Search Results (48,182)

Site-level carbon density data remain limited for many seagrass meadows, especially where the mapped meadow extent has not been paired with repeated carbon-pool measurements. This study quantified biomass carbon density, 0–1 m sediment organic carbon density, total carbon density, and sediment contribution at 10 fixed stations in a meadow dominated by Zostera marina Linnaeus in Caofeidian, Bohai Bay, China, in 2021, 2024, and 2025. Sediment grain-size composition and five water-quality variables were also summarized for 2025 as environmental context. Sediment organic carbon dominated the station-level carbon pool. In 2025, biomass carbon density was 0.269–0.900 Mg C ha⁻¹, sediment organic carbon density was 8.108–39.730 Mg C ha⁻¹, and total carbon density was 8.377–40.566 Mg C ha⁻¹. The median total carbon density was 23.391 Mg C ha⁻¹ in 2021, 18.827 Mg C ha⁻¹ in 2024, and 20.040 Mg C ha⁻¹ in 2025. The rank association between fine sediment fraction and carbon density was positive in 2025 (Spearman’s ρ = 0.491, p = 0.150). These fixed-station records support seagrass monitoring, restoration planning, and sustainable coastal management. They also help link the mapped meadow extent with field carbon data for blue carbon assessment under climate and marine sustainability goals. Full article

High-temperature temporary sealing operations require liquid plug materials that can be placed as low-viscosity precursors, converted into mechanically stable networks under reservoir temperature, and subsequently removed after service. Existing epoxy-based sealing systems generally provide high post-curing strength, but the coordination among pumpability, thermally triggered curing, and post-service degradability remains insufficiently addressed. In this work, an epoxidized soybean oil (ESO)-modified epoxy–anhydride liquid plug was designed to regulate these sequential stages within a single material system. The precursor formulation, rheological transition, curing kinetics, mechanical response, network structure, and degradation behavior were evaluated using viscosity monitoring, curing-time tests, DSC, compression testing, DMA, gel fraction and swelling measurements, FTIR, and high-temperature degradation experiments. The optimized precursor exhibited an initial viscosity of 65.4 ± 2.1 mPa·s, remaining below the pumpability threshold of 100 mPa·s before curing. Its curing time was adjustable within 1–10 h at 120–140 °C through temperature and initiator regulation. ESO incorporation produced a non-monotonic mechanical response, with the optimized network reaching a compressive strength of 112.5 ± 3.5 MPa and an elastic modulus of 142.50 ± 5.26 MPa. FTIR and thermal–mechanical analyses supported the formation of an ester-rich epoxy–anhydride network containing both rigid epoxy-derived segments and ESO-derived flexible chains. In the post-service stage, degradation was strongly temperature dependent, with the characteristic unsealing time decreasing from 84 h at 120 °C to 24 h at 130 °C and 18 h at 140 °C. The combined results define a coupled curing–degradation window in which pumpable placement, thermal network formation, load-bearing sealing, and controlled unsealing are temporally separated but structurally connected. Full article

The high-rate biological contactor (HRBC) is an enhanced-primary, biosorption-based, carbon-diversion wastewater treatment process with short hydraulic retention time (HRT), short solids retention time (SRT), low dissolved oxygen (DO), and high food-to-microorganism ratio (F/M). This paper presents modifications to a commercial full-plant wastewater biodegradation model using extracellular polymeric substances (EPS) in waste activated sludge (WAS) to simulate pilot test biosorption data. Bench-scale HRBC tests found that each mg of EPS as COD (COD_EPS) biosorbed 1.02 mg sCOD contained in raw wastewater. The fraction of AS organics identified as EPS in terms of COD was 37% in a conventional AS (CAS), 33% in a trickling filter-solids contact (TF/SC), and 18% in a membrane bioreactor (MBR). The modeling process used stoichiometry equations to convert EPS from its constituent concentrations (carbohydrates, proteins, humic acids, uronic acids) into COD. The conversion did not alter the finding that the normalized total EPS showed a positive relationship with soluble chemical oxygen demand sCOD biosorption with a 0.91 coefficient of determination. The modified commercial biodegradation model gave a maximum error of −12.6% when simulating pilot-scale results, and 80% of all data points were less than ±10% error. The modified model predicted 16% sCOD biosorption by EPS using the design data for a full-scale HRBC facility currently under construction. Full article

