Search Results (11,123)

Inadequate Municipal Solid Waste (MSW) management constitutes a critical environmental challenge, as approximately 40% of waste reaches uncontrolled disposal sites where open-air incineration generates significant air, soil, and water pollution. The objective of this study was to evaluate the MSW Environmental Management System (EMS) in Chilpancingo de los Bravo, Guerrero, Mexico, through sustainability indicators and applicable Mexican environmental regulations to identify operational and structural deficiencies that guide a comprehensive improvement in its management. The methodology comprised an analysis of the EMS via the Municipal Development Plan, the identification of environmental indicators and applicable Mexican standards, and an evaluation of the EMS through waste characterization and sustainability metrics. A sample of 208 kg was defined in accordance with standards NMX-AA-015-1985 and NMX-AA-022-1985. The results indicate a generation rate of approximately 350 tons per day (1.2 kg/capita/day), with municipal collection coverage of 70% of the territory across 24 daily routes operated by 30 vehicles. Indicators revealed a recycling rate of 4.86%, collection coverage of 79.66%, a 0% treatment rate due to the absence of composting or material recovery facilities, and 95% of waste directed to the Final Disposal Site (FDS). These findings demonstrate substantial deficiencies in the current EMS, highlighting that the systematic application of indicators is an effective diagnostic tool for identifying gaps and guiding evidence-based improvements in MSW governance. Full article

Cloud-based intrusion detection systems (IDSs) increasingly rely on deep learning classifiers to identify malicious traffic; however, this reliance exposes them to adversarial evasion attacks in which adversaries craft near-imperceptible perturbations to bypass detection. Existing defenses based on conventional adversarial training often recover robustness against known perturbation patterns at the cost of degraded detection accuracy on canonical attack categories—a robustness–accuracy trade-off that remains an open challenge in the field. In this paper, we propose GT-CSAT (Game-Theoretic Cost-Sensitive Adversarial Training), a novel defense framework tailored for cloud security environments. GT-CSAT couples an improved Wasserstein GAN with Gradient Penalty (WGAN-GP) threat generator—conditioned on attack semantics to simulate functionally consistent and highly covert traffic variants—with a minimax adversarial training loop governed by a game-theoretic cost-sensitive loss function. The proposed loss function assigns asymmetric misclassification penalties derived from a two-player zero-sum payoff matrix, enabling the detector to maintain vigilance over both novel adversarial variants and well-characterized conventional threats simultaneously. Specifically, misclassifying an adversarially perturbed attack as benign incurs a strictly higher penalty than the symmetric cross-entropy baseline, while the cost weights are dynamically adapted via a Nash equilibrium-inspired update rule during training. We conduct comprehensive experiments on the Cloud Vulnerabilities Dataset (CVD), CICIDS-2017, and UNSW-NB15, which encompass diverse cloud-specific attack scenarios including denial-of-service, port scanning, brute-force, and SQL injection traffic. Under six representative evasion strategies—FGSM, PGD, C&W, BIM, DeepFool, and IDSGAN-style black-box perturbations—GT-CSAT achieves an average robust accuracy of 94.3%, surpassing standard adversarial training by 6.8 percentage points and the undefended baseline by 21.4 percentage points, while preserving clean-traffic detection at 97.1%. These results confirm that the game-theoretic cost structure effectively decouples robustness from accuracy, yielding a Pareto-superior detection profile relative to competing baselines across all evaluated threat models. The source code and experimental configurations have been publicly released to facilitate reproducibility. Full article

In this research, PLA biocomposites reinforced with 20 wt% flax fibers modified with 1, 5, 10, and 20% concentrations of trans-cinnamic acid (TC) were prepared. The materials were systematically characterized to evaluate their structural, thermal, viscoelastic, surface, and functional properties. Thermal stability and phase transitions were analyzed using thermogravimetric analysis (TG) and differential scanning calorimetry (DSC), while viscoelastic behavior and molecular relaxation processes were investigated by dynamic mechanical analysis (DMA). To elucidate failure mechanisms and interfacial quality, fracture surface morphology after tensile testing was observed using scanning electron microscopy (SEM). Surface wettability was determined through water contact angle measurements, and antibacterial activity against Escherichia coli and Staphylococcus aureus was evaluated to assess the functional potential of the developed biocomposites. The results demonstrated that moderate fiber modification improved interfacial adhesion and enhanced thermo-mechanical performance. The highest contact angles were observed for 5% and 10% TC concentrations, indicating increased surface hydrophobicity, while strong antibacterial activity (R ≥ 6) was achieved for 10% and 20% TC. The research confirms that trans-cinnamic acid concentration governs multiple structure–property relationships, enabling controlled tuning of mechanical reinforcement and antibacterial functionality. Full article

