Search Results (1,140)

To overcome the limitations of conventional biopolymer films and reduce reliance on petroleum-based plastics, a nacre-inspired film was developed via 3D printing. During printing process, shear-induced alignment of mica flakes was achieved within a sodium alginate/xanthan gum matrix. Additionally, zinc oxide nanoparticles (ZnO NPs) were incorporated to achieve a synergistic reinforcement effect. Structural analysis revealed that the mica flakes within the film exhibited an oriented distribution, with ZnO NPs uniformly embedded in the interlayer voids, and hydrogen bonding assisted in forming a dense network of the components. Performance testing showed that the tensile strength rose from 13.8 MPa to 62.9 MPa. Improvements in water resistance and thermal stability were also observed. Furthermore, the material exhibited outstanding comprehensive protective properties, including a low water vapor permeability value of 7.587 × 10⁻¹¹ g·m/m²·Pa·s, an ultraviolet blocking rate of 99.37% at a wavelength of 280 nm, and the ability to completely inhibit target bacterial strains, while also possessing good biodegradability and recyclability. Shelf-life tests indicated that the film fabricated in this work could notably prolong the shelf life of strawberries. Biocompatibility test results indicated that the film was safe and non-toxic, and showed no significant cytotoxicity. Full article

Glutathione is an abundant intracellular low-molecular-weight thiol that contributes importantly to cellular redox homeostasis. Besides its well-established role in the antioxidant defense of the cell, glutathione regulates mitochondrial function, metabolism of toxicants, protein thiol oxidation/reduction, redox signaling, and immunity. Disturbances in glutathione metabolism have been shown to play a role in various diseases; however, it has become clear that changes in glutathione metabolism are a part of a complex, multifactorial process. In this review, we summarize current knowledge of the molecular mechanisms governing glutathione synthesis, recycling, compartmentalization, and biological functions, with particular emphasis on redox signaling, the nuclear factor erythroid 2-related factor 2/Kelch-like ECH-associated protein 1 (Nrf2/Keap1) pathway, and reversible protein S-glutathionylation. We further examine how disturbances in glutathione homeostasis interact with mitochondrial dysfunction, chronic inflammation, metabolic stress, and impaired cellular signaling in Parkinson’s disease, Alzheimer’s disease, Huntington’s disease, multiple sclerosis, Wilson’s disease, type 2 diabetes, and nonalcoholic fatty liver disease. We also evaluate current translational interventions targeting restoration of glutathione balance through glutathione supplementation, precursor supplementation, pharmacological modulation of endogenous antioxidant mechanisms, dietary interventions, and changes in lifestyle. Despite the fact that many interventions have been promising at the mechanistic and experimental level, there are still insufficient clinical data because of the problems associated with glutathione availability, tissue specificity, disease variability, and a lack of sufficiently powered clinical trials. The conclusion of this review is that glutathione should not be viewed as a universal therapeutic target; instead, glutathione should be perceived as an important factor contributing to cellular resilience and able to help other disease-specific interventions. Future progress in glutathione-based interventions will likely depend on integrating redox biomarkers, patient stratification, and precision medicine strategies to identify individuals most likely to benefit from targeted modulation of glutathione homeostasis. Full article

