Search Results (12,775)

In protracted humanitarian crises, solid waste management (SWM) becomes a major challenge due to limited resources, inadequate infrastructure, and competing response priorities. Waste generated in humanitarian settings typically consist of heterogeneous streams, where plastics, biodegradable fractions, and packaging materials represent the dominant components. Proper management of this waste is essential to reduce health risks and environmental impacts on local communities. Within this framework, sustainable bio-based alternatives and compostable solutions represent promising alternatives. The EU-funded Bio4HUMAN project promotes the integration of innovative bio-based solutions aligned with humanitarian and sustainability goals. An exploratory assessment focused on analyzing waste production, material composition, and handling practices in two case study locations in Sub-Saharan Africa (Democratic Republic of Congo (DRC) and South Sudan (SS)). The results indicate that humanitarian waste cannot be clearly distinguished from household or commercial waste, as streams are typically mixed. Waste composition is dominated by organic matter (43–65%), followed by plastics (15–33%), while other fractions such as paper, glass, metals, and textiles are less significant. Further insights into challenges and opportunities were obtained through a combination of quantitative surveys (n = 29), qualitative interviews with key informants (KIIs) (44) and group discussions sessions (FDG) (9), direct observations, and literature review. Subsequently, a scoping approach was applied to map and classify suitable sustainable solutions into two main categories: bio-based products (BBPs) and organic waste valorization technologies. These were assessed through life cycle assessment (LCA) in accordance with ISO 14040 and 14044, applying SimaPro v.10.2.0.3 software and the Ecoinvent 3.10 database, and compared against fossil-based alternatives. This study compares two case scenarios: a HDPE oil bottle versus PLA alternative (functional unit 6 L), and PE water container versus PLA alternative (functional unit 10 L). For the oil bottle, PLA shows a lower carbon footprint (1.33 kg CO₂-eq) than HDPE (2.37 kg CO₂-eq). In contrast, for the water container, PLA performs worse (2.22 kg CO₂-eq) compared to PE (1.59 kg CO₂-eq), due to higher material demand. The results suggest that benefits are context-dependent and most evident for lightweight products with high leakage risks, particularly when composting infrastructure is accessible. This study advances previous work on humanitarian SWM by integrating field-based waste flow characterization with context-specific screening and life cycle assessment of bio-based alternatives, providing quantitative evidence on the conditions under which these solutions can effectively reduce environmental burdens in protracted crisis settings. Full article

Against the background of climate change intensifying extreme hail events, the photovoltaic module industry faces a critical trade-off between improving hail resistance and maintaining environmental sustainability. This study establishes an emergy–life cycle coupling assessment framework to systematically evaluate the environmental sustainability of six typical hail resistance enhancement designs across four hail risk scenarios in China. Five hierarchical hypotheses are proposed and validated through quantitative analysis. The optimal design point occurs at 30 mm hail resistance using 3.2 mm tempered glass, achieving a minimum unit environmental impact per impact resistance UEIC of 9.63 × 10¹² sej/mm. The ranking divergence index SDR between coupled emergy–LCA and conventional LCA methods is 0.267, with ecosystem service dependence ESD reaching 0.241 for composite backsheet designs, revealing natural capital overlooked by traditional methods. A complete ranking reversal occurs at a threshold hail frequency of 1.3 events per year, above which the 3.2 mm glass design outperforms standard modules with life cycle emergy input LCEA of 3.20 × 10¹⁴ sej versus 3.41 × 10¹⁴ sej under high-risk scenarios. Material type dominates environmental impact over structural parameters by a factor of 2.32, with recycled aluminum frames reducing ELCI by 12.4%. The dual-optimum design is identified as the 3.2 mm tempered glass scheme, achieving a combined sustainability score CSS of 0.782 and emergy yield ratio EYR of 3.86, outperforming the industry average of 3.61. Multi-objective optimization using NSGA-II yields a Pareto front of 12 non-dominated solutions, with the 3.2 mm glass design maintaining Pareto optimal status in 72% of Monte Carlo iterations. This research provides a quantitative decision-making framework recommending standard modules for regions below one annual hail event, the 3.2 mm glass design for regions between one and four annual events, and steel frame combinations above four annual events, demonstrating that moderate enhancement achieves the optimal balance between hail protection and environmental sustainability. Full article

