Search Results (376)

Retrofitting existing buildings has become a critical strategy for reducing energy consumption, improving thermal comfort, and achieving carbon reduction targets in the built environment. Among retrofit measures, wall insulation plays a pivotal role in minimizing heat loss and enhancing building energy efficiency. Conventional insulation materials, although effective, are often associated with high embodied energy, limited recyclability, and environmental concerns. Consequently, bio-based composite materials derived from natural fibers, agricultural residues, and renewable binders have emerged as promising sustainable alternatives. However, the moisture sensitivity of lignocellulosic materials remains a major challenge that can compromise thermal performance, durability, and long-term service life. This review provides a comprehensive and critical assessment of bio-based hydrophobic composite panels for wall insulation in retrofit applications. Unlike previous reviews that have primarily examined bio-based insulation materials, natural-fiber composites, or hydrophobic modifications separately, this study integrates these interconnected research domains within a unified framework. The review systematically examines raw material selection, composite panel manufacturing processes, hydrophobic surface-engineering strategies, thermal and moisture-related performance, durability characteristics, retrofit implementation approaches, and sustainability considerations. The analysis demonstrates that hydrophobic modification significantly reduces moisture uptake, enhances dimensional stability, and preserves thermal-insulation performance under varying environmental conditions. Natural-fiber-based composites, including hemp, flax, jute, bamboo, coconut fiber, and agricultural residues, exhibit competitive thermal conductivity (λ) values while offering reduced environmental impacts compared with conventional insulation materials. Furthermore, the integration of advanced hydrophobic treatments improves resistance to water penetration, biological degradation, and freeze–thaw damage, thereby increasing the long-term reliability of retrofit insulation systems. Full article

In the context of the circular bioeconomy and environmental protection trends, the efficient use of renewable resources has become a driving force for industry, and lignin represents precisely a renewable carbon resource, abundant in terrestrial biomass that could become a sustainable substitute for fossil resources, under conditions of full exploitation. This study systematically evaluates the biosorption of Manganese (Mn(II)) from aqueous media using unmodified Tripidium bengalense (Sarkanda grass) lignin. Under optimal operating conditions (adsorbent dosage of 5 g/L, pH 6.5, and 20 °C), a highly competitive experimental adsorption capacity of 12.52 mg/g was achieved. Kinetic studies revealed exceptionally rapid uptake rates, with thermodynamic equilibrium established within the first 30 min, fitting perfectly with the pseudo-second-order (Ho-McKay) model (R² ≥ 0.9998). Equilibrium data were best described by the Freundlich isotherm (R² ≥ 0.9886), confirming chemisorption via preferential inner-sphere complexation on a heterogeneous surface. Thermodynamic analysis verified that the process is spontaneous (ΔG ranging from −13.24 to −26.19 kJ/mol) and endothermic (ΔH from 11.21 to 14.83 kJ/mol). FTIR, SEM-EDX, and TG/DTG analyses confirmed successful Mn–O coordination involving phenolic hydroxyl and carboxylic groups. Furthermore, the lignin showed excellent recyclability, maintaining a retention efficiency over 70% (70.7–85.8%) after three desorption-resorption cycles using 1N HCl. Ecotoxicological validation via Sorghum bicolor L. germination tests confirmed the complete detoxification of the post-adsorption filtrates (up to 100% germination capacity), while the Mn(II)-loaded lignin completely suppressed seed germination (0%), proving secure metal immobilization. These findings establish raw Sarkanda grass lignin as an efficient, scalable, and ecologically sustainable biosorbent for heavy metal remediation. Full article

Wind turbine blade (WTB) end-of-life waste is projected to increase significantly, yet no sustainable recycling solution with a clear energy, economic, and environmental (3E) assessment exists. This paper presents a validated 3E model of a WTB thermal recycling pilot (1 t/day) to benchmark recycled glass fibre (rGF) against virgin glass fibre (vGF) and identifies the throughput at which rGF becomes competitive. This subsequently leads to a projection of 3E performance at 5000 t/y plant capacity, at which rGF achieves approximately 46% lower specific primary thermal energy, 92% of the CO₂ emissions of vGF, and a selling price of 80% of vGF for a financial break-even. Building on this baseline, a novel combined material, heat, and power system is proposed and simulated, integrating the WTB recycling pilot with a 20 kWₑₗ/130 kWₜₕ organic Rankine cycle to serve residential buildings. Results show that coupling the pilot with 3000 m² of apartments yields a near net-zero CO₂ and energy-cost residential complex, with overall CO₂ emissions falling below those of standalone residential buildings combined with vGF production when more than 25 apartments are integrated. Full article

