Search Results (752)

Stone Mastic Asphalt (SMA) mixtures are widely used in high-capacity road pavements due to their durability and resistance to permanent deformation. However, although electric arc furnace (EAF) steel slag and recycled crumb rubber have been individually investigated as alternative materials in asphalt mixtures, evidence regarding their simultaneous incorporation in SMA mixtures under full-scale construction and real traffic conditions remains limited. Moreover, quantitative environmental assessments are often restricted to simplified or qualitative approaches, with limited reporting of carbon footprint results. This study investigates the combined use of electric arc furnace (EAF) steel slag aggregates and recycled crumb rubber in SMA mixtures, integrating laboratory evaluation with full-scale field application on a high-traffic motorway. Two SMA 11 mixtures were designed and assessed: one incorporating steel slag aggregates as a replacement for natural coarse aggregates, and another combining steel slag aggregates with recycled crumb rubber added through the dry process (0.8% by mixture mass). Laboratory testing included volumetric characterization, moisture sensitivity and rutting resistance, while field validation covered surface macrotexture, skid resistance, executed thickness and interlayer bonding. Both mixtures fully complied with the applicable technical specifications, achieving indirect tensile strength ratios (ITSR) above 90% and wheel-tracking slopes below 0.07 mm/10³ cycles. A simplified comparative life-cycle assessment (LCA), limited to modules A1–A3, showed a reduction in CO₂-equivalent emissions of approximately 2% for the mixture containing steel slag and up to 27% for the mixture combining steel slag and recycled crumb rubber, mainly due to the valorization of industrial by-products and end-of-life tyres. Overall, the results demonstrate the technical feasibility and potential environmental benefits of these SMA mixtures within the defined scope of laboratory verification, short-term field performance and screening LCA. The contribution of this study lies in providing applied evidence from a full-scale motorway intervention, complementing predominantly laboratory-based studies and offering a quantified environmental comparison under consistent methodological assumptions. Full article

This study examines how different sustainability assessment approaches influence climate-policy choices when evaluating greenhouse gas (GHG) emissions across industrial value chains. Using Spain as an empirical setting, we apply Environmentally Extended Input–Output Tables combined with Production Layer Decomposition to quantify Scope 1–2–3 emissions and assess economic and employment impacts. The results show that indirect emissions dominate most value chains, revealing structural dependencies that are not captured by sector-level inventories. Incorporating social and economic dimensions highlights the need for transition pathways that minimise employment disruption while maximising environmental gains. Although public procurement can enhance the uptake of emerging low-carbon and circular-economy technologies, it has limited quantitative influence on total value-chain emissions. The findings demonstrate that value-chain-based sustainability assessments provide a more comprehensive basis for designing coherent, equitable, and effective decarbonisation strategies. Full article

This study addresses the environmental problems stemming from greenhouse gas (GHG) emissions from public transportation in the cities of Chillán and Chillán Viejo. Specifically, it analyzes emissions from fossil-fuel-powered buses, which contribute to climate change and negatively affect people’s quality of life. Given this situation, the need to reduce these emissions and move towards more sustainable mobility systems is recognized. The main objective of this research is to estimate the CO₂-equivalent reduction that could be achieved by replacing fossil-fuel-powered public transportation with electric vehicles in the aforementioned cities. To this end, the ISO 14064 methodology is used, subject to specific scope and limitations. This study reviews key aspects, including current environmental legislation, Chile’s international commitments regarding climate change, and the state of emissions in the transportation sector, to illustrate the current state of electromobility in Chile. Finally, the impact of the transition to electromobility in public passenger transport by bus is quantified, resulting in a reduction of 9429 tons of CO₂ equivalent emissions, equivalent to 63.4% compared to the 2023 bus fleet, considering the average emission factor of the national electricity system for 2023. The proposal consists of implementing a 100% electric bus public transport system, highlighting its advantages in reducing emissions, improving energy efficiency, improving air quality, and reducing noise pollution. However, this requires a significant financial investment of approximately USD 57 million, excluding public charging stations for electric buses. Furthermore, public policies offering means of accelerating the transition of public transport in Chile are analyzed. Full article

