Search Results (12,850)

The generation of solid waste and the use of non-renewable natural resources in the foundry industry are environmental challenges that require the search for solutions that guarantee the application of circular economy and cleaner production principles. Studies on the reuse of Foundry Sand Waste (FSW) generated in this process can guarantee the minimization of the current environmental impact and contribute to the achievement of sustainability in the industrial sector. The objective of this study is to assess the feasibility of utilizing WFS in the construction of pavement bases and sub-bases, in combination with sandy soil and hydrated lime. The laboratory experimental program included the evaluation of compaction characteristics, California Bearing Ratio (CBR), compressive strength, and resilient modulus. The results indicate that the addition of 25% and 50% WFS yields predicted performance levels ranging from good to excellent. The inclusion of hydrated lime enables the mixtures to be employed in sub-bases and bases, while the increased WFS content further enhances load-bearing capacity by up to 60% and 75% for 25% and 50% WFS, respectively. Full article

With the planning and construction of marine ranching in China, water quality has become one of the critical limiting factors for the development of marine ranching. Due to geographical differences, marine ranches exhibit varying water quality conditions under the influence of the continental shelf. To the best of our knowledge, there is limited research on satellite-based water quality monitoring for marine ranching and the spatiotemporal variations in marine ranches in different geographical locations. Chlorophyll-a (Chl-a) is a key indicator of the ecological health and disaster prevention capacity of marine ranching, as it reflects the conditions of eutrophication and is crucial for the high-quality, sustainable operation of marine ranching. Using a physically based model, this study focuses on the retrieval of Chl-a concentration in Daya Bay. The coefficient of determination (R²) between the model retrieval values and the in situ Chl-a data is 0.69, with a root mean square error (RMSE) of 1.52 μg/L and a mean absolute percentage error (MAPE) of 44.25%. Seasonal variations in Chl-a concentration are observed in Daya Bay and are higher in spring–summer and lower in autumn–winter. In the YangMeikeng waters, Chl-a concentration shows a declining trend with the development of marine ranching. A comparison between the YangMeikeng (nearshore) and XiaoXingshan (offshore) marine ranches suggests that offshore ranching may be less impacted by terrestrial pollutants. The primary sources of Chl-a input in Daya Bay are the Dan’ao River and the aquaculture areas in the northeastern part of the bay. This study can provide valuable information for the protection and management of marine ranching. Full article

Urban green space systems (UGSS) play a crucial role in enhancing citizens’ well-being and promoting sustainable urban development through their ecosystem service values (ESV). However, understanding the spatiotemporal changes, driving factors, and influencing mechanisms of ESV remains a critical challenge for advancing urban green theories and formulating effective policies. This study focuses on Suzhou, China’s third-largest prefecture-level city by economic volume and ecological core city of the Taihu watershed, to evaluate the ESV of its UGSS from 2010 to 2020, identify key driving factors, and analyze their influencing mechanisms. Using the InVEST model combined with the entropy weight method (EWM), we assessed the ESV changes over the study period. To examine the influencing mechanisms, we employed an innovative XGBoost-GWR approach, where XGBoost was used to screen globally significant factors from 37 potential drivers, and geographically weighted regression (GWR) was applied to model local spatial heterogeneity, providing a research perspective that balances global nonlinear relationships with local spatial heterogeneity. The results revealed three key findings: First, while Suzhou’s UGSS ESV increased by 9.92% from 2010 to 2020, the Global Moran’s I index rose from 0.325 to 0.489, indicating that its spatial distribution became more uneven, highlighting the increased ecological risks. Second, climate, topography, landscape pattern, and vegetation emerged as the most significant driving factors, with topographic factors showing the greatest variation (the negatively impacted area increased by 455.60 km²) and climate having the largest overall impact but least variation. Third, the influencing mechanisms were primarily driven by land use changes resulting from urbanization and industrialization, leading to increased ecological risks such as soil erosion, pollution, landscape fragmentation, and habitat degradation, particularly in the Kunshan, Wujiang, and Zhangjiagang Districts, where agricultural land has been extensively converted to constructed land. This study not only elucidates the mechanisms influencing UGSS’s ESV driving factors but also expands the theoretical understanding of urbanization’s ecological impacts, providing valuable insights for optimizing UGSS layout and informing sustainable urban planning policies. Full article