This work examines the machining responses of dry turning in ultrasonic-assisted stir-squeeze cast A356 hybrid nanocomposites reinforced with zirconia (ZrO₂) and graphene oxide (GO). Accordingly, flank wear (VBc) ranged from 0.061 to 0.238 mm, influenced by abrasion, adhesion, built-up edge (BUE) formation, and diffusion mechanisms. Cutting speed had the most significant effect on flank wear (65.65%), followed by depth of cut (18.2%) and feed rate (11.13%), supported by a well-fitted regression model (R² = 0.987; p < 0.05). Surface roughness (Ra) ranged from 1.733 to 7.012 μm, with cutting speed, feed rate, and depth of cut contributing 70.42%, 15.43%, and 9.56%, respectively. The cutting temperature was limited to 127 °C, primarily influenced by cutting speed (60.68%), whereas cutting power varied between 0.353 and 0.644 kW, mainly governed by cutting speed (68.71%) and depth of cut (25.92%). The chip morphology showed a segmented sawtooth pattern due to cyclic fracture initiation during material removal. Multi-criteria optimization using complex proportional assessment (COPRAS) identified v = 90 m/min, f = 0.06 mm/rev, and d = 0.1 mm as the optimal parameters, yielding a tool life of 22.6 min and a machining cost of INR 58.69 per item. This research is further focused on the implementation of different cooling lubrication techniques utilizing environmentally friendly cutting fluids, including Minimum-Quantity Lubrication and nano-MQL, among other types of environments. Full article

The transition towards carbon-neutral construction materials requires innovative solutions that combine reduced embodied energy, enhanced durability and improved building energy efficiency. This study investigates and compares two novel bioaerated low-density composites—BAAC and BIOAERMAC—developed through biologically driven aeration processes incorporating industrial byproducts. BAAC is produced using Saccharomyces cerevisiae and hydrogen peroxide, replacing conventional aluminum powder and improving safety while enabling the valorization of waste-derived yeast. BIOAERMAC is a gypsum-based composite incorporating synthetic anhydrite, microorganisms, peroxides, and recycled rubber from end-of-life tires. The materials were characterized in terms of hygrothermal behavior and dimensional stability, and compared with commercial autoclaved aerated concrete under equivalent mechanical strength conditions. The results highlight significant differences in moisture transport and shrinkage, primarily governed by pore structure and connectivity. BAAC exhibits behavior comparable to conventional AAC, whereas BIOAERMAC shows reduced capillary and hygroscopic absorption, indicating limited pore connectivity, but higher drying shrinkage. These findings demonstrate the effectiveness of bioaeration in tailoring pore structure and controlling the trade-off between moisture transport, durability, and dimensional stability, highlighting the potential of bioaerated composites for low-carbon and energy-efficient building applications. Full article

Machine learning has become a field of growing interest in asphalt pavement engineering, spanning mix design, material characterization, performance prediction, distress detection, sustainability, quality control, and maintenance planning. However, a lack of transparency can undermine engineering trust, defensibility, and field implementation. This systematic scoping review aims to synthesize explainable artificial intelligence (XAI) and interpretable machine-learning applications for asphalt pavement materials and systems, following the PRISMA-ScR guidelines. Major scientific databases were used to identify relevant peer-reviewed studies, which were screened against a set of inclusion and exclusion criteria and categorized into seven research dimensions. A final library of 163 publications was compiled, comprising 73 core evidence studies and 90 supporting references. The review covers techniques such as SHAP, LIME, partial-dependence analysis, attention mechanisms, surrogate models, sensitivity analysis, symbolic modeling, and physically informed interpretation. The use of XAI in performance prediction, material-property interpretation, and modeling for mix design is well developed, while distress/damage analysis, life cycle sustainability, field validation, uncertainty-aware explanation, maintenance decision support, and human-centered evaluation are still relatively underdeveloped. The main contribution is a five-layer framework linking data provenance, model performance, explanation quality, physical plausibility, and decision utility. The review proposes moving from post hoc feature ranking to validated, physically centered, uncertainty-aware, and engineer-in-the-loop decision support for asphalt XAI. Full article