Steel production contributes significantly to global resource consumption and accounts for nearly 8% of worldwide CO₂ emissions. As the construction industry moves toward decarbonization, the reuse of structural steel has emerged as a highly impactful strategy for reducing embodied carbon and extending material life cycles. However, most end-of-life structures are still demolished using conventional methods that prioritize recycling for scrap value rather than recovering reusable steel components, resulting in the loss of high-quality material and reduced environmental and economic benefits. Despite growing interest in circular construction, systematic analyses of real-world structural steel reuse projects remain limited. This restricts the understanding of the practical conditions required for scalable implementation. Moreover, there is a lack of structured approaches for identifying the factors influencing deconstruction and large-scale structural steel reuse across reverse supply chains. This study addresses these gaps by developing a framework of factors affecting efficient deconstruction and structural steel reuse, identified through a thematic analysis of the literature and structured around structure attributes, business attributes, value chain activities, project management, and regulations. Fifteen case studies were analyzed: two from North America, twelve from Europe, and one from Asia. A structural steel reuse classification model is introduced to support cross-case comparison of coordination demands, implementation barriers, and scalability potential within reverse supply chains. The results demonstrate that reuse pathways differ substantially in coordination requirements, implementation complexity, and scalability outcomes. They further indicate that the dominant challenges to structural steel reuse are no longer primarily technical, but instead stem from system-level coordination gaps, limited information availability, and insufficient integration across reverse supply chains. Based on these findings, targeted solutions are identified, including improved dismantling strategies, enhanced documentation systems, dedicated storage infrastructure, and stronger regulatory alignment. This study provides a structured analytical approach and practical recommendations to support decision-making, stakeholder coordination, and the scalable implementation of structural steel reuse. Full article

The whole pavement life cycle is divided into five phases: raw material production, construction, service use, maintenance and rehabilitation, and end-of-life (EOL). Distinct system boundary definitions (cradle to gate, cradle to site, cradle to grave) are clearly distinguished, and two categories of vehicle-related emissions are strictly differentiated: baseline vehicle operation emissions (excluded) and pavement-induced incremental emissions (included only for full cradle-to-grave accounting). According to cited highway pavement inventory data (functional unit: 1 m² full cross-section composite pavement, cradle-to-gate material-only boundary), cement-related materials account for merely 4.7% of total structural material mass yet contribute over 84.5% of material-phase carbon emissions, while asphalt mixture construction emissions generally make up less than 10% of mixing-stage outputs. In the use phase, pavement deformation, rolling resistance elevation and surface texture loss trigger extra vehicle fuel consumption and associated greenhouse gas increments. Maintenance-stage emissions stem from repair material manufacturing, on-site machinery operation and traffic congestion delays during lane closure; milling, transportation and recycling dominate EOL carbon outputs. This review further classifies all emissions into direct engineering emissions and pavement-derived indirect emissions, compares carbon performance and service-life extension effects of eight mainstream maintenance strategies, and thoroughly decomposes milling, stockpiling, haulage and recycling links of waste asphalt, alongside multiple environmental burden allocation methods for reclaimed asphalt pavement (RAP). A full spectrum of green low-carbon technologies is summarized, including biochar bio-materials, RAP, crumb rubber, industrial byproducts, warm-mix asphalt (WMA), cold recycling and CCUS negative-carbon materials. We also balance their emission reduction benefits against potential deterioration risks to rutting resistance, fatigue life and moisture stability. Combined with a life-cycle cost assessment (LCCA), this study analyzes cost-emission trade-offs of all technical routes, and deeply discusses multi-source uncertainty, sensitive input parameters and universal methodological limitations of pavement LCA. Core takeaways indicate that raw material production and long-term service use are the two dominant carbon emission stages; a medium RAP-WMA combination and cold in-place recycling represent the most economically and environmentally balanced mitigation solutions. Major research gaps and targeted future research directions are proposed, providing standardized theoretical support and dual environmental–economic decision references for low-carbon asphalt pavement design and full-life carbon accounting. Full article

The construction sector generates over one-third of all waste in Europe, yet the reuse of building components remains marginal compared to recycling, and circular strategies are rarely aligned on the territorial scale at which materials, stakeholders and infrastructure operate. This paper investigates the regulatory, institutional, infrastructural and operational conditions under which reuse to become a systemic practice. A desk-based comparative analysis of six European contexts (Belgium, the Netherlands, Switzerland, Germany, France, Denmark) was conducted on 282 documents, using a framework of seven dimensions grouped into three macro-families drawn from the literature on territorial circular ecosystems. The findings show that these conditions form a dependency chain of five ordered links: legal recognition of the non-waste status; a standardized pre-demolition audit; preparation and storage physical hubs, in parallel with research infrastructures, absorbing technical uncertainty; a guarantee system covering performance, liability and insurability; and a demand-side activation. The guarantee link is a constraint and a key element in demand activation. Regulation is necessary but not sufficient, since binding instruments target recycling or auditing while reuse remains voluntary in all six contexts. The chain yields a typology of ecosystem configurations and a replicable diagnostic instrument, whose transferability is assessed on the Italian case. Full article

