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Search results for: LIFE CYCLE ASSESSMENT
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Second Life - Problems with the Prolongation of Reality
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Fatigue life improvement using low transformation temperature weld material with measurement of residual stress
PublicationWelding processes often produce high levels of tensile residual stress. Low transformation temperature (LTT) welding wires utilise phase transformation strains to overcome the thermal contraction of a cooling weld. In this paper, the residual stress within each weld was quantified using the milling/strain gauge method, being the strain change measured as the weldment was milled away. The fatigue tests were conducted under uniaxial...
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Simulation of Life Raft Motions on Irregular Wave - An Analysis of Situations Leading to Raft Capsizing
PublicationSuccessful rescue action at sea is based on a. o. a correct choice of rescue means and their reliability. Operational characteristics of life-saving appliances determine their performance in a given water area. Therefore they affect duration time of rescue action and decide this way on survival time of shipwrecked persons. This paper presents impact of characteristics of circular inflatable life rafts on their dynamics in a...
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Development of a Response Assessment Tool for a Floating Dock System
PublicationDocking operations of ships require a response assessment to ensure structural and personnel safety. Environmental loads and improper ballast adjustments are the main threats to the docking operations. They can cause severe structural damages and stability loss to a floating dock system which includes a floating dock and a docked vessel, even if the velocities of the dock and the vessel are very low during the docking process....
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Modeling and simulation of tool cycle in manufacturing cell
PublicationThe paper addresses issues concerning modeling and analysis of tool flow within a three-machine manufacturing cell used for small batch manufacturing of a definite spectrum of prismatic parts. The approach utilizes a method for job and tool allocation to work centers with limited number of machines and capacity of tool resources, based on the analysis of formalized relations: job - tool sets required. Selected tool flow control...
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Strain sequence effect on fatigue life and fracture surface topography of 7075-T651 aluminium alloy
PublicationThe paper studies the effect of strain-loading sequence on fatigue lifetime and fracture surface topographies in 7075-T651 aluminum alloy specimens. Fatigue tests were performed in two ways: (i) constant-amplitude loading and (ii) two series of variable amplitude loading with non-zero mean strain values. The topography of the fatigue fractures was measured over their entire surfaces with the help of an optical confocal measurement...
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Assessment of student language skills in an e-learning environment
PublicationThis article presents the role of various assessment structures that can be used in a VLE. e-Learning language courses offer tutors a wide range of traditional and computer-generated formative and summative assessment procedures and tools. They help to evaluate each student’s progress, monitor their activities and provide varied support, which comes from the tutor, the course structure and materials as well as other participants....
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The environmental dimension of city dwellers’ quality of life and the city’s social and spatial variability
PublicationThe purpose of this paper is to attempt an analysis of the environmental dimension of the quality of life using quantitative surveys conducted among residents of Gdańsk. In the paper, we make reference to the theoretical assumptions ensuing from the concept of a comprehensive and integrated approach to the development of the urban environment, whilst noting the profound impact humans bring to their evaluation of the environmental...
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The Indicators Assessment of Safety and Functionality of Tram Loops
PublicationThe new requirements set for tram loops mean that all stakeholders' expectations regarding their safety and functionality change. This creates a need for new tools for tram loop assessment, which are important interchanges, especially for people living outside the city limits or on their outskirts. The aim of the authors ’research is to create a indicators for assessing the safety and functionality of tram loops. Therefore, the...
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Identification of damages in the inlet air duct of a diesel engine based on exhaust gas temperature measurements
PublicationThe temperature of the exhaust gas of a diesel piston engine, measured in the characteristic control sections of its thermo-flow system, can be a valuable source of diagnostic information about the technical condition of the elements limiting the working spaces thus separated, including the turbocharging system, but also its fuel supply system and replacement of the medium. In standard marine engine measurement systems equipped...
