Search Results (506)

Acid mine drainage (AMD) and acid-generating mine wastes exhibit low pH, high sulfate levels, and complex multi-metal loads that strain conventional treatment. Thermoacidophilic red algae of the order Cyanidiales, particularly Galdieria sulphuraria (G. sulphuraria), have attracted interest as a biological option because they tolerate extreme acidity and elevated temperatures, grow under low light in mixotrophic or heterotrophic modes, and display rapid metal binding at the cell surface. This review synthesizes about two decades of peer-reviewed work to clarify how G. sulphuraria can be deployed as a practical module within mine water treatment trains. We examine the mechanisms of biosorption and bioaccumulation and show how they map onto two distinct configurations. Processed freeze-dried biomass functions as a regenerable sorbent for rare earth elements (REEs) and selected transition metals in packed beds with acid elution for recovery. Living cultures serve as polishing units for divalent metals and, when present, nutrients or dissolved organics under low light. We define realistic operating windows centered on pH 2–5 and temperatures of approximately 25–45 °C, and we identify matrix effects that govern success, including competition from ferric iron and aluminum, turbidity and fouling risks, ionic strength from sulfate, and suppression of REE uptake by phosphate in living systems. Building on laboratory studies, industrial leachate tests, and ecosystem observations, we propose placing G. sulphuraria upstream of bulk neutralization and outline reporting practices that enable cross-site comparison. The goal is an actionable framework that reduces reagent use and sludge generation while enabling metal capture and potential recovery of valuable metals from mine-influenced waters. Full article

This study aims to investigate the influencing factors and mechanisms of barium sulfate (BaSO₄) scaling under low-permeability reservoir conditions, providing a scientific basis for water quality selection during water injection. The effects of key scaling ions and flow conditions on scaling behavior were examined through integrated experimental core flooding tests and molecular dynamics (MD) simulations. Experiments were conducted using synthetic cores simulating the ultra-low permeability Chang-8 Reservoir of the Jiyuan Oilfield, analyzing the impact of ion concentrations (Ba²⁺, SO₄²⁻, Na⁺, Ca²⁺, HCO₃⁻), flow velocity, and injection pressure. MD simulations were performed based on an interfacial SiO₂(010)–BaSO₄ solution model constructed in Materials Studio to elucidate the micro-mechanisms. Results indicate that increasing concentrations of Ba²⁺ and SO₄²⁻ significantly promote scaling. High Ca²⁺ concentration (>8000 mg/L) inhibits BaSO₄ deposition via competitive adsorption. High Na⁺ concentration (>70,000 mg/L) reduces Ba²⁺ activity due to ionic strength effects. When HCO₃⁻ concentration exceeds 600 mg/L, CaCO₃ coprecipitation occurs, reducing effective SO₄²⁻ concentration and thus inhibiting BaSO₄ scaling. Increased flow velocity enhances scaling, whereas elevated injection pressure suppresses deposition. MD simulations reveal that increased ion concentrations decrease the mean square displacement (MSD) of Ba²⁺ and SO₄²⁻, weakening diffusion and enhancing scaling tendency. Elevated temperature promotes ion diffusion and inhibits scaling, while pressure shows negligible effect on ion diffusion at the molecular scale. This study provides theoretical insights for scaling prevention in low-permeability sandstone reservoirs. Full article

The strategic balance between strength and electrical conductivity in Al-Mg-Si alloys is a critical challenge that must be overcome to enable their widespread adoption as viable alternatives to copper conductors in power transmission systems. To address this, the present study comprehensively investigates model alloys with Mg/Si ratios ranging from 1.0 to 2.0. A multi-faceted experimental approach was employed, combining tailored thermo-mechanical treatments (solution treatment, cold drawing, and isothermal annealing) with comprehensive microstructural characterization techniques, including electron backscatter diffraction (EBSD) and scanning electron microscopy (SEM). The results elucidate a fundamental competitive mechanism governing property optimization: excess Mg atoms concurrently contribute to solid-solution strengthening via the formation of Cottrell atmospheres around dislocations, while simultaneously enhancing electron scattering, which is detrimental to conductivity. A critical synergy was identified at the Mg/Si ratio of 1.75, which promotes the dense precipitation of fine β″ phase while facilitating extensive recovery of high dislocation density. Furthermore, EBSD analysis confirmed the development of a microstructure comprising 74.1% high-angle grain boundaries alongside a low dislocation density (KAM ≤ 2°). This specific microstructural configuration effectively minimizes electron scattering while providing moderate grain boundary strengthening, thereby synergistically achieving an optimal balance between strength and electrical conductivity. Consequently, this work elucidates the key quantitative relationships and competitive mechanisms among composition (Mg/Si ratio), processing parameters, microstructure evolution, and final properties within the studied Al-xMg-0.5Si alloy system. These findings establish a clear design guideline and provide a fundamental understanding for developing high-performance aluminum-based conductor alloys with tailored Mg/Si ratios. Full article

