Search Results (7,385)

Excess fluoride originating from phosphate mining activities poses a significant environmental and public health challenge, particularly in arid and semi-arid regions where water resources are limited. This study presents a comparative evaluation of four conventional defluoridation technologies for the treatment of real phosphate mine waters collected from two major Moroccan phosphate mining sites (Youssoufia and Khouribga). The investigated processes included coagulation–flocculation using aluminum sulfate and ferric chloride, chemical precipitation with calcium hydroxide and calcium chloride, adsorption on aluminum oxide (Al₂O₃) and zirconium oxide (ZrO₂), and fluoride removal using calcined bovine bone apatite under both batch and continuous-flow conditions. Adsorption equilibrium was interpreted using Langmuir and Freundlich isotherm models, while the effects of adsorbent dosage, contact time, and water matrix composition were systematically investigated. Among the coagulation processes, aluminum sulfate achieved fluoride removal of up to approximately 82.5% in phosphate washing water and approximately 76.3% in mine drainage water, whereas ferric chloride removed about 52% of the dissolved fluoride under the reported conditions. Lime and calcium chloride exhibited moderate removal efficiencies of 66% and 61%, respectively. Aluminum oxide showed the highest equilibrium adsorption capacity (q_m = 7.14 mg g⁻¹), while zirconium oxide displayed faster fluoride uptake because of its higher surface affinity for fluoride ions. The presence of competing ions in real mine waters was associated with lower adsorption performance compared with synthetic fluoride solutions. Calcined bone apatite proved to be the most effective material, achieving approximately 83% fluoride removal within 20 min under batch conditions and maintaining good performance during continuous fixed-bed operation, producing treated water with fluoride concentrations below the World Health Organization guideline value. Overall, the results demonstrate that calcined bone apatite provides the highest fluoride-removal performance among the investigated materials under the tested conditions. Its waste-derived origin, rapid adsorption kinetics, and effective fluoride removal make it a promising material for the treatment of fluoride-rich phosphate mine waters. The comparative evaluation further indicates that integrating chemical pretreatment with adsorption may represent a promising strategy for the treatment and potential reuse of mining effluents, although the performance of such a combined treatment train should be validated experimentally. Full article

Digital-twin-enabled human–machine collaboration (HMC) has increasingly been proposed as a system-level approach for connecting human operators, robots, sensors, artificial intelligence modules, and manufacturing resources. However, the literature varies substantially in what is called a digital twin, how physical and virtual models are coupled, whether models are updated from physical data, and how far systems have progressed beyond simulation or controlled laboratory demonstrations. This structured integrative review examines the conditions under which a digital twin can function as an integration layer for HMC in sustainable smart manufacturing, rather than assuming that such integration is already established industrial practice. The literature corpus was assembled through searches of the Web of Science Core Collection, Scopus, and IEEE Xplore, complemented by Google Scholar-based citation tracking and backward and forward citation tracing. The core search focused on studies published from 1 January 2020 to 5 August 2026, while earlier seminal studies were retained to support definitions and historical context. Studies were screened using explicit criteria for manufacturing relevance, physical–virtual coupling, state synchronization or model updating, feedback capability, and validation setting, and were critically coded by model type, integration mechanism, deployment maturity, and sustainability evidence. The review compares multimodal perception and human-state modeling, intention understanding and augmented interaction, task allocation and shared planning, digital-twin architectures, adaptive control and safety verification, and human–AI decision-making. The evidence indicates that digital twins are promising as coordination and verification layers, but many reported systems remain conceptual, simulation-based, or limited to controlled physical prototypes. Key barriers include model fidelity, online model updating, real-time synchronization, cross-platform interoperability, safety assurance, human-data governance, and the limited availability of directly measured sustainability outcomes. Future work should prioritize validated hybrid models, traceable model-update mechanisms, staged virtual-to-physical deployment, interoperable data contracts, and longitudinal evaluation of technical, human, economic, and environmental performance. Full article

Early-season winter wheat mapping is crucial for agricultural management and food security, but reliable identification remains challenging under weak spectral conditions during early growth stages. To address this challenge, this study developed a CNN–LSTM with a lag-aware gated fusion model (CL-LGFM) for winter wheat mapping in the Chaohu Basin, China, using a reconstructed 5-day Sentinel-2 NDVI time series and precipitation data from the Global Precipitation Measurement (GPM) mission. The model employs a dual-branch architecture to jointly learn vegetation and precipitation features and introduces a lag-aware dynamic gated fusion module to capture the delayed response of vegetation to precipitation and enhance multi-source feature fusion. The results show that the proposed method achieved reliable early-season winter wheat mapping (OA ≥ 0.90, Kappa ≥ 0.80) on 26 January, at least 10 days earlier than traditional methods, including SVM, RF, DTW, and TCN, using the same reconstructed 5-day NDVI time series. Optimal performance uses a 7 × 7 patch size and 30-day precipitation window. Full article