Circular agriculture has emerged as a promising framework for addressing the inefficiencies and environmental pressures associated with conventional food production systems. Within this context, livestock systems can play a transformative role by enabling waste valorisation, enhancing nutrient recycling, and improving overall resource-use efficiency. This review critically examines the multifunctional role of livestock in circular agriculture, with a particular focus on their capacity to convert non-human-edible biomass, such as crop residues, agro-industrial by-products, and food waste, into high-value animal-sourced foods. Drawing on the recent literature, the analysis explores how livestock systems can be reconfigured to utilise non-human-edible biomass, including crop residues, agro-industrial by-products, and food waste, thereby reducing competition between feed and food while enhancing sustainability outcomes. The findings highlight that livestock can function as biological upcycles, converting low-value materials into high-quality animal products, while also contributing to closed nutrient loops through manure management and integration with crop production. Additional benefits include the generation of renewable energy through anaerobic digestion and improved economic resilience through diversified outputs. However, the extent of these benefits depends on system design, management practices, and regional context. Despite their potential, circular livestock systems face challenges related to greenhouse gas emissions, regulatory constraints, economic feasibility, and knowledge gaps. These challenges highlight the need for a systems-based evaluation that accounts for environmental, economic, and social dimensions. The study concludes that livestock can contribute meaningfully to sustainable food system transitions when aligned with circular principles, but their role must be critically assessed to avoid burden-shifting and unintended environmental impacts. Full article

Vehicle replacement programs have become an important policy instrument for promoting sustainable mobility and accelerating the transition from gasoline vehicles (GVs) to new-energy vehicles (NEVs). In such markets, government subsidies, manufacturer competition, and trade-in strategies jointly shape not only manufacturers’ decisions but also environmental and social outcomes. Motivated by this issue, this study develops a game-theoretic model to examine competitive manufacturers’ optimal pricing and trade-in strategies as well as the government’s socially optimal subsidy level. Furthermore, using numerical examples, we reveal the effect of the action sequences of NEV and GV manufacturers on manufacturers’ pricing and trade-in decisions as well as the government’s socially optimal strategy. The results indicate that (1) manufacturers’ pricing and trade-in strategies are not only affected by government subsidies but also closely related to the gap between consumers’ mileage anxiety and degree of alternative preference. (2) The environmental benefits of recycling old products affect government subsidies on the consumption and production side at different levels. (3) NEV and GV manufacturers diverge in terms of how they respond to the sequence of their business strategies. This study contributes to the sustainability literature by showing how subsidy design and manufacturers’ decision sequence jointly affect sustainable consumption, recycling-related environmental benefits, and the transition toward cleaner mobility. The findings provide implications for sustainable vehicle replacement and support Sustainable Development Goal (SDG) 11, SDG 12, and SDG 13 by promoting cleaner mobility, responsible consumption, and climate action. Full article

Spent mushroom substrate (SMS) return is a vital strategy for agricultural waste recycling and soil fertility improvement, yet its ecological impacts of duration remain poorly understood. This study employed metagenomic sequencing to explore soil fertility, microbial dynamics, and nitrogen cycling across different SMS return durations (0, 1, and 3 years) within rice–mushroom crop rotation systems. Soil nutrients (organic matter, total nitrogen, total phosphorus) initially decreased and then increased throughout the rice growth cycle. The one-year return (y1) induced early nutrient depletion, whereas the three-year return (y3) significantly enhanced late-stage nutrient accumulation. With increasing duration, bacterial and archaeal assembly shifted from stochastic toward deterministic processes, while fungal diversity and stochasticity decreased continuously. Co-occurrence network analysis demonstrated that SMS return increased network complexity and intercommunity competition. This transition was accompanied by a functional shift in keystone taxa from those responsive to exogenous organic matter in y1 to those mediating nitrogen fixation, anammox, and sulfur metabolism in y3. Nitrogen cycling in y1 increased potential N₂O emission risks through nirS upregulation and nosZ downregulation, whereas y3 mitigated inorganic nitrogen loss by upregulating gene abundances of ammonia assimilation, nitrification, and DNRA genes. Notably, the structure of nitrogen-cycling genes fluctuated in y1 but was resilient to y0 levels in y3. These findings demonstrated that while initial SMS return triggered ecological fluctuations and environmental risks, continuous return (y3) achieved functional stability by reshaping microbial niches. This study highlights the importance of SMS return duration in balancing soil fertility enhancement with environmental risk mitigation in sustainable paddy ecosystems. Full article