Despite the growing adoption of Ti6Al4V-ELI made by Laser Powder Bed Fusion (LPBF) in tribologically demanding applications, the influence of hybrid nanoparticle additives on its lubrication behavior under starved contact conditions remains insufficiently explored. The tribological performance of Ti6Al4V was investigated under starved boundary-to-mixed lubrication conditions using engine oil modified with Ag-doped TiO₂ nanoparticles. Double-scan LPBF-fabricated discs were tested in a ball-on-disc configuration against AISI 52100 bearing steel using a TRB³ tribometer. Nanolubricants were prepared by dispersing TiO₂ and Ag–TiO₂ nanopowders with different Ag⁺/Ti⁴⁺ ratios (0.5%, 1.5%, and 2.5%) in SAE 10W-40 engine oil at a constant nanoparticle concentration of 0.05 wt%. Comprehensive physicochemical characterization of the nanopowders and nanolubricants was performed through structural, chemical, optical, morphological, rheological, and stability analyses. Tribological experiments were conducted following a full-factorial design combining three normal loads (5–15 N), three sliding speeds (0.10–0.20 m·s⁻¹), and four lubricant formulations. The steady-state coefficient of friction ranged between 0.281 and 0.359, while the specific wear rate varied from 2.81 × 10⁻⁴ to 4.83 × 10⁻⁴ mm³·N⁻¹·m⁻¹. The contact temperature rise remained relatively moderate, within the interval of 1.9–9.4 °C. Among the investigated formulations, the lubricant containing 1.5% Ag–TiO₂ exhibited the lowest friction coefficient, whereas the formulation with the highest Ag content showed improved stability of tribological performance across the investigated operating domain. These results indicate that Ag-modified TiO₂ nanoparticles are consistent with the formation of protective tribofilms and contribute to the stabilization of friction, wear, and thermal behavior under starved lubrication conditions. ANOVA confirmed that sliding speed and the load–lubricant interaction are the dominant factors governing friction and wear, while normal load controls the thermal response. These findings support the use of Ag–TiO₂ nanolubricants as a viable strategy for stabilizing interfacial behavior in LPBF-fabricated titanium components operating under starved lubrication conditions. Full article

Radon is a significant indoor air pollutant and a leading cause of lung cancer in non-smokers. While geogenic radon potential is well-documented, the specific contribution of building materials—particularly historic stones and those containing industrial by-products—requires precise in situ characterization to ensure public safety. This study investigates radon activity concentrations and surface exhalation rates across three distinct case studies in Slovakia: a mid-20th-century structure with cinder blocks, a UNESCO-protected Gothic building featuring volcanic andesite, and a historic stone plinth. Continuous radon monitoring and accumulation chamber measurements were employed, integrated with the tracking of meteorological parameters. The results revealed the highest surface exhalation rate in cinder block masonry (8.98 Bq m⁻² h⁻¹), followed by andesite ashlars (7.9 Bq m⁻² h⁻¹) and stone (1.87 Bq m⁻² h⁻¹). A clear correlation was observed between indoor radon levels and barometric pressure, whereas the influence of outdoor temperature appeared negligible. An estimated Activity Concentration Index of 0.30 suggests that the volcanic rock is likely radiologically safe for use as a bulk building material. The study concludes that while specific materials contribute to exhalation, indoor radon stability is primarily governed by barometric variations and the effectiveness of floor barriers against geogenic ingress rather than the masonry itself. Full article

