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Search results for: LIFE CYCLE ASSESSMENT
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Strain energy density and entire fracture surface parameters relationship for LCF life prediction of additively manufactured 18Ni300 steel
PublicationIn 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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Advancing sustainable wastewater management: A comprehensive review of nutrient recovery products and their applications
PublicationWastewater serves as a vital resource for sustainable fertilizer production, particularly in the recovery of nitrogen (N) and phosphorus (P). This comprehensive study explores the recovery chain, from technology to final product reuse. Biomass growth is the most cost-effective method, valorizing up to 95 % of nutrients, although facing safety concerns. Various techniques enable the recovery of 100 % P and up to 99 % N, but challenges...
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THE THERMODYNAMIC ANALYSIS OF THE SZEWALSKI HIERARCHIC VAPOUR CYCLE COOPERATED WITH THE SYSTEM OF HEAT RECOVERY
PublicationIn this paper, thermodynamic analysis of the Szewalski hierarchic vapour cycle cooperated with the system of heat recovery from exhaust gases are presented. According to that purpose, the CFM (Computation Flow Mechanics [1,3]) approach has correctly been used. The whole system consists of the first traditional steam cycle, the second organic Rankine cycle (ORC) and system of heat recovery with use of water with temperature 90...
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THERMODYNAMIC ANALYSIS OF A GENERATION IV SCWR NUCLEAR POWER PLANT CYCLE
PublicationThis article presents a flow and thermodynamic analysis of a Generation IV nuclear cycle. An SCWR (Supercritical water reactor) is a high temperature and high pressure reactor that uses water at a temperature above its thermodynamic critical point as the working fluid. The cycle used for the calculations consists of one interstage superheater and 7 regenerative heat exchangers. Division pressure was optimized in view of the cycle efficiency,...
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Thermodynamic analysis of the double Brayton cycle with the use of oxy combustion and capture of CO2
PublicationIn this paper, thermodynamic analysis of a proposed innovative double Brayton cycle with the use of oxy combustion and capture of CO2, is presented. For that purpose, the computation flow mechanics (CFM) approach has been developed. The double Brayton cycle (DBC) consists of primary Brayton and secondary inverse Brayton cycle. Inversion means that the role of the compressor and the gas turbine is changed and firstly we have expansion...
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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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Thermodynamic Cycle Concepts for High-Efficiency Power Plans. Part A: Public Power Plants 60+
PublicationAn analysis was carried out for different thermodynamic cycles of power plants with air turbines. Variants with regeneration and different cogeneration systems were considered. In the paper, we propose a new modification of a gas turbine cycle with the combustion chamber at the turbine outlet. A special air by-pass system of the combustor was applied and, in this way, the efficiency of the turbine cycle was increased by a few points....
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Energy and exergy analysis of negative CO2 emission gas power plant operation using thermodynamic modelling results of the cycle
PublicationA developed cycle of negative CO2 emission gas power plant is presented. The cycle is an oxy-combustion gas turbine cycle where the gas fuel is burnt with pure oxygen, and liquid water is injected to the combustor to keep the temperature at an appropriate level for the gas turbine. The negative level of CO2 emission can be obtained by combining CO2 capture method with the usage of a gas fuel based on sewage sludge gasification....
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BIG PROBLEMS WITH BIG DATA
PublicationThe article presents an overview of the most important issues related to the phenomenon called big data. The characteristics of big data concerning the data itself and the data sources are presented. Then, the big data life cycle concept is formulated. The next sections focus on two big data technologies: MapReduce for big data processing and NoSQL databases for big data storage.
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Wybrane metody przydatne w analizie niezawodności i bezpieczeństwa funkcjonalnego systemów technicznych.
PublicationPrzedstawiono wybrane metody przydatne w analizie niezawodności i bezpieczeństwa funkcjonalnego systemów technicznych takie jak: metoda FMECA (failure mode, effect and criticality analysis, FTA (fault tree analysis, RBD (reliability block diagram) RCM (reliability centered maintenance, LCC (life cycle cost) i PMO (preventive maintenance optimising.