The structural application of Recycled Aggregate Concrete (RAC) in marine and coastal structures remains restricted by its highly variable quality and uncertain durability. Although the adhered old mortar is recognized as the most distinctive feature of RAC, its bidirectional influence on chloride transport, acting as a preferential transport pathway and a chloride-binding reservoir, has not yet been systematically elucidated. This study develops a five-phase mesoscopic numerical framework (natural aggregate, new and old mortars, new and old ITZs) to investigate the bidirectional effects on chloride ingress. The proposed model involves multi-species (K⁺, Na⁺, Cl⁻, OH⁻, Ca²⁺, SO₄²⁻) coupling and thermodynamic chloride binding on AFm and C-S-H phases, with different binding capacities in old and new mortar. This model was validated against published experimental data, demonstrating high accuracy in predicting effective diffusivity across varying replacement rates. Parametric sensitivity analyses reveal that RAC’s chloride resistance is governed by the competition between the “facilitation effect”, caused by the inherent porosity in attached old mortar, and the “retardation effect”, caused by enhanced binding capacity. This work provides new mechanistic insight into the dual effects of old mortar and establishes a robust theoretical tool for the durability design of RAC structures exposed to chloride environments. Full article

Sustainability assessment of road pavements requires the combined consideration of environmental and mechanical performance, since conventional mass-based Life Cycle Assessment (LCA) may lead to misleading conclusions. This study proposes a multi-criteria decision-support framework that integrates LCA results with key mechanical indicators through structural normalisation, enabling the comparison of asphalt mixtures on an equivalent structural basis. Three sustainable asphalt mixtures were analysed, namely Hot Recycled Mix Asphalt (HRMA), Half-Warm Mix Asphalt (HWMA), and Cold Recycled Mixture (CRM), and compared with a reference Hot Mix Asphalt (HMA). Environmental impacts were quantified using a cradle-to-gate LCA, while mechanical performance was characterised through stiffness, fatigue resistance, rutting, and moisture susceptibility. These indicators were integrated into a Structural Contribution index and a Material Environmental Impact Ratio. The results show that, although CRM benefits from cold production and high recycling rates, its lower structural performance reduces its advantage when equivalent thickness is considered. HWMA emerges as the most favourable compromise within the adopted framework, combining lower environmental impacts with competitive structural performance, while HRMA offers the greatest structural contribution with competitive environmental performance. Sensitivity analysis confirms the robustness of the framework under realistic variations in weighting assumptions. The study demonstrates that incorporating structural performance into environmental assessment is essential to avoid misleading conclusions and to support more reliable decision-making in sustainable pavement design. Full article

Forecasting scrap steel prices is crucial for the economic sustainability of recycling operations, yet it remains challenging due to inherent volatility and non-stationary behavior. In this study, we develop and evaluate a delta-targeted Hybrid forecasting pipeline for short horizons of 1, 3, and 7 days. We benchmark classical baselines (Naive, Seasonal Autoregressive Integrated Moving Average (SARIMA), and Exponential Smoothing (ETS)) against recurrent deep learning models (Simple Recurrent Neural Network (RNN), Gated Recurrent Unit (GRU), and Long Short-Term Memory (LSTM)) and recent neural forecasting baselines, including Decomposition-Linear (DLinear), Convolutional Kolmogorov–Arnold Network (C-KAN), and Neural Basis Expansion Analysis for Time Series (N-BEATS), using real-world daily scrap steel price data. The results indicate that delta-targeting generally yields more stable predictive performance than direct raw-price forecasting as the prediction horizon increases. For example, at the 7-day horizon, the predictive fit improves from approximately $R^2\approx 0.87$ for raw-price LSTM to around $R^2\approx 0.90$ for delta-trained recurrent models. At the same horizon, a delta-based RNN achieves the lowest Mean Absolute Percentage Error (MAPE) among the evaluated models (approximately $1.39\%$), while the proposed Hybrid model remains competitive across all tested horizons and maintains a goodness-of-fit of approximately $R^2\approx 0.90$ without uniformly minimizing point error relative to the best-performing recurrent baseline. Attention profiling and permutation-based feature importance analyses indicate that the model places relatively higher weight on calendar-related inputs, consistent with the presence of weekly patterns in the data; these results should be interpreted as sensitivity diagnostics rather than causal evidence. Overall, the findings suggest that delta-transformed targets provide a more suitable prediction space than raw-price targets for short-horizon scrap steel forecasting, while the Hybrid design offers a balanced combination of predictive performance and diagnostic interpretability for operational decision support. Full article

