networks
PublicationThe paper presents issues related to the cooperative transmission in wireless vehicular networks. Cooperative transmission involves the use of mobile terminals as relay stations to improve the transmission quality, improve network performance and reduce energy consumption. The paper presents the methods used to implement cooperative transmission and the types of cooperative networks.
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Certyfikacja wielokryterialna jako narzędzie kształtowania wysokiej jakości przestrzeni miejskiej
PublicationCelem tego artykułu jest omówienie systemów certyfikacji wielokryterialnej - zarówno narzędzi służących ocenie pojedynczych budynków, jak i zespołów zabudowy. Przeanalizowano rolę systemów certyfikacji oraz innowacyjnych technologii jako sposobu redukcji zużycia energii i osiągania wysokiej jakości energetycznej środowiska zbudowanego.
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How to make membrane distillation greener? A review on environmentally friendly and sustainable aspects
PublicationThere is an urgent need for the development of new water resources in order to solve the problem of the world’s growing demand for clean water. Membrane distillation (MD) is a promising alternative to conventional seawater desalination. Although MD itself is often defined as sustainable desalination technology, there are many aspects within the membrane manufacture and process operation that make it far from being green. For instance,...
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Nutrients and Bioactive Components of Human Milk After one Year of Lactation. Implication for Human Milk Banks
PublicationObjective: Specifying the nutrient content and bioactive compounds in milk from long-term lactation for the purpose of finding additional sources of donors’ milk for HMBs. Method: Human milk samples were collected from 43 mothers of term infants (term infant human milk, TIHM) (3–6 weeks of lactation) and 50 mothers who have breastfed for over a year (long-nursing human milk, LNHM). The milk collection time was 24 hours. The analyses...
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Non-destructive Testing of Wooden Elements
PublicationExamining the condition of wooden elements is crucial from the perspective of proper structure performance. If the deterioration in the internal wood condition, which displays no symptoms visible from the outside, is detected, the further spread of the deterioration can be prevented. Test results often point to the necessity of conducting repairs and, renovations, replacing the structure of wooden beams, or even substituting a...
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Chip suction system in circular sawing machine: empirical research and computational fluid dynamics numerical simulations
PublicationThe experimental analysis of the wood chip removing system during its redesigning in the existing sliding table circular saw and computational fluid dynamic (CFD) numerical simulations of the air flow process is presented in the paper. The attention was focused on the extraction hood and the bottom shelter of the actual existing system. The main aim was to perform experimental research on the pressure distribution inside the...
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Modeling sequencing batch reactor operational conditions depending on oxygen concentration
PublicationSequencing batch reactors (SBR) can be used as a fill-and draw activated sludge system for wastewater treatment with considerable operating flexibility and the possibility to conduct experiments under standard conditions and extreme case scenarios. Mathematical modeling and computer simulations provide an opportunity to implement existing wastewater processes in modeling software and evaluate different modifications at low costs...
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Experimental study of boiling heat transfer in the stagnation point of water microjet
PublicationIn the paper presented is a comparison of computational model with experimental data. Numerical model of liquid film with phase change in the stagnation zone due to impingement of the microjet is more widely presented in authors previous work. The radius on which theevaporation process is taking place can be determined from the energy balance on the element of the plate. That radius has also been confirmed experimentally in the...
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Measuring Consumers' Engagement With Brand-Related Social-Media Content. Development and Validation of a Scale that Identifies Levels of Social-Media Engagement with Brands
PublicationThe purpose of the current study was to develop a scale to measure the consumer's engagement with brand-related social-media content, based on three dimensions established in the framework of an earlier theoretical construct, “Consumer's Online Brand-Related Activities” (Muntinga, Moorman, and Smit, 2011). Qualitative techniques were used to generate an initial pool of items that captured different levels of consumer engagement...
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Model and laboratory simulation of a induction motor for diagnostic purposes
PublicationStatistics say that bearings are this part of induction motors which is most susceptible to damage. The equipment employed for bearing diagnostics usually makes use of vibrations as the criterion for technical condition of the bearings. A faulty bearing results in additional motor vibrations. They are reflected in the harmonic content of stator currents. In certain operating conditions the current signal is the sole source of information...
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Mathematical modelling of implant in an operated hernia for estimation of the repair persistence
PublicationThis paper presents mathematical modelling of an implanted surgical mesh used in the repair process of the abdominal hernia. The synthetic implant is simulated by a membrane structure. The author provides a material modelling of the implant based on the dense net model appropriate for technical fabrics. The accuracy of the proposed solution is evaluated by comparing the simulations of the dynamic behaviour of the system with the...
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Analysis of energy efficiency of suburban railway transport network
PublicationRising numbers of agglomeration residents cause increased need for people movement on daily basis. Because of congestion of local roads, air pollution and limited parking space, providing mass transit based on electric traction is reasonable. While the electric rail vehicles are considered highly efficient in themselves, they need to be analyzed as a part of a transport network, because energy consumption depends on operating conditions...