Hybrid nanofluids combining thermally conductive nanoparticles with latent heat-storing nanocapsules have attracted growing interest for near-ambient liquid-based thermal management, yet direct comparisons between mono and hybrid phase-change-material-containing systems on a common experimental basis remain scarce. In this work, water-based mono Al₂O₃, mono polyurethane-nanoencapsulated n-nonadecane (PU-NEPCM), and Al₂O₃/PU-NEPCM hybrid nanofluids were prepared under identical surfactant, sonication, and dispersion conditions, and their thermal conductivity, dynamic viscosity, and Day-1 colloidal stability were characterized over 298–313 K at total volume fractions of 0.1, 0.3, and 0.5 vol.%, with the hybrids prepared at a 50:50 volumetric ratio. At 0.5 vol.% and 313 K, the hybrid (NFH3) exhibited the highest thermal conductivity enhancement (+8.27%), exceeding the corresponding mono Al₂O₃ and mono PU-NEPCM nanofluids by 4.6 and 5.2 percentage points, respectively, while maintaining a moderate viscosity penalty. The hybrid formulations also achieved |ζ| = 32–37 mV, exceeding the conventional electrostatic-stabilization threshold and outperforming both mono families. A two-factor analysis of variance (ANOVA) identified particle concentration as the dominant factor governing both properties (p < 0.001), with temperature becoming statistically significant only for the hybrid viscosity (p = 0.043). The synergy index varied between 0.85 and 1.43 across the tested conditions—reaching values of 1.20–1.43 for the lowest-loaded hybrid (NFH1)—while the performance index remained close to unity (0.97–1.01). These results identify low-loaded Al₂O₃/PU-NEPCM hybrid nanofluids as a balanced and stable candidate for near-ambient liquid-based thermal management applications. Full article

Deep learning has significantly advanced image super-resolution (SR), yet many state-of-the-art models remain too computationally expensive for resource-constrained devices. This paper demonstrates that a highly parameter-efficient design can achieve comparable performance to the very deep super-resolution network (VDSR) with a tiny fraction of parameters. Starting from the classic VDSR architecture (2016), we systematically evaluate three design choices: depthwise separable convolution (DSConv), Hybrid Attention Transformer (HAT), and a local residual connection (LR). HAT provides no performance gain—an honest negative result supported by controlled experiments (increased training, different reduction ratios, and standard convolution baseline). In contrast, LR alone yields a 0.20 dB improvement without introducing any extra parameters. Consequently, we discard HAT and propose DSConv+LR. Our model contains only 49,217 parameters—about 7.4% of VDSR—yet attains a peak signal-to-noise ratio (PSNR) of 35.21 dB on Set5 (×2), which is 99.7% of VDSR’s performance (35.33 dB). On additional benchmarks (Set14, BSD100, and Urban100), DSConv+LR maintains similar relative performance (within 0.12 dB of VDSR). Perceptual loss (AlexNet features, lower better) is 0.2556, slightly better than VDSR (0.2717). We acknowledge that modern lightweight networks such as cascaded residual attention network (CARN) and information multi-distillation network (IMDN) achieve 2–3 dB higher PSNR at the cost of 9–14× more parameters. This work advocates a minimalist approach while honestly reporting both its strengths and limitations. Full article

This study investigates the Mittag–Leffler-type stability properties of fractional perturbed systems with respect to their unperturbed counterparts by incorporating initial time differences into the analysis. In contrast to many existing studies in which initial time effects are neglected, the proposed framework explicitly considers time shifts together with the memory-dependent nature of fractional-order systems. Using Caputo fractional derivatives and Lyapunov-type functionals, new sufficient conditions are established for the stability behavior of perturbed systems relative to the corresponding unperturbed systems under shifted initial times. The obtained results extend existing stability criteria by simultaneously addressing fractional memory effects, perturbation terms, and variations in the initial time. To illustrate the applicability and effectiveness of the theoretical findings, representative examples, numerical simulations, graphical comparisons, and global error analyses are presented. The numerical part is based on the Caputo framework and is further supported by benchmark comparisons involving Riemann–Liouville and shifted Grünwald–Letnikov approaches. The proposed results provide a useful framework for the stability analysis of memory-dependent dynamical systems arising in engineering and applied sciences. Full article