In the present work, polyvinylpyrrolidone (PVP) was selected as the primary raw material and fully dissolved in N,N-dimethylformamide (DMF) solvent. Hydroxymethyl cellulose (HMC), acrylic acid (AA) monomer with outstanding chelating performance, and UR were added in sequence. On this basis, composite nanofiber membrane substrates of PVP/AA/HMC/UR were fabricated by means of electrospinning. Afterwards, silane coupling agent KH-560 was blended with polylactic acid (PLA). A uniform PLA/KH-560 functional coating was covered on the surface of the as-prepared nanofiber membrane via microfluidic coating treatment, and the target composite nanofiber adsorbent was ultimately obtained. Relevant performance characterization results indicated that moderate addition of HMC could greatly optimize the tensile strength of the membrane material, whereas excessive HMC dosage would cause a deterioration in mechanical strength. Moreover, the breaking elongation presented a slight declining trend, and the integrated mechanical stability of the membrane could fully meet the service demands for cyclic reuse. As a functional monomer, acrylic acid effectively boosted the material’s adsorption performance toward typical heavy metal ions, including Zn²⁺, Cu²⁺ and Pb²⁺. In simulated acidic wastewater generated from rare earth mining and extraction (pH = 3 and pH = 6.5), the removal efficiency of the as-prepared material for the three heavy metal ions all exceeded 95%. Even after being soaked in strong acid solution at pH 2 for 8 h, its adsorption rate was still maintained at 88.5%. In the cyclic experiment, the adsorption efficiency stayed above 75% after two recycling runs, decreased to roughly 55% in the third cycle, and dropped below 30% at the fourth reuse stage. The introduction of UR imparted remarkable acid-resistant structural stability to the composite material. The membrane structure remained complete without damage after long-term immersion in a pH 2 strong acid environment, and high-efficiency heavy metal removal capability could be guaranteed when the solution pH was not lower than 3. Targeting the practical treatment dilemma of acidic heavy metal-containing wastewater from rare earth exploitation and extraction, this research successfully developed a novel eco-friendly adsorbent featuring superior acid resistance, high adsorption performance and certain recyclability. This newly designed material makes up for the deficiencies in traditional adsorbents represented by activated carbon, including poor heavy metal removal ability in acidic media and secondary pollution risks resulting from disposable use. The research findings can offer a novel technical reference and feasible approach for the purification of acidic rare earth wastewater in practical engineering applications. Full article

This study investigates the influence of Lewis acids on a novel stratified (Co²⁺,Pd²⁺)₂SiO₄-Pd⁰ olivine catalyst for the Heck–Mizoroki coupling of iodobenzene and methyl acrylate. Comprehensive characterization (ICP-OES, Raman, P-XRD, XPS) confirms the successful synthesis of a material with surface-incorporated Pd²⁺ and bulk Pd⁰ nanoparticles within a Co₂SiO₄ matrix. The promoter-free system with triethylamine base achieved the highest initial rate of 3.92 × 10⁻⁷ mol.s⁻¹ with an average rate of 1.18 × 10⁻⁷ mol.s⁻¹, despite a 30 min induction period. However, ZnCl₂, the weakest acid, showed the most substrate activation and lowered the induction period to 10 min, while AlCl₃ also reduced the induction period to 20 min. FeCl₃ showed the poorest performance, attributed to redox-mediated site poisoning rather than hydrolysis. Selectivity over the catalyst was maintained at >99 mol% towards methyl cinnamate irrespective of the Lewis acid or base used. However, recycling of the catalyst led to a gradual decrease in selectivity toward methyl cinnamate from >99 mol% to ~94.6 mol% over three cycles, while conversion remained consistently high at >99 mol% across all cycles, indicating that the catalyst’s primary activity was largely preserved despite surface evolution toward side-product formation. Lewis acids were found to function primarily as surface modifiers and/or productive substrate activators, with stronger Lewis acids also targeting the olivine framework, as seen from the preferential leaching of Co relative to Pd. Full article

