In spite of the fact that the flexibility of the crankshaft of diesel engines exhibits notable nonlinearities, analytical modeling of such nonlinearities is not yet realized. The present study thus analytically models the effect of eccentricity on flexible crankshaft and piston secondary motion. The eccentricity of the crankshaft is modeled as the summation of the hydrodynamic eccentricity and the dynamic mass eccentricity of the crankshaft. The study also models the absolute value of the vibrational dynamic displacement of the center of the crankshaft. The paper proves that such dynamic displacement of the center of the crankshaft is sensitive to the changes in its independent variables. It was found that the most influential parameters on the dynamic displacement of the center of the crankshaft due to vibration are the natural frequency and the eccentricity of the crankshaft. The modeling of the dynamic displacement in a flexible crankshaft was validated using a case study based on t... [more]

Conventional and emerging paradigms of urbanism require new responses under the current circumstances, especially in relation to the integration of sustainability dimensions and technology advances. The escalating rate of urbanization, coupled with the climate emergency, fundamentally indeed disrupt the challenges that urbanism research and practice deal with, calling for adopting more innovative approaches to urban planning and design. With cities contributing around 65% of Greenhouse Gas (GHG) emissions and experiencing an unprecedented growth of population, contemporary urban policy needs to be redefined and re-assessed accordingly. While numerous urban models, such as the Compact City, the Eco-City, the Sustainable City, and the Smart City, have emerged in response to the challenges of sustainability and urbanization, the 15-Minute City has recently gained a steep popularity. This paper explores the theoretical, practical, and technological foundations of the 15-Minute City, with a... [more]

Biomass use for energy and materials is, on the one hand, one of the key mitigation options to reach the 1.5 °C GMT target set in the Paris Agreement, as highlighted by the IPCC and many other key analyses. On the other hand, particularly in parts of the EU, a strong negative connotation has emerged in public debate and EC policy, with a particular emphasis on the (presumed) displacement effect in markets and land use. This is a remarkable contrast because the reasons to use sustainable biomass, on the one hand, and the possibilities and synergies for supplying sustainable biomass, on the other, are underpinned with strong evidence, also providing insights on how displacement issues can be avoided. Sustainable biomass supplies can contribute 20−30% of the future global and European energy supply, leading to reduced overall mitigation costs, including realizing the net CO2 removal from the atmosphere using BECCS concepts. This paper highlights which options, pathways and preconditions a... [more]

Jevons Paradox has fundamental implications on sustainable development and the UN Sustainable Development Goals (SDGs). The paradox states that technological improvements aiming to increase the energy efficiency risk causing a rebound effect, and an increase in demand, production, and resource exploitation. Third world countries undergoing early-stage technological development may be particularly vulnerable, but it is also relevant in complex economic systems, where policymaking on climate and energy building on insufficient knowledge and attention to rebound effects can impair the desired outcome in terms of climate change mitigation, resource use and sustainable development.

In recent years, carbon cap-and-trade has been promoted by many national governments aiming to limit, or cap, total carbon dioxide emissions. Such a mechanism impacts manufacturers’ remanufacturing decisions, as it increases the cost of carbon emissions. The current literature has recognized the importance of carbon cap-and-trade regulations; however, little attention has been paid to what effect such regulations have on manufacturer’s remanufacturing with the flexibility to engage it in-house or outsource it to third-party remanufacturers. To fill this gap, we develop two theoretical models that, under the carbon cap-and-trade mechanism, allow the manufacturer to engage in remanufacturing operations in-house (Model H) or outsource them to an independent remanufacturer (Model R). The primary goal of this paper is to understand what effects carbon cap-and-trade regulations have on green supply chain management when producing new and remanufactured products. In particular, we find that a... [more]

Traditional wisdom suggests that the interchangeable design in process system engineering, such as modularity or commonality design, can lower the manufacturing cost and act as a revenue driver. Moreover, the interchangeable design will be efficient in both assembling for new production and disassembling for remanufacturing. As such, interchangeable design confronted remanufacturing processing often involves a balance of revenue from cost drivers and cannibalization effects from remanufacturing. Therefore, this paper studies how the original equipment manufacturers’ (OEMs’) interchangeable design impacts the remanufacturing decisions, as well as the economy and environment. Specifically, we develop two theoretical models, in which an OEM makes a strategic choice relating to design interchangeability when the remanufacturing operations are undertaken by itself (Model O) or outsourced to third-party remanufacturers (Model T). This study finds that, although the optimal level of interchan... [more]

Energy transitions’ trend towards sustainable systems has prompted energy systems to shift from being fossil-fuel-based to rely on renewable energy. These transitions have led the power system to occupy the center of modern infrastructures, so assuring its security has become a priority for policy makers. This work presents a tool based on a multidimensional index, the Power System Security Index (PSIx), for the evaluation of policies affecting the security of the supply of electrical energy. The developed frame is applied to the current power system of Argentina, and it is compared to the system in year 2002. Availability of resources and infrastructure are the strengths of the country, while economic, governability, and research, development and innovation spheres leave room for improvement. The further incorporation of more economies to the study would substantially enrich the statistical analysis of the results.