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Thermodynamic Cycle Concepts for High-Efficiency Power Plants. Part B: Prosumer and Distributed Power Industry
PublicationAn analysis was carried out for different thermodynamic cycles of power plants with air turbines. A new modification of a gas turbine cycle with the combustion chamber at the turbine outlet has been described in the paper. A special air by-pass system of the combustor was applied, and in this way, the efficiency of the turbine cycle was increased by a few points. The proposed cycle equipped with an effective heat exchanger could...
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Chapter 7: Engineering Thermodynamics and the Carnot Cycle
PublicationThe chapter presents information about thermodynamics and thermodynamic cycles, especially the history and meaning of Carnot Cycle as well as P-v and T-s Diagrams
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On the independence number of some strong products of cycle-powers
PublicationIn the paper we give some theoretical and computational results on the third strong power of cycle-powers, for example, we have found the independence numbers alpha((C^2_10)^⊠3) = 30 and alpha((C^4 _14)^⊠3) = 14. A number of optimizations have been introduced to improve the running time of our exhaustive algorithm used to establish the independence number of the third strong power of cycle-powers. Moreover, our results establish...
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Assessment of image processing methods for the determination of propagation of squat-type defects in rails
PublicationWe demonstrate the idea of squat-type defect measurement in the rail and the concept of tracking of the defect development using the techniques of image acquisition and image processing as well as the methods of metric spaces. We introduce the concepts of a set diameter δ(A) and the metric ρ1, which come from the properties of plane figures, to compare and to observe the development of the defects. We characterize the feasibility...
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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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Analysis of Organic Rankine Cycle efficiency and vapor generator heat transfer surface in function of the reduced pressure
PublicationIn the paper presented is analysis of the influence of reduced pressure on efficiency and heat transfer area of vapor generator of Organic Rankine Cycle (ORC) in case of subcritical and supercritical parameters of operation. Compared are two cases of subcritical and supercritical ORC featuring a similar arrangement of heat source supply and heat removal, that is featuring the same temperatures of working fluid before the turbine,...
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Evaluation of the efficiency of the duty cycle of refuse collection vehicle based on real-world data
PublicationIn this paper a method of the efficiency evaluation of the duty cycle of Refuse Collection Vehicle is presented. Using real world data, two representative duty cycles were analysed. Total cycle efficiency was calculated, as well as the efficiency of particular cycle phases. Then, energy needed to collect and compact the waste and energy from fuel were compared. Measured and calculated values were shown on the diagrams illustrating...
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Technical and Economic Analysis of the Supercritical Combined Gas-Steam Cycle
PublicationCombined cycle power plants are characterized by high efficiency, now exceeding 60%. The record-breaking power plant listed in the Guinness Book of World Records is the Nishi-Nagoya power plant commissioned in March 2018, located in Japan, and reaching the gross efficiency of 63.08%. Research and development centers, energy companies, and scientific institutions are taking various actions to increase this efficiency. Both the gas...
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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
PublicationEnergy 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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GRAPHENE-BASED SUPERCAPACITORS APPLICATION FOR ENERGY STORAGE
PublicationRecent advances in graphene-based supercapacitor technology for energy storage application were summarized. The comparison of different types of electrode materials in such supercapacitors was performed. The supercapacitors with graphene-based electrodes exhibit outstanding performance: high charge-discharge rate, high power density, high energy density and long cycle-life, what makes them suitable for various applications, e.g....
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Static Model of Steam/Water Cycle for Thermal and Economic Analysis
PublicationThe thermodynamic efficiency of typical conventional and nuclear power plants is insufficient. A large amount of the generated heat is removed to the environment and regarded as a waste. A solution which is commonly used to increase the efficiency and profitability of the existing and planned power plants refers to cogeneration of heat and power. To prepare sophisticated thermodynamic and economic analyses, a precise static model...
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A brief note on entire fracture surface topography parameters for 18Ni300 maraging steel produced by LB-PBF after LCF
PublicationThe concept of entire fracture surface investigation is helpful in explaining fatigue phenomena. In this paper, this method has been applied for 18Ni300 maraging steel using a 3D measurement system. Before post-mortem analysis, the specimens produced by laser beam powder bed fusion (LB-PBF) were tested under low-cycle fatigue (LCF) for eight strain amplitudes in the interval 0.3% to 1.0%. The attention was placed on the relationship...