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Carbon dioxide sequestration by industrial wastes through mineral carbonation: Current status and perspectives
PublicationMineral carbonation using natural minerals or industrial wastes is a safe and promising strategy for CO2 sequestration. Application of industrial wastes for this purpose has significant ecological and environmental value, which is one of the key green technologies in the global carbon mitigation. This review summarizes the current research status of CO2 mineralization by industrial wastes. This work surveys the mechanisms and capacities...
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Analysis of the Possibility of Using New Types of Protective Coatings and Abrasion-Resistant Linings under the Operating Conditions of the Spiral Classifier at KGHM Polska Miedź S.A. Ore Concentration Plant
PublicationA study was carried out to select the appropriate coatings for corrosion protection of the spiral classifier working at KGHM Polska Miedź S.A. Ore Concentration Plant. The abrasion resistance of selected protective coatings and wear-resistant linings was investigated using a DT-523 rotary abrasion tester with Taber CS-10 rubber abrasive discs. The average weight loss of the coatings after a cycle of 2000 revolutions was determined....
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Neoclassical Navier–Stokes Equations Considering the Gyftopoulos–Beretta Exposition of Thermodynamics
PublicationThe seminal Navier-Stokes equations were stated even before the creation of the foundations of thermodynamics and its first and second laws. There is a widespread opinion in the literature on thermodynamic cycles that the Navier-Stokes equations cannot be taken as a thermodynamically correct model of a local "working fluid", which would be able to describe the conversion of "heating" into "working" (Carnot's type cycles) and vice...
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Customer Assessment of Brand Valuation and Social Media
PublicationThe research problem engaged in this article is to determine whether contemporary consumers are able to assess brand equity in the overabundance of brands and products with similar features and qualities. The author argues that in the existing circumstances when differences between brands become insignificant the consumer is not capable of assessing their equity adequately. In order to verify the thesis the author has accepted...
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Effect of pavement roughness and vehicle dynamic loads on decrease of fatigue life of flexible pavements
PublicationDue to the fact that pavement surfaces are not ideally even, dynamic loads of vehicle axles deviate from static loads. Higher dynamic loads contribute to faster pavement distress. The distribution of dynamic loads is similar to normal distribution and can be described by static load and factors DI (dynamic impact) and DLC (dynamic load coefficient). With the deterioration of pavement condition its evenness decreases as well and...
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Assembling and testing of quasi-static hybrid piezoelectric motor based on electroactive lubrication principle
PublicationThe presented paper concerns a novel concept of hybrid piezoelectric motor based on electroactive lubrication principle. Its structure is combined of quasi-static and resonance piezoelectric actuators, synchronizing their work to generate the rotary movement. The hybrid motor topology is compared to the existing piezoelectric motors, regarding its field of applications in embedded systems with very high security requirements. The...
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Design and distribution of air nozzles in the biomass boiler assembly
PublicationDue to energy crisis as well as increasing pollution of the environment, renewable energy sources usage increases all over the world. These facts encouraged authors to start research over developing a uniform biomass boiler calculation model. This paper presents a design of biomass boiler assembly created for ORC (Organic Rankine Cycle) unit since these systems could achieve strong position in energy industry....
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HIGH TEMPERATURE HEAT PUMPS – PERSPECTIVE HEATING SYSTEMS?
PublicationIn the paper presented are authors own concepts of high temperature compressor heat pumps for the utilisation of medium and low temperature sources of heat. Working fluids for use in high temperature heat pumps are discussed, as well as the criteria for their selection. Analyses are presented for the production of in the upper steam source at 130 °C. One-stage systems and cascade systems were analyzed. An analysis of the coefficient...
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Development of chromatographic and mass spectrometry conditions for untargeted lipidomic analysis of human breast milk
PublicationHuman breast milk (HBM) is a complex biofluid containing components which are essential for the proper growth of the newborn (for example nutrients such as carbohydrates, proteins, lipids) and also bioactive substances. According to the literature, most of studies involving HBM nutrients investigations focused essentially on the determination of proteins. The molecular composition of lipids in HBM is not well known as the protein...