The construction of circular economic models in industry represents a critical mechanism for achieving sustainable development goals. However, data on the development of the circular economy, derived from diverse metrics and assessment methodologies, often yield contradictory results. In light of this, the study suggested a new approach to evaluating the potential for circularization. This approach entails identifying key factors influencing circularization and assessing their suitability for the implementation of circular models of different levels. The study identified factors and indicators of the potential for industrial circularization at the regional level. The paper proposed a classification of circular economy models that simultaneously take into account the length of the production cycle and the degree of proximity to the circular economy. The rating method is employed to evaluate the potential of a region for the successful implementation of circular economy models. The rating is calculated by constructing both a general integral circularization potential index and individual sub-indices. The application of this methodology enabled the development of a ranking of Russian regions based on their potential for industrial circularization. To make recommendations, the analyzed regions were divided into four groups, according to an evaluation of the circularization potential. Full article

The study of ecological security patterns is of great significance to the balance between regional economic development and environmental protection. By optimizing the regional ecological security pattern through reasonable land-use planning and resource management strategies, the purpose of maintaining ecosystem stability and improving ecosystem service capacity can be achieved, and ultimately regional ecological security can be achieved. As a typical ecological civilization city in the middle reaches of the Yangtze River, Yichang City is also facing the dual challenges of urban expansion and environmental pressure. The construction and optimization of its ecological security pattern is the key to achieving the harmonious coexistence of economic development and environmental protection and ensuring regional sustainable development. Based on the ecological environment characteristics and land-use data of Yichang City, this paper uses morphological spatial pattern analysis and landscape connectivity analysis to identify core ecological sources, constructs a comprehensive ecological resistance surface based on the sensitivity–pressure–resilience (SPR) model, and combines circuit theory and Linkage Mapper tools to extract ecological corridors, ecological pinch points, and ecological barrier points and construct the ecological security pattern of Yichang City with ecological elements of points, lines, and surfaces. Finally, the community mining method was introduced and combined with habitat quality to analyze the spatial topological structure of the ecological network in Yichang City and conduct ecological security zoning management. The following conclusions were drawn: Yichang City has a good ecological background value. A total of 64 core ecological sources were screened out with a total area of 3239.5 km². In total, 157 ecological corridors in Yichang City were identified. These corridors were divided into 104 general corridors, 42 important corridors, and 11 key corridors according to the flow centrality score. In addition, 49 key ecological pinch points and 36 ecological barrier points were identified. The combination of these points, lines, and surfaces formed the ecological security pattern of Yichang City. Based on the community mining algorithm in complex networks and the principle of Thiessen polygons, Yichang City was divided into five ecological functional zones. Among them, Community No. 2 has the highest ecological security level, high vegetation coverage, close distribution of ecological sources, a large number of corridors, and high connectivity. Community No. 5 has the largest area, but it contains most of the human activity space and construction and development zones, with low habitat quality and severely squeezed ecological space. In this regard, large-scale ecological restoration projects should be implemented, such as artificial wetland construction and ecological island establishment, to supplement ecological activity space and mobility and enhance ecosystem service functions. This study aims to construct a multi-scale ecological security pattern in Yichang City, propose a dynamic zoning management strategy based on complex network analysis, and provide a scientific basis for ecological protection and restoration in rapidly urbanizing areas. Full article