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ACTIVATED BIOCHAR AS AN ADSORBENT OF ORGANIC POLLUTANTS FOR WATER AND WASTEWATER TREATMENT
PublicationThe use of biomass, especially waste biomass, as an alternative energy source is a very important issue today. Pyrolysis is a process of thermal degradation of raw material and one of its products is biochar. This product is mainly distinguished by its high carbon content, and by improving its quality through activation, it can be more widely used. Activated biocarbon has a strongly developed surface and porous structure, and as...
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Waste materials assessment for phosphorus adsorption toward sustainable application in circular economy
PublicationPhosphorus is the main determinant of nutrient enrichment in the water bodies. Many resources including nutrients may be shortly exhausted, assuming current consumption. This scenario leads to growing interest in resources recovery and/or reuse, which together with sustainable energy consumption and waste reduction are the main courses of the circular economy. Usage of coagulants in wastewater treatment plants (WWTP) does not allow...
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Spatial Heterogeneity Impacts of Bilateral Foreign Direct Investment on Green Energy Efficiency in China
PublicationAt present, green energy transformation and climate policy are increasingly connected. The need to improve national competitiveness and implement climate and energy strategies means that an energy-consuming country like China must rapidly enhance its green energy efficiency (GEE) and energy consumption structure. The following paper contributes to the existing literature by analyzing the effects of bilateral FDI on GEE from...
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A concept of zero-dimensional and three-dimensional thermodynamic modelling of steam storage in a steam cycle
PublicationThis work presents the thermodynamic model of steam storage in a steam cycle. The innovative steam storage is an integral part of the unit and thus responds quickly to changes in load. This enhances the primary control reserve while maintaining high efficiency of energy conversion. With regard to power plants, it improves the operational safety of generation units, as it prevents boiler and turbines overload in the case of steep...
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A study of a reduction of a micro- and nanometric bismuth oxide in hydrogen atmosphere
PublicationA reduction of bismuth oxide in hydrogen atmosphere was investigated. The reaction was performed with a material in various structural forms: powder: with micrometric grains, powder with nanometric grains and powder pressed into pellets. The process was performed in both isothermal and non-isothermal conditions. An activation energy of the reaction calculated with Friedman method was found to be about 85 kJ/mol for the reduction...
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Effect of Thermal Treatment of Birch Wood by Saturated Water Vapor on Granulometric Composition of Chips from Sawing and Milling Processes from the Point of View of Its Processing to Composites
PublicationThe goal of this work is to investigate the impact of thermal modification of birch wood with saturated steam on the particle size distribution of the sawing and milling process. Birch wood (Betula pendula Roth) is an excellent source to produce plywood boards. Wastes from mechanical processing of birch wood are suitable to produce composite materials. Granulometric analyses of chips from sawing processes on the PRW 15M frame saw,...
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Krótko- i długookresowe skorygowane krańcowe skłonności do konsumpcji. Gospodarka Polski w latach 1995-2018
PublicationWe wstępnej części artykułu - odwołując się do teorii Keynesa - omówiono i zdefiniowano podstawowe relacje makroekonomiczne pomiędzy konsumpcją globalną a produktem krajowym brutto. W następnej kolejności przeprowadzono analizę informacji statystycznych dotyczących prywatnych wydatków konsumpcyjnych gospodarstw domowych (C) oraz globalnych wydatków konsumpcyjnych społeczeństwa (CO) na tle produktu krajowego brutto (PKB) w Polsce...
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Integrated Photocatalytic Advanced Oxidation System (TiO2/UV/O3/H2O2) for Degradation of Volatile Organic Compounds
PublicationSeveral advanced oxidation processes (AOPs) including photocatalytic processes were studied for effective treatment of complex model wastewater containing a wide variety of VOCs. The studies revealed synergistic effects of TiO2 based processes for improved degradation of the VOCs. A peroxone combined with TiO2/UV system (TiO2/UV/O3/H2O2) with a ratio between the oxygen source from the oxidant to chemical oxygen demand (COD) of...
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Modern technologies in energy demand reducing of public transport — Practical applications
PublicationCity of Gdynia (Poland) exploits one of the most modern trolleybus network in Europe, which has been involved in many projects related to the reduction of energy consumption. Some of them are connected with the improving of energy breaking recovery usage. An experimental stationary storage system at Północna substation, which was tested in 2012-2014, is a bright example of a system which is connected with the improving of the...
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AN OVERVIEW OF HEAT TRANSFER ENHANCEMENT BASED UPON NANOPARTICLES INFLUENCED BY INDUCED MAGNETIC FIELD WITH SLIP CONDITION VIA FINITE ELEMENT STRATEGY
PublicationThe mathematical model of heat generation and dissipation during thermal energy transmission employing nanoparticles in a Newtonian medium is investigated. Dimensionless boundary layer equations with correlations for titanium dioxide, copper oxide, and aluminium oxide are solved by the finite element method. Parameters are varied to analyze their impact on the flow fields. Various numerical experiments are performed consecutively...
