Search Results (25,209)

This study investigates the synthesis and kinetic behavior of a magnetic biochar derived from avocado seed biomass for the removal of hexavalent chromium (Cr(VI)) from aqueous solutions. Magnetite (Fe₃O₄) was synthesized through different routes, including nitrogen-assisted coprecipitation, redox-controlled coprecipitation, polyol, sol–gel, and sonochemical methods, to evaluate their structural properties and iron incorporation efficiency. Based on compositional and crystallographic analyses, the coprecipitation under an inert atmosphere exhibited improved phase purity and higher Fe₃O₄ content, which was selected for in situ incorporation onto biochar produced by pyrolysis at 450 °C. The resulting magnetic material and composite were characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM–EDS), confirming the suitability of the synthesis method and the successful deposition of magnetite onto the porous carbon matrix while preserving its structural integrity. Batch adsorption experiments were conducted at pH 2.0 to evaluate the effect of adsorbent dose and initial Cr(VI) concentration. The adsorption process reached equilibrium within 120 min and was better described by the pseudo-second-order kinetic model (R² ≥ 0.98), suggesting that chemisorption governs the rate-controlling step, with diffusion phenomena contributing but not dominating the overall mechanism. The maximum adsorption capacity predicted by the kinetic model reached 42.49 mg g⁻¹ at an initial concentration of 100 mg L⁻¹. The results demonstrate that avocado-seed-derived magnetic biochar represents a sustainable and effective material for chromium-contaminated water treatment, integrating agro-industrial waste valorization with enhanced adsorption performance and magnetic separability. Full article

Scientific assessment of energy conservation, emissions reduction, public health externalities, and economic costs is crucial for the sustainable development of new energy vehicles (NEVs). Despite minimal emissions during the operational phase of NEVs, the production process of energy, such as electricity and hydrogen, contributes to pollution across the full supply chain, shifting environmental and health burdens to upstream sectors and raising concerns about the overall societal benefits. To address this, we apply a full-chain life cycle assessment (FC-LCA) framework that integrates emissions from vehicle production, energy supply, and end-of-life stages, while simultaneously quantifying health-related mortality attributable to key pollutants. By incorporating upstream energy production structure and downstream industry emissions, this approach captures the complete energy supply chain and enables a systematic comparison between NEVs and conventional vehicles. We further employed and compared ARIMA, LSTM, and Bi-LSTM models to forecast future vehicle demand and defined different forecasting scenarios for China’s passenger vehicle sector. Results provide policy-relevant insights for decision-makers to make informed policy choices concerning the widespread implementation of NEVs in a sustainable manner. Full article

Aluminum alloys, particularly those in the Al-Cu and Al-Mg-Si series, are extensively employed in aerospace, automotive, and structural applications owing to their favorable strength-to-weight ratio. However, optimizing their mechanical and surface properties to meet advanced performance requirements remains a critical challenge. Over the past three decades, extensive research has explored thermochemical treatments, precipitation hardening, and thermomechanical processing, yet most studies have examined these methods in isolation. This review systematically analyzes the influence of each treatment route on microstructural evolution, precipitation behavior, and mechanical performance, with emphasis on grain refinement, precipitation kinetics, surface hardening, and fatigue resistance. Particular attention is given to severe plastic deformation, advanced surface modification techniques, and aging behavior under different conditions. The review also highlights gaps in the current literature, including limited integration of hybrid treatment cycles, insufficient understanding of coupled diffusion-precipitation mechanisms, a lack of high-temperature performance data, and minimal industrial-scale validation. Future research directions are proposed to develop optimized hybrid processing strategies, predictive computational models, and scalable treatment cycles. This consolidated review provides a comprehensive foundation for advancing aluminum alloy design, aiming to achieve tailored surface-to-core property gradients suitable for next-generation aerospace and automotive applications. Full article