Urbanisation-driven housing demand and the environmental burden of sewage sludge disposal highlight the need for low-carbon, circular construction materials. This study evaluates incinerated sanitary sludge ash (ISSA) as a supplementary cementitious material in stabilised earth blocks, aiming to reduce the use of cement and lime while valorising waste sludge. Lateritic soil blocks were produced with a binder-to-soil ratio of 1:7 by mass, in which ISSA partially replaced the primary stabilising binder (cement or lime) at a replacement level of 10–40% within the binder fraction. ISSA’s mineralogical characteristics were analysed using XRD and XRF. The compressive strength and density of earth blocks were measured at 7 and 28 days under curing conditions (29–36 °C; 60–75% humidity). Cement-stabilised blocks were water-cured to support cement hydration, whereas lime-stabilised blocks were air-cured to promote carbonation and pozzolanic reactions. The results, therefore, compared practical binder-specific curing regimes rather than strictly identical curing environments. ISSA exhibited moderate pozzolanic potential, and its incorporation enabled substantial partial replacement of both binders. Cement-stabilised blocks achieved higher strengths, up to 7.7 MPa, after 28 days of curing, whereas lime-stabilised blocks developed strength more gradually, reaching 4.8 MPa. Optimal mixtures were identified at 40% cement + 60% ISSA and 30% lime + 70% ISSA, balancing mechanical performance and binder reduction. A positive density–strength relationship was observed, but chemical bonding predominated over densification effects. ISSA-based stabilised earth blocks show promising structural performance and reduced binder use, but durability and life-cycle assessment need further evaluation before large-scale implementation. Full article

This study critically addresses the challenge of selecting optimal insulation materials for contemporary, energy-efficient building envelopes, a decision with profound environmental, structural, and occupational health consequences. The paper responds to the growing demand for sustainable, resilient solutions by comparing wool, a bio-based, regenerative material, and expanded polystyrene (EPS), a synthetic polymer widely implemented in the construction industry, and advanced laboratory testing (thermal conductivity, moisture buffering, freeze–thaw resistance) is discussed in a comprehensive synthesis of the recent literature. Also, field evaluations from European retrofits and pilot projects (UK, Denmark, Finland, Iceland, Norway, Sweden, Germany and France) further contextualize performance outcomes, and life cycle impacts are considered. Recent results reveal that wool insulation achieves a moisture buffering value (MBV) between 1.8 and 2.7 (g/m²) % RH, minimal vapor resistance (mvr = 1–2), and preserves functional and structural integrity through more than 100 freeze–thaw cycles, leading to significant stabilization of the interior microclimate and enhanced durability. In contrast, EPS delivers lower thermal conductivity (0.032–0.037 (W/mK), critical for reducing heating/cooling demand, but exhibits limited vapor permeability (lvp = 60–150 MN·s/(g·m)), increased risk of condensation and mold, and reduced compressive strength (<22% after 30 cycles), especially when ventilation details are inadequate. Hybrid envelope systems leveraging both EPS and wool are demonstrated to optimize energy efficiency (up to 23% seasonal savings) and reduce interior humidity fluctuations, while lifecycle and recycling assessments show wool panels to be markedly superior in carbon footprint reduction and circularity. The stratification of insulation layers incorporating wool for vapor and moisture control, and EPS for pure thermal resistance is emerging as best practice in sustainable retrofit and new-build projects. Recommendations highlight the necessity for rigorous laboratory validation, international standards alignment, and integrated material design for robust hygrothermal comfort and environmental performance. The review also covers wool- and EPS-based hybrid composites, showing how natural fibers can improve key mechanical properties without compromising thermal insulation performance or environmental benefits. Full article