There is a large and rapidly growing stock of retired power batteries from new energy vehicles in China. Unregulated informal recycling and improper disposal of these waste batteries trigger serious environmental hazards. Though a batch of regulatory policies on battery recycling have been released in recent years, the power battery recycling sector still faces prominent governance bottlenecks, especially ambiguous responsibility division and poor implementability under the entrusted recycling mode. To fill the existing research gap regarding tripartite interest conflicts and pricing mechanisms in entrusted recycling, this paper constructs a three-party evolutionary game model covering power battery producers, recyclers and government regulators. Two pricing models are further developed to distinguish producer self-operated recycling and third-party entrusted recycling channels. Numerical simulation is adopted to investigate multi-stakeholder interest contradictions, dynamic evolutionary trajectories and equilibrium stability of the recycling system, and the influences of subsidy intensity, supervision intensity and recycling cost on participants’ strategic choices are quantitatively analyzed. The research results demonstrate that inadequate government supervision and insufficient economic returns for formal recyclers serve as the primary obstacles hindering the effective deployment of entrusted recycling. An inherent and reasonable price gap exists between self-operated and entrusted recycling modes. Essentially, the price differential of standardized entrusted recycling represents the profit margin conceded by producers to recyclers instead of direct financial subsidies. To solve existing industry problems, this study proposes targeted recommendations for tripartite collaboration. The government should refine the regulatory framework of Extended Producer Responsibility and adopt differentiated reward and penalty mechanisms. Producers are expected to standardize entrusted recycling management and formulate a scientific pricing range for retired batteries. Recyclers ought to advance recycling technologies and maintain standardized operations. Collective efforts from all stakeholders can facilitate the long-term sustainability of the closed-loop recycling system for retired power batteries. Full article

Driven by global carbon neutrality targets, the low-carbon transformation of power systems necessitates rigorous carbon evaluation of grid infrastructure. However, existing assessments of overhead transmission lines often exhibit incomplete life-cycle boundaries and lack a coordinated approach to subjective and objective weight allocation. To address these gaps, this study targets overhead transmission lines and constructs a comprehensive low-carbon evaluation index system comprising 14 indicators across four life-cycle stages, namely design, construction, operation, and recycling. A hybrid evaluation model is proposed based on the combined analytic hierarchy process and entropy weighting method. The analytic hierarchy process is utilized to derive expert-based subjective weights, while the entropy weighting method extracts objective data variations from multiple samples, which are then integrated to obtain robust composite weights. An empirical analysis conducted on a 500 kV double-circuit overhead transmission line project in China validates the proposed framework. The results reveal a comprehensive evaluation score of 80.219, corresponding to a “low-carbon” grade. Moreover, the line loss rate (0.234227), operational carbon emissions (0.133978), and steel consumption per unit length (0.122381) are identified as the pivotal indicators dominating the evaluation outcome. This research provides quantitative support and practical criteria for decision-making regarding low-carbon design, green construction, operational loss reduction, and resource-oriented retirement of transmission line projects. Full article