Aramid fiber is a high-performance fiber with excellent mechanical properties, heat resistance, and corrosion resistance. Its exceptional shear and fatigue properties make it a promising material for civil engineering applications. This study summarizes the basic properties and current development of aramid fiber, as well as the applications of aramid fiber and its composites in civil engineering, including aramid fiber-reinforced composite (AFRP)-concrete/steel composite structures, AFRP rebars, and AFRP rock anchors. The results indicate that the poor interfacial bonding performance between aramid fibers and the resin matrix is the primary bottleneck restricting the application of AFRP composites in civil engineering. Consequently, developing a continuous surface treatment method suitable for industrial-scale production remains a key challenge for the widespread adoption of these composites. Furthermore, in certain specific working conditions and environments—such as seismic retrofitting of rectangular concrete columns, impact/explosion resistance reinforcement, and rock anchoring—AFRPs show the potential to replace traditional inorganic fiber-reinforced polymer composites. However, systematic investigation into the fundamental mechanical properties and long-term service performance of AFRP is still required prior to their practical application. Full article

Tree bark, an abundant by-product of the timber industry, represents a promising feedstock for sustainable construction. This study investigates the thickness swelling, water absorption, hygroscopicity and mechanical (compressive strength) properties of insulation panels produced from hardwood bark (Tilia spp. and Robinia pseudoacacia) via hydromechanical treatment and a wet-forming process. The panels were produced without added adhesives, relying on the formation of hydrogen bonds during the drying phase to ensure structural integrity. Both bark-based insulation boards (thermal conductivity coefficient 0.055–0.057 W/m·K) showed similar hygroscopic behavior, reaching equilibrium moisture contents of max. 25% at 93.9% RH. Water absorption after 24 h immersion was highly material-dependent; Tilia-based panels showed 57.11 ± 5.81%, and Robinia-based panels 320.61 ± 11.34%. Thickness swelling remained low (max. 6% for Robinia), showing significant orthotropic anisotropy. At 10% compressive strain, the Tilia and Robinia bark-based panels showed compressive strengths of 188 ± 14.6 kPa and 298 ± 18.1 kPa, accordingly. These findings demonstrate that hardwood bark can be successfully valorized into high-performance, binderless insulation, supporting circular economic strategies. Full article

The production of green hydrogen via aqueous electrolysis of hydrogen sulfide (H₂S) holds significant potential to address challenges related to sustainable energy generation and environmental protection. The electrocatalytic splitting of water polluted with highly toxic H₂S is attractive for industrial applications because the process: (i) is less power-consuming than direct thermal H₂S decomposition; (ii) achieves high Faradaic efficiencies for hydrogen production; and (iii) yields elemental sulfur as an added-value by-product. This review covers a brief discussion on sulfide-containing water sources and electrochemical methods for hydrogen production from H₂S, specifically Direct, Indirect, and Electrochemical Membrane Reactor (EMR) systems. To become commercially and economically attractive, these approaches require improvements in electrolysis efficiency through the development of low-cost electrode materials that are resistant to sulfur poisoning and corrosion, while possessing high catalytic activity, enhanced stability, and durability. Early research focused on carbon-based materials combined with noble metal oxides, transition metal compounds, and related materials. Since their practical performance is limited, investigations have shifted toward nanostructured electrocatalysts with unique crystal structures and designs, which show significantly improved efficiency for H₂S electrolysis. This review highlights the potential of H₂S electrolysis for hydrogen production, giving special attention to recent advancements in electrode materials. Full article