Surface lignite mines of the Balkan Peninsula face growing pressure due to the CO2 emissions reduction initiatives, rapidly increasing renewable-power capacity, and cheap natural gas. In this frame, the development of a modern mine land rehabilitation strategy is considered as a prerequisite for mitigating the social and economic impacts for the local communities. In the case of western Macedonia lignite mines, these prospects are investigated based on a PEST (political, economic, social, technological) analysis of seven alternative land uses. Urban (industrial) development, green houses, and industrial heritage parks are considered as the most appropriate land uses for mitigating the socioeconomic impacts due to the loss of employments. For the land uses occupying large areas (i.e., agriculture, forestry, livestock farming, and photovoltaic parks), an optimisation algorithm is proposed for determining the mix of land uses that maximise revenue, equity, and natural conservation and min... [more]

The managerial and environmental studies conducted in the energy research area reflect its substantial importance, particularly when optimizing and modifying consumption patterns, transitioning to renewable sources away from fossil ones, and designing plans and systems. The aim of this study is to provide a systematic review of the literature allowing us to identify which research subjects have been prioritized in the fields of energy and sustainability in recent years, determine the potential reasons explaining these trends, and categorize the techniques applied to analyze the uncertainty faced by decision-makers. We review articles published in highly ranked journals through the period 2003−2020 and apply text analytics to cluster their main characteristics; that is, we rely on pre-processing and text mining techniques. We analyze the title, abstract, keywords, and research methodology of the articles through clustering and topic modeling and illustrate what methods and fields consti... [more]

China faces the problem of depletion of its coal resources, and a large number of mines are becoming aged mines. Demand for coal, however, still increases due to the growth of China’s economy. Energy shortage might restrict the sustainability of China’s national economy. As one contribution to a solution, this paper proposes the innovative exploitation method of solid backfill coal mining (SBCM) technology to exploit parts of pillar-blocked (residual coal pillar resources under industrial square, RCPRIS) that protect industrial facilities. Thus, blocked coal resources may be converted into mineable reserves that improve the recovery ratio of mine resources. Also, waste would be removed from the surface reducing hazards of environmental pollution. Based on the case of the Baishan Coal Mine in Anhui, China, numerical simulation is used to study the size of shaft-protecting coal pillars (SPCP) required at different backfill ratios. Results show that the disturbance to a shaft caused by ex... [more]

The use of renewable energies, energy saving, and efficiency are needs of global society. According to the latest estimates, global energy demand could triple by 2050 and, by then, 70% of the world’s population will live in cities. Cities are currently responsible for 80% of greenhouse gas emissions, so they have a key role to play in shifting towards a sustainable energy future. Cities are threatened not only by overcrowding, but also by rising energy demand, obsolete infrastructure, volatile energy markets, and the effects of climate change. This Special Issue aims to advance the contribution of energy saving and the use of renewable energies in order to achieve more sustainable cities.

Modern agriculture represents an economic sector that can mainly benefit from technology innovation according to the principles suggested by Industry 4.0 for smart farming systems. Greenhouse industry is significantly becoming more and more technological and automatized to improve the quality and efficiency of crop production. Smart greenhouses are equipped with forefront IoT- and ICT-based monitoring and control systems. New remote sensors, devices, networking communication, and control strategies can make available real-time information about crop health, soil, temperature, humidity, and other indoor parameters. Energy efficiency plays a key role in this context, as a fundamental path towards sustainability of the production. This paper is a review of the precision and sustainable agriculture approaches focusing on the current advance technological solution to monitor, track, and control greenhouse systems to enhance production in a more sustainable way. Thus, we compared and analyze... [more]

There is significant regional heterogeneity in terms of relative positioning in relation to the issue of sustainability and, in particular, in relation to the implementation of renewable energy. For this reason, the aim of this work is to analyze whether these differences in attributes for each region are likely to condition the expansion of renewable energy production. In this paper, we focus on wind energy. Therefore, the evolution of the installed capacity of wind energy is studied for a set of Spanish regions over the period between 2004 and 2017. The results obtained confirm that, in effect, there are factors linked to investment and environmental knowledge capable of conditioning the deployment of wind energy at the regional level.