This study examines how regulatory heterogeneity in digital services trade relates to the carbon intensity of bilateral trade flows. Using a structural gravity framework estimated with Poisson pseudo maximum likelihood (PPML), we analyzed 10,719 bilateral observations from the Eora Multi-Region Input–Output (MRIO) database over 2014–2020. Bilateral gaps in the OECD Digital Services Trade Restrictiveness Index (DSTRI) were used as the main measure of regulatory heterogeneity, and the overall gap was decomposed into infrastructure-related hard barriers and institutional soft barriers. The results suggest that digital regulatory gaps are associated with a higher carbon intensity in trade while also being associated with lower total embodied emissions through reduced trade volumes. This indicates that lower aggregate emissions under regulatory divergence may reflect contraction in trade activity rather than genuine environmental improvement. The decomposition analysis further suggests that infrastructure-related misalignment is more closely associated with carbon inefficiency, whereas institutional divergence operates mainly through its association with trade volume. In addition, environmental policy stringency in the importing country appears to strengthen the positive association between institutional regulatory gaps and carbon intensity, consistent with the possibility of regulatory overload. The study contributes to the sustainability literature by showing that carbon intensity provides a more informative indicator of sustainable trade performance than aggregate emissions alone in fragmented regulatory environments. It also suggests that digital governance, trade policy, and environmental policy should be considered together in promoting more sustainable forms of international trade, particularly in the context of emerging policy frameworks such as WTO digital trade negotiations, OECD digital governance initiatives, and carbon border adjustment mechanisms (CBAMs). Full article

In recent years, small-borehole wireline coring has become increasingly dependent on trajectory control, downhole condition sensing, and real-time directional decision-making. However, under low-flow conditions, conventional MWD pulser heads tend to generate relatively small pulse amplitudes; as hole depth increases, the pressure signal undergoes stronger attenuation and becomes more susceptible to noise interference, making it difficult to sustain a decodable amplitude under a limited pump-pressure budget. Existing studies have mainly focused on surface decoding and signal processing and therefore do not improve, at the source-structure level, the amplitude output and tool-section incremental pressure loss in low-flow operation. Accordingly, this study develops a compact small-diameter mud-pulse pulser head for 1–3 L/s operation and evaluates its performance through an integrated workflow combining theoretical screening, numerical simulation, and shallow-hole field testing focused on hydraulic pulse generation and surface detectability. The results show that, after selecting appropriate bypass-orifice sets, the proposed pulser head produces stable pressure pulses meeting the surface decoding threshold across 1–3 L/s, while maintaining the tool-section incremental pressure loss within 0.5 MPa over the main operating range. The findings further indicate that, in low-flow regimes, the achievable decoding margin and the incremental-loss ceiling are primarily governed by the upstream hydraulic architecture. This work provides a practical basis for reliable low-flow mud-pulse telemetry in small-borehole wireline coring. Full article

Today, financial institutions’ architecture does not rely on one single technology. Instead, it uses a multi-technology approach in order to cover modern requirements and, at the same time, remain relevant. It integrates technologies such as relational databases, Big Data for analysis, and Cloud environments for distributed capacities within a complex data architecture. At the same time, due to European data governance regulations, governance mechanisms such as encryption, pseudonymization, and incremental versioning must be applied on each architectural layer in order to comply with strict European governance rules. In this study, the impact of data governance is assessed by applying these mechanisms from the data-ingestion level, using diverse data types such as structured, semi-structured, and unstructured data, across relational databases, Big Data analysis, and Cloud distributed systems. In doing so, metrics such as execution time, CPU, and memory usage are assessed in order to properly evaluate the impact of governance mechanisms on financial systems. The results show that governance can be successfully integrated, provided these mechanisms are embedded at the architectural level, ensuring that performance, scalability, and compliance are maintained across the entire processing pipeline. Full article

As a crucial national ecological barrier, China’s Southern Collective Forest Region (SCFR) plays an essential role in maintaining regional ecological security and promoting sustainable development. Understanding the mechanisms driving the evolution of its ecosystem service value (ESV) is of great significance. Based on county-level data from 2000 to 2023, this study integrated the equivalent factor method, spatial autocorrelation analysis, the XGBoost-SHAP model, geographically and temporally weighted regression (GTWR), and partial least squares structural equation modeling (PLS-SEM) to examine the spatio-temporal evolution patterns and driving mechanisms of ESV in the SCFR. The results showed that ESV in the SCFR exhibited an overall downward trend, with a cumulative loss of 1973.77 × 10⁸ CNY. This was primarily due to marked reductions in hydrological and climate regulation services. The spatial distribution of ESV exhibited a significant heterogeneity—higher in the southwestern and southeastern mountainous regions, and lower in the northern plains and coastal zones, with the center of gravity shifting first to the northeast and then to the southwest. Local spatial autocorrelation revealed relatively stable “High–High” and “Low–Low” clustering characteristics, where high-value clusters were consistently distributed in core forest zones, while low-value clusters overlapped highly with urban agglomerations. Socio-economic factors exerted a significantly stronger influence on ESV than natural factors. Population density (POP), land use intensity (LUI), and gross domestic product (GDP) were identified as the dominant drivers, exhibiting distinct non-linear threshold effects and significant spatio-temporal heterogeneity. PLS-SEM analysis further quantified LUI as the dominant direct inhibitory pathway on ESV, highlighting urbanization’s indirect negative effect mediated through intensified LUI. Meanwhile, terrain effects were confirmed to positively influence ESV indirectly by constraining LUI and modulating local climate. The analytical framework of “threshold identification–spatio-temporal heterogeneity–causal pathway analysis” proposed in this study elucidated the complex driving mechanisms of ESV evolution, providing valuable guidance for ecological restoration evaluation and differentiated environmental governance. Full article