This review examines how plant polyphenols enable multifunctional textiles, offering a sustainable alternative to synthetic dyes and nanomaterial-based treatments. A literature search (2001–2025) identified 105 peer-reviewed studies across eight functional areas. Abundant in agricultural and industrial byproducts, plant polyphenols act as natural colorants, bio-adhesives, and performance enhancers—providing coloration, antibacterial activity, UV protection, flame retardancy, deodorization, antioxidant capacity, superhydrophobicity, and more. Their catechol and pyrogallol groups bind strongly to natural and synthetic fibers via hydrogen bonding, π–π stacking, and metal chelation, ensuring durable, nontoxic functionality. We analyze structure–function links and scalable methods, including pad-dry-cure and metal–phenolic network (MPN) assembly, which were validated against ISO, ASTM, and AATCC standards. Polyphenol-based textiles match or exceed conventional ones in key metrics, with added benefits: full biodegradability, low ecotoxicity, and skin compatibility. Key advances include enzymatic polymerization for wash-stable color, MPN tuning for customizable functions, and using waste-derived polyphenols. However, major challenges remain: narrow color range (mostly yellow, brown, black) and poor wash/UV resistance, leading to rapid fading and loss of antibacterial/UV protection after laundering. Solving these is a top priority for future work. Overall, this review delivers a practical, science-based roadmap for high-performance, sustainable textiles that align with the Sustainable Development Goals and meet real-world needs in healthcare, sportswear, and smart wearables. Full article

This study proposes a lightweight crack-segmentation model optimized for industrial and edge-computing environments, where both high accuracy and real-time inference are required. Conventional convolution-based and U-Net-based crack segmentation models offer relatively simple architectural designs, but often suffer from limited boundary precision or an unfavorable accuracy–efficiency trade-off. Swin Transformer-based approaches can model broader contextual information but may still show poor segmentation quality relative to their computational cost in fine crack analysis. To address these limitations, we propose the Stabilized Crack Network++ (SCN++), a U-Net backbone crack segmentation network that integrates edge fusion, hybrid loss with deep supervision, exponential moving average (EMA)-based stabilization, and lightweight post-processing. The model was trained and evaluated on 40,000 concrete surface images, including 20,000 crack images and 20,000 non-crack images, using quantitative metrics such as intersection over union (IoU), Dice coefficient, frames per second (FPS), giga floating-point operations (GFLOPs), and the number of parameters, together with overlay-based qualitative analysis. Compared with the CNN, U-Net, and Swin Transformer baselines, SCN++ achieved the best overall balance between segmentation accuracy and computational efficiency, with an IoU of 0.7346, a Dice coefficient of 0.8457, 35.09 FPS, 8.45 GFLOPs, and only 2.22 M parameters. These results demonstrate that SCN++ effectively mitigates the conventional accuracy–efficiency trade-off and is a strong candidate for practical structural crack segmentation in edge-computing environments. Full article

Amid accelerating urbanization, tensions between economic growth and environmental protection have become increasingly salient. Improving Total Factor Carbon Productivity (TFCP) is crucial for achieving sustainable urban development. Drawing on panel data for 282 Chinese prefecture-level cities from 2009 to 2021, this paper examines the effects and underlying mechanisms of the Low-Carbon City Pilot (LCCP) policy on urban TFCP. The results suggest that the LCCP policy noticeably contributes to higher TFCP, and the finding remains valid after robustness checks and endogeneity corrections. The impact of the policy exhibits marked variation, yielding stronger gains in western regions of China, in small- and medium-sized cities, in cities not dependent on resource extraction, and in major transportation nodes. Technological progress, the optimization of industrial structure, and advances in economic development serve as key intermediary mechanisms. Moreover, the LCCP policy exhibits positive spatial spillover effects that help lift TFCP in neighboring cities. These findings provide empirical support for differentiated low-carbon policy design and regional coordinated low-carbon development, and carry considerable practical and strategic significance for balancing high-quality economic development and ecological protection. Full article

Special economic zones (SEZs) are widely used to stimulate investment, employment, and industrial growth. Yet their contribution to sustainable regional development remains poorly measured. This is especially true in Kazakhstan, where zone-level assessment is largely absent from regional planning frameworks. This study addresses that gap. We construct a Regional Sustainable Development Index (RSDI) that integrates economic, social, and environmental indicators across nine Kazakhstani regions hosting active SEZs. Economic performance alone gives an incomplete picture. Omitting social and environmental dimensions distorts policy conclusions and masks structural imbalances. Our results reveal sharp differentiation across regions. In the Atyrau region, high investment volumes correspond closely with sustainability gains. This suggests structural coherence between zone operations and broader regional outcomes. The Pavlodar region presents a contrasting case. There, the leading driver of sustainability performance is not investment volume but the reduction of environmental pollution. This finding underscores why disaggregating sustainability components matters—the composite index alone is not sufficient. A comparison against official target indicators identifies both achievements and systematic shortfalls. Investment and employment targets are frequently decoupled: capital attraction does not reliably generate proportional job creation. The social dimension remains the weakest across most zones. Environmental governance shows formal recognition but limited implementation. The RSDI framework offers a practical diagnostic tool for public authorities. It makes imbalances visible before they become entrenched. Beyond Kazakhstan, the index provides a transferable instrument for resource-dependent emerging economies seeking to embed sustainability criteria into SEZ governance and regional planning. Full article