In science, technology, engineering, arts, and mathematics (STEAM)-based music education, sound serves as a shared object of listening, inquiry, design, representation, and artistic expression. Sound is approached as musical material, a physical phenomenon, a technological object, a design problem, and a mathematical structure. Learners investigate vibration, pitch, loudness, timbre, duration, rhythm, melody, and acoustic experience; use digital tools to record, replay, visualize, arrange, and create sound; and apply design processes to plan, test, revise, and present sound-based products or performances. Musical understanding is developed through singing, movement, instrumental performance, composition, improvisation, and reflection, while mathematical reasoning is supported through beat, duration, sequence, proportion, pattern, and timing. In this approach, music provides an integrated context in which learners connect sensory experience with conceptual understanding. It is relevant across general music education contexts because it supports listening, discrimination, comparison, organization, creation, performance, and reflection, with activities adapted to learners’ ages, prior musical experience, and educational levels. Full article

AI-assisted digital mural restoration is expanding rapidly, but image similarity alone does not establish whether a digital output can support conservation decision making. We conducted a PRISMA-ScR scoping review of 203 reports identified across the Web of Science Core Collection, IEEE Xplore, and Scopus. Bibliographic, task, model, evaluation, and evidence continuity variables were charted using the Heritage–Intervention–Evidence–Continuity (HIEC) framework. Inpainting or defect restoration accounted for 149 reports (73.4%); CNNs (68, 33.5%), GANs (54, 26.6%), diffusion models (36, 17.7%), and transformers (23, 11.3%) were the most frequent primary model families. Evaluation remained dominated by the SSIM (149, 73.4%) and PSNR (145, 71.4%), whereas expert evaluation, cross-site validation, versioning, and long-term monitoring were much less frequently reported. HIEC organizes the evidence chain across heritage context, intervention boundary, evidence validity, and continuity and governance, yielding a multi-database evidence map and a minimum evidence continuity record for traceable and revisable conservation decisions. The findings distinguish benchmark similarity and visual plausibility from historically credible interpretation and physical conservation outcomes. Evidence continuity represents one contribution to sustainable heritage conservation. Full article

This study evaluates the effect of copper-containing composite nanopowders on the antiwear properties of additive-free I-20A mineral oil. The powders were produced by the same electron-beam evaporation route in argon under different current–time regimes and differed in phase composition and particle characteristics. N1 was synthesized at 1.4 MeV and 20 mA for 15 min and contained 91 wt.% Cu, 2 wt.% Cu₂O, and 7 wt.% CuO (mean particle size 140 nm), whereas N2 was synthesized at 1.4 MeV and 15 mA for 25 min and contained 38 wt.% Cu, 48 wt.% Cu₂O, and 14 wt.% CuO (187 nm). Six separate oil suspensions containing 0.01, 0.1, or 1 wt.% N1 or N2 were evaluated in block-on-ring tests; three independent tests were performed for each lubricant condition (21 individual measurements in total). The lowest mean mass loss was obtained with 1 wt.% N2 (0.00290 ± 0.00015 g), representing a 43.1% decrease relative to pure I-20A oil (0.00510 ± 0.00026 g; Holm-adjusted p = 0.0045). The 0.01 and 0.1 wt.% N2 formulations did not differ significantly from pure oil, whereas 0.01 and 1 wt.% N1 significantly increased mass loss. In selected SEM/EDS regions, the wear scar produced with 1 wt.% N1 showed deeper longitudinal grooves and no detectable Cu, whereas the scar produced with 1 wt.% N2 showed a smoother local morphology and 0.58 wt.% Cu. These local observations are consistent with different particle–surface interactions and greater local retention of Cu-containing material for N2, but they do not identify the copper oxidation state or prove formation of a continuous tribofilm. Overall, the powders exhibited formulation- and concentration-dependent antiwear behavior: 1 wt.% N2 was beneficial, whereas 1 wt.% N1 was strongly detrimental. Because the synthesis regime, phase composition, particle size, and morphology varied together, the observed difference cannot be attributed exclusively to the Cu/Cu₂O/CuO ratio. Full article