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The Comparison of the Crypto- and Fiat Currencies’ Exchange Rate Volatility in The Years 2015–2017
PublicationThe article describes the issues related to exchange rate volatility of crypto- and fiat currencies. The first part presents the issue of exchange rate volatility as well as methods of its evaluation and criteria of the conducted research. In the next part the author presented the essence of currencies and the main currency i.e. fiat money in the global economy in terms of the volume of transactions on the FOREX market. Then the...
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On the production of electricity in Poland using a geothermal binary power plant - A thermodynamic overview - Part I
PublicationPoland has a significant potential of geothermal energy. However, the high-temperature sources that are needed to drive power plants are found in relatively few places. Therefore, the objective of this paper is to consider any location in the northern part of Poland as a possible place to build a binary power plant. A scientific research was confirmed the existence of an elevated temperature gradient in this region. The hot rocks...
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Influence of reactive oxygen species during deposition of iron oxide films by high power impulse magnetron sputtering.
PublicationIron oxide films were deposited using high power impulse magnetron sputtering (HiPIMS) of an iron cathode in an argon/oxygen gas mixture at different gas pressures (0.5~Pa, 1.5~Pa, and 5.0~Pa). The HiPIMS system was operated at a repetition frequency $f = 100$~Hz with a duty cycle of 1~\%. A main goal is a comparison of film growth during conventional and electron cyclotron wave resonance-assisted HiPIMS. The deposition plasma...
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Cooperation of mono- and bi-articular muscles: human lower limb
PublicationObjectives: The aim of this study was to create and analyze a Pareto-optimal problem that would describe cooperation between mono- and bi-articulate lower limb muscles in sagittal plane. Methods: Equations describing the problem were derived and analyzed, additional constrains were introduced and experimental verification based on gait video analysis was performed. Results: Uncertainty of Pareto-optimal solution is shown for the...
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Expert assessment of arguments: a method and its experimental evaluation
PublicationArgument structures are commonly used to develop and present cases for safety, security and other properties. Such argument structures tend to grow excessively. To deal with this problem, appropriate methods of their assessment are required. Two objectives are of particular interest: (1) systematic and explicit assessment of the compelling power of an argument, and (2) communication of the result of such an assessment to relevant...
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Security Assessment of a Turbo-Gas Power Plant
PublicationCritical infrastructures are exposed to new threats due to the large number of vulnerabilities and architectural weaknesses introduced by the extensive use of information and communication technologies. This paper presents the results of an exhaustive security assessment for a turbo-gas power plant.
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Life tests of a rotary single-stage magnetic-fluid seal for shipbuilding applications
PublicationUse of the magnetic fluid seal technology in water is much more difficult technological problem in comparisonto gas or vacuum environment. Some seals constructed up to time been are designed as hybrid, two stagesealing structures with shields or mechanical seals used as protection measures to the magnetic fluid seal.Anyway, there is always problem with immediate contact between magnetic fluid and the environmentalliquid. In the...
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Risk of incorrect pass-fail decisions associated with assessment uncertainty
PublicationA mathematical framework for calculation teacher's and student's risks of incorrect pass-fail decisions under uncertainty of assessment, is presented. The probabilistic model of assessment process is adapted from interdisciplinary probabilistic theory of measurement.
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Load path sensitivity and multiaxial fatigue life prediction of metals under non-proportional loadings
PublicationEngineering components often operate under complex loadings, in which the variable amplitude multiaxial stresses are raised by geometric discontinuities including holes, grooves, fillets and shoulders, etc. Besides, the non-proportional loading will lead to the rotation of maximum principal stress/strain and additional fatigue damage of structural elements in service. Consequently, the multiaxial and non-proportional loading have...
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Quantitative risk assessment of new ship designs in damage conditions
PublicationThe paper is devoted to safety of ships in damage conditions. The novel contribution of the paper is connected with a new Multi-Task ship (MT-ship) design at the preliminary stage of design. There are a few problems at the preliminary stage that should be considered. One problem is connected with if the quantitative risk-based method is a reliable and formal method for safety assessment of such the new design (MT-ship) in damage...