Magnesium phosphate cements (MPCs) are a class of inorganic cements that have gained significant attention in recent years due to their exceptional properties and diverse applications in the construction and engineering sectors, particularly in the confinement of radioactive waste. These cements set and harden through an acid–base reaction between a magnesium source (usually dead-burnt magnesia) and a phosphate source (e.g., KH₂PO₄). The dead-burnt MgO (DBM) used is typically obtained by calcining pure MgCO₃ at temperatures between 1600 and 2000 °C. The present work explores the possibility of using low-grade magnesia (≈58% MgO), a secondary waste product generated during the calcination of magnesite for sintered MgO production. Low-grade magnesia is a by-product from the calcination process of natural magnesite. In this manner, the cost of the products could be substantially diminished, and the cementitious system obtained would be a competitive alternative while enhancing sustainability criteria and recyclability. This paper also evaluates the effect of the M/P ratio and curing conditions (especially relative humidity) on the mechanical, microstructural, and mineralogical development of these cements over a period of up to one year. Results indicate that low-grade MgO is suitable for the preparation of magnesium potassium phosphate cements (MKPCs). The presence of minor phases in the low-grade MgO does not affect the precipitation of K-struvite (KMgPO₄·6H₂O). Moreover, the development of these cements is highly dependent on both the M/P molar ratio and the RH. Systems prepared with an M/P ratio of 3 demonstrated good compressive strengths, low total porosity, and stable mineralogy, which are essential parameters for any cementitious matrix that aims to be considered as a potential confiner of radioactive waste. Full article

Construction, like any other economic activity, can contribute to national income by creating employment opportunities, and raising gross domestic product (GDP). Several researchers have studied the challenges of various aspects of the construction industry (CI), ranging from sustainability, the industrial revolution, small and medium enterprise, building information modelling, and intelligent construction, but this research examines the state of the CI in conflict-affected regions by evaluating the challenging factors impacting this sector of the economy. A total of 150 industry experts participated in this survey across three regions (Africa, Eastern Europe, and the Middle East). In total, 35 challenging factors were identified and classified using exploratory factor analysis (EFA). Using version 4 of Smart Partial Least Squares (PLS), structural equation modelling (SEM) was used to build the model, which produced seven constructs: economic, environment and education, government, industrial, sustainability, technology, training and support. 31 challenging factors were outlined under these constructs, with economic challenges such as high inflation, high-interest rates, and foreign direct investment (FDI) being the most critical of those observed. This study will be of great importance to the governments of nations in the formulation of policies for the CI. At the same time, stakeholders in the CI will collaborate in the advancement of the sector in the affected region. Full article

Material selection is essential for advancing sustainability in construction. Biocomposites contribute significantly to raising the awareness of materials derived from biomass. This paper explores the design development and application of novel natural fibre pultruded biocomposite profiles in a deployable system. Development methods include geometrical studies to create a system that transforms from flat to three-dimensional. Physical and digital models were used to refine the geometry, while connection elements were designed to suit material properties and deployability requirements. The first case study, at a furniture scale, demonstrates the use of the profiles connected using threading methods to create a lightweight multifunctional deployable system enabling easy transport and storage. This system can be locked at various heights for different purposes. The realised structure weighs 4 kg, supporting weights up to 150 kg. The second case study applies the system architecturally in an adaptive kinetic facade, adjusting to the sun’s position for optimal shading, providing up to 70% daylight when open and as little as 20% when closed. These two structures validate the developed deployable system, showcasing the versatility of biocomposite profiles in such configurations. This approach enhances sustainability in architecture by enabling lightweight, adaptable, and eco-friendly building solutions. Full article

With the increasing number of anti-seepage reinforcement projects and the continuous improvement of quality requirements, high-performance and green requirements have also been put forward for grouting materials. Traditional karst cave grouting mainly uses cement-based grouting materials, which not only have high carbon emissions but also do not comply with the sustainable development strategy with regard to being green, low-carbon, and environmentally friendly. A green grouting material made by mixing a slurry A and slurry B is proposed in this paper. The solid phase of slurry A is composed of stone powder and bentonite, for which an anti-washout admixture is necessary. Slurry B is a suspension of thickener (CMC or HPMC) and anhydrous ethanol. By mixing the two slurries evenly, the grouting material is obtained. Experiments were used to investigate the ideal ratios of stone powder, bentonite, and water in slurry A, and the ratio of thickener to anhydrous ethanol in slurry B, and to analyze the development and evolution of the apparent viscosity of slurry A and slurry B after mixing. This study revealed that the optimum ratio of stone powder and bentonite was 4:1, and the most reasonable water–solid ratio was 0.8:1.0. The optimum ratio of anhydrous ethanol to CMC or HPMC in slurry B was 5:1. Slurry B was added to slurry A at a rate of 5~10% to obtain the best grouting material properties. The proposed mixed grouting material would not disperse even in flowing water and could harden and consolidate quickly. The strength of the consolidation grouting body was close to that of wet soil, which can meet requirements for tunnel construction. Full article