Laboratory friction measurements are central to material screening for High-Friction Surface Treatments (HFST), yet metrological aspects including a proposed metrological traceability framework or uncertainty, and reproducibility are consistently underreported. This study applies a metrology-aligned framework to British Pendulum Tester (BPT) measurements performed in three states: dry, wet (water), and water–soap to assess operational adhesion and hysteresis components, document traceability to the International System of Units (SI), and report GUM-style uncertainty with covariance for the adhesion difference. Measurements were obtained for calcined bauxite (CB) and rhyolite (Rhy) in HFST and Coarse gradations across seven polishing protocols (baseline; LAA-1000/2000; MDA-105/180; PSV-10 h/20 h), using n = 3 replicates per Treatment × Material × State. Replicate-based Type A uncertainties were combined with instrument/system Type B components geometry, slider hardness, temperature, soap film consistency, and calibration to yield combined u_c and expanded uncertainty U_(k=2). The Wet–Soap cross treatment physical correlation ellipses demonstrate strong positive correlations (r ≈ 0.88–0.98; p < 0.001) between wet and soap states, supporting the interpretation that wet friction is governed primarily by hysteresis, with adhesion acting as a small offset under BPT kinematics. The slider hardness and temperature typically control the wet state uncertainty budget; including measured Wet–Soap covariance reduces adhesion U_(k=2) by up to ~6.5%, consistent with GUM’s law of uncertainty propagation. Together, these measurement science practices enhance road safety by making laboratory friction data traceable, comparable, and decision-ready. Full article

In guided-wave stimulated Brillouin scattering (SBS), the opto-mechanical coupling strength is determined by the spatial overlap of optical and elastic fields, fundamentally constrained by symmetry. Conventional analyses based on ordinary point groups assume that fields share the waveguide’s symmetry, which is valid for standing-wave modes with zero longitudinal wavenumber. However, in waveguides with longitudinal-axis-reversing operations, such operations flip the wavenumber sign for traveling-wave modes, making the conventional framework insufficient—a limitation not addressed before. Here, we introduce the type-III Shubnikov (magnetic) point groups, combining time reversal with axis-reversing spatial operations, and establish a co-representation theory for such traveling-wave modes. We prove that these modes obey a conjugate symmetry derived from the antiunitary elements of the magnetic point group. From this, we derive a general selection rule for backward SBS: if the waveguide possesses only one nontrivial axis-reversing operation (and no other independent symmetry), the conjugate symmetry allows the coupling to be nonzero. Numerical validations on single-crystal lithium niobate, fused silica, and single-crystal silicon waveguides of a trapezoidal cross-section confirm the predicted conjugate symmetry and show that materials with lower intrinsic symmetry more favorably realize such symmetry-enabled backward SBS. This work represents a systematic introduction of magnetic group theory to nonmagnetic waveguides, offering new insights for material selection and coupling control in guided-wave SBS. Full article

Head-mounted displays (HMDs) create a direct physical interface with the head and face that can constrain comfort during sustained and repeated virtual reality use. This focused narrative review examines three interacting domains of HMD physical comfort: thermal conditions at the headset–skin interface, mechanical loading from head-supported mass and contact forces, and anthropometric compatibility between headset geometry and user anatomy. Exploratory searching was followed during revision by structured searches of Google Scholar, Scopus, and Web of Science, tracker-based screening, source classification, evidence extraction, and evidence-limitation appraisal. The tracker-based review retained 41 sources, including 28 domain-focused and 13 context or framing sources. Two additional contextual references supplied during peer review were incorporated outside the completed tracker-based process, resulting in 43 sources cited in the final manuscript. Thermal comfort was influenced by microclimate conditions, exposure, activity, sealing, and internally generated heat. Mechanical comfort depended on mass, center-of-mass position, pressure, movement, posture, and task demands. Anthropometric evidence demonstrated substantial variation relevant to headset fit and alignment. The heterogeneous evidence does not support universal limits for headset mass, temperature, pressure, cervical angle, or interface geometry. Sustained HMD comfort therefore requires integrated evaluation across devices, users, tasks, and exposure durations. Full article