Waste lubricating oils (WLOs) represent a major stream of hazardous petroleum-based residues, with global generation exceeding 24 million tons annually. Improper disposal of WLOs poses risks to soil, water, and air quality, while their chemical composition makes them a potential secondary resource within circular economy frameworks. This review summarizes conventional, advanced, and emerging technologies reported for the recycling and valorization of WLOs into high-value petrochemicals and carbon-based materials. Established processes such as acid–clay treatment, solvent extraction, and vacuum distillation are discussed together with more recent approaches, including catalytic upgrading, hydrotreatment, membrane separation, and thermochemical conversion methods such as pyrolysis and catalytic cracking. Reported data on process performance, environmental considerations, techno-economic indicators, and life cycle assessment outcomes are comparatively analyzed to outline current trends, technical challenges, and future development directions in WLO recycling. Particular attention is given to thermochemical pathways capable of generating carbonaceous materials, including carbon black, porous carbons, and functional carbon nanostructures with potential applications in adsorption, catalysis, electrochemical systems, and tribological formulations. Hybrid and integrated process configurations described in the literature are highlighted for their potential to improve recovery efficiency, enhance product quality, and reduce environmental burdens. In addition, recent life cycle assessment (LCA) and techno-economic analysis (TEA) studies are reviewed to provide insight into the environmental and economic implications of advanced re-refining systems. Overall, the reviewed literature indicates that WLO recycling represents not only an important element of sustainable lubricant management but also a promising waste-to-carbon strategy for the production of value-added carbon-based materials and petrochemical products. Full article

Ultra-high-voltage direct-current (UHVDC) transmission systems impose stringent requirements on the reliability of insulation materials used in converter transformer bushings. Epoxy resin systems are key insulating materials in resin-impregnated paper (RIP) capacitor bushings, and their processing characteristics, curing behavior, and electrical properties directly affect bushing performance. In this study, two epoxy insulation systems used for resin-impregnated paper (RIP) bushings, namely the imported Araldite LY1564/Aradur 3486 system and the domestic EP-2020/CA-3015 system, were systematically investigated through viscosity, curing, and electrical property tests. The results show that the viscosities of both resins decreased significantly with increasing temperature. At 60 °C, the viscosities of Resin A and Resin B were 151.6 mPa·s and 156.3 mPa·s, respectively. The mixed resin–hardener systems exhibited similar viscosity evolution and comparable pot life characteristics. DSC measurements revealed two-stage curing reactions for both materials, with first exothermic peak temperatures of 65.4 °C and 96.3 °C and second peak temperatures of 269.3 °C and 269.8 °C for Materials A and B, respectively. Electrical testing demonstrated that both materials exhibited similar temperature-dependent dielectric and resistivity behavior, with dielectric loss increasing at elevated temperatures and resistivity decreasing as temperature increased. The volume resistivity trends and dielectric characteristics of the two materials remained highly consistent throughout the investigated temperature range. The results indicate that Material B exhibits processing performance, curing characteristics, and electrical insulation properties comparable to those of Material A. Therefore, Material B demonstrates strong potential for application in UHVDC RIP bushing insulation systems and provides a promising alternative for the localization of key insulating materials. Full article