Critical raw materials (CRMs) sit at the intersection of industrial strategy, climate policy, sustainable development, and geopolitics. This paper reviews how the concept has evolved since the 1939 US Strategic and Critical Materials Stock Piling Act, tracing the gradual addition of economic, energy, technological, environmental, and sustainability criteria to the original military framing. It then compares the methodologies developed by the European Union and the United States over the last fifteen years. The EU has published five consecutive lists between 2010 and 2023; the US has produced parallel frameworks through the U.S. Geological Survey and the Department of Energy, each weighing supply risk, economic importance, environmental impact, and clean energy relevance differently. The 2023 EU list is examined in detail, including the addition of copper and nickel on strategic rather than quantitative grounds. Convergences and divergences across the three frameworks are discussed, alongside their alignment with the United Nations Sustainable Development Goals—particularly SDG 7, SDG 9, SDG 12, and SDG 13—and the progressive integration of circular economy targets, recycling indicators, and environmental impact considerations into criticality assessment. The analysis shows that sustainability has become a structural axis of CRM policy rather than a peripheral concern. The review provides the methodological background for a companion paper that applies the EU methodology to resource-rich Latin American countries (Chile, Brazil, and Peru). Full article

This study examines the role of the ethics of responsibility at individual, societal, and institutional levels and explores its potential to address the ethical challenges of the contemporary world. This ethical framework requires individuals and institutions to consider not only their own interests but also the long-term societal and environmental consequences of their decisions. The study explores how this approach provides guidance in the contexts of technological innovations, environmental crises, and globalization. Technological developments are presented as a domain that both expands the scope of ethics of responsibility and introduces new ethical challenges. It is emphasized that artificial intelligence (AI) systems may give rise to issues such as bias, data privacy violations, and the spread of misinformation through digital platforms. In this context, the necessity of designing “fair AI” and ensuring that digital platforms operate in alignment with ethical principles is emphasized. From the perspective of environmental sustainability, it is stated that while individual efforts, such as recycling and energy conservation, are important, institutions must focus on large-scale initiatives, such as carbon-neutral targets and circular economy models. The article also addresses the criticisms and challenges associated with implementing this framework. The subjective nature of ethical principles and the conflict between diverse cultural values make the universal adoption of this approach difficult. Additionally, the prioritization of individual interests within the capitalist system and the inadequacy of global cooperation are seen as major obstacles to the practical application of ethics of responsibility. This situation underscores the importance of both individual awareness and institutional policies. In conclusion, this framework is presented as an important guide capable of addressing the complex issues of the contemporary world. It is argued that the broader application of this approach is essential in areas such as technological advancements, environmental crises, and global inequalities. Fulfilling the ethical responsibilities of individuals, institutions, and the international community is critical for creating a more equitable and sustainable world. Full article

This paper examines the role of fiscal policy in shaping CO₂ emissions for a sample of 23 countries, including the Euro Area, the United States, Canada, and China, over the period 2000–2023. The analysis moves beyond aggregate fiscal measures to identify taxes and expenditure categories contributing most to reduce CO₂ emissions. We investigate the transmission channels through which fiscal policy affects environmental outcomes and address potential non-linear fiscal effects. The study also highlights the critical role of recycling fiscal resources toward environmentally relevant expenditures. The System GMM results suggest that some market-based mechanisms and targeted public expenditure contribute to reducing CO₂ emissions, while other fiscal tools exhibit opposite or context-dependent effects. A non-linear relationship is detected for compliance emissions. Moreover, results reveal that supply-side and demand-side transmission channels generate contrasting effects on emissions. Finally, the effectiveness of environmental fiscal policies is shown to depend critically on the pattern of fiscal revenue recycling. These results provide important insights for the design of effective fiscal strategies aiming to achieve climate objectives. Full article