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Towards better understanding of context-aware knowledge transformation
PublicationConsidering different aspects of knowledge functioning, context is poorly understood in spite of intuitively identifying this concept with environmental recognition. For dynamic knowledge, context especially seems to be an essential factor of change. Investigation on the impact of context on knowledge dynamics or more generally on the relationship between knowledge and its contextual interpretation is important in order to understand...
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Comparison of requirements for location, maintenance and removal of road advertising between polish and foreign regulations
PublicationThe article gives an overview of Polish and international formal and legal requirements for roadside advertising and the relevant road safety impacts. The analysis focussed on outdoor advertising life cycle consisting of three stages: location, operation and removal of advertising. Experience of road authorities from Australia (Queensland), Republic of South Africa and the United Kingdom was collected. The article is part of a...
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Gas Turbine Cycle with External Combustion Chamber for Prosumer and Distributed Energy Systems
PublicationThe use of various biofuels, usually of relatively small Lower Heating Value (LHV), affects the gas turbine efficiency. The present paper shows that applying the proposed air by-pass system of the combustor at the turbine exit causes tan increase of efficiency of the turbine cycle increased by a few points. This solution appears very promising also in combined gas/steam turbine power plants. The comparison of a turbine set operating...
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Fracture Surface Topography Parameters for S235JR Steel Adhesive Joints After Fatigue Shear Testing
PublicationThis paper presents the experimental results of a study investigating the effect of holes and notches made on the overlap ends on the strength of adhesive joints. Single-lap joints made of S235JR steel sheets bonded with Araldite 2024-2 epoxy adhesive were tested. For comparative reasons, static shear strength tests and high-cycle fatigue strength tests were performed. Adhesive-filled joints having three holes, each with a diameter...
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An Impact of Environmental Disturbances on Combined Cycle Power Plant Control
PublicationCombined cycle power plants operate at thermal efficiency approaching 60 percent. In the same time their performance presents several problems that have to be addressed. E.g. gas turbines are very sensitive to backpressure exerted on them by the heat recovery steam generators as well as to ambient pressure and temperature.
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Analysis and Evaluation of the Working Cycle of the Diesel Engine
PublicationThe paper presents a proposal to apply a quantitative evaluation of the diesel engine with regard to the phenomena occurring during of a working cycle. The proposed procedure when analyzing test results from diesel engine is an attempt to transfer an engine activity evaluation methods in the operational time scale (exploit time), eg. in hours, to the micro-scale (dynamic time) relating only to the execution time of one (several)...
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Experimental tests and numerical simulations of full scale composite sandwich segment of a foot- and cycle- bridge
PublicationIn the paper experimental tests and numerical simulations of a full cross-section segment of ultimately designed foot-and cycle-bridge are presented. The experimental tests were conducted on element with length reduced to 3 m and unchanged (target) cross-section dimensions. The external skin of structure is GFRP laminate while internal core is PET foam. Several quasi-static tests were performed using hydraulic cylinder to generate...
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An energetic analysis of a gas turbine with regenerative heating using turbine extraction at intermediate pressure - Brayton cycle advanced according to Szewalski's idea
PublicationIn this paper, a modification of a simple gas turbine into the Brayton cycle with regenerative heating, using turbine extraction at intermediate pressure, is presented. The main concept of the retrofitting is based on the transfer of heat from the turbine exhaust gases to the air entering the combustion chamber. The extracted gas transfers heat to air via the divided regenerative heat exchanger and after that is compressed and...
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Composite as a Material of the Future in the Era of Green Deal Implementation Strategies
PublicationComposite 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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PARAMETRIC ANALYSIS OF THE EFFICIENCY OF THE COMBINED GAS-STEAM TURBINE UNIT OF A HYBRID CYCLE FOR THE FPSO VESSEL
PublicationA thermal diagram of the combined gas‒steam turbine unit of a hybrid cycle, which is an energy complex consisting of a base gas turbine engine with a steam turbine heat recovery circuit and a steam-injected gas turbine operating with overexpansion, is proposed. A mathematical model of a power plant has been developed, taking into consideration the features of thermodynamic processes of simple, binary, and steam-injected...