Traumatic fractures are common in small animal emergency care, yet subtle fracture lines may be difficult to identify accurately using routine three-dimensional reconstruction workflows, particularly when access to specialized software is limited. This study describes the use of the open-source platform Three-Dimensional Slicer for computed tomography-based reconstruction and three-dimensional printing in a small dog with cranial trauma, with emphasis on documenting a practical and reproducible workflow through voxel resampling. Imaging data were imported into the software, bone structures were segmented using a rapid workflow, voxel spacing was resampled for smoother surface visualization by volume resampling, and the reconstructed model was processed for physical printing. Digital models of different resolutions were generated within minutes, and a life-size skull model was successfully fabricated using fused deposition modeling in less than three hours at a material cost of under one United States dollar. The enhanced model provided an intuitive representation of fracture morphology and spatial relationships compared with routine reconstruction alone. These findings demonstrate that open-source software combined with low-cost printing can provide a rapid, affordable, and user-friendly approach for practical skeletal reconstruction in small animals, with practical value for fracture assessment, preoperative planning, and broader use in resource-limited veterinary settings. Full article

Lithium has become one of the key raw materials for the energy transition due to the central role of lithium-ion batteries in electromobility, energy storage, and the integration of renewable energy sources. However, the rapid increase in demand reveals growing environmental, social, geopolitical, and market tensions. The aim of the paper is a critical synthesis of global lithium utilization from the perspective of challenges, technological innovations, and integrative strategies supporting a more sustainable material–energy system. A broad, systematic literature review covering the entire value chain was applied: resources, extraction, processing, end-use applications, second life of batteries, recycling, and governance. The analysis shows that the strategic importance of lithium arises from the increasing demand pressure from electric vehicles and stationary storage, while the sustainability of the current model is constrained by supply concentration, uneven control over downstream stages, the water–carbon footprint of extraction and processing, social conflicts, and incomplete integration of secondary loops. At the same time, innovations such as direct lithium extraction (DLE), recovery from geothermal brines, design for recycling, second life, and battery passports can partially alleviate these tensions, but they do not eliminate the need for primary supply in the short term. The conclusion of the work is that sustainable global lithium utilization requires simultaneous diversification of sources, development of circular value chains, and multi-level governance integrating resource security, environmental efficiency, and social legitimacy. Full article

The patron saint celebrations of the colonias of Afro-Colombian migrants from the South Pacific region in Cali (Colombia) provide a significant context for understanding the perseverance of paisanaje (a shared experience of origin) bonds and ritual vitality in migration contexts. Organized consistently since the 1960s, these celebrations bring together dispersed communities year after year, activating and reshaping memories, emotions, and collective identities. Building on this celebratory perseverance, this article explores the factors that produce and sustain the emotional and social commitments that transcend the celebration itself. Drawing on the theory of interaction rituals, the concepts of collective effervescence, and embodied memory, this study proposes interpreting these celebrations as spaces where emotion, memory, and social time intertwine. This is based on the understanding that the ritual experience enacts the community through a shared repetition that brings the past to life and projects the expectation of reunion. For this analysis, this study draws on research conducted between 2015 and 2018 and a reflective re-examination of this material in 2026, which included participant observation at 10 celebrations and semi-structured interviews with members of 7 hometown communities or colonias. The results show that longing—the tension between the joy of reunion and the melancholy for what is absent—acts as a constitutive emotional state and the primary amplifier of the ritual’s emotional energy, adding precision to Collins’s model of how energy accumulates and enables the continuity of communal bonds. Full article

To solve the drawbacks of conventional long-cycle wear tests for miniature standing- wave linear ultrasonic motors, an accelerated equivalent wear model and test system were proposed in this work. After primary screening of multiple pair materials, graphite and Al₂O₃ were adopted to modify epoxy films. The optimal friction pair is composed of 6061 hard anodic oxidation film and ECA105 composite film. The matched pair exhibits excellent driving stability and low wear loss, with fatigue wear as the main wear form. Graphite and Al₂O₃ exert synergistic anti-wear and load-bearing effects via forming a stable transfer film on the friction interface. Experimental results confirm that the accelerated test is equivalent to a full-life durability test. The presented method and optimized friction pair can effectively guide the development of high-performance ultrasonic motors. Full article