Contemporary emergency systems operate at the intersection of climate volatility, digital interdependence, and cascading institutional disruptions. Despite growing research on resilience, adaptive governance, and digital transformation, these fields remain largely disconnected, leaving a theoretical gap in explaining how emergency systems perform under compound uncertainty. This integrative review synthesizes 32 peer-reviewed articles (post-2020) using structured narrative methodology and VOSviewer bibliometric analysis to map the field’s intellectual architecture and identify its structural gaps. The analysis reveals six thematic clusters organized around resilience as the central construct, yet characterized by three recurring disconnections: the weak integration between digital transformation and governance theory, the operational underdevelopment of polycentric governance frameworks, and the temporal separation between emergency response and climate adaptation. Drawing on this structural diagnosis, the study advances the Complex Adaptive Governance (CAG) model—a three-layer framework encompassing systemic architecture, adaptive mechanisms, and operational resilience—in which digital interoperability functions as a cross-cutting accelerator. The CAG model reconceptualizes resilience as a relational property of governance ecosystems, enhanced by digital interoperability, and offers design principles for climate-resilient emergency systems aligned with SDG 9, SDG 11, SDG 13, and SDG 16. Full article

Hydrophobic carbon quantum dots (hbCQDs) with tunable photoluminescence were synthesized via a solvothermal approach and further hybridized with Rhodamine B (RhB) to extend emission into the visible range. The hbCQDs exhibit quasi-spherical morphology with an average particle size of 8 nm and predominantly disordered graphitic structure, as confirmed by TEM and XRD analyses. FTIR and XPS characterizations reveal surface functional groups including C–N, C=O/C–O, and S–H, which govern the photoluminescence properties. Pure hbCQDs display blue emission at 453 nm under excitation, with a quantum yield (QY) of 6.2%. Incorporation of RhB leads to dual-emission behavior: the surface-state emission remains in the blue region, while molecular-state emission from RhB appears in the orange-red region. The 0.2 mL RhB–CQD composite exhibits optimal properties, including a QY of 13% and a production yield of 82%, emitting white light under 365 nm UV excitation. Increasing RhB loading to 0.4 mL results in a shift in emission peaks and a reduced QY (<9%), with weaker orange fluorescence. These findings demonstrate that controlled RhB hybridization effectively tunes the emission spectrum of hbCQDs, offering a simple and reproducible strategy to achieve dual-color and white-light emission. The optimized hbCQDs/RhB composites hold significant potential for applications in hydrophobic media-compatible organic optoelectronics, light-emitting devices, and bioimaging. Full article

Particulate organic carbon (POC) and mineral-associated organic carbon (MAOC) are two operationally defined fractions frequently used in studies related to soil organic carbon (SOC) dynamics. However, the changes and governing mechanisms of these fractions, particularly along a restoration chronosequence, remain poorly understood. Here, we investigated changes in SOC fractions, soil properties, and microbial communities across a restoration chronosequence (1, 5, 7, 13, and 20 years) of alpine meadows using a space-for-time substitution approach on the Qinghai–Tibet Plateau. We quantified the contributions of biotic and abiotic drivers using Spearman correlation analysis, linear regression and random forest analysis. The results revealed a unimodal pattern in SOC, POC, and MAOC contents, peaking at 7, 5, and 7 years, respectively, with no further increase thereafter. Restoration duration strongly shaped microbial community structure and observed species richness, but had no significant effect on Shannon index and Pielou index. Random forest analysis identified soil water content (SWC) and total nitrogen (TN) as the primary predictors of SOC. The microbial community composition dominated the variation in POC while enzyme activity was the key driver of MAOC. Our findings highlight that soil carbon accumulation during alpine meadow restoration is a nonlinear process with a temporal threshold, and POC and MAOC are regulated by distinct biotic and abiotic mechanisms. This study provides a theoretical basis for understanding carbon sequestration mechanisms during alpine meadow restoration and developing sustainable grassland management strategies. Full article