Background: Salinity, which hampers wheat growth and development, is one of the major abiotic stresses. Plant-derived smoke (PDS) solution alleviates salt stress and promotes wheat growth and development; however, the underlying molecular mechanisms have not been completely clarified. Methods: In this study, nuclear proteomics was employed to reveal the promotive effect of PDS solution on salt-stressed wheat. Nuclear fractions were isolated from wheat roots, and their purity was confirmed via enrichment of histone H3 and reduction of cytosolic ascorbate peroxidase. Using this nuclear purification technique, label-free nano LC–MS/MS-based nuclear proteomics was performed to identify differentially abundant nuclear proteins in salt-stressed wheat with or without PDS solution treatment. Results: Salt stress decreased histone H2A and DNA polymerase levels, whereas PDS solution treatment of salt-stressed wheat increased levels of histone variants (H2A, H2B, H3, and H4), DNA polymerase, and DNA topoisomerase II. In addition, the PDS solution increased the levels of pre-mRNA cleavage factor Im 25 kDa subunit and RNA helicase in salt-stressed wheat. Immunoblot analysis further validated the increase in histone deacetylase levels triggered by the PDS solution treatment in the salt-stressed wheat. Conclusions: These results suggest that PDS solution alters nuclear proteins in a way that contributes to chromatin remodeling and transcription during salt stress. Full article

Porcine blood meal is a protein and iron-rich animal by-product, but its use in companion animal diets is often limited by poor solubility and variable digestibility caused by thermal processing. This study evaluated whether enzymatic hydrolysis could improve the physicochemical properties, digestibility, iron-related characteristics, and antioxidant capacity of porcine blood meal for potential use in canine diets. Porcine blood meal was hydrolyzed using alcalase or pepsin under controlled conditions, and the resulting hydrolysates were characterized by degree of hydrolysis, electrophoretic peptide profiles, techno-functional properties, in vitro digestibility using a simulated canine gastrointestinal model, heme and non-heme iron fractions, and antioxidant activities. Alcalase treatment produced a higher degree of hydrolysis and more extensive peptide fragmentation than pepsin. Consistent with these structural changes, the alcalase hydrolysate exhibited significantly higher in vitro apparent digestibility. Enzymatic hydrolysis increased extractable heme iron while reducing ferrozine-reactive non-heme iron, suggesting changes in iron binding forms after proteolysis. Hydrolyzed samples also showed enhanced radical scavenging activity and ferric-reducing capacity, whereas superoxide dismutase (SOD)-like activity decreased following hydrolysis. These findings indicate that controlled enzymatic hydrolysis, particularly with alcalase, could improve apparent digestibility and non-enzymatic antioxidant capacity of porcine blood meal, supporting its potential as an iron-containing ingredient in canine diets. Further in vivo studies would be required to confirm iron availability and nutritional efficacy. Full article

A new fractional dynamic sliding mode control (FD-SMC) framework is introduced to reduce chattering in the control of fractional-order chaotic systems. In this method, chattering is eliminated by placing a fractional integrator before the system control input. As a result, the augmented system has a higher dimension than the original system, meaning that additional states are introduced. Effective control therefore requires identifying or estimating these new states or the corresponding plant model. To address this issue, a robust optimal fractional loop-transfer-recovery observer (ROF-LTRO) is developed. Furthermore, the key advantage of sliding mode control (SMC)—its invariance to matched uncertainties—is often lost in many plants such as chaotic systems, because many of them contain mismatched uncertainties. To restore and extend the invariance property, multiple sliding surfaces combined with a virtual control input are employed. In addition, the proposed FD-SMC and ROF-LTRO do not rely on prior knowledge of uncertainty bounds, which is beneficial for practical implementation. Then, a two-stage design procedure based on two-surface definition is presented, and simulation results are provided for the extended fractional Duffing–Holmes chaotic system (EF-DHCS) under both matched and mismatched uncertainties. Full article

Grounding connectors critically influence the safety and long-term reliability of earthing systems through coupled electro-thermal, mechanical, and corrosion behaviors, yet no standardized quantitative framework exists for jointly evaluating these performance dimensions across diverse deployment scenarios. This study introduces a unified multi-criteria evaluation framework applied to six grounding connector configurations spanning four alloy families and three joining technologies. Electro-thermal response was characterized by coupled finite element simulations (0–100 A), mechanical reliability by quasi-static tensile testing (n = 10 per configuration), and corrosion durability by accelerated salt-spray exposure with image-based corroded area fraction quantification. Performance metrics were normalized and aggregated using equal-weight, Analytic Hierarchy Process, and Shannon entropy weighting schemes, with the Technique for Order of Preference by Similarity to Ideal Solution applied for multi-scenario ranking. One-way analysis of variance confirmed statistically significant effects of connector type on tensile performance (F(5, 54) = 3154.90, p < 0.001). The exothermic welded joint achieved the highest mean ultimate tensile load (61.5 ± 1.5 kN), while copper mechanical connectors exhibited the lowest steady-state temperature rise (~2 K above ambient at 100 A). Compression-crimped connectors ranked first under both equal and Analytic Hierarchy Process weighting (closeness coefficients 0.737 and 0.807, respectively), while stainless steel connectors ranked first under corrosion-critical deployment scenarios. Scenario-weighted analyses demonstrate that the optimal material–process combination shifts with environmental severity, current duty, and mechanical demand, providing a reproducible, evidence-based basis for context-dependent connector specification. Full article