This study investigated the effects of rubber substitution ratios (0%, 5%, 10%, 15%) on the frost resistance of rubber concrete with recycled brick–concrete aggregate (BRC). The freeze–thaw (F–T) damage model was established and improved, and the damage mechanism was revealed. The results showed that with the increase in rubber substitution ratio, the frost resistance indices of BRC did not improve or decline synchronously. An increase in rubber content could enhance one index, such as the relative compressive strength, but was often achieved at the expense of reductions in other indices, such as the relative dynamic elastic modulus (RDEM) and relative quality. Consequently, a single indicator was insufficient for evaluating the overall frost resistance. To address this limitation, an entropy weight-based evaluation system was developed. This system integrated the multiple indices into a unified damage score. When combined with defined damage grades, it enabled a holistic assessment of the damage state. For the nonlinear accelerated damage stage during freeze–thaw cycles, the Weibull distribution-based freeze–thaw damage model demonstrated higher prediction accuracy (R² > 0.85) compared to the conventional freeze–thaw fatigue model. The freeze–thaw damage in BRC originated from the competition between “pore deterioration and crack propagation at weak interfaces” and “the elastic buffering effect of rubber.” This study provided a reference for the frost-resistance design and freeze–thaw life prediction of BRC in cold regions. Full article

Background/Objectives: Lower limb amputation (LLA) negatively affects the physical and psychological health of individuals, leading to a lower quality of life and sedentary lifestyle. The objective of this scoping review is to search for evidence regarding physical activity interventions in individuals with LLA, investigating improvements in specific outcomes related to quality of life and performance. Methods: PRISMA guidelines—extension for scoping reviews—were used to structure the study. The research was conducted between 26 July 2023 and 30 September 2023; it was structured by defining two PICO questions (P = amputation, I = physical exercise, O1 = quality of life, and O2 = performance) through Pubmed, Cochrane, and Pedro databases. The study included subjects with LLA of any etiology, in prosthetic or pre-prosthetic phase, practicing non-competitive physical activity. The results were then subjected to both qualitative and quantitative analysis. Results: Of the 615 studies identified, 18 were included in the review. They consisted of 6 systematic reviews (SR), 5 RCTs, 4 case–control studies, 1 case report (CR), and 2 cross-sectional (CS). Physical activity (PA) interventions were extremely heterogeneous and were, therefore, categorized into 6 modalities: surveys were the most reported strategies (57%), followed by personalized training (23%), strength training (13%), endurance training (13%), combined training (2%), and gait training (5%). Due to the heterogeneity of the studies, the variety of interventions proposed and the different outcomes registered, there is no evidence that one approach is more effective than another, while each group showed benefits on different specific outcomes. In total, five outcome categories were identified: quality of life was the most frequently analysed (42%), followed by cardiovascular fitness (20%), muscular fitness (14%), gait parameters (13%), functionality and disability (11%). Conclusions: PA represents a valuable strategy for improving performance and quality of life in individuals with LLA, offering a variety of interventions. Although there is no evidence that one strategy is better than the others, each activity has proven to be effective on specific outcomes, therefore, the choice must depend on the patient’s necessities. The preferred option should be the personalization of the training according to individual needs, coupled with long-term planning and remote monitoring. Creating meeting places and supporting occasions for sports activities could be a valid option. Further research could help to clarify the benefits of such interventions and enhance the understanding of how to optimize the management of LLA patients. Full article

To evaluate the stability of fiber-reinforced cemented foamed backfill (FCFB) in complex underground mining environments, this study investigates the synergistic effects of fiber content and modified coal gangue (MCG) under acidic and high-temperature conditions. Through a systematic analysis of hydration processes, compressive strength, and deformation characteristics, the research identifies critical mechanisms for optimizing backfill performance. Calcination of MCG at 700 °C enhances gelling activity via amorphous phase formation, while modified aluminum dross (MAD) treated at 950 °C develops dense α-Al₂O₃ and spinel phases, significantly improving chemical stability. In acidic environments, the suppression of calcium silicate hydrate (C-S-H) is offset by the development of Al³⁺-driven C-A-S-H gels. These gels adopt a tobermorite-like structure, substantially increasing acid resistance. Mechanical testing reveals that while 1% fiber reinforcement promotes nucleation and densification, a 2% concentration hinders hydration. Compressive strength at 28 days shows constrained growth due to pore inhibition, and failure modes transition from multi-crack parallel failure (3-day) to single-crack tensile-shear failure. Under acidic conditions, strain concentration in the upper sample highlights a competitive mechanism between Al³⁺ migration and fiber anchorage. Ultimately, the coordinated regulation of MCG/MAD and fiber content provides a robust solution for roof support in challenging thermo-chemical mining environments. Full article