Over the past decade, an increasing number of functional microbial-like terpene synthases (MTPSLs) have been reported in non-seed plants. However, whether the traditional Chinese medicinal plant H. serrata harbors such enzymes and their corresponding functions remains unexplored. In this study, we mined the transcriptome of H. serrata and identified a microbial-like terpene synthase, HsMTPSL1, which produces multiple diterpene products. Following isolation and structural elucidation, seven distinct compounds were obtained, representing three skeletal types: spatane, prenylkelsoene-type, and biflorane. Among these, compound 7 is a novel biflorane diterpene. Structural analysis and subsequent mutagenesis revealed critical residues governing the formation of distinct skeletons, uncovering the multifunctional nature of this enzyme. Notably, the S224A mutation significantly enhanced the production of spatane diterpene compound 1 by 11.6-fold, demonstrating the potential for protein engineering to improve the yield of this bioactive marine-specific diterpene. Transcriptomic profiling revealed that HsMTPSL1 is highly expressed in sporangia, and co-expression analysis with cytochrome P450s identified the CYP781 subfamily as candidates potentially involved in the downstream modification of these skeletons. Collectively, we report the first MTPSL from H. serrata and characterize it as a multifunctional diterpene synthase. Through structure-guided mutagenesis, we uncovered the molecular basis of its functional versatility, with the S224A mutation providing a powerful tool for enhancing the yields of all three diterpene skeletons, thereby laying a foundation for future protein engineering and synthetic biology applications. Full article

Open Educational Resources (OER) are widely promoted as mechanisms for expanding access to knowledge and supporting sustainability in higher education. Yet their long-term viability remains constrained by fragmented governance, unstable funding arrangements, weak faculty incentives, policy gaps, and uneven digital infrastructure. This article develops a conceptual and policy-oriented framework that reconceptualizes OER as sustainable knowledge commons embedded within higher education systems rather than merely repositories of open content. Using an integrative review and thematic synthesis of global scholarship on OER sustainability, commons governance, and higher education policy, the study identifies four interrelated governance dimensions: institutional embedding, participatory stewardship, equitable access and inclusion, and long-term resource sustainability. The analysis shows that sustainable OER ecosystems depend not only on open licensing and technological platforms but also on coherent policy design, institutional alignment, academic recognition structures, and collaborative governance arrangements. Each dimension is associated with indicative governance mechanisms and policy indicators such as institutional OER strategies, faculty incentive programs, and shared digital infrastructure. The framework also recognizes institutional diversity, emphasizing that governance models must be adapted to different policy environments, academic cultures, and stages of OER adoption across higher education systems. By conceptualizing OER as governable knowledge commons, the article clarifies how open knowledge initiatives can con-tribute to social equity, educational resilience, and sustainable transformation in higher education. Full article

Understanding the intrinsic Li–H₂ interaction, decoupled from substrate effects, is essential to rationalize the performance of lithium-decorated hydrogen storage materials. To address the current lack of a clean theoretical baseline, we characterized the sequential H₂ adsorption on the gas-phase Li₆ superatomic cluster using high-level density functional theory (DFT), complemented by Energy Decomposition Analysis (EDA), QTAIM, and NICS(0) calculations. Li₆ acts as a structurally rigid platform (RMSD < 0.032 Å) where ligand-induced polarization progressively strengthens its σ-aromaticity (NICS(0) from −2.917 to −13.98 ppm) and increases the HOMO–LUMO gap up to 5.05 eV. EDA identifies the binding as field-activated physisorption, electrostatically dominated (65–67%) and mechanistically distinct from Kubas coordination, as confirmed by QTAIM closed-shell interaction parameters. Negative cooperativity governs an effective loading capacity of n = 2 molecules under cryogenic conditions (T_eq = 143.76 and 114.64 K), while an entropic bottleneck renders higher loading non-spontaneous at all temperatures. These results establish Li₆(H₂)_n as a foundational gas-phase reference, providing a systematic, contamination-free descriptor set for the intrinsic Li–H₂ interaction. This framework is essential for isolating the electronic role of the lithium superatom and unambiguously identifying substrate-induced modulations in supported hydrogen storage materials. Full article