The composition of low-polarity extracts obtained by sequential extraction of the aerial parts of Rhododendron adamsii Rehd. with hexane and methyl tert-butyl ether (MTBE) was investigated using GC-MS. The hexane extract was dominated by non-polar components: squalene, n-alkanes (nonacosane, hentriacontane), sesquiterpenes (trans-nerolidol, spathulenol, β-farnesene), and β-sitosterol. The subsequent MTBE extract was enriched in more polar lipids, primarily free triterpenic acids (ursolic and oleanolic acids). A critical finding was the complete absence of diterpene grayanotoxins in all tested extracts, confirming the safety of the non-polar extraction approach. In bioactivity assays, the total hexane extract demonstrated potent inhibitory activity against the SARS-CoV-2 main protease (3CLpro) with IC₅₀ values of 0.0125–0.025 mg/mL, only one order of magnitude higher than the reference inhibitor disulfiram. Fractionation revealed that the activity was distributed among free acids, bound acids, and the unsaponifiable residue, indicating a multicomponent mechanism. Importantly, none of the samples inhibited HIV-1 protease (IC₅₀ > 0.1 mg/mL), demonstrating selectivity for the cysteine protease 3CLpro over the aspartyl protease of HIV-1. These results highlight that sequential non-polar extraction of R. adamsii provides a grayanotoxin-free lipophilic complex with selective anti-SARS-CoV-2 protease activity, paving the way for bioactivity-guided identification of individual inhibitors. Full article

Microplastics (MPs) are routinely detected throughout wastewater treatment plants (WWTPs), yet current treatment trains were not designed specifically to remove them. This study quantified and characterized visually identified MPs in influent and effluent waters from seven urban WWTPs in Andalusia (southern Spain) during a six-month monitoring period (July–December 2020). The targeted analytical size range was 45–5000 µm, and a subset of particles was further characterized by FTIR. MPs were detected in all sampling campaigns. Concentrations ranged from 6 to 78 items/L in influent and from 12 to 65 items/L in effluent. Fibers were the dominant morphology, and the 100–500 µm size class was the most represented fraction. Among the subset analyzed by FTIR, PA, PP, PVC and LDPE were the most frequent polymer assignments, with PA predominating in the fiber-rich fraction. However, because influent and effluent 24 h time-composite samples were not hydraulic retention time (HRT)-paired and FTIR interpretation was based on a selected subset of particles, the dataset is best interpreted as describing spatiotemporal variability during the study period rather than robust process-specific removal efficiency. Overall, the results support WWTPs as an ongoing pathway for MP release to receiving environments. Full article

The growing need for secure image transmission across public networks requires robust encryption algorithms. Traditional chaos-based image ciphers typically have a small key space, weak avalanche behavior, or are susceptible to differential cryptanalysis. To overcome such inadequacies, this paper suggests a new adaptive image cryptosystem that combines a fractional-order memristive chaotic engine and a non-linear hybrid encryption kernel. The system uses piano-inspired feedback; the keystream generator dynamically adapts to the previously encrypted pixel, enabling powerful Cipher Block Chaining (CBC)-style chaining and content-dependent diffusion. A four-dimensional memristive system is solved by the use of fractional-order calculus, which gives an ultra-large key space (>10⁸⁰) and very high sensitivity to initial conditions—confirmed by a positive largest Lyapunov exponent (1.7199). The encryption kernel maps the traditional Exclusive OR (XOR) with the reversible two-step operation: the modular addition of the plaintext with the first keystream byte and the XOR with the second keystream one, both of which increase non-linearity and confusion. Large-scale experiments with six standard 256 × 256 colour images indicate almost ideal entropy (7.9994), Number of Pixel Change Rate (NPCR) which is 99.62, Unified Average Changing Intensity (UACI) which is 33.43, correlation coefficients are near to zero, very low Gray-Level Co-occurrence Matrix (GLCM) homogeneity (≈0.017) and high contrast (≈4843) and low energy (≈0.006 The ciphertext passes seven National Institute of Standards and Technology (NIST) SP-800-22 statistical tests, is extremely sensitive to keys (a perturbation of 1 × 10⁻¹⁴ alters >99.6% of ciphertext) and resists chosen-plaintext and known-plaintext attacks. Decryption has linear time complexity O(N), and average encryption and decryption times are 3.40 s and 2.75 s for 256 × 256 images. The proposed cryptosystem provides an attractive security–performance trade-off that can be used in high-security systems like medical image protection, privacy-preserving multimedia transmission, and secure cloud storage. Full article