Petroleum-based plastics are non-renewable and degrade poorly, persisting in the environment and causing serious ecological pollution, so urgent development of alternatives is needed. In this study, all-bamboo fiber thermosetting plastics (BTPs) were successfully prepared through selective sodium periodate oxidation of bamboo fibers followed by hot-pressing. The results demonstrate that the oxidation treatment effectively enhanced fiber reactivity and facilitated the formation of dense composite materials during hot-pressing. Compared with petroleum-based plastics (e.g., PVC), BTPs exhibit outstanding mechanical properties: flexural strength reaches 100.73 MPa, tensile strength reaches 83.31 MPa, while the 72 h water absorption and thickness swelling rates are as low as 5.36% and 4.59%, respectively. This study also reveals the mechanism by which residual lignin affects material microstructure formation through competitive oxidation reactions. Although it imparts initial hydrophobicity, it hinders complete fiber activation, leading to the formation of micro-defects. Furthermore, BTPs can completely degrade in 1% NaOH solution within 24 h, demonstrating excellent degradability. This research provides a new strategy for developing high-performance, degradable all-bamboo-based materials and promotes the value-added utilization of bamboo resources. Full article

The development of agricultural new productive forces (ANPFs) represents a vital pathway to overcoming the bottlenecks of agricultural modernization and reshaping agricultural competitiveness. As sustainable development and green transformation have become global priorities, the formation of ANPFs is increasingly viewed as a key engine for promoting resource-efficient agriculture, low-carbon production, ecological protection, and resilient food systems. Using panel data from 16 prefecture-level cities in Anhui Province, China, spanning the period 2010–2023, this study employs the entropy-weighted TOPSIS method to measure the levels of ANPFs and sustainable agricultural development (SAD). A panel data model is then applied to examine the impact of ANPFs on SAD, while a mediation-effect model is used to test the underlying transmission mechanisms. Finally, a spatial econometric model is employed to assess the spatial spillover effects between ANPFs and SAD. The results reveal that ANPFs exert a significant and robust positive impact on Anhui’s SAD, with the strength of this effect decreasing gradually from central to southern and northern regions. Further analysis indicates that the driving influence of ANPFs operates through three key mediating pathways: the improvement of new-type infrastructure, the enhancement of agricultural scientific and technological innovation, and the advancement of agricultural digital transformation. Moreover, ANPFs demonstrate a positive spatial spillover effect, suggesting that the development of new productive forces in one region promotes agricultural modernization in neighboring areas. These findings demonstrate that ANPFs not only enhance productivity but also contribute to sustainable agricultural development. Accordingly, strengthening ANPFs development can serve as an effective strategy for promoting long-term agricultural sustainability, indicating that central Anhui should be prioritized as a core hub for fostering ANPFs, enabling the gradient diffusion of infrastructure, innovation capacity, and digital services toward southern and northern Anhui. Strengthening regional coordination mechanisms will further amplify the spatial spillover of ANPFs, thereby advancing high-quality agricultural development across the province. This study provides new evidence for how ANPFs can support sustainable agricultural transformation, offering policy insights for green growth, food security, and rural revitalization. Full article

In accelerated bridge construction, precast concrete girders are connected to cast-in-place concrete slab using shear transfer reinforcement across the interface plane to ensure the composite action. The steel transverse reinforcement is prone to severe corrosion due to the extensive use of de-icing salts and severe environmental conditions. As glass fiber-reinforced polymer (GFRP) reinforcement has shown to be an effective alternative to conventional steel rebars as flexural and shear reinforcement, the present research work is exploring the performance of GFRP reinforcements as shear transfer reinforcement between precast and cast-in-place concretes. Experimental testing was carried out on forty large-scale push-off specimens. Each specimen consists of two L-shaped concrete blocks cast at different times, cold joints, where GFRP reinforcement was used as shear friction reinforcement across the interface with no special treatment applied to the concrete surface at the interface. The investigated parameters included the GFRP reinforcement shape (stirrups and headed bars), reinforcement ratio, axial stiffness, and the concrete compressive strength. The relative slip, reinforcement strain, ultimate strength, and failure modes were reported. The test results showed the effectiveness and competitive shear transfer performance of GFRP compared to steel rebars. A shear friction model for predicting the shear capacity of as-cast, cold concrete joints reinforced by GFRP reinforcement is introduced. Full article