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Uniform Model Interface for Assurance Case Integration with System Models
PublicationAssurance cases are developed and maintained in parallel with corresponding system models and therefore need to reference each other. Managing the correctness and consistency of interrelated safety argument and system models is essential for system dependability and is a nontrivial task. The model interface presented in this paper enables a uniform process of establishing and managing assurance case references to various types...
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The significance of the properties of water for the working cycle of the kinesin molecular motor
PublicationExplicit solvent molecular dynamics simulations were performed in this study to investigate and discuss several aspects of the influence of the properties of water on the working cycle of a molecular motor from the kinesin superfamily. The main objects of attention were: the binding of the neck linker and the association of the kinesin and the tubulin. The docking of the neck linker is considered a crucial event during the working...
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The use of fibre-reinforced polymers (FRP) in bridges as a favourable solution for the environment
PublicationThe purpose of this article is to show the modern engineering, in which sustainability and taking care of ecology play a significant role. The authors are focused on FRP composite materials and their applications in civil engineering. Case studies showing renovation and design of new bridges with the use of FRP are presented and discussed to clarify benefits, which this solution provides. Main advantages of FRP materials in comparison...
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Hat problem on the cycle C4
PublicationThe topic of our paper is the hat problem. In that problem, each of n people is randomly tted with a blue or red hat. Then everybody can try to guess simultanously his own hat color looking at the hat colors of the other people. The team wins if at least one person guesses his hat color correctly and no one guesses his hat color wrong, otherwise the team loses. The aim is to maximize the probability of win. In this version every...
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A space-efficient algorithm for computing the minimum cycle mean in a directed graph
PublicationAn algorithm is introduced for computing the minimum cycle mean in a strongly connected directed graph with n vertices and m arcs that requires O(n) working space. This is a considerable improvement for sparse graphs in comparison to the classical algorithms that require O(n^2) working space. The time complexity of the algorithm is still O(nm). An implementation in C++ is made publicly available at http://www.pawelpilarczyk.com/cymealg/.
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Exploration of Creativity Techniques in Software Engineering in Training-Application-Feedback Cycle
PublicationCreativity research has proposed about a hundred and fifty creativity techniques. The question is whether they can be applied in software engineering for creativity training or directing creativity in software projects. This paper aims at answering this question via a quasi-experiment conducted in Training-Application-Feedback cycle in which participants express their opinions about selected creativity techniques after training...
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Wpływ produkcji butelek z tworzyw sztucznych na środowisko naturalne. Cz. I. Zastosowanie metody oceny ReCiPe 2016 w celu identyfikacji problemów środowiskowych
PublicationDokonano oceny wpływu opakowań na środowisko naturalne. Głównym celem było przeprowadzenie analizy cyklu życia (LCA) butelki do napojów wykonanej z poli(tereftalanu etylenu) (PET). Za jednostkę funkcjonalną przyjęto łącznie 1000 szt. butelek PET o pojemności 1 L. Granica przyjętego systemu obejmowała kroki od momentu dostarczenia preform do zakładu produkcyjnego aż do ich prawidłowego ukształtowania w procesie produkcyjnym. Z systemu...
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Enhancement of the Brayton cycle efficiency by water or steam utilization
PublicationIn the paper, thermodynamic analysis of two modifications of a Brayton cycle into enhancement cycles with water/steam injection are discussed. The first one deals with a STIG modified system with both interstage compressed air cooling and air heating (heat regeneration) before combustion chamber. The second one, mainly devoted to higher steam/air ratio, is connected with separate steam production in a HRSG. The analysis has been...
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Fractographical quantitative analysis of EN-AW 2024 aluminum alloy after creep pre-strain and LCF loading
PublicationThis paper explores the applicability of a new damage parameter combining both fracture surface topography and loading features to estimate the fatigue lifetime under creep pre-strain and low-cycle fatigue loading. Fractures of EN-AW 2024 aluminum alloy caused by mixed creep and low-cycle fatigue loading are experimentally characterized and quantified via surface topography analysis. The specimens were preliminary damaged in a...