The performance of drug-loaded electrospun nanofibres is governed not only by drug content but also by the spatial distribution of the drug within the fibre matrix, which determines release kinetics and biological response. Here, we demonstrate that dose-dependent surface crystallisation of dexamethasone (DEX) in electrospun polycaprolactone (PCL)/gelatin nanofibres controls drug release behaviour and subsequent macrophage-mediated inflammation. Nanofibre mats containing 0, 1, and 2 wt% DEX (PG0, PG1, PG2) were fabricated and systematically characterised. Scanning electron microscopy revealed a change from homogeneous fibres (PG0) to surface-decorated crystalline domains with increasing drug loading, which indicates a supersaturation-driven phase separation during electrospinning. This morphological evolution directly governs the transport behaviour: PG2 exhibits a pronounced burst release due to surface-localised drug, whereas PG1 shows a balanced release profile with both surface-accessible and matrix-embedded drug fractions. Release characteristics result in different biological outcomes. PG1 and PG2 strongly inhibit pro-inflammatory cytokines (TNF-α and IL-6) in LPS-stimulated macrophages (~70–75% reduction), confirming retained drug bioactivity. However, higher drug loading (PG2) leads to lower fibroblast viability and compromised mechanical integrity. Importantly, PG1 shows a desirable balance of controlled drug release, cytocompatibility (>90% viability) and mechanical performance (~8 MPa) with effective anti-inflammatory activity. Degradation studies also show controlled structural evolution without destabilisation upon pH change, demonstrating suitability for wound environments. These results reveal surface crystallisation as an important design parameter for electrospun drug delivery systems and demonstrate that optimal therapeutic performance is controlled by intermediate drug loading, not maximum loading, providing a mechanistic framework for the rational design of immunomodulatory wound dressings. Full article

The efficiency of anaerobic digestion (AD) of lignocellulosic biomass is strongly determined by biomass yield, chemical composition, and bioavailability, all of which undergo substantial seasonal variation. However, integrated analyses linking these factors with AD performance, process kinetics, and energy-economic efficiency remain limited. This study aimed to evaluate the effect of seasonal variability in the chemical composition of Helianthus annuus biomass on AD efficiency from a technological and economic perspective. The novelty of this study lies in integrating seasonal changes in biomass composition with AD kinetics, CH₄ productivity per hectare, and CHP techno-economic performance to identify the optimal harvest window for Helianthus annuus. The experiments were conducted using biomass harvested from June to December. The results showed significant (p < 0.05) variability in biomass properties, including a progressive increase in lignocellulosic fractions over the growing season, with neutral detergent fiber (NDF) increasing from 30.58 ± 1.8 to 66.58 ± 3.1% TS and acid detergent lignin (ADL) from 5.13 ± 0.5 to 10.35 ± 0.9% TS, accompanied by a decline in substrate bioavailability. The maximum CH₄ yield of 258 ± 13 mL/g VS was obtained in August, with a process rate of 29.0 ± 3.4 mL/g VS·d and the highest utilization of methane potential, reaching 62.5 ± 3.8% (BMP_CH4/TBMP). Correlation and regression analyses indicated that ADL and NDF were the strongest empirical predictors of AD performance within the analyzed dataset, showing a negative association with both CH₄ production yield and kinetics (R² up to 0.86), whereas reducing sugars had a stimulatory effect. Multiple regression models showed high predictive performance, with R² = 0.889 for BMP_CH4. The highest energy and economic efficiency was achieved in summer. In August, CH₄ production reached 3214 ± 596 m³/ha, corresponding to 11.2 ± 2.1 MWh/ha of electricity and a net result of 1559 ± 417 EUR/ha. Increased lignification in the later part of the season led to reduced process efficiency and a deterioration of the economic balance. From a practical perspective, these results demonstrate that harvest scheduling should be based on the trade-off between biomass quantity and biodegradability rather than on biomass yield alone. Full article