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Central heating temperature control algorithm for systems with condensing boilers
PublicationThe problem of control of a central heating system in a small residence is considered. It is assumed that the system is based on a condensing boiler. Since the boiler efficiency depends on a returning water temperature, the proposed control goal is to provide proper air temperature in the residence as well as the lowest possible water temperature. The proposed algorithm is applied to two buildings. Both of them have the same heating...
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Możliwości ograniczenia zużycia energii napędowej urządzeń przez optymalizację doboru wymienników ciepła, właściwą konfigurację i kontrolę przepływu płynów roboczych
PublicationArtykuł poświęcony możliwości ograniczenia zużycia energii napędowej urządzeń na drodze optymalizacji doboru wymienników ciepła, właściwej konfiguracji i kontroli przepływu płynów roboczych. Przedstawiono w nim ocenę zużycia energii w systemach energetycznych o największej energochłonności w realiach Polski. Zwrócono uwagę na możliwość wykorzystania wymienników ciepła o wysokiej efektywności dla zmniejszenia oporu przenoszenia...
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Smart Grid in Practise - Implementation of the Billaterall Supply in Gdynia Trolleybus Network
PublicationSince 2001, trolleybus system in Gdynia has been involved in many activities related to the reduction of power consumption, both in terms of implementation and research and development. In 2011 was introduced the first supercapacitor storage energy system. In PKT started applications of Smart Grid technologies in supply network: the bilateral supply. The paper presents results of these this novel investitions.
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Improving SBR Performance Alongside with Cost Reduction through Optimizing Biological Processes and Dissolved Oxygen Concentration Trajectory
PublicationAuthors of this paper take under investigation the optimization of biological processes during the wastewater treatment in sequencing batch reactor (SBR) plant. A designed optimizing supervisory controller generates the dissolved oxygen (DO) trajectory for the lower level parts of the hierarchical control system. Proper adjustment of this element has an essential impact on the efficiency of the wastewater treatment process as well...
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Application Isssues of the Semi-Markov Reliability Model
PublicationPredicting the reliability of marine internal combustion engines, for instance, is of particular importance, as it makes it possible to predict their future reliability states based on the information on the past states. Correct reliability prediction is a complex process which consists in processing empirical results obtained from operating practice, complemented by analytical considerations. The process of technical state changes...
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Development of Gas Sensor Array for Methane Reforming Process Monitoring
PublicationThe article presents a new method of monitoring and assessing the course of the dry methane reforming process with the use of a gas sensor array. Nine commercially available TGS chemical gas sensors were used to construct the array (seven metal oxide sensors and two electrochemical ones). Principal Component Regression (PCR) was used as a calibration method. The developed PCR models were used to determine the quantitative parameters...
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Mechatronics design, modelling and controlling of the Stewart-Gough platform
PublicationThis paper presents a mechatronics design of a low cost Stewart-Gough platform (SGP) with rotary actuators. The designed SGP is supposed to be applied in a ball & plate control system. The synthesis of the ball & plate control system is also within the subject of the paper. A mechatronics design process of the SGP was conducted with computer-aided design (CAD) software. Unique analytical solutions of an inverse kinematics problem...
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Prediction of manoeuvring abilities of 10000 DWT pod-driven coastal tanker
PublicationThis paper aims to present a new approach in the prediction of manoeuvring abilities of pod-driven ships. A new mathematical model of motions based on MMG methodology was developed and a new type of description of forces acting on azimuth drives is presented. Captive model tests of medium-size coastal tanker and pod open water tests were carried out in CTO S.A. (Ship Design and Research Centre S.A.) to obtain hull hydrodynamic derivatives...
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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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The Dilemmas of Choosing a Suitable Technology for Low Energy and Passive Houses in the Context of their Overheating Issues
PublicationIn compliance with European Union directives, numerous countries are introducing increasingly stricter legal limits on the estimated energy consumption of newly designed residential buildings. However, the fact, that regulations and designers' efforts are focused on decreasing energy consumption (and consequently carbon dioxide emissions) only at the post-occupancy stage, may lead to a significant increase in the carbon footprint...
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Experimental investigation of performance and emission characteristics of a miniature gas turbine supplied by blends of kerosene and waste tyre pyrolysis oil
PublicationFossil fuels are non-renewable sources of energy that could be depleted in the near future, giving rise to amajor energy crisis. Scientists from all over the world are working on new technologies to produce fuelnot only from renewable sources but also from waste. This article is concerned with: (i) waste tyremanagement by means of the pyrolysis process, (ii) investigation of physico-chemical parameters ofwaste tyre pyrolysis oil...
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Selection of drive engines for dredge pumps
PublicationThis 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.