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Dynamic risk assessment in autonomous vehicles motion planning
PublicationArguing that an autonomous mobile system is sufficiently safe to operate in presence of other vehicles and objects is an important element in development of such systems. Traditional approach to assure safety is to distinguish between safe and unsafe area and prevent the autonomous vehicle from entering the unsafe area. The paper presents a model of autonomous vehicle control system which uses risk assessment...
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Forecasting of fatigue life of laser welded joints
PublicationW pracy przedstawiono podstawowe dane na temat stalowych paneli typu sandwich. Zaprezentowano wyniki testów zmęczeniowych elementarnych połączeń teowych spawanych laserowo. Omówiono szczegółowo te cechy, które mają istotny wpływ na statyczne i zmęczeniowe własności złącza. Na podstawie przedstawionych wyników badań zmęczeniowych elementarnych połączeń spawanych laserowo uzyskano krzywą projektową S-N dla jednego z pokazanych modeli...
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Fatigue life of steel, laser welded panels
PublicationW publikacji przedstawiono zagadnienia dotyczące możliwości analizy trwałości zmęczeniowej stalowyxh paneli spawanych laserowo typu sandwich. Przedstawiono wyniki badań laboratoryjnych w skali naturalnej a także krzywe projektowe uzyskane na podstawie systematycznych badań połączeń elementarnych spawanych laserowo. Na podstawie przedstawionych i uogólnionych wyników pokazano propozycję metodyki szacowania trwałości zmęczeniowej...
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End-Of-Life Management of Photovoltaic Solar Modules
PublicationThe PV industry continues to push its credentials as a technology that addresses one of the fundamental challenges of our times – climate change. There are however two major concerns about this technology: first, the potential negative environmental impacts of energy used in the production stage and second, the possible shortage of the valuable materials in the future. The currently dominant semiconductor used in photovoltaic modules...
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Increasing rail life by forecasting fatigue failure.
PublicationReferat poświęcony jest przedłużaniu żywotności szyn i obejmuje zagadnienia prognozowania liczby pęknięć a także planowania szlifowań szyn. Dane pomiarowe pochodzą z wieloletnich badań przeprowadzonych w Katedrze Inżynierii Kolejowej Politechniki Gdańskiej na liniach magistralnych PKP.
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Peer assessment as a method for measuring harmful internet use
PublicationHarmful Internet use (HIU) describes unintended use of the Internet. It could be both self-harm and harming others. Our research goal is to develop a more accurate method for measuring HIU by this novel peer assessment. As such, it may become, with our call for more research, a paradigm shift supplementing every rating scale or other type of Internet use assessment. In addition to classic statistical analysis, structural equations...
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Integration of adsorption chillers with combined cycle gas turbine
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Portable Electronic Nose Based on Electrochemical Sensors for Food Quality Assessment
PublicationThe steady increase in global consumption puts a strain on agriculture and might lead to a decrease in food quality. Currently used techniques of food analysis are often labour-intensive and time-consuming and require extensive sample preparation. For that reason, there is a demand for novel methods that could be used for rapid food quality assessment. A technique based on the use of an array of chemical sensors for holistic analysis...
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Review of Cybersecurity Assessment Methods: Applicability Perspective
PublicationCybersecurity assessments are crucial in building the assurance that vital cyberassets are effectively protected from threats. Multiple assessment methods have been proposed during the decades of the cybersecurity field. However, a systematic literature search described in this paper reveals that their reviews are practically missing. Thus, the primary objective of this research was to fulfil this gap by comprehensively identifying...
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A novel architecture for e-learning knowledge assessment systems
PublicationIn this paper we propose a novel e-learning system, dedicated strictly to knowledge assessment tasks. In its functioning it utilizes web-based technologies, but its design differs radically from currently popular e-learning solutions which rely mostly on thin-client architecture. Our research proved that such architecture, while well suited for didactic content distribution systems is ill-suited for knowledge assessment products....