The accelerating global transition toward low-carbon production and sustainable value chains has intensified interest in practices that enhance environmental performance, particularly green supply chain management (GSCM) and green innovation (GI). Although these practices are widely promoted, empirical findings regarding how GSCM influences GI and carbon-neutral supply chain performance (CNSCP) remain dispersed and context-dependent. This study aims to synthesize and clarify these relationships by conducting a systematic meta-analysis grounded in the Resource-Based View (RBV) and Natural Resource-Based View (NRBV). Analyzing 24 studies published between 2017 and 2025, the research investigates the direct effects of GSCM on GI and CNSCP and examines the moderating roles of key sustainability metrics—CO₂ emissions, renewable energy use, carbon tax, Frontier Technologies Index (FTI), and Global Sustainable Competitiveness Index (GSCI)—across low- and high-income countries. The findings reveal that GSCM significantly enhances both GI and CNSCP. Furthermore, strong sustainability infrastructures and stringent regulatory environments in high-income countries amplify these relationships, whereas infrastructure deficiencies and weaker regulatory systems in low-income countries limit their strength. These results demonstrate that sustainability metrics meaningfully condition the effectiveness of GSCM practices. Overall, this study highlights the strategic importance of GSCM in fostering CNSCP and provides theoretical insights and practical recommendations for policymakers, managers, and governments seeking to achieve long-term carbon neutrality goals. Full article

Background/Objectives: Hypertension represents a leading contributor to cardiovascular disorders and premature mortality. Given the pervasive nature of adverse effects associated with current angiotensin-converting enzyme inhibitors (ACEIs), there is a significant interest in identifying novel bioactive lead compounds from natural sources. This study identifies, for the first time, three novel angiotensin-converting enzyme (ACE) inhibitory peptides released from Bungarus multicinctus (BM) via simulated gastrointestinal digestion (SGD). Methods: Active fractions were enriched by ultrafiltration and subjected to stability assessment. The peptide sequences were then determined using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) and bioinformatics tools, followed by chemical synthesis. Finally, the inhibitory mechanism was investigated using kinetic analysis and molecular docking. Results: The intestinal digest exhibited potent ACE inhibition, with the <5 kDa fraction achieving 79% inhibition at 1 mg/mL and demonstrating favorable stability under varying temperatures, pH, and ionic strengths. Molecular docking revealed strong binding (affinity < −9.9 kcal/mol) of the peptides PPSPPRW, WGFTKF, and PSLFPPRL to key ACE residues—Tyr523, His513, and Arg522—via hydrogen and hydrophobic interactions. Enzyme kinetics characterized PPSPPRW and WGFTKF as competitive inhibitors, and PSLFPPRL as mixed type. The peptides demonstrated acceptable cell viability at lower concentrations, establishing a preliminary safety window for therapeutic application. Conclusions: These findings establish BM as a valuable source of stable, bioactive ACE-inhibitory peptides (ACEIPs) acting as promising lead compounds for antihypertensive therapies. Full article

This study was aimed at analyzing physical fitness in 9–11-year-old children and verifying whether it is affected by body mass index (BMI), peak height velocity (PHV), quartile distribution (QD), and sport practice (SP), also considering any potential effects of sex. One thousand one hundred forty-three Italian primary school children (50.7% males) underwent anthropometric measurements (body mass, height, and BMI) and physical tests for measuring coordination (Plate Tapping, PT), handgrip strength (HandGrip, HG), lower-limb power (standing long jump, SLJ), low-back flexibility (sit-and-reach, SR), and sprint (20 m sprint, 20 m) skills. A series of analyses of covariance (ANCOVAs) were conducted using age as a covariate to examine differences among subgroups for BMI, PHV, QD, and SP in relation to the different physical tests (i.e., PT, HG, SLJ, SL, 20 m). Sex was included in each model as fixed independent variable. Principally, participants with higher SP and BMI reported higher and lower performance (p < 0.001) in SLJ, SR, and 20 m tests, respectively. Differently, for higher BMI levels, higher HG performance was reported (p < 0.001). PHV and QD had isolated effects, whereas no effect emerged for PT. Sex interactions were found only for SP subcategories in SR (p ≤ 0.001, ES range = 0.74–1.30). Although physical performance in 9–11-year-old (non-competitive, pre-puberty) Italian students does not seem to be characterized by involuntary factors (such as PHV and QD), substantial opposite trends seem to exist for voluntary factors (such as BMI and SP), thus suggesting how an adequate lifestyle and physical activity could crucially lead to valuable fitness benefits. Full article