This study investigates the flow and economic valuation of recyclable materials across fifteen Secondary Transfer Stations (STSs) in Dhaka North City Corporation (DNCC), Bangladesh, with the aim of understanding how market dynamics influence material recovery and circular economy potential. Primary data were collected through field surveys, structured questionnaires administered to 50 waste workers, five waste dealers and five local traders. Recovered materials were classified into six major categories, paper, plastic, metal, glass, electronic waste (e-waste), and other materials with further sub-categorization, to capture price variations and material characteristics. The results reveal a highly differentiated recycling market, with prices varying by more than an order of magnitude across materials. High-value materials, including copper wire, scrap aluminum, scrap metal, and electrical wire, are consistently recovered, whereas medium-value materials such as HDPE, PET, polypropylene, PVC, LDPE, Styrofoam, plastic crates, and mixed plastics are recovered selectively depending on market demand. In contrast, low-value materials, including packaging cartons, white paper, glass items, mixed LDPE, damaged LED lights, and mixed wastepaper, are frequently discarded due to weak economic incentives. Despite spatial and socioeconomic differences across STSs, price variability remains relatively low, indicating an integrated city-wide recycling market driven by active trader networks and broader commodity trends. To the best of our knowledge, this is one of the first studies to integrate recyclable material flow with economic valuation across multiple STSs in Dhaka. The findings highlight that recovery efficiency is strongly governed by economic value and informal practices, with limited segregation efficiency and inadequate occupational safety conditions. Enhancing source segregation, improving storage infrastructure, and introducing targeted market and policy interventions for low-value materials are critical for advancing Dhaka’s transition toward a circular and resource-efficient urban waste management system. Full article

The transition to a circular economy (CE) is central to achieving SDG 12, yet institutional transformation varies significantly across countries. This study conducts a comparative institutional analysis of CE transitions in China and Russia to quantify Russia’s institutional lag and assess the maturity of both systems in the context of SDG indicator 12.5.1 (Circular Material Use Rate—CMUR). Drawing on neo-institutional theory, multi-level governance, and institutional trap theory, we develop an original methodology that computes institutional lag through three key milestones, an integrated maturity index across eight institutional components, and CMUR estimates based on official statistics, legislative acts (1998–2025), and industry reports. Our results show that Russia’s average institutional lag relative to China is 15.3 years: Russia’s 2024 municipal solid waste recycling rate (13.9%) matched China’s 2009–2010 level, while China achieved Russia’s 25% target for 2030 in 2018. The integrated maturity index is 8.25 for China versus 5.25 for Russia, with the largest gaps in industrial symbiosis, R&D and human capital, and international integration. Russia’s CMUR stands at 5–7%, compared to 25–30% in China. We also demonstrate that Russia’s high recycling growth is driven by a low-base effect and is not evidence of institutional efficiency; the compound annual growth rate (CAGR) of Russian recycling volume (33.0%) significantly exceeds China’s (13.1%), but this reflects the much lower starting point rather than systemic maturity. We conclude that without systemic institutional reforms—including eco-industrial parks, green finance, and competence centres—Russia will remain at an early CE stage, failing to substantially contribute to SDG 12 by 2030. Full article

Ion-imprinted polymers (IIPs) are advanced adsorbents featuring selective recognition cavities for targeted metal ion capture, offering a promising route to high-efficiency separation in extractive metallurgy. In the present work, the evolution, design principles, synthesis strategies, separation mechanisms, and practical applicability of IIPs for metal recovery from complex aqueous matrices are overviewed. Key material components, including functional monomers, crosslinkers, template ions, initiators, solvents, and support materials, are discussed in relation to adsorption capacity, selectivity, kinetics, stability, and recyclability. Major preparation routes, such as surface imprinting, bulk polymerization, in situ polymerization, and sol–gel methods, are critically compared to clarify their advantages and limitations. Recent applications for base metals, precious metals, and rare-earth elements demonstrate that IIPs can achieve high specificity and rapid equilibrium under optimized conditions. However, their translation from simulated solutions to real leachates remains constrained by interfering ions, organic contaminants, mass transfer resistance, incomplete template removal, and matrix complexity. Mitigation strategies, including sample pretreatment, improved polymer architecture, and hybrid supports, are therefore emphasized. Additionally, chemometric modelling, machine learning, or artificial intelligence-assisted design may be implemented to advance the prospects of IIPs in industry. Conclusively, IIPs represent a strong separation platform, yet industrial deployment requires robust validation with real feed streams and scalable regeneration protocols during column operation, as well as under chemically aggressive conditions at scale. Full article