Graphite-phase carbon nitride (CN) has the advantages of high stability, non-toxicity, and harmlessness in degrading antibiotic pollutants in water. How to achieve the reduction of its electron-hole complexation efficiency as well as the improvement of its recyclability, while at the same time ensuring these advantages, is the focus of this paper. In this study, modified magnetic particles selected from coal gasification slag were used as carriers, which were compounded with CN and then subjected to a simple roasting process to obtain composite magnetic photocatalysts (MCN) with different ratios. The introduction of porous magnetic carriers increased the specific surface area of MCN, provided more active sites, and effectively improved the migration ability and redox capacity of CN carriers. Among them, 50% MCN showed excellent photodegradation performance, and the removal rate of tetracycline reached 82% within 60 min, which was much higher than that of CN. 50% MCN has a saturated magnetisation intensity of 1.55 emu·g⁻¹, which can be regenerated after recycling using a magnetic field, and the degradation efficiency of tetracycline is still more than 70% after five cycles, indicating that 50% MCN has good stability. This work demonstrates that magnetic gasification slag as a modified carrier can effectively promote the separation of photogenerated electron-hole pairs of graphite-phase carbon nitride, which provides a reference for the resourceful utilisation of coal gasification slag, as well as for the construction of g-C₃N₄-based photocatalysts with highly efficient and stable photodegradation activity. This work exemplifies how waste-derived materials can advance photocatalyst design, addressing both efficiency and sustainability challenges in water treatment. Full article

Based on the quasi-natural experiment of “the pilot policy of combining science and technology with finance” (Sci-Tech Finance pilot policy) carried out in China in recent years, this paper constructs a multi-stage difference-in-differences model to explore its impact on corporate ESG performance and the influence mechanisms. The main research findings of this paper are as follows: (1) The Sci-Tech Finance pilot policy significantly enhances corporate ESG performance, a finding that remains consistent after conducting parallel trends testing, propensity score matching, and placebo tests. (2) The policy promotes the corporate ESG performance through three intermediary channels, namely alleviating financial constraints, improving total factor productivity, and enhancing green technology innovation. Notably, the first two intermediary channels exhibit the most prominent effects. (3) The impact of the pilot policy on the corporate ESG performance exhibits heterogeneity at both the regional and corporate levels; it demonstrates a more pronounced impact on corporates located in the Eastern Region, within high digital economic zones, and among high-tech, capital-intensive, heavily polluting, and state-owned corporates. (4) The policy has apparent spatial spillover effects on corporate ESG performance, accounting for about 8% of the direct effect in the pilot areas. This study enriches the literature on the impacts of Sci-Tech Finance on corporate behaviors, providing insights for government regulatory authorities to leverage Sci-Tech Finance policies to promote corporate ESG performance and sustainable development. Full article

Sanitary sewer pipelines frequently experience blockages, structural failures, and overflows, underscoring the dire state of U.S. wastewater infrastructure, which has been rated a D-, while America’s overall infrastructure scores only slightly better at C-. Traditional open-trench excavation methods or excavation technology (ET) for replacing deteriorated pipes are notoriously expensive and disruptive, requiring extensive processes like route planning, surveying, engineering, trench excavation, pipe installation, backfilling, and ground restoration. In contrast, trenchless technologies (TT) provide a less invasive and more cost-effective alternative. Among these, cured-in-place pipe technology (CIPPT), which involves inserting resin-impregnated fabric into damaged pipelines, is widely recognized for its efficiency. However, a comprehensive life cycle cost analysis (LCCA) directly comparing ET and TT, accounting for the net present value (NPV) across installation, maintenance, and rehabilitation costs, remains unexplored. This study aims to establish an LCCA framework for both CIPPT and ET, specifically for sanitary sewer pipes ranging from 8 to 42 inches in diameter. The framework incorporates construction, environmental, and social costs, providing a holistic evaluation. The key costs for ET involve pipe materials and subsurface investigations, whereas TT’s costs center around engineering and design. Social impacts, such as road and pavement damage, disruption to adjacent utilities, and noise, are pivotal, alongside environmental factors like material use, transportation, project duration, and equipment emissions. This comprehensive framework empowers decision makers to holistically assess economic and environmental impacts, enabling informed choices for sustainable sewer infrastructure renewal. Full article