The use of Silicon Carbide (SiC) MOSFETs significantly improves converter performance by increasing efficiency and reducing costs, to the detriment of electro-magnetic emission and reliability. Implementing a predictive maintenance strategy based on a prognosis tool can mitigate this limitation. This literature review offers a methodological synthesis of prognosis design tools for SiC MOSFETs, while also encompassing studies on IGBTs and silicon-based power MOSFETs where these approaches are transferable. The analysis focuses on wear-out prognosis under nominal operating conditions of standard package device, excluding environmental constraints. Articles published up to 2025 were identified in the OpenAlex database using a keyword-based search and manually filtered according to the study scope. Most reviewed works rely on Data-Based prognosis methods, mostly based on neural networks, though out-of-sample validation remains uncommon. Our study also highlights the dependence of Data-Based prognosis performance on the shape of degradation indicator trends. Moreover, the estimation of prediction uncertainty is rarely addressed in the reviewed literature. Despite notable methodological advances, ensuring the reliability of prognosis tools for SiC MOSFETs remains an ongoing research challenge. Full article

This study presents an integrated engineering methodology aligned with the planning phase of the ISO 50001:2018 (Energy Management Systems—Requirements with Guidance for Use. International Organization for Standardization (ISO): Geneva, Switzerland, 2018) energy management standard for the design, sizing, and assessment of a solar thermal system applied to domestic hot water production in a medium-scale hotel building. The proposed framework focuses on the energy review stage of ISO 50001, incorporating site-specific climatic assessment, spatial layout optimization, structural feasibility analysis, and energy performance evaluation to support informed technology selection and system viability. Thermal performance is assessed using real operational data from the case study, complemented by a data-driven multivariable regression-based energy performance indicator (EnPI) that relates electricity consumption to cooling degree days and room occupancy. This regression model, developed in accordance with ISO 50001 recommendations, enables transparent monitoring of energy performance under real operating conditions without relying on black-box predictive techniques. Material selection criteria for absorber plates, heat-transfer components, transparent covers, and insulation layers are discussed to support both initial efficiency and performance stability under site-specific climatic conditions. In addition, an indicative and qualitative analysis of material-dependent performance evolution is introduced to support comparative decision-making, without implying quantitative lifetime prediction. Structural feasibility of the collector support system is examined through finite-element simulations under combined gravitational and wind loads, providing illustrative verification of stress distribution under representative operating conditions. The installed system delivers an annual thermal energy contribution of 8468 kWh, resulting in an estimated reduction of 7.79 t of CO₂ emissions per year. Economic indicators suggest a short payback period and a favorable internal rate of return, which should be interpreted as order-of-magnitude estimates within the planning scope of the methodology. Overall, the proposed methodology provides a replicable and multidisciplinary planning-phase framework aligned with ISO 50001 for the design and assessment of solar thermal systems in medium-scale buildings under real operating conditions. Full article

Driven by cleaner energy demands, environmental regulations, and technological advances, coal science is rapidly evolving, creating the need to understand its transition and transformation within the global energy research landscape. Building upon earlier national- and topic-specific bibliometric studies, this study presents a comprehensive long-term global bibliometric analysis of coal research (1975–2024), based on 272,370 Web of Science records, applying the Cross-Disciplinary Publication Index (CDPI), the Technology–Economic Linkage Model (TELM), VOSviewer, and Excel to assess research growth, structural shifts, and interdisciplinary integration. Results show that coal research is dominated by articles (74%) with publication output peaking at ~19,500 in 2024, reflecting fluctuations in global coal prices due to energy transition market dynamics. CDPI results highlight Energy & Fuels (0.83), Chemical Engineering (0.80), Environmental Sciences (0.77), Materials Science (0.74), and Geosciences (0.66), showing coal’s central role across technology, environment, and geological research domains and revealing a clear shift toward sustainability-oriented and advanced material applications. China leads output (122,130 publications), with strong contributions from the China University of Mining and Technology and the Chinese Academy of Sciences, while the USA, Australia, and Europe maintain strong international collaboration networks. The evolution of coal research can be divided into three major phases: conventional mining, coal preparation, combustion, and coalbed methane commercialization (1975–2004; ~64,000 publications); integrated gasification combined cycle (IGCC) and carbon capture and storage (CCS) technologies (2005–2014; ~58,707 publications); and a recent phase dominated by by-product valorization, carbon capture utilization and storage (CCUS), and digital technologies (AI, IoT, ML) (2015–2024; ~146,174 publications). Contemporary coal research spans three interconnected domains: energy supply (≈36% of global electricity generation and ~15 Gt CO₂ emissions), resource and geoscience applications (including large-scale fly ash utilization and critical element recovery), and environmental and health impacts related to greenhouse gas and pollutant emissions. The findings demonstrate that coal science is transitioning from a conventional fossil fuel-centered discipline toward an integrated, interdisciplinary energy research field, emphasizing emission reduction, resource efficiency, digitalization, and circular economy applications, thereby extending prior bibliometric studies through unprecedented temporal coverage, global scope, and the combined application of CDPI and TELM frameworks, providing critical insights for future energy strategies and policy development. Full article