Architecture design studios are complex learning environments in which knowledge develops through critique, collaboration, individual reflection, material exploration, and increasingly digital forms of practice. Although the physical organization of these spaces influences how such activities unfold, research on furniture arrangement remains fragmented across ergonomics, learning environments, educational research, technology-enhanced education, and participatory design. This structured integrative review examined the mechanisms reported between furniture arrangement, related physical spatial configurations, and learning processes in architecture design studios and relevant adjacent educational settings. It also investigated the pedagogical, ergonomic, technological, and cultural conditions under which these mechanisms were reported as supportive or restrictive. Scopus, Web of Science All Databases, and ScienceDirect were searched on 7 August 2026. The searches identified 64 source-level records: 26 from Scopus, 19 from Web of Science, and 19 from ScienceDirect. Eight duplicate records were identified within the ScienceDirect results. Following cross-source deduplication, title and abstract screening, and full-text eligibility assessment, 15 publications were included in the integrative synthesis. Study characteristics, methodological quality, contextual relevance, furniture-related conditions, pedagogical activities, reported outcomes, explanatory mechanisms, evidentiary directness, and transferability were examined through an integrative, mechanism-oriented synthesis. The resulting relationships were subsequently organized through an abductive framework-development process into the provisional Adaptive Studio Learning Ecosystem (ASLE) framework. ASLE comprises five interrelated dimensions: spatial flexibility, ergonomic responsiveness, pedagogical mediation, technological support, and cultural–participatory fit. The synthesis supports activity–layout alignment rather than a universally optimal furniture configuration and indicates that spatial adaptability becomes educationally meaningful only when supported by appropriate pedagogical practices, ergonomic conditions, technological integration, and patterns of user participation. Because the evidence base includes a limited number of direct architecture-studio studies and relies partly on mechanisms transferred from adjacent settings, ASLE should be treated as a provisional, review-derived framework requiring empirical validation. Full article

N-acetylcysteine (NAC) is a thiol-containing molecule with antioxidant, anti-inflammatory, antimicrobial, and cytoprotective properties that has increasingly been incorporated into hydrogel-based biomaterials. This systematic review evaluates the strategies used to integrate NAC into hydrogels and examines their effects on material properties, controlled release, biocompatibility, and therapeutic activity. The review was conducted according to the PRISMA guidelines using Scopus, PubMed, Web of Science, and SciFinder to identify English-language articles published between 2000 and 2025. Seventy-three studies met the eligibility criteria of this review. NAC has been employed as a physically loaded therapeutic agent, covalently conjugated polymer modifier, contributor to hydrogel crosslinking, metal-coordination ligand, and compound incorporated into nano- and microparticulate carriers dispersed in hydrogel. These approaches enable the modulation of gelation, swelling, adhesion, degradation, and drug-release kinetics. NAC-containing hydrogels have demonstrated robust antioxidant, antimicrobial, antibiofilm, anti-inflammatory, angiogenic, and tissue-regenerative properties in various in vitro and in vivo models, underscoring their potential for advanced biomaterial applications. Release profiles varied from rapid stimulus-responsive delivery to sustained release over several days, depending on the network architecture and the NAC–matrix interactions. However, comparisons among studies were limited by the heterogeneous formulations, release conditions, biological models, and outcome measures. Standardized physicochemical characterization, NAC stability assessment, dose–response evaluation, and rigorous preclinical validation are required to support the translation of NAC-based hydrogels into biomedical applications. We hope that this review will help scientists and innovation centers understand the potential of the NAC-containing hydrogel biomaterials discussed in this study, as well as the opportunities and demands for additional research in this field. Full article

Background: Retinal microvascular assessment has emerged as a promising non-invasive approach for evaluating vascular health. Recent advances in retinal imaging technologies have enabled detailed characterization of retinal vascular structure and function, raising interest in their potential role as biomarkers of exercise-related vascular adaptation. This systematic review with narrative synthesis aimed to summarize current evidence regarding the relationship between exercise, physical fitness, and retinal microvascular biomarkers. Methods: A systematic literature search was conducted in PubMed, Scopus, and Web of Science for studies published from January 2021 to June 2026, followed by a supplementary update search to identify eligible publications available through 31 July 2026. Search terms combined retinal microvascular assessment techniques with terms related to exercise, physical activity, physical fitness, and exercise training. Following screening and eligibility assessment, 42 publications were included in the final qualitative synthesis, comprising 20 publications identified through the initial search and 22 additional publications identified through the supplementary update search. Several publications represented complementary analyses of the same or overlapping study cohorts and were therefore not considered independent replications. Results: The included studies comprised observational studies and exercise intervention trials involving healthy individuals and clinical populations. Retinal biomarkers assessed included vessel diameters, arteriovenous ratio (AVR), vessel density, perfusion density, foveal avascular zone (FAZ), retinal oxygen extraction, wall-to-lumen ratio (WLR), and choriocapillaris perfusion parameters. Several studies reported measurable acute and chronic retinal vascular responses to exercise, although the direction, magnitude, and clinical meaning of these changes varied according to population, exercise modality, imaging technique, and biomarker. Observational studies generally reported associations between higher physical activity or cardiorespiratory fitness and a more favorable retinal vascular profile, but causal interpretation remains limited. Conclusions: Retinal microvascular biomarkers appear sensitive to acute physiological stress and may reflect selected adaptations associated with longer-term exercise exposure. However, retinal responses are heterogeneous and biomarker-specific, and their biological and clinical significance remains incompletely established. Methodological heterogeneity, overlapping study cohorts, and the limited number of adequately powered randomized and longitudinal studies constrain causal interpretation and generalizability. Retinal vascular measures should therefore currently be regarded as candidate biomarkers and research tools rather than validated surrogate outcomes or routine clinical measures. Full article