Energy efficiency is a major concern to achieve sustainability in modern society. Smart cities sustainability depends on the availability of energy-efficient infrastructures and services. Buildings compose most of the city, and they are responsible for most of the energy consumption and emissions to the atmosphere (40%). Smart cities need smart buildings to achieve sustainability goals. Building’s thermal modeling is essential to face the energy efficiency race. In this paper, we show how ICT and data science technologies and techniques can be applied to evaluate the energy efficiency of buildings. In concrete, we apply machine learning techniques to classify buildings based on their energy efficiency. Particularly, our focus is on single-family buildings in residential areas. Along this paper, we demonstrate the capabilities of machine learning techniques to classify buildings depending on their energy efficiency. Moreover, we analyze and compare the performance of different classifie... [more]

The European Union (EU) energy policy for sustainable development has been the topic of continuous debate, research, and analysis, which frequently focused on objectives and the evaluation of quantitative and qualitative performance. Different approaches can be used for the assessment of sustainable development goals. The authors of the article conducted a literature review of relevant research papers dated 2016−2020. The most common are quantitative methods based on hard data. Some qualitative studies based on soft data are also available but rare. This article proposes hybrid Rough Set Data Envelopment Analysis (DEA) and Rough Set Network DEA models that integrate both approaches. Also, the models allow the inclusion of uncertainty in the underlying data. The article uses hard data of the International Energy Agency (IEA) and the results of the EU survey regarding the influence of the socio-economic environment on CO2 emissions in EU countries. The authors demonstrate that multifacet... [more]

Solving the issue of energy security for geographical islands presents a one-of-a-kind problem that has to be tackled from multiple sides and requires an interdisciplinary approach that transcends just technical and social aspects. With many islands suffering in terms of limited and costly energy supply due to their remote location, providing a self-sustainable energy system is of utmost importance for these communities. In order to improve upon the status quo, novel solutions and projects aimed at increasing sustainability not only have to consider optimal utilization of renewable energy potentials in accordance with local conditions, but also must include active community participation. This paper analyzes both of these aspects for island communities and brings them together in an optimization scenario that is utilized to determine the relationship between supposed demand flexibility levels and achievable savings in a setting with variable renewable generation. The results, specifica... [more]

Without experiences of electric buses, public transport authorities and bus operators have faced questions about how to implement them in a cost-effective way. Simple cost modelling cannot show how costs for different types of electric buses differ between different routes and timetables. Tools (e.g., HASTUS, PtMS, and optibus) which can analyse such details are complicated, time consuming to use, and provide insufficient insights into the mechanisms that influence the cost. This paper therefore proposes a method for how to calculate total cost of ownership, for different types of electric buses, in a way which can predict how the cost varies based on route and timetable. The method excludes factors which cause minor cost variations in an almost random manor, in order to better show the fundamental mechanisms influencing different costs. The method will help in finding ways to reduce the cost and help to define a few cases which deserve a deep analysis with more complete tools. Testing... [more]

Sustainable solutions are needed to manage increased energy demand and waste generation. Renewable energy production from abundant sewage sludge (SS) and digestate (D) from biogas is feasible. Concerns about feedstock contamination (heavy metals, pharmaceuticals, antibiotics, and antibiotic-resistant bacteria) in SS and D limits the use (e.g., agricultural) of these carbon-rich resources. Low temperature thermal conversion that results in carbonized solid fuel (CSF) has been proposed as sustainable waste utilization. The aim of the research was to investigate the feasibility of CSF production from SS and D via torrefaction. The CSF was produced at 200~300 °C (interval of 20 °C) for 20~60 min (interval 20 min). The torrefaction kinetics and CSF fuel properties were determined. Next, the differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) of SS and D torrefaction were used to build models of energy demand for torrefaction. Finally, the evaluation of the energy ba... [more]

The main aim of this study is to empirically examine and compares the impacts of oil price shocks, Arab revolutions, some macroeconomics, and bank-specific variables on bank profitability indicators between Conventional and Islamic banks in Gulf Cooperation Council (GCC) countries. The study employed panel Autoregressive-Distributed Lag (ARDL) techniques to examine the causal relationship both at the short and long-run. Our results reveal that most of the variables employed in our study significantly influence Return on Asset (ROA), Return on Equity (ROE), and Net Interest Margin (NIM)/ Net Profit Margin (NPM) for both Conventional Banks (CBs) and Islamic Banks (IBs) similarly in the long run. Findings from our study imply that both CBs and IBs have some similar features in nature, which could be because of the structure of the policies for IBs is in line with the regulatory framework for the CBs. The main finding from the study is the significance of oil price shock and the Arab sprin... [more]