Plug-in hybrid electric vehicles (PHEVs) operate using both electricity and liquid fuel, offering emissions reduction while eliminating driving-range concerns. Determining the optimal electric range or battery capacity is crucial for the total cost of ownership, decarbonization potential, and battery material demand. However, the effect of battery degradation has not been incorporated into market-oriented range-optimization studies. This paper extends the existing MOR-PHEV range optimization model by integrating both cycle-based and calendar-based battery degradations. The results show meaningful optimization benefits, reducing consumer ownership cost by approximately $3000–5000. The optimal solution—defined by the minimized lifetime cost and the optimal battery capacity—is robust across the key external parameters. Intertwined with certain factors, battery degradation can have a significant impact on the optimal battery capacity. Particularly, at faster cycle-based degradation, high driving intensity and high CS efficiency can lead to optimization tipping points, where the degradation effect is so significant that the consumer is better off by choosing a small-battery PHEV (or HEV if the choice space expands beyond PHEV) in order to fully degrade the battery faster, totally avoid the charging behavior cost earlier, and maximally benefit from the high CS efficiency earlier. This points to the importance of reducing the cycle-based degradation coefficient and improving the vehicle energy efficiency and charging convenience. One basis point (0.01%) reduction in the cycle-based degradation coefficient is estimated to reduce the optimal battery capacity by 4.9–5.2 kWh and increase consumer value by $275–497, depending on the battery unit cost. These are useful insights into decision-making regarding battery technology R&D, battery chemistry roadmaps, critical material supply risks, and EV product strategies. While the findings in the study scope depend on assumptions of consumer behavior, battery degradation, vehicle efficiency and charging infrastructure, the expanded MOR-PHEV provides a systematic framework for considering different assumptions in support of user-defined decision context and discussing future research. Full article

This comprehensive study presents an integrated analysis of NO_x reduction strategies and operational optimization for the HYUNDAI-HiMSEN 7H35DFP dual-fuel marine engine. The optimization scope focuses on selective catalytic reduction control strategies and operational decision-making (fuel mode selection, load management) rather than engine hardware modifications, ensuring practical applicability within certified marine engine operational envelopes. The research employs a multifaceted approach combining experimental investigation, computational fluid dynamics (CFD) modeling, and advanced control algorithms to address the stringent IMO Tier III emission standards. The 3500 kW, 7-cylinder engine achieves IMO Tier III compliance through dual pathways: (1) gas mode operation meeting the 2.4 g/kWh limit inherently with measured emissions of 1.41–2.29 g/kWh across 25–100% load without aftertreatment, and (2) diesel mode achieving compliance via SCR aftertreatment, reducing Tier II baseline emissions (7.68–10.71 g/kWh) by 75–82% to final values of 1.60–1.96 g/kWh. The research quantifies NO_x reduction mechanisms separately for each operating mode and establishes optimal operational strategies for mode selection. A MATLAB v2025a-based SCR optimization model successfully predicts optimal urea injection rates, achieving >75% NO_x reduction efficiency across all operating conditions. Multivariate analysis using principal component analysis identifies the following three primary factors explaining 89.3% of dataset variability: combustion intensity (45.2%), fuel mixing characteristics (28.7%), and thermal management (15.4%). CFD analysis reveals that gas mode combustion produces more uniform temperature distributions (peak ~2000 K) compared to diesel operation (>2200 K), directly explaining NO_x generation differences. The developed digital twin framework with machine learning algorithms achieves 94.2% accuracy in SCR catalyst degradation prediction and 91.8% in fuel injection system performance prediction. Waste heat recovery analysis indicates 25–30% of fuel energy resides in exhaust gases, with theoretical energy recovery potential of 8.5–15.3%. This integrated approach validates dual-fuel technology’s capability to meet current and future maritime environmental regulations while maintaining operational flexibility. Full article