The United Nations Sustainable Development Goal (SDG) 11.1 emphasizes improving well-being, ensuring housing security, and promoting social equity. Informal settlements, one of the most vulnerable groups, require significant attention due to their dynamic changes and habitat quality. These areas limit the ability to comprehensively capture spatial heterogeneity and dynamic shifts in regional sustainable development. This study proposes an integrated approach using multi-source remote sensing data to extract the spatial distribution of informal settlements in Mumbai and assess their habitat environment quality. Specifically, seasonal spectral indices and texture features were constructed using Sentinel and SAR data, combined with the mean decrease impurity (MDI) indicator and hierarchical clustering to optimize feature selection, ultimately using a random forest (RF) model to extract the spatial distribution of informal settlements in Mumbai. Additionally, an innovative habitat environment index was developed through a Gaussian fuzzy evaluation model based on entropy weighting, providing a more robust assessment of habitat quality for informal settlements. The study demonstrates that: (1) texture features from the gray level co-occurrence matrix (GLCM) significantly improved the classification of informal settlements, with the random forest classification model achieving a kappa coefficient above 0.77, an overall accuracy exceeding 0.89, and F1 scores above 0.90; (2) informal settlements exhibited two primary development patterns: gradual expansion near formal residential areas and dependence on natural resources such as farmland, forests, and water bodies; (3) economic vitality emerged as a critical factor in improving the living environment, while social, natural, and residential conditions remained relatively stable; (4) the proportion of highly suitable and moderately suitable areas increased from 65.62% to 65.92%, although the overall improvement in informal settlements remained slow. This study highlights the novel integration of multi-source remote sensing data with machine learning for precise spatial extraction and comprehensive habitat quality assessment, providing valuable insights into urban planning and sustainable development strategies. Full article

With economic development and shifting consumption trends, branding has become an important way to improve the efficiency of poverty alleviation supply chains (PASCs) in practice. However, academic research on this topic is limited. To fill this gap in the literature, we constructed a differential game of a PASC that examines how to build a sustainable poverty reduction model through branding, considering government subsidies and supplier’s Nash bargaining fairness concerns. Our findings show the following: (1) Government subsidies can improve the decision-making level and channel efficiency of leading enterprises (E) and poor suppliers (F). Government subsidies are necessary for a PASC to establish a sustainable poverty alleviation mechanism. (2) F’s Nash bargaining fairness concerns only reduce their level of production effort but do not affect the brand construction and corporate social responsibility levels of E. (3) As F’s bargaining power increases, Nash bargaining fairness concerns have a more significant effect on the PASC’s performance. While F’s fairness concerns can enhance their utility to some extent, it ultimately leads to more significant profit losses for both parties. (4) The proposed mixed cost-sharing and revenue-sharing contract can effectively align members’ incentives, enhancing profitability for both parties. Full article

In an enzyme-based fuel cell system, glucose oxidase and laccase were immobilized on carbon paper as the anode and cathode electrodes. A conductive polymer (polypyrrole) was added to improve conductivity. The mediator and enzymes were mixed in a phosphate-buffer solution for entrapment. A Nafion 212 membrane separated the two half-cells. Power density measurements were taken at a glucose concentration of 10 mM across different operating voltages. Potassium hexacyanoferrate III was used as a redox mediator in the anode and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) in the cathode to boost power output. The biofuel cells, constructed from acrylic (40 × 50 × 50 mm) with a working volume of 20 × 30 × 40 mm, were assembled using a rubber gasket to secure the Nafion membrane. The use of micropore tape covering the electrodes extended the system’s operational lifespan. Without the micropore tape, the maximum power density was 57.6 μW/cm² at 0.24 V. With the micropore tape, the cell achieved a maximum power density of 324.9 μW/cm² at 0.57 V, sustaining performance for 20 days. Thus, micropore tape effectively enhances enzyme retention and biofuel cell performance. Full article