Сommercial TiO₂ ceramic membranes were modified using a slip-casting method with coal fly ash (CFA) obtained from a thermal power plant, Almaty, Kazakhstan. The aim was to enhance membrane surface properties for improved oil-in-water emulsion separation while maintaining structural integrity. Suspension of CFA, stabilized with N-dodecylpyridinium chloride (DPC) and polyvinyl alcohol (PVA), was applied as a coating layer on the TiO₂ surface and subsequently sintered under controlled conditions. The resulting membranes were characterized by SEM-EDX (scanning electron microscopy with energy-dispersive X-ray), Raman spectroscopy, contact angle measurements, and zeta potential analysis. The modified membranes exhibited increased hydrophilicity, as indicated by a reduction in water contact angle (WCA) from 43.6 ± 2° to approximately 0°, and a decrease in the underoil contact angle of water (UOCA) from 147.6 ± 2° to 87 ± 2°. Raman spectroscopy confirmed that the TiO₂ structure remained predominantly rutile, with no additional crystalline phases detected from CFA. Despite the improved wettability, pure water and oil-in-water emulsion fluxes decreased slightly, while filtrates displayed smaller oil droplet sizes, indicating enhanced emulsion stability after passage through the modified surface. These findings demonstrate that CFA-modified TiO₂ membranes can serve as a sustainable and cost-effective approach for treating emulsified wastewater, utilizing industrial waste to improve performance without compromising mechanical robustness. Full article

Shell-and-tube heat exchangers are critical components in oil refining, where their thermal and operational performance is strongly affected by fouling, corrosion-related deterioration, and deposit accumulation in tube-bundle cavities. This study investigates the technical condition of selected TK-type heat exchangers used in refinery services and proposes an integrated maintenance-oriented approach for the assessment and removal of severe deposits formed between tubes. The work first classifies heat-exchanger damage into structural and technological categories, emphasizing fouling as a key source of thermal performance degradation and operational inefficiency. A physical interpretation of compacted deposits is then combined with dynamic modeling to evaluate the response of the pollutant medium to pneumoshock excitation. Based on the analytical and simulation results, the main practical outcome of the study is the development of a pneumoshock cleaning device (PCD) for the mechanical removal of deposits from narrow inter-tube spaces. The proposed approach supports a more effective diagnosis of exchanger condition, helps identify suitable cleaning actions for heavily fouled bundles, and contributes to improved maintenance decision-making in refinery thermal systems, although quantitative before-and-after thermal performance validation is beyond the scope of the present study. As an applied developmental study, the work highlights the relevance of fouling-aware inspection and targeted cleaning technologies for extending equipment serviceability and supporting more reliable thermal management in industrial heat-exchange applications. Full article

The production of cultivated meat relies on in vitro animal cell growth and requires the use of scaffolds that structurally resemble key features of the extracellular matrix (ECM), providing mechanical support and biochemical cues for cell adhesion, proliferation, and differentiation. Electrospinning has emerged as a promising technique for manufacturing three-dimensional edible scaffolds because it is robust, versatile, and capable of producing nanofibers with a high surface area-to-volume ratio, tunable porosity, and ECM-like fibrous architectures. Natural biopolymers are promising candidates for the fabrication of electrospun scaffolds, combining biocompatibility, biodegradability, and processing compatibility with food-grade requirements. However, the absence of fully food-grade electrospinning systems, coupled with limited scalable green-processing strategies, remains a critical barrier to industrial translation. In this context, this review presents recent advances in the food-grade electrospinning of natural biopolymers focused on cultivated meat production. Furthermore, scientific gaps in the development of fully edible scaffolds are discussed, along with the need for alternatives to animal-derived materials and synthetic carrier polymers, considering sustainability, consumer acceptance, and the translation from laboratory-scale studies to industrial systems. Finally, this review outlines a strategic roadmap to accelerate the transition from proof-of-concept studies toward scalable, regulatory-compliant, and industrially viable electrospinning technologies for cultivated meat production. Full article