The European Union (EU) Green Deal (EGD) aims to significantly transform and modernize the EU economy, while at the same time envisioning significant changes in agricultural production, especially in livestock farming. Generally, EU Member States implement specific measures that contribute to the achievement of various EGD objectives. Most often, these are part of the national strategies of the EU Common Agricultural Policy. At the same time, it is important to identify the available scientific information on measures that contribute to the achievement of the EGD goals and their various impacts. Usually, each individual measure or practice is aimed at achieving one of the ESD goals, for example, reducing GHG emissions, but in practice, these create multiple side effects that can promote or hinder the achievement of other sustainability goals. This study focuses on the livestock sector and outlines key areas where intervention must occur: feeding, housing, grassland/pasture management, manure management, breeding and genetics—these factors interact and contribute to the achievement of EGD targets. At the same time, this research takes a holistic view of the EGD demands on livestock. In this study, the authors use pictograms and a color-coding system that broadens the scope of impact communication. It translates complex, scientific data into a format that is accessible and easily understood by a wider audience. The results of this study reveal that systematic research is needed to examine livestock farming measures that could change agricultural policies in the long term—from supporting existing measures to creating appropriate sustainable farming systems. Full article

This paper presents an MAUT-based decision-support framework, developed within the NAVGREEN project, to enable the evaluation of alternative fuels and technologies in shipping decarbonization pathways toward zero-emission targets. The framework integrates stakeholder-derived weights elicited through the Analytic Hierarchy Process (AHP) and systematically evaluates alternatives across five criteria: cost, technological maturity, safety and regulatory compatibility, carbon footprint, and social acceptability. Alternatives are mapped into a common utility space through criterion-specific utility functions and aggregated into a composite utility score, enabling transparent and reproducible comparison of single and combined solutions. To strengthen applicability beyond a single illustrative application, the study incorporates a structured scenario and sensitivity analyses (policy stringency, infrastructure constraints, conservative regulatory environments, and weight and parameter perturbations) to assess ranking stability under plausible future conditions. A case study on an Ultramax bulk carrier is used solely to demonstrate the operability and workflow of the method, rather than to empirically validate technology choices across all ship types. Optional AI-assisted elicitation may be used as a supporting aid to harmonize indicative inputs when data are incomplete; however, validation of AI-generated estimates is outside the scope of the present study and is identified as future work. Full article

The built environment is a major contributor to global greenhouse gas emissions and urgently requires decarbonization. Despite the decline in operational carbon emissions, which continue to fall as energy-efficient buildings rise, embodied carbon (EC) emissions from material extraction, production, and construction have become increasingly prominent, accounting for an increasing share of total building emissions. Establishing a benchmark value for buildings is essential for assessing, comparing, and mitigating emissions in new construction because it helps set goals, evaluate performance and resource efficiency, promote sustainable building practices, and lay the groundwork for decarbonizing the urban built environment. Globally, building carbon benchmarks are developed using life cycle assessment and statistical methods, whereas whole-life carbon assessment frameworks are increasingly adopted with regulatory integration. However, broader applicability remains constrained by methodological inconsistencies. This research reviews existing benchmarking studies and identifies discrepancies via semi-systematic and critical analyses. The results reveal that 81% of benchmark studies apply bottom-up approaches, and nearly 88% focus on residential buildings. The range of benchmark values for residential buildings using the bottom-up approach varies from 1.3 to 63.9 kg CO₂e/m²/year, whereas the top-down approach ranges from 1.2 to 27 kg CO₂e/m²/year. The overall range is 1.2 to 92.5 kg CO₂e/m²/year, reflecting substantial variation due to variable scopes, typologies, modeling approaches, and data sources. This research highlights the urgent need for standardized benchmarking methods to ensure comparability across studies, enable effective policy implementation, and support decarbonization. Additionally, this study proposes a framework for establishing EC benchmarks and strategies that promote low-carbon, resource-efficient urban development. Full article

This study introduces a novel approach to producing carbon-negative food ingredients by integrating phycocyanin extraction from Spirulina (Arthrospira platensis) with the application of its residual biomass as a biostimulant for soil organic carbon (SOC) sequestration. A comprehensive life cycle assessment (LCA) was conducted to evaluate the environmental performance of this integrated system, encompassing geothermally powered Spirulina cultivation, phycocyanin extraction, and the use of the waste stream to enhance SOC in degraded Icelandic soils. Although the cultivation and extraction processes are associated with environmental impacts, the SOC sequestration resulting from biostimulant application more than offsets these burdens—yielding a net-carbon-negative natural food colorant under the assumptions applied in this study (−1.60 tCO₂-eq per color unit). This work highlights the potential for such ingredients to contribute meaningfully to Scope 3 emission reductions, in line with science-based targets and the GHG Protocol. Traditionally, food pigments have been overlooked in carbon accounting due to their low inclusion rates and perceived minimal contribution to overall product footprints. This study reframes natural colorants as strategic levers for climate action, offering a pathway for food manufacturers to advance decarbonization while transitioning toward more sustainable, bio-based ingredients. Full article