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Supervisory Control System for Adaptive Phase and Work Cycle Management of Sequencing Wastewater Treatment Plant
PublicationThe paper presents the design of the integrated control system applied to Sequencing Batch Reactor (SBR) in a biological Wastewater Treatment Plant (WWTP) in Swarzewo, which operates under activated sludge technology. Based on the real data records, ASM2d biological processes model and aeration system model, hierarchical control system for dissolved oxygen tracking and cycle management is designed. Internal Model Controller (IMC)...
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Analytical method for calculation of heat source temperature drop for the Organic Rankine Cycle application
PublicationIn the paper presented are considerations on the cooperation of the limited capacity heat source with the Organic Rankine Cycle unit. Usually the heat source providing thermal energy to the Organic Rankine Cycle (ORC) may have twofold characteristics. It can be in the form of a single phase fluid, i.e. as hot exhaust gas or hot liquid, or in some cases it may be available as a phase changing fluid, as for example, technological...
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In vivo imaging of the human eye using a two-photon excited fluorescence scanning laser ophthalmoscope
PublicationBACKGROUND. Noninvasive assessment of metabolic processes that sustain regeneration of human retinal visual pigments (visual cycle) is essential to improve ophthalmic diagnostics and to accelerate development of new treatments to counter retinal diseases. Fluorescent vitamin A derivatives, which are the chemical intermediates of these processes, are highly sensitive to UV light; thus, safe analyses of these processes in humans...
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LCF behavior of 2024AA under uni- and biaxial loading taking into account creep pre-deformation
PublicationThis study presents the results of experimental low-cycle fatigue (LCF) tests of aluminum 2024 alloy T3511 temper in uni- and biaxial loading states. Tests were carried out on both the as-received material (hardened extruded rods) and material with different pre-deformation histories. These deformations were carried out in the creep process at 200 °C and 300 °C for two different levels of at each temperature. The pre-deformed material’s...
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Durability of Asphalt Concrete Subjected to Deteriorating Effects of Water and Frost
PublicationThe paper presents testing of the detrimental effects of water and frost on asphalt pavements. It included laboratory testing of 5 fatigue life of asphalt concrete that was subjected to action of water and frost and field testing of damages caused by water and frost on 6 existing asphalt pavements, such as stripping, raveling, and potholes. Laboratory simulation of water and frost action was based on the 7 original AASHTO T283...
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Inclusive Communication Model Supporting the Employment Cycle of Individuals with Autism Spectrum Disorders
PublicationDifficulties with interpersonal communication experienced by individuals with autism spectrum disorders (ASD) significantly contribute to their underrepresentation in the workforce as well as problems experienced while in employment. Consistently, it is vital to understand how communication within the employment cycle of this group can be improved. This study aims to identify and analyze the possibilities of modifying the communication...
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Different design aspects of an Organic Rankine Cycle turbine for electricity production using a geothermal binary power plant
PublicationIn recent years, pressure has been growing to increase the share of renewable energy sources in electricity generation, which may offer opportunities for the development of geothermal energy in regions that have been so far considered unprofitable in this respect. One such country currently undergoing an energy transition is Poland in which low-temperature geothermal resources are currently used for district heating and recreation...
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Analiza cyklu życia
PublicationAnaliza cyklu życia (LCA, ang. Life Cycle Analysis) z założenia obejmuje podejście „od kołyski aż po grób” w ocenie procesów przemysłowych i produktów. Ta wizja zaczyna się już w momencie wydobycia surowców pierwotnych w celu przetworzenia i wytworzenia produktu, a kończy, gdy wszystkie materiały zostają poddane utylizacji, recyklingowi lub składowaniu. LCA ocenia wszystkie etapy życia produktu z założeniem, że są od siebie współzależne,...
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Insight into heart regeneration
PublicationThe mammalian heart is thought to be incapable of regeneration because of the limited ability of cardiomyocytes. to proliferate. However, it has been recently shown that the neonatal murine heart is able to restore its normal function after coronary artery ligation or even partial resection. Unfortunately, this feature is lost in a few days after birth, although lower vertebrates as zebrafish or newt, retain this ability until adulthood. Therefore,...