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A novel architecture for e-learning knowledge assessment systems
PublicationAbstract. In this paper we propose a novel e-learning system, dedicated strictly to knowledge assessment tasks. In its functioning it utilizes web-based technologies, but its design differs radically from currently popular e-learning solutions which rely mostly on thin-client architecture. Our research proved that such architecture,while well suited for didactic content distribution systems is ill-suited for knowledge assessment...
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A novel architecture for e-learning knowledge assessment systems
PublicationIn this paper we propose a novel e-learning system, dedicated strictly to knowledge assessment tasks. In its functioning it utilizes web-based technologies, but its design differs radically from currently popular e-learning solutions which rely mostly on thin-client architecture. Our research proved that such architecture, while well suited for didactic content distribution systems is ill-suited for knowledge assessment products....
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Usefulness of the voltamperometric method for assessment of the purity of soil
PublicationThis paper presents a voltammetric analysis of soil. It shows that the voltammetry is a useful method for the assessment of soil contaminated with heavy metal ions. There are two major problems with voltammetry analysis: the diffusion coefficient and the measurement system. The paper contains a short literature study of mathematical equations and a study of differences between soil and water measurements. Suggestions of the solution...
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Gazowa mikrosiłownia domowa z modułem ORC - doświadczenia z badania prototypu
PublicationArtykuł zawiera rozważania nad ideą wykorzystania obiegu parowego ORC (Organic Rankine Cycle) do skojarzonej produkcji ciepła i energii elektrycznej dla pokrycia potrzeb indywidualnego odbiorcy. Dokonano w nim podsumowania dotychczasowych prac prowadzonych przez Autorów, które zaowocowały budową demonstracyjno-badawczego stanowiska mikro-CHP z technologią ORC w skali „domowej”, współpracującą z komercyjnym kotłem gazowym. W publikacji...
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The conception of energetic investigations of the multisymptom fatigue of the simple mechanical systems' constructional materials
PublicationThe article presents the basic assumptions of the research project aimed, as the main scientific purpose, an identification of the slow-changeable energy processes surrounding the high-cycle fatigue of constructional materials within the plain mechanical system, especially the marine one, for diagnostic purposes. There is foreseen an application of alternative diagnostic methods based on energetic observations of the multi-symptom,...
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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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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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Analiza możliwości odzyskiwania ciepła odpadowego w przemyśle rafineryjnym z wykorzystaniem układów ORC
PublicationJednym z najważniejszych zagadnień współczesnej techniki jest poszukiwanie nowych możliwości pozyskiwania energii elektrycznej poprzez zagospodarowanie dotychczas niewykorzystanych lub bezużytecznie marnowanych jej źródeł. Jest to niezwykle ważna kwestia zarówno z ekonomicznego, technologicznego, jak i środowiskowego punktu widzenia. Jednym z przykładów nowoczesnych rozwiązań w tej dziedzinie może być zastosowanie układu opartego...
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Criteria for selection of working fluid in low-temperature ORC
PublicationThe economics of an ORC system is strictly linked to thermodynamic properties of the working fluid. A bad choice of working fluid could lead to a less efficient and expensive plant/generation unit. Some selection criteria have been put forward by various authors, incorporating thermodynamic properties, provided in literature but these do not have a general character. In the paper a simple analysis has been carried out which resulted...
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Heavy duty vehicle fuel consumption modelling using artificial neural networks
PublicationIn this paper an artificial neural network (ANN) approach to modelling fuel consumption of heavy duty vehicles is presented. The proposed method uses easy accessible data collected via CAN bus of the truck. As a benchmark a conventional method, which is based on polynomial regression model, is used. The fuel consumption is measured in two different tests, performed by using a unique test bench to apply the load to the engine. Firstly,...
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Ideas of the New European Bauhaus (NEB) in architectural education
PublicationThe New European Bauhaus (NEB) is an interdisciplinary project initiated by the European Commission in 2020 [1], based on three values: sustainability, beauty and community (social inclusion). Its aim is to support the European Green Deal programme [2] by accelerating the transformation of various economic sectors, including construction, to improve the quality of people’s lives and protect the natural environment. Even though...