This study addresses the performance analysis of a subcritical and supercritical Organic Rankine Cycle (ORC) with the addition of a preheater or superheater integrated with a turbofan engine. This analysis will try to explore the heat transfer throughout the evaporator for the purpose of determining the ORC output power and thermal efficiency. A simplified numerical model of the ORC for waste heat recovery is presented. The model depicts the evaporator by using a distributed model, and includes parameters such as the effectiveness, heat capacity and inlet temperature of the waste heat and the organic fluid. For a given set of initial parameter values, the output power and thermal efficiency, as well as the mass flow rate of the working fluid are acquired by solving the system’s thermodynamic cycle with the aid of MATLAB software. The model is then verified by using data from an industrial waste heat recovery system. The connection between the turbofan engine and the ORC system was esta... [more]

The article explores the impact of the quality and volume of energy consumption of the population on the human development index using a sample of a number of countries as an example. The hypothesis concerning the relationship between the amount of energy consumed, the human development index (HDI), and the environment (CO2 emissions into the atmosphere) has been verified. The study results show that the size and rating of the HDI are influenced by such factors as urbanization growth, gross domestic product (GDP), gross national income (GNI) per capita, the share of “clean” energy consumption by the population and business in total energy consumption, the level of socio-economic development, and R&D expenses. In the course of building the model, the recommendations by the United Nations (UN) and the Organization for Economic Co-operation and Development (OECD) were used. The results show that the volume of energy consumption not only affects the human development index in a particular... [more]

Sustainability is becoming more and more important as a decision attribute in the manufacturing environment. However, quantitative metrics for all the aspects of the triple bottom line are difficult to assess. Within the present paper, the sustainability metrics are considered in tandem with other traditional manufacturing metrics such as time, flexibility, and quality and a novel framework is presented that integrates information and requirements from Computer-Aided Technologies (CAx) systems. A novel tool is outlined for considering a number of key performance indicators related to the triple bottom line when deciding the most appropriate process route. The implemented system allows the assessment of alternative process plans considering the market demands and available resources.

Exergy is important and relevant in many areas of study such as Life Cycle Assessment (LCA), sustainability, energy systems, and the built environment. With the growing interest in the study of LCA due to the awareness of global environmental impacts, studies have been conducted on exergetic life cycle assessment for resource accounting. The aim of this paper is to review existing studies on exergetic life cycle assessment to investigate the state-of-the-art and identify the benefits and opportunity for improvement. The methodology used entailed an in-depth literature review, which involved an analysis of journal articles collected through a search of databases such as Web of Science Core Collection, Scopus, and Google Scholar. The selected articles were reviewed and analyzed, and the findings are presented in this paper. The following key conclusions were reached: (a) exergy-based methods provide an improved measure of sustainability, (b) there is an opportunity for a more comprehensi... [more]

Geopolymers are less energy-demanding alternatives to Portland cement binders. The subject of geopolymer rheology has not yet been fully explored, and the available literature is limited to a narrow range of material compositions. This paper presents the rheological and mechanical response of fly-ash based geopolymer mortars. Investigations were made of the effect of different levels of ground granulated blast furnace slag (GGBFS) addition levels on the rheological properties of fresh geopolymers as well as their mechanical performances at 2, 14 and 28 days. The aim of the study was to obtain flow curves and to establish the correlation between shear stress and shear rate. The results have shown that geopolymer mortar is a pseudoplastic liquid presenting shear thinning behavior, moreover, with the increase of GGBFS content, higher material strengths were obtained and the total porosity was reduced.

Lithium ion batteries are experiencing an increased success thanks to their interesting performances, in particular for electric vehicles applications. Their continuous technological improvements in the last years are providing higher energy density and lower manufacturing costs. However, the environmental performance of their supply chain is of paramount importance to guarantee a cleaner alternative to fossil-based solutions on the entire life cycle of the applications. This paper carries out a comprehensive review on the main aspects related to Li-ion batteries manufacturing, to support the readers in understanding the complexity of the subject and the main challenges and opportunities for the future developments of this technology. The paper discusses the expected future demand of batteries; the main aspects related to the supply chain, including existing assets, input materials and alternative technologies; the end-of-life of batteries; the environmental impacts; and the main geopo... [more]