The selection of a final operating point from a Pareto front set of marine diesel engine configurations relies on the critical task of translating operator priorities into quantitative criterion weights. This study isolates this pivotal weighting step and introduces an operator-defined fuzzy weighting module that maps linguistic importance ratings to normalized weights. This module systematically maps important ratings for Specific Fuel Consumption (SFC), Nitrogen Oxides (NOx), and Particulate Matter (PM) into a set of normalized weights for the Multi-Criteria Decision-Making method. The module’s core is a Mamdani-type fuzzy logic module that utilizes triangular membership functions and centroid defuzzification. These fuzzy weights are integrated with the TriMetric Fusion algorithm to generate a robust consensus ranking. Validation on a Pareto front from a two-stroke diesel engine demonstrates the framework’s efficacy: a Fuel-Economy priority selected a configuration with SFC advantage, while a Strict Environmental Compliance priority correctly identified dual emissions strengths. Furthermore, the system effectively mediated trade-offs in a high-competition scenario. Rank correlation analysis confirmed that while the Pareto front nature of the alternatives leads to inherent similarities in rankings, the fuzzy weights induce significant and logical divergences. Future work will focus on validation with real operator feedback and comparative studies with traditional weighting methods. Full article

Background: Blind 5-A-side football is an intermittent sport that requires the development of specific physical, physiological, and technical–tactical variables, making the identification of recovery processes such as sleep, well-being, and athletes’ perceptions key factors in performance. However, to date, no systematic review has analyzed the scientific evidence on performance variables in players with visual impairments. Objective: To identify performance variables in blind 5-A-side football through the analysis of physical fitness factors, physiological demands, technical–tactical actions, and recovery variables. Materials and Methods: The following databases were consulted: Scopus, PubMed (Medline), Web of Science, ScienceDirect, and Google Scholar. This systematic review follows the PRISMA guidelines and those for conducting systematic reviews in sports science. The PICOS strategy was used to select and include studies. The quality of the studies was assessed methodologically using the Joanna Briggs Institute Critical Appraisal Tool. Results: The included studies evaluated multiple aspects of physical and physiological fitness in blind 5-A-side football, with a predominance of descriptive and observational research, although longitudinal interventions in national teams were also identified. The most studied physiological-physical variables are aerobic capacity and cardiovascular response; anthropometry and body composition; strength, power, and injury risk; external competition demands; balance; and postural control. The studies in the technical–tactical dimension focused on the effectiveness of shots on goal and on the characterization of control, dribbling, and shooting actions. The most studied recovery variable was sleep. Conclusions. The evidence suggests that training processes should integrate both improvements in physical fitness and physiological demands, as well as the refinement of decision-making and offensive actions. Despite advances, scientific output in this discipline remains limited, highlighting the need to promote studies with greater methodological rigor and sample diversity. Full article

Balancing high fluidity and stability is a critical challenge in deep-shaft cemented paste backfill (CPB) with high-concentration tailings. This study investigates the synergistic regulation mechanism of a combined admixture system comprising hydroxypropyl methylcellulose (HPMC) thickener and polycarboxylate (PCE) or Melamine-Formaldehyde Resin (MFR) superplasticizers on CPB rheology, mechanical strength, and microstructure. Results indicate that HPMC significantly enhanced anti-segregation performance via intermolecular bridging, substantially increasing yield stress and plastic viscosity. Upon PCE introduction, the steric hindrance provided by its side chains effectively disrupted HPMC-induced flocs and released entrapped water. Consequently, yield stress and plastic viscosity were reduced by up to 22.1% and 64.3%, respectively, with PCE exhibiting markedly superior viscosity-reducing efficiency compared to MFR. Mechanical testing revealed that PCE co-addition did not compromise early-age strength but enhanced 3, 7, and 28-day unconfined compressive strength (UCS) by refining pore structures and promoting the uniform distribution of hydration products. Microstructural analysis unveiled a competitive adsorption mechanism: preferential PCE adsorption dispersed particle agglomerates, while non-adsorbed HPMC formed a viscoelastic network within the pore solution, constructing a stable “dispersion-suspension” microstructure. This work provides a theoretical basis for optimizing high-performance backfill formulations. Full article