Background: Macrophages were long regarded as passive executors of erythrophagocytosis responsible for systemic iron recycling. However, increasing evidence has reframed them as immunometabolic hubs that sense diverse environmental cues to modulate systemic iron homeostasis. Main body: This review examines the molecular architecture underlying macrophage iron metabolism and outlines how iron metabolic processes are dynamically regulated across spatial and temporal scales through the integration of mechanotransductive, mitochondrial, and epigenetic signaling pathways. Across disease contexts, macrophage iron handling displays marked heterogeneity, exemplified by contact-dependent iron transfer in tumors and ferroptosis-driven instability in cardiovascular disease. In cardiovascular pathologies, iron overload is associated with enhanced ferroptosis-related cascades that contribute to atherosclerotic plaque instability. Furthermore, at mucosal interfaces, host–pathogen competition over nutritional immunity highlights epigenetic strategies by which pathogens perturb host iron machinery. Conclusions: Linking these mechanistic insights to clinical translation, emerging therapeutic strategies are discussed that move beyond non-specific systemic iron chelation toward more targeted interventions. These include engineering macrophages for targeted drug delivery, exploiting nanomedicine-based redox modulation to influence macrophage phenotypes, and non-invasive regulation via the gut microbiota–epigenetic axis. Collectively, elucidating macrophage iron metabolic networks provides a conceptual framework for the development of precision approaches to inflammatory, metabolic, and malignant diseases. Full article

The rapid accumulation of plastic waste has become a major environmental concern, while at the same time, it is necessary to create opportunities to rethink how these materials can be reintegrated into productive use, particularly within the construction sector. This study provides a sustainability-oriented review of the reuse of plastic waste, both fossil-based plastics and bioplastics, as building materials, with a specific emphasis on structured decision-support approaches. A systematic literature review was conducted to identify and analyze peer-reviewed studies examining the incorporation of plastic waste into construction applications, including composites, panels, insulation systems, and structural or non-structural components. Particular attention is given to research applying Multi-Criteria Decision Analysis (MCDA) and SWOT analysis as tools for evaluating sustainability performance across environmental, economic, technical, and social dimensions. The findings indicate that recycled plastic and bioplastic-based construction materials can deliver significant advantages, such as diverting waste from disposal pathways, reducing reliance on virgin resources, and, in certain cases, enhancing durability. However, these materials also face important challenges, including limitations in recyclability, concerns related to fire performance, regulatory acceptance, and uncertainties in end-of-life management. MCDA-based studies underscore the critical role of criteria selection and weighting, especially regarding environmental impact reduction and cost competitiveness, in shaping final rankings and decision outcomes. SWOT analyses, in turn, offer complementary strategic insights by highlighting issues related to market readiness, regulatory frameworks, and implementation barriers. By integrating these decision-oriented evaluation approaches, this review contributes to more transparent and evidence-based material selection processes and supports policy development aimed at strengthening circular economy strategies for plastic waste reuse in the built environment. Full article

Reducing the ecological footprint of aviation is a key objective in the development of future aircraft. This is particularly relevant in the emerging field of Urban Air Mobility, which demands sustainable yet industrially feasible solutions due to expected high production rates. As part of the cooperative research project KONKAV, innovative materials and manufacturing methods are being explored to meet these demands. One such approach is the partial consolidation of nonwovens made from recycled carbon fibers, aimed at producing multifunctional, recyclable components for Urban Air Mobility cabin linings for high bending stiffness requirements. This study presents the experimental characterization of various nonwoven architectures, focusing on how different levels of consolidation affect their specific mechanical properties. The partially consolidated structure enables tailored stiffness profiles, making it possible to optimize structural performance while integrating functions such as thermal insulation and acoustic damping directly into the lining. An analytical material model has been developed by analyzing the experimental results. The findings demonstrate that partially consolidated nonwovens can achieve a competitive stiffness-to-weight ratio, with advantages over conventional glass-fiber-reinforced composites in terms of eco-efficiency and circularity. The proposed construction method offers potential for cost-effective, lightweight solutions that support closed-loop material use in aviation interiors. Full article