Background: Childhood oral hygiene behaviors are crucial to preventing oral diseases and can influence the development and progression of malocclusions. The World Health Organization (WHO) Oral Health Questionnaire is a standardized tool for assessing oral hygiene behaviors, oral health-related behaviors, and preventive dental awareness in children. Aim: This study aimed to assess oral hygiene behaviours and examine associations between WHO Oral Health Questionnaire variables and Angle malocclusion classes among children aged 6–9 years. Materials and Methods: This cross-sectional study included 90 children aged 6–9 years from the Pristina region, Kosovo. Data were collected using the WHO Oral Health Questionnaire for Children, which assessed oral hygiene habits, toothbrushing frequency, fluoride awareness, dental attendance, dietary behaviors, oral symptoms, and oral-health-related quality of life. Malocclusion was classified according to Angle classification into Class I, II, and III malocclusions with 3D intraoral scanners, Aerolscan 3. Descriptive statistical analysis, Chi-square (χ²) test, Spearman correlation analysis, and reliability analysis using Cronbach’s Alpha were performed using SPSS Statistics 23.0 (IBM Corp., Armonk, NY, USA) and Statistica 7.1 (StatSoft Inc., Tusla, OK, USA). Results: Most participants reported regular oral hygiene practices, with 46.7% brushing their teeth two or more times daily. However, limited awareness regarding fluoride-containing toothpaste was observed, as most children answered “don’t know” regarding fluoride use. Occasional toothache or oral discomfort was reported by 33.3% of participants, while 23.3% reported dissatisfaction with dental appearance. Difficulty biting hard foods was present in 34.4% of children. Reliability analysis of the Q10 section demonstrated moderate internal consistency (Cronbach’s Alpha = 0.500). Chi-square analysis demonstrated no statistically significant association between Angle malocclusion classes and WHO questionnaire variables (p > 0.05). The highest χ² value was observed for tooth-cleaning frequency (Q7) (χ² = 11.97; p = 0.152), although the association remained statistically non-significant. Psychosocial impact questions and oral health-related quality of life questions also demonstrated no statistically significant association with malocclusion classes. Conclusions: oral hygiene practices, preventative oral health practices, and oral health-related experiences were comparatively similar among children in different Angle malocclusion classes. Although there were no statistically significant correlations found between malocclusion classes and WHO questionnaire variables, the results show that some children have psychosocial concerns about their dental appearance and insufficient awareness of preventive oral health. The WHO Oral Health Questionnaire is a useful epidemiological tool for evaluating pediatric oral health behaviors and may help build youth orthodontic and preventive oral health policies. Full article

The practical application of Li–O₂ batteries is severely hindered by parasitic reactions on the cathode side, which generally lead to large charging over-potentials and degraded cyclic performance. To address this issue, it is essential to integrate high-efficiency catalysts into conventional carbon-based electrodes. Herein, we report a novel La_0.85Ca_0.15Cr_0.85O₃@Ru (LCC@R) hybrid catalyst with an ultralow Ru loading (6.55 wt.%), synthesized via a facile sol-gel combined with in-situ reduction-exsolution method. Mono-dispersed and ultrafine Ru nanocrystals (2–5 nm) are uniformly anchored on the LCC substrate and serve as the catalytically active sites. The Li–O₂ battery with the LCC@R catalyst exhibits a low charge potential of 3.75 V at a current density of 50 mAg⁻¹ with limited capacity of 500 mAhg⁻¹. Impressive cyclic stabilities of up to 80 cycles (at 1000 mAhg⁻¹) and 15 cycles (at 2000 mAhg⁻¹) are achieved. Moreover, a large specific capacity of 8630 mAhg⁻¹ is delivered at 50 mAg⁻¹. Mechanistic studies reveal that the intermediate discharge product LiO₂ can be absorbed on LCC@R, thereby inhibiting the parasitic reactions induced by LiO₂ attack on carbon. The as-prepared LCC@R hybrid material is a promising cathode catalyst for constructing long-cycle-life and low-over-potential Li–O₂ batteries. Full article