In South Asia, smog has become a critical environmental concern that endangers public health, ecosystems, and the regional climate. To determine the primary causes of smog formation in Lahore during peak polluted months (October and November), the current study develops a dual analytical framework that combines cutting-edge machine learning with sector- and pollutant-specific emission analysis. To assess their relationship with Air Quality Index (AQI) and create a high-accuracy predictive model, meteorological factors and emission data from key sectors are used to build Random Forest and extreme gradient boosting (XGBoost) models. The current study evaluates the joint effects of weather and emission loads on AQI variability by integrating atmospheric dynamics with comprehensive emission profiles. The XGBoost model forecasts important pollutants from the transportation, industrial, and agricultural sectors, including carbon dioxide (CO₂), oxides of nitrogen (NO_x), Volatile Organic Compounds (VOCs), and particulate matter, in the second analytical tier. Particulate matter (PM), NO_x, and transport-related pollutants are consistently identified by the models as the primary predictors of AQI, with high prediction performance. Furthermore, a 3-fold split is used for cross-validation, making sure that each fold maintained the data’s chronological order to avoid leakage. The model has modest root mean square error (RMSE) levels (4.32 and 8.14) and high coefficient of determination (R²) values (0.93–0.99). Approximately 90% of Lahore’s annual emissions resulted from the transportation sector. These results offer aid to policymakers to anticipate air quality, identify important emission sources, and execute targeted initiatives to minimize smog and promote a healthier urban environment. The current study also helps in analyzing the causes of atmospheric and sectoral pollution. While the study captures smog dynamics during peak pollution months, its temporal scope is limited, and finer spatial measurements could further improve the generalizability of the results. Full article

Many companies in the mining industry include decarbonization of production among their key strategic goals as part of their internal sustainability strategy. This need is driven by a number of factors: stricter regulation in the area of carbon footprint (introduction of carbon taxes, emissions quotas, reporting requirements); sustained growth in demand for electricity and rising market prices; economic feasibility—the need to optimize operating costs and improve energy efficiency. This study provides a comprehensive technical and economic justification for implementing a hybrid power supply system—combining a solar power plant (SPP) and a gas engine power plant (GPP)—at Solidcore Resources’ Varvarinsky hub in Kazakhstan. The methodology includes modeling the energy balance of the real asset (156.9 GWh of annual energy consumption), calculating the output of a 22.6 MW SPP based on local GHI/PR/η parameters, forming and determining the adaptability coefficient Kₐ (proportion of PV in total monthly electricity generation), conducting an economic assessment (NPV, payback period, sensitivity), and inventorying CO₂ emissions under Scope 1–2. The SPP provides approximately 41.3 GWh of electricity generation per year, with an average annual K_a = 0.263; the 40 MW installed capacity of the gas piston power plant covers the residual demand, forming a stable daily and seasonal balance. The project demonstrates a positive NPV (After Tax) = USD 23.65 million with an estimated payback period of 10 years, while the cost of energy in extraction and processing is reduced by almost three times, and the total reduction in CO₂ emissions will be 51%. Thus, hybridization of energy supply systems is a practical compromise between reliability and decarbonization. Determining the adaptability coefficient K_a allows the flexibility of the system to be taken into account, shows how effectively the new energy system uses renewable energy sources, and can be used to optimize the operation of the energy system to achieve the company’s internal sustainable development goals. Full article

Municipalities aiming for climate neutrality and resilience must take a systemic approach to planning, implementing, and monitoring climate actions, to be able to mobilise the resources needed to achieve this ambitious goal. This involves complementing conventional top-down and technological measures with bottom-up and inclusive strategies that include not only citizen engagement but also the innovation of social practices. This study presents a comparative analysis of social innovation actions for climate neutrality planned by 53 cities from 21 countries participating in the Pilot Programme of the EU-funded project NetZeroCities. By identifying 445 actions across all cities’ pilot programmes and classifying them into 10 categories and 38 sub-categories, it is found that 53.71% of actions are linked with social innovation, offering timely insights into how social innovations are being designed in cities’ urban plans. The results reveal emerging patterns and geographical variations across Europe. With more than half of all social innovation interventions focused on stationary-energy and Scope-3-related emissions reduction, the analysis reveals that cities are increasingly relying on social innovation to foster the behavioural and socio-technical changes needed to shape sustainable energy use, consumption, and mobility patterns. These actions are based on co-creation, co-design, cross-sectoral partnerships, and public-sector capacity building, with regional differences. The comparative approach and analysis contribute to the transdisciplinary discourse on social innovation assessment in systemic innovation for transitions. Full article