Electric two-wheelers (E2Ws) are promoted as lower-emission options in emerging economies. Their long-term cost competitiveness depends mainly on battery durability and how batteries are managed at the end of their life. This research examines Li-ion and nickel-cobalt-manganese (NCM)-type batteries versus the previously common lead-acid batteries in these markets. The study uses a 12-year total cost of ownership (TCO) framework that includes battery degradation, estimated first-life duration, and alternative lifecycle pathways. It covers three sensitivity analysis cases: conservative, base case, and optimistic. Three scenarios are evaluated: (1) no lifecycle management, (2) refurbishment for first-life extension, and (3) integrated lifecycle management with refurbishment, second-life utilisation, and recycling. Results show that managing the battery lifecycle can reduce TCO. The amount of reduction depends on first-life duration, ownership horizon, refurbishment cost, downstream residual value, and use intensity. The greatest TCO gains are found in battery categories with short first-life duration, allowing substantial residual value recovery during ownership. Batteries with first-life durations of 12 years or more provide smaller benefits. These findings support optimising lifecycle pathways for maximum residual value. Improved TCO performance, along with supportive infrastructure, policies, and market development, is critical for broader E2W adoption. Full article

The sustainable utilization of multiple reclaimed pavement materials is a critical pathway toward green highway construction. This study investigates the performance and synergistic mechanisms of cold-recycled mixtures incorporating both Reclaimed Asphalt Pavement (RAP) and Reclaimed Cement-Stabilized Base (RCSB), using emulsified asphalt as the primary binder. A comprehensive experimental program was conducted to evaluate the effects of reclaimed material proportions, mixing sequences, and curing ages on the mechanical strength, moisture susceptibility, and high-temperature stability of the mixtures. Microscopic characterization via Scanning Electron Microscope (SEM) and Energy Dispersive Spectroscopy (EDS) were employed to elucidate the Interfacial Transition Zone (ITZ) evolution. Results indicate that an optimal RCSB incorporation range of 20–40% establishes a robust “stone-to-stone” rigid skeleton, significantly enhancing the splitting strength (up to 0.87 MPa) and durability (Splitting Strength Ratio, TSR > 91%). SEM observations confirm the formation of a dense interpenetrating network structure within this range, where cement hydration products and asphalt films achieve optimal chemo-physical bonding. Exceeding 40% RCSB leads to a moisture-starved state and a sharp decline in dynamic stability due to insufficient binder coating. Micro-morphological characterization reveals that the transition from macro-interfacial debonding to a robust cohesive failure mode is the fundamental driver for the performance peak at 20–40% RCSB. SEM observations confirm the formation of a dense interpenetrating network structure, where cement hydration products successfully anchor into the asphalt film. This optimized ITZ effectively eliminates the stress concentration and aggregate crushing seen in high-RAP mixtures, thereby ensuring superior mechanical integrity. Furthermore, a pre-wetting mixing sequence ensures a high-energy mineral surface that promotes the heterogeneous nucleation of cement. SEM results show that this prevents the competitive adsorption between cement and asphalt, transforming the ITZ from a friable, loose state into a densified crystalline adhesive matrix. Full article

This study develops a Life-Cycle Sustainability Framework for circular business models in the context of post-war economic reconstruction and sustainable value chain transformation. Ukraine is used as the main case study due to its post-war reconstruction context and the need for resource-efficient economic recovery strategies. Under conditions of disrupted supply systems, resource constraints, and structural economic change, circular economy principles are conceptualized as strategic mechanisms for enhancing resilience, resource efficiency, and long-term competitiveness rather than solely as environmental policy instruments. Building on a structured hierarchy of circular business models aligned with product life-cycle stages, the framework emphasizes value retention through functional and usage extension beyond material recovery. The framework includes a hierarchical classification of 12 circular business models and a sustainability evaluation approach based on four criteria (K1–K4), which allow for the comparative assessment of circular business models and their combinations across life-cycle stages. Using secondary statistical data and policy review as analytical inputs, the study identifies sectors with high potential for circular transformation and sustainable investment, including agriculture, energy, industry, construction, and logistics. The results indicate that circular business models applied at early life-cycle stages, such as reuse, repair, and remanufacturing, provide the highest potential for reducing resource intensity and improving long-term economic sustainability, while recycling and energy recovery play a supporting role. These findings highlight how life-cycle-oriented circular strategies can support sustainable reconstruction pathways, strengthen international cooperation, and inform policy and managerial decision-making in transitional economic contexts. Full article