This study investigates the effect of chemical modification of xylite—a fraction derived from Polish lignite—using succinic anhydride (SA) on the morphology and mechanical performance of isotactic polypropylene (iPP) composites. Xylite was incorporated at loadings of 1, 10, and 25 wt% and in two particle size ranges (40–63 µm and 63–125 µm), with and without SA (0.5 and 2 wt%). The composites were characterized by wide-angle X-ray scattering (WAXS), Fourier-transform infrared spectroscopy (FTIR), and tensile testing to evaluate crystallinity (Xc), β-phase content (kβ), and mechanical properties. Unmodified xylite reduced crystallinity (Xc down to ~37%) and significantly decreased ductility, with elongation at break strongly negatively correlated with filler content (r ≈ −0.68), indicating poor dispersion and weak interfacial adhesion. In contrast, SA addition (0.5–2 wt%) partially restored crystallinity (up to ~48%) and increased stiffness (Young’s modulus up to 2120 MPa), while altering β-phase content. FTIR analysis indicated reduced intermolecular hydrogen bonding between xylite surface hydroxyl groups in the presence of SA, consistent with interfacial chemical interactions, likely via esterification. The β-phase content showed a moderate positive correlation with xylite loading (r = +0.43) and a negative correlation with elongation at break (r = −0.46), suggesting that excessive β-phase formation may reduce toughness. Larger particles (63–125 µm) provided slightly improved elongation at break and stiffness. Overall, SA acts as both a compatibilizer and a morphology-directing agent, enabling precise control of the stiffness–ductility balance and crystalline structure in iPP/xylite composites. These results establish chemically modified lignite-derived fillers as a viable strategy for engineering cost-efficient polyolefin materials with tunable structure–property relationships, offering strong potential for scalable industrial implementation. Full article

Urbanization increases pluvial flood risk by expanding impermeable surfaces, which is a trend likely to intensify with climate change. Permeable pavement (PePav) made from industrial byproducts, in accordance with circular economy principles, may improve soil permeability. Public acceptance remains a critical barrier to its implementation. Existing measures of willingness to accept (WtA) new technologies are inconsistent, limiting interdisciplinary collaboration. Therefore, a concise WtA scale was adapted from the Bogardus Social Distance Scale to assess acceptance of PePav at varying levels of proximity in residential contexts, from public flood-prone roads to private yards. The scale was evaluated across three studies: Study 1 (N = 195) and Study 2 (N = 187) utilized mixed student samples, while Study 3 (N = 625) involved a non-student sample. The 5-item solution, identified through factor analysis in Study 1, consistently demonstrated a unidimensional and cumulative structure and satisfactory reliability, even after the proposed PePav ingredient modification in subsequent studies. The scale correlated with recycling experience and professional background, indicating convergent validity, but not with flooding or informal construction experience, across all samples. Study 3 provided evidence of external validity by incorporating empirically well-established Theory of Planned Behavior (TPB) constructs and showing that WtA predicted PePav use beyond TPB variables and demographics. The scale also showed measurement invariance across sample type (student vs. general population) and different levels of construction experience. The constructed WtA scale is suitable for efficiently assessing professional and public acceptance of circular building materials and may have broad cross-disciplinary relevance. This enables timely, targeted interventions and informed policy decisions to advance sustainable technologies in the built environment, with substantial implications for education, professional policy, and sustainable engineering. Nevertheless, further validation is required. Full article