Sun-induced chlorophyll fluorescence (SIF) is an effective proxy for vegetation photosynthesis, but tower-based retrieval suffers from atmospheric path interference under humid and variable conditions. We present a DOAS-based SIF retrieval algorithm that operates in Fraunhofer lines (680–686 nm, 745–758 nm) and water vapour-sensitive bands (717–727 nm). It constructs an adaptive reference spectrum from SCOPE simulations and PCA and incorporates H₂O absorption cross-sections into the fitting process for active atmospheric correction. The algorithm is implemented in a dedicated tower-based system integrating a 1° scanning gimbal with a high-resolution spectrometer. Validation with simulated and field data demonstrates the following: (1) the algorithm retrieves SIF with high fidelity (correlation coefficients >0.9 across all windows); (2) it exhibits lower water-vapour sensitivity and greater cloudy-sky stability than FLD, 3FLD, and SFM, achieving the lowest coefficient of variation (CV = 0.356); (3) over a complete wheat–rice rotation, the retrieved SIF tracks crop growth and phenological stages. This work provides a reliable solution for automated, high-precision tower-based SIF observation under complex atmospheric conditions. Full article

In-storage food loss is a persistent yet under-addressed source of economic, environmental, and social waste in small and medium-sized enterprise (SME) cold chains, where continuous monitoring and lean workflows are typically absent. This study asks how such loss can be reduced under SME constraints and what benefits an intervention designed for that setting could yield. Following a design science approach in a Thai chilled warehouse case, it develops an integrated intervention coupling an Internet of Things (IoT) early-warning platform—ESP-32 and DHT22 sensing with commodity-specific alerting through the LINE Messaging API—with value stream mapping (VSM) of the depositing and withdrawing workflows. Monitoring showed that 7.4% of quality-controlled readings exceeded the 6 °C control threshold. Value stream analysis established that elapsed time is governed by information latency rather than physical work and that produce spends 290 min per handling cycle outside controlled conditions. The redesigned workflows project lead-time reductions of 47.5% and 69.4% and remove 125 min of that exposure. An ex ante Triple Bottom Line assessment estimates approximately 19,700 kg of avoided produce loss, 6500 kg CO₂e, and 590,000 THB retained annually. This study contributes a complementarity account of digital monitoring and process improvement, advancing SDG Target 12.3. Full article

Quantum tunneling is conventionally described by the Schrödinger wave equation with a prescribed static potential barrier, providing accurate transmission probabilities but offering limited insight into the microscopic dynamics of particle–barrier interactions. In this work, we develop a dynamical second-quantization framework in which the barrier is modeled as an ensemble of quantized internal modes rather than as an externally imposed classical potential. The tunneling particle interacts directly with these microscopic barrier excitations through a coupled particle–barrier Hamiltonian, from which the Heisenberg equations of motion are derived. Collective coherent excitations of the barrier modes give rise to an emergent effective barrier that naturally recovers the conventional rectangular barrier and the WKB transmission limit under appropriate conditions. Unlike standard treatments, the present formulation explicitly incorporates microscopic barrier dynamics and provides a unified description of particle–barrier coupling within a second-quantized formalism. The framework further suggests that repeated tunneling events may experience different microscopic interaction histories, motivating a statistical interpretation of tunneling times. Because both the particle and barrier are treated within the same operator formalism, the theory provides a natural foundation for extension to relativistic quantum transport, photonic barriers, cavity quantum electrodynamics, and other structured quantum media. Full article